| 主权项 |
1. A vibrational apparatus, whether uphole or downhole, to be operable as part of a drill string, which apparatus comprises or includes
an elongate casing; an outer elongate assembly substantially coaxially disposed within the casing and constrained against rotation, but not reciprocal longitudinal rectilinear movement, with respect to the casing, the outer elongate assembly having an array of magnets coaxially of and longitudinally of the outer elongate assembly, each magnet of the array having a single pole, whether of mixed or unmixed poles in the array, facing inwardly; an inner elongate assembly at least substantially coaxially disposed within the outer elongate assembly, the inner elongate assembly being adapted to duct a fluid longitudinally of at least part of the vibrational apparatus and providing an array of magnets coaxially of, and longitudinally of, the inner elongate assembly, and at least substantially within, but spaced from, yet coaxially, of the array of the outer elongate assembly, the magnets of the inner elongate assembly each having a single pole, whether of mixed or unmixed poles in the array, facing outwardly; wherein the inner or outer elongate assembly is rotatable under the action of a drive to rotate relative to the other elongate assembly thereby to cause a relative reciprocal rectilinear movement between the inner and outer elongate assemblies as a result of multiple magnetic interactions across the elongate and longitudinally extending annular spacing between the magnetic arrays; and wherein relative rotation of the inner and outer elongate assemblies and the consequential reciprocal rectilinear movement provides a vibrational output from the vibrational apparatus; and wherein the drive derives an input from said fluid to directly or indirectly cause the relative rotation of the inner and outer elongate assemblies yet that fluid is excluded from the said elongate annular spacing, notwithstanding such spacing may contain another fluid. |
