熔体齿轮泵流量特性的理论分析

普通齿轮泵流量品质差,径向力大,不宜在熔体挤出对流量品质要求高的场合中应用,提出了一种适用熔体挤出的齿轮泵。应用数学分析和举例进行MTLAB软件模拟的方法,理论分析了熔体齿轮泵在4种不同齿数特征条件下的啮合位移,叠加运动规律和相应条件下流量均匀性;利用MATLAB软件模拟4种齿数条件下,流量脉动系数相应的变化规律。结果表明:当主动轮齿数Z1=4k时,其流量脉动系数及流量脉动频率与普通外啮合齿轮泵相同;当主动轮齿数Z1=4k+1和Z1=4k+3时,其流量特性基本相同,并且其流量脉动系数较普通外啮合泵有明显提高,流量脉动频率大约是普通外啮合齿轮泵的8倍;当主动轮齿数Z1=4k+2时,其流量脉动系数较普通外啮合泵有明显提高,流量脉动频率大约是普通外啮合齿轮泵的2倍。

Theoretical Analysis on Flow Characteristics of Melt Gear Pump

Due to these problems such as poor flow quality,large radial force,which makes applications of requiring high quality flow characteristics unsuitable such as melt extrusion. A new type of melt gear pump,four idler wheel melt gear pump,was designed. To analysis the flow characteristics. The strict mathematic analysis and the simulation by MTALBA software were conducted. The law of the meshing moment and the stack movement were deeply studied,and the corresponding uniformity of the flow in melt gear pump of four different gear numbers through mathematic deduction was analyzed. The corresponding regulations of four gear numbers about coefficient of flow rate pulsation were simulated with MATLAB software. The result shows: if the number of the gear is 4k( Z1= 4k),its coefficient and frequency of flow rate pulsation are similar with general external gear pump; when the number of the gear is 4k + 1 or 4k + 3,their flow characteristics are very closed,and their coefficient of flow rate pulsation achieve obviously improved,and their frequency is 8 times than the general external gear pump's; when the number of the gear is 4k + 2,its coefficient of flow rate pulsation achieve obviously improved,and their frequency is 4 times than the general external gear pump's.