A rolling-contact shaft member, which is made of high-carbon steel and whose outer peripheral surface serves as a rolling-contact surface that rolling-contacts a mating material, includes: a carbonitrided layer having a carbon concentration of 1.1 to 1.6 wt % and a nitrogen concentration of 0.05 to 0.6 wt % in the range from the surface to the depth of 10 μm. The rolling-contact shaft member has a Vickers hardness of 700 to 840 HV at the outer peripheral surface and has a Vickers hardness of 600 HV or less in its central portion. A maximum value of an absolute value of a gradient of a change in the Vickers hardness from the outer peripheral surface to the central portion is 100 to 340 HV/mm.

A roller lifter includes a first member having a pair of opposed portions opposed to each other and a connecting part connecting the opposed portions to each other, a shaft mounted between the opposed portions to rotatably support a roller brought into contact with a cam, a second member independent of the first member and having a cylindrical portion and an elastic mount elastically held between the opposed portions and the cylindrical portion to mount the first member to the second member.

A mechanical system that forms a cam follower or a rocker arm. The mechanical system includes a support element, a pin extending between two opposite ends along a first axis, and a roller mounted on the pin, movable in rotation relative to the pin around the first axis and adapted to roll on a cam. The support element further comprises an insert having holding members supporting the pin ends, provided with cut-outs having a shape complementary to the shape of the pin-ends, for assembling pin with insert by quarter-turn around the first axis. The pin ends each have a flat surface and an external surface. A first dimension of each pin end, measured perpendicularly to the flat surface, between the flat surface and the external surface of the pin end, is higher than half the outer diameter of the pin ends.

A rocker arm includes a roller, a support shaft coaxially mounted in the roller, walls arranged along a rotation axis and having the roller therebetween and having through holes, respectively, through which end portions of the support shaft are inserted, and each of the walls having an inner surface opposite the roller, and holding members mounted in the respective walls. The holding member includes a tubular portion mounted in each through hole and disposed between an inner peripheral surface of the through hole and an outer surface of an end portion of the support shaft, a first stopper portion included at a first end of the tubular portion to be in contact with the inner surface of one of the walls, and a second stopper portion included at a second end of the tubular portion to be in contact with an end surface of one of the end portions.

A rocker arm includes a roller, a support shaft coaxially mounted in the roller and having a first end portion and a second end portion, walls including at least a first wall and a second wall arranged along the rotation axis and opposite each other with having the roller therebetween, the first wall having a first through hole through which the first end portion is inserted and the second wall having a second through hole through which the second end portion is inserted, and plate portions including at least a first plate portion and a second plate portion arranged opposite each other with having the first wall, the second wall and the support shaft therebetween. The first plate portion is in contact with a first end surface of the first end portion and the second plate portion is in contact with a second end surface of the second end portion.

The cam follower roller device comprises a body, a shaft mounted on the body, a roller mounted on the shaft and able to rotate, and a plain bearing interposed radially between the shaft and the roller. An outer surface and/or an inner surface of the plain bearing comprise a plurality of cavities. The ratio of the sum of the surfaces areas of the cavities to the total surface area of the outer surface, or of the inner surface, in which the cavities are formed is between 2% and 40%. The cavities have a depth between 0.5 μm and 5 μm.

The present invention provides a variable valve mechanism of an internal combustion engine, which includes a rocker arm that includes a roller arm including a roller that rotatably abuts against a cam and a side arm provided at a side of the roller arm and that drives a valve, and a switching device that includes a switching pin and a hydraulic chamber provided inside the rocker arm and that switches a drive state of the valve by displacing the switching pin between a coupling position at which the switching pin extends between the roller arm and the side arm and a non-coupling position at which the switching pin does not extend between the roller arm and the side arm based on variations in hydraulic pressure in the hydraulic chamber. The switching pin is provided on an axis of the roller, and the hydraulic chamber is provided inside the roller arm.

A mechanical system, comprising a support element, a pin extending along a first axis and comprising two opposite ends, each adapted to be fitted in the support element for radial retention of the pin relative to the first axis, and a roller element movable in rotation relative to the pin around the first axis. The mechanical system includes two ribs resting on either side of the ends for axial retention of the pin along the first axis. The mechanical system can be integrated into either an injection pump or a valve actuator.

A variable valve actuation mechanism for an engine; a rocker arm mechanism of the variable valve actuation mechanism is a combined rocker arm mechanism and comprises a valve-side rocker arm and at least one cam-side rocker arm; on a camshaft, each cam-side rocker arm is provided with a cam; one end of the valve-side rocker arm is connected to a valve mechanism, and the other end is provided with a beam structure, the beam structure being located above the cam-side rocker arms and having a certain clearance with the cam-side rocker arms; sliding block and return springs are provided on the cam-side rocker arms; when an oil passage controlled by a solenoid valve is in an off or on state, under the drive of the force of the return springs and a lubrication oil, the sliding block have a first position and a second position, respectively; and when at the first position and the second position, the sliding block enable the cam-side rocker arms and the valve-side rocker arm to form a transmission chain and a disconnected transmission chain, respectively, thus enabling the combined rocker arm mechanism to be able to selectively transmit the driving lift of a cam that corresponds to one of the cam-side rocker arms to the valve-side rocker arm, achieving a variable valve. Also disclosed is an engine which comprises a variable valve actuation mechanism

A phasing mechanism for an internal combustion is provided. The phasing mechanism includes a stator, a rotor configured to rotate relative to the stator, a first plurality of rolling elements configured to engage and move the rotor in a first rotational direction, a second plurality of rolling elements configured to engage and move the rotor in a second rotational direction, and a piston configured to be hydraulically actuated in: i) a first axial direction to move the rotor in the first rotational direction, and ii) a second axial direction to move the rotor in the second rotational direction.