Research On Rack Tooth Forms Of Self-propelled Monorail Mountain Orchard Transporter

With vast land and abundant resources,China is prolific in the production of fruit and fruit processing industry.The cultivate area and yield of citrus in China have been in the first place in the world,but most citrus trees are planted on steep slopes.Due to the rugged terrain,there are many difficulties in the transportation of fruits and materials in hilly lands.In order to solve the problem,monorail mountain orchard transporter and its corresponding rail were designed and manufactured by HZAU surported by Chinese modern agricultural(citrus)technology system.Besides its small fuselage and strong carrying capacity,the transporter can be laid on complex terrain,which meet the application requirements completely.In order to improve the performance of the transporter,the rack tooth forms of monorail mountain orchard transporter was researched in the paper,which provides references for the optimization of the track structure.With monorail mountain orchard transporter as the object,the paper designed another 3 kinds of tooth forms.And the original tooth form is arc tooth form,which is very sensitive to center-distance error and pitch error.The precise modeling of driving wheel and racks were obtained by using Pro/E software and the virtual prototyping model was built by utilizing the dynamics analytical software ADAMS/View of mechanical system.Otherwise,related mechanical properties test and vibration test were conducted.The main contents and conclusions of this paper are summarized as follows:(1)The dynamic models of the transmission system including the driving wheel and racks were established based on the dynamic theory.Another 3 kinds of tooth forms,which were chain wheel tooth form,pin tooth form and cycloidal tooth form were designed and manufactured in the paper.(2)The virtual prototype model of the transmission system including the driving wheel and racks were established based on the dynamic theory and the Hertz impact-contact theory.Then,based on ADAMS/View simulation software,assay and simulate the relation of the tooth forms and the torque of the driving wheel which was generated when the driving wheel was engaged with the racks.Then,orthogonal experiment was carried out with tooth forms,rail gradients and angular velocity as experiment factors and with the average torque as assessment index.It can be concluded that tooth forms,rail gradients and angular velocity had a large effect on the torque.And the importance index for the torque was tooth forms,rail gradients and angular velocity.For the 4 racks,the comprehensive performance of chain wheel tooth form rack was optimal.(3)Mechanical performance tests were carried out on the transporter with tooth forms,rail gradients and angular velocity as experiment factors and with the average torque as assessment index.Experimental results indicated that the tooth forms had great influence on the driving torque,as on the resistance torque.For the 4 racks,the driving torque and the amplitude of the driving torque were the least when the driving wheel was engaged with the rack of chain wheel tooth form.Compared with the rack of arc tooth form,experimental results showed that the rack of chain wheel tooth form had a better comprehensive performance by decreasing the average driving torque by 33.82%,33.45% and 21.59% respectively under the condition that the angular velocity of the drive wheel was +88.08 rad/s,and the rail gradients were +0°,+6°,+12°,respectively;while by 35.55%,27.24% and 30.43% respectively under the condition that the angular velocity of the drive wheel was-88.08 rad/s,and the track gradients were-0°,-6°,and-12°,respectively.(4)A test bench for riding performance was established,and experimental results showed that the transporter has better ride comfort characteristics in three direction while the driving wheel was engaged with chain wheel tooth form rack,no matter the transporter was moving on the horizontal track,climbing the rial or getting down the rail.The transporter was shaked up and down and back and forth while the driving wheel was engaged with pin tooth form rack.And the transporter was shaked left and right while the driving wheel was engaged with cycloidal tooth form rack.(5)The comprehensive properties of the chain wheel tooth form rack is best and the transporter had excellent mechanical properties and riding performance while the driving wheel was engaged wirh chain wheel tooth form rack.In conclusion,the rack of chain wheel tooth form is more suitable for the rail transport than the other tooth form racks.This research provides the important reference for the structural optimization design of the rail.