The invention refers to a motor mechanism (6) for a drug delivery device (1), comprising a storage drum (8) and a torque drum (9) arranged close to each other and a strip (7) of spring sheet metal having two ends, each end attached to one of the drums (8, 9), wherein the strip (7) of spring sheet metal is coiled on the storage drum (8) in a relaxed state, wherein the motor mechanism (6) is chargeable by rotating the torque drum (9) thereby coiling the strip (7) of spring sheet metal onto the torque drum (9) and bending the strip (7) of spring sheet metal the other way round than in the relaxed state thus arriving in a charged state with the strip (7) of spring sheet metal tending to re-coil onto the storage drum (8) thereby generating a torque.本發明係關於用於藥物傳輸裝置(1)之運動機構(6),其係包含彼此靠近地配置的一儲存鼓輪(8)與一力矩鼓輪(9)以及兩端各附著至該等鼓輪(8,9)中之一個的一條(7)彈簧片金屬,其中該條(7)彈簧片金屬盤繞於該儲存鼓輪(8)上呈鬆弛狀態,其中該運動機構(6)可旋轉該力矩鼓輪(9)來儲能,藉此盤繞該條(7)彈簧片金屬於該力矩鼓輪(9)上,以及使該條(7)彈簧片金屬相較於鬆弛狀態會反過來彎曲從而達成儲能狀態,以及該條(7)彈簧片金屬有重新盤繞於該儲存鼓輪(8)上的傾向藉此產生一力矩。6‧‧‧運動機構7‧‧‧條8‧‧‧儲存鼓輪9‧‧‧力矩鼓輪
