I. Application of Rolling Bearings in China's Railway Freight Cars
The application of rolling bearings in China's railway freight cars started relatively late. Initially, Chinese railway freight cars were equipped with sliding bearings.
In the early stages of transitioning from sliding bearings to rolling bearings, and before the bearing type most suitable for China's environmental and track conditions could be definitively determined, rolling bearings were primarily imported. A small number of self-designed bearings were also installed for operational testing. Various types of rolling bearing assemblies were trialed on vehicles at different times, including axle box-mounted short cylindrical roller bearings, axle box-less tapered roller bearings, and axle box-less short cylindrical roller bearings, among others.
With the introduction of new technologies, materials, and processes for railway freight cars, coupled with new requirements for higher speeds and heavier loads, and through repeated technical exchanges with foreign bearing companies, a compact bearing suitable for China's railway freight applications was developed. To date, China's railway freight cars have fully transitioned to using rolling bearings.
II. Advantages of Rolling Bearings Compared to Sliding Bearings in Railway Freight Cars:
1. Smaller Friction Coefficient, Increasing Locomotive Effective Tractive Effort: The friction coefficient of rolling bearings is much smaller than that of sliding bearings. Therefore, equipping railway freight cars with rolling bearings can significantly reduce the vehicle's starting resistance and running resistance.
2. Improved Operational Safety: In sliding bearings, the bushing is in direct contact with the journal axle, resulting in a large contact area. This leads to rapid wear, high heat generation during operation, and difficulty in dissipating this heat. Consequently, this easily causes "hot axle" incidents. Rolling bearings experience less wear, generate less heat, and dissipate heat more easily, thereby reducing the occurrence of "hot axle" and "hot break" incidents and ensuring operational safety.
3. Higher Rotational Speed and Greater Load Capacity: After equipping railway freight cars with rolling bearings, both the loading weight and the permissible operating speed are significantly increased compared to those using sliding bearings.
4. Reduced Maintenance Time, Accelerated Vehicle Turnaround, Improved Vehicle Utilization: For vehicles using rolling bearings, the specific axle examination has been eliminated, one maintenance level has been removed, and the maintenance cycle for railway freight cars has been extended. Under normal circumstances, during auxiliary repairs for freight cars equipped with rolling bearings, only visual and rotational checks of the rolling bearings are performed. If no abnormalities are found, they can continue in service. For vehicles using sliding bearings, due to the relatively frequent axle examinations and longer maintenance times, vehicle utilization efficiency is directly impacted.
5. Reduced Operating Costs, Saving Significant Amounts of Materials like Lubricant and White Metal: Under normal usage conditions, rolling bearings are only removed for general repair, sent back to the factory for major overhaul, or scrapped after reaching the specified service life. In contrast, vehicles with sliding bearings require an axle examination every six months, involving the replacement of lubricant and the bushing.
6. Ease of Use and Simple Maintenance: The production, manufacturing, and repair of rolling bearings have achieved specialization and standardization, offering high interchangeability. Tasks such as bearing adjustment, maintenance, lubrication, installation, and disassembly are all very convenient. Consequently, rolling bearings are widely used in railway vehicles.
2025 October 4th Week VAFEM Product Recommendation
Various of Clutch Release Bearings, more than 500 types different shapes, applying in the most of American, European, Korean, Janpanese, Asian car and truckes.
Each product develops according to the principles "Professional Design, Well Elaboration, Strict Regulations"
More than 50% of the output are OEM quality bearings.
VAFEM Clutch Release Bearings of buses & trucks have been already widely used for city buses and coaches, after improvements and technical innovations, has been proved to be consistency in high quality, steady warranty.
The Grease of Clutch Release Bearing is all used in imported high quality, high temperature resistant grease.
https://www.vafem.com/products/Hydraulic-Clutch-Bearings/912.html
2025-10-24