Tsubakimoto Chain Company

Yoshihiro Kusunoki

Shigekazu Fukuda

Masao Maruyama

Hitoshi Ohara

Takayuki Funamoto

Makoto Kanehira

Hiroshi Horie

Kazumasa Matsuno

A wear-resistant silent chain includes a large number of link plates articulately connected together in an endless fashion by rocker joint pins each composed of a long pin and a short pin. The long and short pins have an outer peripheral surface formed by, at least, a convexly arcuate rocker surface which is adjacent to the convexly arcuate rocker surface of another pin, a load-bearing surface on the side opposite to the rocker surface and being seated on an inner peripheral surface of each of a pair of pin holes formed in each link plate, and a pair of lubricant guide surfaces each extending substantially linearly from one circumferential end of the load-bearing surface to an adjacent circumferential end of the rocker surface while extending divergently with respect to the inner peripheral surface of each of said pin holes. The lubricant guide surface provides a large lubricant collecting area which is sufficient to lubricate the load-bearing surface with an enough amount of lubricating oil and thereby prevents local wear caused between the inner peripheral surface of each pin hole and the load-bearing surface of each pin.

Wear-resistant silent chain

A silent chain include a number of link modules articulately connected together in an endless fashion by rocker joint pins. The rocker joint pins include a first rocker joint pin composed of a first longer pin and a first shorter pin each having a different first thickness in a direction of pitch of the rocker joint pins, and a second rocker joint composed of a second longer pin and a second shorter pin each having a different second thickness in the direction of pitch of the rocker joint pins. The second thickness of the second longer or shorter pin is different from the first thickness of a corresponding one of the first longer and shorter pins. The first joint rocker pin and the second rocker joint pin are arranged in a random pattern along the length of the silent chain so as to suppress generation of periodic noise when teeth of the silent chain and teeth of a sprocket engage with each other.

Silent chain

A silent chain power transmitting device includes a driving sprocket and at least one drive sprocket, and a silent chain stretched over the driving and driven sprockets to provide a tension run and a slack run on opposite sides of the driving sprocket. The driving and driven sprockets have a sprocket pitch (chordal pitch) designed to become substantially equal to a chain pitch of the tension run of the silent chain while operating under load. By thus designing the sprocket pitch relative to the chain pitch, toothed link plates of the silent chain are smoothly guided into sliding contact with teeth of the sprockets without causing objectionable interference or collision. The sprockets and silent chain are substantially free from abnormal wear and hence have an increased degree of durability.

Silent chain power transmitting device

A guide plate a for silent chain is substantially arch-shaped and has a pair of pin holes formed therein at a position adjacent to opposite free ends of the arch-shaped guide plate. The arch-shaped guide plate further has an arcuate inner peripheral surface and an arcuate outer peripheral surface both extending arcuately about a center located at the midpoint of a pitch line segment interconnecting the pair of pin holes. The arcuate inner peripheral surface has a radius of curvature which is in the range of 35 to 45% of the chain pitch, and the arcuate outer peripheral surface is blended with the opposite free ends of the arch-shaped guide plate.

Guide plate for a silent chain

A silent chain includes guide links and articular links arranged in the longitudinal direction of the chain. The guide links each include one or more guide link plates, and the articular links each include two or more articular link plates. When the chain is in the straight-line state, the inside flank of each meshing tooth of any one of the link plates projects outwardly from the outside flank of each meshing tooth of another laterally adjacent one of the link plates. The projecting length of the inside flank relative to the outside flank is allowed to vary between the adjacent links, either in a random fashion or in a regular alternate fashion, along the length of the chain. By thus providing different projecting lengths of the chain's inside tooth flanks, the sliding engagement start time of sprocket teeth relative to the inside tooth flanks of the individual link plates is allowed to vary between the adjacent links, so that the periodic meshing sounds can be prevented from resonating to get louder, with the result that the overall noise level can be minimized.

Two rocker pins inserted into each of two pin holes of each link plate of a silent chain each include a rocker surface, a first non-contact surface opposed to an inner peripheral surface of the pin hole on a side opposite to the rocker surface, a pair of load-bearing surfaces contiguous with both circumferential ends of the first non-contact surface, and two second non-contact surfaces interconnecting the pair of load-bearing surfaces and both circumferential ends of the rocker surface, respectively. A part of the inner peripheral surface of the pin hole is formed in a pair of pin-seating surfaces which is in register with the pair of load-bearing surfaces of each rocker pin, respectively, to prevent rotation of the rocker pin within the pin hole. Since the load-bearing surfaces are supported by the pin-seating surfaces in an exactly matched or registered condition, rotation and wobbling of the rocker pin within the pin hole are securely prevented. Thus, the rocker pins and the link plates are substantially free from local wear which may often result in an excessive wear elongation of the silent chain.

A silent chain includes double rocker joint pins articulately connecting together adjacent links of the chain. The double rocker joint pins are each composed of a longer pin and a shorter pin. The longer pin has a cross-sectional shape different from that of the shorter pin, and the thickness of the longer pin as measured in a direction parallel to a chain pitch line is made greater than the corresponding thickness of the shorter pin. By thus designing the longer pin relative to the shorter pin, the longer pin has a large mechanical strength sufficient to withstand not only an impact force applied when the longer pin is swaged or riveted at opposite ends thereof, but also a shear force and a bending force applied at one time to opposite end portions of the longer pin during power-transmitting operation of the chain.

Growing community of inventors

Osaka, Japan

Yoshihiro Kusunoki