宽V带无级变速器中轴向压力的研究

介绍了宽V带无级变速器的工作原理,阐述了V带当量摩擦系数的计算对于宽V带无级变速器中轴向力确定的重要性,根据平带传动的欧拉公式并结合宽V带无级变速器中V带传动的实际情况,提出了摩擦力方向角,推导出了V带传动的当量摩擦系数,无级变速器在传动过程中V带紧边和松边所受拉力的变化将导致摩擦力方向角的出现,当量摩擦系数是摩擦力方向角的函数,V带从绕进带轮到绕出带轮的过程中,当量摩擦系数逐渐增大,并将包角区域分为动弧区和静弧区,分别推导了宽V带无级变速器中主动轮和从动轮轴向压力的计算公式.     

一种计算V带当量摩擦系数的新方法

对现有V带当量摩擦计算公式做了更正，给出了新的V带当量摩擦系数计算公式。在公式中引入了一个新的参数——V带当量摩擦系数影响角，通过计算及分析可知该参数对V带当量摩擦系数的大小产生波动，但波动的幅度较小。在不计入随带拉力变化引起带宽改变对摩擦力影响、相对滑动等因素前提下，改进后的计算公式比现有公式更加完善。     

计算V带当量摩擦系数的探究

分析了现有当量摩擦系数计算公式的不足.根据V带传动实际情况,将带从紧边绕进主动轮部分分为绕进主动轮阶段、在主动轮中间阶段、绕出主动轮阶段三个阶段,针对影响角γ对V带当量摩擦系数的影响,推导出了V带当量摩擦系数计算公式,并通过实例求出了给定条件下的当量摩擦系数μν的数值,得出了描述α-μν关系的曲线.     

宽V带无级变速器中当量摩擦因数的研究

介绍了宽V带无级变速器的工作原理,阐述了V带当量摩擦因数的计算对于整个宽V带无级变速器设计的重要性,分析了现有的V带传动中当量摩擦因数计算公式的不足,根据平带传动的欧拉公式并结合宽V带无级变速器中V带传动的实际情况,考虑了周向摩擦力和径向摩擦力,提出了摩擦力方向角,推导出了宽V带无级变速器中V带传动的当量摩擦因数的计算公式,并就摩擦力方向角的3种情况分别进行了讨论。     

影响V带当量摩擦因数的摩擦力方向角研究

根据V带传动的实际情况,分析传动带在主动轮和从动轮动弧区内任意位置的周向变形和径向变形,给出摩擦力方向角的计算公式;并运用Matlab软件绘制出动弧角和方向角的关系图.通过分析摩擦力方向角对当量摩擦因数的影响,得出从动轮处当量摩擦因数随摩擦力方向角增大而减小,主动轮处当量摩擦因数随摩擦力方向角绝对值的增大而增大;根据主...     

相似理论在带传动中的应用

本文应用相似理论,来探索解决带传动中的疲劳寿命问题。通过对相似条件的分析,提出相似理论在带传动中应用的可行性,以及通过对带传动疲劳寿命影响因素的分析及试验研究,建立了V带寿命予测准则及V带寿命与主要影响因素的经验公式,从而解决了用某一型号V带的寿命经验公式,可以予测各种型号V带在不同工况下的寿命问题.为V带的寿命计算开辟了一条新路.     

谈V带传动标准体系中的几件事

本文对V带传动标准体系中存在的一些问题，提出个人看法。希望能为标准修订时提供参考。V带传动标准体系中．除了术语标准外，还包含V带、V带轮和V带传动的一系列标准。GB／T11355－1989《V带传动额定功率的计算》是现行系列标准中较早的，它等同采用ISO5292—1980《业V带额定功率的计算》。在标准中，对额定功率的计算规定为基本额定功率只值、传动比引起的附加功率凸几值和带长引起的附加功率凸几值三项之和乘以包角修正系数几：对包角修正系数见的计算公式与柔韧体摩擦的理论公式——欧拉公式不符合。欧拉公式为：Ka＝C（1一）式中…     

分体式V带传动无级变速器的有效圆周力计算

分析了分体式V带无级变速器传动功率不足的原因,验证了影响传动功率的几个重要公式,得出了在分体式V带传动无级变速器设计过程中可以使用的公式和限制使用的公式,并对限制使用的公式进行了修正,使其适用于新型V带无级变速器的设计。     

窄V带传动的可靠性设计研究

考虑与失效相关的内容,利用变差系数等可靠性理论和常规设计方法,推导出窄V带传动的可靠度计算通用公式,使窄V带传动的可靠性设计更趋于合理和完善.     

带传动设计中几个问题的分析

针对机械设计教材及手册中,对带传动设计计算的一些公式未加证明而不利于理解的现状,对带长和带轮中心距的关系、柔韧体摩擦的欧拉公式、弯曲应力及离心拉应力的计算公式等进行了分析推导,对V带与平带传动能力的比较、带的根数计算等教材中未阐述透彻的问题进行了补充说明。     

Axial forces of a V-belt CVT

A simple analytical formula is derived for the axial forces of a V-belt CVT drive. For the driver pulley axial force, belt tension is assumed to be constant by self-locking. For the driven pulley axial force, the whole arc of contact between the belt and the pulley is divided into two regions; (1) inactive and (2) active area. The sliding angle ø for the belt friction is approximated as ø=0 in the active area. It is found that the results of the new formula are in close agreement with the exact solution. The new formula is suggested for the V-belt CVT design due to its simplicity and sufficient accuracy.     

Effect of angular speed on behavior of a V-belt drive system

For a V-belt drive system, the effect of angular speed on the three-dimensional frictional contact behaviors on the contact surfaces between the V-belt and pulley flange is studied in this work. To deal with the frictional contact phenomena for the V-belt drive system, an effective three-dimensional finite element procedure is developed herein. By this procedure, the deformation of the V-belt and the normal/tangential contact forces occurring on the contact surfaces can be estimated accurately. The friction angles of contact points along the edge of the V-belt cross section are also presented for various dynamic friction coefficients. From the computed results, it is found that smaller friction angles are obtained as dynamic friction coefficients get larger. The results achieved are very helpful for the estimation of operation efficiency of the V-belt drive system.     

On the instantaneous and average piston friction of swash plate type hydraulic axial piston machines

Piston friction is one of the important but complicated sources of energy loss of a hydraulic axial piston machine. In this paper, two formulas are derived for estimating instantaneous piston friction force and average piston friction moment loss. The derived formula can be applicable for piston guides with or without bushing as well as for axial piston machines of motoring and pumping operations. Through the formula derivation, a typical curve shape of friction force found from several experimental measurements during one revolution of a machine is clearly explained in this paper that it is mainly due to the equivalent friction coefficient dependent on its angular position. Stribeck curve effect can easily be incorporated into the formula by replacing outer and inner friction coefficients at both edges of a piston with the coefficient given by Manring (1999) considering mixed/boundary lubrication effects. Novel feature of the derived formula is that it is represented only by physical dimensions of a machine, hence it allows to estimate the piston friction force and loss moment of a machine without hardworking experimental test.     

金属带式无级变速器钢环组力学模型的建立

钢环组是金属带的关键组件之一，它的受力状况关系到金属带的承载能力和使用寿命。本文分析了钢环组在静态下和传动中的受力情况，建立了钢环组的力学模型，得到了钢环应力的求解公式，并分析了钢环的应力变化规律，为金属带的设计提供了理论依据。     

On the theory of power transmission by V-belts

The theory of frictional power transmission by a V-belt was studied and a new formulation is proposed for the tension ratio $\text{T}{}_1\text{T}{}_2$ in the linear slip (pseudo-Hookean) regime. The derivation stems from the quasi-static equilibrium equations and considers the previously ignored effects of belt elasticity, flexural rigidity, settling and the monotonic variation of the coefficient of friction along the contact arc. Various algebraic relations between μ and the lateral pressure p, developed from sliding block tests or the adhesion theory of friction, are shown to yield widely differing solutions when substituted in the general formula. For example, the simplest case, constant μ, leads to a significant modification of the conventional Euler solution. An experimental method for the determination of μ at any point on the contact arc of an operating belt is outlined.     

弹性啮合与摩擦耦合带传动动力学试验研究

介绍新型带传动－弹性啮合与摩擦耦合带传动的结构,传动原理在ＰＸ－Ｉ型皮带传动试验机上,研究新型带传动的动力学性能,并与Ｏ型Ｖ带进行对比试验。     

基于AdvantEdge的斜角车削仿真实验确定刀屑摩擦因数的方法

当使用AdvantEdge软件进行切削仿真实验时,刀屑摩擦因数对仿真结果的影响明显,但现有有限元软件未提供刀屑摩擦因数数据库。为建立一种基于AdvantEdge的斜角车削仿真实验的刀屑摩擦因数确定方法,首先提出基于斜角车削的摩擦力计算方法,然后建立AdvantEdge三维斜角车削仿真模型,设定不同切削速度、切削深度、进给量及摩擦因数,通过AdvantEdge仿真正交试验,获得刀屑摩擦因数的经验计算公式。为验证刀屑摩擦因数经验计算公式的正确性,设定不同切削速度和切削深度及进给量的斜角车削正交试验,获得切削力数据,并基于摩擦因数经验计算公式求得对应刀屑摩擦因数。利用求得的摩擦因数数据修改AdvantEdge中刀屑摩擦因数参数,进行残余应力切削仿真实验。仿真实验获得的残余应力与实际切削实验获得的残余应力相比,误差在10%以内,证明提出的刀屑摩擦因数确定方法是正确的。     

指定摩擦系数下富锌漆漆膜厚度的计算研究

对富锌漆接触面间的摩擦系数进行了测量,结果表明：不同处理方式的富锌漆接触面间的摩擦系数差异较大,并且摩擦系数与接触面积成正比。对某2 MW风机主轴与轮毂栓接面间异响的研究表明：喷砂后球型无机富锌漆接触面间的摩擦系数有时可接近于0。通过推导栓接面间的摩擦系数与粗糙度的数学解析表达式,结合球型无机富锌漆膜厚度与粗糙度在一定条件下近似相等的特性,找到了一种指定摩擦系数下富锌漆漆膜厚度的计算方法,保证了栓接面间在喷涂富锌漆后其摩擦系数的可靠性和可计算性。通过测量某塑性材料的摩擦系数,得到了一种简洁的估算该塑性材料的临界应力强度因子的方法。