【作者】 李敬亚；

【导师】 张衍林；

【作者基本信息】 华中农业大学 ， 农业机械化工程， 2011， 硕士

【摘要】 中国是柑橘的重要源产地之一,种植面积和产量均居世界首位。但由于品种结构不合理,成熟期过于集中,且大都分布在岗地和山坡上,柑橘机械化程度低。因而,研究解决柑橘机械化的关键环节——果园运输十分迫切和必要。本论文结合现有果园运输机械和单轨车的特点,设计并制造了一种山地果园单轨运输机,满足无运输道路的山地果园中果实、农药和肥料的运输需要。运输机结构紧凑,主机长1.4m,高1.1m,宽0.8m,额定功率8.8kw,运行速度约1.2m/s,轨道依地形铺设,适应性强,最小转弯半径3.1m,载重300kg最大爬坡角度为47.9°。运输机有前进、倒退和空档三个档位,可在轨道上任意处停动、制动,操作简单,运行安全可靠。利用现代设计方法,将单轨运输机分传动系统、驱动系统、轨道、机架和制动系统等几部分分别进行理论分析和结构设计,将链传动形式用于驱动,齿带为直径无限大的链轮,驱动轮为链条。通过研究驱动轮与齿带的间隙及夹紧轮与轨道间隙,得出运输机最小转弯半径为3.1m。常用制动的响应时间在0.6s之内,紧急制动响应时间在0.08s之内。将轨道支撑杆视为压杆,分析运输机负载直行、转弯和爬坡三种状态下压杆的强度,均满足要求。研究运输机负载直行、转弯和爬坡三种状态下其重心偏移量,均小于偏移极限。通过分析运输机负载爬坡时受力,得出轨道坡度与负载的关系。载重300kg时,最大爬坡角度为47.9°。分析齿带受力形式,其强度满足要求。根据设计和研究结果,绘制装配图和零件图,完成样机的制造,并对其进行性能试验。通过运行试验,得出单轨运输机运行速度偏慢,进行改进后,速度达1.5m/s,最小转弯半径不变,载重300kg的最大爬坡角度37.7°。单轨运输机运行平稳、噪音低、轨道磨损量小。更多还原

【Abstract】 China is an important source of origin of citrus. Its planting area and output double rank first in the world. However, because of the unreasonable breed structure, excessive concentration of mature, and most distribution area:downland and the slopes, the level of citrus mechanization is low. Therefore, studying how to solve the problem of orchard transportation, which is the key link of citrus mechanization, is urgent and necessary.This paper combined characteristic of the existing orchard transport machinery and single-track, designed and manufactured a single-track mountain orchard transport, which met the need of the transportation of the fruit, pesticide and fertilizer in the orchard without transport roads. The machine’s structure was compact. The main engine’s size was 1.4m×0.8m×1.1m, the power rating was 8.8kw. and the speed was about 1.2m per minute. The track, which had good adaptability, was installed according to the terrain. With load of 300kg, the transport could climb the slope less than or equal 47.9°nd made a turn with the radius not more than 3.1m. Operated simply and working safe and reliably, the machine had three gears:forward, backward and neutral, could brake or stop anywhere on the track.The modern design methods were utilized in the thesis to theoretical analysis and structural design to the transmission system, the drive system, the track, the brake systems and the chassis etc. of the machine. Chose the chain transmission principle as the drive mode, saw the rack as a sprocket wheel with infinite diameter and the driving wheel as a chain. By studying the gap between the rack and driving wheel as well as the gap between the champing wheels and the track, got that the minimum turning radius of the transport was 3.1m. The response time of common brake was less than 0.6 seconds, and the emergency brake 0.08 seconds.Regard the supporting steel tube as strut bars, analyzed the strength of the bars in three conditions:the loaded transport moved in straight line, made a turn and climbed. The strength met requirements. Meanwhile studied the distance offset of the transport’s barycenter in three conditions, and the offset was less than the limit. The relationship between the track gradient and the load was acquired by analyzing the force of the loaded transport when it climbed. Loaded with 300kg, the machine could climbed the slope less than or equal 47.9°. At the same time, strength of the rack met the demand.On the basis of the result, completed the Assembly drawing and part drawings, manufactured the prototype and tested its performances. Through the test, the speed was slow. After modifying the structure, the speed was improved 1.5m/s. The minimum turning radius still was 3.1m, while the maximum slope was 37.7°when the transport loaded with 300kg. The transport worked smoothly with low noise and low wear of the track.更多还原