24 June 2021
Industrial functions in difficult environmental situations name for particular bearing options. NKE Austria GmbH has developed hybrid bearings for exactly these functions. Their benefits are offered right here.
NKE hybrid bearings include ultrapure metal bearing rings and ceramic rolling components manufactured from bearing grade silicon nitride Si3N4. “At first look, this materials pairing is very uncommon, nevertheless it affords many benefits in an unlimited vary of functions, which considerably will increase the reliability of the general system,” says Michael Rössl, Utility Engineer at NKE in Steyr, Austria.
The silicon nitride rolling components are 60 % lighter than these made out of metal and are appropriate for very excessive rotating speeds. “Consequently, NKE hybrid bearings can attain restrict speeds which can be over 20 % greater than standard commonplace bearings,” says Rössl. “Even at these very excessive and demanding speeds, NKE hybrid bearings display wonderful efficiency traits and minimal working noise. There are subsequently notably effectively suited to use in high-speed electrical motors.”
The ceramic rolling components have excessive put on resistance and might obtain higher outcomes below extraordinarily demanding situations, reminiscent of poor lubrication, thereby extending service life considerably. “The superb ‘dry-running properties’ of a hybrid bearing play an especially crucial half in considerably enhancing the reliability of an software,” provides the applying engineer.
The tribological properties of a hybrid bearing are superb because of the particular materials pairing of ceramic and bearing metal. Little or no frictional warmth is generated, even at excessive speeds. “In flip, this additionally means that there’s much less energy loss on the bearing and by extension within the software as a complete,” explains Rössl. “Furthermore, a hybrid bearing has a low breakaway torque.”
As well as, the service lifetime of the bearing is prolonged by way of ultrapure bearing metal. The rolling components are corrosion-resistant and have very excessive rigidity. The raceway and curler geometry of the hybrid bearings have been specifically optimised to ensure good contact geometry and excessive load capability. “The hybrid bearings may supply good safety towards ‘standstill marks’, often known as ‘false brinelling’,” Rössl explains one other benefit of the brand new bearings.
Typical functions for hybrid bearings embrace electrical motors (AC/DC), wind turbine turbines, excessive pace functions or traction motors for railway automobiles. “In reality, hybrid bearings with ceramic rolling components are primarily designed for functions through which most electrical isolation is required and/or excessive speeds are concerned. Hybrid bearings supply most isolation safety as a result of the ceramic rolling components themselves have an electrically insulating impact and thus forestall a corresponding passage of present,” says Rössl. “Using frequency inverters usually causes electrical harm to the bearing. With decrease currents, a bearing with an electrically insulating coating amongst different measures may also help to alleviate this. However solely a hybrid bearing affords optimum safety towards very excessive currents.”
The service lifetime of the bearing may be prolonged considerably in different functions as effectively by way of using rolling components made out of silicon nitride. The desk supplies an outline of the commonest hybrid bearing functions and the benefits of the bearings.
Relying on the calls for of the applying and the scale of the bearing, the cages for the hybrid bearings can be found in metal sheet, brass or polyamide; customised cage designs are additionally potential on the buyer’s request. Regularly used hybrid bearing sorts embrace deep groove hybrid ball bearings, which can be found from inventory or with quick lead instances. Different bearing sorts or particular designs may be manufactured to buyer specs upon request. Present bearings may be changed simply: “NKE hybrid bearings can change standard commonplace bearings with none modifications in any respect,” says Rössl. “No extra tools or particular expertise are required to switch them.”