A hydraulic tensioner for an internal combustion engine for tensioning a span of a chain or a belt has a piston with an internal reservoir connected to a high pressure chamber through a check valve assembly. The check valve assembly has a disk seat formed by an internal bulge within the piston; a check valve retainer within the piston, and a moveable disk that is received between the disk seat formed by the internal bulge and the check valve retainer and is moveable between a first position and a second position, and a check valve spring that is received between the check valve disk and the check valve retainer.

A tensioner for a fenestration unit operator includes a base and a guide including a track, the track slidably receiving the base such that the base is restricted to sliding in a first direction with respect to the guide along a sliding axis and a second direction with respect to the guide along the sliding axis that is opposite to the first direction. The tensioner includes a pawl and a ratchet each being a part of one of the sled and the guide, respectively, the pawl being in biased engagement with the ratchet to permit sliding in the first direction and restrict sliding in the second direction, the pawl being configured to be manually disengaged from the ratchet to permit sliding in the second direction. The tensioner includes a pulley coupled to the sled such that the pulley is free to rotate about a rotational axis that is transverse to the sliding axis.

An automatic tensioning apparatus is provided that includes a tensioning drive unit having: a longitudinally extending stationary base frame with a plurality of guides extending between a lower portion and an upper portion, and a plurality of rotatable feed wheels axially secured at the lower portion, as well as a translatable drive frame slidably coupled to the plurality of guides with a drive assembly coupled to the drive frame, the drive assembly including a drive motor and a tensile member interface for engaging and rotationally translating a tensile member. The tensioning drive unit further including a plurality of drive frame actuators actuatable to move the drive frame between a bottom frame position and a top frame position, as well as a sensor for at least indirectly sensing the position of the drive frame along a longitudinal base frame axis.

Disclosed is a belt tensioner having a single-piece plastic body, having a fastening section, that has an adjustment mechanism via which the plastic body can be adjustably fastened, to the carrier; a pressing section configured to press against the drive belt in order to tension the drive belt; and a spring joint device which connects the fastening section and the pressing section to one another, and via which the pressing section is displaceably supported at the fastening section along the deflection direction so that, when the pressing section presses against the drive belt, the amount of the displacement of the pressing section along the deflection direction is dependent on the respective set drive belt tension, wherein the belt tensioner has a setting aid that indicates when the predefined drive belt tension is set by the belt tensioner.

A device for tensioning a belt of a video camera assembly, including a belt tensioner terminal and an elastic thrust element operating on the belt tensioner terminal for thrusting the belt tensioner terminal against the belt. The device further includes an adjustment element for determining an adjustable positioning of the belt tensioner terminal with respect to the belt and at least one constraint element for operating between a rest condition, where it does not constrain the positioning of the belt tensioner terminal, and a constraint condition, where it constrains in position the belt tensioner terminal. The adjustment element is operatively connected to the thrust element in a removable way. Advantageously, the thrust element and the adjustment element share a same operative direction, the at least one constraint element operating or developing along a direction which is orthogonal to said operative direction of the thrust element and of the adjustment element.

A chain tensioner is formed with internal threads each including a push-in-side flank, a protruding-side flank, and a thread top face. The push-in-side flank has a flank angle which is larger than a flank angle of the protruding-side flank. The push-in-side flank and the protruding-side flank are rolled surfaces formed by rolling, and have a surface roughness smaller than Ra 1.0 μm. Each internal thread further includes, at a position at which the protruding-side flank intersects with the thread top face, a chamfer configured to receive a bulge resulting from excess materials pushed out from the protruding-side flank during formation of the internal thread by rolling.

The disclosure relates to a method for detecting belt slip of a belt drive driving a generator of an internal combustion engine, said belt drive having a belt tensioner that can be adjusted in operation and adjusts the pre-tensioning force of the belt according to the detected belt slip. According to said method, the rotational speed profile of the crankshaft is recorded during an angular window of the crankshaft of m.Math.360 degrees and an average value of the crankshaft rotational speed is formed from said rotational speed profile; temporally independently from the recording of the rotational speed profile of the crankshaft, the rotational speed course of the generator shaft is recorded during an angular window of the generator shaft of n.Math.u.sup.−1.Math.360 degrees and an average value of the generator shaft rotational speed is formed from said rotational speed profile.

The present disclosure relates to a belt driven system. The belt driven system may include a master pulley, a slave pulley, a belt around the master pulley and the slave pulley, a tension pulley configured to tension the belt, and a position adjusting device configured to automatically adjust a position of the tension pulley based on an interaction of the tension pulley and the belt.

A belt tensioner having a tensioner base and a tensioning arm axially aligned about a pivot shaft defining a pivot axis, the tensioning arm pivotal in relation to the tensioner base about the pivot axis. The tensioner has a bearing positioned around and sealed against the pivot shaft, with the tensioning arm positioned around the bearing. The bearing forms a radial seal between the bearing and the tensioning arm and between the bearing and the pivot shaft. A torsion spring is positioned externally around a portion of the tensioning arm.

An idler sprocket shaft support device for use with chain-driven equipment (e.g., snowblowers) is provided. The support device includes a spacer through which the sprocket shaft passes through, and an elongate support member coupled to the spacer and extending through an aperture in an adjacent support plate. By locking the elongate support member within the aperture in the adjacent support plate at a particular distance, the spacer also is locked thereby holding the sprocket shaft at a desired positional setting.