Abstract: A hydraulic motor comprises a body and a piston able to slide in a reciprocating movement in a cylindrical housing of the body. A chamber (C1, C2) is formed on each side of the piston and hydraulic switching means are provided for feeding and evacuating the respective chambers (C1, C2), these switching means being able to adopt two stable positions. Control means (H) having elastic means for abruptly bringing about changes in the position of the switching means are included. There are triggering means (13, 15) able, at the end of the stroke of the piston (9), to bring about the change in position of the switching means (G). The piston (9) has a closed cross section and the switching means (G) are arranged in the body (1) of the machine, redially on the outside of the cylindrical housing (7) in which the piston (9) slides.

Abstract: The invention concerns a hydraulic machine, in particular a hydraulic motor, comprising: a body (1), a piston (9) adapted to slide in reciprocating motion in a cylindrical housing (7) of the body, a chamber (C1, C2) being formed on either side of the piston, hydraulic switching means for feeding and evacuating the respective chambers (C1, C2), control means (H) for abrupt change of the position of the switching means, and triggering means (13, 15) for, at the end of the stroke of the piston (9), changing the position of the switching means. The piston (9) is a single acting and non-differential piston, having a closed cross-section and the switching means are arranged in the body (1) of the machine, radially outside the cylindrical housing (7) wherein slides the piston (9).