An infusion pump device, comprising - a housing (14, 15) which is divided into at least three operating layers positioned one above the other, wherein - a first operating layer (fig. 5) includes an epicyclic gear means (7, 100, 200) comprising a rotatable central gear, a stationary outer ring gear surrounding the central gear, and movable planet gears which are arranged between the central gear and the ring gear and in movable engagement with both the central gear and the ring gear, - a second operating layer (fig. 6) includes a roller bearing means (1, 2, 16) comprising a stationary outer ring and a movable inner roller arrangement (1, 2) which is in movable arrangement with the outer ring and coupled with the epicyclic gear means (7, 100, 200) so as to provide a rotational bearing for the central and planet gears (100, 200), wherein the inner roller arrangement (1, 2) of the roller bearing means (1, 2, 16) is non-rotatably coupled with at least the central gear of the epicyclic gear means (7, 100, 200) and comprises a rotatable central roller and movable planet rollers which are arranged between the central roller and the outer ring and in movable engagement with both the central roller and the outer ring, and - a third operating layer (fig. 7) includes a rotary peristaltic pump means (1, 2, 4) comprising a stationary flexible, preferably resilient, tubing which includes a bent portion having an essentially part-cycle form, and a rotor (1, 2) which is provided with engagement elements for locally engaging the bent portion of the flexible tubing so as to squeeze it during rotation for a pump action, wherein the rotor (1, 2) is coupled with the central gear of the epicyclic gear means (7, 100, 200) so that a torque is transferred from the central gear to the rotor (1, 2). - a housing (14, 15) which is divided into at least three operating layers positioned one above the other, wherein - a first operating layer (fig. 5) includes an epicyclic gear means (7, 100, 200) comprising a rotatable central gear, a stationary outer ring gear surrounding the central gear, and movable planet gears which are arranged between the central gear and the ring gear and in movable engagement with both the central gear and the ring gear, - a second operating layer (fig. 6) includes a roller bearing means (1, 2, 16) comprising a stationary outer ring and a movable inner roller arrangement (1, 2) which is in movable arrangement with the outer ring and coupled with the epicyclic gear means (7, 100, 200) so as to provide a rotational bearing for the central and planet gears (100, 200), wherein the inner roller arrangement (1, 2) of the roller bearing means (1, 2, 16) is non-rotatably coupled with at least the central gear of the epicyclic gear means (7, 100, 200) and comprises a rotatable central roller and movable planet rollers which are arranged between the central roller and the outer ring and in movable engagement with both the central roller and the outer ring, and - a third operating layer (fig. 7) includes a rotary peristaltic pump means (1, 2, 4) comprising a stationary flexible, preferably resilient, tubing which includes a bent portion having an essentially part-cycle form, and a rotor (1, 2) which is provided with engagement elements for locally engaging the bent portion of the flexible tubing so as to squeeze it during rotation for a pump action, wherein the rotor (1, 2) is coupled with the central gear of the epicyclic gear means (7, 100, 200) so that a torque is transferred from the central gear to the rotor (1, 2).