Instantaneous Motion of a 2-RCR Mechanism with Variable Mobility

摘要

Mobility is a very important parameter for mechanisms, and many methods for calculating the mobility of mechanisms have been proposed till now since it came to be drawn attention in the middle of 19th century. The CKG formula is widely used in the textbook, manuals and applications. However, it has been proved repeatedly to fail to deal with many classical linkages and modern spatial mechanisms as well. On the other hand, although many modifications or extensions of CKG formulas have been proposed, all of them aim at calculating the number of mobility but ignoring other mobility information, such as type, direction and location of motion. Compared with the existing CKG formulas, the analytical method is regarded as a more general and reliable method which could obtain the full information of mobility. By using this method, this paper investigated the instantaneous motion of a 2-RCR mechanism that the number of its mobility is invariable but the type is variable corresponding to different configurations.