摘要:
A blade-type tensioner (1) for applying tension to a chain comprising a base (4), an arcuately shaped blade shoe (2) having a chain sliding face (2a), a spring (3) provided on a back side of the blade shoe, and a guide member. The blade shoe has a proximal end portion (20) and a distal end portion (21), where the proximal end portion is swingably supported on the base, and the distal end portion is slidably supported on a slide plate (41) of the base. The slide plate is arcuately shaped to form a concavely arcuate arc face (41a) on an opposite side of the distal end portion of the blade shoe, and the distal end portion of the blade shoe has a convexly arcuate arc face (21c) corresponding to the concavely arcuate arc face of the slide plate. The distal end portion of the blade shoe is guided by a self-aligning action of the concavely arcuate arc face of the slide plate in such a way that the distal end portion is centrally positioned in a lateral direction on the slide plate. The guide member (6) comprises a pair of guide portions (6'a) formed integrally on opposite side edges of the distal end portion of the blade shoe, and hang below opposite side ends of the slide plate.
摘要:
A hydraulic tensioner that decreases the number of components, secures an adequate backlash, and prevents backward movement of a plunger. The hydraulic tensioner includes a hollow plunger having rack teeth formed on a portion of an outer circumferential surface, slidably received in a bore of the housing, where the plunger has an inner space to form a fluid chamber with the bore. A roller housing portion, having an inclined surface, located in the housing, receives a wedge-shaped roller having a ratchet portion adapted to engage with the rack teeth of the plunger and a second side surface. The wedge-shaped roller being slidable along the inclined surface of the roller housing portion in a direction crossing an axial centerline of the plunger. The hydraulic tensioner further includes a first spring biasing the plunger in a protruding direction, and a second spring biasing the roller such that the roller moves along the inclined roller surface of the roller housing portion. A "wedge-effect" prevents the plunger from moving backwards.