A system that provides adjustable actuation timing of one or more valve(s) (16) in a piston engine includes a position sensor (12) and a variable valve actuation assembly (10). The valve(s) (16) can be intake and/or exhaust valves in an internal combustion engine of an automobile. The position sensor (12) takes position readings of the valve(s) (16) as the valve(s) (16) actuate in the piston engine. The variable valve actuation assembly (10) controls actuation timing of the valve(s) (16). Actuation timing of the valve(s) (16) is adjustable based, in part or more, upon one or more position reading(s) of the position sensor (12). The variable valve actuation assembly (10) can be a lost motion assembly (10).

An electromagnetic valve actuator (100) and method of control thereof. The electromagnetic valve actuator is for at least one valve (300) of an internal combustion engine (40), the electromagnetic valve actuator comprising: a rotor (102); a stator (101) for rotating the rotor; output means (104, 106) for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means (108, 110, 116, 118) arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor; and phase varying means (400) for varying a phase between the mechanical energy storage means and the output means.

An electromagnetic valve actuator and method of control thereof. The electromagnetic valve actuator is for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising: a rotor; a stator for rotating the rotor; output means for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor and phase varying means for varying a phase between the mechanical energy storage means and the output means.

An electromagnetic valve actuator (100) and method of control thereof. The electromagnetic valve actuator is for at least one valve (300) of an internal combustion engine (40), the electromagnetic valve actuator comprising: a rotor (102); a stator (101) for rotating the rotor; output means (104, 106) for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means (108, 110, 116, 118) arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor; and phase varying means (400) for varying a phase between the mechanical energy storage means and the output means.

A system that provides adjustable actuation timing of one or more valve(s) (16) in a piston engine includes a position sensor (12) and a variable valve actuation assembly (10). The valve(s) (16) can be intake and/or exhaust valves in an internal combustion engine of an automobile. The position sensor (12) takes position readings of the valve(s) (16) as the valve(s) (16) actuate in the piston engine. The variable valve actuation assembly (10) controls actuation timing of the valve(s) (16). Actuation timing of the valve(s) (16) is adjustable based, in part or more, upon one or more position reading(s) of the position sensor (12). The variable valve actuation assembly (10) can be a lost motion assembly (10).

A valve timing control apparatus for an internal combustion engine includes: a power feeding brush including a tip end portion slidably abutted on the slip ring to feed electric power to the slip ring; and a rotation angle sensing mechanism including; a sensed portion provided to the one end portion of the motor output shaft, and a sensing portion provided to the cover member, and arranged to sense a rotation position of the sensed portion; the cover member including a recessed portion formed in an inner surface of the cover member, and recessed in an axially outward direction relative to the position of the opening end of the brush holding hole; and the sensed portion including a tip end portion inserted and disposed within the recessed portion to confront the sensing portion.