Integrated car hub bearing unit

An integrated car hub bearing unit belongs to the field of car parts. Conventional bearing groove curvature adopts a design of unequal curvature generally, but the integrated car hub bearing unit is unsuited for adopting the design of unequal curvature because the integrated car hub bearing unit is free of interference fit and the raceway curvature thereof can not change during usage. The integrated car hub bearing unit utilizes a design of equal curvature, raceway groove curvature of an outer ring is equal to raceway groove curvature on a flange shaft, both the groove curvature coefficients are 0.52, the raceway groove curvature coefficient of a small inner ring ranges from 0.515 to 0.52, and the groove curvature coefficient on the small inner ring changes to be equal to the groove curvature coefficient on the outer ring basically after the small inner ring is in interference fit with the flange shaft, thereby guaranteeing fine contact of raceways and steel balls and prolonging service life.