Electric actuator advancements expand options for replacing hydraulic cylinders

01 March 2022

As electric actuators advance in load handling, durability and intelligence, their potential as hydraulic cylinder replacements continues to grow. Depending on your initial objectives for specifying hydraulic cylinders, there are an increasing number of electric alternatives that might meet – or even exceed – those specifications.

Higher power than expected

Up until about a few years ago, a machine designer building an application such as a signage boom truck would likely have used hydraulic cylinders. If built with hydraulic cylinders, the machine would have needed an oil reservoir, a system of tubing to bring the fluid from the reservoir to the cylinder, and a set of power cables running throughout the boom. Leakage is a possibility at any point, and maintenance demands are high.

A modern electric option for such applications is a hybrid actuator that integrates the lifting capability of a hydraulic system with the cleanliness, compactness and controllability of an electric linear actuator. This combination delivers up to 21kN (4,800lbs.) of force in an electrically powered unit that functions without a complex system surrounding it.

Furthermore, the unit will also deliver shock handling performance comparable to a fully hydraulic system. The boom on the signage truck mentioned earlier, for example, might be subject to wind shear that could damage components of a traditional electric actuator. A hydraulic/electric hybrid system, however, would absorb these sudden shocks.

Longer life than previously available

Machine designers building simple applications, in which basic movements repeat with high frequency, have also typically deployed hydraulic solutions. These provide an acceptable duty cycle of 40 to 80 percent, which contributes to a longer life, but a substantial part of that life is used up to maintain the actuator.

Read the full article in the March issue of DPA