WO2024024297A1

WO2024024297A1 - Alternating-current electric motor inspection device, and alternating-current electric motor inspection method

Info

Publication number: WO2024024297A1
Application number: PCT/JP2023/021527
Authority: WO
Inventors: 祐司丸谷; 淳一四辻; 啓司山下
Original assignee: Ｊｆｅスチール株式会社
Priority date: 2022-07-28
Filing date: 2023-06-09
Publication date: 2024-02-01
Also published as: JP2024017459A

Abstract

An alternating-current electric motor inspection device of the present invention includes a slackness measuring device comprising an impacting device for imparting an impact to a wedge that fixes a stator of the alternating-current electric motor, a first measuring device for measuring an acceleration of the impact imparted by the impacting device, a second measuring device for measuring an acceleration of the wedge, and a housing accommodating the impacting device, the first measuring device and the second measuring device, wherein: the impacting device comprises a leaf spring, a cam which rotates, thereby pushing the leaf spring up and causing the same to deform elastically, a rotation imparting device for causing the cam to rotate, and a flatter for transmitting the impact imparted from the leaf spring to the wedge; and the housing is provided with a magnet wheel which is connected to the housing by way of a resilient body and which is capable of being accommodated inside the housing, and an electromagnet capable of magnetically attracting the housing to an inner peripheral surface of the stator.

Description

AC motor inspection device and AC motor inspection method

The present invention relates to an AC motor inspection device and an AC motor inspection method.

Conventionally, in an AC motor, a technique is known to check whether a wedge that mechanically fixes a coil inserted into a slot of a stator is loose. For example, Patent Document 1 discloses a wedge measuring device that can be inserted into a gap between a stator, which is a stator, and a rotor, which is a rotor of a rotating electric machine. This wedge measuring device consists of a measuring head that detects the pressed state of a wedge coil inserted into a slot, and a moving mechanism that can move this measuring head in the longitudinal direction (axial direction) and circumferential direction of the stator. . Further, Patent Document 2 discloses a wedge striking device for a rotating electrical machine that is inserted into a gap between a rotor and a stator of the rotating electrical machine and strikes a wedge of the rotating electrical machine. Further, Patent Document 2 discloses a wedge inspection system that inspects a wedge using a hitting input waveform when hitting a wedge using this wedge hitting device and a vibration waveform of the wedge.

Japanese Patent Application Publication No. 1-214244 Patent No. 6250241

Patent Document 1 discloses a technique for checking the looseness of a wedge without pulling out the rotor, but the wedge measuring device is not self-propelled, but is a mechanism that moves the measuring head in the axial direction of the motor. , which uses rails and moving wires parallel to the axis of the motor. Therefore, when attaching a wedge measuring device to an electric motor, first, parts of at least one end of both ends of the rail are removed, and the rail is inserted between the rotor and stator of the electric motor. After that, the complicated work of reattaching the component to the end of the rail from which the component was previously removed is required. Further, this rail serves not only as a guide for moving the wedge measuring device in a desired direction, but also as a role for holding the wedge measuring device. Therefore, the rail needs to be strong enough to withstand the load of the wedge measuring device. For this reason, there is a concern that as the rail bends under its own weight, the measurement position of the wedge slack measurement device on the rail may be misaligned, and it may not be possible to accurately check the wedge looseness. be.

Further, Patent Document 2 also discloses a technique for checking the looseness of the wedge without pulling out the rotor. This requires a fixed fulcrum that rotatably supports the striking arm, and furthermore, it is necessary to provide an energy supply section and an absorption section in addition to the striking arm and the striking section, making the mechanism of the wedge striking device complicated. is unavoidable. As a result, the weight of the wedge striking device increases, and the adsorption state of the wedge striking device to the inner circumferential surface of the stator is not stable.As a result, the measurement data is also unstable, making it impossible to accurately check the wedge for looseness. There is a risk.

The present invention has been made in view of the above-mentioned problems, and its objects are to provide an inspection device for an AC motor that can accurately check the looseness of a wedge without pulling out the rotor, and The purpose is to provide an inspection method.

In order to solve the above-mentioned problems and achieve the objectives,
(1) An inspection device for an AC motor according to the present invention includes: a striking device that strikes a wedge that fixes a stator of an AC motor; a first measuring device that measures the acceleration of the strike given by the striking device; a slackness measuring device comprising a second measuring device that measures the acceleration of the wedge; and a casing that houses the striking device, the first measuring device, and the second measuring device; The impact device includes a leaf spring, a cam that rotates to push up the leaf spring and elastically deform it, a rotation imparting device that rotates the cam, and a stopper that transmits the impact from the leaf spring to the wedge. The casing is connected to the casing via an elastic body, and includes a magnetic wheel that can be stored inside the casing, and a magnetic wheel that can be attracted to the inner circumferential surface of the stator. It is characterized by being equipped with an electromagnet.

(2) The AC motor inspection device according to the present invention, in the invention described in (1) above, includes a calculation device that calculates an acceleration ratio that is a ratio of the acceleration of the wedge to the acceleration of the impact given by the impact device to the wedge. , and a determination device that determines the degree of looseness of the wedge using the calculation result of the calculation device.

(3) The method for inspecting an AC motor according to the present invention is such that the slack measuring device included in the inspection device for an AC motor according to the invention of (1) or (2) is connected to the rotor and the stator of the AC motor. The wedge is inserted into a gap formed between the wedges, and the wedge is struck by the loosening measuring device, and the degree of loosening of the wedge is determined from the relationship between the acceleration of the wedge and the acceleration of the applied strike. It is something to do.

(4) In the method for inspecting an AC motor according to the present invention, in the invention described in (3) above, the method for determining the degree of loosening of the wedge includes applying a low-pass filter to the waveform of the acceleration of the impact applied to the wedge. A step of obtaining a peak-held value A1, a step of obtaining a peak-held value A2 after applying a low-pass filter to the waveform of the acceleration of the wedge, and calculating the ratio of A2/A1 each time a strike is made to obtain an acceleration ratio. The process involves performing multiple blows at each measurement point and calculating the average value after eliminating data related to the initial blows.The process is based on the average value of the obtained acceleration ratio. The present invention is characterized by comprising the step of determining the degree of loosening of the wedge from the relationship between the acceleration ratio and the degree of loosening.

The AC motor inspection device and AC motor inspection method according to the present invention have the effect that the looseness of the wedge can be accurately inspected without pulling out the rotor.

FIG. 1 is a block diagram showing a schematic configuration of an inspection device according to an embodiment. FIG. 2 is a diagram showing a state in which a slackness measuring device is inserted into a gap formed between a stator and a rotor of an AC motor. FIG. 3 is a diagram showing a part of a cross section of a stator of an AC motor. FIG. 4 is a side view showing a schematic configuration of the slackness measuring device according to the embodiment. FIG. 5 is a top view showing a schematic configuration of the slackness measuring device according to the embodiment. FIG. 6 is a diagram showing a state in which the leaf spring is elastically deformed by the cam. FIG. 7 is a diagram showing a state in which the striking portion of the leaf spring strikes the abutment bit. FIG. 8 is a side view showing a schematic configuration of the second measuring device. FIG. 9 is a diagram showing the looseness measuring device in a state where the electromagnet is not activated. FIG. 10 is a diagram showing the looseness measuring device with the electromagnet activated.

Embodiments of an AC motor inspection device and an AC motor inspection method according to the present invention will be described below. Note that the present invention is not limited to this embodiment.

FIG. 1 is a block diagram showing a schematic configuration of an inspection device 10 according to an embodiment. As shown in FIG. 1, the inspection device 10 according to the embodiment is a device for inspecting an AC motor, specifically, checking the degree of looseness of a wedge provided in a stator of an AC motor, and is a loosening measuring device. 1, a control device 7, a calculation device 8, a determination device 9, etc. The slackness measuring device 1 is a device that measures the slackness of the wedge by striking the wedge, and includes a striking device 2, a first measuring device 3, a second measuring device 4, and a suction device 5. It is equipped with such things as In addition, specific descriptions of the slackness measuring device 1, striking device 2, first measuring device 3, second measuring device 4, adsorption device 5, control device 7, calculating device 8, determining device 9, etc. This will be explained later.

FIG. 2 is a diagram showing a state in which the looseness measuring device 1 is inserted into a gap formed between the stator 110 and the rotor 120 of the AC motor 100. As shown in FIG. 2, in the inspection device 10 according to the embodiment, the looseness is removed in the gap formed between the stator 110 and the rotor 120 of the AC motor 100 without pulling out the rotor 120 of the AC motor 100. Insert measuring device 1. In the inspection device 10 according to the embodiment, the degree of loosening of a wedge 112 (see FIG. 3) provided on the stator 110, which will be described later, is inspected using the loosening measuring device 1 inserted into the gap.

FIG. 3 is a diagram showing a part of a cross section of the stator 110 of the AC motor 100. As shown in FIG. 3, in the stator 110 of the AC motor 100, a coil 113 is disposed within a slot 114 formed in an iron core 111. The coil 113 is mechanically fixed by pressing the coil 113 with a wedge 112 installed at the opening of the slot 114. As the wedge 112, for example, one made of epoxy resin can be used. Note that in FIG. 3, the area above the iron core 111 and the wedge 112 is a part of the space between the stator 110 and the rotor 120.

Here, the wedge 112 is caused by wear due to thermal deterioration of an insulator (not shown) that electrically insulates the iron core 111 and the coil 113 due to long-term use of the AC motor 100, or mechanical wear due to electromagnetic vibration. As a result, the coil 113 becomes insufficiently fixed. When the vibration of the coil 113 that occurs during operation of the AC motor 100 becomes large, the insulator (not shown) that electrically insulates the iron core 111 and the coil 113 is mechanically damaged, resulting in an electrical short circuit. There is a risk of Therefore, in the inspection device 10 according to the embodiment, the degree of loosening of the wedge 112 is inspected using the loosening measuring device 1.

FIG. 4 is a side view showing a schematic configuration of the looseness measuring device 1 according to the embodiment. FIG. 5 is a top view showing a schematic configuration of the looseness measuring device 1 according to the embodiment. As shown in FIGS. 4 and 5, the slack measuring device 1 according to the embodiment includes a striking device 2, a first measuring device 3, a second measuring device 4, a suction device 5, and a slack measuring device 1 for measuring the slack of these devices. The device 1 includes a casing 6 that accommodates each component of the device 1 inside. The housing 6 has a size that fits into the gap formed between the rotor 120 and the stator 110 of the AC motor 100, and the top plate portion 6a of the housing 6 is located on the rotor 120 side. The body 6 is inserted into the gap so that the bottom plate portion 6b is located on the stator 110 side.

The striking device 2 is a device that strikes a wedge 112 provided on the stator 110. The impact device 2 includes a leaf spring 21, a cam 22 that lifts and elastically deforms the leaf spring 21 by rotation, a rotation imparting device 23 such as a motor that rotates the cam 22, and a wedge of the impact given by the leaf spring 21. 112. The plate spring 21 has one end in the longitudinal direction serving as a fixed end fixed on the fixed pedestal 25, and the other end in the longitudinal direction serving as a free end. On the surface of the leaf spring 21 on the side opposite to the abutting bead 24 through the opening 61 formed in the bottom plate portion 6b of the housing 6, there is a convex protruding toward the abutting bead 24 at a position corresponding to the abutting bead 24. A shaped striking portion 21a is provided. Further, a cam contact portion 21b that can come into contact with a cam surface formed on the outer periphery of the cam 22 is provided at the tip portion on the free end side of the leaf spring 21. The abutting bit 24 is inserted into the bottom plate 6b of the casing 6 via the elastic body 26 to a position where the striking portion 21a of the leaf spring 21 can be struck through the opening 61 formed in the bottom plate 6b of the casing 6. edge of the opening 61). Note that the striking portion 21a and the contact bit 24 only need to be harder than the wedge 112. As the material of the striking part 21a and the contact bit 24, various metal materials can be used, for example.

FIG. 6 is a diagram showing a state in which the leaf spring 21 is elastically deformed by the cam 22. FIG. 7 is a diagram showing a state in which the striking part 21a of the leaf spring 21 strikes the contact bit 24. As shown in FIG. As shown in FIG. 6, the striking device 2 causes the rotation imparting device 23 to rotate the cam 22, thereby pushing up the cam contact portion 21b with the cam 22 and elastically deforming the leaf spring 21. Then, as shown in FIG. 7, by further rotating the cam 22 by the rotation imparting device 23 and releasing the cam contact portion 21b from the cam 22, an impact force due to the elastic force of the leaf spring 21 is generated, and the leaf spring The striking part 21a of 21 strikes the hitch 24.

Here, as shown in FIG. 3, the inner circumferential surface 111a of the iron core 111 and the inner circumferential surface 112a of the wedge 112, which form the inner circumferential surface 110a of the stator 110, are not necessarily in a fixed positional relationship. do not have. Therefore, in the case of a configuration in which the striking portion 21a of the leaf spring 21 directly strikes the wedge 112, the cam contact portion 21b of the leaf spring 21 is released from the cam 22, and the striking portion 21a of the leaf spring 21 strikes the wedge 112. There is concern that the distance traveled before hitting the ball will also vary greatly. Such large fluctuations in the moving distance cause variations in measurement results.

Therefore, in the slackness measuring device 1 according to the embodiment, the striking part 21a of the leaf spring 21 does not directly contact the wedge 112 and give a strike, but instead hits the contacting part 24 that has been brought into contact with the wedge 112 in advance. The striking portion 21a of the spring 21 gives a strike. A structure is adopted in which the striking portion 21a strikes the wedge 112 via the contact bit 24. This makes it possible to suppress the influence of large fluctuations in the travel distance until the striking portion 21a of the leaf spring 21 strikes the wedge 112, as described above. Therefore, in the slackness measuring device 1 according to the embodiment, it is possible to apply a stable striking force to the wedge 112 by the striking device 2, and it is possible to suppress variations in measurement results caused by large fluctuations in the moving distance.

The first measuring device 3 included in the slack measuring device 1 according to the embodiment is a device that measures the acceleration of the impact that the impact device 2 gives to the wedge 112, and is configured using, for example, an accelerometer.

An accelerometer included in the first measuring device 3 is attached near the striking part 21a of the leaf spring 21, and the acceleration of the striking part 21a is measured.

The second measuring device 4 included in the loosening measuring device 1 according to the embodiment is a device that measures the acceleration (response acceleration) of the wedge 112, which is the object to be hit by the hitting device 2, and is, for example, an accelerometer. It is configured using

FIG. 8 is a side view showing a schematic configuration of the second measuring device 4. As shown in FIG. 8, the second measuring device 4 includes a contact member 41,

resin members

42a, 42b, vibration-

proof rubber

43a, 43b, 43c, 43d, an accelerometer 44, and the like. The contact member 41 is disposed at a position corresponding to the wedge 112 through an opening 62 formed in the bottom plate portion 6b of the housing 6. The contact member 41 has a convex shape with the side facing the wedge 112 protruding toward the wedge 112 side. The contact member 41 is held by the two

resin members

42a and 42b sandwiching and compressing the contact member 41. The method of holding the contact member 41 by sandwiching and compressing the contact member 41 between resin members is not limited to the method of sandwiching the contact member 41 between two

resin members

42a and 42b from opposing outsides as shown in FIG. For example, a method may be adopted in which a single resin member surrounding the contact member 41 is used and the resin member presses and holds the contact member 41 from the periphery. The contact member 41 may be made of any material as long as it is harder than the wedge 112, and for example, various metal materials may be used. The

resin members

42a and 42b are placed on the bottom plate portion 6b of the housing 6 via

anti-vibration rubbers

43a and 43b, respectively. Moreover, vibration-

proof rubbers

43c and 43d are interposed between the top plate portion 6a of the housing 6 and the

resin members

42a and 42b. The accelerometer 44 includes an L-shaped plate member 441 and a sensor 442 that measures the vibration of the wedge 112 transmitted to the plate member 441 via the contact member 41. The elongated portion 441a of the plate member 441 is attached to the upper surface of the contact member 41. A sensor 442 is attached to the short portion 441b of the plate member 441. Further, the plate member 441 is not sandwiched or fixed between the

resin members

42a, 42b or the

vibration isolating rubbers

43a, 43b, 43c, and 43d, but is arranged to be able to vibrate. For this reason, for example, a cut may be provided so that the

vibration isolating rubbers

43c and 43d do not come into contact with the elongated portion 441a of the plate-like member 441. The second measuring device 4 attaches an accelerometer 44 to the contact member 41 in contact with the wedge 112, and measures the vibration of the wedge 112 when a blow from the striking portion 21a is applied to the wedge 112 via the contact beam 24.

FIG. 9 is a diagram showing the looseness measuring device 1 in a state where the electromagnet 52 is not activated. FIG. 10 is a diagram showing the looseness measuring device 1 with the electromagnet 52 activated. As shown in FIGS. 9 and 10, the adsorption device 5 is provided with magnetic wheels 51 for movement and an electromagnet 52 that can adsorb the casing 6 to the inner circumferential surface 110a of the stator 110 when measuring looseness. . The magnetic wheel 51 is connected to the top plate 6a of the casing 6 via an elastic body 53 disposed inside the casing 6, and is connected to the top plate 6a of the casing 6 through a wheel opening (not shown) formed in the bottom plate 6b of the casing 6. It is configured to be able to be stored inside the housing 6. As the elastic body 53 that connects the housing 6 and the magnetic wheel 51, for example, a leaf spring or the like can be used. By connecting the casing 6 and the magnetic wheel 51 via the elastic body 53, the casing 6 is lifted off the inner peripheral surface 110a of the stator 110 by the elastic force of the elastic body 53, and the looseness measuring device 1 can be smoothly operated. It can be moved. Note that in order to move the slack measuring device 1 in the longitudinal direction of the AC motor 100 (stator 110), for example, a method is adopted in which a wire is attached to the housing 6 and the wire is pulled from outside the AC motor 100. be able to.

Moreover, by employing the magnetic wheels 51 as wheels for moving the slack measuring device 1 in the longitudinal direction of the AC motor 100 (stator 110), the inner peripheral surface 110a of the stator 110 (the inner peripheral surface of the iron core 111 111a), the magnetic wheel 51 is attracted by magnetic force. This makes it possible to hold the slack measuring device 1 on the inner circumferential surface 110a of the stator 110 no matter what angle the loose measuring device 1 is at with respect to the inner circumferential surface 110a of the stator 110. For example, when the slack measuring device 1 is located in a gap formed between the stator 110 and the rotor 120 such that the inner circumferential surface 110a of the stator 110 is higher than the outer circumferential surface 120a of the rotor 120. There is. Even in this case, it is possible to move the slack measuring device 1 in the longitudinal direction of the AC motor 100 (stator 110) while holding the slack measuring device 1 on the inner peripheral surface 110a of the stator 110. Become.

In the slackness measuring device 1 according to the embodiment, after the slackness measuring device 1 is moved to a predetermined measurement position, the hammering device 2 hits the wedge 112, and the first measuring device 3 and the second measuring device 4 Perform measurements. Further, during impact and measurement, the magnetic wheel 51 is housed inside the housing 6, and the housing 6 is brought into close contact with the inner circumferential surface 110a of the stator 110 of the AC motor 100.

Here, the slack measuring device 1 according to the embodiment uses the magnetic force of the electromagnets 52 disposed on both sides of the housing 6 in the width direction perpendicular to the longitudinal direction to It is possible to bring the peripheral surface 111a) and the housing 6 into close contact with each other. As shown in FIG. 9, this electromagnet 52 is not operated except when measuring slackness (during impact and measurement), such as when moving the slackness measuring device 1. As shown in FIG. 10, the electromagnet 52 is operated only when measuring looseness (during impact and measurement) to magnetically attract the inner circumferential surface 110a of the stator 110.

As shown in FIG. 9, the electromagnet 52 has, for example,

distal ends

521a and 521b on both sides of a U-shaped yoke 52a facing the inner circumferential surface 110a of the stator 110, and a longitudinal direction of the yoke 52a. An electromagnet having an excitation coil 52b in the center can be used. When such an electromagnet 52 is used, a current is applied to the excitation coil 52b while the loosening measuring device 1 is moved to a predetermined measurement position on the inner circumferential surface 110a of the stator 110. As a result, the

tips

521a and 521b of the yoke 52a attract the inner circumferential surface 110a of the stator 110 via the casing 6, and as a result, the casing 6 comes into close contact with the inner circumferential surface 110a of the stator 110 and is fixed. be done. Therefore, the adsorption state of the loosening measuring device 1 to the inner circumferential surface 110a of the stator 110 is stabilized, and as a result, it is possible to obtain stable measurement data, and the looseness of the wedge 112 can be checked with high accuracy.

Note that in order to smoothly move the slack measuring device 1 along the longitudinal direction of the stator 110 of the AC motor 100, a guide rail on which the magnetic wheel 51 is mounted and guides the movement of the magnetic wheel 51 is installed on the inner circumference of the stator 110. It may also be provided on the surface 110a. By providing the guide rail in this way, it is possible to make the part in contact with the magnet wheel 51 smooth, so that the movement of the slack measuring device 1 in the longitudinal direction of the stator 110 can be carried out more smoothly. becomes possible. Further, the guide rail allows the magnet wheel 51 to be sufficiently attracted to the inner circumferential surface 110a of the stator 110 by magnetic force via the guide rail, and the abutting bit 24 of the striking device 2 to be directly attached to the wedge 112 without using the guide rail. It is sufficient if the structure is in contact with the .

Furthermore, when preparing a guide rail to move the slack measuring device 1 in the longitudinal direction of the AC motor 100, by adopting the magnetic wheels 51, it is not necessary to have the guide rail carry the load of the slack measuring device 1. do not have. Therefore, it is possible to simplify the structure of the guide rail, reduce its weight, and improve workability. In addition, since the guide rail can be made lighter, it is possible to suppress the guide rail from bending under its own weight, and to prevent positional deviation from occurring in the measurement position of the wedge 112 measured by the slack measuring device 1 on the guide rail. Since this can be suppressed, the looseness of the wedge 112 can be checked with high accuracy.

Here, the magnet wheel 51 is configured so that the slackness measuring device 1 can be moved along the axial direction of the AC motor 100. Therefore, when inspecting the wedge 112 at another position in the circumferential direction of the AC motor 100, the slackness measuring device 1 must be manually moved to the other position. Note that the magnetic wheels 51 are not limited to those configured so that the looseness measuring device 1 can be moved along the axial direction of the AC motor 100, but can also be configured so that the looseness measuring device 1 can be moved in the circumferential direction of the AC motor 100. may be configured.

The calculation device 8 calculates an acceleration ratio, which is the ratio of the acceleration of the wedge 112 to the acceleration of the impact given by the impact device 2 to the wedge 112, which is the object to be hit. Specifically, the calculation device 8 receives the data of the acceleration of the impact measured by the first measurement device 3 and the second measurement device 4, which is received by wire or wirelessly from the first measurement device 3 and the second measurement device 4. The acceleration ratio is calculated from the data of the acceleration of the wedge 112 (response acceleration) measured by the measuring device 4. The acceleration ratio data obtained by the calculation by the calculation device 8 is transmitted to the determination device 9 by wire or wirelessly.

The determination device 9 determines the degree of loosening of the wedge 112 based on the calculation result (acceleration ratio) received from the calculation device 8. If the wedge 112 is not loose, the vibration of the wedge 112 is small. On the other hand, if the wedge 112 is loose, the wedge 112 will not vibrate in the same manner as the blow, and the acceleration ratio will increase. The relationship between the acceleration ratio and the loosening of the wedge 112 can be determined in advance by conducting a preliminary test. Furthermore, by accumulating measurement results for AC motors 100 that are similar in shape and structure, it is also possible to determine the degree of loosening of the wedge 112 without a preliminary test.

The control device 7 connects the impact device 2 (rotation imparting device 23), the first measuring device 3, the second measuring device 4, the adsorption device 5 (electromagnet 52), etc. of the loosening measuring device 1 with wired or The operation of each of these devices is controlled by wirelessly transmitting control signals.

A method for inspecting an AC motor 100 using the inspection device 10 according to the embodiment involves inserting the looseness measuring device 1 into a gap formed between the stator 110 and the rotor 120 of the AC motor 100. Then, the slackness measuring device 1 gives a blow to the wedge 112 that fixes the coil 113 arranged in the slot 114 of the stator 110, and the ratio of the acceleration of the wedge 112, which is the object to be hit, to the acceleration of the given blow is calculated. The degree of loosening of the wedge 112 is determined from a certain acceleration ratio.

Specifically, first, the cover of the AC motor 100 to be inspected is removed to expose the cross sections of the stator 110 and rotor 120 as shown in FIG. Next, the slack measuring device 1 is inserted into the gap formed between the inner peripheral surface 110a of the stator 110 and the outer peripheral surface 120a of the rotor 120. Then, the looseness measuring device 1 is moved in a direction parallel to the rotation axis of the AC motor 100, and stopped when it reaches a predetermined measuring position. Next, the control device 7 controls the electromagnet 52 to operate the electromagnet 52 of the slack measuring device 1 at a predetermined measurement position, and attaches the housing to the inner circumferential surface 110a of the stator 110 (the inner circumferential surface 111a of the iron core 111). 6 is attracted and fixed by magnetic force. Note that in this state, the contact bit 24 is in contact with the wedge 112.

Then, measurement of the looseness of the wedge 112 by the impact device 2 of the looseness measuring device 1 is started. Specifically, the rotation imparting device 23 is controlled by the control device 7, the rotation imparting device 23 rotates the cam 22, the cam contact portion 21b of the leaf spring 21 is lifted, the leaf spring 21 is elastically deformed, and then the leaf spring 21 is released. do. The striking portion 21a of the leaf spring 21 released in this manner strikes the abutting bit 24 that has been in contact with the wedge 112 in advance, thereby applying a blow to the wedge 112 via the abutting bit 24.

In addition to the impact by the impact device 2, the first measuring device 3 is controlled by the control device 7, and the acceleration of the impact applied to the wedge 112 is measured by the first measuring device 3. The measurement result of the acceleration of the impact measured by the first measurement device 3 is transmitted to the calculation device 8 . The calculation device 8 applies a low-pass filter to the waveform of the impact acceleration, which is data of the impact acceleration measured by the first measuring device 3, and then obtains a peak-held value A1. Further, at the same time as the measurement by the first measuring device 3, the second measuring device 4 is controlled by the control device 7, and the acceleration of the wedge 112 (response acceleration) is measured by the second measuring device 4 from the vibration of the wedge 112. do. The measurement result of the acceleration of the wedge 112 (response acceleration) measured by the second measurement device 4 is transmitted to the calculation device 8 . The calculation device 8 applies a low-pass filter to the waveform of the acceleration (response acceleration) of the wedge 112, which is the data of the acceleration (response acceleration) of the wedge 112 measured by the second measuring device 4, and then peak-holds the waveform. Find the value A2. Then, by dividing the value A2 by the value A1 (A2/A1), the calculation device 8 calculates the acceleration ratio, which is the ratio of the acceleration of the wedge 112 (response acceleration) to the acceleration of the impact that the impact device 2 gives to the wedge 112. seek.

Note that the impact and measurement of each acceleration by the loosening measuring device 1 are performed multiple times for one measurement point, and the average value of the respective acceleration ratios obtained for each impact is used to determine the degree of loosening of the wedge 112. It is preferable to use it as a material. Here, in calculating the average value of each acceleration ratio obtained from multiple strikes, we exclude each acceleration ratio obtained from the first few strikes of the multiple strikes, and calculate each acceleration for the remaining number of strikes. It is preferable to calculate the average value of only the ratios. For example, it is preferable to calculate the average value of each acceleration ratio obtained from the third and subsequent hits. This is due to the following reasons. Due to variations in the surface roughness of the inner circumferential surface 110a of the stator 110, the initial suction state of the casing 6 to the inner circumferential surface 110a of the stator 110 (inner circumferential surface 111a of the iron core 111) may be unstable. Sometimes it happens. However, this is because a stable adsorption state can be achieved by hitting about two times.

The data of the acceleration ratio (average value of the acceleration ratio) calculated by the calculation device 8 is transmitted to the determination device 9. The determination device 9 determines the acceleration ratio (average acceleration ratio) measured in advance or found based on past performance based on the acceleration ratio (average acceleration ratio) that is the calculation result of the calculation device 8. The degree of looseness of the wedge 112 is determined from the relationship between the value) and the degree of looseness of the wedge 112.

Thereby, in the inspection device 10 according to the embodiment, the looseness of the wedge 112 can be accurately inspected without pulling out the rotor 120, which can lead to reductions in construction costs and construction period. Furthermore, in the inspection device 10 according to the embodiment, the striking force of the striking portion 21a of the leaf spring 21 is applied to the wedge 112 via the contacting bit 24 that is brought into contact with the wedge 112 in advance. Therefore, it is possible to apply a stable impact force to the wedge 112 to suppress variations in measurement results, and it is possible to improve the accuracy of determining the degree of looseness of the wedge 112.

The present invention can provide an AC motor inspection device and an AC motor inspection method that can accurately inspect the looseness of a wedge without pulling out the rotor.

1 Looseness measuring device 2 Impact device 3 First measuring device 4 Second measuring device 5 Adsorption device 6 Housing 6a Top plate portion 6b Bottom plate portion 7 Control device 8 Calculation device 9 Judgment device 10 Inspection device 21 Leaf spring 21a Impact portion 21b Cam contact portion 22 Cam 23 Rotation imparting device 24 Abutment bit 25 Fixed base 26 Elastic body 41

Contact members

42a,

42b Resin members

43a, 43b, 43c, 43d Vibration isolating rubber 44 Accelerometer 51 Magnetic wheel 52 Electromagnet 52a Yoke 52b For excitation Coil 53 Elastic body 61 Opening 62 Opening 100 AC motor 110 Stator 110a Inner peripheral surface 111 Iron core 112 Wedge 120 Rotor 120a Outer peripheral surface 441 Plate member 441a Long part 441b Short part 442

Sensors

521a, 521b Tip part

Claims

a striking device that strikes a wedge that fixes a stator of an AC motor;
a first measuring device that measures the acceleration of the impact given by the impact device;
a second measuring device that measures the acceleration of the wedge;
a casing that houses the striking device, the first measuring device, and the second measuring device;
It has a looseness measuring device with
The impact device includes a leaf spring, a cam that rotates to push up the leaf spring and elastically deform it, a rotation imparting device that rotates the cam, and a stopper that transmits the impact from the leaf spring to the wedge. and
The casing is connected to the casing via an elastic body, and includes a magnetic wheel that can be stored inside the casing, and an electromagnet that can attract the casing to the inner peripheral surface of the stator. prepare,
An inspection device for an AC motor, characterized by:
a calculation device that calculates an acceleration ratio that is a ratio of the acceleration of the wedge to the acceleration of the impact applied by the impact device to the wedge;
a determination device that determines the degree of looseness of the wedge using the calculation result of the calculation device;
The AC motor inspection device according to claim 1, further comprising:
The slackness measuring device included in the AC motor inspection device according to claim 1 or 2 is inserted into a gap formed between the rotor and the stator of the AC motor, and the slackness measuring device is inserted into the wedge. A method for inspecting an AC motor, comprising applying a blow and determining the degree of loosening of the wedge from the relationship between the acceleration of the wedge and the acceleration of the applied blow.
The method for determining the degree of loosening of the wedge includes:
calculating a peak-held value A1 after applying a low-pass filter to the waveform of the acceleration of the impact applied to the wedge;
a step of applying a low-pass filter to the waveform of the acceleration of the wedge and then obtaining a peak-held value A2;
calculating the ratio of A2/A1 every time a strike is made to obtain an acceleration ratio;
A step of performing a plurality of blows at each measurement point and calculating an average value after excluding data related to the initial blows;
a step of determining the degree of loosening of the wedge from the relationship between the acceleration ratio and the degree of loosening prepared in advance, based on the average value of the determined acceleration ratio;
4. The method for inspecting an AC motor according to claim 3, further comprising: