Rotary actuators are an integral part of many different machines and equipment, and as such, they should always be of the highest quality.
Finding applications in various fields, from electronic manufacturing, fiber optics, and photonics, to vision systems, industrial robotics, construction, and more, their characteristics have to match their uses.
So, before you buy a new rotary actuator, consider what your specific needs are, what you need the actuator for, and under which circumstances it needs to operate. Having figured that out, there are a few things to keep in mind when purchasing a new rotary actuator, so let’s have a look.
There are a few different rotary actuator styles that are the most popular, and they include:
- Rack and pinion
Each of these different styles has its own strengths and weaknesses, so let’s take a closer look at them.
Vane Rotary Actuators
If you’re looking for an actuator that has high endurance, high rotational speeds, and you want constant control of movement without needing to keep the load in a particular position, vane rotary actuators are for you.
These actuators are mostly used in machine tools, robotics, and for handling containers because of their compact design. There are two sub types of these actuators:
- Single-vane actuators
- Double-vane actuators
Single-vane rotary actuators have the rotary movement of up to 280 degrees, and they’re attached rigidly to the central shaft in a cylindrical housing.
Double-vane actuators have twice the torque, but about half the rotary movement of a single-vane actuator. These actuators provide a higher load balance.
Rack and Pinion Rotary Actuators
Rack and pinion rotary actuators are excellent for a high-speed production application. They are known for their low wear and long life and are a valuable investment.
If there’s restricted building room in an axial direction, these actuators will allow for extensive swiveling. They’re excellent for heavy-duty applications and are perfect for precision control due to their high resistance to drift.
Helical Rotary Actuators
Helical rotary actuators work by converting the linear movement of a piston to rotation by multiple helical gears. Since their angle of rotation is determined by the length of the actuator, any rotation is possible, however, the standard is 90, 180, and 360 degrees.
These actuators have found use in construction, marine operations, mining, military, material handling, valve operations, and more. They can be used for steering applications and lifting positioning, head rotation, boom positioning, and more.
There are 3 types of rotary actuators:
Hydraulic Rotary Actuators
Hydraulic actuators are known for the force that they can produce, and they’re much more powerful than either their pneumatic or electric counterparts. They offer high stability and can hold a constant force and torque without the need for more pressure to the cylinder.
They are, however, not as efficient, since they have a tendency to leak fluids. They also need additional components in order to operate, so their setup is more challenging.
Pneumatic Rotary Actuators
Pneumatic rotary actuators, on the other hand, are very easy to use and install. They’re lightweight and usually come at a lower price, being even more cost-efficient because they’re low maintenance and highly durable.
Pneumatic actuators can be used both in hazardous environments and extreme temperatures because they have no motor, allowing them to meet machine safety and explosion protection requirements.
Electric Rotary Actuators
Electric rotary actuators are the most commonly used type due to their strengths. They have the best precision control positioning, can be modified for any force requirement, and since they leak no fluids, they’re safe for the environment. They can easily be reprogrammed and have greater control of position, velocity, torque, and force.
There are a few things to keep in mind when opting for these actuators – they come at a higher cost, and can overheat, so make sure to maintain them well.
Depending on your specific needs, you have to take into consideration the load capacity of your rotary actuator. Some are able to withhold heavier loads while others are not. Load handling depends on the bearings and gear trains, and a larger actuator will, of course, have a larger load capacity.
Torque output is one of the key factors that affect the quality of rotary actuators. You should choose an actuator that has enough power to accelerate the load from the resting position to your desired speed.
Kinetic Energy Absorption
Getting the load in motion is not as important as stopping it is. You’ll find that the size of the actuator depends on its ability to stop the load, so always pay attention to the kinetic energy absorption ratings from the manufacturer.
Quality rotary actuators are an investment that pays for itself. Extremely durable, compact, and low maintenance, they’re sure to get the job done.