Tsubakimoto Chain Company

Hiroshi Horie

Takayuki Funamoto

Shigekazu Fukuda

Kazumasa Matsuno

Masao Maruyama

Hitoshi Ohara

Yoshinori Iwasaki

Makoto Kanehira

Yoshihiro Kusunoki

Masatoshi Sonoda

Kenshi Suzuki

Toyonaga Saito

Masahiko Konno

Hiroki Ishida

Nobuto Kozakura

Toshifumi Sato

Nobuyuki Onoda

Junichi Tani

In a sliding contact guide for a chain, a guide body is composed of a shoe having a front surface on which the chain slides, and a plate-receiving portion provided on the back of the shoe. The shoe and plate-receiving portion are integrally molded from a synthetic resin. A reinforcing plate is inserted and fitted into a longitudinal slot in the plate-receiving and the sliding contact guide is attached to a frame by a pivot pin which extends through aligned mounting holes in the guide body and the reinforcing plate. Locking pieces formed in the plate-receiving portion, have tapered surfaces on their tips that engage locking holes in the plate and exert a biasing force on edges of the locking holes which urges the plate against the back of the shoe. The reinforcing plate and the guide body are reliably secured together and, even when the guide is vibrated, movement of the reinforcing plate in the slot of the guide body is prevented, so that low noise and long life are attained.

Sliding contact guide for transmission device

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 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

A random arrangement type silent chain is provided, which restricts run-upon and reduces contact noise and vibration noise of the free span of the chain, and also restricts abnormal elongation and excessive load during power transmission. In the silent chain a first link plate, which begins to engage with a sprocket tooth by its inner crotch and sits on the sprocket teeth by its outer flanks, and a second link plate, which engages with and sits on the sprocket teeth only by engagement with its outer flanks, are mixed and combined in an endless chain in the longitudinal direction. The mixture ratio of the first link plates to the total link plates is less than 50%, at least one or more of the second link plates are arranged before and after each of the first link plates, and the number of second link plates arranged before and after each first link plate varies randomly along the length of the chain.

Random arrangement type silent chain

A silent chain includes guide link rows and joint link rows arranged alternately and articulately connected in an endless fashion by rocker joint pins each composed of a longer pin and a shorter pin. In each guide link row, the longer pin is fitted with two guide plates and also inserted through link plates disposed between the guide plates. In each joint link row, the shorter pin is inserted through link plates. The longer pin and the shorter pin are initially formed in a straight configuration and have the same cross-sectional shape. When the silent chain is stretched substantially straight after having been subjected to a proof load, the pitch of the guide plates is made slightly greater than the pitch of adjacent contact points between the longer pins and the shorter pins of the rocker joint pins in the guide link rows so that the longer pins are elastically deformed into a bow-like configuration bent toward the mating shorter pins. The rocker joint pins having the elastically deformed longer pins acquire spring or cushioning properties which are effective to improve the strength of the chain and reduce the operation noise of the silent chain.

Silent chain with rocker joint pins

A rocker joint silent chain includes rocker joints articulately connecting together multiple interleaved link plates and guide plates located outside the interleaved link plates in the widthwise direction of the chain. Each of the rocker joints is composed of a longer pin firmly fitted at opposite ends thereof in a pair of aligned pin-accommodation holes of two opposed guide plates, and a shorter pin having opposite ends projecting from opposite outer surfaces of the interleaved link plates. The ends of the shorter pin are in slight contact with inner surfaces of the guide plates. High-frequency noise and abrasive wear of the rocker joints and link plates, which may occur due to free movement of the shorter pin in the widthwise direction of the chain, can be avoided.

Rocker joint silent chain

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 silent chain power transmitting apparatus includes a silent chain and two or more sprockets with different number of teeth, wherein the sprockets each have a tooth form formed by hobbing with a hob cutter having teeth profiled similarly with the profile of a series of trapezoidal teeth formed by the inside flanks of longitudinally overlapping link plates of the silent chain so as to cut the periphery of a cylindrical workpiece with an amount of addendum modification set in such a manner that an engagement height of the inside flank at the onset of the meshing engagement between the silent chain and the sprocket is in equal to the distance between the sprocket center and the connecting pin centers when the silent chain is wrapped around and seated on the sprocket. The outside flanks of the silent chain have a first portion profiled by an envelope that is tangent to every one of a group of tooth forms of the sprockets when the silent chain is wrapped around the sprockets with different numbers of teeth.

Silent chain power transmitting apparatus

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 drive mechanism includes a silent chain for transmitting power between a larger sprocket and a smaller sprocket, wherein the inside flanks of one link plate of the silent chain are profiled to project outward of the outside flanks of the adjacent link plates, and tooth flank configurations of the larger and smaller sprockets are formed by involute curves arranged to satisfy the expression A Ac&gE;A where A is a pressure angle of the smaller sprocket, A is a pressure angle of the larger sprocket, and Ac is a pressure angle of the inside flanks of teeth of the link plates. With this arrangement, the chordal action of the silent chain is suppressed at both the larger sprocket side and the smaller sprocket side, thereby reducing vibrations and noises accompanied with the chordal action and improving the driving performance and durability.

Silent chain drive mechanism

A silent chain for use with a sprocket has a plurality of interleaved rows of link plates connected together in an endless fashion, each link plate having a pair of teeth. Each of the teeth has an inside flank and an outside flank surface merging at a tip of the tooth. The inside flank has a smooth contact surface which is smaller in width than the smooth contact surface of the outside flank surface. The point where the link plate starts to move into contact with the tooth flank of the sprocket is set to locate in an area having the smooth contact surface at a relatively high rate of occupancy. With this arrangement, noise occurring at the mesh between the link plate and the sprocket can be reduced. The point where the meshing engagement completes is set to locate in an area having the smooth contact surface at a relatively high rate of occupancy. This arrangement improves the wear resistance and fatigue strength of the link plate.

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.

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 rocker pin for use in a power transmission chain has an identifying mark for distinguishing the rocker pin from another rocker pin having a different thickness or a different rocker surface. The identifying mark may include a groove, ridge, colored mark, lustrous streak or the like provided on a peripheral surface except a rocker surface in the longitudinal direction of the rocker pin. The rocker pin having such identifying mark can be visually identified with ease so that the rocker pin is prevented from being mixed with a different kind of rocker pins. This enables easy and confusion-free storage of the rocker pin and prevents incorrect combination of a longer pin and a shorter pin, which may occur when they are used in combination to form a single rocker joint.

Rocker pin and wire stock for producing the same

A chain includes a pair of rocker joint pins inserted through laterally aligned pin holes of two adjacent link plates. The pin holes have a pair of upper and lower pin-position constraining surfaces arranged to face upper and lower flat surfaces, respectively, of each rocker joint pin with a very small clearance defined therebetween so that the rocker joint pin is always kept in position against displacement in a vertical direction relative to the link plates. When the chain is urged to warp or bend into a V shape, each of the rocker joint pins is gripped by the upper pin-position constraining surface of one of the two adjacent link plates and a warp blocking surface of the other of the two adjacent link plate. Thus, such warping of the chain does not take place.

Growing community of inventors

Osaka, Japan

Hiroshi Horie