| 摘要 |
The invention provides a roller drill bit having a body (10), a pin (11) extending from the body and a cutter (12) mounted on the pin for rotation about the pin, the cutter being mounted by a rolling bearing (13) having rolling members (16) disposed in radially inner and outer opposed raceway grooves (19, 20) in the pin and cutter respectively. The pin has an aperture (25) extending parallel to the axis of the pin from outside the drill bit body along to and opening into the radially inner raceway groove. The aperture is dimensioned to allow the rolling members of the bearing to pass along the aperture and into the raceway grooves. A plug (26) is fixed in the aperture to locate the rolling members in the raceway grooves. <IMAGE> |
