The Kinematic Design of Automatic Gear Transmissions for Bicycles

Recently, bicycles are used as exercising machines and traffic vehicles. Planetary gear trains can be used as the transmission systems for bicycles. The purpose of this work is to propose a design methodology for the kinematic design of automatic gear transmissions with planetary gear trains for bicycles. First, applying the check list method (combining and extending methods), the design concepts are proposed. Then, based on the the design concepts proposed and train value equation of planetary gear train, we derive the gear ratio equations of automatic three-speed gear transmissions for each invention. Three automatic three-speed gear transmissions are designed to illustrate the design methodology. Based on the proposed methodology, all automatic gear transmissions with planetary gear trains can be synthesized. Index Terms Automatic gear transmissions, chick list method, kinematic design, planetary gear train.