Abstract: A precise computation method is proposed for the static load-carrying capacity curve of large-size double-row four-point-contact ball bearings. Then the static load-carrying capacity surface of a double row four-point contact ball bearing is obtained. And precise static load-carrying capacity curves and simplified static load-carrying capacity curves are compared. The effect on the static load-carrying capacity curve by the change of negative internal clearance, coefficient of raceway groove curvature radius and free contact angle is analyzed. The results show that the value of the maximum moment load increases and axial load decreases with the increase of the absolute value of the negative clearance. The clearance value changed in the range of –0.2~0 mm has little effect on the load capability of the bearings. The coefficient of raceway groove curvature radius has important effect on the load-carrying capacity of the bearing. With the increase in the coefficient of raceway groove curvature radius, the static load-carrying capacity of the bearing decreases. With the increase in the radial load, static load-carrying capacity first increases and then decreases as the free contact angle increases.

Key words: large size bearing;four-point contact;load-carrying capacity