Design On Centralized Slot Wheeled Precision Metering Device For Rapeseed And Experiment On Its Damaged Rate

Precision sowing techniques has been widely applied at home and abroad, especially such as soybean, corn, peanut and other large size of the seeds. These techniques of large size seeds are maturing and put into agricultural production, but precision planters for rapeseed and other small diameter are less.Metering device is a key component of a planter. Its four work process generally includes fulling seeds, clearing seeds, protect species and pushing seeds. The research object of this paper is mechanical precision metering device for rapeseed. The aims are better sowing uniformity, lower seed damage rate and better daptability. Then a centralized slot wheeled precision metering device for rapeseed was designed. Results of the experiments indicate that this metering device could effectively reslove the seed damage and shaped hole bolcking problems inherited in mechanical metering devices. This metering device could plant four rows one time. Its metering roller is an assign controller. It seeds rapeseed to four tubes accurately, and can design more rows according to the requirements of agriculture.This metering device can meet the needs of high speed planting,and provide a new method of planting to improve the efficiency of metering device. The research contents are as follows:(1) Systematic analysis the status and the development of rapeseed metering device status of different types at home. On this basis, the centralized slot wheeled precision metering wheel was determined. According to the work environment, agronomic requirements and dynamic analysis results, the basic parameters of the key parts of the centralized slot wheeled rapeseed precision metering device, such as the metering roller, cleaning wheel and retaining device and the overall program were determined.(2) Physical and mechanical properties of rapeseed studies were carried out. The three-axis size of the rapeseed, spherical degree, moisture content, grain weight, test weight and sliding friction characteristics were studied. And the rapeseed compression tests was carried out.The maximum load and yield load that the rapeseed could bear were computed. These analysis of the compression strength and other mechanical properties, provided a basis to the parameters designing.(3) The main structural of the centralized slot wheeled precision metering device were designed and the working principle and process of the device were introduced. The main working procedure of the mechanical analysis were done. The key component of the design parameters which affecting the metering performance factors were analyzed. The metering device work movement during the process of rapeseed was studied, and a corresponding mathematical model was built.(4) Study on the main factors that impact the fragmentation rate.And carried out single factor experiments and orthogonal experiments. The results of the experiment sent out the best operating parameters.Then the fragmentation patterns of the metering device were analyzed and improvements were proposed. And the metering device had been improved.