Patent ID: 8869917
Filing Date: 2014-10-28
Classification: E21B,F16C,Y10T

Abstract:
1. A downhole housing, mandrel and bearing assembly comprising: a flex shaft having: a tubular mandrel adapted at a lower end to connect to a drill bit, said tubular mandrel having: a lower tubular housing having: an upper tubular housing having: an upper bearing assembly disposed in the longitudinal passage of the upper tubular housing, said bearing assembly having at least an upper race member, a middle race member disposed below the upper race member and separated from the upper race member by a plurality of thrust balls, and a lower race member disposed below the middle race member and separated from the middle race member by a plurality of thrust balls; and a lower bearing assembly disposed in the longitudinal passage of the lower tubular housing, said bearing assembly having at least an upper race member that is adapted to be received in the shoulder of the lower housing, a middle race member disposed below the upper race member and separated from the upper race member by a plurality of thrust balls, and a lower end race member disposed below the middle race member and separated from the middle race member by a plurality of thrust balls.