What are the Different Types of Linear Actuators?
On the face of it, explaining to someone what a linear actuator is should be an easy prospect. However, the reality is never that simple. While linear actuators at their core are devices used to convert energy into linear motion, there are several different types of linear actuators, each of which produces this motion in a different way. In this blog, we'll take a look at the four most common types of linear actuators, how they work, and the differences between them.
Belt Driven Linear Actuators
As you might infer, a belt-driven actuator is one that uses a tensioned belt to drive linear motion. Belt-driven actuators can be operated manually or connected to a stepper or DC motor for automatic operation. They are ideal for high-speed, low-load applications, especially when long strokes are required. Belt-driven actuators do require proper tensioning, whether they are manually or automatically operated.
Screw Driven Linear Actuators
Screw-driven actuators operate similarly to belt-driven actuators, except that the driving component is a lead screw (ball screws can also be used, but this blog will be devoted to screw-driven actuators). Like belt-driven actuators, screw-driven actuators can be operated manually or with an electric motor, depending on the needs of the application in question. They are best used in applications that require high accuracy over short distances (up to about five feet).
Guidance for lead screw-driven actuators can be provided by parallel shafts or fully supported linear guides, with both options offering different benefits. Linear guides are stronger and more resistant to torsion than parallel shafts, but parallel shafts are generally available in a wider range of materials. Parallel shafts also allow dust to fall off the actuator more easily than actuators using guide rails, making them more suitable for dusty, heavy-duty applications.
Hydraulic Linear Actuator
Hydraulic actuators are configured differently than mechanical actuators such as the aforementioned belt and screw drive actuators. A hydraulic actuator consists of a piston within a cylinder, with an attached pump supplying incompressible hydraulic fluid to move the piston, thereby producing motion. Since the fluid is incompressible, a constant force can be maintained without a continuous fluid supply.
However, hydraulic actuators can leak, causing pressure loss and cleanliness issues, making them a higher maintenance option than pneumatic and mechanical actuators. Ideal for high-force applications, the hydraulic actuator is capable of generating 25 times more force than a pneumatic actuator of the same size and can achieve pressures up to 4000 psi.
Pneumatic actuators work much like hydraulic actuators, with the main difference being that they use compressed air instead of hydraulic oil. They are much simpler than hydraulic actuators, although they do require the compressor to run constantly to maintain air pressure. This simple composition makes pneumatic actuators a more cost-effective choice than almost any other type of actuator, and because air is relatively safe compared to hydraulic fluid or electricity, it can operate in extreme temperatures.
Linear actuators are essential. Hopefully, this blog has shed some light on this topic and made the decision-making process easier. If you still have questions or want to purchase linear actuators, please contact us.
UG Controls is a professional custom valve actuators and accessories manufacturer. For nearly 20 years, we have used our engineering expertise and industry experience to continuously improve our products, striving to provide efficient solutions and competitive prices. UG provides solutions for all industries including chemical, water, oil and gas, mining, power plants, pharmaceuticals, food and beverage and more.