球笼式等速万向节接触应力分析与计算

球笼式等速万向节是前置前驱动轿车的关键部件之一，其性能和寿命与接触应力密切相关。对球笼式等速万向节的接触应力进行了分析，给出了计算方法，并对某一车型的ＢＪ７５型球笼式等速万向节进行了计算，结果表明内滚道接触应力大于外滚道，内滚道易于磨损。     

七沟道球笼式等速万向节磨损及仿真分析

本文中根据Archard磨损理论,对球笼式等速万向节内部进行了磨损分析。通过求出球笼式等速万向节钢球在沟道内的瞬时角速度和沟道与钢球接触点的瞬时角速度,分析钢球在沟道内的瞬时滑滚情况,以此判断钢球在沟道内的滑滚移动状态,从而求出钢球与星形套、钟形壳之间的摩擦力随输入端转角、轴间摆角的变化规律。几何推导及仿真的结果同时得出了球笼式等速万向节的磨损类型为疲劳磨损以及七沟道的万向节内磨损情况明显好于六沟道的结论。文中同时还推导出了体积磨损率与输入轴转速、转角和轴间摆角等的具体关系式,为后续研究奠定了重要的理论基础。     

环叉式等角速万向节的研制

球笼式等角速万向节于20世纪30年代发明,由此推动了前轮驱动轿车的发展.但因制造水平不高,影响了球笼式等角速万向节的使用可靠性,从而使前轮驱动轿车的发展受到制约.时隔30年后,球笼式等角速万向节的专用加工生产线研制成功并投入生产,确保了所要求的加工精度等级.与其它类型等角速万向节相比,球笼式等角速万向节性能优良,被广泛应用在汽车上,进而促进了前轮驱动轿车的发展趋势.     

新型等速万向节——环叉式万向节的基本理论与匀速性分析

等速万向节是发动机前置前驱动轿车的关键部件,目前广泛采用球笼式万向节,但其加工精度要求高,因而价格较高。环叉式万向节是一种高性能的新型等速万向节,而且易于加工,其两项主要技术指标:最大工作夹角αmax≥42°,最大转角差△φmax≤0°3',均达到了代表国际先进水平的球笼式万向节的水平。文中介绍了环叉式万向节的基本理论,并分析了其匀速性。     

球环式万向节(上)

汽车万向节的种类较多,主要有十字轴式、三销式、球叉式、球笼式及弹性万向节等。而目前在传动轴上大多采用十字轴式万向节;在转向桥驱动半轴上则大多采用球叉式万向节。十字轴式万向节,一般用四个滚针轴承,属非等角速万向节。其特点是体积较小、重量     

球叉式等速万向节圆环滚道的机械加工精度分析

球叉式等角速万向节是汽车转向驱动桥中的一个部件。其作用是保证汽车在转弯的情况下,转向驱动轮偏转时,能可靠地传递扭矩、保证车轮等角速旋转。在国内外,这种结构已广泛用于中、小型越野车上。它主要由两个万向节叉和四个主动球、一个中心球组成。两圆环滚道在两个万向节叉里对称地配置,作用力通过主动球从一个万向节叉传到另一个万向节又。由于两圆环滚道的半     

基于汽车NVH提升的传动轴优化仿真分析与实验验证

Birfield球笼万向节具有等速传递、附加弯矩平稳等优点。结合传动轴中间支承的振动对传动轴动力性能和车内噪声的影响,提出采用将中间十字轴万向节替换为Birfield球笼万向节的设计方案。通过ADAMS虚拟样机对三段式十字轴万向节传动轴和Birfield球笼万向节传动轴在不同输入转速、不同主轴轴间夹角条件下进行仿真,分析表明Birfield球笼万向节传动轴的中间支承振动加速度变化和转矩波动更趋于平稳。分别对装有两种传动轴的实验样车进行整车车内噪声实验对比分析,实验表明Birfield球笼万向节能有效改善车内噪声,在中低速区域明显低于十字轴万向节传动轴车辆约5dB,提升了整车NVH性能。     

万向节与传动轴技术发展综述

本文着重介绍国外球笼式等万向节产品设计，系列化，结构发展，应用技术程序和制造技术和概况 。     

一种全新的专利技术汽车用四球销式等速万向节

四球销式等速万向节能克服传统结构三球销式等速万向节存在的不足，具有结构新颖、合理、紧凑、加工和检测方便、工作可靠、承载能力强等特点。     

捷达车球笼频繁漏油

<正>故障现象一辆捷达都市春天手动挡出租车,累计行驶里程约为5万km时出现右侧半轴内球笼(采用VL型伸缩式等速万向节)漏油的现象。当时到某汽车修理厂维修,该厂确认是球笼润滑脂漏出,随即拆下该内球笼,并进行了分解检查,未发现异常,遂按技术要求对该内球笼进行了保养。但该车出厂     

Spatial Dynamics of Multibody Tracked Vehicles Part I: Spatial Equations of Motion

In this paper, the nonlinear dynamic equations of motion of the three dimensional multibody tracked vehicle systems are developed, taking into consideration the degrees of freedom of the track chains. To avoid the solution of a system of differential and algebraic equations, the recursive kinematic equations of the vehicle are expressed in terms of the independent joint coordinates. In order to take advantage of sparse matrix algorithms, the independent differential equations of the three dimensional tracked vehicles are obtained using the velocity transformation method. The Newton-Euler equations of the vehicle components are defined and used to obtain a sparse matrix structure for the system dynamic equations which are represented in terms of a set of redundant coordinates and the joint forces. The acceleration solution obtained by solving this system of equations is used to define the independent joint accelerations. The use of the recursive equations eliminates the need of using the iterative Newton-Raphson algorithm currently used in the augmented multibody formulations. The numerical difficulties that result from the use of such augmented formulations in the dynamic simulations of complex tracked vehicles are demonstrated. In this investigation, the tracked vehicle system is assumed to consist of three kinematically decoupled subsystems. The first subsystem consists of the chassis, the rollers, the sprockets, and the idlers, while the second and third subsystems consist of the tracks which are modeled as closed kinematic chains that consist of rigid links connected by revolute joints. The singular configurations of the closed kinematic chains of the tracks are also avoided by using a penalty function approach that defines the constraint forces at selected secondary joints of the tracks. The kinematic relationships of the rollers, idlers, and sprockets are expressed in terms of the coordinates of the chassis and the independent joint degrees of freedom, while the kinematic equations of the track links of a track chain are expressed in terms of the coordinates of a selected base link on the chain as well as the independent joint degrees of freedom. Singularities of the transformations of the base bodies are avoided by using Euler parameters. The nonlinear three dimensional contact forces that describe the interaction between the vehicle components as well as the results of the numerical simulations are presented in the second part of this paper.     

Finite-element analysis of quasistatic fracture in CV joints under full-turn and full-throttle conditions

Quasistatic fractures at high joint angles constitute a chronic quality problem in CV joints. This type of fracture occurs when a driver unintentionally depresses the brake and accelerator simultaneously under a full-turn retreat condition. In general, the cage in a ball joint can be broken only at these high joint angles. Here we present a flexible quasistatic simulation model developed to simulate fracture in a CV joint. The cause and process of the quasistatic fracture were analyzed using simulations and physical tests. Static fracture simulations and tests at high joint angles showed that, initially, only one of the six cage posts was damaged. In a simulation of one revolution at constant torque, we found that an imbalance in ball loads generated an excessive cage load. Moreover, if this high cage load was applied when the cage protruded outward, the cage post was subjected to severe shear loading. The cage post was damaged in this specific rotational range. Quasistatic fracture simulations and tests at high joint angles showed that all six cage posts were damaged sequentially. Because entire cage posts were damaged, the quasistatic fracture torque was approximately half of the static torque. The plastic strain in each cage post displayed one step-like jump per revolution in the quasistatic simulations. The ball indentation created by a high ball load was interrupted by the cage-window edges as the ball joint rotated. This hindrance by ball indentation triggered the final breakage of the cage, although it was not the major cause of cage fractures.     

基于ABAQUS的万向节淬火应力有限元分析与优化设计

利用有限元分析软件对万向节球笼壳体的最大应力位置和应力分布规律、工件表面淬硬层残余应力随温度的变化、工件表面淬硬层残余应力对万向节球笼壳体工作应力的影响进行了分析.在分析的基础上,提出了万向节的没计原则.通过优化壳体的厚度等参数和淬硬层厚度,减轻了壳体的质量,提高了壳体的性能.     

利用创新理论改进柴油机球形接头结构的研究

针对柴油机低压管路中普遍采用的球形接头密封结构存在的"跑冒滴漏"问题,利用知识管理结合创新的方法、创新的思路,解决工程中的实际问题.球形接头渗漏属于典型的技术归零问题,采用了"故障诊断和排故"流程进行求解.首先利用系统分析和问题分解对球形球头渗漏问题进行分析研究,查找问题的根本原因,形成分解图,构建故障结构组件模型;然...     

石太客运专线特长隧道Ⅰ型板式无砟轨道施工与造价

为了满足客运专线铁路的快速发展需要,进一步推广Ⅰ型板式无砟轨道的应用,结合石太客运专线太行山特长隧道Ⅰ型板式无砟轨道施工的成功经验,对特长隧道无砟轨道物流组织、施工测量、底座混凝土、铺板、铺轨等关键技术以及施工造价做深入详细的剖析,使客运专线铁路特长隧道Ⅰ型板式无砟轨道施工工艺标准化、规范化,为今后的客运专线长大隧道内无砟轨道的推广应用以及城市轨道交通无砟轨道施工提供有益的参考。     

大吨位徐变仪球铰非线性接触分析

因研究桥用高强度混凝土材料徐变性能的需要,自主研制了大吨位徐变仪。对于处于接触受力状态的徐变仪球铰区域,先用Hertz接触理论估算球铰区域尺寸范围,然后利用ANSYS通用有限元软件对该区域分别取2种垫板凹槽球径的模型进行接触分析,通过对比球铰区域的最大接触压力、mises应力、第3主应力来进一步确定垫板凹槽的合理球径。用该徐变仪对2座大桥成功进行了高强度混凝土徐变试验,并实际验证了试验荷载下徐变仪球铰区域的受力性能,以及有限元接触分析结果的正确性。     

严寒地区高速铁路路基密封胶应用研究

哈大高铁作为在东北严寒地区建造的第一条无砟轨道高速铁路，对无砟轨道变形有着极为苛刻的要求。水作为路基冻胀的必要条件之一，如何阻止地表水下渗路基本体是控制路基冻胀变形的关键因素，以此为出发点，重点对哈大高铁新型路基与轨道结构缝密封胶的应用研究进行了阐述。     

Study on rail corrugation of a metro tangential track with Cologne-egg type fasteners

In Chinese metro lines, rail corrugation on both tangential and tight curved tracks with Cologne-egg type fasteners is very severe. Based on the viewpoint of friction-induced vibration causing rail corrugation, the rail corrugation on a tangential track with Cologne-egg type fasteners is studied in this paper. A vibration model of an elastic multiple-wheelset-track system with Cologne-egg type fasteners is established. Both the complex eigenvalue analysis and the transient dynamic analysis are performed to study the stability and the dynamic performance of the wheelset-track system. The simulation results show that a low rail support stiffness value is responsible for rail corrugation on the tangential track. When the Cologne-egg fasteners characterised by a lower stiffness value are replaced with the DTVI2 fasteners characterised by a higher stiffness value, rail corrugation disappears. However, rail corrugation on tight curved tracks cannot be suppressed using the same replacement. The above conclusions are consistent with the corrugation occurrences in actual metro tracks.     

RCA水泥稳定基层的集料性能改善研究

采用室内球磨方法,对破碎的旧水泥混凝土路面板块进行处理后得到的再生集料的表面薄弱层进行处理,获得抗破碎能力强、吸水率低的加工再生粗集料和大量的球磨粉料。通过抗压强度试验、不同浸水时间的无侧限抗压试验及冻融循环试验,结果表明,水泥稳定全球磨加工再生集料具有较好的抗压能力、抗水稳定性及抗冻性能,并且在试验路段的基层中取得了较好的使用效果。