Investigation on contact angle of ball bearings

As an important structure parameter, contact angle is also a judgement factor for the working performance of ball bearings. However, under some conditions, the ball may roll over the raceway shoulder, and contact angle is not enough for estimating this phenomenon. Thus, edge angle and edge distance are proposed as compensatory judgement factors in the current study. A six-degree dynamic model with time-varying contact stiffness was developed for investigating effects of initial contact angle, raceway groove curvature factors, number of balls, axial load, shaft speed, friction coefficient and raceway misalignment on contact angle, contact stiffness, edge angle and edge distance. Inapposite initial contact angle may make the ball roller over the raceway shoulder, inner raceway misalignment have significant influences on the stable motion of ball bearings, and more harmonics frequencies about contact angle appear. Comparison of contact angle from presented model with Jones–Harris model under axial load shows reasonable qualitative agreement.