Overview of the main classifications of gear pumps

Gear pumps can be divided into two categories: external meshing and internal meshing. The production of some industrially developed gear pumps accounts for a large proportion of hydraulic pumps. Compared with external gear pumps, internal gear pumps are highly valued for their small size, light weight, low noise, good self-priming performance, and small flow pulsation. Their output accounts for a large proportion of the total output of gear pumps. The production ratio of some developed internal and external gear pumps is close to 1:1. Gear pumps are one of the earliest hydraulic components produced in China, with pressures ranging from 0.5Mpa to 25Mpa (high pressure reaching 31.5Mpa) and flow rates ranging from 3L/7min to 400L/min; The production of internal meshing gear pumps in China is not large, especially for internal meshing cycloidal gear pumps and other non involute gear pumps, which are still in their early stages. Gear pumps can be divided into ordinary gear pumps, special gear pumps, and high parameter polymer conveying gear pumps according to their applications. Ordinary gear pumps are mostly used for transporting oil liquids or in hydraulic systems, therefore, they are also known as oil pumps or hydraulic pumps. Special gear pumps can be used to transport high viscosity liquids, with a working pressure usually not exceeding 1.5 Mpa, and are applied in industries such as petrochemicals, textiles, food, coatings, etc. Gear pumps for polymer transportation are used to transport high-temperature, high-pressure, viscous polymers in chemical processes. From ordinary gear pumps to gear pumps for polymer transportation, their difficulty levels continue to escalate with the demanding working conditions.