High-speed trains must provide top comfort, even in Siberian winters. As market leader and globally active equipment manufacturer for high-speed trains, such as the ICE 3, ContiTech provides for excellent suspension comfort, even at -50°C. The elastomer specialist has developed an exceptionally cold-resistant secondary suspension system especially for these conditions.
Here, state-of-the-art testing technology comes into play: a tri-axial test rig with a climate chamber that can achieve temperatures between -50°C and +120°C. “With this test rig, we are the only ones in Europe who can simulate the suspension properties of a high-speed train, while traveling though Siberia in winter,” declared Hubertus Gawinski, head of R&D at ContiTech Air Spring Systems.
On the tri-axial test rig, all load conditions that an air spring can experience in reality can be tested. In just a few weeks, an entire life cycle can be simulated and the performance of a component tested under realistic conditions. “With separately controllable hydraulic cylinders, actual driving conditions are simulated, right down to the smallest detail,” says Gawinski, describing the working principle. At the same time, lateral forces of up to 5t that the air springs are subjected to can be realized. “Loads of this kind arise, for example, when a high-speed train roars down a straight stretch of track at a speed over 250km/h.”
For the simulated application in the cold regions of Eastern Europe and Northern Asia, the secondary suspension system was also cooled down to an ambient temperature of -50°C in a climate chamber and then subjected to the realistic loads while in operation. The special challenge here was to maintain cooling while the multiple axles are in operation. Since the hydraulic cylinders cannot be positioned inside the cooling chamber for reasons of function and energy technology, the power is transmitted to the test specimen by means of an ingenious rod. Flexible insulating elements between the rod and the immobile parts of the test rig ensure sufficient heat insulation.
“Here we took advantage of the performance spectrum of our products, using the unrestricted diaphragm air springs, which are usually used for the secondary suspension systems in rail vehicles, as insulating elements,” says Gawinski, describing the solution.