Screw ring cone retention apparatus and method for rock bits
AssigneeSmith International, Inc.
InventorBrian C. Muma
Life of this patent
Estimating the term…
Abstract
This invention teaches a means to retain a cutter cone onto a journal bearing of an earth boring rotary cone rock bit. Complementary and registering annular grooves are formed in the bearing surfaces of the journal and the cone. A tangential entry groove transitions from an end of the journal to the annular groove in the journal. Simultaneous 360.degree. rotation and axial movement of the cone over the journal, in combination with a ring distortion ramp block in the cone, threads an end of a split cone retention ring through the entry groove in the journal into the registering annular grooves, thereby retaining the cone on the journal.
Claims20
An apparatus to retain rotary cutter cones on journal bearings of an earth boring rock bit comprising:
- a rock bit body forming a first pin end and a second cutter end, one or more journal bearings project from one or more legs extending from said bit body, said journal bearings being adjacent said second cutter end,
- said rotary cutter cone forming cone bearing surfaces therein, said cone bearing surfaces complement bearing surfaces formed by said journal bearing projecting from said leg of said bit body,
- complementary and registering annular grooves formed by said cone and said journal bearing, a tangential entry groove is formed in said journal, said entry groove extends from an end of said journal to said annular groove in said journal,
- a split cone retention ring, said split cone retention ring having first and second ends, said ring is positioned in said annular groove in said cone prior to assembly of the cone onto the journal, and
- means retained within said cone to distort an end of said split ring to align said end of said split ring with said tangential entry groove in said journal, said ring is moved into said complementary and registering grooves in said cone and said journal to rotatively retain said cone onto said journal when said cone is simultaneously moved over said journal bearing and rotated about 360.degree..
A method of rotatively retaining a cone onto a journal of an earth boring rock bit comprising the steps of:
- forming an annular groove in a bearing surface of said journal,
- forming a tangential entry groove in said journal, said entry groove extends from an end of said journal to said annular groove in said journal,
- forming a complementary and registering annular groove in a bearing surface formed by said cone,
- placing a split cone retention ring in said annular groove formed in said cone prior to assembly of said cone onto said journal,
- forming an angled ramp means contained within said cone, said ramp means serves to distort an end of said split ring to align said end of said ring with said tangential entry groove in said journal, and
- moving said cone axially over said journal while simultaneously rotating said cone thereby moving said split ring through said tangential entry groove into said complementary and registering annular grooves formed in said journal and said cone through about 360.degree. of rotation thereby rotatively securing said cone to said journal.
Dependencies are inferred from the claim text.