摘要 |
This drilling device includes a hydraulic motor, coaxially surrounding the drill rod, for rotating the drill. The rotor of the motor directly rotates the drill, without the use of gears. Advantageously, the rotor includes a replaceable adapter sleeve that has a shape conforming to the peripheral shape of the drill. By replacing the sleeve, drill rods of different shape or size can be accommodated. The rotor may be of the wing cell type, wherein a plurality of radially moveable vanes or wings project radially from a circular rotor into contact with the inner wall of a non-circular cylinder wall. The vanes define cells within which the hydraulic fluid presses against the vanes so as to impart rotation to the rotor, sleeve and drill.
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