Wheelset (rail transport)

A set of wheels for rail vehicles consists of the axle, the two wheel discs and bearing housing on the sides, depending on the application are on the shaft even brake discs and / or gears mounted to the drive. Wheelsets transferred to a weight of the vehicle on the road or the rails and lead to other vehicle on the track.

A distinction Treibradsatz and wheelset. A drive wheelset transmitting acceleration and deceleration forces on the rails. A wheelset that is free of drive forces, increasing the vehicle mass to be housed, the guidance of the vehicle and possibly the transmission of braking forces used.

With steam locomotives drive axles additional distinction in fuel and Kuppelradsätze. During the Treibradsatz is directly driven by the steam engine, the drive takes place indirectly with the Kuppelradsätzen, usually through side rods or the Luttermöller final drive via gears.

In contrast to an axis of the axle can thus also transmit torque.


In general, the two wheel discs have sloping treads and are rigidly connected to the axle ( by press-fitting ). This combination causes the sinus run, which keeps the vehicle in the lane at high speeds but tends to be unstable. Only in a few exceptional cases, the wheel discs are not rigidly connected to the axle. Case of axle with adjustable track width, the wheel discs on the axle shaft can be moved, twisting against each other is prevented.

Any keys that are present in steam locomotives from fuel and Kuppelradsätze, are as the lead in pressing for the two wheel discs stand with their pins at a certain angle to each other.

Losradfahrwerke be developed only recently; because of the lack of rotational coupling they do not lead to the sine - wave or run. They are used, inter alia, the Talgo ( treated as a single - chassis single ) and at various trams, here mainly because of the possibility of low-floor design due to the lack of axle and the positive arc running, even at small radii.

The wheelset bearings are usually outside of the wheel discs (outdoor storage ). Among other things, in passenger cars in America, trams and metro trainsets they can also be located within the wheel discs, thereby setting the lower Kragweite a favorable flow of power. The installation between the wheel discs but requires separable bearings, since the bearings can be installed only after the pressing of the wheel disc, and also should be replaceable without removing the wheel disc. The drive axles of steam locomotives usually have an internal storage, since the rods are disposed outwardly from the wheel plane. Also other locomotives have for transmitting the driving forces additional, attached to the wheelset elements such as pins on the wheel discs, a bent axle shaft for steam locomotives or additional shaft seats for the gear of the drive for electric locomotives and Zahnradlokomotiven.

Modern vehicles are equipped instead of directly acting on the wheel tread brake blocks with disk brakes, additional brake discs. These are either attached to the wheel discs or on its own sitting on the axle shaft.

For the distance and speed measurement, the traction control, slip protection and possibly other systems, the rotation of the wheel is detected by sensors. These are often located odometer pulse outside of the axle bearings.


The wheelset is subject to high stresses during operation. The axle is claimed by the force acting on the bearing weight on bending. Because the wheel rotates when rolling the vehicle, the bending load is an alternating stress. The wheel discs must assume powers of guidance and drive or brake. When the brake shoes will be added an additional burden by heating and wear of the tread. Also, disc brakes initiate a heat load.


For this reason, axle and wheel disc have been measured regularly and are searched for cracks. The tear test is carried today with an ultrasonic testing, eddy current testing and magnetic particle testing. Previously, only visual inspections could be carried out. Therefore, steam engines had red wheels in the color cracks were easier to recognize. For freight wagons, wheel discs are struck for testing with a hammer. From the rebound of the hammer and the sound of the wheel disc can be concluded that the presence of cracks. The treads are processed; when reaching the so-called operating limit sizes tires or wheel disk to be replaced.


  • DIN EN 13103 " Railway applications - Wheelsets and bogies - Wheels axles - Design and calculation Directive; German version prEN 13103:2006 (draft standard ).

This standard is applicable to axles for rolling stock, which is intended for use under normal operating conditions, such as prevail in Europe. The competent national committee for the DIN is within the NA 087 Standards Committee infrastructure and rail vehicles (FSF ) of the Sub-Committee NA 087-00-02 AA landing gear.

  • The identification of the Wheel arrangement of a vehicle is defined in DIN 30052.