| The gearbox is an important part of vehicle powertrain. Although the traditional mechanical transmission has higher efficiency, but today’s vehicle emmission regulations are becoming stricter and stricter, the gearbox’s efficiency will need more higher in the future. Efficient transmission can not only reduce the fuel consumption of cars, but also can reduce the generation of heat. Low temperature can lower the gear contact fatigue and scuffing failure and effectively prolong the life of gear, bear and lubricant. In the present studies of transmission efficiency have focused on establishing the transmission efficiency loss prediction model. There are few systematic through theoretical and experimental study the effect of gear, bear and lubricant on the transmission efficiency. In this paper, through theoretical analysis of the various influence factors of gearbox transmission efficiency. Designed the test method of gearbox transmission efficiency, studied the effect of different levels lubricant, gear precision, Bearing fit quality and Bearing seal on the transmission efficiency. The main research works are as follows:1) Analyzed the various influence factors of power transmission losses. Studied the mechanism of gear meshing power loss and using the the method of geometry and kinematics analyze the influencing factors of gear sliding friction and rolling friction power loss. Designed a method to test the gears of unload power loss and researched.2) Analyzed the generating mechanism of bearing friction torque and the influence factors. The calculation methods of the bearing friction torque and power loss are given. Experiment tested the effect of the seals and grease on the bearing friction torque and obtained the result that the seals are the key factors of the bearing friction torque. And tested the effect of bearing seals on the transmission efficiency.3) Introduced the standards and performance requirements related to lubricant. Multi-grade gear oil were introduced in detail in the mechanism of energy saving and emission reduction and tested the effect of multi-grade gear oil on transmission efficiency, vehicle fuel consumption and sliding distance.4) elaborated the effect of gear accuracy and bearing fit precision on the transmission rotary precision and tested the effects of two kinds of factors on the transmission efficiency.5) Transmission transmission efficiency test method, test conditions, test bench, structure principle of control system, measurement of torque and speed and oil temperature’s control was introduced. |
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