Actuators are devices that convert energy into physical motion. This device uses either electricity or pneumatic or hydraulic as an energy source. The pneumatic actuator provides two kinds of physical motion: linear and rotary. A pneumatic actuator converts compressed air into mechanical motion that regulates one or more final control elements. Where rotary actuators rotate the final control elements. Pneumatic Rotary Actuators are work based on three mechanisms: Scotch Yoke, Vane, and Rack & Pinion.
Scotch Yoke Pneumatic Rotary Actuator
The Scotch Yoke converts linear force into rotary motion and torque and the linear force receives from the pressurized piston or compressed spring. In the scotch yoke type actuator, there is a piston on one side and a spring on the opposite side. When the piston receives energy from compressed pneumatic air, it slides towards the spring. On the other side, a spring squeezes and the output shaft placed in the middle rotates. When de-energized the piston, spring pushes the piston to its earlier position and again the output shaft rotates and completes the toque.
Pneumatic Vane Actuator
Pneumatic Vane Actuator also known as Pneumatic vane motor. It works on a simple mechanism. A one piece vane and shaft create rotary motion to the output shaft. The vane is placed in two piece clam shell enclosures. The vane separates the enclosure into two air chambers. By creating the pressure differential across the vane, torque is provided to the output shaft. The torque output of the rotary vane actuator remains constant throughout the full rotation of the shaft.
Rack & Pinion Rotary Actuator
Rack & Pinion Rotary Actuators have rack gear and pinion gear. The pinion gear is connected to the central output shaft. Rack rotates the pinion by sliding left to right and right to left. To slide this rack, there is a piston connected to one side or both sides. Compressed air is used to energize the piston. The piston moves towards the middle hence the connected rack also slides and the pinion rotates. When airflow stops, the spring on the other side connected to the rack pushes back the rack and piston to their earlier position and this time also the pinion rotates and completes the torque.
Single Acting Actuator & Double Acting Actuator
Generally known as spring-return actuators, a single acting pneumatic actuator uses pneumatic air supply to open the valve and a spring (or springs) to close the valve. The actuator can also be set backward so that pneumatic air closes the valve and the spring is used to open the valve; this is called a normally open system.
The Double Acting Pneumatic Actuator is the most popular type of pneumatic valve actuator. Double acting actuators select for their low price and excellent durability. Since the lack of mechanical springs in most models reduces the least durable component in the actuator. A double acting actuator can cycle millions of times before failing.
Benefits of Pneumatic Actuator
In comparison to other actuators, pneumatic actuators are the far better option for you. There are lots of advantages of pneumatic actuators. Here we discuss a few of them.
(i) High Force & Speed Of Movement
When used in linear motion control applications, pneumatic actuators can deliver high forces and fast movement speeds. The device works by using air pressure and flow.
(ii) High Durability
It doesn’t matter how excessively the actuator use, overheating will not be a problem. Comparatively, these devices can sustain constant pressures and offer a long term use than alternative devices.
(iii) High Reliability
Pneumatic actuators are highly reliable in terms of functionality. A significant contributing factor to this is the ability to maintain high levels of control during the conversion of gas to energy. In addition to their high durability, they also exhibit high performance, which means that these devices have a long lifespan.
(iv) Clean Technology
In applications where hygiene is crucial, pneumatic actuators are the preferred device. Compressed air is free of harmful chemicals, so the application protects from contamination due to its use rather than fluids. Pharmaceutical, food, and beverage companies value this, of course.
(v) Cost Effective
As a result of its ease of installation and maintenance, the pneumatic actuator is often use as the most cost-effective option for industrial applications. Although the benefits target above are probably consider more valuable from a practicality standpoint, cost remains a significant consideration for all application managers in the current economic climate.
In The End
A pneumatic rotary actuator is a device that’s utilize for converting mechanical power into linear power. They typically use compressed air or nitrogen to create the linear force necessary to move the device. Benefits of Pneumatic Rotary Actuators, For the most part, pneumatic rotary actuators commonly take place in applications that require precise linear and rotary motion.
