querry

• Size
• Mounting
• Duty
• Function
• Rating
• Supply arrangements
• Overload equipment

All these things are different.

Andter to your Quedtion:

AC servo motors are based on induction motor designs; DC servo motors are based on dc motor designs and ac brushless servo motors are based on synchronous motor designs

AC servo motors are basically two-phase, reversible, induction motors modified for servo operation. An induction motor designed for servo use is wound with two phases physically at right angles. A fixed or reference winding is excited by a fixed voltage source, while the control winding is excited by an adjustable or variable control voltage, usually from a servoamplifier.

Brushless dc servo motors resemble a dc shunt motor turned inside out. The servo motor features a rotating field is obtained by placing three stator windings around the interior of the stator punching. The windings are then interconnected so that introducing a three-phase excitation voltage to the three stator windings (which are separated by 120 electrical degrees) produces a rotating magnetic field.

AC motors are of two kinds - induction and synchronous motors. Induction ac motors are the simplest and most rugged electric motor and consists of two basic electrical assemblies: the wound stator and the rotor assembly. The induction ac motor derives its name from currents flowing in the secondary member (rotor) that are induced by alternating currents flowing in the primary member (stator). The combined electromagnetic effects of the stator and rotor currents produce the force to create rotation.