Dynamic performances of a magnetic thrust bearing based on new soft magnetic composites

Abstract

According to the material theory and analysis method, the characteristics of the soft magnetic composites were analyzed. As the required magnetic properties can be achieved by adjusting the formulation ratio, the high electrical resistivity (about 10−4 Ωm) and decent magnetic properties were obtained. Based on the good performance, soft magnetic composites were firstly applied to the magnetic thrust bearings. The dynamic models including the dynamic stiffnesses, magnetic force based on the effective reluctance model were analyzed. The parameters for soft magnetic composites were obtained by experiments and theoretical calculations. The results showed that the dynamic bandwidth of magnetic force for the bearing with MgO-based soft magnetic composites can reach more than 1000 Hz, which is far beyond that for carbon steel bearing. If the magnetic permeability is further increased to 650, the dynamic bandwidth of the electromagnetic force can also exceed 1000 Hz for the magnetic thrust bearings made by soft magnetic composites. Therefore, the possibility of magnetic thrust bearing made by soft magnetic composites instead of carbon steel materials is equipped with the satisfactory performance, which may provide a theoretical basis and technical support for high-performance magnetic thrust bearing.

Structural optimization and dynamic characteristics of the new type 3-degrees of freedom axial and radial hybrid magnetic bearing

“…Due to its unique surface insulation structure, SMCs have a higher resistivity without affecting the magnetic properties, which is about 3 orders of magnitude higher than that of traditional carbon steel. 13,26…”

“…Due to its unique surface insulation structure, SMCs have a higher resistivity without affecting the magnetic properties, which is about 3 orders of magnitude higher than that of traditional carbon steel. 13,26 In order to obtain the influence of different frequencies and different materials on the equivalent reluctance of bearing, the detailed calculation and analysis in this paper has been carried out. Based on the structure parameters optimized by APSO algorithm, the frequency responses of axial and radial reluctance are analyzed.…”

“…It was mentioned in literature 12 that the use of high-resistivity soft magnetic composite materials can greatly reduce eddy current loss, in which the bandwidth of magnetic thrust bearing made of SMCs had a larger bandwidth (about 1000 Hz) than that of traditional carbon steel materials (about 100 Hz). 13 In order to enable the designed magnetic bearing to be applied more efficiently in actual working conditions, it is necessary to optimize the design of bearing structural parameters. For magnetic bearings with a simple structure, the structural parameters can be calculated directly by the magnetic circuit method or the empirical formulas, 14,15 but this method is not highly accurate and not suitable for magnetic bearings with complex structures.…”

“…It was mentioned in literature 12 that the use of high-resistivity soft magnetic composite materials can greatly reduce eddy current loss, in which the bandwidth of magnetic thrust bearing made of SMCs had a larger bandwidth (about 1000 Hz) than that of traditional carbon steel materials (about 100 Hz). 13…”

A novel permanent magnet bias hybrid thrust magnetic bearing with extremely simple structure for high-speed rotating machinery

“…1 As a type of magnetic bearing (MB), TMB offers a number of advantages, such as, absence of mechanical contact, no requirement for lubrication, low power consumption, and active vibration suppression. 2,3 Therefore, it is being extensively used in the high-speed rotating machineries, such as flywheel energy storage systems, [4][5][6] high-speed motors, 7 turbo machinery, 8,9 and precision machine spindles. 10,11 In general, the TMBs are classified into three categories: active, passive, and hybrid TMBs.…”