At present, the needle roller bearing widely used in hydraulic gear pump has many advantages: high bearing capacity; small friction coefficient, small friction when starting and working, high mechanical efficiency; can be applied to high and low speed at the same time; can be applied to a large temperature range; strong oil pollution resistance.

But at the same time, it also has many disadvantages: large noise, large size, inconvenient overall structure layout; especially in the hydraulic gear pump, long needle roller bearing is needed, which leads to the bearing performance is more sensitive to the manufacturing and assembly accuracy, high requirements for needle roller accuracy, and strict requirements for heat treatment process specification; At present, this kind of wave needle bearing is a non-standard part, which needs special customization and high cost.

In recent years, with the R & D and manufacturing technology of Du bearing gradually improved and matured in China, its bearing capacity and service life correspondingly increased, while the price also decreased, and its application is more and more widely. Generally, the allowable specific pressure of Du bearing can be stabilized at 34mpa. If the structure is reasonable and enough lubrication is guaranteed, the allowable specific pressure can be stabilized at 44Mpa, and the maximum specific pressure of bearing can reach 58mpa.

The substrate of Du bearing is low carbon cold rolled steel plate, the middle layer is sintered spherical bronze powder, and the friction surface layer is rolling modified polytetrafluoroethylene. The wall thickness of the shaft sleeve is 0.7 ~ 2.5mm, and the thickness of the friction surface layer is 0.02-0.06mm. Tin and copper plating can be used for steel back corrosion protection.