Abstract :
Internal parallel move gears transmission is a new type of mechanical transmission which is classified as planet gear with little teeth difference. With a lot of merits, for example, compact structure, large transmission ratio, large transmission capacity within per unit weight and large overloading capacity, it can be widely applied in many fields such as vehicle engineering, heavy machinery, aerospace industry and military equipment. In these areas it can completely replace cylindrical gear transmission and worm gear transmission, therefore, there are great prospects in the applications of the internal parallel move gears transmission. However, the tooth difference between the external gear and the internal gear is so little that there could be some kinds of interferences in the process of cutting and assembling gear, resulting in scrap. And the most important parameters in shifting gears transmission are meshing angle and shifting coefficient, the former deterinied by the bending strength of the tooth root and the equation of center distance, but it´s very complicated to select shifting coefficient in the process of actual design. This paper studies the new approach of selecting shifting coefficient in internal parallel move gears transmission by employing the optimum designing method of machinery and mathematical software LINGO through the actual design instance.