球活塞式液压泵球塞副摩擦动力学模型与特性研究

发布时间：2018-02-21 18:12

本文关键词： 球活塞式液压泵弹流润滑边界滑移摩擦动力学泄漏特性　出处：《北京理工大学》2014年博士论文　论文类型：学位论文

【摘要】：球活塞式液压泵因其结构简单，易于实现大排量、大功率等特点为许多液压机械无级变速装置所采用。在球塞泵运行中，球活塞、缸体、作用环等构件组成的运动副处于复杂的润滑状态下，并表现出较强的非线性动力学特征。本文全面考虑了以球活塞为中心的球塞副摩擦学特性与动力学模型的耦合关系，建立了作用环-球活塞-缸体构件组的摩擦动力学模型。应用该模型，揭示了球塞副的动力学行为，接触润滑特性以及效率特性等。本文考虑边界滑移效应，建立了球活塞-缸孔摩擦副润滑模型。根据纯滚动假设，进行球塞副基本运动和受力状态分析，获得各接触对在不同位置和时刻的载荷分布规律，确定了球活塞与缸孔侧壁间处于周期性变载荷、变卷吸速度的大滑滚比点接触弹流润滑状态。应用速度边界条件分析边界滑移速度特性，根据油膜极限剪切力理论，引入Circular流变模型对等效粘度进行计算，并用于修正广义雷诺方程。应用多重网格法和Gauss-Seidel松弛迭代法联立求解，获得了接触区的油膜分布和压力分布等润滑特性，并计算油膜剪切力和承载力。运用摩擦系数对求解结果进行分析，揭示了球塞副特殊工况下的油膜剪切特性。采用与实际结构一致的模拟试验装置，对计算结果进行验证。本文建立了球活塞三自由度摩擦动力学模型，包含摩擦学模型、动力学模型及结构变形三个组成部分。首先明确了建模体系中使用的坐标系及相互间的转换关系。在此基础上，运用既已建立的球活塞-缸孔摩擦副润滑模型，和球活塞-作用环接触副弹流润滑模型，构成摩擦学模型。运用有限元方法，对球塞副构件间多点耦合结构变形进行计算，并将结果引入摩擦学模型作为计算条件。对球塞副构件间的各项受力和运动关系进行分析，建立非线性动力学方程组，采用数值方法进行求解。基于上述摩擦学模型、变形关系和动力学模型，建立了多项因素非线性耦合的球塞副摩擦动力学模型。采用耦合求解方法，实现了球活塞动力学特性、摩擦副弹性形变特性及润滑特性的耦合求解。根据对球活塞摩擦动力学模型在不同工况和结构参数条件下的求解结果，研究了工作周期内球活副构件间的动态接触力学特性，获得单个球活塞的动力学行为。重点针对球活塞-作用环间滑移行为特性及其影响因素进行了分析，揭示了球塞副多接触点耦合受力特性和微观运动特性。根据单球塞副的稳态和动态分析结果，对球塞泵整机效率特性进行计算，，并加以试验验证。对球塞副间的油膜压力和剪切动态过程进行了研究，得到各种工况下的润滑特性。探讨了球活塞直径、作用环尺寸、空心球活塞等结构参数对摩擦动力学特性的影响规律。基于摩擦动力学特性，分析了球活塞-缸孔偏心缝隙动态变化特性，并基于此对球活塞-缸孔副的偏心圆环泄漏流动进行建模和计算，得到不同工况和结构下的效率特性，并进行了单球塞副泄漏量模型试验和整机容积效率的试验验证。
[Abstract]:Ball piston hydraulic pump because of its simple structure, easy realization of large displacement, high power characteristics for many hydraulic machinery stepless speed change device used in ball piston pump. In operation, the ball piston, cylinder, ring components such as the movement of vice in the lubrication under complicated state, and shows strong nonlinear dynamic characteristics. Considering the coupling between the piston with the ball as the center of the ball tribological characteristics and kinetic model, established the friction dynamic model of ring - Cylinder - piston ball components. This model is used to reveal the dynamic behavior of ball piston pair, contact lubrication characteristics and efficiency characteristics.
In this paper, considering the boundary slip effect, a ball piston cylinder bore lubrication friction model. According to the assumption of pure rolling, ball piston movement and basic analysis of stress state, the contact load distribution in different locations and time, determine the periodic load variable ball piston and cylinder hole wall in between. Variable entrainment speed big slide roll ratio Point Contact Elastohydrodynamic Lubrication. The analysis of application of boundary slip velocity boundary condition, the ultimate shear force of oil film theory, introducing the Circular rheological model of equivalent viscosity were calculated and used to modify the generalized Reynolds equation. The application of multigrid method and Gauss-Seidel iterative relaxation method to solve the system, obtain the contact area of the oil film distribution and pressure distribution of the lubrication characteristics, and calculate the shear force of oil film and bearing capacity. The friction coefficient to analyze the results, reveals the special work of ball piston pair The oil film shear characteristics under the condition of the condition are verified by the simulation test device which is consistent with the actual structure.
This paper establishes the ball piston with three degrees of freedom dynamic friction model, including tribological model, dynamic model and structural deformation of three parts. Firstly, clarifies the relationship between the use of modeling system in the coordinate system and the inter conversion. On this basis, the use of both established ball piston - cylinder friction and lubrication model. The ball piston ring contact elastohydrodynamic lubrication model, a friction model. Using the finite element method, the multi coupled structure deformation of ball piston pair between components are calculated, and the results into the tribological model as a calculation condition. The ball piston pair between components by analyzing the relationship between force and motion, a nonlinear dynamic equation group, is solved by numerical method. The tribological model based on relationship between deformation and dynamic model, the establishment of a number of factors with nonlinear coupling of ball piston friction dynamic model using. The coupling solution method is used to solve the dynamic characteristics of the ball piston, the elastic deformation characteristics of the friction pair and the coupling of the lubrication characteristics.
According to the results of ball piston friction dynamic model under different operating conditions and structure parameters, studied the working period of the ball live dynamic contact mechanical properties of side components, obtain the dynamics of individual ball piston. The key factor for the ball piston ring role slip behavior characteristics and influence factors are analyzed, revealing the ball multi contact plug coupling force characteristics and micro motion characteristics. Based on the single ball piston pair of static and dynamic analysis results of ball piston pump efficiency characteristics are calculated and verified. The ball piston pair between the oil film pressure and shear dynamic process were studied. The obtained lubrication characteristics under various conditions the discussion on the ball. The diameter of the piston, ring size, influence of piston hollow ball and other structural parameters on dynamic characteristics of friction. Friction Dynamics Characteristics Based on the analysis of ball piston cylinder Kong Pian heart Based on the dynamic characteristics of the gap, the leakage flow of eccentric ring of spherical piston cylinder port pair is modeled and calculated, and the efficiency characteristics under different conditions and structures are obtained. The model test of single ball plug pair leakage and the volumetric efficiency test of the whole ball are carried out.

【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH137.51

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