US1972744A

US1972744A - Rotary piston and cylinder construction

Info

Publication number: US1972744A
Application number: US611985A
Authority: US
Inventors: Lister William
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-01-11
Filing date: 1923-01-11
Publication date: 1934-09-04
Anticipated expiration: 1951-09-04

Description

LiS TER 1,972,?44

ROTARY PISTON AND CYLINDER CONSTRUCTION Sept 4, Original Filed Jan. 11, 1923 4 Sheets-Sheet l Sept. 4, 1934. w. LISTER ROTARY PISTON AND CYLINDER CONSTRUCTION Original Filed Jan. 11, 1923 4 Sheets-Sheet 2 Sept. 4, 1934. w LISTER 1,972,744

' Original Filed Jan. 11, 1923 4 Sheets Sheet 5 Sept; 4, 1934. w. LISTER ROTARY PISTON AND CYLINDER'CONSTRUCTION 11, 1923 4 SheetsSheet 4 Original Filed J cm.

Patented Sept. 4, 1934 UNITED STATES PATENT OFFHQE ROTARY PISTUN AND CYLINDER CONSTRUCTION Renewed February 8, 1934 6 Claims.

My invention is concerned with rotary piston and cylinder construction designed primarily for steam engines, but which can be used for rotary pumps, compressors, etc., and is intended to produce a device of the class described that will be highly efilcient and prevent any possible loss of pressure in the device due to leakage.

To illustrate my invention, I annex hereto four sheets of drawings, in which the same reference characters are used to designate identical parts in all the figures, of which,-

Fig. 1 is a central vertical section through an engine embodying my invention;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 7 is a central vertical sectionillustrating a portion of the mechanism seen in Fig. 2, but with the blade in a different position;

Fig. 8 isa section on the line 8-8 of Fig. '7; i

25 and Fig. 9 is a detail in perspective illustrating some of the parts separated.

The complete cylinder is preferably made up of the outer cylindrical casing ring closed by the end plates 33 and having secured therein the inner cylindrical ring 25, as hereinafter described. The casing is preferably constructed of the central casting 20, generally annular in shape, and having the inlet aperture 21 and the outlet aperture 22 located in suitable sleeve-like extensions from the main cylindrical body. A third extension or lug 23 is internally threaded and receives the set screw 24 which engages the ring 25, fitting closely inside of the ring 20, of the same width, and having its inner surface eccentric to the ring 20 and also to its own outer surface. This inner surface is made up substantially of four parts, the smaller section 26 being formed on a circular curveconcentric with the ring 20, and it is opposed by asurface 27 likewise circular and concentric, while the two

surfaces

26 and 27 are connected by the surfaces 28 and 29, which are curved, but on different centers from the

surfaces

26 and 27. The design of these four surfaces is such that the effective diameter of the eccentric internal surface thus produced is the same in any position of the blade or blades whose ends co-operate therewith. The ring has the inlets 30 and 31 registering with. the inlets 22 and 21 tion, and composed of spring metal. I understood of course that the function of these and are preferably threaded, as seen at 32, so that a nozzle of any desired design can be screwed into either of them, depending on which way it is desiredv to have the engine rotated.

I preferably, especially for the largerunits, install either a Corliss or a poppet valve on the inlet port for the purpose of cutting off the steam to get fuller expansion. The open cylinder thus formed is closed at its ends by the end plates 33, symmetrical in design, and which have the flanges 34 overlapping the outer edges of the ring 20, to which they are secured by the screws 35, as will be readily apparent. The central portions of the end plates have the bosses 36 which form bearings for the shaft 3'7, and on 7 the inner faces of the ends are the circular recesses 38, which are concentric with the shaft 3'7, and are of the same radius as the portion 26 of the surface of the ring 25.

The shaft 37 is preferably provided with the 7 enlarged central portion 39, through which passes the rectangular opening 40 to accommodate the blade or blades 41v therethrough. The rotor is made up of the enlarged central portion of this shaft 37, and the semicylindrical halves 30 42, which have the central portion of full diameter, with the reduced portions 43 of somewhat smaller diameter, and the reduced portions 44 of stillsmaller diameter forming seats for the rings 45, best seen in Fig. 3, which are secured by the screws 46 to the ends of therotor sections, thus forming at each end an annular channel adapted to receive the expanding rings 47, made up of two

sections

47 and 47*, as described at length further on inthe specifica- It will be rings 47 isto form a packing and prevent the escape of the steam past them and out the bearings of the shaft 3'7. The two halves 4.2 of the rotor are secured together by the screws 49, as clearly shown in Fig. 3, and the dowel pins 50 may be employed for positioning the rings 45 before the screws 46ers driven. I preferably pin the rotor to the shaft 37 by the pins 51, 1 seen in Figs. 2 and 3.

As the piston blade slides through the center of the rotor with its ends co-operating with the eccentric inner periphery of the ring 28, it will be obvious that to co-operate therewith perfectly,

the ends at least of the piston blade must be capable of some relative movement to make the desired perfect contact, and that as a result the piston blade must be compound, and not merely a simple integral blade.

The blades 41 may take various forms, but I prefer to employ a pair of said blades, and provide each blade with a sliding contact rib 52 mounted to slide in recesses formed in the ends of the blades 41 and pressed outward by the springs 53 set in pockets 54 in the bottoms of the recesses in the blades accommodating the ribs 52. This construction ensures steam-tight engagement of the ends of the blades with the

surfaces

26, 27, 28 and 29, and it will be noted from the dotted-line position shown in Fig. 1 that the two ribs 52 can occupy difierent positions to make a double engagement with said surfaces in all positions of the blades. It is desirable to have the ends of the blades pressed in steam-tight engagement with the ends of the channel 40 through the enlarged portion of the shaft and with the corresponding offsets 55 of the rotor sections 42, with which offsets the ends of the blades engage, and, for this purpose, I form the blades 41 in two

sections

41 and 41*, as best seen inFig- 2, and themeeting edges of these sections are provided with intermeshing rectangular teeth 56, so'that the two sections of the blades can be thrust toward theends of the engine under the impulse of the helicallycoiled expanding springs 5'7 set in the recesses 58 formed in the sections of the blades, as clearly shown in Fig. 2. It is desirable, of course, that the contact ribs 52 also have their ends pressed against the offset portions 55 and the surfaces 59 of theend plates, and to obviate the necessity of employing springs for these ribs, which are also divided into

sections

52 and 52*, as seen in Fig. 2, like thesections of of the blade proper, I provide in the ribs the radially-extending channels 60, which are engaged by the ribs 61 formed on the inner surfaces of the recesses in the ends of the blades 41, as seen in Fig. 6. By this means, it will be obvious that the contact ribs 52 will have their ends moving with the ends of the blades 41 to ensure the desired steam-tight contact.

It is also desirable to provide means for preventing the escape of the steam from one side of the piston to the other between the adjacent surfaces of the pairs of blades 41, and for this purpose I employ the construction shown in Fig. 6 where the sections 42 are provided near their ends with the rectangular recesses 62,

which recesses are tapered in depth, as shown in Fig. 6, and receive in their bottom the tapered plate or key 63, which is pressed against the contact bar 64 overlying it by the helicallycoiled expanding spring 65 located in the end of the recess and held to its work by the'screw 66 threaded into the portions of the rotor 42 directly-beneath the offsets 43 thereof. With the construction shown, it will be obvious that the pressure of the spring 65 acts throughthe keys 63 and bars 64 to press the two blades 41 into engagement so as to prevent the passage of steam between them.

' In Figs. 7, 8 and 9, I have illustrated in detail the

packing rings

47 and 47 whosediameters are made adjustable to secure more efficient action. The ring is made in two sections, 47

and-47 with their adjacent surfaces tapered,

shifting, I provide them with the

lugs

47 and 47 which fit into the correspondinglyshaped recesses 45 formed in the inner faces of the rings 45 If the ring 47 becomes worn so as to permit some leakage, by turning the screws 46 it can be expanded so as to take up the wear and secure as tight a joint as is desirable.

The set screw 24 is screwed down as tightly as may be desired, and it will be understood that the tighter it is screwed down, the more closely the section 26 of the inner periphery of the annulus 20 engages the rotor, thus enabling me to prevent any possibility of steam leaking by the section 26 to the exhaust side due to its pressure.

The structure and purposes of the various features having been thus described, the mode of operation of the apparatus will be readily apparent without further explanation.

While I have shown and described my inven tion as embodied in the form which I at present consider best adapted to carry out its purposes, it will be understood that it is capable of modifications, and that I do not desire to be limited in the interpretation of the following claims except as may be necessitated by the state of the prior art.

What I claim as new, and desire to secure by Letters Patent of the United States, is:

1. In a device of the class described, the'combination with a cylinder having inlet and outlet ports and the eccentric interior portion with the concentric end portions of smaller diameter, of a rotor mountedconcentrically in the cylin- 'der, a blade sliding radially through the rotor and engaging the eccentric interior of thecylinder'with its ends, expanding rings mounted in annular grooves in the rotor within the smaller portions of the cylinder and engaging said smaller portions for the purpose described, and means for the adjusting the peripheral diameter of the expanding rings to take up wear, said means consisting of transversely beveled rings within the expanding rings, and me'chanismfor forcing said beveled ringstoward the center and holding them in the positions to which they are moved. 1 V

2. In a device of the class described, the combination with a cylinder having inlet and outlet ports and the eccentric inner portion with the concentric end portions of smaller diameter, of a rotor mountedconcentrically in the cylinder, a blade sliding radially through the rotor and engaging the eccentric interior of the cylinder with its ends, expanding rings mounted on reduced annular portions of the rotor within the smaller portions of the cylinder and engaging said portions for'the purpose described, transv ersely beveled rings within the expanding rings, retaining ring also upon the still more reduced annular portions'of the cylinder to hold the expanding and beveled rings inplace, and screws cooperating with the retaining rings for forcing them toward the center. Y

' 3. Ina device of the class described, the combination with a cylinder having inlet and'outlet ports, of a rotor journaled therein eceentrically of the bore of the cylinder, a compound piston ist its

blade sliding/through the centerj of the rotor,

packing bars 'in the rotor engaging the faces of the blade, tapering pressure bars mounted to slide in the rotor longitudinally of the axis thereof and engage the packing bars, the-engaging faces 'of the rotor. being. correspondingly tapered, and springs in the rotor to engage the ends of the pressure bars and thereby press the packing bars against the faces of the blade with substantially unvarying pressure.

4. In a device of the class described, the combination with a cylinder having inlet and outlet ports and the eccentrically located bore or interior portion with the concentrically located end portions of smaller diameter, of a rotor mounted concentrically in the cylinder with its ends extending into said smaller end portions, a compound blade sliding radially through the rotor and engaging the eccentric interior of the cylinder with its ends, and expanding rings mounted in annular grooves in the rotor within the smaller portions of the cylinder and engaging said smaller portions for the purpose described, the single opening of each of said expanding rings being in line with the radial space covered by the adjacent end of the blade.

5. In a device of the class described, the combination with a cylinder having inlet and outlet ports and the eccentrically located bore or interior portion with the concentrically located end portions of smaller diameter, of a rotor mounted concentrically in the cylinder with its ends extending into said smaller end portions, a compound blade sliding radially through the rotor and engaging the eccentric interior of the cylinder with its ends, expanding rings mounted in annular grooves in the rotor within the smaller portions of the cylinder and engaging said smaller portions for the purpose described, the single opening in each of said expanding rings being in line with the radial space covered by the adjacent end of the blade, and retaining rings secured upon the still more reduced annular portions of the rotor to hold said rings in place.

6. In a device of the class described, the combination with a cylinder having inlet and outlet ports, of a rotor journalled therein eccentrically of the bore of the cylinder, a compound piston blade sliding through the center of the rotor, packing bars in the rotor engaging the faces of the blade, pressure bars mounted to slide in the rotor longitudinally of the axis thereof and engage the packing bars to take up automatically the wear thereon, and springs in the rotor to engage the pressure bars and thereby press the packing bars against the faces of the blade with substantially unvarying pressure.

WILLIAM LISTER.