Abstract: A tensioner may be part of a power system to tension an endless power transmitting element. The tensioner includes an arm having an arm arbor with a slot therethrough that is rotatable about a first axis, a bushing having a sleeve that includes a cut-out and a removable sleeve-segment that has a protrusion thereon, the sleeve-segment being receivable in the cut-out with the protrusion in the slot, and a spring coupled to the arm for rotation of the arm about the first axis into tensioning engagement with a power transmitting element. The spring is positioned where it can radially expand into contact with the protrusion of the bushing, at least the protrusion on the sleeve-segment, as the arm is rotated in a direction opposite the direction of tensioning engagement such that the bushing is urged radially outward relative to the arm arbor to provide frictional damping.

Abstract: An inverted tooth chain and sprocket drive system in which the initial contact distance ICD, the meshing impact angle Sigma (?), the link plate entrance angle Beta (?), and other aspects of the meshing geometry are controlled and optimized to reduce noise and vibration by using a particular chain link plate form and, in preferred cases, by modifying the sprocket tooth pressure angle. The system can include first and second sprockets for which the pressure angle can be controlled to ensure that the desired values for the initial contact distance ICD, the meshing impact angle Sigma (?), and the link plate entrance angle Beta (?) are equal for both sprockets even though the sprockets have different tooth counts. For a chain pitch P in the range of 6.35 mm to 7.7 mm, the initial contact distance ICD is controlled such that 0.49P?ICD?0.53P, the meshing impact angle Sigma (?) is controlled such that ??34°, and the link plate entrance angle Beta (?) is controlled such that ??9°.

Abstract: A mechanical tensioner for a traction drive element is provided. It includes a housing with a bore having an open end and a closed bottom. A plunger having a first end is located in the bore. The first end of the plunger has a tapered slot or tapered opening defined therein forming a hollow wall portion of the plunger. The hollow wall portion is discontinuous in a circumferential direction. A wedge insert is located at least partially in the slot or opening. The wedge insert has an outer surface with a contact area that is complementary to the tapered slot or tapered opening. A spring is located between the wedge insert and closed bottom of the housing. The spring forces the wedge insert into the tapered slot or tapered opening with an increase in force as the plunger is depressed into the bore in the housing. This forces the hollow wall portion outwardly in order to provide a friction damping feature that increases with the distance that the plunger is depressed.

Abstract: In a chain guide mechanism in which a pair of chain guides, at least one of which is a pivoted guide, are connected by mounting bosses a bridge so that the chain guides and bridge can be preassembled along with a chain and driving sprocket to form an integrated unit for installation in an engine, the chain guides include a chain-engaging guiding surface extending in a first direction from a location adjacent the mounting bosses, and a chain pressing portion extending in a second direction, opposite the first direction, substantially from the same location adjacent the mounting bosses. The pressing surfaces clamp the chain against the sprocket when a pivotable chain guide is rotated so that its chain engaging surface is moved away from the chain.

Abstract: In a chain guide mechanism, fixed and movable guides are attached to a guide bridge by cooperation of bosses on the guides with boss-receiving holes formed in spaced-apart elements of arms of the bridge. A fixed guide is held against rotation by cooperation of a projection on its mounting boss with a notch in a boss-receiving hole in a guide bridge arm element. A base, extending from an intermediate location at which the arms come together has a pressing structure that engages bosses on a driving sprocket, and a groove for receiving teeth of the driving sprocket.