You’ll find actuators in everything from cell phones to the Mars Rover. Linear hydraulic actuators operate the wheel brakes and landing gear in aircraft.
NASA built the Mars Rover with 31 electric actuators to move its legs and arms. Without them, the Curiosity rover couldn’t perform the functions NASA scientists designed it to do.
While their functions sound similar, electric and hydraulic linear actuators perform their functions by different means. If you’re unsure which one you need for your application, we discuss the differences between them in this guide.
What is an Actuator?
An actuator converts energy into torque to control the movement of a mechanism. Actuators get powered by hydraulic fluid, electric current, or pneumatic pressure.
The two basic types of actuators are linear and rotary.
What’s a Hydraulic Linear Actuator?
A linear hydraulic actuator gets powered by hydraulic fluid. Typically, this fluid is oil made from different oils. The fluid creates pressure which moves cylinders in a straight line or linear motion.
The Pros to hydraulic actuators are:
- High load capacity
- Constant pressure
- Initial cost is affordable
- Simple Design
Hydraulic actuators are very powerful and can handle applications that need high force. They can also handle heavy weight and constant pressure. The initial cost of hydraulic actuators are usually low, and they have a simple, yet rugged construction.
There are some cons as well:
- Operating cost
- Limited motion control
- Low operating efficiency
- High maintenance
Hydraulic linear actuators are durable and rugged, but this gives way to some disadvantages. The actuator itself costs less than other types, but it needs extensive maintenance to run at its max capability. This leads to higher operating costs.
Because of the sheer nature of which it works, leaks do occur. In higher temperature environments, this can lead to damage if it’s not monitored on a consistent basis.
It performs at slower speeds that aren’t as efficient. Hydraulic systems operate at 25-44% efficiency, much lower than it’s electric counterpart.
What’s an Electric Actuator?
Electric linear actuators convert energy into motion with electricity. The electric motors turn a lead screw that’s fitted with a nut on a thread. The nut moves on the thread depending on which direction the screw rotates.
This converts into linear movement. The advantages of electric actuators are:
- Low maintenance
Electric actuators are designed for speed and accuracy. As such, it operates at up to 80% efficiency. They’re also able to stop at any position, and the screw units are self-locking in the event of a power failure for safety.
Unlike hydraulic actuators, electric actuators are self-contained and don’t have external components. This allows them to be smaller in size with little maintenance.
There are disadvantages to electric actuators:
- Sensitive to certain operating environments
- Can overheat
- Complicated design
The initial cost and installation are higher than a hydraulic actuator due to its design and construction. But they don’t need a lot of maintenance, so they’re operating cost is lower than hydraulic.
While they operate in most environments, electric actuators aren’t suitable for hazardous or flammable areas. If an electric actuator runs for a continuous period, it’s vulnerable to overheating.
Keeping Industry Productive
Now that you know the differences between an electric and hydraulic linear actuator, you can choose the right one for your application. We can help.
Kor-Pak Corporation’s journey began more than 40 years ago. Our philosophy of providing quality products at low prices with exceptional customer service keeps us going strong today.