Internal combustion engine valve lift and cam duration control system
A mechanism is described for varying the lift, timing and duration of a valve member associated with an internal combustion engine having a camshaft, a cam on the camshaft, and a rectilinear reciprocatable valve member for opening and closing a valve port in communication with a combustion chamber of the engine. The mechanism comprises an elongated rocker arm having a first pivot end and a second end forming a valve member actuating free end and an intermediate portion extending therebetween. The free end has a shaped valve member contact formation projecting therefrom and the pivot end has a circular opening therethrough receiving a pivotal mounting assembly therethrough having an exterior cylindrical surface within and corresponding substantially to the diameter of the circular opening forming the surface about which the rocker arm pivots. A pair of eccentric means form a first eccentric member and a second eccentric member collectively defines a pivot axis within the circular opening for the rocker arm, the first eccentric member comprising a shaft having cylindrical end portions journaled for rotation about a shaft axis and an eccentric cylindrical portion located within the opening of the rocker arm. The eccentric cylindrical portion is concentric with a first eccentric axis spaced from the shaft axis, and the second eccentric member comprises a tubular sleeve defining the exterior cylindrical surface and having a cylindrical bore having an inner diameter corresponding to the eccentric cylindrical portion of the shaft rotatably supported on the surface of the latter and concentric with a second eccentric axis spaced from the shaft axis and the first eccentric axis, a first means for rotating the shaft.
- Assignee:
- NOV; NOV-87-049003; EDB-87-064376
- Patent Number(s):
- US 4643141
- OSTI ID:
- 7083714
- Resource Relation:
- Patent File Date: Filed date 26 Jan 1986
- Country of Publication:
- United States
- Language:
- English
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