Measurement Method and Device for Dynamic Impact Load of Wheel Motor Bearing

Abstract

The present invention relates to a method and device for measuring the dynamic impact load of a wheel-side motor bearing, including collecting the vibration load spectrum of the wheel-side motor under actual road loads, processing the vibration load spectrum to obtain a test load spectrum; inputting the test load spectrum into a control system, fixing the wheel-side motor on a three-axis vibration table, and using the test load spectrum to drive the three-axis vibration table through a power amplifier to simultaneously generate three-axis vibration loads consistent with the vibration environment in actual road use; collecting the vibration responses of the stator and rotor of the wheel-side motor in real time, and analyzing and processing to obtain the dynamic impact load of the motor bearing. The present invention has high collection accuracy and strong operability, can effectively simulate the multi-axis vibration stress environment in the real use environment, and can well meet the high-precision measurement requirements in complex environments.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing measurement of in-wheel motors, and particularly to a method and device for measuring the dynamic impact load of in-wheel motor bearings. Background Art

[0002] During the actual use of the bearings of in-wheel motors, they are subjected to various dynamic impact loads, which is an important factor affecting the fatigue life of the motor bearings. Due to the existence of bearing clearance, there will be dynamic impact loads with a very short duration on the inner and outer rings of the motor bearings in the vibration environment of actual road loads. In actual situations, due to space limitations, it is impossible to arrange sensors, so effective measurement cannot be carried out.

[0003] Currently, in order to test the dynamic impact load, a single-axis vibration table is used for excitation. This method cannot truly and effectively simulate the multi-axial vibration environment in actual road loads. At the same time, the excitation load spectrum for driving the vibration table is generally not the measured road load spectrum of this motor. Therefore, the vibration response generated by its bearings is very different from the actual situation, and it is impossible to effectively simulate the real road vibration situation of this motor during actual use. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that it is impossible to effectively simulate the real road vibration situation of the motor during actual use, so as to provide a method and device for measuring the dynamic impact load of in-wheel motor bearings that can effectively simulate the real road vibration situation of the motor during actual use.

[0005] To solve the above technical problem, a method for measuring the dynamic impact load of in-wheel motor bearings of the present invention includes the following steps: collecting the vibration load spectrum of the in-wheel motor in the actual road load, and processing the vibration load spectrum to obtain a test load spectrum; inputting the test load spectrum into a control system, fixing the in-wheel motor on a three-axial vibration table, connecting the power amplifier to the three-axial vibration table, and using the test load spectrum to drive the three-axial vibration table to simultaneously generate three-axial vibration loads consistent with the vibration environment of actual road use through the power amplifier; collecting the vibration responses of the stator and rotor of the in-wheel motor in real time, and analyzing and processing to obtain the dynamic impact load of the motor bearings.

[0006] In an embodiment of the present invention, the method for collecting the vibration data of the in-wheel motor in the actual road load is: arranging a first acceleration sensor at the fixed mounting foot position of the in-wheel motor to collect the road vibration load spectrum of the in-wheel motor in the actual use environment.

[0007] In an embodiment of the present invention, the method for processing the vibration load spectrum is as follows: the collected road vibration load spectrum is processed such as compression, extrapolation, superposition, and time-domain reconstruction according to the principle of consistent damage to obtain the test load spectrum.

[0008] In an embodiment of the present invention, the method for collecting the vibration responses of the stator and rotor of the in-wheel motor in real time is as follows: an axial monitoring sensor and a radial monitoring sensor are installed on the stator of the in-wheel motor, and at the same time, a second acceleration sensor is installed on the stator of the in-wheel motor to collect the vibration condition of the rotor of the in-wheel motor relative to the stator during the vibration of the three-axis vibration table.

[0009] The present invention also provides a measuring device for the dynamic impact load of the in-wheel motor bearing, including: a first acquisition and processing system for collecting the vibration load spectrum of the in-wheel motor under the actual road load and processing the vibration load spectrum to obtain the test load spectrum; a control system, the control system is connected to the first acquisition and processing system, inputs the test load spectrum into the control system, the control system is connected to a power amplifier, and uses the test load spectrum to drive a three-axis vibration table to generate exciting forces in three axial directions simultaneously through the power amplifier, and the in-wheel motor is placed on the three-axis vibration table; a second acquisition and processing system, the second acquisition and processing system is connected to the control system for collecting the vibration responses of the stator and rotor of the in-wheel motor in real time and analyzing and processing to obtain the dynamic impact load of the motor bearing.

[0010] In an embodiment of the present invention, the three-axis vibration table is respectively provided with an X-axis vibration table, a Y-axis vibration table, and a Z-axis vibration table, wherein the X-axis vibration table, the Y-axis vibration table, and the Z-axis vibration table are mutually orthogonal, the in-wheel motor is arranged on the vibration table surface, and the vibration table surface is simultaneously connected to the X-axis vibration table, the Y-axis vibration table, and the Z-axis vibration table.

[0011] In an embodiment of the present invention, the in-wheel motor is provided with an axial monitoring sensor and a radial monitoring sensor.

[0012] In an embodiment of the present invention, the stator of the in-wheel motor is provided with a sensor mounting fixture, and the axial monitoring sensor and the radial monitoring sensor are mounted on the sensor mounting fixture

[0013] In an embodiment of the present invention, the vibration table surface is provided with a motor clamping body, and the in-wheel motor is fixed on the motor clamping body.

[0014] In an embodiment of the present invention, the stator of the in-wheel motor is provided with a second acceleration sensor.

[0015] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0016] The measuring method and device for the dynamic impact load of the in-wheel motor bearing of the present invention collect the vibration load spectrum of the in-wheel motor under the actual road load, process the vibration load spectrum to obtain the test load spectrum. Since the measured road load is used as the driving spectrum, a reliable vibration excitation source is ensured, and a real and reliable vibration input is guaranteed. The test load spectrum is input into the control system, and the in-wheel motor is placed on a three-axis vibration table. The test load spectrum is used to drive the three-axis vibration table to generate exciting forces in three axial directions simultaneously through a power amplifier. The exciting forces are transmitted to the in-wheel motor and then to the inner and outer rings of the bearing to be measured, which is beneficial to effectively simulating the multi-axis vibration stress in the real use environment. The vibration responses of the stator and rotor of the in-wheel motor are collected in real time, and the dynamic impact load of the motor bearing is obtained through analysis and processing. Since the actual vibration stress environment is better simulated, the inner and outer rings of the bearing of the tested motor are excited to generate vibration responses consistent with the use environment, thus more accurately simulating the actual vibration stress environment. In addition, due to the simple principle, high acquisition accuracy, and strong operability of this method, it can effectively simulate the multi-axis vibration stress environment in the real use environment and can well meet the high-precision measurement requirements of such complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the drawings, where

[0018] Figure 1 is a schematic diagram of the measuring method for the dynamic impact load of the in-wheel motor bearing of the present invention;

[0019] Figure 2 is a schematic diagram of the measuring device for the dynamic impact load of the in-wheel motor bearing of the present invention;

[0020] Figure 3 is Figure 2 an enlarged view of the motor fixture in

[0021] Description of the reference numerals in the drawings: 10 - three-axis vibration table, 11 - X-axis vibration table, 12 - Y-axis vibration table, 13 - Z-axis vibration table, 14 - vibration table surface, 20 - in-wheel motor, 21 - motor fixture, 30 - sensor mounting fixture, 31 - axial monitoring sensor, 32 - radial monitoring sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Embodiment 1

[0023] As Figure 1As shown in the figure, this embodiment provides a method for measuring the dynamic impact load of a wheel-side motor bearing, including the following steps: Step S1: Collect the vibration load spectrum of the wheel-side motor under actual road loads, and process the vibration load spectrum to obtain a test load spectrum; Step S2: Input the test load spectrum into the control system, fix the wheel-side motor on a three-axis vibration table, and use the test load spectrum to drive the three-axis vibration table through a power amplifier to simultaneously generate three-axis vibration loads consistent with the vibration environment in actual road use; Step S3: Collect the vibration responses of the stator and rotor of the wheel-side motor in real time, and analyze and process them to obtain the dynamic impact load of the motor bearing.

[0024] For the method for measuring the dynamic impact load of the wheel-side motor bearing in this embodiment, in Step S1, the vibration load spectrum of the wheel-side motor under actual road loads is collected, and the vibration load spectrum is processed to obtain a test load spectrum. Since the measured road load is used as the driving spectrum, a reliable vibration excitation source is ensured, and a true and reliable vibration input is ensured; in Step S2, the test load spectrum is input into the control system, the wheel-side motor is fixed on a three-axis vibration table, and the test load spectrum is used to drive the three-axis vibration table through a power amplifier to simultaneously generate three-axis vibration loads consistent with the vibration environment in actual road use. After the vibration load is transmitted to the wheel-side motor and then to the inner and outer rings of the bearing to be measured, it is conducive to effectively simulating the multi-axis vibration stress in the actual use environment; in Step S3, the vibration responses of the stator and rotor of the wheel-side motor are collected in real time, and the dynamic impact load of the motor bearing is obtained through analysis and processing. Since the actual vibration stress environment is better simulated, the inner and outer rings of the bearing of the measured motor are excited to generate vibration responses consistent with the use environment, so as to more accurately simulate the actual vibration stress environment; in addition, due to the simple principle, high acquisition accuracy, and strong operability of this method, it can effectively simulate the multi-axis vibration stress environment in the actual use environment and can well meet the high-precision measurement requirements of such complex environments.

[0025] The method for collecting the vibration data of the wheel-side motor under actual road loads is as follows: A first acceleration sensor is arranged at the fixed mounting foot position of the wheel-side motor to collect the road vibration load spectrum of the wheel-side motor in the actual use environment, so as to ensure accurate collection of the road load spectrum of the wheel-side motor in the actual use environment. In the actual use of the present invention, one such first acceleration sensor is arranged at each of the four fixed mounting feet of the wheel-side motor.

[0026] The method for processing the vibration load spectrum is as follows: The collected road vibration load spectrum is processed by compression, extrapolation, superposition, time-domain reconstruction, etc. in accordance with the principle of consistent damage to obtain the test load spectrum. While ensuring the fatigue damage of the original load spectrum, the time history of the load spectrum is significantly compressed, and finally the test load spectrum is generated. The measured road load spectrum is used for analysis and processing to compile the test load spectrum in order to obtain a reliable environmental vibration excitation source and ensure a true and reliable vibration input.

[0027] The method for real-time collecting the vibration responses of the stator and rotor of the in-wheel motor is as follows: An axial monitoring sensor and a radial monitoring sensor are installed on the stator of the in-wheel motor. At the same time, a second acceleration sensor is installed on the stator of the in-wheel motor to collect the vibration condition of the rotor of the in-wheel motor relative to the stator during the vibration of the three-axis vibration table, so that the vibration response of the rotor of the in-wheel motor relative to the stator can be collected in real time. Wherein, the rotor of the in-wheel motor is connected to the inner ring of the bearing; the stator of the in-wheel motor is connected to the outer ring of the bearing.

[0028] In this embodiment, the axial monitoring sensor and the radial monitoring sensor are non-contact eddy current sensors. The non-contact eddy current sensors can collect the real-time vibration response of the rotor connected to the inner ring of the in-wheel motor bearing relative to the stator of the in-wheel motor in real time. It not only has a simple principle, but also has high acquisition accuracy, a small sensor volume, strong operability, and good vibration resistance, and can well meet the high-precision measurement requirements of such complex environments.

[0029] Embodiment 2

[0030] As Figure 2 and Figure 3 shown, this embodiment provides a measuring device for the dynamic impact load of an in-wheel motor bearing, including a first acquisition and processing system for collecting the vibration load spectrum of the in-wheel motor in the actual road load and processing the vibration load spectrum to obtain the test load spectrum; a control system, the control system is connected to the first acquisition and processing system, inputs the test load spectrum into the control system, the control system is connected to a power amplifier, the power amplifier is connected to a three-axis vibration table, and the test load spectrum is used to drive the three-axis vibration table 10 to simultaneously generate exciting forces in three axial directions through the power amplifier, and the in-wheel motor 20 is placed on the three-axis vibration table 10; a second acquisition and processing system, the second acquisition and processing system is connected to the control system for real-time collecting the vibration responses of the stator and rotor of the in-wheel motor 20 and analyzing and processing to obtain the dynamic impact load of the motor bearing.

[0031] This embodiment provides a measuring device for the dynamic impact load of a wheel motor bearing, including a first acquisition and processing system for acquiring the vibration load spectrum of the wheel motor under actual road loads, processing the vibration load spectrum to obtain a test load spectrum. Since the measured road load is used as the driving spectrum, a reliable vibration excitation source is ensured, and a true and reliable vibration input is guaranteed; a control system, the control system is connected to the first acquisition and processing system, inputs the test load spectrum into the control system, the control system is connected to a power amplifier, the power amplifier is connected to a three-axis vibration table 10, and the test load spectrum is used to drive the three-axis vibration table 10 to generate exciting forces in three axes simultaneously through the power amplifier, and the wheel motor 20 is placed on the three-axis vibration table 10. After the exciting force is transmitted to the wheel motor 20, it is then transmitted to the inner and outer rings of the bearing to be measured, which is conducive to effectively simulating the multi-axis vibration stress in the actual use environment; a second acquisition and processing system, the second acquisition and processing system is connected to the control system for real-time acquiring the vibration responses of the stator and rotor of the wheel motor 20 and analyzing and processing to obtain the dynamic impact load of the motor bearing. Since the actual vibration stress environment is better simulated, the inner and outer rings of the bearing of the measured motor are excited to generate vibration responses consistent with the use environment, thus more accurately simulating the actual vibration stress environment; in addition, this method has a simple principle, high acquisition accuracy, and strong operability, ensuring effective simulation of the multi-axis vibration stress environment in the actual use environment and can well meet the high-precision measurement requirements of such complex environments.

[0032] As Figure 2 and Figure 3 shown, an X-axis vibration table 11, a Y-axis vibration table 12, and a Z-axis vibration table 13 are respectively provided on the three-axis vibration table 10, wherein the X-axis vibration table 11, the Y-axis vibration table 12, and the Z-axis vibration table 13 are orthogonal to each other. The wheel motor 20 is arranged on a vibration table surface 14, and the vibration table surface 14 is simultaneously connected to the X-axis vibration table 11, the Y-axis vibration table 12, and the Z-axis vibration table 13. The three-axis vibration table 10 is driven by the power amplifier to generate three-axis vibration loads consistent with the actual road use vibration environment simultaneously, and the vibration loads are transmitted to the wheel motor 20 through the vibration table surface 14, thereby realizing three-direction vibration excitation of the wheel motor 20 and being conducive to simulating the dynamic impact loads received by the inner and outer rings of the bearing during the vibration process of the actual road load.

[0033] In order to monitor the vibration of the rotor of the in-wheel motor 20 relative to the stator during the three-axis vibration process, an axial monitoring sensor 31 and a radial monitoring sensor 32 are provided on the in-wheel motor 20. Specifically, the axial monitoring sensor 31 and the radial monitoring sensor 32 are provided on the stator of the in-wheel motor 20. A sensor mounting fixture 30 is provided at the resolver end of the in-wheel motor 20. The sensor mounting fixture 30 is fixed to the stator of the in-wheel motor 20, and the axial monitoring sensor 31 and the radial monitoring sensor 32 are mounted on the sensor mounting fixture 30. In order to accurately monitor the axial displacement, the number of the radial sensors 32 can be two. As a variant, in order to accurately collect the vibration response generated by the in-wheel motor 20 during the vibration process, a sensor mounting fixture 30 is also provided at the spline end of the in-wheel motor 20, which is opposite to the resolver end of the in-wheel motor 20. The axial monitoring sensor 31 and the radial monitoring sensor 32 are provided on the sensor mounting fixture 30, which is beneficial to improving the measurement accuracy.

[0034] In this embodiment, the sensor mounting fixture 30 and the in-wheel motor 20 are fixed with 6 M6 screws. In addition, the sensor mounting fixture 30 needs to have sufficient stiffness in the three axes in the test frequency band, the first-order frequency is higher than the test upper limit frequency and more than 10 times the rotational speed frequency of the in-wheel motor 20. For example, in this test, the motor speed is 2000 r / min ≈ 33.3 Hz, that is, the first-order frequency of the fixture needs to be > 333 Hz.

[0035] In order to ensure the measurement accuracy, a motor fixture 21 is provided on the vibration table 14. The in-wheel motor 20 is fixed to the motor fixture 21, so that the exciting forces in three axes generated by the three-axis vibration table 10 can be effectively transmitted to the in-wheel motor 20 through the vibration table 14 and the motor fixture 21, thereby realizing the vibration excitation in three directions on the in-wheel motor 20, which is beneficial to simulating the dynamic impact load received by the stator and rotor connected by the inner and outer rings of the bearing during the actual road load vibration process. In addition, in order to effectively simulate the actual installation state of the in-wheel motor 20 and ensure good vibration transmission ability, the first-order frequencies in three directions of the motor fixture 21 need to be greater than the upper limit frequency of the test load spectrum.

[0036] A second acceleration sensor is provided on the stator of the in-wheel motor 20. Through the second acceleration sensor, the vibration response of the stator connected to the outer ring of the bearing during the vibration process can be monitored. Specifically, the vibration condition of the stator of the in-wheel motor 20 is monitored by arranging second acceleration sensors at positions of the end cover and the machine base close to the bearing chamber. The number of the second acceleration sensors can be two, and they are contact three-axis acceleration sensors.

[0037] In the present invention, the real-time vibration signals monitored by the rotor and stator of the in-wheel motor 20 are collected and stored by the second acquisition and processing system. Through the analysis and processing of the collected real-time data, the dynamic impact loads received by the stator and rotor connected to the inner and outer rings of the bearing during the vibration process of the in-wheel motor 20 simulating the actual road load are calculated, providing a basis for the next bearing fatigue life analysis. Specifically, the vibration time history of the stator and rotor connected to the inner and outer rings of the in-wheel motor bearing can be accurately measured, and then an effective dynamic impact load spectrum can be obtained through a series of data analysis and processing techniques, which is used to calculate the bearing fatigue life and applied to the product design and selection to ensure the reliability during use.

[0038] The control system is a vibration controller; the second acquisition and processing system includes a dynamic signal acquisition and analyzer. In the present invention, the test load spectrum is input into the vibration controller, and this test load spectrum is used to drive the three-axis vibration table 10 to simultaneously generate exciting forces in three axial directions. The exciting forces are transmitted to the in-wheel motor 20 through the motor fixture 21 and then transmitted to the inner and outer rings of the bearing to be tested. Among them, the outer ring of the bearing is connected to the stator of the in-wheel motor, and three-axis acceleration sensors are arranged at appropriate positions to collect the three-direction acceleration vibration responses here; the inner ring of the in-wheel motor bearing is connected to the rotor of the in-wheel motor. Since the in-wheel motor 20 is in the rated speed state, only a non-contact measurement method can be selected. In the present invention, three mutually orthogonal high-precision eddy current sensors are arranged at both ends of the rotor of the in-wheel motor 20, and the eddy current sensors are fixed at the resolver end and spline end of the in-wheel motor 20 through the sensor mounting fixture 30 with good rigidity, non-contact real-time collecting the displacement of the rotor of the in-wheel motor relative to the stator, and analyzing and processing to obtain the final dynamic impact load of the motor bearing, so as to realize the measurement of the dynamic impact load received by the in-wheel motor bearing at the rated speed under the vibration environment simulating the road load spectrum in the laboratory.

[0039] In addition, the present invention is not necessarily limited to the bearing measurement of the in-wheel motor of new energy vehicles, and can include other fields that require accurate measurement of the dynamic vibration impact response of bearings in vibration environments.

[0040] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for measuring the dynamic impact load of a wheel hub motor bearing, characterized in that, Including the following steps: Step S1: Collect the vibration load spectrum of the in-wheel motor under actual road loads, and process the vibration load spectrum to obtain a test load spectrum; Step S2: Input the test load spectrum into the control system, fix the in-wheel motor on a three-axis vibration table, and use the test load spectrum to drive the three-axis vibration table through a power amplifier to simultaneously generate three-axis vibration loads consistent with the actual road use vibration environment; Step S3: Collect the vibration responses of the stator and rotor of the in-wheel motor in real time, and analyze and process them to obtain the dynamic impact load of the motor bearing. The method for collecting the vibration responses of the stator and rotor of the in-wheel motor in real time is as follows: Install an axial monitoring sensor and a radial monitoring sensor on the stator of the in-wheel motor, and at the same time install a second acceleration sensor on the stator of the in-wheel motor to collect the vibration of the rotor of the in-wheel motor relative to the stator during the vibration of the three-axis vibration table.

2. The method for measuring the dynamic impact load of the in-wheel motor bearing according to claim 1, wherein: The method for collecting the vibration data of the in-wheel motor under actual road loads is as follows: Arrange a first acceleration sensor at the fixed mounting foot position of the in-wheel motor to collect the road vibration load spectrum of the in-wheel motor in the actual use environment.

3. The method for measuring the dynamic impact load of the in-wheel motor bearing according to claim 1, characterized in that: The method for processing the vibration load spectrum is as follows: Compress, extrapolate, superimpose, and perform time-domain reconstruction on the collected road vibration load spectrum according to the principle of consistent damage to obtain a test load spectrum.

4. A measuring device for the dynamic impact load of a wheel-side motor bearing, characterized in that, Including: A first acquisition and processing system for collecting the vibration load spectrum of the in-wheel motor under actual road loads and processing the vibration load spectrum to obtain a test load spectrum; A control system, the control system is connected to the first acquisition and processing system, inputs the test load spectrum into the control system, the control system is connected to a power amplifier, the power amplifier is connected to a three-axis vibration table, and uses the test load spectrum to drive the three-axis vibration table through the power amplifier to simultaneously generate exciting forces in three axes, and the in-wheel motor is fixed on the three-axis vibration table; The three-axis vibration table is respectively provided with an X-axis vibration table, a Y-axis vibration table, and a Z-axis vibration table, where the X-axis vibration table, the Y-axis vibration table, and the Z-axis vibration table are mutually orthogonal, the in-wheel motor is arranged on the vibration table surface, and the vibration table surface is simultaneously connected to the X-axis vibration table, the Y-axis vibration table, and the Z-axis vibration table; A second acquisition and processing system, the second acquisition and processing system is connected to the control system, and is used for collecting the vibration responses of the stator and rotor of the in-wheel motor in real time, and analyzing and processing them to obtain the dynamic impact load of the motor bearing. The in-wheel motor is provided with an axial monitoring sensor and a radial monitoring sensor.

5. The measuring device for the dynamic impact load of the in-wheel motor bearing according to claim 4, characterized in that: A sensor mounting fixture is provided on the stator of the in-wheel motor, and the axial monitoring sensor and the radial monitoring sensor are mounted on the sensor mounting fixture.

6. The measuring device for the dynamic impact load of the in-wheel motor bearing according to claim 4, wherein: A motor clamping body is provided on the vibration table surface, and the in-wheel motor is fixed on the motor clamping body.

7. The measuring device for the dynamic impact load of the in-wheel motor bearing according to claim 4, wherein: A second acceleration sensor is provided on the stator of the in-wheel motor.

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