Best Practices for Selecting & Sizing Guide Wheels
Linear Motion | Harsh Environments | Smooth Motion | Long Lengths | Low Noise | Clean Room | High Temperature | Rotary Motion | Best Practices
DualVee Motion Technology | UtiliTrak Linear Guides | MinVee Miniature Linear Slides | LoPro Actuated Linear Guides
For more than 30 years, Bishop-Wisecarver Corporation (BWC) has been developing best practices for matching guide wheel linear motion properties to customer requirements, based on engineering and empirical experience. By sharing knowledge and experience, selecting a guide wheel with the properties best-suited for a given linear motion application should be much easier and result in a system that reduces design costs and engineering change orders, as well as lower warranty, assembly, installation and mounting costs.
While much attention has been focused on the precision and speed of other linear motion guides, guide wheel systems have their niche too. Guide wheel systems routinely operate in environments with high humidity, high concentrations of liquid and solid particulates, operating temperatures up to 500°F (autoclavable), noise level limitations, very long travels, and meet tolerances as high as +/- 0.001” (+/- 0.03mm). Compared to other linear motion systems, guide wheels have less friction, are much faster to assemble and very cost efficient.
By matching the component properties of a guide wheel system to a given application, engineers can ensure trouble-free operation during predicted lifespan, as well as reduced costs, lead time and field failures. The bearing type, wheel and track material must be matched to the environment and loads, as well as accuracy, lifecycle and cost requirements. Based on engineering expertise and empirical experience, we have developed a process for ensuring the best match of guide wheel system to application, beginning with the operating environment.
Bearing Type Selection
The environment determines what type of guide wheel bearing is required, e.g. sealed or shielded. Environments with heavy concentrations of liquid or fine/powdery particulates can displace and/or change the properties of the bearing lubricant, causing premature wear and failure of the bearing. Specifying a sealed bearing for this operating environment can prevent damage to the ball and raceways, ensuring the predicted lifespan of the linear motion system.
Generally, shielded bearings are used in environments with heavy concentrations of such large particulates as metal flakes that can work in between the ball and bearing raceway. The larger debris can cause premature wear and such damage as brinelling or spalling.
Note: In contaminated environments, a de-rating factor based on the severity of the contamination must be used for sizing. This is discussed in the section on guide wheel sizing.
Download the complete white paper, Best Practices for Selecting and Sizing Guide Wheels for Your Linear Motion Needs.