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The high thermal stability of the balls used in CeramicSpeed bearings means that we can offer a unique HighTemp bearing series, for use in operating environments where the temperature reaches up to 2600C or 3500C. Ceramic balls have a low coefficient of thermal expansion – only a quarter of that of steel balls, and don’t microweld to the races. These properties mean that CeramicSpeed HighTemp bearings can be used with a lower degree of play than other high temperature bearings, improving their function at a high RPM. Ceramic balls also create a lower degree of wear on the races, and used together with high quality lubricants from Klüber, provide you with a solution which has an extremely long lifetime in high temperature operating environments.

Optimized internal radial clearance
SKF high temperature 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.
Lubrication solution
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 Y-bearings and Y-bearing units

During operation, the graphite maintains a very thin film on the bearing’s raceways and rolling elements to prevent metal-to-metal contact. Graphite ages at a much higher temperature than oil and grease, and therefore does not lose its lubricating properties in 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.
Ideal operating environment
Because 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.

The most common sealing alternatives for high temperature bearings incorporate integrated or external shields or labyrinth seals. These arrangements have a rather low complexity and none of these arrangements are capable of keeping the bearing dry in a wet environment.

Therefore, the bearings should be used in a high temperature, dry environment.
high temperature bearings 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.

SKF High temperature bearings provide:

reduced total operating cost through increased bearing service life
relubrication-free operation 1)
reduced machine complexity
reduced environmental impact
excellent performance in hot conditions, dry environments and low rotational speed applications

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.

Typical areas where SKF high temperature bearings are used include:

metals industry (cooling beds for steel plate)
food and beverage industry (continuous baking ovens, wafer baking ovens)
paint lines
Self-Lubrication – it can handle low lubricity fluids such as light hydrocarbons, liquefied gases and hot water in which metallic bearings can wear excessively
Dry Running – survives dry starts, flashing and loss of suction for prolonged periods without damage
Extreme Temperatures – continues to perform in applications at cryogenic temperatures to -450°F without becoming brittle or seizing, up to 1000°F+, well above the limits of plastic, surviving thermal shock
Wet – self-lubricating so there is no additional lubricant to wash away, it resists attack by most corrosive liquids such as Sulfuric Acid, Hydrochloric Acid, Chlorine Water and caustics
Non-Galling – Survives high speed contact that would gall metal parts – it permits closer running clearances between rotating parts resulting in lower shaft vibration
Improved Efficiencies – Allows closer running clearances which can provide higher pump efficiencies through reduced vibration
Dimensionally Stable – Maintains dimensional stability when submerged, under load and over wide temperature ranges providing a constant running clearance

The benefits and features of high temperature Y-bearings and Y-bearing units include:

no need for relubrication – the bearings are lubricated with graphite-based high temperature lubricants and, as such, are lubricated for the life of the bearing
simple replacement – the boundary dimensions are the same as those of standard bearings and units
operating temperature up to 350 °C (660 °F) – the internal radial clearance and the lubricant are optimized for operation at high temperatures
simple mounting and dismounting – the grub (set) screws in the inner ring make mounting/dismounting easy
protection against contamination – shields and flingers (designation suffix 2F) protect the bearing
improved running in – the entire bearing surface is manganese phosphate coated
no colour flaking – the housing is coated with a high temperature resistant coating