JP5100528B2 - Single-phase induction motor air gap eccentricity inspection apparatus, air gap eccentricity inspection method, air gap eccentricity adjustment method, and single-phase induction motor manufactured using the same - Google Patents

Description

  The present invention relates to an air gap eccentricity inspection device, an air gap eccentricity inspection method, and an air gap eccentricity inspection method capable of accurately determining the quality of an air gap by measuring the amount and direction of air gap eccentricity during rotor rotation. The present invention relates to an air gap eccentricity adjusting method and a single-phase induction motor manufactured using these methods.

  Conventionally, as a measure of the air gap eccentricity of a single-phase induction motor, the single-phase induction motor is energized and the vibration generated in the state where the rotor is rotating is measured, whereby the air gap of the single-phase induction motor is measured. Some have been proposed that estimate the eccentricity.

  For example, the AC current that flows through the main winding or auxiliary winding is adjusted, and a drive circuit that allows the rotor to rotate at a rotation cycle smaller than the cycle of the AC current is configured. The vibration detection sensor is mounted in the direction perpendicular to the winding direction of the winding, which is larger than the above, and by measuring the amplitude or shape of the vibration waveform of the vibration obtained during rotation drive, the above changes that change according to the phase of the rotor Some calculate the eccentricity of the air gap. (For example, see Patent Document 1)

JP 2007-37323 A

  In such a conventional air gap eccentricity measuring method, since it does not have a function of examining the rotational speed of the rotor, when setting the condition parameters for different models, the relationship between the voltage applied to the motor and the rotational speed is determined one by one. There is a problem in that it is necessary to investigate using an optical sensor or the like, which requires time. Furthermore, even if the same model is used, the rotational speed of the rotor varies from one motor to another, but the variation in the rotational speed cannot be recognized. There was a problem of lowering.

  This invention has been made to solve the above-described problems, and can accurately measure the eccentric state (the amount and direction of eccentricity) of the air gap, and from the obtained eccentricity measurement result, An air gap eccentricity inspection device, an air gap eccentricity inspection method, and an air gap adjustment method for a single-phase induction motor capable of reliably determining whether an air gap is good and further adjusting the air gap based on air gap eccentricity data. The purpose is to provide.

  In order to solve the above problems, an air gap eccentricity inspection apparatus for a single-phase induction motor according to the present invention comprises a rotor that rotates together with a main shaft, a main winding and an auxiliary winding, and an air gap is formed between the rotor and the rotor. In a single-phase induction motor comprising a stator arranged to have, a means for applying an AC voltage to the motor, a current measuring means for measuring a current waveform of a current flowing through the motor, and the AC voltage to the motor The vibration measuring means for measuring the vibration waveform of the single-phase induction motor in the direction in which the unbalanced magnetic attractive force generated in the rotor is maximized when applied, and the rotation of the rotor from the result measured by the current measuring means. The eccentricity state of the air gap is estimated from the calculated rotor speed, the measured current waveform and the vibration waveform, and the estimated air gap deviation is calculated. Condition characterized in that a determination means for determining acceptability of the air gap on the basis of.

  An air gap eccentricity inspection method for a single-phase induction motor according to the present invention includes a rotor that rotates together with a main shaft, a stator that includes a main winding and an auxiliary winding, and that has an air gap between the rotor and the rotor. A single-phase induction motor comprising: a step of applying an AC voltage to either the main winding or the auxiliary winding to measure a current waveform flowing in the winding; and switching the circuit to the main winding Measure the current waveform flowing in the winding by applying AC voltage to both the auxiliary winding and the auxiliary winding, and measure the vibration waveform of the motor vibration in the direction that maximizes the unbalanced magnetic attraction generated in the rotor Calculating the rotor speed from the measured current waveform, calculating the eccentric amount and direction of the air gap from the calculated rotor speed and the measured current waveform and vibration waveform, and calculating Air And having a step of determining the quality of the air gap on the basis of the eccentricity and the eccentric direction of the cap.

  Furthermore, an air gap eccentricity adjusting method for a single-phase induction motor according to the present invention includes a rotor that rotates together with a main shaft, a main winding and an auxiliary winding, and is arranged so as to have an air gap between the rotor. A step of measuring the current waveform flowing in the winding by applying an AC voltage to either the main winding or the auxiliary winding, and switching the circuit to the main winding. The AC waveform is applied to both the wire and the auxiliary winding to measure the current waveform flowing in the winding, and the vibration waveform of the motor in the direction that maximizes the unbalanced magnetic attraction generated in the rotor A step of measuring, a step of calculating the rotational speed of the rotor from the measured current waveform, a step of calculating an eccentric amount and an eccentric direction of the air gap from the calculated rotational speed of the rotor and the measured current waveform and vibration waveform, Calculated And determining whether the air gap is good or bad based on the eccentric amount and direction of the gap, and adjusting the air gap by deforming the shell to which the stator is fixed based on the determination result. To do.

  According to the present invention, the rotational speed of the rotor is calculated from the current waveform flowing in the winding of the motor, and the eccentric state of the air gap is calculated from the calculated rotational speed of the rotor, the measured current waveform, and the vibration waveform. Even in the case of various types of motors, the measurement conditions can be easily set using common parameters. Furthermore, there is an effect that it is possible to accurately estimate the eccentric state of the air gap by reducing the influence due to variations in the rotational speed of the rotor during vibration measurement.

Embodiment 1 FIG.
An air gap eccentricity inspection apparatus and an air gap eccentricity inspection method for a single phase induction motor according to the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a longitudinal cross-sectional view of a rotary compressor 100 for a refrigeration / air conditioner having a single-phase induction motor as a product example of a single-phase induction motor to which the present invention is applied. FIG. 2 is a transverse cross-sectional view as seen from the direction of arrow A in FIG.

  The single-phase induction motor mainly includes a rotor 102 and a stator 103. A cylindrical space between the rotor 102 and the stator 103 is shown as an air gap 101. The stator 103 is shrink-fitted and fixed to a shell 104 that is a pressure vessel. The rotor 102 is fixed integrally with the main shaft 105 by shrink fitting. The main shaft 105 is supported by a slide bearing (not shown) that is present in the frame 106 and the cylinder head 107. The frame 106 and the cylinder head 107 are fixed to the cylinder 108 with bolts (not shown), and the cylinder 108 is attached to the shell 104 at three welding points 109 (only one point is shown in FIG. 1). It is fixed by welding.

  The winding of the stator 103 is composed of two types of windings called a main winding 110 and an auxiliary winding 111. The stator 103 is supplied with electric power from an AC power source (not shown) outside the compressor through a terminal 112 fixed to the shell 104 by welding. A muffler 114, which is a suction port for gas before compression, and a discharge pipe 113 for discharging the compressed gas to the outside are fixed to the shell 104 by brazing, and the gas before compression is sucked from the muffler 114 and is stored in the cylinder 108. , And discharged from the frame 106 into the shell 104 and then discharged out of the rotary compressor 100 through the discharge pipe 113.

FIG. 3 is a schematic diagram of an air gap eccentricity inspection apparatus using a compressor for a refrigeration / air conditioner including a single-phase induction motor as a measurement target. 4 is a cross-sectional view in the lateral direction as viewed from the direction of arrow B in FIG.
By connecting the connection terminal 120 to the terminal 112 of the rotary compressor 100, an AC voltage can be applied to the single-phase induction motor in the rotary compressor 100 from an external power source (not shown). An ammeter 121a is attached to the conducting wire energizing the main winding 110, and an ammeter 121b is attached to the conducting wire energizing the auxiliary winding 111.

  A circuit for energizing the motor can be automatically switched by a switch (not shown). 5 to 8 show examples of energization circuits. FIG. 5 is a circuit diagram for energizing both the main winding 110 and the auxiliary winding 111 (hereinafter referred to as rotational energization). The circuit includes a main winding switch 144 and an auxiliary winding switch 145. By connecting the auxiliary winding resistor 148 and the auxiliary winding capacitor 149 to the auxiliary winding 111 by connecting the main winding switch 144 to the contact B143 side and the auxiliary winding switch 145 to the contact C146 side. Thus, the magnetic flux induced by the main winding 110 becomes larger than the magnetic flux induced by the auxiliary winding 111, and the rotor 102 rotates (hereinafter, such rotation is referred to as forward rotation, and the energized state for forward rotation is positive. This is called rotational energization).

FIG. 6 is a circuit diagram similar to FIG. 5, in which the main winding switch 144 is grounded to the contact A142 side,
By connecting the main winding resistor 141 and the main winding capacitor 140 to the main winding 110 by connecting the auxiliary winding switch 145 to the contact D147 side, the magnetic flux induced by the auxiliary winding 111 is changed to the main winding. The magnetic flux induced by the line 110 becomes larger, and the rotor 102 rotates in the direction opposite to the normal rotation (hereinafter, such rotation is referred to as reverse rotation, and the energized state in the reverse rotation is referred to as reverse rotation energization).

  FIG. 7 is a circuit diagram for energizing either the main winding or the auxiliary winding (hereinafter referred to as lock energization). The circuit includes a main winding energizing switch 151 and an auxiliary winding energizing switch 152. . When the main winding energizing switch 151 is grounded and the auxiliary winding energizing switch 152 is not grounded, an AC voltage is applied only to the main winding 110, and the rotor 102 is locked and an unbalanced magnetic attractive force is applied (hereinafter referred to as this). Such an energized state is called main lock energization).

FIG. 8 is a circuit diagram similar to FIG. 7. When the main winding switch 151 is not grounded and the auxiliary winding switch 152 is grounded, an AC voltage is applied only to the auxiliary winding 111, and the rotor 102 Is an unbalanced magnetic attractive force in the locked state (hereinafter, such energized state is referred to as auxiliary lock energization). The ammeters 121a and 121b measure current waveforms of currents flowing through the main winding and the auxiliary winding, respectively, in four energization states of forward rotation energization, reverse rotation energization, main lock energization, and auxiliary lock energization.

The acceleration pickup 122 measures the vibration generated when the motor is energized. There are two accelerometers 122. As shown in FIG. 4, vibrations generated in the direction perpendicular to the magnetic flux induced by the main winding 110 by the accelerometer 122a (hereinafter referred to as the auxiliary winding direction) are measured. The vibration generated in the direction perpendicular to the magnetic flux induced by the winding (hereinafter referred to as the main winding direction) is measured. The acceleration pickup 122 can be moved in the radial direction of the rotary compressor 100 by an acceleration pickup cylinder 123 (see FIG. 3). When the vibration is measured, the acceleration pickup 122 is pressed against the rotary compressor 100 via the pickup vibration isolator 124 and is energized. Measure vibrations that occur during the process.

  The rotary compressor 100 is fixed by the clamp claws 125 so that the rotary compressor 100 does not roll over when the acceleration pickup 122 is pressed against the rotary compressor 100. The clamp claw 125 can grip the rotary compressor 100 from the lateral direction by the thrust of the clamp cylinder 127 through the clamp vibration damping material 126. The rotary compressor 100 is disposed on the work vibration isolation material 128. An anti-vibration material 130 is disposed under the measurement unit base plate 129 to prevent external vibration from propagating to the measurement unit.

The measured vibration electrical signal is amplified by the amplifier 131. The electric signal of the measured current and the amplified vibration signal are recorded in the computer 132 by an A / D board (not shown). The computer 132 calculates the rotational speed of the rotor from the difference between the current value during energization of the rotation and the current value during energization of the lock, and based on the recorded current waveform and vibration waveform and the calculated rotational speed of the rotor, the air gap eccentric direction and the air The gap eccentricity is calculated, and the calculated result is displayed by the computer display 133. The voltage regulator 134 can adjust the AC voltage supplied to the main winding 110 and the auxiliary winding 111. Further, the magnitude of the alternating current flowing through the electric motor is adjusted by the resistor 135 and the capacitor 136. The above electric devices are fixed by a frame 137.

Next, an inspection method for the air gap eccentric state will be described with reference to the flowchart of FIG. The steps of this flowchart are 1 to 33, and the steps are hereinafter denoted as ST.
ST1: The rotary compressor 100 is installed on the work vibration isolation material 128.
ST2: The clamp pawl 125 is advanced by the clamp cylinder 127, and the rotary compressor 100 is fixed.
ST3: Connect the connection terminal 120 to the terminal 112.
ST4: The acceleration pickup 122 is advanced by the acceleration pickup cylinder 123 and pressed against the rotary compressor 100.

ST5: The circuit is switched so that the forward rotation energization state is established. Specifically, according to ST5-1 to ST5-3 below.
ST5-1: In the drive circuit for the single-phase induction motor shown in FIG. 5, the connection destination of the main winding switch 144 is the contact B143 side.
ST5-2: In the drive circuit of the single-phase induction motor shown in FIG. 5, the auxiliary winding switch 145 is connected to the contact C146 side, and the auxiliary winding resistor 148 and the auxiliary winding capacitor 149 are connected in series with the auxiliary winding 111. Connect. As a result, the current flowing through the individual windings is adjusted so that the current flowing through the main winding 110 is large and the current flowing through the auxiliary winding 111 is small. The magnitude of the magnetic flux is made larger than the magnitude of the magnetic flux induced by the auxiliary winding 111.
ST5-3: The voltage of the AC power supply is adjusted to a specific voltage by the voltage regulator 134.

ST6: An AC voltage is applied to the workpiece, and measurement of the current flowing through the main winding 110 and vibration in the auxiliary winding direction is started.
ST7: The current waveform flowing through the main winding 110 is measured by the ammeter 121a. The vibration waveform in the auxiliary winding direction is measured by the acceleration pickup 122a.
ST8: When the predetermined measurement time has elapsed, the measurement is terminated, and the energization is also terminated at the same time.
ST9: The measured current waveform is taken into the computer 132 through an A / D board (not shown) and recorded. The measured vibration waveform is amplified by the amplifier 131, and is taken into the computer 132 through an A / D board (not shown) and recorded.

ST10: Switch the circuit so that the main lock is energized. In the drive circuit for the single-phase induction motor shown in FIG. 7, the main winding energizing switch 151 is grounded and the auxiliary winding 152 is not grounded.
ST11: An AC voltage is applied to the workpiece, and the current waveform of the current flowing through the main winding 110 is measured by the ammeter 121a.
ST12: The current waveform of the current flowing through the main winding 110 is measured by the ammeter 121a.
ST13: When a predetermined measurement time has elapsed, the measurement is terminated and at the same time, the energization is terminated.
ST14: The measured current waveform is taken into the computer 132 through an A / D board (not shown) and recorded.

ST15: The respective effective values are calculated by the computer 132 from the current waveform measured during normal rotation energization and the current waveform measured during main lock energization. Further, the number of rotations of the rotor is calculated from the difference in the effective value of the current by a method described later.
ST16: The computer 132 calculates the eccentric direction and the amount of eccentricity of the air gap in the auxiliary winding direction from the current waveform measured at the time of forward rotation energization, the vibration waveform in the auxiliary winding direction, and the calculated rotor speed.

The above is the inspection flow for setting the main winding magnetic flux to be large, and the inspection flow for setting the auxiliary winding magnetic flux to be large is shown below.
ST17: The circuit is switched so that the reverse rotation energization state is established. Specifically, according to ST17-1 to ST17-3 below.
ST17-1: In the drive circuit of the single-phase induction motor shown in FIG. 6, the main winding switch 144 is connected to the contact A142 side, and the main winding resistor 141 and the main winding capacitor 140 are connected in series with the main winding 110. Connect.
ST17-2: In the drive circuit for the single-phase induction motor shown in FIG. 6, the auxiliary winding switch 145 is connected to the contact D147 side. As a result, the current flowing in each winding is adjusted so that the current flowing in the main winding 110 is small and the current flowing in the auxiliary winding 111 is large, and the magnitude of the magnetic flux induced by the auxiliary winding 111 during energization is increased. The height is made larger than the magnitude of the magnetic flux induced by the main winding 110.
ST17-3: The voltage of the AC power supply is adjusted to a specific voltage by the voltage regulator 134.

ST18: An AC voltage is applied to the workpiece, and measurement of the current flowing through the auxiliary winding 111 and vibration in the main winding direction is started.
ST19: The current waveform flowing through the auxiliary winding 111 is measured by the ammeter 121b. The vibration waveform in the main winding direction is measured by the acceleration pickup 122b.
ST20: When the predetermined measurement time has elapsed, the measurement is terminated, and at the same time, the energization is also terminated.
ST21: The measured current waveform is taken into the computer 132 through an A / D board (not shown) and recorded. The measured vibration waveform is amplified by the amplifier 131, and is taken into the computer 132 through an A / D board (not shown) and recorded.

ST22: Switch the circuit so that the auxiliary lock is energized. In the drive circuit of the single-phase induction motor shown in FIG. 8, the main winding energizing switch 151 is not grounded, and the auxiliary winding 152 is grounded.
ST23: An AC voltage is applied to the workpiece, and the current waveform of the current flowing through the auxiliary winding 111 is started by the ammeter 121b.
ST24: The current waveform of the current flowing through the auxiliary winding 111 is measured by the ammeter 121b.
ST25: When a predetermined measurement time has elapsed, the measurement is terminated, and at the same time, the energization is terminated.
ST26: The measured current waveform is taken into the computer 132 through an A / D board (not shown) and recorded.

ST27: The computer 132 calculates each effective value from the current waveform measured during reverse rotation energization and the current waveform measured during auxiliary lock energization. Further, the number of rotations of the rotor is calculated from the difference in the effective value of the current by a method described later.
ST28: The computer 132 calculates the eccentric direction and the eccentricity of the air gap in the main winding direction from the current waveform measured during reverse rotation energization, the vibration waveform in the auxiliary winding direction, and the rotor speed calculated above.
ST29: Judge the quality of the air gap 101 from the air gap eccentricity in the auxiliary winding direction estimated from the results of ST16 and the air gap eccentricity in the main winding direction estimated from the results of ST28. Is displayed on the display 133.
ST30: The acceleration pickup 122 is moved backward by the acceleration pickup cylinder 123.
ST31: Remove connection terminal 120 from terminal 112.
ST32: The clamp pawl 120 is moved backward by the clamp cylinder 127.
ST33: Remove the rotary compressor 100 from the workpiece damping material 128.

Here, the size of the auxiliary winding resistor 148 and the capacity of the auxiliary winding capacitor 149 connected in ST5-2 in the flowchart of FIG. 9, the magnitude of the voltage adjusted in ST5-3, connected in ST17-1 The size of the main winding resistor 141 and the capacity of the main winding capacitor 140, and the magnitude of the voltage adjusted in ST17-3 are slow, less than 2/3 of the period of the alternating current flowing in each winding. The value is adjusted so that the rotor 102 rotates in the rotation cycle, and there are various combinations of values. By performing vibration measurement while slowly rotating the rotor, the influence of noise appearing in the vibration waveform can be reduced, and the measurement accuracy can be improved.
Here, as a means for adjusting the magnetic flux induced in the air gap by each winding, a voltage regulator, a capacitor, and a resistor are used. However, a current regulator that adjusts the current of the winding may be used. .

  Next, a method for calculating the rotational speed of the rotor from the difference between the effective values of the currents flowing through the windings during energization of rotation and energization of the lock will be described. The rotational speed of the rotor of the single phase induction motor is determined by the balance between torque and load. When AC voltage is applied to a single-phase induction motor, during rotation energization, it flows through the winding due to various factors such as applied voltage fluctuation, load fluctuation, motor temperature fluctuation, stator and rotor assembly fluctuation, etc. The effective value of current varies. On the other hand, since the rotor does not rotate when the lock is energized, the influence of the load is not included in the variation in the effective value of the current flowing through the winding. Therefore, rotation energization and lock energization are continued, and in each case, the effective value of the current flowing in the winding is calculated, and by taking the difference between them, fluctuations in the voltage applied to the motor, temperature variations in the motor, stator and Excluding factors such as rotor assembly variations, the load can be examined.

  FIG. 10 shows the relationship between the number of rotor rotations and the difference in effective value of the current flowing through the windings during energization of rotation and energization of lock (hereinafter referred to as current difference) for three different models. The horizontal axis is the rotational speed of the rotor, and the vertical axis is the current difference. In general, the relational expression varies depending on the model, but when the rotor rotates slowly, the relationship between the rotational speed and the current difference is almost the same regardless of the model, so when controlling the rotor so that it rotates slowly, Regardless, common parameters can be used. As described above, according to the present invention, the difference between the current when only the main winding is energized and the current when the main and auxiliary windings are energized is not dependent on the model or individual differences within a certain rotational speed range. This is based on finding a fact that has a certain relationship with the number, and as a result, it can be easily deployed to a large number of models and greatly contributes to shortening the development period.

  Next, a method of estimating the eccentric amount and the eccentric direction of the air gap from the measured current waveform and vibration waveform and the calculated rotor rotational speed will be described. Prepare a number of samples of an electric motor with known air gap eccentricity and eccentricity in advance, conduct a confirmation experiment, and set various parameters. That is, before the rotary compressor is sealed by welding, the eccentric state of the air gap is measured with a gauge or the like, and the magnitude of vibration when a predetermined AC voltage is applied is measured, and the magnitude of vibration and the eccentricity of the air gap are measured. Set parameters from quantity correlation.

Since the air gap eccentricity and the measured vibration magnitude have a linear correlation, the air gap eccentricity can be calculated by multiplying the vibration magnitude by the parameter set above. The magnitude of vibration is obtained from the RMS amplitude of the vibration waveform. Alternatively, the vibration waveform may be obtained from an average value of absolute values of vibrations in a direction having a larger absolute value of vibrations in a positive direction and a negative direction. Further, it may be obtained by an average value between an average value of absolute values of vibration intensity in the positive direction and an average value of absolute values of vibration intensity in the negative direction.

  Further, since the magnitude of vibration is correlated with the rotational speed of the rotor, and the rotational speed of the rotor is correlated with the current difference, the current difference and the magnitude of vibration are correlated. FIG. 11 shows the current difference and the magnitude of vibration when forward rotation energization is performed for two different motors (No. 1 and No. 2) having the same air gap eccentricity of the same model. The horizontal axis is the current difference, and the vertical axis is the magnitude of vibration. A substantially linear relationship is observed between the current difference and the magnitude of the vibration, and it can be said that the magnitude of the vibration increases as the absolute value of the current difference increases.

  It should be noted that no. Although there are a plurality of points 1, this is a point when the starting torque is insufficient and the rotor does not rotate even in the energized state of rotation. In such a case, the variation in the magnitude of vibration is large. Therefore, the measurement accuracy can be improved by determining the target current difference in advance and correcting the magnitude of vibration from the difference between the current difference during measurement and the target current difference.

  On the other hand, there are two methods for estimating the eccentric direction of the air gap: a method of estimating from the vibration waveform and a method of obtaining from the phase difference between the vibration waveform and the current waveform. As a method of estimating from the vibration waveform, for example, when there is an unbalance of the air gap 101 in the direction perpendicular to the main winding 110, an unbalance in the direction orthogonal to the magnetic flux occurs when a current flows through the main winding 110 and a magnetic flux is induced. A magnetic attraction force works, and the rotor 102 moves toward the narrower air gap. For example, when an AC voltage is applied to a single-phase two-pole induction motor, the magnetic flux increases as the absolute value of the current increases, and the unbalanced magnetic attractive force also increases.

  As described above, since the unbalanced magnetic attractive force is always zero or more in the narrow direction of the air gap, the magnitude of the vibration on the + side of the vibration waveform is compared with the magnitude of the − side vibration. Can be estimated. As a method for obtaining the phase difference between the vibration waveform and the current waveform, when the absolute value of the current is maximized (that is, when the current waveform is an extreme value), the unbalanced magnetic attractive force is also maximized. It takes a maximum or minimum value depending on the eccentric direction of the air gap with a phase delay from the extreme value. Therefore, the time when the current waveform takes the extreme value and the time when the vibration waveform takes the maximum value or the minimum value are calculated, and the eccentricity direction of the air gap can be estimated by obtaining the difference.

Air gap eccentricity and air gap in two directions, perpendicular to the magnetic flux induced when current is passed through the main winding 110 and perpendicular to the magnetic flux induced when current is passed through the auxiliary winding 111 From the calculation result of the eccentric direction, the air gap eccentric state can be expressed as a two-dimensional coordinate system, and the quality of the air gap can be determined.
By configuring as described above, the eccentricity state of the air gap can be inspected using the common parameters for various types of single-phase induction motors, so that the development period can be shortened. Furthermore, in the finished state of the product, where the positional relationship between the rotor 102 and the stator 103 cannot be directly observed, even if there are variations or disturbances in processing or assembly for each single-phase induction motor, the air gap eccentricity state is accurately inspected. Will be able to.

Embodiment 2. FIG.
In the present embodiment, an inspection apparatus for accurately inspecting the air gap eccentric direction and the air gap eccentric amount by adjusting the frequency of the voltage to be energized during measurement will be described. The rotary compressor 100 including the single-phase induction motor is the same as that described in the first embodiment, and a description thereof will be omitted.
The appearance of the inspection apparatus is the same as that of FIG. 3, but there is a difference in the drive circuit shown in FIGS. 12 and 13, and a frequency adjuster 153 is added.

  FIG. 14 shows an inspection flowchart in the present embodiment. Here, only differences from the first embodiment will be described. In the first embodiment, the driving circuit of ST5 is switched in ST5-1, the connection destination of the main winding switch 144 is the contact B143 side, and the connection destination of the auxiliary winding switch 145 is the contact C146 side in ST5-2. An auxiliary winding resistor 148 and an auxiliary winding capacitor 149 are connected in series with the winding 111, and then the voltage is adjusted to a specific voltage by the voltage regulator 134 in ST5-3. However, in this embodiment, in ST5-1, the connection destination of the main winding switch 144 is the contact B143 side, and in ST5-2, the connection destination of the auxiliary winding switch 145 is the contact C146 side, and the auxiliary winding 111 The point that the auxiliary winding resistor 148 and the auxiliary winding capacitor 149 are connected in series is the same as that of the first embodiment. Thereafter, in ST5-3, the power supply frequency is adjusted to a specific frequency by the frequency adjuster 153. The difference is that the voltage is adjusted to a specific voltage by the voltage regulator 134 in ST5-4.

  In the first embodiment, the drive circuit of ST11 is switched in ST17-1, the connection destination of the main winding switch 141 is the contact A142 side, and the connection destination of the auxiliary winding switch 145 is the contact D147 side in ST17-2. The main winding resistor 141 and the main winding capacitor 140 are connected in series to the main winding 111, and then the voltage is adjusted to a specific voltage by the voltage regulator 134 in ST17-3. However, in this embodiment, the connection destination of the main winding switch 141 is the contact A142 side in ST17-1, and the connection destination of the auxiliary winding switch 145 is the contact D147 side in ST17-2, The point that the main winding resistor 141 and the main winding capacitor 140 are connected in series is the same as that of the first embodiment, but after that, the power frequency is adjusted to a specific frequency by the frequency adjuster 153 in ST17-3. The difference is that the voltage is adjusted to a specific voltage by the voltage regulator 134 in ST17-4.

  Here, the size of the auxiliary winding resistor 148 and the capacity of the auxiliary winding capacitor 149 connected in ST5-2 in the flowchart of FIG. 14, the power supply frequency adjusted in ST5-3, and adjusted in ST5-4 Magnitude of voltage, magnitude of main winding resistor 141 connected in ST17-1 and capacity of main winding capacitor 140, power supply frequency adjusted in ST17-3, magnitude of voltage adjusted in ST17-4 This is a value adjusted so that the rotor 102 rotates at a slow rotation period of 2/3 or less of the magnetic flux period, and there are various combinations of values. By performing vibration measurement while slowly rotating the rotor, the influence of noise appearing in the vibration waveform can be reduced, and the measurement accuracy can be improved. In addition, although the voltage regulator, the capacitor | condenser, and the resistor were used as a means to adjust the magnetic flux induced by each coil | winding, you may use the current regulator which adjusts the electric current of a coil | winding.

  As an effect of the present embodiment, when the integral multiple of the power supply frequency is equal to the natural frequency of the single-phase induction machine, the resonance and the measured vibration become large, and it may be difficult to determine the direction of vibration. By setting the natural frequency of the single-phase induction machine and the vibration frequency of the rotor to different frequencies, the vibration direction of the rotor can be measured with high accuracy and the quality of the air gap eccentricity can be accurately determined. be able to.

In the first or second embodiment, the fixed impedance type capacitor / resistor is incorporated in the drive circuit. However, a variable type capacitor / resistor may be used. The drive circuit corresponding to the machine can be configured at a relatively low cost.
In addition, a capacitor and a resistor were used as means for adjusting the ratio of the magnitude of the magnetic flux induced by the main winding 110 and the auxiliary winding 111 generated when alternating current was applied. The impedance of each winding may be adjusted.
FIG. 3 shows a type of pickup that presses against a measuring body and measures vibration, but a type that is attached with a magnet or an adhesive may be used. In that case, a clamp mechanism for clamping the shell and a cylinder are installed. Since this is not necessary, the detection device can be configured at low cost.

Furthermore, although the acceleration pickup is exemplified as the means for detecting vibration, for example, a vibration detecting means for detecting vibration from displacement or position information may be used.
In FIG. 3, a clamp-type ammeter is shown as an ammeter for measuring current. However, an ammeter may be incorporated in the drive circuit in advance.
In the first or second embodiment, the method for calculating the rotational speed of the rotor based on the relationship between the current difference and the rotational speed of the rotor has been described. However, the rotational speed of the rotor, the main winding, and the auxiliary winding for each motor model. Investigate the relationship between the current flowing through the wire or the phase difference of the applied voltage, and accurately check the eccentricity of the air gap even when using the method of calculating the rotor speed based on the relationship between the phase difference and the rotor speed There is no change to what you can do.
Further, in the flowcharts of FIGS. 9 and 14, the main lock energization is performed after the forward rotation energization is performed, and then the auxiliary lock energization is performed after the reverse rotation energization is performed. However, the order may be changed. . For example, even if reverse rotation energization is performed, then forward rotation energization is performed, then main lock energization is performed, and then auxiliary lock energization is performed to measure current and vibration, the effects of the present invention can be obtained. Further, before the measurement, the motor may be warmed up by performing preliminary energization to apply a higher voltage to the motor than at the time of measurement.

Embodiment 3 FIG.
In the present embodiment, an air gap eccentricity adjustment method that adjusts after checking the air gap eccentricity state will be described. FIG. 15 is a sectional view showing a uv coordinate system for two-dimensionally expressing the air gap eccentric state, and FIG. 16 is a sectional view showing a method for adjusting the air gap eccentric state.

The rotary compressor 100 including the single-phase induction motor to be inspected is the same as that described in the first embodiment, and the method for inspecting the air gap eccentricity of the rotary compressor 100 is also the case of the first embodiment. Is the same. Hereinafter, a method for adjusting the air gap eccentricity based on the inspection result will be described in detail.

Since the rotary compressor 100 has a single-phase induction motor assembled in a sealed container in a finished product state, the air gap eccentricity is inspected by direct means such as visual observation or measurement with a gap gauge. I can't. In the first embodiment, the air gap state of the single-phase induction motor in such a state can be inspected, and the inspection result can be expressed as a vector in the uv coordinate system shown in FIG.

  In FIG. 15, the acceleration pickup 122a is the u axis and the acceleration pickup 122b is the v axis. In the first embodiment, the results of the air gap eccentric direction and the eccentric amount in the auxiliary winding direction calculated in ST16 in FIG. 9 are represented by coordinates on the u axis, and the main winding direction calculated in ST28 in FIG. By expressing the result of the air gap eccentric direction and the amount of eccentricity with coordinates on the v-axis, the direction in which the air gap of the single-phase induction motor becomes narrow can be two-dimensionally represented.

Since the single-phase induction motor to be inspected is fixed inside the shell 104, the air gap state of the single-phase induction motor can be adjusted by deforming the shell 104. As a method of deforming the shell 104, for example, there is a method of heating and distorting the shell 104, and the shell 104 can be deformed by a burner 160 as shown in FIG.
The rotary compressor 100 is installed on a rotary table 162 having a rotating mechanism that is rotated by a servo motor (not shown), and the height of the burner 160 is set so that the flame 161 of the burner 160 hits between the stator 103 and the welding point 109. To fix. After the burner 160 is ignited, the rotary table 162 is rotated and heated on the circumference of the shell 104.

Generally, when the shell 104 is heated from the outside, the shell 104 is deformed so as to be concave in the heated direction after being cooled. Since the stator 103 is shrink-fitted and fixed to the shell 104, the center axis of the stator 103 is inclined according to the deformation of the shell 104, and the air gap eccentric state changes. According to the inspection result of the air gap eccentric state, the air gap eccentric state can be adjusted by heating from a narrow direction of the air gap and adjusting the heating amount according to the air gap eccentric amount. As a result, the noise of the electric motor can be reduced and a highly efficient electric motor can be realized stably.

  Although FIG. 16 shows a method of heating by the burner 160, the heating means of the shell 104 is not limited to the burner, and for example, high-frequency heating, laser, TIG welding, or the like may be used. In high-frequency heating, laser, and TIG welding, the amount of heating with respect to the shell 104 can be controlled more easily than the burner, so that the air gap eccentricity can be adjusted with high accuracy. In the present embodiment, the heating method has been described as means for deforming the shell 104. However, the shell 104 may be deformed by hitting it with a hammer or the like.

Embodiment 4 FIG.
In the present embodiment, a single-phase induction motor manufactured using an inspection method and an adjustment method for an air gap eccentricity of a single-phase induction motor according to the present invention will be described. In general, in order to improve the output of a single-phase induction motor, it is conceivable to increase the size of the motor, but there are the following problems.
For example, in the case of increasing the size in the radial direction, it is necessary to change the size of the press die used at the time of manufacturing the stator and the size of the shell holding the electric motor. For this reason, when there is a lineup of motors with various outputs, it is expensive to change manufacturing equipment and peripheral members.
In addition, when the size is increased in the height direction, the air gap is greatly decentered only when the rotor is assembled slightly inclined from the axis of the stator at the time of assembling the electric motor. Therefore, a highly accurate assembly technique is required. .

According to this embodiment, even if the winding specifications are changed for each model, the conventional method for calculating the rotational speed of the rotor from the phase difference between the current flowing through the main winding and the auxiliary winding or the applied voltage, and In contrast, it is possible to calculate the rotor speed using common parameters, so it can be applied to models with different winding specifications without taking time to start up, shortening the development period. can do.
Further, in the state of being sealed in the container, the air gap eccentric state is inspected by the air gap eccentricity inspection apparatus described in the first embodiment, and the air gap eccentric state is adjusted by the method described in the third embodiment. Even a model with a high motor height can be assembled with high accuracy, and a low-noise and high-efficiency motor can be realized. In the third embodiment, the method for adjusting the air gap eccentric state has been described. Of course, manufacturing equipment using this method may be manufactured and used for adjusting the air gap eccentricity.

Schematic sectional view of a rotary compressor containing a single-phase induction motor, Fig. 1 is a lateral cross-sectional view as viewed from arrow A, Schematic of the air gap inspection device of the present invention, FIG. 3 is a lateral cross-sectional view as seen from arrow B, The schematic diagram of the drive circuit of the normal rotation electricity supply state in connection with Embodiment 1 of this invention, The schematic diagram of the drive circuit of the reverse rotation energization state in connection with Embodiment 1 of this invention, The schematic diagram of the drive circuit of the main lock energization state concerning Embodiment 1 of the present invention, The schematic diagram of the drive circuit of the auxiliary lock energization state concerning Embodiment 1 of the present invention, The flowchart figure which showed the air gap inspection method in connection with Embodiment 1 of this invention. Relationship diagram between rotor speed and current difference, Relationship diagram between current difference and vibration magnitude, FIG. 5 is a schematic diagram of a drive circuit in a normal rotation energization state according to Embodiment 2 of the present invention; Schematic diagram of the drive circuit in the reverse rotation energization state according to the second embodiment of the present invention, The flowchart figure which showed the air gap inspection method in connection with Embodiment 2 of this invention. Sectional drawing showing the air gap eccentric state using uv coordinate system in connection with Embodiment 3 of this invention, It is a schematic diagram which shows the adjustment method of the air gap eccentric state in connection with Embodiment 3 of this invention.

Explanation of symbols

100 rotary compressor, 101 air gap, 102 rotor, 103 stator, 104 shell,
105 spindle, 106 frame, 107 cylinder head, 108 cylinder, 109 welding point,
110 main winding, 111 auxiliary winding, 112 terminals, 113 discharge pipe, 114 muffler,
120 connection terminals, 121a ammeter, 121b ammeter, 122 accelerometer,
122a accelerometer, 122b accelerometer,
123 Acceleration pickup cylinder, 124 pickup vibration isolator, 125 clamp claw,
126 Clamp vibration isolator, 127 Clamp cylinder, 128 Workpiece vibration isolator,
129 Measurement unit base plate, 130 Anti-vibration material, 131 Amplifier, 132 Computer,
133 computer display, 134 voltage regulator, 135 resistor, 136 capacitor,
137 mount,
140 Main winding capacitor, 141 Main winding resistor, 142 Contact A, 143 Contact B,
144 Main winding switch, 145 Auxiliary winding switch, 146 Contact C, 147 Contact D,
148 Auxiliary winding resistor, 149 Auxiliary winding capacitor, 150 AC power supply,
151 Main winding energization switch, 152 Auxiliary winding energization switch, 153 Power frequency adjuster.

Claims (8)

In a single-phase induction motor comprising a rotor that rotates with a main shaft, and a stator that is provided with a main winding and an auxiliary winding and that is arranged to have an air gap between the rotor,
Means for applying an alternating voltage to the motor;
Current measuring means for measuring the current waveform of the current flowing through the motor;
Vibration measuring means for measuring the vibration waveform of the single-phase induction motor in the direction in which the unbalanced magnetic attractive force generated in the rotor is maximized when the AC voltage is applied to the motor;
The rotational speed of the rotor is calculated from the result measured by the current measuring means, the eccentric state of the air gap is estimated from the calculated rotational speed of the rotor and the measured current waveform and vibration waveform, and the estimated air Determination means for determining the quality of the air gap based on the eccentric state of the gap;
An air gap eccentricity inspection device for a single-phase induction motor, characterized by comprising:   When an AC voltage is applied to the main and auxiliary windings, the magnetic flux induced in the air gap by one of the main and auxiliary windings is induced in the air gap by the other winding. 2. A drive circuit for rotating and energizing the rotor in a state larger than a magnetic flux and a drive circuit for energizing only one of the main winding and the auxiliary winding are provided. Air gap eccentricity inspection device for single-phase induction motors.   2. A drive circuit for providing a voltage adjusting mechanism for changing the voltage of the AC power supply, and for rotating the rotor at a rotation period of 2/3 or less of the frequency of the AC voltage to be applied. The air gap eccentricity inspection apparatus for a single-phase induction motor according to claim 2.   Rotating energization for energizing both the main and auxiliary windings and a lock energization for energizing only one of the main and auxiliary windings are provided. 4. The single-phase induction motor according to claim 1, wherein the number of rotations of the rotor is calculated from a difference between the current value of the energizing rotation and the current value of the energizing lock. 5. Air gap eccentricity inspection device.   The air gap eccentricity inspection apparatus for a single-phase induction motor according to any one of claims 1 to 4, further comprising a frequency conversion mechanism for changing the frequency of the AC voltage. A single-phase induction motor comprising a rotor that rotates together with a main shaft, and a stator that includes a main winding and an auxiliary winding and is arranged to have an air gap between the rotor,
Applying an alternating voltage to either the main winding or the auxiliary winding to measure the current waveform flowing in the winding;
Switch the circuit and apply AC voltage to both the main and auxiliary windings to measure the current waveform flowing in the windings, and the motor in the direction that maximizes the unbalanced magnetic attractive force generated in the rotor Measuring the vibration waveform of the vibration of
Calculating the rotor speed from the measured current waveform;
Calculating an eccentric amount and an eccentric direction of the air gap from the calculated rotational speed of the rotor and the measured current waveform and vibration waveform;
Determining whether the air gap is good or not based on the calculated eccentric amount and eccentric direction of the air gap;
An air gap eccentricity inspection method for a single-phase induction motor. A single-phase induction motor comprising a rotor that rotates together with a main shaft, and a stator that includes a main winding and an auxiliary winding and is disposed so as to have an air gap between the rotor,
Apply AC voltage to both the main and auxiliary windings, measure the current waveform flowing in the windings,
Switch the circuit, apply an AC voltage to either the main winding or the auxiliary winding, measure the current waveform flowing in the winding, and maximize the unbalanced magnetic attractive force generated in the rotor. Measure the vibration waveform of the single-phase induction motor vibration in the direction
Calculate the rotor speed from the measured current waveform,
Calculate the eccentric amount and the eccentric direction of the air gap from the measured current waveform and vibration waveform and the calculated rotor speed,
The quality of the air gap is determined based on the calculated eccentric amount and direction of the air gap,
An air gap adjustment method for a single-phase induction motor, wherein the air gap of the single-phase induction motor is adjusted by deforming a shell to which the stator is fixed based on the determination result.   A single phase induction motor manufactured by inspecting an air gap eccentric state by the method of claim 6 or adjusting an air gap eccentric state by the method of claim 7.

Images