Abstract: Thanks to characteristics of compact structure, high load strength and good manufacture technics, the movable teeth transmission is expanded to the nonuniform transmission filed. The basic structure of nonconstant mechanism with movable rods is introduced. The profile formula of inner ring is constructed by simple cosine function and the outer is built under given transmission ratio. The continuous rotation condition, the transmission efficiency and the pressure angle among the rods, inner and outer rings of movable teeth device are discussed, which could provide theory base for its design. In addition, according to the initial position of movable rods, the mechanism is divided to two basic types. Ten different results are developed by fixing the rods, inner ring and outer ring separately. A movable teeth device with kinematic feature of elliptical gears is designed. An analysis of ten motion types of the mechanism is made under a set of same geometric datum. The simulation states that the nonuniform mechanism with movable teeth has bright application prospects by means of simple manufacturing process and transmission diversity.

Key words: movable teeth transmission;nonconstant transmission;tooth profile model;pressure angle