Double row Bearing
Double row cylindrical roller bearings have two kinds of structure: cylindrical inner hole and conical bore (bearing post code plus k). This kind of bearing has the advantages of compact structure, large rigidity, large bearing capacity and small deformation after load, especially suitable for spindle support of machine tools. The conical inner hole can also play the role of micro-adjustment clearance, and can simplify the positioning device structure, easy installation and disassembly. The common double row cylindrical roller bearings have the following several forms:
NN, Nnu type
The outer ring of the NN-type bearing has no edge, and the inner ring has a middle retaining edge in the center of the side. The shaft can be allowed to produce a displacement of two directions in the axial direction relative to the housing.
The outer ring of the NNU type bearing has a middle retaining edge and an inner ring without a block edge. The shaft can be allowed to produce a displacement of two directions in the axial direction relative to the housing. Therefore, this kind of structure is suitable for the swimming end bearing. The cage of the type bearing is used as the solid cage of the vehicle system.
The NNF type bearing is a double row full cylindrical roller bearing, the bearing consists of a belt in the outer ring, two of the two-side inner ring of the structure type. The rollers are guided by the retaining edges of the inner ring, and the two inner rings are fastened together with a fastening ring. In addition to the structure can withstand a large radial load and axial load, but also can withstand overturning moment, therefore, commonly used as fixed-end bearings.
NNF type of bearing with contact seal on both sides. Bearing filled with grease, grease working temperature of-50 ℃ to +110℃, but due to the limitations of sealed materials, the working temperature of the bearing is limited to 40 ℃ to +80℃. In the case of good working condition, the NNF bearing with sealing is not required to be maintained, if the bearing is in the water vapor or polluted environment for a long time, and in the middle and high speed operation, the bearing can be lubricated by lubricating oil trough and lubricating hole on the outer ring.
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