초록 ▼

A downhole motor and bearing assembly for high pressure operation has a tubular housing with an inlet and outlet for flow of drilling fluid. A stator is supported in the housing and a rotor is supported for rotary movement in the stator. An open tubular shaft is connected to the rotor for rotary mov

A downhole motor and bearing assembly for high pressure operation has a tubular housing with an inlet and outlet for flow of drilling fluid. A stator is supported in the housing and a rotor is supported for rotary movement in the stator. An open tubular shaft is connected to the rotor for rotary movement in the housing. The bearing assembly has bearing members in the housing in fixed spaced relation for carrying downward and upward longitudinal thrust loads. Since the motor is designed for high pressure operation, conventional bearings tend to wear out rapidly. In this motor and bearing assembly, the pressure of drilling fluid passing through the motor is bled into the down hole side of the bearings where the pressure is applied against an upset on the bearings shaft having an exposed area on the lower side sufficient to produce an upward thrust partially or completely offsetting the downward thrust produced by the pressure drop across the drill bit. The pressure balanced bearing assembly is operable in combination with any motor operating on flow of fluid, including Moineau motors, turbodrills, etc.

대표청구항 ▼

A bearing assembly for assembly on a fluid-operated downhole motor on the fluid outlet end therefrom comprising a tubular housing having an inlet and an outlet for flow of fluid there through, a stator supported in a fixed position in said housing, a rotor supported for rotary movement in said stato

A bearing assembly for assembly on a fluid-operated downhole motor on the fluid outlet end therefrom comprising a tubular housing having an inlet and an outlet for flow of fluid there through, a stator supported in a fixed position in said housing, a rotor supported for rotary movement in said stator, said assembly comprising a bearing housing adapted to be removably secured on the outlet end of said motor housing, a shaft for supporting a drill bit and adapted to be connected to said rotor and supported for rotary movement in said bearing housing, said housing being operable to receive drilling fluid under pressure flowing from said motor for discharge there through into the borehole, bearing means cooperable with said shaft and said bearing housing to carry a longitudinally downward thrust load of said shaft, and hydraulically operated means positioned on the fluid inlet side of said bearing housing relative to said bearing means, including an opening through the wall of said bearing housing into the borehole and means exposed to the drilling fluid in the housing operable to apply an upward thrust to said shaft substantially counterbalancing part or all of the downward force applied to said bearing assembly by the pressure drop from the inlet side of said bearing means through the wall of said bearing housing into the borehole.