You Should Also Know About The Knowledge Of Magnetic Pumps

Jul 13, 2025

Magnetic drive pump is a new type of centrifugal chemical process pump that uses magnetic coupling to achieve non-contact torque transmission, no shaft seal, full seal, no leakage, corrosion resistance, and no pollution based on centrifugal pumps.
Magnetic pump is a leak free fluid conveying machinery that does not have dynamic seals. Mainly designed for centrifugal pumps in vane pumps, it usually consists of a pump body, isolation sleeve, and connecting components to form a shielded sealed chamber that can withstand pressure. There is a rotating permanent magnetic field outside the sealed chamber, which drives the magnetic rotor components inside the sealed chamber to rotate synchronously through the action of the magnetic field. The rotor components inside the sealed chamber drive the impeller to do work on the fluid. Due to the absence of dynamic sealing in the shielding and sealing chamber composed of stator components, and the fact that the rotating shaft that drives the impeller to do work does not pass through the shielding and sealing chamber, zero leakage and no pollution of the magnetic pump are ensured.

01 The structural principle of magnetic pump
1. A magnetic drive pump (referred to as a magnetic pump) is usually composed of an electric motor, a strong coupling, and a centrifugal pump. Its main feature is to use a magnetic coupling to transmit power. When the electric motor drives the outer magnetic rotor of the magnetic coupling to rotate, magnetic lines pass through the gap and isolation sleeve, acting on the inner magnetic rotor, causing the pump rotor to rotate synchronously with the electric motor and transmit torque without mechanical contact. At the power input end of the pump shaft, due to the liquid being enclosed in a stationary isolation sleeve without dynamic sealing, there is no leakage at all.
2. The magnetic drive pump adopts advanced technology design and follows the high efficiency and reliability of the original centrifugal pump in terms of hydraulics. It eliminates the traditional mechanical seal device and replaces the rigid connection between the motor and pump with a contactless flexible connection, fundamentally eliminating shaft seal leakage.
02 Scope of application and conveying medium of magnetic pump
Magnetic driven centrifugal chemical process pump is widely used in the production processes of chemical, petrochemical, metallurgical, pharmaceutical, printing and dyeing, papermaking, electroplating and other enterprises to transport corrosive or non polluting liquids with a relative density of less than 1.84, viscosity similar to water, and free of iron filings and solid particles. It is particularly suitable for the transportation of flammable, explosive, volatile liquids and toxic and valuable media.
03 Transmission characteristics and transmission mode of magnetic pump
1. Transmission characteristics
The magnetic drive of the magnetic pump adopts a push-pull dense cylindrical structure, which can transmit about 1.5 times the torque of the dispersed magnetic structure under the same magnetic volume. This structure maximizes the utilization of magnetic energy and greatly reduces the weight of the inner and outer rotors, reducing the impact of the weight and imbalance of the rotor system on the sliding bearings.

2. Transmission form

There are two structural forms of magnetic transmission.

(1) Disc-shaped magnetic coupling

The disc-shaped magnetic coupling consists of two facing annular magnets and an isolation sleeve in between. There will be a significant axial force between the two magnets, and measures to balance the axial force and thicken the isolation sleeve must be taken, otherwise the isolation sleeve will deform and be damaged.

(2) Cylindrical magnetic coupling

The cylindrical magnetic coupling has no axial force. The cylindrical magnetic coupling is composed of inner and outer rotors. The substrate of the inner and outer rotors is made of ordinary steel that can be magnetized. Multiple permanent magnets are tightly arranged in the parallel axis direction between the outer circular surface of the inner rotor and the inner circular surface of the outer rotor, forming a "combined push-pull magnetic circuit". Theory and practice have proven that this cylindrical "combined push-pull magnetic circuit" can achieve a larger transmission torque per unit magnetic volume under the same magnetic circuit parameters, which is about four times that of traditional dispersed magnetic circuits. The magnetic pump adopts this cylindrical "combined push-pull magnetic circuit".