GB598279A - Volume compensator for hydraulic systems - Google Patents

Abstract

598,279. Telemotor gear. DEHN, F. B. (Adel Precision Products Corporation). Sept. 14, 1945, No. 23806. [Class 69 (ii)] In a volume compensator A for a hydraulic system comprising a housing 1, Fig. 1, with two coaxial cylinder bores 2, 3 of different diameters and a spring- pressed dual piston 7, 8 separating the bores 2, 3 to form two liquid chambers, and comprising ports 12, 18 for connecting the chambers with liquid lines B, C respectively, the dual piston is hollow to receive a portion of a spring 24 urging the piston to put the liquid in the chambers under pressure. The hydraulic system comprises a pump and slave unit D, E connected by the lines B, C, and the volume compensator A which is also connected to the lines B, C by one-way restrictor valves 15, 22. Each restrictor valve comprises a cylindrical housing 28, Fig. 5, in the bore 29 of which is located a square-sectioned hollow valve 30 urged against a seat 32 by a light spring 33. Restricted fluid flow between the lines B or C and the bores 2 or 3 when the valve 30 is seated is effected by means of a passage 30a, a radial port 35, a groove 38, an L-shaped port 37 in a plug 36 and a port 34. Hydraulic locking means for the slave unit E comprises spring-loaded valves 47, 48 controlling fluid flow through passages 49a, 50a, and a fluid-actuated valve-operating piston 54 reciprocable in a bore 55 and provided with projections 56, 57 to unseat that valve 47 or 48 which is not opened by fluid in line B or C. Bleeder valves 43, 44 on opposite sides of the slave piston 45 serve to bleed air from the system and to introduce working fluid. Leakage may be made up by a needle valve 42 in the pump unit D.