A bearing for a ball screw drive may include a ball nut that is rotatable about a longitudinal axis and intended to receive a threaded spindle concentrically. The ball nut may be arranged in an inner ring and at least partially in an intermediate ring and an outer ring of the bearing. A belt pulley may be connected to the intermediate ring for rotation therewith, wherein an outer circumferential surface of the inner ring may be convex in some regions and an inner circumferential surface of the intermediate ring may be concave in some regions. The ball nut may be arranged in the bearing so as to be tiltable with respect to the belt pulley. The inner ring may be connected to the ball nut for rotation therewith and may be immovable in an axial direction. The intermediate ring may be connected via spring elements to the inner ring for rotation therewith.

In a tripod type constant velocity universal joint 1, when D1 represents a large inner diameter being a diameter of a circle connecting radially outer end portions of roller guide surfaces 7 and D2 represents a small inner diameter being a diameter of a circle connecting radially inner end portions of the roller guide surfaces 7, a ratio D2/D1 between the small inner diameter D2 and the large inner diameter D1 is set within a range of from 0.73 to 0.80. Further, when d represents a large diameter of a spline formed in a trunnion hub 8 of a tripod member 3 and PCD represents a pitch circle diameter of the roller guide surfaces 7, a ratio d/PCD between the large diameter d and the pitch circle diameter PCD is set to 0.60 or more.

An electric power steering device includes a worm which is swingably connected to the rotation shaft of an electric motor through a joint. A first end portion and second end portion of the worm are supported by a first bearing and a second bearing, respectively. A pair of elastic members elastically urge the worm to an axial neutral position. An annular leaf spring which is held by a housing urges the second end portion toward a worm wheel through the second bearing. A synthetic resin member having a sliding contact surface which is in contact with the leaf spring is integrally disposed on the second bearing.

A bearing for a ball screw drive may include a ball nut that is rotatable about a longitudinal axis and intended to receive a threaded spindle concentrically. The ball nut may be arranged in an inner ring and at least partially in an intermediate ring and an outer ring of the bearing. A belt pulley may be connected to the intermediate ring for rotation therewith, wherein an outer circumferential surface of the inner ring may be convex in some regions and an inner circumferential surface of the intermediate ring may be concave in some regions. The ball nut may be arranged in the bearing so as to be tiltable with respect to the belt pulley. The inner ring may be connected to the ball nut for rotation therewith and may be immovable in an axial direction. The intermediate ring may be connected via spring elements to the inner ring for rotation therewith.