【作者】 张宁；

【导师】 高玉周； 张常青；

【作者基本信息】 大连海事大学 ， 交通运输工程（专业学位）， 2017， 硕士

【摘要】 大型造粒机在塑料行业应用较为广泛,其中最主要的组成部位是熔体齿轮泵,齿轮泵可适用于高温高粘度聚合物熔体的输送、增压、计量,使其不受压力和温度等条件变化的影响。本课题所研究的熔体齿轮泵在实际应用过程当中,由于物料成分不均匀,改变了齿轮之间的剪切应力和挤压应力,导致齿轮泵电机转矩迅速升高,齿轮在其使用寿命内产生磨损和裂纹等问题。本课题的主要研究对象是CME-450造粒机的齿轮泵,齿轮泵在工作当中发生电机转矩迅速升高的现象。停工后将齿轮泵拆解,发现物料严重污染,在经过探伤试验后发现齿轮在不同部位产生裂纹并且齿轮端面严重磨损。本试验采用显微硬度仪、光学显微镜(OM)、扫描电子显微镜等对齿轮进行显微结构和成分分析,确定物料污染和齿轮泵出现裂纹的原因;并运用ANSYS软件模拟分析齿轮泵在生产过程中的受力情况,与试验结果互相印证,得到结论如下:1、研究结果表明:齿轮轴部位没有发现贯穿性裂纹,所以物料的污染并非冷媒泄露污染。2、齿顶、齿面、齿端面,均出现磨损现象,齿轮部位存在温度场使得靠近齿根部位的组织发生改变。3、通过有限元模拟分析,齿轮转子的抗弯刚度不足,或相关部位间隙设置不合理,造成设备在运行过程中出现了超出设计标准的摩擦磨损和摩擦发热量,导致物料高温裂解,形成污染物料,此过程恶性循环。4、建议:在使用齿轮泵加工物料之前应分析物料的流动性是否与齿轮泵的剪切应力相匹配,流动性较差的高聚物(HDPE-1158)不适合此种加工方式。更多还原

【Abstract】 Melt gear pump is an important component of the large extrusion pelleting machine,suitable for high temperature and high viscosity of the polymer melt conveying,pressurization,metering,make its not affected by pressure and temperature conditions change.Pump with pressure between extrusion machine and mold,and can match the parameters of the extrusion machine,the output increase and tolerance requirements strictly to provide uniform melt.Due to the different material composition will change gear,the shear stress between the rapid rise in gear pump motor torque,gear wear and cracks within its service life,etc.The main research object of this experiment is Dalian granulating CME-450 plastic machinery factory production of gear pump,gear pump in the work of motor torque rise rapidly.After testing experiment found that gear crack and in different parts of the gear face serious wear and tear.This experiment combined with microhardness tester,optical microscope(OM),scanning electron microscope(SEM)analysis of materials such as pollution and the cause of the crack of gear pump;And use Ansys software simulation analysis on the stress distribution,the gear pump with the experimental results to confirm each other,come to a conclusion as follows:1.According to the results,it showed that gear axle parts found no perfoliate crack so material pollution is not a refrigerant leakage pollution.2.The grinding phenomenon occurs at the top of tooth,the tooth surface and the root and the temperature exists in it,so that the tissue near the tooth root changes.3.Through the finite element simulation and analysis of the gear rotor bending stiffness is insufficient,cause equipment appeared in the process of running from the friction wear and friction calorific value of design standards,resulting in material high temperature cracking formation pollution materials,form a vicious circle.4.In the use of gear pump and processing material should be analyzed before the material liquidity is match the shear stress of the gear pump,less liquid polymer(HDPE-1158)is not suitable for this kind of processing methods.更多还原