An electricity generating device comprising a housing; a first lobed rotor and a second lobed rotor rotatably arranged in a fluid passage enclosed by the housing such that the lobes of the first and the second lobed rotor intermesh to create a barrier between a high-pressure and a low-pressure side of the housing during operation of the device; a first electricity generator to which the first lobed rotor is coupled, the first electricity generator being capable of varying the load of the first lobed rotor; and a second electricity generator to which the second lobed rotor is coupled, the second electricity generator being capable of varying the load of the second lobed rotor. There is also provided a method of synchronizing rotational positions of a first lobed rotor coupled to a first electricity generator and a second lobed rotor connected to a second electricity generator in a turbine.

An electricity generating device comprising a housing; a first lobed rotor and a second lobed rotor rotatably arranged in a fluid passage enclosed by the housing such that the lobes of the first and the second lobed rotor intermesh to create a barrier between a high-pressure and a low-pressure side of the housing during operation of the device; a first electricity generator to which the first lobed rotor is coupled, the first electricity generator being capable of varying the load of the first lobed rotor; and a second electricity generator to which the second lobed rotor is coupled, the second electricity generator being capable of varying the load of the second lobed rotor. There is also provided a method of synchronizing rotational positions of a first lobed rotor coupled to a first electricity generator and a second lobed rotor connected to a second electricity generator in a turbine.

A method for measuring load performance of a positive displacement motor (PDM) test coupon. The test coupon comprises a partial length of a PDM stage and is received inside a sealable test chamber. In some embodiments, the test coupon may be cut from a failed PDM stage. The test chamber is filled with test fluid. In some embodiments, the test fluid may be drilling fluid sampled from a live well. Rotation of the rotor on the test coupon actuates rotation of the stator. A braking torque is applied to the stator rotation, enabling evaluation of, for example, fatigue load performance of test coupon. Additional embodiments comprise the rotor axis and the stator axis being offset in order to simulate rotor/stator eccentricity in a full size PDM stage.

An internal gear pump includes a housing having a pump chamber in which an inner rotor and an outer rotor are arranged. A suction port in communication with a suction path and a discharge port in communication with a discharge path are formed at the housing. The pump chamber includes an inner wall having a suction region at a suction port-side and a discharge region at a discharge port-side. The suction region includes a first suction region extending towards the suction path from a pressing point, where the outer rotor is pressed when the internal gear pump is in operation, and a second suction region between the first suction region and the discharge region. A groove that enlarges a clearance between the outer rotor and the inner wall is formed in the first suction region, but the groove is not formed in the second suction region.

A screw spindle pump having a housing hi which a drive spindle and at least one running spindle having profile assemblies which engage inside each other are received, the free end of the drive spindle and the end portion of the running spindle being supported on a plate which is arranged in the housing, the plate having two faces which are inclined in opposing directions relative to each other and which form a V-shape and on which one of the spindles is supported, respectively.

A drilling motor system for drilling a subterranean well includes a stator tube, the stator tube being an elongated tubular member with a central stator bore. A stator elastomer layer is located within the central stator bore, lining a wall of the central stator bore. The stator elastomer layer has an elastomer bore that includes a plurality of stator lobes extending in a helical pattern along an axial length of the central bore. A rotor is located within the elastomer bore, the rotor being an elongated member that includes a plurality of rotor lobes extending in a helical pattern along an axial length of the rotor. The stator elastomer layer includes a failure detection system, the failure detection system operable to identify a region of damaged stator elastomer layer.

A turbomachine that can be operated as a motor and as a pump, having an axially fixedly mounted shaft, including a power section with rotating inlet and outlet and an associated controller. Because the axial forces (Fgx) have been made independent of the sense of rotation the turbomachine is significantly more reliable, and because the sealing forces have been adjusted it has significantly greater reliability (η) in both running directions. It can be operated with fluids and gases. The turbomachine can be extended by adding a control device and a drive for the control device so as to provide a freewheel function, a braking function and/or blocking function, and so as to shift, modify and optimize the characteristic curves across the entire control range. In both the clockwise and anticlockwise directions the turbomachine has in principle the same properties, although these can be modified and optimized by the control device.

A turbomachine that can be operated as a motor and as a pump, having an axially fixedly mounted shaft, including a power section with rotating inlet and outlet and an associated controller. Because the axial forces (Fgx) have been made independent of the sense of rotation the turbomachine is significantly more reliable, and because the sealing forces have been adjusted it has significantly greater reliability (η) in both running directions. It can be operated with fluids and gases. The turbomachine can be extended by adding a control device and a drive for the control device so as to provide a freewheel function, a braking function and/or blocking function, and so as to shift, modify and optimize the characteristic curves across the entire control range. In both the clockwise and anticlockwise directions the turbomachine has in principle the same properties, although these can be modified and optimized by the control device.

A flow-through assembly for use in a downhole drilling string includes a Moineau-type motor, means for selectively activating the motor such as a ball catch component that selectively causes drilling fluid to enter into or bypass the motor, and a rotating variable choke assembly that is driven by a rotor of the motor. The choke assembly varies the flow rate of drilling fluid as rotation causes ports of the choke assembly to enter into and out of alignment with each other. In one embodiment, the choke assembly comprises a faceted rotary component including bypass ports on the facets of the component. In another embodiment, the choke assembly comprises a tapered rotary component that rotates in a complementarily tapered stationary component.

A flow-through assembly for use in a downhole drilling string includes a Moineau-type motor, means for selectively activating the motor such as a ball catch component that selectively causes drilling fluid to enter into or bypass the motor, and a rotating variable choke assembly that is driven by a rotor of the motor. The choke assembly varies the flow rate of drilling fluid as rotation causes ports of the choke assembly to enter into and out of alignment with each other. In one embodiment, the choke assembly comprises a faceted rotary component including bypass ports on the facets of the component. In another embodiment, the choke assembly comprises a tapered rotary component that rotates in a complementarily tapered stationary component.