A tensioner device, includes a housing defining a cavity with a plunger disposed in the cavity. A spring is engaged with the plunger for biasing the plunger in an outward direction. An oil passage is in communication with the cavity for delivering pressurized oil to the cavity and an oil reservoir is disposed in the housing and in communication with the cavity. The oil reservoir includes a vent opening at a vertical level at least as high as the oil passage into the cavity so that oil is maintained with the cavity when the tensioner is installed in an inverted orientation.

A tensioner device, includes a housing defining a cylindrical bore. A plunger is disposed in the bore and has a non-cylindrical outer surface. A spring is engaged with the plunger for biasing the plunger in an outward direction and an oil passage is in communication with the cylindrical bore for delivering pressurized oil to the bore. The non-cylindrical outer surface provides hydraulic clearance areas between the plunger and the bore to provide improved damping without high damping force.

A tensioning and damping element for endless chain drives, especially for roller chain drives, can be used for endless chain drives, which are to be tensioned diametrically. The material is an elastic plastic. All told, the known tensioning and damping elements, in conjunction with the wear of the chain, the load changing phases, as well as the reversing according to the degree of deformation, have the disadvantage of a phased running irregularity, an increased running noise and of wear-intensive areas in the toothed rim. An element with a ring part and a toothed rim of arc-shaped teeth with, in each case, axially opposite bulges in the roller-seating and, between these, roller-seating depressions, grooves, which are disposed peripherally between the ring part and the bulges, an extended pitch and extended roller-seatings with the advantageous profile shape similar to a semielliptical curve lying on the root circle.

To provide a chain tensioner capable of constantly providing an appropriate reaction force and damping characteristics for a variety of tension fluctuations irrespective of chain elongation, and capable of accommodating the tension fluctuations. The chain tensioner includes a distal end plunger 130 slidably inserted in a distal end bore 121 of a plunger 120, and a distal end biasing means 141 accommodated inside a second oil pressure chamber 102 such as to be able to expand and contract and to urge the distal end plunger 130. The chain tensioner further includes a check valve unit 150 that stops oil flowing from an oil pressure chamber 101 into the second oil pressure chamber 102, and a first relief valve unit 160 that releases oil toward the oil pressure chamber 101 when the pressure reaches or exceeds a predetermined high level.

A tensioner comprising a shaft, a base, a pivot arm pivotally engaged with the base, a pulley journalled to the pivot arm, a first spring urging a first damping member into a frictional engagement with the pivot arm, the first spring engaged with the base, the first damping member imparting a damping force greater in a first pivot arm direction than in a second pivot arm direction, and a second spring disposed in the pivot arm and urging a second damping member into a frictional engagement with a base surface, the base surface comprises an arcuate form having a radius that is variable from a minimum value to a maximum value.

A tensioner device, includes a housing defining a cavity with a plunger disposed in the cavity. A spring is engaged with the plunger for biasing the plunger in an outward direction. An oil passage is in communication with the cavity for delivering pressurized oil to the cavity and an oil reservoir is disposed in the housing and in communication with the cavity. The oil reservoir includes a vent opening at a vertical level at least as high as the oil passage into the cavity so that oil is maintained with the cavity when the tensioner is installed in an inverted orientation.

A tensioner device, includes a housing defining a cylindrical bore. A plunger is disposed in the bore and has a non-cylindrical outer surface. A spring is engaged with the plunger for biasing the plunger in an outward direction and an oil passage is in communication with the cylindrical bore for delivering pressurized oil to the bore. The non-cylindrical outer surface provides hydraulic clearance areas between the plunger and the bore to provide improved damping without high damping force.

Provided is a simple-structured tensioner that can reduce processing and assembling workload as well as increase the degree of design freedom. A tensioner 10 includes an oil supply hole 33 formed in a sleeve bottom 32 and a check valve 50 disposed on a front face of the sleeve bottom 32. The check valve 50 includes a check ball 51 and a retainer 52. The sleeve bottom 32 includes a ball seat 34 which protrudes in a cylindrical shape toward the front side integrally with and continuously from the edge of the oil supply hole 33 and on which the check ball 51 is seated.

The invention relates to a tensioning device for a traction drive, comprising a receiving housing, a roller carrier which is pivotably connected to the receiving housing, a helical tension spring which is supported at the receiving housing and at the roller carrier in circumferential and axial direction, wherein the roller carrier and the receiving housing are axially fixed relative to one another by the helical tension spring, a bearing arrangement by which the roller carrier is supported in the receiving housing so as to be rotatable around a rotational axis, a damping arrangement for damping a rotational movement of the roller carrier relative to the receiving housing, wherein the damping arrangement is arranged so as to be axially spaced from the bearing arrangement and is axially loaded by a tensile load of the helical tension spring.

A tensioner comprising a shaft, a base, a pivot arm pivotally engaged with the base, a pulley journalled to the pivot arm, a first spring urging a first damping member into a frictional engagement with the pivot arm, the first spring engaged with the base, the first damping member imparting a damping force greater in a first pivot arm direction than in a second pivot arm direction, and a second spring disposed in the pivot arm and urging a second damping member into a frictional engagement with a base surface, the base surface comprises an arcuate form having a radius that is variable from a minimum value to a maximum value.