A switching hydraulic fluid gallery de-aeration arrangement for a switchable valve arrangement is disclosed. A housing for a hydraulic lash adjuster assembly is positioned in a bore of a cylinder head. The housing includes a first, hydraulic lash adjuster fluid port in a first annular groove, and a second switching hydraulic fluid port in a second annular groove. A top land and a bottom land are positioned next to the annular grooves and each have a primary outer diameter. A middle land is defined axially between the grooves. The middle land has a reduced outer diameter relative to the primary outer diameter, or the bore has an annular groove between the top and bottom lands that defines a restricted flow path between a hydraulic lash adjuster fluid gallery and a switching hydraulic fluid gallery that maintains hydraulic fluid in the switching hydraulic fluid gallery.

A method for operating a camshaft adjuster, which includes an adjusting transmission with an input shaft, an output shaft connected in a non-rotatable manner with a camshaft, and an adjusting shaft, whereby the adjusting shaft is driven by an actuator, characterized by the fact that the actuator drives the adjusting shaft by overcoming a torque that is dependent on its angular position.

A switching hydraulic fluid gallery de-aeration arrangement for a switchable valve arrangement is disclosed. A housing for a hydraulic lash adjuster assembly is positioned in a bore of a cylinder head. The housing includes a first, hydraulic lash adjuster fluid port in a first annular groove, and a second switching hydraulic fluid port in a second annular groove. A top land and a bottom land are positioned next to the annular grooves and each have a primary outer diameter. A middle land is defined axially between the grooves. The middle land has a reduced outer diameter relative to the primary outer diameter, or the bore has an annular groove between the top and bottom lands that defines a restricted flow path between a hydraulic lash adjuster fluid gallery and a switching hydraulic fluid gallery that maintains hydraulic fluid in the switching hydraulic fluid gallery.

A method for manufacturing a poppet valve 10 from an intermediate valve products is disclosed. The intermediate valve products have an intermediate valve head 14 with a pressing protrusions 15. A peak 15a of the pressing protrusions 15 is located in a normal direction X2 of the seat surface N, which is positioned on a normal line X2 passing a reference point P3 set on a line segment K connecting a base point P1 in an inner side and a base point P2 in an outer side of the seat surface N; a position of the reference point P3 is set such that a relation between a length L1 from the base point P1 to the reference point P3 and a length L2 from the base point P2 to the reference point P3 meets a formula of L1/L20.5.

The present disclosure provides a valve timing adjustment apparatus for an internal combustion engine. The apparatus includes an anti-rotation mechanism for inhibiting a position change between a rotor and a housing by inhibiting or preventing relative rotation of the rotor to the housing. The anti-rotation mechanism includes: a plurality of locking grooves formed on the ratchet plate with different depths and connected to each other; and a locking pin member having an outer pin elastically disposed in a fitting hole formed in one of the vanes, and an inner pin elastically disposed inside the outer pin. In particular, the inner pin locks the rotor to the housing when the outer pin and the inner pin are sequentially fitted in the locking grooves by torque from the camshaft.

A lean-burn gasoline engine (110), comprising an air intake port having an air intake port inlet, an air intake port outlet, and an air channel (45) connecting the air intake port inlet to the air intake port outlet, a combustion chamber (50) having a combustion chamber inlet being connected to the air intake port outlet, the combustion chamber inlet having a throat where the air intake port outlet meets the combustion chamber inlet, a movable valve (51) comprising a valve head top surface (62) that faces the air intake port and a valve stem (63), the movable valve (51) being arranged to move between a closed state for closing off the combustion chamber inlet and an opened state wherein intake air can flow from the air intake port into the combustion chamber (50), a valve guide opening (69) in a wall of the air channel opposite the top surface (62) of the movable valve (51), and a valve guide passage (66) extending into the wall and away from the valve guide opening (69), the valve guide passage (66) housing a valve guide (65) arranged to guide the valve stem (63) and permit movement of the movable valve (51) between the closed state and an opened state. The valve guide (65) has a first end proximate the movable valve being positioned within the valve guide passage (66) such that airflow through the air channel (45) is not impeded by the valve guide (65).

A sliding member according to the present invention is used in presence of lubricant oil, and includes a sliding surface made of a base material, and a recessed portion provided in the sliding surface, wherein the sliding surface satisfies a condition expressed by following Equation.

[00001]$2/\mathrm{Ra}100$

In Equation, represents a ratio of a total volume of the recessed portion on the sliding surface to an area of a portion of the sliding surface in which the recessed portion is not formed, and Ra represents a center line average roughness of the sliding surface in the portion in which the recessed portion is not formed.

A hydrogen engine using fuel gas containing hydrogen, including: a cylinder; a piston movable within the cylinder; a cylinder head forming a combustion chamber with the piston, and including an intake port connected to the combustion chamber and a fuel supply port connected to the combustion chamber; an intake valve for opening and closing the intake port; a fuel supply valve for opening and closing the fuel supply port; and a valve train commonly provided for the intake valve and the fuel supply valve, and configured to open and close the intake valve and the fuel supply valve in conjunction with each other. The hydrogen engine is configured such that a valve opening timing of the fuel supply valve is more retarded than a valve opening timing of the intake valve.