Design And Research Of Power Transmission System For The Chassis Of High-clearance Amphibious Self-propelled Sprayer

A machinery with high inter-row trafficability and plant protection efficiency is urgently needed for pest control during the middle and later periods of the crop growth. General plant protection machinery can’t apply pesticide to high stalk crops,such as rice and corn, in the mid to late growth stage. It also became the bottleneck of agricultural production technology. The key to this problem is the lack of large high-clearance and self-propelled boom sprayer. Therefore, it is urgently needed to develop high-clearance and self-propelled boom sprayer with high efficiency and security, which can control the pests of crops, such as rice and corn, in the mid to late growth stage, in order to promote the growth of agricultural production and farmers’ incomes. The key to solving the technical bottleneck of agricultural production, and promoting the sustainable development of agriculture is researching and producing a high-clearance, amphibious and self-propelled boom sprayer, which is suitable for China’s agricultural production.This paper proposes a power chassis design scheme for a self-propelled and high-clearance boom sprayer. This power chassis adopts the four-wheel drive and hydraulic four-wheel steering structure. It has high ground clearance, amphibiousness and good mobility, etc.At first, the design goal of the machine is put forward. The overall scheme is designed and basic parameters are determined for the self-propelled and high-clearance boom sprayer. Then the chassis transmission scheme is determined.According to the transmission system scheme, the rotating speed of engine, the number of gears, speed range and the size of the driving wheel, the total transmission ratio of each gear transmission is calculated. Next, the reasonable distribution of the total transmission ratio is conducted, and the structure scheme of the gearbox is determined. The theory speed and transmission ratio of each gear transmission are determined, referring to products abroad in the same power grade. Aiming at the key parts of transmission gear mechanism in the gearbox, the goal is to improve the gear strength and bearing capacity. Gear parameters are optimized using KISSsoft software,in order to get higher gear performance. The parts are designed, modeled and assembled using three-dimensional design software Pro/E to find and modify the unreasonable design of structure. The motion simulation model of gear transmission iscompleted. The dynamics simulation analysis of power transfer in the gearbox is carried out, and the reliability of the design is confirmed.Then, the match between the parameters of spraying hydraulic power transmission system and engine working characteristics is studied.Displacement of hydraulic pump and hydraulic motor is determined according to the required running speed and the hydraulic motor speed. Choosing the best matching scheme to ensure the best match between spray speed and spray machine efficiency, at the same time to guarantee the engine work in the area of the high fuel economy and to achieve the goal of high efficiency, energy saving and environmental protection.Finally, sprayer vehicle model is established, the whole vehicle model parameters are improved and the dynamic property and fuel economy of the sprayer vehicle are analyzed and calculated in the Cruise software. The sprayer speed,acceleration, gradability and other dynamic performance and fuel consumption are simulated and calculated.