Why is it more suitable to use plastic gears for gear pumps conveying low viscosity liquids

Author: Lin Qiangxing, Shanghai Suofu Industrial Co., Ltd

Many users have a mentality when choosing pumps. They always think that products like gear pumps are best metal gears. When they hear about plastic gears, they feel that the products are low-end and not durable. Here, I will briefly introduce the material selection of gear pump gear and bearing in low viscosity situations.

In the working process of the gear pump, the rotating parts are mainly the driving wheel and the driven wheel. They are not only responsible for transmitting torque, but also for completing the function of pressurizing and conveying liquid. This requires that the gear pair not only has good rigidity, but also has good self lubrication, good dimensional accuracy and corrosion resistance. The three requirements of rigidity, dimensional accuracy and corrosion resistance are easy to understand, but why should gear materials have good self lubrication? The reason is that when the gears mesh with each other, there is relative sliding between the tooth surfaces of the two gears. If the self-lubricating property of the material is poor, such as the ordinary 316 stainless steel gear, they are very easy to lock at a slightly higher speed. Therefore, when selecting gear materials, especially when transporting liquids with low viscosity or poor lubricity (such as water or some solvents), special attention should be paid to the self lubrication of gear materials.

The gear of the NP series micro magnetic gear pump of Shanghai suofe industry adopts special filled and Reinforced PEEK material as the gear and bearing material, and uses high-precision injection molding technology. It can solve the requirements of rigidity, accuracy, self lubrication and corrosion resistance within the range of 20bar pressure difference, providing a good choice for everyone to use under small flow and medium and low pressure.

Original link: why gear pumps for low viscosity liquids are more suitable for plastic gears