Structural Parameter Optimization And Bearing Capacity Analysis On Hydrostatic Journal Bearing Of Large-scale Ball Mill

Ball mill, which works as a traditional powder machine, has been widely used in the area of mining, building material, chemical and metallurgies industry etc. But there are several problems in the production of mines following the global financial crisis, boosting energy demands and pushing up the cost recent years, the problems include that how to improve concurrent processing capability and lower production costs. So, the large efficient mining equipments are attracting more and more attention, and study on the large-scale ball mill is increasingly becoming the focus of domestic and overseas scholars.Hydrostatic bearing works as the supporting part of ball mill under the low speed and heavy load condition, which load-bearing capability directly affects the production efficiency, energy consumption and production capacity. Some experts focus on the pocket structure parameter of hydrostatic bearings resent years. They combine very simply throttle and suitable pocket for obtaining good comprehensive hydrodynamic and hydrostatic characteristics. A lot of research on the pocket structure and the stiffness of oil film has been done abroad. At the same time our domestic scholars have compute the field of velocity and pressure of hydrostatic bearings with numerical calculation method and obtained the carrying capacity of oil film, determined suitable pocket.For this reason, some common hydrostatic bearings used on ball mill are summarized in the paper, including category, peculiarity, development and application scopes.The work principles of constant pressure delivery oil and the constant flow delivery oil hydrostatic bearing are also expounded. The author has deduced the load-bearing capability and stiffness of oil film for capillary-compensated hydrostatic bearing, orifice-compensated hydrostatic bearing and constant flow delivery oil hydrostatic bearing, based on the derivation process of the load-bearing capability and stiffness of planar oil film. The author use MQY5585ball mill, made by Northern Heavy Industries Group Co.Ltd as an example to explore the relation between pocket structure, parameter, circumference position and load-bearing capability, flow, power consumption of hydrostatic bearing, then propose optimized design for hydrostatic bearing of MQY5585ball mill.(1) The rectangular pocket hydrostatic bearing model, triangular pocket hydrostatic bearing model and round pocket hydrostatic bearing model with different sealing area are built to analyze the effect of oil film. All the models prove the advantages of the rectangular pocket hydrostatic bearing.(2) The author discusses the circumference positions how to influence the load-bearing capability of bearing at a constant Friction power, Then draw conclusions that the hydrostatic bearing reach the maximum load-bearing capacity when attitude angle of bearing is15degrees.(3) The author discusses wrap angle of pocket and width of pocket discusses how to influence the load-bearing capability of bearing, flow and power consumption of pump, then choose optimal available wrap angle of pocket and width of pocket, and propose two optimization plans. The optimization plans significantly lowers flow and power consumption of pump, based on the premise that load-bearing capacity of oil film remain about the same.(4) The author discusses the sealing area how to influence the load-bearing capability of bearing, t-hen draw conclusions that the hydrostatic bearing could reach the maximum load-bearing capacity when the ratio of the sealing area to the bush area is0.735.(5) The author discusses the proportionality of pocket how to influence the load-bearing capability of bearing, t hen draw conclusions that the hydrostatic bearing could reach the maximum load-bearing capacity when the ratio of width of pocket to width of bearing bush is0.57, and the ratio of wrap angle of pocket to wrap angle of half bearing bush.