Variable compression ratio systems for opposed-piston and other internal combustion engines, and related methods of manufacture and use
AssigneePinnacle Engines, Inc.
InventorJames Montague Cleeves
Life of this patent
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Abstract
Various embodiments of methods and systems for varying the compression ratio in opposed-piston engines are disclosed herein. In one embodiment, an opposed-piston engine can include a first phaser operably coupled to a first crankshaft and a second phaser operably coupled to a corresponding second crankshaft. The phase angle between the crankshafts can be changed to reduce or increase the compression ratio in the corresponding combustion chamber to optimize or at least improve engine performance under a given set of operating conditions.
Claims20
A method for varying the compression ratio in an engine having a first piston that cooperates with a second piston to define a combustion chamber therebetween, the method comprising:
- moving the first piston back and forth in a first cycle between a first bottom dead center (BDC) position and a first top dead center (TDC) position according to a first piston timing;
- moving the second piston back and forth in a second cycle between a second BDC position and a second top dead center TDC position according to a second piston timing;
- while moving the first piston according to the first piston timing and the second piston according to the second piston timing, periodically opening and closing at least one passage in fluid communication with the combustion chamber according to a valve timing;
- and
- while maintaining the valve timing, varying the compression ratio of the combustion chamber by—
- changing the first piston timing relative to the valve timing;
- and
- changing the second piston timing relative to the valve timing.
A method for assembling an internal combustion engine, the method comprising:
- operably disposing a first piston in a first bore and a second piston in a second bore to define a combustion chamber therebetween;
- operably coupling the first piston to a first crankshaft and the second piston to a second crankshaft, wherein the first piston and the second piston define a first combustion chamber volume therebetween when the first crankshaft and the second crankshaft are in phase;
- and
- operably coupling a first phaser to the first crankshaft and a second phaser to the second crankshaft, wherein the first phaser is configured to selectively change the operational phase of the first crankshaft relative to the second crankshaft and independently of a valve timing of at least one valve, and the second phaser is configured to selectively change the operational phase of the second crankshaft relative to the first crankshaft and independently of the valve timing of the at least one valve, to selectively change the combustion chamber volume from the first combustion chamber volume to a second combustion chamber volume, greater than the first combustion chamber volume.
An opposed-piston engine comprising:
- a first piston movably disposed in a first bore;
- a second piston movably disposed in a second bore, wherein the first piston faces toward the second piston to define a combustion chamber therebetween;
- a first crankshaft operably coupled to the first piston;
- a second crankshaft operably coupled to the second piston;
- a first phaser operably coupled to the first crankshaft, wherein operation of the first phaser changes the phase angle of the first crankshaft relative to the second crankshaft and independently of a valve timing of at least one valve during operation of the engine;
- and
- a second phaser operably coupled to the second crankshaft, wherein operation of the second phaser changes the phase angle of the second crankshaft relative to the first crankshaft and independently of the valve timing of the at least one valve during operation of the engine.
Dependencies are inferred from the claim text.