Patent ID: 8803398

Claim:
A coreless electric machine apparatus including a first and a second cylindrical member movable relative to each other, comprising: a permanent magnet arranged on the first member; N-phase (N is an integer of 2 or more) air-core electromagnetic coils arranged on the second member; and a coil back yoke arranged on the second member, wherein the electromagnetic coils include effective coil areas for generating a force to move the first member relatively to the second member, and coil end areas, the effective coil areas of the N-phase electromagnetic coils have the same shape, and are arranged in a cylindrical area between the permanent magnet and the coil back yoke, the coil end area of at least (N−1)-phase electromagnetic coil among the N-phase electromagnetic coils is bent to an inner peripheral side or an outer peripheral side of the cylindrical area to prevent interference with the coil end area of the electromagnetic coil of another phase, each of the electromagnetic coils includes a conductor bundle in which a conductor is wound M (M is an integer of 2 or more) times, coil sub-aggregates are provided, each of which includes the N electromagnetic coils of the respective N phases and in each of which a conductor bundle forming an effective coil area of a first-phase electromagnetic coil contacts a conductor bundle forming an effective coil area of another phase electromagnetic coil, and the conductor bundle forming the effective coil area of the another phase electromagnetic coil is contained in an air-core portion of the electromagnetic coil of the first phase, and the coil sub-aggregates are arranged along the cylindrical area, in which the coil sub-aggregates do not overlap each other in a radiation direction of the cylindrical area, and the adjacent coil sub-aggregates contact each other.