Construção de uma engrenagem magnética coaxial

Abstract

Mechanical gears are widely used in virtually any system involving a rotating machine and a load, are of vital importance for the processes in which they are inserted, mainly in Wind Generation to approximate the speed of the turbine the speed of the generator. The magnetic gear to the permanent magnets on which this work is based, transmits torque without mechanical contact, so the problems due to friction are solved as well as the complications arising from the operation at high speeds. They also have greater durability and reliability, as well as the inherent protection in case of overload. In order for the torque transmission from one rotor to another to be possible and optimal, the rotors must have the same number of poles. However, in order to obtain non-unitary transmission ratios, we must have a different number of poles in the two rotors (external and internal). This makes it necessary to use the modulators whose role is to allow in certain parts of the air gap the flow is greater and in other parts the flow is greatly attenuated. The proper choice of the number of modulators ensures that in this distorted field in the air gap there is a field harmonic with the same number of poles of the other rotor thus enabling the magnetic coupling. This magnetic gear uses permanent magnets, so the ratio of the shaft speeds is constant, being determined by the division between the number of poles of the external and internal rotors. Analytical and numerical models, more specifically, Computational Finite Element Method (using the Maxwell ANSYS program) were used to understand the physical phenomena involved and the design of prototypes.