Patent ID: 8162766
Filing Date: 2012-04-24
Classification: F16D,Y10S

Abstract:
1. A fixed type constant velocity universal joint, comprising: an outer joint member having an inner spherical surface in which a plurality of track grooves extending in an axial direction are formed; an inner joint member having an outer spherical surface in which a plurality of track grooves extending in the axial direction while paired with the track grooves of the outer joint member are formed; a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member, and being configured and arranged to transmit a torque; and a cage interposed between the inner spherical surface of the outer joint member and the outer spherical surface of the inner joint member, and being configured to hold the plurality of balls, the outer joint member and the inner joint member each having a center curvature of the track grooves being offset from each other in a direction opposite to the axial direction by an equal distance with respect to a joint center, and wherein a pitch circle diameter (PCD) gap in a ball track formed between the track grooves of the outer joint member and the track grooves of the inner joint member is equal to or larger than 25 μm, and the plurality of balls are configured and arranged in the ball track such that upon transmission of rotational torque to the constant velocity universal joint, contact of each of the plurality of balls with a portion on a no-load side of the ball track is reduced relative to a PCD gap less than 25 μm, so as to reduce frictional heating.