Abstract: In a roller chain transmission, the diameter D of the rollers, the outer diameter d of the pins and height H of the inner plates satisfy the relationships 0.72P?D?0.79P, 0.40P?d?0.44P, and 0.96P?H, with respect to the chain pitch P. The sprocket teeth are asymmetric in that the chain entering side and the chain leaving side differ, and the radius R1 of an arc of the tooth gap bottom, the radius R2 of the chain entering side tooth flank and the radius R3 of the chain entering side tooth head portion satisfy the relationships 0.505D?R1?0.505D+0.069D, P?(0.505D+0.069D)?R2?P?0.505D, and 0.08?R3?0.13P. The transmission chain exhibits improved endurance and quietness, smooth operation, and resistance to elongation due to wear.

Abstract: A roller chain transmission comprises a sprocket having at least first teeth and second teeth having different tooth forms, the first teeth and second teeth being randomly arranged, and the number of the second teeth not exceeding four times of the number of the first teeth. The roller chain may also have pins of slightly differing diameters, randomly arranged along the length of the chain.

Abstract: In a roller chain transmission, the diameter D of the rollers, the outer diameter d of the pins, and the height H of the inner plates satisfy the relationships 0.72P?D?0.79P, 0.40P?d?0.44P, and 0.96P?H, with respect to the chain pitch P. The radius r of the arc of the tooth gap bottom of the sprocket teeth satisfies the relationship 0.505D?r?0.505D+0.069{square root over (D)}. The transmission chain exhibits high durability due to improved strength and wear resistance under high loads.

Abstract: In a roller chain having cylindrical pins rotatably fitting into bushings on which the rollers are disposed, a vanadium carbide layer formed on the cylindrical pin surfaces avoids abnormal wear elongation of the chain, and allows smooth articulation of the chain over a long period of time, even when the lubricating oil is in an extremely deteriorated condition due to oxidation.

Abstract: A roller chain transmission comprises a sprocket having at least first teeth and second teeth having different tooth forms, the first teeth and second teeth being randomly arranged, and the number of the second teeth not exceeding four times of the number of the first teeth. The roller chain may also have pins of slightly differing diameters, randomly arranged along the length of the chain.

Abstract: In a roller chain transmission, the diameter D of the rollers, the outer diameter d of the pins, and the height H of the inner plates satisfy the relationships 0.72P≦D≦0.79P, 0.40P≦d ≦0.44P, and 0.96P≦H , with respect to the chain pitch P. The radius r of the arc of the tooth gap bottom of the sprocket teeth satisfies the relationship 0.505D≦r≦0.505D+0.069{cube root}{square root over ( )}D. The transmission chain exhibits high durability due to improved strength and wear resistance under high loads.

Abstract: In a roller chain transmission, the diameter D of the rollers, the outer diameter d of the pins and height H of the inner plates satisfy the relationships 0.72P≦D≦0.79P, 0.40P≦d≦0.44P, and 0.96P≦H, with respect to the chain pitch P. The sprocket teeth are asymmetric in that the chain entering side and the chain leaving side differ, and the radius R1 of an arc of the tooth gap bottom, the radius R2 of the chain entering side tooth flank and the radius R3 of the chain entering side tooth head portion satisfy the relationships 0.505D≦R1≦0.505D+0.069{cube root}D, P−(0.505D+0.069{cube root}D)≦R2≦P−0.505{cube root}D, and 0.08≦R3≦0.13P. The transmission chain exhibits improved endurance and quietness, smooth operation, and resistance to elongation due to wear.

Abstract: In ratchet type tensioner, low cost, high strength and excellent wear resistance, are realized by utilization of a pawl composed of a sintered alloy having a density of 6.8 g/cm3 or more, and containing 5-15 wt % Co, a total of 2.0-10 wt % of at least one metal from Ni, Cr and Mo, and the balance Fe and impurities.

Abstract: In a ratchet type tensioner comprising a housing, a plunger slidable in, and protruding from, the housing, and biased in a protruding direction, a ratchet mechanism comprising a rack formed on a side surface of the plunger, and a pawl provided on the housing and engageable with the rack to prevent the return movement of the plunger, the pawl is composed of a sintered alloy having a density of at least 7.2 g/cm3. The sintered alloy is formed by warm molding, high temperature sintering, recompression, or combinations thereof, and preferably contains a total of 0.5 to 8 weight % of at least one element from the group consisting of Nickel, Copper and Molybdenum. The balance of the composition of the sintered alloy consists of Iron and impurities. The invention provides a ratchet type tensioner having a high strength and excellent wear resistance at a low cost.

Abstract: In a silent chain, wear of the connecting pins and bushings, and wear elongation of the chain itself, are suppressed by the formation of through holes in the approximate centers of the teeth of toothed link elements for relieving strains in the inner peripheries of the bushings due to press-fitting of the bushings into the toothed link elements. The shortest distances between the bushing hole on the one hand, and the through-hole, the outside tooth surface and the inside tooth surface, on the other hand, are made substantially equal to one another. The through holes also reduce the weights of the individual link elements and contribute to a reduction in overall weight of the chain.

Abstract: In a roller chain having cylindrical pins rotatably fitting into bushings on which the rollers are disposed, a vanadium carbide layer formed on the cylindrical pin surfaces avoids abnormal wear elongation of the chain, and allows smooth articulation of the chain over a long period of time, even when the lubricating oil is in an extremely deteriorated condition due to oxidation.

Abstract: In a sintered sprocket at least the tooth surface layer contains carbon in the range from 0.6 to 1.2 mass % and nitrogen in the range from 0.05 to 0.5 mass %. The structure of the tooth surface layer comprises a tempered martensite structure and a residual austenitic structure, the residual austenitic structure being 10 to 50 volume % of the tooth surface layer. The density of the tooth surface layer is at least 7.4 g/cm3. Metallic elements contained in a base material comprise at least one metal selected from Ni, Cu and Mo in an amount in the range from 0.5 to 5 mass % the balance being Fe and inevitable impurities. The sintered sprocket exhibits high strength and wear resistance and can be manufactured at low cost.

Abstract: A sintered, flanged cam pulley includes a sintered cam pulley body and an annular flange caulked to the sintered cam pulley body. The sintered cam pulley body has at an end portion thereof an axial annular projection and a stepped portion formed on an outer periphery side of the annular projection. An inner peripheral surface of the annular flange is fitted on the stepped portion of the sintered cam pulley body. The tip of the annular projection is deformed plastically from the inner to the outer periphery side of the annular projection by a caulking roller. The caulking roller has a first conical surface of a large angle and a second conical surface of a small angle contiguous to the first conical surface, the first and second conical surfaces being formed on an outer peripheral surface of the caulking roller. The annular flange is thereby caulked to the sintered cam pulley body.

Abstract: A timing drive sprocket for a direct injection engine having excellent wear resistance, durability and quiet operation is produced by suppressing wear acceleration at the sprocket tooth surfaces resulting from deterioration of the engine oil, even in a direct injection engine of the kind in which the lubricating oil is likely to deteriorate rapidly. In the timing drive sprocket, a surface hardened layer is formed on at least a tooth surface of the sprocket by a carbonitriding and tempering treatment.

Abstract: In a silent chain, wear of the connecting pins and bushings, and wear elongation of the chain itself, are suppressed by the formation of through holes in the approximate centers of the teeth of toothed link elements for relieving strains in the inner peripheries of the bushings due to press-fitting of the bushings into the toothed link elements. The shortest distances between the bushing hole on the one hand, and the through-hole, the outside tooth surface and the inside tooth surface, on the other hand, are made substantially equal to one another. The through holes also reduce the weights of the individual link elements and contribute to a reduction in overall weight of the chain.

Abstract: In an inner link plate, which forms a link assembly of a silent chain, positions K, L, M and N where the respective distances between a bush hole, and the outside surface portion, the inside surface portion, the back surface portion and the shoulder portion reach the shortest distances are located in the vicinity of a hypothetical circle substantially concentric with the bush hole, and at the same time the shortest distances k, 1, m and n in the respective positions K, L, M and N are formed to be the plate thickness t of the inner link plate or more.

Abstract: To provide a silent chain that can restrict abrasion of connection pins and the bushings and can restrict the abrasive elongation of chain so as to be especially used for a diesel engine. A circularity of bushings used in the link assembly thereof is easily maintained. The silent chain includes: a guide plate; a link assembly having an inner link plate; a middle link plate; and a connection pin that connects them freely bendably. The bushings of the link assembly have no seam being made as solid type, and a plurality of concave areas for reserving oil are formed on surfaces of both end portions thereof. The notched concave areas have a depth that does not reach the inner link plate fixed to the bushing.

Abstract: To provide a silent chain in which a number of parts and weight thereof are reduced and a sprocket designed optimally for the silent chain. The silent chain is made up of guide plates arranged inside in the chain width direction; link assemblies, at least one of which is arranged on both outsides of the guide plate; and outer link plates further arranged on outermost sides, and they are assembled in an interlinked manner and connected by connection pins freely bendable. The link assembly has a unified structure in which at least two inner link plates having a pair of teeth that engage with the sprocket teeth are connected by a pair of bushings. The sprocket thereof has a groove capable of inserting the guide plate being arranged inside in the silent chain width direction, and formed with a ring shape inside of an outer circumference width direction.

Abstract: A sintered, flanged cam pulley includes a sintered cam pulley body and an annular flange caulked to the sintered cam pulley body. The sintered cam pulley body has at an end portion thereof an axial annular projection and a stepped portion formed on an outer periphery side of the annular projection. An inner peripheral surface of the annular flange is fitted on the stepped portion of the sintered cam pulley body. The tip of the annular projection is deformed plastically from the inner to the outer periphery side of the annular projection by a caulking roller. The caulking roller has a first conical surface of a large angle and a second conical surface of a small angle contiguous to the first conical surface, the first and second conical surfaces being formed on an outer peripheral surface of the caulking roller. The annular flange is thereby caulked to the sintered cam pulley body.

Abstract: To provide a pivotal structure of an oscillating member facilitating management of parts and fixing work. The cylindrical peripheral face (11A) of a collar (11), which is fixedly secured by screwing a bolt (4) being inserted in a bolt insertion hole (11C ) into a tapped hole (13) in a fixed part (12), is rotatably fitted in a bearing hole (9) bored in a pivot guide portion (6) provided on the side of the pivotal support end of an oscillating member and, by means of collar movement restricting faces (8A, 10A) at the pivot guide portion (6), the cylindrical peripheral face (11A) is prevented from coming off the bearing hole (9). Since, the collar (11) is previously incorporated in the pivot guide portion (6) before the oscillating member is secured to the fixed part (12) and such assemblies can be arranged as a set of parts, management of parts and fixing work are made easier.