Dynamic Pressure Of The Oil Film Bearing In Rolling Mill Cavitation Phenomenon Research

With the development of the modern rolling mill, high-performance oilfilm bearing is becoming more and more important, and the operatingcharacteristics of the film determines the performance and life of the oil filmbearing in certain extent, which includes the issues of bearing capacity of the oilfilm, the minimum thickness, temperature rise, cavitation, oscillation and so on,cavitation and oscillation have a crucial impact on the stability of the oil film.In the basis of previous research, this paper researches on the causes ofhydrodynamic oil film bearing cavitation and factors of affecting cavitationprocess in the oil film. And use rolling mill oil film test platform to collect dataand analysis the temperature, bearing area pressure and the inlet pressure.The main research contents and conclusions are as follows:1. Based on research of flow field with cavitation, uses domain blockstructured grid in calculation domain to solve the problem of poor quality of theboundary layer mesh. Then, a gas-liquid mixture numerical simulation methodis established to solve phase transition in the film cavitation process by FiniteVolume Method.2. Based on the study of fluid high-speed rotary characteristics in the oilfilm pressure field, uses the SMIPLE algorithm to tackle the problem ofcoupling of pressure and speed, gets the full oil film pressure field, andexperimental verification for bearing pressure value.3. Uses the numerical simulation method established in this paper, couplingwith the oil film pressure field, successful to simulate the process of cavitationin the oil film, and studies the distribution of cavity in cavitation area. Study hasfound: oil film cavitation area main body is composed of cavity which volumefraction is larger than0.2, and the number of cavity while the volume fraction isless than0.2more than60%, but total volume is less than2%, and mainlydistributed near the edge of the cavitation and the oil outlet.4. According to different working condition, this paper study the Differentinfluence factors of cavitation process, including, viscosity and surface tension of oil, inlet pressure and speed of bearing. The study found that，intensity ofcavitation increase with the increase of the viscosity of the lubricating oil, andviscosity determine the position of cavitation nascent by influencing on theseparation of boundary layer; Although the cavitation area has small growthwith the increase of surface tension, but the maximum diameter of the cavitycan reach smaller; inlet pressure no significant effect on the cavitation process;Rotation speed of bearing directly determine the size, shape, position ofcavitation zone by influencing on oil film pressure. The changes of speed islarger, the migration phenomenon is more obvious.