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Cylindrical Roller Bearing Category

wallpapers Tech 2020-06-09
Cylindrical roller bearings are separate bearings, which are very convenient for installation and disassembly. Cylindrical roller bearings can withstand large radial loads and are suitable for use in high-speed operations.
This kind of bearing allows the angle error (inclination) of the inner ring axis and the outer ring axis to be small, only 2′~4′. Therefore, the machining accuracy of the shaft and the bearing seat is relatively high. Otherwise, uneven load or stress concentration may easily occur at the contact portion of the raceway. However, the correction of roller or raceway contact bus can reduce the occurrence of stress concentration.
Cylindrical roller bearings can be divided into single-row, double-row and multi-row cylindrical roller bearings and other structures according to the number of rows of rolling elements installed. Bearings of different structures are also expressed in the design of the position of the rib. Among the commonly used cylindrical roller bearings are the following forms:
Single-row cylindrical roller bearings: Single-row cylindrical roller bearings are separable bearings, which are easy to install and remove. Both rings can be tightly fitted, and the contact line between the modified roller and the raceway can reduce stress concentration.
Double-row cylindrical roller bearings: Double-row cylindrical roller bearings are swimming bearings, and their separability makes installation and disassembly very convenient. Both ferrules can be fitted tightly. Double row cylindrical roller bearings are almost not allowed to have a tilt angle.
 
Single row bearing
N, NU type
N-type bearings have no ribs on the outer ring and ribs on both sides of the inner ring. It can allow the displacement of the shaft relative to the bearing seat in both axial directions. The NU type bearing has ribs on both sides of the outer ring and no ribs on the inner ring. It can also allow displacement of the shaft relative to the bearing housing in both axial directions. Therefore, this type of structure is suitable for use as a bearing at the traveling end.
NJ, NF type
NJ bearings have ribs on both sides of the outer ring, and ribs on one side of the inner ring. Can withstand a certain amount of unidirectional axial load. Type NF has ribs on one side of the outer ring and ribs on both sides of the inner ring. It can also bear a certain amount of unidirectional axial load. Therefore, this type of structure is suitable for use as a unidirectional axial positioning bearing.
NUP, NFP type
NUP type bearings have ribs on both sides of the outer ring, a single (fixed) rib on one side of the inner ring, and a detachable flat ring on the other side. Can withstand a certain amount of bidirectional axial load.
The NFP type bearing has a (fixed) single rib on one side of the outer ring, and a detachable flat rib on the other side, with ribs on both sides of the inner ring. It can also bear a certain amount of bidirectional axial load. This kind of structure bearing can limit the displacement of the shaft relative to the bearing seat in two directions of the axial direction. Therefore, it is suitable for use as a fixed-end bearing.
NH(NJ+HJ)type
NH type bearing is the structure of the combination of NJ type bearing and HJ type oblique ring. Because the inner ring of the NUP type bearing is short, and the flat retaining ring is not fixed, it is not convenient to use, and the NH type bearing can use the width of the entire inner ring of the NJ type bearing to maintain a tighter fit with the shaft. And NH type bearing is more convenient in installation and disassembly.
The NH type bearing can limit the displacement of the shaft relative to the bearing seat in two directions of the axial direction. Therefore, it is suitable for use as a fixed-end bearing.
 
Double row bearing
Double-row cylindrical roller bearings have two structures: cylindrical inner hole and conical inner hole (bearing code plus K). This type of bearing has the advantages of compact structure, high rigidity, large load-bearing capacity, and small deformation after being loaded, and is particularly suitable for supporting the spindle of the machine tool. The conical inner hole can also play the role of slight adjustment of the clearance, and can simplify the structure of the positioning device and facilitate the installation and disassembly. Commonly used double row cylindrical roller bearings have the following forms:
NN, NNU type
The outer ring of the NN type bearing has no ribs, and there are ribs on both sides of the inner ring and middle ribs in the middle. It can allow the displacement of the shaft relative to the bearing seat in the axial direction in two directions.
NNU type bearings have ribs on both sides of the outer ring and a middle rib in the middle, while the inner ring has no ribs. It can allow the displacement of the shaft relative to the bearing seat in the axial direction in two directions. Therefore, this type of structure is suitable for use as a free-end bearing. The cage of this type of bearing mostly adopts the car-made solid cage.
NNF type
The NNF type bearing is a double row full complement cylindrical roller bearing. The bearing consists of one outer ring with middle ribs and two inner rings with double ribs. The rollers are guided by the ribs of the inner ring, and the two inner rings are fixed together with fastening rings. In addition to being able to withstand large radial and axial loads, this structure can also withstand overturning moments, so it is often used as a fixed-end bearing.
NNF type bearings use contact seals on both sides. The bearing is filled with grease. The operating temperature of the grease is -50°C to +110°C. However, due to the limitation of the sealing material, the working temperature of the bearing is limited to -40°C to +80°C. Under good operating conditions, NNF bearings with seals do not need to be maintained. If the bearings have been exposed to water vapor or polluted environment for a long time, and are running at medium or high speeds, the oil grooves and oil holes on the outer ring can be used. Relubricate the bearings.
 
Four-row bearing
Four-row cylindrical roller bearings are mainly used in cold and hot rolling mills, blanking machines and other rolling mill machinery. The bearings are of a separate structure. The bearing rings and rolling element components can be easily separated. Therefore, the bearings are cleaned, inspected or Installation and disassembly are very convenient.
FC type
The FC type bearing is composed of two outer rings and one inner ring, each side of the outer ring has a rib in the middle and a middle rib, and the inner ring has no rib.
FCD type
FCD type bearings are actually composed of two NN type bearings.
FC type and FCD type bearings can allow the displacement of the shaft relative to the bearing seat in the axial direction in two directions. Therefore, this type of structure is suitable for use as a free-end bearing. The cage of this type of bearing mostly adopts car-made entity 13:58.