MULTISTAGE PUMP

Abstract

The invention relates to a multistage pump (1), including a pump body (4), at a lower end of which a base element (2) is arranged, and at an upper end of which a head element (3) is arranged. At least the base element (2) is made from sheet steel and has an inlet port (5) and an outlet port (16). The inlet port (5) and the outlet port (16) are mechanically connected to each other by a pipe (6) running through the base element (2).

Claims

1. A multistage pump, comprising: a base element; a head element; a pump body with a lower end and an upper end, the base element being arranged at the lower end and the head element being arranged at the upper end, wherein at least the base element is made from sheet steel and has an inlet port and an outlet port; and an elongate carrier running through the base element, the inlet port and the outlet port being mechanically connected to each other by the elongate carrier, wherein the elongate carrier is a pipe.

2. A multistage pump according to claim 1, wherein a suction connecting piece is fitted at a first end of the pipe located at the inlet port, and a pressure connecting piece is fitted at a second end of the pipe located at the outlet port.

3. A multistage pump according to claim 1, wherein the base element comprises a base cup which forms a cylindrical outer circumferential wall of the base element.

4. A multistage pump according to claim 3, wherein the suction connecting piece and the pressure connecting piece are respectively connected fixedly by welding to the pipe.

5. A multistage pump according to claim 3, wherein the pipe is connected fixedly, by expanding and/or welding, to the base cup.

6. A multistage pump according to claim 3, wherein the pipe is connected fixedly, by expanding and/or welding, to the base cup.

7. A multistage pump according to claim 1, further comprising an inner pipe for separating fluid entering the pump at the inlet port having a first pressure and fluid being discharged from the pump at the outlet port having a second pressure, the inner pipe comprising a plurality of stacked pipe elements.

8. A multistage pump according to claim 1, wherein the inlet port and the outlet port are arranged at opposing sides at the circumference of the base element.

9. A multistage pump according to claim 1, wherein the pipe connecting the inlet port and the outlet port is a straight pipe with a circular cross section.

10. A multistage pump according to claim 7, wherein at least a first hole is formed in the pipe for providing a passage for the fluid entering the pump through the inlet port to the pump body, so as to pass through a plurality of pump stages arranged within the pump body.

11. A multistage pump according to claim 10, wherein at least one second hole is formed in the pipe adjacent to the outlet port for providing a passage from the inner pipe to the outlet port for the fluid which has passed through the at least one pump stage.

12. A multistage pump according to claim 7, further comprising a disc-shaped member having substantially a same diameter as an inner diameter of the pipe is arranged within the pipe, so as to seal the fluid entering the pump through the inlet port from the fluid being discharged from the pump through the outlet port.

13. A multistage pump according to claim 12, wherein: at least a first hole is formed in the pipe for providing a passage for the fluid entering the pump through the inlet port to the pump body, so as to pass through a plurality of pump stages arranged within the pump body; at least one second hole is formed in the pipe adjacent to the outlet port for providing a passage from the inner pipe to the outlet port for the fluid which has passed through the at least one pump stage; and the disc-shaped member is arranged between the first hole and the at least one second hole of the pipe.

14. A multistage pump according to claim 1, wherein the pipe runs through a suction chamber center, formed within the base element.

15. A multistage pump according to claim 3, wherein the pipe runs through an annular space formed between the inner pipe and the base cup.

16. A multistage pump according to claim 3, wherein the base cup is connected at its upper end to a cylindrical outer sleeve of the pump body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the drawings:

[0024] FIG. 1 shows a multistage pump according to a preferred embodiment of the invention, whereby the lower half of the pump is shown in sectional view and the upper half in regular side view;

[0025] FIG. 2 shows a detail of a lower portion of the multistage pump of FIG. 1 in a cut open perspective view;

[0026] FIG. 3 shows an exploded view of a pipe and connecting pieces for a pump according to an embodiment of the invention;

[0027] FIG. 4 shows a base element including a pipe and connecting pieces for a pump according to an embodiment of the invention;

[0028] FIG. 5 shows a perspective view of the base element, partially cut open;

[0029] FIG. 6A shows a perspective view of the pipe of the multistage pump shown in FIG. 1; and

[0030] FIG. 6B shows a perspective view of the pipe of the multistage pump shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Referring to the drawings, FIG. 1 shows a multistage pump 1 according to a preferred embodiment of the invention, whereby the lower half of the pump 1 is shown in sectional view and the upper half in regular side view. As can be seen, basically the pump 1 can be subdivided in three sections, namely, the lowermost part of the pump 1 is formed by the base element 2, the uppermost part of the pump 1 is formed by a head element 3, and in between the base element 2 and the head element 3, there is arranged a pump body 4. When the pump 1 is activated, fluid, or in particular, water, enters the pump 1 through an inlet port 5 in the base element 2, then passes through a pipe 6 so as to enter through a first hole 7 of the pipe 6 the pump body 4 in which a plurality of pump stages 8, 8, 8, etc. are provided, each having an impeller and an diffuser.

[0032] In the pump body 4, the fluid is passed on from stage to stage upwards within a first annular space 12 surrounded by an inner pipe 9 which consists of a plurality of stackable pipe elements 9, 9, 9, etc., whereby basically each one of the pump stages 8, 8, 8, etc. is surrounded by one of the stackable pipe elements 9, 9, 9, etc. The stackable inner pipe 9 rests on an inner cup member 10 of the base element 2, which in turn is surrounded by an outer base cup 11 of the base element 2. The fluid, after having been passed through the pump stages 8, 8, 8, etc. in the pump body 4, then reaches the head element 3 of the pump 1 then flows back, e.g., through holes of a bearing ring not shown here, into a second annular space 13 which is formed between a jacket or outer sleeve 14 of the pump body 4 and the inner pipe 9. The outer sleeve 14 is sealingly connected, in particular by means of an O-ring 31, to the outer base cup 11 of the base element 2. When the fluid having passed through the second annular space 13 downwards reaches the base element 2 again, it will be discharged from the pump 2 by first passing through a second hole 15 or a plurality of second holes 15, provided in the circumference of the pipe 6 into the pipe 6 and from there, the fluid leaves the pump 1 again through the outlet port 16 of base element 2.

[0033] FIG. 2 shows a detail of a lower portion of the multistage pump 1 of FIG. 1 in a cut open perspective view. Here, the arrangement of a number of pump stages 8, 8, 8, 8, etc. can be seen which are arranged one on top of the other, and each of which is surrounded by a respective element 9, 9, 9, 9, etc. of the stackable inner pipe 9. The elements 9, 9, 9, 9, etc. are connected to each other and together form the inner pipe 9. The lowermost member of the stackable inner pipe 9 rests on and is connected to the inner cup member 10 of the base element 2. The outer jacket of the pump 1 in its middle and lower sections is formed by the outer sleeve 14 encasing the pump body 4 with the plurality of pump stages 8, 8, 8, 8, etc., and the outer base cup 11 of the base element 4.

[0034] Further, as already mentioned above, the base element 2 has an inlet port 5 and an outlet port 16 arranged at the opposing side at the circumference of the base cup 11. The inlet port 5 and the outlet port 16 are mechanically connected to each other by the pipe 6 which passes through the annular space 30 formed between the outer base cup 11 and the inner cup member 10 as well as through the interior space of inner cup member 10 itself, forming a suction chamber of the base element 1. Within the pipe 6, there is arranged a disk-shaped member 17 which basically has the same or a just slightly smaller diameter as the inner diameter of the pipe 6 so as to seal a low pressure section 18 on the inlet side of the pipe 6 from a high pressure section 19 at the outlet side of the pipe 6. Further, both ends of the pipe 6 are provided with respective connecting pieces 20, 20 for connecting the pump 1 to respective external inflow and outflow pipes not shown here.

[0035] FIG. 3 shows the pipe 6 as well as the respective connecting pieces 20, 20 for a multistage pump 1 according to embodiments of the invention in an exploded view. Each one of the connecting pieces 20, 20 can be formed for example by a sleeve 21, 21 which is substantially cylindrical, or by a stepped sleeve 22, 22. The connecting pieces 20, 20 to be fitted on the pipe 6 at the suction or inlet side and the pressure or outlet side of the pump 1 are identical and connected to the pipe by welding.

[0036] FIG. 4 shows a base element 2 including the pipe 6 and connecting pieces 20, 20 for a pump 1 according further embodiments of the invention. As can be seen here, the connecting piece 20, 20 can consist of, a flange part 23, 23, a ring part 24, 24, or a ring part 25, 25 to be fixedly connected to the respective pipe end 26, 26, for example, by welding. FIGS. 3 and 4 show different examples of connecting pieces 20, 20 which make clear that it is very easy to adapt this pump to any connecting system.

[0037] FIG. 5 shows a perspective view of the base element 2, partially cut open at the outlet end of the pipe 6 and base cup 11. As can be seen here, the ring part 25, 25 is fixedly connected to the pipe end 26 at the outlet or pressure side of the pump 1 by means of welding. Further, the pipe 6 is connected to the base cup 11 by welding and to the inner cup member 10 by expanding so that sufficient mechanical strength is provided for the base element 2 of the pump 1, since the components of the base element 2, namely, the base cup 11 and the inner cup member 10 are formed from sheet metal. Also, it can be seen that the disc-shaped member 17 is arranged within the pipe 6 between the first hole 7 on the inlet side or low pressure side, and the plurality of second holes 15 on the outlet side or high pressure side so as to sealingly separate the low pressure section 18 from a high pressure section 19.

[0038] FIG. 6A and FIG. 6B respectively show perspective views of the pipe 6 of the multistage pump shown in FIG. 1, whereby FIG. 6B shows the outlet side of the pipe 6 or high pressure section 19 with the front part of the pipe 6 cut out so that the arrangement of the disc-shaped member 17 between the first hole 7 and the plurality of second holes 15 can be seen. Further, it can be seen that the first hole is arranged at an upper or top part of the pipe 6 which, when assembled in the base element 2 and to the pump 1 is directed towards the pump body 4 or the annular space 12 in which the pump stages 8, 8, 8, etc. are arranged. The first hole 7 has an elongated shape with rounded corners 27 and substantially V-shaped recesses 28 at at least one of the lateral edges 29 of the first hole 7. This hole 7 is part of the suction mouth of the first pumpstage. The second holes 15 are arranged symmetrically around the outer circumference of the pipe 6 at the outlet end and are substantially rectangular, whereby all second holes 15 are formed identically and spaced apart from each other at equal distances.

[0039] The multistage pump 1 being provided with the pipe 6 arranged within the outer base 11 of the base member 2 acts as a stiffening element and provides for sufficient strength when using sheet metal as material for the member of the base member 2.

[0040] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

APPENDIX

Reference Numerals

[0041] 1 multistage pump [0042] 2 base element [0043] 3 head element [0044] 4 pump body [0045] 5 inlet port [0046] 6 pipe [0047] 7 first hole [0048] 8, 8, 8, . . . pump stages [0049] 9 inner pipe [0050] 9, 9, 9, . . . elements of inner pipe [0051] 10 inner cap member [0052] 11 outer base cup [0053] 12 first annular space [0054] 13 second annular space [0055] 14 outer sleeve [0056] 15 second holes [0057] 16 outlet port [0058] 17 disc-shaped member [0059] 18 low pressure section [0060] 19 high pressure section [0061] 20, 20 connecting pieces [0062] 21, 21 inner sleeve [0063] 22, 22 outer sleeve [0064] 23, 23 outer flange part [0065] 24, 24 intermediate ring part [0066] 25, 25 inner ring part [0067] 26, 26 pipe end [0068] 27 rounded corner [0069] 28 recess [0070] 29 lateral edge [0071] 30 third annular space [0072] 31 O-ring