Magnetic drive gear pump working characteristics

In recent years, magnetic drive gear pumps have developed rapidly. A large amount of research and development resources have been and will continue to be applied to this technology. The cost of magnetic steel materials will continue to decrease while its strength will continue to increase. Existing magnetically driven pumps have the same degree of reliability as ordinary pumps while eliminating the weakest components, such as seals are not needed here. In addition, the overall price of magnetically driven pumps showed a downward trend.

The current design is based on application experience. This allows the magnetic drive gear pump to have a relatively simple and robust construction, allowing the magnetic drive pump to have exactly the same reliability as a mechanical seal pump.

It is very important to extend the interval between two overhauls as much as possible, so reliability has become a basic focus in current design and development. Reducing the wear between the two magnetic couplings while enhancing the cooling means that the magnetically driven pump can provide an optimized solution in more applications than before.

A typical example is that one manufacturer has adopted a proven and patented technology that overcomes the problems of resistance loss, overheating, and wear in the inner bearing housing. This is achieved by balancing the liquid in the pump and the following working principle: There are radial holes in the rotor connected to the hollow pump shaft. During operation, centrifugal forces act on the liquid in the radial bores, creating a negative pressure in the hollow shaft connected to the magnetic drive section. The differential pressure pushes the fluid in two separate chambers behind the rotor, effectively removing the heat generated by friction and magnetic losses. These cavities are respectively connected with the inlet and the outlet. Compared to other magnetically driven pumps, this type of system retains the pump's good self-priming capability because the "cooling liquid" does not short the inlet and outlet directly. Sufficient cooling liquid production and inlet pressure difference, viscosity and shaft speed has nothing to do. Moreover, this system has a more important and unique advantage, namely that the magnetic drive gear pump of the manufacturer ROTAN can be reversed without affecting the operation of its cooling system. Because the steering is reversed, the flow of liquid in the system is simply the opposite direction.

In an internal gear pump, it is very important to maintain control of the axial clearance (ie, the distance between the rotor end face and the head end cap of the pump head). In the design of the magnetic drive gear pump, the axial clearance is controlled by two face-to-face thrust bearings. This design minimizes the bearing load, thereby reducing wear and extending service life. This is also achieved by some of the cavities mentioned above. These cavities can generate hydraulic thrust equal to the front of the rotor and maintain balance.

In summary, these design features ensure that the number of repairs is reduced, eliminating the possibility of failure of the seal, which normally results in the shutdown of the pump.