Tuned absorbers for rails

Abstract

A tuned absorber (5A, 5B) for attachment to a railway rail (1) comprises a body (6) formed of elastomeric material and of at least one region of a first material, denser than the elastomeric material, located within the elastomeric material and forming an active mass (7m1, 7m2, 7m3). A member (8) of a second material denser than the elastomeric material is also located within the elastomeric material, adjacent to the active mass (7m1, 7m2, 7m3), for coupling to the rail (1) so as to provide a resonant surface against which the active mass (7m1, 7m2, 7m3) can vibrate. Alternatively, or in addition, a tuned absorber (5A, 5B) has a first active mass (7m1) and at least one further active mass (7m2, 7m3) arranged so as to be effectively coupled for vibration in a first frequency range and such that the or each further active mass (7m2, 7m3) is decoupled from the first active mass (7m1) for vibration in a second frequency range higher than the first. Alternatively, or in addition, attachment means for applying a securing force to maintain a tuned absorber (5A, 5B) in position on the rail web (1c) comprise a spring steel strap (40) having an overcentre device which locates on the rail foot (1b) and is operable, when snapped into a closed position, to apply a compressive force to the tuned absorber (5A, 5B).

Description

technical field [0001] The invention relates to a rail tuned damper and a device equipped with such a tuned damper. Background technique [0002] When a train passes by, the rails and supporting structures will vibrate, and the most influential vibration frequency ranges from about 50Hz to 5kHz. As a result of these vibrations, the trains, rails and supporting structures generate noise. The dynamic contact pressure between rough train wheels and rails is the main source of vibrations that generate noise, so one way to control rail noise is to reduce the roughness of the rails and wheels, for example by grinding the rails or using energy Materials that slow down rail roughening, however, these measures can be expensive. The biggest contributors to the overall so-called "rolling noise" of a train are the rails and train wheels. [0003] In terms of mechanical properties, the dynamic forces transmitted to the sleepers, the degree of vertical settlement of the track and the c...

AI Technical Summary

Problems solved by technology

[0005] If the direct damping of track components does not contribute significantly to the improvement of the overall noise level, then the ensuing problem is that the performance of these components will deteriorate dramatically due to the energy absorbed by the damping

[0009] Using a tuned damper of the type disclosed in WO 99 / 15732, namely having two resonant frequencies and a relatively high damping attenuation factor, can A noise attenuation of about 6dB is obtained, but the fabrication of the prior art dampers requires the continuous layer to be glued to the rail before the rail is laid on the track

Other existing designs, such as using a threaded system or screws to secure the shock absorber to the rail base, are also very difficult to attach to existing rails

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