Hot gas engine with dual crankshafts

Claim 2

A hot gas engine comprising: (a) an engine block, (b) a displacer cylinder in said engine block and having central axis and with a shiftable displacer piston therein, (c) an expander cylinder in said engine block and having central axis and with a shiftable expander piston therein, (d) a heat exchange means connected across said displacer cylinder and expander cylinder, (e) a crankcase on one end portion of said engine block and located so as to communicate with ends of the expander and displacer cylinders, said engine block having a dimension measured along the central axis of said cylinder which is substantially greater than the like dimension of said crankcase, said engine block not being sealed from said crankcase against substantial pressure differential, (f) a first crankshaft in said crankcase operatively connected to said shiftable displacer piston and being rotatable therewith, (g) a second crankshaft in said crankcase operatively connected to said shiftable expander piston and being rotatable thereby, (h) first coupling means on said first crankshaft, (i) second coupling means on said second crankshaft, and (j) a power output shaft operatively coupled to one of said coupling means or one of said crankshafts and providing a power output from said hot gas engine.

Claim 3

The hot gas engine of claim 1 wherein said second crankshaft is disposed in a generally parallel plane with said first crankshaft.

Claim 4

The hot gas engine of claim 1 wherein said power output shaft is provided with a third coupling means in operative engagement with said first and second coupling means.

Claim 5

The hot gas engine of claim 3 wherein said first and second coupling means each comprises a coupling element respectively rotatable with said first and second crankshafts and said third coupling means comprises a third coupling element which is rotatable with said first and second coupling elements and causes rotation of said power output shaft with said first and second coupling elements.

Claim 6

The hot gas engine of claim 4 wherein said first and second coupling elements are gears and said third coupling element is a gear in meshing engagement with said first and second gears.

Claim 7

The hot gas engine of claim 5 wherein said third gear is an idler gear.

Claim 8

The hot gas engine of claim 1 wherein said first and second coupling means are gears which are disposed in operative meshing engagement and said power output shaft is connected to one of said first or second crankshafts.

Claim 9

The hot gas engine of claim 1 wherein continuous belt means extends between said first and second and third coupling means.

Claim 10

A hot gas engine comprising: (a) an engine block with an expander cylinder and a displacer cylinder, (b) an expander piston shiftable in said expander cylinder, (c) a displacer piston shiftable in said displacer cylinder, (d) heat exchange means connected across said expander cylinder and displacer cylinder, (e) a crankcase on one end portion of said engine block and located so as to communicate with ends of the expander and displacer cylinders, said engine block having a dimension measured along the central axis of said cylinders which is substantially greater than the like dimension of said crankcase, (f) an expander crankshaft and a displacer crankshaft in said crankcase, (g) first connecting means operatively connecting said expander piston to said expander crankshaft, (h) second connecting means operatively connecting said displacer piston to said displacer crankshaft, (i) seal means in said cylinders to prevent oil in said crankcase from passing into said expander cylinder and displacer cylinder and said heat exchange means, said seal means being effective to maintain said expander cylinder and displacer cylinder and heat exchange means and crankcase at substantially the same average pressure to permit operation throughout the engine at substantially the same average pressure and thereby avoid the need for dynamic seals, and (j) an output power shaft operatively connected to at least one of said crankshafts to provide a power output from said engine.

Claim 11

A hot gas engine comprising: (a) an engine block with an expander cylinder and a displacer cylinder, (b) an expander piston shiftable in said expander cylinder, (c) a displacer piston shiftable in said displacer cylinder, (d) heat exchange means connected across said expander cylinder and displacer cylinder, (e) a crankcase on one end portion of said engine block and located so as to communicate with ends of the expander and displacer cylinders, said engine block having a dimension measured along the central axis of said cylinders which is substantially greater than the like dimension of said crankcase, (f) an expander crankshaft and a displacer crankshaft in said crankcase, (g) first connecting means operatively connecting said expander piston to said expander crankshaft, (h) second connecting means operatively connecting said displacer piston to said displacer crankshaft, (i) seal means in said cylinders to prevent oil in said crankcase from passing into said expander cylinder and displacer cylinder and said heat exchange means, said seal means being effective to maintain said expander cylinder and displacer cylinder and heat exchange means and crankcase at substantially the same average pressure to permit operation throughout the engine at substantially the same average pressure and thereby avoid the need for dynamic seals, and (j) an output power shaft operatively connected to at least one of said crankshafts to provide a power output from said engine.

Claim 12

The hot gas engine of claim 9 wherein a crosshead is located in each of said expander cylinder and displacer cylinder to maintain alignment of the piston rods and reduce side loads therefrom.

Claim 13

The hot gas engine of claim 9 wherein the seal means comprises a seal block and a sealing element therein which is in a relatively dry state and prevents oil passage therebetween but does not substantially seal against large pressure differential thereacross.

Claim 14

A hot gas engine comprising: (a) an engine block, (b) a displacer cylinder in said engine block having a central axis and with a shiftable displacer piston therein, (c) an expander cylinder in said engine block and having a central axis and with a shiftable expander piston therein, (d) a heat exchange means connected across said displacer cylinder and expander cylinder, (e) a crankcase on one end portion of said engine block and located so as to communicate with ends of the exapnder cylinder and the displacer cylinder, said engine block having a dimension as measured along the central axis of said cylinder which is substantially greater than the like dimension of said crankcase, (f) an expander piston rod connected to and being movable with said expander piston, (g) a displacer piston rod connected to and being movable with said displacer piston, (h) a first connecting member at one end of said expander piston rod and being shiftable therewith and being designed to reduce side load forces, (i) a first connecting rod connected to said first connecting member, (j) a second connecting member at one end of said displacer piston rod and being shiftable therewith and being designed to reduce side load forces, (k) a second connecting rod connected to said second connecting member, (l) seal means in each of said cylinders to prevent oil in said crankcase from passing into said expander cylinder and displacer cylinder and said heat exchange means, said seal means being effective to maintain said expander cylinder and displacer cylinder and heat exchange means and crankcase at substantially the same pressure to permit operation throughout the engine at substantially the same pressure and thereby avoid the need for dynamic seals, (m) a first crankshaft in said crankcase operatively connected to said shiftable displacer piston through said second connecting rod and being rotatable thereby, (n) a second crankshaft in said crankcase operatively connected to said shiftable expander piston through said first connecting rod and being rotatable thereby, said second crankshaft being generally parallel to said first crankshaft, (o) first coupling means on said first crankshaft, (p) second coupling means on said second crankshaft, and (q) a power output shaft operatively coupled to at least one of said coupling means or one of said crankshafts and providing a power output from said hot gas engine.

Claim 15

A hot gas engine comprising: (a) an engine block, (b) a displacer cylinder in said engine block having a central axis and with a shiftable displacer piston therein, (c) an expander cylinder in said engine block and having a central axis and with a shiftable expander piston therein, (d) a heat exchange means connected across said displacer cylinder and expander cylinder, (e) a crankcase on one end portion of said engine block and located so as to communicate with ends of the exapnder cylinder and the displacer cylinder, said engine block having a dimension as measured along the central axis of said cylinder which is substantially greater than the like dimension of said crankcase, (f) an expander piston rod connected to and being movable with said expander piston, (g) a displacer piston rod connected to and being movable with said displacer piston, (h) a first connecting member at one end of said expander piston rod and being shiftable therewith and being designed to reduce side load forces, (i) a first connecting rod connected to said first connecting member, (j) a second connecting member at one end of said displacer piston rod and being shiftable therewith and being designed to reduce side load forces, (k) a second connecting rod connected to said second connecting member, (l) seal means in each of said cylinders to prevent oil in said crankcase from passing into said expander cylinder and displacer cylinder and said heat exchange means, said seal means being effective to maintain said expander cylinder and displacer cylinder and heat exchange means and crankcase at substantially the same pressure to permit operation throughout the engine at substantially the same pressure and thereby avoid the need for dynamic seals, (m) a first crankshaft in said crankcase operatively connected to said shiftable displacer piston through said second connecting rod and being rotatable thereby, (n) a second crankshaft in said crankcase operatively connected to said shiftable expander piston through said first connecting rod and being rotatable thereby, said second crankshaft being generally parallel to said first crankshaft, (o) first coupling means on said first crankshaft, (p) second coupling means on said second crankshaft, and (q) a power output shaft operatively coupled to at least one of said coupling means or one of said crankshafts and providing a power output from said hot gas engine.

Claim 16

The hot gas engine of claim 12 wherein said power output shaft is provided with a third coupling means in operative engagement with said first and second coupling means.

Claim 17

The hot gas engine of claim 13 wherein said first and second coupling means each comprises a coupling element respectively rotatable with said first and second crankshafts and said third coupling means comprises a third coupling element which is rotatable with said first and second coupling elements and causes rotation of said power output shaft with said first and second coupling elements.

Claim 18

The hot gas engine of claim 14 wherein said first and second coupling elements are gears and said third coupling element is a gear in meshing engagement with said first and second gears.

Claim 19

The hot gas engine of claim 15 wherein said third gear is an idler gear.