Research On Design Theory And Method Of Small Rotary Buffer

Rotary falling is a common phenomenon,which widely exists in the mechanical structures such as the cover plate of household electrical appliances,the luggage cabinet of trains,and various automatic equipment frames.The free falling of the load under the action of gravity will not only brings damage to the structure,but also causes huge security risk.In order to improve the performance of the product and protect the structures and operators,recently,a new structure of installing a rotary buffer at the center of rotation has been gradually applied.At present,when designing this type of rotary buffer,Chinese producer designers mainly design through experience,lacking systematic design theory and method.Therefore,to develop the systemic research on rotary buffer has practical significance.The working principle of the screw drive rotary buffer is analyzed.After deducing the transmission characteristics of the screw drive structure and calculating the output resistance moment of the buffer,the mathematical model of rotary buffer-load system is established.The numerical algorithm is used to solve the model and calculate the dynamic performance of the load under the action of the rotary buffer.The range of structural parameters is determined and the matching design method of rotary buffer-load system is analyzed.A user graphical interface for calculating load drop performance by Matlab GUI is created.The failure forms of the screw drive rotary buffer is analyzed.The structural stress simulation of the shaft,push rod and shell of the buffer is carried on by the finite element software Ansys.Combining the stress and deformation nephogram of the simulation results,the structural parameters optimization design of the buffer parts is carried out.The contact stress between parts under dangerous working condition is reducedThe working principle of blade viscous rotary buffer is analyzed.The rheological experiment of damping medium is carried out to obtain its rheological characteristics.The resistance moment output model of the buffer is established,and the mapping relationship between the resistance moment-angular velocity of buffer and the pressure difference-flow of throttle gap is deduced.The pressure difference-flow characteristics of the throttle gap are simulated by the computational fluid dynamics software Fluent,and the parameters of the resistance moment output model are identified by the simulation results.The performance of the load drop is calculated using the obtained parameters,and the influence of the throttle gap parameters to the buffer performance is analyzed.The experimental platform of the buffer performance is designed and established.The load with different parameters is simulated by the falling rod and weight.The angle sensor and torque sensor are used to collect the falling angle of the falling rod and the output resistance moment of the rotary buffer respectively.The output signal of the sensors is processed by the signal acquisition module.The program for the experimental platform is written,which can communicate with the signal acquisition module by Modbus protocol and record the experimental data automatically.The experiment is carried out on the screw drive and the blade viscous rotary buffer respectively.Comparing the experimental result and calculation result,the correctness of the computing method of mathematical model is verified.