Abstract: Surface indentation and oil film shortage on rollers is prevented and longer service life of a roller bearing is achieved, by preventing wear debris from being caught and accumulated in pockets of a holder of the roller bearing. Positions and dimensional relations of the diameters of inner and outer ring raceways, the inner and outer diameters of the holder, and inner and outer protrusions which are provided to pillar parts of the holder to prevent the rollers from coming off are defined such that the inner and outer protrusions of the pillar parts always do not come into contact with the outer circumferential surfaces of the rollers in the state where the rollers and the holder are incorporated between inner and outer members. As a result, lubricant oil is smoothly circulated in gaps formed between the outer circumferential surfaces of the rollers and the pillar parts of the holder.

Abstract: A chain guide includes a guide base (21) disposed to face one side of a timing chain (5) for transmitting torque, and having an opposed pair of side plates (22) each formed with a plurality of shaft engaging portions (25) arranged along a circular arc. Roller shafts (31) have their ends supported by the respective shaft engaging portions (25) Rollers (41) for guiding the chain are rotatably supported by the respective roller shafts (31). Noncylidrical surface engaging portions are formed on the ends of the roller shafts (31) and on closed ends of the shaft engaging portions (50) to rotationally fix the roller shafts (31), thereby preventing the roller shafts (31) from rotating under drag torque applied from the rollers (41).

Abstract: A cam follower is constituted by an outer ring which has an outer track surface in its inner circumference; a stud which has an inner track surface opposed to the outer track surface, a flange portion abutting on one side of the inner track surface, a side plate fitting portion and a mounting shaft portion abutting on another side of the inner track surface in this order, and a fiber flow formed continuously from the flange portion to the inner track surface along their outer circumferences; rolling elements which are arranged between the outer track surface and inner track surface; and an inner side plate which is pressed into the side plate fitting portion to work with the flange portion for limiting axial movement of the outer ring and the rolling elements.

Abstract: A chain guide is provided which reduces moving resistance of a camshaft-driving, torque-transmitting timing chain. The chain guide includes a guide base (21) provided on one side of the timing chain (5) to face the timing chain and having an opposed pair of side plates (22). The side plates support the respective ends of roller shafts (31) each rotatably supporting a chain-guiding needle roller bearing (41). Each needle roller bearing includes a retainer (43) guided by the needle roller elements (45). With this arrangement, the outer races (42) of the bearings, which guide the movement of the timing chain (5) while kept in rolling contact with the timing chain, encounter less rotational resistance. This in turn reduces moving resistance of the timing chain (5) and thus fuel consumption.

Abstract: A chain guide having excellent durability is provided. The chain guide includes a guide base arranged along a portion of an outer periphery of a chain for transmitting torque and elongated in the direction in which the chain travels; a plurality of roller shafts attached to the guide base so as to be spaced apart from each other along the direction in which the chain travels; and rollers rotatably supported by the respective roller shafts. The distance between the centers of each adjacent pair of the rollers is set to be shorter in the area where a larger load is applied to the rollers.

Abstract: An object of the present invention is to provide a chain guide superior in silence, which includes: a guide base extending in a traveling direction of a chain; a plurality of roller shafts attached to the guide base at an interval along the traveling direction of the chain; and rollers each rotatably supported by one of the roller shafts. The roller has a cylindrical outer circumferential surface for guiding the chain. The outer circumferential surface of the roller has a cylindricity not greater than 20 ?m.

Abstract: A roller bearing retainer (13) includes a pair of annular ring parts (14) and a plurality of column parts (15) each including a column center part (16) provided in an axial center region so as to be positioned relatively on the radial inner side, a pair of column end parts (17) provided in axial end regions so as to be positioned relatively on the radial outer side, and a pair of column sloped parts (18) positioned between the column center part (16) and the pair of column end parts (17), and connecting the pair of ring parts to each other. A thickness of each part of the column center part, the pair of column end parts, and the pair of column sloped parts is smaller than a thickness of a boundary part between the adjacent parts.

Abstract: Surface indentation and oil film shortage on rollers is prevented and longer service life of a roller bearing is achieved, by preventing wear debris from being caught and accumulated in pockets of a holder of the roller bearing. Positions and dimensional relations of the diameters of inner and outer ring raceways, the inner and outer diameters of the holder, and inner and outer protrusions which are provided to pillar parts of the holder to prevent the rollers from coming off are defined such that the inner and outer protrusions of the pillar parts always do not come into contact with the outer circumferential surfaces of the rollers in the state where the rollers and the holder are incorporated between inner and outer members. As a result, lubricant oil is smoothly circulated in gaps formed between the outer circumferential surfaces of the rollers and the pillar parts of the holder.

Abstract: A chain guide is provided by which a chain can be guided silently. The chain guide includes: a guide base arranged along a portion of the outer periphery of a chain for transmitting torque and elongated in the direction in which the chain travels; a plurality of roller shafts spaced apart from each other in the longitudinal direction of the guide base; and a plurality of rollers for guiding the chain. The rollers are rotatably supported by the respective roller shafts. The rollers guide the chain by rolling. An arrangement interval between each adjacent pair of the rollers is set such that any two of the pins by which pieces of the chain are joined together do not pass any two of the rollers at the same time.

Abstract: The present invention is to suppress wear of outer diameter surfaces of chain guiding rollers (41) in a chain guide and extend the life. Respective shaft ends of a plurality of roller shafts (31) are supported by pairs of facing side plate portions (22) of guide bases (21) arranged to face each other in a one-side part of a timing chain (5) for transmitting torque. Each of the rollers (41) formed by a plurality of chain guiding roller bearings is rotatably supported by each of the plurality of roller shafts (31). Rollers whose surface hardness is greater than surface hardness of the timing chain (5) by 4 points or more of Rockwell hardness are used as the rollers (41), so as to prevent earlier wear of the outer diameter surfaces of the rollers (41) due to contact with the timing chain (5).

Abstract: A timing chain (5) is looped over a driving sprocket (2) attached to a crankshaft (1) and driven sprockets (4) attached to camshafts (3). A pivotable chain guide (A1) having a plurality of rotatable rollers (41) for guiding movements of the timing chain (5) is provided on one side of the slack side of the timing chain (5). Adjustment force of a chain tensioner is applied to a remote end of the chain guide remote from the center of pivoting movement of the chain guide, thereby pressing the rollers (41) against the timing chain (5). The ratio (D1/D2) between the pitch circle diameter D1 of the driving sprocket (2) and the outer diameter D2 of the rollers (41) is determined within the range of 5/3 to 5/1. This prevents insufficient lubrication of the chain guiding rollers (41), makes it easy to lay out the engine.

Abstract: A chain guide includes a plurality of roller shafts provided on one side of a timing chain for torque transmission and spaced from each other in the longitudinal direction of a guide base facing the timing chain. The respective roller shafts rotatably support chain guiding rollers in the form of needle roller bearings. The rollers are cylindrical members having the same diameter over the entire axial direction such that the rollers are movable in the axial direction relative to the timing chain. The rollers are supported so as to be movable in the axial direction. When the rollers and the timing chain move relative to each other in the axial direction and the rollers move relative to the roller shafts in the axial direction, contact portions between the rollers and the roller shafts are displaced in the axial direction, so that radial loads are not locally applied.

Abstract: A shell type outer ring 2 of a shell type needle roller bearing 1 is formed by a pressing combined with an ironing step, and the lubricating conditions in this ironing step on the outer-diameter ironed surface, which becomes the outer-diameter surface of the outer ring 2, are in a substantially fluid lubricating state so as to restrict the circumferential surface roughness of the inner-diameter surface, the inner-diameter roundness, and the amount of uneven thickness of the tubular portion to predetermined value ranges, thereby prolonging the life of the shell type needle roller bearing and lowering the acoustic level during use.

Abstract: An outer ring for rocking bearing (11a) includes a raceway surface (12a) on the inner diameter side and has flange parts (13a) and (13b) provided by bending axial both ends to the inner diameter side. The flange parts (13a) and (13b) are provided with bent parts (17a) and (17b) axially bent toward the raceway surface (12a) side so as to enfold a retainer arranged on the inner diameter side. Thus, the retainer can be enfolded by the bent parts (17a) and (17b). Therefore, even when the retainer comes to be moved to the inner diameter side of the outer ring for rocking bearing (11a), the retainer is caught by the bent parts (17a) and (17b), so that the movement of the retainer to the inner diameter side is restricted and rollers and the retainer can be prevented from dropping off.

Abstract: The present invention provides a rolling bearing which is excellent in strength, rigidity, heat resistance, and dimensional accuracy while being able to hold rolling elements in a stable manner and reduce manufacturing cost without degrading performance as a bearing and a manufacturing method for the rolling bearing. To achieve the object, the present invention adopts a rolling bearing including a cage provided with a plurality of pockets for housing and hold the rolling elements arranged at specific intervals in a circumferential direction in a peripheral wall of a cylindrical member. The cage is formed integrally by metal powder injection molding; and the cage includes a housing space for the rolling elements and a rolling-element fall-out prevention structure is formed by applying compressive working to an outer edge of the housing space in a direction from an outer circumferential surface toward a radial center of the cage.

Abstract: A needle roller bearing (21) as a roller bearing comprises an outer ring (22) having a plurality of outer ring members (22a) and (22b) split by a split line extending in the axial direction of the bearing, and a plurality of needle rollers (23) arranged along the track surface of the outer ring (22). The outer ring member (22a) is in the form of a semicircular shape having a center angle of 180° and has an engagement click (22c) bent from one circumferential side end to the radial outer side. The two outer ring members (22a) and (22b) are connected in the circumferential direction to form the annular outer ring (22).

Abstract: An object of the invention is to provide a pump tappet capable of bearing a large load from a pump plunger even if a case, which is a constituent member of the pump tappet, has a reduced thickness in its intermediate bottom. The invention thus contributes to reduced weight of the overall pump tappet. The case for the pump tappet is formed from an intermediary workpiece 40, which is made by means of a cold forging process of pressing a central region of a round steel material from both surfaces thereby pushing a portion of the material in the central region radially outward, forcing the material to flow axially in an up-down direction, so that an intermediate bottom 40e has a continuous fiber flow.

Abstract: An outer ring for rocking bearing (11a) includes a raceway surface (12a) on the inner diameter side and has flange parts (13a) and (13b) provided by bending both axial ends to the inner diameter side. The flange parts (13a) and (13b) are provided with bent parts (17a) and (17b) axially bent toward the raceway surface (12a) side so as to enfold a retainer arranged on the inner diameter side. Thus, the retainer can be enfolded by the bent parts (17a) and (17b). Therefore, even when the retainer comes to be moved to the inner diameter side of the outer ring for rocking bearing (11a), the retainer is caught by the bent parts (17a) and (17b), so that the movement of the retainer to the inner diameter side is restricted and rollers and the retainer can be prevented from dropping off.

Abstract: A retainer comprises a roller retaining click which is bent from an inner diameter edge of a rib portion toward the inside in an axial direction and extends so as to protrude and positioned between adjacent rollers. A part of the retainer other than the roller retaining click is hardened by high-frequency quenching and high-frequency tempering.

Abstract: Two or more arcuate members (2A, 2B), each having a plurality of pockets (3) defined therein for accommodating corresponding rollers, are placed one above the other to form a ring shaped assembly and are subsequently connected non-separably together by means of a retention ring (4) to thereby complete the cage (1). The arcuate members (2A, 2B) are so connected together that its inner periphery may assume a position radially inwardly of the outer diameter of a shaft such that in a condition having been assembled onto the shaft, they can displace in a direction radially outwardly against an elastic compressive force of the retention ring (4) to invite a circumferential gap (S) at each joint between the arcuate members (2A, 2B).