The invention relates to a method for producing a spray channel (4) on a shaft tube (1), via which with finished shaft tube (1) fluid (5) can be output from within the shaft tube (1) to the outside, having the steps introducing at least one through-opening (7) with a diameter D.sub.1≥1.5 mm into the shaft tube (1), arranging at least one additional element (8) in or on the through-opening (7) in such a manner that the spray channel (4) is at least partly formed by the additional element (8).

The invention also relates to a camshaft (2) having a shaft tube (1) produced with such a method.

A supply pump includes a housing that has a tappet receiving chamber, which receives a plunger drive mechanism, and oil for lubricating respective lubricating portions of the plunger drive mechanism is temporarily retained in the tappet receiving chamber. In the housing, a communication hole opens in an inner peripheral wall surface of a tappet guide and guides the oil from a tappet upper side chamber into a tappet lower side chamber at the time of upwardly moving a tappet.

Provided is a lubricant feed mechanism for an engine capable of achieving manufacturing cost reduction. A lubricant feed mechanism for an engine (1) is configured to feed lubricant through a cylinder head (10), a camshaft (an intake-side camshaft (40); an exhaust-side camshaft (42)), a cam cap (50), and an oil feed member (100) to a cam (a cam (40a); a cam (42a)) of a valve gear (30). The oil feed member (100) is formed by folding one panel member, and the inside surface of the oil feed member (100) in the folded state is recessed so as to form an oil passage (a first oil passage (114); a second oil passage (116); a third oil passage (118)) for guiding lubricant fed through the cam cap (50) to the cam.

A continuous variable valve duration apparatus includes a cam unit, a cam formed on the cam unit, a camshaft inserted into the cam, a guide bracket, a guide shaft mounted on the guide bracket and disposed perpendicular to the camshaft, wherein a guide screw thread is formed on the guide shaft, a wheel housing disposed within the guide bracket, an inner wheel rotatably inserted into the wheel housing and movable perpendicular to the camshaft, a worm wheel disposed within the wheel housing, wherein an inner screw thread configured to engage with the guide screw thread is formed inside the worm wheel and an outer screw thread is formed on the worm wheel, a control shaft, a control worm formed on the control shaft, and a wheel elastic portion mounted to the wheel housing.

A method for producing a spray channel on a shaft tube, whereby a completed shaft tube can output fluid from within the shaft tube to outside of the shaft tube, the method may include introducing at least one through-opening with a diameter D.sub.1≥1.5 mm into the shaft tube and arranging at least one additional element in or on the at least one through-opening such that the spray channel is at least partly formed by the at least one additional element.

A system comprises a follower lever and a follower roller rotatably coupled to the follower lever. A pin is rotatably coupled to the follower roller, the pin comprising a first outer portion including a first diameter and a second outer portion including a second diameter. A central portion is positioned between the first outer portion and the second outer portion, the central portion including a third diameter, the third diameter being smaller than the first diameter and the second diameter. One or more first channels is defined by the first outer portion, the one or more first channels positioned within the first outer portion and configured to direct fluid away from the central portion as the pin rotates.

An engine includes: a crankshaft disposed vertically; a piston that is connected to the crankshaft via a connecting rod and reciprocates in a cylinder; a cylinder head forming a combustion chamber of the cylinder at an end face of a movable portion of the piston; an intake valve and an exhaust valve disposed at the cylinder head, the intake valve being configured to take in fuel-air mixture, which is a mixture of fuel and air, the exhaust valve being configured to exhaust the fuel-air mixture; a low-rotation rocker arm (rocker arm) that drives the intake valve and the exhaust valve by rotation of a cam shaft; and a rocker shaft that supports the low-rotation rocker arm such that the low-rotation rocker arm is swingable, and an oil holding portion extending in an axial direction of the rocker shaft is provided between the rocker shaft and the low-rotation rocker arm.

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.

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.

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.