LINEAR ACTUATOR

An actuator acts like a human wrist in that an object can be rotated to a new position in similar manner, but an actuator is capable of more complex angles of rotation and comes in a variety of sizes with a equally diverse selection of models and torques. A ball screw drives the actuator motor and makes linear motion possible. The load of a linear actuator is unsupported and attached to a rod or screw, which can be driven by belt or gear and sometimes driven directly.

Linear Actuator Specifications

Before buying a linear actuator, you should examine particular performance specifications:

• Maximum rated speed, generally rated at no load or low

• Stroke, which gives the approximate distance between fully retracted and fully extended rod locations

• Backlash, which indicates error of position from change of direction

• Motor type - AC and AC servo, DC and DC servo, Stepper, DC brushless and DC brushless servo

• Continuous Power - this specification does not provide peak power rating information, but refers to sustainable power only

• Maximum Rated Load or Maximum Rated Force

Hydraulic Rotary Actuators

These use a fluid that is pressurized and incompressible for rotating the mechanical parts. Pneumatic actuators are eclipsed by the power of hydraulic systems because of the greater torque produced from higher pressure.

Tables and circular shafts make up a hydraulic rotary actuator's elements of rotation. A bolt pattern is typical of tables and allows the mounting of other components. Circular shafts, however, consist of a keyway. A single output exists on one side of an actuator for single-shaft component and double-shaft provides both sides with an output.

The piston's internal diameter contain splines that match the shaft's helical spline teeth and shaft rotation is converted to linear motion as a result. The shaft is rotated by the piston being displaced by hydraulic pressure. The shaft locks in place by hydraulic liquid being trapped when the control valve closes.

Backlash and Torque

Pneumatic rotary positioning is very precise due to the cross porting of double piston bores and the actuator performing at the end of rotations with zero backlash. Precision control is common use for the rotary actuator because of this high torque output and the actuator's drift resistance. High cycle speeds and heavy payloads of pneumatic rotary actuators are unmatched by comparable units because in these type of rotary actuators pinion breakage is eliminated by being ultra-thin and having two output flange hard stops internally.

The Basic Electronic Actuator

A new generation of electric actuator, the ELQ enables traditional 4-20 mA and the new fieldbus communication. Drive inserts that are easily mounted and a universal power supply are product innovations of the ELQ, making it the most revolutionary electrical actuator on the market.