scholarly journals Method and Test Bench for Hydro-Mechanical Continuously Variable Transmission Based on Multi-Level Test and Verification

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 358
Author(s):  
Hanzheng Dai ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Zhenguo Lu ◽  
Zhiyuan Sun ◽  
...  
Keyword(s):  
Test Bench ◽  
Structural Characteristics ◽  
Continuously Variable Transmission ◽  
Transmission System ◽  
Functional Test ◽  
Mechanical Transmission ◽  
Verification Method ◽  
Variable Transmission ◽  
Multi Level ◽  
The Impact

According to the structural characteristics of Hydro-mechanical continuously variable transmission (HMCVT), a multi-functional test bench was developed, and the basic structure, working principle, and test functions of the test bench were introduced. The test bench has the following characteristics: To analyze the impact of mechanical transmission and hydraulic transmission on the HMCVT transmission system, the performance can be tested separately by using a test bench; the coupling characteristics of the hydraulic transmission and mechanical transmission can also be tested; it can also test and verify the performance of the HMCVT transmission system and the control system; the test bench has a simple structure, diverse functions, and convenient operation. Using the multi-functional test bench, this paper proposes a method of multi-level test and verification. Through this method, the simulation models are revised and improved many times, and the accuracy of the models is improved, which are consistent with the physical model, and eventually, the accuracy of the simulation result is improved. This method is used to test and verify the hydraulic transmission system, analyze the characteristics of the hydraulic transmission system, and verify the feasibility and practicability of the multi-level verification method.

Limited-slip and torque-vectoring effect of a dual continuously variable transmission

2016 ◽  
Vol 231 (3) ◽  
pp. 372-382 ◽  
Author(s):  
I-Ming Chen ◽  
Yuan-Yao Huang ◽  
Tai-Her Yang ◽  
Tyng Liu
Keyword(s):  
Dynamic Model ◽  
Rear Wheel ◽  
Continuously Variable Transmission ◽  
Transmission System ◽  
Transmission Model ◽  
Differential Model ◽  
Torque Vectoring ◽  
Continuously Variable Transmissions ◽  
Variable Transmission ◽  
Final Drive

This study investigates the limited-slip and steering characteristics of a dual continuously variable transmission system. The dual continuously variable transmission is a unique final drive system composed of two continuously variable transmissions, with one continuously variable transmission connected to each rear wheel. In this study, a dynamic model of the dual continuously variable transmission system is derived, and models of the conventional final drive systems, i.e. the solid axle and the open differential, are used as benchmarks. In the simulations, the dual continuously variable transmission model, the solid axle model and the open differential model are applied to a vehicle dynamic model for split- μ road tests and a series of steering tests. According to the results of the split- μ road tests, the limited-slip function of a dual continuously variable transmission system is verified. The results of the steering tests show that different torque distributions for the inside wheels and the outside wheels while cornering can be controlled with different gain values of the continuously variable transmissions; for this reason, the application of the dual continuously variable transmission system as a torque-vectoring device is proposed, and a basic setting principle is presented. The results of this study establish a fundamental knowledge for developing the dual continuously variable transmission as an advanced final system for improving the vehicle dynamics.

scholarly journals Analysis and experiment of HMT stationary shift control considering the effect of oil bulk modulus

2020 ◽  
Vol 12 (11) ◽  
pp. 168781402096832
Author(s):  
Xueliang Li ◽  
Lu Zhang ◽  
Shujun Yang ◽  
Nan Liu
Keyword(s):  
Experimental Study ◽  
Bulk Modulus ◽  
Control Method ◽  
Simulation Analysis ◽  
Continuously Variable Transmission ◽  
Mechanical Transmission ◽  
Reverse Time ◽  
Shift Quality ◽  
Shift Control ◽  
Variable Transmission

In order to improve the shift quality of hydro-mechanical continuously variable transmission, the effect of tangent bulk modulus and different control methods on the shift quality were analyzed. Theoretical analysis and experimental study on the tangent bulk modulus of oil were carried out to obtain the effect law of air content on the tangent bulk modulus of oil. A four-cavity model of a closed hydraulic circuit was established based on a two-stage arithmetic type hydro-mechanical transmission. By means of simulation analysis and experimental study, the effect of the tangent bulk modulus of oil on the shift quality is studied. The lean control method of reasonably controlling displacement ratio and prolonging the reverse time of load torque is put forward. The results show that this method can reduce the fluctuations of the speed of the fixed displacement motor and the oil pressure of the original low-pressure side. This method can also improve the shift quality and provide reference for the study of the shift process of hydro-mechanical continuously variable transmission.

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