An infusion pump comprises at least three operating layers. A first layer includes epicyclic gear means comprising a rotatable central gear, a stationary outer ring gear, and movable planet gears arranged between the central gear and the ring gear in movable engagement with the central and ring gears. A second layer includes roller bearing means comprising a stationary outer ring and a movable inner roller arrangement in movable arrangement with the outer ring and coupled with the epicyclic gear means to provide a rotational bearing for the central and planet gears. A third layer includes rotary peristaltic pump means comprising stationary flexible tubing which includes a bent portion having an essentially part-cycle form and a rotor having engagement elements to squeeze the bent portion during rotation for a pump action, wherein the rotor is coupled with the central gear to transfer torque from the central gear to the rotor.
