Gear oil transfer pump are used in the systems of petroleum, chemical, marine, petrochemical machinery and other mechanical products. Its main features are simple structure, small size, light weight, good self-priming performance, pollution resistance, reliable use, long service life, easy manufacture, convenient maintenance, and low price. economy. Gear oil pumps also have many shortcomings, mainly including large flow and pressure pulsation, large noise, invariable displacement, and low high temperature efficiency. In foreign countries, the research of variable gear oil pump is in progress.

In recent years, the working pressure of the gear oil pump has been greatly improved, the rated pressure reaches 25MPA, and the _ pressure reaches 31.5MPA. In addition, there have been many improvements in the product structure, especially the advent of triple and quadruple gear oil pumps, which partially make up for the shortcomings of gear oil pumps that cannot be variable. Its field of use is also expanding, and many hydraulic equipment that used axial piston pumps in the past have also switched to gear oil pumps.

In some developed industries abroad, the output of internal gear oil pumps accounts for a large proportion, and the output ratio of some internal and external gear pumps is close to 1:1. The output of internal gear oil pumps in my country is not large, especially the involute gear oil pump. The shape of the internal gear oil pump is still in the development stage.

Gear oil pump is one of the earliest hydraulic components produced in my country, with pressure from 0.5MPA to 25MPA (_pressure 31.5MPA) and gear oil pump with flow rate from 2.5L/min to 400L/min. In addition to the service life, the product performance has approached or reached the foreign level, and the product structure has also been innovative. According to statistics, the gear oil pump models produced in my country include CB gear oil pump, CB-B gear oil pump, CB-F gear oil pump, KCB gear oil pump, 2CY gear oil pump, YCB gear oil pump, BB-B gear oil pump, NYP high viscosity gear oil pump Oil pump, NCB high viscosity gear oil pump, etc.