Abstract: The assembly method includes packaging of items for shipment and secures components of the assembly in a fashion and in the related position required for further assembly, as a unit, to an engine that is in the process of being assembled. The timed assembly arrives at the engine plant secured together such that it allows handling, at least in part, as a single component and with its parts arranged in the relative position required for proper timing and for securing to other components of the engine. The chain (44) is pinned between a tensioner pin (66) and the tensioner chain contacting surface (60) and between a guide pin (74) and the guide or snubber chain contacting surface (88). The tensioner is preferably pinned in a state of minimum extension.

Abstract: A power transmission device includes a tubular stabilizer which is arranged between a primary pulley and a secondary pulley, and through which a string portion of a power transmitting chain is passed so as to be movable relative to the stabilizer whereby movement of the power transmitting chain is restricted. The stabilizer is supported by the power transmitting chain and is moved in the traveling direction of the power transmitting chain as the power transmitting chain moves in the traveling direction, and a movement of the stabilizer of which the amount is larger than or equal to a predetermined amount is restricted by a restricting device.

Abstract: A chain tensioner includes a cylindrical cylinder having an open end and a bottom, a cylindrical plunger axially slidably inserted in the cylinder and having a bottom and an open end located in the cylinder, a screw rod mounted in the cylinder and having an external thread on an outer periphery thereof, wherein the plunger has a protrusion on an inner periphery thereof which is in threaded engagement with the external thread of the screw rod, and wherein the external thread has a pressure flank for receiving pressure when a force is applied that tends to push the plunger into the cylinder, and a clearance flank, the pressure flank having a larger flank angle than the clearance flank, whereby the external thread is serration-shaped, and a return spring mounted between the plunger and the screw rod and biasing the plunger in a direction to protrude from the cylinder, thereby pressing a chain with the plunger, wherein the protrusion extends only a limited arcuate range of the inner periphery of the plunger.

Abstract: The high-performance sliding rack ratchet tensioner is inexpensively manufactured. A rack having rack teeth is slidingly received in a rack slot on the side of the piston. The rack slot is preferably open-ended on the end facing the tensioner arm. The rack and piston are both received in a piston bore in the tensioner body. The rack length is preferably shorter than the rack slot length to provide backlash. A pawl mounted in a pawl bore perpendicular to the rack bore engages the rack. The open-ended rack slot allows the rack to be inserted after the piston during assembly. The rack and pawl preferably have shark fin-shaped teeth. The pawl preferably has dummy teeth to ensure that the load is shared by the center teeth.

Abstract: A tensioner for a belt drive, comprising: a base carrying a pin defining an axis; a tensioning arm, which can rotate about the pin and supports an idle pulley; and a damping element, which is constrained to a hinge point eccentric with respect to the axis and is carried by one between the base and the tensioning arm so as to co-operate with a friction surface carried by the other between the base and the tensioning arm. The belt tensioner further comprises a resilient element having a first end portion connected in a single point to the damping element and a second end portion connected to the other between the base and the tensioning arm to cause a rotation of the damping element about the hinge point against the friction surface.

Abstract: The hollow plunger of a hydraulic tensioner for an engine timing chain protrudes from a tensioner housing in an oblique downward direction. An inner sleeve fixed to the housing slidably protrudes into the interior of the plunger, and has a ball check valve at its protruding end. Oil is supplied though the sleeve and the check valve to a high pressure oil chamber formed inside the plunger, and flows outward through a two-part leakage path formed by a gap between the sleeve and the interior of the plunger and a gap between the exterior of the plunger and an interior wall of a plunger-accommodating hole in the housing. Any air that enters the tensioner accumulates in a region surrounding the upper end of the sleeve, rather than in the high oil pressure chamber inside the plunger.

Abstract: A hydraulic tensioning system (1), which is used in traction mechanism drives, particularly chain drives of internal combustion engines, is provided. The tensioning system (1) includes a piston (3), which is designed in the shape of a crucible, subjected to a pressure by a pressure spring (8), guided in a linearly displaceable manner in a housing (2) and spring-loaded against a traction mechanism. Hydraulic fluid can flow out of a pressure chamber (5) depending on an actuating direction of the piston (3) via an overpressure valve (11) forming a damper and associated with the piston (3) or can enter via a one-way valve (7) of the housing (2) into the pressure chamber (5). The overpressure valve (11) encloses a valve plate (15) that is integrated in the piston (3), and a pressure spring (8) of the piston (3) surrounds an outside of the valve housing (12) of the overpressure valve (11).

Abstract: In a chain tensioner, an expansible ring is disposed in an internal groove formed in the inner wall of a plunger-accommodating hole near an open end thereof. The ring cooperates with grooves formed on the plunger to exert a ratchet action. The relationship between the angles of the surfaces of the internal groove and the grooves on the plunger allows the plunger to protrude, restricts retraction of the plunger on start-up of a chain transmission, but allows retraction when chain tension becomes excessive. In one embodiment, in which the ring is a C-ring, the tensioner housing can be formed with external threads for mounting in a threaded hole on a timing chain cover or other engine part. In other embodiments, the ring can have externally protruding levers for manipulation of the ring.

Abstract: The present invention is directed to decrease the impact sound of the ratchet mechanism generated at the time of piston retraction. The tensioner includes a piston 3 slidable in the piston bore 2a of the housing 2 and an expandable circlip member 5 engageable with the engagement groove 3a of the piston 3. The piston bore 2a has a guide groove 20 formed therein that has front and rear stop surfaces 20a, 20b adapted to contact the circlip member 5. The engagement groove 3a is formed by a round seat portion S0 that the circlip member 5 is adapted to seat, a piston-retraction restricting portion S0S1 that is formed on the front side of the round scat portion S0 and a piston-advance permitting portion S0S2 that is formed on the front side of the round seat portion S0.

Abstract: A ratchet mechanism of the ratchet tensioner comprises a toothed ratchet element slidable in a housing and movable in a sliding direction, a plunger movable in an advance/setback direction and having rack teeth engageable by the teeth of the ratchet element, and a ratchet-biasing spring for biasing the ratchet element so that its teeth engage the rack teeth. The rack teeth have stop surfaces facing in the setback direction and sliding surfaces facing the advancing direction. The sliding surfaces are curved surfaces bulging in the advancing direction and in the direction of disengagement of the ratchet element from the rack teeth, the bulge being in an area extending from an entry starting location to an entry ending location.

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: The invention relates to a tensioner assembly for a traction medium drive, specifically a chain drive, with at least two traction medium wheels and a flexible traction medium, comprising a tensioning rail which can be pressed against the traction medium by means of a tensioning device, wherein the tensioning rail is applied against at least one sliding guide and can be displaced along the at least one sliding guide by means of the tensioning device.

Abstract: A chain tensioner has a plunger (14) slidably fitted in a bottomed cylinder (12) formed in a housing (11), and configured to resiliently urge the plunger (14) by a return spring (13) in the direction along which the plunger (14) is projected out from the cylinder (12), wherein the chain tensioner is configured to attach an engagement clip (19) to the opening of the cylinder (12), and to provide an engagement portion engageable with the engagement clip (19) to the end of the plunger (14) on the projection side thereof, so as to allow the engagement clip (19) and the engagement portion to engage with and disengage from each other corresponding to the position of rotation of the plunger (14).

Abstract: A pivot joint for a single blade spring tensioner or double blade spring tensioner generates a biased friction loss at a pivot joint. The friction torque generated in one direction of joint rotation is greater than the friction torque generated in the opposite direction of rotation. In one embodiment, the direction of torque bias at the joints is used to make the damping of the blade spring greater in compression than in extension. High damping in compression and low damping in extension is a desirable characteristic for a tensioner in most applications. The device may be designed to act as a one-way clutch or as a two-way clutch. The device may also be designed to apply large friction torques only when the joint undergoes large amplitude motions (loss of control).

Abstract: A chain tensioner includes a plunger axially slidable in a cylinder to define a pressure chamber, filled with hydraulic oil, whose volume is variable upon axial plunger movement. A restricted passage defined between the plunger and the cylinder communicates the chamber with outside. A spring biases the plunger to increase the pressure chamber volume. An oil supply passage supplies oil to the pressure chamber and a check valve allows only oil flow into the pressure chamber, and includes an annular valve seat, a check ball movable into and out of contact with the valve seat, and a check ball retainer formed by drawing. The retainer includes a tubular portion with a bottom at one end. The tubular portion has an opening, formed by punching outwardly, through which oil can flow in and out. The opening extends to a border between the tubular portion and the bottom of the retainer.

Abstract: A hydraulic tensioner for a drive system, including a flexible, inextensible drive element, has a bi-directional travel limiter associated with a hydraulically biased tensioning cylinder. The travel limiter is bi-directional because it limits not only loading of the tensioning cylinder against a tensioner shoe in a direction tending to tighten a drive element, but also resists movement of the tensioner shoe in a direction tending to allow slack in a drive element.

Abstract: A tensioner for a power transmission system includes two tensioning arms operatively engaged with a strand of either the chain or the belt of the power transmission system. The upper end of each tensioning arm is connected to a one way rotational clutch which is pivotally mounted between the upper ends of the tensioning arms. The one way clutch rotates in one direction in response to changing chain loads to adjust the tension substantially equally on both strands at the same time. In order to prevent over-tensioning, a damping means is included in the one-way clutch. When a pre-determined overload threshold is reached, the amount of torque required to overcome the coefficient of friction of a spring in the damper allows the one way clutch to slip in the direction opposite from its normal rotational direction, thereby relieving the overload condition on the chain.

Abstract: A pivot joint for a single blade spring tensioner or double blade spring tensioner generates a biased friction loss at a pivot joint. The friction torque generated in one direction of joint rotation is greater than the friction torque generated in the opposite direction of rotation. In one embodiment, the direction of torque bias at the joints is used to make the damping of the blade spring greater in compression than in extension. High damping in compression and low damping in extension is a desirable characteristic for a tensioner in most applications. The device may be designed to act as a one-way clutch or as a two-way clutch. The device may also be designed to apply large friction torques only when the joint undergoes large amplitude motions (loss of control).

Abstract: A hydraulic auto-tensioner includes a high-pressure oil chamber and a low-pressure oil chamber, and oil (L) in the high-pressure oil chamber passes through a clearance (G) between a cylinder (17) and a piston portion (18) of a plunger and leaks into the low-pressure oil chamber from an end of the clearance (G) near an end surface of the cylinder (17). A recessed groove (40) is provided in an inner peripheral surface of the cylinder (17) by a conical surface (41) having a groove angle of 5 to 15 degrees from the end of the clearance (G), a throttle portion (45) projecting onto the piston portion (18) side is provided further toward the end surface side of the cylinder than the groove (40) in the inner peripheral surface of the cylinder (17), and a throttle gap (A) larger than the clearance (G) is formed between the throttle portion (45) and the piston portion (18).

Abstract: In a spring-loaded tensioner lever having a coiled torsion spring accommodated in a space inside the lever, a stopper mechanism, comprising a pin held removably in a hole in the lever, holds an arm of the torsion spring against movement in the unwinding direction while the lever, or the chain, is being mounted on a mounting surface. The pin and a bent end of the arm of the spring fit into holes in the mounting surface positioned so that a pivot shaft-receiving hole of the lever is automatically aligned with a shaft-mounting hole in the mounting surface.

Abstract: A shoe tensioner for a synchronous belt drive, having a guide member adapted to cooperate with a drive belt and hinged at one end about a first axis; elastic means cooperating with the guide member to tension the belt; and connecting means for connecting the tensioner to a supporting wall. More specifically, the elastic means include a coil spring.

Abstract: Systems and methods for automatic belt tensioning in low speed, low volume fluid recovery. A required amount of tension is maintained across the recovery system's belt driven components under changing torque loads and operating speeds. This is accomplished by adjusting the distance between a motor output and a speed reducer input in response to a change in torque load between the motor and speed reducer. The required amount of tension is further achieved by adjusting the distance between an output of the speed reducer and a crank wheel in response to a change in torque load between the speed reducer and crank wheel.

Abstract: An apparatus for tensioning a chain is provided that compensates for the affect of temperature on oil viscosity by providing, in addition to a continuously open oil leakage path, an additional leakage path open only at lower temperatures when oil is more viscous and leaks at a slower rate. Thus, overall oil leakage at lower temperatures is similar to that at higher temperatures, when the additional leakage path is closed, and the less viscous higher temperature oil leaks at a faster rate from the continuously open oil leakage path. Accordingly, the affect of temperature on hydraulic stiffness of the tensioner assembly is minimized.

Abstract: The present invention relates to a tensioner, in particular a tensioner for a driving chain of an internal combustion engine, comprising a tensioning plunger which is axially movably guided in a plunger bore of a plunger reception means and an adjuster for readjusting the shift of the operating range of the tensioning plunger caused by wear. The adjuster comprises a hydraulic adjusting element and a closable pressure chamber provided on the bottom of the plunger bore. The adjusting element delimits the pressure chamber against the plunger bore and is axially movably guided in said plunger bore.

Abstract: A tensioner for a power transmission system includes two tensioning arms operatively engaged with the strand of the chain or the belt of the power transmission system. The upper end of each tensioning arm is connected to a two way damper which is pivotally mounted between the upper ends of the tensioning arms. When a pre-determined chain tension overload threshold is reached, the amount of torque required to overcome the coefficient of friction the damper allows the tensioner to adjust the tension in the chain with minimal oscillations and minimal phase change variation.

Abstract: In a hydraulic tensioner, at least a part of a bar is located within a coil spring that biases a plunger in the protruding direction. The bar reduces the volume of the high pressure oil chamber of the tensioner.

Abstract: An engine chain or belt tensioning system includes a tensioner pivot arm with a ratcheting means that includes backlash in an engine timing system. The tensioner system includes a tensioner pivot arm having a fixed pin, radially projecting ratchet teeth, a tensioner pivot arm biasing device, and a ratchet mechanism that engages the radially projecting ratchet teeth. The ratchet mechanism is oriented such that the tensioner pivot arm freely rotates in one direction, but backdrive is limited in the opposite direction.

Abstract: A belt tension adjustment apparatus and a robot arm having the belt tension adjustment apparatus are disclosed. The belt tension adjustment apparatus includes a tension measurement part for measuring tension of a belt running on an endless track, a tension adjustment part for pressing the belt in a direction inclined with respect to a surface of the belt to apply a pressing force to the belt, and a controller for controlling the tension adjustment part depending on the measured tension. The belt tension adjustment apparatus prevents variation of a running speed of the belt and maintains tension of the belt.

Abstract: A variable leakdown chain drive tensioner system includes a chain drive tensioner in operable communication with a chain. The chain drive tensioner includes a tensioner body with at least one leakage hole defining a first leakdown path and a tensioner piston assembly in operable engagement with the tensioner body. As the chain wears, the tensioner piston assembly is moveable from a first position, allowing flow through the first leakdown path, to at least a second position, substantially blocking flow through the first leakdown path. The tensioner body may also include a second leakage hole defining a second leakdown path and the tensioner piston may also have a third position. The first position would allow flow through the first and second leakdown paths, the second position would allow flow through only the second leakdown path, and the third position would substantially block flow through both the first and second leakdown paths.

Abstract: A tensioner operable to substantially maintain a specified tension in a flexible drive, such as a belt or chain, includes a spring, mounted laterally to the pivot shaft of the tensioner, which biases the tensioner arm towards the flexible drive. The spring is arcuate in shape and is maintained in a correspondingly arc-shaped spring retainer on a mounting plate of the tensioner. The arcuate shape of the spring and spring guide on the tensioner arm follows as the tensioner arm pivots towards and away from the flexible drive. The tensioner also has a wear take up mechanism to maintain the friction bushing in continuous engagement with the tensioner arm.

Abstract: A tensioner for an endless transmission belt includes a plunger body and a plunger. The plunger is movably provided in the plunger body to press the endless transmission belt. A pressure chamber provided between the plunger and the plunger body is configured to store hydraulic oil supplied from an oil pump. A check valve is provided in the plunger body, configured to be opened to supply the hydraulic oil to the pressure chamber when a pressure in the pressure chamber is lower than an oil pressure from the oil pump, and configured to be closed when the pressure is higher than the oil pressure. A relief valve is provided in the plunger body within a width of the plunger in a direction orthogonal to a longitudinal direction of the plunger and configured to discharge the hydraulic oil in the pressure chamber when the pressure exceeds a predetermined value.

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 chain drive tensioner system with translating pivot point is disclosed. The chain drive tensioner system with translating pivot point includes a chain drive tensioner assembly and a tensioner arm in operable communication with a chain. The chain drive tensioner assembly is in operable communication with the tensioner arm, and the tensioner assembly is moveable between a first tensioner position and a second tensioner position. The tensioner arm includes an internal gear and an external gear rotatably mounted within the internal gear, such that movement of the tensioner assembly from the first tensioner position to the second tensioner position along with concurrent rotation of the external gear within the internal gear is operable to move the tensioner arm laterally from a first position to a second position.

Abstract: A tensioner that includes a blade shoe (106), at least one blade spring (112), a ramp 122), and a brake (132). The blade shoe has a curved chain sliding face, an underside, opposite the chain sliding face, a proximal end pivotally attached to ground and a distal end. The ramp is fixed to ground and has a ramp surface (122a) for contacting the chain sliding face or the underside of the blade shoe. The brake is self-energizing, pivotally fixed to ground and has a friction contact surface (132a) for contacting the distal end portion (106c) of the chain sliding face, the blade spring, or the underside of the blade shoe for restricting movement of the distal end of the blade shoe in one direction and allowing movement in the opposite direction.

Abstract: In a hydraulic chain tensioner having a housing, a hollow plunger slidable in a plunger-accommodating hole in the housing, and a hollow sleeve extending into the plunger from a bottom of the plunger-accommodating hole, and a check valve mounted at the opposite end of the sleeve, a passage is provided on the outer surface of the sleeve to accelerate the balance of pressure between a first high pressure chamber between the check valve and the protruding end of the plunger and a second high pressure chamber between the inner end of the plunger and the bottom of the plunger-accommodating hole. In an alternative embodiment, balance is accelerated by communication between the second high pressure chamber and an oil reservoir inside the sleeve on the upstream side of the check valve.

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 for tensioning a belt includes a support housing that defines, at least in part, a spring cavity and an arm pivotably attached to the support housing. A spring is disposed in the spring cavity and is operatively connected to the arm and support housing to bias the arm to pivot relative to the support housing. The spring is a round wire coil spring having an unloaded axial height and wherein the spring cavity has a height greater than the unloaded axial height of the spring.

Abstract: A camshaft drive system for an internal combustion engine includes a drive sprocket fixed upon a crankshaft of the engine and a driven sprocket fixed upon a camshaft of the engine. A flexible power transmission element extends between the drive sprocket and driven sprocket. A tensioning device for the flexible power transmission element includes a linear actuator and a number of movable contactors for engaging and tensioning both the slack side and the tight side of the power transmission element, such that proper phasing of the camshaft with respect to the crankshaft is maintained.

Abstract: A dual backlash tensioner includes a support having a recess therein. A plunger is slidable in the recess and includes a shoe extending outward from the recess. A first resilient member acts between the support and the plunger and urges the shoe outwardly. An oscillatable stop cam having first and second teeth spacedly disposed thereon is engagable with the plunger. The stop cam is pivotally mounted on the support. A second resilient member urges the first tooth toward engagement with the plunger. The plunger has a control portion opposing the stop cam that includes a toothed rack and an adjoining depression positioned toward the shoe. The stop cam teeth are adapted to engage the toothed rack.

Abstract: A plunger 4 and a spring 6 biasing the plunger 4 outwardly are mounted in a cylinder chamber 2 formed in a housing 1. The housing 1 is provided with an oil supply passage 8 communicating with a pressure chamber 7 formed in the back of the plunger 4. The housing 1 has an outer diameter that is substantially constant over the entire axial length, so that such housings can be mass-produced by pressing. It is thus possible to lower the cost of the chain tensioner.

Abstract: A chain tensioner for use with a chain of a vehicle engine, includes a housing and a plunger slidably mounted in a cylinder chamber formed in the housing. The plunger is biased outwardly by a return spring mounted in a pressure chamber defined in the cylinder chamber by the plunger. A check valve is provided in the cylinder chamber to prevent backflow of hydraulic oil in the pressure chamber. A relief valve, provided in the plunger, opens above a relief pressure, thereby discharging hydraulic oil in the pressure chamber. An oil leakage clearance is defined between the plunger and the inner wall of the cylinder chamber. The relief pressure and the oil leakage clearance dimension are determined such that the tension in the chain is kept at such a level that vibrations of the chain are minimum at any temperature of hydraulic oil and at any engine revolution speed.

Abstract: A hydraulic tensioning device is provided for a traction mechanism drive, in particular for a chain or belt drive of an internal combustion engine. The device includes a tensioning piston which is guided in a displaceable manner in a cylinder, with a pressure chamber being defined between the tensioning piston and the cylinder which is used to receive hydraulic fluid. A pressure relief valve is provided which limits the pressure in the pressure chamber. The pressure relief valve (8) includes, at least partially, a pre-assembled assembly (10) which can be inserted or is inserted into the tensioning piston (4).

Abstract: An apparatus for indicating an automotive power transmission belt dynamic is provided. The apparatus includes a belt tensioner including a support housing and an arm rotatably connected to the support housing. A pulley is carried by the arm, the pulley having a belt-engaging surface. A spring is connected to the arm and support housing to bias the arm to pivot relative to the support housing. A sensor is responsive to an input associated with a position of the arm relative to the sensor, the sensor providing an indication in response to receipt of the input. A signaling device is configured to provide a signal to a user in response to the indication provided by the sensor.

Abstract: A V-belt continuously variable transmission (CVT) for a straddle-type vehicle includes a measurement plate for a rotational speed sensor for detecting a rotational speed of a primary sheave shaft to control a speed change ratio. The measurement plate is disposed on an opposite end of the primary sheave shaft, to one end of which a driving force of an engine is input, with respect to a primary sheave.

Abstract: A chain tensioner includes a housing having a closed bottom. A rod is axially movably inserted in the housing for pressing a chain. A wear ring is mounted to the outer periphery of the rod and is biased by a return spring mounted in the housing in a direction away from the bottom of the housing. A nut member is mounted between the wear ring and the bottom of the housing so as to be coaxial with the housing and axially movable relative to the housing. A ring-shaped spring member is provided between the nut member and the bottom of the housing to support the nut member. A screw rod is provided between the rod and the bottom of the housing and in threaded engagement with the nut member. A spring is provided between the screw rod and the bottom of the housing to bias the screw rod in a direction away from the bottom of the housing. The screw rod has an end surface that is in abutment with the rod.

Abstract: A hydraulic tensioner comprising a piston slidably inserted in a piston bore of a housing having rack teeth on an outer circumference thereof, a piston spring biasing the piston in a protruding direction, a pawl member having teeth engageable with the rack teeth of the piston to permit protruding movement of the piston but to block reverse movement of the piston provided in a pawl hole of the housing, and a pawl spring in a pawl spring hole of a generally elliptical cross-section that biases the pawl member in an engaging direction of the teeth of the pawl member with the rack teeth of the piston. A long axis of the generally elliptical cross-sectional shape of the pawl spring is oriented toward an axial direction of the piston. Wire portions of the pawl spring substantially follow the long axis that contacts an upper surface of the pawl member.

Abstract: A tensioner for a traction drive includes a cylinder arranged in a housing at a distance to a housing wall to thereby define an interior space which contains hydraulic fluid. A piston is received in the cylinder for back-and-forth movement and bounds a pressure chamber containing hydraulic fluid. The piston has a cylinder-distal end which is operatively connected to a spring-biased tension roller supported on a traction member. Formed between the piston and the cylinder is a leakage gap, and a reservoir for hydraulic fluid is provided in an area of the leakage gap to prevent ingress of air into the pressure chamber, when the traction drive is at a rest.

Abstract: An apparatus is described for the intermittent drive of a spindle (1) for a workpiece fixture, especially a forging machine, comprising a traction gear (7) consisting of a traction means (13) guided endlessly about a driving wheel (6) and a driven wheel (8), a continuous rotary drive (5) for the driving wheel (6) and a superposition drive (10) performing rotary oscillations. In order to provide advantageous constructional conditions it is proposed that the superposition drive (10) comprises a support (11) which can be displaced in a rotary oscillating manner about the axis of the driven wheel (8), and deflection rollers (12) held on the support (11) for the traction strands (14) moving towards and away from the driving wheel (6).

Abstract: A chain tensioner includes a housing defining a cylinder chamber, and a plunger having a small-diameter end and a spring both mounted in the cylinder chamber. A register ring is fitted in a ring-receiving groove formed in the inner periphery of the cylinder chamber near its open end. A plurality of annular grooves are formed in the outer periphery of the plunger so as to be axially spaced from each other at equal intervals. The register ring is adapted to be press-fitted in one of the annular grooves. With the register ring trapped between an engaging surface of a first annular groove which is one of the annular grooves located nearest to the front end of the plunger and a locking surface of the ring-receiving groove, an outer cylindrical surface of the plunger extending forwardly from the first annular groove has its front portion supported by an inner cylindrical surface of the cylinder chamber extending forwardly from the ring-receiving groove.

Abstract: The check valve unit of a hydraulic tensioner comprises a check ball, a ball guide and a disc-shaped retainer. The retainer is fixed to the high pressure oil chamber side of the ball guide by crimping an annular portion of the ball guide over the outer edge of the retainer so that substantially all of an annular circumferential portion of the high pressure chamber side of the retainer is held underneath the crimped portion of the ball guide. The crimped portion of the ball guide forms a recess for receiving and positioning a plunger-biasing spring. A ball seat is similarly secured to the inflow side of the ball guide by crimping.