Free-piston engine
OwnerRobert B. Hammettinventor
Life of this patent
Estimating the term…
Abstract
This gas pressure generating engine has a totally unconnected piston running between a combustion chamber and a rebounding volume. The piston uncovers the outlet port after moving a short distance from the combustion chamber and utilizes the rest of the piston's long stroke to draw in new air; and after turning around at the stroke's end to pump to the outlet a large part of the drawn-in air. The remainder of the drawn-in air is further compressed for combustion. The stroke of the piston is restricted only by the energy it receives from the combustion chamber. The rebounding volume's pressure is adjustable to adjust the pressure-volume ratio of the outlet gas. A tuned valve in the outlet and a tuned blowdown tube maximize gas momentum scavenging of the combustion chamber to improve the efficiency and extend the operating range.
Claims27
Apparatus utilizing energy to pump gas comprising:
- a piston fitted to a using, said piston freely moving in said casing in response to gas pressure differences on said piston;
- a pressure chamber to one side of said piston comprising means to increase the pressure or volume of gas in said pressure chamber to cause outward acceleration of said piston;
- a rebounding vole to the other side of said piston opposing the outward movement of said piston by the gas pressure in said rebounding volume;
- said rebounding volume maintaining a substantially constant pressure opposing said outward movement of said piston;
- said piston executing a stroke between said pressure chamber and said rebounding volume;
- an intake means through which gas enters said pressure chamber;
- and an outlet port in said casing located so as to be uncovered by said piston substantially before said piston has reached the outward end of said stroke of said piston.
A free-piston internal combustion engine comprising:
- a piston fitted to a casing;
- a combustion chamber to contain gas under high pressure to one side of said piston;
- means releasing combustion products from said combustion chamber after a partial expansion from said high pressure by said piston's movement in said casing;
- a further expansion by a continuation of said movement of said piston after said release the drawing in of gas by said continuation of movement;
- said piston executing a stroke in said casing away from said combustion chamber before being returned by a rebounding means;
- and the length of said stroke of said piston being in proportion to said high pressure in said combustion chamber
A free-piston internal combustion engine comprising:
- a piston fitted to a casing;
- a combustion chamber to one side of said piston;
- means releasing combustion products after a partial expansion of said combustion chamber by said piston;
- a further expansion of by said piston after said release;
- rebounding means operating on said piston to oppose the movement caused by the pressure of said combustion chamber;
- said rebounding means taking energy from the outward travel of said piston and giving back to said piston on its return inward travel energy substantially equal in amount to said taken energy.
Dependencies are inferred from the claim text.