A variable belt tensioner for an engine includes: a first damper; and a second damper connected to the first damper through a driver. The first damper, the second damper, and the driver causes a belt connected to a crankshaft pulley and a starter-generator pulley to have a first tensile strength when the engine including the crankshaft pulley starts, the first damper, the second damper, and the driver causes the belt to have a second tensile strength that is less than the first tensile strength when an electric power is generated by the starter-generator pulley, and the first damper, the second damper, and the driver causes the belt to have a third tensile strength that is less than the second tensile strength when the vehicle is accelerated by the engine.

A vehicle includes a chain tensioner that serves as an oil damper using oil supplied from an oil pump. The vehicle includes a controller that controls a traveling mode of the vehicle in a BEV mode or a non-BEV mode. When shifting the traveling mode from the BEV mode to the non-BEV mode, the controller executes a high-pressure process for controlling the oil pump such that a supply pressure of oil supplied to the chain tensioner becomes higher when a duration of the BEV mode is greater than or equal to a specified time than when the BEV mode duration is less than the specified time.

To provide a simple-structured chain tensioner that reduces the burden of work required for assembling and maintenance, sufficiently damps the motion of the plunger, and helps reduce machining costs and size increases of the plunger and tensioner body. The chain tensioner includes a tensioner body with a plunger bore, a plunger, and a biasing member that biases the plunger. The plunger has raised portions with which a locking member engages. The plunger bore is provided with a locking member holding part on one side that is open. The locking member holding part is provided with an inclined surface at one end in the plunger entry direction, the inclined surface becoming progressively shallower in the plunger entry direction. The locking member can deform elastically in a cross section when engaging with the raised portion of the plunger.

To provide a tensioner that has a simple structure and is easy to assemble, and is configured to smoothly relieve pressure during oil release with reduced flow resistance so that the oil pressure in an oil pressure chamber is kept stable in a favorable manner. A relief valve unit includes a cap member that fits with a seat member to retain a stopper member inside the seat member. An external relief hole, which causes a relief-side space in a plunger hole to communicate with the outside of a plunger, opens radially in an outer circumferential surface of the plunger.

A tensioner comprising a carrier pivotably mountable to a mounting surface, an arm having a first pulley journalled thereto and a second pulley journalled thereto, the arm slidingly engaged with the carrier for a linear movement with respect to a carrier axis A-A, and a spring disposed between the carrier and the arm, the spring resisting an arm movement along carrier axis A-A.

The present invention relates to an auto-tensioner containing a base having a cylindrical part, a rotating member supported rotatably to the base, a pulley provided at the rotating member, a friction member sandwiched between the cylindrical part and the rotating member, and a coil spring locked to the friction member and the base and disposed in a state of being compressed in an axial direction, thereby biasing the rotating member in one direction, in which the friction member has an arcuate surface capable of sliding along the cylindrical part, a first locking part located further toward the one direction side than the arcuate surface in a circumferential direction of the cylindrical part and locked to the rotating member, and a second locking part locked to one end of the coil spring.

A hydraulic tensioning device for a chain drive of an internal combustion engine, having a receptacle and having a tensioning piston which is guided in displaceable fashion in a cylindrical hollow space of the receptacle and which has a piston hollow space, wherein the piston hollow space together with the cylindrical hollow space of the receptacle forms a pressure chamber, and having a pressure relief valve unit arranged in the piston hollow space. The pressure relief valve unit is a preassembled structural unit and comprises a spring, a closing body and a valve seat and also a valve receptacle which surrounds the valve seat in a first subsection, wherein the valve receptacle forms an interference fit with the valve seat, and wherein the valve receptacle or the valve seat in a second subsection form an interference fit with the inner shell surface of the tensioning piston.

A tensioner comprising a base defining a hole, the hole having a center C, the hole having a diameter sufficient to receive a driven pulley, a rotary arm engaged with the base by a retaining member connected to the base, the rotary arm rotatable about the center C, a pivot arm mounted to the rotary arm on a pivot, the pivot offset from center C, a first pulley journalled to the rotary arm, a second pulley journalled to the pivot arm, a torsion spring engaged between the rotary arm and the pivot arm for biasing the second pulley toward the first pulley, a damping member frictionally engaged between the base and the rotary arm, and the rotary arm defining a portion for receiving a first pulley fastener whereby a first pulley position is adjustable.

A chain drive system for an engine includes a plurality of sprockets. A chain is drivingly engaged with the plurality of sprockets. A guide assembly engages the chain and includes a metal support plate adapted to be secured to the engine and a plastic plate is supported by the metal plate and includes a chain guide surface in direct contact with the chain. An elastomeric insert is disposed between the metal plate and the plastic plate for reducing the transmission of noise and vibration between the plastic plate and the metal plate.

A variable belt tensioner for an engine includes: a first damper; and a second damper connected to the first damper through a driver. The first damper, the second damper, and the driver causes a belt connected to a crankshaft pulley and a starter-generator pulley to have a first tensile strength when the engine including the crankshaft pulley starts, the first damper, the second damper, and the driver causes the belt to have a second tensile strength that is less than the first tensile strength when an electric power is generated by the starter-generator pulley, and the first damper, the second damper, and the driver causes the belt to have a third tensile strength that is less than the second tensile strength when the vehicle is accelerated by the engine.