All You Need to Know About Actuators
The critical function of an actuator is to control or move a system or a mechanism. Actuators require a source of energy to operate, and the source could be hydraulic fluid pressure, pneumatic pressure or electric current. The energy is converted into motion which is the basic principle of how
Types of actuators
Actuators are divided into various categories based on the energy type. The classification of actuators depends on the type of energy applied to cause motion.
Pneumatic Actuator for High Speed and High Frequency
Linear pneumatic actuators are made of a hollow cylinder which consists of a piston which is put into motion by an external compressor or a manual pump. The linear force is generated when the
increase of pressure causes the cylinder to move along the piston’s axis. The piston typically falls back into its original position by a spring-back force or fluid on the other end of the piston.
The biggest benefit of pneumatic actuators is that they are simple. They are cost effective having low maintenance cost, can easily resist overheating and have the ability to withstand wet and moisture-ridden environments. These actuators are inherently shock proof, explosion proof and spark proof. In spite of all these benefits, pneumatic actuators fail to provide a viable solution where stiffness, positioning and accuracy are required. Also they tend to encounter pressure loss and air compressibility, making these actuators less efficient in comparison to others. Therefore electric actuators are preferred for applications with controllable speed and positioning accuracy for intermediate stops.
Hydraulic Actuators for Heavy Loads, Less Frequent Motion and Low Duty Cycle
The way hydraulic actuators operate is very similar to pneumatic actuators. However, in hydraulic actuators, the cylinder moves due to an in compressible liquid from a pump or air pressure instead of
Hydraulic actuators are suitable for high-force applications. They can hold force and torque constant even if the pump is unable to supply more fluid or pressure due to the in compressibility of fluids. Hydraulic cylinders, while robust and reliable, require pressurized oil and regular maintenance to achieve consistent levels of positioning accuracy. Fluid leaks are common, which cause end-product and environmental contamination. This makes hydraulic actuators less efficient.
Also they require many companion parts like fluid reservoir, motors, pumps, release valves, and heat exchangers, along with noise-reduction equipment making them a complex system with high space requirement.. Therefore the hydraulic systems become large and difficult to accommodate
Electric Actuators for High Efficiency, High Load Carrying Capacity and Medium to HighFrequency
Electric actuators mainly convert the electrical energy to torque. The lead screw turns due to the electric motor that is connected to it mechanically. The speed of the motor depends on the voltage of the input. Electrical actuators offer the highest precision-control positioning. They can be easily incorporated into the various motion control systems with the help of programmable logic controller (PLCs), human machine interface (HMIs) and other devices that improve motion control, diagnostics, and collection of data. Besides, electric linear actuators also offer unlimited positioning capacities along with data feedback. They offer complete control of motion profiles and can include encoders to control velocity, position, torque, and applied force. As compared to pneumatic and hydraulic actuators electric actuators have less noise. The environmental hazards are eliminated as there are no fluids leaks. Motion control systems have become more complex. However, electric linear actuators offer ideal solutions to handle complex motion profiles with higher efficiency such as speed control, acceleration, deceleration, etc. Besides, electric actuators also offer unlimited positioning capacities along with data feedback. Although the initial cost of electric linear actuators may be higher, the overall cost of ownership is less because of reduced maintenance costs, efficient energy use, and efficiency.
Total Cost of Ownership includes the initial acquisition cost and operating costs.
Total cost of ownership = initial purchase cost + [(years of service) x (yearly operating cost)]
Read Electric Rod Actuators vs Hydraulic Cylinders to know more
Phoenix Mecano India is at the forefront when it comes to the development and production of electric linear actuators. We provide customized system solutions and system configurations depending on the requirement of our clients.