Pneumatic or Hydraulic Motors Whats The Difference?

For many years, the arguments have been raging between which is the best kind of linear actuator, a pneumatic or hydraulic motor. Each one of these designs basically fulfils the same function, so what’s the difference? Every style of linear actuator has its own advantages and disadvantages which put them ahead of their competitors, but what are they?

How Do These Linear Actuators Actually Work?

• Pneumatic Motors – This type of linear actuator consists of a piston within a hollow cylinder. Pressure, which is provided via an external compressor or a manual pump, forces this piston to move within the cylinder.
  
  As pressure increases, the cylinder moves along the axis of the piston, which creates a linear force. The piston then returns to its original position, either by a spring-back force, or by fluid which enters the opposite side of the piston.
• Hydraulic Motors – These linear actuators work in a very similar way to their pneumatic alternatives. However, an incompressible liquid from an external pump causes the cylinder to move, rather than pressurised air. Hydraulic Motors are some of the most reliable and powerful linear actuators available on the market today, and have a wide range of industrial and domestic applications.

The Pros And Cons Of Pneumatic And Hydraulic Motors

• Pneumatic Motors –
  
  • Advantages –
    • Pneumatic motor designs are simple! They also offer a wide range of pressure ratings and bore sizes, so you will be able to find one to match almost any system specification.
    • Pneumatic linear actuators generate extremely precise motion and are accurate to within 0.1 inches.
    • They are safe in extreme environments and meet a wide range of safety requirements due to their lack of magnetic interference and traditional motors.
  • Disadvantages –
    • Due to the loss of pressure, pneumatics are less-efficient than other linear-motion methods. Air delivery limitations mean that lower pressures will force much lower forces and slower speeds.
    • Pneumatics must be perfectly sized for the specific job.
    • Air can easily be contaminated by oil, or lubrication, which leads to downtime and maintenance.
    • Although air is freely available, companies will still have to pay for compressed air, making it into a consumable.
  • Hydraulic Motors –
    
    • Advantages –
      • Hydraulic motor designs are reliable and sturdy, and are well-suited for high-force applications.
      • They can produce forces up to 25 times larger than pneumatic alternatives of equal size.
      • Hydraulic motors can operate in pressures of up to 4,000 psi.
      • They have a high-horsepower to weight ratio.
      • A hydraulic linear actuator can hold force and torque constant, without the pump supplying additional fluid or pressure.
      • Hydraulic motor designs can have their pumps and motors positioned a considerable distance from the system, with only minimal loss of power.
        
    • Disadvantages –
      • Hydraulics will, occasionally, leak fluid. Much like their pneumatic alternative, this can lead to a lowered efficiency.
      • Leaked fluid can result in potential damage or a cleanliness problem in ill-maintained systems.
      • Hydraulic systems require many companion parts, which can include a fluid reservoir, additional motors and release valves.
        

Pneumatic Or Hydraulic Motors – Which Is The Best For Your Needs?

Here at Flowfit, we offer an unbeatable range of hydraulic motors for both domestic and industrial applications. We believe that the added strength of hydraulic systems gives them the edge over their pneumatic motor alternatives.

For more information, feel free to contact our friendly and helpful sales team on 01584 876 033. Alternatively, you can email our hydraulic specialists directly on sales@flowfitonline.com, and we will get back to you as soon as we can!