Abstract:
A tensioning device to impart tension to a chain or belt comprising a tensioner arm, a supporting member, a pivot, and a biasing element. The tensioner arm has a proximal end with a curved engaged surface formed on a lower surface thereof, a distal end opposite the proximal end, and an arcuately curved chain sliding surface extending between the proximal end and the distal end. The supporting member has an engaging surface for slidably contacting the engaged surface of the proximal end of the tensioner arm, such that the force exerted by a chain passing over the chain sliding surface is transmitted from the engaged surface to the engaging surface. The pivot couples the tensioner arm to the supporting member. The biasing element is between the supporting member and imparts a resilient force on the distal end of the tensioner arm.
Abstract:
A mechanical anti-backdrive chain tensioner includes a four-sided planar piston and plastic chain shoe assembly. A pair of helical compression springs of opposite helices urges the piston and shoe assembly into the chain, and a ratchet plate pawl prevents backdrive of the piston but is designed with a predetermined amount of backlash. The planar-sided piston permits a large engagement area with the mating ratchet plate pawl. The large pawl contact area of the planar piston reduces tooth stress and withstands much higher anti-backdrive loads than prior art tensioners. The outer helical spring preferably has an outer diameter equal to the diameter of a bore hole in the piston and an inner diameter equal to the outer diameter of the inner spring to produce frictional damping upon extension and compression of the springs.
Abstract:
A blade tensioner system for a chain that imparts tension to a chain that drivingly connects to a driven shaft to a drive shaft in an engine. The blade tensioner comprises a blade shoe and mating block. The blade shoe has an arcuately curved chain sliding face, a proximal end portion, and a distal end portion having a pair of tapered sides joined by a bottom and at an angle. The mating block has a channel with a pair of tapered sides joined by a bottom and at a second angle for receiving the distal end portion. When load on the chain increases, the tapered sides of the distal end portion and the bottom contact and wedge with the tapered sides of the channel of the mating block, damping chain vibration.
Abstract:
A sprocket is provided with a plurality of teeth spaced about its periphery, the sprocket including roots located between pairs of adjacent teeth. The roots have root radii defined as the distance between the center of sprocket and the point along the root closest to the sprocket center in the radial direction. Roots have three distinct radii. a cushioning material for receiving the impact while engaging a chain has a geometry means substantially following the contours of the sprocket teeth geometry.