高速水润滑轴承电动离心式空压机关键技术研究

发布时间：2018-03-05 21:01

本文选题：燃料电池汽车　切入点：空气压缩机　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：在当今能源与环境双重危机下,以氢为原料的燃料电池汽车以其能量转换效率高和环境友好等优点,受到国内外政府、企业和研究机构的格外关注。燃料电池汽车的研究涉及多个学科领域,其中空气压缩机为燃料电池提供必需的压缩空气,是其关键子系统之一。但国内尚未完全掌握燃料电池汽车用空压机的关键技术,相关研究也较少,严重制约了我国燃料电池汽车产业的发展。因此,本文对燃料电池汽车用空压机及其机械结构、轴承等关键技术进行了研究。提出了水润滑轴承支承、永磁同步电机驱动的离心式空压机方案,并对空压机结构设计中的关键技术进行了理论与实验研究。充分利用电机气隙较大的特点,设计密封套,解决了中置式电机的水密封难题;通过转子动力学设计,大幅提高了系统临界转速;通过降损设计,有效减小了转子搅水损耗。空压机最终达到了 100000rpm、10kW的设计目标,并实现了稳定运行。在紊流条件下对空压机中使用的水润滑径向轴承和止推轴承的静态特性进行了研究,分析了轴承间隙、腔宽和腔长等结构参数,以及供水压力、偏心和转速等工作参数的影响,为高速水润滑轴承的设计提供了参考。润滑膜稳定性是水轴承在高速空压机中应用的关键问题,通过对腔的旋转与固定、节流结构、腔数、腔形及其参数的理论与实验研究,提出了具有良好稳定性的孔式环面节流阿基米德螺旋线腔轴承结构。此外,还研究了大Sommerfeld数条件下紊流对轴承稳定性的影响。针对车载使用时可能遇到的冲击和振动载荷,建立了考虑粗糙接触、部分膜润滑和紊流全膜润滑的理论模型,对孔式环面节流阿基米德螺旋线腔轴承冲击和振动响应进行了分析。发现其具有较强的各向异性,腔深较大的上游区域是其抗冲击、振动能力最差的方向,频率为1000Hz的冲击和振动对轴承威胁最大。所设计的轴承发生轴与轴瓦摩擦接触的临界冲击为160G,振动幅值为100G,满足车载使用的要求。此外,还发现轴承的抗冲击、振动能力与稳定性相矛盾,抗冲击、振动能力的提高会降低其稳定性。
[Abstract]:Under the dual crisis of energy and environment, the fuel cell vehicle with hydrogen as the raw material, because of its high energy conversion efficiency and environmental friendliness, has been received by the domestic and foreign governments. Research on fuel cell vehicles involves a number of disciplines, including air compressors that provide the necessary compressed air for fuel cells, It is one of its key subsystems. However, the key technology of fuel cell automobile air compressor has not been fully grasped in our country, and the related research is relatively few, which seriously restricts the development of fuel cell automobile industry in our country. In this paper, the key technologies of air compressor and its mechanical structure, bearing and so on for fuel cell vehicle are studied, and the scheme of centrifugal air compressor driven by water lubricated bearing and permanent magnet synchronous motor (PMSM) is put forward. The key technologies in the structure design of air compressor are studied theoretically and experimentally. The seal sleeve is designed to solve the water seal problem of the middle motor by fully utilizing the large air gap of the motor. The critical speed of the system is greatly increased, and the rotor churning loss is effectively reduced by reducing the loss. The air compressor finally reaches the design goal of 100000rpmm10kW. The static characteristics of water lubricated radial bearing and thrust bearing used in air compressor are studied, and the structural parameters such as bearing clearance, cavity width and cavity length, as well as water supply pressure are analyzed. The influence of eccentricity and rotational speed provides a reference for the design of high speed water lubricated bearing. The stability of lubricating film is the key problem in the application of water bearing in high speed air compressor. Based on the theoretical and experimental study of cavity shape and its parameters, the structure of orifice annular throttled Archimedes helical cavity bearing with good stability is proposed. The influence of turbulence on bearing stability under the condition of large S ommerfeld number is also studied. A theoretical model considering rough contact, partial film lubrication and turbulent total film lubrication is established for the shock and vibration loads that may be encountered in vehicle use. The shock and vibration responses of orifice orifice throttled Archimedes helical cavity bearing are analyzed. It is found that the bearing has strong anisotropy and the upstream region with larger cavity depth is the direction of its shock resistance and worst vibration ability. The impact and vibration of the bearing with frequency of 1000Hz are the greatest threat to the bearing. The critical impact of friction contact between the bearing and the bearing bearing is 160 Gand the vibration amplitude is 100 G. it is found that the bearing is anti-shock, and the vibration amplitude is 100G. in addition, it is found that the bearing is anti-shock. The vibration ability is contradictory to the stability. The improvement of shock resistance and vibration ability will reduce its stability.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U469.7

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