Electric Cylinders
Description
Electrical cylinders are actuators that convert electrical energy into linear motion. They are also known as linear actuators or electric cylinder actuators. This linear motion can be used for clamping, blocking, or ejecting and is provided via a motor driven ball screw, lead screw or acme screw assembly. The load is attached at the end of the screw. The screw is direct, belt or gear driven and is self-locking. This is a major feature of electrical cylinders over pneumatic and hydraulic actuators. A complete unit of an electrical cylinder consists of a motor transmission unit, motor brake, sensors and end limit switches. Backlash is the play between the screw and the nut, without the rotation of the screw or nut. Reaction torque is the torque required to prevent rotation of the cylinder with the load. Stroke is the maximum distance of the shaft from its fully extended position to the retracted position.
Types
Based on the design of their linear motion, electrical cylinders are classified as:
Motor driven ball screw assembly - for high speed and high efficiency
Lead screw assembly - for precision motion control
Acme screw assembly - has a square thread form and is used for high loads; is used for applications where slow speed is desired
Features
The features of electrical cylinders are:
Parts can be positioned exactly
Dampers, rotors can be adjusted precisely
Self locking, so no hydraulics required thereby reducing operating cost as no hydraulic filters, no fluid leak, and no chance of fire hazard
Applications
They are used in the following user sectors where linear motion is utilized: