A belt transmission system comprises: a first pulley; a second pulley; a belt; and an automatic tensioner having a first tension pulley and a second tension pulley applying tension to a portion of the belt located at a tension side and a portion of the belt located at a slack side of the belt, and an arm. Force from the belt makes the first tension pulley and the second tension pulley rotate in the same direction. When the first tension pulley rotates in a direction tensioning the belt, the second tension pulley also rotates in a direction tensioning the belt.

An automatic belt tensioner for a hybrid vehicle is disclosed. The automatic belt tensioner includes an arm body including an upper arm on which first and second idlers are mounted and a lower arm on which a third idler is mounted. The automatic belt tensioner further includes a spring provided between the upper arm and the lower arm and providing elastic force for relative longitudinal movement of the upper arm and the lower arm, and a rail bracket mounting the arm body on an engine and guiding relative longitudinal vertical motion of the arm body.

The invention relates to a belt tensioning device for a crusher or a screening machine for tensioning at least one circulating drive belt (20) which is deflected about a belt pulley (12) of a drive (10) and has a load strand (21) and an empty strand (22). The drive (10) can be driven with a crushing assembly, a screening unit, a generator, or the like of the crusher by means of the drive belt (20). The vibrational stress acting on the machine chassis can be significantly reduced in that the belt tensioning device has two tensioning rollers (47), each of which is rotatably mounted on a holder (41, 51) of a tensioning part (40, 50). One tensioning roller (47) is paired with the empty strand (22) and the other is paired with the load strand (21). Additionally, the two tensioning parts (40, 50) can be adjusted relative to each other between an open position and a tensioning position, in which the tensioning parts are held against each other at least opposite the tensioning direction, in particular the tensioning parts can be blocked against each other, and the complete closed system can be freely moved linearly using actuators (44.2) according to the load situation.

An apparatus for assembling an engine includes an engine jig configured to load the engine on which a pump sprocket, a cam sprocket, an auto tensioner, and an engine belt are preliminarily mounted. The apparatus includes: a pump sprocket fastening unit disposed on a first die disposed on a first side of the engine jig and configured to clamp and fully fasten the pump sprocket in order to fixedly mount the pump sprocket preliminarily mounted to the engine; a cam sprocket fastening unit disposed on the first die and configured to clamp, rotate, and fully fasten the cam sprocket in order to fixedly mount the cam sprocket preliminarily mounted to the engine; and an auto tensioner fastening unit disposed on the first die, and configured to clamp, rotate, and fully fasten the auto tensioner in order to fixedly mount the auto tensioner preliminarily mounted to the engine.

A dynamic belt-tensioning apparatus for a treadmill includes a base having a first end and a second end spaced from the first end. A foot-striking platform is movably supported by the base so as to allow vertical movement of the platform during operation of the treadmill. A drive belt has a fixed circumference and is positioned above a top portion of the platform. A drive roller is pivotally mounted adjacent to the first end of the base and engages the drive belt. A tensioning roller is pivotally mounted to the base and is capable of a range of movement to provide substantially constant tension to the drive belt in response vertical movement of the platform.

A drive arrangement is provided which includes: a first and second rotatable members; an endless loop member, extending around the first and second rotatable members, arranged to convey drive from the first rotatable member to the second rotatable member; a first support, arranged to support the first rotatable member and the second rotatable member, having at least one aperture therein; a guide member, defining at least part of a path of the endless loop member between the first rotatable member and the second rotatable member; and a second support, arranged to support the guide member, the second support being connected to the guide member through the at least one aperture in the first support such that guide member is movable, via the at least one aperture, to engage and disengage drive from the first rotatable member to the second rotatable member.

A traction tensioning device which has one or more upper chain assemblies driven by an upper sprocket pulley and one or more lower chain assemblies driven by a lower sprocket pulley. Each of the upper and lower chain assemblies has a plurality of pads mounted to the chain assemblies. The upper chain assembly is mounted to a movable platen. The lower chain assembly is mounted to a fixed platen. The upper chain assembly and the movable platen are raised and lowered with respect to the lower chain assembly thereby creating a tension on a strip of material passing between the upper and lower chain assemblies.

The belt drive assembly includes a frame having a first plate including an inner surface, an outer surface, a first end, and a second end, a second plate including an inner surface, an outer surface, a first end, and a second end, and a shaft disposed between the first plate and the second plate. The belt drive assembly also includes a first pair of idler pulley wheels positioned coaxially at one end of the first plate, a second pair of idler pulley wheels positioned coaxially at one end of the second plate, a drive pulley wheel rotatably mounted onto the outer surface of the first plate, a driven pulley wheel rotatably mounted onto the outer surface of the second plate, and an endless belt trained on the drive pulley wheel, on each idler pulley wheel, and on the driven pulley wheel.

A spindle rotation unit includes: a plurality of attachment portions that are arranged in a base; a spindle that is rotatably attached to any one of the plurality of attachment portions; a motor plate that is attached to the base; a motor attachment flange that is attached to the motor plate; a driving motor that is attached to the motor attachment flange; and a transfer member that connects the driving motor and the spindle and transfers a rotational driving force of the driving motor to the spindle. The motor attachment flange is provided with an opening portion through which the transfer member is inserted and the motor attachment flange is disposed in the motor plate to allow its position to be adjustable so that the opening portion is opened toward a predetermined attachment portion to which the spindle is attached among the plurality of attachment portions.

In one aspect the invention relates to a tensioner that is capable of precognitively anticipating when it is desirable to increase the tension in a belt or other endless drive element so as to prevent belt slip prior to events that would raise the risk of it.