US2453515A

US2453515A - Restraining mechanism for freepiston units

Info

Publication number: US2453515A
Application number: US562249A
Authority: US
Inventors: Kalitinsky Andrew
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1944-11-06
Filing date: 1944-11-06
Publication date: 1948-11-09
Anticipated expiration: 1965-11-09

Description

RESTRAINING MECHANISM FOR FREE-PISTON LII HTS 'Fileq Nov. 6, 1944 2 She'ets-Sheec 1 FIG! W m. A. KALHTINSKY mww' Nov. 9, 1948. A. KALIVTINSKY 5 RESTRAINING MECHANISM- FOR FREE-PISTON mums Filed Nov. 6, 1944 2 Sheets-Sheet 2 INVENTOR' Patented Nov. 9, I948 can-E STATES mam bps-IC Application November 6, 194 1.,saaruatsam Theopposed pistons of a free-piston unit are nor-mally 'maintained at equaldistances from the center f the engine by a restraining linkage. 'i riecepnumg application of Ward, Serial No. 62 248jfiledN0vember 6, 1944, has a linkage including 'a "sleeve having right and lefthand threads engaging with corresponding high-pitch threads on rods extending from the pistons. A feature of 'this invention is 'the use of a pair of interconnected sleeves, each of which is threaded for engagement by one of the pair of rods extending from the opposed pistons.

'Anoiih'e'r feature -is the interconnection of the sleeve so that the sleeves may be similarly threaded. One of the sleeves may carry a cam for actuating an engine accessory. One feature of the invention is the use of the two sleeves to permit a longer piston stroke without seriously lengthening the unit, since the ends of the rods may pass each other during operation of the unit.

The rate of piston reciprocation is determined primarily by the mass of the moving elements of which the restraining linkage forms a part. A feature of this invention is a linkage, the weight of which is easily changed for varying the rate of piston reciprocation. The pair of sleeves, which oscillate as the pistons reciprocate may be relatively heavy, if desired, for a slow rate of piston reciprocation.

Other objects and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates what is now considered a preferred embodiment of the invention.

Fig. l is a sectional view through the free-piston unit.

Fig. 2 is a fragmentary sectional view of the restraining mechanism.

The unit shown includes an engine cylinder having reciprocating pistons l2 and M to which compressor pistons I6 and I8 in cylinders and 22 are integrally connected. Sleeves 24 and 26 attached to the compressor pistons complete the reciprocating piston assemblies. The sleeves in combination with

stationary pistons

28 and 30 form air spring cylinders.

The piston assemblies are moved apart by the burning of fuel injected into engine cylinder l0. Air compressed in the air spring cylinders on the power stroke returns the piston assemblies.

Intake manifold 3 conducts air to intake valves 36 through which air alternately enters opposite ends of the compressor cylinders. The compressed air leaves the cylinders through discharge valves 38, also at opposite ends of the 6 Claims. (01. #4 57) compressor -cylinders, 'and passes mpugn scavengeiiianifold 40 through *ports i-l and which are uncovered 'by pistons 12 and "M at the end ofthe power stroke, thereby permitting air to be blown through the 5 engine cylinder. Gasirom the engine cylinder discharges through exhaust ports 46 and 48 into exhaust manifold 50.

LA *iiiechanis'm interconnects the piston assemblies to maintain "theinalways ateoual distances from the center of the engine cylinder. The linkage 'shownf'includes spaced parallel sleeves 52 '54 fo'taitab ly supported by bearings fidand 53 "and having intrhgaging gear teeth 6!] and 62 "for simultaneous rotation. sleeves 52 and '54 have triternn highpitch tnreaa grdcvesfsa and E6 engaging with threads 68 and 1B on rods 12 and i4 extending from compressor pistons [l6 and Hi. If either piston assembly tends to move out of phase, it is prevented by the interconnected sleeves.

Either set of gear teeth or 62 may drive accessories such as theffuel pump or a cam 16 may be mounted on either of

sleeves

52 or 54 for driving an accessory, not shown.

The rate of piston reciprocation in afree-piston unit is dependent primarily upon the weight of the moving masses of the unit. Since the sleeves, which oscillate as the pistons reciprocate, constitute a part of the moving mass, the rate of reciprocation of the unit may be adjusted by changing the weights of these sleeves.

Although only one restraining linkage has been described, it will be understood that a pair of these linkages may be used for balancing the restraining action on the opposed pistons.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. A free-piston unit having opposed pistons, in combination with a restraining mechanism for said pistons, including a pair of rods, one extending from each of the opposed pistons, a pair of rotary sleeves, one for each rod, said sleeves having interengaging means for rotation in unison and interengaging threads on the sleeves and the associated rods for turning the sleeves as the rods are reciprocated with the pistons.

2. A free-piston unit having opposed pistons, in combination with a restraining mechanism for said pistons, including a pair of, rods, one extending from each of the opposed pistons, a pair of rotary sleeves, one for each rod, said sleeves having interengaging means for rotation in unison and interengaging threads on the sleeves and the associated rods for turning the sleeves as the rods are reciprocated with the pistons, one of said sleeves having accessory actuating means thereon.

3. A restraining mechanism for the opposed pistons of a free-piston unit, said mechanism including a pair of rods, one extending from each piston, a pair of rotary sleeves, one for each rod, said sleeves being parallel to each other and having interengaging means for rotation in unison, interengaging threads on the rods and sleeves for turning the sleeves as the rods are reciprocated with the pistons and means for supporting the sleeves in fixed axial position.

4. A restraining. mechanism for the opposed pistons of a free-piston unit, said mechanism including a pair of rods, said rods being parallel, and one extending from each piston, a pair of rotary sleeves, one for each rod, said sleeves having interengaging means for rotation in unison, interengaging threads on the sleeves and the associated rods for turning the sleeves as the rods are reciprocated with the pistons and means for supporting the sleeves in fixed axial position.

5. A restraining mechanism for the opposed pistons of a free-piston unit, said mechanism including a pair of parallel rods extendin toward each other from the opposed pistons, a pair of sleeves engageable by said rods, said sleeves having interengaging means for rotation in opposite directions, each sleeve having similarly arranged threads thereon, cooperating threads on the associated rods for turning the sleeves as the rods are reciprocated with the pistons and means for supporting the sleeves in fixed axial position.

Number sociated rods for turning the sleeves as the rods are reciprocated with the pistons, one of said sleeves having a cam for actuating an accessory for the unit and means for supporting the sleeves in fixed axial position.

ANDREW KALITINSKY.

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

UNITED STATES PATENTS Name Date Eccler 1 July 11, 1876 Roebling Oct. 12, 1897 Robson July 27, 1915 Junkers Mar. 5, 1929 Junkers July 30, 1929 Janicke Nov. 19, 1940 De Veau Dec. 16, 1941 Pescara Mar, 14, 1944 FOREIGN PATENTS Country Date Italy Mar. 5, 1939 Number