Multi-stage centrifugal pump having tie rods formed from sheet metal

• US 10,808,703 B2
• Filed: 12/07/2016
• Issued: 10/20/2020
• Est. Priority Date: 12/17/2015
• Status: Active Grant

• Current Assignee: Grundfos Holding A/S (POUL DUE Jensen's FOND)
• Original Assignee: Grundfos Holding A/S (POUL DUE Jensen's FOND)
• Inventors: Mikkelsen, Steen, Due Jensen, Niels, Lundsted Poulsen, Brian
• Primary Examiner(s): Wilensky, Moshe
• Assistant Examiner(s): Bui, Andrew Thanh
• Application Number:
  US16/060,215
• Publication Number:
  US 20180363659A1
• Time in Patent Office: 1,413 Days
• CPC Class Codes: F04D 1/066 the casing consisting of a plurality of annuli bolted together
• CPC Class Codes: F04D 29/426 especially adapted for liquid pumps
• CPC Class Codes: F04D 29/628 especially adapted for liquid pumps
• CPC Class Codes: F05D 2230/54 by sheet metal manufacturing

Abstract

A multistage centrifugal pump has a foot part (2) and a head part (9), between which pump stages are integrated. The head part (9) and the foot part (2) are connected via tie-rods (11) which with one end are fastened on the head part (9) and with the other end are fastened on the foot part (2). The tie-rods (11) at one end comprise a thread (14), with which they are tightened on the head part (9). The tie-rods (11) are formed from sheet metal. At the end opposite the thread, the tie-rods include a recess, with which recess the tie-rods are each positively fixed on the foot part (2), at least in the tensile direction (22).

Claims

1. A multi-stage centrifugal pump comprising:

a foot part;

a head part;

pump stages integrated between the foot part and the head part, said pump being designed as an inline pump;

a suction connection and a delivery connection in the foot part, wherein the pump stages are surrounded by an annular channel, by way of which a last pump stage is connected to the delivery connection, the annular channel having an outer channel wall;

tie-rods arranged on the outer channel wall, said tie-rods connecting the head part and the foot part to one another, each of the tie-rods being fixed with one end to the head part and with another end to the foot part, wherein the tie-rods each comprise a thread end, with which thread end the tie-rods are tightened on the head part or on the foot part and the tie-rods comprise at least one sheet metal section, one of the foot part and the head part comprising a plurality of fixing projections, each of the tie-rods comprising at least one recess in the at least one sheet metal section at the another end, wherein each of the tie-rods is positively fixed on the one of the foot part and the head part at least in a pulling direction via one of the fixing projections extending into the at least one recess.

2. The centrifugal pump according to claim 1, wherein the tie-rods at the other end each comprise at least one tie-rod projection positively fixing the other end to the foot part or to the head part, at least in a tensile direction, the pulling direction being parallel to a longitudinal axis of the head part, the tensile direction defining a radial direction relative to the longitudinal axis of the head part.

3. The centrifugal pump according to claim 2, wherein the tie-rod projection is formed by a sheet metal part which is connected to a part of the tie-rod formed from sheet metal, by way of welding, the tie-rod projection being located adjacent to the recess.

4. The centrifugal pump according to claim 3, wherein the sheet metal part which forms the tie-rod projection surrounds the part of the tie-rod which is formed from sheet metal, in a U-shaped configuration and comprises at least one opening for receiving a weld seam.

5. The centrifugal pump according to claim 2, wherein the tie-rod projection is arranged in a peripheral direction of the annular channel wall and further comprising another tie-rod projection wherein two projections are arranged in opposite peripheral directions.

6. The centrifugal pump according to claim 2, wherein the at least one tie-rod projection is arranged in a peripheral direction of the annular channel wall and is formed by an edge recess in the sheet metal, said at least one tie-rod projection projecting in a peripheral direction with respect to the edge recess.

7. The centrifugal pump according to claim 6, wherein the tie-rods each comprise an edge recess on both longitudinal sides, said edge recesses being arranged at the same height.

8. The centrifugal pump according to claim 1, wherein each thread comprises a threaded bolt which by way of welding is connected to the sheet metal section of the tie-rod.

9. The centrifugal pump according to claim 1, wherein hole recesses are provided in the head part, through which hole recesses the thread ends of the tie-rods are led and are fixed and tightened in each case by way of a nut, wherein the head part comprises a motor support.

10. The centrifugal pump according to claim 1, wherein the outer channel wall comprises a cylindrical wall section in the region of the annular channel, between the foot part and the head part comprises a surface with a curvature and the at least one sheet metal section of the tie-rods comprises a curvature which is adapted to the curvature of the cylindrical wall section.

11. The centrifugal pump according to claim 2, wherein rod recesses which comprise an introduction part and a holding part are provided in the foot part, wherein the introduction part is configured such that an end of the tie-rod can be led through, and the holding part is configured such that the end of the tie-rod can be brought with the at least one tie-rod projection into the holding part by way of radially displacing or by way of pivoting or by way of both radially displacing and pivoting, such that the tie-rod is positively held at least in a direction of a pump longitudinal axis, the introduction part comprising an introduction part width, the holding part comprising a holding part width, the introduction part width being greater than the holding part width.

12. The centrifugal pump according to claim 11, wherein the rod recesses are arranged in the foot part in a circular configuration around the pump longitudinal middle axis and introduction parts are covered by a component of the pump for the positive fixation of the tie-rods.

13. The centrifugal pump according to claim 11, wherein the holding parts connect radially outwards onto the introduction parts of the rod recesses, and a cylindrical section of the component positively fixes the ends of the tie-rods in the rod recesses.

14. The centrifugal pump according to claim 11, wherein the rod recesses are arranged in an axial wall of the foot part.

15. The centrifugal pump according to claim 11, wherein the introduction parts of the rod recesses are arranged in a radial wall and the holding parts of the recesses are arranged in an axial or radial wall of the foot part.

16. The centrifugal pump according to claim 1, wherein both the head part and the foot part or the head part or the foot part is configured as a metal cast part, wherein the foot part is configured for placing the pump on a support surface and the head part is configured for receiving an electric motor which drives the pump.

17. The centrifugal pump according to claim 1, wherein the at least one sheet metal section extends at least from the foot part up to the head part.

18. The centrifugal pump according to claim 11, wherein the foot part comprises a pot-shape structure and the rod recesses are arranged in the region, in which the pot base merges into the pot wall.

19. The centrifugal pump according to claim 1, further comprising:

a plurality of supports, wherein the at least one sheet metal section is radially inwardly supported in a region of the head part by the supports.

20. A multi-stage centrifugal pump comprising:

a foot part comprising a suction connection and a delivery connection;

a head part;

a plurality of pump stages integrated between the foot part and the head part, the pump stages being surrounded by an annular channel, wherein a last pump stage is connected to the delivery connection via the annular channel, at least a portion of the annular channel being defined by an outer channel wall;

a tie-rod arranged opposite the outer channel wall, the head part being connected to the foot part via at least the tie-rod, the tie-rod comprising a first end portion and a second end portion, the first end portion comprising a tie-rod projection, the second end portion comprising a threaded end portion, the second end portion being fixed to one of the head part and the foot part, wherein another one of the head part and the foot part comprises a fixing projection, the tie-rod comprising at least one sheet metal section, the at least one metal section comprising a first metal section portion and a second metal section portion, the tie-rod projection comprising a tie-rod projection portion, the first metal section portion being located between the tie-rod projection portion and the second metal section portion, wherein each of the tie-rod projection portion and the second metal section portion extends to a position located radially beyond the first metal section portion with respect to a longitudinal axis of the tie-rod, the tie-rod projection portion, the first metal section portion and the second metal section portion defining a recess, at least a portion of the fixing projection being arranged in the recess to positively fix the first end portion to the another one of the head part and the foot part.