Research On Mechanism Of Fretting Wear For Powertrain Gear Shaft Shoulder Based On Thermo-structural Coupling Analysis

Fretting is a reciprocating movement of small amplitude between the contact surfaces and fretting wear occurs because of this movement. Fretting wear may change the mechanism performances, reduce the reliability and life of the machine, sometimes it even leads to a serious accident. The damage is also increasing in the field of high-tech because of the surface wear induced and micro-cracks expanded caused by fretting, such as nuclear power industry, aerospace, artificial planting limb and so on. Therefore, it has a very important practical significance to do the research about the mechanism of fretting wear and the factors which have effects on fretting wear then corresponding measures could be taken to prevent it.Therefore, supported by the school-enterprise cooperation project "Research on Mechanism of Fretting Wear for Powertrain Gear Shaft Shoulder",in this paper, the fretting wear phenomenon of an aviation power gear shaft shoulder that matches with the bearing inner ring surface was studied by using FEM software ABAQUS. The job and innovations of this paper lies in following respect:(1) To determine the factors that influence fretting wear of the shaft shoulder and establish the finite element model and mathematical model of the gear shaft lay a strong research base for thermal coupling analysis.(2) Analyze the source of heat generated which affect the shaft shoulder. The geometric model and FEM model of the helical bevel gear and double row circular cone roller bearing have been proposed based on FEM theory. A simulation is made to calculate the heat generated by the bevel gears that are engaged and by the rotational friction of the double row circular cone roller bearing. Then the temperature of the gear and bearing can be calculated by using the results of the simulation. At last, make a summary for the law how the temperature of the gear and bearing changes as the speed increases.(3)The heat stress field of the shaft shoulder could be simulated by using thermal-structural coupling method. An analysis is made to study the relationship between fretting wear and the temperature. The rate of the fretting wear can be figured up with the formula of oxidative wear and verify the theory put out by this paper.