GB1151123A - Improvements in or relating to Internally Meshing Gear Pumps. - Google Patents

Abstract

1,151,123. Internally-meshing gear pumps and motors. O. ECKERLE. Aug. 26, 1966 [Aug.31, 1965], No.38419/66. Heading F1F. In an internally-meshing gear pump (or motor) comprising a driven (or driving) pinion, a corotating internally-toothed ring gear and a sickleshaped filling piece therebetween, the pinion and ring gear are mounted in pressure-relieved hydrostatic bearings and the filling piece is suspended to be slidable transversely and swivellable about a longitudinal axis, and rotatable about an axis perpendicular to the longitudinal axis. As shown in Figs.1 and 2, the shaft on which the pinion 5 is formed is hydrostatically supported in bearing plates 20, 21' and each bearing plate includes a spring-loaded compensating piston 21 having a pressure relief area 22 and a pressure area 23 subjected to pump discharge pressure. The pressure area 23 is connected to the pumping chamber by an annular recess 31, passages 32, 33 and a recess 34 in the bearing plate and a bore in an axial pressure piston 35 which fits the recess 34. The recess 34 and the piston 35 which is formed with a flange having a pressure relieving recess approximate to the shape of the filling piece 8. The compensating pistons 21 urge the pinion 5 sealingly against the filling piece 8 which is swivellably supported on a pin 10 and the filling piece in turn against the ring gear without undue frictional force. At the same time the pistons 35 are urged into sealing engagement with the side faces of the pinion, ring gear and filling piece to seal the pump chamber, again without undue frictional force. Pump discharge pressure also passes through radial holes in the ring into a pressure relieving recess 7 of a control piston 6 subjected on its opposite face to pressure in the pump discharge connection 14. The control piston 6 also urges the pinion, ring gear and filling piece into sealing engagement with each other without undue frictional force oppositely to the compensating pistons 21. The pin 10 is supported at each end in a block 41, Fig. 4, which blocks slide in slots in 40 in the bearing plates 20, 21' to allow transverse movement of the filling piece 8. The pinion shaft may be separate from the driven shaft and inter-connected therewith by a clutch. In another embodiment, the control piston may be acted upon by a pair of pressure pistons (52, 53, Fig.5, not shown) and the pin 10 and an additional fastening bolt (57) are inserted non-slidably in the bearing plates 20, 21' so that the bearing plates move with the filling piece 8. In other embodiments the pin 10 is guided in elongated slots in the bearing plates and the compensating pistons are located in bores in the bearing plates which are disposed tangentially to the pinion shaft.