Design and optimisation of three-pole radial-axial HMB with independent radial and axial carrying capacity

The bias flux density in axial and radial air gaps of the three-pole radial-axial HMB is usually selected as a same value and the bias flux density is usually half of the saturation flux density. As a result the radial carrying capacity is proportional to the axial carrying capacity. But in most conditions, the axial and radial carrying capacity is required to be independent with each other. The carrying capacity in one of radial or axial direction will be larger than the required carrying capacity, which will lead to larger volume, heavier weight and higher power loss. In this paper, the three-pole radial-axial HMB is designed based on different bias and saturation flux density in radial and axial air gaps. In this case, the radial and axial carrying capacity can be designed independently and the volume and weight of the three-pole radial-axial HMB can be reduced.