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US 5,022,358 AGranted
Low energy hydraulic actuator
AssigneeNorth American Philips Corporation
InventorWilliam E. Richeson
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AssigneeNorth American Philips Corporation
InventorWilliam E. Richeson
Estimating the term…
An electronically controllable hydraulically powered asymmetrical valve actuating mechanism for use in an internal combustion engine of the type having engine intake and exhaust valves with elongated valve stems is disclosed. The actuator is a bistable electronically controlled hydraulically powered transducer having an armature including a power piston which is reciprocable between first and second positions along with a hydraulic arrangement for powering the armature from a first (engine valve closed) position to a second position. A bistable control valve is operable in one of its stable states to supply high pressure hydraulic fluid to one face of the piston to power the armature and in the other of its stable states to relieve the high pressure fluid from the piston. The mechanism has a compressible resilient arrangement such as a coil spring or a chamber in which air is compressed during motion of the armature from the first position to the second position. This compression of the air not only slows armature motion as it nears the second position, but also provides a potential energy store for powering the armature back to its initial position. The control valve remains in said one stable state to temporarily prevent reversal of armature motion when the motion of the armature has slowed to a stop, the control valve returning to the other of its stable states on command to allow the spring or air compressed in the chamber to return the armature to the first position.
An asymmetrical bistable hydraulically powered actuator mechanism reciprocable between each of two stable positions and comprising:
An electronically controllable hydraulically powered asymmetrical valve actuating mechanism for use in an internal combustion engine of the type having engine intake and exhaust valves with elongated valve stems, the actuator comprising;
A bistable electronically controlled hydraulically powered transducer having an armature reciprocable between first and second positions, hydraulic means for powering the armature from the first position to the second position, said hydraulic means including a bistable control valve operable in one of its stable states to supply high pressure hydraulic fluid to power the armature and in the other of its stable states to relieve the high pressure fluid from the armature, a chamber in which air is compressed during motion of the armature from the first position to the second position, compression of the air slowing armature motion as it nears the second position, the control valve remaining in said one stable state to temporarily prevent reversal of armature motion when the motion of the armature has slowed to a stop, the control valve returning to the other of its stable states on command to allow the air compressed in the chamber to return the armature to the first position.
An asymmetrical bistable electronically controlled hydraulically powered transducer having an armature reciprocable between first and second positions, hydraulic means for powering the armature from the first position to the second position, a coil spring which is compressed during motion of the armature from the first position to the second position, compression of the coil spring slowing armature motion as it nears the second position, the hydraulic means maintaining pressure on the armature to temporarily preventing reversal of armature motion when the motion of the armature has slowed to a stop, the hydraulic means being disableable on command to allow the compressed coil spring to return the armature to the first position.
Dependencies are inferred from the claim text.