Improved opposed piston engine
OwnerPaul Ellisinventor
Life of this patent
Estimating the term…
Abstract
The invention relates to an opposed piston engine comprising at least one cylinder, at least two pistons arranged to be reciprocated within the same cylinder in an opposed manner, at least one intake port through the cylinder wall, at least one exhaust port through the cylinder wall, at least one shaft arranged to be rotated by reciprocal motion of the opposed pistons, at least one reciprocatable sleeve valve within the cylinder for controlling porting of one or both of the at least one intake port and the at least one exhaust port, a sleeve valve driving mechanism for controlling reciprocal motion of the at least one sleeve valve, and a dwell mechanism. The dwell mechanism is configured to induce at least one period of dwell of the at least two pistons during their respective cycles of piston motion.
Claims43
An opposed piston engine comprising:
- at least one cylinder;
- at least two pistons arranged to be reciprocated within the same cylinder in an opposed manner;
- at least one intake port through the cylinder wall;
- at least one exhaust port through the cylinder wall;
- at least one shaft arranged to be rotated by reciprocal motion of the opposed pistons;
- at least one linear reciprocatable sleeve valve positioned within the cylinder and surrounding at least one of the at least two pistons;
- a sleeve valve driving mechanism for controlling linear reciprocal motion of the at least one sleeve valve so as to control porting of one or both of the at least one intake port and the at least one exhaust port;
- and
- a dwell mechanism;
- wherein the dwell mechanism is configured to induce at least one period of dwell of the at least two pistons during their respective cycles of piston motion.
An opposed piston engine according to any of the preceding claims, wherein the timing of porting events during the engine cycle is controllable independently of the position of the pair of opposed pistons within the cylinder.
An opposed piston engine according to according to any of the preceding claims, arranged so that the reciprocal motion of the at least one sleeve valve controlled by the sleeve valve driving mechanism is linked to the reciprocal motion of the at least two pistons.
An opposed piston engine according to any of the preceding claims, wherein the dwell mechanism is configured to induce a period of dwell of the pistons at their respective BDC positions during the cycle of piston motion.
An opposed piston engine according to any of the preceding claims, wherein the dwell mechanism is configured to induce a period of dwell of the pistons at their respective TDC positions during the cycle of reciprocal piston motion.
An opposed piston engine according to any of the preceding claims, wherein the dwell mechanism is a cam mechanism.
An opposed piston engine according to claim 17, wherein the piston cam mechanism includes one or more piston cams for each piston and one or more cam followers coupled to each of the pistons which remain in contact with the cam surface of the respective one or more piston cams for each piston during the cycle of piston movement.
An opposed piston engine according to any of the preceding claims wherein the sleeve valve driving mechanism is a cam mechanism.
An opposed piston engine according to any of the preceding claims, including at least two sleeve valves, one sleeve valve surrounding each of the at least two pistons, the sleeve valves arranged to be reciprocated by the sleeve valve driving mechanism in an opposed manner within the same cylinder.
An opposed piston engine according to 24, wherein a plurality of intake ports is provided through the cylinder wall at a location between the TDC and BDC positions of the first sleeve valve reciprocatable sleeve valves and a plurality of exhaust ports is provided through the cylinder wall at a location between the TDC and BDC positions of the second sleeve valve.
An opposed piston engine according to any of the preceding claims, wherein an intake tract leading to the at least one intake port is bifurcated to allow streams of scavenging and charging air to be of separate origin, such as from a mechanical pump for scavenging air and from an exhaust turbocharger for charging air.
An opposed piston engine according to any of the preceding claims, wherein the at least one shaft is an output shaft for power take-off.
An opposed piston engine according to any of the preceding claims, wherein the engine operates a two stroke cycle.
An opposed piston engine according to any of the preceding claims, wherein the engine is a compression ignition engine.
An opposed piston engine substantially as hereinbefore described with reference to the accompanying drawings.
Dependencies are inferred from the claim text.