Abstract: Apparatus for eliminating cavitation in a main pump in which the rotor of a supercharging pump is connected to the rotor of the main pump such that the latter rotor drives the rotor of the supercharging pump. Permanent communication is established between the delivery side of the supercharging pump and the induction inlet of the main pump. A hydraulic fluid reservoir is connected to the inlet of the supercharging pump and it is also connected to the delivery side of the supercharging pump through the intermediary of a valve which controls the flow of hydraulic fluid to the reservoir from the delivery side of the supercharging such that when the pressure at the induction inlet of the main pump exceeds a predetermined value flow is established to the reservoir in order to avoid the appearance of cavitation in the main pump. Leakage flow within the main pump is also recycled to the reservoir continuously through the valve.

Abstract: A distributing unit for a dual-action hydraulic electro-distributor of the type comprising, firstly, a distribution stage provided with a bore in which a slide is mounted so as to slide between two end positions with a spring return to a central or neutral position and, secondly, a piloting stage with valves controlled selectively by solenoids, each of the valves being adapted, when actuated, to communicate the feed pressure to the corresponding end of the slide and, when not actuated, to set the corresponding end chamber of the bore to return to the tank, wherein untimely displacement of the slide, e.g.