ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Considering the practical problem that the high-speed planting operation leads to the seed feeding capability insufficient and the difficulty of precise adjustment of feeding quantity of the existing centrifugal metering device, a prototype of spinning disc high-speed metering device for rapeseed with a spiral was developed. Based on the mechanical and physical properties and parameters and the demand of planting quantity for rapeseed, a spiral seed feeding device was proposed and the mechanical model of seed feeding were established and the main structural parameters were analyzed and determined. A three-factor quadratic orthogonal combination test was performed to establish a mathematical model between seed feeding rate, stability variation coefficient of seed feeding rate, damage rate and speed, blade width, and lead. The analysis result showed that the sequence of factors affecting the seed feeding rate were lead, blade width and speed, and the the sequence of factors affecting the stability variation coefficient of seed feeding rate and the damage rate were both speed, lead and blade width. The optimal parameter combination was established when the speed was 81r/min, the blade width was 4mm and the lead was 15mm. The bench verification test results showed that the seed feeding rate was 92.7g/min, the stability coefficient of variation was 0.32%, and the damage rate was 0.29% of the seed feeding device under the optimum combination of parameters. The seed feeding rate was varied from 36.55g/min to 190.94g/min, the stability variation coefficient of the seed rate was less than 1.29%, and the damage rate was less than 0.5%. The field experiment showed that when the planting speed of the seeder was 10km/h, the uniformity variation coefficient of rapeseed seeding was 9.4%, and the planting density was 48~60 plants/m2, which could complete high-speed seeding. It could meet the performance requirements of rapeseed and would provide a reference for the structure improvement of spinning disc metering device for rapeseed.