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Facing with the situation that global oil resources are depleting, environmentalpollution is increasingly serious and national regulations on vehicle emission is ofincreasingly high demand, human beings must find a environmental and energy-savingway, and continue to enjoy the benefits of convenient life and rapid social developmentof vehicles. So it accelerates the development of hybrid electric vehicles and pureelectric vehicles. However, no breakthrough in key technology of pure electric vehicleand fuel cell vehicle is obtained, making hybrid electric vehicles become the maindirection of automobile industry.Dynamic coupling mechanism is the core part of the transmission system of thehybrid electric vehicle, and it couples the power of the engine with the motor to achievethe various operation modes of the hybrid electric vehicle, such as the pure electricdrive, the engine drive, hybrid drive, light-load charge, regenerative braking and so on.Its performance has a direct impact on the performance of the vehicles’ dynamics, fueleconomy and emission,and it is key to the successful development of the hybrid electricvehicle.At present, domestic and foreign research field of hybrid electric vehicle dynamiccoupling mechanism is concentrated more on the structural design, mode switching andcontrol of dynamic coupling mechanism, etc, and less on overall temperaturedistribution of the dynamic coupling mechanism. Dynamic coupling mechanism willgenerate heat in the work process, resulting in its temperature raising, the hightemperature will lead to work failure and damage of the clutch and the motor., thusaffecting the work performance of the dynamic coupling mechanism and vehicleperformance. Therefore, study the temperature distribution of the dynamic couplingmechanism has a great significance, it could prevent the oponent’s deterioration due tohigh temperature, or even failure.This paper explores the dynamic coupling mechanism of hybrid electric vehicle,combines the different operation modes of hybrid electric vehicles, then the temperaturefield of dynamic coupling mechanism is simulated, analyzed, and it gets the temperaturefield distribution. Finally,the paper regards the ISG (Integrated Starter and Generator)motor in the dynamic coupling mechanism as the research object, studies the ISGmotor’s temperature field and does the temperature experiment. Specific research is reflected in the following respects:(1) Introducing the function and classification of hybrid electric vehicle anddynamic coupling mechanism, analyzing the domestic and foreign research of thedynamic coupling mechanism, and further analyzing the domestic and foreign researchof the dynamic coupling mechanism’s temperature field.(2) Analyzing the working states and heat sources of the dynamic couplingmechanism in the different operation modes of hybrid electric vehicle, such as the pureelectric alone drive, the engine alone drive, hybrid drive and so on. As the hybridelectric vehicle has many operation modes, this article selects only three typicaloperation modes—the pure electric alone drive, the engine alone drive and the motorstarts the engine—to simulate and analyze the temperature field of the dynamiccoupling mechanism.(3) Combining with the actual model of the dynamic coupling mechanism, usingthe PROE to establish a three dimensional model of the dynamic coupling mechanism,and using the heat transfer theory to calculate some thermodynamic parameters,such asthe heat source of the dynamic coupling mechanism, convective heat transfer coefficient,heat flux and so on, finally the simulation model is established and the temperature fieldis got of the dynamic coupling mechanism by COMSOL software. Meanwhile, thispaper also analyzes the influence of cooling liquid’s flow on temperature field of thedynamic coupling mechanism.(4) Regarding the ISG (Integrated Starter and Generator) motor in the dynamiccoupling mechanism as the research object, studies the ISG motor’s temperature fieldunder the rated working state and peak working state, and when the hybrid electricvehicle is pure electric operation mode, and it does the ISG motor’s temperatureexperiment to verify the the correctness of the the ISG motor model and simulationmethod.
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