Electric Linear Actuators Offer Significant Cost Savings
When selecting a linear actuator, folks often overlook electric actuators because the upfront cost is typically higher than that of fluid actuators; however, due to their precision, flexibility, energy efficiency, environmentally friendliness and low maintenance, the lifecycle cost of electric actuators is often significantly lower than that of the other options.
What’s the Difference between Electric Actuators and Other Types?
In simple terms, the role of any linear actuator is to create motion in a straight line. They are employed in a myriad of industrial applications including food and beverage processing, material handling, robotics and motion control. Actuators are available as electrically, pneumatically or hydraulically driven, so the main difference between actuator types lies in how they are powered. Pneumatic actuators are driven by gases, typically provided by an electric motor running an air compressor. Hydraulic actuators are driven by liquids, typically provided by an electric motor or an internal combustion engine running a hydraulic pump. Electric actuators are driven by some mechanical transmission being run by an electric motor. They all use some sort of prime mover (electric motor or internal combustion engine) and some sort of transmission (pump/compressor and a fluid or purely mechanical) to change rotary motion to linear motion. Electric linear actuators are somewhat more complex than their fluid-powered counterparts because of their mechanical transmission, such as a ball screw, roller screw, worm gear, belt drive, rack and pinion, etc. However, technological advancements enable electric actuators to perform at higher speeds with greater precision and better efficiency than other types of actuators, which can help manufacturers increase production and quality with relatively low operational costs.
While pneumatic and hydraulic actuators offer lower initial cost, ease of use and high thrust, they have disadvantages that electric actuators do not. Hydraulic actuators are subject to oil leaks, which could result in position drift in the best case or fires, health hazards and environmental or product contamination issues in the worst case. Pneumatic actuators require extensive preparation of large volumes of air involving filtering, dehumidifying, adding oil mists for some actuators and removing oils for others. Because air is compressible and acts like a spring, pneumatic actuators typically cannot be used for precise motion control.
Because electric actuators have no intermediate fluid with mass, inertia, turbulence, compressibility and viscosity, they provide far more efficient and precise control of speed, position and force compared to fluid-powered actuators. The holding torque of their electric motors and their mechanical transmissions help prevent position drifting and many electric actuators offer continuous position feedback, allowing them to handle more complex motions such as multi-point positioning applications. These features make electric actuators more capable of repeating specific motion profiles to enhance quality and consistency or production. In addition, it is not difficult to change or adjust the motion parameters of an electric actuator if the application changes, making them more flexible and adaptable than other types of actuators.
How Do Electric Actuators Save Money?
In the manufacturing industry, there is a unanimous demand to increase energy efficiency. Incorporating electric actuators can help accomplish this. Statistics show that electric linear actuators typically operate at around 75% efficiency, while hydraulic and pneumatic actuators typically operate at around 50% and 25% efficiency, respectively. The superior efficiency of electric actuators is partly due to the fact that they only consume electricity when creating motion and they don’t have to spend energy moving fluid to do it.
Electric actuators have far fewer risks of contamination, which is especially important in the food and beverage, pharmaceutical and medical device industries.
Maintenance costs are also minimal for electric actuators. Even in high-performance applications, electric actuators only require periodic greasing or lubrication changes, which are simple, inexpensive tasks compared to replacing large volumes of hydraulic oil, various filters and numerous seals.
Thanks to advances in technology, electric actuators are able to deliver higher levels of productivity, precision and quality with the best efficiency and repeatability for complex motion applications while reducing energy use, maintenance and risk of environmental or product contamination.
For more information on how electric linear actuators can benefit your business, please contact John Henry Foster.