At present, the design and research of gears with small number of teeth and large reduction ratio are less in China, and most of them are about cylindrical gears and helical gears. The research on hypoid gears with small number of teeth and large reduction ratio mostly stays in the stage of theoretical research, and there is no or little machining practice. The main reason is that it is very difficult to process hypoid gears with small number of teeth and large reduction ratio by using the existing gear processing machine tools and generating method. Shi Nianfeng, Liang Guiming and Yang Hongbin studied and analyzed the helical gear with small number of teeth and large number of teeth ratio, introduced its design method and the machining characteristics of forming method, and finally carried out machining simulation in CAD software.
Zhou Ming and Su Dapeng studied the design characteristics of gears with few teeth and the equipment transformation in processing. According to the design principle of bevel gear, Liang Guiming puts forward the non-zero displacement design method, and successfully designs two kinds of spiral bevel gears with large reduction ratio (the number of small gear teeth is 3 and 4 respectively). Finally, according to the design method, the spiral bevel gear with small number of teeth and large reduction ratio is processed. However, the spiral bevel gear designed by this method can only be processed by generating method. This limits the application and popularization of this method in actual production and processing, especially for Hypoid Gears widely processed by forming method. Zhang Jinliang designed two kinds of large reduction ratio hypoid gears with 3 and 4 small gear teeth and 37 large gear teeth by using the design method of virtual pitch cone of wheel blank. The three-dimensional simulation of the two kinds of large reduction ratio hypoid gears was carried out by using three-dimensional software, and the local comprehensive analysis method was adopted, The tooth contact analysis and meshing transmission error of the two kinds of hypoid gears with large reduction ratio are studied.
At present, there are many researches on the gears with small number of teeth and large reduction ratio abroad, which are also about cylindrical gears or helical gears. There is no or very little research on the hypoid gears with small number of teeth and large reduction ratio. Japan Co., Ltd. has some research on hypoid gear with small number of teeth and large reduction ratio, which can make the transmission ratio reach 60. However, due to the confidentiality of the technology, some relevant information about hypoid gear technology with small number of teeth and large reduction ratio is difficult to find.
With the development of science and technology and the progress of mechanical industry, higher requirements are put forward for the miniaturization, high speed and low consumption of gear transmission. Improving the gear ratio of single-stage transmission has become an important means to realize the miniaturization, high speed and low consumption of gear device. Hypoid gear transmission with small number of teeth and large reduction ratio can ensure high transmission efficiency and adopt large single-stage transmission ratio, which creates conditions for reducing the volume of transmission device and production cost. In the future, the demand for gear transmission with small number of teeth and large reduction ratio will be more urgent, and hypoid gear transmission with small number of teeth and large reduction ratio will be more and more applied.
In view of this, the research on hypoid gear with small number of teeth and large reduction ratio will not only make up for the deficiency of meshing theory and design method of current hypoid gear, but also lay a certain theoretical foundation for the development of gear transmission technology with small number of teeth and large reduction ratio. In order to meet the development of small volume, high speed and low consumption gear transmission technology in China’s machinery industry, it provides certain theoretical and technical guidance.