Development Of Thin Film Sensor For Transient Temperature Test Of High-speed EMU Axle Box Bearing

With the rapid development of technology and modern industry, and people’s increasing requirements for the quality of material life, Vigorously developing the high-speed train has been identified as an important work of government. As increasing speed and load of train vehicle, it is necessary to propose higher demands for train safety technologies, and detecting the train axle temperature is an imptortant job among them. When a train is running, the frequent shocks caused by locomotive and rail lead bearings heat. If the bearings wear and defects, abnormal heat will happen and increase, which will influence train’s regular running, and the worst case, will affect seriously rail tansport safety and lead to huge loss of lives and properties.This paper designed a coaxial needle thin film temperature sensor, to achieve real-time monitoring the transient temperature of the axle box bearings.This paper summarizes the theory of thermal analysis of tapered roller bearings based on movement of axle box bearings. Based on the theory, researching the steady-state temperature field ditribution of axle box bearing TAROL unit in simulation and computing aspects with ANSYS finite element software thermal analysis method and thermal network method. Using hot assembly method to make the NiCr/NiSi coaxial component, and sputtering NiCr/NiSi thin films in the end face of NiCr/NiSi coaxial component with the technology of DC pulse magnetron sputtering to develop the coaxial needle thin film temperature sensor successfully. Studying the static and dynamic performances of the coaxial needle thin film temperature sensor with the self-developed static and dynamic calibration systems, getting its Seebeck coefficient and dynamic response time.From result of the ANSYS finite element software thermal analysis, it is obtained that the temperature in bearing exhibits a characteristic of "above low-below high ". With thermal network method it is got the highest temperature happens in the contact point between the bottom roller and bearing inner ring, and the lowest temperature happens in axle-box. Researches done on thin films show that they are continuous and dense and have good conductive property. Static and dynamic performance tests display the Seebeck coefficient and dynamic response time of the coaxial needle thin film temperature sensor are41.5μV/℃and0.016ms respectively.