MINEX®-S – magnetic coupling

Magnetic coupling with separating can for non-contact torque transmission

MINEX®-S is a permanent magnet synchronous coupling which transmits the torque contactlessly via the magnetic forces between the inner and outer rotor. Its main function is to serve as a seal element in pumps and agitators, where it guarantees hermetic separation between the drive and output ends. In the case of critical media (aggressive acids and bases etc.), it acts as a reliable sealing method and prevents leakage along with the associated consequences. MINEX®-S also features overload protection — if the maximum coupling torque and maximum angle of rotation are exceeded, the transmission of force is automatically interrupted.

Highlights

Non-contact torque transmission via permanent magnets
Hermetic separation of drive and output ends
Resistant to aggressive media
Torques ranging from 0.15 to 1,000 Nm
Overload protection for drive and unit

Structure and function

The coupling consists of an internal and an external rotor. The inner side of the outer rotor is lined with high-quality permanent magnets of alternating polarity. The magnets of the inner rotor are concealed by encapsulating them in a welded magnet covering that is impermeable to liquids.

In an idle state, the north and south poles of the rotors face each other, and the magnetic field is completely symmetrical. It is only when the rotor starts turning that the magnetic field lines are deflected, thereby allowing torques to be transmitted across the air gap.

This results in synchronous operation with constant backlash. The main component of MINEX®-S is the separating can, which is permanently attached to the unit at the output end and separates the inner from the outer rotor.

The separating can ensures low-vibration torque transmission without the need for a mechanical connection, and provides hermetic separation between the drive and output ends — the sealing is achieved statically (e.g. flat gasket or O-ring).

The metal versions of the separating can cover the largest application range. However, they also result in eddy current losses and this may call for cooling measures.

Separating cans of the magnetic couplings and their features

MINEX®-S	Version Separating can made of metal	Version Separating can made of PEEK CFK	Version Separating can made of oxide ceramics
Permanent magnet	●	●	●
Contactless	●	●	●
Maintenance-free	●	●	●
Torsionally flexible	●	●	●
Low-vibration	●	●	●
Max. Torque range TKN [Nm]	1,000	370	550
Max. Pressure resistance [bar]	up to 90 bar (depending on size)	up to 16 bar at 130 °C	up to 25 bar (depending on size)
Shaft diameter [mm]	Ø 5 pre-drilled	Ø 5 pre-drilled	Ø 5 pre-drilled
Max. temperature resistance [°C]	150/300 (depending on magnetic material)	130	300
ATEX	●	●	●
Special features/application areas	Most common version Covers the widest power range Particularly suitable for pump drives and fluid applications High t_max [°C] and p_max [bar]	No eddy current losses Energy-efficient and economic Particularly suitable for dry running For medium requirements with regard to tmax [°C] and pmax [bar]	No eddy current losses Energy-efficient and economic Particularly suitable for dry running High tmax [°C] and pmax [bar]