A comprehensive engineers' reference source for radial ball bearings and thrust ball bearing




Grease (standard): Grease is deposited between the balls in the bearing raceways in carefully controlled clean conditions, according to the specified quantity. Bearings are not normally rotated after this process, so that run-in is necessary to distribute the grease evenly.

Oil (standard): Oil is deposited in the bearing raceways in carefully controlled clean conditions. Normally, oil quantity is not specified by the user, but is factory determined according to bearing size. In some cases a specified weight of oil can be used. Contact Dynaroll for more information.

Centrifuging: For torque sensitive applications, centrifuging may be specified to remove excess oil, leaving a very thin film.

Vacuum impregnation: If the bearing retainer (cage) is made from a porous material, then vacuum impregnation can be used to force lubricant into the pores, providing an oil reservoir. When a porous retainer is used with grease, then the cage may be impregnated with the base oil to prevent leaching from the grease.

Plating: Bearings may be immersed in an oil or grease that has been diluted with a carrier solvent. When the carrier evaporates, the bearing surfaces are completely coated with a small amount of the original lubricant which acts both as a corrosion shield (if applicable) and a lubricant where only a very small amount is required (e.g. for low torque). The choice of solvent must be compatible with the base lubricant. Contact Dynaroll for more details of the plating process.

Dry (no lubricant): Bearings may be specified without any lubricant. However, they may be susceptible to corrosion. Bearings made from 52100 chrome steel are always supplied with a coating of corrosion-inhibitor (even when supplied "dry"), since, without this coating, corrosion would be rapid and unavoidable.

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