High temperature bearings and bearing units

SKF high temperature bearing and bearing unit

SKF high temperature bearings and bearing units are designed to deliver increased reliability, reduced complexity and decreased environmental impact in operating temperatures up to 350 °C (660 °F). Because SKF high temperature bearings correspond to the ISO dimensions of grease-lubricated bearings, production efficiencies and cost savings can be realized with a simple change to the SKF bearing solution.

The environmental benefits of SKF high temperature bearings are so significant in many applications that they are included in the "SKF Beyond Zero" product portfolio.

Bearing benefits and features

  • Reduced total operating cost
    The bearings are designed to maintain the radial clearance needed for high temperature operation and so will not seize, even when they cool rapidly, and therefore provide a long service life.
  • Virtually maintenance-free operation
    The bearings are lubricated for life and do not need relubrication. Only variant VA201 without shields requires relubrication.
  • Excellent performance under severe conditions:
    • hot conditions
    • dry environments
    • low rotational speeds
  • Reduced environmental impact
  • Reduced machine design complexity
Lubrication solutions

SKF high temperature bearing designs and variants incorporate various graphite-based lubrication solutions, including:

  • lubricating paste composed of a polyalkylene glycol/graphite mixture
  • graphite cages (segmented or coronet)

For an overview of lubricant types, and other characteristics, for high temperature deep groove ball bearings and insert bearings and ball bearing units, refer to table 1 and table 2.

During operation, the graphite maintains a very thin film on the bearing’s raceways and rolling elements to reduce wear significantly. Graphite ages at a much higher temperature than oil and grease, and therefore does not lose its lubricating properties at the high temperatures at which it is recommended for use, so the need for relubrication is eliminated.

With many variants, all surfaces of the bearing and, where applicable, shields and flingers are manganese phosphate coated to enhance adhesion of the lubricant to the metal and provide some protection against corrosion.

Operating environment

SKF high temperature bearings are designed to provide solutions to common issues in high temperature applications. In addition to operations involving high temperatures and low rotational speeds, it is important to consider environmental conditions in the process area.

Since high temperature bearings are supplied without preservative oils and must be used without grease or oil lubrication, the anti-corrosion property of the bearings is limited. Therefore, the bearings should be used in a dry environment or with a proper sealing solution to keep the bearings dry.

Typical applications
  • metals industry (cooling beds, roller tables, furnaces)
  • food and beverage industry (continuous baking ovens, wafer baking ovens)
  • automotive industry (paint lines, heat treatment ovens)
  • glass industry (glass tableware or flat glass manufacturing processes)
  • construction industry (tiles, mineral wool manufacturing)
Assortment

The SKF standard assortment of high temperature bearings and bearing units corresponding to ISO standards includes:

  • Deep groove ball bearings (fig. 1)
  • Insert bearings (Y-bearings) (fig. 2)
  • Ball bearing units (fig. 3)

The assortment includes variants that contain food-grade lubricants registered by NSF as category H1 (lubricant acceptable with incidental food contact, for use in and around food processing areas). The NSF registration confirms the lubricant fulfils the requirements listed in the US Food and Drug Administration's guidelines under 21 CFR section 178.3570.

Customized bearings

In addition to high temperature bearings corresponding to ISO standards, SKF offers an assortment of customized high temperature bearings (fig. 4, fig. 5).

These bearings are customized for use in applications such as:

  • automatic wafer baking ovens in the food and beverage industry
  • industrial furnaces
  • chains

For additional information, contact SKF.

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