Selectable 2-stroke/4-stroke camshaft drive system
OwnerJonathan Austin Mainventor
Life of this patent
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Abstract
A camshaft drive system is described for a selectable two-stroke/four-stroke internal combustion engine with exhaust and intake poppet valves opened and closed by at least one camshaft. In a preferred embodiment of the system, the camshaft is connected permanently to a planetary gear set which is driven continuously by the engine crankshaft, and means are provided for setting the planetary gear set in one of two selectable stable modes to function either as a gear box or as a rigid coupling.
Claims22
A camshaft drive system for a selectable two stroke/four stroke internal combustion engine, having a crankshaft and a plurality of poppet valves operated by at least one camshaft to coordinate gas exchange events, the camshaft drive system comprising:
- a planetary gear set comprising a ring gear, a sun gear, at least one planetary gear, and a planetary gear carrier;
- said planetary gear set being coupled to the camshaft;
- setting means for setting said planetary gear set in at least a first or a second selectable modes, wherein the planetary gear set operates as a gear box in said first mode and as a rigid coupling in said second mode;
- wherein said planetary gear set is adapted to be driven in synchronous relationship to the engine crankshaft.
A camshaft drive system for a selectable two stroke/four stroke internal combustion engine operation, having a crankshaft and a plurality of poppet valves operated by at least one camshaft to coordinate gas exchange events, the camshaft drive system comprising:
- a planetary gear set having a plurality of members comprising a ring gear member, a sun gear member, and a planetary gear carrier member;
- wherein a first of said members being permanently affixed to the camshaft, and a second of said members being coupled to said crankshaft;
- a brake coupled to the third member of said planetary gear, said brake being operable for setting said planetary gear set in at least a first or a second selectable mode, wherein the planetary gear set function either as a gear box or as a rigid coupling.
A method of selecting between operating an internal combustion engine in a two cycle operation mode, or a four cycle operation mode, said engine having a crankshaft and a plurality of valves operated by a camshaft, wherein selecting between a four cycle and a two cycle operation mode requires modifying of valve timing, the method comprising the steps of:
- coupling the crankshaft and the camshaft via a planetary gear set;
- operating said gear set in a first or second coupling modes, to select between two cycle engine operation and four cycle engine operation;
- wherein when operated in said first coupling mode the planetary gear set rotates the camshaft at the same speed as the crankshaft;
- and,
- wherein when operated in said second coupling mode the planetary gear set rotates the camshaft at a speed different than that of the crankshaft.
A camshaft drive system for a selectable two-stroke/four-stroke internal combustion engine with exhaust and intake poppet valves opened and closed by at least one camshaft, wherein the camshaft is connected permanently to a planetary gear set which is driven continuously by the engine crankshaft, and wherein means are provided for setting the planetary gear set in one of two selectable stable modes to function either as a gear box or as a rigid coupling.
Dependencies are inferred from the claim text.