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

In view of the problems faced in the land preparation operation in northeast China, such as more clods, serious soil stubble and thickened plow bottom layer, a driven soil crushing and preparation combination machine mainly applicable to potato fields was designed according to the power conditions of the existing Dongfanghong-75 and 802 tractors. This was a new type of machine designed according to the advanced foreign soil conservation tillage method and developed by combining the soil conditions of the northeast and the requirements of potato field preparation. The overall structure and working principle of the machine were described. By designing the soil crushing roller, the author clarified and analyzed the soil crushing roller motion process, the resistance of the wedge-shaped teeth during the working process of the soil crushing roller and the power required during the operation of the soil crushing roller. Based on EDEM discrete element simulation technology, a component-soil simulation model was established with soil crushing rate as test index, and end deflection angle of crushing straight tooth, length of crushing straight edge and unit speed as test influencing factors for simulation experiments. The field tests were conducted on the basis of simulation. The test results showed that the designed soil crusher had a soil crushing rate of 98.45%, an average tillage depth of 14.5cm, a unit speed of 5.7m/s and a crushing roller power consumption of 19.24kW, which proved to have a good operation effect and met the requirements of potato field preparation.