Tension distribution in multiple V-belt drives

Determination of the tension distribution in a multiple V-belt drive represents a statically indeterminate problem. The analysis can be split into four parts viz: initial tension, torque transmission, tension distribution and statistics. Here a unified theory is presented based on reasonable assumptions. Focus is directed to the maximum belt tension. Simulations have been performed with measured data. Non-linearities caused by gross slip seem to have a minor influence. A simple approximation is presented which sufficiently well fits the simulated results.     

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.     

金属基V带的新结构

针对现有V带的发展现状及局限性，提出了两种新型V带—金属片绳式V带和柱绳式V带，并对其结构、原理等进行了分析。     

Multimotor electrohydraulic drives in automatic control systems

A generalized structure is proposed for a control system with a multimotor drive, for practically all drive applications in automatic control systems. Methods of drive control are analyzed, and the interaction conditions of the hydraulic motors are determined. An example illustrates the proposed means of reducing motor interaction.     

叉车自动称重系统的设计

简述叉车自动称重装置的工作原理及在叉车上安装该装置的必要性 ,比较分析了国内外几种叉车自动称重设计方案 ,为我国叉车称重系统的合理设计提供了一些思路。     

Intercomparison of automatic fission track counting systems

The methods of counting fission tracks by two image analyzing computers and a spark counting system are compared with a standard microscopy technique. In this comparison, for automatic fission track counting, the two commercially available image analyzer instruments, the Quantimet 720 and the Leitz-Texture Analyzing System (TAS) and a specially designed spark counter, the UTASC system, have been used. The results showed that the relative counting efficiencies of the Quantimet 720, the Leitz-TAS and the UTASC system are 0.974±0.010, 0.988±0.013 and 0.955±0.010, respectively     

金属带式无级变速传动电液控制技术

无级变速传动是汽车的一种理想传动方式。本文阐述了金属带式无级变速传动的工作原理,介绍了国内外金属带式无级变速传动电液控制技术的发展概况,并设计了电液控制系统。针对金属带式无级变速传动电液控制技术若干关键问题进行了详细分析,包括速比和夹紧力的控制、CVT和发动机的综合控制以及CVT的传动效率等,指出电液控制技术是金属带式无级变速传动的重要发展方向之一。     

改造装泊流量和累积量的自动控制

矿煤装运量的不断增加 ,使未安装流量和累积量显示装置的斗轮机因过载或分配煤仓剩余过多而频繁停机 ,导致分配煤仓放料时间过长 ,严重地影响了生产 ,装驳效率只能达到设计能力的 4 5 % ,费时费力。究其原因 ,是由于斗轮机无法控制取料量而造成。为此 ,需对斗轮机加以改造 ,装配电子称量系统来控制取料量。1　可行性分析　　由于斗轮机各单机具有PLC功能 ,且与中控室通过现场总线通信和交换数据 ,因此可将电子秤采集到的数据通过总线传达到中控室 ,操作人员可以通过MV85 0人机界面观察和设定取料总量 ,并通过单机子程序实行对取料总量和最…     

Improving the life of artillery systems

The factors that affect the wear and durability of artillery systems are considered. The dependence of the barrel wear on the number of shots fired is determined experimentally. The use of wear-free technology in barrel manufacture reduces the wear by an order of magnitude and thus extends barrel life.     

双离合器自动变速器控制系统研究

在分析双离合器自动变速器结构的基础上,对该型变速箱的核心控制系统,包括双离合器自动变速器的转速测量、挡位测量、离合器压力测量以及换挡控制系统等关键技术进行了深入的研究,结合车辆的动力学特性,从理论与试验两方面分析了车辆起步过程中的关键要素.实践表明,对双离合器自动变速器的研制与开发具有指导意义.     

金属带式车用无级变速器

金属带无级变速器是汽车用变速器发展的新方向。介绍金属带式无级变速器的发展历史和现状、基本原理、基本结构及发展趋势。     

复合金属V带的研究

针对现存各种V带的不足，提出了一种新型结构的复合V带，进行了组合理论及强度计算方法研究，对样品传动滑差性能和寿命进行了的试验。结果表明，复合金属V带传动功率大、差率小，是一种性能较好的新型大功率传动带。     

基于Kisssoft的V带传动设计

Kisssoft是一款用于机械传动设计分析的软件,计算操作过程简便,计算结果精确。文中借助其V带设计专家系统对V带传动进行参数设计和传动准确性进行校核,重点介绍了该系统参数化设计的过程,进而提高产品的开发效率。     

普通V带传动的简便优化设计

通过对普通Ｖ带传动的计算准则及相关数据进行分析,按最小带传动体积要求求出了各带型的最佳小轮直径,提出了一种简单实用的普通Ｖ带传动的优化设计方法。     

Manufacturing variation models in multi-station machining systems

In product design and quality improvement fields, the development of reliable 3D machining variation models for multi-station machining processes is a key issue to estimate the resulting geometrical and dimensional quality of manufactured parts, generate robust process plans, eliminate downstream manufacturing problems, and reduce ramp-up times. In the literature, two main 3D machining variation models have been studied: the stream of variation model, oriented to product quality improvement (fault diagnosis, process planning evaluation and selection, etc.), and the model of the manufactured part, oriented to product and manufacturing design activities (manufacturing and product tolerance analysis and synthesis). This paper reviews the fundamentals of each model and describes step by step how to derive them using a simple case study. The paper analyzes both models and compares their main characteristics and applications. A discussion about the drawbacks and limitations of each model and some potential research lines in this field are also presented.     

Numerical optimization in the design of automatic unloading systems

Numerical optimization is proposed in the design of automatic unloading systems. In optimization, the total power losses of the pump in system operation are minimized. The optimization algorithm is presented.     

Overcoming nondifferentiability in optimization synthesis of automatic control systems

We solve the problem of minimizing the ravine non-differentiable function defining the quality of the pole location in the synthesis of automatic control systems with reduced-order controllers. The relationship between the objective functions of the location of the polynomial roots and their derivatives is studied. The possibility of conversion from the non-differentiable characteristic of the location of the polynomial roots to a smooth characteristic of its derivative.     

Robust on-line relay automatic tuning of PID control systems

In this paper, a robust on-line relay automatic tuning method for PID control systems is developed which expand on the application domain of Astrom's renowned relay autotuning method. In the proposed configuration, a relay is applied to an inner loop of a controller-stabilised process in the usual manner. Using the induced limit cycle oscillations from the closed-loop system, the controller settings may be re-tuned non-iteratively to achieve enhanced performance without disrupting closed-loop control. Two control tuning methodologies are developed -- a direct and an indirect method based on an explicit process model. Simulation examples and a real-time experiment are provided to illustrate the practical appeal and potential advantages of the proposed method over the basic one.