Three way electro hydraulic distribution device for e.g. automatic gear box of vehicle, has piston balanced in pressure and alternatively connecting impeller channel to flash ring or to reservoir return line using sealing faces

摘要

The device has a piston (3) movable axially in a cylinder (2) under antagonistic effects of a return spring (4) and magnetic stress produced by an electromagnetic circuit. Positions of the piston in energy-less state and under electrical energy of a coil respectively determine facial sealings on its sides (33,34) to isolate an impeller channel (35), such that a three way switch alternatively connects the channel to a flash ring or to a reservoir return line using the facial sealings.