| 摘要 |
Inner notches (225A, 226A) for adjusting cogging torque of a rotor (21) are formed on a stator (22) in a small-size power generator (20). Since the inner notches (225A, 226A) are formed on an inner periphery of a rotor accommodation hole (230) within angular range of +/-45 DEG around a magnetic flux direction of a first magnetic circuit (100) having smaller magnetic reluctance at a rotation center of the rotor (21), the cogging torque can be effectively reduced. Accordingly, even when a size of components such as an oscillating weight and a power spring is reduced for making a thin timepiece, rotation startability of the rotor can be improved, thus improving power generation efficiency of the small-size power generator. <IMAGE> |
