How exactly does an electric actuator compare to other types of actuators? Many people believe that pneumatic actuators are simply cheaper, so that is the best option for their application. In some cases, this couldn’t be further from the truth.
Electric actuators are more efficient in some cases. This means the actuator performs better and can even save money when in use.
Below we will discuss in what cases electric actuators make more sense specifically when it comes to performance and price.
Simple Versus Complicated Applications
Pneumatic cylinders perform very well when an application only requires movement from point A to point B. However, when an application requires multiple points of positioning and many starts and stops, pneumatic systems will require additional parts and installation changes to aid the pneumatic cylinder. This is where things start to get a bit more expensive.
Electric motion systems, on the other hand, use servo drives and motor technology to make more complicated applications simple to navigate. Often, these tasks are implemented by using a drive alongside a PLC, HMI, or other controller.
Even better, electric motion systems have improved reliability and accuracy due to better control of position and speed. So, if your application requires many stops and position changes, electric actuators may be your go-to selection.
Force Requirements & Responsiveness
Pneumatic cylinders operate on a fluid power basis. The nature of air is compressible which can cause a delay in the generation of force due to the time it takes to build pressure.
Electrical systems don’t have this delay in reaction time. Force is generated by motor torque which means that force is generated nearly instantaneously. So, if a delay in timing is an issue, pneumatic technology may not be the right choice for your application.
System Build Costs
When comparing hydraulic, pneumatic, and electric actuation costs, you must not only consider the price of the equipment but also the cost of fluids, filters, system, and set-up costs. Downtime is expensive, and the longer it takes to install a system, the more money your company spends.
Pneumatic and hydraulic systems undoubtedly take longer to install and require more equipment fitting. Once the costs of installation and accessories are included onto the bill, often electric systems come to cost less than hydraulic or pneumatic systems.
Even more, pneumatic and hydraulic systems tend to have higher costs of ownership than their electric counterpart. Overall, pneumatic and hydraulic systems tend to have higher hidden costs than electric ones.
When trying to determine the true cost of your equipment, including the initial cost plus the hidden cost, you should perform a total cost of ownership analysis (or TCO). The equation below can help you determine this cost:
TCO = initial purchase cost + (years of service x yearly operating costs*)
*Yearly operating costs = Replacement + maintenance + electricity + process control + lost production due to changeover + any other cost factors present in your application
For certain applications, product contamination may be a concern. Industries such as food and beverage, medical manufacturing, and a few other industries can’t allow for any contamination to take place.
Pneumatic systems especially risk product contamination, however, hydraulic power can also lead to contamination. Electric actuators and systems eradicate the risk for contamination and can supply your business with peace of mind.
Velocity and Acceleration Needs
Pneumatic actuators can reach high speeds at a low per-unit cost. The catch is that there is less speed control in a pneumatic system. Even more, acceleration and deceleration are hard to control without the use of shock absorbers.
Speed control is much easier achieved using electric systems. Deceleration and acceleration happen quickly and without the use of shock absorbers.
Maintenance Needs & Costs
Pneumatic and hydraulic cylinders can experience pressurization problems when seals break or leak. While these systems provide long-lasting performance, upkeeping them is the only way to prevent downtime and expensive repair.
Electric actuators on the other hand don’t require the same intensive maintenance. In fact, little to no maintenance is generally required for electric actuators.
Pneumatic systems generally need to operate constantly to maintain pressure within a cylinder. They also have a tendency to lose efficiency due to compressor system leaks.
Electric systems only need to run when doing work. Even better, they run at higher rates of efficiency than pneumatic or hydraulic systems.
This means you save money on your electricity costs!
Electric actuators hold many benefits over their pneumatic or hydraulic counterparts. However, certain applications may reap benefits from pneumatic or hydraulic motion. It really comes down to the type of application you have and specific needs that your business requires.
We recommend contacting a specialist for help determining the best motion system for your application and needs.