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.

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 features a bearing sleeve couples to a pump shaft, and includes a bearing sleeve surface having bores for receiving fasteners; and an adjusting nut having a central bore with central bore threads to rotationally couple to pump shaft threads, is configured to rotate in relation to the bearing sleeve and move the pump shaft axially to adjust an impeller clearance between a working side of an impeller arranged on the pump shaft and a casing of the pump, and is configured with an adjusting nut surface having openings different in number than the bores, sets of corresponding bores and openings aligning at angular adjustment intervals, e.g. every 9 or 15°, when the adjusting nut is rotated in relation to the bearing sleeve in either direction in order to receive fasteners to couple the adjusting nut to the bearing sleeve when the adjustment of the impeller clearance is completed.

A submersible well pump has diffusers fixed within the housing and an impeller mounted between each of the diffusers. Spacer sleeves located between and in abutment with hubs of adjacent ones of the impellers define a stack wherein the impellers rotate in unison with the shaft and are axially movable in unison with each other relative to the shaft. A stop shoulder on the shaft abuts the lower end of the stack. A spring mounted in compression around the shaft in abutment with the upper end of the stack urges the lower end of the stack against the stop shoulder. Upward movement of the stack requires further compression of the spring. Up thrust and down thrust gaps between each impeller and adjacent diffusers prevent up thrust and down thrust from being transferred to any of the diffusers.

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 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 vacuum pump includes a housing with an inlet port, a rotor part in the housing, the rotor part including a recess part facing the inlet port, and a plurality of rotating blades, a rotating shaft overlapping the recess part, and a capping part overlapping the rotating shaft and covering the recess part.

Apparatus and methods are described including a blood pump that includes an impeller that has proximal and distal bushings, and is configured to pump blood through a subject's body. A frame, which includes proximal and distal bearings, is disposed around the impeller. An axial shaft passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. The axial shaft is coupled to at least one of the proximal and distal bushings of the impeller, such that the at least one bushing is held in an axially-fixed position with respect to the axial shaft, and is not held in an axially-fixed position with respect to the proximal and distal bearings. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an impeller that has proximal and distal bushings, and is configured to pump blood through a subject's body. A frame, which includes proximal and distal bearings, is disposed around the impeller. An axial shaft passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. The axial shaft is coupled to at least one of the proximal and distal bushings of the impeller, such that the at least one bushing is held in an axially-fixed position with respect to the axial shaft, and is not held in an axially-fixed position with respect to the proximal and distal bearings. Other applications are also described.

Pumps and fluid-handling devices for modifying at least one property of a fluid and related method comprise a compensation assembly including at least one biasing element to enable a hydraulic insert to move within a housing.