Research on Non-Uniform Contact Bearing Characteristics of Conical Deformed Friction Pairs in Hydro-Viscous Drive

The hydro-viscous drive can ideally realize the soft start and overload protection of the heavy scraper conveyor, effectively reduce the occurrence of belt breaking and chain breaking accidents, and thus greatly improve the safety and service life of mining equipment. However, the transient thermal accumulation of the wet friction pair in the soft start-up process can easily cause conical buckling deformation of the steel sheet, which aggravates the uneven contact of the friction pair and seriously affects the normal operation of the equipment. Therefore, by establishing the equivalent contact model of conical deformation friction pair and using the combination of finite element simulation and MATLAB numerical solution, the variation law of oil film thickness is obtained. The variation law of oil film pressure and micro-convex peak contact pressure is found out based on Reynolds equation and Greenwood-Tripp contact model, and the bearing characteristics of friction pair in non-uniform contact state are analyzed. The results show that the macroscopic oil film thickness reaches the limit in the middle diameter region at the beginning of the soft start, and then extends to both sides of the inner and outer diameter until the dual steel sheet is completely flattened, the peak oil film pressure is concentrated in the middle diameter region, the maximum value is 2.65MPa, and the radial oil film pressure is distributed in a lower open parabola. At the beginning of soft start, the contact pressure of micro-convex peak reached the peak value of 7.25 MPa in the middle diameter region for 3 seconds, and then slightly decreased-increased-decreased rapidly from the middle diameter region to both sides of the inner and outer diameter. The research results provide theoretical basis and technical support for identifying and restraining the buckling deformation of the friction pair of hydro-viscous drive and improving the safety, reliability and service life of mechanical equipment.