TRIPOD TYPE CONSTANT VELOCITY UNIVERSAL JOINT AND METHOD FOR PRODUCING SAME

摘要

Provided is a tripod type constant velocity universal joint, including: an outer joint member (2) including three track grooves (5) each formed so as to have roller-guide surfaces (6) arranged to face each other in a circumferential direction of the outer joint member (2); a tripod member (3) including three leg shafts (7) projecting in a radial direction of the tripod member (3); and roller units (4) each including a roller (11) and an inner ring (12) for supporting the roller (11) in a freely rotatable manner. The inner ring (12) is externally fitted to corresponding one of the three leg shafts (7). The roller (11) is movable along the roller-guide surfaces (6) of corresponding one of the three track grooves (5). Each of the three leg shafts (7) includes a region formed into a substantially circular-arc shape in horizontal cross-section that is orthogonal to an axial line (O) of the each of the three leg shafts (7). The each of the three leg shafts (7) has an outer peripheral surface held in contact with an inner peripheral surface (12a) of the inner ring (12) in a direction that is orthogonal to an axial line of the tripod type constant velocity universal joint. The outer peripheral surface of the each of the three leg shafts (7) and the inner peripheral surface (12a) of the inner ring (12) have a clearance (m) formed therebetween in a direction of the axial line of the tripod type constant velocity universal joint. The each of the three leg shafts (7) includes an outer peripheral surface region (7a) that is finished through grinding and held in contact with the inner peripheral surface (12a) of the inner ring (12). The each of the three leg shafts (7) includes a grinding relief portion (17) formed at an end portion in the circumferential direction of the outer peripheral surface region (7a).