Static And Dynamic Characteristics Of Novel Magnetic Suspension Coupling

As a bridge between the direct acting electro-mechanical converter and the two-dimensional valve body,the feedback amplifier mechanism plays an important role in position feedback,motion conversion and thrust amplification.However,the existing two-dimensional servo proportional valve mechanical feedback amplification mechanism has friction and wear and other non-linear links,which has a significant impact on the static characteristics of the valve.Based on the permanent magnetic suspension technology,this paper presents a new type of non-contact magnetic suspension coupling,which suspends the oblique wing rotor and valve core in the middle position by the magnetic repulsion force,and realizes the function of position feedback and motion conversion at the same time,so as to completely eliminate the adverse effect of the traditional mechanical feedback amplification mechanism on the valve control characteristics due to the friction and wear of the contact belt and other factors.The main research work and achievements of this paper are as follows:(1)In view of the influence of the traditional mechanical feedback amplification mechanism on the static characteristics of the two-dimensional valve,such as linearity,repeatability and hysteresis,a three-dimensional model of the magnetic suspension coupling section is designed,the structural principle of the magnetic suspension coupling section is described in detail,and the process of force displacement conversion of the coupling section depending on the magnetic suspension principle is described.The size design and checking calculation of the spring required for the magnetic suspension coupling are carried out to ensure the continuity of force transmission between the electro-mechanical converter and the magnetic suspension coupling.(2)Based on the theory of electromagnetic field,the mathematical analytical model of the magnetic suspension coupling is established.The key structural parameters,i.e.the working air gap,the angle ? and the influence of the magnetic fluid on the magnetic moment,are discussed.The direction of the parameterized design of the magnetic suspension coupling is determined.On this basis,the static and dynamic characteristics of the magnetic suspension coupling are simulated by finite element method and multi-body kinematic analysis on ANSYS Maxwell and Adams platform respectively.(3)In order to verify the theory and simulation,three kinds of experimental prototypes with different angles of 12°,15° and 18° are processed,and the static and dynamic characteristics of the magnetic suspension coupling are studied by setting up an experimental platform.The simulation results are in good agreement with the experimental results.When the external proportional electromagnet pushes the external actuator to move 3 mm,the maximum magnetic moment can reach 0.252 N·m,and the step response time is about 120 ms.The parameterized design shows that the reduction of the working air gap and the increase of the angle ? of the inclined wing pitch can improve the magnetic moment and dynamic response of the inclined wing pitch,while the addition of magnetic fluid in the air gap can improve the magnetic moment,but at the same time affect the step response.The research work has an important reference value for the following practical application of the magnetic suspension coupling in the two-dimensional servo proportional valve.