PUMP IMPELLER, HOUSING ELEMENT AND PUMP HEREWITH

Abstract

A pump impeller, which can be part of a pump, has an impeller surface and blades being arranged on the impeller surface, wherein at least one of the blades is a blade of the first type which has a blade edge which is inclined toward the front in the rotational direction. The pump impeller can also have blades of a first type and of a second type, the blade geometries thereof differing from one another. A housing element for a pump or of a pump has a housing inner wall defining a flow channel for a fluid medium extending along a central axis. The cross section of the flow channel is greater in a main flow direction and the housing inner wall has a surface structure configured such that it counteracts a return flow counter to the main flow direction along the housing inner wall of the fluid medium.

Claims

1. Pump impeller (1) with an impeller surface (11) and a rotational direction (DR), wherein blades (2, 3) are arranged on the impeller surface (11), wherein at least one of the blades (2, 3) is a blade of the first type (2), characterized in that the blade geometry of the blade of the first type (2) has a blade edge (22) which is inclined toward the front in the rotational direction (DR).

2. Pump impeller (1) with an impeller surface (11) on which blades (2, 3) are arranged, characterized in that at least one of the blades (2, 3) is a blade of the first type (2), characterized in that at least one of the blades (2, 3) is a blade of the second type (3), wherein the blade geometry of the blade of the first type (2) differs from the blade geometry of the blade of the second type (3).

3. Pump impeller (1) according to claim 2, characterized in that the blade geometry of the blade of the first type (2) has a blade edge (22) which is inclined toward the front in the rotational direction (DR).

4. Pump impeller (1) according to claim 1, characterized in that the blade edge (22) is inclined by an angle (w1) relative to an imaginary rotational plane in which the impeller surface (11) rotates in the rotational direction (DR), wherein the angle (w1) is preferably between 55° and 87° or between 60° and 80° or between 65° and 75°.

5. Pump impeller (1) according to claim 1, characterized in that the blade edge (22) is arranged on a base body (21) of the blade geometry of the blade of the first type (2), wherein the base body (21) adjoins the impeller surface (11) and, in particular, the blade edge (22) is arranged spaced apart from the base body (21).

6. Pump impeller (1) according to claim 2, characterized in that the blade geometry of the blade of the second type (3) comprises a base body (31) which adjoins the impeller surface (11) and comprises a blade cover (32) which adjoins the base body (31), wherein a pumping channel (13) is configured between the blade cover (32), the base body (31) and the impeller surface (11).

7. Pump impeller (1) according to claim 6, characterized in that this pump impeller has a rotational direction (DR), and a blade channel (12), which is configured in the rotational direction (DE) between the blade of the second type (3) and another of the blades (2, 3), is partially covered by the blade cover (32).

8. Pump impeller (1) according to claim 6, characterized in that the blade cover (32) is oriented with a maximum deviation of +/−20°, preferably +/−10°, further preferably +/−5° and particularly preferably +/−2°, parallel to an imaginary rotational plane in which the impeller surface (11) rotates in the rotational direction (DR).

9. Pump impeller (1) according to claim 6, characterized in that this pump impeller has a rotational direction (DR) and the blade cover (32) protrudes over the base body (31) counter to the rotational direction (DR).

10. Pump impeller (1) according to claim 1, characterized in that the blade geometry of the blades of the first type (2) does not have a blade cover.

11. Pump impeller (1) according to claim 1, characterized in that the same number of blades of the first type (2) and blades of the second type (3) is provided.

12. Pump impeller (1) according to claim 1, characterized in that the blades of the first type (2) and the blades of the second type (3) are arranged alternately one behind the other in the one rotational direction (DR) of the pump impeller (1).

13. Pump impeller (1) according to claim 1, characterized in that the pump impeller (1) is configured as a vortex impeller.

14. Housing element (100) for a pump (200) or of a pump (200), with a housing inner wall (103) which defines a flow channel (105) for a fluid medium extending along a central axis (M), wherein the cross section of the flow channel (105) is greater in a main flow direction (H), characterized in that the housing inner wall (103) has a surface structure (101) which is configured such that it counteracts a return flow counter to the main flow direction (H) along the housing inner wall (103) of the fluid medium.

15. Housing element (100) according to claim 14, characterized in that the surface structure (101) has at least one shoulder (102).

16. Housing element (100) according to claim 15, characterized in that the at least one shoulder (102) is configured in an annular or annular segment-shaped manner.

17. Housing element (100) according to claim 15, characterized in that the surface structure (101) has at least one or two or three further shoulders (102).

18. Housing element according to claim 15, characterized in that the shoulder (102) is configured to be spiral-shaped and preferably is wound radially outwardly starting from the central axis (M).

19. Housing element (100) according to claim 15, characterized in that the shoulder (102) is configured to be step-shaped.

20. Housing element (100) according to claim 14, characterized in that the housing inner wall (103) has a conical basic shape, the surface structure (101) being configured thereon.

21. Housing element (100) according to claim 14, characterized in that the housing element (100) is configured as a releasable top cover of a pump housing (201) and/or the housing element (100) forms an impeller chamber (206) of a pump housing (201) and/or the housing element (100) is an insert element in an impeller chamber (206) of a pump housing (201).

22. Pump (200) with a pump housing (201) in which a pump impeller (1) is rotatably mounted, a fluid medium being able to be pumped from a pump inlet (203) of the pump housing (201) to a pump outlet (204) of the pump housing (201), wherein a) the pump housing (201) has a housing element (100), the housing element comprising a housing inner wall (103) which defines a flow channel (105) for a fluid medium extending along a central axis (M), wherein the cross section of the flow channel (105) is greater in a main flow direction (H), characterized in that the housing inner wall (103) has a surface structure (101) which is configured such that it counteracts a return flow counter to the main flow direction (H) along the housing inner wall (103) of the fluid medium, the flow channel (105) thereof being arranged between the pump inlet (203) and the pump impeller (1), and/or b) the pump impeller (1) is configured according to claim 1.

23. Pump (200) according to claim 22, characterized in that the pump impeller (1) is arranged in the direction of the main flow direction (H) relative to the surface structure (101) of the housing element (100).

Description

[0044] Further features, details and advantages of the invention emerge from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings, in which:

[0045] FIG. 1 shows a plan view of a pump impeller;

[0046] FIG. 2 shows a perspective view of the pump impeller of FIG. 1 from below;

[0047] FIG. 3 shows a perspective view of a pump impeller from above;

[0048] FIG. 4 shows a schematic development of a pump impeller;

[0049] FIG. 5 shows a perspective view of a housing element;

[0050] FIG. 6 shows a cross section through the housing element of FIG. 5;

[0051] FIG. 7 shows a schematic view from above of a housing element with annular segment-shaped shoulders;

[0052] FIG. 8 shows a schematic view from above of a housing element with a spiral-shaped shoulder;

[0053] FIG. 9 shows a cross section of a shoulder;

[0054] FIG. 10 shows a cross section of an alternative shoulder; and

[0055] FIG. 11 shows a cross section through a pump.

[0056] According to FIG. 1 and FIG. 2 a pump impeller 1 has an imaginary rotational axis DA about which the pump impeller 1 is designed to rotate during operation (simply called rotational axis DA hereinafter). The rotational axis DA runs through an impeller hub 14 in the centre of an impeller surface 11, wherein the impeller hub 14 has a feather key groove 15. A shaft of a drive unit of a pump may be received by the impeller hub 14. The rotational axis DA is coaxial to the impeller hub 14. The impeller surface 11 is closed and formed such that a pumped fluid leaves the pump impeller 1 radially. The pumped fluid is discharged at right-angles to the rotational axis DA.

[0057] The pump impeller 1 additionally has three blades of the first type 2 and three blades of the second type 3 which are arranged on the impeller surface 11. The impeller surface 11 is oriented at right-angles to the rotational axis DA and the pump impeller 1 is configured as a vortex impeller. The impeller surface 11 between the blades 2, 3 is configured in each case so as to be closed so that no fluid is able to pass parallel to the rotational axis DA through the pump impeller 1.

[0058] The pump impeller 1 is rotatable in a rotational direction DR about the rotational axis DA. In this case it is the preferred rotational direction DR during operation. The blades of the first type 2 and the blades of the second type 3 are arranged alternately one behind the other in the rotational direction DR.

[0059] The blades of the first type 2 have a blade pressure surface 24 and a blade suction surface 23. The blades of the second type 3 accordingly have a blade pressure surface 34 and a blade suction surface 35. The blade pressure surfaces 24 run in each case in a convex manner in a direction R radially away from the rotational axis DA. The blade suction surfaces 23 run in each case in a concave manner in the direction R, which corresponds to the radius. This results in a so-called curved blading. Along this path of the blades 2, 3 the blade pressure surfaces 24 and blade suction surfaces 23 form circular segments. The blades of the first type 2 and second type 3 have a uniform material thickness 25, 37. Thus the path of the respective blade pressure surface 24, 34 and the blade suction surface 23, 35 is at least substantially parallel.

[0060] The blade geometry of the blade of the first type 2 differs form the blade geometry of the blade of the second type 3.

[0061] The blade geometry of the blade of the first type 2 has a base body 21 which adjoins the impeller surface 11. The base body 21 runs parallel to the rotational axis DA and is oriented at right angles to the impeller surface 11. A blade edge 22 adjoins the base body 21. The blade edge 22 in this regard is spaced apart from the impeller surface 11. A curvature 27 runs between the base body 21 and the blade edge 22. Alternatively it may be a sharp bend. Due to the curvature 27 the blade edge 22 is inclined by an angle w1 of approximately 70° relative to an imaginary rotational plane in which the impeller surface 11 (during operation) rotates in the rotational direction DR. In particular, the angle w1 should be between 55° and 87° or between 60° and 80° or between 65° and 75°. Accordingly, the blade edge 22 is inclined at an angle of w2 of approximately 20° relative to the base body 11 which is oriented in the present case at right angles to the rotational plane. Due to the uniform material thicknesses 25, 37 the blade pressure surface 24 and the blade suction surface 23 are parallel. Thus both the blade pressure surface 24 and the blade suction surface 23 are inclined at the angles w1 and w2. Additionally, the blade edge 22 and therewith both the blade pressure surface 24 and the blade suction surface 25 are inclined toward the front in the rotational direction DR. The blade edge 22 has a free end 26, to the extent that no further element adjoins the blade edge 22. The base body 21 forms together with the blade edge 22 the blade pressure surface 24 and the blade suction surface 23.

[0062] The blade of the second type 3 has a base body 31 and a blade cover 32. The base body 31 adjoins the impeller surface 11 and is oriented at right-angles relative to the base body 31. Additionally, the base body 31 is oriented parallel to the rotational axis DA. The blade cover 32 adjoins the base body 31 and is arranged spaced apart from the impeller surface 11. In particular, the blade cover 32 is oriented parallel to the imaginary rotational plane in which the impeller surface 11 (during operation) rotates in the rotational direction DR. A pumping channel 13 thus formed is defined on three sides by the blade cover 32, the base body 31 and the impeller surface 11. The blade cover 32 is also oriented at right-angles to the base body 31 and the rotational axis DA. The blade cover 32 is also oriented parallel to the impeller surface 11. In this case, the blade cover 32 protrudes over the base body 31 counter to the rotational direction DR, thus over the blade suction surface 35.

[0063] The pumping channel 13 is defined between the blade suction surface 35 of the base body 31 and the blade cover 32 of the blade of the second type 3 and the impeller surface 11. A blade channel 12 is formed between blades 2, 3 which are adjacent in the rotational direction DR. A part of the blade channel 12 is formed by the pumping channel 13. The blade channel 12 is partially covered to approximately 25-75% by the blade cover 32, so that along the blade channel 12 a gap 16 remains free for the inflow of fluid. The gap 16 extends over the entire length l of the blade wheel channel 12, wherein the length l runs radially to the rotational axis DA. The blade cover 22 in this case covers the width b of the blade channel 12, wherein the width b extends in the rotational direction DR. The pumping channel 13 is open on a radially outer blade wheel edge 17 so that a pumped fluid may escape in the radial direction R out of the pumping channel 13. The blade wheel edge 17 is located on the outer circumference of the pump impeller 1.

[0064] A pump impeller 1 shown in FIG. 3 differs, however, from the pump impeller of FIGS. 1 and 2 in that instead of the three blades of the second type 3, it has blades of the first type 2. Thus the pump impeller 1 exclusively has blades of the first type 2, namely here in particular six thereof.

[0065] The sketch of FIG. 4 shows a development of a pump impeller 1, wherein the blade geometries differ from those of FIG. 3 such that the blade edge 22 does not form a free end 26. Instead a blade cover 32 is adjoined thereto, said blade cover in principle having the same features as the blade cover of the blades of the second type 3 of FIGS. 1 and 2. Whilst the blade edge 22 is inclined toward the front in the rotational direction, i.e. in the direction of the blade pressure surface 24, the blade cover 32 protrudes from the end of the blade edge 22 toward the rear in the rotational direction, in particular beyond the blade suction surface 23.

[0066] A further modification of the pump impeller 1 according to the invention may comprise that in contrast to the view of FIGS. 1 and 2 it is provided that in each case pairs consisting of a blade of the first type 2 and a blade of the second type 3 may be provided, wherein a greater blade spacing is formed between the first type of blade 2 provided with the blade edge 22 and the adjacent second type of blade 3 provided with the blade cover 32. In particular, the opening angle between the blade pressure surface 24 of the blade of the first type 2 and the blade suction surface 35 of an adjacently arranged blade of the second type 3 is greater than the opening angle between the blade pressure surface 34 of the blade of the second type 3 relative to the blade suction surface 23 of an adjacently arranged blade of the first type 2.

[0067] According to FIG. 5 and FIG. 6 a housing element 100 is configured as a releasable top cover, in particular with a fastening flange, of a pump 200. The housing element 100 advantageously has screw holes 107 in the fastening flange. The housing element 100 additionally as a housing inner wall 103. The housing inner wall 103 has a conical basic shape which extends along a central axis M. The housing inner wall 103 defines a flow channel 105 for a fluid medium which is able to be pumped in a main flow direction H through the flow channel 105. The main flow direction H is coaxial to the central axis M. A fluid inlet opening 104 is provided at the start in the main flow direction H. The flow channel 105 widens in the main flow direction H. The surface structure 101 is configured such that it counteracts a return flow counter to the main flow direction H along the housing inner wall 103.

[0068] In this regard, the surface structure 101 has an inflow surface 106 which protrudes transversely to the return flow. The inflow surface 106 has a plurality of shoulders 102 which form an undercut relative to the conical housing inner wall 103. The shoulders 102 are in each case formed rotationally symmetrically relative to the central axis M. In this sense, the shoulder 102 is of annular configuration, wherein the shoulder runs in a circumferential direction U around the central axis M. In the present case, a total of four shoulders 102 are provided, wherein a greater or smaller number of shoulders 102 may also be provided. The shoulders 102 are arranged evenly spaced apart in the main flow direction H and in a direction R2 radial thereto. Thus the shoulders 102 in each case run parallel to one another. The further shoulders 102, the number thereof being variable, are also of annular configuration.

[0069] Alternatively to the annular configuration, the shoulders 102 may be configured to be annular segment-shaped according to FIG. 7, wherein the shoulders 102 run in the circumferential direction U around the central axis M and are arranged evenly spaced apart in the main flow direction H and the direction R2. A further possibility is to configure the shoulder 102 to be spiral-shaped, said shoulder being wound radially outwardly to the central axis M as shown in FIG. 8. In the case of a plurality of revolutions of the spirals, a plurality of shoulders, which in each case form an obstruction to a return flow, are also produced to a certain extent in section.

[0070] As shown in FIG. 9 a shoulder 102 has a wedge-shaped cross section Q. The shoulder 102 may also have a trapezoidal cross section Q according to FIG. 10. Further alternatives may have a round or oval cross section. Preferably, however, in the direction of the main flow direction H no cross-sectional tapering through the shoulders 102 is produced. In contrast, a stepwise cross-sectional tapering is produced in the direction counter to the main flow direction H.

[0071] A pump 200 according to the invention, which is configured as a vortex pump, has according to FIG. 11 a pump housing 201. A pump impeller 1 according to the invention is provided in the pump housing 201 as shown for example in FIGS. 1, 2, 3 and 4. The pump impeller 1 is rotatably mounted and is driven by a drive unit 202.

[0072] The fluid medium is able to be pumped through the pump housing 201 from a pump inlet 203 to a pump outlet 204. The pump inlet 203 and the pump outlet 204 are oriented at right-angles to one another. The pump outlet 204 leads radially from the pump impeller 1 out of an impeller chamber 206 in which the pump impeller 1 is located.

[0073] The pump housing 201 has a housing element 100 according to the invention. The housing element 100 forms a wall of the impeller chamber 206. The pump impeller 1 is arranged in the main flow direction H opposite the housing element 100, wherein the central axis M is parallel and coaxial to the rotational axis DA. The fluid inlet opening 104 of the housing element 100 is located in the region of the pump inlet 203. The flow channel 105 is arranged between the pump inlet 203 and the pump impeller 1. A free space 207 is formed in the flow channel 105 and between the pump inlet 203 and the pump impeller 1, no further flow guidance elements being provided therein. A vortex is formed in this space 207 since the fluid is excited into rotation by the pump impeller 1. An overpressure at the pump outlet 204 then leads to a return flow on the inner wall of the housing element 100. Here, the shoulders form obstructions to the flow for the return flow and conduct the return flow back into the main flow direction H.

[0074] Alternatively, the housing element 100 may be configured as a releasable top cover with a fastening flange and may be fastened by means of screws as a fastening device to the remaining pump housing 201.

[0075] A further alternative may consist in the housing element 100 being inserted as an insert into the interior of the pump housing 101. To this end, the pump housing 101 should form a seat for the housing element.

[0076] The invention is not limited to one of the above-described embodiments but may be modified in many different ways.

[0077] All of the features and advantages, including structural details, spatial arrangements and method steps, emerging from the claims, the description and the drawing may be essential to the invention both individually and in very different combinations.

TABLE-US-00001 List of reference numerals 1 Pump impeller 11 Impeller surface 12 Blade channel 13 Pumping channel 14 Impeller hub 15 Feather key groove 16 Gap 17 Blade wheel edge 2 Blade of first type 21 Base body 22 Blade edge 23 Blade suction surface 24 Blade pressure surface 25 Material thickness 26 Free end 27 Curvature 3 Blade of second type 31 Base body 32 Blade cover 34 Blade pressure surface 35 Blade suction surface 37 Material thickness 100 Housing element 101 Surface structure 102 Shoulder, projecting portion, step 103 Housing inner wall 104 Fluid inlet opening 105 Flow channel 106 Inflow surface 200 Pump 201 Pump housing 202 Drive unit 203 Pump inlet 204 Pump outlet 206 Impeller chamber 207 Free space b Width of blade channel l Length of blade channel DR Rotational direction DA Rotational axis H Main flow direction R Direction radially to rotational axis R2 Radial direction M Central axis Q Cross-sectional profile U Circumferential direction w1 Angle w2 Angle