Modeling Analysis And Structure Design Of Fluid Suspension 3-DOF Motor

With the substantial increase of the industrialization and the rapid development of high and new science and technology,the requirement for the stability and precision of the device is more and more stringent.However,the traditional multi-degree-of-freedom motion needs more than one motors operate by their transmission mechanism simultaneously,which not only take up a lot of space,but hard to operate.Besides,the operation of mechanical transmission mechanism is very complex,the friction between the gears in the whole operation system will greatly affect the stability of the system and the response time,which will reduce the efficiency of the motor,so it has been unable to keep up with the pace of the development of modern science.In the view of the questions above,many scientific researchers has began to focus on the development of the motor which can realize multi-degree-of-freedom movement,then a variety of permanent magnetic multi-DOF motors are proposed and produced.Because of the single connection mode of bearing supporting between the stator and rotor of the motor,the friction affect the rotor parts,which leads to a limited movement precision and poor torque output ability.So a novel type of three-degree-of-freedom motor with a fluid suspension structure is proposed in this paper.Compared with the traditional design methods,the sealing fluid between the stator and the rotor can reduce the friction greatly and maximumly improve the performance and stability of the motor.Moreover,the motor is maximum approximation of red eyes,easy to be miniaturized and integrated.The specific contents of the work are summarized as follows:1)At first,a new type of fluid suspended type three-degree-of-freedom motor is presented in the paper along with its practical significance,then the complete structure parameters and operation principle of the motor are discussed.The innovation of the motor is that the space between the stator and rotor is filled with fluid,to reduce the friction loss as much as possible.Besides,the air gap magnetic induction density is obtained by using the analytical method,which has effects on the motor torque.2)The geometric model of the motor is set up based on the ANSOFT software,the principle of meshing is introduced in detail,and the comparison curves of magnetic induction intensity in different subdivision modes are given;the scalar values of magnetic flux density are obtained under two magnetizing modes: the radial magnetization and parallel magnetization;the three components curves of magnetic flux density of a single rotor PM pole are also given in the spherical coordinate system.In the evaluation of motor performance,there is an important factor can not be ignored,that is the motor's torquecharacteristics.After understanding the basic properties of the motor magnetic field,the electromagnetic torque value is extracted in the static magnetic field,which is imported into MATLAB to get the three-dimensional graph.Meanwhile,the magnetic field characteristics of stator coils are analyzed and calculated.3)In order to has a better study of the electromagnetic properties of this new type motor,the equivalent magnetic network method is selected,which has higher calculation precision among the current motor magnetic field solving methods.Based on the calculation of the boundary conditions and the small unit's parameters,the magnetic induction intensity curves that nearby or far away from the rotor poles are obtained.4)The specific expressions of the motor's electromagnetic torque is obtained by using the virtual displacement method,as selecting the motor's spin rotation as an example where the element is triangle shape;and the torque calculation is completed by using the Maxwell tensor method;then the experimental platform is built based on the above and the torque values are measured.The rationality of the theoretical method adopted is proved by comparing the two methods above.5)The motor's trajectory tracking is preliminarily realized by using the PD algorithm.The dynamic model of the motor is built by the virtual prototype software ADAMS,and the movement features of the motor's rotor poles are analyzed.