Abstract: A reversible motor includes a rectilinear shaft (1) having peripherally arranged semi-spherical cavities (24) each engaging the ball-appendage (25) of a radial cylinder (21). A related piston (28) reciprocates axially within each cylinder chamber (27) and is also furnished with a ball-appendage (29) connected within a spherical socket (30) located in a traverse (31). The traverse joins two discs (32 and 33) together whose inner cylindrical surfaces rotatably surround a pair of stationary eccentric rings (38) rotatably engaging the shaft (1). The shaft rotates by means of a drive hub connected to the actual shaft and having arms (42) in contact with a recess (43) formed in the rotating discs (33). A roller wheel (45) protruding laterally from each of the radial arms into the recess (43) transmits rotation to the drive hub.