Development Of Adaptive Gravity Damping Device For Lar Ge Slope Mountainous Orchard Transporter

Targeting the practical problems of particularly difficult to transport fruits, high labor intensity, low efficiency and without suitable transport domestically in large slope mountainous orchard transportation, the paper developed a large slope mountainous orchard transporter, and introduced the overall structure of the transporter, working principle and the design of the key components. The paper focused on the adaptive gravity damping device, introduced the design process of the device, established the dynamics model, and analyzed it. The test platform was built, and brake torque and brake drum temperature was tested; the radiator was developed, and brake drum temperature was tested in the condition; the three-dimensional entity model of the adaptive gravity damping device was established with the Pro/Engineer software, and heat-structure coupling analysis was completed with the ANSYS software.The main contents and conclusions of this study are as follows:1) Combining the topographic features of the large slope mountainous orchard, a large slope mountainous orchard transporter was developed, and the overall structure and working principle of the transporter was introduced. The transporter does not require electric power or fuel oil for power, instead the gravity of the fruits and shipping boxes to complete the transport operations. Shipping boxes can complete the movement process safely and reliably in the order of accelerate-uniform-slow down-stop. Remote control is used, and the operation is learned easily. Its cost is low, and it is popularized easily.2) The truck shoe drum brake was refitted by the principle of centrifugal feedback, and the adaptive gravity damping device was developed with the simple structure, small size, low cost. The braking force is adapted to the gravity, and it can ensure the shipping box to drop along the wire rope uniformly. It does not need operation by people. The structure was developed with pure mechanical structures, which is safely and reliably.3) By analyzing the movement and force of the adaptive gravity damping device movement and gravity force, the dynamic model of the device was established. Through analysis, we know that the braking torque provided by the device is related to speed primarily in the certain circumstances of the structure and parameters, and the relationship is a quadratic function. Larger braking torque can be got by increasing the brake drum radius, brake shoe radius or selecting the shoe with greater density.4) The mechanical transmission model was established. Through analyzing the gravity drive and uniform braking, we know that the different carrying capacity can be got by changing the growth box ratio, and the relationship is a and carrying capacity is proportional to the cube of the transmission ratio. Balancing speed increases with the larger carrying amount, and the relationship is a quadratic function. Change of the carrying amount has little effect on the balancing speed, and the effect gets smaller with larger ratio. In order to ensure transport safety, the ideal descending speed is got by changing the carrying capacity or ratio. Carrying capacity is proportional to the brake drum peripheral radius Rl, brake shoe radius R1, and brake shoe mass m. Carrying capacity is inversely proportional to the cube of the wheels radius, and carrying capacity gets smaller with larger slope.5) Three-dimensional solid model of the adaptive gravity damping device was established by Pro/Engineer software, and simulated the movement of the brake shoes at different speeds. The radial displacement of the brake shoes got larger with larger speed, and it was consistent with the actual situation.6) Test bench of the adaptive gravity damping device was designed and built, and brake torque and brake drum temperature conditions at different speeds was got by the test bench.The relationship of the brake torque and the speed of brake shaft is a quadratic function, and the brake torque gets larger with larger speed, which is consistent with the results of the dynamics model analysis. Under the cooling conditions of cooling fan, the maximum speed the drum could maintain the temperature balance was640r/min, and the brake torque was32N.m, which did not meet the conditions of use. The radiator was designed, and the test was completed under the cooling conditions of the radiator. The maximum speed the drum could maintain the temperature balance was820r/min, and the brake torque was46N.m, which met the conditions of use.7) Through the thermal-structural coupling analysis for the brake drum, the maximum principal stress of the brake drum was106MPa, and the maximum radial deformation was0.11185mm, which met the strength and stiffness requirements of the brake drum.