Thin Section Bearings Lubrication Maintenance for Optimum Performance

The lubricant in an anti-friction bearing serves to reduce friction and wear between moving parts, to dissipate heat, and to prevent corrosion of critical surfaces. Selection of the proper thin section bearings lubricant must be based on satisfaction of the operating conditions, including rotational speed, type and magnitude of loads, and ambient temperature.

The three types of thin section bearings lubricant commonly used are:

oil
grease
dry film or surface treatment

Oil normally provides more complete lubrication. Because of its liquid state, it provides better coverage of the critical surfaces and assists in dissipating heat more readily from your thin section bearings, the latter being especially true when circulation and cooling are provided. In high speed applications where the heating effect is more pronounced, oil is generally mandatory (see page 77). Where minimum torque is a requirement, oil will usually provide lower friction values.

Grease offers certain advantages of its own. Because it is more easily retained, the design of bearing housings and seals is simplified. In many applications, the lubricant itself serves to exclude contaminants when used in conjunction with labyrinths or close clearances between the rotating and stationary structures. Applications using a high quality bearing grease will perform for long periods of time with little or no maintenance where operating conditions are not severe. For the higher speeds within the range suitable for grease lubrication, a channeling type grease is recommended.

Dry films and surface treatments have been used as bearing lubricants in applications subject to environmental extremes, particularly where conventional lubricants cannot be tolerated or will not survive. A wide variety of types are available and can be furnished, including Tungsten disulfide, graphite, and Molybdenum disulfide.

It is important to note that the quantity of lubricant affects bearing performance under certain operating conditions. Only relatively small amounts of lubricant are necessary to reduce friction and wear if a film can be maintained on all contacting surfaces. Where speed is significant, excessive amounts of oil or grease will result in higher operating temperatures, leading to the possibility of early bearing fatigue.

Unsealed thin section bearings are supplied with a coating of preservative type lubricating oil for the prevention of corrosion during storage. For best performance it is recommended that this preservative be removed with clean solvent prior to lubricating during assembly. If this is not done, the end user should verify the lubricant used is compatible with the preservative.

In applications where minimum torque is required, the coating should be removed by washing with a clean petroleum solvent followed by immediate relubrication with a light spindle oil. When desired, it is a common commercial option to have Reali-SlimŽ thin section bearings factory-lubricated with a commercial grease or oil for direct installation by the customer. Sealed bearings are packed approximately one-third full with a multi-purpose industrial grease. Exterior surfaces are given a light coating of the same lubricant for protection during storage in the original package.

The initial grease pack is usually good for the life of the bearing, but operating conditions may cause the grease to lose its properties before the theoretical bearing fatigue life. If relubrication proves necessary, grease may be injected with a hypodermic syringe. In most cases, however, it is better practice to replace a bearing with identified grease failure. If required, sealed bearings can be supplied with alternate greases as a commercial option.

Thin section bearings, with or without seals, can be supplied with optional lubricants. Shown in the accompanying table are some of the greases and oils more frequently specified. Several have been developed to meet the requirements of unusual operating conditions. Because of this, and the variation in cost, it is recommended that lubricants be selected with the assistance of a thin section bearings lubrication expert.

Due to the finite shelf life of any wet lubricant, factory lubricated bearings should not be held more than 2 years prior to use.

Contact Kaydon Bearings for refurbishment instructions for product held beyond 2 years of receipt.

It is an unfortunate fact that most bearings fail due to abuse and/or neglect. To realize the full potential life of a Kaydon Reali-SlimŽ thin section bearing, protection must be afforded against the intrusion of foreign matter of all types. Fresh oil or grease must be introduced with sufficient frequency to cleanse the bearing to assure continued good lubrication.

Proper bearings lubrication will help to assure the longevity and performance of your thin section bearings, open, bearings, sealed bearings, stainless steel bearings, lightweight bearings, turntable bearings, slewing ring bearings, large diameter bearings, heavy duty turntable bearings, used for applications ranging from military equipment, medical equipment, aerospace equipment or any other machinery, commercial or industrial application.