Design Of Diagnosis And Measurement System Of Wheel-sets

With the large-scale construction of domestic high-speed rail ,and the continuous improvement of train speed, the security problems are gaining increasingly extensive attention. The wheel-sets unit, as important components of the wheel train, supports the full static and dynamic loads from rolling stock. The wear, scratches, peeling, cracks and other defects present to the wheel tread surface and near surface are the major factors endangering traffic safety. Thus, it must be timely an effectively to detect the state of the train wheel, find out the defections in time, and repair it or replace the gauge wheel, to prevent the train accidents. The traditional way of regular maintenance cannot meet the demand of vehicle maintenance because of it's low efficiency and difficult to check out the mini-cracks and internal defections in the wheel tread. So, it's urgent to develop the dynamic testing methods, techniques and equipments to achieve on-line and real-time detection on the tread defects and geometric parameters of the wheel-sets. while the train is running.Firstly, the paper researched the wheel tread failure types, causes and hazards of the rail vehicle. Secondly, according to the comprehensive analysis and summary on the current research situation of the non-destructive testing technology of the wheels based on wide range of detection techniques on the wheels, the paper proposed a general planning of "dynamic diagnosis and measurement system on wheels", and conceived the organizational structure and detection process of the "system". Thirdly, this paper has an emphasis on "wheel detection and testing module" consisted in "system". It explained the measurement principle and error analysis of the geometric dimensions of wheel, including flange thickness, flange width, wheel diameter, flange wear, tread wear, rim width, distance between backs of wheel rims, based on light section image measurement combined with laser displacement sensor in detail. The detection principle of rail vehicle wheel tread defects based on electromagnetic ultrasonic testing technology is also introduced. The paper designed a non-destruct testing device with electromagnetic acoustic surface wave. Designing of the equipment includes the system scheme and the electromagnetic acoustic transducer(EMAT).