To provide a tensioner capable of preventing slipping between a rack portion and ratchet pawls and securing a large backlash with a simple structure. The tensioner includes a ratchet rotatably mounted on a housing and having a front pawl and a rear pawl spaced apart in a front and rear direction on a side face positioned opposite the rack portion. The ratchet includes an additional pawl formed between the front pawl and the rear pawl in the front and rear direction on the side face positioned opposite the rack portion.

Described embodiments include a reconfigurable belt tensioner that can be used to add, remove, and/or reposition peripheral accessories of an engine installation, for example, in an automobile or another vehicle. The tensioner has a housing, an arm with an axle, and a spring installed in the housing. The axle is inserted into and fastened to the housing. The arm rotates around the axle. When the arm is rotated, the spring provides the force that tends to return the arm and the housing to the original position. The tensioner can be reconfigured by repositioning the spring relative to the housing and/or the arm, changing the angle between the housing and the arm. The tensioner may be used, for example, on an LS-based GM small-block engine, and allow operation with and without the air conditioning compressor or other accessories.

In an aspect, a tensioner is provided for an endless drive member, and includes a shaft-and-base unit, a tensioner arm, a pulley, and a tensioner spring. The shaft-and-base unit is mountable to be stationary relative to an engine, and includes a fastener aperture for a fastener. The tensioner arm is pivotable relative to the shaft-and-base unit about a tensioner arm axis. The pulley is rotatably mounted to the tensioner arm for rotation and is engageable with an endless drive member. The tensioner spring is positioned to urge the tensioner arm in a first direction relative to the shaft-and-base unit. The tensioner spring includes a plurality of coils that are arranged generally helically about a longitudinal axis and are spaced radially from one another and generally increase in distance away from the axis in a longitudinal direction.

An axle in particular of a universal carrier frame, which includes an arm of the axle, a power drive unit, swivel drive units, swivel distribution systems, travel distribution systems. At one end of the arm of the axle, a front portal suspension of a front wheel is rotatably arranged. At the other end of the arm of the axle, a rear portal suspension of the rear wheel is rotatably arranged. The front portal suspension of the front wheel and the rear portal suspension of the rear wheel comprise an angular chain transmission comprising a drive shaft having a longitudinal axis, a driven shaft having a longitudinal axis, a link chain for connecting the drive shaft and the driven shaft, and a pulley angular system of the link chain to define the angle (a) between the longitudinal axis of the drive shaft and the longitudinal axis of the driven shaft.

A belt tension adjustment device includes a driving pulley attached to a power transmission shaft, a driven pulley arranged in a driven device, a tension pulley, a loop belt arranged between the driving pulley, the driven pulley, and the tension pulley, and configured to transmit a rotational driving force of the power transmission shaft to the driven device, and a tension adjustment mechanism to adjust tension of the loop belt. The tension adjustment mechanism includes a support shaft rotatably supported, a rotational operation mechanism to rotate the support shaft about an axis of the support shaft, and a rotating member coupling the support shaft and the tension pulley, configured to change a relative position of the tension pulley with respect to the driving pulley and the driven pulley in accordance with rotating of the support shaft.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

An object of the present invention is to provide a chain guide that can reduce vibration and noise while maintaining necessary strength, rigidity, and durability. The chain guide has a support wall extending forward from a boss part, which constitutes a circumferential wall of a pivot shaft, along a plane perpendicular to a pivot axis line. The support wall includes a base part that is provided with a running surface-side rib, and a connecting portion with a cross-sectional area thereof reducing toward the boss part. The running surface-side rib is not in contact with the boss part. The chain guide does not include a connecting portion that has a larger width than the thickness of the support wall and extends in a pivoting direction on a back side of the running surface-side rib in a region at a pivot shaft side end thereof.

An object of the present invention is to provide a chain guide mechanism that can readily integrate all the components in a simple structure and enhance work efficiency during assembly or maintenance. The chain guide mechanism of the present invention is configured to be able to integrally support, on a frame, components including a plurality of sprockets, a chain, a fixed chain guide, and a pivoting chain guide. The frame includes a pivoting chain guide holding part that holds a mounting boss of the pivoting chain guide in a state of a loose fit. The pivoting chain guide holding part is configured to allow the mounting boss to be fitted therethrough from one side.

To provide a simple-structured tensioner lever capable of consistently exerting a correct reaction force to various fluctuations of tension accompanying varying chain behaviors, whereby vibration and noise when the chain runs can be reduced. The tensioner lever of the present invention includes a lever body having a shoe surface that slidably guides a chain; a first pressing spring configured to have a first pressing arm extending from one end of a first helical part, with a distal end portion contacting the lever body to form a first loading point, and a first support arm extending from the other end of the first helical part, with a distal end portion contacting and being supported by a first support part provided to an attachment surface to form a first support point; and a second pressing spring supported on the lever body at a different position from that of the first pressing spring.

A tensioner for an accessory drive of an internal combustion engine has a belt on a first pulley connected to a drive shaft of the engine and a second pulley connected to an electric machine. The tensioner has a base configured to be fixed to a casing of the electric machine, a first ring rotating with respect to the base about a first axis, a second ring rotating with respect to the first ring about a second axis distinct from the first axis, a first tensioning pulley carried by the first ring and rotating with respect to it about its own axis, a second tensioning pulley carried by the second ring and rotating with respect to it about its own axis and elastic means acting on the first and on the second ring to push the first and the second pulleys into contact with respective spans of the belt.