A device (2,100) for delivery of predetermined doses of liquid medicament, which device is adapted to be in a medicament delivery state and in a medicament non-delivery state, said device is adapted to comprise- a cartridge (10,103) adapted to contain the liquid medicament and a piston sealingly and slidably arranged in said cartridge- an energy accumulating member (26114) adapted to accumulate energy in terms of at least one predetermined step when the device is in the medicament non-delivery state- an elongated threaded plunger rod (16,126) adapted to be arranged in the interior of the device- a plunger rod driving member (4047128) engaged to the threaded plunger rod (16126) and adapted to be in a driven state when the device is in the medicament delivery state and adapted to be in a non-driven state when the device is in the medicament non-delivery state, wherein the rotation of the plunger rod driving member (4047128) due to the output torque of energy accumulating member (26114) drives the threaded plunger rod (16126) and allows said rod which is in contact with the piston, to be driven towards the proximal end of the cartridge with a predetermined distance and expels a predetermined dose of the liquid medicament from the cartridge whereina bearing (41,46), coupled to or supported on an outer cover (55,48108), is arranged and designed to effectively pick up forces acting on the proximal part of the device in the longitudinal direction thereof whereby more of the accumulated energy that results from the stepwise rotational tensioning of the energy accumulating member (26114) positioned at the distal end of the device, is brought to an efficient output torque.
