Railway applications

BS EN 13260:2020 pdf free.Railway applications一Wheelsets and bogies一Wheelsets —Product requirements.
The test must be performed on a press equipped with a device to record forces.
The force is applied gradually up to the value F, between one of the hub faces of the fitted element and the axle.
For press-fitted wheels, the dismantling test should be performed at least 48 hours after the fitting.
For shrink-fitted wheels, the test is to be done when the wheel and axle have returned to the same temperature after the fitting.
4.2.2 Fatigue characteristics
4.2.2.1 General
This subclause defines the fatigue limit values for rotational bending for 10 cycles. These values are used to calculate the maximum permissible axle seat stresses that are necessary for the application of EN 13103-1. These values are valid for “conventional” axle designs, wheels and the assembly process and do not need to be verified for product qualification.
NOTE 1 A design is considered “conventional” when the parameters defining the assembled parts fulfil the requirements of European Product and Design Standards for internal and external journals (e.g. roughness, geometry, interference adjustment, overflow, diameter ratios, steel grades, etc.).
For other types 01’ design or assembly process (e.g. cooling a wheelset, specific diameter ratio, new materials, specific surface coating of the wheel seat, etc.), the following characteristics must be verified and tested at least once in the event of a new or modified set of parameters affecting the assembly.
These fatigue characteristics are not the same for a solid axle and a hollow axle. This is the result of the axle bore effect on stress distribution.
For a solid axis, only one fatigue limit (F3) must be determined under the fitting surfaces.
For a hollow axle, given that the fitting effect is greater on journals than on other fitting surfaces due to the difference in metal thickness, two fatigue limits must be considered:
— under the wheel seat, excluding journals, limit F4.
— under journal wheel seat, limit F5,
If necessary, the fatigue limit F3 or F4 must be verified by testing during qualification (see Annex D). The fatigue limit F5 can be calculated using the ratios F4/F.s = 1.17 and Fi/Fs = 1.28.
NOTE 2 FatIgue characteristics Fi and F2 of the axle are defined in EN 13261.
For fatigue testing of wheelsets, a wheel or test wheel with similar dimensions (especially the hub) must be press-fitted or shrink-fitted on the wheel seat. The interference must fulfil the requirements of 4.1.2.
The area of the test piece where the crack should initiate must have geometry, environment and surface characteristics representative of the axle.
Examples of test pieces are given in Annex B.
4.2.2.4 Test method
Tests must he carried out on machines that can create rotating bending stresses in the area where cracks initiate.
For each limit F3 and F4, it must be verified on three test pieces that no cracks spread after 10 cycles of a load creating a surface stress equal to F3 or F4. Indications with a depth of less than 0.5 mm should not be considered as crack propagations.
These stress levels must be calculated on the wheel seat according to the beam theory, without taking into account the interference stresses.
4.2.3 Electrical resistance
The electrical resistance of each wheelset, measured between the treads of the two wheels must not exceed 0.01 fi.
The device and method used for this measurement must be defined in the technical specification. 4.2.4 Dynamic imbalance
4.2.4.1 Maximum permissible values
For the wheelset of a vehicle that can travel at speeds greater than 120 km/h, the maximum dynamic imbalance values are shown in Table 2. They are measured in the wheel plane.
For category I wheelsets, the dynamic imbalance must be measured individually.
For category 2 wheelsets (speed greater than 120 km/h). the dynamic imbalance must be measured individually, unless otherwise specified in the technical specification.
For a powered wheelset, balancing is achieved after the proper placement and balancing of each component (wheels, brake discs and other components such as couplings and gears). Therefore, dynamic imbalance measurement is not necessary.
4.2.4.2 Test piece
The imbalance is measured on a fully assembled and machined wheelset.
4.2.4.3 Test method
The device and method used for this measurement must be defined in the technical specification.
4.2.5 Dimensions and tolerances
4.2.5.1 General
The dimensions of the wheelset must correspond to the design drawings, and the dimensional and geometrical tolerances to be applied when assembling the different parts of the wheelset are given in the following subclauses.
They depend on the category of the wheelset.
The values are given for measurements made without any load on the wheelset.
4.2.5.2 Wheels
Unless otherwise specified in the technical specification, the parameter tolerances defined in Figure 1 must be those given in Table 3.
If there are more than two seats for brake discs, tolerances for dimensions such as a3 orf-fi (see Figure 3) are the same as in 4.2.5.3.3.
4.2.5.4 Cylindrical gear wheels for powered axle, reducing gears, etc.
The parameter tolerances defined in Figure 4 must be those given in Table 7.
The different manufacturing processes leading to the “ready to assemble” state of the axle should not create residual stresses that may cause fatigue crack initiation.The requirements are given in EN 13261.
4.2.7 Protection against corrosion and mechanical damage
The components of the wheelset must be protected in accordance with the requirements of their respective standards.
Cavities caused by the overhang of the wheel hub on the wheel seats must be protected by an anti-corrosion product, which will be defined in the technical specification.
The constituent parts of the wheelset must be marked in accordance with the corresponding standards.
The wheelset must at least be identified by the following marks (in accordance with the technical specification):
1) type of wheelset,
2) order number,
3) assembler s marks，
4) date of assembly,
5) owner’s marks.
These marks must be at the end of the journal that already bears the marks of the axle defined in EN 13261 and below these latter marks.
At the end of the other journal, half of the surface must be reserved for maintenance. The other half of this surface is free.
Marks must be permanent, for example by stamping, dot peen marking or engraving. The protruding burrs from stamping must be levelled to allow in-service ultrasonic examination.
5 Product qualification
Product qualification must be carried out in accordance with the requirements set out in Annex D.
6 Conditions of supply of the product
The conditions for the supply of the product must be carried out in accordance with the requirements set out in Annex E.BS EN 13260 pdf download.Railway applications