Abstract: A wellbore rotating instrument system includes a source of rotational energy for transmission thereof to within a wellbore. At least one magnetic gear assembly is coupled at its input to an output of the source. A rotating load is coupled at its input to a rotational output of the magnetic gear assembly. The at least one magnetic gear assembly comprises a housing, a stator disposed in the housing proximate an inner wall thereof, a second shaft rotatably supported on bearings disposed at longitudinally spaced apart locations inside the housing and a first shaft rotatably supported inside the output shaft. The stator comprises a plurality of magnets disposed in generally circular laminations. The second shaft comprises a non-magnetic, electrically non-conductive body and a plurality of pole pieces disposed circumferentially therearound. The first shaft comprises magnets disposed around its exterior circumference and shaped to fit rotatably within the second shaft.

Abstract: An electrical submersible pump system includes at least one electric motor coupled to a mechanism for hanging the pump system in a wellbore. At least one magnetic gear assembly is coupled at its input to an output of the at least one electric motor. A protector assembly is coupled at an input thereof to an output of the at least one magnetic gear assembly. A pump is functionally coupled at its input to a rotational output of the protector assembly. The protector assembly includes a tortuous path assembly having one end of each of a plurality of tortuous paths therein in fluid communication with fluid in the wellbore. The tortuous paths each have another end in fluid communication with dielectric fluid disposed within the protector, the at least one magnetic gear and the at least one electric motor.

Abstract: A wellbore rotating instrument system includes a source of rotational energy for transmission thereof to within a wellbore. At least one magnetic gear assembly is coupled at its input to an output of the source. A rotating load is coupled at its input to a rotational output of the magnetic gear assembly. The at least one magnetic gear assembly comprises a housing, a stator disposed in the housing proximate an inner wall thereof, a second shaft rotatably supported on bearings disposed at longitudinally spaced apart locations inside the housing and a first shaft rotatably supported inside the output shaft. The stator comprises a plurality of magnets disposed in generally circular laminations. The second shaft comprises a non-magnetic, electrically non-conductive body and a plurality of pole pieces disposed circumferentially therearound. The first shaft comprises magnets disposed around its exterior circumference and shaped to fit rotatably within the second shaft.