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.

An engine includes a crankcase defining a crankcase space, a first shaft disposed at least partially within the crankcase and supported for rotation by the crankcase, and an oil pump coupled to the first shaft and operable to draw low pressure oil from the crankcase and discharge a flow of high pressure oil. A pressure relief path is positioned to selectively receive a portion of the flow of high pressure oil and a pressure relief assembly is coupled to the pressure relief path and is arranged to spray the portion of the high pressure flow that passes through the pressure relief passage against an interior surface of the crankcase.

A camshaft cover, a camshaft assembly, and a double-cylinder engine are provided. The camshaft cover has an integral structure, and includes a first shaft cover portion, a second shaft cover portion, a first connecting portion and a second connecting portion. The first connecting portion and the second connecting portion are connected between the first shaft cover portion and the second shaft cover portion, and spaced apart axially.

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 rocker shaft assembly configured to support a rocker arm and deliver oil to the rocker arm and related method of making is provided. The rocker shaft assembly includes a core shaft and a sleeve. The core shaft has a core body including a main oil supply channel formed thereon. The sleeve has passages formed thereon. The sleeve is disposed around the core shaft. The main oil supply channel aligns with at least one of the passages on the sleeve. The main oil supply is milled into the core shaft.

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.

A camshaft cover, a camshaft assembly, and a double-cylinder engine are provided. The camshaft cover has an integral structure, and includes a first shaft cover portion, a second shaft cover portion, a first connecting portion and a second connecting portion. The first connecting portion and the second connecting portion are connected between the first shaft cover portion and the second shaft cover portion, and spaced apart axially.

A valve timing adjustment device includes: a driving rotating body that rotates with a crankshaft; a driven rotating body that rotates with a camshaft; a reduction mechanism configured to change a relative rotation phase of the driving rotating body and the driven rotating body by a driving force of an actuator; and a filter unit capable of capturing a foreign matter contained in lubricating fluid supplied into the reduction mechanism. The reduction mechanism includes: an internal gear portion having internal teeth formed inward in a radial direction, and an external gear portion having external teeth formed outward in the radial direction to mesh with the internal teeth. The driven rotating body has a supply hole penetrating in an axial direction. The filter unit has holes penetrating in the axial direction, and the holes are arranged in a flow path of the lubricating fluid connected to the supply hole.

A lubricating oil supply structure includes: a shaft; a bearing supporting the shaft and having an oil supply port, through which lubricating oil is supplied to between the shaft and the bearing, and an oil introduction port, through which the lubricating oil is introduced; a first oil passage, connected to the oil supply port, distributing the lubricating oil from an oil pump toward the oil supply port; a second oil passage, connected to the oil introduction port, supplying the lubricating oil introduced through the oil introduction port to a supply destination; a connection oil passage, formed by a gap between the bearing and the shaft, connecting between the first oil passage and the second oil passage, and a throttle portion, formed on a part of the connection oil passage, suppressing a flow of the lubricating oil from the oil supply port toward the oil introduction port.

A valve drive for a cylinder head of an internal combustion engine has a camshaft which is rotatably mounted in a first and a second camshaft bearing and which includes at least one cam with a first cam curve and a second cam curve that differs from the first cam curve. A gas exchange valve can be actuated by the first or the second cam curve via a cam follower. A camshaft section is provided, by which the cam can be moved by an actuator such that the gas exchange valve can be actuated either via the first or the second cam curve via the cam follower. The camshaft and the cam have a fixed position relative to each other. The camshaft can be axially moved in the first and the second camshaft bearing. The camshaft bearings consist of a camshaft bearing block and a common bearing frame. A lubricant supply bore is provided which opens into a fourth lubricant groove in the bearing frame in order to supply the bearing points with lubricant. A first lubricant groove is provided in the first camshaft bearing block, and a second lubricant groove is provided in the second camshaft bearing block. These lubricant grooves correspond to the fourth lubricant groove and are open in the direction of the cam follower.