Step motors are an economical choice for accurate positioning at lower speeds. Can overheat A continuous running motor will overheat, increasing wear and tear on the reduction gear.
The case for pneumatic actuators Pneumatic actuators provide high force and speed at low unit cost in a small footprint. Electric actuators allow for precise control and positioning, easy maintenance, and low replacement costs, as electronics are separate from the actuator. The two technologies are so different that one cannot be a drop-in replacement for the other.
Hydraulic actuators can have their pumps and motors located a considerable distance away with minimal loss of power.
Speed — Pneumatic actuators can operate at variable and very high speeds; electric actuators run at fixed, moderate speeds. They can overheat, however, meaning they must be reliably sealed from moisture. Pneumatics and hydraulics also go through a two-step energy conversion process that results in relatively low energy efficiency.
Reliable with diligent maintenance. Commonly used motors for electric actuators include steppers and servos. Maintains power Hydraulic actuators can have their pumps and motors located a considerable distance away with minimal loss of power.
Easily contaminated Even though air is readily available, it can be contaminated by oil or lubrication, leading to downtime and maintenance which incurs costs. Because electric actuators can substantially reduce changeover costs largely due to the fact that they can retain condition settingsthe annual cost savings associated with changeovers must be considered as part of the implementation decision.
Primer How to Decide Between Pneumatic and Electric Actuators The debate surrounding the pros and cons of electric and pneumatic actuators has been raging for years and still no easy answer exists.
Small compressors are efficient and economical when used to power a small number of pneumatic devices. The lifting or moving of heavy loads is not best suited to pneumatics.
These actuators consist of a ball, Acme, or roller screw connected to an electric motor by a coupler. Pneumatic actuators are most economical when the scale of deployment matches the capacity of the compressor.
Electromechanical actuators are usually less expensive in applications where fluid power is not available. Components of an electric actuator include the mechanical actuator that translates motor rotation to linear speed and thrust, the motor, an electronic driver or amplifier to power the motor, and a controller to control motion.
A mechanically connected electric motor turns a lead screw; a threaded lead or ball nut with corresponding threads that match those of the screw is prevented from rotating with the screw. The increased controllability of electromechanical actuators can often be used to eliminate the need for changeover when switching from one product to another.
Many factors are driving the migration from fluid power to electromechanical solutions. Finally, electromechanical systems are simply cleaner and quieter than fluid power systems. Pneumatic linear actuators consist of a piston inside a hollow cylinder.
Again, the issue here revolves around how much precision you really need. This is mainly due to air compressor flow rates, air is very agile and can flow through pipes very quickly and easily with little resistance, while hydraulic oil is a viscous substance and requires more energy to move.
Even though air is readily available, it can be contaminated by oil or lubrication, leading to downtime and maintenance. Force and speed on pneumatic actuators are easily adjustable and are independent of each other. Each has inherent advantages and disadvantages.
Cost comparison To better compare actual costs between pneumatic and electronic actuators, consider this example: A mechanically connected electric motor turns a lead screw. The two technologies are so different that one cannot be a drop-in replacement for the other.
Though this is not to say pneumatic actuators cannot deliver very precise motion. Pneumatics Vs Hydraulics The pros and cons of each system Pneumatics offer a very clean system, suitable for food manufacturing processes and other processes which require no risk of contamination.
Disadvantages Hydraulics will leak fluid. However, steppers may lose synchronization with the controller when employed open loop without an encoder or if they are undersized for an application. An actuator moves or controls loads and mechanisms; the actuator is operated by energy namely either pressurised fluid, air or electricity, typically sourced by utilising a pneumatic, hydraulic or electric pump.
But this is also a relatively efficient use of hydraulics. One of the reasons for this is, in high force applications, the efficiency of a hydraulic cylinder approaches percent. And because it's a high-pressure application, piston pumps will be essential.
The overall efficiency of an axial piston pump in good condition is 92 percent. Home» Electric vs. Pneumatic Actuators.
Motion Control Electric vs. Pneumatic Actuators. Two smaller compressors often are less expensive to run than one larger unit. Photo courtesy Bimba Manufacturing Co. and reserving them for applications in which they can improve process efficiency. Pneumatic actuators have advantages in cost.
One of the reasons for this is, in high force applications, the efficiency of a hydraulic cylinder approaches percent.
And because it's a high-pressure application, piston pumps will be essential. Quadrants of the Power Efficiency Diamond of a hydraulic machine are all interrelated.
Changing any one affects the symmetry of the diamond. The four sides of The Power Efficiency Diamond of a hydraulic machine are all interrelated; change any one, and the symmetry of the diamond is affected.
For help on this issue, we referred to information from Bob Kral at Bimba Manufacturing Company, a supplier of pneumatic, electric and hydraulic actuators. According to Kral, the choice of pneumatic or electric actuators involves an evaluation of performance.Efficiencies of hydraulic vs pneumatic actuators