Hydraulic engine with compact brake

A hydraulic motor comprising:

• a casing;
• a reaction member integral with or secured to the casing and having an internal periphery that defines a reaction profile;
• a cylinder block which is mounted so that the cylinder block and the reaction member rotate relative to each other about an axis of rotation, the cylinder block comprising a plurality of piston-and-cylinder sets comprising cylinders and pistons, disposed radially relative to the axis of rotation and suitable for being fed with fluid under pressure;
• an internal fluid distributor constrained to rotate with the casing about the axis of rotation, and provided with distribution ducts that can put the cylinders in communication with fluid feed and exhaust ducts;
• and
• a braking system comprising first and second braking means constrained to rotate respectively with the casing and with the cylinder block about the axis of rotation, a brake piston having a substantially radial active braking face to which a brake member is secured, said piston being suitable for taking up both a brake-releasing position and a braking position in which said piston urges the first and second braking means into braking engagement so as to prevent the cylinder block and the casing from rotating relative to each other, and means for displacing the brake piston between said braking and brake-releasing positions;
• said brake piston being constrained to rotate with the casing about the axis of rotation and the brake member which is secured to the active braking face of said piston being a first brake member belonging to the first braking means.