Turbodrills play an important role in underground energy mining. The downhole rotational speed of turbodrills is one of the key parameters for controlling the drilling technology. Therefore, it is necessary to measure the rotational speed of the turbodrills in real time. However, there is no dedicated speed sensor for the working environment of turbodrills at present. Therefore, based on the working principle of triboelectric nanogenerator (TENG), a self-powered speed sensor which can measure the speed of the turbodrills is proposed in this study. Besides, since the sensor is self-powered, it can operate without power supply. According to the laboratory test results, the measurement error of the sensor is less than 5%. In addition, the self-powered performance of the sensor was also explored in this study. The test shows that the maximum generating voltage of the sensor is about 27 V, the maximum current is about 7 μA, the maximum power is about 2 × 10-4 W, and the generated electricity can supply power for ten LED (light-emitting diode), which not only meets the power supply requirements of the sensor itself, but also makes it possible to further power other underground instruments.
Keywords: self-powered; speed sensor; triboelectric nanogenerator (TENG); turbodrills.