Patent ID: 7705482

Claim:
A tool comprising: a nonmagnetic tool housing; a cylindrical rotor inside the tool housing and rotatable in response to a flow of pressurized fluid through the tool housing; magnets mounted in the rotor; a stator on the exterior of the tool housing, the stator dimensioned to cooperate with the magnets to, upon rotation of the rotor, generate electrical current for supply to a load, wherein the stator comprises: an inductor core having opposing ends connected by a middle portion; a coil wound around the middle portion, where both the inductor core and coil are configured to be arced between the opposing ends about the axis of rotation of the rotor, and the inductor core is configured to provide a consistent gap between the face of the inductor core and the face of each magnet while each magnet is being rotated between positions proximal the opposing ends, the inductor core having a length to enable its opposing ends to each be simultaneously radially aligned with a respective magnet in the rotor to complete a magnetic circuit through the inductor core.