BALL BEARING HOUSED UNITS
TIMKEN HOUSED UNIT CATALOG Download 3D Models and 2D Drawings at cad.timken.com
The ideal oil (as far as viscosity is concerned) would be the same viscosity at all temperatures. All oils become less viscous (thin-out) when heated and more viscous (thickened) when cooled. However, oils do not vary in viscosity to the same extent. Some thicken or thin more rapidly than others. The term viscosity index, or VI, is used to rate oils according to their temperature-viscosity behavior. Oils with the highest viscosity index are more resistant to changes in viscosity with changes in temperature than lower viscosity index oils. Obviously, high viscosity-index lubricants are most suitable for bearing applications experiencing wide temperature variations. The National Lubricating Grease Institute (NLGI) classification of grease consistency is shown below (table A-5):
TABLE A-5. NLGI CLASSIFICATIONS
NLGI Grease Grades Penetration No. 0 355-385 1 310-340 2 265-295 3 220-250 4 175-205 5 130-160 6 85-115
The pour point is the lowest temperature at which a fluid will flow or can be poured. It is important in applications exposed to low temperatures that the lubricating fluid selected has a pour point lower than the minimum ambient temperature.
TYPES OF LUBRICATION
Timken understands the importance of friction management. Our line of application- and environment-specific lubricants has been developed by leveraging our knowledge of tribology and antifriction bearings, as well as how these two elements affect overall system performance. Timken lubricants help bearings and related components operate effectively in demanding industrial operations. High- temperature, anti-wear and water-resistant additives offer superior protection in challenging environments. Similar to our bearings, all Timken lubricants are backed by highly trained customer service and technical support associates. Industrial customers turn to Timken for comprehensive friction management solutions. We help customers analyze performance and suggest options that make sense for their unique operating conditions and maintenance intervals.
Bearing Type Grease Type Grease Temperature Range Radial bearings (double shielded, and single and double shielded) Polyurea thickener Petroleum oil -34.44 C to +135 C (-40 to +275 F) Wide-inner-ring ball bearings (contact seal types) Polyurea thickener Petroleum oil -34.44 C to +135 C (-40 to +275 F) Wide-inner-ring ball bearings (labyrinth seal types) Synthetic thickener Synthetic hydrocarbon fluid -53.89 F to +162.75 C (-65 F to +350 F)
NOTE: Open-type bearings and single-shielded types are not prelubricated. They have a rust-preventative coating only and must be lubricated by the customer or end-user before operation.
Bearings that have been factory pre-lubricated use a high-quality grease. Bearings with contacting lip seals and shields contain No. 2 polyurea base grease. Bearings with non-contacting labyrinth seals (suffix KLL in bearing part number) contain a No. 2 modified clay base grease. For normal conditions of service, these bearings require no further lubrication. Normal service is considered as operating in a clean, dry environment at temperatures between -34 C to +82 C (-30 F to +180 F ) and at dN values (bore in millimeter multiplied by speed in RPM) less than 175000. If service is considered abnormal due to speed, temperature or exposure to moisture, dirt or corrosive chemicals, periodic relubrication may be advisable. Excessive relubrication may cause high operating temperatures due to grease churning. General guidelines for relubrication are provided in table A-7.
Failure to observe the following warnings could create a risk of death or serious injury.
Proper maintenance and handling practices are critical. Always follow installation instructions and maintain proper lubrication.