When buying a linear actuator, it’s important to choose a product that will fit best with your application and specific demands. Whether you want a high load capacity, a longer duty cycle or something that requires very little maintenance, you’ll need to research each ‘type’ of actuator thoroughly.
In this post, we’ll discuss the advantages and disadvantages of two of the most popular types of linear actuators – hydraulic and electric – to help you find the perfect device for the job.
Hydraulic linear actuators
These actuators are powered by pumps of incompressible oil. The pressure that the fluid creates moves the cylinders and, in turn, helps move your application.
- Load capacity. Unlike electric linear actuators, hydraulic actuators are suited to high-force applications and are customizable to almost any weight. They are also the most powerful actuator on the market and are suitable to work under heavy pressures.
- Convenience. The external pumps and motors for this type of actuator can be placed a reasonable distance away from the application without affecting the power supply.
- Constant pressure. Due to the incompressibility of liquid, a hydraulic actuator can hold constant force without the pump having to supply more pressure.
- Leakages. These actuators require expensive plumbing, maintenance and continuous checks. Due to the nature of the product, the likelihood of oil leakages is high. Additionally, high temperature environments can cause damage to the product if not monitored diligently.
- Components. Hydraulic linear actuators are not contained and require numerous external components. If you’re looking for a small device, these may not be the best for your needs.
- Speed. These devices are hard to control accurately and may suffer from ‘stick slip’. Put simply, this is where a linear actuator jolts and jerks in the transition between being still and moving.
- Cost. Although the cost of the initial components is relatively low, the cost of installation and maintenance can be pricey. Unfortunately, if you want your hydraulic actuator to run smoothly, the cost of regular maintenance is a necessary price to pay.
Electric linear actuators
Unlike the hydraulic variant, these linear actuators are powered exclusively by motors. The motor powers the lead screw, which is fitted with a nut that runs up and down the thread. This converts the rotary motion into linear movement.
- Precision and speed. This actuator offers repeatable capabilities with easy, automatic operation controls. The speed of the device is also easily controlled and smooth.
- Less maintenance. As there’s no risk of fluid leakages, there’s very little requirement for regular maintenance. This, of course, reduces costs and increases productivity for both the application and your team.
- Quick installation. Setting up electric actuators only requires simple wiring, meaning you can install your device quickly and cheaply.
- Load holding and safety. Most electric actuators contain acme screw units (or fail-safe brakes) which are self-locking in the event of a power failure.
- Contained. These actuators don’t require external pumps or motors and are therefore much smaller and take up less space.
- Unsuitable environments. Although these actuators will perform well in most environments, installation in hazardous or flammable areas requires the use of equipment rated for these conditions. Only actuators specifically created for use in environments where flammable or explosive gases or particulates are present should be used in these applications. This is necessary in order to prevent injury or damage.
- Overheating. If left running for too long, or over the specified duty cycle, electric actuators may overheat and reduce efficiency.
- Cost. The initial cost of purchasing an electric actuator is high. However, the running and maintenance costs after this are significantly lower than that of a hydraulic actuator
Which is best for you?
Although both variations create a reliable and powerful linear motion for your application, each have their own advantages and disadvantages. So when making your decision, pick the right actuator for your application, specifications and environment.
At the end of the day, making the wrong choice can only cause more hassle in the future, so if you need more guidance to inform your decision, get in touch with a professional who can advise you further.