Constant velocity universal joint

A constant velocity universal joint including an outer joint component, an inner joint component inserted in the outer joint component, and a torque transmitting component that is interposed between the outer joint component and the inner joint component and performs torque transmission, the constant velocity universal joint comprising:

• a recess-projection engagement configuration that connects the inner joint component and a shaft pressed fitted into the inner joint component, wherein:
• the recess-projection engagement configuration has axially-extending projections provided on one of an outer diameter surface of the shaft and an inner diameter surface of the inner joint component, and recesses engaging with the projections in close contact and formed on the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component by the projections being pressed into the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component along an axial direction;
• concave portions are formed, on the one of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component, between the projections that are adjacent in the circumferential direction;
• convex portions are formed, on the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component, between the recesses that are adjacent in the circumferential direction;
• engagement contacting regions of the projections and the recesses engaging with the projections are in close contact over the whole region;
• radial gaps are formed between the concave portions and the convex portions;
• the constant velocity universal joint includes an outer member serving as the outer joint component in which a plurality of guide grooves extending in the axial direction are formed on an inner circumferential surface, an inner member serving as the inner joint component in which a plurality of guide grooves extending in the axial direction are formed on an outer circumferential surface, torque transmitting balls disposed on ball tracks formed by the guiding grooves of the outer member and the guiding grooves of the inner member working in cooperation, and a holder having pockets that holds the torque transmitting component, and balls are used as the torque transmitting component;
• one of either the track grooves of the outer joint component or the track grooves of the inner joint component is formed by cold forging;
• constituent elements including the outer joint component, the inner joint component, the balls, and a cage are mounted by random matching;
• the inner joint component and the shaft fitted into an axial hole of the inner joint component are connected by the recess-projection engagement configuration;
• engagement contacting regions of the projections of one of either the inner joint component or the shaft and the recesses of a partner component engaging with the projections are in close contact over the whole region;
• and
• a PCD gap of ball tracks formed by the track grooves of the outer joint component and the track grooves of the inner joint component working in cooperation with the outer joint component is −0.02 to +0.3 millimeters.

A constant velocity universal joint including an outer joint component, an inner joint component inserted in the outer joint component, and a torque transmitting component that is interposed between the outer joint component and the inner joint component and performs torque transmission, the constant velocity universal joint comprising:

• a recess-projection engagement configuration that connects the inner joint component and a shaft pressed fitted into the inner joint component, wherein:
• the recess-projection engagement configuration has axially-extending projections provided on one of an outer diameter surface of the shaft and an inner diameter surface of the inner joint component, and recesses engaging with the projections in close contact and formed on the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component by the projections being pressed into the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component along an axial direction,
• concave portions are formed, on the one of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component, between the projections that are adjacent in the circumferential direction,
• convex portions are formed, on the other of the outer diameter surface of the shaft and the inner diameter surface of the inner joint component, between the recesses that are adjacent in the circumferential direction,
• engagement contacting regions of the projections and the recesses engaging with the projections are in close contact over the whole region,
• radial gaps are formed between the concave portions and the convex portions,
• a recess-projection running along the axial direction is provided on at least a portion of the projection side in the axial direction, and
• the recess-projection running along the axial direction on the projection side is formed into a saw-tooth shape.