Abstract：In order to investigate the fretting wear behavior of angular contact ball bearings under different loads, oscillation angles, and number of cycles, a series of tests for angular contact ball bearings (QJ208) were performed under dry condition on a self-made bearing fretting wear test rig with four axial loads (2.5, 5.0, 10.0, and 20.0 kN), three oscillation angles (0.88?, 1.21?, and 1.54?) and two cycle numbers (2?104 and 12?104). The fretting wear behavior was analyzed in combination with microscopic examinations on worn scars. The results show that the fretting wear on the outer ring reduces with the increasing load, but increases with the increasing oscillation angle. As the number of cycles increases, the growth rate of wear slows down. In addition, the wear mechanism is dominated by fatigue wear at the oscillation angle of 0.88?, and by abrasive wear at the oscillation angle of 1.54?. For each ball, the wear damage on the outer ring is more serious than that on the inner ring.
