A hydraulic machine includes a casing with a body and a cover; a separation member which can make a reciprocating movement and defines two chambers; hydraulic switching elements including a distribution member; a compartment in the body of the casing connected to a pressurized-liquid inlet, and initiating elements including a pusher connected to the separation member, these initiating elements being able, at the end of the stroke, to cause a sudden change in the position of the switching elements, under the action of an elastic member to reverse the stroke. The distribution member has a distribution slide valve applied against a flat plate which is fixed relative to the body of the casing, the slide valve being able to slide in a fluid-type manner, without a seal, against the plate, which has orifices connected respectively to the chambers and to a liquid outlet orifice.