Sealmaster<sup>®</sup> High Temperature Furnace Bearings Solution
A baking facility was replacing over 100 bearings on a tunnel oven annually and re-lubricating the bearings every two weeks. Periodically, they would have to replace bearings more frequently. If they experienced an unplanned failure, the conveying belt would get damaged and this could more than double the cost of the change out and increase the total downtime.
After review of the application and inspection of the removed bearings, a Sealmaster® high temperature bearing solution was selected. It consisted of one fixed and one expansion bearing per shaft, using the Sealmaster reduced maintenance taper land design and high temperature bearing features: increased internal clearance, high temperature Nomex®* seals, a high temperature Krytox®* 226 grease, and air handling housing fit. After five years, the bearings are still operating successfully.
Food - Baking
OEE - Overall Equipment Effectiveness
KEY CUSTOMER NEED(S) AND BENEFITS FROM SEALMASTER® PRODUCTS
The average cost to re-lubricate the old bearings every two weeks and change the bearing once per year for a five year period is over $35,000, not including belt damage costs. The cost of the Sealmaster® solution is under $10,000, resulting in a cost savings of $25,000 and more uptime.
Building from the standard features of the Sealmaster® Gold performance mounted ball bearing, this bearing has the following features.
FEATURES AND BENEFITS
- High temperature bearing with increased radial internal clearance to accommodate thermal expansion of components and Nomex®* seal and high temperature Krytox®* grease.
- Controlled air handling housing fit that results in more clearance between the bearing outer diameter and housing bore to accommodate thermal growth differences of the materials.
- Axial shaft expansion is compensated by a non-expansion (fixed) and expansion (float) arrangement. Many bearings are offered in both fixed and float arrangements and have identical mounting dimensions. It is recommended to use both units on one shaft in high temperature application to help account for linear shaft expansion.
- Sealmaster reduced maintenance bearings are the result of a patented tapered lands bearing race profile which means that critical lubricant is circulated more efficiently, while requiring no regular service intervals. The bearings are supplied from the factory with a plug instead of a lubrication fitting.The outer land surface in a conventional bearing is parallel to the axis of the inner ring. The tapered lands surface is tapered in a radial direction toward the bearing race. This subtle yet crucial design change allows lubricant to more easily flow back to the raceway. With improved bearing lubricant circulation comes significantly longer bearing service life. This improved circulation and service life comes without any reductions in bearing radial or thrust capacities. For bearings that are maintained and relubricated on a regular basis, there is no significant difference in expected service life.
* NOMEX and Krytox are believed to be the trademarks or trade names of E.I. du Pont de Nemours and Company and are not owned or controlled by Regal Beloit Corporation.