Four Tips to Specifying Polyurethane for Conveyor Applications
Drive wheels are used in many conveyor applications to advance items and in automatic guided vehicles to drive the vehicles. Polyurethane drive wheels are a popular choice because they have good dynamic properties, good wear properties, and provide a high coefficient of friction. While polyurethane treads are commonly used in drive wheel applications, there is much to consider when designing the wheel for the application.
1. Load and Torque
It is critical to understand how much load the drive wheel will carry as well as how much torque will be applied. These values are needed to properly size the drive wheel. If these values are underestimated it could lead to polyurethane tire delamination from the wheel core and/or tire failure. Underestimating the load on the wheel will also affect how much driving force will be able to be transmitted to the contacting surface.
2. Speed and Duty Cycle
The speed of operation is also critical to successfully designing a drive wheel. The faster the wheel is traveling the lower the overall load rating of the polyurethane tire will be. This is because polyurethane generates heat as it is deformed, so under heavy loads at high speeds more heat is built up than can be dissipated and tire failure occurs. This fact also makes duty cycle important, because the longer a tire is used, the more heat that builds up and the chances for failure increase. When designing a drive wheel with a polyurethane tread, be sure to fully understand the speed of operation, the duty cycle of the application and or the jobs/hour rate.
3. Environment
The type of environment is important to what type of polyurethane can be used. Certain urethanes perform better in wet or humid environments while others are better suited for exposure to certain chemicals and solvents. Understanding the operating environment will help in choosing the correct type of polyurethane.
4. Coefficient of Friction
The coefficient of friction of the polyurethane is also critical to the performance of the drive wheel. When the coefficient of friction is multiplied by the normal load on the wheel, the amount of driving force is calculated. This value becomes critical to understanding how much force can actually be transmitted to the contacting surface of the polyurethane. So the higher the coefficient of friction, the smaller the wheel load needs to be to obtain the same driving force as polyurethane with lower coefficient of friction.
Understanding the points in this article will give you a good first step in properly designing a polyurethane tread for a drive wheel application. The more information that is known about the application, the higher the chances of correctly designing the polyurethane treaded wheel.
When you are dealing with difficult applications where drive wheels are a key component consider the extensive application knowledge of the Caster Concepts engineering group. The group has years of technical and application knowledge that you will find helpful to minimize maintenance costs and allow you to expect a very satisfying life cycle for the drive wheels.