Abstract: The invention relates to a hydraulic camshaft adjuster (1) having a stator (2), a rotor (3) rotatable relative to the stator (2) within a limited angular range, and a hydraulic supply (4) having two working channels (5, 6) and a shifting valve (7), wherein the two working channels (5, 6) for adjusting the rotor (3) relative to the stator (2) in two opposite directions of action can be connected to a pump (10) for pressurisation or to a reservoir (11) for pressure relief, depending on the shifting position (8, 9) of the shifting valve (7), wherein the hydraulic supply (4) has a return pump (12) that can be actuated by displacing the shifting valve (7) between its shifting positions (8, 9) and by the actuation of which one of the two work-ing channels (6) can be pressurised for returning the rotor (3) into a predetermined position.

Abstract: Filtering pullies with a hub adapted to be fixed to a rotating shaft, a crown mounted coaxially and rotationally free on the hub, at least one elastic group arranged circumferentially with respect to the hub and the crown and interposed, each, between a pair of first elements integral with the hub and between a pair of second elements integral with the crown are disclosed. The at least one elastic group is placed with a circumferential interference (?) with respect to the first elements integral with said hub.

Abstract: Provided is a tensioner which has a small total number of components and no risk of incorrect assembly, allows easy load change, is easy to assemble, and excellently stabilizes an oil pressure in a pressure oil chamber. The tensioner 100 includes a relief mechanism that relieves oil to the outside of a plunger 110 when the oil pressure in the pressure oil chamber formed between the plunger 110 and a plunger containing hole 121 in a housing 120 increases, relief holes 141 extending through the plunger 120 from the inside of a plunger inner space 111 to an outer circumferential side thereof, and a hole closing member 142 that is pressed into an opening of each of the relief holes 141 on the outer circumferential side.

Abstract: An information handling system mouse has input buttons at an upper surface with selectable response to an end user press. An arrangement of magnets cooperate to establish a distance for the input button to move to complete an input at a switch to provide the end user with a selected of a spring or cantilever type of input response. For example, electropermanent magnets are configured to attract or repel a permanent magnet so that the amount of input button press motion adjusts along with the resistance against an input button press.

Abstract: The present disclosure provides systems and methods to compensate for backlash within a cam phasing system. For example, compensating for backlash by commanding a predetermined amount of additional actuator movement to account for backlash within a cam phaser. According to some aspects, a spring is provided within a cam phaser to unidirectionally take up the backlash within the cam phasing system.

Abstract: A variable valve timing assembly for a combustion engine comprises: a phaser configured to receive therein a camshaft; wherein the phaser includes a phaser exterior body that is cylindrical-shaped, a phaser interior body that is cylindrical-shaped and within the phaser exterior body, a phaser exterior spline on an exterior of the phaser exterior body, and a phaser interior spline on an exterior of the phaser interior body; a phaser inner housing disposed within the phaser and configured to receive therein the camshaft; wherein the phaser inner housing includes an inner housing interior spline that mates with the phaser interior spline; an advancing chamber configured to receive fluid from and discharge fluid to the camshaft; a retarding chamber configured to receive fluid from and discharge fluid to the camshaft; and a main housing that encloses therein the phaser and the phaser inner housing, and is configured to engage a timing chain/belt.

Abstract: To provide a control device capable of calculating a cam phase equal to an actual cam angle even when a corresponding cam angle signal detection range is exceeded by changing a cam phase by a variable valve mechanism. In addition to the conventional cam angle measuring function, a cam angle measuring means for advancing or retarding beyond a cam angle measurement reference position, and a means for determining that the cam angle signal advances or retards beyond the cam angle measurement reference position are provided. By switching the cam angle measuring function according to a determination result as to whether the cam angle signal exceeds the cam angle measurement reference position, it is possible to improve the time resolution of the angle measurement while maintaining the cam phase change amount at the same wide angle as the conventional one.

Abstract: A piston engine described allows identical cylinder heads rather than requiring mirror image left and right heads. The engine has front and rear sides, with engine block containing two opposing cylinder banks. Identical heads mounted on block, with overhead camshaft structures in each head. Crankshaft between banks has front and rear gears. At rear is reverse-rotation gear mechanism with internal and external gears. External gear engages crankshaft's rear gear. First chain connects reverse-rotation internal gear to first camshaft sprocket on one head at rear. Second chain connects crankshaft's front gear to second camshaft sprocket on other head at front. Allows driving overhead camshafts of identical heads rather than requiring left and right mirror image heads.

Abstract: A combustion engine for a vehicle includes a first centrifugal device for varying timing of a first plurality of suction or relief valves with respect to the drive shaft. A driving disc is mounted idle on a first camshaft which controls the valves, and at least one driven disc is integral with the camshaft. Drive elements for transmitting motion from the driving disc to the driven disc are interposed between the two discs causing a relative rotation of the driven disc with respect to the driving disc when the rotation speed of the discs exceeds a predetermined threshold. A distribution system connects the drive shaft with the driving disc so as to cause the rotation thereof. A second gear meshes with a first gear so that rotation of the driving disc mounted on the first camshaft causes the rotation of the second camshaft to control other valves of the engine.

Abstract: A torque-limiting torsion gimbal for connecting an electric motor to a camshaft phaser includes an elongated body configured to extend from an end of a motor shaft of the electric motor to an input of a planetary gear assembly of the camshaft phaser; an angular-displacement-resistant end of the elongated body configured to engage an end of the motor shaft; and a key, positioned at another end of the elongated body opposite to the angular-displacement-resistant end, and configured to be received within and engage a slot at the input of the planetary gear assembly of the camshaft phaser to transmit torque from the electric motor to the planetary gear assembly; the elongated body prevents an angular displacement of the motor shaft relative to the input of the planetary gear assembly and permits the angular displacement of the motor shaft relative to the input of the planetary gear assembly when a mechanical stop of the camshaft phaser is engaged.

Abstract: To provide a simple-structured chain guide assembly frame capable of reliably maintaining a correct positional relationship between a driven sprocket and a sprocket holding portion without the possibility of driven sprocket detachment. The chain guide assembly frame includes a main body having a fixed-guide-side sprocket holding portion and a pivoting-guide-side sprocket holding portion. The fixed-guide-side sprocket holding portion includes a first fixed-guide-side support portion that supports a driven sprocket at a first contact point, and a second fixed-guide-side support portion that supports the driven sprocket at a second contact point located more outside than the first contact point. When the driven sprocket is in an erected state in which the driven sprocket is supported at the first contact point and second contact point, the vector of gravity acting on the gravity center of the driven sprocket points between the first contact point and second contact point.

Abstract: A cylinder crankcase for an internal combustion engine includes at least one riser duct. The cylinder crankcase comprises at least one additional riser duct, which is configured to exchange oil between the main oil gallery and the cylinder head. The cylinder crankcase also comprises a connecting duct, via which the at least one riser duct and the at least one additional riser duct are connected in an oil-conducting fashion.

Abstract: A camshaft phaser arrangement configured for adjusting a phase between a first camshaft element and a second camshaft element is disclosed. The arrangement includes a rotor configured to be drivably connected to the first camshaft element. The rotor is configured to be selectively rotationally driven via hydraulic fluid such that rotation of the rotor phases the first camshaft element. A phasing adjuster is configured to pivot based on rotation of the rotor. The phasing adjuster includes a first engagement element configured to engage with a second engagement element on the second camshaft element, such that rotation of the rotor is configured to phase the second camshaft via the phasing adjuster.

Abstract: A lubrication system for internal combustion engines, in particular for vehicles with a rideable saddle, said system comprising a crank chamber in which at least one connecting rod is accommodated, and a basin or pan for collecting a lubricating liquid, wherein said crank chamber and said collection basin or pan are put in mutual communication by means of a first opening obtained in said crank chamber, wherein the flow of said lubricating liquid through said first opening from said crank chamber into said basin is adjusted by means of a first adjusting element adapted to be switched to an open position so as to allow the discharge of said lubricating liquid from said crank chamber into said collection basin or pan at a predetermined switching gas pressure value inside said crank chamber.

Abstract: A control system for an engine including intake and exhaust valve phase variable devices and a control device is provided. At an engine temperature below a first determination temperature, the control is performed so that an exhaust valve close timing is at or retarded from the exhaust top dead center, an intake valve open timing is retarded from the exhaust valve close timing, and the fuel supply to the combustion chamber starts in an intake stroke on a retarding side of the exhaust valve close timing. At the engine temperature above the first determination temperature and below a second determination temperature, the control is performed so that a negative overlap with both the exhaust and intake valves closed during a period including the exhaust top dead center, or a positive overlap with both the exhaust and intake valves opened during a period including the exhaust top dead center, occurs.

Abstract: A chain cover includes a first member, which is made of a hard plastic, and a second member, which is made of a material different from the hard plastic. The first member is formed by insert molding with the second member as an insert. A first joint surface is formed in a peripheral portion around an insertion hole. The first joint surface is joined to the first member. The first joint surface includes a first joint portion, which includes a lattice-shaped recess portion, and a second joint portion, which includes grooves. The grooves extend in a direction in which the peripheral portion extends, while being arranged in an intersecting direction, which intersects with the extending direction. The second joint portion is provided to be closer to a space adjacent to the peripheral portion than the first joint portion.

Abstract: A chain cover includes a first member, which is made of a hard plastic, and a second member, which is made of a material different from the hard plastic. The first member includes a back face, which faces an engine main body. The second member is joined to the first member. Only the back face of the first member includes a groove, which receives a seal member. The seal member provides a seal between the first member and the engine main body.

Abstract: An electromagnetic valve actuator and method of control thereof. The electromagnetic valve actuator is for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising: a rotor; a stator for rotating the rotor; output means for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor and phase varying means for varying a phase between the mechanical energy storage means and the output means.

Abstract: An internal combustion engine system includes an internal combustion engine including a cylinder, an intake valve and an exhaust valve, a cylinder injection valve, and a variable valve drive mechanism, and a control device that controls the cylinder injection valve and the variable valve drive mechanism. The control device includes a calculation unit that calculates a first crank angle section where a temperature of the cylinder is equal to or higher than a boiling point of the fuel in a compression stroke before completion of warming-up of the internal combustion engine and a second crank angle section where the temperature of the cylinder is equal to or higher than the boiling point of the fuel in the valve closed period, and an injection controller that executes fuel injection in the first and second crank angle sections by the cylinder injection valve.

Abstract: A strain wave gear, in particular for an electromechanical camshaft adjuster, comprises a housing element, an internally toothed drive element connected thereto in a rotationally fixed manner, an elastic, externally toothed gear element, and an internally toothed output element. The drive element has positive locking elements with which it is connected to the housing element.

Abstract: An engine includes at least one cylinder, a first intake valve and a second intake valve associated with the cylinder, to control a flow of intake air from a first intake duct and a second intake duct, respectively. The two intake ducts communicate with a common intake manifold, so as to receive air at the same pressure. During the intake stage, in each cylinder operating cycle, initially an opening and closing movement of only the first intake valve is activated, while the second intake valve remains closed and, subsequently, an opening and closing movement of only said second intake valve is activated, while the first intake valve remains closed. In this way, the two air flows at the same pressure entering the cylinder give rise to a high turbulent kinetic energy, to the advantage of combustion efficiency and reduction of harmful exhaust emissions.

Abstract: In an internal combustion engine that includes a cylinder block and a cylinder head, and has a cam chain chamber on a side of the cylinder block, a beam member that traverses the cam chain chamber is disposed in the cam chain chamber.

Abstract: A variable valve timing assembly includes an electric motor; a first set of gears driven by the electric motor; a first set of grooves and ball bearings driven by the first set of gears; a second set of grooves and ball bearings driven by the first of grooves and ball bearings; wherein the first set of grooves and ball bearings converts rotational movement of the first set of gears to axial rotational movement of the first set of ball bearings; wherein the axial movement of the first set of ball bearings causes rotational movement of the second set of grooves; whereby the rotational movement of the second set of grooves enables rotation of a camshaft engaged to a valve.

Abstract: In an internal combustion engine that includes a cylinder block and a cylinder head, and has a cam chain chamber on a side of the cylinder block, a beam member that traverses the cam chain chamber is disposed in the cam chain chamber.

Abstract: A harmonic ring gear system can include at least one inner gear with external toothing, the at least one inner gear defining an axis of rotation; at least one outer gear with internal toothing arranged concentrically to the at least one inner gear about the axis of rotation, the internal toothing spaced apart from the external toothing; a pin ring positioned between the at least one inner gear and the at least one outer gear, the pin ring comprising a multiplicity of pins; and a rotary transmitter configured to lift a portion of the pins of the multiplicity of pins off the external toothing and press the portion of the pins into the internal toothing.

Abstract: A phasing mechanism for an internal combustion is provided. The phasing mechanism includes a stator, a rotor configured to rotate relative to the stator, a first plurality of rolling elements configured to engage and move the rotor in a first rotational direction, a second plurality of rolling elements configured to engage and move the rotor in a second rotational direction, and a piston configured to be hydraulically actuated in: i) a first axial direction to move the rotor in the first rotational direction, and ii) a second axial direction to move the rotor in the second rotational direction.

Abstract: The present disclosure provides a shift by wire (SBW) driving actuator capable of improving control performance and durability through control of a brushless direct current (BLDC) motor by an inductive sensor, and improving gear transmission efficiency by introducing a multistage teeth-shaped transmission unit configured to connect a sun gear and an output shaft of a reducer to transmit a rotational force to reduce a load resulting from eccentric rotation of the sun gear.

Abstract: Provided is a timing chain cover that allows suppressing vibration transmission. A timing chain cover of the present disclosure houses a timing chain transmitting a rotative force of a crankshaft to a camshaft in one end side of an internal combustion engine. The timing chain cover includes a chain cover main body and a damping resin layer formed on an abutment surface of the chain cover main body. The abutment surface abuts on an internal combustion engine main body. The damping resin layer contains a heat resistant resin and a damping filler. The damping filler converts a vibration energy into a heat energy.

Abstract: This disclosure relates to a control valve for a hydraulic camshaft phaser. The control valve includes a screw body having a cavity, a plurality of connections opening into the cavity, and a sleeve-shaped hydraulic guide element firmly inserted radially inside the cavity. At least part of the hydraulic guide element consists of plastic. The hydraulic guide element includes a plurality of pressure medium channels which open into its radial interior, each of which is connected to at least one of the connections. A control piston is displaceably accommodated in the hydraulic guide element, and, depending on the position of the control piston, connects the connections to each other. A sealing contour provided on a radial outer side of the hydraulic guide element contacts the screw body, sealing the pressure medium channels with respect to each other and/or with respect to axial ends of the hydraulic guide element.

Abstract: An electrically-actuated variable camshaft timing (VCT) phaser is employed for use with an internal combustion engine (ICE). The electrically-actuated VCT phaser includes a gear set assembly and a fixture. The gear set assembly has an input gear and an output gear, among other possible components. The input gear receives rotational drive input from an engine crankshaft, and the output gear transmits rotational drive output to an engine camshaft. The fixture is secured in the gear set assembly. Amid installation of the electrically-actuated VCT phaser on the ICE, the fixture constrains rotational movement of the gear set assembly. After installation, the fixture can be removed from the gear set assembly.

Abstract: An engine (E) includes a crankcase body (19), a crankcase cover (20) covering a case opening portion (19b) of the crankcase body (19), a crankshaft (2), a cylinder base portion 21a located inside the crankcase body (19), a cylinder block (21b) located outside the crankcase body (19). The crankcase cover (20) is detachably attached to an upper portion of the crankcase body (19).

Abstract: A marine engine has an intake camshaft, an exhaust camshaft, and a crankshaft. Combustion in the marine engine causes rotation of the crankshaft which in turn causes rotation of the intake camshaft and exhaust camshaft. Rotation of the intake camshaft operates intake valves for controlling inflow of air to the marine engine. Rotation of the exhaust camshaft operates exhaust valves for controlling outflow of exhaust gas from the marine engine. A cam phaser is located at least partially inside at least one of the intake camshaft and the exhaust camshaft and is configured to vary a timing of operation of at least one of the intake valves and exhaust valves.

Abstract: An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

Abstract: An engine includes a crankshaft and a timing gear to be attached to the crankshaft so as to rotate integrally with the crankshaft. A fitting projection is provided on either one of the crankshaft and the timing gear, and a fitting recess to be fitted with the fitting projection, and erroneous-assembling prevention ribs to sandwich the fitting recess in a circumferential direction are provided on the other one of the crankshaft and the timing gear.

Abstract: An engine valve actuation system includes a rotatable camshaft having a cam lobe, and a lifter arm assembly having a lifter arm with a roller in contact with the cam lobe. A bushing is positioned in a pin bore of the lifter arm and journals the lifter arm upon the pin for reciprocation in response to rotation of the camshaft. An incoming oil passage extends to the pin bore, and an outgoing oil passage extends from the pin bore. The outgoing oil passage forms an oil spray port defining an oil spray path oriented to direct a spray of oil at the roller and/or the cam lobe. An oil feed groove is formed in at least one of the lifter arm or the bushing and fluidly connects the incoming oil passage to the outgoing oil passage.

Abstract: A cam shaft drive device includes a chain, a guide lever, a chain chamber, which is provided in a cylinder head, a support bolt, which pivotably supports the guide lever, the support bolt including a head portion, a male screw portion, and a shaft portion, which is inserted through the support hole of the guide lever, an insertion hole, which is through which the support bolt is inserted, and a female screw hole, which is provided in the rear wall and into which the male screw portion is screwed, wherein a length from a rear end to a front end of the shaft portion is longer than an axial distance from a front end of the support hole to a front end of the insertion hole in a state where the guide lever abuts on the rear wall.

Abstract: An auxiliary machine-driving device has a first idler roller disposed between an engine roller and a first rotating roller; a second idler roller disposed between the first rotating roller and a second rotating roller; a third idler roller disposed between the second rotating roller and the engine roller; and a linking mechanism driven by one actuator to switch the first idler roller between a state in which the first idler roller contacts the engine roller and the first rotating roller, and a state in which the first idler roller separates from the engine roller and the first rotating roller, and to switch at least one of the second and third idler rollers between a state in which the at least one roller contacts two rollers adjacent the at least one roller, and a state in which the at least one roller separates from the two rollers.

Abstract: A synchronous drive is provided in which a non-circular rotor generates a fluctuating corrective torque to counteract a fluctuating load torque on a driven rotor. The angular orientation of the non-circular rotor can vary relative to the driven rotor so as to change the phase angle of the fluctuating corrective torque relative to the driving rotor. The arrangement may be applied in internal combustion engines with variable valve timing (VVT) systems, wherein the phase angle of a fluctuating load torque presented on a cam rotor, due to forces arising from actuation of intake and/or exhaust valves by the camshaft, varies relative to the crankshaft. The phase angle of the fluctuating corrective torque is also varied relative to the crankshaft to maintain phase relationship with the fluctuating load torque and thereby maintain reduced cam torsional vibrations and span tensions provided by the non-circular rotor during operation.

Abstract: An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode can include a rocker shaft and a rocker arm. The rocker shaft can define a pressurized oil supply conduit. The rocker arm can receive the rocker shaft and is configured to rotate around the rocker shaft. The rocker arm can have an oil supply passage defined therein. A valve bridge can engage a first exhaust valve and a second exhaust valve. A hydraulic lash adjuster assembly can include first and second plunger bodies, the first plunger body can engage the valve bridge. A pressure relief valve assembly can be configured to selectively release oil from the hydraulic lash adjuster assembly.

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: A variable cam timing system in an engine is provided. The variable cam timing system includes a camshaft receiving rotational input from a crankshaft. The camshaft includes a valve cam rotationally actuating a valve coupled to a cylinder and a null cam actuating a null follower including a null spring exerting a return force on the null cam during interaction between the null cam and the null follower, where the null follower is independent from the cylinder.

Abstract: A centrifugal pendulum device has a pendulum mass carrier and at least two pendulum masses that are pivotably received on it along a pendulum raceway and are adjacent circumferentially, wherein the pendulum masses are operatively coupled with one another by elastic coupling means and the elastic coupling means includes a guide element.

Abstract: The present invention relates to an adjustable camshaft for the valve gear of an internal combustion engine having an outer shaft, on which at least one first cam is arranged which is connected fixedly to said outer shaft so as to rotate with it, and having an inner shaft which extends through the outer shaft and to which at least one second cam is connected fixedly so as to rotate with it and is mounted rotatably on the outer shaft, and it being possible for oil to be conducted from a gap between the outer shaft and the inner shaft through an oil duct in the outer shaft into the region between the second cam and the outer shaft. According to the invention, the second cam is sealed at least partially against the outer shaft by means of at least one sealing element.

Abstract: A chain guide includes a plurality of roller shafts provided on one side of a timing chain for torque transmission and spaced from each other in the longitudinal direction of a guide base facing the timing chain. The respective roller shafts rotatably support chain guiding rollers in the form of needle roller bearings. The rollers are cylindrical members having the same diameter over the entire axial direction such that the rollers are movable in the axial direction relative to the timing chain. The rollers are supported so as to be movable in the axial direction. When the rollers and the timing chain move relative to each other in the axial direction and the rollers move relative to the roller shafts in the axial direction, contact portions between the rollers and the roller shafts are displaced in the axial direction, so that radial loads are not locally applied.

Abstract: A gear is described for a spur gear stage without play having a hub (1) and a sprocket (2), which is divided along its axis-normal division plane into two partial sprockets, namely into a hub-fixed sprocket part (3) and a sprocket ring (4) which is mounted so it is coaxially rotatable in relation thereto, and which forms springs (6) sectionally enclosing the hub (1) in the circumferential direction, which are integrally connected at their bases (11) to the sprocket ring (4) and which are supported with their free ends (7) protruding toward the hub (1) on stops (8) of the hub (1).

Abstract: A reciprocating piston mechanism comprises a crankcase and a crankshaft (rotatable about a crankshaft axis) which has at least a crankpin having a crankpin. A connecting rod includes a big end rotatably mounted on the crankpin and a small end rotatably connected to a piston. The crank member is provided with a crank member gear that meshes with an intermediate gear, both gears of which are external gears along with first and second auxiliary gears. The intermediate gear meshes with the first auxiliary gear. The first auxiliary gear is fixed to the second auxiliary gear via a common auxiliary shaft that mounts to the crankshaft and rotates with respect thereto about an auxiliary shaft axis that extends parallel to the crankshaft axis. The second auxiliary gear meshes with a central gear. The central gear is an internal gear, which has a center line that coincides with the crankshaft axis.

Abstract: A plurality of cylinders are disposed in parallel in a vehicle width direction, a clutch chamber is disposed in either one of the right and the left in the vehicle width direction, an intake manifold, a fuel injection device, a throttle body, and an intake pipe are disposed between a cylinder assembly and an air cleaner in an upper part of a crankcase assembly. The throttle body is disposed on an opposite side in the vehicle width direction of the clutch chamber.

Abstract: A valve timing controller includes a rotation transmit component; a housing including an outer shape part fixed to the rotation transmit component and a plurality of partition parts extending from the outer shape part inward in a radial direction; and a vane rotor including a boss part and a plurality of vane parts radially extending from the boss part. The vane rotor is rotated relative to the housing on an advance side or a retard side according to a pressure of operation oil in an advance chamber and a retard chamber. The outer shape part of the housing has a dome shape.

Abstract: The present invention provides a timing chain drive device which has high mechanical strength of the timing chain contact surface and small sliding resistance, and which, even when being brought into contact with a timing chain running at high speed, is difficult to wear. A first chain guide and a second chain guide, which give tension to a timing chain so as to prevent the timing chain from being slackened, are arranged, and a plurality of rollers, each of which is supported by a rolling element, are arrayed in each of the first chain guide and the second chain guide so as to be brought into contact with the timing chain.

Abstract: Camshaft unit (1) having a first camshaft (2), which is phase-adjustable with respect to a crankshaft, a second camshaft (3), which is disposed concentric to the first camshaft (2) and is always in phase with the crankshaft, a camshaft adjuster (5) with which the first camshaft (2) is phase-adjustable with respect to the crankshaft, a connecting member (4), which is displaceable in the axial direction of the camshafts (2, 3) and has first toothed section (16) that meshes with counter-toothed section (6) on the first camshaft (2), and an adjusting drive (9) by which a connecting member (4) can be displaced axially, wherein through an axial advance, a relative rotation of the first camshaft (2) with respect to the connecting member (4) takes place.