A rotor centrifugal force equivalent test method and test tooling

Abstract

The present invention discloses a rotor centrifugal force equivalent test method and test fixture, which relates to the field of motors and is applicable to rotors with straight pole slots, V-shaped pole slots or U-shaped pole slots. The key points of its technical solution include: using the straight pole slots in the rotor pole slots as test pole slots, and the test pole slots include a test surface perpendicular to the radial direction of the rotor; tensile test: after the rotor is stationary, a test tensile force is applied radially outward to the test surface of each test pole slot; the test tensile force includes a design limit value, and during the test process, the initial value of the applied test tensile force is less than the design limit value, and then gradually increases until it reaches or exceeds the design limit value; size detection: during the tensile test process or after the tensile test is completed, the outer circumferential size of the rotor is measured. The present invention has the advantages of simple testing technology and low cost.

Description

Technical Field

[0001] The present invention relates to the field of motors, and more particularly to a rotor centrifugal force equivalent testing method and testing tooling. Background Art

[0002] During the design phase, the motor rotor's deformation in the risk zone must be verified to prevent motor bore scraping. Existing testing methods and devices typically require the rotor to be installed before overspeed testing. However, if motor bore scraping occurs during installed testing, the motor will be scrapped after disassembly, resulting in a significant waste of resources and making it impossible to actually measure the rotor's deformation in the risk zone.

[0003] The existing Chinese patent with publication number CN113841024A discloses a method and device for measuring the strain of an object subjected to centrifugal force. The method includes placing a rotor in a container of a rotating test bench that can be connected to a drive device, triggering a camera and a short-time laser as a short-time lighting unit, and photographing at least one area of ​​the surface of the rotor, and transmitting the first image as an initial state to an evaluation unit, accelerating the rotor and re-triggering the camera and the short-time laser as a short-time lighting unit at at least one rotational speed, and photographing at least one additional image of the previously photographed area of ​​the surface, transmitting the additional image as a measurement state to the evaluation unit, and the evaluation unit calculating the strain of the rotor in the photographed area of ​​the surface by means of digital image correlation.

[0004] In the above patent, the rotor is tested in an unassembled state, but the rotor needs to be accelerated to a certain speed by a rotating test bench to generate centrifugal force.

[0005] Testing the rotor while it is rotating at high speed also has the problems of high testing technology difficulty and high testing cost. Summary of the Invention

[0006] In view of the shortcomings of the prior art, one of the objectives of the present invention is to provide a rotor centrifugal force equivalent testing method, which has the advantages of simple testing technology and low cost.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A rotor centrifugal force equivalent test method is applicable to a rotor having straight-line, V-shaped, or U-shaped pole slots, wherein the straight-line pole slots of the rotor are used as test pole slots, and the test pole slots include a test surface perpendicular to the rotor radial direction;

[0009] Tension test: After the rotor is stationary, a radially outward test tension is applied to the test surface of each test pole slot. The test tension includes the design limit value. During the test, the initial value of the applied test tension is less than the design limit value, and then gradually increases until it reaches or exceeds the design limit value.

[0010] Dimensional inspection: During or after the tensile test, measure the outer circumference of the rotor.

[0011] Furthermore, after the rotor is left to stand, the ambient temperature of the rotor is adjusted, and tensile tests are performed at different ambient temperatures.

[0012] Furthermore, the axial length of the rotor used for testing is smaller than the axial length of the rotor actually installed.

[0013] In view of the deficiencies in the prior art, another object of the present invention is to provide a rotor centrifugal force equivalent test fixture, which has the advantages of simple testing technology and low cost.

[0014] To achieve the above object, the present invention provides the following technical solutions:

[0015] A rotor centrifugal force equivalent test fixture, the fixture being applicable to rotors having straight-line, V-shaped, or U-shaped pole slots, wherein the straight-line pole slots of the rotor are used as test pole slots, and the test pole slots include a test surface perpendicular to the rotor radial direction;

[0016] The tooling includes a base, a fixed shaft seat is provided in the base; a plurality of tension mechanisms uniformly distributed along the circumferential direction are provided on the outer wall of the base, the tension mechanisms are connected to cables extending into the base; the ends of the cables away from the tension mechanisms are connected to a pressure plate;

[0017] During the test, the rotor is mounted on a fixed shaft seat, and each test pole slot of the rotor is then connected to a pressure plate. The pressure surface of the pressure plate on the rotor is the test surface of the test pole slot, and the cable includes a radial extension section connected to the pressure plate.

[0018] Furthermore, the pressure plate includes a first support plate, and the bottom wall of the first support plate is vertically provided with a second support plate and a third support plate; the second support plate is used to be embedded in the test pole slot, and the third support plate is provided with a through hole extending radially, and the through hole is used to connect the cable.

[0019] Furthermore, the pressure plate further includes a fourth support plate, and the fourth support plate is respectively provided with a second slot cooperating with the second support plate and a third slot cooperating with the third support plate.

[0020] Furthermore, the tension mechanism includes a screw drive mechanism, and the screw drive mechanism includes a drive plate, and a dynamometer or a force sensor connected to the cable is provided on the drive plate.

[0021] Furthermore, the screw drive mechanism includes a hand-cranked screw drive mechanism or a motor screw drive mechanism.

[0022] Furthermore, a cover is provided on the base.

[0023] Furthermore, a temperature regulating device is provided in the base.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. The rotor is kept in a stationary state without rotating to generate centrifugal force. A radial tensile force is then used to deform the rotor risk area. The deformation of the rotor risk area is then measured to determine whether motor bore scraping occurs. While achieving the same goal, the tensile force test in the present invention is equivalent to the centrifugal force test. The testing method in the present invention is technically less difficult, easy to operate, and has a low testing cost.

[0026] 2. The present invention can conveniently implement rotor strength testing under the dual conditions of variable temperature and variable stress; for example, the rotor can be placed in low temperature, high temperature, or gradually rising ambient temperature to simulate the operating temperature of the rotor in the motor, thereby improving the comprehensiveness, accuracy, and reliability of the test results;

[0027] 3. The axial length of the rotor used for testing in the present invention is smaller than the axial length of the actual installed rotor; that is, there is no need to test the entire rotor; only a rotor section needs to be stacked by silicon steel sheets, which can effectively reduce testing costs and avoid waste of resources.

[0028] 4. The test tooling has a simple structure, is easy to operate and has low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the rotor in the embodiment;

[0030] Figure 2 Schematic diagram of the structure of a rotor centrifugal force equivalent test tool in Example 2 Figure 1 ;

[0031] Figure 3 Schematic diagram of the structure of a rotor centrifugal force equivalent test tool in Example 2 Figure 2 ;

[0032] Figure 4 Schematic diagram of the structure of a rotor centrifugal force equivalent test tool in Example 2 Figure 3 ;

[0033] Figure 5 This is a cross-sectional view of the pressure plate and the rotor in Example 2.

[0034] In the figure: 1. rotor; 11. test pole slot; 2. base; 3. cover; 4. fixed shaft seat; 5. screw drive mechanism; 51. drive plate; 52. rocker; 6. dynamometer; 61. cable; 7. pressure plate; 71. first support plate; 711. second support plate; 712. third support plate; 713. through hole; 72. fourth support plate. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to the accompanying drawings.

[0036] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

[0037] Example 1:

[0038] A rotor centrifugal force equivalent test method, referring to Figure 1 , which is suitable for rotors with straight pole slots, V-shaped pole slots or U-shaped pole slots, and the straight pole slots in the rotor pole slots are used as test pole slots 11, and the test pole slots 11 include a test surface perpendicular to the radial direction of the rotor; specifically, the test pole slot 11 includes two plane areas perpendicular to the radial direction of the rotor, wherein the plane area located on the radial outer side, that is, facing the rotor axis, is the test surface; in this embodiment, the pole slots on the rotor 1 are U-shaped pole slots, including three-section U-shaped pole slots and a straight pole slot, and the straight pole slot is used as the test pole slot 1 1; the test pole slot 11 is close to the outer circumference of the rotor and is located in the rotor risk zone, so the test pole slot 11 is used to test and verify the deformation amount of the rotor risk zone; in other optional embodiments, for a rotor with a straight-line pole slot, the straight-line pole slot is used as the test pole slot, and for a rotor with a V-shaped pole slot, the straight-line pole slot is used as the test pole slot; in this embodiment, four pairs of pole slots are provided on the rotor 1. Of course, in other optional embodiments, it can also be applicable to rotors with three pairs of pole slots, five pairs of pole slots or six pairs of pole slots, which is not limited here.

[0039] Tension test: After the rotor 1 is stationary, a radially outward test tension is applied to the test surface of each test pole slot 11. The test tension includes a design limit value. During the test, the initial value of the applied test tension is less than the design limit value and then gradually increases until it reaches or exceeds the design limit value. For the test tensions applied to multiple test pole slots 11, during the gradual increase process, preferably, all test tensions are increased synchronously. Of course, in other optional embodiments, multiple test tensions may be increased sequentially, or two opposing test tensions may be increased synchronously, without limitation herein.

[0040] Dimensional Inspection: During or after the tensile test, measure the outer circumference of the rotor. This can be done using a variety of existing methods, such as an outside micrometer, three-dimensional coordinate measurement, or visual inspection, without limitation. If continuous measurement of the rotor's outer circumference is required during the tensile test, an outside micrometer or visual inspection can be used. An outside micrometer is preferred, as it is convenient and has low testing costs.

[0041] When designing the rotor, the design pressure value of the test surface can be calculated through software simulation, and then the design limit value of the test tension that the test surface can withstand can be calculated based on the actual force-bearing area on the test surface; in the process of gradually increasing the test tension to the design limit value, if the rotor breaks, it can be directly judged that the deformation of the rotor risk zone does not meet the requirements; if the rotor does not break, when the test tension reaches the design limit value, the outer circumferential size of the rotor is measured to obtain the actual deformation of the rotor risk zone, and then it is judged based on the actual deformation whether the motor will sweep the bore; of course, after the test tension reaches the design limit value, the test tension can be continued to increase to obtain the critical value of the tension that the rotor can actually withstand, and measure the critical deformation of the rotor risk zone.

[0042] In the prior art, to verify the strength of a rotor, the rotor is installed for testing or directly driven for rotation testing. The deformation of the rotor's risk zone is then verified to determine whether motor bore sweeping has occurred. In this embodiment, the rotor is kept stationary, without the need for rotation to generate centrifugal force. A radial pull is then used to deform the rotor's risk zone. The deformation of the rotor's risk zone is then measured to determine whether motor bore sweeping has occurred. While achieving the same goal, the tensile test in this embodiment is equivalent to a centrifugal force test. The testing method in this embodiment is technically less difficult, easier to operate, and has low testing costs.

[0043] Preferably, after the rotor is left to stand, the ambient temperature of the rotor is adjusted, and tensile tests are performed at different ambient temperatures; that is, in this embodiment, the rotor strength test under the dual conditions of variable temperature and variable stress can be conveniently implemented; for example, the rotor is placed at a low temperature, high temperature or gradually rising ambient temperature to simulate the operating temperature of the rotor in the motor, thereby improving the comprehensiveness, accuracy and reliability of the test results; preferably, the axial length of the rotor used for testing is less than the axial length of the actual installed rotor; that is, in this embodiment, it is not necessary to test the complete rotor, but only necessary to stack a section of the rotor by silicon steel sheets, for example, the axial length of the rotor is 10 mm, thereby effectively reducing the testing cost and avoiding waste of resources.

[0044] Example 2:

[0045] A rotor centrifugal force equivalent test fixture, refer to Figures 1 to 5 In this embodiment, the tooling is suitable for rotors with straight pole slots, V-shaped pole slots or U-shaped pole slots. The straight pole slots in the rotor pole slots are used as test pole slots, and the test pole slots include a test surface perpendicular to the radial direction of the rotor; specifically, the test pole slot 11 includes two plane areas perpendicular to the radial direction of the rotor, among which the plane area located on the radial outer side, that is, facing the rotor axis, is the test surface; in this embodiment, the pole slots on the rotor 1 are U-shaped pole slots, including three-section U-shaped pole slots and a straight pole slot, and the straight pole slot is used as the test pole slot 11; the test pole slot 11 is close to the outer circumference of the rotor and is located in the rotor risk zone, so the test pole slot 11 is used to test and verify the deformation amount of the rotor risk zone; in other optional embodiments, for a rotor with a straight-line pole slot, the straight-line pole slot is used as the test pole slot, and for a rotor with a V-type pole slot, the straight-line pole slot is used as the test pole slot; in this embodiment, four pairs of pole slots are provided on the rotor 1. Of course, in other optional embodiments, it can also be applicable to rotors with three pairs of pole slots, five pairs of pole slots or six pairs of pole slots, and there is no limitation here.

[0046] Reference Figures 1 to 5In this embodiment, the tooling includes a base 2, in which a fixed shaft seat 4 is provided; a plurality of circumferentially evenly distributed tension mechanisms are provided on the outer wall of the base 2, and the tension mechanism is connected to a cable 61 extending into the base 2; the end of the cable 61 away from the tension mechanism is connected to a pressure plate 7; during the test, the rotor 1 is sleeved on the fixed shaft seat 4, and then each test pole slot 11 of the rotor 1 is connected to the pressure plate 7, the pressure surface of the pressure plate 7 on the rotor 1 is the test surface of the test pole slot, and the cable 61 includes a radial extension section connected to the pressure plate 7; specifically, in this embodiment, eight test pole slots 11 are provided on the rotor 1, and the number of tension mechanisms is the same as the number of test pole slots. The number of grooves 11 is the same, so eight tension mechanisms need to be evenly distributed on the outer wall of the base 2 along the circumferential direction; preferably, in order to facilitate the arrangement of the tension mechanisms, the side wall of the base 2 in this embodiment is a regular octahedron; of course, in other optional embodiments, the shape of the base 2 can be adjusted according to the number of tension mechanisms, which is not limited here; in this embodiment, the fixed shaft seat 4 is fixedly arranged at the center position of the inner bottom wall of the base 2, so as to ensure the uniformity of each test tension; the fixed shaft seat 4 is provided with an annular support surface for supporting the rotor 1, and a positioning shaft section for passing the rotor is provided in the middle of the annular support surface, so as to ensure the stability of the rotor in a stationary state.

[0047] Reference Figures 1 to 5 In this embodiment, the entire length direction of the cable 61 is arranged radially, so as to facilitate the application of radial test tension; using the cable to directly apply tension to the pressure plate 7 is beneficial for the pressure plate 7 to apply pressure only to the test surface, avoiding the rotor from being subjected to forces in other directions; of course, in other optional embodiments, rollers or other methods can also be used to change the direction of force transmitted by the cable 61, so that the cable 61 has a radial extension section connected to the pressure plate 7, and there is no limitation here.

[0048] Reference Figures 1 to 5Specifically, in this embodiment, the pressure plate 7 includes a first support plate 71, and the bottom wall of the first support plate 71 is vertically provided with a second support plate 711 and a third support plate 712; the second support plate 711 is used to be embedded in the test pole slot 11, and the third support plate 712 is provided with a through hole 713 extending in the radial direction, and the through hole 713 is used to connect the cable 61; after the pressure plate 7 is connected to the rotor 1, the second support plate 711 is embedded in the test pole slot 11, and after the pressure plate 7 receives the tension, the second support plate 711 contacts the test surface of the test pole slot 11; the end of the cable 61 can be connected to the through hole 713 by a bolt, so as to facilitate the application of radial tension; preferably, the third support plate 712 is provided with a through hole 713 extending in the radial direction, and the through hole 713 is used to connect the cable 61; After one support plate 71 contacts the top wall of the rotor 1, the center line of the through hole 713 is opposite to the axial middle position of the rotor; preferably, the pressure plate 7 also includes a fourth support plate 72, and the fourth support plate 72 is respectively provided with a second slot that cooperates with the second support plate 711 and a third slot that cooperates with the third support plate 712; after the fourth support plate 72 is connected to the second support plate 711 and the third support plate 712, it will not fall off due to the tight fit of the plate groove, and the setting of the fourth support plate 72 can improve the stability of the connection between the pressure plate 7 and the rotor 1; of course, in other optional embodiments, the structure of the pressure plate 7 can be adjusted as needed, which is not limited here.

[0049] Reference Figures 1 to 5 Specifically, in this embodiment, the tension mechanism includes a screw drive mechanism 5, and the screw drive mechanism 5 includes a drive plate 51, and a dynamometer 6 connected to the cable 61 is provided on the drive plate 51; the screw drive mechanism 5 can control the drive plate 51 to move in a straight line direction, and the straight line motion direction is arranged in the radial direction, so that the screw drive mechanism 5 can drive the dynamometer 6 to apply radial tension to the cable 61; the self-locking property of the screw drive mechanism 5 can ensure that the position of the dynamometer 6 remains unchanged; specifically, in this embodiment, the screw drive mechanism 5 includes a rocking wheel 52 for driving the screw to rotate; that is, the hand-cranked screw drive mechanism 5 is used in this embodiment, and the dynamometer that directly displays the tension value can be used to facilitate rotation. The test force is applied radially, and the tension value can be measured in real time. The structure is simple, the operation is convenient, and the production cost is low. During the test, eight operators can respectively control the screw drive mechanism 5 to achieve synchronous control as much as possible. Of course, in other optional embodiments, a motor screw drive mechanism can also be used. Then, by controlling eight motors, the synchronous movement of the eight motor screw drive mechanisms can be achieved. Of course, a force sensor can also be used to measure the tension value, and then the data of the force sensor is synchronized to the host computer in real time to achieve a comprehensive record of the tension during the tension test, thereby facilitating analysis. Of course, in other optional embodiments, the tension mechanism can also choose other methods, which are not limited here.

[0050] Reference Figures 1 to 5Preferably, a cover 3 is provided on the base 2, and preferably, the cover 3 is a transparent cover so as to facilitate observation of the state of the rotor; a chamber is formed between the cover 3 and the base 2, and by changing the temperature in the chamber, the rotor can be subjected to tensile testing at different ambient temperatures; for example, by adding liquid nitrogen to the base 2, the chamber can be placed in a low-temperature state, thereby achieving tensile testing of the rotor in a low-temperature state; preferably, a temperature regulating device (not shown in the drawings) is provided in the base 2; the temperature regulating device is used to regulate the temperature in the chamber, such as low temperature, high temperature or continuous temperature change, etc.; the temperature regulating device can adopt a variety of devices in the prior art, such as a heating tube, a semiconductor heater or a heating tube combined with a cooler, etc., which are not limited here.

[0051] Reference Figures 1 to 5 In this embodiment, the axial length of the rotor used for testing is smaller than the axial length of the actually installed rotor; that is, in this embodiment, it is not necessary to test the complete rotor, but only a section of the rotor needs to be stacked by silicon steel sheets, for example, the axial length of the rotor is 10 mm, thereby effectively reducing the testing cost and avoiding waste of resources.

Claims

1. A rotor centrifugal force equivalent test fixture, characterized by: The tool is suitable for a rotor with a straight pole slot, a V-shaped pole slot or a U-shaped pole slot, and the straight pole slot in the rotor pole slot is used as a test pole slot, and the test pole slot includes a test surface perpendicular to the radial direction of the rotor; The tooling includes a base, a fixed shaft seat is provided in the base; a plurality of tension mechanisms uniformly distributed along the circumferential direction are provided on the outer wall of the base, the tension mechanisms are connected to cables extending into the base; the ends of the cables away from the tension mechanisms are connected to a pressure plate; During the test, the rotor is mounted on a fixed shaft seat, and each test pole slot of the rotor is then connected to a pressure plate. The pressure surface of the pressure plate on the rotor is the test surface of the test pole slot, and the cable includes a radial extension section connected to the pressure plate.

2. The rotor centrifugal force equivalent test fixture according to claim 1, characterized in that: The pressure plate includes a first support plate, and the bottom wall of the first support plate is vertically provided with a second support plate and a third support plate; the second support plate is used to be embedded in the test pole slot, and the third support plate is provided with a through hole extending radially, and the through hole is used to connect the cable.

3. The rotor centrifugal force equivalent test fixture according to claim 2, characterized in that: The pressure plate further includes a fourth support plate, and a second slot cooperating with the second support plate and a third slot cooperating with the third support plate are respectively formed on the fourth support plate.

4. The rotor centrifugal force equivalent test fixture according to claim 1, characterized in that: The pulling mechanism includes a screw drive mechanism, and the screw drive mechanism includes a drive plate. A dynamometer or a force sensor connected to the cable is provided on the drive plate.

5. The rotor centrifugal force equivalent test fixture according to claim 4, characterized in that: The screw drive mechanism includes a hand-cranked screw drive mechanism or a motor screw drive mechanism.

6. The rotor centrifugal force equivalent test fixture according to claim 1, characterized in that: A cover shell is arranged on the base.

7. The rotor centrifugal force equivalent test fixture according to claim 6, characterized in that: A temperature regulating device is arranged in the base.

8. A rotor centrifugal force equivalent test method, applicable to rotors having straight, V-shaped, or U-shaped pole slots, characterized by: The method adopts the rotor centrifugal force equivalent test fixture according to any one of claims 1 to 7; a straight pole slot in a rotor pole slot is used as a test pole slot, and the test pole slot includes a test surface perpendicular to the radial direction of the rotor; Tension test: After the rotor is stationary, a radially outward test tension is applied to the test surface of each test pole slot. The test tension includes the design limit value. During the test, the initial value of the applied test tension is less than the design limit value, and then gradually increases until it reaches or exceeds the design limit value. Dimensional inspection: During or after the tensile test, measure the outer circumference of the rotor.

9. The rotor centrifugal force equivalent testing method according to claim 8, characterized in that: After the rotor is left to stand, the ambient temperature of the rotor is adjusted, and tensile tests are performed at different ambient temperatures.

10. The rotor centrifugal force equivalent testing method according to claim 8, characterized in that: The axial length of the rotor used for testing is smaller than the axial length of the rotor actually installed.

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