Papers by Keyword: CVT

Abstract: Taking CVT plug-in hybrid electric vehicle as the study subject, the objective function of the energy economy is created. In view of engine, motor efficiency and CVT efficiency coupled relationship; proposed reverse optimization algorithm to solve function. The target speed ratio of optimal energy economy is obtained in different SOC (State Of Charge), velocity, acceleration and slope.

Abstract: In view of the working principle and characteristics of the CVT with electronic control and a motor as actuator (EM-CVT), a economical car performance is studied by means of combination of simulation calculation and prototyping test. EM-CVT mathematic model is established and embedded into the simulation software Cruise to finish the whole vehicle modeling. The performance comparison between vehicle with EM-CVT and automatic transmission is presented after simulation based on the experiment data on the EM-CVT prototype under UDC, which indicates that the vehicle fuel consumption with EM-CVT is reduced distinctly with the same power performance.

Abstract: This paper introduces an electro-mechanical dual acting pulley continuously variable transmission (EMDAP CVT) system and presents a method of measuring belt-pulley clamping force indirectly using a DC motor current sensor. The EMDAP CVT mainly consists of two movable primary (input) and secondary (output) pulley sheaves connected by metal pushing V-belt. Two DC motor’s actuation systems adjust the CVT ratio. Additionally, the secondary actuation system controls belt-pulley clamping force by adjusting the flatness of the spring discs placed at the back of each secondary pulley sheave to keep the belt tight and prevent belt slip. Ideally, a force sensor is used to measure the belt-pulley clamping force however the use of force sensor inside transmission gearbox is not feasible due to high temperature and oily environment. A viable solution for indirectly measuring the clamping force using current sensor for DC motor is proposed. Since the DC motor actuates the movable pulleys to clamp the belt, the relationship between the DC motor current and belt-pulley clamping force can then be investigated experimentally. The results will give positive impact on precisely controlling belt-pulley clamping force of EMDAP CVT using current sensor which is relatively simpler and less expensive than force sensor.

Abstract: The goal of the present contribution is to propose a new control strategy of drive train for the improvement of efficiency of regenerative braking system. In this new control strategy, the backward numerical solution is utilized to realize the cooperative operation of the electric machine and CVT. The analysis for the proposed control strategy is fulfilled based on the vehicle model. The results show that, compared to the existing one without considering the affect of CVT’s efficiency, the proposed control strategy could make more kinetic energies in the vehicle be recaptured.

Abstract: Taking CVT plug-in hybrid electric vehicle as the study subject, the objective function of the energy economy is created. In view of engine, motor efficiency and CVT efficiency coupled relationship; proposed reverse optimization algorithm to solve function. The target speed ratio of optimal energy economy is obtained in different SOC (State Of Charge), velocity, acceleration and slope. On the Matlab/Simulink platform, the system simulation model is built and simulated. The results shows that the target speed ration optimized control law in the case of no additional hardware cost , energy economy save about respectively 3.6% ,4.6%,6.7% in driving cycles of the NEDC,UDDS,HWFET before optimization.

Abstract: In order to conduct lubricating characteristic analysis on automobile continuously variable transmission, this paper divides overall model of transmission on the basis of the idea of blocking simulation. Then it generates shed oil model of differential mechanism and oil gathering model of oil groove. Set monitoring surface at the position of reverse gear shaft catcher groove in shed oil model of differential mechanism and oil groove in oil gathering model of oil groove to monitor its conditions of oil-taking. Consider the received flow from the two monitoring surfaces in simulation process as evaluation index of effects of transmission lubrication system, as well as conduct quantitative evaluation on lubricating effects of transmission lubrication system. The results show that all of working condition with second gear 1500rpm, reverse gear shaft and oil groove have comparative ideal lubrication effects on input axis.

Abstract: Completed solid model of hydraulic mechanical power split CVT using Pro/E software basing on the transmission principle, achieved the whole transmission without interference assemble by the interference analysis and checking the gap. Carried on dynamics simulation analysis using ADAMS software, obtained the variation of plungers’ centroid and the bearing force in the rear end cover, it laid the theoretical foundation for subsequent experimental analysis.

Abstract: Pulley strain aggravated whole-Part abrasion, affected friction and lubricates state of metal belt continuously variable transmission. Pulley strain was analyzed by analytical method and finite element analysis. The results indicate that with the increase of transmission ratio, the driver pulley compressive strain is increases after reduces for a while, and the driven pulley increase. Compressive strain dense when radius is lesser and vice versa. Two methods results are basically the same, whereby demonstrating that the model is rational and that the analysis results are reliable.

Abstract: By the field test, we carried on the physicochemical tests, the lubrication performance test, the ferrographic analysis and ICP tests for different mileage of CVTF, we also ran the electron microscope analysis of the key components of steel belt of CVT’s friction pair and bevel pulley. The transformation law of CVTF’ lubrication, the inoxidizability, the friction durability friction, the antifriction performance, the attenuation characteristics of functional elements and the abrasion mechanism of Cone wheel and steel belt are investigated.The result showed that there was the presence of extreme pressure film on the surface of friction pair, the physicochemical parameters of CVTF changed very small, the wear metal elements in petrol within 3000km increased slowly.

Abstract: This paper proposed a metal belt continuously variable transmission (MB-CVT) model on the basis of elastic mechanics theory to describe the strain energy power loss (SEPL) of metal rings. The metal rings were simplified as combined thin wall cylinder model in the arc part and simple tension model in the straight part. The results show that, the SEPL scope of the metal rings are 27.15-86.73W, the SEPL reduced when the transmission ratio is 1. This result shows a well agreement with the theory analysis.