Phase change coupling
AssigneeMechadyne PLC
InventorsTimothy Mark Lancefield, Ian Methley
Life of this patent
Estimating the term…
Abstract
A phase change coupling is disclosed for allowing the angular position of a drive member 10 of a camshaft 12 to be varied in relation to the camshaft. The coupling is additionally provided with a locking mechanism for preventing rotation of the drive member relative to the camshaft in only one direction during cranking of the engine, so that, during cranking of the engine, the drive member 10 is rotated in only one sense relative to the camshaft by the camshaft torque reversals until it reaches a predetermined start-up angular position.
Claims8
A phase change coupling for an engine, comprising first means driven by an engine generated hydraulic pressure for varying the angular position of a drive member of the engine camshaft in relation to the camshaft, characterised by a locking mechanism that is operative only during cranking of the engine to lock the drive member mechanically to the camshaft in one direction of relative rotation and to permit the drive member and the camshaft to be rotated relative to one another steplessly in the opposite direction by the reaction torque of the camshaft on the drive member, whereby, when the engine generated hydraulic pressure is insufficient to drive the first means, the drive member and the camshaft are moved by the reaction torque of the camshaft towards a predetermined relative position suitable for starting the engine, forces acting directly on the locking elements serving to release the locking mechanism when sufficient hydraulic pressure is generated by the engine to drive the first means.
In an internal combustion engine having a camshaft and a phase change coupling comprising first means driven by an engine generated hydraulic pressure for varying the angular position of a drive member of the camshaft relative to the camshaft, a locking mechanism that is operative only during cranking of the engine to lock the drive member mechanically to the camshaft in one direction of relative rotation and to permit the drive member and the camshaft to be rotated relative to one another steplessly in the opposite direction by the reaction torque of the camshaft on the drive member, whereby, when the engine generated hydraulic pressure is insufficient to drive the first means, the drive member and the camshaft are moved by the reaction torque of the camshaft towards a predetermined relative position suitable for starting the engine, forces acting directly on the locking elements serving to release the locking mechanism when sufficient hydraulic pressure is generated by the engine to drive the first means, the engine further comprising means for disabling the fuel supply to the engine until said predetermined relative position of the drive member and the camshaft is reached.
Dependencies are inferred from the claim text.