Winding arrangement in single-drive bearingless motor with radial gap

Abstract

A novel single-drive bearingless motor with high passive stiffness and wide gap factor has been proposed.The single-drive bearingless motor has only one set of three phase windings. It generates both torque and axial suspension force independently with only one three-phase inverter and one displacement sensor. Therefore, the single drive bearingless motors have the advantages of low cost and small size. Only axial direction z-axis is actively positioned. The other axes, radial movements x and y, and tilting movements ex and �" are passively stable by repulsive passive magnetic bearings. The stator consists of six C-shaped cores and one set of three-phase windings. A novel V-shaped winding structure is proposed to generate the torque and active axial force simultaneously. In this paper, the winding arrangement is presented. In addition, the mathematical calculation is carried out.

Fold Angle of Winding Arrangement in Single-Drive Bearingless Motor with Radial Gap

“…In this paper, the mathematical calculations are carried out. This paper is an extension of earlier paper (19) . The relationship between torque and active axial force with respect to the fold angle of the V-shaped winding is given.…”

Principle of a Novel Single-Drive Bearingless Motor With Cylindrical Radial Gap

“…In [19], mathematical torque calculation of the V-shaped winding with a virtual winding has been proposed. The number of virtual windings is estimated, and the axial length of the virtual windings is also calculated.…”

“…Let us also assume that k is the number of layers in the radial direction around the stator core of the actual windings. These definitions are shown in detail in [19]. The U-phase torque T Lu is given as; One of U-phase windings is wound in the range of -π / 6 < θ s < π / 6.…”

“…On the other hand, the authors have studied possibilities of torque improvement. When the fold angle is increased, the torque can be improved twice as high as that of the prototype machine as presented in [19]. In addition, the authors have been developing modified winding structure to increase the torque.…”