Electric rod actuators vs. hydraulic cylinders: A comparison of the pros and cons of each technology
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By Aaron Dietrich, Director of Marketing
Hydraulic cylinders, known for their high force at an affordable cost, have been widely used in factory automation equipment and other special automation equipment for decades. Hydraulics are rugged, relatively simple to deploy and provide a low cost per unit of force. In recent years, electric rod actuator (cylinders) have become more flexible, precise and reliable
with increasingly larger force capacities. These advancements in electric rod actuators have created an ongoing debate over which technology— hydraulic cylinder or electric actuator—offers the best overall solution for the same application. This paper will consider a variety of factors affecting the performance and cost of each technology, including: motion control
capabilities; system components and footprint; force capabilities; speed capabilities; temperature; life and maintenance of devices; data collection; efficiency/utility costs; leaks and environmental concerns; as well as a few additional factors.
The main reason engineers select an electric actuator system over a hydraulic cylinder system is the flexibility of its motion control capabilities: position control (multiple positions, accuracy); velocity control; control of acceleration/ deceleration; control of output force; and complex control of all these motion variables on the fly. Electric actuators, coupled with a servo drive and motor system, have infinite control over position; accuracy and repeatability levels are far beyond the capabilities of a hydraulic system.
Standard hydraulics are great for end-to-end position applications, but mid-stroke positioning is more complicated, requiring a control valve and operator assistance. Mid-stroke positioning is...