Railway bearings are applied to railway bearings 03 04 2. Wheel axle bearings. The wheel axle system of railway locomotives and vehicles adopts different structural designs due to different application conditions. Locomotives and passenger cars have axle boxes, and the bearings are connected to the bogie through the axle box. Railway freight cars do not have axle boxes, and the bearings are connected to the steering frame side frame through the bearing saddle. The bearing bears the impact load generated between the wheel set and the bogie frame, and also bears the axial load generated during vehicle turning. The axle bearing structure includes cylindrical roller bearings, cylindrical roller bearing units, tapered roller bearings, and tapered roller bearing units. According to the application requirements of railway bearings, wheel axle bearings should have a long maintenance free cycle, convenient maintenance structural design, and high reliability. The classification and application of wheel axle bearings on railway vehicles are divided into the following types based on the design technology and application of their vehicle types: cylindrical roller bearing unit, double row tapered roller bearing unit, single row tapered roller bearing, single row cylindrical roller bearing, cylindrical roller bearing unit, circular roller bearing unit, mainly used in railway locomotives, passenger cars, and urban rail vehicle axle boxes, Generally, it is a double row cylindrical roller bearing with sealing devices on both sides or two paired single row cylindrical roller bearings with sealing devices on one side. The bearing unit is filled with lubricating grease before supply and installation, and there is no need to add lubricating grease during installation. Due to the overall sealing device of the bearing, it has a longer maintenance cycle. This type of bearing has a special structural design inside, and the corrected linear contact between the rollers and raceways avoids edge stress, making it particularly suitable for bearing high radial loads in applications and also able to withstand partial axial loads. Compared to tapered roller bearing units, cylindrical roller bearing units are easy to disassemble and assemble, making it convenient for bearing maintenance and repair. The double row cylindrical roller bearing unit is paired with a single row cylindrical roller bearing unit 3. The double row tapered roller bearing unit bearing unit has complete sealing, and has been filled with lubricating grease and adjusted for clearance before supply and installation. The overall unit design is conducive to the installation and disassembly of the bearing, and the bearing is pressed onto the journal through cold pressing installation method. The internal design of the bearing adopts an ECP structure, optimizing the inner ring edge and roller base surface to reduce bearing sliding friction and operating temperature rise. At the same time, a modified linear contact design is adopted between the roller centerline and raceway to avoid edge stress and ensure that the bearing is particularly suitable for bearing the combined load of radial and axial loads in applications. We use FEM (finite element) analysis and calculation support, and conduct comprehensive performance tests to ensure the optimal design of the bearing structure. The finite element method not only describes the bearing's bearing stress magnitude, but also can truly reflect the stress gradient distribution of the bearing. To reduce the bending deformation of the shaft during heavy loads, we adopt a compact design for the bearing units used in railway vehicles with large axle loads, shortening the distance between the bearings and the shoulder, reducing the length of the journal, improving the rigidity of the shaft, reducing the micro wear and tear of the bearings, reducing bearing application failures, and improving the service life of the bearings. The compact structure design and the good sealing device compared to traditional design can effectively prevent the leakage of lubricating grease, prevent external impurities and water from immersing in the bearing, effectively reduce bearing failure, extend maintenance cycle, and ensure the long service life of the bearing. The labyrinth seal structure is superior to the contact seal in terms of sealing effect and reducing temperature rise, but due to its large axial size, it is not conducive to reducing the impact of micro wear on bearings; The composite seal is designed as an integral structure, which is easy to assemble and disassemble, can shorten the axial width of the bearing, and is suitable for the compact structure design of the bearing. It has good sealing effect, low friction torque, and low operating temperature rise. It is widely used in large axle load railway freight car bearings and urban rail axle box bearings. Contact sealing labyrinth sealing composite sealing 4 single row tapered roller bearings This series of bearings is generally used on low-speed urban rail low-floor light rail vehicles. Due to the structural limitations of the trailer bogie of low-floor light rail vehicles, conventional axle boxes and axles cannot be used, and low-floor special axles need to be used. The bearings are installed inside the wheel set, and the inner ring of the bearing matches the special axle, while the outer ring matches the wheel set, with the wheel set as the axle box, The outer ring of the bearing rotates, and this application is called an embedded hub bearing unit. The ZWZ embedded hub bearing unit installed on independent wheelsets of light rail low-floor vehicles consists of a pair of tapered roller bearings, which are manufactured using high-precision manufacturing technology to ensure high installation accuracy and operational performance of the bearings. Adopting reasonable matching clearance ensures high rigidity of the wheel set and ensures the stability of vehicle operation. Embedded axle box bearings are one of the most widely used bearings in railway applications, and have been tested on various railway vehicle wheel sets. They are commonly used in axle boxes of railway locomotives, passenger cars, subways, and light rail vehicles. These bearings are generally NJ/NJP type matching applications, suitable for bearing high radial loads and certain axial loads. The bearing has a special internal structural design, with rolling element and raceway modification design to avoid edge stress and ensure high bearing capacity. The use of plastic steel cages facilitates high-speed rotation of the bearing.