Abstract:Screening is one of the critical processes of grain harvesting. The performance of the combine harvester is directly affected by the operating quality of the screening device. The performance of the screening devices can meet the basic requirements of grain harvesting. However, the development of screening technology was affected by some factors, for example, the diversity of agricultural materials, the complexity of the operating environment, and the requirements for agricultural machinery of having the capability of high-speed operation, which resulted in the increase of the throughput and the irregular change of the moisture content. And the difficulty of high-quality-efficient screening would be increased. Screen structure and its driving mechanism were the critical parts of the screening device. The motion of particles on the screen, such as slipping, being thrown upwards, static, and so on, was affected by the shape of the screen, the configuration of the screen hole, the screen material, and other factors. And the performance of the screening device would be affected. The driving mechanism of the screen could achieve the multi-dimensional motion of the screen. The reasonable motion of the screen could accomplish the rapid dispersion of the materials on the screen for penetrating the screen holes efficiently. And the screening efficiency of the device could be improved. The screening technology’s key idea was to solve the contradiction among the screening efficiency, loss percentage of grains, and the impurity percentage of grains. In other words, the grains should penetrate the screen holes efficiently, and the materials other than grains should not penetrate the screen holes but discharge from the device. The purpose of screening was to recover of the full-value grains to ensure the economic value of the grains. These problems were considered, such as particles blocking screen holes, low screening efficiency of devices in a high-throughput, poor fluidity of particles, and wet particles adhering to the screen surface. The research status of screening devices applying to grain was investigated based on the screen’s structure and its driving mechanism. The reference and supplement of grain screening technology, and the efficient and intelligent development of screening devices were discussed. A reference was provided for the research of the grain screening technology and the design of the innovative device in China.