Drives and Actuators           

The several drives used in CNC machines are following :

1. Spindle drives to provide the major spindle power for cutting.

2. Feed drives to drive the axis as per the programme.

Spindle Drives

In viewpoint of the large material elimination rates utilized in the CNC machines, large power motors are utilized. Further the speed is normally infinitely variable. Therefore to provide such a control normally DC motors are utilized. Infinite speed control is attained by varying the voltage infinitely. Though, with the growth in the microprocessor controlled frequency converters, the use of AC motors is being preferred in the current creation of CNC machine tools. One more benefit of using the AC drive for spindle is that it may also be utilized for positioning the spindle axis (C-axis) such like in Turn Mill centres.

Feed Drives

The feed drives that are utilized in CNC machine tools are following

1. DC Servo motors

2. Brush less DC servomotors

3. AC Servo motors

4. Stepper motors