Shaft voltage testing device and testing system of motor

Abstract

The invention relates to the technical field of shaft voltage testing, and provides a shaft voltage testing device and system of a motor, the shaft voltage testing device comprises a testing assembly and a testing module, the testing assembly comprises an end cover, a first conductive part, a second conductive part, a first wire and a second wire, and the end cover is used for being connected with the axial end part of a shell assembly of the motor; the first conductive part is used for being conductively connected with a rotating shaft of the motor and can synchronously rotate along with the rotating shaft; the second conductive part is in insulated connection with the end cover and is in conductive contact with the first conductive part; the first wire is conductively connected with the end cover and the test module; the second wire is conductively connected with the second conductive member and the test module. The test module is used for outputting shaft voltage of the rotating shaft. The second electric wire transmits the electric signal of the rotating shaft to the test module, so that the shaft voltage can be measured without stopping the motor, replacement and installation are easy, replacement and installation can be achieved by disassembling the end cover and the first conductive part, and the convenience of the shaft voltage test device is improved.

Description

Technical Field

[0001] This application relates to the field of shaft voltage testing technology, specifically to a shaft voltage testing device and system for an electric motor. Background Technology

[0002] The shaft voltage of a motor refers to the potential difference between the end of the motor shaft and ground during motor operation due to electromagnetic induction or other physical effects. Shaft voltage is not an externally applied power supply voltage, but rather a parasitic electrical phenomenon caused by changes in the motor's internal magnetic field. Normally, when the shaft voltage is at a low level, the lubricating oil film formed between the shaft and bearing provides excellent insulation. However, once the shaft voltage rises to a certain critical value due to specific factors, it will break down the oil film, triggering a discharge phenomenon and forming a closed loop of shaft current. Therefore, a testing device is needed to detect the shaft voltage of a motor. Summary of the Invention

[0003] This application provides a shaft voltage testing device and system for an electric motor, capable of detecting the shaft voltage of the motor.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a shaft voltage testing device and system for an electric motor. The shaft voltage testing device includes testing components and a testing module. The testing components include: End cap, used for connection to the axial end of the motor housing assembly; A first conductive element is used to conductively connect with the rotating shaft of the motor, and the first conductive element can rotate synchronously with the rotating shaft; The second conductive element is insulated from the end cap and is in conductive contact with the first conductive element. A first wire conductively connects the end cap and the test module; The second wire is electrically connected to the second conductive component and the test module, which is used to output the shaft voltage of the rotating shaft.

[0005] According to the above technical means, by using the end cap as a grounding reference terminal, a first conductive component that rotates synchronously with the shaft is used to achieve a conductive connection with the shaft, while the second conductive component maintains continuous conductive contact with the first conductive component. Then, the end cap is connected to the test module through the first wire, and the second conductive component is connected to the test module through the second wire. The test module collects and calculates the potential difference between the shaft potential transmitted by the second conductive component and the grounding potential of the end cap, thereby outputting the shaft voltage value of the shaft.

[0006] In some embodiments, the first conductive element forms a first through hole for through which the rotating shaft passes.

[0007] In some embodiments, the test assembly includes a plurality of the first conductive elements, each of which has a different diameter for its first through-hole.

[0008] In some embodiments, the second conductive element includes: The conductive post is in conductive contact with the radial or axial end face of the first conductive element.

[0009] In some embodiments, the second conductive element includes: The main body forms a second through hole, and the conductive post is disposed in the second through hole. The first conductive element and the conductive post are in conductive contact with each other on the end face of the conductive post that is radially away from the main body.

[0010] In some embodiments, the second conductive element includes a plurality of conductive posts, which are distributed circumferentially along the second through hole.

[0011] In some embodiments, the shaft voltage testing device includes a bearing, the end cap forms a stop, and the rotating shaft is connected to the sidewall of the stop via the bearing.

[0012] In some embodiments, the shaft voltage testing device includes an insulating sleeve that is fitted around the outer periphery of the bearing and connected to the sidewall of the stop.

[0013] In some embodiments, the end cap forms multiple stops, each stop having a different diameter.

[0014] In some embodiments, the shaft voltage testing device includes multiple sets of the testing components, with at least one set of the testing components respectively disposed at both ends of the rotating shaft in the axial direction.

[0015] Another embodiment of this application provides a testing system, the testing system comprising: The shaft voltage testing device described in any of the above items; The motor includes a housing assembly whose axial end is connected to the end cover of the shaft voltage testing device.

[0016] The shaft voltage testing device provided in this application embodiment maintains conductive contact between the first and second conductive components during shaft rotation. This allows direct transmission of the shaft's electrical signal to the second conductive component, and the second wire transmits the signal to the testing module, enabling shaft voltage measurement without stopping the motor. The first wire transmits the electrical signal from the end cap to the testing module, and the second wire directly transmits the signal from the second conductive component to the testing module. Since the end cap and the second conductive component remain relatively stationary, the risk of wire tangling is reduced. The shaft voltage can be measured using the potential difference between the end cap and the shaft. Replacement is easy; the end cap and the first conductive component can be removed for replacement, improving the convenience of the shaft voltage testing device. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the shaft voltage testing device in some embodiments of this application; Figure 2 for Figure 1 A magnified view of a section at point A in the middle; Figure 3 for Figure 1 A magnified view of a section at point B in the middle; Figure 4 This is a schematic diagram of the structure of the first conductive element in some embodiments of this application; Figure 5 This is a schematic diagram of the structure of the second conductive element in some embodiments of this application; Figure 6 This is a cross-sectional view of a second conductive element in some embodiments of this application.

[0018] Among them, 1-test component; 100-housing component; 11-end cap; 12-first conductive element; 120-first through hole; 13-second conductive element; 131-conductive post; 132-body; 1320-second through hole; 14-first wire; 15-second wire; 2-test module; 200-rotor; 3-bearing; 300-shaft; 4-insulating sleeve; 5-insulating frame. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, embodiments of the technical solutions of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of this application more clearly, and are therefore merely examples and should not be used to limit the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0021] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0022] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that combinations can be made in any suitable manner without contradiction; for example, different combinations of specific technical features / embodiments can form different implementations. To avoid unnecessary repetition, the various possible combinations of specific technical features / embodiments in this application will not be described separately.

[0023] It should be noted that in this application, "multiple" includes two or more.

[0024] In related technologies, the measurement of shaft voltage of rotating shafts generally includes the following methods: (1) High internal resistance AC millivoltmeter method: A high input impedance AC millivoltmeter (such as a transistor / thermoelectric potential millivoltmeter) is used to directly measure the voltage difference U1 between the two ends of the rotating shaft and the bearing housing voltage to ground U2. This method requires the motor to be stopped before contacting the rotating shaft, and online monitoring cannot be achieved. (2) Measurement with a combination of special brush and insulated handle: A special brush with a long insulated handle (≥300mm) is used to contact the surface of the rotating shaft and measured with an AC voltmeter. Measurement with a combination of special brush and insulated handle: The brush is easily wrapped and tangled under high-speed rotation, causing personal injury or equipment damage. Each measurement requires stopping the machine to install / remove the brush, which is not suitable for high-frequency detection. (3) Electromagnetic induction method: The shaft voltage value is calculated by detecting the change of electromagnetic field inside the bearing through a sensor. In a weak magnetic field environment (such as low speed and light load), the signal-to-noise ratio is low and it is easy to miss the detection; different motor types require customized calibration curves, and the universality is poor. (4) Capacitive Coupling Method: This method uses a capacitive sensor to couple the shaft voltage to the measurement circuit, suitable for high-frequency signal capture. Humidity and temperature changes cause parasitic capacitance fluctuations, affecting measurement stability; space needs to be reserved near the rotating shaft for electrode installation, making it difficult to modify existing equipment; capacitance changes caused by mechanical vibration may be misjudged as voltage fluctuations. (5) Opto-isolation Method: This method uses opto-isolation technology to transmit signals to a safe area, avoiding electrical interference. High-precision opto-conversion modules are expensive, and the system is complex; the nonlinear characteristics of the relationship between luminous intensity and voltage conversion require software compensation; dust and oil covering the optical window will cause signal attenuation.

[0025] This application provides an embodiment of a motor shaft voltage testing device. Please refer to [link to relevant documentation]. Figures 1 to 3The shaft voltage testing device includes a testing component 1 and a testing module 2. The testing component 1 includes an end cap 11, a first conductive element 12, a second conductive element 13, a first wire 14, and a second wire 15. The end cap 11 is used to connect to the axial end of the motor housing assembly 100. The first conductive element 12 is used to conductively connect to the motor shaft 300 and can rotate synchronously with the shaft 300. The second conductive element 13 is insulated from the end cap 11 and makes conductive contact with the first conductive element 12. The first wire 14 conductively connects the end cap 11 and the testing module 2. The second wire 15 conductively connects the second conductive element 13 and the testing module 2. The testing module 2 is used to output the shaft voltage of the shaft 300.

[0026] The motor provided in this application embodiment can be used in automobiles, such as new energy vehicles.

[0027] The shaft voltage of a motor refers to the potential difference that occurs between the end of the motor shaft 300 and the ground during motor operation due to electromagnetic induction or other physical effects.

[0028] The shaft 300 is used to mount the rotor 200 of the motor. The rotor 200 includes the rotor core and windings, and completes energy conversion and power output through rotational motion.

[0029] End cap 11 is connected to the axial end of housing assembly 100, and end cap 11 serves as a grounding reference terminal.

[0030] For example, the housing assembly 100 may have a generally annular structure with an opening at its axial end, and the end cap 11 may seal the opening at the axial end of the housing assembly 100. This prevents dust, contaminants, and other external environmental pollutants from entering the motor and affecting its performance, thereby improving the anti-interference capability of the testing equipment.

[0031] The first conductive element 12 can be fixed to the rotating shaft 300. During the synchronous rotation of the first conductive element 12 with the rotating shaft 300, the first conductive element 12 and the second conductive element 13 maintain a relatively sliding conductive contact.

[0032] The second conductive element 13 can be fixed to the end cap 11. Since the second conductive element 13 is insulated from the end cap 11, there is no electrical conduction between the second conductive element 13 and the end cap 11.

[0033] The testing principle of the testing device generally includes: using the end cap 11 as a ground reference terminal, the first conductive element 12, which rotates synchronously with the shaft 300, is conductively connected to the shaft 300, while the second conductive element 13 maintains continuous conductive contact with the first conductive element 12. The end cap 11 is then connected to the testing module 2 via the first wire 14, and the second conductive element 13 is connected to the testing module 2 via the second wire 15. The testing module 2 collects and calculates the potential difference between the potential of the shaft 300 transmitted by the second conductive element 13 and the ground potential of the end cap 11, thereby outputting the shaft voltage value of the shaft 300.

[0034] The first conductive element 12 and the second conductive element 13 make conductive contact without relative friction between them and the rotating shaft 300. Therefore, the risk of the rotating shaft 300 generating debris due to friction affecting the shaft voltage test can be reduced.

[0035] The electrical signal of the rotating shaft 300 is exported through the conductive connection between the second conductive element 13 and the first conductive element 12, allowing testing even during high-speed rotation of the shaft 300, thus enabling shaft voltage measurement without shutting down the motor. The first wire 14 conducts the electrical signal from the end cap 11 to the test module 2, and the second wire 15 directly conducts the electrical signal from the second conductive element 13 to the test module 2. Since the end cap 11 and the second conductive element 13 remain relatively stationary, the risk of wire tangling is reduced. The shaft voltage can be measured through the potential difference between the end cap 11 and the rotating shaft 300. Replacement is easy; the end cap 11 and the first conductive element 12 can be removed for replacement, improving the convenience of the shaft voltage testing device.

[0036] In some embodiments, the test module 2 is located outside the motor. A first conductive element 12 is disposed on the motor shaft 300, and a second conductive element 13 is disposed on the end cover 11. The end cover 11 is then assembled along the axial direction of the housing assembly 100. When the end cover 11 is assembled, the first conductive element 12 and the second conductive element 13 are electrically connected. A first wire 14 can conduct the electrical signal of the end cover 11 to the test module 2, and a second wire 15 can conduct the electrical signal of the shaft 300 to the test module 2, thereby completing real-time monitoring of the shaft voltage. This enables a static test module 2 that conducts electrical signals from the high-speed rotating shaft 300 to the outside of the motor, reducing the difficulty of testing the shaft voltage of the variable frequency motor. The structure is simple and easy to install.

[0037] The shaft voltage testing device provided in this application embodiment maintains conductive contact between the first conductive element 12 and the second conductive element 13 during the rotation of the shaft 300. This allows direct conduction of the electrical signal from the shaft 300 to the second conductive element 13, and the second wire 15 conducts the electrical signal from the shaft 300 to the testing module 2, enabling shaft voltage measurement without stopping the motor. The first wire 14 conducts the electrical signal from the end cap 11 to the testing module 2, and the second wire 15 conducts the electrical signal from the second conductive element 13 to the testing module 2. Since the end cap 11 and the second conductive element 13 remain relatively stationary, the risk of wire tangling is reduced. The shaft voltage can be measured by the potential difference between the end cap 11 and the shaft 300. Replacement is easy; the end cap 11 and the first conductive element 12 can be removed for replacement, improving the convenience of the shaft voltage testing device.

[0038] The method of insulating the second conductive element 13 from the end cap 11 is not limited. For example, the shaft voltage testing device includes an insulating frame 5, which insulatingly connects the second conductive element 13 and the end cap 11.

[0039] The insulating frame 5 has an insulating function. For example, the insulating frame 5 can be made of insulating materials, such as plastic or ceramic insulating materials, etc.

[0040] The shape of the insulating frame 5 is not limited; for example, the insulating frame 5 can be circular.

[0041] In some embodiments, at least one of the housing assembly 100 and the end cap 11 is provided with a mounting hole through which the first wire 14 and the second wire 15 can be connected to the test module 2 outside the motor.

[0042] For example, the end cover 11 is provided with a mounting hole, through which the first wire 14 and the second wire 15 can pass through the mounting hole and extend to the outside of the motor.

[0043] The number of mounting holes is unlimited; for example, the number of mounting holes can be one or more.

[0044] The first wire 14 and the second wire 15 can be sealed through the mounting hole. For example, the gap between the first wire 14 and the wall of the mounting hole, and the gap between the second wire 15 and the wall of the mounting hole can be sealed by a seal.

[0045] Test module 2 is a device for acquiring different types of electrical signals. It can record electrical signals to obtain voltage or current data, and display them visually on a monitor for easy observation and analysis by the user.

[0046] The type of test module 2 is not limited. For example, test module 2 may include an oscilloscope, etc., which can display the axis voltage as a waveform.

[0047] The type of motor in this application is not limited. For example, the motor in this application can be a water-cooled motor, an air-cooled motor, or an oil-cooled motor, etc.

[0048] The method of fixing the first conductive element 12 to the rotating shaft 300 is not limited. For example, the first conductive element 12 can be detachably connected to the rotating shaft 300 or not detachably connected.

[0049] In some embodiments, please refer to Figure 4 The first conductive element 12 forms a first through hole 120, which is used to pass through the rotating shaft 300.

[0050] The rotating shaft 300 passes through the first through hole 120 and is disposed in the first conductive element 12, thereby increasing the contact area between the first conductive element 12 and the rotating shaft 300 and improving the electrical signal transmission efficiency.

[0051] For example, the rotating shaft 300 can be interference-fitted with the first through hole 120 to achieve a fixed connection between the rotating shaft 300 and the first through hole 120.

[0052] The shape of the first conductive element 12 is not limited. For example, the shape of the first conductive element 12 can be an annular shape, which has a simple structure.

[0053] A conductive path is established between the first conductive element 12 and the rotating shaft 300, both of which are conductive structures. For example, both the first conductive element 12 and the rotating shaft 300 are made of conductive metal.

[0054] The material of the first conductive element 12 is not limited. The first conductive element 12 can be oxygen-free copper or aluminum alloy, etc., which can reduce costs.

[0055] In some embodiments, the rotating shaft 300 includes a first stepped surface, and one axial end of the first conductive element 12 abuts against the first stepped surface. On the one hand, this facilitates the positioning and assembly of the first conductive element 12 to the rotating shaft 300; on the other hand, it can reduce the risk of the first conductive element 12 shifting axially.

[0056] In some embodiments, please refer to Figures 1 to 4 The test component 1 includes multiple first conductive elements 12, and the diameter of the first through hole 120 of each first conductive element 12 is different.

[0057] Different types of motors may have different diameters of shaft 300. A first conductive element 12 matching the diameter of the shaft 300 can be selected and assembled onto the corresponding shaft 300. For example, multiple first conductive elements 12 with different diameters of first through holes 120 can be manufactured so that they can be adapted according to the radial dimension of the shaft 300. If the radial dimension of the shaft 300 is large, a first conductive element 12 with a larger diameter of first through hole 120 can be selected. Conversely, if the radial dimension of the shaft 300 is small, a first conductive element 12 with a smaller diameter of first through hole 120 can be selected.

[0058] In this embodiment, multiple first conductive elements 12 can be adapted to different types of motors, improving versatility.

[0059] The number of first conductive elements 12 is not limited. For example, the number of first conductive elements 12 can be two or more.

[0060] In some embodiments, please refer to Figure 5 and Figure 6 The second conductive element 13 includes a conductive post 131, which makes conductive contact with the radial end face or the axial end face of the first conductive element 12.

[0061] For example, the first conductive element 12 and the second conductive element 13 are radially engaged, and the conductive post 131 is in conductive contact with the radial end face of the first conductive element 12. The electrical signal of the rotating shaft 300 is transmitted radially to the conductive post 131 through the first conductive element 12.

[0062] For example, the first conductive element 12 and the second conductive element 13 are axially engaged, and the conductive post 131 is in conductive contact with the end face of the first conductive element 12 along the axis. The electrical signal of the rotating shaft 300 is conducted to the conductive post 131 through the first conductive element 12 along the axis.

[0063] The material of the second conductive element 13 is not limited. For example, the second conductive element 13 can be metal graphite or resin-impregnated graphite, etc.

[0064] In some embodiments, please refer to Figure 5 and Figure 6 The second conductive element 13 includes a main body 132, which forms a second through hole 1320. A conductive post 131 is disposed in the second through hole 1320. The first conductive element 12 and the conductive post 131 are in conductive contact with each other at the end face of the first conductive element 12 that is radially away from the main body 132.

[0065] Specifically, the main body 132 may surround the outer periphery of the first guide member, and in the radial direction, the conductive post 131 is located between the main body 132 and the first conductive member 12.

[0066] In some embodiments, the conductive post 131 may not be disposed in the second through hole 1320, but may be disposed on the main body 132, and the first conductive element 12 and the conductive post 131 may be in conductive contact with the end face of the conductive post 131 that is axially away from the main body 132.

[0067] The shape of the main body 132 is not limited. For example, the shape of the main body 132 may include, but is not limited to, a ring.

[0068] The shape of the conductive post 131 is not limited. For example, the conductive post 131 can be roughly cylindrical, elliptical, or prismatic, etc.

[0069] In some embodiments, please refer to Figure 5 and Figure 6 The second conductive element 13 includes multiple conductive posts 131, which are distributed circumferentially along the second through hole 1320. This improves the electrical signal transmission efficiency of the rotating shaft 300. The conductive posts 131 can also support the main body 132 of the second conductive element 13, maintaining the stable operation of the second conductive element 13. At the same time, multiple conductive posts 131 work together, and the non-conductivity of a single conductive post 131 does not affect the continued conductivity of other conductive posts 131, thus extending the service life of the second conductive element 13.

[0070] The number of conductive posts 131 is not limited; for example, the number of conductive posts 131 can be two or more.

[0071] It should be noted that, unless otherwise stated, in the embodiments of this application, the axial direction refers to the direction of the rotation axis of the rotating shaft 300, the radial direction is the direction perpendicular to the axial direction, and the circumferential direction is the circumferential direction around the axial direction.

[0072] In some embodiments, please refer to Figures 1 to 3 The shaft voltage testing device includes a bearing 3, an end cover 11 forming a stop, and a rotating shaft 300 connected to the side wall of the stop through the bearing 3.

[0073] For example, the rotating shaft 300 passes through the bearing 3, and the radial end face of the bearing 3 is connected to the side wall of the stop on the end cover 11.

[0074] In this embodiment, the bearing 3 is assembled on the side wall of the stop and supports the rotation of the shaft 300. On the one hand, the positioning effect of the stop ensures the coaxiality of the bearing 3 and the shaft 300, reduces the magnetic circuit asymmetry problem caused by eccentricity, and thus reduces the interference of shaft voltage fluctuation on the test results. On the other hand, the stop structure can enhance the limiting effect of the end cover 11 on the bearing 3, prevent radial movement or axial displacement when the shaft 300 rotates at high speed, improve the operating stability of the shaft 300, and ensure that the first conductive element 12 and the second conductive element 13 always maintain conductive contact.

[0075] In some embodiments, please refer to Figures 1 to 3 The shaft voltage testing device includes an insulating sleeve 4, which is fitted around the outer periphery of the bearing 3 and connected to the side wall of the stop.

[0076] In this embodiment, the insulating sleeve 4 insulates the bearing 3 and the end cover 11. On the one hand, it can achieve electrical isolation between the bearing 3 and the stop of the end cover 11, blocking the current path between the rotating shaft 300 and the end cover 11. On the other hand, the insulating sleeve 4 can fill the assembly gap between the bearing 3 and the side wall of the stop, improving the coaxiality and structural rigidity of the bearing 3 installation.

[0077] In related technologies, when the shaft voltage exceeds the insulation strength of the bearing lubricating oil film, a series of chain reactions occur, such as arc discharge, intensified electro-corrosion, lubrication failure, or metal migration. This causes mechanical damage to the motor, resulting in "washboard"-like patterns on the inner ring / rolling elements of the bearing, cage melting and deformation, and may also lead to motor performance degradation, such as excessive vibration values ​​(especially radial vibration), abnormal bearing noise (high-frequency howling), or abnormal temperature rise (10-20°C higher than normal, or even higher). For motors used in new energy vehicles, this damage greatly interferes with the vehicle's NVH performance, causes drive system vibration, reduces user experience, and may even pose safety hazards.

[0078] In some embodiments, the interior of the insulating sleeve 4 is coated with an insulating coating that can block the path of harmful current flowing through the bearing 3, thereby preventing the lubricating oil film of the bearing 3 from breaking down due to excessive shaft voltage, generating high temperature to melt the metal, and preventing electro-corrosion damage.

[0079] For example, the end cap 11 is assembled onto the rotating shaft 300 along the axial direction of the housing assembly 100 until the bearing 3 contacts the rotating shaft 300. The bearing 3 is insulated from the end cap 11 by the insulating sleeve 4. The end cap 11 can be considered as grounded. One end of the first wire 14 is connected to the side wall of the stop on the end cap 11, and the other end is connected to the test module 2, thereby transmitting the electrical signal of the end cap 11 to the test module 2. The shaft voltage can be measured by calculating the potential difference between the end cap 11 and the rotating shaft 300.

[0080] In some embodiments, the end cap 11 forms multiple stops, each with a different diameter.

[0081] In some embodiments, the shaft 300 includes a second stepped surface, and one axial end of the bearing 3 abuts against the second stepped surface.

[0082] For example, multiple stops with different diameters can be used to install bearings 3 of different diameters, improving the versatility of the shaft voltage testing device.

[0083] The number of stops is unlimited; for example, there can be two or more stops.

[0084] Here, the diameter of the stop can vary. Different diameter stops can be provided inside different end caps 11 to accommodate bearings 3 of different diameters, allowing for installation and mating with rotating shafts 300 of different diameters. Alternatively, stops of different diameters can be provided on the same end cap 11. For example, the sidewall of the stop can be stepped, with the diameter decreasing towards the end cap 11 along the axial direction. This allows for the installation of bearings 3 of different diameters on rotating shafts 300, improving the versatility of the shaft voltage testing device. This enhances the adaptability of the end cap 11.

[0085] In some embodiments, please refer to Figures 1 to 3 The shaft voltage testing device includes multiple sets of testing components 1, with at least one set of testing components 1 respectively installed at both ends of the rotating shaft 300 in the axial direction. In this way, multiple sets of testing components 1 test multiple positions at both ends of the rotating shaft 300, preventing missed detections and improving the accuracy of shaft voltage testing.

[0086] In some embodiments, the end cover 11 includes a front cover and a rear cover. Taking the test assembly 1 as an example where there are two sets, the first conductive element 12 is directly assembled on one end of the rotating shaft 300, and the second conductive element 13 is connected to the front cover. The front cover can be regarded as grounded. The first wire 14 conducts the electrical signal of the front cover to the test module 2. When the front end cover is assembled axially to the housing assembly 100, the first conductive element 12 and the second conductive element 13 are electrically connected. The first conductive element 12 transmits the electrical signal of one end of the rotating shaft 300 to the second conductive element 13, and conducts it to the test module 2 through the second wire 15. The shaft voltage of the motor can be measured by calculating the potential difference between the front cover and the rotating shaft 300.

[0087] Another set of test components 1 is assembled at the other end of the shaft 300. The first conductive element 12 of the other set of test components 1 is assembled to the other end of the shaft 300, and the second conductive element 13 is connected to the rear end cover. The rear end cover can be regarded as grounded. The first wire 14 conducts the electrical signal of the rear end cover to the test module 2. When the rear end cover is assembled to the housing assembly 100 along the axial direction, the first conductive element 12 and the second conductive element 13 are electrically connected. The first conductive element 12 transmits the electrical signal of one end of the shaft 300 to the second conductive element 13, and conducts it to the test module 2 through the second wire 15. The shaft voltage of the motor can be measured by calculating the potential difference between the rear end cover and the shaft 300.

[0088] Another embodiment of this application provides a shaft voltage testing system, including a shaft voltage testing device according to any one of the above, and a motor. The motor includes a housing assembly 100, and the axial end of the housing assembly 100 is connected to the end cover 11 of the shaft voltage testing device.

[0089] For example, the axial end of the housing assembly 100 is fixedly connected to the end cover 11. The connection can be detachable or non-detachable. The detachable connection includes, but is not limited to, stud connection or bolt connection. Taking the bolt connection between the end cover 11 and the housing assembly 100 as an example, the convenience of disassembling and installing the end cover 11 and the housing assembly 100 is improved.

[0090] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way.

Claims

1. A device for testing the shaft voltage of a motor, characterized in that, The shaft voltage testing device includes a testing component and a testing module. The testing component includes: End cap, used for connection to the axial end of the motor housing assembly; A first conductive element is used to conductively connect with the rotating shaft of the motor, and the first conductive element can rotate synchronously with the rotating shaft; The second conductive element is insulated from the end cap and is in conductive contact with the first conductive element. A first wire conductively connects the end cap and the test module; The second wire is electrically connected to the second conductive component and the test module, which is used to output the shaft voltage of the rotating shaft.

2. The shaft voltage testing device according to claim 1, characterized in that, The first conductive element forms a first through hole, which is used to pass through the rotating shaft.

3. The shaft voltage testing device according to claim 2, characterized in that, The test assembly includes multiple first conductive elements, each of which has a different diameter for its first through hole.

4. The shaft voltage testing device according to claim 1, characterized in that, The second conductive element includes: The conductive post is in conductive contact with the radial or axial end face of the first conductive element.

5. The shaft voltage testing device according to claim 4, characterized in that, The second conductive element includes: The main body forms a second through hole, and the conductive post is disposed in the second through hole. The first conductive element and the conductive post are in conductive contact with each other on the end face of the conductive post that is radially away from the main body.

6. The shaft voltage testing device according to claim 5, characterized in that, The second conductive element includes a plurality of conductive pillars, which are distributed at circumferential intervals along the second through hole.

7. The shaft voltage testing device according to claim 1, characterized in that, The shaft voltage testing device includes a bearing, the end cover forms a stop, and the rotating shaft is connected to the side wall of the stop through the bearing.

8. The shaft voltage testing device according to claim 7, characterized in that, The shaft voltage testing device includes an insulating sleeve, which is fitted around the outer periphery of the bearing and connected to the side wall of the stop; and / or, The end cap forms multiple stops, each with a different diameter.

9. The shaft voltage testing device according to any one of claims 1 to 8, characterized in that, The shaft voltage testing device includes multiple sets of the testing components, with at least one set of the testing components respectively arranged at both ends of the rotating shaft in the axial direction.

10. A testing system, characterized in that, include: The shaft voltage testing device according to any one of claims 1 to 9; The motor includes a housing assembly whose axial end is connected to the end cover of the shaft voltage testing device.

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