Innovative permanent-magnet couplings – Abrasion free connections for delicate fields of application

RINGFEDER POWER TRANSMISSION  is known for developing and producing technically innovative high-quality driving elements. On our worldwide known brand “GERWAH®”, we sell permanent-magnetic couplings, which are the ultimate answer to the application problems arising when working with the traditional mechanical couplings.

In contrast to the standard application, our GERWAH® magnetic couplings do not transmit the torque via mechanical joints, which are subject to wear, but use magnetic forces instead. This means that they work completely wear-free and without the need to establish direct contact between the two shafts - a fact that makes them suitable to you for use in fields of application where strict hygiene regulations have to be observed or in acid or alkaline surroundings. These maintenance-free couplings are your best choice when the vibration of the axes is not supposed to be transmitted, when a partition wall must not be perforated or when wear-free overload protection has to be guaranteed.

Depending on your construction and the principle of function, two different kinds of couplings are available: On one hand, there is the synchronous coupling, on the other the hysteresis coupling - both of which are available as a disc coupling (with axial magnetic discs) or as a rotor coupling (with two interlocked exterior and interior rotors).

Wear-free overload protection by cutting the link

The permanent-magnet synchronous couplings transmit the torque via permanent-magnetic power. Thus it is possible to transmit power over a defined distance and through non-magnetic substances without establishing direct contact between the two shafts. Synchronous couplings can be applied in pump and vacuum technology where power has to be transmitted through partition walls. That way, seals become redundant. When the operating torque is exceeded, the link is cut automatically and the device is used as a wear-free coupling. In contrast to mechanical safety couplings, the rotational speed and the duration of disengaging do not have any influence on function or service life. GERWAH® synchronous couplings are available for torques up to 1,000 Nm. Other variants are available on request. These couplings can be used in packaging lines or in shredder facilities in the field of waste disposal.

For special fields of application, for instance a screw test device in test engineering, couplings with chuck rotation are available. In clockwise rotation a torque of 15 Nm is permitted. In reverse rotation the coupling is limited to 5Nm.

Consistent and attached torque at overload

Besides the permanent-magnetic synchronous coupling, RINGFEDER POWER TRANSMISSION, offers wear-free hysteresis units which can be used in special fields of application. The extraordinary feature: Due to the combination of the magnets, the unit does not require any external power.

The hysteresis material allows a consistent and attached torque even if the chosen operating torque is exceeded. The driving feature can continue to rotate without causing any damage - the set torque will continue to be transmitted. After the overload is eliminated, the coupling can immediately restart operating so that it is not necessary to switch on the driving feature again.

Hysteresis couplings are used in capping machines in the beverage, cosmetics, and detergent industry as well as in medical device technology whenever bottles are sealed with screw tops. During this process the tops are screwed up to the point when the maximum torque has just been exceeded. Right then, the coupling limits the torque until the screw head has moved to the next bottle. Additionally, the hysteresis coupling can be used for limiting the speed of the winding bobbins for yarns and fibers in the textile industry or slowing down assembly lines in conveying engineering.

Since there are no wearing parts and consequently no wear particles, hysteresis couplings can be operated in aseptic environments or where strict hygiene regulations apply.

Production of individualized models

Synchronous and hysteresis couplings can be manufactured according to customers' individual specifications and requirements. Furthermore our experts are glad to offer a helping hand when it comes to using and operating their products. Thanks to the fact that maintenance is not necessary and blind installation possible, magnetic couplings can be used in places which are hard or even impossible to reach. Furthermore, the magnetic couplings succeed in connecting the rotating shafts in locations such as the clean room where traditional couplings fail.