Adaptive Thin Film Temperature Sensor for Bearing's Rolling Elements Temperature Measurement

Area of Science:

• Materials Science
• Mechanical Engineering
• Sensor Technology

Background:

• Increasing train speeds necessitate early detection of bearing issues to prevent catastrophic failures.
• Bearings experience rapid temperature fluctuations during operation, posing a challenge for traditional monitoring methods.

Purpose of the Study:

• To develop and evaluate a thin film thermocouple temperature sensor for real-time measurement of train bearing rolling element temperatures.
• To assess the sensor's performance characteristics, including linearity, Seebeck coefficient, fitting error, repeatability, and dynamic response time.

Main Methods:

• Utilized DC pulse magnetron sputtering to deposit Al2O3, NiCr, NiSi, and SiO2 films on an aluminum alloy substrate.
• Investigated the microstructure, static and dynamic characteristics, and repeatability of the deposited thin films.
• Integrated the adaptive film temperature sensor onto a bearing testing machine for rolling element temperature measurement.

Main Results:

• The developed sensor exhibits excellent linearity between 30-180 °C with a Seebeck coefficient of 40.69 μV/°C.
• Achieved a nonlinear fitting error below 0.29% and a maximum repeatability error of 4.55%.
• Demonstrated a rapid dynamic response time of 1.42 μs and measured rolling element temperatures 6-10 °C higher than the outer ring.

Conclusions:

• The thin film thermocouple temperature sensor is effective for real-time monitoring of bearing rolling element temperatures.
• The sensor's performance metrics indicate its suitability for detecting critical temperature variations in high-speed train bearings.
• This technology can provide crucial data for predictive maintenance and enhance the safety of railway operations.