A centrifugal pump for lifting clean water or water with suspended solids includes a hollow body having a front opening, a volute with a delivery port, and an impeller accommodated in the body and designed to be coupled to a motor, with blades tips substantially coplanar at an annular peripheral area. A cover of the front opening includes a flange, an annular wear plate, rigidly joined to the flange and located at a predetermined axial distance from an annular peripheral area of the impeller, and an adjustment system, mounted onto the flange and accessible from the outside, to controllably adjust the axial distance of the wear plate, and to both calibrate the axial position of the wear plate and lock the wear plate in the calibrated position. A method of adjusting the axial distance of the wear plate from an impeller in a centrifugal pump.

An impeller assembly and a pump for pumping a liquid, including a pump chamber and an impeller arranged to rotate in the pump chamber, the impeller being suspended in a lower end of an axially extending drive shaft unit, wherein the lower end of the drive shaft unit is received in a cylinder-shaped recess of the impeller, wherein the impeller is displaceable back and forth in the axial direction in relation to the drive shaft unit. The impeller further includes an axially extending hole that connects the cylinder-shaped recess and the pump chamber and that the drive shaft unit includes an axially extending pin that projects from the lower end of the drive shaft unit, wherein the pin is arranged in the hole.

A pump for pumping a liquid, includes an impeller and an axially extending drive shaft assembly, wherein a distal end of the drive shaft assembly is received in a central recess of the impeller. The drive shaft assembly includes a drive shaft and a connector. The connector includes a sleeve that is in telescopic engagement with the drive shaft. During operation of the pump the impeller is displaceable in the axial direction in relation to the sleeve between a distal rest position and a proximal position. The impeller is biased towards the distal rest position by a spring member arranged between the sleeve and the impeller. The connector includes a hollow adjustment screw that is in threaded engagement with an interior side of the sleeve to limit the maximum degree of telescopic overlap between the sleeve and the drive shaft.

A multistage pump with axial thrust optimization is disclosed includes a pump discharge nozzle and a bypass system coupled to the pump discharge nozzle. The bypass system includes a throttle valve operatively coupled to the pump discharge nozzle, and a bypass line provided at the multistage pump. The bypass line is conducts flow from the throttle valve to a clearance gap of an axial thrust balancing arrangement. The throttle valve may be actuated to adjust a balancing flow through the bypass line such that pressure at the clearance gap is adjusted to increase and decrease fluid pressure at the clearance gap to balance axial thrust at different operating states of the multistage pump.

A centrifugal pump for delivering a medium comprising solid admixtures includes a blade-free space arranged in front of an impeller. The centrifugal pump has a suction-side arrangement that permits variable sizing of the blade-free space. The suction-side arrangement permits the efficiency of the centrifugal pump to be increased while avoiding blockages.

A multistage pump with axial thrust optimization is disclosed includes a pump discharge nozzle and a bypass system coupled to the pump discharge nozzle. The bypass system includes a throttle valve operatively coupled to the pump discharge nozzle, and a bypass line provided at the multistage pump. The bypass line is conducts flow from the throttle valve to a clearance gap of an axial thrust balancing arrangement. The throttle valve may be actuated to adjust a balancing flow through the bypass line such that pressure at the clearance gap is adjusted to increase and decrease fluid pressure at the clearance gap to balance axial thrust at different operating states of the multistage pump.

A rotodynamic pump for pumping a fluid includes an impeller, a housing surrounding the impeller, and a pressure regulating mechanism. The pressure regulating mechanism is configured to adjust the clearance between the impeller and the impeller housing to regulate pressure of the fluid downstream of the impeller. A method of regulating the delivery pressure is also disclosed.

A hydraulically powered rotary actuator is described including: a hydraulic linear actuator which is moveable in both directions between a retracted position and an extended position; a clutch device which is operable between an engaged condition and a disengaged condition; and a rotary output member; wherein the linear actuator is coupled to the rotary output member by way of the clutch.

A hydrodynamic heater pump may include a housing and a stator fixed relative to the housing. A rotor may be coaxially aligned with and positioned adjacent the stator. The rotor and the stator define an interior region of a hydrodynamic chamber operable for heating a fluid present within the interior region of the hydrodynamic chamber. The rotor may be attached to a drive shaft for concurrent rotation therewith. The rotor may be moved axially along an axis of rotation of the drive shaft between a pumping mode position and a heating mode position. The rotor may be located a first distance from the stator when arranged in the heating mode position and a second distance from the stator when arranged in the pumping mode position. The second distance may be greater than the first distance.

A gas turbine engine has an engine core and a bypass duct. A fan drives the flow through the bypass duct. A bypass efficiency is defined as the efficiency of the fan compression of the bypass flow. The bypass efficiency is a function of the bypass flow rate at a given set of conditions. The bypass flow rate at the optimum bypass efficiency is appreciably lower than the maximum bypass flow rate at the given conditions. This results in increased design flexibility and improved overall engine performance.