大型球磨机静压轴承的承载能力分析及结构参数优化

发布时间：2019-06-10 18:05

【摘要】：球磨机作为传统的粉磨设备,广泛应用于矿业、建材、化工、冶金等工业领域。但近年来,伴随全球经济危机,能源需求提升、生产成本提高等因素,矿山工业面临着一系列新的技术问题,包括如何提高处理能力、降低生产费用。所以,高效大型矿山设备越来越受到现代企业的青睐,球磨机大型化日趋成为国内外研究的热点。液体静压轴承作为球磨机的关键支承部件,处于重载、低速恶劣环境下,其承载能力和可靠性直接影响球磨机的作业效率、能耗及生产能力。近些年,很多学者将静压轴承的油腔结构作为研究重点,用尽可能简单的节流器和合理的油腔进行搭配,获得良好的动静性能。国外对静压轴承油腔形状和油膜刚度进行了很多研究,国内也有研究者通过数值计算方法,对球磨机液体静压轴承的流场速度及压力分布进行计算,得到了油膜的承载能力,并以此确定出合适的油腔结构。基于此,本文概述了球磨机上常用轴承的种类、特点、发展及适用场合。阐述定量供油和定压供油方式下液体静压轴承的承载原理及各自优点。借鉴单腔平面油膜的承载能力和刚度的推导,分别针对毛细管节流式油膜、小孔节流式油膜以及定量供油式油膜的承载能力和油膜刚度进行推导。以北方重工设计制造的MQY5585球磨机为例,应用FLUENT研究探讨油腔形状、尺寸、位置与轴承承载能力、流量、油泵功耗的关系,并对应用在MQY5585球磨机上的静压轴承进行了优化设计。 (1)建立了不同封油面积下的矩形油腔静压轴承油膜模型、三角形油腔静压轴承油膜模型、圆形油腔静压轴承油膜模型,证明了矩形油腔静压轴承的优越性和实用性。 (2)在主轴摩擦功率一定的情况下,研究探讨了油腔周向位置对轴承承载能力的影响,得出当油腔偏离角为15°时,轴承承载能力最大。 (3)针对MQY5585球磨机现行静压轴承,研究探讨了油腔宽度和包角与轴承承载能力、油泵功耗以及油泵流量的关系,选取最佳油腔宽度和包角,提出了两个优化方案,在保证了承载能力与原轴承基本一致的情况下,大大降低了油泵功耗,节约了生产成本。 (4)分析了轴承封油面积对承载能力的影响,提出当封油面积与轴瓦面积比约为0.735时,轴承承载能力最大。 (5)分析了油腔比例系数对轴承承载能力的影响,提出当油腔宽度与轴瓦宽度比为约为0.57；单个油腔包角与半个轴瓦包角比为0.47时,轴承的承载能力最大。
[Abstract]:As a traditional grinding equipment, ball mill is widely used in mining, building materials, chemical industry, metallurgy and other industrial fields. However, in recent years, with the global economic crisis, energy demand, production costs and other factors, the mining industry is facing a series of new technical problems, including how to improve processing capacity and reduce production costs. Therefore, the efficient large-scale mining equipment is more and more favored by modern enterprises, and the large-scale ball mill has become the focus of research at home and abroad. As the key supporting component of ball mill, hydrostatic bearing is in heavy load and low speed harsh environment, its bearing capacity and reliability directly affect the working efficiency, energy consumption and production capacity of ball mill. In recent years, many scholars focus on the oil cavity structure of hydrostatic bearings, and use the simple throttle and reasonable oil cavity as far as possible to obtain good dynamic and static performance. The shape of hydrostatic bearing cavity and the stiffness of oil film have been studied abroad. Some domestic researchers have also calculated the flow field velocity and pressure distribution of hydrostatic bearing of ball mill by numerical calculation method, and obtained the bearing capacity of oil film. Based on this, the suitable oil cavity structure is determined. Based on this, this paper summarizes the types, characteristics, development and application of bearings commonly used in ball mills. The bearing principle and advantages of hydrostatic bearings under quantitative oil supply and constant pressure oil supply are described. Based on the derivation of bearing capacity and stiffness of single cavity plane oil film, the bearing capacity and oil film stiffness of capillary throttle oil film, small orifice throttle oil film and quantitative oil supply oil film are deduced respectively. Taking the MQY5585 ball mill designed and manufactured by Northern heavy Industry as an example, the relationship between the shape, size and position of oil cavity and bearing capacity, flow rate and power consumption of oil pump is studied by FLUENT, and the static pressure bearing applied to MQY5585 ball mill is optimized. The main results are as follows: (1) the oil film model of rectangular oil cavity hydrostatic bearing, triangular oil cavity hydrostatic bearing oil film model and circular oil cavity hydrostatic bearing oil film model under different oil sealing areas are established, which proves the superiority and practicability of rectangular oil cavity hydrostatic bearing. (2) under the condition of certain friction power of the main shaft, the influence of the circumferential position of the oil cavity on the bearing capacity is studied and discussed, and it is concluded that when the deviation angle of the oil cavity is 15 掳, the bearing capacity is the largest. (3) aiming at the current hydrostatic bearing of MQY5585 ball mill, the relationship between oil cavity width and inclusion angle and bearing capacity, oil pump power consumption and oil pump flow rate is studied and discussed. The optimum oil cavity width and inclusion angle are selected, and two optimization schemes are put forward. Under the condition that the bearing capacity is basically consistent with the original bearing, the power consumption of the oil pump is greatly reduced and the production cost is saved. (4) the influence of bearing oil sealing area on bearing capacity is analyzed, and it is pointed out that when the ratio of oil sealing area to bearing area is about 0.735, the bearing capacity is the largest. (5) the influence of oil cavity proportion coefficient on bearing capacity is analyzed, and it is pointed out that when the ratio of oil cavity width to bearing width is about 0.57 and the ratio of single oil cavity angle to half bearing angle is 0.47, the bearing capacity is the largest.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.36

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