Patent ID: 8869917

Claim:
A downhole housing, mandrel and bearing assembly comprising: a flex shaft having: an upper end adapted to receive rotational torque power from a downhole motor power output, a lower portion with a longitudinal cavity, at least a portion of said cavity having threads, a lower end having a connector; a tubular mandrel adapted at a lower end to connect to a drill bit, said tubular mandrel having: an upper portion of the tubular mandrel with an external surface containing threads adapted to connect to the threads in the longitudinal cavity of the flex shaft, a longitudinal passage through the tubular mandrel from an upper end to the lower end, a shoulder disposed on a portion of the external surface of the tubular mandrel between the upper portion of the tubular mandrel and a lower portion of the tubular mandrel, said upper portion having a first outside diameter d 1 and said lower portion having a second outside diameter d 2 , wherein the second outside diameter d 2 is greater than the first outside diameter d 1 ; a lower tubular housing having: a longitudinal passage from an upper end of the housing to a lower end of the housing, an upper portion having threads disposed on at least a portion of an external surface, a shoulder disposed between the upper portion of the housing and a lower portion of the housing, said upper portion having a first inside diameter d 3 and said lower portion having a second inside diameter d 4 , wherein the second inside diameter d 4 is greater than the first inside diameter d 3 ; an upper tubular housing having: a longitudinal passage from an upper end of the housing to a lower end of the housing, said longitudinal passage having a lower portion with an internal diameter adapted to receive an upper bearing assembly, said lower portion of the longitudinal passage adapted to connect to the threads on the upper portion of the lower tubular housing; 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.