The wheel and axle system of excavator vehicles adopts different structural design due to different application conditions. The locomotive and buses have axle boxes, the bearings are connected with the bogie through the axle box, and the bearings are connected with the side frame of the bogie through the bearing saddle.

The bearing bears the impact load between the wheel pair and the bogie frame, and also bears the axial load generated by the vehicle turning.

The wheel shaft bearing structure includes cylindrical roller bearing, cylindrical roller bearing unit, tapered roller bearing and conical roller bearing unit.

According to the application requirements of bearings, the wheel shaft bearings should have a long maintenance-free cycle, convenient maintenance of structural design and high reliability.

Wheel shaft bearings classification and its application Vehicle wheel shaft bearings are divided into the following types according to the different design technology and application of their models: cylindrical roller bearings, unit double column cone roller bearings, unit single column cone roller bearings, single column cylindrical roller bearings, cylindrical roller bearings, unit cylindrical roller bearings.

Unit is mainly used in railway locomotives, passenger cars and urban rail vehicle axle boxes. Generally, it is double cylindrical roller bearings with sealing devices on both sides or two paired single cylindrical roller bearings with sealing devices. The bearing unit has been filled with grease before supply and installation, and no grease is added during installation.

Because the bearing has an integral sealing device, it has a long maintenance period.

This kind of bearing has a special structural design, the modified linear contact between the roller and the roller channel avoids the edge stress, so that the bearing is particularly suitable to withstand high radial load, but also can withstand part of the axial load.

Compared with the cone roller bearing unit, the cylindrical roller bearing unit is easy to disassemble and assemble, facilitating the repair and maintenance of bearings.

Double column cylindrical roller bearing, unit matching single column cylindrical roller bearing, unit double column cone roller bearing, unit bearing unit has a complete seal, fill the grease and adjust the gap, the overall unit design conducive to the installation and disassembly of bearing, bearing by cold pressure installation method pressure on the journal.