Metro

Axtone offers Crash components for subway cars, providing passive protection of the vehicle in accordance with European standard EN 15227.

The components are designed to cater for Customer's individual needs. They are characterised by excellent performance parameters resulting from the application of peeling technology.

The following products illustrate just some of the possible solutions.

Subway
Shock absorbers for automatic and semi-permanent couplers
Elastomer shock absorbers for automatic and semi-permanent couplers have good working parameters and operational reliability within the required range of temperatures. The free-flowing elastomer maintains its properties for many years. The material is also recyclable. app_shock-absorbers-for-automatic-and-semi-permanent-couplers

Elastomer shock absorber designed for central couplers of passenger cars. It all the requirements of chinese standards. KX-CHP shock absorber has good working parameters and operational reliability within the required range of temperatures. The free-flowing elastomer maintains its properties for many years. The material is also recyclable. The shock absorber’s technical parameters meet the most demanding requirements of the clients, thus it can be used in the heaviest duty applications - currently it is used in a train on the Golmud – Lhasa route at the altitude of 5000 m above mean sea level.

kx chp shock absorber Technical documentation  

In metros coil springs can be used as primary or secondary suspension. Due to space and load requirements regarding the primary springs, linear spring sets are usually used.

Linear coil spring means a cylindrical coil spring with constant diameter and constant wire diameter. The spring ends are either “closed and ground” or “taper rolled, closed and ground”.

Linear spring set means that two linear coil springs with the same length are put together one into the other. Therefore the inner spring has a smaller outer diameter than the inner diameter of the outer spring. The inner spring also has a smaller wire diameter. The two springs of one set must have different coiling directions (one left, one right hand coiled).

If coil springs are also used in the secondary suspension, single coil springs are usually installed. As the lateral deflections are quite high, these springs must have a bigger length than primary springs.

The direction of the lateral displacement under vertical load (“chasse”) is marked on the springs and they have to be mounted into the vehicle according to the correct orientation of this marking.

TKS springs can also be used in metros as secondary suspension, because due to the big load difference between the empty and the fully loaded vehicle (for example in the rush hour), a progressive characteristic has advantages.

A TKS spring is a single spring with a progressive characteristic due to an inconstant inclination of the coils and an inconstant cross section of the wire. The low stiffness at tare load, the smooth and continuous transition of the stiffness with increasing numbers of passengers and a high end stiffness for the maximum loaded vehicle ensure a better ride quality under all those conditions.

As the maximum load in metros is very high and a low vehicle height is requested, the space for the coil springs is very limited. The stress in such coil springs is thus usually rather high so that the springs for metros require a high material grade and production quality.

metro

Ring-Springs

Production of rings used for friction springs which meet the requirements of the chart UIC 827-2 takes place in the Czech company owned by the Group. The springs are manufactured in a wide range of various diameters from 80 to 400 mm. The rings are used in friction springs of Ringfeder type applied in buffers, tractive apparatuses, pull rod bars and automatic couplers.

Features:

  • Hot formed, highest quality materials;
  • Various shapes possible;
  • Linear characteristic;
  • Safe against overloading;
  • Big damping due to friction;
  • Characteristic independent of the speed;
  • Characteristic independent of the temperature;
  • Proven in rail applications.

Ring-Springs2

Basic technical dates of friction springs:
F Spring terminal force d1 Inner diameter
Se Stroke for 1 element b/2 Half ring width
We Spring work for 1 element D2 Guide outer diameter
he Height of 1 element d2 Guide inner diameter
Ring-Springs3

Example of spring calculation

  • This spring consists of 4 elements type 19600:
  • End force = 600 kN
  • Stroke = 4 x 4,4 (Se ) = 17,6 mm
  • Spring work (Absorbed energy) = 4 x 1300 (We) = 5200 J
  • Spring length = 4 x 23,4 (he) = 93,6 mm

By adding additional elements, we increase the stroke (length of the spring), the absorbed energy (spring work) but the end force will remain the same. End force still 600 kN.

Ring-Springs4

During the operation of the friction spring two thirds of the input energy is dissipated as frictional heat. The recoil force at any point on the diagram is approximately equal 1 / 3 of the relative compressive force F. The capacity of the spring is represented by the total area shown below the load curve.

Ring-Springs5

Friction springs are generally designed to „block”, so it is therefore ensured that the admissible stresses cannot be exceeded and the friction spring will not be damaged.

Applications:

  • Buffers;
  • Draw gears;
  • Draw bars;
  • (Semi) automatic couplers .