Search

This paper presents the results of tests on the railway disc brake with regard to the weight wear of friction pads. The tests were carried out at a certified brake test bench where the friction-mechanical characteristics of the railway brake were determined. The test stand was additionally equipped with a thermal imaging camera to observe the contact between the brake pads and the brake disc. The scientific goal of the test is to evaluate the relationship between the weight wear of friction pads and the quantities characterizing the braking process. The quantities characterizing the braking process included pad-to-disc contact area, friction pad thickness, pad-to-disc pressure, and braking speed. A regression model to estimate the friction pad wear on the basis of a single braking with the given input quantities was determined. The greatest influence on the increase in weight wear of friction pads has the braking velocity, which was confirmed by the value of the correlation coefficient of the regression model at value 0.81. The pressure of the friction pad to the disc and the friction pad thickness do not have a significant effect on the weight wear described by the regression model, and the obtained correlation coefficient for these parameters was lower than the value of 0.2. [ABSTRACT FROM AUTHOR]

The article presents an overview of the construction of automatic couplers and their digital version of the DAC for freight wagons. In the article, particular attention was paid to the process related to the development and popularization of the design of automatic digital couplers in the European Union countries. Poland, the automatic coupler train was presented in July 2022 and tested under various conditions. This is related to the current trend of improving rail safety and accelerating the procedure of forming trains, and, consequently, sending a freight train on its way. Automatic digital couplers will allow, in addition to mechanical connection, also pneumatic and electrical connection without the participation of an employee for coupling and uncoupling carriages. [ABSTRACT FROM AUTHOR]

Increasing the speed of trains forces the application of a greater braking power, i.e. the capability of the brake system of rapidly absorbing and dispersing the stored heat energy. The instability of operation results from the occurrence of vibrations on the friction component, which affects the efficiency of the braking process. In practice, it means that when braking, the vehicle variable friction resistance may lead to an uneven braking process. The effects of such changes can be manifested in the form of vibrations with high input amplitude. The vibrations generated by the working components are distributed throughout the vehicle, which also adversely affects the driving comfort. The purpose of this paper is to determine the resonant frequencies of selected components of the railway disc brake. This paper presents a method of assessing the thickness of the brake pads of a railway disc brake based on the results of parameterization of the time-frequency map a( t, f) of vibrations generated by the brake components. Methods of time-frequency analysis were suggested as a tool of time-frequency selection of the vibration signal. The authors described an algorithm of the method and presented an example illustrating the application of the synchronously averaged short-time Fourier transform for the extraction of the signal components related to the braking process. As a result of parameterization of the map a( t, f) signal parameters, values covariant with the thickness of the disc brake were obtained. [ABSTRACT FROM AUTHOR]