Hybrid cylindrical roller bearings
Hybrid cylindrical roller bearings are commonly used in electric motors, especially traction motors, and in applications running under severe operating conditions. They can accommodate heavy radial loads and high speeds.
The NU design cylindrical roller bearing, which has two integral flanges on the outer ring and no flanges on the inner ring, is the standard variant for hybrid cylindrical roller bearings (fig. 1).
Depending on their series and size, SKF hybrid cylindrical roller bearings are fitted with one of the following cages:
- a glass fibre reinforced PA66 cage, window-type, roller centred (designation suffix P)
- a glass fibre reinforced PEEK cage, window-type, roller centred (designation suffix PH)
- a machined brass cage, riveted, roller centred (designation suffix M)
a machined brass cage, window-type, inner or outer ring centred, depending on the bearing design (designation suffix ML)
For additional information, refer to Cages.
The lubricants generally used for rolling bearings do not have a detrimental effect on cage properties. However, some synthetic oils and greases with a synthetic oil base and lubricants containing EP additives, when used at high temperatures, can have a detrimental effect on polyamide cages. For additional information about the suitability of cages, refer to Cages and Cage materials.
Hybrid bearings with special steel rings and coatings
Hybrid bearings can be customized for specific application requirements. For additional information about the following variants, contact the SKF application engineering service.
- bearing rings stabilized for temperatures ≤ 300 °C (570 °F)
- bearing rings made of through-hardened stainless steel for enhanced corrosion and wear-resistance and with good high temperature properties
- bearing rings made of through-hardened stainless steel for cryogenic temperatures
- bearing rings made of high-temperature tool steel
- coating with zinc chromate or thin dense chromium for corrosion protection
coating based on molybdenum for low friction, especially in vacuum or gas applications