Product Catalogue

The rollers of cylindrical roller bearing are usually guided by two ribs of a bearing ring. The cage, roller, and guiding bearing ring make up an assembling unit which can be separated from another bearing ring. The bearing is of separable bearing. This bearing has easy mounting and dismounting. The advantages show especially when the inner ring and outer ring are interference fit with the shaft and housing. 

The bearings of this type are generally used to support radial load only, and only single row bearings with ribs on both inner ring and outer ring can stand relative small steady axial load or intermittent axial load. Comparing with the same-sized deep groove ball bearings, the bearings of this type have greater radial load capacity. However, the bearings of this type have very high processing requirements for the relevant parts fitted with the shaft and shell hole.

1)  The N type and NU type cylindrical roller bearings with ribs on the outer ring or without ribs on the inner ring have a heavy radial load capacity and high limiting speed without limiting the axial displacement of the shaft and housing and supporting axial load.

2) The NF type, NJ type, NH (NJ + HJ) type, NUP type, NF type, NJ type cylindrical roller bearings with ribs on both inner ring and outer ring can limit the axial displacement of shaft or housing in single direction and support small single-direction axial load. The H type, NUP-type bearings can limit the axial displacement of shaft or housing in both directions within the axial clearance range and withstand the small axial load in both directions.

3) The RNU type and RN type cylindrical roller bearings without inner ring or outer ring are used in parts with limited radial dimension, the journal or the surface of the housing hole are directly taken as the rolling surface of which the hardness, machining accuracy and surface quality should be similar to the raceway of bearing ring.

4) The strengthened cylindrical roller bearings with E as suffix are in the design structure optimized in recent years. They have a large number of rollers with big length and diameter, thus the load capacity is high. The bearings are preferred to be used in design applications.

(2)The FC type, FCD type and FCDP type four-row cylindrical roller bearings are mainly used for heavy machinery, such as rolling mill. The codes indication method is different from the code notation of the conventional bearing.

When the outer diameter of the single row cylindrical roller bearings D≤400mm, the steel plate (or with) pressed cage is generally used. When outer diameter D≤400mm, the steel or brass solid cage is used. The four-row cylindrical roller bearings adopt brass solid cage or pin cage.  

Cylindrical roller bearings don’t allow axis tilt relative to shell hole. However, the single row cylindrical roller bearings allow the mutual tilt of inner and outer ring axis up to 21. If the load is heavy, the permissible error is slightly large, but not exceeding 41.

The single row cylindrical roller bearings can be manufactured into different classes of tolerance according to the needs. The tolerance values can be seen in aforementioned “preface page 25”. The tolerance classes of the four row cylindrical roller bearings are divided into 0 class, 6 class and 5 class.

BEM has two series of precision cylindrical roller bearings, including the single row N10K and double row NN301K. The cylindrical roller bearings belong to the line contact with load capacity and rigidity higher than point contact angular contact ball bearings (including bearing in multi-joint configuration). However, the permissible speed is much lower. Therefore, cylindrical roller bearings are commonly used in medium and large machine tools with great radial load, high rigidity requirement and relatively not too high speed. The most commonly used cylindrical roller bearing for machine tool is tapered bore double row cylindrical roller bearings. The bearings of this type can support heavy radial load with separable inner ring and outer ring and can not take axial load. Therefore, they are generally combining used with double direction angular contact thrust ball bearings.

The single row cylindrical roller bearings are usually used as floating type support and combining used with angular contact bearings as the fixed type support. The taper of inner ring tapered bore is 1:12 fitted with tapered shaft diameter of spindle. Thus, the required radial clearance or radial preload can be adjusted by axial displacement on the tapered spindle. The bearing ribs of N10K and NN30K series are set on the inner ring, and their outer rings are separable

The bearing with suffix W33 has lubrication groove and three lubrication holes on the outer rings which is easy for sufficient bearing lubrication. The radial clearance of cylindrical roller bearings is generally supplied with C1. The bearing rings are not interchangeable. C1 is not given in the bearing code, and when it is needed, the bearings are supplied according to C2 clearance class. The radial clearance of cylindrical roller bearings is seen in “the tolerance of the bearing”.

The bearing code examples:

N1020K.M.SP.C.2

The cylindrical roller bearing is particularly suitable for grease lubrication, but the distribution of the grease must ensure that the cylindrical roller end surface of inner ring will obtain sufficient lubrication. Assuming the low lubricant amount is required in oil lubrication, such as assembled in parallel together with angular contact ball bearings, the single oil line is required to avoid the steep increase of bearing temperature led by excessive lubrication because of the entering of excessive lubricants of angular contact ball bearings flow angular contact ball bearings.

The preload of cylindrical roller bearing adopts radial preload, which makes the circum circle diameter of rolling elements is slightly larger than the diameter of the outer ring raceway, thus generate bearing internal interference. For cylindrical roller bearing with tapered bore on the inner ring, the radial expansion of bearing inner ring can be achieved through changing the location of the inner ring on tapered surface of shaft.

The preload (i.e. the amount of interference) of high-speed cylindrical roller bearing is recommended to choose from 0 to 5 μm, and the preload can be appropriately increased when bearing is at the low speed. The best preload of bearing can be determined by experiment according to the bearing size, accuracy and working conditions, such as the speed, load, lubrication conditions, and allowable temperature rise etc.