US784614A - Rotary engine. - Google Patents

Description

No. 784,614. PATBNTED MAR. 14, 1905.

' J. D. BUCHANAN.

ROTARY ENGINE.

APPLICATION FILED JULY 29,1904.

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v PATENTED MAR. 14, 1905. J. D.BUGHANAN.

ROTARY ENGINE.

- APPLIOATION FILED JULY 29,1904.

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- Witnesses Inventor.

Attorneys Patented March 14, 1905.

PATENT OFFICE.

JOHN D. BUCHANAN, OF MEMPHIS, TENNESSEE.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 784,614, dated March 14, 1905.

Application filed July 29, 1904. Serial No. 218,716.

- **Tennessee, have invented a new and useful Rotary Engine, of which the following is a specification.

This invention relates to rotary steam-engines, andhas for its principal object to provide a perfectly-balanced easy-running engine for use in places where the pressure of steam is in excess of that actually required for the operation of the engine.

In river-boats carrying freight from landing to landing and especially in larger boats where the boilers frequently carry from two hundred to two hundred and fifty pounds of steam-pressure for the operation of the propelling-engine it is necessary when landing to either draw the fires or to allow the steam to escape from the boiler in order to prevent dangerous increase in pressure during the time the engines are inoperative. The lat ter course is universally followed and the steam is allowed to escape to the air or water and is wasted. In modern practice the load- 'ing and unloading of vessels is in many cases accomplished by means of small engines which operate conveying devices, and these engines, which Work best at a pressure of less than one hundred pounds, cannot consume all of the high pressure of the boilers, so that even during the operation of unloading at landings there is still an unavoidable waste of steam. It is found, moreover, that in the use of these loading and unloading engines, especially of the rotary type, excessive wear occurs when high-pressure steam is admitted to said engines, and the movable piston-wings are thrown in and out so rapidly and with such force that the engine is soon unfit for use.

The present invention therefore is designed to overcome difficulties formed in the operation of small rotary engines where the steam-pressure is in excess of that required for the operation of the engine and to utilize the excess pressure in balancing the engine, so that all of the movable parts may practically ride on the steam and injury to the parts prevented. All of the steam-pressure will thus be utilized to some advantage, although all of the pressure and force of the steam is not converted into power, and it is to be understood that the present engine is not constructed with a view of economically using steam, but rather with a view of utilizing to some advantage steam which otherwise would be wholly wasted.

A further and important object of the invention is to [obtain an almost perfect balance by the introduction of steam simultaneously at both ends of the cylinder and its exhaust at the center of the cylinder, so that steam will not be compelled to travel across the cylinder, and thus subject different portions of the piston-wings to varying pressure.

With these and other objects in view, as will more fully hereinafter appear, the invention consists of the novel construction and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size, and minor details of the structure may be made without departing from the spiritor sacrificing any of the advantages of the invention.

In the accompanying drawings, Figure 1 Similar numerals of reference are employed for the reception of a transversely-disposed shaft 5, to'which is secured the cylindrical piston-drum 6. The piston-drum is provided wth two sets of wing-receiving recesses Sand 9, the recesses overlapping and being disposed in staggered relation-that is to say, the recesses 8 extend from one end of the cylinder to a point somewhat beyond the center and the recesses 9 extend from the opposite end of the piston also to a point beyond the center, so that the recesses will to some extent overlapand each recess of one set is disposed midway between two adjacent recesses of the opposite set. In the several recesses are arranged piston-wings 10, that move in lines radial of the piston-drum into contact with the inner surface of the cylinder, being proj ected outward into the steamspace under steam-pressure and being forced inward as they gradually ride against the two abutments 11 and 12, that are formed integral with the cylinder, and in this connection it is to be noted that the two steamspaces are arranged in vertical alinement with one above and one below the pistondrum, so that the pressures being equal at the top and bottom the bearings will have to support no more than the weight of the pis tondrums and there will be no auxiliary pressure or impact of steam imposed upon them.

Each of the cylinder- heads 2 and 3 is provided with a pair of steam-inlet ports 12, the two ports of each head being in communication and being supplied with steam through a main steam-pipe 14, and these steam-inlet ports are arranged at points immediately in advance of the abutments at both cylinderheads, so that steam will simultaneously-enter from both ends of the cylinder, and endwise pressures on the piston will thus be balanced, the steam during the operations of the engine moving toward the center of the cylinder and escaping through ports 16 formed in the wall of the cylinder. The steam entering from one end of the cylinder will be met by steam under similar pressure entering at the opposite end of the cylinder, and the steam will therefore exercise practically uniform pressure at all points in the length of the piston-wings, the end thrust and irregular torque of engines which feed at one end and discharge at the other being thereby overcome.

In each end of the piston-drum is arranged an annular recess 18, in communication with all of the )iston-wing-receiving recesses, and said annular recess is further in communication with a port 19, leading through the bearing to said port, being supplied with steampressure through a pipe 20 and the steam passing through the annular recess and to all of the piston-wing-receiving recesses, so that piston-wings will be held outward in contact with the inner curved wall of the cylinder. It is found that when the pressure of steam is in excess of that required or even operating under ordinary pressure the outward movement of the piston-wings will result in considerable noise when the wings strike the walls of the cylinder, and, furthermore, there is considerable unnecessary wear on the outer edges of the wings and the surface of the cylinder with which they are in contact. T o overcome this difficulty, the inner curved wall of the cylinder is provided with a number of grooves 21, which extend completely around the cylinder, and with these grooves communicate steam-supply pipes 22, which may be connected directly to the boiler or to the main steam-pipes, the steam being preferably directed in lines tangential to the piston-drum, so that the impact of the steam will to some extent be utilized on the wings as they successively move outward into the steam-space.

Each of the piston wings is provided with one or more projecting lugs 23, that are of a width slightly greater than the thickness of the wing, presenting a rather extensive surface that is arranged at an oblique angle to the general lines of the wing. These lugs enter the grooves of the cylinder, and their inclined faces are so presented that the current of steam passing through the grooves must act to force the piston-wings inward toward the center of rotation of the drum, the inclined face of each lug being so arranged with relation to the adjacent wall of the groove that the steam must flow througha gradually-contracting space, so that the pressure is utilized to the best advantage in resisting the outward pressure of the steam which enters the wing-receiving recesses of the piston. The inner and outer faces of the piston-wing are thus both subjected to pressure, the two forces being opposed to each other and the piston-wing being thus balanced to some extent, so that frictional wear between the outer edge of the piston-wing and the adjacent surface of the cylinder will be minimized. The area of the grooves and lugs is of course properly proportioned with respect to the area of the wings, the latter area being of course the greatest, so that the steam cannot act to force the wings wholly within the recesses, and thus prevent the operation of the engine.

It is to be understood that this invention is intended for use only where the steam or other fluid under pressure may be wasted, and it would be of little or no value where economy of operation is essential.

Having thus described the invention,what is claimed is- 1. In a rotary engine, a cylinder provided with a continuous groove in its inner circular wall, a drum arranged within the cylinder and provided with wing-receiving recesses, and wings mounted within said recesses and provided with projecting lugs entering said groove.

2. In a rotary engine, a cylinder having a grooved Wall, a piston-drum provided with wing-receiving recesses, and wings mounted in the recesses and provided with lugs adapted to enter the grooves, said lugs having their faces arranged at an oblique. angle with respect to the bottom of the groove.

3. The combination in a rotary engine, of a cylinder having a grooved inner wall, a drum arranged within the cylinder and provided with piston-wing-receiving recesses, a plurality of wings arranged in the recesses and each having a projecting lug adapted to enter the groove, the Width of the lug being greater than the thickness of the wing.

4. The combination in a rotary engine, of a cylinder having a grooved wall, a piston-drum having wing-receiving recesses, a wing disposed in each recess and provided with a lug projecting beyond the general line of the outer edge of the wing, the width of the lug being greater than the thickness of the wing, and its outer face being inclined with respect to the outer edge of the wing.

5. The combination in a rotary engine, of a cylinder having a groove forming a continuous steam-passage, a drum arranged within the cylinder, and piston-wings carried by the drum and provided with projecting lugs that partly enter said groove.

6. The combination in a rotary engine, of a cylinder having steam-inlet ports at its opposite ends and provided with an approximately centrally-disposed escape-port, a drum arranged within the cylinder and having a pair of sets of wing-receiving recesses arranged in staggered relation, and piston-wings disposed in said recesses.

7. The combination in a rotary engine, of a cylinder having steam-inlet ports at its opposite ends and provided with an approximately centrally disposed escape-port, apiston-drum Y cylinder having a pair of inlet-ports disposed at its opposite ends and provided with an approximately central escape-port, a pistondrum disposed within the cylinder and having a pair of sets of piston-wing-receiving recesses disposed in staggered relation, and a pair of sets of piston-wings disposed in the recesses and having their adjacent ends overlapping. In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

JOHN D. BUCHANAN. Vitnesses J. H. JoonUM, Jr., J. M. WALKER.

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