The principle of operation, design and features of calculation of magnetic moments of non-contact single-stage magnetic gears, which differs from mechanical gears by unlimited resource, high level of reliability and lack of maintenance, is considered.

The aim of the study is to develop an algorithm for calculating the magnitude of the magnetic moments of coaxial magnetic gears.

Research methods that are used to achieve this goal combine the advantages of analytical approaches and numerical simulation methods. The calculating moments algorithm development and analysis of technical parameters are based on the magnetic circuit theory. Verification of the decisions related to the structure of the equivalent circuit of the magnetic core of the gear is made using the finite element method.

The designed algorithm is based on the assumption of an interaction between two harmonic waves of the magnetomotive force of high-speed and low-speed rotating parts of the gear with the resultant magnetic field, in which magnetic conductive ring with variable magnetic conductivity in tangential direction is located. Integral indicators of such interaction, in particular magnetic moments are determined through the derivative of energy of the magnetic field by the angle of rotation of the corresponding rotor.

The FEM-analysis of the magnetic field allow to develop the equivalent circuit of the magnetic core of the gear, the parameters of which are determined on the basis of the magnetic circuit parts size and the magnetic properties of used materials. The solution of the system of linear equations that describe this equivalent circuit gives values that characterize the magnetic field of the gear (magnetic fluxes, MMF poles, magnetic voltage drops). They are directly used in the algorithm for calculating magnetic moments.

The article contains a description of the design and operation principle of the coaxial magnetic gears. A comparison of the results of calculating the maximum moments of such gears with different gear ratios, obtained using the proposed analytical algorithm and FEM-analysis is given.

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