Industrial rotary actuators add rotational movement or drive to machinery, appliances and even large boats. They usually have either keyed shafts or tables. Some only move smoothly in one direction while others reverse, make stops or alternate slow an fast speeds.

An industrial rotary actuator may also operate within an angle range smaller than 360 degrees, like 45, 90 or other multiples of 45 degrees. The main differences between rotary actuators are due to drive method:

1. Electric rotary actuators often feature control and indexing for stroke variation or multi-stop movement.

2. Pneumatic rotary actuators work well for loading and factory automation.

3. Hydraulic rotary actuators are faster and more powerful than pneumatic actuators, with heavy duty applications.

Action Steps
The best contacts and resources to help you get it done

Buy an electric rotary actuator from quality rotary actuator distributors

Besides max load and torque, compare the supply voltages and rotation angles and speeds of various electrical rotary actuators. These actuators have many specialized uses in labs and hospital machinery, as well as industrial uses including the manufacture of semiconductors.

I recommend: Concise Motion Systems carries a nice selection of electric rotary actuator units with integrated motors that range in power and have max output speeds as high as 232 RPM and as low as 12 RPM. Honeywell products are available from many sources, including Lesman Instrument Company. They have a huge selection of Honeywell electric rotary actuator motors.

Buy a pneumatic rotary actuator from rotary actuator suppliers that have it all

Anything pneumatic uses pressurized air to produce movement. In this case, the movement is rotational. When buying a pneumatic rotary actuator, look for the max load and torque, as well as its operational temperature range. You'll also want to match the rotational angle with your application, weather it is loading, unloading, assembly line automation or anything else along those lines.

I recommend: Perhaps not quite as many companies supply wide selections of pneumatic rotary actuators as the other types, but IC Fluid Power, Inc. does a nice job covering the bases with only a few models. AGI Automation Components has many models to choose from and clearly publish all the details you need to make a good choice.

Buy a hydraulic rotary actuator from quality rotary actuator manufacturers

For all rotary actuators, max load, max torque and rotation angle are important specs. However, in the case of hydraulic rotary actuators, you should also pay attention to max pressure. These rotary actuators are the hardest working, functioning as dives for barges and bulldozers. They are also elements of many automobile steering systems.

I recommend: Helac Corporation is an industry leader that manufactures an extensive line of tough rotary hydraulic actuators for a broad array of applications. If you're looking for maximum torque for major machinery, Flo-Tork goes the distance. They have many products with max pressures up to 3,000 psi and a huge design they refer to as Megatork. It has a max torque of 50 million pound-inches.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Many hydraulic and pneumatic rotary actuators use a rack-and-pinion combination to convert linear motion to rotational. For higher torque, look for actuators with two or more pistons. These types have racks on either side of one pinion.