异型腔旋叶式计量泵的优化分析与设计

发布时间：2018-01-04 04:40

本文关键词：异型腔旋叶式计量泵的优化分析与设计　出处：《浙江大学》2011年硕士论文　论文类型：学位论文

【摘要】：在已有异型腔旋叶式计量泵的基础上进行优化分析,并生产优化分析后的样机,进行实验测定计量精度、容积效率。首先,参考已有的高次过渡曲线的性能和特点,通过分析过渡曲线的径向速度、加速度和加速度率所导致的振动冲击,推导出了一条简单、易于加工的五次与正弦函数组合过渡曲线。计算机仿真与分析结果表明：五次方组合过渡曲线的速度、加速度和加速度率在过渡点处满足了理论理想无冲击过渡渐变,并且五次方组合过渡曲线的加速度率曲线比八次方加速度率曲线平缓,激荡频率也相对较小,加速度率的最大值也比七次和八次方过渡曲线相对较小。在此基础上,分析了叶片顶端形状对叶片摩擦磨损的影响及对流量脉动的影响,并获得了叶片顶端圆弧曲率半径的最大值,同时也计算了阻尼孔的大小。其次,列出了叶片的静态和动态受力方程。为了提高异型腔旋叶式计量泵计量精度的稳定性、减少动力损耗、控制叶片的振动,摩擦、磨损及侧向力,以叶片与一种五次方组合过渡曲线定子内腔构成的运动副为研究对象,分析了异型腔旋叶式计量泵的叶片压力角特性。根据该运动副的几何结构和叶片受力、运动的特点,分别求出了每一模型的压力角与叶片转角、叶片厚度以及叶片顶端几何参数之间的函数关系,同时描述了圆弧顶叶片顶端接触点的变化规律。分析与计算结果表明：随着叶片转角的变化,压力角幅值先增大再减小；在圆弧顶端叶片形状下,压力角的变化与叶片厚度无关,并且随着叶片顶弧面曲率半径的增大而增大；在平顶顶端叶片形状下,压力角幅值随着叶片厚度的增加而增大。并且利用ANSYS对叶片的振动模态和可靠性进行了计算机仿真分析,得到了叶片振动模态值和可靠性影响因素。再次,列出了具体的间隙密封流量表达式,得到了特定条件下间隙引起的密封漏流量。并且通过建立流量数学方程对叶片厚度,叶片顶端形状,叶片运动稳定性,导流槽形状对出流口流体回流可能引起的流量脉动进行了分析计算,获得了这些参数与流量的关系曲线。分析与计算结果表明：叶片顶端形状对瞬时流量几乎没有影响；随着叶片厚度的增大,流量脉动也随之增大；叶片的振荡频率越大流量的脉动性也越大；随着出流口导流槽宽度的增大,回流流量对流量产生的脉动也随之增加。最后,在机械结构优化分析的基础上,生产了计量泵样机,设计了实验标定方案,对样机进行计量精度、容积效率等相关性能参数的测定。
[Abstract]:On the basis of the existing special-shaped cavity rotary vane metering pump, the optimization analysis is carried out, and the prototype after optimized analysis is produced, and the measurement accuracy and volumetric efficiency are measured experimentally. Firstly, referring to the performance and characteristics of the existing high-order transition curve, a simple method is derived by analyzing the vibration shock caused by the radial velocity, acceleration and acceleration rate of the transition curve. The results of computer simulation and analysis show the speed of the quintic combined transition curve. The acceleration and acceleration rate meet the theoretical ideal transition gradient at the transition point, and the acceleration rate curve of the quintic combined transition curve is slower than that of the eighth power acceleration rate curve, and the shock frequency is relatively small. The maximum acceleration rate is also smaller than that of the seventh and eighth power transition curves. On this basis, the effects of blade tip shape on blade friction and wear and flow pulsation are analyzed. The maximum radius of curvature of the arc at the tip of the blade is obtained, and the size of the damping hole is also calculated. Secondly, the static and dynamic force equations of the blade are listed. In order to improve the stability of measurement accuracy, reduce the power loss, control the blade vibration, friction, wear and lateral force. The characteristics of blade pressure angle of a special cavity rotary vane metering pump are analyzed based on the geometry structure of the rotor and the force on the blade. The characteristics of the motion, the relationship between the pressure angle of each model and the blade rotation angle, blade thickness and the geometric parameters of the blade tip are obtained respectively. The analysis and calculation results show that the pressure angle amplitude increases first and then decreases with the change of blade rotation angle. Under the shape of the blade at the top of the arc, the change of the pressure angle is independent of the blade thickness, and increases with the increase of the curvature radius of the top arc of the blade. Under the shape of flat-top blade, the amplitude of pressure angle increases with the increase of blade thickness, and the vibration mode and reliability of the blade are simulated and analyzed by ANSYS. The vibration modal values and reliability factors are obtained. Thirdly, the specific expression of clearance seal flow rate is listed, and the sealing leakage flow caused by clearance under certain conditions is obtained, and the blade thickness and blade tip shape are obtained by establishing the flow mathematical equation. The stability of blade movement and the shape of the guideway are analyzed and calculated for the flow pulsation caused by the reflux of the outlet fluid. The relationship curves between these parameters and the flow rate are obtained. The results of analysis and calculation show that the tip shape of the blade has little effect on the instantaneous flow rate. With the increase of blade thickness, the flow pulsation also increases. The greater the oscillation frequency of the blade, the greater the pulsation of the flow rate. With the increase of the width of the outlet channel, the pulsation of the flow rate is increased. Finally, based on the optimization analysis of mechanical structure, the prototype of metering pump is produced, the experimental calibration scheme is designed, and the measurement accuracy, volumetric efficiency and other related performance parameters of the prototype are measured.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH38

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