Motor bearing systems

Numerous bearing systems are used in the electric motor industry. These systems even vary for a given manufacturer based on the motor size, type, enclosure, speed, and application. This article focuses on anti-friction rolling-element, grease- or oil-lubricated bearings used in vertical and horizontal motors. Although common in large motors, the hydrodynamic sleeve and plate-type bearings are beyond the scope of this article. The primary focus is on industrial applications that use more traditional types of bearings, lubricating systems, and enclosures. It is acknowledged that there are other specialized bearings in operation and other types of machinery where the principles of the article may have application. A comparison is made between the different types of bearing systems available. Loading, speed, coupling, and life factors are considered. The various methods of lubrication, sealing, mounting, and clamping are reviewed. Recommendations are given for a wide variety of industrial applications. The primary focus of this article is on conrad-type ball bearings, with the understanding that other types of bearings are, used for specific applications. These bearings can be open, shielded, or sealed.