8 Types of Rotary Actuators and Their Various Applications

Actuators use either manual or automatic valve control, and their accessibility of resources like compressed air or electricity influences their selection. There are a variety of applications for a rotary actuator, including airplanes and motion control systems.

1. Manual Rotary Actuator

A worm drive is used in a manual rotary actuator to augment the torque an individual may provide to shut a valve manually. Due to the self-locking ability of multiple worm drives, ball valves and quarter-turn butterflies use them. Huge hand wheels are commonly used in these actuators to increase the usable torque of the operator.

2. Electric Rotary Actuator

An electrical rotary actuator utilizes electromagnetic power from an electric motor to rotate mechanical parts. They have indexing and control features that let you stop at various places along a stroke.

The actuator’s rotating component can be a circular shaft or a flat table. Tables provide a bolt type for mounting additional elements, whereas circular shafts usually have keyways.

3. Fluid-Powered Rotary Actuator

These actuators utilize hydraulic air or oil to power cylinders that move scotch yokes, rack-and-pinion, and shaft operation in vaned rotors. A Fluid-powered rotary actuator can turn from 90 degrees to 360 degrees according to the valve or device’s specifications.

4. Rack and Pinion Rotary Actuator

These mechanical devices are used in industry to regulate dampers and valves automatically. The rack and pinion of this actuator are simply two gears that convert linear motion into rotary motion. Racks are bars of linear gearing mesh with the pinions of round gears. A linear force is given to the rack to rotate the pinion.

5. Scotch Yoke Rotary Actuator

A valve is attached to one end of the actuator’s sliding bar. The other connects to a yoke with a groove that moves swiftly in either direction. When the piston shifts, the sliding block is driven, the yoke turns, and the bar pushes to open the valve.

Scotch Yoke Rotary Actuator opens and closes valves in industries to control the flow of fluids and separate components like feed lines, tanks, and filters.

6. Helical Actuators

The use of pneumatic pressure operates the spinning helical actuator. The linear input changes into an oscillating output through a cylinder and helical gears. The following are the three cylinders that make up a helical actuator:

• A revolving shaft with three pins serves as the drive mechanism
• The actuating tube with three helical slots
• The helically slotted outer tube

The outer tube’s three keys prevent the inner cylinder from sliding too far. These keys fit cylinder grooves. As the helical cylinder’s outer cylinder rotates, air pressure compresses an external spring, opening the valve.

7. Electrohydraulic Actuators

All electric devices have the advantage of being simple, powerful, and reliable. It is often more cost-effective to use a single hydraulic power pack to supply multiple hydraulic actuators. High-speed operation or fail-safe mechanisms make these actuators ideal for controlling valves requiring significant thrusts or torques.

8. Vane Rotary Actuator

One or two vanes couple to a hub in a hydraulic or pneumatic vane actuator, and the vane can rotate anywhere from 90 to 280 degrees within a wedge-shaped or circular chamber. The movement to the output stem occurs by turning the hub between stops using air or oil pressure.

The Use of Rotating Actuators

A rotary actuator is a common component of motion-control systems that operate tools like grab handlers and clamps. The rotary actuator is also widely used in portable construction equipment.

The aircraft industry relies on linear and rotary actuators to control motion precisely. They operate landing gear and other flight surfaces like elevators and ailerons.

There are several uses for an electric rotary actuator, including high-power switching gears, the electric power industry, the automobile industry, and the packaging business.

Rotating actuator is used in manufacturing, shipping, material handling, robotics, and metalworking. A specialized rotary actuator can turn arms and booms in agricultural and underwater settings.

Conclusion

An electric, fluid-powered, or manually operated rotary actuator transfers mechanical energy into oscillatory motion. Before deciding on any actuator, it is crucial to consider the torque, rotation, package size, powering method, application, and mechanical features. Most of the time, these actuators are used in the oil and gas sectors.

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