Bearing Mounting and Fitting: Bearing Handling || Dynaroll Bearing Design Factors Part 2

Bearing Handling

Miniature and instrument-sized ball bearings are high precision machine parts with tolerances and raceway finishes that are measured in millionths of an inch. At the same time, their small size and often thin sections makes them vulnerable to excessive handling forces. High quality bearings cannot be expected to fulfill their performance potential if they are mistreated or contaminated and most small bearing failures can be traced to the user’s poor handling techniques. Common sense in handling a precision part goes a long way towards avoiding such problems, and the user should consider the following as good manufacturing practices.

Avoid contamination: Bearings are supplied in packages that are usually sealed after final inspection in class 100 clean room conditions. Even sub-micron contaminants can have a serious adverse affect on torque, noise, bearing life, etc.

Contamination is avoided by installing bearings in a clean environment. While a clean room or laminar flow workbench is recommended, these are not essential for normal applications as long as basic precautions are used.

• Never handle bearings with bare hands. Use talc-free finger cots or surgical gloves. This is also important to avoid corrosion of 52100 chrome steel bearings.
  
• Work areas and benches should be cleaned daily to avoid dust build up.
  
• Keep bearings in original packaging until used. Never leave bearings exposed to the environment.
  
• Work tools must be kept clean and burr-free
  
• It is preferable that assembly workers wear clean external clothing (caps, smocks, shoe-covers) that meets clean-room specifications. No make-up or cosmetic powder.
  
• Mating components should be cleaned prior to use. Be careful in the choice of cleaning materials as regular cotton swabs and cleaning cloths may add contamination from lint. Use specific lint-free clean room products.
  

Bearing Mounting and Fitting, Page 10: Bearing Failure Due to Bearing Force,
Moisture,and/or Poor Alignment