Patent ID: 7481283

Claim:
A wellbore motor and rotary tool system, comprising: means for converting flow of fluid in a wellbore into rotational energy; a magnetic gear member operatively coupled at an input thereof to the means for converting; and a magnetic gear member output adapted to couple rotationally to a rotary wellbore tool, the magnetic gear member including an input shaft rotationally coupled to the means for converting, an output shaft disposed externally to the input shaft, and a magnet section disposed externally to the output shaft, the input shaft, the output shaft and the magnet section disposed inside a housing, the magnet section including a plurality of magnets circumferentially spaced about an interior of a magnet retainer, the magnet retainer having an external shape for cooperatively engaging an interior surface of the housing so as to prevent rotation therebetween, wherein a number of the magnets is selected to provide a selected rotational speed ratio between the input shaft and the output shaft.