Needle roller bearing is special type of cylindrical roller bearing. The rolling elements of QIBR needle roller bearings are long cylindrical roller bearings with small diameters (the ratio of diameter to length of the rollers is between 1:2.5 and 1:10). With flat or light rounding ends, the radial section size is small. Needle roller bearings have high radial load carrying capacity and good bearing rigidity. It is especially suitable for use in applications where radial mounting dimensions are limited. Needle roller bearings can only withstand pure radial loads and cannot limit the axial displacement of the shaft and housing.

Needle roller bearings generally consist of outer ring, inner ring, roller, and cage. But some structures do not have cage, some have no inner ring, some have no outer ring, but only the needle roller and cage assembly.

The outer dimensions of QIBR needle roller bearings conform to GB/T273.3 "Genera plan for the outer dimensions of rolling bearing radial bearing", GB/T290 "Dimensions of rolling bearing crushing outer ring needle roller bearings", JB/T7918"Rolling bearings radial needles and cage assembly", JB/T 3588 "Dimensions and tolerances of rolling bearing full complement needle roller bearing ", JB/T3370 "Rolling bearing universal joint cylindrical roller bearing" and other regulations.

The tolerance of QIBR standard needle roller bearings meets the requirements of GB/T307.1 "Tolerance of rolling bearing radial bearing" and other standards. The clearance of QIBR standard needle roller bearings are divided into two types, bearings with inner and outer rings meet the requirements of GB/T4604 "radial clearance of rolling bearings". The clearance of bearings without inner/outer ring or with only one ring is the diameter tolerance of the matching shaft diameter or the bearing housing bore.

The dimensional tolerance grade of QIBR needle roller bearings is generally made according to P0 (normal grade) and clearance according to group 0 (basic group). If customers have other special requirements (including non-standard) for size, tolerance and clearance, QIBR are able to provide the corresponding product.

Bearing cage

The high-quality cage used by QIBR bearings ensure that the rollers and balls are evenly distributed in the bearing rings and can be rotated properly.

The cage is divided into stamped cage, brass solid cage, reinforced nylon 66 etc. Bearing cages that operate under high temperature or harsh conditions are recommended to use steel cages or brass solid cages, four-row cylindrical roller bearing is recommended to use brass solid cages. QIBR offers a wide range of advice and options depending on the operating conditions.

Radial clearance

The radial clearance is the gap between the steel ball and the ring. QIBR are able to tailored to you based on temperature conditions, interference fit, misalignment of the bearing axis, required noise level and speed.

The classification of needle roller bearings

The QIBR standard needle roller bearings are ribs or elastic steel rings on both sides of the outer ring, and the inner ring has no ribs. This type is NA type, there are single row and double row needle roller bearings, and the type without inner ring is RNA type needle roller bearing. The needle roller bearings without cages are of the NAV type and the RNAV type, and both the inner and outer rings without the ribs are of the NAO type. There are K types that without outer rings and inner rings, only the needle rollers and the cage assembly.

NA type needle roller bearing

RAN type needle roller bearing (without inner rings)

NAV type needle roller bearing (without cage)

RNAV type needle roller bearing (without inner rings and cage)

Double row NA type needle roller bearing

NAO type needle roller bearing

K type needle roller bearing

NA, RNA type are needle roller bearings with double ribs on outer ring (or rigid ring) and with cage, high limiting speed, divided into single row and double row. If the shaft cannot be used as a raceway, that is, if it is impossible or uneconomical to harden the shaft, such a needle bearing with inner ring can be used. Suitable for applications requests high speed.

The bearing capacity of NAV, RNAV and NAO needle bearings are greater than NA and RNA type bearings, but the speed performance is lower than NA and RAN type bearings. It is suitable for conditions of low-speed and high loading capacity.

Because there is no inner and outer rings for K-type needle roller bearings, the surface of the shaft and the inner surface of the bearing housing has to work as a raceway, so it request high accuracy of dimensions and shape to the surface of the shaft and the inner surface of the bearing housing, the advantages is space saving.