Theoretical Model and Experimental Research on Friction and Torque Characteristics of Hydro-viscous Drive in Mixed Friction Stage

The hydro-viscous drive(HVD)has been widely used in fan transmission in vehicles,fans,and scraper conveyors for step-less speed regulation or soft starting.In the mixed friction stage,the contact,friction,and torque characteristics of friction pairs are very complex and change at any time.The characteristics of the frictional and hydrodynamic lubrication states were studied in order to calculate and predict the friction and torque characteristics of the friction pairs in the mixed friction stage.The fluid torque was calculated by applying the average shear stress model and the load-carrying capacity of asperity was determined on the basis of the fractal contact theory.In addition,the contact friction coefficient of the friction pairs was taken into consideration and measured by using the MM1000-Ⅲfriction and wear testing machine.The asperity friction torque and total torque in the mixed friction stage were obtained and finally,the test rig for the torque characteristics was set up.The results show that the contribution to the total torque is shared by the oil film and the asperity friction.The friction coefficient decreases sharply at first and then increases with a change in the relative rotational speed,following the Stribeck curve closely,and the contact frictional coefficient slowly decreases with increase in the pressure between the friction pairs.The torque between the friction pairs is provided by the asperity friction,and the torque due to the oil film reduces to zero.When the thickness of the oil film is small,a major contribution to the total torque is due to the asperity friction.The total torque also increases with the decrease in the film thickness ratio.Therefore,by theoretical analysis and experimental verification,the torque of the friction pairs in the mixed friction stage can be accurately calculated using the average shear stress model and asperity friction torque model.

液体黏性调速离合器主动轴的有限元分析

对液黏调速离合器主动轴采用传统力学方法进行受力分析,运用ANSYS软件进行有限元验证,掌握了该轴的应力应变规律,指出径向油孔φ22附近存在最大应力应变,为主动轴优化提供了参考依据。

液粘传动系列装置的研究

介绍了液粘传动技术的国内外发展应用情况,对液粘传动系列装置的工作内容及技术关键进行了具体阐述,提出了技术实施方案,设计了流程图并指出目前该领域的发展前景。

液粘技术及其应用研究综述

针对矿用运输机械特殊的使用环境及对其大惯量制动安全可靠性能的要求，阐述了液粘技术的概念、性能与特点，研究了液粘技术在煤矿下运带式输送机应用的设计方案、液粘制动器的结构、液压系统设计及预计达到的主要技术指标，指出了该技术用于煤矿机械时在核心结构、设计计算、散热防爆和使用维护等方面应当注意的事项。研究结果表明，液粘制动装置制动力矩大、可靠性高、稳定性好、控制方便，能满足大功率下运带式输送机的制动要求。

几种典型的液粘调速器转速控制系统的分析

详细分析了现有的几种典型的液粘调速离合器转速控制系统及其各自的优缺点 ,并提出一种完善液粘调速器转速控制系统性能的新方法。

基于简化预测控制的液粘调速试验台速比控制

液体粘性调速离合器是一种新型无极调速装置,于20世纪80年代在国内开始迅速发展并已经广泛应用于大功率风机、水泵调速系统中,但是在技术上仍然具有优化空间。液粘离合器试验台有助于液粘调速技术的理论和实践研究。在设计研发液体粘性离合器试验台的过程中,提出了基于模型预测控制的简化算法,结合高速数据采集系统实现对电液比例阀的精准闭环控制,在额定输入转速下实现输出轴无极调速。通过简化的预测控制算法优化了双闭环液粘调速离合器试验台速比控制,具有更高的稳定精度和更快的响应速度,对液粘调速技术的研究具有重要意义。