Patent ID: 9493990
Filing Date: 2016-11-15
CPC Classification: E21B

Claim Text:
1. A computer implemented method for designing a roller cone drill bit having a bit body with at least a first support arm, a second support arm, and a third support arm with each support arm having a spindle extending therefrom along with a first cone assembly having a first cutting structure, a second cone assembly having a second cutting structure and a third cone assembly having a third cutting structure, the method comprising: providing a computer configured to determine a minimal moment center of at least one cone assembly; determining with the computer a first minimal moment center located along a first axis of rotation of the first cone assembly rotatably coupled around a first spindle where a first bending moment of the first spindle is minimized, the first minimal moment center determined based on the first cutting structure of the first cone assembly; determining with the computer a second minimal moment center located along a second axis of rotation of the second cone assembly rotatably coupled around a second spindle where a second bending moment of the second spindle is minimized, the second minimal moment center determined based on the second cutting structure of the second cone assembly; determining with the computer a third minimal moment center located along a third axis of rotation of the third cone assembly rotatably coupled around a third spindle where a third bending moment of the third spindle is minimized, the third minimal moment center determined based on the third cutting structure of the third cone assembly; designing a first bearing assembly for the first spindle with the first bearing assembly having an associated center disposed proximate the first minimal moment center; designing a second bearing assembly for the second spindle with the second bearing assembly having an associated center disposed proximate the second minimal moment center; and designing a third bearing assembly for the third spindle with the third bearing assembly having an associated center disposed proximate the third minimal moment center.