Abstract: A one-way clutch includes an inner ring, an outer ring disposed coaxially with the inner ring, a plurality of rollers interposed between the inner and outer rings, a cage holding the rollers to locate these rollers in a circumferential direction of the inner and outer rings. When the rollers are brought into biting engagement with an outer peripheral surface of the inner ring and an inner peripheral surface of the outer ring, the inner and outer rings rotate in unison, and when the rollers are disposed out of biting engagement with the inner and outer rings, the inner and outer rings rotate relative to each other. Grooves are formed in the outer peripheral surface of the inner ring, and each of the grooves serves to increase a contact pressure of the corresponding roller relative to the inner ring at part of a region of contact between the roller and the inner ring.

Abstract: A one-way clutch includes an inner ring, an outer ring disposed coaxially with the inner ring, a plurality of rollers interposed between the inner and outer rings, a cage holding the rollers to locate these rollers in a circumferential direction of the inner and outer rings. When the rollers are brought into biting engagement with an outer peripheral surface of the inner ring and an inner peripheral surface of the outer ring, the inner and outer rings rotate in unison, and when the rollers are disposed out of biting engagement with the inner and outer rings, the inner and outer rings rotate relative to each other. Grooves are formed in the outer peripheral surface of the inner ring, and each of the grooves serves to increase a contact pressure of the corresponding roller relative to the inner ring at part of a region of contact between the roller and the inner ring.

Abstract: An auto tensioner comprises a fixing shaft having an arm supporting portion, an arm supported around the arm supporting portion of the fixing shaft so as to be swingable, for keeping the belt tension constant, a tension pulley supported rotatably at a free end of the arm, a friction pressing plate disposed so as to oppose the arm and blocked from rotating relative to the arm supporting portion, a friction plate disposed between the arm and the friction pressing plate so as to supply the arm with a swing resistance, and a twisting coil spring for pressing the arm against the friction plate so as to make the friction plate in contact with the friction pressing plate, wherein the friction pressing plate has a plurality of concave portions for collecting wearing particles generated because of a friction between the friction plate and friction pressing plate and wearing particles are collected in the concave portions so as to prevent the wearing particles from staying between the friction plate and friction pressi

Abstract: An auto tensioner comprising a support shaft whose one end is fixed to a target attaching object and which has an arm support portion, an arm whose one end is rotatably supported by the arm support portion of the arm and which has a pulley support portion projecting fowardly and axially beyond the top end of the support shaft, a tension pulley which is rotatably supported by the pulley support portion of the arm and arranged at a position offset from the support shaft and a friction plate arranged between one end of the arm and the arm support portion of the support shaft and adapted to apply a rotary resistance to the arm. Further, the friction plate is provided with a load bearing member in its zone where a load resulting from the offset arrangement of the tension pulley is applied whereby the zone of the friction plate can have a sufficient degree of load-resistant property.

Abstract: A hydraulic valve lifter for use in an internal combustion engine, comprises an inverted cup-like body, an inverted cup-like plunger housed within the body, a high pressure chamber defined between the body and the plunger, and an oil passage through which an oil is fed to the high pressure chamber. At least one oil discharge hole is defined in the plunger and extends from the oil passage to open to a valve stem so as to lubricate between the valve stem and a valve guide.