An apparatus and method for testing the strength of gears in an electric drive axle assembly.

Abstract

This invention discloses a testing device and method for the strength of gears in an electric drive axle assembly. The device includes a high-voltage distribution cabinet, a low-voltage power supply, a vehicle control unit (VCU), a host computer, an output motor, an output motor controller, a gearbox, a gearbox controller, a motor under test, a motor under test controller, a shifting mechanism for the motor under test, and several high-voltage and low-voltage connectors. The strength of the electric drive axle gears is detected by testing the maximum torque that the input shaft, intermediate shaft, and output shaft of the motor under test can withstand. This invention is easy to install and operate, offers multiple gear combinations, allows selection of different torque distributions, and enables various torque experiments on the gears, ensuring rigorous testing. It also saves debugging time, eliminating the need for fine-tuning the stress on the electric drive axle; the strength of the electric drive axle can be directly adjusted according to the experimental results.

Description

Technical Field

[0001] This invention relates to a testing device and method for the strength of gears in an electric drive axle assembly, belonging to the field of automotive manufacturing technology. Background Technology

[0002] Currently, the electric drive axle is a highly integrated transmission system that combines electronic control, motor, reducer, and drive axle. It consists of three main components: motor, inverter, and electric drive transmission. Existing drive axle torque test benches can only test the torsional stiffness and static torsional strength of the half-shafts. There is a lack of dedicated test benches for separately testing the stiffness and torque of the electric drive axle output shaft and intermediate shaft, and experimental data and analysis of the entire electric drive axle assembly are also lacking. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a testing device and method for the strength of gears in an electric drive axle assembly, which can quickly detect the strength of the input shaft, output shaft, and intermediate shaft of the electric drive axle.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A testing device for the strength of gears in an electric drive axle assembly, characterized in that it includes a high-voltage distribution cabinet, a low-voltage power supply, a vehicle control unit (VCU), and a host computer, and:

[0006] The output motor includes an output motor controller, an output motor high-voltage connector, and an output motor low-voltage connector. The output motor is equipped with an output motor high-voltage wiring harness terminal.

[0007] The transmission, the transmission controller, the transmission controller low-pressure connector and the transmission solenoid valve assembly, wherein the transmission solenoid valve assembly integrates a shift solenoid valve, a gear position sensor and an air circuit interface;

[0008] The test includes a motor under test, a motor under test controller, a high-voltage connector for the motor under test, a low-voltage connector for the motor under test, and a gear shifting mechanism for the motor under test. The motor under test includes an input shaft, an intermediate shaft, and an output shaft connected by gears. The strength of the gears is tested by the test device. The motor under test is equipped with a high-voltage wiring harness terminal.

[0009] The output motor is connected to the gearbox, and the output end of the output motor is provided with a transmission shaft connected to the motor under test, which is used to transmit the rotational torque of the output motor to the input shaft of the motor under test.

[0010] Two sets of high-voltage wire harnesses are led out from the output end of the high-voltage distribution cabinet and respectively connected to the input end of the output motor high-voltage connector and the motor under test high-voltage connector. The output ends of the output motor high-voltage connector and the motor under test high-voltage connector are respectively connected to the high-voltage wire harness terminals of the output motor and the motor under test, which are used to provide high-voltage working power to the output motor and the motor under test.

[0011] The output end of the low-voltage power supply is equipped with an emergency stop switch and a fuse box. Several high-voltage wires are led out from the output end of the low-voltage power supply and connected to the low-voltage connectors of the output motor, the gearbox controller, and the motor under test, respectively, to provide low-voltage operating power to the output motor, the gearbox, and the motor under test.

[0012] Preferably, the bottom of the motor under test is provided with a fixing mechanism, including a differential lock and a set of locking points and a set of half shafts located on both sides of the differential lock, with the two ends of the half shafts connected to the differential lock and the locking points respectively.

[0013] Preferably, the vehicle control unit (VCU), the host computer, the output motor controller, the transmission controller, and the motor under test are communicatively connected, wherein...

[0014] The vehicle controller (VCU) is used to receive real-time data from the output motor, the motor under test, the gearbox, and the shift mechanism of the motor under test, process the data and feed it back to the host computer, as well as receive instructions from the host computer and issue the received instructions to each controller.

[0015] The host computer is used to allow the operator to input control signals to control the test device, including calibrating the output torque of the output motor.

[0016] The output motor controller is used to control the torque and speed of the output motor, and to acquire information about the output motor, including torque, speed, temperature and fault status.

[0017] The transmission controller has several input terminals and output terminals. The input terminals are equipped with a solenoid valve assembly, an input shaft speed sensor, an output shaft speed sensor, and an air circuit interface. The solenoid valve assembly is used to simulate the gear shifting of the transmission. The input shaft speed sensor and the output shaft speed sensor are used to simulate the rotation state of the input shaft and output shaft of the transmission and output speed signals.

[0018] The motor controller under test is used to control the torque and speed of the motor under test, and to acquire information about the motor under test, including torque, speed, temperature, and fault status.

[0019] Preferably, the output motor high-voltage connector and the tested motor high-voltage connector are equipped with a functional module that converts DC power to AC power.

[0020] Preferably, the gearbox has two gears and two speed ratios. The gearbox solenoid valve assembly includes a first solenoid valve, a second solenoid valve, a first solenoid valve sensor, and a second solenoid valve sensor. The first and second solenoid valves are used to simulate the two gears of the gearbox. That is, when the host computer gives the instruction: the gearbox is engaged in first gear, the first solenoid valve executes the instruction, and the first solenoid valve sensor monitors whether the current gear is in first gear. If it is in first gear, the host computer is notified that the gear engagement was successful; otherwise, the engagement is not reported.

[0021] Preferably, the motor under test has two gears and two speed ratios. The motor under test is equipped with a speed sensor and a temperature sensor. The gear shifting mechanism of the motor under test is equipped with a gear shifting motor position sensor. That is, when the host computer gives the instruction: the motor under test is in first gear, the gear shifting mechanism of the motor under test executes the instruction, and the gear shifting motor position sensor of the motor under test detects whether it is currently in first gear. If it is in first gear, it reports to the host computer that the gear shifting was successful; otherwise, it reports that the gear shifting failed.

[0022] A method for testing the strength of gears in an electric drive axle assembly, applied to the aforementioned testing device, characterized by comprising the following steps:

[0023] S1. Adjust the gearbox and the motor under test to their maximum gear ratio combination for testing. The gearbox ratio is a. max The speed ratio of the motor being tested is b max ;

[0024] S2. Adjust the output torque of the output motor via the host computer. When the output torque of the output motor is c m If the intermediate shaft of the tested motor (6) is damaged, then the maximum torque C that the intermediate shaft of the tested motor can withstand is determined. m =a max *b max *c m ;

[0025] S3. Manually rotate the motor under test to adjust the meshing angle between the input shaft, intermediate shaft, and output shaft to 120°, and then perform other speed ratio combination tests.

[0026] S4. Using the methods from S1 to S3, test the input and output shafts of the motor under test to determine the maximum torque C that the input shaft of the motor under test can withstand. in And the maximum torque C that the output shaft can withstand out ;

[0027] S5. Compare the maximum torque C that the intermediate shaft of the tested motor can withstand. m Maximum torque C that the input shaft can withstand in and the maximum torque C that the output shaft can withstand out The maximum value among the three is taken as the maximum torque C that the tested motor can withstand.

[0028] The advantages of this invention are:

[0029] 1) It can accurately determine the maximum torque that the electric drive axle (i.e. the motor under test) can withstand, and multiple sensors distributed on the electric drive axle can analyze the data.

[0030] 2) Due to the characteristics of the gearbox and electric drive axle assembly, there are multiple gear combinations, and different torque distributions can be selected to conduct various torque tests on the gears to ensure the rigor of the experiments.

[0031] 3) The method of the present invention can detect the temperature of the output motor and the motor under test in real time, ensuring that the experimental results are not affected by temperature.

[0032] 4) The method of the present invention utilizes the characteristics of CAN-BUS, uses CAN lines to connect various controllers, and the data is processed by VCU and fed back to the host computer. This control method can ensure that no data is lost when the electric drive axle assembly is damaged.

[0033] 5) It saves debugging time for the electric drive axle assembly, eliminating the need for fine-tuning the force on the electric drive axle, and allowing direct adjustment of the electric drive axle strength based on the experimental results. Attached Figure Description

[0034] Figure 1 A schematic diagram of the setup for testing the strength of gears in an electric drive axle assembly;

[0035] Figure 2 This is a schematic diagram showing the motor under test fixed to the base of the experimental platform.

[0036] Figure 3 This is a low-voltage schematic diagram;

[0037] Figure 4 This is a schematic diagram of force transmission;

[0038] Figure 5 A schematic diagram showing the wiring for the output motor;

[0039] Figure 6 A schematic diagram of the resolver of the motor under test;

[0040] Figure 7 This is a schematic diagram of the resolver of the output motor;

[0041] Among them, 1-output motor, 2-gearbox, 3-gearbox solenoid valve assembly, 4-drive shaft, 5-high voltage distribution cabinet, 6-motor under test (electric drive axle assembly), 7-high voltage connector of motor under test, 8-controller of motor under test, 9-low voltage connector of motor under test, 10-shifting mechanism of motor under test.

[0042] 11-Locking point, 12-Half shaft, 13-Differential lock, 14-Host computer, 15-Vehicle controller (VCU), 16-Low voltage power supply, 17-Emergency stop switch, 18-Fuse box, 19-Transmission controller, 20-Low voltage connector for output motor;

[0043] 21- Output motor high voltage connector; 22- Output motor controller; 23- Output motor resolver cable; 24- Test motor resolver cable; 25- High voltage harness connection; 26- Output motor high voltage harness connection terminal; 27- Test motor high voltage harness connection terminal; 28- Gearbox controller low voltage connector; 29- Test motor fixing point; 30- Experimental bench base. Detailed Implementation

[0044] Example 1

[0045] This embodiment proposes a testing device for the gear strength of an electric drive axle assembly, including a high-voltage distribution cabinet, a low-voltage power supply, a vehicle control unit (VCU) and a host computer, as well as an output motor, an output motor controller, a gearbox, a gearbox controller, a gearbox solenoid valve assembly, a motor under test, a motor under test controller, and a motor under test shifting mechanism. The motor under test includes an input shaft, an intermediate shaft, and an output shaft connected by gears. The strength of the gears is tested by the testing device. That is, the testing device and method of this invention are designed to simulate the process of the motor under test driving on the road. Since the motor under test is actually a vehicle gearbox assembly, the output shaft, input shaft, and intermediate shaft of the motor under test must be made of the same material. The input shaft, intermediate shaft, and output shaft work together through gear engagement, and the strength of the input shaft, intermediate shaft, and output shaft is higher than that of the gears. Therefore, the gear strength of the electric drive axle can be measured using the testing device (experimental bench) provided by this invention.

[0046] The vehicle control unit (VCU), host computer, output motor controller, transmission controller, and tested motor controller are communicatively connected. The VCU receives real-time data from the output motor, tested motor, transmission, and the tested motor's shifting mechanism, processes the data, and feeds it back to the host computer. It also receives instructions from the host computer and distributes these instructions to each controller. The host computer allows operators to input control signals to control the testing device, including calibrating the output motor's output torque. The output motor controller controls the output motor's torque and speed, and acquires information about the output motor, including torque, speed, temperature, and fault conditions. The transmission controller has several input and output terminals. The input terminals include a solenoid valve assembly, an input shaft speed sensor, an output shaft speed sensor, and an air interface. The solenoid valve assembly simulates transmission gear shifting, while the input and output shaft speed sensors simulate the rotation of the transmission's input and output shafts and output speed signals. The tested motor controller controls the tested motor's torque and speed and acquires information about the output motor, including torque, speed, temperature, and fault conditions.

[0047] The following is combined Figures 1 to 7 The apparatus shown is described in detail as an example.

[0048] like Figure 1 and Figure 2 As shown, the device includes a high-voltage distribution cabinet 5, a low-voltage power supply 16, a vehicle controller VCU 15 and a host computer 14, an output motor 1, an output motor controller 22, an output motor high-voltage connector 21, an output motor low-voltage connector 20, a gearbox 2, a gearbox controller 19, a gearbox controller low-voltage connector 28, a gearbox solenoid valve assembly 3, a motor under test 6, a motor under test controller 8, a motor under test high-voltage connector 7, a motor under test low-voltage connector 9, a motor under test shifting mechanism 10, a motor under test fixing point, and a test bench base 29.

[0049] 1. Wiring harness

[0050] (1) The high-voltage wiring harness is led out from the high-voltage distribution cabinet 5, and two sets of high-voltage wiring harnesses are led out and connected to the output motor high-voltage connector 21 and the tested motor high-voltage connector 7. For detailed wiring method, see Figure 5 (Output motor display) The high-voltage wiring harness is connected as shown in high-voltage wiring harness connection 25. The output motor high-voltage connector 21 and the tested motor high-voltage connector 7 have DC to AC conversion functions, so the high-voltage wiring harness is connected to the output motor high-voltage wiring harness terminal 26 and the output motor high-voltage wiring harness terminal 27.

[0051] (2) The low-voltage power supply is provided by the low-voltage power supply 16 (24V). An emergency stop switch 17 and a fuse box 18 are provided to ensure the safety of the experimental environment. The low-voltage power supply of the gearbox 2 is provided by the gearbox controller 19; the low-voltage power supply of the output motor 1 is provided by the output motor controller 22; and the low-voltage power supply of the motor under test (electric drive axle assembly) 6 is provided by the motor under test controller 8. The power supply of the motor under test controller 8, the vehicle controller VCU 15, the gearbox controller 19, and the output motor controller 22 is provided by the emergency stop switch 17.

[0052] (3) All MCUs communicate in series. The communication harness of the output motor controller 22 is connected to the vehicle controller VCU15 via the output motor controller low-voltage connector 20, the communication harness of the transmission controller 19 is connected to the vehicle controller VCU15 via the transmission controller low-voltage connector 28, and the communication harness of the motor controller 8 under test is connected to the vehicle controller VCU15 via the voltage under test low-voltage connector 9.

[0053] (4) such as Figure 6 As shown, the resolver harness of the motor under test 6 is connected to the low-voltage connector 9 via the resolver cable 24, transferring the signal to the motor under test controller 8. The motor under test controller 8 processes the signal and transmits it to the vehicle controller VCU15 via the communication harness. Figure 7 As shown, the motor resolver harness of output motor 1 is connected to the low-voltage plug-in 20 of the motor controller via output motor controller 23, and the signal is transferred to output motor controller 22. Output motor controller 22 processes the signal and transmits it to vehicle controller VCU15 via communication harness.

[0054] (5) Since the amount of information controlled is small, the CAN network load problem is not considered.

[0055] 2. Assembly plan

[0056] (1) The overall assembly scheme is a direct connection type. The output motor 1 and the gearbox 2 are assembled in the traditional P2 assembly method. The output motor and the motor under test are connected through the transmission shaft 4.

[0057] (2) Two half-shafts 12 are set up to achieve better fixation. The motor under test 6 is fixed to the experimental platform base 30 by bolts. The differential lock 13 is connected to the two half-shafts 12 respectively, and the locking points 11 at both ends are connected to each half-shaft 12 respectively. The motor under test is securely fixed by the drive shaft, locking points, half-shafts and differential lock. The gear shifting mechanism of the motor under test can be used to select the gear, and the gearbox controller can be used to select the speed ratio.

[0058] Example 2

[0059] This embodiment proposes a test method for the gear strength of an electric drive axle assembly. A motor inputs torque to the gearbox to increase the torque. The torque is then output from the gearbox and input to the drive shaft, and from the drive shaft to the electric drive axle assembly. After input, the torque is further increased. The output shaft of the electric drive axle is connected to the differential, and the differential is rigidly connected to the test bench. When the motor output torque is 10 Nm, the torque input to the electric drive axle assembly is Nm * gearbox speed ratio a * electric drive axle speed ratio b = electric drive axle torque c. The maximum value of electric drive axle torque c can be considered the maximum torque that the electric drive axle output shaft can withstand.

[0060] The method specifically includes the following steps:

[0061] S1. Adjust the gearbox and the motor under test to their maximum gear ratio combination for testing. The gearbox ratio is a. max The speed ratio of the motor being tested is b max ;

[0062] S2. Adjust the output torque of the output motor via the host computer. When the output torque of the output motor is c m If the intermediate shaft of the tested motor is damaged, then determine the maximum torque C that the intermediate shaft of the tested motor can withstand. m =a max *b max *c m ;

[0063] S3\Manually rotate to adjust the meshing angle between the input shaft, intermediate shaft, and output shaft of the motor under test to 120°, and perform other speed ratio combination tests;

[0064] S4. Using the methods from S1 to S3, test the input and output shafts of the motor under test to determine the maximum torque C that the input shaft of the motor under test can withstand. in And the maximum torque C that the output shaft can withstand out ;

[0065] S5. Compare the maximum torque C that the intermediate shaft of the tested motor can withstand. m Maximum torque C that the input shaft can withstand in and the maximum torque C that the output shaft can withstand out The maximum value among the three is taken as the maximum torque C that the tested motor can withstand.

[0066] Detailed description Figure 1 The control scheme of the device shown, combined with Figure 4 As shown in the force transmission diagram, the gearbox has two gears with speed ratios of 1 and 1.5; the tested motor has two gears with speed ratios of 1.5 and 2.5.

[0067] (1) The experiment began with a combination of high speed ratios for testing, with the gearbox in second gear and a speed ratio of 1.5; the motor under test was in second gear and a speed ratio of 2.5.

[0068] (2) When the motor output torque is controlled by the host computer to 100 Nm, the intermediate shaft of the tested motor is damaged. It can be known that the maximum torque that the intermediate shaft can withstand is 375 Nm.

[0069] (3) Considering the rigor of the experiment, and the meshing angle between the input shaft, intermediate shaft and output shaft of the motor under test is less than 120°, the input shaft, intermediate shaft and output shaft of the motor under test can be manually rotated by 120° to test other speed ratio combinations.

[0070] (4) The testing principle for the input and output shafts of the motor under test is the same.

[0071] (5) Since the output shaft, input shaft and intermediate shaft of the tested motor are made of the same material, the maximum torque C that the tested motor can withstand is the maximum torque that the output shaft, input shaft and intermediate shaft of the tested motor can withstand.

[0072] This invention utilizes the characteristics of CAN-BUS, using CAN lines to connect various controllers, and the data is processed by the VCU (Vehicle Control Unit) and fed back to the host computer. This control method can ensure that no data is lost when the electric drive axle assembly is damaged.

[0073] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A testing device for the strength of gears in an electric drive axle assembly, characterized in that, Including a high-voltage distribution cabinet (5), a low-voltage power supply (16), a vehicle control unit (VCU) (15), and a host computer (14), and: The output motor (1), the output motor controller (22), the output motor high voltage connector (21) and the output motor low voltage connector (20) are provided, and the output motor (1) is provided with an output motor high voltage harness terminal (26). The gearbox (2), gearbox controller (19), gearbox controller low-pressure connector (28) and gearbox solenoid valve assembly (3) are provided, wherein the gearbox solenoid valve assembly (3) integrates a shift solenoid valve, a gear position sensor and an air circuit interface. The test motor (6), the test motor controller (8), the test motor high voltage connector (7), the test motor low voltage connector (9), and the test motor shifting mechanism (10) are included. The test motor (6) includes an input shaft, an intermediate shaft, and an output shaft connected by gears. The strength of the gears is tested by the test device. The test motor (6) is provided with a test motor high voltage harness terminal (27). The output shaft, input shaft, and intermediate shaft of the test motor (6) are made of the same material. The input shaft, intermediate shaft, and output shaft work together through gears. The strength of the input shaft, intermediate shaft, and output shaft is higher than that of the gears. The output motor (1) is connected to the gearbox (2), and the output end of the output motor (1) is provided with a transmission shaft (4) connected to the motor under test (6) for transmitting the rotational torque of the output motor to the input shaft of the motor under test (6). Two sets of high-voltage wire harnesses are led out from the output end of the high-voltage distribution cabinet (5) and connected to the input ends of the output motor high-voltage connector (21) and the motor under test high-voltage connector (7), respectively. The output ends of the output motor high-voltage connector (21) and the motor under test high-voltage connector (7) are connected to the high-voltage wire harness terminals of the output motor (1) and the motor under test (6), respectively, to provide high-voltage working power to the output motor (1) and the motor under test (6). The output end of the low-voltage power supply (16) is equipped with an emergency stop switch (17) and a fuse box (18). Several high-voltage wires are led out from the output end of the low-voltage power supply (16) and connected to the low-voltage connector (20) of the output motor, the low-voltage connector (28) of the gearbox controller and the low-voltage connector (9) of the motor under test, respectively, to provide low-voltage working power for the output motor (1), the gearbox (2) and the motor under test (6).

2. The testing device for the gear strength of an electric drive axle assembly according to claim 1, characterized in that: The bottom of the motor under test (6) is provided with a fixing mechanism, including a differential lock (13) and a set of locking points (11) and a set of half shafts (12) located on both sides of the differential lock (13). The two ends of the half shafts (12) are respectively connected to the differential lock (13) and the locking points (11).

3. The testing device for the gear strength of an electric drive axle assembly according to claim 1, characterized in that, The vehicle control unit (VCU) (15), the host computer (14), the output motor controller (22), the gearbox controller (19), and the motor controller under test (8) are communicatively connected. The vehicle controller VCU (15) is used to receive real-time data from the output motor (1), the motor under test (6), the gearbox (2) and the shift mechanism (10) of the motor under test, process the data and feed it back to the host computer (14), and receive instructions from the host computer (14) and publish the received instructions to each controller. The host computer (14) is used to provide operators with input control signals to control the test device, including calibrating the output torque of the output motor; The output motor controller (22) is used to control the torque and speed of the output motor (1) and to acquire information about the output motor (1), including torque, speed, temperature and fault status. The input terminal of the gearbox controller (19) is equipped with a solenoid valve assembly, an input shaft speed sensor, an output shaft speed sensor and an air circuit interface. The solenoid valve assembly is used to simulate gear shifting of the gearbox. The input shaft speed sensor and the output shaft speed sensor are used to simulate the rotation state of the input shaft and output shaft of the gearbox and output speed signals. The motor controller (8) is used to control the torque and speed of the motor under test (6) and to acquire information about the motor under test (6), including torque, speed, temperature and fault status.

4. The testing device for the gear strength of an electric drive axle assembly according to claim 1, characterized in that: The output motor high voltage connector (21) and the tested motor high voltage connector (7) are equipped with a functional module that converts DC power to AC power.

5. The testing device for the gear strength of an electric drive axle assembly according to claim 1, characterized in that: The gearbox (2) has two gears and two speed ratios. The gearbox solenoid valve assembly (3) includes a first solenoid valve, a second solenoid valve, a first solenoid valve sensor, and a second solenoid valve sensor. The first solenoid valve and the second solenoid valve are used to simulate the two gears of the gearbox. That is, when the host computer (14) gives the instruction: the gearbox (2) is engaged in first gear, the first solenoid valve executes the instruction, and the first solenoid valve sensor monitors whether the current gear is in the first gear position. If it is in the first gear position, the host computer (14) is fed back that the gear engagement is successful; otherwise, the gear engagement fails.

6. The testing device for the gear strength of an electric drive axle assembly according to claim 1, characterized in that: The motor under test (6) has two gears and two speed ratios. The motor under test (6) is equipped with a speed sensor and a temperature sensor. The motor under test shifting mechanism (10) is equipped with a motor under test shifting motor position sensor. When the host computer (14) gives the instruction: the motor under test (6) is in first gear, the motor under test shifting mechanism (10) executes the instruction, and the motor under test shifting motor position sensor detects whether it is in first gear. If it is in first gear, it will report to the host computer (14) that the shifting is successful; otherwise, it will report that the shifting is unsuccessful.

7. A method for testing the strength of gears in an electric drive axle assembly, applied to the testing apparatus described in any one of claims 1 and 6, characterized in that, Including the following steps: S1. Adjust the gearbox (2) and the motor under test (6) to the maximum gear, i.e., the high speed ratio combination, and perform the test. The gearbox speed ratio is: The speed ratio of the motor being tested is ; S2. Adjust the output torque of the output motor (1) via the host computer (14). When the output torque of the output motor (1) is If the intermediate shaft of the tested motor (6) is damaged, then the maximum torque that the intermediate shaft of the tested motor can withstand is determined. ; S3. Manually rotate the motor under test (6) to adjust the meshing angle between the input shaft, intermediate shaft and output shaft to 120° and perform other speed ratio combination tests. S4. Using the methods from S1 to S3, test the input shaft and output shaft of the motor under test (6) to determine the maximum torque that the input shaft of the motor under test can withstand. and the maximum torque that the output shaft can withstand. ; S5. Compare the maximum torque that the intermediate shaft of the tested motor (6) can withstand. Maximum torque that the input shaft can withstand and the maximum torque that the output shaft can withstand The maximum value among the three is taken as the maximum torque C that the tested motor can withstand.

Images