Abstract: In an aspect, an isolation device is provided for a belt and a component shaft in an engine. The device includes a hub, a pulley, an isolation spring and a damping member that is fixed rotationally relative to the hub and is engageable frictionally with the pulley. Torque transmission through the spring below a selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils of the spring that is sufficiently small that the spring avoids pressing the damping member against the pulley. Torque transmission through the spring above the selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils that is sufficiently large that the isolation spring applies a radial force to press the damping member against the pulley so as to generate frictional damping.

Abstract: In an aspect, an isolation device is provided for a belt and a component shaft in an engine. The device includes a hub, a pulley, an isolation spring and a damping member that is fixed rotationally relative to the hub and is engageable frictionally with the pulley. Torque transmission through the spring below a selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils of the spring that is sufficiently small that the spring avoids pressing the damping member against the pulley. Torque transmission through the spring above the selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils that is sufficiently large that the isolation spring applies a radial force to press the damping member against the pulley so as to generate frictional damping.

Abstract: In an aspect, a tensioner includes a shaft and base unit that is mountable to an engine, an arm pivotable about the shaft and base unit, a pulley on the arm engageable with a belt, a spring urging the arm in a free arm direction, a first damping member fixed on the shaft and base unit, which receives a first radial force from a first segment of the spring causing a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm, and a second damping member on the arm, which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the spring, causing a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit.

Abstract: In an aspect, a tensioner includes a shaft and base unit that is mountable to an engine, an arm pivotable about the shaft and base unit, a pulley on the arm engageable with a belt, a spring urging the arm in a free arm direction, a first damping member fixed on the shaft and base unit, which receives a first radial force from a first segment of the spring causing a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm, and a second damping member on the arm, which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the spring, causing a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit.

Abstract: In an aspect, a tensioner is provided for maintaining tension in an endless drive member in a belt-in-oil drive system. The tensioner includes a base that is mountable to a stationary structure and that has a circumferential wall that defines an arm pivot axis, an arm having a radially inner arm surface, and an endless drive member engagement surface that is engageable with an endless drive member, a bushing positioned between the radially inner arm surface and the circumferential wall of the base cup, and a tensioning spring. The arm is supported on the base cup via the bushing. The tensioning spring is positioned to bias the arm in a first direction about the arm pivot axis.

Abstract: In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

Abstract: In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a bushing that is positioned radially between the pulley and the tensioner arm to support the pulley radially during relative rotation between the pulley and the tensioner arm, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

Abstract: In an aspect, a tensioner is provided for maintaining tension in an endless drive member in a belt-in-oil drive system. The tensioner includes a base that is mountable to a stationary structure and that has a circumferential wall that defines an arm pivot axis, an arm having a radially inner arm surface, and an endless drive member engagement surface that is engageable with an endless drive member, a bushing positioned between the radially inner arm surface and the circumferential wall of the base cup, and a tensioning spring. The arm is supported on the base cup via the bushing. The tensioning spring is positioned to bias the arm in a first direction about the arm pivot axis.

Abstract: A tensioner having a closing-type torsion spring that is employed to bias a pivot arm about a pivot shaft. The tensioner includes a damper, which contacts an inside surface of the torsion spring to dampen torsional vibration transmitted through the torsion spring, and a one-way clutch that is configured to permit unencumbered rotation of the pivot shaft in one rotational direction but to resist rotation of the pivot shaft in an opposite direction.

Abstract: In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

Abstract: In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a bushing that is positioned radially between the pulley and the tensioner arm to support the pulley radially during relative rotation between the pulley and the tensioner arm, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

Abstract: A tensioner having a closing-type torsion spring that is employed to bias a pivot arm about a pivot shaft. The tensioner includes a damper, which contacts an inside surface of the torsion spring to dampen torsional vibration transmitted through the torsion spring, and a one-way clutch that is configured to permit unencumbered rotation of the pivot shaft in one rotational direction but to resist rotation of the pivot shaft in an opposite direction.

Abstract: A tensioner having a closing-type torsion spring that is employed to bias a pivot arm about a pivot shaft. The tensioner includes a damper that continuously contacts an inside surface of the torsion spring to dampen torsional vibration transmitted through the torsion spring.

Abstract: A tensioner having a backstop device which allows free rotation of the pivot arm in a first direction but controls rotation of the pivot arm in a second, opposite direction. The backstop device permits a predetermined, limited amount of free rotation in the second direction and thereafter, employs a braking device to prevent rotation in the second direction if the torque that acts on the pivot art is less than a predetermined threshold.

Abstract: A tensioner having a closing-type torsion spring that is employed to bias a pivot arm about a pivot shaft. The tensioner includes a damper that continuously contacts an inside surface of the torsion spring to dampen torsional vibration transmitted through the torsion spring.

Abstract: A tensioner for tensioning a flexible drive means, such as a timing belt or chain, includes a pulley to contact the belt. The pulley is mounted on a tensioner arm and the tensioner arm can be rotated about a pivot shaft mounted to the tensioner by a spring. The axis about which the pulley rotates is spaced from the axis of the rotation of the tensioner arm with respect to the pivot shaft and the spacing of these axes of rotation results in the pulley moving through an eccentric towards or away from the belt when the tensioner arm is rotated. A stop is used to limit the range of movement of the tensioner arm between a desired range of movement defined by a free arm stop and a backstop. The position of the stop is adjustable by an installer. The angular range of movement of the tensioner arm is adjustable from a position suitable for installation of the tensioner to a position suitable for operation of the installed tensioner.

Abstract: A tensioner has a base plate and a pivot arm. A first end of the pivot arm is pivotally mounted to the base plate for rotation about a first axis. A spring biases the pivot arm to rotate in a tensioning direction. A push rod assembly is pivotally mounted to the second end of the pivot arm. The push rod assembly is rotatable about a second axis extending parallel to the first axis. The push rod assembly frictionally engages the pivot arm generating frictional forces counter acting and damping the spring bias. When the tensioning guide is forced to rotate in the tensioning direction, the acting moment arm of the push rod force causing the guide to rotate towards the endless drive, is considerable longer at the end of the tensioning stroke than in the beginning of the stroke.

Abstract: A tensioner enables easy and reliable reinstallation of the tensioner and belt in the field service while simultaneously making it possible to utilize a one-way clutch device to ensure continuous belt tension control without cumbersome manual alignment and/or realignment procedures. The tensioner has a pivot shaft configured for mounting on an engine surface. A tensioner arm is mounted on the pivot shaft for pivotal movement between a free arm stop position and premount stop position. A belt-engaging pulley is mounted for rotation on the tensioner arm. A base cup is rotatably mounted around an end of the pivot shaft. The base cup has an arcuate slot having a free arm stop end and a premount stop end. The tensioner arm cooperates with the arcuate slot limiting the pivotal movement of the tensioner arm. A spring is coupled between the tensioner arm and the base cup biasing the tensioner arm in a belt-tensioning direction.

Abstract: A tensioner having a backstop device which allows free rotation of the pivot arm in a first direction but controls rotation of the pivot arm in a second, opposite direction. The backstop device permits a predetermined, limited amount of free rotation in the second direction and thereafter, employs a braking device to prevent rotation in the second direction if the torque that acts on the pivot art is less than a predetermined threshold.

Abstract: A tensioner (10) features a backstop device (40) which allows free rotation of the pivot arm (20) in one direction but not the other. Reverse rotation is prevented by friction that is able to resist torque on the pivot arm (20) under ordinary operating conditions which otherwise could permit belt tooth-skip to occur. In disclosed embodiments, the backstop device (40) includes a stop sleeve (50) and a clamp holder (60) which are axially interlocked and are able to rotate relative to each other. A clutch spring (80) surrounds permits relative rotation between the stop sleeve (50) and the clamp holder (60) in one direction but not the other. A clamp (70) retained within the clamp holder (60) frictionally engages the pivot shaft. A viscous coupling may be used in place of the frictional clamp.