US2435233A

US2435233A - Air cooling means for free piston engines

Info

Publication number: US2435233A
Application number: US611498A
Authority: US
Inventors: Jr George A Mueller; Paul S Shirley
Original assignee: LIMA HAMILTON CORP
Current assignee: LIMA HAMILTON CORP; LIMA-HAMILTON Corp
Priority date: 1945-08-20
Filing date: 1945-08-20
Publication date: 1948-02-03
Anticipated expiration: 1965-02-03

Description

Feb. 3, 1948. G. A. MUELLER, JR. ETAL 14 3 I AIR COOLING MEANS FOR FREE PIST ON ENGINES Filed Aug. 20, 1945 2 Sheets-Sheet l INVENTORQ George A. Mus/k5]:

ATTORNEYQS Feb. 3, 1948.

e. A. MUELLER, JR.', arm, AIR COOLINQ MEANS FOR FREE PISTON ENGINES 2 she tssheet z Filed Aug. 20, 1945 INVENTOR George 4. Mud/end} Paul 6 6/7/r'/e I Patented Feb. 3, 1948 AIR COOLING MEANS FOR FREE PISTON ENGINES George A. Mueller, Jr.,

Hamilton, Ohio,

assignors, ments, to Lima-Hamilton York, N. Y., a corporation of and Paul 8. Shirley,

by mesne assign- Corporation, New Virginia Application August 20, 1945, Serial No. 611,498 9 Claims. (Cl. 123-46) This invention relates to internal combustion engines of the free piston type, and particularly to cooling means for the power cylinders therof.

An object of the invention i the provision of simple and efficient means, made effective by running of the engine, for circulating a cooling fluid, preferably air, in a confined space around the combustion chamber lining and lengthwise thereof.

Another object of the invention is the provision of simple cooling means in connection with the power cylinder lining of an internal combustion free piston engine whereby the compressor pistons on an outstroke create a vacuum in a space around said liner to cause air under at least atmospheric pressure to flow therein, and on an instroke to cause such air to flow lengthwise of the liner and exhaust from said space atthe opposite end of the liner to the air intake.

Further objects and advantages of the invention will be apparent from the following detailed description and from the accompanying drawings, in which Fig. 1 is a central longitudinal section of an ing of an internal combustion free piston engine interiorly of which is provided the customary combustion chamber 2 and at each end thereof cylinders 3 and 4 forming the respective air compressor chamber 5 and bounce chamber 6, with the chambers 2 and 6 of substantially the same diameter and with the chamber 5 of larger diameter. Two oppos ng piston sets are provided, each including pistons 1, 8 and 9 working, respectively, in the chambers 2, 5 and 6 and operating in a manner well understood in the art. A synchronizing connection between the piston sets causes them to have opposed movements in unison and includes a rack-bar l projecting inwardly from each compressor piston 8 through an airtight guide opening in the inner end wall of the cylinder 3 and connected with the other rackbar through an interposed pinion Ii, as is common in the art. The rack portions of the bars are at the outer sides of the guides.

Fuel is injected into the combustion chamber 2 through a centrally disposed nozzle i2 and ex-- haust from the chamber takes place through a conduit l3, while scavenging air is admitted to the chamber from a conduit l4 leading, in the present instance, from a scavenging receiver i5. This receiver has communication with both compressor chambers through ports "5 therein that are uncovered by the pistons 8 when substantially midway of their inward strokes.

The wall of the combustion or power chamber 2 is formed by a cylindrical liner 20 set within an outer cylinder2l in spaced concentric relation thereto to form a space 22 therebetween that is open at its opposite ends to the spaces 23 and 24 at the inner end portions of the respective cylinders 3. In the present instance the

parts

20 and 2| constitute separate members, one inserted within the other, and spaced by suitable lugs or other parts projecting from one or the other. The spacing means includes nipple portions 25 forming exhaust and scavenging ports 26 and 21, respectively, in the liner 20. The liner 20 is preferably formed within the passage 22 with a spiral rib or fin portion 28 restricting the passage and serving as a cooling fin for the liner in surrounding relation to the combustion chamber 2.

Air is admitted, in the present instance. to the space 23 from the atmosphere through an inlet 29 having an inwardly opening valve 30 therein and is exhausted to the atmosphere from the space '24 through an outlet conduit 3| having an outwardly opening valve 32 therein. It is thus apparent that during an outstroke of the pistons a vacuum is created in the spaces 22, 23 and 24, causing air to rush therein through the inlet 29, and during an instroke of the pistons this air is caused to rush through the liner space 22 in the direction of the exhaust 3i, thus effecting an efiicient and continuous cooling of the combustion chamber wall. unidirectional flow of cooling air along the power cylinder liner, so that an eflicient use of the air stream for cooling is obtained.

Air is admitted to thecompressor' chambers 5 through respective inlet passages 35 and inward, ly opening valves 36 and is discharged from such chambers to a receiver 31 through outwardly opening valves 38 and conduits 39. Nothing new is claimed for this.

We wish it understood that our invention is not limited to any specific construction, arrangement or form of th parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described our invention, what we claim as new. and desire to secure by United States Letters Patent, is:

1. In an internal combustion free piston engine having a power cylinder liner, compressor pistons at opposite ends of the liner, and spaces at the inner sides of said pistons, means providing communication between said spaces in close relation to said liner, one of said spaces having a valved inlet for low pressure air and the other a valved outlet away from said communication, whereby air is drawn into said spaces and said communication through said inlet on an outstroke of the pistons and is forced therefrom and through said outlet on an instroke of the pistons to effect cooling of the liner. Y

2. In an internal combustion free piston en- This action maintains a gine having a power cylinder liner, compressor pistons at opposite ends of the liner, and spaces at the inner sides of said pistons, means including said liner providing communication between said spaces, a valved inlet for a cooling fluid to one of said spaces and a valved outlet for the free flow of fluid from the other of said spaces away from said communication, whereby a cooling fluid is drawn into said spaces and said communication through said inlet on an outstroke of the pistons and is forced therefrom and caused to flow in one direction through said outlet on an instroke of the pistons.

3. In an internal combustion free piston en-' gine having a combustion chamber, spaces at opposite ends of said chamber, and pistons working in said spaces, means forming a liner for the combustion chamber and a passage connecting said spaces, a check valve controlled inlet for a cooling fluid to one of said spaces and a check valve controlled outlet for the free flow of fluid from the other of said spaces and said passage, whereby on an outstroke of the pistons fluid is drawn into said spaces and passage through the inlet and on an instroke of the pistons is forced 7. In aninternal combustion engine of the two chamber communicating with said passage near the scavenging inlet, whereby cooling fluid is moved through said passage from the end near the exhaust to and out of the end near the scavenging inlet on both the expansion and the contraction of said chambers.

8. In an internal combustion engine having a working cylinder with a combustion chamber therein, opposed working pistons in said cylinder,

means synchronizing the working pistons, and

from said spaces and passageand through said outlet.

4. In an internal combustion free piston engine having a. cylinder wall forming a combustion chamber, spaces at opposite ends ofsaid chamber and oppositely moving pistons in said spaces, said cylinder wall having a space substantially around and lengthwise of its combustion chamber surface opening communication between said spaces, a check valve controlled inlet to one of said spaces for air under substantially atmospheric pressure and a check valve controlled outlet for the free flow of air from said other spaces, whereby on an outstroke of the pistons fluid is drawn into said spaces from the inlet and on an instroke of the pistons is forced from said spaces and through said outlet.

5. In an internal combustion free piston engine having a cylinder wall forming a combustion chamber, spaces at opposite ends of said chamber, and oppositely moving pistons in said spaces, means cooperating with said cylinder wall to form a substantially encircling passage from one end to the other thereof which opens communication between said spaces, baflie fins on said wall within said passage, one of said spaces having a check valve controlled inlet for cool low pressure air and the other space having a check valve controlled outlet for the free flow'of air away from said passage, whereby on an outstroke of the pistons fluid is drawn into said spaces and passage from the inlet and on an instroke of the. pistons is forced from said spaces and passage and through said outlet without a material heating compression of the air.

6. In an internal combustion engine means to cool the working cylinder thereof comprising means forming a passage around said cylinder from end' to end thereof, two expansible and contractible chambers, one in constant communication with each end of said passage, means to expand and contract the two chambers simultaneously, a check valve controlled inlet for cooling fluid into one only of said chambers and a check valve controlled outlet from the other of said chambers, whereby cooling fluid is moved through said passage from the chamber having the inlet to the chamber having the outlet both when the chambers expand and when they contract.

a compressor cylinder at each end of the working cylinder with a compressing piston therein connected to and moving with the adjacent working piston, means providing a cooling passage around the working cylinder and in constantly free communication with both of said compressor cylinders, a check valve controlled inlet into one only of said compressor cylinders and a check valve controlled outlet from the other only of said compressor cylinders, whereby cooling fluid is moved through said passage in the. same direction upon both the working and compressing strokes of the working pistons.

9. In an internal combustion engine having a working cylinder with a combustion chamber, opposed working pistons in said cylinder, means to synchronize said pistons, means providing an exhaust outlet at one end and a scavenging inlet at the other end of the combustion chamber, compressor cylinders at the ends of the working cylinder and a piston in each compressor cylinder connected to and moving with the adjacent working piston, means providing a cooling passage around the working cylinder and constantly open into the compressor cylinder at its opposite ends, a check valve controlled inlet into the compressor chamber at the exhaust end of the working cylinder and a check valve 'controlled outlet from the compressor chamber at the scavenging end of the working cylinder,

whereby cooling fluid is moved through said passage from the compressor cylinder at the exhaust end to the compressor cylinder at the scavenging end on both the workingstroke and the compressing stroke of the working pistons.

GEORGE A. MUELLER, JR. PAUL S. SHIRLEY.

REFERENCES CITED The following references are of record in the file of this patent: