Contrary to popular belief, the total cost of electric actuators is actually lower than that of hydraulic cylinders. Although the upfront cost of electric linear actuators may exceed that of hydraulic systems, the additional benefits described below tip the balance in favor of electric linear actuators.
Control
Electric linear actuators equipped with servo motors and connected to a controller allow full control of piston position, speed, acceleration, and force with just a few keystrokes. The control of these parameters in hydraulic systems can be designed into the system, but there is very limited ability to change the motion profile after installation.
Energy Consumption
Electric linear actuators consume energy only when in motion.
They convert over 95% of the input energy into thrust during movement. In contrast, hydraulic systems run their pumps continuously to maintain line pressure, reducing efficiency to below 50%.
Maintenance
Electric linear actuators require almost no maintenance, only needing a small amount of grease applied regularly. Hydraulic systems require regular filter replacements, adding hydraulic oil, and checking hoses for wear or damage. Years of empirical data on the dynamic capacity of ball screw/bearing systems enable accurate service life predictions.
Noise Generation
Electric linear actuators are silent, except when in motion, and even then, they are almost noiseless. Hydraulic systems typically have high-horsepower motors running continuously, which generate significant noise.
Space Requirements
Electric linear actuators are self-contained units installed where force or motion is needed, connected to the system controller via small-diameter cables.
Hydraulic systems have cylinders installed where force or motion is required, connected via at least two hoses to a reservoir equipped with a motor, pump, and filter, with these reservoirs located near the cylinders.
Environmental Concerns
Electric linear actuators are mechanical devices that do not contain or produce harmful substances. Hydraulic systems are powered by high-pressure fluids flowing through hoses and must be carefully maintained to prevent leaks. If hydraulic oil is released, it can cause product damage and/or environmental harm. Additionally, fluid vapors can create environmental issues and surface contamination, requiring extra cleaning of finished components.
