Cylindrical roller bearings,The cylindrical roller and raceway are linear contact bearings. Large load capacity, mainly bearing radial load. The friction between the rolling element and the ring flange is small, so it is suitable for high-speed rotation. According to whether the ring has rib or not, it can be divided into single row cylindrical roller bearings such as Nu, NJ, NUP, N and NF, and double row cylindrical roller bearings such as NNU and NN. The inner ring and outer ring of the bearing can be separated.

Cylindrical roller bearing with no rib in inner ring or outer ring, its inner ring and outer ring can move relative to each other in axial direction, so it can be used as free end bearing. The cylindrical roller bearing with double rib on one side of inner ring and outer ring and single rib on the other side can bear a certain degree of axial load in one direction. Generally use steel stamping cage, or copper alloy car solid cage. However, some cages are formed by polyamide.

1. The roller and raceway are in line contact or repair line contact, with large radial bearing capacity, suitable for bearing heavy load and impact load.

2. Small friction coefficient, suitable for high speed, the limit speed is close to deep groove ball bearing.

3. Type N and type Nu can move axially to adapt to the change of relative position between shaft and shell caused by thermal expansion or installation error, and can be used as free end support.

4. The machining requirements of shaft or seat hole are high. After the bearing is installed, the relative deflection of outer ring axis should be strictly controlled to avoid contact stress concentration.

5. The inner ring or outer ring can be separated to facilitate installation and disassembly

The cylindrical roller is in line contact with the raceway and has large radial load capacity. It is not only suitable for bearing heavy load and impact load, but also suitable for high-speed rotation.

The raceway and rolling element of cylindrical roller bearing are geometric. After the improved design, it has higher bearing capacity. The new structural design of the rib and roller end face not only improves the axial bearing capacity of the bearing, but also improves the lubrication conditions of the contact area between the roller end face and the rib, and improves the service performance of the bearing.

1. N0000 with no rib on the outer ring and nu0000 with no rib on the inner ring are cylindrical roller bearings. This kind of bearing can accept larger radial load, high limit speed, no binding of axial displacement of shaft or shell, and can not accept axial load.

2. Nj0000 and nf0000 cylindrical roller bearings with both inner and outer rings can restrain the axial displacement of the shaft or shell in one direction, and can accept small one-way axial load. Nu0000 + hj0000, nj0000 + hj0000 and nup0000 bearings can restrain the axial displacement in both directions of the shaft or the shell in the axial clearance field of the imported bearing, and can accept small bidirectional axial load

Cylindrical roller bearing is a kind of separate bearing, which is very convenient for installation and disassembly. Cylindrical roller bearing can bear large radial load and is suitable for high speed operation.

The angle error (inclination) between the inner ring axis and the outer ring axis is very small, only 2 ′～ 4 ′. Therefore, the machining accuracy of shaft and bearing seat is relatively high, otherwise, uneven load or stress concentration is easy to appear in the contact part of raceway. However, the stress concentration can be reduced by modifying the contact bus of roller or raceway.

Cylindrical roller bearings can be divided into single row, double row and multi row cylindrical roller bearings according to the number of rows of rollers. Different structure bearings are also shown in the design of rib position. The commonly used cylindrical roller bearings are as follows:

Single row cylindrical roller bearing: single row cylindrical roller bearing is separable bearing, easy to install and disassemble, two rings can adopt tight fit, the contact line between roller and raceway can reduce stress concentration.

Double row cylindrical roller bearing: double row cylindrical roller bearing belongs to floating bearing, its separability makes installation and disassembly very convenient. Both ferrules can be tight fit. Double row cylindrical roller bearings are almost not allowed to have an inclination angle.

Single row bearing

N. Nu type

The outer ring of n-type bearing has no rib, and both sides of inner ring have rib. The axial displacement between the shaft and the bearing pedestal can be allowed. Nu type bearing has rib on both sides of outer ring and no rib on inner ring. The axial displacement between the shaft and the bearing pedestal can also be allowed. Therefore, this kind of structure is suitable for use as a floating end bearing.

NJ, NF

NJ bearing has rib on both sides of outer ring and one side of inner ring. It can bear a certain amount of one-way axial load. NF type outer ring has rib on one side and inner ring has rib on both sides. It can also bear a certain amount of one-way axial load. Therefore, this kind of structure is suitable for single direction axial positioning bearing.

NUP, NFP

NUP type bearing has rib on both sides of outer ring, single rib on one side of inner ring and separable flat ring on the other side. It can bear a certain amount of bidirectional axial load.

One side of NFP bearing outer ring is provided with (fixed) single rib, while the other side is provided with separable flat retaining ring, and both sides of inner ring are provided with rib. It can also bear a certain amount of bidirectional axial load. This kind of structural bearing can limit the axial displacement of the shaft relative to the bearing seat in both directions. Therefore, it is suitable to be used as a fixed end bearing.

NH (NJ + HJ) type

NH type bearing is a combination of NJ type bearing and HJ type oblique retaining ring. Because the inner ring of NUP bearing is short, and the flat retaining ring is not fixed, it is inconvenient to use. NH bearing can use the width of the whole inner ring of NJ bearing to keep a closer fit with the shaft. Moreover, NH bearing is more convenient in installation and disassembly.

NH type bearing can limit the axial displacement of the shaft relative to the bearing seat in both directions. Therefore, it is suitable to be used as a fixed end bearing.

Double row cylindrical roller bearing has cylindrical bore and conical bore (bearing code plus K). This kind of bearing has the advantages of compact structure, high rigidity, large bearing capacity and small deformation after being loaded. It is especially suitable for machine tool spindle support. The conical inner hole can also play the role of micro adjusting the clearance, and can simplify the structure of the positioning device, which is convenient for installation and disassembly. The commonly used double row cylindrical roller bearings have the following forms:

NN, NNU type

The outer ring of NN bearing has no rib, the inner ring has rib on both sides, and the middle rib. The shaft can be allowed to produce displacement in two directions in the axial direction relative to the bearing pedestal.

NNU bearing has rib on both sides of the outer ring, middle rib in the middle and no rib in the inner ring. The shaft can be allowed to produce displacement in two directions in the axial direction relative to the bearing pedestal. Therefore, this kind of structure is suitable for moving end bearing. The cage of this type of bearing is mostly made of solid cage.

Nnf type

Nnf bearing is a double row full loaded cylindrical roller bearing, which consists of one outer ring with middle rib and two inner rings with double rib. The roller is guided by the rib of the inner ring, and the two inner rings are fixed together with fastening rings. The structure can not only bear large radial load and axial load, but also can bear overturning moment, so it is often used as fixed end bearing.

Both sides of nnf bearing adopt contact seal. The bearing is filled with grease, and the working temperature of the grease is - 50 ℃ to + 110 ℃. However, due to the limitation of sealing materials, the working temperature of the bearing is only between - 40 ℃ and + 80 ℃. Under good working conditions, the nnf bearing with seal does not need maintenance. If the bearing is in water vapor or polluted environment for a long time and operates at medium and high speed, the bearing can be lubricated through the lubricating oil groove and lubricating oil hole on the outer ring.

The four row cylindrical roller bearing is mainly used in cold rolling mill, hot rolling mill, blooming mill and other rolling mill machinery. The bearing is a separate structure, and the bearing ring and rolling element components can be easily separated. Therefore, the cleaning, inspection, installation and disassembly of the bearing are very convenient.

FC type

FC bearing is composed of two outer rings and one inner ring. Each outer ring has a rib on both sides, a middle rib in the middle and no rib in the inner ring.

FCD type

FCD bearing is actually composed of two NN bearings.

FC type and FCD type bearings can allow axial displacement in two directions between the shaft and the bearing pedestal. Therefore, this kind of structure is suitable for moving end bearing. The cage of this type of bearing mostly adopts turning solid 13:58.

Application

Large and medium motors, rolling stock, machine tool spindle, internal combustion engine, generator, gas turbine, reducer, rolling mill, vibrating screen and lifting and transportation machinery, etc.