GB1085232A - Improvements in or relating to hydraulic motors - Google Patents

Abstract

1,085,232. Hydraulic reciprocating motors. CHAMBERLAIN INDUSTRIES Ltd. June 25, 1964 [June 25, 1963; March 25, 1964], Nos. 25285/63 and 12759/64. Heading F1A. [Also in Division F2] A hydraulic motor has radial cylinders 10 with pistons 15 engaging an eccentric 14 through sliding shoes 16, a drive shaft 13 being connected to eccentric 14 and, through an Oldham coupling, to a rotary valve 17. The valve has annular channels 26, 27 communicating with inlet and outlet connections 22, 23, and with arcuate channels 24, 25 which sequentially register with cylinder passages 21. Pairs of balancing recesses 30, 31 at each end of the valve are connected to channels 24, 25 through bores in the valve. Plastics sealing rings 35, e. g. of P. T. F. E., are mounted in annular grooves, either the groove walls or the rings being fluted to prevent pressure build-up, Fig. 5 (not shown). Further pressure balancing of the valve 17 is provided by scallops 36, transverse passage 37 and axial passage (38) Fig. 3 (not shown). Piston shoe 16 engages the piston 15 through a ball head with a ring contact with the internal piston surface Fig. 4 (not shown). The shoe bearing surface 41 is hydraulically relieved by liquid from the working chamber passing through the piston and passage 42 and throttle 44. In Fig.8 (not shown), a filter (57) is mounted in the piston passage, and the throttle insert (44) is tapered to trap foreign matter and to lock the insert in position. Piston rings of P. T. F. E. are either wedge-shaped, Fig. 6 (not shown), or trapezoidal, Fig. 7 (not shown), so that axial pressure forces them into contact with the piston and the cylinder wall. The piston shoes 16 are located by rings 45 and discs 46. Rings 45 may be recessed into the shoes.