General description of magnetic couplings:
The magnetic couplings of the MINEX® range are permanent-magnetic couplings transmitting the torque without contact through magnetic forces between two magnetic rotors.
The standard type MINEX®-S with containment shroud and magnets positioned radially ensures hermetic separation of driving and driven side in pumps and agitators. As a hysteresis coupling version it is in turn suitable as a wear-free overload protection alternatively to classical safety couplings. With the disk coupling which is optionally available the magnets face each other axially so that torques can be transmitted through plane walls. The transmittable torque can be varied by adjusting the air gap.
Function of magnetic couplings:
Magnetic couplings operate without contact and free from wear. The magnetic couplings are made up of an external and internal rotor equipped with high-quality magnets of changing polarity. The external rotor is usually fastened on the driving side and the magnets are bonded barely. The magnets of the internal rotor on the driven side are fully encapsulated by a magnet cover welded to form a liquid-tight seal. In their non-operative states the north and south poles of the rotors are opposite to each other and the magnetic field is symmetrical. It is only when the rotors are twisted that the magnetic field lines are moved, hence the torque is transmitted through the air gap. Then there is a synchronous operation under a constant torsion angle.
If the maximum coupling torque and the maximum torsion angle are exceeded, the power transmission is interrupted. MINEX-S provide overload protection for drive and power pack. After eliminating the reason for overload (e. g. damage of the bearing or locking of the internal rotor) both rotors can be re-synchronised and re-accelerated.
Sealing function of magnetic couplings:
The main component of the MINEX-S magnetic coupling is the so-called containment shroud that is fixed to the driven-side power pack separating internal and external rotor. It ensures a completely leak-proof separation of product space and atmosphere.
Sealing is made statically, e. g. by means of a flat seal or an O-ring, thus eliminating the need to use dynamically loaded sealing elements. As a standard KTR supplies both metallic and non-metallic containment shrouds. The metallic types cover the widest application range, yet causing eddy current losses which might require cooling measures. If eddy current losses can definitely be excluded, the energy-efficient alternative materials PEEK ceramics are available.
Retrofit Kits for conveying pumps
Flange pumps with a conventional shaft sealing such as gland, shaft seal or something similar as a standard version can be retrofitted with the MINEX®-S magnetic coupling without much designing effort.
Retrofit for PUR foaming processes
When conveying and metering the media polyol and isocyanate in PUR processing plants, ambient air has to be prevented from penetrating into the process, since otherwise adverse reactions might be generated.
KTR provides standard conversion kits for reliable sealing of such drives, among other things for axial piston pumps type REXROTH A2VK and ROTARY POWER series C offering the following benefits:
- maintenance-free operation
- significantly reduced downtimes
- no more problems with sealing
- better efficiency and higher process reliability
The subassemblies are available for all motor-pump-combinations and with various materials.
KTR hydraulic components such as KTR bellhousings, foot flanges and damping rods