System, method and apparatus for downhole torque-transferring ball screw
AssigneeGeneral Downhole Tools, Ltd.
InventorsMichael Harvey, David Devlin, Jovan Vrcar
Life of this patent
Estimating the term…
Abstract
A downhole tool has a main body that is cylindrical and includes a top coupling that couples to a drill string. A second body that is cylindrical is positioned at least partially within the main body. The second body has a bottom coupling that couples to a drill bit. Springs are positioned within the downhole tool and transmit an axial force to the drill bit. A first set of grooves is formed on an interior of the main body, and a second set of grooves is formed on an exterior of the second body. Balls travel within the first and second sets of grooves. At least some of the balls simultaneously engage the main body and the second body.
Claims20
A downhole apparatus, comprising:
- an outer body comprising an axis and a first coupling that is configured to couple the downhole apparatus to a drill string, and inner grooves formed in an interior of the outer body;
- an inner body positioned at least partially within the outer body, the inner body has a second coupling configured to couple to another portion of the drill string, outer grooves formed in an exterior of the inner body, and the outer grooves together with curved transition sections form closed loop grooves;
- a spring positioned within the downhole apparatus and configured to transmit an axial force to a cutting element of the drill string;
- balls configured to travel in the inner grooves, the outer grooves, and the curved transition sections of the outer grooves, with at least some of the balls simultaneously engaging the interior of the outer body and the exterior of the inner body;
- and
- the inner grooves, the outer grooves and the curved transition sections of the outer grooves are contiguous and uninterrupted.
A downhole tool for dampening torsional shock and vibration of a drill string with a drill bit, the downhole tool comprising:
- an outer body having an axis and inner grooves formed in an interior surface thereof;
- an inner body co-axially positioned at least partially within the outer body and axially movable relative to the outer body, the inner body having outer grooves formed in an exterior surface thereof;
- a spring configured to regulate relative axial motion between the inner and outer bodies;
- a fluidic diode configured to dampen relative axial motion between the inner and outer bodies;
- balls received in the inner and outer grooves;
- and
- a centering spring configured to secure the balls in the inner and outer grooves.
A method of using a downhole tool for dampening torsional shock and vibration of a drill string with a drill bit, the method comprising:
- coupling an outer body to the drill string, the outer body having an axis;
- coupling an inner body to the drill bit, and axially moving the inner body and the outer body relative to each other;
- biasing the inner and outer bodies relative to each other;
- dampening axial motion of the inner and outer bodies;
- recirculating balls between the inner and outer bodies and regulating axial motion therebetween;
- and
- the outer bodies comprise grooves that are closed loops with curved transitional groove sections that are contiguous, uninterrupted and recirculate the balls in the closed loops.
Dependencies are inferred from the claim text.