What is a Pneumatic Rotary Actuator and Pneumatic Chucks?

Single-vane type and Double-vane type actuators

By: Justin Uhm

A pneumatic rotary actuator is a driver apparatus that is commonly used to compress air into revolving energy with a limited angle of revolution so that the actuator evolves back and forth at that angle.

Pneumatic rotary actuators are used for automatic opening and closing of ball valves, opening and closing of automatic doors, operation of industrial robots, and directional conversion of conveyors. 

Pneumatic chucks are actuated pneumatically by a mounted or integrated cylinder

In this article, we will cover the different types of rotary actuators and how both the actuator and chuck function and how are they applied. 

Types of Pneumatic Rotary Actuators

In this segment, I am going to go over the different types of rotary actuators. There are 2 main types. The vane type, which uses hydraulic or pneumatic power to open, close, or turn. It also uses precise movement for ergonomic lifting for transfer of movement. 

Another type of actuator is the piston type. Piston type uses pressurized hydraulic fluid to displace a piston to generate motion. 

Vane Type Rotary Actuators 

The vane-type rotary actuator is like the vane-type pneumatic motor, but its revolving angle is limited and its output is determined by the vane’s pressure-receiving area and working air pressure. As shown in Figure 1, the number of vanes determines whether an actuator is a single vane or double vane type.

Tilting the angle decreases as the number of vanes increases, but the torque increases. The single vane type applies about 270-300 degrees of tilting angle, while the double vane type apples about 90-120 degrees. Also, the vane type rotary actuator is subject to a small amount of air leakage because it cannot be completely air-tightened. 

Piston Type Rotary Actuators

The piston-type rotary actuator is a driver apparatus that uses a mechanical system to convert the motion of a straight line of a piston (of pneumatic cylinder) into revolving motion to acquire torque (see Figure 1). Piston-type rotary actuation is classified according to the type of mechanical system that converts the motion of the straight line into motion of revolution: rack and pinion type (a round gear usually smaller gears meshed together), screw type, crank type, and yoke type. Generally, the rack and pinion type is used because it can adjust the rotary actuator’s tilting angle. 

Single-vane type and Double-vane type actuators
Figure. 1 Vane-type rotary actuator
Single-vane type actuator on the left and a double-vane type actuator on the right

The rack and pinion-type actuator shown in Figure. 2 acquires torque by revolving the pinion that is positioned in the center of the rack that is directly connected to the piston. The rack and pinion-type are the most efficient type of rotary actuator and can have an embedded buffering tool inside. The efficiency of an ordinary rack and pinion type rotary actuator is 80-90 percent. 

Figure. 2 Rack and pinion type rotary actuators
Figure. 2 Rack and pinion type rotary actuators

Figure. 3, shows the different types of pinion type rotary actuators that TPC automation carry. It shows three different types 

TPC rack and pinion type rotary actuators
Figure 3 TPC rack and pinion type rotary actuators

What is a Pneumatic Chuck?

A pneumatic chuck is a driver apparatus that converts a piston’s horizontal, straight-line motion that is generated by compressed air into a vertical motion straight-line motion against the finger of a crank lever. Pneumatic chuck is installed on automated lines or on industrial machinery production lines for the clamping or conveying of objects. 

Figure. 4 shows the internal configuration of a pneumatic chuck, and Figure 5 shows TPC’s pneumatic chuck. 

Internal configurations of a pneumatic chuck Figure. 5 TPC pneumatic chuck
Figure. 4 Internal configurations of a pneumatic chuck (left)
Figure. 5 TPC pneumatic chuck (right)

Contact us at this links with any questions about your projects. Our expert sales team will gladly help with any inquiries you might have. 

Check out all the pneumatic products at our store at https://store.tpcautomation.com.

Have a question about pneumatics? To ask our experts click the button below.

Ask a TPC Pneumatics Expert a Question