Patent GB-1270993-A (GB)
Title: Rotary piston devices
Inventor: BANCROFT CHARLES
IPC: F01C1/07
Filed: 1969-07-22
Abstract: 1,270,993. Rotary-piston machines. C. BANCROFT. July 22, 1969 [Aug. 5, 1968], No. 36891/69. Heading F1F. A rotary-piston machine of the kind in which pistons alternately accelerate and decelerate while moving in a rotary manner about a single annular chamber contained in a stator housing, comprising four sets of angularly spaced vane pistons successively disposed in the said chamber, each set having at least two vanes secured to a support member, a rotatably mounted crank-shaft in the stator housing having an offset crank-pin, a plurality of connecting members each having its axis offset from the crank-shaft axis, at least one of the connecting members being rotatably mounted with its offset axis concentric with the axis of the offset crank-pin and engaged for rotation on the crankshaft by gear means inter-connecting the said one connecting member with the stator housing wherein each of the piston sets is connected to at least two of the connecting members by means of radially slidable pivotable bearings, to at least the said one connecting member mounted on a crank-pin and to at least one connecting member common to all the sets of pistons. In one embodiment, an I.C. engine 243, Fig. 1, according to the invention drives an intake blower 241 and also compresses air or generates compressed gas to supply a compressed gas motor 239, which may alternatively be a turbine. The blower 241 supplies compressed air through intake ports 229 to the engine wherein it is further compressed and at full compression just prior to or just after the injection of fuel through injectors 233 a portion of the compressed air or combustible gas is delivered through valve controlled conduits 238 to the gas motor 239. Spark-plugs 232 ignite the remaining combustible gas or the remaining compressed air with injected fuel to drive the engine. When compressed air uncontaminated with fuel is delivered to the gas motor a further fuelinjector 246 and a further spark-plug 247 may be provided. The fuel-injector being controlled by a bi-metallic or other temperature sensor unit 244 supplemented if desired by a pressure-sensitive device (not shown). The engine 243 comprises a stator housing 221, Fig. 13, having an annular chamber 36 within which four piston sets 31, 32, 33, 34, Fig. 16, each having four vanes are successively arranged and secured to respective ring-shaped support members 41, 42, 43, 44 by which they are connected to the crank-shaft 224 through at least one captive connecting member 220 and to each other by at least one floating connecting member 225. Captive connecting member 220 is supported by needle bearings on the crankpin of the crank-shaft 224 and is formed with four radial arms each carrying a pivot pin 41i, 42i, 43i, 44i, Fig. 14, which co-operate via pillow blocks 41h, 42h, 43h, 44h with radial guideways 41g, 42g, 43g, 44g formed on members 41c, 42c, 43b, 44b respectively. Members 41c, 42c are bolted to flange portions 41b, 42b of support members 41, 42 for the piston sets 31, 32 and members 43b, 44b co-operate with support members 43, 44 for the piston sets 33, 34. Teeth formed on the connecting member 220 co-operate with teeth formed on a part 226 secured to the housing 221. Floating connecting member 225 is formed on one side with a pair of diametral pivot pins 41f, 42f, Fig. 15, co-operable via pillow blocks 41e, 42e with radial guideways 41d, 42d formed on the flanged portions 41b, 42b of support members 41, 42 and on its other side with a pair of diametral pivot pins 43f, 44f disposed at 90 degrees to the first pair. The pins 43f, 44f are co-operable via pillow blocks, 43e, 44e with radial guideways 43d, 44d formed on the members 43b, 44b. The shaft 224 is formed with a balance weight to the crank-pin. The end faces of the support 43, 44 close one side of the chamber 36 and are of the same cross-sectional area as the end-plate 227 of the housing 221 to ensure that the thrust resulting from the internal pressures within the chamber 36 are balanced out. Sealing rings 41k, 43k, 44k between the support members and between the support member 44 and the internal periphery of the chamber 36 provide sealing between the respective members. In Fig. 16, vane pistons 32 are in minimum velocity position of the operating cycle, vane pistons 33 are decelerating and approaching vane pistons 32, vane pistons 34 have begun their accelerating advance and vane pistons 31 are moving at maximum velocity. The upper right and lower left vane pistons 32, 33 contain between them the compressed charge drawn in previously through intake ports 229. Just prior to these pistons reaching the positions shown in Fig. 16, spring-loaded valves 236 open to discharge compressed air to the motor 239. The remaining compressed air is transferred to firing chambers 232 into which the fuel is injected and the mixture ignited by spark-plugs 234. The mixture expands into the space between vane pistons 32, 34 and drives the latter to exercise the power stroke. Alternatively air mixed with fuel from carburetter system may be admitted to the intakes 229. A compressed gas by-pass 242 may be fitted connecting a conduit 238 to a position ahead of a vane piston 34, whilst heated by its compression the by-pass gas is substantially cooler than the expanding combustion gases and provides cooling of the chamber and supplements the output torque. The motor 239 may have three piston sets with four vane pistons in each set as described in the Specification with reference to Figs. 2 to 7 (not shown) or four piston sets with two vane pistons in each set as described with reference to Figs 8 to 12 (not shown). In this latter embodiment, a control valve controlling the admission and discharge of gas to and from the motor, comprises pairs of spring-loaded pistons 179, 181, Fig. 12, slidable in chambers 174, 176 on opposite sides of a partition 177 and fixed to a rod 178. The pairs of pistons are cross-linked by connecting rods 206 and a rocker shift lever assembly 204 connected to variable ring gear angular shifting mechanism Fig. 10 (not shown) by links attached to the opposite ends of rocking beams, one at each end of a shifting sleeve 203 and to amplifying linkage. Levers 207 connected to rods 206 are connected to a shift plate 211 by pivot pins 209 and pivot about anchor blocks 208. The shift plate 211 is fixed to or forms part of the shift sleeve 203. The variable ring gear angular shifting mechanism controls the accelerating and decelerating movements of the vane pistons so that the control valve controls the flow of gas to and from the motor in correct phase with vane piston movement. The amplifying linkage gives pivoting movement to the sleeve of about 55 degrees for an angular movement of about 20 degrees for the levers 207. In another embodiment, Fig. 8 (not shown) the control mechanism is duplicated on the other side of the annular chamber. Splash lubrication ensures ample lubrication of all the sealing ring assemblies. Lubricant drawn in at regions of low-pressure is forced towards regions of higher pressure to lubricate all sliding surfaces between the support members and the shell. Instead of operating as an I.C. engine the device may be driven by steam. These vane piston engines may serve as power units to provide output torque to drive, e.g., boats, motor vehicles and small aircraft.