Hybrid deep groove ball bearings

Hybrid deep groove ball bearing
Deep groove ball bearings are the most widely used bearing type, especially in electric motors. SKF hybrid deep groove ball bearings:
  • are non-separable
  • are suitable for high speeds
  • accommodate radial loads and axial loads in both directions because their uninterrupted raceway grooves have a close osculation with the balls
  • are available with a bore diameter ranging from 5 to 180 mm
  • with a bore diameter d ≤ 45 mm, are most suitable for electric motors in the power range 0,15 to 15 kW as well as for power tools and high-speed drives
    SKF hybrid deep groove ball bearings in this size range are the most cost-effective solution against electrical erosion.

Basic design bearings

  • are available with a bore diameter d ≥ 10 mm (fig. 1)

Sealed bearings

  • use the same seals as described under Capped bearings
  • are lubricated for the life of the bearing and should not be washed or relubricated
  • are virtually maintenance-free
When capped bearings must operate under certain conditions, such as very high speeds or high temperatures, grease may appear between the inner ring and capping device. For bearing arrangements where this would be detrimental, appropriate actions should be taken.


Seals made of FKM (fluoro rubber) exposed to an open flame or temperatures above 300 °C (570 °F) are a health and environmental hazard! They remain dangerous even after they have cooled.

Read and follow the safety precautions under this WARNING.

Greases for sealed bearings

The standard grease, suitable for most common operating conditions of electric motors and generators, is indicated by the designation suffix WT (table 1).

For additional information about greases, refer to Selecting a suitable grease.

Grease life

The estimated grease life is typically at least twice as long as for same-sized bearings with steel balls (→ Grease life for capped bearings).

XL hybrid bearings

  • are identified by the designation suffix VA970
  • are designed to meet the application requirements for electric generators in larger wind turbines.
  • are available for the most commonly used generator sizes (→ product table)


SKF hybrid deep groove ball bearings are fitted with one of the following cages:
  • a stamped steel cage, riveted, ball centred (no designation suffix)
  • a glass fibre reinforced PA66 cage, snap-type, ball centred (designation suffix TN9)
  • a glass fibre reinforced PEEK cage, snap-type, ball centred (designation suffix TNH)
  • a machined brass cage, riveted, ball centred (designation suffix M)

For additional information, refer to Cages.

When used at high temperatures, some lubricants can have a detrimental effect on polyamide cages. For additional information about the suitability of cages, refer to Cages.

Hybrid bearings with special steel rings and coatings

For specific application requirements, hybrid bearings can be customized:
  • 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
  • ring coating with zinc chromate or thin dense chromium for corrosion protection
  • ring coating based on molybdenum for low friction, especially in vacuum or gas applications
For availability and detailed information, contact SKF.
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