JP4878920B2 - Air gap eccentricity measuring apparatus for motor and air gap eccentricity measuring method - Google Patents

Description

  The present invention relates to an air gap eccentricity measuring device and an air gap eccentricity measuring method for an electric motor used for a compressor or the like.

In this type of conventional air gap eccentricity measuring device and air gap eccentricity measuring method, the vibration waveform before starting the rotation of the motor is detected and the direction of the air gap eccentricity is determined, but in order to accurately measure the vibration waveform Needed a highly accurate vibration measurement system.
For example, in the air gap eccentricity measuring method disclosed in Patent Document 1, vibration detection sensors are mounted in a maximum suction direction by a main winding of an electric motor and in a phase angle direction of 90 degrees with respect to the maximum suction direction. The amount and direction of the rotor air gap deviation of the motor are determined based on the strength and direction of vibration generated in the locked state before the start of rotation obtained by the detection sensor. According to this method, since there is a minimum air gap of the rotor portion in the direction of vibration that occurs before the start of rotation at the start of the electric motor, the signal waveform detected by the first sensor or detected by the second sensor By observing the rising edge of the vibration signal of each of the signal waveforms, the direction in which the rotor falls, that is, the air gap eccentric direction can be measured.

JP-A-6-284655

  However, in the prior art as described above, when measuring the air gap eccentric direction, the calculation is performed by observing the rising edge of the vibration waveform detected by the acceleration sensor. When disturbed, it is difficult to determine the vibration direction. Therefore, a highly accurate vibration waveform measurement system for removing the influence of disturbance is required, and the apparatus becomes expensive.

  The present invention has been made to solve the above-described problems, and accurately measures the air gap eccentricity (the amount and direction of eccentricity) without requiring a highly accurate vibration waveform measurement system. It is an object of the present invention to provide an air gap eccentricity measuring device and an air gap eccentricity measuring method for an electric motor that can perform the above-described operation.

  In the air gap eccentricity measuring apparatus of the electric motor according to the present invention, the rotating means for rotating the rotor by applying a voltage to the electric motor in which the rotor is disposed through the air gap in the stator held in the cylindrical casing. A deformation means for locally elastically deforming the outer peripheral portion of the casing in a radial direction of the casing and changing a positional relationship between the rotor and the stator; and disposed on an outer peripheral side surface of the casing; Based on the magnitude of vibration of the rotor before and after the outer periphery of the housing is elastically deformed, and the magnitude of vibration of the rotor measured by the measuring means, the eccentric amount of the air gap and And a calculating means for calculating the eccentric direction.

In the method for measuring the air gap eccentricity of the electric motor according to the present invention, a voltage is applied to the electric motor in which the rotor is disposed through the air gap in the stator held in the cylindrical casing, and the rotor is rotated. A step, a second step of measuring the magnitude of the vibration by a measuring unit that measures vibration from the outer peripheral side surface of the casing, and a deforming unit that elastically deforms the outer peripheral portion of the casing in the radial direction of the casing. A third step of changing a positional relationship between the rotor and the stator;
After the third step, the measurement means again measures the magnitude of vibration from the outer peripheral side surface of the housing, and the magnitude of vibration measured by the second and fourth steps. And a fifth step of calculating an eccentric amount and an eccentric direction of the air gap.

  According to the present invention, even when the electric motor is in a complete state where the positional relationship between the rotor and the stator cannot be directly observed, the housing is elastically deformed in a known direction to change the air gap eccentricity, and before and after the deformation. By measuring the vibration level of the motor, the air gap eccentricity in the deformed direction can be easily calculated, and a highly accurate vibration measurement system is not required. Accurate measurement is possible.

Embodiment 1 FIG.
A motor air gap eccentricity measuring method and an air gap eccentricity measuring apparatus according to Embodiment 1 of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a longitudinal cross-sectional view of a compressor for a refrigeration / air conditioner including a single-phase induction motor as a product example of an electric motor to which the present invention is applied. FIG. 2 is a cross-sectional view seen from the arrow A in FIG.
103 and 105 are main components of the single-phase induction machine, and are called a rotor and a stator, respectively.
A cylindrical space between the rotor 103 and the stator 105 is called an air gap 100. The stator 105 is shrink-fitted and fixed to the shell 102 which is a cylindrical casing (pressure vessel). The rotor 103 is fixed integrally with the main shaft 104 by shrink fitting. The main shaft 104 is supported by a plain bearing (not shown) that is present in the frame 106 and the cylinder head 109. The frame 106 and the cylinder head 109 are fixed to the cylinder 107 with bolts (not shown), and the cylinder 107 is attached to three welding points 108 (only one point is shown in FIG. 1) on the shell 102. Are fixed by welding. A terminal 110 supplies current to the main winding 114 and the auxiliary winding 113 provided in the stator 105. The terminal 110 is fixed to the shell 102 by welding. The shell 102 is fixed with a muffler 112 which is a suction port for gas before compression and a discharge pipe 111 which discharges the compressed gas to the outside by brazing. After the gas before compression is sucked from the muffler 112, the cylinder 107 After being compressed inside and discharged from the frame 106 into the shell 102, it is discharged out of the shell 102 through the discharge pipe 111. Reference numeral 99 denotes a foot portion fixed by welding to the shell 102, and is provided with a reference hole.

FIG. 3 is a schematic configuration diagram of an air gap eccentricity measuring apparatus according to Embodiment 1 in which a compressor for a refrigeration air conditioner including a single-phase induction motor is a measurement target. 4 and 5 are cross-sectional views in the lateral direction as seen from the arrows B and C in FIG.
117 is a connection terminal for energizing the single phase induction motor in the compressor via the terminal 110. Reference numeral 118 denotes an acceleration pickup that measures vibrations generated when energized. As shown in FIG. 4, 90 ° is provided on the outer peripheral side surface of the shell 102 so as to be orthogonal to the winding directions of the main winding 113 and the auxiliary winding 114. They are arranged in two directions with different angles. The acceleration pickup 118 can be moved in the radial direction of the shell 102 by the acceleration pickup forward cylinder 120. When the vibration is measured, the acceleration pickup 118 is pressed against the shell 102 via the pickup vibration isolator 119, and measures the vibration generated when energized.
Reference numeral 129 denotes a pressing portion used to deform the shell 102 and change the air gap. Reference numeral 130 denotes a pressing cylinder that generates a pressing force, and faces the acceleration pickup 118 on the outer peripheral side surface of the shell 102 as shown in FIG. It is arranged below the position to be. Reference numeral 131 denotes a pressing support that supports the pressing force by a surface or a point, and 132 denotes a pressing support cylinder for moving the pressing support 131 in the radial direction of the shell. As shown in FIG. These are disposed at positions facing the pressing cylinder 130.
The positions of the pressing portion 129 and the pressing support 131 can be changed in two stages: a position where the pressing portion 129 and the pressing support 131 are in contact with each other and a position where the shell 102 is deformed to change the air gap eccentric state.
Reference numeral 122 denotes a clamp claw for preventing the compressor from rolling over the measurement unit base plate 125 due to the radial force of the acceleration pickup advance cylinder 120, and the thrust of the clamp cylinder 123 via the clamp vibration isolator 121. Thus, the shell 102 can be gripped from the lateral direction. A workpiece vibration isolator 124 is disposed under the shell 102. An anti-vibration material 126 is disposed below the measurement unit base plate 125 to prevent external vibration from propagating to the measurement unit.
Reference numeral 128 denotes a computer that records the magnitude of vibration generated when power is supplied, calculates an air gap eccentricity amount and eccentricity from the magnitude of vibration, and 116 is a computer display that displays vibration measurement results.
Reference numeral 127 denotes a driving circuit for driving the rotor by applying a voltage to the main winding 114 and the auxiliary winding 113, and 133 is a pedestal for fixing electric devices.

FIG. 6 is a flowchart showing an air gap eccentricity measuring method according to the first embodiment.
The details of the air gap eccentricity measuring method for the single-phase induction motor according to the first embodiment will be described below in accordance with this flowchart.
ST (Step) 1: A work (a compressor for a refrigeration / air conditioner including a single-phase induction motor) is placed on the work vibration isolation material 124.
ST2: The clamp claws 122 on the left and right in the figure are advanced using the clamp cylinder 123, the shell 102 is clamped from the lateral direction, and the workpiece is gripped.
ST3: The acceleration pickup 118 is moved forward by using the acceleration pickup cylinder 120, and the acceleration pickup 118 is pressed against the shell 102 from two directions different from each other by 90 degrees. Then, the two pressing parts 129 and the pressing support 131 are advanced by the pressing part cylinder 130 and the pressing support cylinder 132, respectively, and are brought into contact with the shell 102.
ST4: The connection terminal 117 and the terminal 110 are connected, a voltage is applied by the drive circuit 127, and the rotor 103 is rotated.
ST5: The magnitude of vibration is measured from two directions with the acceleration pickups 118-1 and 118-2, and recorded in the computer 128.
ST6: The pressing portion 129-1 is further advanced to deform the shell 102.
ST7: The magnitude of vibration is measured from the direction of the pressing portion 129-1 with the acceleration pickup 118-1, and recorded in the computer 128.
ST8: The pressing portion 129-1 is retracted to the position in ST3, and then the pressing portion 129-2 is further advanced to deform the shell 102.
ST9: The magnitude of vibration is measured from the direction of the pressing portion 129-2 by the acceleration pickup 118-2 and recorded in the computer 128.
ST10: Based on the magnitude of vibration in ST5, ST7, ST9, the air gap eccentric amount and the air gap eccentric direction are calculated.
ST11: End energization.
ST12: The two acceleration pickups 118 are moved backward using the acceleration pickup advance cylinder 120. Using the pressing part cylinder 130 and the pressing support cylinder 132, the two pressing mechanism pressing parts 129 and the pressing support 131 are moved backward.
ST13: The clamp pawl 122 is moved backward using the clamp cylinder 123.
ST14: Remove the workpiece from the apparatus.
Here, it is desirable to press the pressing force and the pressing position in ST6 and ST8 with a force that does not cause the shell 102 to have a residual strain, that is, a so-called elastic deformation.

In general, when there is an imbalance in the gap in the direction orthogonal to the magnetic flux, the rotor 103 moves in the narrow gap direction.
FIG. 7 is a schematic diagram showing the state of the magnetic field when the magnetic flux induced in the air gap by the main winding 114 is larger than the magnetic flux induced in the air gap by the auxiliary winding 113. In FIG. Since an unbalance occurs in the gap A to gap B direction perpendicular to the winding direction of the wire 114, an unbalanced magnetic attractive force acts in the narrow gap A direction, and the rotor 103 moves in the gap A direction. . Conversely, when the gap B is narrower than the gap A, an unbalanced magnetic attractive force acts in the gap B direction, and the rotor 103 moves in the gap B direction (not shown).

FIG. 8 is a longitudinal cross-sectional view at the position where the acceleration pickup 118 is shown, showing the air gap eccentric state before and after deformation of the shell 102 due to pressing. Since the cylinder 107 is fixed by welding at three welding points 108 (only one point is shown in FIG. 1) on the shell 102, the stator 105 and the cylinder 107 are connected from the outer periphery of the shell 102 as shown in FIG. When the gap is pressed and the shell is deformed in the radial direction of the shell 102, the positions of the stator 105 and the rotor 103 change as shown in the right figure of FIG. Become.
As shown in FIG. 8, when the magnitude of vibration measured in ST7 or ST9 is smaller than the magnitude of vibration measured in ST5, it can be determined that the pressing direction is narrow in the air gap eccentric state before pressing.
Conversely, as shown in FIG. 9, when the magnitude of vibration measured in ST7 or ST9 is larger than the magnitude of vibration measured in ST5, the air gap eccentric state before pressing is narrower in the direction opposite to the pressing direction. I can judge.
As described above, the air gap eccentric direction can be determined from the magnitude of vibration before and after pressing.

For the air gap eccentricity, the relationship between the air gap eccentricity in the direction of each acceleration pickup 118 and the absolute value of the vibration magnitude is investigated in advance, and based on the vibration magnitude measured in ST5. The air gap eccentricity can be calculated.
FIG. 10 is a schematic diagram showing the relationship between the magnitude of vibration and the amount of air gap eccentricity in the direction perpendicular to the magnetic flux.
That is, the magnitude of vibration of the acceleration pickup 118-1 of ST5 is F1, the magnitude of vibration of the acceleration pickup 118-2 of ST5 is F2, and the air gap obtained from the magnitude of vibration in the direction of the acceleration pickup 118-1. Assuming that the amount of eccentricity is Y (F1) and the amount of air gap eccentricity obtained from the magnitude of vibration in the direction of the acceleration pickup 118-2 is X (F2), the vector representing the eccentric state of the air gap obtained in ST10 is as follows: Calculated as in equation (1).
(Sign (F2) x X (F2), Sign (F1) x Y (F1)) ... (1)
Here, Sign (F1) and Sign (F2) are signs (+ or-) indicating the air gap eccentric direction obtained by comparing the values of ST5, ST7 and ST9 as shown in FIG. 8 or FIG.

  As described above, according to the air gap eccentricity measuring apparatus of the electric motor of the first embodiment, a voltage is applied to the electric motor in which the rotor is disposed through the air gap in the stator held in the cylindrical casing. A rotating means for rotating the rotor; a deforming means for locally elastically deforming the outer periphery of the casing in a radial direction of the casing; and changing a positional relationship between the rotor and the stator; and an outer periphery of the casing Measuring means for measuring the magnitude of vibration of the rotor before and after elastically deforming the outer periphery of the housing by the deforming means, and the magnitude of vibration of the rotor measured by the measuring means. Based on the above, the calculation means for calculating the eccentric amount and the eccentric direction of the air gap is provided, so that the air gap eccentric amount and the eccentric direction of the motor can be accommodated without requiring a highly accurate vibration measurement system. And it can be accurately measured.

Embodiment 2. FIG.
FIG. 11 is a schematic configuration diagram showing an air gap eccentricity measuring apparatus according to Embodiment 2 of the present invention. 12 is a cross-sectional view in the lateral direction as viewed from the arrow D in FIG. The cross-sectional view in the horizontal direction seen from the arrow B in FIG. 11 is the same as FIG.
In the second embodiment, as a means for deforming the shell 102, the shell 102 is heated and deformed instead of the pressing mechanism (the pressing portion 129, the pressing cylinder 130, the pressing support 131, and the pressing support cylinder 132) of the first embodiment. There is a heating torch 134 that can The heating torch 134 is a kind of gas burner, and is disposed away from the outer periphery of the shell 102 and can be heated without contacting the shell 102.

FIG. 13 is a flowchart showing an air gap eccentricity measuring method according to the second embodiment.
The details of the air gap eccentricity measuring method will be described below according to this flowchart.
ST1-1: A work (a compressor for a refrigeration / air conditioner including a single-phase induction motor) is placed on the work vibration isolation material 124.
ST2-2: Using the clamp cylinder 123, the clamp claws 122 on the left and right in the figure are advanced, the shell 102 is clamped from the lateral direction, and the workpiece is gripped.
ST3-2: The acceleration pickup 118 is advanced by using the acceleration pickup cylinder 120, and the acceleration pickup 118 is pressed against the shell 102 from two directions different from each other by 90 degrees.
ST4-2: The connection terminal 117 and the terminal 110 are connected, energized by the drive circuit 127, and the rotor is rotated.
ST5-2: The magnitude of vibration in two directions is measured by the acceleration pickup 118-1 and the acceleration pickup 118-2, and recorded in the computer 128.
ST6-2: The shell 102 is heated and deformed in the direction of the acceleration pickup 118-1 by the heating torch 134-1, and the magnitude of vibration in the direction of the acceleration pickup 118-1 during heating is measured and recorded in the computer 128.
ST7-2: Heating of the heating torch 134-1 is stopped and cooled.
ST8-2: The shell 102 is heated and deformed in the direction of the acceleration pickup 118-2 by the heating torch 134-2, and the magnitude of vibration in the direction of the acceleration pickup 118-2 during heating is measured and recorded in the computer 128.
ST9-2: The heating of the heating torch 134-2 is stopped, and the air gap eccentric amount and the air gap eccentric direction are calculated based on the magnitude of vibration in ST5-2, ST6-2, and ST8-2.
ST10-2: The two acceleration pickups 118 are moved backward using the acceleration pickup cylinder 120.
ST11-2: Retract the clamp pawl 122 using the clamp cylinder 123. ST12-2: Remove the workpiece from the apparatus.
Here, since the heating torch 134 does not directly contact the shell 102 in ST5-2, the magnitude of the vibration can be accurately measured without attenuating the vibration.
In ST6-2 or ST8-2, it is desirable that the amount of heat does not cause plastic strain due to heat, that is, the amount of heat that causes so-called thermoelastic deformation.

FIG. 14 is a longitudinal cross-sectional view at the position where the acceleration pickup 118 is shown, showing the air gap eccentric state before and after deformation of the shell 102 by heating. Since the cylinder 107 is welded and fixed to the shell 102 at three welding points 108 (only one point is shown in FIG. 1), the shell 102 is interposed between the stator 105 and the cylinder 107 as shown in FIG. When the shell is heated and deformed in the radial direction from the outer periphery, the shell 102 locally expands, the positions of the stator 105 and the rotor 103 change as shown in the right side of FIG. 14, and the position where the air gap 100 is wide is heated. It becomes narrower in the direction (direction of the heating torch 134).
As shown in FIG. 14, when the magnitude of vibration measured in ST6-2 or ST8-2 is smaller than the magnitude of vibration measured in ST5-2, the air gap eccentric state before heating has a wide heating direction. It can be judged.
On the contrary, as shown in FIG. 15, when the magnitude of vibration measured in ST6-2 or ST8-2 is larger than the magnitude of vibration measured in ST5-2, the air gap eccentric state before heating is in the heating direction. It can be judged that the opposite direction is wide.

Here, the magnitude of vibration of the acceleration pickup 118-1 of ST5-2 is F1, the magnitude of vibration of the acceleration pickup 118-2 of ST5-2 is F2, and the magnitude of vibration in the direction of the acceleration pickup 118-1. The air gap eccentricity obtained in ST9-2 is Y (F1), and the air gap eccentricity obtained from the magnitude of vibration in the direction of the acceleration pickup 118-2 is X (F2). A vector representing the state is calculated as in the following equation (2).
(Sign (F2) x X (F2), Sign (F1) x Y (F1)) (2)
Here, Sign (F1) and Sign (F2) are signs (+) indicating the air gap eccentric direction obtained by comparing the values of ST5-2, ST6-2, and ST8-2 as shown in FIG. Or-).

  As described above, according to the second embodiment, the heating torch 134 is used as a means for elastically deforming the shell 102, and the shell 102 can be deformed in a non-contact manner, so that the air gap eccentric state can be accurately calculated.

Embodiment 3 FIG.
FIG. 16 is a schematic configuration diagram of an air gap eccentricity measuring apparatus according to the third embodiment. 17 and 18 are cross-sectional views in the lateral direction as seen from arrows E and F in FIG.
In FIG. 16, reference numeral 135 denotes a work rotation table for rotating a work, and the work can be rotated by a motor (not shown) in a specific angle direction. Reference numeral 136 denotes a rotary shaft, which is located at the rotation center of the rotary table 135.

FIG. 19 is a flowchart showing an air gap eccentricity measuring method according to the third embodiment.
The details of the air gap eccentricity measuring method will be described below according to this flowchart.
ST1-3: A work (a compressor for a refrigeration / air conditioner including a single-phase induction motor) is placed on the work vibration isolation material 124. The position of the workpiece is positioned at the rotation center of the rotary table 135.
ST2-3: Using the clamp cylinder 123, the clamp claws 122 on the left and right in the drawing are advanced, the shell 102 is clamped from the lateral direction, and the workpiece is gripped.
ST3-3: The acceleration pickup 118 is moved forward using the acceleration pickup cylinder 120, and the acceleration pickup 118 is pressed against the shell 102 from two directions different from each other by 90 degrees. Then, the pressing part 129 and the pressing support 131 are advanced by the pressing part cylinder 130 and the pressing support cylinder 132 and brought into contact with the shell 102.
ST4-3: The connection terminal 117 and the terminal 110 are connected, and the drive circuit 127 is energized to rotate the rotor.
ST5-3: The magnitude of vibration is measured by the acceleration pickup 118 and recorded in the computer 128.
ST6-3: The pressing portion 129 is further advanced to deform the shell 102.
ST7-3: The magnitude of vibration in the direction of the pressing portion 129 is measured by the acceleration pickup 118 and recorded in the computer 128.
ST8-3: The acceleration pickup 118 is moved backward using the acceleration pickup cylinder 120. Using the pressing part cylinder 130 and the pressing support cylinder 132, the pressing part 129 and the pressing support 131 are moved backward.
ST9-3: Retract the clamp pawl 122 using the clamp cylinder 123. ST10-3: Rotate the workpiece in a specific direction. The above ST2-3 to ST9-3 are performed a plurality of times (the total number of measurements is N (an integer of 2 or more))
ST11-3: Energization is terminated, and the air gap eccentric amount and the air gap eccentric direction are calculated from the magnitudes of vibrations of ST5-3 (existing a plurality of times) and ST7-3 (existing a plurality of times).
ST12-3: The work is removed from the apparatus.
Here, it is desirable that the pressing force and the pressing position of ST6-3 be pressed with a force that does not cause the shell 102 to have a residual strain, that is, a so-called elastic deformation.
In ST10-3, the work is rotated by a motor (not shown) on the rotary table 135, but may be performed by a person instead of the motor if the rotation angle is known.

In ST10-3, performing ST2-3 to ST9-3 a plurality of times has the following effects.
The measurement result of ST5-3 obtained at the rotation angle rotated by ST10-3 (assumed to be θn, where n represents the nth number of measurements and θn is the rotation angle of the nth measurement). F (θ (n)), air gap eccentricity calculated by the magnitude of vibration in each direction of accelerometer 118, Xn (F (θn)), Sign (F (θn)), each rotation as shown in the figure When the sign (+ or-) indicating the direction obtained by comparing the values of ST5-3 and ST7-3 for each angle is used, the air gap eccentricity amount for each rotation angle calculated by ST5-3 and ST7-3 and A vector representing the eccentric direction is expressed by the following equation (3).
(Sign (F (θn)) × Xn (F (θn)) × cos (θn), Sign (F (θn))
× Xn (F (θn)) × sin (θn)) (3)

  Here, a vector representing the eccentric state of the air gap obtained in ST11-3 is calculated as in the following equation (4).

ここで、Xn は、あらかじめ各回転角度毎にてエアギャップ偏心量と振動の大きさとの関係から求めることができる計算式である。
また、エアギャップの偏心状態を表すベクトル成分の分母は、Sign(F(θn))×Xn(F(θn))×cos(θn)またはSign(F(θn))×Xn(F(θn))×sin(θn)の値についてnを1からN（Nは全計測回数）に変えたときの総和を示す。

Here, Xn is a calculation formula that can be obtained in advance from the relationship between the amount of eccentricity of the air gap and the magnitude of vibration for each rotation angle.
Also, the denominator of the vector component representing the eccentric state of the air gap is Sign (F (θn)) × Xn (F (θn)) × cos (θn) or Sign (F (θn)) × Xn (F (θn) ) × sin (θn) The total value when n is changed from 1 to N (N is the total number of measurements).

  As described above, according to the third embodiment, the air gap eccentric amount and the eccentric direction can be calculated for each of a plurality of rotation angles, and the average can be obtained, and the air gap eccentric direction and the air gap eccentric amount can be accurately calculated. Can be calculated.

Embodiment 4 FIG.
FIG. 20 is a schematic configuration diagram of an air gap eccentricity measuring apparatus according to the fourth embodiment. 21 is a cross-sectional view in the lateral direction as viewed from the arrow G in FIG. The cross-sectional view in the horizontal direction seen from the arrow E in FIG. 20 is the same as FIG.
In FIG. 20, reference numeral 135 denotes a work rotation table for rotating a work, and the work can be rotated by a motor (not shown) in a specific angle direction. Reference numeral 136 denotes a rotary shaft, which is located at the rotation center of the rotary table 135.

FIG. 22 is a flowchart showing an air gap eccentricity measuring method according to the fourth embodiment.
The details of the air gap eccentricity measuring method will be described below according to this flowchart.
ST1-4: A work (a compressor for a refrigeration / air conditioner including a single-phase induction motor) is placed on the work vibration isolation material 124. The position of the workpiece is positioned at the rotation center of the rotary table 135.
ST2-4: The clamp claws 122 on the left and right in the drawing are advanced using the clamp cylinder 123, the shell 102 is clamped from the lateral direction, and the workpiece is gripped.
ST3-4: The acceleration pickup 118 is moved forward using the acceleration pickup cylinder 120, and the acceleration pickup 118 is pressed against the shell 102 from two directions different from each other by 90 degrees.
ST4-4: The connection terminal 117 and the terminal 110 are connected, and the drive circuit 127 is energized to rotate the rotor.
ST5-4: The magnitude of vibration is measured by the acceleration pickup 118 and recorded in the computer 128.
ST6-4: The shell 102 is heated and deformed in the direction of the acceleration pickup 118 by the heating torch 134, and the magnitude of vibration in the direction of the acceleration pickup 118 during heating is measured and recorded in the computer 128.
ST7-4: Heating of the heating torch 134 is stopped and cooled.
ST8-4: The acceleration pickup 118 is moved backward using the acceleration pickup cylinder 120.
ST9-4: Retract the clamp pawl 122 using the clamp cylinder 123. ST10-4: Rotate the workpiece in a specific direction. The above ST2-4 to ST9-4 are repeated a plurality of times (the total number of measurements is N (an integer of 2 or more)).
ST11-4: The energization is terminated, and the air gap eccentric amount and the air gap eccentric direction are calculated from the magnitude of the vibration of ST5-4 (existing plural times) and ST6-4 (existing plural times).
ST12-4: Remove the workpiece from the apparatus.
Here, in ST5-4, since the heating torch 134 does not directly contact the shell 102, the magnitude of the vibration can be accurately measured without damping the vibration.
Here, ST6-4 is desirably an amount of heat that does not cause plastic strain due to heat, that is, an amount of heat that causes so-called thermoelastic deformation.
In ST10-4, the work is rotated by a motor (not shown) on the rotary table 135. However, if the rotation angle is known, a person may perform the work instead of the motor.

Performing ST2-4 to ST9-4 a plurality of times in ST10-4 has the following effects.
Measurement result of ST5-4 obtained at a certain rotation angle rotated by ST10-4 (assumed to be θn, n represents the number of times of the nth measurement, and θn is the rotation angle of the nth measurement). F2 (θn), and the air gap eccentricity calculated by the magnitude of vibration in each direction of the acceleration pickup 118 as Xn (F2 (θn)) and Sign (F2 (θn)) for each rotation angle as shown in the figure Is a sign (+ or-) indicating a direction obtained by comparing the values of ST5-4 and ST6-4, and the air gap eccentricity amount and the eccentric direction for each rotation angle calculated by ST5-4 and ST6-4. The vector representing is expressed by the following equation (5).
(Sign (F (θn)) × Xn (F2 (θn)) × cos (θn), Sign (F2 (θn))
× Xn (F2 (θn)) × sin (θn)) (5)

  Here, a vector representing the eccentric state of the air gap obtained in ST11-4 is calculated as in the following equation (6).

ここで、Xn は、あらかじめ各回転角度毎にてエアギャップ偏心量と振動の大きさとの関係から求めることができる計算式である。
ここでエアギャップの偏心状態を表すベクトル成分の分母は、Sign(F2(θn))×Xn(F2(θn))×cos(θn)またはSign(F2(θn))×Xn(F2(θn)) ×sin(θn)の値についてnを1からN（Nは全計測回数）に変えたときの総和を示す。

Here, Xn is a calculation formula that can be obtained in advance from the relationship between the amount of eccentricity of the air gap and the magnitude of vibration for each rotation angle.
Here, the denominator of the vector component representing the eccentric state of the air gap is Sign (F2 (θn)) × Xn (F2 (θn)) × cos (θn) or Sign (F2 (θn)) × Xn (F2 (θn) ) Xsin (θn) indicates the total when n is changed from 1 to N (N is the total number of measurements).

  As described above, according to the fourth embodiment, since the average value is calculated from each measurement value, the air gap eccentric direction and the air gap eccentric amount can be calculated with high accuracy from the magnitude of vibration during heating before heating.

In the second and fourth embodiments, the heating torch 134 of the gas burner is shown as an example of the heating means. However, it is sufficient that a heat quantity that does not cause plastic strain due to heat, that is, a heat quantity that causes so-called thermoelastic deformation. For example, a high-frequency heater or an arc welder may be used.
In the first to fourth embodiments, the vibration is measured from the opposite direction of the pressing portion 129 or the heating torch 134. However, the same as the pressing portion 129 or the heating torch 134 as shown in FIG. You may measure from the direction.
Moreover, in each schematic diagram of the said Embodiment 1-4, although the press part 129 or the heating torch 134 has deform | transformed a part of outer periphery of the shell 102 between the stator 105 and the cylinder 107 locally, As long as the air gap eccentricity can be changed in a known direction, it is obvious that other locations are possible.
In the first to fourth embodiments, the acceleration pickup is used when measuring the magnitude of vibration. However, it may be one that can detect speed or displacement.

It is a longitudinal direction sectional view of a compressor which has a single phase induction motor which is a measured object. It is sectional drawing seen from the arrow A direction of FIG. It is a schematic block diagram of the air gap measuring device which concerns on Embodiment 1 of this invention. FIG. 4 is a cross-sectional view seen from the direction of arrow B in FIG. 3 according to the first embodiment. FIG. 4 is a cross-sectional view seen from the direction of arrow C in FIG. 3 according to the first embodiment. 3 is a flowchart showing an air gap measurement method according to Embodiment 1. FIG. It is the schematic diagram which showed the relationship between the strength of vibration and the air gap eccentricity of the direction orthogonal to magnetic flux. FIG. 5 is a schematic diagram showing a state of an air gap change when vibration is reduced after pressing in the first or third embodiment. FIG. 5 is a schematic diagram showing an air gap change when vibration increases after pressing in the first or third embodiment. It is explanatory drawing which showed the relationship between the magnitude | size of a vibration, and the air gap eccentricity of the direction orthogonal to magnetic flux. It is a schematic block diagram of the air gap measuring device which concerns on Embodiment 2 of this invention. It is sectional drawing seen from the arrow D direction of FIG. 6 is a flowchart showing an air gap measurement method according to Embodiment 2. FIG. FIG. 6 is a schematic diagram showing how the air gap changes when vibration is reduced during heating in the second or fourth embodiment. FIG. 6 is a schematic diagram showing how an air gap changes when vibration increases during heating in the second or fourth embodiment. It is a schematic block diagram of the air gap measuring device which concerns on Embodiment 3 of this invention. It is sectional drawing seen from the arrow E direction of FIG. It is sectional drawing seen from the arrow F direction of FIG. FIG. 6 is a flowchart showing an air gap measurement method according to Embodiment 3. It is a schematic block diagram of the air gap measuring device which concerns on Embodiment 4 of this invention. It is sectional drawing seen from the arrow G direction of FIG. FIG. 6 is a flowchart showing an air gap measurement method according to Embodiment 4. 6 is a schematic diagram showing a case where the vibration measurement direction and the pressing direction are the same in Embodiment 1 or 3. FIG. 6 is a schematic diagram showing a case where the vibration measurement direction and the heating direction are the same in Embodiment 2 or 4. FIG.

Explanation of symbols

99 feet, 100 air gaps, 102 shells, 103 rotors,
104 spindle, 105 stator, 106 frame, 107 cylinder,
108 welding points, 109 cylinder heads, 110 terminals, 111 discharge pipes,
112 Muffler, 113 Auxiliary winding, 114 Main winding, 116 Display,
117 connection terminal, 118 acceleration pickup, 119 pickup vibration isolator,
120 acceleration pickup forward cylinder, 121 clamp vibration isolator,
122 Clamp claw, 123 Clamp cylinder, 124 Workpiece vibration isolator,
125 measurement unit base plate, 126 anti-vibration material, 127 drive circuit,
128 Computer, 129 Pressing part, 130 Pressing part cylinder, 131 Pressing support, 132 Pressing support cylinder, 133 Mounting base, 134 Heating torch, 135 Rotary table, 136 Rotating shaft

Claims (12)

Rotating means for applying a voltage to an electric motor in which a rotor is disposed through an air gap in a stator held in a cylindrical casing, and rotating the rotor;
Deformation means for locally elastically deforming the outer periphery of the housing in a radial direction of the housing and changing a positional relationship between the rotor and the stator;
Measuring means that is arranged on the outer peripheral side surface of the casing and measures the magnitude of vibration of the rotor before and after the outer peripheral portion of the casing is elastically deformed by the deforming means;
An air gap eccentricity measuring apparatus for an electric motor, comprising: calculating means for calculating an eccentric amount and an eccentric direction of the air gap based on the magnitude of vibration of the rotor measured by the measuring means.   2. The air gap eccentricity measuring device for an electric motor according to claim 1, wherein the measuring means is arranged in two directions that are different by an angle of 90 degrees on the outer peripheral side surface of the casing.   The motor is a single-phase induction motor having a main winding and an auxiliary winding, and the measuring means is arranged in a direction orthogonal to the winding direction of the main winding and the auxiliary winding, respectively. An air gap eccentricity measuring device for an electric motor according to claim 2.   The motor air gap eccentricity measuring device according to any one of claims 1 to 3, wherein the deformation means is a pressing mechanism that mechanically presses the outer peripheral portion of the housing.   The motor air gap eccentricity measuring device according to any one of claims 1 to 3, wherein the deforming means is a heating means arranged apart from the outer peripheral portion of the housing.   Means for changing the rotation angle of the stator relative to the deformation means and the measurement means, and the measurement means includes a rotor of the rotor before and after the outer periphery of the housing is elastically deformed at a different rotation angle of the stator. 6. The motor air gap eccentricity measuring apparatus according to claim 1, wherein the magnitude of vibration is measured a plurality of times. A first step of rotating the rotor by applying a voltage to an electric motor in which a rotor is disposed through an air gap in a stator held in a cylindrical housing;
A second step of measuring the magnitude of vibration by a measuring means for measuring vibration from the outer peripheral side surface of the housing;
A third step of changing a positional relationship between the rotor and the stator by a deformation means for elastically deforming the outer periphery of the housing in a radial direction of the housing;
A fourth step of measuring the magnitude of vibration again from the outer peripheral side surface of the housing by the measuring means after the third step;
And a fifth step of calculating an eccentric amount and an eccentric direction of the air gap based on the magnitude of vibration measured in the second and fourth steps. . A first step of rotating the rotor by applying a voltage to an electric motor in which a rotor is disposed via an air gap in a stator held in a cylindrical housing;
A second step of measuring the magnitude of vibration by a measuring means for measuring vibration from the outer peripheral side surface of the housing;
A third step of changing a positional relationship between the rotor and the stator by a deformation means for elastically deforming the outer periphery of the housing in a radial direction of the housing;
A fourth step of measuring the magnitude of vibration again from the outer peripheral side surface of the housing by the measuring means after the third step;
A fifth step of changing the rotation angle of the stator relative to the deformation means and the measurement means;
The second to fifth steps are performed a plurality of times, and the eccentric amount and the eccentric direction of the air gap at each rotation angle of the stator are calculated based on the magnitude of vibration measured by these steps. 6 steps,
And a seventh step of calculating a two-dimensional air gap eccentricity and direction from the calculation result of the eccentricity and eccentricity of the air gap at each angular position of the stator. Air gap eccentricity measuring method.   The method of measuring an air gap eccentricity of an electric motor according to claim 7 or 8, wherein the measuring means is arranged in two directions that are 90 degrees different from each other on an outer peripheral side surface of the casing.   The electric motor is a single-phase induction motor having a main winding and an auxiliary winding, and the measuring means are arranged in directions orthogonal to the main winding and auxiliary winding winding directions, respectively. The method for measuring an air gap eccentricity of an electric motor according to claim 9.   The method of measuring an air gap eccentricity of an electric motor according to any one of claims 7 to 11, wherein the deforming means is a pressing mechanism that mechanically presses the outer peripheral portion of the housing. The method for measuring an air gap eccentricity of an electric motor according to any one of claims 7 to 11, wherein the deforming means is a heating means arranged to be separated from the outer peripheral portion of the casing.

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