Brush Servo Motors
An older technology that can be run with simple motor controls, such as 2 or 4 quadrant servo drives, but have parts (graphic or precision metal brushes) that require maintenance. Today's preferred servo motor is brushless. This is normally done with a primary feedback device like Halls Sensors. A brushless servo motor will normally have an encoder or resolver for accurate position feedback that can be used to control both position and/or velocity.
Brushless Servo Motors
Brushless servo motors can be rotary, linear or frameless in construction. They can perform very simple motion or be used in highly dynamic requirements. Applications include: robotics, CNC machinery, laser cutting, packaging, printing, material handling and many other automated manufacturing processes. The brushless servo motor has no component maintenance but does require a servo drive that can electronically commutate the motor.