脉冲爆震轴向载荷对双半内圈球轴承疲劳寿命的影响

To solve the problem that periodic and strong unsteady axial load in pulse detonation turbine engine (PDTE) may reduce the reliability of the ball bearing, a fatigue life prediction model for a split inner ring ball bearing was established by using damage mechanics theory and finite element method. The fatigue life of the split inner ring ball bearing under the periodic and strong unsteady axial load introduced by pulse detonation combustor (PDC) was studied. The results show that two half inner rings initiate cracks at the position of the maximum shear stress on the subsurface of the contact zone and then the cracks gradually spread to the surface, which leads to the fatigue failure of the bearing. In the PDC detonation process, the fatigue life of the first half inner ring is higher because the shear stress range that causes fatigue damage is smaller. In the fill and purge process, the fatigue life of the second half inner ring is lower due to the contact friction effect and larger shear stress range caused by the balls roll through the second half inner ring. After the reasonable design of the peak value of axial load introduced in the detonation process of PDC, the fatigue life of the split inner ring ball bearing in PDTE is mainly determined by the contact state of the second half inner ring and the lubrication condition of the bearing.