定速比牵引传动——高速传动的新选择

本文总结了用于高速、超高速场合的定速比牵引传动的研究结果，分析了高速牵引传动的特点和机构设计方法，提出了两种比较完善的行星牵引机构，对机构的设计和实验研究表明，定速比牵引机构完全能够胜任高速、超高速传动。     

Friction and film‐forming behaviour of five traction fluids

There is growing interest in the use of toroidal‐type traction drives to provide continuously variable transmissions for use in medium‐ to high‐power automotive engines. These transmissions require the use of specially designed traction fluids to provide high friction in full‐film elastohydrodynamic lubricated contacts. This study has measured the film‐forming and traction properties of five commercially available and developmental traction fluids to provide data needed to predict their performance in traction drives. Some differences in performance between the fluids have been noted.     

Investigation into the traction coefficient in elastohydrodynamic lubrication

The elastohydrodynamic traction coefficients of two Chinese aviation lubricating oils were investigated for various loads, rolling velocities, and lubricant inlet temperatures using a self‐made test rig. Traction coefficient versus slide‐to‐roll ratio curves were generated. The concept of critical load varying with the lubricant temperature is proposed. This paper presents a new empirical formula for the dynamic performance design of high‐speed rolling bearings, that relates traction coefficient with normal load, rolling velocity, and lubricant inlet temperature. The coefficients of the formula may be computed by regression analysis of the experimental data. Two example calculations are presented. The predicted results from the formula agree well with experimental observations.     

滚动冲击压实机静态仿真分析

通过仿真研究滚动冲击压实机变矩器的无因次特性、发动机变矩器的共同输入输出特性和牵引车的牵引特性.仿真结果表明:发动机转矩特性曲线和变矩器输入扭矩曲线的交点是发动机与变矩器共同工作的稳定点,其工作范围是变矩器输入扭矩曲线与发动机外特性曲线所围成的最大区域;1挡、2挡、倒挡最高车速分别为11.054,35.44,14.812km.h-1;最大有效牵引功率为54kW;最大牵引效率为53%;额定滑转率为29%;变矩器最大输出功率对应的牵引力为61kN;附着条件决定的最大牵引力为83kN.     

汽车牵引式无级变速器的传动特性研究

在分析了牵引式无级变速器基本结构和工作原理的基础上,着重分析了在半接触角和摆动角变化时诸如传动比、滑动率、接触区的自转角速度和传动效率等的传动特性。研究表明,存在一个半接触角使得无级变速器在整个速比范围内,滑动率较小,自转角速度的绝对值较小,传动效率也较高。随着动力滚子半接触角的增大,接触区的压力随着摆动角的增大而增大,传动比也会增大,但速比范围会有所减少。     

In situ observation of phosphorous and non-phosphorous antiwear films using a mini traction machine with spacer layer image mapping

Since 1940s the principal source of an antiwear additive in crankcase applications has been due to a family of additives known as zinc dialkydithiophosphate (ZDDP). In this study, we have applied a novel technique, the mini traction machine with spacer layer image mapping (MTM SLIM), to study film formation characteristics of monoblend oils containing only basestock and ZDDP and also fully forrmulated oils containing a boron antiwear additive. The purpose of this study was initially to understand the build up of ZDDP film and then to establish whether boron compounds alone could provide significant antiwear films under mixed rolling and sliding contact.     

Effects of type of lubricant and shape of tooth profile upon efficiency of gear drives

To reduce energy consumption, it is important to increase the efficiency of gears used for power transmission. In the present work, the efficiencies of gear drives with standard and profile shifted involute gears are measured by changing the type of lubricating oil. A new equation for calculating efficiency is derived by taking into account the additional friction torque that depends on the shape of the teeth. The efficiencies calculated with the new equation agree well with those obtained by experiments conducted using two planetary gear drives with different tooth shapes and with different reduction ratios (u = 4. 89 and 151). The new equation is applicable to the design of gear drives with higher efficiency.     

Influence of the size,geometry, and material of the rollers on EHD traction

The influence of the parameters relating to the rolling elements on traction in EHD contacts is experimentally studied on a two-roller machine, in which experiments with point contacts are conducted for two paraffinic mineral oils, a synthetic naphthene, and a synthetic ester. Firstly, it is shown that the same traction curves are obtained in both internal and external contacts when the effective radius in rolling direction of the rollers is equal. The effect of an increase in the size of the rollers is to increase the film thickness and this results in a gentle decline in the maximum traction coefficient. As the effective radius in transverse direction is increased, so the traction decreases for a paraffinic mineral oil, while that for a synthetic naphthene remains constant independent of the geometry of the rollers. Finally, the effect of the material of the rollers is studied, employing rollers made of steel, ceramics, phosphorus bronze, brass, and aluminium alloy. The traction obtained under an identical normal load can be arranged according to the effective elastic modulus of the rollers for each oil. However, under identical contact pressure the same maximum traction curve is obtained independent of the material, but the decline in traction in the thermal region is slightly steeper with the ceramic than with the steel rollers because of the difference in the temperature rise of the fluid film.     

带有圆锥齿轮的复合行星传动功率流与传动效率分析

对带有圆锥齿轮的复合行星传动进行运动分析,在此基础上采用虚功率理论分析该复合行星传动在不考虑啮合功率损失和考虑啮合功率损失时的功率流,在定义速比与转矩比的情况下,获得复合行星传动效率表达式,进一步研究速比、转矩比和啮合功率损失系数及几何参数比对复合行星传动效率的影响规律,并开展相关试验验证。理论分析表明：在复合行星传动啮合功率损失系数和几何参数比被确定的情况下,复合行星传动效率随着转矩比的增大而增大,但随着速比的增大呈先减小后增大趋势;在复合行星传动速比和转矩比及几何参数比被确定的情况下,各齿轮副的啮合功率损失系数对复合行星传动效率的影响存在差异;在复合行星传动速比和转矩比及各齿轮副的啮合功率损失系数被确定的情况下,复合行星传动效率随着几何参数比的增大而增大。传动效率试验表明：选用高精度等级的锥齿轮、增大复合行星传动机构的转矩比及其行星轮的节圆半径可提高复合行星传动机构的传动效率。     

常功率无级变速器(CP-CVT)工作原理和分析

本文是一种新颖的常功率无级变速器(CP-CVT)牵引传动发表的系列论文的首篇.本文提出了常功率的基本机能原理和证实了该装置的特性.该装置属于大家知道的圆环牵引传动系列,它由两个输入盘、一个圆锥形环和另一圆环、一个锥形输出盘和若干钢球组成.各钢球的转轴按相对于输入和输出圆盘的几何位置作自行调整,输出转矩的变化使钢球相对盘的位置改变从而造成速比变化,首先进行钢球运动学和动力学分析,再推论了有关功率传递动力学公式和几何参数.最后提出CP-CVT可提供的良好的功能稳定功率特性满足汽车工业要求的结论.     

一种CR-CR型自动变速器的运动分析和效率计算

以CR- CR双排行星齿轮机构四挡自动变速器为例,运用单排行星齿轮机构一般运动规律的特性方程式对该类变速器进行运动分析,采用啮合功率法将行星齿轮机构转化为定轴轮系机构,对自动变速箱的传动效率进行计算.所述方法为其进一步自动变速箱的结构改进和性能提高提供了一定的理论基础.     

EHL traction and related rheological parameters under high temperature conditions

An approximate formula is presented for the maximum traction coefficient in EHD conditions, by making some reasonable simplifications of an Eyring fluid model. Experiments are conducted for some mineral and synthetic hydrocarbon oils over a wide range of temperatures. Among the rheological parameters related to maximum traction, the representative stress τ₀, is determined from the experimental traction curve while the effective viscosity-pressure coefficient α is obtained in a high pressure viscometer. When the temperature is raised, α falls and τ₀ rises. The behaviour of τ₀ for some paraffinic oils follows the Eyring theory while the effect of the dissociation of molecular clusters appears with the naphthenic oils. The increase in temperature causes a reduction in the maximum traction coefficient, which can be predicted with sufficient accuracy by the formula using the rheological parameters expressed as a function of temperature.     

Gearbox power loss. Part III: Application to a parallel axis and a planetary gearbox

In the third part of this work, the rolling bearing torque loss model, the lubricant factor extracted from the FZG tests with wind turbine gear oils and the loss factor for helical gears, developed in Part I and Part II of this work, will be applied to predict the power loss in a parallel axis and a planetary gearbox. The numerical results obtained are compared with those from experimental tests.     

高速润滑脂7007和7018拖动特性的研究

阐述了用自行设计的高速润滑脂弹流拖动力试验台在充分供脂条件下国产7007和7018润滑脂进行的拖动力测试，获得了不同载荷，速度条件下的两种润滑脂的拖动系数与滑滚比之间关系曲线，通过对试验数据的处理，采用适当的数学模型和国际通用的无量纲参数作为表达式，提出了可供工程上使用的这两种润滑脂的弹流拖动系数计算公式。     

修正的T-J模型分析高速航空润滑脂7018的拖动特性

在自行研制的高速润滑剂拖动特性试验台上对高速航空润滑脂7018进行拖动特性的试验,得出了该润滑脂的拖动系数随速度、温度、负载的变化规律;根据试验数据推导出润滑脂的流变参数;基于修正的T-J模型,求出高速航空润滑脂7018拖动力的大小。结果表明:根据修正的T-J模型计算出的高速航空润滑脂7018的拖动系数和试验值非常接近;高速航空润滑脂7018在试验条件下表现为弹塑性,拖动系数随着滚动速度的增大而减小;当载荷小于转折载荷时,随载荷的增加拖动系数增加,当载荷大于转折载荷时,随载荷的增加拖动系数减小。     

Experimental and computational investigation of the traction coefficient of a ball traction drive device

Traction drive is a new kind of drive manner in which the power is transmitted by a thin oil film between transmission elements. This paper describes a ball traction drive device. The quasi-dynamics analysis was carried out for the transmission components of the ball traction drive device. The traction coefficients of oils Ub2 and HH-20 were calculated respectively with different rheological models. The elastohydrodynamic lubrication (EHL) film thickness and the traction coefficient between traction drive elements were measured. The results of the calculations are consistent with experiments.     

行星锥环无级变速器几何滑动率数值计算方法

本文根据牵引式行星锥环无级变速器的结构特点和传动原理，推导了各接触点牵引系数和传动系数的计算公式，提出了一种确定牵引传动滚动点和圆周力作用点位置的数值计算方法，计算了XM750型无级变速器几何滑动率的理论曲线，测试证明理论曲线与实验曲线基本吻合。     

精密行星滚柱丝杠的传动特性

设计了一种基于行星滚柱丝杠的精密传动机构。根据机电伺服系统的使用要求,分析了行星滚柱丝杠的传动特性。详细阐述了该传动机构的组成、工作原理和主要特点,分析了传动精度和传动效率这两项核心技术指标,得到了各项误差对传动精度的影响程度,如行星滚柱丝杠单向传动误差和回程误差,驱动电机、联轴器、支撑轴承、测量装置和控制系统等的中间装置误差,以及环境因素误差等,推导了传动效率与接触角、螺旋升角的相互关系。最后,构建了实验平台,测试了行星滚柱丝杠的传动精度和传动效率,结果表明其传动精度优于1.5μm,传动效率优于74%。得到的结果验证了设计的传动机构结构紧凑、承载能力强、传动效率高,传动精度好,在精密传动领域有较大的应用价值。     

基于TRIZ的点接触弹流牵引力测试仪的创新设计

基于TRIZ理论,对球槽式点接触弹流牵引力测试仪进行创新设计。通过对传统的双圆盘试验机和球盘试验机的分析,以改善适用性及多用性为目的,针对设计过程中的技术矛盾与物理矛盾,根据TRIZ理论的矛盾矩阵表,选择合适的发明原理,对已有的球盘试验机进行改进,设计出一种新型的牵引力测试仪。该测试仪可以连续地对不同自旋值下的弹流牵引力进行测量,操作过程简单方便,能够模拟环面型无级变速器、滚动轴承的典型工况。结果表明,TRIZ理论成功地实现了点接触弹流牵引力测试仪的创新设计,能够高效地指导产品的设计。     

列车牵引运行仿真系统的设计

以行车线路纵断面、机车、车辆及列车编组等特性数据为基础,将列车牵引计算、列车运行分析、机车电路仿真等相关内容有机地结合起来.利用面向对象的Visual C 编程技术实现了机车牵引运行仿真系统设计与制作.大量测试数据表明该系统功能完善、易学实用、计算结果准确,可用于机车牵引运行的教学与培训.