A linear driver

A linear driver is composed of a stator, a rotor and an excitation element. The stator is made up of a circular plate and a center rod which is fixed and perpendicular to the circular plate and is threaded connected to the rotor. The shape of the excitation element corresponds to the shape of the circular plate, and they stick together. The stator, the rotor and the excitation element have a common central axis. When the excitation element is supplied with power, it excites a vibration of the stator and then drives a threaded rotation of the rotor with respect to the stator, thus performing a linear motion of the rotor in the axial direction in the meanwhile.