Design And Research Of Spiral Drive Device For Crab Pond Bait Boats

(1)Crab pond bait requirements and overall design of crab pond bait boats.According to the baiting requirements of the crab pond and the feeding mode of the river crab,the basic functional module of the spiral-driven bait boat is designed,and the structure and size of the feeding box and the throwing device are mainly designed.Based on the bait boat for small and medium-sized farmers to do promotion,the design of the feeding box loading capacity of 20-25 kg.The throwing device adopts the turntable type to throw the material according to the needs of the speed adjustment,which can effectively reduce the bait crushing rate,and the size of the one-material box between the hulls is constrained.(2)Spiral drive design and how it works.The spiral drive device is the only power source of the bait boat,which is mainly composed of several parts of the shell body,the rotating shaft,the fixed shaft,the rotating taper,and the fixed cone,of which the pontoon part of the shell body needs 40 kg load according to the loading volume of the material box and the hull weight.According to the size of the tank and the constraints of the hull,the diameter of the pontoon is set to 200 mm,and the effective length is 660 mm.The spiral blade is the main part of the hydrodynamic generated by the screw drive,so its modeling and parameters are analyzed.The drive motor is placed inside the housing,for waterproof and volume considerations,the F5085 type motor is selected as the drive motor,and the internal structure of the drive device and the cooperation relationship between the drive device are designed according to the size of the motor.Finally,the steering and force principles of the spiral drive device on the surface of the water are analyzed.(3)Calculation model construction and hydrodynamic analysis of spiral drive device.In order to make the spiral drive device can obtain sufficient hydrodynamic performance,the unstructured tetrahedral grid is used for partitioning,the calculation model of the spiral drive device is established,and the relationship between the spiral blade pitch,height,thickness and hydrodynamic performance is studied.The ratio of jet speed to growth rate is taken at 60mm;the resistance experiment shows that the height of the spiral blade is proportional to the resistance received,the pitch of the blade is proportional to the resistance,and the growth rate ratio is taken at 255mm;the thickness is inversely proportional to the resistance and proportional to the jet speed.The number of blades is inversely proportional to the resistance to which it is affected,and the jet velocity increases less after the number of 3 blades.After a comprehensive evaluation of the four parameters,considering the difficulty of processing and the cost performance,the blade height of the propeller spiral blade is 60 mm,the pitch is 255 mm,the blade thickness is 8mm,and the number of blades is 3 to meet the bait requirements of crab pond.(4)Prototype and testing of screw drive device.In order to verify the feasibility of the calculation model of the spiral drive device,the prototype was tested on site,and in order to improve the fault tolerance rate of the test and reduce the cost of the test,the first calculation model feasibility test was carried out by a small prototype before the prototype.Then the test prototype is printed according to the ratio of 11:8,due to the high requirements of the screw drive device on the airtightness,the printing material is selected as a photosensitive resin that can be molded at one time.After the overall trial production of the test prototype is completed,in order to verify whether its speed can meet the bait requirements of the crab pond,the speed of the prototype is measured when driving laterally in the longitudinal direction,and the results are 0.62/s At 0.68m/s,it can meet the needs.Finally,the resistance test is used to verify the effectiveness of the calculation model,and the resistance measured by the prototype is 83.27 N,and the error with the resistance value of 87.92 N in the simulation results is 5.58%,and the error is controlled at 6 In the % range,the computational model is feasible.After the comparison and verification of the resistance test of the spiral drive device and the numerical simulation,it can be seen that the test error is controlled within 6%,the calculation model of the screw drive device is feasible,and the driving speed of the screw drive device in the water is tested,and the results show that the speed of the spiral drive device can be used for crab pond bait,and when the blade parameter is selected as high as 60 mm,pitch 2 55 mm,blade thickness of 8mm,number of blades is 3 when the hydrodynamic performance is better.