Abstract:

Aiming at a new type radial telescopic tire building drum used for radial tire building,based on the principle of superposition,a tire building drum mechanism was decomposed into several kinematic sub-chains which possessed the same mobility.Further structural decomposition of the driving unit,several planar six linkage and three bar four kinematic pair branch chains were gotten.The partial freedom,virtual constraints and common constraints of all the kinematic chains were judged based on screw theory and their degrees of freedom were analysed respectively.According to the principle of substitution of the generalized kinematic pair,mobility of the complex loop mechanism composed by multiple sub-chain was studied.
By structural decomposition of the tire building drum mechanism,the number and property of mobility for the mechanism was obtained.

Key words: mobility, screw theory, multi-loop coupling, tire building drum mechanism

摘要：

针对一种用于子午线轮胎成形的新型轴/径向伸缩成形鼓机构,应用叠加原理,将成形鼓机构以自由度相等的基本驱动单元进行拆分。通过进一步对驱动单元进行结构分解,得到平面六杆机构及三杆四副支链等基本运动链。运用螺旋理论,对各简单平面机构及支链进行局部自由度、虚约束及公共约束的判定,分别计算其自由度;并依据广义运动副替代原则,得到多个子链组合而成的复杂多环路机构的自由度。通过对成形鼓机构的结构分解,得到了机构自由度数并对其性质进行了判定。

关键词: 自由度, 螺旋理论, 多环耦合, 成形鼓机构