Lifting and transporting machinery has the characteristics of intermittent movement, and each machinery is often in the working state of starting, braking and forward and reverse. Although it does not operate at high speeds, it is often loaded and subject to corrosion by dust or seawater for long periods of time. Continuous operation of equipment in harsh environments requires high efficiency, continuous, stable, reliable, easy maintenance and long service life. Correspondingly, the requirements of low speed, heavy load, high reliability and long life are put forward for the support bearing. At present, bearings are mainly used in gearboxes, traveling mechanisms, hoisting mechanisms, luffing mechanisms, and slewing mechanisms.