Needle Roller Bearings

Application and characteristics of needle roller bearings

Needle roller bearings are roller bearings with cylindrical rollers that are thin and long relative to their diameter. Such rollers are called needle rollers. Despite their small cross-section, the bearings have a high load-bearing capacity and are therefore particularly suitable for applications where radial space is limited.

The needle roller profile is slightly constricted near the end face. The result of the correction of the needle roller and raceway line contact is that destructive edge stresses are avoided. In addition to the bearings listed in the catalogue for general engineering applications, such as open stamped cup needle roller bearings (1), closed stamped cup needle roller bearings (2), needle roller bearings with inner ring (3) and needle roller bearings without inner ring (4), SKF can also supply various types of needle roller bearings, including: 1. Needle roller cage assemblies 2. Needle roller bearings without flanges 3. Self-aligning needle roller bearings 4. Combined needle roller/ball bearings 5. Combined needle roller/thrust ball bearings 6. Combined needle roller/cylindrical roller thrust bearings.

Drawn cup needle roller bearings

Drawn cup needle roller bearings are needle roller bearings with thin stamped outer rings. Their main features are very low cross-sectional height and high load bearing capacity. They are mainly used for compact, inexpensive bearing configurations where the inner hole of the bearing housing cannot be used as a raceway for the needle roller cage assembly. The bearing and the bearing housing must be installed in an interference fit manner. If the axial positioning functions such as the housing shoulder and the retaining ring can be omitted, the inner hole of the bearing housing can be made simpler and more economical.

Drawn cup needle roller bearings mounted on the shaft end are available in double-sided open type (1) and single-sided closed type (2). The base end face of the closed stamped outer ring can withstand a small axial guide force.

Drawn cup needle roller bearings are generally not equipped with an inner ring. In situations where the shaft neck cannot be hardened and ground, the inner ring listed in the table can be used. The hardened steel plate outer ring of the drawn cup needle roller bearing is inseparable from the needle roller cage assembly. The free space for storing lubricant can extend the relubrication interval. The bearings are generally designed in a single row. The exceptions are the wider bearings 1522, 1622, 2030, 2538 and 3038 series, which are equipped with two needle roller cage assemblies. The outer ring of the bearing has a lubricating oil hole. According to user needs, all single-row stamped outer ring needle roller bearings with shaft diameter greater than or equal to 7mm can be equipped with an outer ring with a lubricating oil hole (code suffix AS1).

Stamped outer ring needle roller bearings with oil seals

In situations where oil seals cannot be installed due to space limitations, open-end or closed-end stamped outer ring needle roller bearings (3 to 5) with oil seals are available. This type of bearing is equipped with a friction oil seal made of polyurethane or synthetic rubber, which is filled with lithium-based grease with good rust resistance and is suitable for operating temperatures of -20 to +100℃.

The inner ring of the oil-sealed bearing is 1mm wider than the outer ring, which ensures that the oil seal works well and avoids contamination of the bearing when the shaft has a slight displacement relative to the bearing box. The inner ring of the bearing also has lubrication holes, which can be used to add lubrication from the outer ring or inner ring according to the needs of the bearing configuration.