The Pole Curves in the Finite Displacements of Planar Four-Bar Linkages

• Main Authors: Jun-Min Yang, 楊竣閔
• Other Authors: Chintien Huang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/92464617158076775116

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 91 === When a rigid body undergoes a planar finite displacement from one position to another, there exists a point that does not move. This point is called pole. When a body undergoes infinite displacements from a certain position, the curve traced by all the poles is called the pole curve. Given the locations of poles, we can find the corresponding positions of the body. Conversely, if we know the displacements of the body, we can obtain the pole curve. This thesis studies the pole curves of the finite displacements of planar four-bar linkages. There have been a lot of research reports on the paths traced by coupler points of a four-bar mechanism, called coupler curves. However, the research about the pole curves in the finite displacements of planar four-bar linkages was seldom seen. Building on the principle of the graphical synthesis technique, this thesis analyzes the locations of poles and derives the mathematical formula of the pole curves. The characteristics of the pole curves are then investigated. Due to the complex of the pole-curves, we can obtain the pole curve of a general four-bar linkage only by using numerical methods. For the special four-bar linkages that contain sliders, the analytic expressions of their pole curves have been derived.