Patent GB-423925-A (GB)
Title: Improvements in and relating to fluid pressure motors
IPC: F01B17/02
Filed: 1933-05-06
Abstract: 423,925. Fluid pressure motors. SULLIVAN MACHINERY CO., 400, North Michigan Avenue, Chicago, U.S.A. May 6, 1933, No. 13283. Convention date, May 20, 1932. [Class 122 (ii)] Comprises a motor for operating pumps for use in raising oil from wells. Heated compressed air is supplied to the motor and is exhausted with considerable residual pressure to the compressing plant. The motor is pivotally supported from a cross-member of a framework, and comprises a single-acting cylinder 7 with a lower head 8 with separate admission and exhaust valves connected to spring-pressed pistons provided with a plurality of actuating-areas which . are subjected to cylinder-pressure in a predetermined order to move the valves in one direction, and in a reverse order to reverse the valve movements. The pressure is supplied to the areas from the same side of the cylinder. Air is supplied through a preheater to pipe 12 and is exhausted at 13. The piston-rod 16 is connected to the rod of the well pump. The admission valve 25 is operated by a piston 36 with an extension 39 which is acted upon by a spring 40. The exhaust valve 42 is provided with a stem 43 upon which a spring 45 acts to close the valve. The stem 46 is seated in a bore 47 in the piston 48 whose lower area is equal to the effective top area of the valve. The piston 48 comprises heads 49, 50 provided with actuating- areas 63, 64. The heads 36, 39 have areas 61, 62. The cylinder communicates with the areas 61, 64, through connections 71, 74, respectively and with areas 62, 63 through connections 72, 721, 73, 731 respectively. The connections are controlled by hand-operated valves housed in fittings 75, 85, Figs. 2, 3, 4. The fitting 75 is connected to the branch 71, by a port 76 to the cylinder, and interconnects branches 73, 73<1>. The valve 78 normally closes the connection 76, 73<1>. When reversed, the branch 73<1> is closed and 73, 71 are opened to the cylinder. In the fitting 85, the cylinder connection 86 communicates with the branch 74. When the valve 87 is operated, the branch 72<1> is closed, and branch 72 is opened to the cylinder. When the piston passes port 76, fluid passes to area 61, but valve 25 remains open. When the piston passes port 73<1> area 63 is subject to pressure, but the exhaust valve remains closed. When the piston passes port 72<1> fluid is supplied to the area 62, the valve is balanced and closed by the spring 40. The piston rises to position C when the port 86 is passed. The exhaust valve is then balanced, and opened by the spring 54, the cylinder pressure below the piston drops to 100 lbs. per square inch. The weight of the rod lines, &c., move the piston downwards. The surface 64 is opened to exhaust, but the exhaust valve remains open. When the piston passes port 72<1>, the area 62 is exhausted, but the admission valve 25 remains closed. When the upper edge of the piston 15 overruns port 73<1>, the surface 63 is exhausted, and the exhaust valve is closed by the back pressure. The piston now moves downwardly against compression. When the piston top passes port 76, the area 61 is exhausted to atmosphere, and the valve 25 is opened. To operate at very slow speeds the connections 72<1>, 73<1> are closed. When the pump is to operate continuously on the slow stroke, the connections 72<1>, 73<1> are eliminated and the orifices plugged. A number of different points 91, 92, 93 are provided for connecting to the ends of the passages 72<1>, 73<1> to modify the expansion or compression. When operating without expansion and compression, the spring 40, being compressed, while the spring 54 is distended and opposed by spring 45, ensures the closure of the admission valve before the opening of the exhaust valve.