| 摘要 |
A tensioner (22) for a power transmission belt (21) that is adapted to be operated in an endless path, a part therefor, and methods of making the same. The tensioner (22) comprises a support unit (36) for being fixed relative to the belt (21), a belt engaging unit (38) carried by the support unit (36) and being movable relative thereto, a mechanical spring unit (39) operatively associated with the support unit (36) and the belt engaging unit (38) for urging the belt engaging unit (38) relative to the support unit (36) and against the belt (21) with a force to tension the belt (21), and a fluid dampening unit (40) operatively associated with the support unit (36) and the belt engaging unit (38) to dampen the movement of the belt engaging unit (38) relative to the support unit (36) in at least one direction of movement thereof. The mechanical spring unit (39) may comprise a pair of springs (79, 79A, 79B, 79C) disposed in substantially parallel spaced relation, with the fluid dampening unit (40, 40A, 40B, 40C) having at least a part thereof disposed between the springs and in substantially parallel relation therewith. The belt engaging unit (38C) and the support unit (36C) may have a tongue and groove arrangement (200) for providing for sliding movement therebetween. The fluid dampening unit (40, 40A, 40C) may comprise a piston (85, 147, 233) and cylinder (84, 135, 217) arrangement. Alternatively, the fluid dampening unit (40B, 40D, 40E) may comprise a rotary dampening arrangement. |
