GB1256798A - - Google Patents

Abstract

1,256,798. Semi-rotary fluid-driven motors. CITROEN S.A. (AUTOMOBILES CITROEN, BERLIET, PANHARD). March 27, 1969 [March 29, 1968], No.16150/69. Heading F1F. A semi-rotary motor, or actuator, has a vertical shaft 4 extending through units, or "stages", A- -D coupled mechanically in series and hydraulically in parallel with one another, each stage comprising a casing 1 containing an abutment 3 and a sleeve 2 furnished with a vane 2a. The sleeve of the stage D is fixed to the shaft, the sleeves of the other stages being capable of angular displacement relative to the shaft and coupled to the casing of the stage thereabove. Whereas the casing of the stage A is fixed, the casings of the other stages are capable of angular displacement about the shaft, which can turn about its own axis relative to the casing of the stage A. Conduits 5, 6 in the casing of the stage A, conduits 7, 8 in each sleeve, bores 11, 12 in the shaft and annular channels 9, 10, 11a, 12a are provided for admission and discharge of the working fluid to and from chambers 1a, 1b in each stage. Angular displacement of the sleeves relative to the respective casings results in greater angular displacement of the shaft relative to the casing of the stage A, which displacement may exceed 360 degrees, depending upon the number of stages. A second embodiment, Figs. 4 and 5 (not shown), differs chiefly in that the motor is effectively inverted, the shaft (104) being fixed and the casing (101) of the uppermost stage (D 1 ) is coupled to an output gear-wheel (113). Each stage has two diametrically-opposed abutments (103) and two diametrically-opposed vanes (102a) on the sleeve (102). The stages can be actuated independently for one direction of angular displacement and either independently or simultaneously, for the other direction to which end one pair of chambers (101a) in each stage is connected to a respective bore (111) in the shaft and the other pair of chambers (101b) is connected to a common bore (112) in said shaft. The abutments in the various stages span different angles. At least one of the stages may serve as a shock absorber, its respective bore (111) being permanently pressurized. Since such a stage, or stages, can absorb shock in one direction of angular displacement only, one of the stages may be arranged to absorb shock in the other direction. A counter-pressure may be applied to the, or each, shock-absorbing stage through the bore (112) and adjustable valve (not shown).