ac servo motor controller of the stator winding single-phase asynchronous motor and controller, its stator is equipped with two on the spatial difference of 90 ° electrical Angle of winding, namely the field winding and control winding. Runtime exciting winding is always combined with certain ac excitation voltage, the control winding is more small or phase change with signal control voltage. The structure of rotor and cage rotor hollow rotor cup type two kinds. Cage rotor structure and general squirrel-cage asynchronous motor rotor is the same, but do slender rotor, the rotor conductor with high resistivity of the material is made. Its purpose is to reduce the rotational inertia of the rotor, increase the starting torque of the input signal of the rapid response and to overcome the phenomenon of rotation. The hollow cup is divided into outer stator and rotor of ac servo motor stator inner stator two parts. The structure of the outer stator and cage ac servo motor stator, the same core put two phase winding groove. Hollow glass rotor by nonmagnetic conductive materials (Such as aluminum)Make thin wall cylinder, in between the inside and outside of the stator. Fixed on the rotating shaft at the bottom of the cup, cup arm thin and light, the thickness is in commonly 0. 2 -0. 8 mm, thus the moment of inertia is small, fast and sensitive.