Ball Bearing Lubrication Methods
Centrifuging as oil-lubricated bearing removes excess oil and leaves only a very thin film on all surfaces. This method is used on low torque bearings and can be specified for low torque applications.
Vacuum Impregnation of Cages
Vacuum impregnation, used with ball bearings containing porous cages, forces lubricant into the pores, using the cage as an oil reservoir. Then this method is used with a greased bearing, its purpose is to prevent the cage material from leaching oil from the lubricant. Normally, the base of the grease is used in the cage to prevent incompatibility.
Grease packing approximately 1/4 to 1/3 of a ball bearing's internal free volume is one of the most common methods of lubrication. Grease quantities are controlled by the use of special lubrication equipment. IBSCO is able to control the amount of lubricant to 0.5mg if specified.
Grease planting consists of mixing a quantity of grease and solvent to the desired consistency, lubricating the bearing with this mixture, then evaporating the solvent at a moderate temperature, leaving a thin film of grease on the raceways, balls and cage. Grease planting is used to lower torque values of grease packed bearings.
Oil plating consists of mixing a quantity of oil and solvent to the desired consistency, lubricating the solvent at a moderate temperature, leaving a thin film of oil on the raceways, balls and cage. Oil plating is used to greatly lower torque values of oil lubricated bearings and can be specified for extremely low torque applications.
The maximum usable operating speed of a grease lubricant is dependant on the type of base oil. The speed factor is a function of the bore of the bearing (d) in millimeters (mm) and the speed of the bearing (N) in revolutions per minute (RPM) where:
Table of fn vs Cage, Lubricant Types and Ring Rotating
|Metal Cage||Phenolic or Polyimide|
|2-Piece or Crown Type||Crown Type||Full Section Type|
To determine whether a particular bearing will operate satisfactorily at the required speed, multiply that bearing's value (Nmax/fn) by the proper factor taken from the fn vs Cage table shown. Note that the table takes into account lubricant and cage type. When petroleum or synthetic ester oils are used, the maximum speed Nmax is dictated by the ball cage material and design or centrifugal ball loads rather than lubricant.
For full ball complement types, the listed Nmax values apply regardless of the lubricant type or whether the inner ring or outer ring rotates. For speed limit values Nmax, the Nmax/fn values shown in the product listings must be multiplied by the fn values tabulated above.
|Type||dN||Temperature Range °F (°C)|
|Petroleum||600,000||-25 to +250
(-32 to +121)
|Diester||400,000||-65 to +350
(-54 to +177)
(-73 to +204)
|Perfluorinated Polyether||200,000||-112to +400
(-80 to +204)
dN=d (bearing bore, mm) x N (RPM)
IBSCO is an authorized re-lubrication center for NHBB and NMB adhere to the strict guidelines set forth by the NHBB Quality control department for all cleaning and re-lubrication methods used in our processes.
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