GB1495727A - Radial piston fluid handling devices - Google Patents

Abstract

1495727 Reciprocating pumps K EICKMANN 28 Nov 1974 51658/74 Heading F1A In a radial-piston pump a rotor 9 has pistons 2 with pivoted shoes 12 that engage with a cam, or "guide", ring 33 and lie between annular plates 14 secured to either the rotor or the guide ring, the radial dimensions of the shoes being less than those of fins 23 extending circumferentially of the rotor between the cylinders 10 for the pistons. The shoes when the respective pistons are in the fully retracted position thus lie radially below the outer surfaces of the adjacent fins (as shown on the left-hand sides of Figs. 1 and 2). An annular slot 24 saves the ring 33 from being fouled by the fins. Lubricating and pressure-balancing recesses 16 and passages 21 may be formed in the shoes. Substantially hemi-spherical portions of the shoes are retained in the pistons by virtue of the matching shapes of the seats for these portions. A second embodiment, Figs. 5 and 6 (not shown), differs in that the shoes are free to move both radially and axially relative to the pistons and lubricant is fed to the shoe surfaces through narrow helical passages (63) in the pistons. A third embodiment, Fig. 7 (not shown), has two sets of pistons disposed axially side-by-side in a common rotor and radial projections (75) on the shoes extending into an annular channel (78) in the rotor. In a fourth embodiment, Figs. 8, 9 and 10 (not shown), the shoes pivot about axially-orientated axes only and can move axially between the plates 14.