If an engine coolant temperature is equal to or lower than a first low-temperature determination value and a battery temperature is equal to or lower than a second low-temperature determination value when a request to start up an engine is made, the advancement driving of a variable valve operating mechanism is first started. Then, when an advancement amount of the variable valve operating mechanism later becomes equal to or larger than a prescribed startup start determination value, is started.

An electrically-controlled variable camshaft timing (VCT) system including a sun gear, having an inner axial surface, configured to communicate torque from an output shaft of an electric motor to a gearbox assembly; and a collet sleeve having at least one slot configured to engage the output shaft of the electric motor and a relief section permitting radial-inward compression and an outer axial surface that releasably engages the inner axial surface of the sun gear such that the outer axial surface of the collet sleeve is engaged with the inner axial surface of the sun gear while an amount of torque applied to the sun gear by the output shaft is below a predetermined torque threshold and the sun gear and the collet sleeve are angularly displaced relative to each other when an amount of torque applied to the sun gear by the output shaft is at or above the predetermined torque threshold.

An electrically-actuated variable camshaft timing (VCT) phaser assembly, comprises a sun gear configured to receive input from an electric motor and one or more planet gears having radially-outwardly-extending gear teeth that engage the sun gear; a first ring gear, having radially-inwardly extending gear teeth that engage the radially-outwardly-extending gear teeth of the sun gear, configured to receive rotational output provided by a crankshaft; a second ring gear, having radially-inwardly extending gear teeth that engage the radially-outwardly-extending gear teeth of the sun gear, configured to couple to a camshaft; one or more planet gear pins that carry the planet gear(s) and engage a planetary gear set to prevent the relative rotation of the planet gear pin(s) relative to the planetary gear set; and one or more springs that bias the planet gear pin(s) and the planetary gear(s) toward the first ring gear and the second ring gear.

An electrically-actuated variable camshaft timing (VCT) phaser assembly, comprises a sun gear configured to receive input from an electric motor and one or more planet gears having radially-outwardly-extending gear teeth that engage the sun gear; a first ring gear, having radially-inwardly extending gear teeth that engage the radially-outwardly-extending gear teeth of the sun gear, configured to receive rotational output provided by a crankshaft; a second ring gear, having radially-inwardly extending gear teeth that engage the radially-outwardly-extending gear teeth of the sun gear, configured to couple to a camshaft; one or more planet gear pins that carry the planet gear(s) and engage a planetary gear set to prevent the relative rotation of the planet gear pin(s) relative to the planetary gear set; and one or more springs that bias the planet gear pin(s) and the planetary gear(s) toward the first ring gear and the second ring gear.

If an engine coolant temperature is equal to or lower than a first low-temperature determination value and a battery temperature is equal to or lower than a second low-temperature determination value when a request to start up an engine is made, the advancement driving of a variable valve operating mechanism is first started. Then, when an advancement amount of the variable valve operating mechanism later becomes equal to or larger than a prescribed startup start determination value, is started.

A valve opening and closing timing control device includes: a driving-side rotating body that rotates synchronously with a crankshaft of an internal combustion engine around a rotating shaft core; a driven-side rotating body that rotates integrally with a valve opening and closing camshaft of the internal combustion engine around the same shaft core as the rotating shaft core; a gear mechanism that sets a relative rotation phase between the driving-side rotating body and the driven-side rotating body by displacement of a meshing position; a motor that enables displacement of the meshing position of the gear mechanism by rotating a rotating shaft; and a control unit that controls the drive of the motor. The control unit intermittently performs control to energize the motor for one phase for a predetermined time after the internal combustion engine is stopped.

A valve opening and closing timing control device includes: a driving-side rotating body that rotates synchronously with a crankshaft of an internal combustion engine around a rotating shaft core; a driven-side rotating body that rotates integrally with a valve opening and closing camshaft of the internal combustion engine around the same shaft core as the rotating shaft core; a gear mechanism that sets a relative rotation phase between the driving-side rotating body and the driven-side rotating body by displacement of a meshing position; a motor that enables displacement of the meshing position of the gear mechanism by rotating a rotating shaft; and a control unit that controls the drive of the motor. The control unit intermittently performs control to energize the motor for one phase for a predetermined time after the internal combustion engine is stopped.

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 (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 rotary electromagnetic actuator is provided which is suitable for opening and closing a valve for example. The actuator comprises a rotor, a stator, and a biasing arrangement for applying a torque to the rotor during at least part of its rotation. A plurality of stable rest positions for the rotor are defined by forces acting on the rotor and the actuator is controllable to move the rotor from one stable rest position to another. The torque applied by the biasing arrangement varies with the rotational position of the rotor such that at a primary rest position and at least a second rest position, it is sufficiently low to enable selection of those positions, and then it increases beyond the second rest position.