Koyo Seiko Company, Ltd.

Hirotsugu Okuse

Kenji Takahashi

Kazuo Uchida

Masahiro Noguchi

Hiroshi Sato

Yoshitsugu Fujiwara

A retainer for a needle bearing has an improved durability owing to the improved strength of its stay portions at the roots thereof, and an improved lubricating property. The retainer 10 is made by forming a plurality of longitudinally spaced apart pockets 11 for needle rollers in a strip of material, bending it into a cylindrical shape and joining its butt ends together. Every two adjoining pockets 11 define therebetween a stay portion 13 having a pair of axially extending sides S which are substantially parallel to each other. Every two adjoining stay portions 13 have between their radially inner ends a distance L1 which is smaller than the diameter of each needle roller 9f. Each stay portion 13 has a pair of protrusions 14 extending from its axially middle and radially outer part to the centers of two adjoining pockets 11, and the protrusions 14 in each pocket 11 have therebetween a distance L2 which is smaller than the diameter of the needle roller 9. Each protrusion 14 has a beveled surface 15 formed along its radially inner edge and adapted to make surface contact with the needle roller 9 in each pocket 11.

Needle bearing retainer and a needle bearing

A valve rotating apparatus of an internal-combustion engine comprises a valve biased in the closing direction by a coil spring, a valve lifter disposed on an engine head in such manner as to be vertically movable together with the valve, a cam formed on a cam shaft for directly driving the valve through the valve lifter, and a thrust rolling bearing retaining the coil spring, the thrust roller bearing comprising an upper washer, a lower washer, and balls held by a cage between the upper and lower washers. The cage is provided between its inner and outer circumferences with a plurality of pockets at regular spatial intervals, a plurality of balls being housing in each pocket; and the inner or outer periphery of each of the upper and lower washers is provided with an axially extending cylindrical portion. The upper washer has the degree of freedom for movement in all directions including X and Y directions, within the same plane. Accordingly, the thrust rolling bearing follows the radial displacement of the coil spring caused by its bending or the like, so that the thrust rolling bearing is moved together with the coil spring, and the intake/exhaust valve can be smoothly rotated. The thrust rolling bearing can also be applied between the valve lifter and a pad disposed thereon.

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Chofu, Japan

Hirotsugu Okuse