Patent GB-1050228-A (GB)
IPC: F04C2/46
Abstract: 1,050,228. Rotary-piston pumps. BETEILIGUNGSUND PATENTVERWALTUNGS G.m.b.H. Dec.11, 1964 [Dec. 12, 1963], No. 50586/64. Heading F1F. A rotary-piston machine of the hingedabutment type, which is intended to be included in apparatus for transforming a reciprocating motion into a rotary motion, or vice versa, of the kind described in Specification 894,227, comprises an elliptical or polygonal piston 5 Figs. 1 and 2, (not shown) engaging with a single pair of diametrally-opposed pivoted-abutments or rockers 19, 20, each rocker being provided with two pairs of axially-orientated or helical sealing-strips 27, 28 and supported by a pin 21 on one side and a shaft 22 on the other side which are lodged in end covers 6, 7 of a housing 1. The sealing-strips on each rocker are disposed such that pressures in four working chambers 11--14 effect lateral forces on the pin 21 and the shaft 22 which neutralize one another. Each of the strips 28 engages with an arcuate surface 29 on a wear-resistant body 30 which is fixed in the housing 1 by pins 31 whereas the ends of each rocker engage with arcuate sealing-strips 24 whose ends abut sealing rings 25 for the end faces of the piston, the strips 24 and the rings 25 being lodged in the end covers 6, 7. Journals 8 for the piston are carried by bearing bushes 9 in the end covers 6, 7 and provided with gear teeth 10 for engagement with gearing connected to a further rotary-piston machine (not shown in the drawings). Inlet and outlet passages 15, 16 communicate with a cylinder 2 containing a reciprocating piston (not shown in the drawings) whereas further inlet and outlet passages 17, 18 communicate with a similar cylinder 3, these passages being similar to those shown in Fig. 5 (not shown) of the drawings accompanying the aforementioned Specification. The strips 27, 28 in each rocker may be loaded by pressure communicated to their innermost edges from the adjacent working chambers through passages 32, 33 which are formed in the rockers and controlled by a non-return valve 34 such that said edges are subject to the pressure of liquid in whichever of the two adjacent working chambers the pressure is greatest. The rockers may be modified in that a single sealing-strip 41 Figs.4 to 9, (not shown) in each rocker 40 engages with the piston 5, two pairs of such rockers being disposed around the periphery of the piston to form four working chambers. Each rocker is provided with three further sealing-strips 42, 43, 44 which are disposed in various ways according to the nature of the rocker so as to prevent unbalanced lateral forces acting on the trunnions 50 for the rocker. Pressures acting on opposed faces of each rocker are balanced by transverse passages 48, 49 in the rocker. If the strips 41--44 are assymetrically spaced apart from one another (Fig.7), balancing of said forces is effected by rendering the longitudinal dimensions of the strips accordingly (Fig.8). The rockers may be actuated by a cam 60 Fig. 10, (not shown) attached to a shaft 61 for the piston and engaging with an arm 57 fixed to one of the trunnions 50 of each rocker, the cam being axially-movable so that a spring (not shown in the drawings) lifts each rocker from contact with the piston to render the machine inoperative. The machine may include three cylinders, which are similar to the cylinders 2, 3, and six rockers having single sealing- strips in contact with the periphery of the piston.