Hydraulic actuator a hydrostatic mode of operation, then in an emergency, and advantages of the flight control.

摘要

A hydraulic actuator (1) comprising at least a system of double action jack (10), a mobile switching member (17), mounted in a recess (16) hydraulically connected, on the one hand to the jack, on the other hand, through a hydraulic distribution member (33), to feed and exhaust ducts of fluid (34, 35) of the isolating valves (38, 39), a reserve of fluid (47) connected to the discharge duct, and a control (51) adapted to control this mobile switching member between a neutral configuration, in which the jack is hydraulically isolated from the hydraulic distribution member and an active configuration of service in which the cylinder communicates with said dispensing member may be hydraulic, characterized in that it further comprises a pump unit controlled with variable speed (60, 61) connected by an auxiliary circuit of the branch (71, 72, 73, 31, 32, 41), on the one hand, with the recess (16) of the slide, on the other hand, with the reserve of fluid (47), the mobile switching member being to three positions, and being provided with a means of additional control (49) adapted to control said mobile switching member between said neutral configuration and a second active configuration in which the cylinder communicates with the auxiliary circuit, so that the actuator, the pump unit and the auxiliary circuit constitute a hydrostatic transmission.