Design And Research Of A Miniature Electric Tiller For Facility Agriculture

Even though the facility agriculture started a little late in China,in recent years it has vigorously developed and the scales of facility agriculture expands continuously,which has been obtained powerful extension in rural areas.At the end of 2014,the total areas of modern greenhouses had reached to 4.1 million hectare,accounting for more than 85 percent of all over the world.And of course the area and yield of facility agriculture were both ranked first.In spite of the large area and huge yield,most of the facilities are simple,low-cost,low level of mechanization of operating,and most of the operating is still handed which is of great labor intensity and low production capability.And the conventional use of diesel and gasoline engines as the driving force caused much pollution on environment.In the current new normal development environment,as people’s environmental awareness and a gradual increase in labor costs also increased year by year,this put forward high demands for the mechanized farming in facility agriculture.Therefore,for the above reasons,a new miniature electric tiller was designed and developed in order to adopt low-cost domestic facilities.The main contents include as the followings:1.A miniature electric tiller for facility agriculture was designed and the motor selection was analyzed.Proposed the open structure of the tiller to solve the problem of farming(?)could support various ancillary equipment in different location and orientation.And the configuration of machine body was designed to be simplicity,which could be more convenient to change the outfitting tools.It was also easer to store and transport.Designed and developed the miniature electric tiller by choosing one kind of open architecture.The single-phase motor was used as the power source,then the suitable power of motor was calculated.In order to achieve the purpose of simplifying the tiller and combine the actual conditions within the facility,inverter technology was applied to the speed control without the use of transmission.Then a speed experiment was carried out on the single-phase motor equipped with a inventor,and the results showed that the speed performance could meet the needs of low frequency constant torque speed,high frequency constant power speed.2.Analysed,selected and designed the main key components structure of the tiller.The detailed design including the calculation of the transmission ratio,choose the appropriate reducer and check the input and output shafts of reducer.The structural types of rotary roller and operating parameters were analyzed and calculated,which include the types and parameters of rotary blade,blade shaft and the arrangement of blades on the shaft.In the condition of meeting the installation requirements and farming conditions,the frame was design compactly.Then all parts were assembled virtually in CATIA.3.Implemented static analysis on the main key parts of the miniature electric tiller.Static analysis of the cutter shaft and the frame then were present in the paper based on the finite element anaylsis method in ANSYS.The abstract load of torque was applied with 3D surface effective element,which is intuitive and efficient.Then the stress analysis was carried on the frame under two different operational conditions after the whole miniature electric tiller force anaylsis.The results showed that both of the static analysis of two key point components meet the requirements.It is safe when the tiller works in the respect of theory.4.Experiment research on working perfomance of the miniature electirc tiller was carried on.Based on three-dimensional design model the prototype machine was manufactured,then the rotary test was carried on the prototype machine.Taking the frequency of the in venter as a test factor,the ploughing depth,the capability of cutting and smashing soil and economic performance were calculated after the experiment.The results showed that the maximum average ploughing depth is 11.56cm and the rate of soil pulverization is 82.5%.Therefore the design and main characteristics of the miniature electric tiller meet the requirement.The power consumption is 44kW.h/hm2,so it has a nice performance of fuel economy compared to the same power oil-fueled engine tillers.