Patent ID: 8967299
Filing Date: 2015-03-03
Classification: E21B

Abstract:
1. A downhole motor comprising: a housing; a stator mounted in said housing, said stator having a first stator end and a second stator end; a rotor rotatably mounted in said stator, said rotor having a first rotor end portion extending out of said first stator end and a second rotor end portion extending out of said second stator end; a drive shaft assembly, said drive shaft assembly, including a drive shaft having a first drive shaft end operatively connected to said second end portion of said rotor and a second drive shaft end; an output shaft having a first output shaft end operatively connected to said second drive shaft end and a second output shaft end connected to a bit box, said output shaft and said bit box having an axis extending longitudinally through said drive shaft and said bit box said bit box having an axially facing, annular recess extending from the top surface of said bit box along said axis in the longitudinal direction; a first thrust bearing assembly in surrounding relationship to said output shaft and disposed proximal said first output shaft end, said first thrust bearing assembly having a first rotating thrust bearing rotatable with said output shaft and a first stationary thrust bearing mounted in said housing and in engagement with said first rotating thrust bearing; a second thrust bearing assembly in surrounding relationship to said output shaft and disposed proximal said second output shaft end, said second thrust bearing assembly comprising a second rotating thrust bearing, at least a portion thereof being received in said axially facing, annular recess of said bit box and rotatable with said output shaft and a second stationary thrust bearing in engagement with said second rotating thrust bearing; and a radial bearing assembly disposed in said housing in surrounding relationship to said output shaft and between said first and second thrust bearing assemblies.