Abstract:
A housing is rotatable synchronously with a crankshaft of an engine. A plurality of external teeth arrangements is respectively shaped into a ring form and is formed integrally with the housing in one piece and is configured to mesh with a plurality of chains, respectively, each of which is wound around the crankshaft or a sprocket that is rotatable. A cam plate is connected to a camshaft of the engine and is rotatable relative to the housing. A plurality of stoppers is formed integrally with the housing in one piece while the stoppers are configured to limit relative rotation between the housing and the cam plate within a predetermined range when the stoppers contact the cam plate. Each stopper is placed at a position, at which the stopper does not overlap with any of the external teeth arrangements in a view taken in an axial direction of the housing.
Abstract:
An endless band drive system having a variable center distance between the drive pulley and the driven pulley also has a rotatable control shaft and an endless band guide, where the guide is positioned by the rotatable control shaft for maintaining a slackless endless band with change of pulley center distance. Rotation of the control shaft pivots the endless band guide thereby maintaining a slackless endless band with change of the pulley center distance. Preferably, the rotatable control shaft also provides means for adjusting the center distance between the drive pulley and the driven pulley. The present invention provides a slackless endless band system for a variable compression ratio engine having a variable center distance between the drive pulley mounted on the crankshaft and the driven pulley mounted on the camshaft. The system provides slackless operation of the endless band at two or more compression ratio values.
Abstract:
An internal combustion engine includes a crankshaft rotatable about a crankshaft axis; a camshaft rotatable by the crankshaft about a camshaft axis; an engine cover defining an engine cover volume within the internal combustion engine; a drive member disposed within the engine cover volume which transfers rotational motion from the crankshaft to the camshaft; a camshaft phaser disposed within the engine cover volume which controllably varies the phase relationship between the crankshaft and the camshaft; an actuator which operates the camshaft phaser; and an actuator mount within the engine cover volume which mounts the actuator structurally independent of the engine cover, thereby allowing removal of the engine cover independently of the actuator.
Abstract:
A device for setting the relative rotational position of a camshaft (2, 3) of an internal combustion engine (11) relative to a crankshaft (1) driving the camshaft (2, 3), having a traction mechanism drive (4) wrapping around the crankshaft (1) and the camshaft (2, 3), which includes a loaded traction-mechanism section (8, 9) and a non-loaded traction-mechanism section (7), and a tensioning device (5, 6, 10) for changing the length of the loaded traction-mechanism section (8, 9). The tensioning device (5, 6, 10) is supported on the internal combustion engine (11) and has an adjustment device (20) that can be fixed.
Abstract:
A chain drive having a phaser such as a hydraulic vane phaser interposed between a timing chain and a driving or driven shaft is provided. The phaser or the vane are controlled to oscillate more at certain engine speeds to thereby reduce the tensioning force on the chain at the certain engine speeds.
Abstract:
A variable valve timing camshaft drive system is provided with an adjusting device arranged between the loose end and the load end of a chain which is operative between chain wheels of two parallel camshafts of an internal-combustion engine. For tightening the chain and influencing the relative rotating position of a camshaft--variable valve timing--the device comprises a first hydraulic piston and a second hydraulic piston. The first hydraulic piston can be alternately acted upon by pressure and, in the process, takes up two end positions. By means of a third hydraulic piston, the first hydraulic piston may also be fixed in an intermediate position.
Abstract:
A driveshaft in the form of a crankshaft (12) or a camshaft (212) drives a camshaft (16, 216) by means of a chain (20, 220) which is trained around a sprocket (14, 214) on the driveshaft and another sprocket (18, 218) on the driven camshaft. The driven camshaft is selectively advanced or retarded in its position by lengthening or shortening one portion (20a, 220a) of the chain and simultaneously lengthening or shortening another portion (20b, 220b) thereof by extending one hydraulic tensioning device (22, 122, 222, 322) and simultaneously retracting another hydraulic tensioning device (24, 124, 224, 324). A spool valve member (50) is controllably positioned within a valve body (48), in response to instructions from an engine control unit (58) which acts through a pulse width modulated solenoid (56) to increase or decrease a load acting on one end of the spool, to permit or prevent hydraulic fluid from flowing from one tensioner to another as a result of a pressure differential between the tensioners. The pressure differential exists as a result of torque reversals in the driven camshaft during its normal rotation, the torque reversals having the effect of changing the levels of tension within the portions of the chain that are engaged by the tensioners.
Abstract:
An internal-combustion engine has a camshaft drive in which the outlet camshaft driven by the crankshaft drives the inlet camshaft via a chain. For the tensioning of the chain, two hydraulic pistons are pressed in opposite directions with respect to one another against the loose end and the load end of the interior side of the chain. For adjustment of the relative camshaft rotating position, the unit consisting of the hydraulic piston and the chain is shifted transversely to the camshafts so that the loose end is shortened and the load end is lengthened, or vice versa.
Abstract:
A variable camshaft timing system for an internal combustion engine varies the relative angular position between the intake camshaft and the exhaust camshaft by controlling the path of the timing belt. First and second idler arms, each having an idler wheel connected thereto, are independently pivoted around a common pivot point by means of a pair of positioning cams operatively connected to an electric stepping motor. The motor is controlled from an electronic control unit which receives signals indicating the engine operating characteristics and through a look-up table steps the positioning cams which in turn pivots the idler arms to rotate the intake camshaft relative to the exhaust camshaft thereby changing the intake valve timing.
Abstract:
An internal combustion engine has n member of cylinders, a piston in each cylinder connected to a crankshaft (2), each piston being in phase or out of phase with the others by A.degree. or a multiple thereof (A=720/n), cams for actuating inlet and exhaust valves to each cylinder, and a cam drive mechanism (5) which rotates the cams in phased relationship with the crankshaft (2) to open the valves in sequence for a desired angle of rotation of the crankshaft. The cam drive mechanism also includes means for combining the rotational movement of the cams with a phased oscillatory movement of the camshaft (3) and cams of variable amplitude about the axis of rotation at a frequency f times the crankshaft frequency so that over the period which the valves are opened and/or their timings variable, f has the following values:f=2n when the number of cylinders n=1;f=n or n/2 when n=2;and f=n/2 when n=3 or more. The selection of the frequency of the oscillations allows all the cams to be mounted on the same camshaft.