【作者】 贺镇；

【导师】 黄茂林；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2006， 博士

【摘要】 平面闭链机构是现代机械产品中应用最为广泛的基本结构形,该机构是以“平面约束结构”为基础来保证其能够实现平面运动,这种人为的强制平面约束,使平面机械系统成为超静定的过约束结构。实际上,由于机械的工作受到各种因素(尤其是形位误差)的影响,造成了对平面约束的干扰,使其具有不确定性,因而导致理论上不影响机械顺畅运动的过约束形成障碍,并对机械的工作性能造成一系列有害影响。寻求新的、性能良好的、具有自调与自适应性的新型连杆机构,并在新的应用中不断完善与创新,使其能够高效率、高稳定地可靠工作并具有较低的生产成本,以满足现代科学技术发展和市场竞争的需要,乃是当前机构学所共同关注的问题。这些问题的解决有着重要的理论意义和工程应用价值。本文以工程实际中广泛使用的平面六杆机构为研究对象,以高效、高可靠性、高稳定性及低成本为主要目标,对多回路机构中的平面约束不确定性的传递与影响度,自调机理与自调结构的合理配置;机械的自适应性机理与实现原则,自适应机构中力的静定与超静定分析与功能结构设计准则;外部自适应与内部误差的自调结构的工程化设计等方面进行了分析与研究。论文的主要研究内容及创新点有以下几部分:⑴以平面闭链Watt型6杆机构为研究对象,首次对多回路平面闭链机构无过约束结构能够实现自调的机理与自调特性进行了详细分析研究,得到了机构能够实现自调的运动副轴线允许误差角以及自调结构的最适宜的运动副配置方式。本文对机构自调特性分析的结果表明,具有空间运动副结构的平面闭链Watt型6杆机构,由于其具有自调性,机构对角度误差的敏感度减小。在进行自调机构结构设计时,要发挥良好的自调作用,Ⅲ、Ⅳ级副,在串联型式的多回路机构中一般应配置在二元素杆上;在并联型式的多回路机构中要使多元素杆具有自调构件的作用时,该构件上的Ⅲ级副至少应有两个,而且Ⅳ(或Ⅴ)级副不能多于1。为了简化结构及保持机构的平面运动性质,最好是使多副杆的所有运动副均为Ⅴ级副,而在其外接悬杆上选择配置3个Ⅲ级副构成“平面自调结构组”。⑵通过系统深入地进行运动副误差对多回路平面闭链连杆机构约束不确定性影响度的单因素定量分析方法及规律的研究,得到了机构中不同运动副误差、不同运动副元素(销和孔)误差和不同平面内误差对机构约束不确定性的影响度,从而为自调机构的结构设计及其精度设计提供了理论依据。同时,这些结论也为今后进一步综合考虑运动副误差研究约束不确定性影响在过约束机构系统中的传递与耦合提供了数学基础。本文的分析结果表明,在多回路机构中除整转副外,更多还原

【Abstract】 Plane closed-chain mechanism is the most widely used basic structural modality in modern machinery products, and it takes the‘plane constraint structure’as its core to maintain plane movement. With this contrived plane constraint, a plane machinery system becomes a statically indeterminate over-constraint structure. Actually, machinery work is affected by various factors (especially the error of profile and position), thus interfered the plane constraint and made it indeterminate. This brings obstacles to over-constraint that would not affect the smooth movement of machinery theoretically, further brings a series of blights to the machinery performance. Therefore, we focus on seeking new link gear with good performance, self-adjusting and self-adaptability; by perfecting and innovating in application, make it works in credibility with high-efficiency, high-stability and low cost, thus to meet the requirement of the development of modern sci-tech and market competition. The resolve of those problems is important in theory and valued in engineering.Taking the object of plane closed-chain six-bar mechanism, which widely used in actual engineering, targeting on high efficiency, high credibility, high stability and lower cost, aiming at the plane constraint in multi-loop mechanism, this article analyzed and studied the transmission and influencing degree of its indetermination; the reasonable configuration of its self-adjusting mechanism and structure; the self-adaptability mechanism and achieving rule. It also analyzed the statically determinate and over statically determinate of force in self-adapt mechanism, and the design rule for performance structure; the engineering design of the self-adjusting structure for exterior self-adapt and internal error. Including the following parts and innovation points:1. Taking the Type Watt plane closed-chain six-bar mechanism as object, initially analyzing and studying in detail the self-adjusting mechanism and characteristics of the multi-loop plane closed chain when the non over-constraint mechanism is able to self-adjust, we got the permissible error-angle of kinematinc pair axis when the mechanism can self-adjust, and the most feasible configuration mode of the self-adjusting structure. The analyzed result of the characteristic of self-adjusting mechanism indicates that, the Type Watt plane closed six-bar mechanism with dimensional kinematinc pair structure, its sensitivity to angle error is decreased as it更多还原