JP4474469B2 - Single-phase induction motor air gap eccentricity inspection device and air gap correction method - Google Patents

Description

  The present invention relates to an air gap eccentricity inspection apparatus and an air gap correction method for a single-phase induction motor.

  Conventionally, there has been a method of estimating the eccentric state of the air gap of a single-phase induction motor by measuring vibration generated in a restrained state (also referred to as a locked state) in which a single-phase induction motor is energized and the rotor does not rotate. For example, a voltage lower than the rated voltage is applied to either the main winding or auxiliary winding of a single-phase induction motor to bring it into a locked state, and the gap between the rotor and stator is determined from the applied voltage waveform and the vibration waveform generated in the locked state. The state of was detected.

  When a voltage is applied to the main winding or the auxiliary winding, a current flows and a magnetic flux is generated, and a magnetic attractive force acts on the rotor. When the magnetic flux is maximized, the magnetic attractive force is also maximized, and the rotor moves toward the narrower air gap. For example, if the magnetic flux waveform is ¼ wavelength behind the voltage waveform, the vibration waveform takes a maximum value or a minimum value when the voltage waveform becomes zero, and the sign and the air gap eccentric direction coincide with each other. The eccentric direction of the gap can be determined. Further, the magnitude of the air gap eccentric state can be estimated from the magnitude of the amplitude of the vibration waveform, and thus the eccentric direction and the magnitude of the eccentricity of the air gap are detected (see Patent Document 1).

  In addition, there is an apparatus that determines the amount and direction of the air gap eccentricity of the rotor from the vibration waveform generated in the locked state before the electric motor is energized and the rotation at the start is started. Since the sign of the rising edge of the vibration waveform generated in the locked state matches the eccentric direction of the air gap, the eccentric direction of the air gap is determined from the sign of the rising edge of the vibration waveform. In addition, the eccentricity of the air gap can be estimated from the maximum value of the amplitude of the vibration waveform, and thus the eccentric direction and the eccentricity of the air gap are detected (see Patent Document 2).

JP-A-60-152262 (1 page 4 to 11 line, 2 page 32 to 56 line, FIG. 8) Japanese Patent Application Laid-Open No. 06-284655 (2 pages 2 to 11, 2 pages 70 to 76, 4 pages 1 to 93, FIG. 6)

  The conventional air gap eccentricity inspection device for a single-phase induction motor is configured as described above. In Patent Document 1, the eccentric direction of the air gap is determined from the voltage waveform applied to the motor and the measured vibration waveform. In this case, the phase difference between the voltage waveform and the vibration waveform (in the above example, a ¼ wavelength deviation) is detected, and when the eccentric direction of the air gap is determined from the sign of the extreme value of the vibration waveform, In the product, the phase difference between the voltage waveform and the vibration waveform varies from motor to motor, and the current waveform and vibration waveform measured for the motor also vary from phase to phase for each current cycle. There was a problem that an error may occur in the judgment of the direction.

  Further, in Patent Document 2, when the eccentric direction of the air gap is determined from the rise of the measured vibration waveform, it is difficult to determine the point at which the vibration waveform rises due to noise mixing, and a band pass filter or the like is used. Even if the frequency is selected, it takes a lot of labor to set the parameters for determining the eccentric direction of the air gap, so it is difficult to set the parameters so that the eccentric direction of the air gap can be determined for different models. There was a problem that.

  In an actual product, the eccentric state of the air gap may change due to the rotation of the spindle depending on the processing accuracy and assembly accuracy of the parts. For example, the center axis of the rotor that is shrink-fitted and fixed with respect to the main axis that is the center of rotation may be eccentric or the main axis may be curved. In such a case, the main axis rotates and the phase of the rotor changes. The eccentric state of the air gap also changes.

  In such a case, if the amount of eccentricity and the direction of eccentricity of the air gap are estimated by measuring vibration in a locked state where the rotor does not rotate as in the prior art, changes in the air gap eccentricity due to the phase of the rotor are taken into account. Therefore, an error may occur in determining whether the air gap is good or bad.

  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 object of the present invention is to provide an air gap eccentricity inspection device and an air gap correction method for a single-phase induction motor that can reliably determine whether an air gap is good and can further correct the air gap based on air gap eccentricity data. To do.

  An air gap eccentricity inspection apparatus for a single-phase induction motor according to the present invention includes 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 and the rotor. Is used to inspect the eccentricity of the air gap of a single-phase induction motor, and measures the current waveform of the current flowing through the main and auxiliary windings and means for applying an AC voltage to the main and auxiliary windings. Vibration measurement that measures the vibration waveform of the vibration of the single-phase induction motor in the direction that maximizes the unbalanced magnetic attractive force generated in the rotor when AC voltage is applied to the current measuring means and the main and auxiliary windings The amount of eccentricity of the air gap is calculated according to the means and the amplitude of the vibration waveform, and the eccentric direction of the air gap is calculated based on the time change of the phase difference between the vibration waveform and the current waveform. It is provided with a means for determining the quality of the air gap on the basis of the eccentric direction.

  An air gap correction method for a single-phase induction motor according to the present invention includes 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 and the rotor. A method for correcting an air gap of a single-phase induction motor, in which an AC voltage is applied to a main winding and an auxiliary winding, a current waveform of a current flowing through the main winding and the auxiliary winding is measured, and the main winding and the auxiliary winding are measured. When an AC voltage is applied to the winding, the vibration waveform of the single-phase induction motor in the direction that maximizes the unbalanced magnetic attractive force generated in the rotor is measured, and the amplitude of the air gap is determined by the measured vibration waveform amplitude. In addition to calculating the amount of eccentricity, the eccentric direction of the air gap is calculated based on the time change of the phase difference between the vibration waveform and the current waveform, and the air gap is determined based on the calculated amount and direction of the eccentricity of the air gap. To determine the is intended to correct the eccentricity of air gap by deforming the shell stator is fixed on the basis of the determination result.

  According to the air gap eccentricity inspection apparatus for a single-phase induction motor according to the present invention, the stator includes a rotor that rotates together with the main shaft, a main winding and an auxiliary winding, and is arranged to have an air gap between the rotor. Is used to detect the eccentricity of the air gap of the single-phase induction motor consisting of current measuring means for measuring the current waveform of the current flowing in the main winding and auxiliary winding, and AC in the main winding and auxiliary winding. Vibration measuring means for measuring the vibration waveform of the vibration of the single-phase induction motor in the direction in which the unbalanced magnetic attractive force generated in the rotor is maximized when a voltage is applied, and the amplitude of the vibration waveform measured by the vibration measuring means To calculate the air gap eccentricity, and calculate the air gap eccentric direction by the time change of the phase difference between the vibration waveform and the current waveform. Is provided with the means for determining the quality of the air gap Zui, without being affected by variation or disturbance of each single-phase induction motor, it is possible to determine the air gap eccentric direction and the eccentric amount accurately.

  According to the method for correcting an air gap of a single-phase induction motor according to the present invention, 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 A method of correcting an air gap of a single-phase induction motor comprising: applying an AC voltage to a main winding and an auxiliary winding, measuring a current waveform of a current flowing through the main winding and the auxiliary winding, and measuring the main winding When an AC voltage is applied to the auxiliary winding, the vibration waveform of the single-phase induction motor in the direction that maximizes the unbalanced magnetic attractive force generated in the rotor is measured, and the eccentricity of the air gap is determined by the amplitude of the vibration waveform. And the eccentric direction of the air gap is calculated by the time change of the phase difference between the vibration waveform and the current waveform, and the quality of the air gap is determined based on the calculated eccentric amount and the eccentric direction of the air gap. Therefore, since the eccentricity of the air gap is corrected by deforming the shell to which the stator is fixed based on this determination result, the eccentricity of the air gap can be corrected easily and accurately. .

Embodiment 1 FIG.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view showing a rotary compressor 100 for a refrigeration / air conditioner having a single-phase induction motor therein, and FIG. 2 is a lateral sectional view taken along line AA in FIG. The single-phase induction motor is mainly composed of a rotor 102 and a stator 103. An air gap 101 that is a cylindrical space exists between the rotor 102 and the stator 103.

  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) provided 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 welded to the shell 104 at three welding points 109 (only one point is shown in FIG. 1). It is fixed.

  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) provided outside the compressor through a terminal 112 fixed to the shell 104 by welding. The shell 104 is fixed with a muffler 114 which is a gas inlet before compression and a discharge pipe 113 which discharges the compressed gas to the outside by brazing. After the gas before compression is sucked from the muffler 114, the cylinder 104 After being compressed in 108, discharged from the frame 106 into the shell 104, and then discharged to the outside of the rotary compressor 100 through the discharge pipe 113.

  FIG. 3 is a cross-sectional view showing an air gap eccentricity inspection apparatus for a single-phase induction motor using a rotary compressor 100 for a refrigeration / air-conditioning machine containing the single-phase induction motor as an object to be measured, and FIG. 4 is a cross-sectional view of FIG. 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 AC power source (not shown). An ammeter 121 a is attached to the conducting wire energizing the main winding 110, and an ammeter 121 b is attached to the conducting wire energizing the auxiliary winding 111.

  Vibration generated when the single phase induction motor is energized is measured by the acceleration pickups 122a and 122b. As shown in FIG. 4, the direction in which the unbalanced magnetic attractive force generated in the rotor 102 when the AC voltage is applied to the main winding 110 by the acceleration pickup 122a is maximized (generally, the direction in which the auxiliary winding exists) In the following, vibration generated in the auxiliary winding direction) is measured, and the unbalanced magnetic attractive force generated in the rotor 102 when the AC voltage is applied to the auxiliary winding 111 by the acceleration pickup 122b is maximized (generally, generally). Since this is the direction of the main winding, the vibration generated in the main winding direction is measured below.

  Each of the acceleration pickups 122a and 122b can be moved in the radial direction of the rotary compressor 100 by the acceleration pickup cylinder 123, and is pressed against the rotary compressor 100 via the pickup vibration isolator 124 during vibration measurement. The vibration of the shell 104 generated when energized is measured. The rotary compressor 100 is fixed by the clamp claws 125 so that the rotary compressor 100 does not roll over when the acceleration pickups 122a and 122b are 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 via 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 electric signal is amplified by the amplifier 131. The electric signal of the current measured by the ammeters 121a and 121b and the amplified vibration signal are recorded in the computer 132 by an A / D board (not shown). The computer 132 calculates the air gap eccentric direction and the air gap eccentric amount based on the recorded current waveform and vibration waveform, and the calculated results are displayed on the display 133 of the computer.

  The AC voltage applied to the main winding 110 and the auxiliary winding 111 can be adjusted by the voltage regulator 134. That is, when oil is applied to the main bearing and the main shaft 105 rotates at a high speed, an oil film reaction force may be generated on the main bearing, and an error may occur in the measured vibration. By adjusting the AC voltage applied to the line 110 and the auxiliary winding 111, the rotational speed of the rotor 102 can be reduced, and such an error can be prevented from occurring. The magnitude of the alternating current flowing through the single-phase induction motor is adjusted by the resistor 135 and the capacitor 136. The above electric devices are fixed by a gantry 137.

  An AC voltage is applied to the rotary compressor 100 from the AC power source (not shown) via the connection terminal 120 and the terminal 112, and the current flowing in the main winding 110 and the current flowing in the auxiliary winding 111 are respectively measured by the ammeter 121a and the current. Simultaneously with the measurement by the meter 121b, vibration generated in the rotary compressor 100 is measured by the acceleration pickup 122a and the acceleration pickup 122b.

  The time change of the phase difference between the current waveform and vibration waveform measured by the computer 132 is calculated, the air gap eccentric direction is estimated from the time change of the calculated phase difference, and the air gap eccentricity is estimated from the measured vibration waveform size. To do. Measure the auxiliary winding direction and the main winding direction respectively, and estimate the air gap eccentric direction and air gap eccentricity for the auxiliary winding direction estimated from the measurement results, and the air gap eccentric direction and air for the main winding direction. The quality of the air gap eccentricity is determined from the gap eccentricity.

  Next, details of the air gap eccentricity inspection means will be described with reference to the flowchart of FIG. First, the rotary compressor 100 is installed on the work vibration isolation material 128 (STEP 500). Next, the clamp pawl 125 is advanced by the clamp cylinder 127 to fix the rotary compressor 100 (STEP 501). Next, the connection terminal 120 is connected to the terminal 112 (STEP 502). Next, the acceleration pickups 122a and 122b are advanced by the acceleration pickup cylinder 123 and pressed against the rotary compressor 100 (STEP 503).

  Next, the drive circuit is switched so that the magnetic flux generated by flowing a current through the main winding 110 is larger than the magnetic flux generated by flowing a current through the auxiliary winding 111 (STEP 504). FIG. 6 is a circuit diagram showing a drive circuit in the air gap eccentricity inspection apparatus. The main winding switch 144 is connected to the contact 143 side (STEP 504-1).

  Then, by connecting the auxiliary winding switch 145 to the contact 146 side, the auxiliary winding resistor 148 and the auxiliary winding capacitor 149 are connected in series to the auxiliary winding 111 (STEP 504-2). As a result, the current flowing through the main winding 110 is increased, and the current flowing through the individual windings is adjusted so as to decrease the current flowing through the auxiliary winding 111, and is generated by the main winding 110 in the air gap 101 when energized. The magnitude of the magnetic flux is set to be larger than the magnitude of the magnetic flux generated by the auxiliary winding 111.

  Next, the voltage of the AC power source 150 is adjusted to a specific voltage by the voltage regulator 134 (STEP 504-3). Next, an AC voltage is applied to the single-phase induction motor, and measurement of current flowing in the main winding 110 and vibration in the auxiliary winding direction is started (STEP 505). The current waveform flowing through the main winding 110 is measured by an ammeter 121a. The vibration waveform in the auxiliary winding direction is measured by the acceleration pickup 122a (STEP 506).

  When a predetermined measurement time has elapsed, the measurement is terminated, and at the same time, energization is terminated (STEP 507). The measured current waveform is captured and recorded in the computer 132 via an A / D board (not shown). The measured vibration waveform is amplified by the amplifier 131, and is captured and recorded in the computer 132 via an A / D board (not shown) (STEP 508).

  From the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the eccentric direction and the eccentric amount of the air gap in the auxiliary winding direction are calculated by the computer 132 (STEP 509). FIG. 7 is a flowchart for showing this calculation method. FIG. 8 is a graph showing examples of measured current waveforms and vibration waveforms.

As a method for calculating the time change of the phase difference between the current waveform and the vibration waveform, in the flowchart of FIG. The difference from the time at which (valley) is taken is calculated for each half wavelength of the current waveform, and the calculated time difference is represented by a frequency distribution. Details are shown below. The time when the current waveform takes the extreme value is t _n−1 , t _n , the time when the vibration waveform takes the maximum value is t1 _m−2 to t1 _{m + 2,} and the time when the vibration waveform takes the minimum value is t2 _{m− 2} ~ t2 _{m + 2} . FIG. 9 is a graph showing the current half-wavelength in FIG. 8 in an enlarged manner. The difference between the time t _{n at} which the current waveform takes an extreme value and the time at which the vibration waveform takes the maximum values t1 _m and t1 _{m + 1} is defined as p1 _n , _m , p1 _n , _{m + 1} . The difference between the time t _n when the current waveform takes the extreme value and the time when the vibration waveform takes the minimum values t2 _m and t2 _{m + 1} is defined as p2 _n , _m , p2 _n , and _{m + 1} .

In FIG. 7, first, a time t _i (i = 0, 1,..., N,...) When the current waveform becomes an extreme value (mountain, valley) is calculated from the current waveform flowing in the main winding 110 (STEP 600). Next, from the vibration waveform in the auxiliary winding direction, a time t1 _j (j = 0, 1,..., M,...) At which the vibration waveform reaches a maximum value (peak) is calculated (STEP 601). Next, from the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the difference in time between the maximum value of the vibration and the maximum value of the current between the current half wavelengths p1 _i , _j = to calculate the t1 _j -t _i (STEP602).

Next, from the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the number k1 (p of maximum values that becomes p = p1 _i , _j (i, j = 0, 1,...) At each time p. ) Is calculated (STEP 603). FIG. 10 is a graph showing the difference in the time difference between the extreme values of the current waveform and the vibration waveform and the distribution of the number of extreme values that are shifted. The horizontal axis is shifted time p, and the vertical axis is the number k1 (p) of maximum values corresponding to the shifted time, or the number k2 (p) of minimum values described later.

In FIG. 10, for the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the sum h1 = Σk1 (Δp) of k1 (Δp) is calculated for a specific range Δp of time p (STEP 604). Here, a specific determination method for the specific range Δp will be described later. Next, as shown in FIG. 8, the time t2 _j (j = 0, 1,..., M,...) At which the vibration waveform becomes the minimum value (valley) is calculated from the vibration waveform in the auxiliary winding direction (STEP 605). ). Next, from the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the time difference p2 _i , _j = between the minimum value of the vibration and the maximum value of the current between the current half-wavelengths for each half cycle of the current waveform. to calculate the t2 _j -t _i (STEP606).

Next, from the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the number of minimum values k2 (p = p2 _i , _j (i, j = 0, 1,...) For each time p ( p) is calculated (STEP607). In FIG. 10, the sum h2 = Σk2 (Δp) of k2 (Δp) is calculated for a specific range Δp of time p for the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction (STEP 608). .

  Next, regarding the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the air gap 101 is compared by comparing the number h1 of maximum values and the number h2 of minimum values in which the time difference falls within a specific range Δp. Is determined (STEP609). That is, when h1> h2, it is determined that the air gap 101 is eccentric in the positive direction of the acceleration pickup 122a.

  When h1 <h2, it is determined that the air gap 101 is eccentric in the negative direction of the acceleration pickup 122a. As used herein, the positive side and the negative side of the acceleration pickup 122a refer to the vibration direction in which the sign of the vibration waveform is positive, and the vibration direction in which the sign of the vibration waveform is negative. That's it.

  Finally, the amount of eccentricity of the air gap 101 is calculated from the magnitude of vibration in the auxiliary winding direction (STEP 610). Here, the magnitude of the vibration can be obtained from the effective value of the vibration waveform, and is obtained from the average value of the absolute values of the vibrations having the larger absolute value of the vibrations in the positive direction and the negative direction. May be. 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.

  Although the case where the magnetic flux generated by the main winding 110 is larger than the magnetic flux generated by the auxiliary winding 111 has been described above, the case where the magnetic flux generated by the auxiliary winding 111 is larger is described below. This will be described based on a flowchart. The drive circuit is switched so that the magnetic flux generated by passing current through the auxiliary winding 111 is larger than the magnetic flux generated by passing current through the main winding 110 (STEP 700).

  FIG. 12 is a circuit diagram showing a drive circuit in the air gap eccentricity inspection apparatus. By connecting the main winding switch 144 to the contact 142 side, the main winding resistor 141 and the main winding resistor 141 are connected in series with the main winding 110. The winding capacitor 140 is connected (STEP 700-1). Then, the auxiliary winding switch 145 is connected to the contact 147 side (STEP 700-2). As a result, the current flowing through the main winding 110 is reduced, the current flowing through the individual windings is adjusted so that the current flowing through the auxiliary winding 111 is increased, and is generated by the auxiliary winding 111 in the air gap 101 when energized. The magnitude of the magnetic flux is set to be larger than the magnitude of the magnetic flux generated by the main winding 110.

  Next, the voltage of the AC power supply 150 is adjusted to a specific voltage by the voltage regulator 134 (STEP 700-3). Next, an AC voltage is applied to the single-phase induction motor, and measurement of current flowing in the auxiliary winding 111 and vibration in the main winding direction is started (STEP 701). The current waveform flowing in the auxiliary winding 111 is measured by an ammeter 121b. The vibration waveform in the main winding direction is measured by the acceleration pickup 122b (STEP 702).

  When a predetermined measurement time elapses, the measurement is terminated, and at the same time, energization is terminated (STEP 703). The measured current waveform is captured and recorded in the computer 132 via an A / D board (not shown). The measured vibration waveform is amplified by the amplifier 131, and is captured and recorded in the computer 132 via an A / D board (not shown) (STEP 704). From the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the eccentric direction and the eccentric amount of the air gap in the main winding direction are calculated by the computer 132 (STEP 705). FIG. 13 is a flowchart for illustrating this calculation method.

In FIG. 13, first, a time t ′ _i (i = 0, 1,..., N,...) When the current waveform becomes an extreme value (mountain, valley) is calculated from the waveform of the current flowing through the auxiliary winding 111 (STEP 800). ). Next, the time t1 ′ _j (j = 0, 1,..., M,...) At which the vibration waveform reaches the maximum value (mountain) is calculated from the vibration waveform in the main winding direction (STEP 801). Next, from the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the difference in time p1 ′ _i , _j between the maximum value of the vibration and the maximum value of the current between the current half-wavelengths for each half cycle of the current waveform. = T1 ′ _j −t ′ _i is calculated (STEP 802).

Next, from the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the number k1 of local maxima that becomes p = p1 ′ _i , _j (i, j = 0, 1,...) At each time p. '(P) is calculated (STEP 803). Next, for the current waveform flowing through the auxiliary winding 111 and the vibration waveform in the main winding direction, the sum h1 ′ = Σk1 ′ (Δp) of k1 ′ (Δp) is calculated for a specific range Δp of time p (STEP 804). ). Next, a time t2 ′ _j (j = 0, 1,..., M,...) At which the vibration waveform becomes a minimum value (valley) is calculated from the vibration waveform in the main winding direction (STEP 805).

Next, from the current waveform flowing through the auxiliary winding 111 and the vibration waveform in the main winding direction, the time difference p2 ′ _i between the local minimum value of the vibration and the current extreme value between the current half wavelengths for each half period of the current waveform. _j = t2 ′ _j −t ′ _i is calculated (STEP 806). Next, from the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the number of minimum values k2 that becomes p = p2 ′ _i , _j (i, j = 0, 1,...) At each time p. '(P) is calculated (STEP 807). For the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the sum h2 ′ = Σk2 ′ (Δp) of k2 ′ (Δp) is calculated for a specific range Δp of time p (STEP 808).

  Next, regarding the current waveform flowing in the auxiliary winding 111 and the vibration waveform in the main winding direction, the number h1 ′ of maximum values and the number h2 ′ of minimum values in which the time difference falls within a specific range Δp is compared. The eccentric direction of the gap 101 is determined (STEP 809). That is, when h1 '> h2', it is determined that the air gap 101 is eccentric in the + direction of the acceleration pickup 122b. If h1 '<h2', it is determined that the air gap 101 is eccentric in the negative direction of the acceleration pickup 122b.

  Then, the amount of eccentricity of the air gap 101 is calculated from the magnitude of vibration in the main winding direction (STEP 810). Returning to the flowchart of FIG. 11 again, the air gap eccentricity estimated based on the current waveform flowing in the main winding 110 and the vibration waveform in the auxiliary winding direction, the current waveform flowing in the auxiliary winding 111 and the main winding direction The quality of the air gap 101 is determined based on the air gap eccentricity estimated based on the vibration waveform, and the result is displayed on the display 133 of the computer (STEP 706). A method for determining whether the quality is acceptable will be described later.

  Then, the acceleration pickups 122a and 122b are moved backward by the acceleration pickup cylinder 123 (STEP 707). Next, the connection terminal 120 is removed from the terminal 112 (STEP 708). Next, the clamp pawl 120 is moved backward by the clamp cylinder 127 (STEP 709). Finally, the rotary compressor 100 is removed from the work slowing material 128 (STEP 710).

  Here, the size of the auxiliary winding resistor 148, the capacity of the auxiliary winding capacitor 149, the size of the main winding resistor 141, the capacity of the main winding capacitor 140, and the magnitude of the voltage adjusted by the voltage regulator 134. The size of the resistor, the capacitance of the capacitor, and the voltage are adjusted so that the rotor 102 can be rotated at a rotation period of 2/3 or less of the frequency of the AC voltage applied to each winding. There are combinations.

  When the capacitor capacity and voltage are adjusted so that the rotor speed increases, the unbalanced magnetic attractive force acting on the rotor increases and the reaction of the rotor during vibration increases. In the vibration waveform in such a case, it is difficult to determine whether the vibration is caused by an unbalanced magnetic attractive force or the reaction. On the other hand, when the capacitor capacity and voltage are adjusted so that the rotor speed is reduced, the unbalanced magnetic attractive force acting on the rotor is reduced and the reaction of the rotor during vibration is also reduced. The vibration due to force becomes clear, and the air gap eccentric direction can be easily determined. In addition, as the rotational speed of the rotor is smaller, the phase of the rotor at the point of time when the unbalanced magnetic attractive force becomes maximum varies, and the air gap eccentricity that changes according to the phase of the rotor can be accurately measured. In particular, when the capacitor capacity and voltage are adjusted so that the rotor rotates at a rotation cycle of 2/3 or less of the frequency of the AC voltage applied to each winding, vibration with a frequency twice the applied voltage frequency as shown in FIG. Therefore, the unbalanced magnetic attractive force is maximized three times or more during one rotation of the rotor, and vibrations at three or more different rotor phases can be measured. Even if it is bad, it is possible to reliably determine whether the air gap is eccentric.

  In the above configuration, the voltage regulator, the capacitor, and the resistor are used as means for adjusting the magnetic flux induced in the air gap 101 by each winding, but the current for adjusting the winding current is shown. A regulator may be used.

  Next, a specific determination method for the specific range Δp will be described. The specific range Δp needs to be set according to the power supply frequency applied to the single-phase induction motor. For example, when the vibration waveform to be measured includes a lot of frequency components from 2 to 6 times the current frequency. In this case, a range in which the time p is from 0 second to about 1/12 to 1/4 of the current period is selected.

  Also, for example, an experiment for setting Δp using a single-phase induction motor whose air gap eccentric direction is known in advance is performed, a frequency distribution table as shown in FIG. 10 is created, and a set value for a specific range Δp is determined. There is a way. For example, when the eccentric direction of the air gap is on the + side of the acceleration pickups 122a and 122b, k1 (p)> k2 (p) or k1 ′ (p)> k2 ′ (p) in the created frequency distribution table. Is defined as Δp, and when the eccentric direction of the air gap is on the negative side of the acceleration pickups 122a and 122b, for example, k1 (p) <k2 (p), Alternatively, a range where k1 ′ (p) <k2 ′ (p) is found and this may be defined as Δp.

  When a plurality of ranges can be selected, it is preferable that the time p is positive and close to 0. This is because the unbalanced magnetic attractive force (excitation force acting on the rotor) becomes maximum when the current waveform becomes an extreme value, and the rotor vibrates in a direction where the air gap becomes narrow. This is because the air gap is eccentric in the direction of the sign of the extreme value of the vibration waveform. In FIG. 10, the range of Δp is a range in which the time p is positive and close to 0 as described above.

  In view of the above, the measurement of eccentricity in the case where the vibration waveform to be measured contains many frequency components from the second frequency to the sixth frequency of the current frequency will be described below. When the vibration waveform measured as described above contains a lot of frequency components from the second frequency to the sixth frequency of the current frequency, the specific range Δp is about 1/12 to 1/4 of the current cycle. Select the range up to. Furthermore, when selecting the specific range Δp as described above, it is preferable that the time p is positive and close to 0. Therefore, as shown in FIG. A range from about 1/12 to 1/4, in which time p is positive and close to 0, is selected.

  Then, in this specific range Δp, the sum h1 = Σk1 (Δp) of k1 (Δp) is calculated as described above, and the sum h2 = Σk2 (Δp) of k2 (Δp) is calculated, and the time difference is specified. The eccentricity direction of the air gap 101 is determined by comparing the number h1 of maximum values falling within the range Δp with the number h2 of minimum values. That is, when h1> h2, it is determined that the air gap 101 is eccentric in the direction of the positive side of the acceleration pickup, and when h1 <h2, it is determined that the air gap 101 is eccentric in the direction of the negative side of the acceleration pickup. To do. Then, the amount of eccentricity of the air gap 101 is calculated from the magnitude of the vibration.

  There is a difference of several milliseconds between the extreme value of the current waveform and the maximum value and the minimum value of the vibration waveform every half cycle of the current waveform, and the deviation varies. For example, as shown in FIG. 10, a range in which the time p is Δp is set in advance, and the sum Σk1 (Δp) of the number of local maximum values in the range is compared with the sum Σk2 (Δp) of the number of local minimum values. Thus, the eccentric direction of the air gap can be determined.

  For example, when the air gap 101 is eccentric in the direction perpendicular to the winding direction of the main winding 110, when a current flows through the main winding 110 and a magnetic flux is induced, an unbalanced magnetic attractive force is perpendicular to the magnetic flux. The rotor 102 moves to the narrower side of the air gap 101. 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.

  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, and the vibration waveform is also an extreme value in the direction of narrow air gap. As a typical example of the relationship between the current waveform and the vibration waveform, an example in which the vibration waveform is a vibration having a frequency double that of the current waveform as shown in FIG.

  However, there is a phase shift between the phase of the extreme value of the actually measured current waveform and the maximum and minimum values of the vibration waveform, which is a double frequency of the current frequency, and the frequency is 4 times or 6 times the current frequency. Since higher-order vibrations such as frequency and disturbances are also measured, the measured vibration waveform is as shown in FIG. 8, for example, and it is difficult to determine the air gap eccentric direction.

  Therefore, as shown above, the current waveform and the vibration waveform are calculated by calculating the frequency distribution of the difference between the time when the current waveform becomes the extreme value and the time when the vibration waveform becomes the maximum value and the time when the vibration waveform becomes the minimum value for each half wavelength of the current waveform. It is possible to clearly grasp the deviation. By setting the specific range Δp in advance as described above for the time lag, the air gap eccentric direction can be accurately determined.

In the above description, the case of calculating the time t _i or t ′ _i of the extreme value of the current waveform has been described. For example, instead of the time when the current waveform becomes the extreme value, the time when the current waveform becomes zero is calculated. Then, t _i or t ′ _i may be obtained. In the above description, the case where the air gap eccentric direction is estimated using the current waveform and vibration waveform supplied to the single-phase induction motor has been described. For example, the single-phase induction motor is not the current waveform supplied to the single-phase induction motor. You may make it measure the waveform of the voltage applied to an electric motor, and obtain | require the phase difference of a voltage waveform and a vibration waveform.

  Next, means for determining whether the air gap is good or bad will be described. Since the unbalanced magnetic attractive force acting on the rotor 102 is determined by the magnitude of the magnetic flux and the amount of eccentricity of the air gap, the relationship between the amount of eccentricity of the air gap and the magnitude of the vibration must be investigated in advance in the direction of measuring the vibration. Thus, the air gap eccentricity can be estimated from the magnitude of the vibration. That is, the air gap eccentricity is measured with a gauge or the like before the rotary compressor 100 is sealed by welding, and the magnitude of vibration when a predetermined AC voltage is applied is measured. The magnitude of vibration and the air gap eccentricity are measured. Data indicating the correlation with the quantity is created.

  After assembling the rotary compressor 100, the direction perpendicular to the magnetic flux induced when the main winding 110 is energized and the direction perpendicular to the magnetic flux induced when the auxiliary winding 111 is energized. Since the air gap eccentricity can be estimated by comparing the magnitude of vibration measured in each of the two directions with the previously prepared data, the air gap eccentricity and the air gap eccentricity as described above can be estimated. Based on the calculation result of the 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.

  With the above-described configuration, according to the present invention, in the completed state of the product in which the positional relationship between the rotor 102 and the stator 103 cannot be directly visually observed, there are variations and disturbances in processing and assembly for each single-phase induction motor. Even in this case, the air gap eccentricity state can be accurately inspected without incorporating noise removing means such as a noise filter in the drive circuit or the measurement system.

Embodiment 2. FIG.
In the present embodiment, only one of the main winding 110 and the auxiliary winding 111 is used as a winding through which a current flows during measurement, and the air gap eccentric direction and the air gap eccentric amount when the rotor 102 is in the locked state. Is to inspect. A rotary compressor 100 including a single-phase induction motor is the same as that shown in FIGS. 1 and 2, and a rotary compressor 100 for a refrigeration / air-conditioner that includes a single-phase induction motor is a single unit to be measured. The external appearance of the air gap eccentricity inspection device for the phase induction motor is the same as that shown in FIGS. 3 and 4, but the drive circuit is different.

  15 and 16 are circuit diagrams showing a drive circuit in an air gap eccentricity inspection apparatus according to Embodiment 2 of the present invention. In the figure, a main winding energization switch is used as a drive circuit for flowing current through the rotary compressor 100. 151 and an auxiliary winding energizing switch 152 are provided. In the drive circuit diagram shown in FIG. 15, when the main winding switch 151 is on and the auxiliary winding switch 152 is off, a current flows only through the main winding 110. In the drive circuit diagram shown in FIG. 16, when the main winding switch 151 is off and the auxiliary winding switch 152 is on, a current flows only through the auxiliary winding 111.

  In the present embodiment, the switching of the drive circuit is different from that in the first embodiment. That is, in the first embodiment, an AC voltage is applied to the motor and the rotor 102 is rotated. However, in this embodiment, the AC voltage is applied only to the main winding 110 or the auxiliary winding 111. The rotor 102 does not rotate and vibrates in a locked state.

  In the switching of the drive circuit of STEP 504 in the first embodiment, as shown in FIG. 6, the connection destination of the main winding switch 144 is the contact 143 side, and the connection destination of the auxiliary winding switch 145 is the contact 146 side. The auxiliary winding resistor 148 and the auxiliary winding capacitor 149 are connected in series with the auxiliary winding 111. On the other hand, in the present embodiment, as shown in FIG. 15, the main winding energization switch 151 is turned on and the auxiliary winding energization switch 152 is turned off, so that only the main winding 110 has a current. I was allowed to flow.

  In the switching of the drive circuit of STEP 700 in the first embodiment, as shown in FIG. 12, the connection destination of the main winding switch 144 is the contact 142 side, and the connection destination of the auxiliary winding switch 145 is the contact 147 side. The main winding resistor 141 and the main winding capacitor 140 are connected in series with the main winding 110. On the other hand, in the present embodiment, as shown in FIG. 16, the main winding energization switch 151 is turned off and the auxiliary winding energization switch 152 is turned on to supply current only to the auxiliary winding 111. I was allowed to flow.

  With the configuration described above, when an AC voltage is applied to the single-phase induction motor, the rotor 102 is locked without rotating, and the air gap eccentric direction and eccentricity are estimated from the vibration waveform and current waveform in the locked state. can do. The means for estimating the air gap eccentric direction and the amount of eccentricity is the same as described in the first embodiment.

  In this embodiment, since vibration is measured in a locked state where the rotor 102 does not rotate, for example, even when there is not enough lubricating oil between the main shaft 105 and the main bearing (not shown), the main bearing (not shown). Without being damaged, the air gap eccentric direction and the air gap eccentric amount can be measured.

Embodiment 3 FIG.
In the present embodiment, the air gap eccentric direction and the air gap eccentric amount are accurately inspected by adjusting the frequency of the voltage applied during measurement. A rotary compressor 100 including a single-phase induction motor is the same as that shown in FIGS. 1 and 2, and a rotary compressor 100 for a refrigeration / air-conditioner that includes a single-phase induction motor is a single unit to be measured. The external appearance of the air gap eccentricity inspection apparatus for the phase induction motor is the same as that shown in FIGS. 3 and 4, but the drive circuit is different. In this embodiment, a frequency adjuster 153 is added. .

  17 and 18 are circuit diagrams showing a drive circuit in an air gap eccentricity inspection apparatus according to Embodiment 3 of the present invention. In the switching of the drive circuit of STEP 504 in the first embodiment, as shown in FIG. 6, the connection destination of the main winding switch 144 is the contact 143 side, and the connection destination of the auxiliary winding switch 145 is the contact 146 side. The auxiliary winding resistor 148 and the auxiliary winding capacitor 149 are connected in series to the auxiliary winding 111, and the voltage is adjusted by the voltage regulator 134 so that the voltage becomes a specific voltage.

  In contrast, in the present embodiment, as shown in FIG. 17, the connection destination of the main winding switch 144 is on the contact 143 side, and the connection destination of the auxiliary winding switch 145 is on the contact 146 side. An auxiliary winding resistor 148 and an auxiliary winding capacitor 149 are connected in series with the line 111. After that, the frequency adjuster 153 adjusts the power supply frequency to a specific frequency, and the voltage adjuster 134 adjusts the voltage so that it becomes a specific voltage.

  In the switching of the drive circuit of STEP 700 in the first embodiment, as shown in FIG. 12, the connection destination of the main winding switch 144 is the contact 142 side and the connection destination of the auxiliary winding switch 145 is the contact 147 side. The main winding resistor 141 and the main winding capacitor 140 are connected in series to the main winding 110, and then the voltage is adjusted to a specific voltage by the voltage regulator 134.

  In contrast, in the present embodiment, as shown in FIG. 18, the main winding switch 144 is connected to the contact 142 side, and the auxiliary winding switch 145 is connected to the contact 147 side. The main winding resistor 141 and the main winding capacitor 140 are connected in series to the line 110, and then the power supply frequency is adjusted to a specific frequency by the frequency regulator 153, and the voltage is adjusted to a specific voltage by the voltage regulator 134. To adjust.

  Here, the size of the auxiliary winding resistor 148, the capacity of the auxiliary winding capacitor 149, the size of the main winding resistor 141, the capacity of the main winding capacitor 140, the power supply frequency adjusted by the frequency adjuster 153, and The magnitude of the voltage adjusted by the voltage regulator 153 is the size of the resistor, the capacitance of the capacitor, and the magnitude of the voltage adjusted so that the rotor 102 rotates at a rotation period equal to or less than 2/3 of the period of the magnetic flux. And combinations of various values. In addition, a voltage regulator, a capacitor, and a resistor are used as means for adjusting the magnetic flux induced by each winding here, but a current regulator that adjusts the current of the winding may be used.

  In the present embodiment, when an integer multiple of the power supply frequency is equal to the natural frequency of the single-phase induction machine, a resonance phenomenon occurs, the measured vibration becomes large, and the direction of vibration becomes difficult to determine. However, by adjusting the power supply frequency by the frequency adjuster 153, measurement can be performed while avoiding the resonance frequency, and the quality of the air gap eccentricity state can be accurately determined.

  In the first or third embodiment, the fixed impedance type capacitor and resistor are incorporated in the drive circuit. However, a variable type capacitor and resistor may be used. A drive circuit that can be used for a phase induction machine can be configured at a relatively low cost. In the first or third embodiment, as a means for adjusting the ratio of the magnitude of the magnetic flux induced by the main winding 110 generated when an alternating current flows and the magnitude of the magnetic flux induced by the auxiliary winding 111 Although an example using a capacitor and a resistor has been shown, the reactance may be connected to adjust the impedance of each winding.

  Further, FIG. 3 shows the case where the acceleration pickups 122a and 122b, which are types that measure vibrations by being pressed against a measuring body, are used, but a type that is attached by a magnet or an adhesive may be used. Since it is not necessary to install a clamping mechanism and a cylinder for clamping the shell 104, the inspection apparatus can be configured at low cost.

  FIG. 3 shows an example in which the vibration measured by the acceleration pickups 122a and 122b is amplified by the amplifier 131. However, the acceleration pickup is configured to have a built-in preamplifier, and a function for supplying power to the preamplifier is provided separately. The amplifier 131 may not be provided outside.

  Further, although the case where the acceleration pickups 122a and 122b are provided as the means for detecting the vibration is illustrated, for example, a vibration detecting means of a type that detects the vibration from the displacement or position information may be installed. Further, although FIG. 3 shows a case where clamp-type ammeters 121a and 121b are provided as ammeters for measuring the current, an ammeter may be incorporated in the drive circuit in advance.

Embodiment 4 FIG.
In the present embodiment, the rotor 102 is locked by using only the main winding 110 or the auxiliary winding 111 as a winding to which a voltage is applied during measurement, and the frequency adjuster 153 is used to set the frequency of the voltage applied during measurement. By adjusting, the air gap eccentric direction and the air gap eccentric amount are accurately inspected.

  A rotary compressor 100 including a single-phase induction motor is the same as that shown in FIGS. 1 and 2, and a rotary compressor 100 for a refrigeration / air-conditioner that includes a single-phase induction motor is a single unit to be measured. The external appearance of the air gap eccentricity inspection apparatus for the phase induction motor is the same as that shown in FIGS. 3 and 4, but the drive circuit is different and a frequency adjuster 153 is provided.

  19 and 20 are circuit diagrams showing a drive circuit in an air gap eccentricity inspection apparatus according to Embodiment 4 of the present invention. In the figure, a main winding energizing switch is used as a drive circuit for flowing current through the rotary compressor 100. 151 and an auxiliary winding energizing switch 152 are provided. In the drive circuit diagram shown in FIG. 19, when the main winding switch 151 is on and the auxiliary winding switch 152 is off, a current flows only through the main winding 110. In the drive circuit diagram shown in FIG. 20, when the main winding switch 151 is off and the auxiliary winding switch 152 is on, a current flows only through the auxiliary winding 111.

  In the following description of the operation in the present embodiment, differences from the second embodiment will be described. In the second embodiment, as shown in FIG. 15, the main winding energization switch 151 is turned on, the auxiliary winding energization switch 152 is turned off, and a current is supplied only to the main winding 110. Thereafter, the voltage regulator The voltage is adjusted to a specific voltage by 134.

  On the other hand, in the present embodiment, as shown in FIG. 19, the main winding energization switch 151 is turned on and the auxiliary winding energization switch 152 is turned off so that a current flows only through the main winding 110. Thereafter, the frequency adjuster 153 adjusts the power supply frequency to a specific frequency, and the voltage adjuster 134 further adjusts the voltage to a specific voltage.

  In the second embodiment, as shown in FIG. 16, the main winding energization switch 151 is turned off and the auxiliary winding energization switch 152 is turned on so that a current flows only through the auxiliary winding 111. After that, the voltage is adjusted by the voltage regulator 134 so as to become a specific voltage.

  On the other hand, in the present embodiment, as shown in FIG. 20, the main winding energization switch 151 is turned off and the auxiliary winding energization switch 152 is turned on so that the current flows only through the auxiliary winding 111. After that, the frequency regulator 153 adjusts the power supply frequency to a specific frequency, and the voltage regulator 134 adjusts the voltage so as to become a specific voltage.

  Here, the power supply frequency adjusted by the frequency adjuster 153 and the magnitude of the voltage adjusted by the voltage adjuster 134 are such that the power supply frequency is not an integral multiple of the natural frequency of the single-phase induction motor, and is affected by noise. Are adjusted to be minute, and there are various combinations of values. Further, here, the voltage regulator 134 is used as a means for adjusting the magnetic flux induced by each winding, but a current regulator for adjusting the current of the winding may be used.

  In this embodiment, as in the case of the second embodiment, vibration is measured in a locked state where the rotor 102 does not rotate. For example, when there is not enough lubricating oil between the main shaft 105 and the main bearing (not shown). However, the air gap eccentric direction and the air gap eccentric amount can be measured without damaging the main bearing (not shown).

  Further, in the present embodiment, as in the case of the third embodiment, when an integer multiple of the power supply frequency is equal to the natural frequency of the single-phase induction machine, a resonance phenomenon occurs and the measured vibration becomes large, and the vibration However, by adjusting the power supply frequency by the frequency adjuster 153, it is possible to measure while avoiding the resonance frequency, and it is possible to accurately determine whether the air gap is eccentric. It becomes like this.

Embodiment 5 FIG.
In the present embodiment, a method of correcting after checking the air gap eccentricity will be described. FIG. 21 is a sectional view showing a uv coordinate system for two-dimensionally expressing the air gap eccentric state, and FIG. 22 is a sectional view showing a method for correcting 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 eccentric state of the air gap of the rotary compressor 100 is also the case of the first embodiment. Is the same. Hereinafter, a method for correcting the air gap eccentric state 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. 21, 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 STEP 509 in FIG. 5 are represented by coordinates on the u-axis, and the main winding direction calculated in STEP 705 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 corrected 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 corrected by heating from a narrow direction of the air gap and adjusting the heating amount according to the air gap eccentric amount.

  Although the method of heating with the burner 160 is shown in FIG. 22, 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 corrected 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, for example, a hammer.

1 is a longitudinal sectional view showing a rotary compressor 100 for a refrigeration / air conditioner having therein a single-phase induction motor according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is sectional drawing which shows the air gap eccentricity inspection apparatus of the single phase induction motor which used the rotary compressor 100 for refrigeration and an air conditioning machine which has a single phase induction motor as a to-be-measured body. It is a BB line horizontal direction sectional view in FIG. It is a flowchart which shows the air gap inspection method. It is a circuit diagram which shows the drive circuit in an air gap eccentricity inspection apparatus. It is a flowchart which shows the air gap inspection method. It is a graph which shows the example of the measured current waveform and vibration waveform. It is the graph which expanded and showed the current half wavelength part in FIG. It is a graph which shows distribution of the time difference of the extreme value of a current waveform and a vibration waveform, and the number of extreme values which have shifted. It is a flowchart which shows the air gap inspection method. It is a circuit diagram which shows the drive circuit in an air gap eccentricity inspection apparatus. It is a flowchart which shows the air gap inspection method. It is a graph which shows the typical example of a current waveform and a vibration waveform. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 2 of this invention. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 2 of this invention. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 3 of this invention. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 3 of this invention. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 4 of this invention. It is a circuit diagram which shows the drive circuit in the air gap eccentricity inspection apparatus by Embodiment 4 of this invention. It is sectional drawing which shows the uv coordinate system for expressing the air-gap eccentric state by Embodiment 5 of this invention two-dimensionally. It is sectional drawing which shows the method for correcting an air gap eccentric state.

Explanation of symbols

101 air gap, 102 rotor, 103 stator, 104 shell,
105 main shaft, 110 main winding, 111 auxiliary winding, 121a, 121b ammeter,
122a, 122b accelerometer, 134 voltage regulator,
153 Frequency adjuster.

Claims (7)

  An air gap eccentricity inspection apparatus for a single-phase induction motor comprising a rotor that rotates together with a main shaft, and a stator that is provided with a main winding and an auxiliary winding and has an air gap between the rotor and the main winding. Means for applying an AC voltage to the winding and the auxiliary winding; current measuring means for measuring a current waveform of a current flowing through the main winding and the auxiliary winding; and the AC voltage applied to the main winding and the auxiliary winding. A vibration measuring means for measuring a vibration waveform of a single-phase induction motor in a direction in which the unbalanced magnetic attractive force generated in the rotor is maximized when applied, and an eccentric amount of the air gap based on the amplitude of the vibration waveform And calculating the eccentric direction of the air gap according to the time change of the phase difference between the vibration waveform and the current waveform, and based on the calculated eccentric amount and the eccentric direction of the air gap. Air gap eccentricity inspection apparatus of the single-phase induction motor, characterized in that a determination means for determining acceptability of said air gap.   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. An air gap eccentricity inspection apparatus for a single-phase induction motor according to claim 1, further comprising a drive circuit for rotating the rotor in a state larger than the magnetic flux.   3. An air gap eccentricity inspection apparatus for a single-phase induction motor according to claim 2, further comprising a drive circuit for rotating the rotor at a rotation cycle equal to or less than 2/3 of the frequency of the AC voltage to be applied.   2. The single-phase circuit according to claim 1, further comprising a drive circuit capable of applying an alternating voltage to only one of the main winding and the auxiliary winding and switching the winding to which the alternating voltage is applied. Air gap eccentricity inspection device for induction motors.   The air gap eccentricity inspection device for a single-phase induction motor according to any one of claims 1 to 4, further comprising a voltage adjustment mechanism for changing the AC voltage.   The air gap eccentricity inspection device for a single-phase induction motor according to any one of claims 1 to 5, further comprising a frequency conversion mechanism for changing the frequency of the AC voltage.   An air gap correction method for 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 and the rotor. When AC voltage is applied to the main and auxiliary windings to measure the current waveform of the current flowing through the main and auxiliary windings, and when the AC voltage is applied to the main and auxiliary windings , Measuring the vibration waveform of the vibration of the single-phase induction motor in the direction in which the unbalanced magnetic attractive force generated in the rotor is maximized, and calculating the amount of eccentricity of the air gap based on the amplitude of the measured vibration waveform; The eccentric direction of the air gap is calculated from the time variation of the phase difference between the measured vibration waveform and the measured current waveform, and is calculated based on the calculated eccentric amount and the eccentric direction of the air gap. The air gap of the single-phase induction motor is characterized by determining whether the air gap is good or not and correcting the air gap of the single-phase induction motor by deforming the shell to which the stator is fixed based on the determination result. How to fix.

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