The concept of vibration-damping and vibration-isolating complex passive-active magnetic support based on a complete magnetic-electromagnetic suspension of a vertical rod-shaft

The article considers the issues of conceptual design of a complex vibration-damping and vibration-isolation fully magnetic support of a passive-active type. The project of this support is based on a complete combined magnetic-electromagnetic suspension of a small-sized rotor with control elements. This suspension is practically implemented in the form of a laboratory-experimental rig with radial passive magnetic bearings made of ring rare-earth permanent magnets and with an axial controlled electromagnetic thrust bearing with armored-type cores located in a mirror-like manner relative to the movable disk in the axial direction. The vibration damping characteristics of this axial bearing can be varied by changing the active resistances in the electromagnet circuits or by implementing pre-defined control algorithms when increased vibrations occur. Its vibration-isolation properties can be achieved by creating quasi-zero stiffness sections on the force characteristics, which is ensured by the choice of the control law. To prove this possibility, the search for such force and stiffness characteristics in the work was carried out using numerical mathematical modeling. It has been demonstrated that, due to the use of a corresponding law for controlling power electromagnets in the disk axial position control system, this electromechanical support allows for the required vibration-damping and vibration-isolation characteristics to be provided. It is conceptually shown that in the case of a vertical shaft arrangement, this magnetic suspension can be considered as a whole as a passive-active vibration-damping and vibration-isolation complex support for either a load located above or a body suspended below. The rotor can then be considered as a non-rotating rod-shaft that holds the vibration-isolated load. The possibilities of numerical determination of the required force and stiffness characteristics depending on the parameters of the axial electromagnetic support and control system are investigated. The distinctive features of the numerical algorithm used to solve the problem are shown, with an analysis of their influence on the accuracy of the simulation. The results of the analyses and their verification are presented. Thus, the possibility of using a complete magnetic-electromagnetic suspension of a model rotor as a whole as a vibration-damping and vibration-isolation complex fully magnetic support of a passive-active type has been conceptually confirmed. With a relatively large mass and dimensions of the vibration-insulated object, it is possible to use several such complex supports in a coordinated combination by introducing cross-connections into the control system of the axial electromagnetic support elements. With a relatively large mass and dimensions of the vibration- isolated object, it is possible to use several such complex supports in a coordinated combination by introducing cross-connections into the control system of the axial electromagnetic supporting elements.