Ball retainer

Claim 1

A ball retainer for the centering apparatus of a universal joint for a rotary drive line, comprising: a yoke having a ball receiving cavity at one end thereof; a first spherical surface formed in said ball receiving cavity, said spherical surface defining an axial direction and a radial direction in a plane normal to the axial direction and opening in its substantially largest dimension in the radial direction outwardly away from said yoke; a ball for being retained in said cavity and slidably mating with the first spherical surface; a ball retainer ring for keeping the ball in the cavity, said retainer ring having an inner end and an outer end; a second spherical surface on the ball retainer ring for mating with the ball when the ball is mating with the first spherical surface, said second spherical surface opening in its substantially largest dimension in the radial direction toward said yoke, said outer end of the ball retainer ring intersecting said second spherical surface at said substantially largest dimension in the radial direction of said second spherical surface; and a circular retainer spring for locking the retainer ring to the yoke; the ball receiving cavity having at one end an enlarged circular opening coaxial with the first spherical surface, said opening being defined by a first shoulder facing outwardly in the axial direction and having a radially inward edge and a radially outward edge, said radially inward edge intersecting the first spherical surface at said substantially largest dimension in the radial direction of said first spherical surface and said radially outward edge intersecting a cylindrical surface for engaging the outer periphery of the ball retainer ring with a clearance, said cylindrical surface having a groove formed therein which defines a second shoulder facing in the axial direction toward the first spherical surface; the ball retainer ring having a groove around its outside circumference to receive the retainer spring, said groove having a side facing in the axial direction toward the first spherical surface, said ball retainer ring being insertable into said circular opening with said side of said groove passing beyond the axial position of the second shoulder of the circular opening and said groove allowing the retainer spring to be substantially fully compressed into said groove; wherein the retainer spring is compressed into the groove in the retainer ring to insert the retainer ring into the circular opening, and expands behind the second shoulder after the retainer ring is inserted past the position where the side of the groove is aligned with the second shoulder of the ball receiving cavity when said retainer spring clears said shoulder so that the retainer ring locks the ball in the ball receiving cavity between the first and second spherical surfaces with a space between the first shoulder and the inner end of the ball retainer ring, a loose sliding fit between the ball and the ball receiving cavity and with the retainer ring freely rotatable in the circular opening.