JP5338399B2 - Refrigerant flow control device for rotating electrical machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for control of a coolant flow rate in a rotary electric machine, capable of achieving sufficient cooling and high efficiency. <P>SOLUTION: The device for control of the coolant flow rate in the rotary electric machine includes a flow rate control valve for changing a flow rate to be supplied into a motor and a flow rate to be flown back to a coolant reservoir out of the coolant to be scooped to the upper part in a housing, depending on a reaction force of the output torque of the rotary electric machine. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an apparatus for controlling a refrigerant flow rate of a rotating electrical machine.

  Conventionally, the technique described in Patent Document 1 is known as a liquid level adjustment means for adjusting the oil level in the housing. In this publication, there is an oil catch tank that receives and stores the oil pumped up by the gear, a drain valve that opens and closes the oil discharge port of the tank, and when the transmission is in the parking position, the drain valve is released and the oil catch tank is opened. The oil in the tank is returned to the case to increase the oil level in the case. On the other hand, when the drive system shift position is selected, the drain valve is closed and the oil catch tank is placed inside the case. A technique is disclosed in which the oil level in the housing is lowered by storing the oil in the housing.

JP 2008-51176 A

  However, even when the shift position of the drive system is selected, a state of low rotation and high torque is naturally assumed, and there is a problem that sufficient cooling cannot be performed if the oil level is simply lowered. Further, if the oil level is increased so that sufficient cooling can be achieved even at low rotation, there is a problem that friction increases at high rotation and efficiency decreases.

  The present invention has been made paying attention to the above problem, and an object thereof is to provide a refrigerant flow control device for a rotating electrical machine capable of supplying a refrigerant flow rate according to a driving state.

  In order to achieve the above object, in the refrigerant flow control device for a rotating electrical machine of the present invention, the refrigerant is pumped up using a pump driven by a rotor, and is returned to the refrigerant flow rate and the refrigerant reservoir in the flow path communicating with the upper part in the housing. The flow rate control valve which changes the refrigerant | coolant flow rate in a flow path with the reaction force with respect to the output torque of a rotary electric machine was provided.

  At low rotation and high torque, the amount of refrigerant pumped up is small, but the reaction force is large, so that a large amount flows into the housing by the flow control valve. Therefore, it is possible to sufficiently cool even at a low rotation. On the other hand, at the time of high rotation and low torque, although the amount of the refrigerant pumped up is large, the reaction force is small, so that a large amount is recirculated to the refrigerant reservoir by the flow control valve. Therefore, the efficiency can be improved by suppressing the friction.

FIG. 3 is a schematic diagram illustrating a drive unit according to the first embodiment. FIG. 3 is a schematic diagram illustrating a configuration of a reaction force transmission mechanism according to the first embodiment. FIG. 3 is a schematic diagram illustrating the lubrication characteristics of the drive unit according to the first embodiment. It is a characteristic view showing the relationship between the stroke amount of the flow control valve of Example 1 and flow characteristics. FIG. 6 is a characteristic diagram illustrating a final flow characteristic setting process according to the first embodiment. It is a characteristic view showing the relationship between the stroke amount of the flow control valve 11 of Example 2 and flow characteristics. FIG. 6 is a schematic diagram illustrating a configuration of a reaction force transmission mechanism according to a third embodiment. FIG. 10 is a schematic diagram illustrating a configuration of a drive unit according to a fourth embodiment.

  FIG. 1 is a schematic diagram showing the configuration of a drive unit of Example 1 to which a refrigerant flow control device for a rotating electrical machine according to the present invention is applied. The drive unit includes a cylindrical housing 1 that is closed on both sides, a stator 2 that is fixedly supported on the inner periphery of the housing 1 and includes a plurality of coils, and a plurality of permanent magnet pairs. It has a rotor 3 that rotates and a drive shaft 4 that rotates together with the rotor 3. The stator 2 and the rotor 3 constitute a motor (rotating electric machine). As shown in FIG. 1, the housing 1 represents a state mounted on a vehicle or the like, and the upper direction in FIG. 1 coincides with the upper vertical direction when mounted on the vehicle (hereinafter referred to as “upper”), and the lower direction. Corresponds to the lower part in the vertical direction when the vehicle is mounted (hereinafter referred to as lower). In the following description, the terms “high” and “low” represent the concept along the vertical direction.

  A refrigerant reservoir 7 into which a part of the rotor 3 is immersed is formed in the lower part of the housing 1. A first side wall 1a that closes the cylindrical portion is formed on the left side surface of the housing 1, and an oil pan 6 is attached below the first side wall 1a. The refrigerant reservoir 7 in the housing 1 and the oil pan 6 are communicated with each other via a flow path 8. In addition, an oil pump 10 is connected to the rotor 3, and the oil in the oil pan 6 is pumped up to the upper portion of the housing 1 in accordance with the rotational speed of the rotor 3.

  The drive shaft 4 is provided with a planetary gear mechanism PG as a speed reduction mechanism. The planetary gear mechanism PG includes a sun gear S, a pinion carrier PC that supports the pinion P, and a ring gear R. The drive shaft 4 is connected to the sun gear S, the output shaft 5 is connected to the pinion carrier PC, and the ring gear R is supported so as to be slightly rotatable relative to the housing 1. A reaction force transmission mechanism 20 for operating a flow rate control valve 11 described later is disposed on the outer periphery of the ring gear R, and the operation of the flow rate control valve 11 is controlled via the reaction force transmission mechanism 20. The reaction force transmission mechanism 20 will be described later. The output shaft 5 is connected to drive wheels of a vehicle not shown in the figure, and is configured as an in-wheel motor.

  A suction oil passage 101 connected to the suction side of the oil pump 10 is connected to the oil pan 6. A flow rate control valve 11 is provided in the discharge oil passage 102 connected to the discharge side of the oil pump 10. On the downstream side of the flow control valve 11, the first flow path 103 connected to the oil supply port 103 a that opens to the upper part in the housing 1 and the oil pumped up connected to the oil pan 6 are returned to the oil pan 6. The second flow path 104 is connected. The flow control valve 11 controls the distribution amount for distributing the oil pumped up by the oil pump 10 to the first flow path 103 and the second flow path 104.

  FIG. 2 is a schematic diagram illustrating the configuration of the reaction force transmission mechanism 20. As shown in FIG. 2A, the reaction force transmission mechanism 20 includes a reaction force transmission rod 21 that extends from the outer periphery of the ring gear R toward the outer periphery, a reaction force generation cylinder 22, and a reaction force generation cylinder 22. A reaction force generating piston 23 that is stowed and strokes when the reaction force transmission rod 21 is actuated, and a return spring 24 that urges the reaction force generation piston 23 or the reaction force transmission rod 21 to an initial position are attached.

  Further, a reaction force transmission pipe 25 that transmits the pressure generated in the reaction force generation cylinder 22 to the flow control valve 11 side, and a pressure receiving surface that is formed at one end of the flow control valve 11 and receives the pressure generated in the reaction force transmission pipe 25. 26 and a return spring 27 that urges the flow control valve 11 to the initial position. The position of the flow control valve 11 shown in FIG. 2 indicates a state where a moderate reaction force is generated, and the initial position where the reaction force is not generated is located at the right end in FIG. The flow rate control valve 11 communicates the discharge flow path 102 and the first flow path 103 when the reaction force is large, and communicates the discharge flow path 102 and the second flow path 104 when the reaction force is small. Is in the middle, the discharge channel 102 communicates with both the first channel 103 and the second channel 104.

  As shown in FIG. 2B, the motor torque output from the rotor 3 to the drive shaft 4 is decelerated according to the reduction ratio of the planetary gear mechanism PG and output from the output shaft 5 (output torque). At this time, reaction force torque acts on the ring gear R. The reaction force transmission rod 21 is actuated by this reaction force torque, and pressure is generated in the reaction force generation cylinder 22 to drive the valve operating piston 26.

[Lubrication]
Next, the lubrication action in the drive unit of Embodiment 1 will be described. FIG. 3 is a schematic diagram illustrating the lubrication characteristics of the drive unit according to the first embodiment. The discharge flow rate by the oil pump 10 is proportional to the rotation speed of the oil pump 10. In other words, since the rotor 3 and the oil pump 10 rotate integrally, the discharge flow rate of the oil pump 10 is restricted by the rotational speed. On the other hand, the required oil amount of the motor is determined by the loss characteristics at each operating point of the motor. The higher the loss, the higher the required flow rate because the possibility of heat generation is higher. The lower the loss, the lower the possibility of heat generation, the lower the required flow rate. That is, the required oil amount of the motor is not in a linear relationship with the motor rotational speed, and is determined by the rotational speed and torque.

  Therefore, an oil pump 10 that rotates integrally with the rotor 3 is provided, and the flow rate control valve 11 is adjusted by using a reaction force so that most of the pumped oil flows into the first flow path 103 during high torque, thereby reducing the low torque. Sometimes, the flow control valve 11 is adjusted using a reaction force so that most of the pumped oil flows into the second flow path 104. Specifically, as shown in the motor output characteristic of FIG. 3, the flow control valve 11 is controlled so as to have a flow characteristic along the equal loss map.

[When obtaining flow characteristics c (L / min)]
For example, when the motor is operated at point A representing low rotation and high torque as the operating point of the motor, the flow rate pumped by the oil pump 10 is relatively small if the rotation is low. Since the flow rate control valve 11 is operated by a reaction force according to the output torque, all the pumped oil flows to the first flow path 103 side to ensure a sufficient flow rate. That is, if the output torque is high, the reaction force becomes large. Therefore, it is possible to increase the flow rate flowing to the first flow path 103 side and obtain sufficient cooling performance.

  On the other hand, when operating at point B representing high rotation and high torque, the flow rate pumped up by the oil pump 10 is relatively large if the rotation is high. Since the flow control valve 11 is operated by a reaction force according to the output torque, a part of the pumped-up oil flows to the first flow path 103 side and the other flows to the second flow path 104 side. That is, the flow rate that flows to the first flow path 103 side is decreased by the amount that the output torque has decreased. Thereby, even if the rotation speed increases, the same flow rate characteristic c (L / min) as that at point A can be obtained.

[When obtaining flow characteristics b (L / min) (<c)]
Next, when the motor is operated at a point C representing low rotation torque as the operation point of the motor, the flow rate pumped by the oil pump 10 is relatively small if the rotation is low. Since the flow control valve 11 is operated by a reaction force corresponding to the output torque, most of the pumped oil flows to the first flow path 103 side, and the output torque is lower than the point A to the second flow path 104 side. The flow rate according to the motor loss is ensured. On the other hand, when operated at a point D representing torque during high rotation, the flow rate pumped up by the oil pump 10 is relatively large if the rotation is high. In order to operate the flow control valve 11 according to the output torque, a part of the pumped oil is caused to flow to the first flow path 103 side, and is flowed to the second flow path 104 side by the amount corresponding to the decrease of the output torque. That is, the flow rate that flows to the first flow path 103 side is decreased by the amount that the output torque has decreased. Thereby, even if the rotation speed increases, the same flow rate characteristic b (L / min) as that at the point C can be obtained. In addition, when obtaining the flow rate characteristic a (L / min), the amount returned to the second flow path 104 by the flow rate control valve 11 further increases.

  Here, the flow rate characteristic setting process will be described. FIG. 4 is a characteristic diagram showing the relationship between the stroke amount of the flow control valve 11 and the flow characteristics. As shown in FIG. 4A, the relationship between the stroke position of the flow control valve 11 and the flow rate flowing through the first flow path 103 is examined. In this case, when the oil pump 10 is driven at a constant rotational speed (3000 rpm), as shown in FIG. 4B, the flow rate gradually increases at the initial stage of the stroke, and the flow rate increases almost linearly at the later stage of the stroke. The increasing characteristics can be seen. Since the stroke amount is determined by the reaction force, it can be seen that the relationship between the motor output torque and the flow rate is as shown in FIG.

  FIG. 5 is a characteristic diagram showing a final flow rate characteristic setting process. When the flow rate control valve 11 is fixed at a certain position and the rotation speed of the oil pump 10 is changed, the flow rate flowing through the first flow path 103 increases linearly with respect to the rotation speed (see FIG. 5A). ). Therefore, when the flow rate characteristics with respect to the motor output torque described in FIG. 4 are overlapped, the flow rate characteristics with respect to the rotation speed can be drawn for each motor output torque, and this drawn range becomes the flow rate adjustable range. By using this relationship, as shown in FIG. 3, the flow rate characteristic is set to a characteristic corresponding to the motor loss by the rotation speed and torque.

As described above, the following operational effects can be obtained in the first embodiment.
(1) A motor (rotary electric machine) having a rotor 3 housed in a housing 1, an oil pan 6 that stores oil (refrigerant), and oil that is driven by the rotor 3 and stored in the oil pan 6 is stored in the housing 1. The oil pump 10 pumped up, the first flow path 103 connected to the upper part of the housing 1 connected to the discharge port side of the oil pump 10, and the oil pan 6 connected to the discharge port side of the oil pump 10 are connected. When the reaction force is high and the reaction force is high, the supply amount to the first flow path 103 side is increased as compared with when the reaction force is low. And a flow rate control valve 11 for reducing the supply amount to the side.

  At the time of low rotation and high torque, although the oil pumped up by the oil pump 10 is small, most of the oil flows into the housing 1 by the flow control valve 11, so that it can be sufficiently cooled even at low rotation. On the other hand, at the time of high rotation and low torque, although a lot of oil is pumped up by the oil pump 10, most of the oil is returned to the oil pan 6 by the flow rate control valve 11.

  Further, the motor loss and the required flow rate on the motor side have a correlation. At this time, by adjusting the flow rate using the motor reaction force, the optimum flow rate adjustment can be achieved by a mechanical configuration without providing a special electronic control actuator or the like. That is, even if the oil pump discharge amount is defined by the rotational speed, the flow rate actually supplied to the motor side can be set to a flow rate corresponding to the motor loss.

  (2) The motor has a sun gear S connected to the rotor 3, a carrier PC connected to the output shaft 5, and a ring gear R. The flow control valve 11 acts between the housing 1 and the ring gear R. It was decided to operate by the reaction force. Therefore, stable motor control can be achieved by using an element that does not cause a problem even if some relative movement occurs, rather than using a stator 2 having an important positional relationship with the rotor 3.

  (3) The motor is an in-wheel motor of an electric vehicle. In-wheel motors are very limited in layout due to the limited tire size. At this time, since the flow rate can be controlled independently of the other units, a refrigerant flow rate control device with good mountability can be provided.

  Next, Example 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 6 is a characteristic diagram showing the relationship between the stroke amount of the flow control valve 11 of Example 2 and the flow characteristics. As shown in FIG. 6A, the flow rate characteristic is set such that the flow rate change is set to be smaller at the initial stroke, and the flow rate change is set to be large at the latter stage of the stroke. Specifically, as shown in FIG. 6B, as the shape of the flow rate control valve 11, a slope is formed on the first flow path 103 side, thereby forming a flow rate change sensitivity adjusting unit. Thereby, when the stroke becomes large, the flow rate can be increased geometrically. On the other hand, if a slope is formed on the second flow path 104 side, the flow rate does not change much even when the stroke becomes large, and the flow rate can be increased greatly when the stroke is small.

  (4) By setting the flow rate change rate when the motor output torque is low and the flow rate change rate when the output torque is high, the flow rate characteristic can be set freely according to the motor characteristics. Thus, it is possible to achieve refrigerant flow rate control according to the state.

  Next, Example 3 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 7 is a schematic diagram illustrating the configuration of the reaction force transmission mechanism 20 according to the third embodiment. In the third embodiment, dampers 30 and 31 are provided on the return springs 24 and 27 from the viewpoint of preventing divergence caused by vibrations generated in a motor or the like. This damper may be provided only on one return spring.

  (5) Since the dampers 30 and 31 (attenuation members) are provided between the housing 1 and the ring gear R and / or the flow control valve 11, the flow characteristics do not change due to vibration, and torque fluctuations can be prevented. .

  FIG. 8 is a schematic diagram illustrating the configuration of the drive unit according to the fourth embodiment. In the first embodiment, the oil pan 6 is attached integrally with the drive unit. On the other hand, in Example 4, the oil pan 6 is a separate body, and both are connected by piping. In the case of an in-wheel motor that has many layout restrictions, this arrangement can increase the degree of freedom in layout.

  Each embodiment has been described above, but other configurations may be employed within the scope of the present invention. For example, although the speed reduction mechanism is provided in the first embodiment, the flow rate control valve 11 may be operated according to the reaction force generated in the stator without the speed reduction mechanism. In the first embodiment, an example in which the pipe is configured outside the housing is shown. However, an oil passage may be formed in the housing, and the same configuration as that in the first embodiment may be used by using the oil passage. Moreover, although the example which connects only the flow path 8 about the connection of the refrigerant | coolant reservoir 7 and the oil pan 6 was shown, the appropriate orifice characteristic was set to this flow path, and the height of the oil liquid level in the refrigerant | coolant reservoir 7 was set. It is good also as a structure adjusted suitably. In this case, the friction acting on the motor can be optimally controlled, and the efficiency of the motor can be further increased.

  Further, although the oil pump 10 is disposed on the side opposite to the output shaft 5 of the motor, it may be disposed on the same side as the output shaft 5 of the motor.

DESCRIPTION OF SYMBOLS 1 Housing 2 Stator 3 Rotor 4 Drive shaft 5 Output shaft 6 Oil pan 7 Refrigerant accumulation 8 Flow path 10 Oil pump 20 Reaction force transmission mechanism 30 Drain
PG planetary gear mechanism (reduction mechanism)

Claims (5)

A rotating electric machine having a rotor housed in a housing;
A refrigerant reservoir for storing refrigerant;
A pump driven by the rotor and pumping the refrigerant stored in the refrigerant reservoir to the upper part of the housing;
A first flow path connected to a discharge port side of the pump and connected to an upper portion in the housing;
A second flow path connected to the discharge port side of the pump and connected to the refrigerant reservoir;
When the reaction force is high and the reaction force is high, the supply amount to the first flow path side is increased and the supply amount to the second flow path side is decreased when the reaction force is high. A flow control valve;
A refrigerant flow control device for a rotating electrical machine, comprising: The refrigerant flow control device for a rotating electrical machine according to claim 1,
The flow rate control valve is set so that a flow rate change rate when the output torque of the rotating electrical machine is low is different from a flow rate change rate when the output torque is high. In the refrigerant | coolant flow control apparatus of the rotary electric machine of Claim 1 or 2,
The rotating electrical machine has a sun gear connected to the rotor, a carrier connected to the rotating electrical machine output shaft, and a ring gear.
The flow rate control valve is actuated by a reaction force acting between the housing and the ring gear. In the refrigerant | coolant flow control apparatus of the rotary electric machine of Claim 3,
A refrigerant flow control device for a rotating electrical machine, wherein a damping member is provided between the housing and the ring gear and / or the flow control valve. In the refrigerant | coolant flow control apparatus of the rotary electric machine as described in any one of Claims 1 thru | or 4,
The rotary electric machine refrigerant flow control device, wherein the rotary electric machine is an in-wheel motor of an electric vehicle.

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