Rotary drill bit
AssigneesSandvik Aktiebolag, Aktiebolaget Skf
InventorsGosta Norlander, Angelo Vignotto, Mario Micca
Life of this patent
Estimating the term…
Abstract
A rotary roller bit comprising at least one rotatably carried roller cutter (12) and provided with sealing means (21) for preventing impurities from entering into the bearing system (14, 15, 16,) of the roller cutter. For purposes of preventing axial and wobbling movements of the roller cutter (12) relative to the bit head from creating high contact pressure at the contact surface between the sealing means (21) and the surface against which same seals the sealing means (21) is provided with an elastically yieldable tongue (25) which extends radially relative to the rotational axis of the roller cutter (12).
Claims15
A rotary roller bit comprising a head having a bearing shaft, at least one roller cutter, said roller cutting being rotatably carried on said bearing shaft over bearing means and having an annular sealing means, said annular sealing means being disposed in an annular gap between said head and roller cutter for sealing said bearing means, characterized in that said sealing means comprises a main body and an elastically yieldable tongue firmly attached to said main body of the sealing means, said tongue being formed of a nonmetallic elastic material and having a length substantially exceeding its thickness, said tongue extending from said main body in a direction having a radial component relative to the rotational axis of the roller cutter so that its free end is radially spaced from its end being attached to the main body of the sealing means, thereby causing axial or wobbling movements of the roller cutter relative to the head to be taken up mainly by the yielding movement of tongue relative to the main body.
A rotary roller bit comprising a head, at least one roller cutter, said roller cutter being rotatably carried on a bearing shaft over bearing means and an annular sealing means, said annular sealing means being disposed in an annular gap between said head and roller cutter for sealing said bearing means, characterized in that said sealing means comprises an elastically yieldable tongue, said tongue being firmly attached to the main body of the sealing means and having a radial extension relative to the rotational axis of the roller cutter so that its free end is radially spaced from its end being attached to the main body of the sealing means, thereby causing axial or wobbling movements of the roller cutter relative to the head to be taken up mainly by the yielding movement of the tongue relative to the main body, the main body of the sealing means is connected to one of the mutually rotatable head and roller cutter, the yieldable tongue being adapted to provide a first dynamic seal against the other of the mutually rotatable members, and the sealing means is provided with a second dynamic seal which is of the free-spaced type.
A rotary roller bit comprising a head, at least one roller cutter, said roller cutter being rotatably carried on a bearing shaft over bearing means and an annular sealing means, said annular sealing means being disposed in an annular gap between said head and roller cutter for sealing said bearing means, characterized in that said sealing means comprises an elastically yieldable tongue, said tongue being firmly attached to the main body of the sealing means and having a radial extension relative to the rotational axis of the roller cutter so that its free end is radially spaced from its end being attached to the main body of the sealing means, thereby causing axial or wobbling movements of the roller cutter relative to the head to be taken up mainly by the yielding movement of the tongue relative to the main body, the flushing channel having a direction such that its intersects a plane passing through the rotational axis of the roller cutter, thereby producing the tangential flushing flow.
A rotary roller bit comprising a head, at least one roller cutter, said roller cutter being rotatably carried on a bearing shaft over bearing means, and an annular sealing means, said annular sealing means being disposed in an annular gap between said head and roller cutter for sealing said bearing means, characterized in that said sealing means comprises an elastically yieldable tongue, said tongue being firmly attached to the main body of the sealing means and having a radial extension relative to the rotational axis of the roller cutter so that its free end is radially spaced from its end being attached to the main body of the sealing means, thereby causing axial or wobbling movements of the roller cutter relative to the head to be taken up mainly by the yielding movement of the tongue relative to the main body, the removing means further comprising a nozzle means which is mounted in the mouth of the flushing channel, said nozzle means being adapted to produce the tangential flushing flow.
Dependencies are inferred from the claim text.