Tsubakimoto Chain Company

Toyonaga Saito

Nobuto Kozakura

Hiroshi Horie

Tsutomu Haginoya

Shigekazu Fukuda

Takayuki Funamoto

Kazumasa Matsuno

Yoshinori Iwasaki

Koichi Ichikawa

Masatoshi Sonoda

Kenshi Suzuki

Toshifumi Sato

Takero Nakagawa

In a transmission comprising an endless silent chain and a sprocket the inside tooth faces of the link plates of the chain are identical to tooth profiles, arranged axially, of a hob cutter for forming teeth of the sprocket. The inside and outside tooth faces also satisfy Hi&equals;Ho&plus;Hs, where Hi is the distance from a pin center line Lp to a pitch line Li of the inside tooth faces, Ho is a distance from the pin center line to a pitch line Lo of the outside tooth faces, and Hs is the amplitude of polygonal motion of the chain. Each link plate also has a concave bottom surface between its teeth to avoid interference with edges of the involute teeth arising due to the chain polygonal motion amplitude when the outside tooth faces are brought into meshing engagement with the involute teeth and become seated thereon.

Silent chain power transmission apparatus

A wear-elongation resistant silent chain includes guide link rows and articular link rows articulately connected together in an alternate fashion along the length of the chain by connecting pins inserted through respective pin holes of guide plates, guide link plates and articular link plates, with guide plate retainers secured to respective both ends of the connecting pins so as to keep the guide plates in position against removal from the connecting plates. The guide link plate and the articular link plates have different thicknesses so dimensioned as to balance the tensile strength of the guide link plate in one guide link row and the tensile strength of the articular link plates in the adjacent articular link row connected together by one of the connecting pins, thereby suppressing bending of the connecting pin. By thus suppressing the bending of connecting pin, wear elongation of the chain is prevented from occurring during power transmitting operation of the chain.

Wear-elongation resistant silent chain

A silent chain is provided with strength and elongation of respective link rows made uniform, elongation of every link made equal regardless of elastic and/or plastic deformation, and inexpensive production cost. The silent chain includes a first link row, a second link row, a connection pin and a pin stopper. Each of the first and second link rows consists of a guide plate and the same number of link plates whose shapes and sizes are the same. The first and second link rows are staggered in the longitudinal direction of the chain, and connected in alternating, interleaved relationship by connection pins. The guide plates and the link plates of the first and second link row are relatively rotatable to the connection pins. The first and second link rows are alternately arranged in mirror image symmetry.

Silent chain in which strength and elongation of link row are uniformized

Each link plate of a low noise silent chain has an inside meshing surface formed on the inside flank of each link tooth. The inside meshing surface includes a convexly arcuate mesh start portion disposed on a tip side of each link tooth, and a convexly arcuate mesh guide portion disposed on a root side of each link tooth. The arcuate mesh guide portion has a radius of curvature and a circular arc length which are greater than a radius of curvature and a circular arc length, respectively, of the convexly arcuate mesh start portion. When the silent chain engages a sprocket, the engagement proceeds smoothly and continuously from the inside meshing surface to the outside meshing surface. This contributes to the reduction of the noise level of the silent chain as a whole through suppression of meshing sound of the outside meshing surface and vibratory chain noise.

Low noise silent chain

A double-meshing-type silent chain of a silent chain drive includes link plates having the identical side profile. Each link plate has two meshing teeth and a flat back face formed opposite to the meshing teeth. Two kinds of links are alternately arranged in the longitudinal direction of the chain, while the adjacent links are connected by pins. In one kind of link, an odd number of the link plates are disposed in the width direction of the chain. In the other kind of link, an even number of the link plates are disposed in the width direction of the chain. In each link, the link plates are oriented such that the meshing teeth of link plates located at widthwise opposite ends project outwardly with respect to the chain and the meshing teeth of the remaining link plates project inwardly with respect to the chain. Various types of sprockets used for meshing with the double-meshing-type silent chain are also disclosed.

Double-meshing-type silent chain drive and sprocket used therein

A silent chain is provided which has reduced elongation based on wear and which is capable of maintaining a high accuracy over a long period of time in use. The inner surfaces of pin holes formed in at least joint trains of plates have been subjected to shaving, and a hard layer of at least one hard metal carbide selected from a group including CrC, TiC, VC and NbC, is formed on the surface of each pin. By shaving the inner surface of each pin hole, the surface pressure applied between the pin hole inner surface and the pin inserted therein becomes lower, whereby the wear of the pin and the pin hole is diminished. Further, since the hard layer on the pin surface is very hard and is chemically stable, the affinity of each plate for the inner surface of each pin hole formed therein is small. Thus, even under the condition of boundary lubrication, it is difficult for adhesion to occur between the pin hole inner surface and the pin inserted therein. Consequently, the amount of pin wear is lessened so that it becomes possible to minimize the elongation of the chain based on wear.

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Osaka, Japan

Toyonaga Saito