A rotary actuator is commonly used to oscillate a joint in situations when there’s a lack of proper requirements for motion, weight or space. In such situations, it’s impractical to mount a conventional cylinder, which means that there needs to be another solution to this problem and a rotary actuator is that solution.
Since these actuators are mountable at the joints of most equipment, they are perfect for bridging the problems with long stroke lengths that come with the use of cylinders.
A big advantage of these actuators is that they aren’t limited to the 90 degrees axis, which is a standard for most cylinders. Instead, rotary actuators can attain great arc lengths. It all depends on the needed requirements and configurations.
Hydraulic rotary actuators
When there’s any type of motion application that includes heavy-duty and high-torque motion, the best tools for the job are hydraulic rotary actuators. They possess an extremely high dynamic response, excellent mechanical stiffness, high-power per unit volume and weight, as well as immensely high force capabilities.
This makes them perfect for providing the necessary heft for steering, testing, bending, mixing, clamping, indexing, turning, lifting, and other similar applications. On top of all this, rotary actuators are also efficient and compact which allows them to safely, securely and instantaneously produce all-angle high torque in any direction.
Because of that, such actuators are widely and commonly used in all sorts of heavy-duty aerospace, marine, mobile, and machine tool applications where high levels of control and precision are required.
When rotary actuators are combined with a suitable motor and mounted right to a load in the rotation, they provide the most excellent control for positioning, smooth reveals, deceleration, operating speed, and acceleration.
This is especially important for all sorts of electrical and power transmissions, as such transmissions include weight and bulk that might pose a serious problem if out of control. Since hydraulic rotary actuators come with an extremely compact design, this allows for a huge amount of flexibility that takes care of those weight and bulk problems.
Additionally, all actuators are fully and completely enclosed, which ensures the proper level of protection from moisture, dirt, and dust, as well as that they can withstand all types of severe conditions.
Different styles of hydraulic rotary actuators
Hydraulic actuators come in three most common types such as:
- Vane rotary actuators – a perfect fit for all sorts and types of applications that require high precision positioning, movement control, rotational speeds, and endurance.
- Rack and pinion – ideal for the highest torque demands and heavy-duty applications.
- Helical design – perfect for all sorts of applications in the valve, mining industries, military, material handling, marine, energy, and construction operations.
Pneumatic rotary actuators
Rotary actuators in pneumatics are mostly used for those applications that require the conversion of compressed air pressure into a vibrating rotary motion. Their main characteristic is their extreme durability.
Aside from that, they also provide high force and, more importantly, the much-needed simplicity in operating. On top of all that, they are extremely functional and operable in a wide variety of hazardous environments.
Types of pneumatic rotary actuators
Similarly to hydraulic rotary actuators, there are two types of pneumatic rotary actuators:
- Vane
- Rack and pinion
Vane rotary actuators
There are two styles of vane rotary actuators: single vane style and double vane style. A single vane style limits the rotational motion to 280 degrees, which allows for a higher rotational range. A double vane rotary actuator limits the motion to no more than 100 degrees, which can double the force on the construction but provides a lesser rotary motion range.
Rack and pinion
This type of rotary actuator uses a cylinder rotor that is mounted to a rack cog. The rack and rotor move in a linear manner when actuated, which makes the rotor gear and output shaft rotate. To double the unit volume of torque, there’s a double rack actuator with two frameworks on both sides of the rotor cog.
Most professionals and experts tend to overlook rotary actuators simply because they’re used to pneumatic cylinders. The truth is, while these cylinders may be more common, rotary actuators can greatly simplify all types of necessary applications.
Since they are equipped with internal bearing sets, they are considered as self-contained elements that have the ability to support heavy loads. Furthermore, they also completely eliminate the need to construct and design external pillow block carriages, and they behave extremely well in all types of harsh environments, which makes them highly durable and easy to maintain.
