Servo Motors & Drives

Servo Motors & Drives

What is a Servo Motor?

Servo Motors are rotary or linear actuators that enable control of both angular and linear acceleration, velocity, and positioning. They come in both brush and brushless types, however brushless is today’s preferred version. Both of these can be operated in either continuous or peak torque ranges. Continuous torque is possible throughout regular operation of the motor, while peak torque can only be attained for a short time.

Brush Servo Motors

DC Brushed Motors that have winding in the rotor and permanent magnets on the stator. Carbon brushes and a mechanical commutator provide a current path through the windings to achieve motor torque. A DC motor will continuously rotate if a DC power source is applied across its terminals.

Brush servo motors are constructed with simpler technology so they can be run with simple motor controls. However, some of their parts (graphic or precision metal brushes) require maintenance.

Brushless Servo Motors

Brushless Servo Motors that have windings in the stator and permanent magnets attached to the rotor. No brushes are used. Motor rotation is achieved by means of electrical commutation performed by the drive. Brushless servo motors provide high acceleration, high torque, and no maintenance. Brushless Servo Motors offer the highest torque-to-weight ratio and are commonly used in the highest throughput, precision and demanding applications.

A brushless servo motor does not require component maintenance but will require use of a servo drive to electrically commutate the motor. Traditionally this is achieved using a primary feedback device with an encoder/resolver that is used to control both position and/or velocity.

Brushless servo motors can be made as rotary, linear, or frameless with the ability to perform simple or dynamic motion. Some typical applications include:

  • Robotics
  • CNC Machinery
  • Laser Cutting
  • Packaging
  • Printing
  • Material Handling
  • Automated Manufacturing Processes

What is a Servo Drive?

Servo Drives, sometimes called servo amplifiers, are devices that have the ability to take a low power command signal from a motion controller and turn it into high power current/voltage. This is then applied to servo motor windings in order to produce torque.

Analog drives have a small amount of processing capability and execute all drive functionality in the analog domain. Unlike analog drive, digital drives have additional intelligence which allows them to have more functionality, diagnosis capabilities, and easier configuration.

Intelligent, or Smart, Drives combine some, or all, of a motion controller’s functionality with the high-power electronics of a motor drive. They vary in the amount of control functionality and type of communication interface and there are generally two types: fieldbus based and deterministic bus based.

Applications of Servo Drives

Servo Drives are used in many of the same applications as servo motors, such as:

  • Robotics
  • CNC Machinery
  • Automated Manufacturing

For more information, browse our selection of servo motors & drives below!