| As oil crops and quality protein forage crops, the planting area of rape have been in the first place in China. Owing to the short suitable period of rape harvest, coarse and tall rape stalk, numerous and intertwined branches, significant differences in pod maturity of rape and complexity of the harvest characteristics, easy fried pod, the harvesting losses will be serious if the method of harvesting has been inappropriate. Therefore, rape harvesting should be timely, efficient, high quality, low consumption. The degree of rape mechanized harvesting is low in China, with the method of traditional manual harvesting, the problems of long retting time, hard sledding and large harvest losses are becoming increasingly prominent, realization of rape mechanized harvesting is imperative to achieve. Meanwhile, owing to the early harvesting period and long suitable harvesting period, the adaptability of break harvesting is strong for rape, and total harvesting losses are less, which is related to the high yield and bumper harvest of rape. Research on rape windrower that adapts to the national conditions, has become a urgently needed production.As the connecting bridges of prime mover and working parts, the transmission part is a major component of harvester. Largely, merits of transmission determines decide the performance and reliability of harvester. Currently, the motor units of before-hanging rape windrower are numerous, the defects are usually present, such as long power, complex structure and so on. Improving the transmission performance is one of the major technical problems that await to solve for harvester, it is also an effective way to improve operation quality of the whole machine. In order to solve the practical problems of existing harvester, a new type of hydraulic driving system was developed, based on analyzing the present research status of power systems in rape harvester, the working principles and types of hydraulic driving system, and researching the drive demands of4SY-1.8rape windrower. The research contents of this paper are as follows:(1) Design of hydraulic driving system for4SY-1.8rape windrower. Based on analyzing the working principle and working process of various working parts in the4SY-1.8rape windrower, the driving demand of4SY-1.8rape windrower was clear, and a new type of hydraulic drive system was developed. In addition to this, the type of hydraulic actuators used to drive working parts, as well as the way of volume throttle adjusting speed composed by the load-sensing pump were determined.(2) Theoretical analysis and calculation of load distribution, as well as the test analysis on the hydraulic driving system were conducted. Based on the load analysis and calculation on hydraulic components driving various working parts, the selection of corresponding hydraulic components was determined, apart from this, the hydraulic driving system was built. Furthermore,the ideal adjustment parameters of operation for the system and the power consumption of the working parts as well were obtained by no-load tests and field tests.The results could provide references for further improvement and optimization of the hydraulic driving system.(3) The distribution of pipe internal flow in the hydraulic driving system was analyzed by simulation. By constructing the math model, moreover, using FLUENT software, numerical analysis on the piping internal flow field of typical partial obstruction in the pipelines of hydraulic driving system was carried out. The distribution characteristic of the flow field inside the pipe was obtained from the research results. Furthermore, based on the distribution characteristic, the pipeline layout improvement program was proposed.(4) The tube losses of hydraulic driving system were analyzed and the preferred tube diameters were determined. Due to analyze on the components of tube losses and system losses, the pressure tubing loss of the branches of the main moving parts in the system was obtained. In order to elect the preferred tube diameters, the method of comprehensive evaluation was developed. |
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