GB997878A - Revolving piston machine with principal and auxiliary revolving pistons - Google Patents

Abstract

997,878. Rotary piston machines. A. MENCIK VON ZEBINSKY. Feb. 1, 1962 [Feb. 6, 1961; Oct. 20, 1961], No. 3849/62. Heading F1F. A rotary piston machine operable as a pump, compressor, I.C., steam or gas engine, or a hydraulic or pneumatic motor, comprises a principal piston A, Fig. 1, and a co-operating auxiliary piston B mounted for rotation at constant speed in the same direction on spaced apart parallel shafts with the principal piston having a profile comprising the major portion having the same radius as a basic circle 2 and two circular arcs of radius R tangential thereto intersecting at a point 3 or meeting in an arc opposite to the mid point of the basic circle portion and the auxiliary piston having a profile which corresponds with the major portion of an auxiliary circle 6 centred on the basic circle and of radius less than two-thirds that of the basic circle and a circular arc centred on the intersection point 3 having a radius equal to that of the two circular arcs and wherein the perpendicular distance of a line 5, 5 joining the intersection points of the auxiliary circle with its circular arc from the common centre is at least two-tenths of the radius of the auxiliary circle. The construction of the profiles of the principal and auxiliary pistons are shown in Fig. 1. The housing surrounding the principal piston is circular having a radius equal to the distance of the common centre 1 from the intersection point 3. On clockwise rotation of the pistons, fluid is sucked in at E after the passage of the point 3 and is compressed during the following stroke and forced out at D. In Fig. 2, a further auxiliary piston B 1 is fitted, providing an abutment between chambers V 2 , V 1 . During clockwise rotation of the pistons, fuel-air mixture sucked into chamber V 1 through inlet D during the preceding revolution is compressed and pushed out at E by the point 3 and forced into a container F. The fuel-air mixture is then admitted through the inlet G after the passage of the point 3 and ignited. It then expands in the chamber V 2 and is finally exhausted through outlet H. The pistons are interconnected by gearing to provide synchronised movement therebetween and permit the use of contactless seals and the omission of lubricant between the pistons with the consequent non-pollution of the working fluid with oil. Seals inserted in dove-tail grooves at the point 3 and the intersection points on the auxiliary pistons may however be fitted or alternatively labyrinth seals, Fig. 5b, may be included over an arcuate portion of the piston profile located at point 3. The gearing may comprise a gear on each piston and an intermediate gear engaging those gears mounted on a shaft offset from a straight line joining the piston axes with the gear wheels slightly conical and the intermediate wheel axially adjustable to take up backlash and wear. The embodiment shown in Fig. 2, may be adapted to operate as a two-stage compressor. Air sucked in at G being compressed in the chamber V 2 and then exhausted through H into an inter-cooler. It is re-admitted at D and further compressed in the chamber V 1 before passing through the outlet E to its point of use. Several principal pistons, three in Fig. 6, may be mounted on a common shaft 1 separated by intermediate side walls with the points 3 angularly staggered and a corresponding number of co-operating auxiliary pistons mounted on a common shaft 7. The machine may be liquid or air cooled. In Fig. 9, cooling air is admitted at L 1 on either side of the principal piston 2, passing over the bearings 31 and through cooling fins 27 to cool the hub and central web of the piston. It is then directed by fins 26 over side flanges 25 of the piston and thence through fins 29 between the machine housing C 2 and an outer-casing to finally leave at L 2 . In another embodiment, Fig. 10, cooling air entering at L 1 divides into two streams to cool both the shaft 1 and hub 1b and the piston periphery. Parts 33 may be designed as reinforcing ribs and cooling liquid or air may circulate through pockets 32 in the housing. A separate impeller may also be used to circulate the cooling air. Further embodiments are described in Figs. 7 and 8 (not shown) in which the profiles of the principal and auxiliary pistons are somewhat modified.