Page 5 of catalogue Bearing Technology for Rail Vehicles of Schaeffler Technologies GmbH & Co. KG

Rolling Bearings for Gearboxes, Traction Motors, Axle Suspension Bearing Supports
Gearbox Bearings Rolling bearings in gearboxes stabilize the shaft and support the transmission of forces. This means that they must withstand extreme loads in complex environmental conditions. The bearing types mostly used are tapered Roller bearings, four point contact bearings, and Cylindrical roller bearings. Less often used are Deep groove ball bearings, Spherical roller bearings, and Angular contact ball bearings. The bearing arrangement demands flexibility. It depends on the design of the gearbox and the operating conditions. The main requirements of bearings in gearboxes are: • high speeds • high loads • vibrations and shocks • high temperatures • high guidance accuracy • compact designs The bearings are selected in conjunction with the gearbox manufacturer while taking these factors in consideration. A calculated operating life of more than 1.5 million kilometers is usually a prerequisite. Characteristic features of FAG gearbox bearings: • reinforced internal design • special cage design • reduced tolerances and adjusted internal clearance • retaining slots in the outer ring to prevent unintentional rotation Traction Motor Bearings Rolling bearings for Traction motors must fulfill the challenging requirements placed on them regarding reliability and long operating life. Traction motor bearings developed by Schaeffler Group Industrial are specially designed to meet these requirements. Cylindrical roller bearings and deep groove Ball bearings are usually used. The normal calculated operating life for traction motor bearings of more than million kilometers is reached due to: • special cage design • reinforced internal design • adjusted tolerances and internal clearance • efficient current insulation made of ceramics Axle Suspension Roller Bearings In electric freight locomotives two rolling bearings fitted into a housing support the traction motor that is arranged transverse to the direction of travel. The motor rests directly on the wheelset shaft in these two so-called axle suspension roller bearings. So that the axle suspension roller bearings achieve long operating life (nominal operating life of over million kilometers), roller bearings with high load carrying capacity are used. High loads caused by vibrations and shocks are supported by special Tapered roller bearings with reinforced sheet metal cages. Special designs with collars on the outer rings or with current insulation for example, are also available on request.
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