GB1269063A - Improvements in or relating to rotary piston machines - Google Patents

Abstract

1,269,063. Rotary-piston machines. AVIATION SUPPLY MINISTER OF. Dec.4, 1969 [Dec. 6, 1968], No. 58177/68. Heading F1F. A rotary piston machine including a piston mounted for rotation within a casing, wherein the circumferential periphery of the piston sweeps over a spherical path of constantly varying width, and a substantially ring-like sealing member comprising an oblique section of a hollow sphere is interposed between the circumferential periphery of the piston and the casing. The invention is described with reference to a rotary-piston machine of the nutating piston type comprising a disc-like piston 1, Fig. 1, having radial diametrically disposed lobes 18, 20 on one face, radial diametrically disposed lobes (17), 19 at 90 degrees to the other lobes on the other face and part spherical bosses 5, 6 and a casing having end housings 2, 3 with an interposed part-spherical housing 4 so that when the piston rotates the lobes 18, 20 and 17, 19 sequentially abut the plane end-faces of the housings 2, 3 to form variable volume chambers. Between the part-spherical rim of the piston 1 and the part-spherical inner periphery of the housing 4 is disposed a resilient ring-like sealing member 25 in the form of an oblique section of a hollow sphere having around its periphery a plurality of circumferentially spaced transducers 29, Fig. 3, which sense the proximity of the ring-like member with respect to the rotor and control actuators 28, one for each transducer, which as shown are screws, to vary said proximity. At slow speeds when sealing is paramount the ring 25 is adjusted into close proximity to the piston and at higher speeds when sealing is not so important and wear rates greater, the screws 28 are adjusted so that the clearance between the piston and ring 25 is greater. In a modification, the transducer signals may be used with appropriate circuitry to operate electropneumatic, electro-hydraulic or electromechanical actuators. Each of the lobes 17, 18, 19, 20 may comprise a seal member 30, Fig. 4, supported by a pair of flanged keeper plates 31, 32 and resiliently loaded by a cruciform section resilient synthetic rubber strip 35.