According to one aspect of the present invention, a sliding member includes: a sliding surface against which an outer surface of a cam abuts; and a groove having a spiral shape or a plurality of grooves having an annular shape, which are provided on the sliding surface.

The sliding surface includes a central region having a circular shape and including a center of the sliding surface, and a first annular region located outside the central region. A ratio R.sub.C of a width L2 of the groove to a pitch L1 of the groove in the central region is larger than a ratio R.sub.O1 of the width L2 of the groove to the pitch L1 of the groove in the first annular region.

Systems and methods for intermittent supply of lubricating oil to a tip of a rocker arm assembly. In one embodiment, a lubricating oil may be selectively to a tip of a rocker arm via oil channels aligned only during opening of a valve coupled to the tip.

An adapter for a roller tappet of an engine may include a body and a support. The body may be combined with a cylinder block of the engine. The body may include oil inlet connected to main gallery of the cylinder block to receive an oil from the main gallery. The support may be extended from one end of the body to support the roller tappet. The support may include a first oil passageway connected to the oil inlet. The first oil passageway is formed through the body and the support to supply the oil supplied from the oil inlet to the roller tappet. Thus, the oil may be supplied from the main gallery to the roller tappet through the oil passageway so that it may not be required to form an additional oil passageway, which may supply the oil to the roller tappet, in the cylinder block.

A fuel pump includes a camshaft that rotates in accordance with operation of an engine and a tappet provided in contact the camshaft. An ECU includes an angle determination unit configured to determine whether a rotation angle from a start of rotation of the camshaft when starting the engine is under a predetermined angle required for forming an oil film on a sliding portion of the tappet, and a control unit configured to, when the rotation angle from the start of rotation of the camshaft is determined to be under the predetermined angle, execute a limit process including at least one of limiting a fuel discharge pressure of the fuel pump or limiting a rotation of the camshaft.

Provided is a tappet capable of supplying lubricating oil to a cam even when provided with a lash adjuster. A tappet (10) includes: a lash adjuster (11) having a plunger (14) and a body (13) in which the plunger (14) is housed so as to be vertically movable, wherein the plunger (14) has a top portion (16) against which a lower end portion of a push rod (88) slidably abuts; and a tappet body (12) which has an assembly hole (45) in which the body (13) is inserted, has a cup-like shape, and has a lower surface portion (27) which slidingly contacts a cam (70). The tappet body (12) has an oil guide passage (30) extending so as to guide lubricating oil from the push rod (88) side to the cam (70).

A tubular structure comprises a first end and a second end, a cylindrical outer structure, and at least one inner cavity defined by the cylindrical outer structure and the first and second ends. The first and second ends each include a recess and a cap press fit within the recess. The caps provide a connection point for the ends of the tubular structure. Each end includes a vent in fluid communication with the inner cavity during manufacturing of the tubular structure, prior to insertion of the caps. An isotropic internal support structure extends longitudinally between the ends within the cylindrical outer structure and defines an oil flow channel extending through the tubular structure, each cap includes a cap orifice aligned with the oil flow channel, and the cylindrical outer structure, the first and second ends, and the internal support structure are continuously and unitarily formed.

A cylinder head assembly is for an internal combustion engine. The cylinder head assembly includes a cylinder head and first and second valves coupled to the cylinder head. The first and second valves are associated with a combustion chamber partially defined by the cylinder head. The cylinder head assembly also includes a fixed member coupled to the cylinder head and a valve bridge engageable with the first and second valves. The valve bridge is axially moveable along an axis relative to the fixed member to move the first and second valves together between an open position and a closed position. The cylinder head assembly further includes an anti-rotation feature between the valve bridge and the fixed member. The anti-rotation feature restricts rotational movement of the valve bridge about the axis.

In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop. A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.

In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop.

A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.

An engine device including, in a cylinder block thereof, a cylinder bore, a cam chamber accommodating a camshaft, a push-rod chamber accommodating a push-rod, and a tappet holder configured to hold a tappet in a slidable manner, the tappet being configured to transmit the drive force from the camshaft to the push-rod. The tappet holder partitions the cam chamber and the push-rod chamber. A bypass passage communicating the cam chamber with the push-rod chamber is formed between the tappet holder and the cylinder bore.