Hydraulic motor

A multi-piston hydraulic motor, comprising a stationary housing;

• a rotor having a central axis of rotation and mounted in said housing, said rotor having a plurality of hollow radially extending pistons spaced from each other in a circumferential direction;
• a plurality of cup-shaped cylinders located in said housing and spaced from each other in the circumferential direction, each cylinder being mounted on and displaceable over the respective piston, said housing having two cam tracks spaced from each other in an axial direction of the rotor, each of said cylinders having two journals extending oppositely in said axial direction, each of said journals having axes and carrying a control roller abutting against the respective cam track and cooperating therewith;
• a central control shaft concentrically mounted in said rotor and conveying a pressure fluid, said control shaft communicating with said hollow pistons to feed the pressure fluid to said hollow pistons, said rotor having a flange portion on a driven side thereof, said flange portion being coaxial with said central axis;
• said rotor being mounted in said stationary housing by a single roller bearing formed as a four-point ball bearing to absorb radial forces and axial forces in both axial directions exerted on said rotor in operation, said bearing being positioned between said flange portion and said housing and being radially outwardly offset at a greater distance from said central axis than the axes of said journals.