齿轮泵无困油摆线齿廓的逆向设计与低脉动措施

为解决齿轮泵困油现象和流量脉动大的结构性问题,基于摆线齿轮的传动优势和圆摆线的成形原理,以最能体现齿轮泵性能的齿数和滚圆半径系数为构造参数,以齿顶圆心角、齿顶半径系数和齿顶压力角为功能参数,逆向构建出重合度为1的摆线齿廓,并通过双齿轮副构造和脉动系数最小化的两大措施,解决了原有单一齿轮副流量脉动大的结构性问题。结果表明,摆线齿廓逆向设计方法简单、结果精准,能被一般工程技术人员直接采用;单一齿轮副的重合度为1,可确保齿轮泵的无困油现象;双齿轮副轴向π/齿数的错位装配易于实现,轴向综合重合度为2,可确保摆线齿轮副的传动平稳性;最小齿数为6且不存在根切现象,双齿轮副较单一齿轮副具有75%左右的脉动改善率,基于脉动最小化的最佳摆线齿廓参数可直接应用于生产实践。为摆线齿轮泵无困油低脉动的进一步研究与开发提供了理论基础。     

摆线泵流量特性分析及计算机仿真

根据摆线泵的啮合线方程,建立了用几何法求解摆线泵的瞬时流量、排量、流量脉动率的数学模型.应用Matlab/Simulink仿真工具对泵的流量特性进行了仿真,作出了泵的瞬时流量变化曲线,并分析了影响流量脉动率的因素.     

摆线泵流量脉动率的影响因素仿真分析

文章分析了影响流量脉动率的因素,并以某汽车自动变速器用一齿差摆线泵为载体,利用Pumplinx软件对该摆线泵进行CFD流体动力学仿真,得出流量脉动曲线图;分析不同工况与泵内部结构对流量脉动率的影响;提出了降低一齿差摆线泵流量脉动率的有效措施,为摆线泵的结构设计、加工制造、故障诊断、减振和降噪等方面提供了重要的理论依据。     

定子齿数为偶数时的摆线马达理论排量及流量脉动率分析

推导了定子齿数为偶数时的摆线马达的理论排量和流量脉动率公式,并与定子齿数为奇数时摆线马达的理论排量和流量脉动率进行定量对比。分析表明,定子齿数为偶数时摆线马达的流量脉动率比定子齿数为奇数时的摆线马达大得多。而当k1、k2和BR2Z值相同时,不论定子齿数是奇数还是偶数,只要齿数相近,其理论排量相差不大。分析结果可为摆线马达的设计开发提供理论依据。     

基于非圆齿轮驱动的恒流量高阶椭圆凸轮泵设计

凸轮泵是一种结构紧凑、无磨损且适用范围广的高性能容积泵。针对新式椭圆凸轮泵流量脉动大的性能缺陷,提出了基于非圆齿轮变速驱动的脉动平抑方法。在阐明高阶椭圆凸轮泵工作原理的基础上,建立了泵的瞬时流量公式,并分析了转子偏心率、阶数及长半轴长度对瞬时流量的影响;针对大脉动流量的成因,提出了基于非圆齿轮的平抑方案,根据瞬时流量公式反求出平抑用非圆齿轮的传动比,通过留数定理证明了非圆齿轮的封闭性,为该非圆齿轮的设计奠定理论基础。分析结果表明:非圆齿轮变速驱动的高阶椭圆凸轮泵可以实现恒流量输出,平抑齿轮和同步齿轮间的相位角误差是制约流量是否恒定的关键参数。     

低脉动齿轮泵的主动设计及特性分析

针对现有齿轮泵流量脉动大的问题,提出一种低脉动齿轮泵齿轮齿廓的主动设计方法,即通过控制齿轮泵的流量脉动系数,主动控制齿廓形状。根据齿轮啮合原理,在引入极距和压力角函数的基础上,推导齿轮泵的瞬时流量和脉动系数的数学表达式,建立低脉动齿轮泵主动设计的数学模型,推导流量脉动系数的临界条件,给出了其设计流程。并通过具体实例,详细说明了低脉动齿轮泵的主动设计过程,分析了低脉动齿轮泵的特性,并与相同参数的渐开线齿轮泵进行了对比,研究成果可为降低齿轮泵的流量脉动、提高齿轮泵的工作平稳性和寿命,提供一种新的思路。     

摆线齿轮泵低速特性的仿真与实验研究

增速液压泵在风力发电增速系统中是一个极为关键的部件。为了研究摆线齿轮泵作为风力发电增速泵的使用特性,建立了摆线齿轮泵用于风力发电增速系统中的流量特性模型,并利用AMESim仿真软件对低速、大扭矩下的摆线齿轮泵进行了数学建模与系统仿真,同时对AMESim模型进行了低速、大扭矩工况的实验验证。分析了摆线齿轮泵低速工况下流量脉动,结果表明在低速工况下摆线齿轮泵每个周期存在多次流量脉动,且脉动较大,脉动频率与外转子齿数相同。     

外啮合微小齿轮泵流场模拟分析与优化

为了揭示微小齿轮泵的几何参数与其工作性能之间的关系，利用Fluent动网格技术，对汽车尾气处理装置中微小齿轮泵进行二维数值模拟分析，探究顶隙、齿轮齿数等几何参数对微小齿轮泵流量和精度的影响规律。结果表明，在其他条件相同时，随着顶隙增大，平均流量逐渐变小，流量脉动率逐渐增大，顶隙由0.02 mm变化为0.3 mm时，平均流量减小约33%，流量脉动率增大约18%，精度降低；随着齿轮齿数增大，流量和流量脉动率均减小，齿轮齿数由14增大到28时，平均流量减小约54%，流量脉动率减小约95%，精度逐渐提高，齿轮齿数对流量脉动率的影响幅度明显高于对流量的影响效果。     

基于MATLAB外啮合齿轮流量计的流量特性仿真研究

分析了普通外啮合齿轮流量计的瞬态流量,由齿轮马达的瞬态流量特性推导出了流量计的瞬态流量数学模型,给出了不同齿数情况下流量计的流量脉动,研究了脉动率和齿轮齿数的关系,利用MATLAB软件模拟了流量计的流量特性仿真曲线,证明了可以用适当增大从动轮齿数的方法来降低流量计的流量脉动。     

复合齿轮泵理论及应用预测

本文结合内、外啮合齿轮泵的优点,提出了一种新型的液压径向力平衡的齿轮泵－复合齿轮泵。从理论上推导了标准齿轮及变位齿轮时泵的瞬态流量特性,得出结论：标准齿轮复合齿轮泵的流量脉动率远小同种类型的外啮合齿轮泵;变位齿轮复合齿轮泵的流量脉动率较同种类型标准齿轮复合轮泵的流量脉动率为小。进而对该泵的应用提出了一些建议。     

Effects of meridional flow passage shape on hydraulic performance of mixed-flow pump impellers

During the process of designing the mixed-flow pump impeller, the meridional flow passage shape directly affects the obtained meridional flow field, which then has an influence on the three-dimensional impeller shape. However, the meridional flow passage shape is too complicated to be described by a simple formula for now. Therefore, reasonable parameter selection for the meridional flow passage is essential to the investigation. In order to explore the effects of the meridional flow passage shape on the impeller design and the hydraulic performance of the mixed-flow pump, the hub and shroud radius ratio (HSRR) of impeller and the outlet diffusion angle (ODA) of outlet zone are selected as the meridional flow passage parameters. 25 mixed-flow pump impellers, with specific speed of 496 under the design condition, are designed with various parameter combinations. Among these impellers, one with HSRR of 1.94 and ODA of 90° is selected to carry out the model test and the obtained experimental results are used to verify accuracies of the head and the hydraulic efficiency predicted by numerical simulation. Based on SIMPLE algorithm and standard k-ε two-equation turbulence model, the three-dimensional steady incompressible Reynolds averaged Navier-Stokes equations are solved and the effects of different parameters on hydraulic performance of mixed-flow pump impellers are analyzed. The analysis results demonstrate that there are optimal values of HSRR and ODA available, so the hydraulic performance and the internal flow of mixed-flow pumps can be improved by selecting appropriate values for the meridional flow passage parameters. The research on these two parameters, HSRR and ODA, has further illustrated influences of the meridional flow passage shape on the hydraulic performance of the mixed-flow pump, and is beneficial to improving the design of the mixed-flow pump impeller.     

水压柱塞泵配流盘阻尼槽结构优化及试验研究

针对水压柱塞泵U形阻尼槽的结构参数进行研究,通过流场仿真对比不同阻尼槽结构参数下水压柱塞泵的流量特性,确定水压柱塞泵的压力、流量脉动率最优的阻尼槽结构参数,从而降低水压柱塞泵的流体振动。仿真结果表明,在现有结构参数下当水压柱塞泵阻尼槽宽度设置为2mm、深度为0.8mm、配流盘预升/泄闭死压角为11.8°时,柱塞泵的压力和流量脉动率最小。开展了水压柱塞泵的振动试验,对比了阻尼槽优化前后的试验数据,试验结果表明优化后的阻尼槽结构能够有效降低水压柱塞泵的振动。     

A novel technique of using a thyristor driven pump as the final control element and flow indicator of a flow control loop

In the present paper, design of a flow control loop using a thyristor driven pump as final control element has been described. In this technique, the load current of a thyristor driven pump motor has been utilized as a mass flow sensing parameter of a fluid passing through a pipeline. This thyristor driven pump has been utilized as a final control element of a flow control loop and the speed of the pump has been selected as the manipulated variable. The non-linearity between the thyristor input signal and pump output has been eliminated by using a modified PID control technique with inverse derivative control action. Thus without using any conventional flow meter and control valve only the thyristor driven pump has been utilized both as the final control element and flow indicating device by using the proposed technique. The whole system has been designed, fabricated and tested by using tap water as the flowing liquid through a pipe line. The experimental results along with the theoretical analysis are compared and reported in the paper.     

余弦齿轮泵的流量及其脉动特性分析

对外啮合余弦齿轮泵的瞬时流量及流量不均匀系数等公式进行了理论推导.运用Matiab软件对余弦齿轮泵的流量及脉动进行了计算及数值仿真.结果表明,与相同参数的渐开线齿轮泵相比,余弦齿轮泵的平均流量大,而流量脉动要明显小于渐开线齿轮泵,并随齿数的增多而逐渐减小.研究结果可为余弦齿轮泵的设计和推广应用提供依据.     

Effects of Blade Number on Characteristics of Centrifugal Pumps

The blade number of impeller is an important design parameter of pumps,which affects the characteristics of pump heavily.At present,the investigation focuses mostly on the performance characteristics of axis flow pumps,the influence of blade number on inner flow filed and characteristics of centrifugal pump has not been understood completely.Therefore,the methods of numerical simulation and experimental verification are used to investigate the effects of blade number on flow field and characteristics of a centrifugal pump.The model pump has a design specific speed of 92.7 and an impeller with 5 blades.The blade number is varied to 4,6,7 with the casing and other geometric parameters keep constant.The inner flow fields and characteristics of the centrifugal pumps with different blade number are simulated and predicted in non-cavitation and cavitation conditions by using commercial code FLUENT.The impellers with different blade number are made by using rapid prototyping,and their characteristics are tested in an open loop.The comparison between prediction values and experimental results indicates that the prediction results are satisfied.The maximum discrepancy of prediction results for head,efficiency and required net positive suction head are 4.83%,3.9% and 0.36 m,respectively.The flow analysis displays that blade number change has an important effect on the area of low pressure region behind the blade inlet and jet-wake structure in impellers.With the increase of blade number,the head of the model pumps increases too,the variable regulation of efficiency and cavitation characteristics are complicated,but there are optimum values of blade number for each one.The research results are helpful for hydraulic design of centrifugal pump.     

航空燃油离心泵抗汽蚀优化设计及仿真

针对航空燃油离心泵工作时出现的汽蚀问题,采用正交试验法对离心泵叶轮进行优化设计.选取叶轮出口直径D2、叶轮出口宽度b2、叶片数Z、叶片厚度H为正交试验的4个因素,完成了正交试验并对试验结果进行极差分析,得到了以泵汽蚀余量为优化指标的影响排序,并最终获得最优参数组合.通过流场仿真对现用离心泵和优化后离心泵的泵汽蚀余量和蒸...     

基于AMESim的连续混配撬负载敏感液压系统仿真分析

 在分析连续混配撬液添泵系统工作特点的基础上,选择负载敏感液压系统作为其液压动力系统。为验证连续混配撬负载敏感液压系统性能,利用AMESim仿真软件搭建连续混配撬液添泵液压系统仿真模型,得到泵出口压力、泵输出流量及功率变化曲线。结果表明：泵输出流量稳定时,泵出口压力与各负载中最大压力的差值为负载敏感阀的设定压力;流量按需分配,在泵最大流量允许范围内,泵输出流量始终随着系统所需流量的变化而变化;负载敏感泵输出功率始终与负载所需功率相匹配,系统具有无溢流损失、节能等优点。     

直线共轭齿轮泵的基本参数优化设计

讨论了直线共轭齿轮泵设计的基本参数和几何尺寸的计算公式。以流量脉动最小和单位体积排量最大为目标函数,以重合度、啮合角、齿廓重迭干涉等条件为约束函数,建立了优化设计数学模型。对两种齿数组合的齿轮泵进行了优化设计,所得结果能满足设计性能要求,且具有通用性。     

四径向轮齿轮泵优化设计及仿真

针对传统齿轮泵流量脉动大、振动明显、噪声高等缺点,设计一种四径向轮齿轮泵。首先分析了四径向轮齿轮泵的瞬态流量特性,并建立了其流量、流量脉动系数和流量脉动频率等数学模型。然后,建立多目标函数并以MATLAB软件为平台对四径向轮齿轮泵进行参数优化。最后,分别对相同理论流量和额定压力的四径向轮齿轮泵、三径向轮齿轮泵及传统外啮合齿轮泵进行流量特性仿真,并将其结果进行对比分析。结果表明,四径向轮齿轮泵在结构设计合理的情况下,对减小齿轮泵的流量脉动,从而减小齿轮泵振动和噪声和提高齿轮泵工作性能及降低成本方面均具有重要作用。     

离心泵叶轮内部湍流流动的数值计算及试验

对IH65型离心泵叶轮内部流动进行研究,基于Reynolds时均化的N-S方程和标准的k – e 两方程湍流模型,运用流场计算软件Fluent,计算该泵叶轮在不同工况下的内部流场,并将计算结果与粒子图像测速仪(PIV)实测结果进行比较。在对该泵叶轮内部流速分布、压力分布以及试验得到的流动撞击、二次流、回流等现象分析的基础上,提出设计上的一些改进措施,为该型泵叶轮优化设计及其内部两相流动研究提供参考。