SKF Needle roller bearing

SKF Needle roller bearings without inner ring, NK 37/20 37x47x20

Needle roller bearings type RNA 49, RNA 69, NK and NKS
Needle roller bearings with raceways made of carbon chromium bearing steel are bearings with a low sectional height and a relatively high load carrying capacity. Bearings without an inner ring are an excellent choice for bearing arrangements, if the shaft can be hardened and ground. Since the inner ring is dispensed with, the shaft can be designed stronger and even more rigid as a result. In addition, the axial displaceability of the shaft relative to the housing is contingent solely on the width of the shaft's raceway.
The bearings with flanges on the outer ring are designed primarily as single-row bearings. In every instance the outer ring, needle rollers and cage constitute a self-retaining unit. Bearings of the RNA 49 series are also available with contact seals (suffix 2RS). This provides the bearings with effective protection against infiltration of pollutants and against leakage of lubrication grease.
Main dimensions: ISO 15:2011 / DIN 620:2000 / ISO 1206:2001 / DIN 617:1993 at the bearings with row (R)NA 48, (R)NA 49 und (R)NA 69

Prefixes:
RNA 49 / RNA 69 Needle roller bearings with flanges on the outer ring, without inner ring
NK / NKS Needle roller bearings with flanges on the outer ring, without inner ring

Suffixes:
2RS Sheet steel reinforced contact seals of acrylonitrile-butadiene rubber (NBR) on both side
TN Injection moulded cage of polyamide 66, the cage is glass fibre reinforced.