The Importance of Choosing the Right Vane Material for Air Tools

Published on June 26, 2024

Tools that work pneumatically have numerous components, with vanes being a particularly important part of many motors that power an air tool. Vanes act as a turbine, bringing in pressurized air that pushes against them to turn the motor within pneumatically operated devices. Countless workers across many economic sectors rely on pneumatic power, including those in the agricultural, automotive, dry cleaning, energy, food and beverage, HVAC, pharmaceutical, plastics, railroad, and woodworking industries.

Many of the pneumatic tools used by industry use vanes when harnessing the power of compressed air. Tool vanes are affixed to a metal rotor within precisely made slots, sliding in and out of these slots as the rotor spins. As these air tool vanes rotate, they capture this compressed air to make the rotor turn. Though the exact type of material necessary for these vanes depends on the application, the materials from which vanes are made must be sufficiently durable to ensure proper performance and a longer lifespan.  

How to Choose the Right Material for Air Tool Vanes

The three most common motors used for pneumatic tooling involve either pistons, turbines, or vanes. The design using vanes is the most basic type, consisting of only a front-end plate, rotor, vanes, cylinder, and rear-end plate. Pneumatic motors offer advantages over electric motors in certain applications. A larger electric motor will produce power at the same rate as a smaller pneumatic motor. Air-powered motors also produce less heat and experience fewer overloads than electric motors, which are generally more reliable.

However, the faster a pneumatic motor runs, the lower the van’s estimated lifespan within the motor. When there’s a bigger motor, it must then run at lower speeds and pressures to decrease wear on the air tool. Vanes used for pneumatic motors make devices generally less expensive, lighter weight, and smaller than those using pistons, so they’re often used for portable air tools.

Basic working principles of motors powered by compressed air using vanes involve: 

  • Compressed air is forced into the motor through an inlet.
  • As this compressed air flows into the motor, it forces vanes equipped with springs against the interior cylinder wall of the motor’s chamber.
  • A pressure differential develops on both sides of each vane, causing the rotor to turn.
  • Vanes slide along the chamber’s interior wall as the rotor spins to preserve a seal.
  • Once an air tool vane reaches the outlet, it’s forced back by the spring.
  • Compressed air exits the motor before the sequence recurs.

At lower speeds, this spring force is stronger than the centrifugal force of the air tool vanes, causing it to press against the cylinder’s wall before the rotor turns. Once speed increases, the centrifugal force approaches the spring force, eventually surpassing it to cause vanes to slide along the chamber’s interior wall. At higher speeds, the spring force keeps the air tool vanes being flung from the motor and against the chamber wall.  

Typically, air tool vanes require a small amount of lubricant with these types of motors, though the compressed air also acts to lubricate. Certain pneumatic motors don’t require any lubricant at all, however, and instead feature air tool vanes made from materials that have low friction coefficients. These types of tool motors also have bearings that are permanently lubricated. However, lubricated motors are often used as the air tool vanes tend to last longer.

Different Materials Used for Air Tool Vanes 

The materials from which air tool vanes are made should offer mechanical properties like high strength and hardness to keep them from damage due to components interacting with the vanes. These materials should also resist water, organic compounds, high temperatures, friction, and deformation. Deformity resulting from wear affects a motor’s torque, so manufacturers of these vanes often use high-performance polymers and composites. These materials must also handle the pressure from compressed air without impeding the movement of or overly wearing the air tool vanes.

Examples of materials used for air tool vanes and their applications include: 

  • Aramid fiber (Kevlar®) composite fabric features a high-temperature epoxy resin that resists moisture and provides exceptional strength. It is used for applications in lubricated pneumatic motors.
  • ‍Aramid fiber (Kevlar®) composite fabric with high-temperature phenolic resin to provide superior mechanical strength in harsh and high-heat environments for applications that include vacuum pumps for the dairy, mining, petroleum refining and other industries.
  • Aramid fiber (Kevlar®) fabric featuring high-temperature phenolic resin offers good mechanical strength at high temperatures and an excellent thermal expansion coefficient for applications like vacuum pumps in cement processing, liquid waste, refrigeration, and other industries.
  • Cotton fabric featuring phenolic resin with molybdenum disulfide for lighter-duty applications like air compressors, blowers, and vacuum pumps.
  • Laminate with a fabric base with resin-containing lubricant that decreases the need for lubrication via the compressed air supply, specifically for use with air tool vanes on rotors for pneumatic rotors to lengthen vane lifespans.
  • Very finely woven cotton fabric featuring high-temperature phenolic resin impregnated with resin to augment dimensional stability when exposed to stress for applications like air motors, smaller air tools and starter motors.

Air Tool Vanes by Spaulding Composites 

Providing air tool vanes for going on half a century, Spaulding Composites has considerable experience with the market for pneumatic tools. Spaulding has the capabilities to fabricate parts and products with complex geometries and tight tolerances at volume. Used by prominent air tool manufacturers, we take great pride in the mechanical properties, quality and reliability of our custom composites. Spaulding Composites invites you to check out our capabilities for making durable air tool vanes, along with various other products and service, by contacting one of our friendly representatives today.