Electric Actuators vs. Hydraulic Actuators

Electric automation

In the world of industrial automation, one of the most critical components of any system is also the one people just don’t think too much about – the actuator. It’s the element of a system that is responsible for moving and controlling a system – usually some type of industrial robot or automated arm of some kind.

Two of the main types of actuators you’re likely to encounter are electric and hydraulic versions. They’re both still responsible for the same end application, but they go about it in entirely different ways. From that perspective, the difference between hydraulic and electrical actuators is actually quite large – and requires you to keep a few key things in mind.

Hydraulic Actuator Advantages and Disadvantages

As the name suggests, a hydraulic actuator is one that uses hydraulic power to enable the movement in the system it is connected to. Liquid from an attached pump is transported into a cylinder, which forces a piston to begin to move. ­­Speed is dictated by the flow of the pump, and pressure is, in turn, what produces the forces that are ultimately exerted by the actuator.

The major benefit here is that because this type of actuator uses fluids, the actuator will be able to give out a tremendous amount of force – making them suitable for larger industrial applications in particular.

Hydraulic actuators are also known for their ability to give off a constant and consistent amount of force, as the pump doesn’t need to supply additional fluid. This is because hydraulic fluid is incompressible. In addition to high force, hydraulic actuators can also work at very high speeds.

Of course, hydraulic actuators are not without their potential fair share of disadvantages. Anything that uses hydraulic fluid to operate can always potentially leak, which will lead to an immediate drop in efficiency in the system it controls. This can also cause that fluid to build up on the floor, creating problems in terms of cleanliness and even safety as well.

Likewise, hydraulic actuators require a lot of related items to work including pumps, motors, heat exchangers and more. Any of these components can break down at some point, leading to costly periods of downtime and maintenance if left unchecked.

Electric Actuator Advantages and Disadvantages

Electric actuators, on the other hand, work a bit differently. Here, a motor is used to generate rotational motion that is then used to turn a lead screw. The turning of that screw is what generates linear motion, which is how the actuator is able to control whatever device or system it is connected to.

The major benefit with electric actuators is that they produce an incredibly high level of precision – especially compared to their hydraulic and pneumatic counterparts. They’re also built to offer complete control over that motion. They can easily be programmed with custom speeds, varying stroke lengths and even varying forces depending on the application.

Because there are fewer moving parts, there is far less to “break down” – making maintenance much easier than with hydraulic actuators. They also tend to be far quieter than their hydraulic counterparts for the same reason.

Perhaps the biggest disadvantage for most organizations comes by way of their higher initial costs. Though, depending on your perspective, that return on investment may be worth it within the context of how you’re planning on using the actuator and automated system in the long run. Along the same lines, it’s also true that the price for electric actuators and related components has been on the decline over the years – to the point where this may not be much of a disadvantage for much longer.

They are not, however, appropriate for all working conditions. They shouldn’t be used in areas where safe or flammable materials are stored, for example.

Finally, while the electric actuators themselves aren’t necessarily large, the electric motors used to power them can be – thus creating an issue in environments where space is a concern.

In the end, both electric actuators and hydraulic actuators certainly have their place in industrial environments. From that point of view, one isn’t necessarily “better” than the other – they’re just different and are used for different reasons. Only by carefully considering your own needs will you be able to work your way backwards to choose the actuator that can suitably meet them. If you’d like to find out more information about the major differences between electric actuators and hydraulic actuators, or if you’d just like to discuss your automation needs and related topics with an expert, please don’t hesitate to contact JHFoster today.