Efficiency Analysis And Experimental Research On Mechanical Transmission

Transmission,as an important part of powertrain,has a direct impact on vehicle dynamic performance and fuel economy.The efficiency is an essential factor to evaluate transmission,and reflects its comprehensive performance.Therefore,research on transmission efficiency not only has positive influence on environment,but also helps to improve the quality of vehicles.This thesisregards one mechanical transmission as the study object and researches from the factors which affect the transmission efficiency for analyzing four aspects effects on the transmission efficiency,including gear meshing,bearings friction,churning and oil sealing power loss.And these factors' values are calculated by theoretical formula.Then,Based on the relevant parameters of mechanical transmission,the transmission model is established by Romax software,including shaft,bearings,gears,etc.The relationships of speed,torque,gear,oil temperature respectively with transmission efficiency are discussed combined with the actual working condition and simulation results.In order to meet experimental requirement,this thesis selects closed test bench consideringof test condition,cost and cyclesimultaneously according to the relevant national standard QC/T568.1-2011 and QC/T29063.1-2011.The versatility of the test bench is taken into account in the design process to confirm the mechanical structure and control system.The bench control mode is that the upper machine connects with the machine through Ethernet,so as to realize automatic control.After experiment on this transmission,simulation resultsfrom Romax software are comparedwiththose from the test bench.The resultsof these two remain the samebasically so that the accuracy of simulation conclusion is approved.At the same time,in order to prove that the simulation model can reflect the test results,correlation analysis is established betweensimulation results and experimental data.The correlation coefficient is 0.9374,which also shows a high-positive correlation under the same conditions.The model established by Romax can be proved effective.On the initial stage of product development,simulation analysis by Romax not only enables users to accurately analyze performance of transmission,also shorten the development cycle and saves the cost of test.Thethesisresearchesand analyzes on mechanical transmission efficiency through Romax modeling with simulation and test bench experiment.Itproves the relationship oftransmission efficiency respectively with speed,torque,gear and oil temperature,furthermore the validityof simulation model can be approved.This research provides strong supports for the design and production of automobile transmission.The research conclusion is also applicable to other mechanical transmissions,and achieves reference function for the related research.