In an aspect, a tensioner is provided for an endless drive member, and includes a shaft-and-base unit, a tensioner arm, a pulley, and a tensioner spring. The shaft-and-base unit is mountable to be stationary relative to an engine, and includes a fastener aperture for a fastener. The tensioner arm is pivotable relative to the shaft-and-base unit about a tensioner arm axis. The pulley is rotatably mounted to the tensioner arm for rotation and is engageable with an endless drive member. The tensioner spring is positioned to urge the tensioner arm in a first direction relative to the shaft-and-base unit. The tensioner spring includes a plurality of coils that are arranged generally helically about a longitudinal axis and are spaced radially from one another and generally increase in distance away from the axis in a longitudinal direction.

In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

An internal combustion engine includes a cylinder head, a support structure, a cam pulley, and a seal member. The support structure is provided above the cylinder head and supports the camshaft. The cam pulley is provided at an end of the camshaft. A timing belt is wound around the cam pulley. A seal member is provided to cover a gap provided between the cylinder head and the support structure at a facing surface facing the cam pulley. The seal member provides sealing between the cylinder head and the support structure in an axial direction of the camshaft.

Methods and systems are provided for a cam drive system of an engine. In one example, a front end of an engine includes an idler gear assembly including an idler gear and idler pulley, the idler gear in meshing engagement with a first end of a crankshaft and the idler pulley coupled to and sharing a rotational axis with the idler gear. The front end of the engine may further include first and second camshaft pulleys positioned vertically above the idler gear assembly and a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley.

A valvetrain service tool for an automobile engine comprises a bracket adapted to be removably mounted onto a structural member of an engine, and a pin slidably supported within the bracket, wherein, the pin is slidable between a first position and a second position, further wherein, when the pin is moved from the first position to the second position, the pin engages a cam sprocket of the engine to support the cam sprocket and allow service to be performed to the valvetrain of the engine without removing the cam sprocket.

The present disclosure employs a pair of camshafts for intake valves. A first phase controller is installed at a first end of the first intake camshaft connecting to a crankshaft. A second phase controller is installed at a second end of the first intake camshaft connecting to a second intake camshaft. Each phase controller can advance or retard phase angles to modify intake valve timing and intake valve lift. This set up is duplicated for the exhaust valves to modulate exhaust valve timing and exhaust valve lift. First and second camshafts are connected via a series of levers, which merge rotational outputs of both camshafts into one. The phase controllers can be differential gear sets, epicyclical gear sets, or a combination thereof.

Provided is an opposed-piston engine which attains high output, ensures combustion toughness, and includes a simplified configuration of a crankshaft counter-rotation synchronization mechanism which rotates crankshafts in engine units in opposite directions. An opposed-piston engine 10 of the present invention includes a first engine unit 11 and a second engine unit 21. The first engine unit 11 and the second engine unit 21 respectively include a first cylinder 12 and a second cylinder 22 independent of each other. In addition, a first valve driving mechanism 19 and a second valve driving mechanism 20 which control valves also function as a crankshaft counter-rotation synchronization mechanism 29 which rotates a first crankshaft 14 of the first engine unit 11 and a second crankshaft 24 of the second engine unit 21 in the opposite directions.

There is provided a pulley system for a crankshaft, the pulley system including: a crankshaft rotatably supported by a cylinder block; a crank pulley connected to one end of the crankshaft, and having an accessory belt wrapped the crank pulley; a crank timing pulley connected to one end of the crankshaft, and having a timing belt wrapped around the crank timing pulley; a timing belt cover mounted on a front wall of the cylinder block, and having an opening through which a portion of the crank pulley passes; and a stopper structure restricting the accessory belt from moving into an inner space of the timing belt cover. In particular, the timing belt and the crank timing pulley are placed in the inner space of the timing belt cover, and the crank pulley is placed in an outer space of the timing belt cover.

The present disclosure relates to a 2-cycle engine with a valve system that generates power during every one crankshaft rotation. The 2-cycle engine of the present disclosure includes the valve system opening and closing an air intake valve and an exhaust valve and includes a turbocharger. In the turbocharger, the air intake valve and the exhaust valve are respectively opened and closed once during one crankshaft rotation, and the valve system is configured to control the turbocharger using difference between an air intake pressure and an exhaust pressure. Accordingly, a current air intake reaches a target air intake.

A device for adjusting camshaft phase is proviced that includes a stator, a rotor and two guard caps that limit the rotor are fixedly provided at axial ends of the stator. The device further includes a belt pulley that is sleeved on the periphery of the stator and the guard caps and fixedly connected to the stator or the guard caps. An annular seal is disposed on the device and includes a first sealing portion and a second sealing portion located at axial ends. The seal body is fixedly provided between the stator, the guard caps and the belt pulley, and the annular seal encloses a sealed cavity. The stator, the rotor and the guard caps are fixedly provided in the sealed cavity.