Linear or reciprocating electrical machines of tubular construction including superconducting windings

摘要

A synchronous tubular electrical machine comprised of a radial outer member that has a substantially cylindrical inner surface, a radial inner member that is substantially cylindrical and is coaxially disposed within the outer member such that it may move reciprocally relative to the outer member in the axial direction. A plurality of axially spaced circumferential armature coils are electrically insulated from one another and are formed as part of one of the members (either the outer member or the inner member), and a plurality of axially spaced circumferential superconducting coils are formed as part of the other member. During operation of the tubular machine, each superconducting coil is maintained in a superconducting state and an electrical current is supplied to each superconducting coil in such a manner that the current flowing around each coil is in the opposite direction to the current flowing around the coils adjacent to it.