With the development of the mechanical lifting technologies and the improvement of requirements for working conditions, the technologies of port cranes, dock cranes and other lifting machines have been improved.
The large-scaled cranes used at ports would be working under ocean climate conditions with salt mists, high humidity and significant temperature difference. Those large-scaled cranes working at inner river ports will also be subject to the impacts from industrial air and harsh climates. When the equipment at ports is working, several movements shall be carried out at the same time and different loads are overlapped. Therefore, high-quality bearing products are needed for brakes, reducers, pulley sets and hooks to ensure such operation.