Oscillating piston engine

Abstract

An engine configuration that uses multiple opposing piston pairs to form respective expansion chambers for expanding a gas within to move the pistons to drive a main shaft. The engine can be configured to operate as an internal combustion engine that uses diesel fuel, gasoline, or natural gas, or it can be configured as an expander to convert high pressure high temperature gas to rotary power. The pistons may be mounted on the circumference of one or more disks. For any given set of choices of numbers of pistons and sizes of pistons, disks, and gears, there are disclosed dimensional constraints useful for more efficient functioning of the engine. This engine can be provided with a compact design which results in high power to weight ratios.

What is claimed is: 
     
         1 . An engine comprising:
 a plurality of piston pegs;   a piston pair including a first piston arranged opposing a second piston, wherein each piston is comprised of one of said piston pegs and a piston body having a slot for receiving a portion of the one of the piston pegs;   a housing for forming a chamber corresponding to the piston pair, such that the first piston and the second piston are arranged within the chamber for forming an expansion volume between said first piston and said second piston for extracting energy from an expanding gas;   a pair of opposing structures each configured to connect to another portion of the piston peg of a respective one of the piston pairs such that one of said pair of opposing structures oscillate in opposition to the other of said pair of opposing structures in response to extracting energy from the expanding gas;   a main shaft passing through said opposing structures; and   piston transmission mechanisms for converting the oscillation of the opposing structures into a rotation of said main shaft.   
     
     
         2 . The engine of  claim 1 , wherein said piston transmission mechanisms included at least one crank shaft that is offset from, but parallel to, said main shaft, wherein each one of said crank shafts is connected to a respective one or more of said opposing structures using one or more connecting structures configured to convert the oscillating motions of said opposing structures into rotational motions of the crank shafts, and wherein each one of said crank shafts is connected to said main shaft configured to rotate the main shaft. 
     
     
         3 . The engine of  claim 2 , wherein each one of said opposing structures is comprised of a disk configured with a hole for receiving said main shaft and a plurality of non-circular holes each configured for receiving a respective one of said crankshafts. 
     
     
         4 . The engine of  claim 3 , further comprising one or more additional piston pairs. 
     
     
         5 . The engine of  claim 4 , wherein each one of said pistons are configured to move back-and-forth in an arc that is in a fixed position with respect to an axis of the engine. 
     
     
         6 . The engine of  claim 2 , wherein each crank shaft is connected to said main shaft using a crankshaft gear connected to the respective crank shaft in connection with a common gear connected to said main shaft. 
     
     
         7 . The engine of  claim 2 , wherein each connecting structure is comprised of a push rod connected to a crank on a respective one of said crank shafts. 
     
     
         8 . The engine of  claim 2 , wherein each one of said one or more crank shafts is provided at a fixed location with respect to said main shaft. 
     
     
         9 . The engine of  claim 1 , wherein said chamber has a radius of curvature, and wherein said piston bodies are formed having a curvature that matches the curvature of said chamber. 
     
     
         10 . The engine of  claim 1 , wherein said first piston is arranged with a third piston to form another expansion volume between said first piston and said third piston. 
     
     
         11 . An engine comprising:
 a plurality of piston pegs;   a piston pair including a first piston arranged opposing a second piston, wherein each piston is comprised of one of said piston pegs and a piston body having a slot for receiving a portion of the one of the piston pegs in a removable manner;   a housing for forming a chamber corresponding to the piston pair, such that the first piston and the second piston are arranged within the chamber for forming an expansion volume between said first piston and said second piston for extracting energy from an expanding gas;   a pair of opposing structures each configured to removably connect to another portion of the piston peg of a respective one of the piston pairs such that one of said pair of opposing structures oscillate in opposition to the other of said pair of opposing structures in response to extracting energy from the expanding gas;   a main shaft passing through said opposing structures; and   at least one crank shaft that is offset from, but parallel to, said main shaft, wherein each one of said crank shafts is connected to a respective one or more of said opposing structures using one or more connecting structures configured to convert the oscillating motions of said opposing structures into rotational motions of the crank shafts, and wherein each one of said crank shafts is connected to said main shaft configured to rotate the main shaft.   
     
     
         12 . The engine of  claim 11 , wherein each one of said opposing structures is comprised of a disk configured with a hole for receiving said main shaft and a plurality of non-circular holes each configured for receiving a respective one of said crankshafts. 
     
     
         13 . The engine of  claim 12 , further comprising one or more additional piston pairs. 
     
     
         14 . The engine of  claim 13 , wherein each one of said pistons are configured to move back-and-forth in an arc that is in a fixed position with respect to an axis of the engine. 
     
     
         15 . The engine of  claim 11 , wherein each crank shaft is connected to said main shaft using a crankshaft gear connected to the respective crank shaft in connection with a common gear connected to said main shaft. 
     
     
         16 . The engine of  claim 11 , wherein each connecting structure is comprised of a push rod connected to a crank on a respective one of said crank shafts. 
     
     
         17 . The engine of  claim 11 , wherein each one of said one or more crank shafts is provided at a fixed location with respect to said main shaft. 
     
     
         18 . The engine of  claim 11 , wherein said chamber has a radius of curvature, and wherein said piston bodies are formed having a curvature that matches the curvature of said chamber. 
     
     
         19 . The engine of  claim 11 , wherein said first piston is arranged with a third piston to form another expansion volume between said first piston and said third piston. 
     
     
         20 . An engine comprising:
 a plurality of piston pegs;   a plurality of piston pairs, each piston pair including a first piston arranged opposing a second piston, wherein each piston is comprised of one of said piston pegs and a piston body having a slot for receiving a portion of the one of the piston pegs, wherein each one of said pistons are configured to move back-and-forth in an arc that is in a fixed position with respect to an axis of the engine;   a housing for forming a chamber corresponding to the piston pair, such that the first piston and the second piston are arranged within the chamber for forming an expansion volume between said first piston and said second piston for extracting energy from an expanding gas;   a pair of opposing structures each configured to removably connect to another portion of the piston peg of a respective one of each of the piston pairs such that one of said pair of opposing structures oscillate in opposition to the other of said pair of opposing structures in response to extracting energy from the expanding gas;   a main shaft passing through said opposing structures; and   at least one crank shaft that is offset from, but parallel to, said main shaft, wherein each one of said crank shafts is connected to a respective one or more of said opposing structures using one or more connecting structures configured to convert the oscillating motions of said opposing structures into rotational motions of the crank shafts, and wherein each one of said crank shafts is connected to said main shaft configured to rotate the main shaft.