A valve spring collar (10) for supporting spring forces of closing springs (40) that act on gas exchange valves (32) in an internal combustion engine has a plate-shaped main body (12). A through opening (14) leads through the main body (12) for receiving and attaching a valve stem (36) of the gas exchange valve (32). The valve spring collar (10) also has at least one cavity (16). A method for producing the valve spring collar (10) includes at least one additive production method step.

A valve train of an internal combustion engine may include a camshaft, first and second cams, a rocker arm assembly having a displacement bolt, which may be adjustable between at least first and second positions in the axial direction and on which at least one cam roller, may be mounted in an axially fixed and rotatable manner, wherein the displacement bolt may be mounted in associated bearing lugs of the rocker arm assembly, a guide contour arranged on the camshaft and having first and second guide tracks, a switching pin, which may be arranged in the displacement bolt and which may optionally engage with the first or second guide track to adjust the displacement bolt between the first and second positions. In the first and second positions, the cam roller may cooperate with the first and second cams, respectively. First and second catch recesses may be provided on the displacement bolt. A catch device may engage with a catch element, which may be biased into the first or second catch recess and which may secure the displacement bolt in the first or second position. The first and second guide tracks may cross one another in a crossing region. A third catch recess may be provided between the first and second catch recesses, wherein a first catch protuberance may be arranged between the first and the third catch recesses, and a second catch protuberance may be arranged between the second and the third catch recesses, wherein the catch element may engage with the third catch recess in the crossing region.

A sliding member includes a base substrate and a coating layer formed on the base substrate. The coating layer includes a steel portion derived from austenitic stainless steel particles and a copper portion derived from copper particles or copper alloy particles. The steel portion and the copper portion are bonded to each other via an interface between the steel portion and the copper portion.

A regenerative valve hydraulic actuator includes a high-pressure accumulator fed by a high-pressure feed hydraulic pump, an actuator defining an actuator hydraulic chamber for actuatingby way of a progressive lever arm ratio levera valve provided with a valve return device, a valve lifter hydraulic valve placed between the high-pressure accumulator and the actuator hydraulic chamber, a lifter check valve which connects a low-pressure accumulator to the actuator hydraulic chamber, a valve closure hydraulic valve placed between the chamber and a closure and regeneration hydraulic motor which recovers energy previously invested to open the valve.

An engine roller lifter for use in a leak-valvetrain of an internal combustion engine includes a body, a roller and an anti-rotation plug. The body includes an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines an opening. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. The anti-rotation plug is received at the opening and has a plug body including an anti-rotation protrusion that extends radially beyond an outer peripheral surface of the plug body. The anti-rotation plug can be staked into the opening of the body.

A constant volume combustion system includes at least one combustion chamber having at least one admission port and an exhaust port. The system also includes at least one elastically deformable tongue made of ceramic matrix composite material forming an air admission valve, the tongue being present inside the chamber and being positioned facing the admission port, the tongue having a first end that is stationary relative to an inside wall of the chamber and a second end, opposite from the first end, the second end being free and movable relative to the inside wall.

A variable valve actuation mechanism is provided for an internal combustion engine including at least one valve for control of gas admission to a cylinder of the engine and/or gas exhaust from the cylinder. The mechanism includes two concentrically arranged camshafts, a cam set comprising two cams, each fixed to a respective of the camshafts, whereby the camshafts are arranged to be turned in relation to each other, so as to change the combined profile of the cams, and a cam follower adapted to follow the combined profile of the cams and to actuate at least one of the at least one valve in dependence on the combined profile of the cams, wherein the cam follower includes two rollers, each roller being adapted to follow a respective one of the cams.

A split-cycle engine includes: a first cylinder housing a first piston, wherein the first piston performs an intake stroke and a compression stroke, but does not perform an exhaust stroke; a second cylinder housing a second piston, wherein the second piston performs an expansion stroke and an exhaust stroke, but does not perform an intake stroke; and a valve chamber housing a valve, the valve comprising an internal chamber that selectively fluidly couples to the first and second cylinders, wherein the valve and internal chamber move within the valve chamber and relative to the first and second cylinders.

A cam follower is provided. The cam follower includes a polycrystalline diamond element, including an engagement surface. The engagement surface of the polycrystalline diamond element is positioned on the cam follower for sliding engagement with an opposing engagement surface of a cam. The cam includes at least some of a diamond reactive material.

A valve with an opening is driven by an electric motor to rotate around the cylinder of an opposed piston engine such that the opening separately matches an intake and exhaust opening on the cylinder to allow fuel to enter the combustion chamber of the engine and allow exhaust to be expelled. The intake and exhaust cylinder openings may be separated from each other by approximately sixty degrees of the outside of the cylinder.