Analysis of Friction Moment of Gyroscope Frame Bearing

For the applications of demanding small and stable friction moment of gyroscope frame bearings, the model of bearing's friction moment is built. Based on the existing analyses that include the friction moments caused by elastic hysteresis, sliding due to the contact race curvature, pivoting between the ball and the inner/outer race and lubrication, the friction moment caused by ribbon or crown cage are mainly introduced. Through comparing the calculated bearing's starting and kinematic friction moment to the experimental results measured by YZC-II tester, an acceptable consistent is achieved. The analyses show that the proportion of friction moment caused by cage increases with the decreasing loads. This proportion is larger in the bearing's starting friction moment and smaller in the kinematic friction moment. According to the calculated results of 4 kinds of frame bearings at different speeds, the speed has little influence on the friction moment when the bearings work at lower 2 r/min, but when the speed increases, it will have a big influence on the value of starting friction moment and the fluctuation range of kinematic friction moment.