Variants

Cages

Depending on their design, series and size, SKF drawn cup needle roller bearings are fitted with one of the cages shown in table 1.

Double row drawn cup needle roller bearings are equipped with two cage assemblies (fig. 1).

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.

Sealing solutions

For applications where a sufficiently effective seal is not available, or cannot be used for space reasons, SKF supplies certain drawn cup needle roller bearings as sealed bearings. They include:
  • drawn cup needle roller bearings with open ends, sealed on one side, designation suffix RS (fig. 2), available for shaft diameters ranging from 8 to 50 mm
  • drawn cup needle roller bearings with open ends, sealed on both sides, designation suffix .2RS (fig. 3), available for shaft diameters ranging from 8 to 50 mm
  • sealed drawn cup needle roller bearings with a closed end, designation suffix RS (fig. 4), available for shaft diameters ranging from 10 to 25 mm

These integral contact seals are made of PUR, FKM or NBR. Sealed drawn cup needle roller bearings are, under normal conditions, an extremely cost-effective solution to exclude solid contaminants and moisture and retain the lubricant in the bearing.

In addition to integral bearing seals, SKF also supplies an assortment of external seals that can be used for needle roller bearing arrangements. Appropriate power transmission seals are listed in the product table, when available. For information about these seals, refer to the product information, available under Seals.

Greases for capped bearings

Drawn cup needle roller bearings with one or two seals are supplied greased. They are filled with high-quality grease under clean conditions.

The relatively large quantity of grease in the bearings means they can be operated for long periods before relubrication is required. SKF recommends SKF LGWA 2 grease, if relubrication is required.

The technical specifications for the initial grease fill and the grease for relubrication are listed in table 2.

WARNING

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 Seal materials.

Relubrication features

Depending on the design and size, SKF supplies needle roller bearings with different features to facilitate efficient lubrication and relubrication.
All double row drawn cup bearings have one lubrication hole in the outer ring (fig. 1), as standard.
On request, SKF can supply any single row drawn cup needle roller bearing for inside diameters under the rollers Fw ≥ 7 mm with a lubrication hole in the outer ring (fig. 5).
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