Patent ID: 7878914

Claim:
A constant velocity joint for a drive system having a first rotating shaft and a second rotating shaft coupled with the constant velocity joint, the constant velocity joint comprising: a hollow housing having an opening at one end, and a closing at its opposite end fixed to an end of the first rotating shaft, an inner face of the housing including a plurality of guide grooves extending in an axial direction of the housing and spaced equally apart in a circumferential direction of the housing, each groove having a pair of side faces opposing to each other; a tripod disposed at an end of the second rotating shaft, having a plurality of trunnions each positioned in a corresponding one of the guide grooves and being spaced equally apart in a circumferential direction of and at an angle normal to the second rotating shaft; and an inner roller having a spherical inner face for receiving an outer end portion of each of the trunnions therein, an outer roller mounted on an outer face of each inner roller with needle rollers engaged between the inner and outer rollers, and allowing the outer face of each outer roller to roll and move in the corresponding one of the guide grooves and for transmitting a load between the first and second rotating shafts to drive the driving system; wherein each of the trunnions includes a pair of cylindrical protrusions opposingly disposed and protruded to a distance from an outer surface of the trunnion in a direction normal to the axis of the trunnion, each of the cylindrical protrusions including a spherical surface at its distal end for surface-to-surface contact with the spherical inner face of the inner roller while defining a gap around the cylindrical protrusion and between the surface of the trunnion and the spherical inner face of the inner roller; wherein each of the inner rollers includes a pair of grooves each formed in a diametric direction and on the bottom portion of the inner roller facing a boss of the tripod, the pair of grooves sized for receiving the pair of cylindrical protrusions of the trunnion while inclining the inner roller to a predetermined degree with respect to the trunnion for assembly.