Magnetic couplings

A permanent magnetic synchronising coupling is a special type of coupling based on permanent magnets. It enables contactless, synchronised transmission of torques between two shafts without mechanical contact or friction. The magnets are arranged in such a way that they generate a common magnetic field that causes the shafts to rotate at exactly the same rate. This contactless transmission makes them an extremely reliable solution, especially in demanding industrial applications.

Metau magnetic couplings are available with neodymium magnets (Ne), with which a torque range of 9.4 to 580 Nm is available, and alternatively with samarium cobalt (SmCo) for a range of 6 to 380 Nm. The magnetic couplings with neodymium magnets can be used up to a temperature of 120°C and those with samarium cobalt magnets up to a temperature of 300°C.

Depending on the required pressure resistance, chemical resistance and the need for as little or no eddy current loss as possible, various materials are available for the containment shroud. You can choose between stainless steel, titanium and technopolymer (PEEK). Metau magnetic couplings can also be supplied in accordance with ATEX.

The permanent magnetic synchronising coupling is an innovative technology based on the principle of contactless magnetic force transmission. It enables a precise and maintenance-free connection between two shafts without the need for mechanical contact or friction.

Structure and components:
There are two main components inside the clutch: the input side (primary side) and the output side (secondary side). Both sides are equipped with permanent magnets that are strategically placed to create a common magnetic field. The magnets are positioned so that they attract each other and create a stable connection when the shafts rotate.

Magnetic field and synchronisation:
The permanent magnets on both sides are aligned to create a synchronous magnetic field. This means that the magnetic poles are arranged in such a way that they attract each other when the shafts rotate at the same rate. This magnetic field acts like an invisible bridge that transmits the rotary motion from the input shaft to the output shaft.

Torque transmission without contact:
When the drive shaft is set in motion, the permanent magnets generate a magnetic field that also rotates the output shaft. As there is no mechanical contact, there is no friction or wearing parts. Power is transmitted exclusively by the magnetic field, which makes the magnetic coupling extremely low-maintenance.

Automatic synchronisation:
A decisive advantage is the magnetic coupling’s ability to synchronise the shafts precisely. The magnetic field ensures that the speeds of both shafts always match. If the output side is decelerated or accelerated by external influences, the magnetic field automatically adjusts to ensure precise synchronisation.

Decoupling in the event of overload:
In the event of an overload or blockage, the magnetic coupling can decouple automatically. This means that the magnetic fields separate to prevent damage to the system. As soon as the load returns to the normal range, the magnetic coupling re-establishes the connection – all without contact or mechanical intervention.

Magnetic couplings offer a number of advantages that make them a favoured solution in industrial drive technology:

• • • Contactless power transmission: As there are no mechanical contacts, magnetic couplings are wear-free and require hardly any maintenance. This significantly increases the service life of your systems.

    • Low maintenance and long service life: The contactless operation eliminates wear parts such as shaft seals, mechanical seals, packings and coupling stars, which significantly reduces maintenance costs.

    • Vibration and shock damping: Magnetic couplings can effectively dampen vibrations and shocks, which increases the service life of the entire drive unit.

    • Corrosion resistance: Magnetic couplings are ideal, especially in aggressive or damp environments, as they are hermetically sealed and have no mechanical contacts.

    • Various designs: Magnetic couplings are available in different sizes and designs to meet the specific requirements of different industries.

    • Leak-free pumping: Pumps equipped with magnetic couplings are hermetically sealed. This ensures that a medium can be pumped without leaking.

    • Hermetic separation: A magnetic coupling ensures a hermetic seal between  drive and driven side. In harsh environmental conditions, such as in autoclaves, the drive motor may have to be relocated to the outside, depending on the design, and only the driven fan is exposed to high temperatures and high pressure inside the autoclave. The magnetic coupling separates the internal and external spaces from each other and yet a reliable torque transmission can be realised.

     

Permanent magnet synchronising coupling technology is undergoing a dynamic development process driven by advances in materials science, electronics and manufacturing technologies. Below are some exciting trends and innovations that could shape the future of this innovative clutch technology:

Use of advanced magnetic materials:
The development of new, more powerful magnetic materials, such as high-performance NdFeB magnets, enables even stronger magnetic fields in a smaller installation space. This leads to more compact, more efficient clutches with higher torque and better temperature resistance.

Integration of sensor technology and IoT:
Future permanent-magnet synchronising clutches could be equipped with integrated sensors that provide real-time data on temperature, magnetic field strength, wear or overload. Networking as part of the Internet of Things (IoT) allows maintenance intervals to be optimised, failures to be detected at an early stage and system availability to be increased.

Improved energy efficiency and environmental friendliness:
With a focus on sustainable technologies, future couplings will be designed to be even more energy-efficient. By using more environmentally friendly materials and optimised production techniques, resource consumption and the carbon footprint can be further reduced.

Extended areas of application:
Innovations could bring the permanent magnetic synchronising clutch into new industries and applications, for example in medical technology, aerospace or renewable energy. These clutches will be increasingly in demand, particularly in areas that require high precision, reliability and low maintenance.

Miniaturisation and integration into complex systems:
Further developments in micro-manufacturing are enabling ever smaller designs. This means that permanent magnet synchronising couplings can be integrated into highly complex, space-saving systems, for example in miniature robotics or portable medical devices.

Opting for magnetic couplings brings numerous advantages that make your systems more efficient, more durable and require less maintenance. Here are some reasons why this technology is the right choice:

• • • High reliability: Thanks to contactless operation, magnetic couplings are virtually wear-free and offer a long service life.

    • Low maintenance: Fewer moving parts mean less maintenance and lower operating costs.

    • Environmentally friendly: As no mechanical friction parts wear out, magnetic couplings are environmentally friendly and sustainable. The non-contact power transmission means that the drive and the driven sides can be hermetically separated from each other. Environmentally harmful media can be pumped leak-free with a magnetically coupled pump.

    • Versatility: They are available in various designs and can be integrated into a wide range of applications.

     

• • • Food and beverage industry: For hygienic, wear-free and contactless drive solutions that meet the high cleanliness requirements. Magnetic couplings are hermetically sealed and prevent contamination, making them ideal for processing and packaging. In the food industry, magnetic couplings are used in magnetic agitators and magnetic mixers for example.

    • Chemical industry: Magnetic couplings are used in chemical production because they can safely transfer aggressive media. Their hermetic seal protects against leaks and corrosion, which increases the safety and longevity of the systems. In the chemical industry, magnetic couplings are primarily used in pumps for shaft sealing and power transmission.

    • Pharmaceutical production: Precise, hygienic and reliable drive systems are required here. Magnetic couplings ensure contactless power transmission that meets high cleanliness standards and enables easy cleaning.

    • Automation technology: In conveyor systems, packaging machines, robotics and other automated systems, magnetic couplings ensure wear-free, precise and low-maintenance power transmission. They are ideal for applications where a contactless connection is required.

    • Power generation: In wind turbines, generators and other energy systems, magnetic couplings ensure efficient and reliable transmission of torques, especially in environments with high loads or extreme conditions.

    • Medical devices: Due to their hygienic properties and contactless transmission, magnetic couplings are also used in medical devices where a sterile environment must be guaranteed.

    • Mechanical engineering: There are numerous applications in mechanical engineering. Magnetic couplings are used, for example, for contactless power transmission in fans for use in autoclaves or in compressors.

     

Magnetic couplings are an innovative, reliable and low-maintenance technology that demonstrates its strengths in numerous industries. Thanks to their contactless power transmission, they offer protection against wear, overload and corrosion, making them an extremely durable and low-maintenance solution. Magnetic couplings impress with their high efficiency and flexibility, particularly in demanding applications where precise and safe power transmission is required. They enable the contactless transmission of torques, which means that there are no mechanical wear parts that require regular maintenance or replacement. This results in considerable cost savings during operation and increased system availability.

In addition, magnetic couplings offer excellent protection against overload and unwanted feedback to the drive system. In the event of sudden malfunctions or blockages, the coupling can automatically disengage, preventing damage to motors or other components. The contactless transmission also ensures virtually wear-free operation, which significantly extends the service life of the components.

They are available in various sizes and designs, making them suitable for both small and large power ranges. They can also be equipped with additional functions such as temperature monitoring to make operation even safer and more efficient.

With increasing demands for efficiency, reliability and sustainability in the industry, magnetic couplings are a future-proof solution. They help to minimise maintenance costs, reduce operating costs and extend the service life of systems. Overall, magnetic couplings therefore represent an innovative technology that paves the way for modern, sustainable drive systems and will play an important role in many industries – be it the food industry, medical technology, chemicals or power generation.