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Bearing solutions for connecting rail carriages and bogies

Schaeffler is continuously developing and optimising the design of its bearing solutions for these applications

In rail transport, the demand for compact, cost effective solutions for connecting vehicle bodywork is higher than ever. 

For light passenger trains in particular, vehicles that are accessible throughout in low-floor and multiple compartment designs are being developed. This facilitates more open cars and carriages, enabling passengers to board and exit the vehicles more easily and quickly. This requires flexible and compact bearing solutions. 

Schaeffler is continuously developing and optimising the design of its bearing solutions for these applications.

Bearings for connecting railcar bodies and bogies

In modern trams and metros, railcar bodies and bogies are often connected using slewing rings in four-point contact design. 

High demands are placed on these bearings in the form of high contamination, high vibration and long operating times. They also have to facilitate long maintenance intervals and so need to be completely reliable. 

The installation points for mounting and maintenance of these bearings are difficult to access.

Slewing rings from Schaeffler are designed to overcome these difficult conditions: effective seals that provide improved protection against steam/water jet cleaning; special lubricating grease; preloaded raceway systems; corrosion protection; and long maintenance intervals. Other special designs are available such as slewing rings with additional covers and integrated, adjustable roll dampers.

Spherical plain bearings for connecting railcar bodies

In many modern rail vehicles, individual rail carriages are connected by passages that enable passengers to move freely from one carriage to the next. 

Carriages are connected securely using ELGES maintenance-free spherical plain bearings or ELGES rod ends with ELGOGLIDE coatings from Schaeffler. These bearings combine high load carrying capacities under extreme loads (eg, buffer impact loads in accordance with EN 12663) with small bearing dimensions, low bearing friction and long operating life.

The upper central joints connect the rail carriages in the roof area. 

Depending on the overall design, maintenance-free radial spherical plain bearings or rod ends facilitate the required turning and tilting movements, including longitudinal tilts when the train is cornering or travelling uphill and downhill.

The lower central joints connect the rail carriages in the floor area of the vehicle. These bearings must facilitate all movements when travelling uphill or downhill, and must safely transfer the acceleration forces between the rail carriages. In low floor vehicles, they also support the weight of the overlying railcar body. 

Angular contact spherical plain bearings or thrust spherical plain bearings are used as the main bearing support or for the lift-off protector.

Special spherical plain bearings for the lower central joint

Rather than sourcing single components, a complete lower central joint unit simplifies the assembly of adjacent structures. 

The joint is fixed using bolted connectors in the upper and lower housing of the rail carriage. The bearing unit itself comprises a special spherical plain bearing with an integrated lift-off protector.

Radial spherical plain bearings

Maintenance-free designs with ELGOGLIDE sliding fabric as well as radial spherical plain bearings that require maintenance with or without rod ends are used for connecting rail carriages to each other. These bearings can be supplied with corrosion protection and are characterised by their high efficiency, long operating life and low friction.

Maintenance-free rod ends

These comprise a spherical plain bearing and a shaft for fixing. They can support loads in a tensile or compressive direction. Maintenance-free designs with an ELGOGLIDE sliding fabric and corrosion-resistant zinc plating are available.

Thrust spherical plain bearings/angular contact spherical plain bearings

Thrust spherical plain bearings and angular contact spherical plain bearings are the ideal solution for supporting high axial loads. 

In the maintenance-free design version with ELGOGLIDE sliding fabric in particular, they are characterised by above-average efficiency and long operating life.

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