Fixed-type constant-velocity universal joint

A fixed type constant velocity universal joint rotationally driven by an electric motor, the fixed type constant velocity universal joint comprising:

• an outer joint member provided with eight track grooves on an inner spherical surface;
• an inner joint member provided with eight track grooves on an outer spherical surface;
• eight torque transmitting balls disposed between the track grooves of the outer joint member and the track grooves of the inner joint member;
• a cage having a pocket that holds each of the torque transmitting balls, an outer spherical surface that fits with the inner spherical surface of the outer joint member, and an inner spherical surface that fits with the outer spherical surface of the inner joint member;
• and
• grease sealed inside the outer joint member, wherein
• a curvature center of the track grooves of the outer joint member and a curvature center of the track grooves of the inner joint member are offset by an equal distance axially opposite to a joint center,
• the grease has an initial consistency of consistency number of 1 to 2 and mixing stability of 390 to 440, and
• an initial pocket gap δ represented by a difference (H−DBALL) between an axial width H of the pocket and a diameter DBALL of each of the torque transmitting balls is −21 μm or more and −6 μm or less.