| 摘要 |
A downhole drilling motor comprises a first elastomer stator molded to an inner surface of a housing in a drillstring where the first elastomer stator has a first number of lobes. A dual purpose, helical shaped hollow member is positioned within the first elastomer stator, where the dual purpose hollow member has a second number of lobes formed on an external surface to form a first rotor. The second number of lobes is one less than the first number of lobes. A second elastomer stator is adhered to an inner surface of the dual purpose helical shaped hollow member, where the second elastomer stator has a second helical shaped cavity with the second number of lobes. A second helical shaped rotor is positioned within the second helical cavity, and has a third number of lobes one less than the second number of lobes. |
