Linear actuation is an essential technology that has supported manufacturing operations around the world since the beginning of the industrialized age. Converting energy into useful work has been and continues to be an enabling, challenging, and costly factor in manufacturing operations.
Today, the conversion of raw energy into a controlled linear force is a critical factor in industries with a historically high content of automation, such as automotive, packaging, and material handling. Escalating concerns over the cost and availability of energy, however, are now causing designers in many other industries such as oil and gas, defense, marine, mobile equipment, and entertainment to take a fresh look at energy-efficient electromechanical actuation technologies to replace traditional hydraulic and pneumatic solutions.
Although systems are extremely power-dense, hydraulic actuators have the lowest energy conversion efficiency of the three actuator types.
Based on US Department of Energy studies, industrial users consume approximately 20 percent of the electrical power generated in the US, and 40 percent globally. Furthermore, the studies indicate that 40 percent of industrial applications do not use energy-efficient technologies, intensifying the energy consumption issue. Transportation consumes more than 25 percent of US electrical power.
Clearly, energy-efficient actuation technology has an important role to play in the reduction of energy consumption and resulting emissions.
Global competition for resources
Competition for energy resources continues to increase among developing nations around the globe. Growing energy demand and fossil fuel shortages makes reliable, affordable, and environmentally responsible electric power generation and delivery a critical, potentially limiting factor in modern societies. Actuation system design and implementation is increasingly affected by these global energy trends and shortages. At the same time, actuator technology and application development is becoming an increasingly important player in the efficient use of energy.
European countries, particularly Germany, have taken a proactive stance on energy use by introducing the Future Energy Concept intended to address energy resource competition, an increasing standard of living and overall energy consumption. The concept assumes that progress can be achieved through the application of renewable energy sources like wind or bio energy. However, alternative energy sources are not yet capable of adding the capacity needed to cover all energy needs. The concept scope also includes improvements in energy efficiency and that all possible residential and industrial uses must be considered. Studies project a potential of savings of 10 billion€ per year in German industry.
Current actuator technologies
Current linear actuator technologies include hydraulic, pneumatic, and electromechanical systems. Each has a long application history and each has experienced significant technological improvement over time. They differ markedly in the areas of precision, potential work output, system cost, energy consumption, maintenance, emission byproducts, scaling, and other factors. And while historically overlooked, Total-Cost-of-Ownership (TCO) is quickly becoming a major factor in the actuator system buying decision, primarily due to heightened awareness of the impact that the cost of energy required for operation has over the life of the machine. This, obviously, drives bottom line business decisions. Research has shown that more than 95 percent of TCO can be the energy cost to operate an actuator-driven system. Clearly, energy cost estimates can dominate the selection process for any actuator application.