Electromagnetic machine with at least one pair of concentric rings having modularized magnets and yokes

An electromagnetic machine comprising one or more pairs of concentric rings arranged on a common axis, each pair of concentric rings having a modular first ring and a concentric modular second ring, said first ring and said second ring having opposing first and second surfaces separated by a gap wherein:

• said first ring comprises magnet modules separated by circumferential gaps from adjacent magnet modules, each of said magnet modules comprising a permanent magnet and two pole pieces, one of said pole pieces being on one side of said permanent magnet and the other of said pole pieces being on the other side of said permanent magnet, wherein each of said pole pieces has a side facing one of the circumferential gaps opposite a side facing the permanent magnet, each magnet being magnetized in a tangential direction transverse to said common axis, the polarity of the magnets being such that there are magnetic poles alternating in polarity around said first ring at said first surface, the magnetization of the permanent magnet in a said magnet module being oppositely directed to the magnetization of the permanent magnets in both of the adjacent magnet modules;
• and
• said second ring comprises several laminated yokes, each yoke defining at least one pair of slots in said second surface, said slots extending parallel to said common axis, rectangular coils of wire located in pairs of adjacent slots, said yoke and said coils in said yoke defining a yoke module separated by circumferential gaps from adjacent yoke modules;
• wherein one of said first and second rings of each of said one or more concentric pairs being continuously rotatable relative to the other of said first and second rings about said common axis.