耐腐蚀超洁净涡旋真空泵用屏蔽电动机设计研究

发布时间：2018-09-11 06:37

【摘要】：目前,涡旋真空屏蔽泵在国内比较少见,常见的传统结构涡旋真空泵泵头与电机以轴承机械密封,漏率较高。当涡旋真空泵用于传输有毒有害介质式时,容易污染工作环境。首先,本课题从4L涡旋真空泵用屏蔽电机的设计出发,总结了屏蔽电机的设计特点,对屏蔽套涡流损耗的计算方法进行了推导。归纳了一种以Ansoft软件辅助设计为基础的屏蔽电机电磁设计流程。分别针对采用导磁材料Sus430屏蔽套和不导磁材料Sus321屏蔽套设计了两套电磁方案,并进行有限元仿真。分析了分别采用两种屏蔽套材料,在电机电磁设计上需要注意的异同点,以及屏蔽套材料对电机工作性能的影响。其次,利用Solidworks和Ansys Workbench分别对两套电磁方案进行建模和温度场分析,温度场分析过程中认为气隙近似绝对真空,考虑屏蔽套内表面与转子外表面的热辐射作用。仿真得到电机各部件的温度分布图。两套方案套绕组温度都略高于设计要求,Sus430屏蔽套方案较Sus321屏蔽套方案整体温度较小。对机壳采取强制对流措施后,电机各部分温度满足设计要求。然后将稳态温度场的计算结果进行应力场耦合计算,得到两种方案中屏蔽套的热形变和热应力分布特性。综合以上分析结果,可知两套设计方案均能达到设计要求,Sus430屏蔽套方案在电枢电流、起动转矩、最大转矩、效率、功率因数和温升方面表现较好。最后,建立了一个屏蔽电机的简化模型,分析气隙中热辐射和稀薄气体热传导两种热量传递作用随气隙真空度变化的规律。对简化模型分析可知,随着气隙真空度由接近绝对真空到一个标准大气压变化的过程中,一开始热辐射起主要作用,随着压强变大,空气热导率增加,由空气热传导引起的热流密度逐渐增加,由热辐射引起的热流密度逐渐减小。总热流密度的变化呈上升趋势,屏蔽套内表面与转子铁心外表面之间的温度差减小。对于真空屏蔽电机的温度场分析,当把屏蔽套内表面作为绝热面,计算得到的屏蔽套内表面和转子铁心外表面温度相差较大时,需要考虑气隙中的热量传递作用。
[Abstract]:At present, vortex vacuum shielding pump is rare in China. The traditional structure of vortex vacuum pump head and motor with bearing mechanical seal, leakage rate is higher. When the vortex vacuum pump is used to transfer toxic and harmful medium, it is easy to pollute the working environment. Firstly, based on the design of the shielded motor for 4L vortex vacuum pump, the design characteristics of the shield motor are summarized, and the calculation method of the eddy current loss of the shield sleeve is deduced. An electromagnetic design flow of shielded motor based on Ansoft software aided design is summarized. Two sets of electromagnetic schemes are designed for magnetic conduction material Sus430 shield sleeve and unmagnetic material Sus321 shield sleeve respectively, and the finite element simulation is carried out. In this paper, the similarities and differences of two kinds of shielding sleeve materials in the electromagnetic design of the motor are analyzed respectively, and the influence of the shielding sleeve materials on the working performance of the motor is also analyzed. Secondly, Solidworks and Ansys Workbench are used to model and analyze the temperature field of the two sets of electromagnetic schemes respectively. In the process of temperature field analysis, the air gap is considered as an absolute vacuum, and the thermal radiation between the inner surface of the shield sleeve and the outer surface of the rotor is considered. The temperature distribution of each part of the motor is obtained by simulation. The winding temperature of the two sets of schemes is slightly higher than that of the design requirements. The overall temperature of the two schemes is lower than that of the Sus321 shielding sleeve scheme. After the forced convection measures are taken on the housing, the temperature of each part of the motor meets the design requirements. Then the calculation results of steady temperature field are coupled with the stress field to obtain the thermal deformation and thermal stress distribution characteristics of the shielding sleeve in the two schemes. Combined with the above analysis results, it can be seen that both sets of design schemes can meet the design requirements. The two sets of design schemes show good performance in armature current, starting torque, maximum torque, efficiency, power factor and temperature rise. Finally, a simplified model of shielded motor is established to analyze the variation of heat transfer between air gap and rarefied gas with air gap vacuum. The analysis of the simplified model shows that with the change of air gap vacuum from an absolute vacuum to a standard atmospheric pressure, the thermal radiation plays a major role at the beginning, and with the increase of the pressure, the thermal conductivity of the air increases. The heat flux caused by air heat conduction increases gradually, and the heat flux caused by heat radiation decreases gradually. The change of total heat flux shows an upward trend, and the temperature difference between the inner surface of the shield sleeve and the outer surface of the rotor iron core decreases. For the analysis of the temperature field of vacuum shielded motor, when the inner surface of the shield sleeve is taken as the adiabatic surface and the temperature difference between the inner surface of the shield sleeve and the outer surface of the rotor iron core is large, the heat transfer in the air gap should be considered.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB752;TM32

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