Magnetic coupling is a major application of the permanent magnet which mainly uses attractive force between opposite magnetic poles, and hence formed non-contact transmission between internal and external mechanical system without friction and noise. The basic structure of magnetic couplings contains outer rotor, inner rotor, and isolation shell which involve permanent magnets, soft magnetic material, and magnetic shielding material. Permanent Magnets in magnetic couplings should have high enough remanence to generate ideal torque. High enough intrinsic coercivity will avoid demagnetization and ensure favorable thermal stability. Magnetic shielding material is mainly utilized to support and protect the permanent magnets. Besides a certain corrosion resistance, magnetic shielding material should also have low permeability to guarantee much of magnetic flux travel between a pair of poles.
Characteristics of Magnetic Couplings
- Transform traditional dynamic seal into static sealing. Hence achieve zero leakage transmission of power.
- Transmission of vibration can be avoided, then ensure stable running of equipment with non-contact transmission.
- Release over-load protection.
- Simple structure, easy to assemble, debug and maintain.
- Different movement forms can be achieved like linear movement, rotational movement and screw composite motion.
- Eliminate pollution.
Classification of Magnetic Couplings
- Can be divided to synchronous type, eddy current type and hysteretic type base on coupling principle.
- Can be classified to linear type, rotational type, and screw type according to movement form.
- Can be classified to cylinder type and disc type according to structural form.
- Can be divided to intermittently type and combined type according to magnet arrangement.