塔式起重机载重滑轮组的稳定性研究

对塔式起重机载重滑轮组的稳定性进行了深入讨论并推出了各参数之间的关系式以及My对稳定性的影响。另外,还提供了具体的实验数据。     

对接斜滑块开模制动的注塑模设计

斜滑块分型和推出机构是带轮槽塑件注塑模结构设计的重点。本文分析了带轮塑件的工艺特性,给出了实用的注塑模结构,介绍了注塑模各系统的结构设计,论述了模具的工作原理。该模具利用开模制动装置和斜滑块分型推出机构,完成塑件的分型和脱模,保证产品的生产质量。模具结构紧凑,推出可靠,安装维修操作方便,成型塑件质量好,生产效率高。     

Clearance and friction-induced dynamics of chain CVT drives

A continuously variable transmission (CVT) is an emerging automotive transmission technology that offers a continuum of gear ratios between desired limits. A chain CVT is a friction-limited drive as its performance and torque capacity rely significantly on the friction characteristic of the contact patch between the chain and the pulley. Moreover, such a CVT is susceptible to clearance formation due to assembly defects or extensive continual operation of the system, which further degrades its performance and leads to early wear and failure of the system. The present research focuses on developing models to understand the influence of clearance and different friction characteristics on the dynamic performance of a chain CVT drive. A detailed planar multibody model of a chain CVT is developed in order to accurately capture the dynamics characterized by the discrete structure of the chain, which causes polygonal excitations in the system. A suitable model for clearance between the chain links is embedded into this multibody model of the chain CVT. Friction between the chain link and the pulley sheaves is modeled using different mathematical models which account for different loading scenarios. The mathematical models, the computational scheme, and the results corresponding to different loading scenarios are discussed. The results discuss the influence of friction characteristics and clearance parameters on the dynamic performance, the axial force requirements, and the torque transmitting capacity of a chain CVT drive.     

滑轮组的环式穿绳法

用以往方法穿绕的滑轮组，在起吊应用中常存在一些问题。环式穿绳法的滑轮组，可防止在起吊作业中动滑轮组翻和钢丝绳扭绞。文中介绍这种滑轮组的具体穿绳方法及应用效果。     

钣制带轮近净成形技术及应用前景

钣制带轮以其精度高、节能、节材、动平衡好、无环境污染等特点,逐步淘汰铸/锻造后经机加工生产的其他形式的传统带轮,具有良好的社会效益和经济效益.钣制带轮是以金属板料为毛坯,经过落料、拉深等冲压工序制成圆筒状,然后将其装夹在带有顶压座的芯模上,使其随主轴一起旋转,通过若干不同齿形的旋压成形轮分别沿径向施加压力而成形.分析钣制带轮近净成形技术的研究现状,阐述应用近净成形技术生产带轮的优点,介绍带轮数控旋压设备的发展趋势,最后论述钣制带轮近净成形技术的发展以及应用情况.     

张紧轮匹配设计验证方案研究

柴油机零部件与整机的匹配,都有其性能和可靠性方面的最优匹配方案,本文以张紧轮为例,介绍了产品设计中零部件匹配的选取、优化及验证过程,并采用统计学理论来评价匹配的合理性。     

GT2A4型45吨自动压力机圆边部件的技术改造

指出了ＧＴ２Ａ４型４５吨自动压力机的圆边部件设计上的问题,并介绍了对该圆边部件进行的技术改造。     

Fracture analysis of collapsed heavy-duty pulley in a long-distance continuous conveyors application

In this paper we present a case study of a heavy-duty pulley that failed after 2.1 × 10⁷ cycles. The pulley was installed as a take up on a continuous conveyor under a load of 350 kN transmitted by the counterweight tower. The failure was analyzed using (a) finite element analysis by Ansys, (b) field data analysis, and (c) fracture macro examination. The prior FEA analysis showed that the pulley was designed according to its field application and moreover when re-simulated, by applying higher loads, revealed high potential towards its safety factor. The field examination showed that the conveyor did not suffer any overload that would contribute to the pulley collapse. The macro failure analysis revealed stress discontinuities and fatigue symptoms such as beach marks and even chevron marks within the welding region. In the meantime the welding region did not show evidence of thermal affected zone (TAZ), which is the key to its mechanical strength. The case analysis showed that the pulley was designed in accordance with British Standard [British Standards Institution, BS 5400:1980. Steel, concrete and composite bridges: Part 10: code of practice for fatigue; 1980] but a welding failure generated unexpected stresses and weakness on the welding region which generated fatigue and the final fracture.     

皮带盘固有频率对柴油机扭振的影响

利用东南大学ANZT6扭振测试系统对一款新开发的国四发动机进行扭振测试,以期从不同固有频率的皮带盘样件中找出与发动机的最佳匹配方案。     

大型游艺机自旋滑车运行程序控制的设计

时大型游艺机自旋滑车运行程序控制进行了创新设计，采用可编程序控制器PLC取代传统的继电一接触控制，使设备运行更加安全可靠，提高了产品的市场竞争能力，并取得了较好的经济效益和社会效益。