Pneumatic linear actuators consist of a piston inside an empty cylinder. It moves the pressure from an external compressor or manual pump. As the pressure increases, the cylinder moves along the piston axis, creating a linear force. Then the piston returns to the original position.
The benefits of pneumatic actuators arise from their simplicity. Most pneumatic aluminum cylinders have optimal maximum pressure. The pneumatic drive generates precise linear movement, ensuring accuracy and repeatability in a very high range.
Typical applications of pneumatic actuators include areas with extreme temperatures. When it comes to safety and inspection, using air, pneumatic cylinders avoid the use of hazardous materials. They meet the requirements of explosion protection and machine safety because they do not cause magnetic interference due to the lack of motors.
In recent years, pneumatics has made many advances in miniaturization, integration of materials with electronics and state control. The cost of pneumatic actuators is low compared to other actuators. Pneumatic actuators are also lightweight, require minimal maintenance and have durable components that make pneumatics a cost-effective method of linear motion.
Disadvantages of pneumatic cylinders
The losses of pressure and air compressibility make the pneumatics less efficient than other methods of linear motion. Restrictions on compressors and air supply mean that operations at lower pressures will have lower forces and lower speeds. The compressor must run continuously under pressure, even if it is not working.
To be really efficient, pneumatic cylinders must be tailored to the specific task. Therefore, they can not be used for other applications. Accurate control and efficiency require proportional regulators and valves, but this increases costs and complexity. In order to return to its position, the piston of the actuator requires the force of a return spring or fluid supplied on the other side of the piston.
Although the air is readily available, it can be contaminated with oil or grease, leading to downtime and maintenance. Companies still have to pay for compressed air, making them consumable, and the compressor and lines are another problem with maintenance.