Patent ID: 8159111
Filing Date: 2012-04-17
Classification: H02K

Abstract:
1. A driving device comprising: a motor comprising a rotating shaft; a clutch gear fixed to the rotating shaft; a first rotating portion sleeved on the rotating shaft corresponding to the clutch gear, the first rotating portion comprising a first end meshing with the clutch gear and a second end opposite to the first end; a second rotating portion engaged with the second end of the first rotating portion, wherein the first rotating portion is rotated following the rotation of the clutch gear and is pressed by an axial force from the clutch gear to move toward the second rotating portion; a piezoelectric assembly sandwiched between the second end of the first rotating portion and the second rotating portion so that the piezoelectric assembly is capable of sensing the axial force applied to the second rotating portion by the first rotating portion, the piezoelectric assembly being capable of converting the axial force into a voltage; and a controlling unit electrically connected to the motor and the piezoelectric assembly, the controlling unit configured for storing a predetermined voltage, and for determining whether the voltage output by the piezoelectric assembly equals to or exceeds the predetermined voltage and for deactivating the motor if the voltage output by the piezoelectric assembly equals to or exceeds the predetermined voltage.