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

Aiming at the problems of difficult leveling, poor stability, complex operation and poor safety of traditional tractor in slope operation, a kind of omnidirectional leveling hillside crawler tractor (abbreviated as hillside tractor) was developed. Firstly, based on the analysis of the leveling principle of hillside crawler tractor under condition of slope, the lateral leveling scheme based on parallel four-bar mechanism and the longitudinal leveling scheme based on double frame mechanism were proposed. Secondly, the key components of the hillside tractor (omnidirectional leveling device, walking system, stepless speed regulation drive system based on hydrostatic drive (HST), multi-functional hydraulic system, slope adaptive hydraulic suspension device) were selected, designed and created. Finally, the performance test of hillside tractor was carried out. The test results showed that the vehicle body leveling could be realized on the 0°~15°lateral slope and 0°~10°longitudinal slope, which could effectively improve the stability and safety of the slope driving and operation;the stepless speed regulation of 0~8km/h could be realized, which could meet the speed requirements of flat driving, climbing, contour line operation and other working conditions;the driving, braking, steering, and omnidirectional (lateral and longitudinal) leveling of hillside tractor and posture adjustment of farm tools could be realized by remote control, which greatly improved the convenience of operation;the ground pressure of hillside tractor was 0.025MPa, which indicated that it had good trafficability on soft road and swamp;the steering performance of hillside tractor was good, and the minimum turning radius was 1728mm, which could be used in relatively narrow slope working environment such as hilly areas;the flat deviation rate of hillside tractor was 55%, and the deviation rate after leveling on 15°slope was 5.75%, which was less than 8.62% without tractor leveling, and all met the requirements of corresponding national standard (≤6%); the maximum lifting force of the hydraulic suspension device was 8.2kN, which can meet the operation requirements;the stability of rotary tillage depth on slope land met the national standard (≥85%).The research result had a good reference for the research and development of agricultural machinery in hilly areas.