Optimal Structure Design and Performance Tests of Seed metering Device with Fluted Rollers for Precision Wheat Seeding Machine

摘要

In view of drawbacks of the seed metering device with fluted roller, which is widely applied in wheat drill seeding, we provided an optimized design of structure based on basic structures of traditional devices, which usually have the disadvantages of poor adjustability of working parameters, poor working performance with consistency, a relatively higher error of output quantity of sowing, etc.. The main working parameters of the new designed seed metering device, such as opening of fluted roller, and sowing clearance between brush and fluted roller, are accurately adjustable. The main innovation points of the new device are as follow: 1. A new mode of adjusting the opening of fluted rollers by ‘opening adjustment mechanism’ which can effectively solve the problem of poor consistency of opening adjustment. 2. A "7"-shaped brush installation mechanism was designed to accurately locate the brush installation position and accurately adjust the sowing clearance between fluted roller and brush. This design improves the operating accuracy and stability. 3. A combined-type structure of the fluted roller, which is convenient to replace the fluted rollers by hand, which improved the adaptability of the seed metering device. The indoor and in-field performance tests of the designed seed metering device were carried out respectively. 10 seed metering devices were installed on a test platform to run at rotation speed from 2 to 30 r/min during the indoor tests. The average variable coefficient of seeding quantity was 2.3%, the maximum variable coefficient was 3.6%, the standard deviation of variable coefficient was 0.57%. While during the tests in field, 3 levels of target sowing quantity (225kg/hm2,300kg/hm2,375kg/hm2) and 2 levels of vehicle speeds (approximately 2Km/h and 3Km/h respectively ) were set to carry out two-factor cross experiments. 10 seed metering device were installed on a rotary cultivator platform which was driven by a 62.5Kw tractor. The average variable coefficient of seeding quantity was 2.6%, the maximum variable coefficient was 3.8%, the standard deviation of variable coefficient was 0.56%. The test results showed that the performance of the designed seed metering device has high stability and consistency, related research results can be applied to fertilizing in field and provide technical support for the precision seeding and variable rate fertilization, which has a good application prospect in precision agriculture.