Quasi-static analysis of thrust-loaded angular contact ball bearings part II: Results and discussion

Abstract

Ball bearings are widely employed mechanical components characterized by high precision and quality, and usually play important roles in various rotary machines and mechanisms. Many advanced applications require a deep understanding of their various kinematic and tribological characteristics that are essential to predict the fatigue endurance, relieve the vibration and minimize the power dissipation of ball bearings in particular applications. An angular contact ball bearing under a specified operating condition is simulated with the quasi-static/creepage analytical model proposed in the preceding article. The results demonstrate that the ball bearing is a statically determinate system. That the balls spin on both inner and outer races means the ball is controlled by neither the inner nor the outer raceway. The friction between the ball and raceway renders the inner and outer contact angles unequal. The larger the coefficient of friction is, the larger the angle deviation. The tangential traction perpendicular to the rolling direction due to the spin induces a gyro-like rotation of the ball with respect to the raceway even if no inertial effects are considered. The tangential elastic compliance of contacting surfaces gives rise to locked areas within the contact patch and transforms the sliding lines from circles into spirals. The differential slip due to the close conformity of the ball and raceway makes the sliding and traction distributions asymmetric, which will influence the location of the spinning center of the ball with respect to the raceway. The quasi-static/creepage model can be used to reveal the operating behaviors of ball bearings running under steady conditions and to optimize the design of ball bearings for specific applications.