BS/EN 13260-2020 pdf download.Railway applications-Wheelsets and bogies – Wheelsets Product requirements.
Note 1 to clause: Category 1 is generally selected when the traffic speed is greater than 200 km/h. The wheelset is then composed of wheels and a category I axle, according to EN 13262 for wheels and EN 13261 for axles.
Note 2 to clause: Category 2 is divided into sub-categories (2a and 2b) to specify certain characteristics:
— 2a) max. speed s 120 km/h;
— 2b) 120 < max. speeds 200 km/h.
Note 3 to clause: These categories can also be defined in accordance with the technical specification.
4 Product definition
4.1 Assembly of components
4.1.1 General
Before assembly, the various components of the wheelset must fulfil the geometric requirements of the specific documents that define them. In particular, the axle and wheels must be in the ready to assemble state defined in EN 13262 for wheels and EN 13261 for axles.
The components of the wheelset can be shrink-fitted or press-fitted to the axle. The wheels should be fitted with an oil injection hole.
The interference fits to be used must be defined by the technical specification, depending on the characteristics of the material used for this element and the forces and moments to be transmitted through the fit. This interference must be defined according to the geometric tolerances of the wheel seats whose interference values are given in 4.1.2.
In the case of shrink-fitting, the whole wheel should be heated and its temperature should not exceed 250°C. If a different heating method is used, proof must be provided that it has had no influence on the characteristics of the wheel, as defined in EN 13262.
If another fitting method is used, it must be defined in the technical specification. It must at least demonstrate that the characteristics of the axle and wheel as defined In EN 13261 and EN 13262 are not affected by the fitting. Then the mechanical resistance of the assembly (see 4.2.1) must be demonstrated and the traceability documents for each fitting must be defined to give the same type of information as that defined in E.6.
The static imbalance of the two wheels on each wheelset must be within the same diametric plane and on the same side of the axle. The static imbalance of the brake discs must be in the same plane as the wheels but on the opposite side of the axle.
For press-fitting, the force-displacement curve ensures that the fitting has not damaged the contact surfaces and that the specified interference is effective.
The shape of the curve to be achieved is defined in Annex A.
The final fitting force F1is a function of the force F defined in 4.2.1 and must be within the range:
O.85FcFi’c 1.4SF
This range applies to:
— press-fitting of one-piece wheels;
— with Li/dm 0.8 to 1.1, where dm is the mean diameter of the wheel seat, and Li is the fitting length (in mm);
— molybdenum-based pastes (MoS2) and tallow.
If other lubricants are used, they must be defined in the technical specification and verified with the product qualification in accordance with Annex D, including the dismantling test in accordance with subclause 4.2.1.
4.1.3.2 Measurement method
The press used for assembling must have a calibrated system to plot the diagram representing the force value at each position of the element to be fitted, obtained during the displacement of the element on the axle. The x-axis scale of the displacement must be at least 0.5 times the actual displacement of the element to be fitted, The y-axis scale of force must allow the force to be read at each point of the curve at an accuracy of 25 KN. The accuracy of the force sensor must be 10 KN. The x-axis and y-axis can be inverted.
In the case of point recording, at least one point must be plotted per millimetre of relative displacement of the parts to be fitted and per 25 KN variation in force.
4.2 Wheelset characteristics
4.2.1 Mechanical resistance of assemblies
4.2.1.1 General requirements
Annexes A and E define the need for this test.
4.2.1.2 Results to be achieved
In order to transmit moments and forces between the axle and the wheel, the assembly must be able to withstand an axial force F for 30 s, without displacement between one element and another.BS/EN 13260-2020 pdf download.