Patent GB-190608422-A (GB)
Title: Improvements in or relating to Balanced Rotary Steam Engines and Compound Rotary Engines, Air Compressors, Pumps and the like.
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1906-04-07
Granted: 1907-04-04
Abstract: 8422. Thompson, W. P., [Austin, W. K.]. April 7. Compound an d multiple-expansion ; valves and valvegear; packing drums; fixed-abutment type with piston having outwardly-sliding vanes. In a rotary engine in which diametrical vanes slide in slots in a rotary drum situated eccentrically within the casing, three cylinders working at the same pressure are arranged on one shaft, and, when required, the motive fluid is used expansively by compounding two or more engines. One valve serves for distributing and reversing. A cylinder A, Figs. 1 and 2, is situated between two shorter cylinders B, Figs. 1 and 3. Three drums, which carry the sliding vanes, are keyed to a common shaft S. The casing is so arranged that the working space for the central cylinder is diametrically opposite to the working spaces of the other cylinders, whereby transverse balancing is attained. The central cylinder, Fig. 2, is provided with ports 13, 14, communicating with the valve chamber and with spaces 17, 18 in the double walls of the cylinder. Communication between the interior of the cylinder and the spaces 17, 18 is established by openings 19, 20, 21, 22, 23, 24. The spaces 17, 18 are also in communication with the cylinders B. The valve consists of two pistons 68 carried by a hollow stem 69, actuated by a rod 6. An inlet port 9 and exhaust port 8 communicate with the valve-chest. The construction of the drum and vanes is shown in Figs. 2 and 8. The vanes P, P<1>, P<2>, P<3>, carrying rocking shoes 53, are coupled together in pairs by two or more connecting-bars 56 which are passed through tapered bushings 57 carried by the drum and shaft. The ends of the bars are inserted in sockets containing springs 59. Within the bushings 57 and extending into the sockets in the vane are tubes 57 x which serve as guides for the bars 56, the passage of steam between the tubes and rods being prevented by packing-rings mounted centrally on the latter. The cylinder heads are made with segmental slots 76, 77, Fig. 2, with radial passages 78, 79. Steam is thus admitted behind the vanes and presses them against the casing during the working stroke, and is exhausted through the other slot and passage during the exhaust stroke. The outside cylinders are similar to the central cylinder except for the arrangement of the steam passages. Two steam spaces 34, 35, Fig. 1, are arranged side by side, but are not interconnected except by way of the working chamber. Fig. 3 is a section taken through the passage 35. Ports 36, 37, 38 open out from the space 35 to the interior of the cylinder. The passage 34 is similar to the passage 35 except that it extends up the right-hand side of the cylinder. The external sides of the outside drums are packed by spring - pressed rings 64, Fig. 1, guided in annular grooves in the end covers, and carrying pins sliding in slots in the end covers. The operation of the engine is as follows, reference being made to Fig. 5, which shows a developed plan of the cylinders and ports :-When the valve is in the position sbown in Fig. 2, steam enters the pipe 9, and passes round the exterior of the valve stem, through the port 13, and into the space 17. Part of the steam passes into the central cylinder, rotating the vanes and drum in a clockwise direction, is exhausted into the space 18, and passes thence to the exhaust port 14 and exhaust pipe 8. The remainder of the steam divides and passes along longitudinal passages 26 formed in the casing and enters the spaces 35 in the outside casings and passes into the cylinders through the openings 36, 37, 38. The steam is exhausted through openings 39, 40, 41 into the spaces 34, passes along longitudinal passages 29 which converge into the space 18 in the central cylinder, and is exhausted with the exhaust from the central cylinder. To reverse the engine the valve is moved over to the left. The port 14 then becomes the inlet port and the port 13 the exhaust port, the exhaust passing into the hollow valve stem and then through the pipe 8. The direction of flow in the passages shown in Fig. 5 is reversed. When the valve occupies a mean position, the ports 13, 14 are both covered by the pistons 68 and the engine is stopped. When it is desired to use expansive working, a number of the engines described above may be compounded. A triple-expansion engine is described in which the steam-supply piping is so provided with valves that one or two engines may be cut out. When a multiple-expansion engine is arranged with the shafts in line it is desirable to provide a sliding coupling on account of the unequal expansion of the shafts. The adjacent ends of shafting are formed with male and female parts t, u, Fig. 12, the former having a slot through which passes a cotter pin u<1> carried by the shaft u. The dimensions of the slot t<1> are such that a certain amount of relative axial movement of the shafts is allowed, but no relative rotation. The engines may be placed with the shafts parallel and connected together by suitable gearing. The engine may be used as a pump, air-compressor, or the like. Specification No. 11,241, A.D. 1887, is referred to.