Rotary Actuator Guide:What is a Rotary Actuator and Work?

Table of Contents
• Types Of Rotary Actuators
• Hydraulic Rotary Actuator
• Pneumatic Rotary Actuator
• Electric Rotary Actuator
• What is a Rotary Actuator
• What is a Hydraulic Rotary Actuator
• What is a Pneumatic Rotary Actuator
• What is a Electric Rotary Actuator
• Advantages of Rotary Actuators
• How Does a Rotary Actuator Work
• How Does a Hydraulic Rotary Actuator Work
• How Pneumatic Rotary Actuator Works
• How Electric Rotary Actuator Works
• Cost of Rotary Actuator
• Hydraulic Rotary Actuator Price
• Pneumatic Rotary Actuator Price
• How to Use Rotary Actuator
• How to Wire a Rotary Actuator
• Rotary Actuator Applications

Types Of Rotary Actuators

Common types include pneumatic rotary actuators, which use compressed air; hydraulic rotary actuators, powered by fluid pressure; electric rotary actuators, which use electrical energy; Each type offers specific advantages based on force, speed, and control precision.

What is a Rotary Actuator

A rotary actuator is a mechanical device that converts energy, typically electrical, hydraulic, or pneumatic, into rotational motion. It is used in various industries for precise control of angular movement, providing accurate positioning in systems such as robotics, manufacturing equipment, and automotive applications.

What is a Hydraulic Rotary Actuator

A hydraulic rotary actuator is a mechanical device that uses hydraulic pressure to produce rotational motion. It converts fluid power into rotary torque and is commonly used in industries，such as manufacturing for tasks like controlling valves, steering systems, and positioning equipment. Its compact design and high torque output make it suitable for heavy-duty applications where precise rotational movement is required.

What is a Pneumatic Rotary Actuator

A pneumatic rotary actuator is a mechanical device that converts compressed air energy into rotational motion. It is commonly used in industrial automation, robotics, and control systems to drive valves, dampers, or other mechanical components. The actuator operates by using the pressure of compressed air to rotate a shaft, providing precise and reliable motion control. These actuators are valued for their simplicity, speed, and cost-effectiveness in applications requiring rotational force.

What is a Electric Rotary Actuator

An electric rotary actuator is a mechanical device that converts electrical energy into rotational motion. These actuators provide precise, controllable movement and are favored for their efficiency, reliability, and ability to operate without the need for hydraulic or pneumatic systems.

Advantages of Rotary Actuators

High Torque Output: They provide strong rotational force, making them ideal for tasks requiring substantial torque.
Compact Design: Rotary actuators are typically smaller and lighter compared to linear actuators, saving space in machinery.
Precision Control: They enable accurate rotational positioning, crucial for tasks that demand fine control, such as robotics and automation.
Energy Efficiency: Often more energy-efficient than linear actuators for rotational tasks, reducing operating costs.
Versatility: Used in various applications like CNC, valves, robotics, conveyor systems, and aerospace, making them adaptable across industries.
Reduced Wear: With fewer moving parts than linear actuators, they generally have a longer service life and lower maintenance needs.

How Does a Rotary Actuator Work

Rotary actuator is a mechanical device that converts energy (usually electrical, pneumatic, or hydraulic) into rotational motion. It typically consists of a motor, gears, and a shaft, which delivers rotational force to an output. The actuator’s function is to rotate a load or perform a rotational movement within a specified range.

How Does a Hydraulic Rotary Actuator Work

hydraulic rotary actuator is a device that converts hydraulic energy into rotational motion. It operates based on the principles of fluid mechanics, typically using pressurized hydraulic fluid to generate torque.
Hydraulic Fluid Input: Pressurized hydraulic fluid enters the actuator from a pump, often controlled by a valve to regulate flow and pressure.
Torque Generation: The fluid is directed into a cylinder, where it pushes against a piston or gear, creating rotational force (torque). The size and pressure of the fluid determine the amount of torque produced.
Rotational Output: The actuator's output shaft rotates, performing mechanical work, such as turning a valve or driving other rotating components.
Control: The rotation direction and speed are controlled by adjusting the flow and pressure of the hydraulic fluid.

How Pneumatic Rotary Actuator Works

Pneumatic rotary actuator converts compressed air into rotational motion. It typically consists of a cylinder, piston, and vane or rack-and-pinion mechanism. When compressed air enters the actuator, it pushes the piston, which rotates the shaft or vane. The rotation is either clockwise or counterclockwise depending on the airflow direction.

Key components:

1. Cylinder: Houses the piston and provides a chamber for compressed air.
2. Piston: Moves within the cylinder in response to air pressure, producing rotational motion.
3. Rotary Shaft or Vane: Converts linear motion from the piston into rotary motion.

Advantages:

• Quick response and high torque output.

Pneumatic rotary actuators are valued for their simplicity, reliability, and ability to handle heavy loads with minimal maintenance.

How Electric Rotary Actuator Works

electric rotary actuator is a device that converts electrical energy into rotational motion. It typically consists of an electric motor, a gear train, and an output shaft. The motor drives the gear system, which amplifies the torque and adjusts the speed to the desired level. The output shaft then rotates, producing mechanical motion. Electric rotary actuators are used in a wide range of applications, from robotics to industrial automation, providing precise control of rotational movement.

Key components:

1. Electric Motor: Converts electrical energy to mechanical energy.
2. Gear Mechanism: Modifies speed and torque.
3. Output Shaft: Delivers the rotational motion to the load.
   

Cost of Rotary Actuator

The cost of a rotary actuator varies depending on factors such as size, type, torque, and application.

Hydraulic Rotary Actuator Price

On average, industrial-grade hydraulic rotary actuators can range from $500 to $10,000 or more. Custom solutions with higher performance specifications or specialized features may exceed.

Pneumatic Rotary Actuator Price

On average, price of a pneumatic rotary actuator range from $100 to $1,000, with specialized models potentially costing more. Basic actuators are typically lower priced, while those designed for high precision or heavy-duty applications can be more expensive. To get a more specific price, it's important to consider the actuator's specifications and the supplier's offerings.

How to Use Rotary Actuator

Here’s a concise guide on how to use rotary actuators:

1. Selection: Choose the appropriate rotary actuator based on the application requirements (torque, speed, precision, and load capacity). Types include electric, hydraulic, and pneumatic actuators.

2. Integration: Connect the actuator to the system through shafts, gears, or couplings. Ensure compatibility with the control system (e.g., PLC, motor driver).

3. Control: Use electrical signals (for electric actuators) or pressure (for hydraulic/pneumatic actuators) to control the actuator’s movement. This can be done via switches, sensors, or automated control systems.

4. Operation: Upon activation, the actuator rotates in a specific direction, based on input commands, and provides the necessary motion to operate machinery, valves, or robotic arms.

5. Maintenance: Regularly inspect for wear and tear, ensure proper lubrication, and check seals to maintain optimal performance.

How to Wire a Rotary Actuator

To wire a rotary actuator, follow these simplified steps:

1. Understand the Wiring Diagram

• Obtain the actuator's wiring diagram from the manufacturer, ensuring you know the connections for power, ground, control signals, and feedback (if applicable).

2. Power Supply

• Connect the positive terminal of the power supply to the actuator's power input (typically labeled as +V or DC+).
• Connect the negative terminal of the power supply to the actuator's ground (GND or DC-).

3. Control Signals

• If the actuator uses a control signal (e.g., 0-10V, PWM, or analog), connect the signal wire to the actuator's control input.
• Some actuators may require an external controller or PLC for signal input.

4. Limit Switches / Feedback (if applicable)

• If the actuator has limit switches or feedback sensors, connect these to the appropriate input terminals (e.g., limit switch wiring or encoder feedback).

5. Grounding

• Ensure proper grounding of the actuator to avoid electrical interference or damage.

6. Test the Connections

• Once all connections are made, test the actuator to ensure it responds correctly to control signals and the movement is as expected.

7. Safety Considerations

• Ensure proper safety protocols are in place, such as using appropriate fuses, isolating power during installation, and verifying correct voltage and current ratings.

Rotary Actuator Applications

1. Industrial Automation & Robotics

• Robotic arms, material handling, packaging machines.

2. Aerospace & Defense

• Aircraft control surfaces, missile guidance, landing gear.

3. Automotive & Transportation

• Steering, active suspension, throttle/valve control.

4. Oil & Gas

• Valve automation, drilling, offshore equipment.

5. Medical Equipment

• Surgical robots, prosthetics, medical imaging.

6. Renewable Energy

• Wind turbine blade control, solar panel tracking.

7. Entertainment & Simulation

• Theme park rides, flight/driving simulators.

8. Construction & Heavy Machinery

• Excavators, cranes, tunnel boring machines.

9. Marine & Subsea

• Submarine hatches, ship steering, ROVs.

Types: Hydraulic Rotary Actuator (high torque), Pneumatic Rotary Actuator (fast), Electric Rotary Actuator (precise).

If you want to know more about Rotary Cylinder, please read the article 《Guide to Rotary Cylinder》.