Abstract
The present invention relates to a centrifugal pump and a bearing retainer for the centrifugal pump. The centrifugal pump has a shaft, a bearing for supporting the shaft, and a bearing retainer for the bearing. The bearing retainer comprises a ring section adapted to surround the bearing and an elastic section adjacent the ring section, wherein the elastic section comprises multiple slits, dividing the elastic section into multiple resilient parts, wherein the multiple resilient parts are adapted to receiving and supporting the bearing, thereby creating a compression force in radial direction perpendicular to the axis of the shaft, allowing the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer.
Claims
1. A centrifugal pump having a shaft and a bearing for supporting said shaft, said centrifugal pump further comprising a bearing retainer (10) for said bearing, wherein said bearing retainer comprises: at least one ring section (2) adapted to surround said bearing, said ring section having an inner radius perpendicular to the axis of said shaft; at least one elastic section (4) adjacent said ring section, wherein at least a part of said elastic section has an inner radius perpendicular to the axis of said shaft, which inner radius is smaller than said radius of said ring section; said elastic section comprising multiple slits (6), dividing said elastic section into multiple resilient parts (8); said multiple resilient parts (8) being adapted to allowing receiving and supporting said bearing, thereby creating a compression force in radial direction perpendicular to the axis of said shaft, allowing said bearing retainer to hold said bearing in a fixed position with respect to said bearing retainer; wherein said elastic section (4) comprises an oblique subsection (17) adjacent said ring section (2), and a cylindrical subsection (18) adjacent said oblique subsection (17), wherein said oblique subsection (17) comprises a wall which is slanted with respect to the shaft of the pump, and said cylindrical subsection (18) comprises a wall which is parallel to the shaft of the pump.
2. A bearing retainer (10) for a bearing for supporting the shaft of a pump, said bearing retainer comprising: at least one ring section (2) adapted to surround the bearing, said ring section having an inner radius perpendicular to the axis of the shaft; at least one elastic section (4) adjacent said ring section, wherein at least a part of said elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than said radius of said ring section; said elastic section comprising multiple slits (6), dividing said elastic section into multiple resilient parts (8); said multiple resilient parts (8) being adapted to allowing receiving and supporting the bearing, thereby creating a compression force in radial direction perpendicular to the axis of the shaft, allowing said bearing retainer to hold the bearing in a fixed position with respect to said bearing retainer; wherein said elastic section (4) comprises an oblique subsection (17) adjacent said ring section (2), and a cylindrical subsection (18) adjacent said oblique subsection (17), wherein said oblique subsection (17) comprises a wall which is slanted with respect to the shaft of the pump, and said cylindrical subsection (18) comprises a wall which is parallel to the shaft of the pump.
3. The bearing retainer according to claim 2, wherein said slanted wall forms a curved slope, connecting said ring section with said cylindrical subsection.
4. The bearing retainer according to claim 2, wherein said bearing retainer has an even wall thickness.
5. The bearing retainer according to claim 2, wherein said at least one ring section (2) comprises a wall, and said at least one elastic section (4) comprises a wall; and wherein said wall of said at least one ring section (2) and said wall of said at least one elastic section (4) has substantially the same and even wall thickness.
6. The bearing retainer according to claim 2, wherein said wall of said oblique subsection (17) and said wall of said cylindrical subsection (18) has substantially the same and even wall thickness.
7. The bearing retainer according to claim 2, wherein said multiple resilient parts (8) allows receiving and supporting the bearing at a first temperature, thereby creating a compression force in radial direction perpendicular to the shaft, and wherein said multiple resilient parts (8) allows maintaining a compression force in radial direction perpendicular to the shaft at a temperature higher than said first temperature.
8. The bearing retainer according to claim 2, wherein said multiple resilient parts (8) are adapted to allow said bearing retainer to remain in contact with the bearing when the temperature changes.
9. The bearing retainer according to claim 2, wherein said multiple resilient parts (8) are adapted to allow said bearing retainer to remain in contact with the bearing at a temperature of at least 350 C., preferably at least 400 C., more preferred at least 450 C., preferably at least 500 C., more preferred at least 550 C., preferably at least 600 C., more preferred at least 650 C., preferably at least 700 C., more preferred at least 750 C., preferably at least 800 C., more preferred at least 850 C.
10. The bearing retainer (10) of claim 2, further comprising: an additional ring section adjacent said elastic section, such that said elastic section is positioned between said ring section and said additional ring section.
11. The bearing retainer of claim 2, further comprising: an additional elastic section adjacent said ring section, such that said ring section is positioned between said elastic section and said additional elastic section.
12. The bearing retainer according to claim 2, wherein said bearing retainer (10) has a first end and a second end opposite said first end in an axial direction, and further has a center positioned in the middle between said first end and said second end, and wherein said bearing retainer (10) has a smaller external diameter at said center of said bearing retainer (10) than the external diameter at said ends of said bearing retainer (10).
13. The bearing retainer according to claim 2, wherein said bearing retainer has a first end and a second end opposite said first end in an axial direction, and said bearing retainer further has a center positioned in the middle between said first end and said second end, and wherein said bearing retainer has a larger external diameter at said center of said bearing retainer than the external diameter at said ends of said bearing retainer.
14. The bearing retainer according to claim 2, wherein said bearing retainer has a first end and a second end opposite said first end in an axial direction, and wherein said bearing retainer has a smaller external diameter at one end of said bearing retainer than the external diameter at the other end of said bearing retainer.
15. The bearing retainer according to claim 2, wherein said bearing retainer (10) has a first end and a second end opposite said first end in an axial direction, and wherein said bearing retainer (10) further comprises a sealing surface at one of said ends, said sealing surface impeding fluid from passing between said bearing retainer (10) and the bearing.
16. The bearing retainer according to claim 2, wherein said bearing retainer has a first end and a second end opposite said first end in an axial direction, wherein said multiple slits extend to said ends of said bearing retainer.
17. The bearing retainer according to claim 2, wherein said multiple slits (6) have a length to wide ratio of at least 2:1, more preferred at least 3:1, preferably at least 4:1, more preferred at least 5:1, preferably at least 6:1, more preferred at least 7:1, preferably at least 8:1, more preferred at least 9:1, preferably at least 10:1, more preferred at least 11:1, preferably at least 12:1, more preferred at least 15:1.
18. The bearing retainer according to claim 2, wherein said multiple slits (6) extend into said oblique subsection (17) of said elastic section (4).
Description
FIGURES
[0079] Aspects and embodiments of the present invention are described below, in a short description followed by a detailed description of the Figures.
[0080] FIG. 1 shows a schematic longitudinal cross section of a centrifugal pump according to an embodiment of the invention.
[0081] FIG. 2 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention.
[0082] FIG. 3 is a photograph of a bearing inside a bearing retainer according to an embodiment of the invention.
[0083] FIG. 4 is a photograph of a bearing (left in the picture) and a bearing retainer (right in the picture) according to an embodiment of the invention.
[0084] FIG. 5 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the slits are oblique.
[0085] FIG. 6 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the elastic section comprises a part having a wave shaped form.
[0086] FIG. 7 shows a schematic top view of a cross section of a bearing retainer according to an embodiment of the invention.
[0087] FIG. 8 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the slits are linear with a bend in each end.
[0088] FIG. 9 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the slits are shaped like a wave.
[0089] FIG. 10 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the slits are shaped like a wave.
[0090] FIG. 11 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention in a holder.
[0091] FIG. 12 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention, wherein the bearing retainer has multiple slits extending to the ring sections of the bearing retainer.
[0092] FIG. 13 shows a schematic sectional view through the guiding chamber of a centrifugal pump according to an embodiment of the invention showing an unassembled bearing and a bearing retainer, wherein the bearing may support the shaft of a pump. FIG. 13 is rotated 180 with respect to FIG. 1.
[0093] FIG. 14 is a schematic perspective representation of a bearing retainer according to an embodiment of the invention holding a bearing, wherein the bearing retainer has multiple slits extending to the ring sections of the bearing retainer.
[0094] FIG. 15 shows a schematic side view of a cross section of a bearing retainer according to an embodiment of the invention comprising two elastic sections adjacent a ring section. A holder holds the bearing retainer, which holds a bearing, supporting a shaft.
[0095] FIG. 16 shows a schematic side view of a cross section of a bearing retainer according to an embodiment of the invention. The bearing retainer holds a bearing and an additional bearing contacts and co-rotates with the shaft of the pump.
[0096] FIG. 17 shows a schematic cross section of a bearing retainer according to an embodiment of the invention. The front part of the bearing retainer has been cut open revealing the inner backside of the bearing retainer.
DETAILED DISCLOSURE
[0097] A more detailed description of the Figures follows below.
[0098] FIG. 1 shows a schematic longitudinal sectional view through a centrifugal pump according to an embodiment of the invention. The centrifugal pump comprises a bottom part having a pump foot (121) on which the pump is supported, a flange (122) which surrounds a suction branch consisting of an inlet (123) for suction and an outlet (132) for creating pressure. The centrifugal pump has a shaft (126) and a bearing (109) for supporting the shaft and a bearing retainer (110) which supports the bearing. The axis of rotation of the shaft, i.e. the axis of the shaft, is indicated with a line (x-x). The centrifugal pump has a first pump stage consisting of an impeller (124) and a stage guide (125) and the centrifugal pump consists in total of three impellers and three stage guides arranged vertically over one another. The centrifugal pump further has a channel for liquid (130) and an outer stainless steel tube (131). The centrifugal pump comprises a top part consisting of a motorchair (127), a coupling-rotator (128) and a shaft seal (129). The centrifugal pump further comprises a motor (not shown) for rotating the shaft (126).
[0099] FIG. 2 is a schematic perspective representation of a bearing retainer (10) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has a ring section (2) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (4) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The bearing retainer has a ring section (12) adjacent the elastic section (4). The elastic section comprises multiple slits (6) which are parallel to the axis of the shaft (not shown). The slits divide the elastic section into multiple resilient parts (8). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection (17) adjacent the ring section, which has a wall, which is slanted with respect to the shaft of the pump. The bearing retainer further comprises a cylindrical subsection (18) adjacent the oblique subsection, which has a wall, which is parallel to the shaft of the pump.
[0100] FIG. 3 is a photograph of a bearing inside a bearing retainer according to an embodiment of the invention. The bearing (black part) is the non-rotating part of the full bearing. The other part, the rotating part, is mounted on a shaft. Both bearing parts are made of a ceramic material.
[0101] FIG. 4 is a photograph of a bearing (left in the picture) and a bearing retainer (right in the picture) according to an embodiment of the invention.
[0102] FIG. 5 is a schematic perspective representation of a bearing retainer (510) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has a ring section (502) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (504) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple oblique slits (506) which divides the elastic section into multiple resilient parts (508). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection adjacent the ring section, which has a wall, which is slanted with respect to the shaft of the pump. The bearing retainer further comprises a cylindrical subsection adjacent the oblique subsection, which has a wall, which is parallel to the shaft of the pump.
[0103] FIG. 6 is a schematic perspective representation of a bearing retainer (610) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has one ring section (602) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (604) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises a part having a wave shaped form. This wave shaped form provides a number of supporting points of contact to a bearing (not shown). The elastic section comprises multiple slits (606) which are parallel to the axis of the shaft (not shown). The slits divide the elastic section into multiple resilient parts (608). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection adjacent the ring section, which has a wall which is slanted with respect to the shaft of the pump.
[0104] FIG. 7 is a schematic top view of a cross section through the middle of a bearing retainer (710) according to an embodiment of the invention. The bearing retainer holds a bearing (709) for supporting the shaft of a pump. Visible features include multiple slits (706) in the elastic section which divides the elastic section into multiple resilient parts (708). The elastic section comprises a part having a wave shaped form. This wave shaped form provides a number of supporting points of contact to the bearing. The multiple resilient parts are adapted to receive and support the bearing and create a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer.
[0105] FIG. 8 is a schematic perspective representation of a bearing retainer (810) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has one ring section (802) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (804) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (806) which are linear with a bend in each end. The slits (806) divides the elastic section into multiple resilient parts (808). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer.
[0106] FIG. 9 is a schematic perspective representation of a bearing retainer (910) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has one ring section (902) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (904) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (906) which are shaped as a wave. The slits (906) divide the elastic section into multiple resilient parts (908). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection adjacent the ring section, which has a wall, which is slanted with respect to the shaft of the pump. The bearing retainer further comprises a cylindrical subsection adjacent the oblique subsection, which has a wall, which is parallel to the shaft of the pump.
[0107] FIG. 10 is a schematic perspective representation of a bearing retainer (1010) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has one ring section (1002) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (1004) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (1006) which are shaped like a wave. The slits (1006) divide the elastic section into multiple resilient parts (1008). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection adjacent the ring section, which has a wall, which is slanted with respect to the shaft of the pump.
[0108] The bearing retainer further comprises a cylindrical subsection adjacent the oblique subsection, which has a wall, which is parallel to the shaft of the pump.
[0109] FIG. 11 is a schematic perspective representation of a bearing retainer (10) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer is placed in a holder (1101). The holder has an upper part (1103), a lower part (1105) and a connecting belt (1107) which connect the upper and lower part of the holder. The bearing retainer can act as a spacer between the holder and the bearing.
[0110] FIG. 12 is a schematic perspective representation of a bearing retainer (1210) according to an embodiment of the invention for a bearing for supporting the shaft of a pump. The bearing retainer has one ring section (1202) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (1204) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (1206) which divides the elastic section into multiple resilient parts (1208). The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The bearing retainer has a first end and a second end opposite the first end in an axial direction, wherein the multiple slits (1206) extend to the ring sections of the bearing retainer.
[0111] FIG. 13 shows a schematic sectional view through the guiding chamber of a centrifugal pump according to an embodiment of the invention showing an unassembled bearing (1309) and a bearing retainer (1310), wherein the bearing (1309) may support the shaft (not shown) of the pump. The bearing retainer is welded to the inner guide cup of a guiding chamber of a centrifugal pump. FIG. 13 is rotated 180 with respect to FIG. 1.
[0112] FIG. 14 is a schematic perspective representation of a bearing retainer (1410) according to an embodiment of the invention, wherein the bearing retainer holds a bearing (1409) for supporting the shaft of a pump. The bearing retainer has one ring section (1402) adapted to surround the bearing, wherein the ring section has an inner radius perpendicular to the axis of the shaft. The bearing retainer has one elastic section (1404) adjacent the ring section, wherein at least a part of the elastic section has an inner radius perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (1406) which divides the elastic section into multiple resilient parts (1408). The multiple resilient parts are adapted to receive and support the bearing and create a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The elastic section comprises an oblique subsection (1417) adjacent the ring section, which has a wall, which is slanted with respect to the shaft of the pump. The bearing retainer has a first end and a second end opposite the first end in an axial direction, wherein the multiple slits (1406) extend to the ring sections of the bearing retainer.
[0113] FIG. 15 shows a schematic side view of a cross section of a bearing retainer (1510) according to an embodiment of the invention. A holder (1501) holds the bearing retainer (1510), which holds a bearing (1509) supporting the shaft (1526) of a pump. The bearing retainer has one ring section (1502) adapted to surround the bearing (1509), wherein the ring section has an inner radius (r.sub.1) perpendicular to the axis of the shaft. The bearing retainer has two elastic sections (1504, 1504) adjacent the ring section, wherein at least a part of the elastic section has an inner radius (r.sub.2) perpendicular to the axis of the shaft, which inner radius is smaller than the radius of the ring section. The elastic section comprises multiple slits (not shown) which divides the elastic section into multiple resilient parts. The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer.
[0114] FIG. 16 shows a schematic side view of a cross section of a bearing retainer (1610) according to an embodiment of the invention for a bearing (1609) for supporting the shaft (1626) of a pump. There is a second bearing (1613) which contacts and co-rotates with the shaft (1626) of a pump. The bearing retainer has one ring section (1602) adapted to surround the bearing, wherein the ring section has an inner radius (r.sub.1) perpendicular to the axis of the shaft. The bearing retainer has an elastic section (1604) adjacent the ring section, wherein at least a part of the elastic section has an inner radius (r.sub.2) perpendicular to the axis of the shaft, which inner radius is smaller than the inner radius of the ring section. The elastic section comprises multiple slits (not shown) which divides the elastic section into multiple resilient parts. The multiple resilient parts are adapted to receive and support the bearing and creates a compression force in radial direction perpendicular to the axis of the shaft. This allows the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer. The circles show a welding seam (1615), which welds the bearing retainer (1602) to the stage guide of the pump. The welding can be a continuous seam, or it can be spot weldings. Other types of mechanical fixation are also possible, though welding is the most common approach.
[0115] FIG. 17 shows a schematic cross section of a bearing retainer (1710) according to an embodiment of the invention for a bearing (1709) for supporting the shaft of a pump. The bearing retainer is placed within a holder (1701). The holder has a sealed surface in the bottom, which sealed surface comprises an opening, allowing the shaft to pass through the sealed surface. The front part of the retainer has been cut open to create a squared window, so that the inner backside of the bearing retainer (1714) is visible. The arrow indicates the direction of insertion of the bearing into the bearing retainer. The bearing retainer (1710) has a ring section (1702), and an elastic section adjacent the ring section (1702). The elastic section comprises an oblique subsection (1717), and a cylindrical subsection (1718) adjacent said oblique subsection (1717), wherein said oblique subsection (1717) comprises a wall which is slanted with respect to the shaft of the pump, and said cylindrical subsection (1718) comprises a wall which is parallel to the shaft of the pump. The slanted wall forms a curved slope, connecting the ring section (1702) with the cylindrical subsection (1718).
[0116] All cited references are incorporated by reference.
[0117] The accompanying Figures are provided to explain rather than limit the present invention. It will be clear to the person skilled in the art that aspects, embodiments and claims of the present invention may be combined.
[0118] Unless otherwise mentioned, all measurements are conducted under standard conditions (ambient temperature and pressure).
