Online Symmetric Magnetic Excitation Monitoring Sensor for Metal Wear Debris

Abstract

The metal wear debris in mechanical transmission can feedback the characteristics of mechanical equipment failure, and its online monitoring efficacy directly affects the operating performance of mechanical equipment. Specific to the need for online fault detection of the mechanical transmission system, a double-coil reverse excitation method is adopted to provide a magnetic field environment for metal wear debris testing in the lubricating oil circuit of the mechanical transmission system. Based on the magnetic field distribution model of a single-coil solenoids, a coupling magnetic field distribution model of reverse-symmetric double-coil magnetic excitation is established. On the basis of detecting the coils to obtain the signals of magnetic field disturbance when metal water debris passing through the magnetic excitation field, an online monitoring sensor for metal wear debris with a reverse-symmetric double-coil magnetic excitation balance magnetic field is developed. Taking the monitoring of metal wear debris in a large-aperture flow channel as an example, a semi-physical simulation test has been carried out on metal wear debris in different grain diameters and textures, whose experimental results indicate that this sensor can detect <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$100 ~\mu \text{m}$ </tex-math></inline-formula> ferromagnetic metal and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1000 ~\mu \text{m}$ </tex-math></inline-formula> non-ferromagnetic metal in an 8 mm flow channel, which, as a detection sensor for metal wear debris, can also be used for metal wear debris monitoring in the mechanical lubricants of mechanical transmission and engines.