A rear-drive hybrid transmission assembly fixed-gear bench durability test method

Abstract

A bench durability test method for a fixed-gear rear-wheel-drive hybrid transmission assembly belongs to the field of automotive transmission testing technology. The method includes: test bench construction and installation and debugging of the hybrid transmission under test; calibration of the core parameters of the hybrid transmission under test; conducting a break-in test; designing six typical operating conditions: EV, series, parallel, direct drive, maximum torque, and maximum vehicle speed. The speed and torque parameters for each operating condition are determined through the conversion relationship between actual vehicle speed, transmission ratio range, and power parameters. The test cycle consists of EV mode cycles and non-EV mode cycles, with EV mode and non-EV mode interleaved to simulate the random switching characteristics of actual vehicle operating conditions. The test process is monitored. This invention can accurately assess the actual durability performance of key transmission components, improve the accuracy and reliability of test data, shorten the development cycle, reduce costs, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to a bench durability test method for a fixed gear position of a rear-wheel drive hybrid transmission assembly, belonging to the field of automotive transmission testing technology. Background Technology

[0002] The hybrid transmission is the core drivetrain component of hybrid electric vehicles, responsible for power distribution, speed regulation, and torque transmission. Its durability directly determines the vehicle's driving safety, power performance, and service life. As hybrid electric vehicles expand into commercial vehicles and special-purpose vehicles, the operating conditions of hybrid transmissions become more complex, and reliability requirements are further increased. Bench durability tests are necessary to simulate the full-scenario operation of real vehicles and assess the operational stability of key components under fixed gear positions.

[0003] Existing durability testing methods for hybrid transmission assemblies have the following shortcomings:

[0004] 1. The test conditions are limited, covering only basic electric drive and direct drive modes, and do not include typical real vehicle conditions such as series, extreme torque, and extreme vehicle speed, which cannot fully assess the transmission's durability performance in all scenarios.

[0005] 2. The test parameters are out of touch with the actual vehicle scenario. Parameters such as speed and torque are not accurately converted in combination with the transmission ratio range and power transmission characteristics, resulting in deviations between the test results and the actual operating conditions of the vehicle, and thus limited reference value.

[0006] 3. The lack of precise monitoring throughout the entire process and post-test system testing makes it difficult to trace the cause of failure and to fully analyze the wear and performance degradation patterns of components.

[0007] Therefore, there is an urgent need to design a durability testing method that is scientifically sound, comprehensive in terms of operating conditions, and precise in parameters to meet the needs of hybrid transmission R&D and mass production verification. Summary of the Invention

[0008] To address the problems existing in the background art, the present invention provides a method for durability testing of a fixed gear position bench for a rear-wheel drive hybrid transmission assembly.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a method for durability testing of a fixed-gear rear-wheel drive hybrid transmission assembly on a test bench, the method comprising the following steps:

[0010] S1. Test bench setup and installation and debugging of the tested hybrid transmission;

[0011] S2. Calibrate the core parameters of the tested hybrid transmission;

[0012] S3. Conduct a break-in test;

[0013] S4. Conduct multi-condition cyclic durability tests;

[0014] S5. Monitoring of the test process.

[0015] Furthermore, step S1 includes the following steps:

[0016] S101. Fix the hybrid transmission to be tested on the test bench in the same horizontal mounting state as the actual vehicle;

[0017] S102. Add lubricating oil to the tested hybrid transmission according to the actual vehicle filling standard;

[0018] S103. Install temperature sensors at the drain port and cooler of the tested hybrid transmission respectively;

[0019] S104. Connect the controller wiring harness and the electronic pump wiring harness, and debug the CAN communication system;

[0020] S105. Install protective devices on all rotating parts.

[0021] Furthermore, the core technical parameters mentioned in S2 include:

[0022] Battery rated voltage and operating voltage range;

[0023] Peak speed, peak torque, and peak power of the drive motor;

[0024] The generator's peak speed, peak torque, and peak power;

[0025] Drive motor speed ratio, engine direct drive speed ratio, and generator speed ratio;

[0026] Communication methods;

[0027] Cooling method;

[0028] Requirements for adding lubricating oil.

[0029] Furthermore, step S3 includes the following steps:

[0030] S301, running in power generation mode for 30 minutes, with the following parameters: engine input speed 3000 r / min, input torque 100 Nm;

[0031] S302, running in electric drive mode for 30 minutes, with the following parameters: electronic pump speed 3000 r / min, drive motor speed 1 / 4 of the maximum speed, drive motor torque 150 Nm, and oil temperature controlled to be stable at 80℃.

[0032] Furthermore, step S4 includes the following steps:

[0033] S401 is designed for six typical operating conditions: EV, series, parallel, direct drive, extreme torque, and extreme speed. The speed and torque parameters for each operating condition are determined by the conversion relationship between actual vehicle speed, transmission ratio range, and power parameters.

[0034] S402. The test cycle consists of an EV mode cycle and a non-EV mode cycle, with EV mode and non-EV mode alternating to simulate the random switching characteristics of real vehicle operating conditions.

[0035] Furthermore, in S401,

[0036] The parameters for EV mode are set as follows:

[0037] Set three speed gradients: 20km / h, 40km / h, and 60km / h;

[0038] The corresponding drive motor torques are 0.7×maxNm, 0.6×maxNm, and 0.4×maxNm, respectively.

[0039] The corresponding running times are 6 minutes, 10 minutes, and 10 minutes, respectively.

[0040] The electric pump remains operational to ensure a stable lubrication flow rate;

[0041] The parameters for the cascade mode are set as follows:

[0042] Set three speed gradients: 40km / h, 60km / h, and 80km / h;

[0043] The corresponding drive motor torques are 0.5×maxNm, 0.35×maxNm, and 0.25×maxNm, respectively.

[0044] The generator torque is uniformly 0.7×maxNm, and the engine speed is 2000-3000rpm with a torque of 0.5×maxNm;

[0045] The corresponding running times are 20 minutes, 30 minutes, and 40 minutes, respectively.

[0046] The parameters for parallel mode are set as follows:

[0047] Set three speed gradients: 60km / h, 70km / h, and 80km / h;

[0048] The corresponding drive motor torques are 0.4×maxNm, 0.48×maxNm, and 0.56×maxNm, respectively.

[0049] The corresponding generator torques are 0.5×maxNm, 0.58×maxNm, and 0.66×maxNm, respectively.

[0050] The corresponding engine torques are 0.35×maxNm, 0.42×maxNm, and 0.49×maxNm, respectively.

[0051] The running time for each speed range is 10 minutes;

[0052] The parameters for direct drive mode are set as follows:

[0053] Set three speed gradients: 80km / h, 100km / h, and 120km / h;

[0054] The corresponding engine torques are 0.59×maxNm, 0.62×maxNm, and 0.6×maxNm, respectively.

[0055] The corresponding running times are 15 min, 10 min, and 5 min, respectively.

[0056] The parameters for the extreme torque mode are set as follows:

[0057] Vehicle speed 70km / h, drive motor torque 1×maxNm, engine torque 1×maxNm; electric pump speed 1000-3000rpm, running time 0.5min;

[0058] The parameters for the maximum speed mode are set as follows:

[0059] Vehicle speed 175km / h, drive motor torque 0.2×maxNm, engine torque 0.8×maxNm; running time 1min.

[0060] Furthermore, step S5 includes the following steps:

[0061] S501: Real-time continuous monitoring is performed using a high-precision sensor and a high-speed data acquisition system, with a monitoring frequency of not less than 10Hz.

[0062] S502, the monitoring indicators include transmission fluid parameters, power component parameters, cooling system parameters and CAN communication status;

[0063] S503. Record the cycle number and step number during the experiment;

[0064] S504. In case of danger, immediately trigger the emergency stop switch to record the operating conditions, parameter range, and fault phenomena at the time of the fault.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] This invention designs six typical operating conditions covering all scenarios, including low speed, medium speed, high speed, high torque, and high-speed limits, encompassing EV, series, parallel, direct drive, extreme torque, and extreme speed. It employs a cyclical approach to simulate random switching of real-vehicle operating conditions, making the test results closer to actual usage. The speed and torque parameters for each operating condition are scientifically calculated based on the hybrid transmission's gear ratio range, actual vehicle speed, and power transmission characteristics, avoiding discrepancies between parameters and actual vehicle conditions. This allows for precise assessment of the actual durability performance of key transmission components. Furthermore, it includes standardized bench setup, parameter calibration, and break-in testing, combined with precise monitoring throughout the entire process and post-test performance retesting and disassembly. This method establishes a complete closed-loop system encompassing "pre-test setup, in-test monitoring, and post-test analysis," significantly improving the accuracy and reliability of test data. It can rapidly acquire transmission durability performance data, pinpoint design defects and fault causes, providing a scientific basis for product design optimization and control strategy iteration. This effectively shortens the R&D cycle and reduces outsourced testing costs and subsequent rectification costs. Furthermore, its test procedures and parameter ranges can be flexibly adjusted according to the structural characteristics and design parameters of different hybrid transmission models. It is not only applicable to rear-wheel-drive hybrid transmissions but can also be extended to the assembly durability testing of other types of hybrid transmissions, demonstrating broad application prospects. Detailed Implementation

[0067] The technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] A bench durability test method for a fixed gear position rear-wheel drive hybrid transmission assembly, the method comprising the following steps:

[0069] S1. Test bench setup and installation and debugging of the tested hybrid transmission;

[0070] S2. Before the formal test, fully calibrate the core parameters of the hybrid transmission under test;

[0071] S3. Conduct a break-in test;

[0072] To eliminate minor machining defects in components such as gears, bearings, and clutches during the manufacturing process of the tested hybrid transmission, to achieve proper running-in of each moving part, and to avoid premature wear of components caused by direct durability testing, the running-in test was conducted in alternating power generation mode and electric drive mode.

[0073] S4. Conduct multi-condition cyclic durability tests;

[0074] S5. Monitoring of the test process.

[0075] Furthermore, step S1 includes the following steps:

[0076] S101. Fix the test hybrid transmission on the test bench in the same horizontal installation state as the actual vehicle, ensuring that the installation benchmark is consistent with the actual vehicle. Then connect the power and loading devices: the input end of the test hybrid transmission is rigidly connected to the drive dynamometer through a coupling, and the output end is connected to the absorption dynamometer in sequence through the drive shaft, torque sensor, gearbox, and coupling to simulate the power input and load state of the actual vehicle.

[0077] S102. Add the specified type of ATF lubricating oil to the tested hybrid transmission according to the actual vehicle filling standard;

[0078] S103. Temperature sensors are installed at the drain port and cooler of the tested hybrid transmission to monitor the oil temperature in the oil pan and the cooling oil temperature in real time; a transmission oil temperature control device is installed to regulate the transmission oil temperature; and a motor temperature control device is installed to monitor and control the operating temperature of the drive motor and the generator.

[0079] S104. Connect the controller wiring harness and the electronic pump wiring harness, and debug the CAN communication system to ensure that the control signals and data transmission are normal.

[0080] S105. Install protective devices on all rotating parts to ensure the safety of the test process.

[0081] Furthermore, the core technical parameters mentioned in S2 include:

[0082] Battery rated voltage and operating voltage range;

[0083] Peak speed, peak torque, and peak power of the drive motor;

[0084] The generator's peak speed, peak torque, and peak power;

[0085] Drive motor speed ratio, engine direct drive speed ratio, and generator speed ratio;

[0086] Communication method: CAN communication;

[0087] Cooling methods: Water cooling is used for electronic control, and oil cooling is used for motor cooling;

[0088] Lubricating oil filling requirements shall be performed in accordance with the drawings.

[0089] All calibration parameters were controlled within the design range of the tested hybrid transmission, thus establishing a clear test benchmark.

[0090] Furthermore, step S3 includes the following steps:

[0091] S301, running in power generation mode for 30 minutes, with the following parameters: engine input speed 3000 r / min, input torque 100 Nm;

[0092] S302, running in electric drive mode for 30 minutes, with the following parameters: electronic pump speed 3000 r / min, drive motor speed 1 / 4 of the maximum speed, drive motor torque 150 Nm, and oil temperature controlled to be stable at 80℃.

[0093] Furthermore, step S4 includes the following steps:

[0094] S401 and S4 are the core components of the test. Based on the real-vehicle application scenarios of the tested hybrid transmission, and combined with its transmission ratio range and power transmission characteristics, six typical operating conditions are designed: EV, series, parallel, direct drive, limit torque, and limit speed. The speed and torque parameters of each operating condition are determined through the conversion relationship between real vehicle speed, transmission ratio range, and power parameters, accurately matching the power output state of the actual vehicle operation.

[0095] S402. The test cycle consists of an EV mode cycle and a non-EV mode cycle, with EV mode and non-EV mode alternating to simulate the random switching characteristics of real vehicle operating conditions.

[0096] The total number of test cycles was 150, divided into 3 groups. Each group included 50 EV mode cycles and 50 non-EV mode cycles (non-EV modes included series, parallel, direct drive, maximum torque, and maximum speed).

[0097] During the test, EV mode was allowed to be interspersed with other modes to simulate the random switching characteristics of real vehicle operating conditions.

[0098] Furthermore, in S401,

[0099] The parameters for EV mode are set as follows:

[0100] Set three speed gradients: 20km / h, 40km / h, and 60km / h;

[0101] The corresponding drive motor torques are 0.7×maxNm, 0.6×maxNm, and 0.4×maxNm, respectively.

[0102] The corresponding running times are 6 minutes, 10 minutes, and 10 minutes, respectively.

[0103] The electric pump remains operational to ensure a stable lubrication flow rate;

[0104] Pure electric drive, without engine involvement, simulating low-speed and medium-speed pure electric driving scenarios in real vehicles, with an electronic pump operating to ensure stable lubrication flow:

[0105] ①Low speed range: vehicle speed 20km / h, drive motor torque 0.7×maxNm, running for 6 minutes;

[0106] ②Low-medium speed range: vehicle speed 40km / h, drive motor torque 0.6×maxNm, running for 10 minutes;

[0107] ③ Medium speed range: vehicle speed 60km / h, drive motor torque 0.4×maxNm, running for 10 minutes.

[0108] The parameters for the cascade mode are set as follows:

[0109] Set three speed gradients: 40km / h, 60km / h, and 80km / h;

[0110] The corresponding drive motor torques are 0.5×maxNm, 0.35×maxNm, and 0.25×maxNm, respectively.

[0111] The generator torque is uniformly 0.7×maxNm, and the engine speed is 2000-3000rpm with a torque of 0.5×maxNm;

[0112] The corresponding running times are 20 minutes, 30 minutes, and 40 minutes, respectively.

[0113] The engine drives the generator to produce electricity, and the electric motor drives the vehicle to move, simulating a real vehicle driving at medium speed:

[0114] ①Low-medium speed range: vehicle speed 40km / h, drive motor torque 0.5×maxNm, generator speed calculated based on engine speed, generator torque 0.7maxNm, engine speed 2000-3000rpm, torque 0.5×maxNm, running for 20 minutes;

[0115] ② Medium speed range: vehicle speed 60km / h, drive motor torque 0.35×maxNm, generator speed calculated based on engine speed, generator torque 0.7maxNm, engine speed 2000-3000rpm, torque 0.5×maxNm, running for 30 minutes;

[0116] ③ Medium and high speed range: vehicle speed 80km / h, drive motor torque 0.25×maxNm, generator speed calculated based on engine speed, generator torque 0.7maxNm, engine speed 2000-3000rpm, torque 0.5×maxNm, running for 40 minutes.

[0117] The parameters for parallel mode are set as follows:

[0118] Set three speed gradients: 60km / h, 70km / h, and 80km / h;

[0119] The corresponding drive motor torques are 0.4×maxNm, 0.48×maxNm, and 0.56×maxNm, respectively.

[0120] The corresponding generator torques are 0.5×maxNm, 0.58×maxNm, and 0.66×maxNm, respectively.

[0121] The corresponding engine torques are 0.35×maxNm, 0.42×maxNm, and 0.49×maxNm, respectively.

[0122] The running time for each speed range is 10 minutes;

[0123] The engine and electric motor work together to drive the vehicle, simulating a real vehicle's mid-speed acceleration scenario, to assess the transmission's load-bearing durability under multi-power source coordination.

[0124] ① The vehicle speed is 60km / h, the drive motor torque is 0.4×maxNm, the generator speed is calculated based on the engine speed and the torque is 0.5×maxNm, the engine speed is calculated based on the vehicle speed and the torque is 0.35×maxNm, and the operation time is 10 minutes.

[0125] ② The vehicle speed is 70km / h, the drive motor torque is 0.48×maxNm, the generator speed is calculated based on the engine speed and the torque is 0.58×maxNm, the engine speed is calculated based on the vehicle speed and the torque is 0.42×maxNm, and the operation time is 10 minutes.

[0126] ③ The vehicle speed is 80km / h, the drive motor torque is 0.56×maxNm, the generator speed is calculated based on the engine speed and the torque is 0.66×maxNm, the engine speed is calculated based on the vehicle speed and the torque is 0.49×maxNm, and the operation time is 10 minutes.

[0127] The parameters for direct drive mode are set as follows:

[0128] Set three speed gradients: 80km / h, 100km / h, and 120km / h;

[0129] The corresponding engine torques are 0.59×maxNm, 0.62×maxNm, and 0.6×maxNm, respectively.

[0130] The corresponding running times are 15 min, 10 min, and 5 min, respectively.

[0131] The engine directly drives the vehicle, simulating a real vehicle driving at high speed:

[0132] ① Medium speed range: vehicle speed 80km / h, engine speed calculated based on vehicle speed, torque 0.59×maxNm, run for 15 minutes;

[0133] ②High-speed section: vehicle speed 100km / h, engine speed calculated based on vehicle speed, torque 0.62×maxNm, run for 10 minutes;

[0134] ③ Ultra-high speed section: vehicle speed 120km / h, engine speed calculated based on vehicle speed, torque 0.6×maxNm, run for 5 minutes.

[0135] The parameters for the extreme torque mode are set as follows:

[0136] Simulating high torque output scenarios such as climbing hills and rapid acceleration of real vehicles, the transmission's load-bearing capacity under high torque is tested: vehicle speed 70km / h, drive motor torque 1×maxNm, generator speed calculated based on engine speed, engine speed calculated based on vehicle speed, engine torque 1×maxNm; electric pump speed 1000-3000rpm, running time 0.5min.

[0137] The parameters for the maximum speed mode are set as follows:

[0138] Simulate a real vehicle's high-speed extreme driving scenario to assess the transmission's operational stability at high speeds: vehicle speed 175km / h, drive motor torque 0.2×maxNm, generator speed calculated based on engine speed, engine speed calculated based on vehicle speed, engine torque 0.8×maxNm; running time 1min.

[0139] Furthermore, step S5 includes the following steps:

[0140] S501. The entire test uses high-precision sensors and a high-speed data acquisition system to monitor key indicators in real time and continuously, with a monitoring frequency of no less than 10Hz, to ensure the integrity and accuracy of the data.

[0141] S502, the monitoring indicators include transmission fluid parameters, power component parameters, cooling system parameters and CAN communication status;

[0142] Transmission fluid parameters include oil pan temperature, cooler temperature, main oil circuit pressure, front / rear lubrication pressure, clutch pressure, and fluid flow rate under series and parallel operation conditions.

[0143] The power component parameters include the speed, torque, and power of the drive motor / generator (all controlled within the calibrated peak parameter range), and the engine speed and torque (matching the actual vehicle power output range).

[0144] Cooling system parameters include coolant temperature and coolant flow rate (to match the heat dissipation requirements of water cooling / oil cooling).

[0145] The communication parameter is for CAN communication status.

[0146] S503. Arrange for a dedicated person to be on duty throughout the entire process and record the cycle number and step number during the experiment;

[0147] S504. If any dangerous situation such as abnormal vibration, overheating, overpressure, or communication interruption occurs in the test sample or equipment, the emergency stop switch shall be triggered immediately to terminate the test. The operating conditions, parameter ranges, and fault phenomena at the time of the fault shall be recorded in detail to provide a basis for subsequent fault investigation.

[0148] After the test, the performance of the tested hybrid transmission was retested and disassembled for inspection. The wear and performance degradation of each component were analyzed, and the test data were compiled and analyzed.

[0149] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

[0150] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bench durability test method for a fixed gear position of a rear-wheel drive hybrid transmission assembly, characterized in that: The method includes the following steps: S1. Test bench setup and installation and debugging of the tested hybrid transmission; S2. Calibrate the core parameters of the tested hybrid transmission; S3. Conduct a break-in test; S4. Conduct multi-condition cyclic durability tests; S5. Monitoring of the test process.

2. The durability test method for a fixed gear position bench of a rear-wheel drive hybrid transmission assembly according to claim 1, characterized in that: S1 includes the following steps: S101. Fix the hybrid transmission to be tested on the test bench in the same horizontal mounting state as the actual vehicle; S102. Add lubricating oil to the tested hybrid transmission according to the actual vehicle filling standard; S103. Install temperature sensors at the drain port and cooler of the tested hybrid transmission respectively; S104. Connect the controller wiring harness and the electronic pump wiring harness, and debug the CAN communication system; S105. Install protective devices on all rotating parts.

3. The durability test method for a fixed gear position bench of a rear-wheel drive hybrid transmission assembly according to claim 1, characterized in that: The core technical parameters mentioned in S2 include: Battery rated voltage and operating voltage range; Peak speed, peak torque, and peak power of the drive motor; The generator's peak speed, peak torque, and peak power; Drive motor speed ratio, engine direct drive speed ratio, and generator speed ratio; Communication methods; Cooling method; Requirements for adding lubricating oil.

4. The durability test method for a fixed gear position bench of a rear-wheel drive hybrid transmission assembly according to claim 1, characterized in that: S3 includes the following steps: S301, running in power generation mode for 30 minutes, with the following parameters: engine input speed 3000 r / min, input torque 100 Nm; S302, running in electric drive mode for 30 minutes, with the following parameters: electronic pump speed 3000 r / min, drive motor speed 1 / 4 of the maximum speed, drive motor torque 150 Nm, and oil temperature controlled to be stable at 80℃.

5. The durability test method for a fixed gear position bench of a rear-wheel drive hybrid transmission assembly according to claim 1, characterized in that: S4 includes the following steps: S401 is designed for six typical operating conditions: EV, series, parallel, direct drive, extreme torque, and extreme speed. The speed and torque parameters for each operating condition are determined by the conversion relationship between actual vehicle speed, transmission ratio range, and power parameters. S402. The test cycle consists of an EV mode cycle and a non-EV mode cycle, with EV mode and non-EV mode alternating to simulate the random switching characteristics of real vehicle operating conditions.

6. The method for durability testing of a fixed-gear bench for a rear-wheel-drive hybrid transmission assembly according to claim 5, characterized in that: In S401, The parameters for EV mode are set as follows: Set three speed gradients: 20km / h, 40km / h, and 60km / h; The corresponding drive motor torques are 0.7×maxNm, 0.6×maxNm, and 0.4×maxNm, respectively. The corresponding running times are 6 minutes, 10 minutes, and 10 minutes, respectively. The electric pump remains operational to ensure a stable lubrication flow rate; The parameters for the cascade mode are set as follows: Set three speed gradients: 40km / h, 60km / h, and 80km / h; The corresponding drive motor torques are 0.5×maxNm, 0.35×maxNm, and 0.25×maxNm, respectively. The generator torque is uniformly 0.7×maxNm, and the engine speed is 2000-3000rpm with a torque of 0.5×maxNm; The corresponding running times are 20 minutes, 30 minutes, and 40 minutes, respectively. The parameters for parallel mode are set as follows: Set three speed gradients: 60km / h, 70km / h, and 80km / h; The corresponding drive motor torques are 0.4×maxNm, 0.48×maxNm, and 0.56×maxNm, respectively. The corresponding generator torques are 0.5×maxNm, 0.58×maxNm, and 0.66×maxNm, respectively. The corresponding engine torques are 0.35×maxNm, 0.42×maxNm, and 0.49×maxNm, respectively. The running time for each speed range is 10 minutes; The parameters for direct drive mode are set as follows: Set three speed gradients: 80km / h, 100km / h, and 120km / h; The corresponding engine torques are 0.59×maxNm, 0.62×maxNm, and 0.6×maxNm, respectively. The corresponding running times are 15 min, 10 min, and 5 min, respectively. The parameters for the extreme torque mode are set as follows: Vehicle speed 70km / h, drive motor torque 1×maxNm, engine torque 1×maxNm; electric pump speed 1000-3000rpm, running time 0.5min; The parameters for the maximum speed mode are set as follows: Vehicle speed 175km / h, drive motor torque 0.2×maxNm, engine torque 0.8×maxNm; running time 1min.

7. A bench durability test method for a fixed gear position rear-wheel drive hybrid transmission assembly according to claim 1 or 6, characterized in that: S5 includes the following steps: S501: Real-time continuous monitoring is performed using a high-precision sensor and a high-speed data acquisition system, with a monitoring frequency of not less than 10Hz. S502, the monitoring indicators include transmission fluid parameters, power component parameters, cooling system parameters and CAN communication status; S503. Record the cycle number and step number during the experiment; S504. In case of danger, immediately trigger the emergency stop switch to record the operating conditions, parameter range, and fault phenomena at the time of the fault.