Basic knowledge of cylindrical roller bearing

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 rib is small, and it is suitable for high-speed rotation. According to whether the ring has rib or not, it can be divided into NU, NJ, NUP, N, NF and other single row cylindrical roller bearings, and NNU, NN and other double row cylindrical roller bearings. The bearing is a separable structure of inner ring and outer ring.

Cylindrical roller bearing without rib on inner or outer ring, whose inner ring and outer ring can move relative to each other in axial direction, can be used as free end bearing. Cylindrical roller bearing with double ribs on one side of the inner ring and outer ring and single rib on the other side of the ring can withstand axial load in one direction to a certain extent. Generally, pressed steel cages or solid copper alloy cages are used. However, some of them use polyamide shaped cages.

The roller of cylindrical roller bearing is in line contact with the raceway, so the radial load capacity is large. It is not only suitable for bearing heavy load and impact load, but also suitable for high-speed rotation. At the same time, it improves the lubrication condition of the contact area between the roller end face and the rib, and improves the service performance of the bearing. WeChat of bearing staff is very noteworthy! It is generally applicable to large and medium-sized motors, rolling stock, machine tool spindles, internal combustion engines, generators, gas turbines, reduction boxes, rolling mills, vibrating screens, lifting and transportation machinery, etc.

Bearing characteristics

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

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

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

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

5. The inner ring or outer ring can be separated for easy installation and removal.

Product characteristics

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 in geometric shape. After improved design, the bearing has a high bearing capacity. The new structural design of the rib and roller end face not only improves the axial bearing capacity, but also improves the lubrication condition of the contact area between the roller end face and the rib, and improves the service performance of the bearing.

Accuracy class

Cylindrical roller bearings can be classified into PO, P6, P5, P4 and P2 according to the accuracy level. The accuracy level is sorted from low to high.

Structural form

1. N0000 type cylindrical roller bearing without rib on outer ring and NU0000 type cylindrical roller bearing without rib on inner ring This kind of bearing can accept larger radial load, has high limit speed, does not bind the axial displacement of shaft or shell, and cannot accept axial load.

2. The cylindrical roller bearings NJ0000 and NF0000 with ribs on the inner and outer rings can restrain the axial displacement in one direction of the shaft or housing, and can accept smaller unidirectional axial loads. NU0000+HJ0000, NJ0000+HJ0000 and NUP0000 bearings can restrain axial displacement in both directions of the shaft or housing in the axial clearance field of imported bearings. And can accept small bidirectional axial load.

Bearing material

The materials used to manufacture bearing components have a great impact on the performance and reliability of rolling bearings. General considerations for bearing rings and rolling elements include: hardness related to bearing capacity, fatigue resistance under rolling contact and lubrication conditions with different cleanliness, and dimensional stability. For the cage, friction, strain and inertia force shall be considered, and in some cases, chemical interaction with certain lubricants, solvents, coolants and refrigerants shall be considered. The relative importance of these considerations is also affected by other working parameters, such as corrosion, high temperature, impact load or the combination of these factors.

The contact seal ring embedded in the rolling bearing also has a significant impact on the performance and reliability of the bearing. The materials used in its manufacture must have excellent oxidation resistance, heat resistance or chemical corrosion resistance.