A magnetic bearing (1, 2, 3) has two bearing members (5, 7) each of which
carries a set of bearing elements (4, 6) and the bearing elements (4) of
a said set carried by one member (5) interleaved with the bearing
elements (6) of a said set carried by the other member (7) to define
three or more substantially parallel interleaf gaps (11) between
successive elements (4, 6, 4, . . . ) so that bearing forces can be
developed as a result of magnetic shear stresses acting across those gaps
(11). The magnetic bearing achieves its bearing forces as the sum of
force contributions from a number of parallel (or nearly-parallel)
airgaps (11) and each of these individual airgap force contributions
comes about as the integration of magnetic shear stress over the airgap
area brought about by causing lines of magnetic flux to cross the airgap
at an angle to the normal. A source (3) of magneto-motive force is
arranged that at least one set of flux lines (12) comes to exist which
crosses three or more of the interleaf gaps (11) and at least the
majority of the bearing force is developed as a result of magnetic shear
stresses acting across such interleaf gaps (11).