Tsubakimoto Chain Company

Isamu Okabe

Tadasu Suzuki

Tomotaka Koga

Toshifumi Sato

Kenichi Uotani

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&#x2266;D&#x2266;0.79P, 0.40P&#x2266;d&#x2266;0.44P, and 0.96P&#x2266;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&#x2266;R1&#x2266;0.505D+0.069D, P&#x2212;(0.505D+0.069D)&#x2266;R2&#x2266;P&#x2212;0.505D, and 0.08&#x2266;R3&#x2266;0.13P. The transmission chain exhibits improved endurance and quietness, smooth operation, and resistance to elongation due to wear.

Roller chain transmission device

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.

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&#x2266;D&#x2266;0.79P, 0.40P&#x2266;d&#x2266;0.44P, and 0.96P&#x2266;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&#x2266;r&#x2266;0.505D+0.069{square root over (D)}. The transmission chain exhibits high durability due to improved strength and wear resistance under high loads.

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.

Silent chain

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. It is possible to obtain a high flange pressure output and a high flange loosening torque and further possible to set a wide caulking quantity control range.

Caulking roller and sintered flanged pulley caulked by the caulking roller

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.

Pivotal support structure for oscillating member

To reduce a sliding resistance of a tensioner lever of a transmission chain and to suppress any flapping vibration in a free span portion of the transmission chain, a tensioner lever (1,11) has a tensioner sprocket (2,12) disposed in registry with a bent portion of a transmission chain C having a minimum bent radius of curvature. The tensioner sprocket is pressed by the tensioner lever against the slack run of the transmission chain to form the bent portion, and a shoe member (3,13) is mounted between the tensioner sprocket and a proximal end (1', 11') of the tensioner lever to slidably guide the free span portion of the run.

Growing community of inventors

Osaka, Japan

Isamu Okabe