Patent GB-947351-A (GB)
Title: Rotary pumps, compressors and engines
IPC: F02B41/02
Filed: 1961-10-13
Abstract: 947,351. Rotary compressors, pumps and engines. J. M. S. LARPENT. Oct. 13, 1961 [Oct. 19, 1960; April 18, 1961], No. 36835/61. Heading F1F. A rotary pump, compressor or engine of the 'geared piston type, comprises a fixed cylindrical casing 1, Fig. 1, having inlet and outlet ports 26, 27, a concentric rotor 2 having diametrically opposite ports 23 and a pair of sector-shaped pistons 16 oscillatable within and rotatable with the rotor 2. The rotor 2 closed at one end by a plate 3, Fig. 3, is divided by a partition 8 into a compartment housing the pistons and a compartment housing a pair of satellite pinions 11 and a pinion 14 secured on a fixed shaft 15. To reduce weight cranked-ended, hollow shafts 10 mount the pinions 11. The cranked ends 12 being connected through rods 22 to the pistons 16. With the pistons initially symmetrically disposed about a plane of symmetry AA and the rotor 2 rotating in the direction of the arrow, fluid entering the inlet port 26 is sucked into the rotor through the adjacent port 23, the close together ends of the pistons then opening apart whilst the other ends move towards each other to expel the fluid from a previous cycle through the other port 23 and through the outlet port 27. The pinions 11 and the pinion 14 are made the same diameter to give a 1/1 gear ratio. The diameter ratio may be varied according to requirements to give one, two, four or six oscillations of the pistons 16 for every revolution of the shaft 4. Operating with a 1/1 gear ratio as a two-stroke I.C. engine, a two-part casing 68, 69, Figs. 8, 9, 10, includes an air intake port 50, a port 51 connected to a combustion chamber formed between concentric cylinders 52, 53 mounted on the casing, a port 57 leading from the combustion chamber and two rings of ports 58, 62, 63 and 59, 60, 61 controlled by a rotary valve 70. On rotation of the rotor 32 in the direction of arrow 49, air sucked in through the port 50 passes through the left-hand rotor port 35 to be compressed between the pistons 31a, 31b. On the port 35 approaching the port 51, the air is injected into the combustion chamber into which fuel is also injected through a fuel injector at 55. As a consequence of the temperature prevailing from a previous combustion the mixture ignites, passes through ports 54, the port 57 and port 35 to rotate and separate the pistons 31a, 31b and is finally exhausted through the port 58, valve 70 and outlet passage 71. The valve 70 which is rotated by the pinion 34 connected to the output shaft through a spoked wheel 65 and linkage 73 opens each port 58, 62, 63; in turn to the outlet passage 71. At a position corresponding to fuel injection, fresh air from a fan (not shown) is drawn in through an inlet 72 and the port 59 to drive out residual combustion gases from the exhaust chamber. When ports 35 have passed beyond the ports 58, 59, the corresponding chamber continues to expand and fresh air is drawn in through port 60 and thence port 61 after the port 63 has been closed. After bottom dead centre when the chamber begins to decrease in size this air is ejected through the port 50 after having cooled the inner walls of the chamber. A spark-plug 56 is fitted for starting. Spring-biased sealing strips such as 47, 48 seal the pistons with respect to the periphery and end walls 36, 37 of the rotor. Bolts 78, 79 with resilient convex washers 80, 81 beneath the nuts secure the two casing parts 68, 69 together. The bolts on one side are made hollow and oil or compressed air is supplied therethrough from a pump to a jack 82 to compressthe washers and urge the part 68 away from the part 69 and thus permit escape of oil or air from between the rotor and casing through a line 83 until a position of equilibrium is established. This feature allows any wear between the rotor and its casing to be automatically taken up. A pulley 84 mounted on the rotor shaft and driving the dynamo has its arms shaped as fan blades to draw in air and pass it through orifices into a steel casing 88 to cool the hottest part of the casing. Direct injection may be replaced by preliminary carburretion and the diameter ratio of the pinions may be changed to give two or more explosions per revolution of the engine shaft. Two units relatively displaced by 180 degrees may be joined together to give the equivalent of a conventional 8 cylinder, 4-stroke reciprocating piston engine.