The present disclosure provides a sprocket structure of an engine including a crank sprocket provided in a cylinder block of an engine and driven by a crank shaft, a high pressure pump sprocket configured to receive rotational force from the crank sprocket through a timing belt, and a cam sprocket having an interior installed on a camshaft and an exterior rotatably coupled to the timing belt so as to be driven. Since a tensioner is fixed in a state in which tension is applied to the timing belt through jigs of the crank sprocket and the high pressure pump sprocket and the cam sprocket having a dual-structure, loss of tension is reduced, thus minimizing occurrence of an error of the timing belt to enhance quality of a product.

A valve open-close timing control device includes a driving rotator, a driven rotator, a phase adjusting mechanism, a sensor unit, a storage configured to store the plurality of divided regions consecutively provided, as a plurality of divided length information pieces corresponding to divided lengths of the divided regions, and an actual phase acquisition unit configured to start acquisition of the crank angle signal and the cam angle signal along with start of actuation control of actuating the internal combustion engine, specify one of the divided regions by referring to the divided length information pieces stored in the storage in accordance with the crank angle signal at timing set in accordance with the cam angle signal, and acquire the relative rotation phase as an actual phase in accordance with the crank angle signal corresponding to the boundary of the divided region thus specified and the reference crank angle signal.

A rotor for a hydraulic camshaft adjuster. The rotor includes a first rotor element and a second rotor element. At least one of the rotor elements has oil channels separated from each other by radially arranged elevations. Each elevation of the first rotor element has a first joining profile and the second rotor element forms a complementary-shaped second joining profile corresponding to the position of each first joining profile, wherein the first and the second joining profile engage with each other in the assembled rotor. The first joining profile of the first rotor element has a notch and an elevation and the second joining profile of the second rotor element has a notch and an elevation formed in such a way that prior to the joining of the two rotor elements, a height of the elevation of the second joining profile, which engages in a notch of the first joining profile, is less than a height of the notch of the first joining profile, and a height of the elevation of the first joining profile, which engages in a notch-of the second joining profile, is less than a height of the notch of the second joining profile.

The overhead camshaft engine (10) includes a cylinder block (11), a crankcase (12) attached to a lower part of the cylinder block to define a crankcase chamber (32), a bearing retaining member (60) attached to a part of the cylinder block, a crankshaft (20) rotatably supported by a pair of bearings (21, 22) supported by the cylinder block and the bearing retaining member, respectively, and a crankshaft pulley (53) attached to a part of the end of the crankshaft projecting outward from the bearing supported by the bearing retaining member.

In an overhead cam engine (10) having a first bearing (21) supported by the cylinder block (11), and a second bearing (22) supported by a bearing retaining member (60) attached to the cylinder block inside a crankcase chamber (12) for rotatably supporting a crankshaft (20), the crankshaft is provided with a reduced diameter portion (24b) having a smaller outer diameter than an adjoining part of the crankshaft on a side of the second bearing facing away from a cylinder (15) defined in the cylinder block, and a crankshaft pulley (53) is mounted on the reduced diameter portion.

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.

An Oldham coupling includes: a driven Oldham flange that is formed at a drive-side rotor; a drive Oldham flange that is formed at a planetary rotor; and an Oldham intermediate that is configured to synchronize rotation of the driven Oldham flange and rotation of the drive Oldham flange. A thrust section is formed at a rotor plate portion which is a portion other than the Oldham coupling. The thrust section is configured to limit tilting of the planetary rotor relative to the driven Oldham flange when the thrust section contacts the planetary rotor in an axial direction. There is satisfied a relationship of θ2>θ1 where: θ1 is a maximum tilt amount of the planetary rotor relative to the driven Oldham flange; and θ2 is a maximum tilt amount of the planetary rotor in a clearance formed at the Oldham coupling.

A synchronous belt drive system comprising a first obround sprocket having a toothed surface and at least one linear portion disposed between two arcuate portions, the arcuate portions having a constant radius, the linear portion having a predetermined length, a sprocket having a toothed surface, the sprocket engaged to the first obround sprocket by an endless toothed member, and the first obround sprocket having a magnitude and a phase such that an angular displacement timing error between the sprocket and the first obround sprocket is less than 1.5 degree peak to peak.

To provide a tensioner capable of preventing slipping between a rack portion and ratchet pawls and securing a large backlash with a simple structure. The tensioner includes a ratchet rotatably mounted on a housing and having a front pawl and a rear pawl spaced apart in a front and rear direction on a side face positioned opposite the rack portion. The ratchet includes an additional pawl formed between the front pawl and the rear pawl in the front and rear direction on the side face positioned opposite the rack portion.

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.