How to select the right air motor. - (Guide)

If you're reading this you probably already know that air motors are devices that convert compressed air into rotational power. They are extremely versatile, and can be used for mixing liquid substances, moving, drilling, milling, grinding, and other things.

What you may not know is the best way to select one. Air motors come in varying shapes, and sizes, with different speeds, & power outputs. They can be used with
conveyor belts, machine tools, automatic feed devices, on bottling machines, with food processing machines, and much more. Each application may require a different type of air motor. So how do you select one?

Steps for selecting an air motor:

Step 1: Determine speed & torque requirements. Each application will likely have speed, and power requirements. How fast does the air motor need to go? How powerful does it need to be? A 2500 rpm air motor with 5.31 lbf·in of torque will work much differently than a 150 RPM with 144.26 lbf.in of torque.

Step 2: Calculate the power (in watts) of the air motor needed. Use the formula:

For example, if you need an air motor which operates at 500 RPM, at 2.5 N.m load the formula would look like this: (3.14 x 2.5 x 500) ÷ 30 = 130.8 Watts. Therefore you'd need an air motor that is 130.8 watts.

Step 3: Determine if you need a reversible or non-reversible air motor. Some air motors can reverse, others can not. Know what you need for your application before selecting one. 

Step 4: Determine the type of spindle needed. Does your application require a smooth spindle, threaded spindle, or collet spindle?

Step 5: Determine if you need a mounting flange / flange bracket. If you do, make sure to include it in your order.

Here's a graphic recapping the steps.

Once you have all the information gathered you can check to see which air motors closest match your requirements. If you can't find any that work, feel free to contact us and we may be able to point you in the right direction.