Pump and hydraulic unit of a pump

Patent metadata

Field	Value
Publication number	US-12092129-B2
Application number	US-202218568622-A
Country	US
Kind code	B2
Filing date	Jun 7, 2022
Priority date	Jun 8, 2021
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A hydraulic unit of a pump for pumping liquid comprising solid matter, the hydraulic unit comprising a housing and an impeller seat, the housing having an axial inlet opening and an outlet opening, and the impeller seat having an axial inlet defined by an inlet wall. The impeller seat has an inlet radius (R) measured from an axially extending centre axis (A) to a circular intersection between the inlet wall and the upper surface of the impeller seat, and the impeller seat comprises a guide pin connected to and extending radially inwards from the inlet wall. The guide pin has a tip radius (r) measured from an axially extending centre axis (A) to the radially innermost part of the guide pin, and has a guide pin angle (μ) defined between a cut water line of a cut water and a radius of the impeller seat.

First claim

The invention claimed is:

1. A hydraulic unit of a pump configured for pumping liquid comprising solid matter, the hydraulic unit comprising:
a housing defining a volute and an impeller seat located in the volute;
the housing having an axial inlet opening and an outlet opening,
the impeller seat having an axial inlet defined by an inlet wall,
the impeller seat having an inlet radius (R) measured from an axially extending centre axis (A) to a circular intersection between the inlet wall and an upper surface of the impeller seat; and
the impeller seat comprising a guide pin connected to and extending radially inwards from the inlet wall;
the guide pin having a tip radius (r) measured from an axially extending centre axis (A) to a radially innermost part of the guide pin, and

the housing comprising a cut water,
an imaginary 15%-circle offset radially inwards from the circular intersection fifteen percent of the difference between the inlet radius (R) and the tip radius (r);

a cut water line defined by a radius of the impeller seat tangent to a most downstream point of the cut water, viewed in a direction of rotation of the pump, the cut water line located downstream a radius of the impeller seat perpendicular to the outlet opening, viewed in the direction of rotation of the pump; and
a guide pin angle (μ) between the cut water line and a radius of the impeller seat intersecting a leading edge of the guide pin at the imaginary 15%-circle, viewed in the direction of rotation of the pump, is equal to or more than 3 degrees and equal to or less than 25 degrees.

2. The hydraulic unit of claim 1 , wherein a cut water line angle (α) between the cut water line and the radius of the impeller seat perpendicular to the outlet opening, viewed in the direction of rotation of the pump, is more than 0 degrees and equal to or less than 20 degrees.

3. The hydraulic unit of claim 1 , wherein the impeller seat comprises a feeding groove arranged in the upper surface of the impeller seat and extending from the inlet wall to the periphery of the impeller seat.

4. The hydraulic unit of claim 3 , wherein the feeding groove has a groove inlet at the inlet wall of the impeller seat, the groove inlet having a first upstream edge at the circular intersection, wherein the first upstream edge of the groove inlet is located upstream a first radius of the impeller seat intersecting a second upstream edge of the guide pin at the imaginary 15%-circle, viewed in the direction of rotation of the pump.

5. The hydraulic unit of claim 4 , wherein:
a groove inlet upstream edge line is a second radius of the impeller seat intersecting the upstream edge of the feeding groove ( 14 );
a groove inlet upstream edge angle (λ) between the radius of the impeller seat intersecting the second upstream edge of the guide pin at the imaginary 15%-circle, viewed in the direction of rotation of the pump, and the groove inlet upstream edge line is equal to or more than 0 degrees and equal to or less than 30 degrees.

6. The hydraulic unit of claim 3 , wherein the feeding groove has a groove inlet at the inlet wall of the impeller seat, the groove inlet having a downstream edge at the circular intersection, wherein the downstream edge of the groove inlet is located downstream a radius of the impeller seat intersecting an upstream edge of the guide pin at the imaginary 15%-circle, viewed in the direction of rotation of the pump.

7. The hydraulic unit of claim 1 , wherein the guide pin angle (μ) is equal to or more than 3 degrees and equal to or less than 20 degrees.

8. The hydraulic unit of claim 1 , wherein the guide pin angle (μ) is equal to or more than 3 degrees and equal to or less than 15 degrees.

9. The hydraulic unit of claim 1 , wherein an imaginary 40%-circle is offset radially inwards from the circular intersection forty percent of the difference between the inlet radius (R) and the tip radius (r), wherein the guide pin comprises a leading edge configured for scraping off pollutants from an impeller of the pump, and wherein the guide pin, at least between the inlet wall and the imaginary 40%-circle, comprises a pre-leading edge located upstream the leading edge of the guide pin, viewed in the direction of rotation of the pump and viewed in an axial direction.

10. The hydraulic unit of claim 9 , wherein an axial distance between the pre-leading edge and the leading edge of the guide pin is more than 1 mm and equal to or less than 4 mm.

11. Pump for pumping liquid comprising solid matter, the pump comprising:
an open impeller having a cover plate;
a centrally located hub; and
at least two spirally swept blades connected to the cover plate and to the hub, each blade of the at least two spirally swept blades of the impeller comprising:
a leading edge adjacent the hub,
a trailing edge at the periphery of the impeller, and
a lower edge, the lower edge extending from the leading edge to the trailing edge and separating a suction side of the blade from a pressure side of the blade; and

the hydraulic unit of claim 1 , the leading edge of a first blade of the at least two spirally swept blades configured to cooperate with the guide pin of the impeller seat during operation of the pump and the lower edge of the first blade located opposite the upper surface of the impeller seat.

12. The pump of claim 11 , wherein the impeller is displaceable back and forth in an axial direction in relation to the impeller seat during operation of the pump.

13. The pump of claim 11 , wherein the radially innermost part of the guide pin is located radially outside the hub of the impeller.

14. The pump of claim 11 , wherein a gap between the leading edge of the first blade of the impeller and the upper surface of the guide pin is equal to or more than 0.05 mm and equal to or less than 1 mm.

Assignees

• Xylem Europe Gmbh

Inventors

• Bredwad Viktor
• Ramström Stefan

Classifications

• F04D7/04

  the fluids being viscous or non-homogenous · CPC title

• F04D29/445

  especially adapted for liquid pumps · CPC title

• F04D29/428

  Discharge tongues (F04D17/04 takes precedence) · CPC title

• F04D29/2288

  for comminuting, mixing or separating · CPC title

• F04D29/426 Primary

  especially adapted for liquid pumps · CPC title