Couplings are widely used in various general machinery to connect two shafts so that they rotate together to transmit torque and motion. Permanent magnet coupling step-by-step synchronous permanent magnet coupling and moment-limiting permanent magnet coupling and standard permanent magnet coupling. This paper mainly introduces the development and principle of synchronous permanent magnet coupling.
Traditional couplings must transmit torque through the interconnection of the driving shaft and the driven shaft. Its structure is complex, its manufacturing precision is high, and it is easy to cause damage to the components when overloaded. Especially when the driving shaft and the driven shaft work in two different media that need to be isolated from each other, sealing elements must be used for dynamic sealing, so there is a problem of either increasing the rotation resistance to ensure reliable sealing, or leaking due to poor sealing . In addition, with the wear and aging of sealing elements, the leakage will be aggravated, especially in the system where harmful gas (hazardous liquid) exists, once it leaks, it will pollute the environment and endanger life.
Traditional couplings are all contact couplings, which can be divided into elastic couplings and rigid couplings according to whether they have elastic parts inside. The elastic coupling has elastic parts made of metal springs or rubber plastics inside, so it has the function of buffering and absorbing vibration and the ability to adapt to axis deviation. It is suitable for occasions with variable load impact, frequent starting and forward and reverse rotation, and also suitable for occasions where the two axes cannot be strictly aligned. There are no elastic parts in the rigid coupling, so there is no ability to cushion and absorb vibration.
The magnetic transmission coupling is a non-contact coupling. It is generally composed of two magnets inside and outside. The two magnets are separated by an isolation cover in the middle. The inner magnet is connected to the driven part, and the outer magnet is connected to the power part. In addition to the function of buffering and absorbing vibration of the elastic coupling, the biggest feature of the magnetic transmission coupling is that it breaks the structural form of the traditional coupling and adopts a new magnetic coupling principle to realize the non-passage between the driving shaft and the driven shaft. Direct contact can transmit force and torque, and can change dynamic seal into static seal to achieve zero leakage. Therefore, it is widely used in occasions with special requirements for leakage.
