Abstract: A bearing arrangement for a turbine rotor of a turbine is adapted to be mounted in a drill string and to be driven by the flow of drilling fluid. The bearing arrangement includes a turbine chamber surrounding the turbine rotor and having an inflow and an outflow, a stator on which the turbine rotor is rotatably mounted, and a cavity formed between the turbine rotor and the stator and accommodating at least one radial plain bearing and being separated from the turbine chamber by an axial plain bearing constructed as a bearing ring seal and by a conveyor screw which is disposed on the turbine rotor and operates to convey from the cavity to the turbine chamber.

Abstract: The invention is directed to a turbine (3) for generating power in a drill string (2), including a turbine rotor (10) drivable by a fluid and a bypass device having a first bypass channel bypassing the turbine rotor (10). For varying the volumetric flow through the bypass channel, provision is made for a valve (28) and a control device driven by the fluid and having a drive element (24) by means of which the valve (28) is movable anywhere between a first and a second position. The drive element (24) produces a flow resistance in the fluid flow path downstream from the turbine rotor (10) and downstream from the valve (28) and in the flow direction takes support upon a spring (26).

Abstract: A controllable pressure reducing valve has a housing which includes an inner chamber extending in the direction of a longitudinal axis and an inlet opening and an outlet opening. The inlet opening and the outlet opening open into the inner chamber at an axial relative distance. The inner chamber includes between the mouths of the inlet opening and the outlet opening at least one annular wall having a cylindrical valve bore. An axially movable valve body which is arranged in the inner chamber, extends through the valve bore and has a piston-type portion guided in the valve bore and adapted to close the valve bore. The piston-type portion includes at least one control recess bounded by a control step which extends in axial direction and in circumferential direction and combines with an edge of the valve bore to form a controllable valve opening.

Abstract: The invention is directed to a turbine (3) for generating power in a drill string (2), including a turbine rotor (10) drivable by a fluid and a bypass device having a first bypass channel bypassing the turbine rotor (10). For varying the volumetric flow through the bypass channel, provision is made for a valve (28) and a control device driven by the fluid and having a drive element (24) by means of which the valve (28) is movable anywhere between a first and a second position. The drive element (24) produces a flow resistance in the fluid flow path downstream from the turbine rotor (10) and downstream from the valve (28) and in the flow direction takes support upon a spring (26).

Abstract: The invention is directed to a controllable pressure reducing valve (1) having a housing (2) which includes an inner chamber (3) extending in the direction of a longitudinal axis and having an inlet opening (15) and an outlet opening (17), said inlet opening (15) and said outlet opening (17) opening into the inner chamber (3) at an axial relative distance, and said inner chamber (3) including between the mouths of the inlet opening (15) and the outlet opening (17) at least one annular wall (11) having a cylindrical valve bore (20) and an axially movable valve body (4) which is arranged in the inner chamber (3), extends through the valve bore (20) and has a piston-type portion (29) guided in the valve bore (20) and adapted to close the valve bore (20). The piston-type portion (29) includes at least one control recess (45) bounded by a control step (46) which extends in axial direction and in circumferential direction and combines with an edge of the valve bore (20) to form a controllable valve opening.

Abstract: Bearing Arrangement for a Turbine Rotor of a Drill String Turbine The invention is directed to a bearing arrangement for a turbine rotor (10) of a turbine (3) adapted to be mounted in a drill string (2) and to be driven by the flow of drilling fluid, comprising a turbine chamber (11) surrounding the turbine rotor (10) and having an inflow (7) and an outflow (8), a stator (12, 15) on which the turbine rotor (10) is rotatably mounted, and a cavity (32) formed between the turbine rotor (10) and the stator (12, 15) and accommodating at least one radial plain bearing (16, 17) and being separated from the turbine chamber (11) by an axial plain bearing (18) constructed as a bearing ring seal and by a conveyor screw (22) which is disposed on the turbine rotor (10) and operates to convey from the cavity (32) to the turbine chamber (11).

Abstract: The invention is directed to a device for the generation of pressure pulses, being intended for transmitting signals, in a fluid-carrying channel (2), using a pulser (1) designed to be integrated in the channel (2) and having a housing (4) and an adjustable throttling device by means of which the flow resistance can be varied at at least one point of the channel (2), an electrical generator (16), an impeller (9) exposed to the fluid passing through the channel and designed to drive the generator (16), a control device by means of which the load of the generator (16) can be varied in response to control signals, and an actuating device that is connected to the throttling element (12) and effects an adjustment of the throttling element responsively to the driving torque of the generator (16).