Bearing Technology and Services for Rail Vehicles
In close partnership with manufacturers and operators, the Business Unit Rail of Schaeffler Group Industrial (INA/FAG) develops and manufactures solutions for any bearing application in rail vehicles. The product portfolio includes axlebox bearings together with housings as well as bearings and components for traction motors and gearboxes, for railcar connectors and tilting mechanisms, for doors and numerous other applications. Schaeffler Group Industrial has more than 100 years of experience in railway applications. This means it offers customers comprehensive technical expertise, superior quality and products that are perfectly matched for every application.

The reliability of the bearings under extreme conditions is proved on test rigs developed in-house. The Rail Test Bay at the FAG location in Schweinfurt has been approved and certified by the German Federal Railway Office as a test center for rail vehicle bearing supports. In addition it is authorized to carry out “performance testing for axlebox bearings – railway applications” in accordance with DIN EN ISO/IEC 17025:2000. The management system of Schaeffler Group Industrial’s Business Unit Rail meets the requirements of the new International Railway Industry Standard (IRIS) and was certified accordingly effective August 1, 2008 by Technical Inspection Agency, TÜV Süd. The corresponding audit covered the Business Unit Rail including its Sales, Development, Design and Application Engineering departments as well as the Production sector and central functions such as Occupational Safety and Quality Management.

Rolling bearings for gearboxes and traction motors
Modern rail vehicles combine a high level of travelling comfort economically with low noise disturbance and high performance. Bearings from Schaeffler Group Industrial, incorporated in gearboxes, traction motors and axle suspension bearing supports, make an important contribution to this. Rolling bearings in gearboxes support the shaft and facilitate the transmission of forces. This means that they must with-stand extreme loads in complex environmental conditions. The most frequently used bearing types are tapered roller bearings, four-point contact bearings and cylindrical roller bearings. Deep groove ball bearings, spherical roller bearings and angular contact ball bearings are also used. The bearing arrangement demands flexibility. It depends on the gearbox design as well as on the operating conditions. Rolling bearings for traction motors must meet very challenging requirements regarding reliability and long operating life. The traction motor bearings developed by Schaeffler Group Industrial are specially designed and manufactured to meet these requirements. Cylindrical roller bearings and deep groove ball bearings are preferred for these applications.

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. The roller bearings used offer high load carrying capacity in order to ensure a nominal operating life of over 2 million kilometers. For instance, specially developed tapered roller bearings with reinforced sheet metal cages have proved their worth under such high loads caused by vibration and shocks. They are able to accommodate particularly high radial and axial loads. Special designs with collars on the outer rings or with current insulation are also available upon request. Depending on the demands for load capacity and on the ambient conditions, cylindrical roller bearings and spherical roller bearings are used as well.

Axlebox bearings
FAG axlebox bearings are subject to extreme loads at the interface between the wheelsets and the bogie frame and have to meet a wide range of technical requirements. The rolling bearing components must pass a series of tests according to DIN EN 12080, including ultrasonic testing of the inner and outer rings, in order to comply with the highest quality class known as “Class1”. Compliance with DIN EN 12082 is verified on special axlebox bearing test rigs. Axlebox bearings are developed in close cooperation with manufacturers and rail vehicle operators in order to achieve products that are optimized for the operating environment in question. Cylindrical roller bearings and ready-to-fit cylindrical roller bearing units as well as spherical roller bearings and tapered roller bearings are used for such applications. Ready-to-fit TAROL units are especially easy to install and are based on double-row tapered roller bearing units. During manufacture they are sealed and greased and their clearance is adjusted. Schaeffler Group Industrial can provide these bearing units in metric and imperial dimensions, along with all the necessary components and bolts for quick and safe mounting. Customer-specific individual parts, spare parts and housing adapters are available upon request. The housing as a connecting element between the bogie and the wheelset has the task of transmitting forces reliably. Its design depends on how the forces are introduced into the housing. The optimized shape improves the pressure distribution inside the rolling bearing so that the specific load is reduced and peak loads are prevented. The optimum design is ensured by means of complex tests that are supported by FEM calculations. The finite element method describes not only complex geometries, but also the complex progression of the force flow in the housing in a realistic manner. The materials used for axlebox bearing housings are spheroidal graphite cast iron, cast steel or aluminum alloy casting.

Bearings for tilting technology
Rail vehicles with tilting technology reach considerably higher speeds on conventional routes than vehicles without tilting technology. INA products such as yoke type track roller units, cylindrical roller bearings with annular groove and needle roller thrust cylindrical roller bearings are used in the main tilting mechanism of the rail vehicles, in stabilizing systems such as anti-roll bars and in the drive units for the tilting motion. Moreover, maintenance-free standard spherical plain bearings of the ELGES brand with ELGOGLIDE® sliding fabric are used for the main tilting mechanism. They ensure high load carrying capacity, extremely high reliability and long operating life.

Further fields of applications:


Bearings for automatic gage adjustment mechanisms
Bearings for brake systems
Bearings for connecting railcar bodies and bogies as well as railcar bodies with each other
Bearings for door systems

Services
Schaeffler Group Industrial’s services include expert advice on applications, comprehensive design expertise, rolling bearing calculation and testing. A close-knit network of field service sales engineers as well as service and sales technicians ensure customer proximity and fast reaction times. In addition, Schaeffler subsidiary FAG Industrial Services (F’IS) offers special services such as professional and economic reconditioning of railway bearings.

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