JP7628816B2 - Power transmission mechanism - Google Patents

Description

This disclosure relates to a power transmission mechanism that transmits power generated in a drive mechanism to a driven mechanism.

Conventionally, the technology described in Patent Document 1 is known as a technology for transmitting the power generated in the motor section to operate the driven side configuration. Patent Document 1 discloses a technology related to an expansion valve in which the stator of the motor is arranged on the atmospheric side and the rotor is arranged inside a refrigerant-sealed can structure, thereby rotating the output shaft on the high-pressure refrigerant atmosphere side.

JP 2020-34140 A

In the case of the technology described in Patent Document 1, if the motor is not positioned so that it is facing upward in the direction of gravity, there is a risk that oil will flow into the rotor and the inner wall of the casing. If oil flows in, the viscous resistance of the oil will hinder the rotation of the rotor, affecting the rotation of the output shaft. There is also a risk that the grease on the reduction gear placed inside the casing will be washed away by the oil. This places restrictions on the degree of freedom in mounting devices with power transmission mechanisms.

One possible solution to these problems is to use a configuration in which the driving side, which includes the motor, and the driven side, where the valve body and other components are located, are connected in a non-contact manner using magnetic force. By using this configuration, it is possible to separate the driving side from the driven side, which is thought to eliminate the constraints caused by oil and other factors.

However, if the drive side and driven side are connected in a non-contact manner using magnetic force, the drive side is permitted to operate even if the driven side is locked. This makes it difficult to detect the occurrence of locking on the driven side from the operation of the drive side. In this respect, it is clearly different from the configuration in Patent Document 1, in which the operation of the drive side is also restricted if the driven side is locked.

In view of the above, the present disclosure relates to a power transmission mechanism that transmits power generated in a drive mechanism to a driven mechanism that is connected in a non-contact manner using magnetic force, and aims to provide a power transmission mechanism that can detect locking of the driven mechanism.

In order to achieve the above object, a power transmission mechanism according to one embodiment of the present disclosure has a drive side mechanism (10), a driven side mechanism (35), a non-contact connection unit (60), and a lock determination unit (71). The drive side mechanism has a motor unit (11), a drive side shaft (14, 33s), and a drive side magnet (20). The motor unit outputs a drive force by electromagnetic force. The drive side shaft rotates in response to the operation of the motor unit. The drive side magnet is disposed at the end of the drive side shaft.

The driven side mechanism has a driven side shaft (41) and a driven side magnet (40), and is partitioned off from the drive side mechanism. The driven side shaft rotates due to the driving force transmitted from the drive side shaft. The driven side magnet is disposed at the end of the driven side shaft.

The non-contact coupling unit has a driving magnet and a driven magnet, and couples the driving shaft and the driven shaft in a non-contact manner using magnetic force. The lock determination unit determines whether or not the driven magnet is locked by using a fluctuation in rotation load related to the operation of the driving magnet. The driving mechanism unit (10) has a reduction mechanism unit (30) that reduces the angular velocity output by the motor unit at a predetermined reduction ratio to obtain the angular velocity of the driving magnet. The non-contact coupling unit (60) is a magnetic coupling (60a) composed of a driving magnet and a driven magnet. The value obtained by multiplying the number of poles of the motor unit by the reduction ratio of the reduction mechanism unit is different from the number of poles of the magnetic coupling, and the reduction ratio of the reduction mechanism unit is different from the number of poles of the magnetic coupling.

According to this, in the power transmission mechanism, the drive shaft of the drive mechanism and the driven shaft of the driven mechanism are connected in a non-contact manner using magnetic force at the non-contact connection section. Therefore, if the driven magnet and the driven shaft are locked while the drive magnet is rotating together with the drive shaft, the rotational load of the drive shaft and the drive magnet will periodically fluctuate due to the influence of the magnetic force acting between the drive magnet and the driven magnet. According to the power transmission mechanism, by using the fluctuation in the rotational load in the drive mechanism, it is possible to determine whether or not the driven magnet in the separately partitioned driven mechanism has locked.

The symbols in parentheses for each means described in this section and in the claims indicate the corresponding relationship with the specific means described in the embodiments described below.

1 is a cross-sectional view showing a configuration of an expansion valve according to a first embodiment. FIG. 2 is an explanatory diagram illustrating a configuration of a power transmission mechanism in the first embodiment. 2 is a block diagram showing a control system of the expansion valve according to the first embodiment. FIG. 5 is a graph showing a result of a frequency analysis of an input current in the first embodiment. 4 is a flowchart relating to a lock determination control in the first embodiment. FIG. 6 is a cross-sectional view showing a configuration of an expansion valve according to a second embodiment. FIG. 11 is a cross-sectional view showing a configuration of an expansion valve according to a third embodiment. FIG. 11 is an explanatory diagram showing a configuration of a power transmission mechanism in a third embodiment. FIG. 11 is a cross-sectional view showing a configuration of an expansion valve according to a fourth embodiment. FIG. 13 is an explanatory diagram showing a configuration of a power transmission mechanism in a fourth embodiment. FIG. 13 is a block diagram showing a control system of an expansion valve according to a fifth embodiment. 13 is a graph showing the results of a frequency analysis of an envelope of a driving current in the fifth embodiment. FIG. 13 is a block diagram showing a control system of an expansion valve according to a sixth embodiment. 13 is a graph showing the results of a frequency analysis of a driving current in the sixth embodiment. FIG. 13 is a block diagram showing a control system of an expansion valve according to a seventh embodiment. 23 is a graph showing the results of a frequency analysis of a determination voltage in the seventh embodiment. FIG. 13 is a block diagram showing a control system of an expansion valve according to an eighth embodiment. 13 is a graph showing the results of a frequency analysis of a driving current in the eighth embodiment. FIG. 13 is a block diagram showing a control system for an expansion valve according to a ninth embodiment. 13 is a graph showing the results of a frequency analysis of a line voltage in the ninth embodiment. FIG. 23 is a cross-sectional view showing the configuration of an expansion valve according to a tenth embodiment. 23 is a graph showing the results of a frequency analysis of acceleration in the tenth embodiment. 13 is a flowchart showing a modified example of lock determination control.

Below, multiple embodiments for implementing the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment may be given the same reference numerals, and duplicated descriptions may be omitted. In cases where only a portion of the configuration is described in each embodiment, other previously described embodiments may be applied to the other portions of the configuration. In addition to combinations of parts that are specifically specified as being possible in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

First Embodiment
A first embodiment of the present disclosure will be described with reference to Figures 1 to 5. In the first embodiment, a power transmission mechanism 1 according to the present disclosure is applied to an expansion valve Ev. The expansion valve Ev is a so-called electric expansion valve, and reduces the pressure of the refrigerant by transmitting a driving force generated by an electromagnetic force in a motor section as a driving source, thereby moving a valve body. In other words, the power transmission mechanism 1 is applied to the expansion valve Ev to transmit the power generated in a motor section 11 and control the movement of a valve body 48.

In the following embodiment, the expansion valve Ev including the power transmission mechanism 1 is a small, high-output, high-resolution electric expansion valve, and is arranged as one of the components of the refrigeration cycle in the vehicle air conditioning system. Although not shown in the figure, the refrigeration cycle has at least a compressor, a condenser, and an evaporator in addition to the expansion valve Ev.

The expansion valve Ev is located between the condenser and the evaporator in the refrigeration cycle, and reduces the pressure of the refrigerant flowing out of the condenser and causes it to flow toward the evaporator. The vehicle air conditioner also has an air conditioning control device, and the amount of pressure reduction (i.e., the throttle opening) of the expansion valve Ev is controlled by a control signal from the air conditioning control device.

First, the schematic configuration of the expansion valve Ev according to the first embodiment will be described with reference to Figs. 1 and 2. As shown in Fig. 1, the expansion valve Ev according to the first embodiment includes a power transmission mechanism 1 according to the present disclosure, and has a drive side mechanism section 10 and a driven side mechanism section 35.

The expansion valve Ev is disposed vertically in the vehicle. Vertical disposition means that the axial direction of the valve body 48 is approximately parallel to the vertical direction of the vehicle, and the driving side mechanism 10 is disposed above the driven side mechanism 35.

The power transmission mechanism 1 transmits the driving force generated by the driving mechanism 10 to the driven mechanism 35 using magnetic force.

The driving side mechanism 10 has a motor 11 and a motor case 15. The motor 11 has a stator 12, a rotor 13, and a shaft 14, and in the first embodiment is configured as a three-phase motor 11a. The shaft 14 rotates integrally with the rotor 13. Therefore, the shaft corresponds to an example of a driving side shaft. The motor case 15 is joined to a sealing plate 51 that constitutes the upper surface of the main body 50 in the driven side mechanism 35, and houses the motor 11 inside.

The stator 12 is fixed to the motor case 15. In the first embodiment, the stator 12 is cylindrical and has a stator coil 12a. The stator 12 in the first embodiment generates a rotating magnetic field inside the stator core by passing a three-phase AC current (U-phase, V-phase, W-phase) through the stator coil 12a via the circuit unit 70. The number of slots in the stator 12 in the first embodiment is nine.

The rotor 13 is disposed inside the stator 12, which is cylindrically configured. As shown in FIG. 3, the rotor 13 has multiple pairs of magnets, each consisting of a north pole and a south pole, arranged along the circumferential direction. In the first embodiment, there are six north poles and six south poles, so the rotor 13 has 12 poles.

The motor case 15 is formed with an axial alignment section for axially aligning (centering) the shaft 14 of the drive side mechanism 10 and the rotating member 41 of the driven side mechanism 35. The axial alignment section is fitted into the main body 50 of the driven side mechanism 35. As shown in FIG. 1, a circuit section 70 is housed inside the motor case 15.

As shown in FIG. 1, the driven mechanism 35 has a rotating member 41, a female screw member 42, a screw member 43, a ball 44, a ball receiving member 45, a guide member 46, a coil spring 47, a valve body 48, and a main body 50.

The rotating member 41, the female screw member 42, the screw member 43, the ball 44, the ball receiving member 45, the guide member 46, the coil spring 47, and the valve body 48 are housed in the main body 50. The main body 50 is formed with a valve chamber 52, an inlet side connection port 53, an outlet side connection port 54, and a valve seat 55.

The rotating member 41 is a rod-shaped member that is rotatably supported inside the main body 50. The rotating member 41 rotates due to the driving force transmitted from the driving mechanism 10 via the power transmission mechanism 1. Therefore, the rotating member 41 in the first embodiment corresponds to an example of a driven shaft.

The rotating member 41 is arranged coaxially with the shaft 14. An engagement groove 41a is formed at the end of the rotating member 41 opposite the drive side mechanism unit 10. A protruding piece 43a of the screw member 43 engages with the engagement groove 41a of the rotating member 41. The screw member 43 is arranged coaxially with the rotating member 41. This allows the rotational force of the rotating member 41 to be transmitted to the screw member 43.

The protruding piece 43a is formed on one end of the screw member 43. A male thread is formed on the outer circumferential surface of the screw member 43. The male thread of the screw member 43 screws into a screw hole 42a formed in the female screw member 42 to form a screw mechanism. The female screw member 42 is cylindrical and fixed inside the main body 50. As a result, when the screw member 43 rotates, the screw member 43 moves in the axial direction.

A ball 44 abuts against the screw member 43 at a portion opposite the rotating member 41. The ball receiving member 45 receives the ball 44. A valve body 48 is connected to the end of the ball receiving member 45 opposite the valve seat 55.

The valve body 48 is a rod-shaped member disposed within the valve chamber 52. The valve body 48 is disposed coaxially with the screw member 43 and is held axially movable by a guide member 46 fixed within the valve chamber 52.

A coil spring 47 is disposed between the valve body 48 and the ball receiving member 45 and the guide member 46. The coil spring 47 biases the valve body 48 and the ball receiving member 45 in a direction in which the valve body 48 moves axially away from the valve seat 55.

In the driven mechanism 35, when the screw member 43 rotates and moves axially, the valve body 48 also moves axially. As the valve body 48 moves axially, the valve body 48 comes into contact with the valve seat 55 or separates from the valve seat 55, opening and closing the valve chamber 52.

The valve chamber 52 is connected to an inlet side connection port 53 and an outlet side connection port 54 via a refrigerant flow path formed inside the main body 50. A refrigerant pipe extending from the outlet of the condenser in the refrigeration cycle of the vehicle air conditioner is joined to the inlet side connection port 53 by, for example, brazing.

The outlet side connection port 54 is connected, for example by brazing, to a refrigerant pipe that extends toward the inlet of the evaporator in the refrigeration cycle of the vehicle air conditioner. Therefore, in the expansion valve Ev, when the valve body 48 moves away from the valve seat 55 in the valve chamber 52, the refrigerant flows from the inlet side connection port 53 to the outlet side connection port 54 and is decompressed and expanded.

As shown in FIG. 1, the power transmission mechanism 1 of the expansion valve Ev includes a non-contact connection part 60. The non-contact connection part 60 includes a magnetic gear 60b and a sealing plate 51. The magnetic gear 60b includes a driving side magnet 20, a pole piece 25, and a driven side magnet 40.

In the power transmission mechanism 1 according to the first embodiment, the driving magnet 20 is attached to the end of the shaft 14 of the motor unit 11 and rotates integrally with the shaft 14. Therefore, when a rotational force that rotates the rotor 13 is transmitted in the motor unit 11, the driving magnet 20 rotates around the shaft 14.

The driving magnet 20 is formed in a disk shape, and at least one pair of magnets consisting of an N pole 20n and an S pole 20s is arranged along the circumferential direction on the underside of the driving magnet 20. The number of poles of the driving magnet 20 in the first embodiment is four.

Inside the motor case 15, a pole piece 25 is disposed below the driving magnet 20. In other words, the pole piece 25 is disposed between the driving magnet 20 and the driven magnet 40, and has multiple soft magnetic bodies. The pole piece 25 modulates the magnetic flux between the driving magnet 20 and the driven magnet 40.

As shown in FIG. 2, the soft magnetic bodies in the pole piece 25 are each frustum-shaped and are joined to the underside of the motor case 15. The soft magnetic bodies in the pole piece 25 are arranged at regular intervals along the circumferential direction. The number of poles in the pole piece 25 is the same as the total number of poles in the driving magnet 20 and the driven magnet 40.

In the above embodiment, the pole pieces 25 are spaced apart from each other, but non-magnetic material may be placed between the soft magnetic bodies. In this case, stainless steel or resin may be used as the non-magnetic material. It is also possible to use a configuration in which the motor case 15 does not have a bottom surface, and the pole pieces 25 are embedded in the sealing plate 51.

The driven magnet 40 is arranged to face the driving magnet 20 and the pole piece 25 via the underside of the motor case 15 and the sealing plate 51. The sealing plate 51 separates the internal space of the main body 50 in the expansion valve Ev from the outside, and seals the internal space of the main body 50. The sealing plate 51 is made of a non-magnetic material (e.g., SUS305), and the outer edge of the sealing plate 51 is fixed to the upper surface of the main body 50. Therefore, the sealing plate 51 can prevent the refrigerant (high-pressure refrigerant) in the internal space of the main body 50 from leaking out to the outside of the main body 50.

The driven magnet 40 is disposed in the internal space of the main body 50 located below the sealing plate 51, and is formed in a disk shape. On the upper surface of the driven magnet 40, a plurality of pairs of magnets each consisting of an N pole 40n and an S pole 40s are disposed at approximately equal intervals along the circumferential direction. The number of poles of the driven magnet 40 is greater than the number of poles of the driving magnet 20, and is 40 in the first embodiment.

A rotating member 41 is joined to the center of the lower surface of the driven magnet 40. As described above, the rotating member 41 is arranged coaxially with the shaft 14 and is supported so as to be rotatable together with the driven magnet 40.

Next, the operation of the power transmission mechanism 1 in the first embodiment will be described. When the motor unit 11 starts to operate, the shaft 14 rotates together with the rotor 13, and the drive side magnet 20 also rotates integrally.

The magnetic force of the driving magnet 20 acts on the magnetic pole of the driven magnet 40 via the pole piece 25, the underside of the motor case 15, and the sealing plate 51. At this time, the magnetic flux flowing between the magnetic pole of the driving magnet 20 and the magnetic pole of the driven magnet 40 is modulated by the pole piece 25 located in between, and the driven magnet 40 rotates in the opposite direction to the rotation direction of the driving magnet 20.

That is, the power generated by the motor unit 11 is transmitted from the driving side mechanism unit 10 to the driven side mechanism unit 35 in a non-contact manner between the driving side magnet 20 and the driven side magnet 40 by using magnetic force.

The driven magnet 40 rotates so that the relationship between the rotational speed of the driven magnet 40 and the rotational speed of the driving magnet 20 is a rotational speed according to a predetermined reduction ratio. In this case, the reduction ratio is determined by the ratio between the number of poles of the driving magnet 20 and the number of poles of the driven magnet 40.

When the driven magnet 40 and the rotating member 41 rotate, the power generated by the motor unit 11 is transmitted to the valve body 48, moving the valve body 48 relative to the valve seat 55. This allows the expansion valve Ev to adjust the throttle opening of the refrigerant flow path in the valve chamber 52, allowing the refrigerant to be appropriately decompressed and expanded in the refrigeration cycle of the vehicle air conditioner.

Next, the circuit unit 70 according to the first embodiment will be described with reference to FIG. 3. The circuit unit 70 according to the first embodiment is disposed inside the motor case 15. The circuit unit 70 in the first embodiment has a circuit board on which multiple electronic components are mounted for controlling the three-phase motor 11a, which is the motor unit 11.

As shown in FIG. 3, the circuit unit 70 is electrically connected to the three-phase motor 11a, which is the motor unit 11, and the battery B. The battery B supplies power to various electrical devices in the vehicle, and is, for example, a rechargeable secondary battery (in this embodiment, a lithium ion battery). The circuit unit 70 receives input power from the battery B and outputs a drive current for driving the three-phase motor 11a.

The circuit unit 70 has electronic components such as an ECU for controlling the operation of the expansion valve Ev, and functions as a control unit for the operation of the expansion valve Ev. The circuit unit 70 has a lock determination unit 71. The lock determination unit 71 constitutes part of the control unit, and determines whether or not the power generated in the drive side mechanism unit 10 is not transmitted to the driven side mechanism unit 35 during the operation of the expansion valve Ev, causing a lock on the driven side.

Specifically, the lock determination unit 71 executes a lock determination control program shown in the flowchart of Fig. 5 to determine whether the driven side is locked and an operation error has occurred in the valve body 48. Details of the lock determination control program will be described later. Also, an input current sensor 73a is connected to the circuit unit 70 according to the first embodiment. The input current sensor 73a is a sensor for measuring the value of the input current input from the battery B to the circuit unit 70. In the first embodiment, the lock determination unit 71 performs frequency analysis using a fast Fourier transform on the detection result of the input current sensor 73a, and determines whether or not a lock has occurred on the driven side based on the analysis result.

The behavior of the power transmission mechanism 1 configured as described above when the driven side configuration (e.g., the driven side magnet 40 and the rotating member 41) is locked will be described. First, a case will be described in which the power from the driving side mechanism 10 is normally transmitted to the driven side configuration, and the driven side configuration rotates around the rotating member 41 as an axis.

The non-contact connection part 60 in the first embodiment is a magnetic gear 60b composed of a driving magnet 20, a pole piece 25, and a driven magnet 40. The driving magnet 20 has multiple magnetic pole pairs (two pairs in this embodiment) consisting of an N pole 20n and an S pole 20s. The N pole 20n and the S pole 20s are arranged in a ring shape at a predetermined pitch on the underside of the driving magnet 20.

The driven magnet 40 also has multiple magnetic pole pairs (20 pairs in this embodiment) consisting of N poles 40n and S poles 40s. The N poles 40n and S poles 40s are arranged in a ring shape at a predetermined pitch on the upper surface of the driven magnet 40.

The pole pieces 25 have multiple soft magnetic bodies made of laminated silicon steel plates or the like. Each pole piece 25 is arranged in a ring shape at a predetermined pitch between the magnetic poles of the driving magnet 20 and the driven magnet 40. In this embodiment, 22 soft magnetic bodies are arranged as pole pieces 25, which is the sum of 2, which is the number of magnetic pole pairs in the driving magnet 20, and 20, which is the number of magnetic pole pairs in the driven magnet 40. Each of the 22 soft magnetic bodies is fixed to the bottom surface of the motor case 15 by welding or the like.

In addition, in the magnetic gear 60b, when the driving magnet 20 rotates due to the operation of the motor unit 11, the magnetic interaction between the driving magnet 20 and the driven magnet 40 causes the driven magnet 40 and the rotating member 41 to rotate in the opposite direction to the driving magnet 20.

Specifically, the magnetic flux in the driving magnet 20 is modulated by being divided by the pole pieces 25 arranged at a predetermined pitch. As a result, the modulated magnetic flux originating from the driving magnet 20 is modulated to a state in which it meshes with the magnetic flux of the driven magnet 40, and interlinks with the magnetic flux of the driven magnet 40, transmitting the power from the driving mechanism 10 to the driven mechanism 35.

At this time, when the driving magnet 20 rotates in a predetermined direction (e.g., clockwise), the driven magnet 40 rotates in the opposite direction to the driving magnet 20 (i.e., counterclockwise). The angular velocity of the driven magnet 40 is a value obtained by reducing the angular velocity of the driving magnet 20 at a predetermined reduction ratio. The reduction ratio of the magnetic gear 60b is determined by the number of magnetic pole pairs arranged in the driven magnet 40/the number of magnetic pole pairs arranged in the driving magnet 20.

Next, we will explain the fluctuation of the rotational load on the driving magnet 20 when the magnetic gear 60b in the first embodiment is in a standard state. The standard state refers to a state in which power is suitably transmitted between the driving magnet 20 and the driven magnet 40, and both the driving magnet 20 and the driven magnet 40 rotate smoothly.

In the standard state, the fluctuation in the rotational load between the driving magnet 20 and the driving magnet 20 during one rotation occurs at the point where the number of magnetic pole pairs of the driving magnet 20 and the number of magnetic pole pairs of the driven magnet 40 are the least common multiple.

For example, in the standard state, if the driving magnet 20 rotates 10 times per second clockwise and the driven magnet 40 rotates once per second counterclockwise, the relative rotational speed difference between the driving magnet 20 and the driven magnet 40 is 11 rotations per second. Therefore, the fluctuation in the rotational load in the standard state occurs at 220 Hz.

Next, we will explain the fluctuation of the rotational load when the magnetic gear 60b in the first embodiment is in a locked state. Note that the locked state means that the driving magnet 20 is in a freely rotatable state, but the driven magnet 40 is stuck for some reason.

Considering the locked state using the example of the standard state described above, the action of the driven magnet 40 and the pole piece 25 causes the four-pole spatial harmonic to be fixed in the gap between the driving magnet 20 and the pole piece 25. As a result, the four poles of the driving magnet 20 and the rotation speed of the shaft 14 cause a fluctuation in the rotation load of 20 Hz.

In the first embodiment, the driving magnet 20 is integrated with the rotor 13 of the motor unit 11 via the shaft 14. Therefore, when a fluctuation in the rotational load occurs in the locked state, the fluctuation in the rotational load of the driving magnet 20 appears as a fluctuation in the input current due to the speed feedback related to the motor unit 11.

Therefore, in the first embodiment, the lock determination unit 71 performs frequency analysis on the detection result of the input current sensor 73a,
Furthermore, since the frequency of the fluctuations in the input current that occur in a locked state is different from the frequency of the fluctuations in the drive current to the motor unit 11, it is possible to detect that the driven side magnet 40, etc., has locked by identifying the frequency of the fluctuations in the input current.

When comparing the results of the frequency analysis of the input power in the standard state with the locked analysis result RL, by focusing on a certain specific frequency (hereinafter referred to as the specific frequency), it becomes easier to determine whether the driven magnet 40, etc., is locked.

Figure 4 is a graph showing an example of a locked-state analysis result RL obtained by performing a frequency analysis on the detection result of the input current sensor 73a by the lock determination unit 71. As can be seen from the locked-state analysis result RL shown in Figure 4, a peak in the input current appears at a specific frequency fs, which is due to fluctuations in the rotation load caused by the locking of the driven magnet 40, etc.

The peak of the specific frequency fs in the first embodiment can be more clearly identified by satisfying the condition that the number of poles of the motor unit 11 and the number of poles of the drive side magnet 20 are different (for example, the number of poles of the motor unit 11 is 12 and the number of poles of the drive side magnet 20 is 4).

In this way, with the power transmission mechanism 1 according to the first embodiment, the lock determination unit 71 performs frequency analysis of the input current and compares the standard state with the locked state, making it easy to determine whether the driven magnet 40, etc., is locked.

Next, the contents of the lock determination control in the power transmission mechanism 1 according to the first embodiment will be described with reference to FIG. 5. As described above, the expansion valve Ev including the power transmission mechanism 1 is installed as a component of the refrigeration cycle in the vehicle air conditioner installed in the vehicle. Therefore, the lock determination control is executed by the lock determination unit 71 when the vehicle is started.

First, in step S1, which is executed when the vehicle is started, the motor unit 11 that constitutes the drive side mechanism unit 10 is driven. At this time, the motor unit 11 operates the rotor 13 at a constant rotation speed.

When the process proceeds to step S2, a signal analysis process is performed on the input current detection result in step S1. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the input current detection result detected when the motor unit 11 is driven in step S1.

In step S3, it is determined whether or not the lock determination condition is satisfied. The lock determination condition refers to a condition under which the driven magnet 40 or the like is determined to be locked, and in the first embodiment, the result of frequency analysis of the input current is that the value of the input current at a specific frequency fs exceeds a reference value.

The reference value is determined based on the standard state, for example, based on the value of the input current at a specific frequency fs as a result of frequency analysis of the input current in the standard state.

If the result of the frequency analysis of the input current indicates that the value of the input current at a specific frequency fs exceeds the reference value, the process proceeds to step S12; otherwise, the process proceeds to step S4.

In step S4, it is determined whether an air conditioner start signal has been received. The air conditioner start signal is a control signal output from an air conditioning control device that constitutes a vehicle air conditioner, and is output when, for example, an operation is performed using the vehicle's operation panel to instruct the start of air conditioning operation. If the air conditioner start signal has not been received, processing waits until the air conditioner start signal is received, and if the air conditioner start signal is received, processing proceeds to step S5.

When the process proceeds to step S5, the motor unit 11 constituting the drive side mechanism unit 10 is driven as part of the initialization process associated with the start of air conditioning operation in the vehicle air conditioner. In this case, as in step S1, the motor unit 11 operates the rotor 13 at a constant rotation speed.

In step S6, a signal analysis process is performed on the input current detection result in step S5. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the input current detection result detected when the motor unit 11 is driven in step S5.

In step S7, similar to step S3, it is determined whether the lock determination condition is met. If the result of the frequency analysis of the input current indicates that the input current value at the specific frequency fs exceeds the reference value, the process proceeds to step S12; otherwise, the process proceeds to step S8.

In step S8, since it has been determined in steps S4 to S7 that the driven magnet 40 or the like has not been locked, the air conditioning operation in the vehicle air conditioner is started based on the air conditioner start signal.

At this time, the vehicle air conditioner selects an operation mode based on the detection signals of the air conditioning control sensors and the operation signal from the operation panel, and outputs control signals to each component of the vehicle air conditioner based on the selected operation mode. Therefore, a drive control signal for the motor unit 11 is output to the expansion valve Ev to realize opening control based on the operation mode.

In step S9, the motor unit 11 constituting the drive side mechanism unit 10 is driven during the air conditioning operation of the vehicle air conditioner. As the air conditioning operation of the vehicle air conditioner is being performed, a control signal is output to the motor unit 11 of the expansion valve Ev to realize a throttle opening degree according to the state of the air conditioning operation, and the motor unit 11 operates the rotor 13 based on the control signal.

In step S10, a signal analysis process is performed on the detection result of the input current associated with the opening control of the expansion valve Ev in step S9. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the detection result of the input current detected when the motor unit 11 is driven in step S10.

In step S11, as in steps S3 and S7, it is determined whether the lock determination condition is met. If the result of the frequency analysis of the input current indicates that the value of the input current at a specific frequency fs exceeds the reference value, the process proceeds to step S12; if not, the process returns to step S9 and the lock determination of the driven magnet 40, etc. during air conditioning operation continues.

When the process proceeds to step S12, a lock occurrence signal is output based on the determination that the lock determination conditions are met in steps S3, S7, and S11. The lock occurrence signal is a signal indicating that the driven magnet 40 or the rotating member 41 is stuck and locked. After the lock occurrence signal is output, the lock determination control is terminated.

The lock occurrence signal can be output to, for example, an air conditioning control device of a vehicle air conditioner or a control device on the vehicle body side. When the lock occurrence signal is output to the air conditioning control device, the air conditioning control device stops the operation of the power transmission mechanism 1 (i.e., the operation of the expansion valve Ev). Also, if the lock determination conditions are met in steps S7 and S11, the air conditioning operation of the vehicle air conditioner may be stopped.

According to the power transmission mechanism 1 of the first embodiment, by executing the lock determination control shown in FIG. 5, it is possible to constantly monitor whether or not a lock has occurred in the driven magnet 40, etc. In other words, when a lock occurs in the driven magnet 40, etc., it is possible to recognize the occurrence of the lock and take measures to eliminate the lock.

As described above, according to the power transmission mechanism 1 of the first embodiment, the shaft 14 of the driving side mechanism 10 and the rotating member 41 of the driven side mechanism 35 are connected in a non-contact manner using magnetic force by the magnetic gear 60b, which is the non-contact connecting part 60. Therefore, if the driven side magnet 40 and the rotating member 41 are locked while the driving side magnet 20 is rotating, the rotational load of the shaft 14 and the driving side magnet 20 will periodically fluctuate due to the influence of the magnetic force between the driving side magnet 20 and the driven side magnet 40.

The power transmission mechanism 1 can use the fluctuation in the rotational load in the drive mechanism 10 to determine whether or not the driven magnet 40 in the separately partitioned driven mechanism 35 has been locked.

As shown in Figures 1 and 2, the non-contact connection unit 60 in the power transmission mechanism 1 according to the first embodiment is composed of a magnetic gear 60b with a pole piece 25 disposed between the driving magnet 20 and the driven magnet 40. In this configuration, the number of poles in the motor unit 11 is different from the total number of poles of the N poles 20n and S poles 20s in the driving magnet 20.

As a result, in the frequency analysis in the lock determination control shown in FIG. 5, the specific frequency fs can be clearly distinguished, and the accuracy of determining whether or not the lock determination condition is met can be improved. Since it is possible to determine whether or not the lock determination condition is met at a frequency different from the drive current of the motor unit 11, it is possible to suppress erroneous detections caused by an increase in the drive current due to aging of the equipment, etc.

As shown in Figures 3 to 5, in the power transmission mechanism 1 according to the first embodiment, a frequency analysis is performed on the input current of the motor unit 11, and if the input current at a specific frequency fs exceeds a reference value, it is determined that the driven magnet 40 is locked.

This makes it possible to accurately determine the locking of the driven side magnet 40 in the driven side mechanism section 35, which is separated from the drive side mechanism section 10, based on fluctuations in the input current, which are relatively easy to detect.

(Modification of the first embodiment)
In the first embodiment described above, the number of poles of the motor unit 11 and the number of poles of the drive side magnet 20 are configured to be different, and the value of the specific frequency fs in the locked state analysis result RL is used to determine whether or not the lock determination condition is satisfied.

As a modified example of the first embodiment, it is also possible to configure the lock determination condition to use two types of specific frequency fs and specific frequency fss values.

One of the conditions for adopting this embodiment is that 1/2 of the number of poles in the motor unit 11 is different from the least common multiple of 1/2 the number of poles in the driving magnet 20 and 1/2 the number of poles in the driven magnet 40. By satisfying this condition, it is possible to determine whether or not the lock determination condition is satisfied using the peak at a specific frequency fs in the locked state analysis result RL shown in Figure 4.

In addition, the condition that the least common multiple of the number of poles of the motor unit 11 and the number of salient poles in the stator 12 of the motor unit 11 is different from the least common multiple of 1/2 the number of poles in the driving side magnet 20 and 1/2 the number of poles in the driven side magnet 40 is satisfied. This makes it possible to utilize the value of the specific frequency fss, and as shown in Figure 4, the specific frequency fss indicates a frequency higher than the specific frequency fs.

In this way, by using the value of the specific frequency fs and the value of the specific frequency fss as the lock determination conditions, it is possible to determine with greater accuracy whether or not the driven magnet 40, etc., is locked.

Second Embodiment
Next, a second embodiment, which is different from the first embodiment, will be described with reference to Fig. 6. In the second embodiment, the configuration of the non-contact connecting portion 60 is different from that of the first embodiment. The other configurations are the same as those of the first embodiment, so that the description will be omitted.

As shown in FIG. 6, the power transmission mechanism 1 is also arranged in the expansion valve Ev according to the second embodiment. In the power transmission mechanism 1 of the second embodiment, a magnetic coupling 60a is adopted as the non-contact connecting part 60. The magnetic coupling 60a is composed of a driving side magnet 20 and a driven side magnet 40. In other words, in the case of the magnetic coupling 60a, unlike the magnetic gear 60b described above, a pole piece 25 is not arranged between the driving side magnet 20 and the driven side magnet 40.

The driving side magnet 20 according to the second embodiment is formed in a disk shape, as in the first embodiment, and at least one pair of magnets consisting of an N pole 20n and an S pole 20s is arranged along the circumferential direction on the underside of the driving side magnet 20. The number of poles of the driving side magnet 20 in the second embodiment is eight.

The driven magnet 40 according to the second embodiment is formed in a disk shape, as in the first embodiment, and is disposed in the internal space of the main body 50 located below the sealing plate 51, as shown in FIG. 6. A plurality of pairs of magnets, each consisting of an N pole 40n and an S pole 40s, are disposed at approximately equal intervals along the circumferential direction on the upper surface of the driven magnet 40. The number of poles of the driven magnet 40 in the second embodiment is the same as the number of poles of the driving magnet 20, which is 8.

In the second embodiment, the number of magnetic poles of the driving magnet 20 and the number of magnetic poles of the driven magnet 40 are the same, so the driving magnet 20 and the driven magnet 40 rotate synchronously due to magnetic interaction. In other words, the rotational speed of the driven magnet 40 is equal to the rotational speed of the driving magnet 20.

According to the second embodiment, by exerting magnetic interaction between the driving side magnet 20 and the driven side magnet 40 via the motor case 15 and the sealing plate 51, the power generated in the driving side mechanism 10 can be transmitted to the driven side mechanism 35 using magnetic force.

Even in the power transmission mechanism 1 according to the second embodiment, when the driven magnet 40 or the like is stuck and locked, the driving magnet 20 can continue to rotate without restriction. In this case, the rotational load on the driving magnet 20 fluctuates at a specific frequency fs depending on the number of poles of the magnetic coupling 60a (i.e., the number of poles of the driving magnet 20 or the number of poles of the driven magnet 40).

In the second embodiment, the fluctuation in the rotational load also appears as a fluctuation in the input current, etc., due to speed feedback. As a result, in the power transmission mechanism 1 according to the second embodiment, it is possible to detect the occurrence of locking of the driven magnet 40, etc., by performing frequency analysis on the input current, etc.

In this configuration, the number of poles of the motor section 11 is different from the number of poles of the magnetic coupling 60a. The number of poles of the magnetic coupling 60a is the total number of poles of the N poles 20n and S poles 20s of the driving side magnet 20, and is the total number of poles of the N poles 40n and S poles 40s of the driven side magnet 40.

As a result, in the power transmission mechanism 1 according to the second embodiment, the specific frequency fs can be clearly distinguished in the frequency analysis during the lock determination control, as in the above-described embodiment, and the accuracy of determining whether or not the lock determination condition is satisfied can be improved.

As described above, according to the power transmission mechanism 1 of the second embodiment, even if the non-contact connecting portion 60 is configured as a magnetic coupling 60a, the same effects as those of the above-mentioned embodiment can be obtained from the same configuration as those of the above-mentioned embodiment.

In other words, according to the power transmission mechanism 1 of the second embodiment, even when a magnetic coupling 60a is used as the non-contact connecting part 60, the locking of the driven side magnet 40 in the driven side mechanism part 35, which is partitioned separately from the driving side mechanism part 10, can be accurately determined.

In addition, in the second embodiment, the number of poles of the motor unit 11 is different from the number of poles of the magnetic coupling 60a. Therefore, in the power transmission mechanism 1 according to the second embodiment, the specific frequency fs can be clearly distinguished by frequency analysis in the lock determination control, as in the above-mentioned embodiment.

Third Embodiment
Next, a third embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 7 and Fig. 8. In the third embodiment, the configuration of the drive side mechanism 10 is different from that of the above-described embodiment. The configuration of the driven side mechanism 35 and the like is the same as that of the above-described embodiment, so a repeated description will be omitted.

As shown in Figures 7 and 8, in the power transmission mechanism 1 according to the third embodiment, the power generated in the motor section 11 is configured to be transmitted to the driving side magnet 20 via the reduction mechanism section 30.

The reduction mechanism 30 according to the third embodiment is configured with a planetary gear mechanism and has a sun gear 31, an output gear 33 which is a ring gear, and a carrier which rotatably supports three planetary gears 32 which mesh with these gears. The reduction mechanism 30 utilizes the differential of the planetary gear mechanism to significantly reduce the rotation of the rotor 13 of the motor 11 and transmit it to the drive magnet 20.

In the power transmission mechanism 1 according to the third embodiment, a sun gear 31 is attached to the lower end of the shaft 14. As described above, the shaft 14 rotates integrally with the rotor 13, so the sun gear 31 rotates in synchronization with the rotation of the rotor 13.

As described above, the output gear 33 is composed of a ring gear and has a predetermined number of internal teeth on the inside of the ring gear. As shown in Figures 7 and 8, the sun gear 31 is disposed in the center of the ring associated with the output gear 33.

The carrier is formed in a ring shape and is fixed to the motor case 15 so as to be positioned between the external teeth of the sun gear 31 and the internal teeth of the output gear 33. The three planetary gears 32 are arranged so as to mesh with the external teeth of the sun gear 31 and the internal teeth of the output gear 33, respectively, and are supported rotatably by the carrier.

By configuring in this way, in the reduction mechanism 30, the rotation of the sun gear 31 is reduced at a predetermined reduction ratio and transmitted to the output gear 33. An output shaft 33s is attached to the output gear 33. In the third embodiment, the output shaft 33s is arranged coaxially with the shaft 14 and the rotating member 41, and rotates together with the output gear 33.

As shown in Figures 7 and 8, in the third embodiment, a driving magnet 20 is attached to the lower end of the output shaft 33s. The driving magnet 20 rotates integrally with the output gear 33 as it rotates. In other words, in the third embodiment, the rotation of the rotor 13 of the motor unit 11 is reduced at a predetermined reduction ratio and transmitted to the output gear 33, so that the driving magnet 20 is rotated by the motor unit 11.

In the power transmission mechanism 1 according to the third embodiment, a magnetic coupling 60a is used as the non-contact connecting part 60, and is composed of a driving magnet 20 and a driven magnet 40. The configuration and function of the magnetic coupling 60a have already been explained in the second embodiment, so a repeated explanation will be omitted.

Therefore, even in the third embodiment, fluctuations in the rotational load are manifested as fluctuations in the input current, etc., due to speed feedback. As a result, even in the power transmission mechanism 1 according to the third embodiment, it is possible to detect the occurrence of locking of the driven magnet 40, etc., by performing frequency analysis on the input current, etc.

In the third embodiment, the motor unit 11 is configured to satisfy the condition that the reduction ratio of the reduction mechanism unit 30 is different from the number of poles of the magnetic coupling 60a. In the third embodiment, the motor unit 11 is configured to satisfy the condition that the reduction ratio of the reduction mechanism unit 30 is different from the number of poles of the magnetic coupling 60a.

By configuring it in this way, the power transmission mechanism 1 according to the third embodiment can also clearly distinguish the specific frequency fs in the frequency analysis during the lock determination control, as in the above-described embodiment, thereby improving the accuracy of determining whether or not the lock determination condition is satisfied.

As described above, according to the power transmission mechanism 1 of the third embodiment, even if the reduction mechanism section 30 is arranged between the motor section 11 and the driving side magnet 20, the same effect as in the above-mentioned embodiment can be obtained from the same configuration as in the above-mentioned embodiment.

In other words, according to the power transmission mechanism 1 of the third embodiment, even if the power is transmitted to the driving magnet 20 via the reduction mechanism 30, the locking of the driven magnet 40 in the driven mechanism 35, which is partitioned separately from the driving mechanism 10, can be accurately determined.

In addition, in the third embodiment, the value obtained by multiplying the number of poles of the motor unit 11 by the reduction ratio of the reduction mechanism unit 30 is different from the number of poles of the magnetic coupling 60a, and the reduction ratio of the reduction mechanism unit 30 is different from the number of poles of the magnetic coupling 60a. Therefore, in the power transmission mechanism 1 according to the third embodiment, the specific frequency fs can be clearly distinguished by frequency analysis in the lock determination control, as in the above-mentioned embodiment.

Fourth Embodiment
Next, a fourth embodiment, which is different from the above-described embodiment, will be described with reference to Figures 9 and 10. In the fourth embodiment, the configuration of the motor unit 11 in the drive side mechanism unit 10 is different from that of the above-described embodiment. The configurations of the driven side mechanism unit 35 and the non-contact connecting unit 60, etc. are the same as those of the first embodiment described above, so that a repeated description will be omitted.

As shown in Figures 9 and 10, the power transmission mechanism 1 according to the fourth embodiment employs an axial gear motor 11b as the motor section 11. The axial gear motor 11b has a stator 12, a rotor 13, and a shaft 14, and the stator 12 and the rotor 13 are arranged to overlap in the axial direction of the shaft 14.

The axial gear motor 11b is able to secure a sufficient opposing area between the stator 12 and the rotor 13 by arranging the stator 12 and the rotor 13 so that they overlap in the axial direction. In other words, the axial gear motor 11b achieves both a thin motor section 11 and the maintenance of high torque.

The stator 12 in the axial gear motor 11b is constructed by winding three-phase (i.e., U-phase, V-phase, and W-phase) stator coils 12a around a stator core having a ring-shaped back yoke and multiple teeth extending vertically from the back yoke.

As shown in FIG. 10, the rotor 13 is formed in a disk shape and is arranged coaxially below the stator 12. The rotor 13 has a rotor magnet arranged in an annular shape and arranged to face multiple teeth on the stator 12. One end of the shaft 14 is joined to the center of the rotor 13. A drive magnet 20 is attached to the other end of the shaft 14, which extends downward from the rotor 13.

Therefore, in the fourth embodiment, when the rotor 13 rotates due to the operation of the axial gear motor 11b, the driving magnet 20 rotates integrally with the rotor 13 and the shaft 14. Also, as shown in FIG. 9, inside the motor case 15, a pole piece 25 is disposed below the driving magnet 20, as in the first embodiment.

In other words, according to the power transmission mechanism 1 of the fourth embodiment, the power generated by the axial gear motor 11b can be transmitted to the driven side magnet 40 and the valve body 48 of the driven side mechanism part 35 via the magnetic gear 60b, which is the non-contact connecting part 60.

In the power transmission mechanism 1 according to the fourth embodiment, fluctuations in the rotational load on the driving magnet 20 affect the input current, etc., so that it is possible to detect the occurrence of locking of the driven magnet 40, etc., just as in the first embodiment.

As described above, according to the power transmission mechanism 1 of the fourth embodiment, even if an axial gear motor 11b is used as the motor section 11 of the drive side mechanism section 10, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

In other words, according to the power transmission mechanism 1 of the fourth embodiment, even if the motor section 11 is configured as an axial gear motor 11b, the locking of the driven side magnet 40 in the driven side mechanism section 35, which is partitioned separately from the drive side mechanism section 10, can be determined with high accuracy.

In the fourth embodiment, the rotor 13 of the axial gear motor 11b and the driving magnet 20 can be integrated into a disk shape. In this case, the upper surface of the disk-shaped magnet is made to interact with the stator 12 of the axial gear motor 11b to generate electromagnetic force, and the lower surface of the disk-shaped magnet is made to interact with the pole piece 25. When the non-contact connection unit 60 is made of a magnetic coupling 60a, the lower surface of the disk-shaped magnet is made to interact with the upper surface of the driven magnet 40.

Fifth Embodiment
Next, a fifth embodiment, which is different from the above-described embodiments, will be described with reference to Figs. 11 and 12. In the fifth embodiment, a method for determining whether locking of the driven side magnet 40, etc. has occurred is different from that of the above-described embodiments. The basic configurations of the drive side mechanism 10, the driven side mechanism 35, etc. are the same as those of the above-described embodiments, so a repeated description will be omitted.

As shown in FIG. 11, in the power transmission mechanism 1 according to the fifth embodiment, a three-phase motor 11a is used as the motor section 11 constituting the drive side mechanism section 10. The circuit section 70 according to the fifth embodiment has a lock determination section 71, a three-phase inverter circuit 72, and a drive current sensor 73b.

The lock determination unit 71 is the same as in the first embodiment. The drive current sensor 73b is a sensor for detecting the drive current supplied to the stator coil 12a of each phase in the three-phase motor 11a.

The three-phase inverter circuit 72 is a power conversion circuit that converts DC power supplied from battery B into AC power, and is configured by combining multiple MOSFETs. As shown in FIG. 11, the three-phase inverter circuit 72 is electrically connected to battery B and the three-phase motor 11a, converts the DC power of battery B into three-phase AC, and supplies it to the stator coils 12a of each phase of the three-phase motor 11a.

The three-phase inverter circuit 72 according to the fifth embodiment has a rectifier circuit (RCF) and an envelope detector (ENV). The rectifier circuit generates a three-phase AC waveform by converting a three-phase signal into an analog signal, and also full-wave rectifies the three-phase AC waveform. The envelope detector detects and outputs the envelope of the full-wave rectified waveform.

Next, the lock determination control in the fifth embodiment will be described with reference to FIG. 12. When the non-contact connection part 60 is in a locked state, the driving magnet 20 rotates, but the driven magnet 40 is stopped. Therefore, the fluctuation of the rotation load between the driving magnet 20 and the driven magnet 40 occurs at a constant cycle due to magnetic interaction, as in the above-mentioned embodiment.

As a result, the rotational speed of the drive magnet 20 fluctuates with fluctuations in the rotational load. Because the drive current of the motor section 11 flows at a frequency synchronized with the rotational speed of the drive magnet 20, etc., the frequency of the drive current also fluctuates with fluctuations in the rotational load, and this is also reflected in the envelope of the drive current.

In the fifth embodiment, when determining whether or not the lock determination condition is satisfied, a frequency analysis is performed on the envelope of the drive current output from the envelope detector of the three-phase inverter circuit 72. FIG. 12 shows an example of the result of the frequency analysis on the envelope of the drive current. FIG. 12 shows a standard analysis result RS and a locked analysis result RL. The standard analysis result RS shows the result of the frequency analysis on the envelope of the drive current in the standard state. And the locked analysis result RL shows the result of the frequency analysis on the envelope of the drive current in the locked state.

As described above, when the driven magnet 40 or the like is locked, the value of the envelope of the drive current fluctuates with the fluctuation of the rotational load. For this reason, as shown in FIG. 12, at a specific frequency fs corresponding to the fluctuation of the rotational load, the peak value in the locked analysis result RL shows a value that is significantly larger than the value in the standard analysis result RS.

Therefore, in the fifth embodiment, the lock determination unit 71 performs frequency analysis on the envelope of the drive current, making it possible to detect the occurrence of locking of the driven magnet 40, etc.

In the lock determination control of the fifth embodiment, the lock determination condition is that the value of the envelope of the drive current at a specific frequency fs exceeds a reference value in the result of frequency analysis of the envelope of the drive current. In this case, the reference value is determined based on the standard state, and is determined, for example, based on the value of the envelope of the drive current at a specific frequency fs in the result of frequency analysis of the envelope of the drive current in the standard state (i.e., the standard analysis result RS).

In this case, if the value of the envelope of the drive current at a specific frequency fs exceeds a reference value, it can be determined that a fluctuation in the rotational load on the drive magnet 20 has occurred, and that the driven magnet 40, etc. has stuck and is in a locked state. If not, it can be determined that power is being properly transmitted between the drive magnet 20 and the driven magnet 40, and that the drive magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

As described above, according to the power transmission mechanism 1 of the fifth embodiment, even if a frequency analysis is performed on the envelope of the drive current of the three-phase motor 11a, the same effect as in the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the fifth embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the driving mechanism section 10, based on the fluctuation of the envelope of the drive current.

Sixth Embodiment
Next, a sixth embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 13 and Fig. 14. In the sixth embodiment, the method of determining whether the motor unit 11 and the driven magnet 40 are locked is different from that of the above-described embodiment. The configuration of the other components, such as the driven mechanism unit 35, is the same as that of the above-described embodiment, so a repeated description will be omitted.

As shown in FIG. 13, in the power transmission mechanism 1 according to the sixth embodiment, a DC motor 11c is used as the motor section 11. The DC motor 11c is a DC commutator motor having a commutator and brushes.

The circuit unit 70 according to the sixth embodiment has a lock determination unit 71 and a drive current sensor 73b. The battery B and the DC motor 11c are electrically connected to the circuit unit 70. The lock determination unit 71 is the same as in the above-mentioned embodiment. The drive current sensor 73b according to the sixth embodiment is a sensor for detecting the drive current supplied to the DC motor 11c.

Next, the lock determination control in the sixth embodiment will be described with reference to FIG. 14. In the power transmission mechanism 1 according to the sixth embodiment, a DC motor 11c having a commutator and brushes is used as the motor section 11. Therefore, in the DC motor 11c, the direction of the current is switched by the commutator and brushes when the rotation phase of the rotor 13 reaches a predetermined phase in order to keep the rotation direction of the rotor 13 in a predetermined direction.

Therefore, when a frequency analysis is performed on the drive current of the DC motor 11c, as shown in Figure 14, peaks due to current switching by the commutator and brushes appear in both the standard analysis result RS and the locked analysis result RL.

In the sixth embodiment, when the non-contact connection part 60 is in a locked state, the fluctuation in the rotational load between the driving magnet 20 and the driven magnet 40 occurs at a constant period due to magnetic interaction, as in the above-mentioned embodiment. Since the period in which the rotational load fluctuates is different from the period related to the current switching of the commutator and brushes, at a specific frequency fs, the peak of the drive current related to the locked analysis result RL can be clearly distinguished from the value of the drive current related to the standard analysis result RS.

Therefore, in the sixth embodiment, the lock determination unit 71 performs frequency analysis on the drive current of the DC motor 11c, making it possible to detect the occurrence of locking of the driven magnet 40, etc.

In the lock determination control of the sixth embodiment, the lock determination condition is that the drive current at a specific frequency fs exceeds a reference value in the results of frequency analysis of the drive current of the DC motor 11c. In this case, the reference value is determined based on the standard state, and is determined based on the value of the drive current at a specific frequency fs in the results of frequency analysis of the drive current of the DC motor 11c in the standard state (i.e., the standard analysis result RS).

In this case, if the value of the drive current of the DC motor 11c at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotation load on the drive magnet 20 has occurred, and that the driven magnet 40, etc. has stuck and is in a locked state. If not, it can be determined that power is being properly transmitted between the drive magnet 20 and the driven magnet 40, and that the drive magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

As described above, according to the power transmission mechanism 1 of the sixth embodiment, even if a frequency analysis is performed on the drive current of the DC motor 11c, the same effect as the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the sixth embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the driving mechanism section 10, based on the fluctuations in the drive current of the DC motor 11c.

Seventh Embodiment
Next, a seventh embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 15 and Fig. 16. In the seventh embodiment, the method of determining whether the driven magnet 40, etc., is locked is different from that of the above-described embodiment. The remaining configurations of the driven mechanism portion 35, etc. are the same as those of the above-described embodiment, and therefore will not be described again.

As shown in FIG. 15, in the power transmission mechanism 1 according to the seventh embodiment, a three-phase motor 11a is used as the motor section 11 constituting the drive side mechanism section 10. The circuit section 70 according to the seventh embodiment has a lock determination section 71, a three-phase inverter circuit 72, and a determination voltage specification section 74.

The lock determination unit 71 is the same as in the embodiment described above. And, the three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the embodiment described above, and converts the DC power of the battery B into three-phase AC and supplies it to the stator coils 12a of each phase of the three-phase motor 11a.

The three-phase inverter circuit 72 according to the seventh embodiment determines the duty ratio, which is the ratio between the on-time and off-time of the motor unit 11, and supplies power to the DC motor 11c based on the determined duty ratio. In other words, PWM control is performed on the three-phase motor 11a.

Specifically, a predetermined triangular wave is compared with the judgment voltage, and the duty ratio of the voltage supplied to the three-phase motor 11a is determined by the ratio of the period during which the triangular wave is higher than the judgment voltage to the period during which the triangular wave is lower than the judgment voltage. The judgment voltage specification unit 74 specifies the judgment voltage for determining the duty ratio. For example, when a triangular wave and a judgment voltage are input to the comparator, the judgment voltage specification unit 74 specifies the value of the judgment voltage input to the comparator.

Next, the lock determination control in the seventh embodiment will be described with reference to FIG. 16. As described above, the operation of the three-phase motor 11a in the seventh embodiment is controlled by PWM control. Therefore, the higher the duty ratio, the faster the rotation speed of the rotor 13 in the three-phase motor 11a, and the lower the duty ratio, the slower the rotation speed of the rotor 13.

For this reason, in the seventh embodiment, when the driven magnet 40 or the like is stuck and locked, causing the rotational load on the driving magnet 20 to fluctuate, the duty ratio will fluctuate in conjunction with the fluctuation in the rotational load. As described above, the duty ratio is determined by comparing the triangular wave with the judgment voltage, so the judgment voltage fluctuates with the same period as the fluctuation in the duty ratio.

On the other hand, in the standard state, there is no large fluctuation in the rotational load between the driving magnet 20 and the driven magnet 40, so there is no large fluctuation in the duty ratio and the judgment voltage.

In the lock determination control according to the seventh embodiment, a frequency analysis is performed on the determination voltage. As shown in FIG. 16, in the locked analysis result RL, a peak in the determination voltage appears at a specific frequency fs that corresponds to fluctuations in the rotation load. On the other hand, in the standard state, there is no large fluctuation in the rotation load, and the drive magnet 20 and the driven magnet 40 rotate appropriately. For this reason, in the standard analysis result RS, the value of the determination voltage does not fluctuate greatly at the specific frequency fs.

Therefore, in the seventh embodiment, the lock determination unit 71 performs frequency analysis on the determination voltage related to the PWM control, thereby making it possible to detect the occurrence of locking of the driven magnet 40, etc.

In the seventh embodiment, the lock determination condition is that the determination voltage at a specific frequency fs exceeds a reference value in the results of frequency analysis of the determination voltage related to PWM control. In this case, the reference value is determined based on the standard state, and is determined based on the value of the determination voltage at a specific frequency fs in the results of frequency analysis of the determination voltage in the standard state (i.e., the standard analysis result RS).

In this case, if the value of the judgment voltage at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotational load on the driving magnet 20 has occurred, and that the driven magnet 40, etc. has stuck and is in a locked state. If not, it can be determined that power is being properly transmitted between the driving magnet 20 and the driven magnet 40, and that the driving magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

As described above, according to the power transmission mechanism 1 of the seventh embodiment, even if a frequency analysis is performed on the judgment voltage related to the PWM control of the motor unit 11, the same effect as in the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the seventh embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the drive mechanism section 10, based on the fluctuation of the judgment voltage.

Eighth embodiment
Next, an eighth embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 17 and Fig. 18. In the eighth embodiment, the method of determining whether the driven magnet 40 or the like is locked is different from that of the above-described embodiment. The remaining configurations of the driven mechanism 35 and the like are the same as those of the above-described embodiment, and therefore will not be described again.

As shown in FIG. 17, in the power transmission mechanism 1 according to the eighth embodiment, a three-phase motor 11a is used as the motor section 11 constituting the drive side mechanism section 10. The circuit section 70 according to the eighth embodiment has a lock determination section 71, a three-phase inverter circuit 72, and a drive current sensor 73u.

The lock determination unit 71 is the same as in the embodiment described above. And, the three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the embodiment described above, and converts the DC power of the battery B into three-phase AC and supplies it to the stator coils 12a of each phase of the three-phase motor 11a.

The drive current sensor 73u according to the eighth embodiment is a sensor that detects the drive current of the U phase among the U phase, V phase, and W phase for the three-phase motor 11a. The drive current sensor 73u only needs to detect the drive current for any one phase of the drive current for the three-phase motor 11a.

Next, the lock determination control in the eighth embodiment will be described with reference to FIG. 18. When the non-contact connection part 60 is in a locked state, the driving magnet 20 rotates, but the driven magnet 40 is stopped. Therefore, the fluctuation in the rotation load between the driving magnet 20 and the driven magnet 40 occurs at a constant cycle due to magnetic interaction, as in the above-mentioned embodiment.

Because the driven magnet 40 is stopped, when the driving magnet 20 rotates, there are states where the magnetism acts to attract and where the magnetism acts to repel between the driving magnet 20 and the driven magnet 40. The rotation speed of the driving magnet 20 accelerates and decelerates due to the influence of the magnetic attraction and repulsion between the driving magnet 20 and the driven magnet 40. The driving current of the motor unit 11 flows at a frequency synchronized with the rotation speed of the driving magnet 20, etc., so the frequency of the driving current also fluctuates with the fluctuation of the rotation speed.

In the following description, the specific frequency when the rotation speed is slowed down due to the influence of the magnetic force between the driven magnet 40 is referred to as the first specific frequency fsa, and the specific frequency when the rotation speed is increased due to the influence of the magnetic force between the driven magnet 40 is referred to as the second specific frequency fsb.

On the other hand, in the standard state, the drive magnet 20 and the driven magnet 40 rotate at a constant rotational speed, so the frequency of the drive current is also constant. The frequency corresponding to the constant rotational speed in the standard state is called the standard frequency fc.

In the lock determination control according to the eighth embodiment, a frequency analysis is performed on the drive current of one of the phases of the three-phase motor 11a. As shown in FIG. 18, in the standard analysis result RS, a peak in the drive current appears at the standard frequency fc.

On the other hand, in the locked analysis result RL, a peak in the drive current appears at a first specific frequency fsa that is lower than the standard frequency fc. The drive current at the first specific frequency fsa indicates the value at the point in time when the rotational speed of the drive side magnet 20 slows down due to fluctuations in the rotational load.

In addition, in the locked analysis result RL, a peak in the drive current appears at a second specific frequency fsb that is higher than the standard frequency fc. The drive current at the second specific frequency fsb indicates the value at the point in time when the rotational speed of the drive side magnet 20 increases due to a change in the rotational load.

As described above, in the standard state, the driving magnet 20 and the driven magnet 40 rotate at a constant rotational speed, so a peak appears at the standard frequency fc, but no peak appears at the first specific frequency fsa or the second specific frequency fsb.

Therefore, in the eighth embodiment, by performing a frequency analysis on the driving current of any one phase of the three-phase motor 11a and comparing the values of the first specific frequency fsa and the second specific frequency fsb, it is possible to detect the occurrence of locking of the driven magnet 40, etc.

In the lock determination control in the eighth embodiment, the lock determination condition is that the drive current at the first specific frequency fsa and the second specific frequency fsb exceeds a reference value as a result of frequency analysis of the drive current of any one phase of the three-phase motor 11a.

In this case, the reference values are determined based on the standard state. For example, the reference value for the first specific frequency fsa is determined based on the value of the drive current at the first specific frequency fsa in the standard analysis result RS. Furthermore, the reference value for the second specific frequency fsb is determined based on the value of the drive current at the second specific frequency fsb in the standard analysis result RS.

If the value of the drive current at the first specific frequency fsa exceeds the reference value, it can be determined that a fluctuation in the rotational load on the drive magnet 20 has occurred, and that the driven magnet 40, etc. has stuck and is in a locked state. If not, it can be determined that power is being properly transmitted between the drive magnet 20 and the driven magnet 40, and that the drive magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

When the drive current value exceeds the respective reference value at either the first specific frequency fsa or the second specific frequency fsb, it is determined that the driven magnet 40 or the like is locked, thereby making it possible to more reliably detect the occurrence of a locked state.

In addition, the system may be configured to determine that a lock state has occurred if the drive current value exceeds the respective reference value at either the first specific frequency fsa or the second specific frequency fsb.

As described above, according to the power transmission mechanism 1 of the eighth embodiment, even if a frequency analysis is performed on the drive current of one of the phases of the three-phase motor 11a, the same effect as the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the eighth embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the drive mechanism section 10, based on the fluctuation of the drive current of one of the phases of the three-phase motor 11a.

Ninth embodiment
Next, a ninth embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 19 and Fig. 20. In the ninth embodiment, the method of determining whether the driven magnet 40, etc., is locked is different from that of the above-described embodiment. The rest of the configuration of the driven mechanism portion 35, etc. is the same as in the above-described embodiment, so a repeated description will be omitted.

As shown in FIG. 19, in the power transmission mechanism 1 according to the ninth embodiment, a three-phase motor 11a is used as the motor section 11 constituting the drive side mechanism section 10. The circuit section 70 according to the ninth embodiment has a lock determination section 71, a three-phase inverter circuit 72, and a line voltage sensor 73c.

The lock determination unit 71 is the same as in the embodiment described above. And, the three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the embodiment described above, and converts the DC power of the battery B into three-phase AC and supplies it to the stator coils 12a of each phase of the three-phase motor 11a.

The line voltage sensor 73c is a sensor that detects the value of the voltage between any two of the three phases for the three-phase motor 11a. For example, the line voltage sensor 73c detects the value of the line voltage between the U phase and the V phase of the U phase, V phase, and W phase for the three-phase motor 11a.

Next, the lock determination control in the ninth embodiment will be described with reference to FIG. 20. As described above, when in a locked state, the fluctuation in the rotational load between the driving side magnet 20 and the driven side magnet 40 occurs at a constant cycle due to magnetic interaction, as in the above-mentioned embodiment.

And because the driven magnet 40 is stopped, when the driving magnet 20 rotates, there are states where the magnetism acts to attract and where the magnetism acts to repel between the driving magnet 20 and the driven magnet 40. Therefore, the rotation speed of the driving magnet 20 side accelerates and decelerates due to the influence of the magnetic attraction and repulsion between the driving magnet 20 and the driven magnet 40. Since the drive current of the motor section 11 flows at a frequency synchronized with the rotation speed of the driving magnet 20, etc., the line voltage of any two phases in the three-phase motor 11a also fluctuates with the fluctuation in the rotation speed.

In the lock determination control according to the ninth embodiment, a frequency analysis is performed on the line voltage of any two phases of the three-phase motor 11a. As shown in FIG. 20, in the standard analysis result RS, a peak of the line voltage appears at the standard frequency fc.

On the other hand, in the locked state analysis result RL, the drive current peaks appear at the first specific frequency fsa and the second specific frequency fsb. The line voltage at the first specific frequency fsa indicates the value at the point when the rotation speed of the drive side magnet 20 slows down due to fluctuations in the rotation load. The line voltage at the second specific frequency fsb indicates the value at the point when the rotation speed of the drive side magnet 20 increases due to fluctuations in the rotation load.

As described above, in the standard state, the driving magnet 20 and the driven magnet 40 rotate at a constant rotational speed, so a peak appears at the standard frequency fc, but no peak appears at the first specific frequency fsa or the second specific frequency fsb.

Therefore, in the ninth embodiment, by performing frequency analysis on the line voltage of any two phases of the three-phase motor 11a and comparing the values of the first specific frequency fsa and the second specific frequency fsb, it is possible to detect the occurrence of locking of the driven magnet 40, etc.

In the lock determination control of the ninth embodiment, the lock determination condition is that the line voltage at the first specific frequency fsa and the second specific frequency fsb exceeds a reference value as a result of frequency analysis of the line voltage of any two phases of the three-phase motor 11a.

In this case, the reference values are determined based on the standard state. For example, the reference value for the first specific frequency fsa is determined based on the value of the line voltage at the first specific frequency fsa in the standard analysis result RS. Furthermore, the reference value for the second specific frequency fsb is determined based on the value of the line voltage at the second specific frequency fsb in the standard analysis result RS.

If the value of the line voltage at the first specific frequency fsa exceeds the reference value, it can be determined that a fluctuation in the rotation load on the driving magnet 20 has occurred and that the driven magnet 40 and other magnets are in a locked state. If not, it can be determined that the driving magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

When the line voltage value exceeds the respective reference value at either the first specific frequency fsa or the second specific frequency fsb, it is determined that the driven magnet 40, etc., is locked, thereby making it possible to more reliably detect the occurrence of a locked state.

As described above, according to the power transmission mechanism 1 of the ninth embodiment, even if a frequency analysis is performed on the line voltage of the three-phase motor 11a, the same effect as in the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the ninth embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the drive mechanism section 10, based on the fluctuation in the line voltage of the three-phase motor 11a.

Tenth embodiment
Next, a tenth embodiment, which is different from the above-described embodiment, will be described with reference to Fig. 21 and Fig. 22. In the tenth embodiment, the method of determining whether the driven magnet 40, etc., is locked is different from that of the above-described embodiment. The rest of the configuration of the driven mechanism portion 35, etc., is the same as in the above-described embodiment, so a repeated description will be omitted.

In the power transmission mechanism 1 according to the tenth embodiment, the circuit section 70 has a lock determination section 71 and an acceleration sensor 73d. As shown in FIG. 21, the acceleration sensor 73d is disposed in the motor case 15 of the drive side mechanism section 10, and detects changes in acceleration occurring in the drive side mechanism section 10. Therefore, in the power transmission mechanism 1 according to the tenth embodiment, the acceleration sensor 73d can detect vibrations caused by the operation of the motor section 11 of the drive side mechanism section 10.

Next, the lock determination control in the tenth embodiment will be described with reference to FIG. 22. As described above, in the standard state, there is almost no fluctuation in the rotational load between the driving side magnet 20 and the driven side magnet 40, and the driving side magnet 20 and the driven side magnet 40 rotate integrally. In other words, the driving side mechanism 10 vibrates at a constant period due to the driving side magnet 20 and the driven side magnet 40 rotating integrally.

On the other hand, in the locked state, the driven magnet 40 is stopped, so when the driving magnet 20 rotates, the rotational load fluctuates due to magnetic interaction with the driven magnet 40. The fluctuation in the rotational load changes the rotational speed of the driving magnet 20 and the shaft 14, and vibrations due to the fluctuation in the rotational load occur in the driving mechanism 10 including the motor unit 11.

The period of vibration occurring in the locked state differs from the period of vibration occurring in the standard state due to the influence of magnetism between the driving side magnet 20 and the driven side magnet 40. As a result, by analyzing the period of vibration occurring in the driving side mechanism part 10 using the acceleration sensor 73d, it is possible to determine whether or not the driven side magnet 40, etc., is locked.

In the lock determination control according to the tenth embodiment, frequency analysis is performed on the detection signal of the acceleration sensor 73d. As shown in FIG. 22, in the standard analysis result RS, an acceleration peak appears at the standard frequency fc. The standard frequency fc corresponds to the period of occurrence of vibration due to the rotation of the driving magnet 20 and the driven magnet 40 in the standard state.

On the other hand, in the locked analysis result RL, an acceleration peak appears at a specific frequency fs. The acceleration peak at the specific frequency fs is caused by vibration of the drive side mechanism part 10 due to fluctuations in the rotation load.

As described above, in the standard state, the driving magnet 20 and the driven magnet 40 rotate at a constant rotational speed, so a peak appears at the standard frequency fc, and no acceleration peak appears at the specific frequency fs.

Therefore, in the tenth embodiment, by performing frequency analysis on the detection signal of the acceleration sensor 73d and comparing the value of the specific frequency fs, it is possible to detect the occurrence of locking of the driven magnet 40, etc.

In the lock determination control of the tenth embodiment, the lock determination condition is that the acceleration value at the specific frequency fs exceeds a reference value in the result of frequency analysis of the detection signal of the acceleration sensor 73d. In this case, the reference value is determined based on the standard state, and is determined based on the acceleration value at the specific frequency fs in the standard analysis result RS, for example.

If the acceleration value at a specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotational load on the driving magnet 20 has occurred, and that the driven magnet 40 and other magnets are in a locked state. If not, it can be determined that the driving magnet 20 and the driven magnet 40 are in a standard state in which they can rotate.

As described above, according to the power transmission mechanism 1 of the tenth embodiment, even if a frequency analysis is performed on the acceleration detected by the acceleration sensor 73d, the same effect as in the above-mentioned embodiment can be obtained from a configuration similar to that of the above-mentioned embodiment.

In other words, the power transmission mechanism 1 according to the tenth embodiment can accurately determine the locking of the driven magnet 40 in the driven mechanism section 35, which is partitioned separately from the drive mechanism section 10, based on the fluctuation in acceleration detected by the acceleration sensor 73d.

Other Embodiments
Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments.

(1) In the above-described embodiment, the occurrence of locking of the driven magnet 40, etc. is constantly monitored by determining whether the locking determination conditions are met when the vehicle is started, when the vehicle air conditioner is started, and during air conditioning operation according to the flowchart shown in FIG. 5.

However, the timing of the lock determination control and the determination of the lock determination condition is not limited to the above-mentioned timing and can be changed as appropriate. For example, instead of the flowchart shown in FIG. 5, the flowchart shown in FIG. 23 can be executed.

As shown in FIG. 23, first, in step S21, it is determined whether or not an error occurrence signal has been received. If an error occurrence signal has been received, the process proceeds to step S22, and if an error occurrence signal has not been received, the lock determination control shown in FIG. 23 is terminated.

The error occurrence signal is a control signal output from an externally placed control device, and is output when it is believed that there is an error in the operation of the power transmission mechanism 1. For example, if the refrigerant temperature or refrigerant pressure in the refrigeration cycle of the vehicle air conditioner indicates an obviously abnormal value, the air conditioning control device of the vehicle air conditioner outputs an error occurrence signal.

In step S22, the motor unit 11 is driven to check the operation of the power transmission mechanism 1. At this time, similar to step S2 and the like, the rotor 13 is operated at a constant rotation. In step S23, a signal analysis process is performed on the output signal (e.g., input current) output by driving the motor unit 11 in step S22. The contents of the signal analysis process are the same as those of step S3 and the like, and frequency analysis is performed on the output signal.

When the process proceeds to step S24, it is determined whether or not the lock determination condition is met. If the lock determination condition is met, it is determined that the driven magnet 40, etc. is in a locked state and a lock occurrence signal is output in step S25.

If the lock determination condition is not met, in step S26, it is determined that the driving magnet 20 and the driven magnet 40 are in a standard state in which they can rotate, and a normal signal is output. The normal signal indicates that the driving magnet 20 and the driven magnet 40 are in a standard state in which they rotate together.

The lock determination control according to the modified example shown in FIG. 23 is configured to drive the motor unit 11, perform frequency analysis, and perform a determination regarding the lock determination conditions in response to receipt of an error occurrence signal from outside. Therefore, the power transmission mechanism 1 according to the modified example can determine whether a lock has occurred in the driven magnet 40, etc., at an appropriate timing. Furthermore, the processing load on the lock determination unit 71 can be reduced compared to a configuration that constantly monitors.

(2) In the above-described embodiment, a frequency analysis is performed on the input current, etc., corresponding to the fluctuation of the rotation load on the driving magnet 20, and based on the result of the analysis, it is determined whether the driven magnet 40, etc. is locked, but this is not limited to the above.

For example, it is possible to adopt a method of determining that a locked state exists when the period of the waveform of a signal corresponding to the fluctuation of the rotation load on the driving magnet 20 exceeds a reference value. Examples of signals that correspond to this method include the input current to the circuit unit 70 and the voltage signal of the Hall element that measures the rotation of the rotor 13.

(3) It is also possible to adopt a method of determining that a locked state exists when the amplitude of the waveform of a signal corresponding to the fluctuation of the rotational load on the driving magnet 20 exceeds a reference value. Examples of signals corresponding to this method include the input current to the circuit unit 70 and the phase current of the motor unit 11.

(4) Furthermore, as a method for determining whether the driven magnet 40, etc. is locked, a sensor (e.g., a Hall element or a search coil) for detecting the rotation of the driven magnet 40 may be disposed. In this case, if the detection signal of the sensor detects that the driven magnet 40 is not rotating in response to a rotation command given to the motor unit 11, it is determined that the magnet is locked.

(5) In the third embodiment, a planetary gear mechanism is used as the reduction mechanism unit 30, but this configuration is not limited to this. Various reduction mechanisms such as cycloid gears can be used as the reduction mechanism unit 30 as long as the reduction mechanism unit 30 is configured to reduce the rotational speed of the drive side and output the reduced speed.

(6) In the above embodiment, the positional relationship between the driving magnet 20 and the driven magnet 40 in the non-contact connection portion 60 is in the axial direction along the shaft 14 (the up-down direction in FIG. 1, etc.), but this is not limited to this.

The driving magnet 20 and driven magnet 40 in the non-contact connecting part 60 may be arranged in the radial direction (diameter direction) centered on the shaft 14. In this arrangement, if the non-contact connecting part 60 is configured as a magnetic gear 60b, the pole piece 25 is configured to be located between the driving magnet 20 and driven magnet 40 in the radial direction.

(7) In the above embodiment, the expansion valve Ev is disposed vertically in the vehicle, but the expansion valve Ev may be disposed horizontally in the vehicle. A horizontal arrangement means an arrangement in which the axial direction of the valve body 48 is approximately parallel to the front-rear and left-right directions of the vehicle. It is also possible to adopt an arrangement in which the drive side mechanism 10 is located below and the driven side mechanism 35 is located above as the arrangement of the expansion valve Ev.

(8) In the above-described embodiment, the power transmission mechanism 1 is applied to the expansion valve Ev of a vapor compression refrigeration cycle, but is not limited to this. As long as the power transmission mechanism 1 has a configuration in which the power generated in the driving side mechanism 10 including the motor unit 11 is transmitted to the driven side mechanism 35 via a non-contact connecting unit 60 such as a magnetic coupling 60a, it can be used in various devices. For example, the power transmission mechanism 1 may be used as a configuration for a flow control valve in a fluid circuit, or as a configuration for a rotating machine such as a small pump.

REFERENCE SIGNS LIST 1 power transmission mechanism 10 driving mechanism 11 motor 14 shaft 20 driving magnet 25 pole piece 35 driven mechanism 40 driven magnet 41 rotating member 60 non-contact connecting portion

Claims (8)

a drive-side mechanism section (10) including a motor section (11) that outputs a drive force by electromagnetic force, a drive-side shaft (14, 33s) that rotates in association with the operation of the motor section, and a drive-side magnet (20) disposed at an end of the drive-side shaft;
a driven-side mechanism section (35) that is partitioned off from the drive-side mechanism section and includes a driven-side shaft (41) that rotates by the driving force transmitted from the drive-side shaft and a driven-side magnet (40) that is disposed at an end of the driven-side shaft;
a non-contact connection unit (60) having the driving side magnet and the driven side magnet, and connecting the driving side shaft and the driven side shaft in a non-contact manner by utilizing a magnetic force;
a lock determination unit (71) that determines whether or not the driven magnet is locked by using a fluctuation in a rotation load related to the operation of the drive magnet,
The drive side mechanism (10) has a reduction mechanism (30) that reduces the angular velocity output by the motor at a predetermined reduction ratio to obtain an angular velocity of the drive side magnet,
The non-contact connection portion (60) is a magnetic coupling (60a) constituted by the driving side magnet and the driven side magnet,
A power transmission mechanism in which a value obtained by multiplying the number of poles of the motor unit by the reduction ratio of the reduction mechanism unit is different from the number of poles of the magnetic coupling, and the reduction ratio of the reduction mechanism unit is different from the number of poles of the magnetic coupling . 2. The power transmission mechanism according to claim 1, wherein the lock determination unit (71) performs a frequency analysis of an input current to the motor unit, and determines that a lock of the driven magnet has occurred when the input current at a predetermined specific frequency (fs) exceeds a reference value. The motor unit (11) is a three-phase motor (11a),
2. The power transmission mechanism according to claim 1, wherein the lock determination unit performs a frequency analysis on a drive current of the three-phase motor, and determines that a lock has occurred in the driven magnet when the drive current at a predetermined specific frequency (fs) exceeds a reference value. The motor unit (11) is a DC motor (11c) having a commutator and brushes,
2. The power transmission mechanism according to claim 1, wherein the lock determination unit performs a frequency analysis on a drive current of the DC motor, and determines that a lock has occurred in the driven magnet when the drive current at a predetermined specific frequency (fs) exceeds a reference value. The motor unit (11) is a three-phase motor (11a),
a three-phase inverter circuit (72) for determining a duty ratio, which is a ratio of an on time to an off time in the three-phase motor, from a relationship between a predetermined triangular wave and a determination voltage determined in conjunction with a fluctuation in the rotation load;
2. The power transmission mechanism according to claim 1, wherein the lock determination unit (71) performs a frequency analysis on the determination voltage, which changes in conjunction with fluctuations in the rotational load, and determines that a lock has occurred in the driven magnet when the determination voltage at a predetermined specific frequency (fs) exceeds a reference value. The motor unit (11) is a three-phase motor (11a),
2. The power transmission mechanism according to claim 1, wherein the lock determination unit (71) performs a frequency analysis on a current of any one of the phases in the three-phase motor, and determines that a lock has occurred in the driven magnet when a current of the one phase at a predetermined specific frequency (fsa, fsb) exceeds a reference value. The motor unit (11) is a three-phase motor (11a),
2. The power transmission mechanism according to claim 1, wherein the lock determination unit (71) performs a frequency analysis on line voltages for any two phases of the three-phase motor, and determines that a lock has occurred in the driven magnet when the line voltage at a predetermined specific frequency (fsa, fsb) exceeds a reference value. an acceleration sensor (73d) disposed in the drive side mechanism portion (10) for detecting acceleration caused by vibration accompanying fluctuations in the rotation load;
2. The power transmission mechanism according to claim 1, wherein the lock determination unit (71) performs a frequency analysis on the acceleration detected by the acceleration sensor, and determines that a lock of the driven magnet has occurred when a change in the acceleration at a predetermined specific frequency (fs) exceeds a reference value.

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