Coupling Unit with Thermal Separation Effect

Abstract

A pump assembly includes a coupling unit which connects a pump casing to a motor casing. The coupling unit includes at least one thermal barrier which inhibits heat conduction between the pump casing and the motor casing.

Claims

1-13. (canceled)

14. A pump arrangement, comprising: a pump housing; a motor housing; and a coupling unit configured to connect the pump housing and the motor housing to each other, wherein the coupling unit includes at least one thermal conduction barrier.

15. The pump arrangement as claimed in claim 14, wherein the at least one thermal conduction barrier includes at least one thermal conduction barrier between the pump housing and the motor housing at all axial sections of the coupling unit.

16. The pump arrangement as claimed in claim 14, wherein the thermal conduction barrier is a material recess.

17. The pump arrangement as claimed in claim 14, wherein the coupling unit directly connects the pump housing and the motor housing.

18. The pump arrangement as claimed in claim 14, wherein a shape of the coupling unit include one or more of a cylindrical shape, a trumpet-funnel shape, a conical shape, and a shape of a body having a polygonal base face.

19. The pump arrangement as claimed in claim 14, wherein the coupling unit is constructed integrally with a motor-side pressure cover of the pump housing.

20. The pump arrangement as claimed in claim 14, wherein the coupling unit is constructed integrally with a pump-side motor cover.

21. The pump arrangement as claimed in claim 14, wherein a thermal conductivity of the coupling unit material is at least one of less than 400 W/m.Math.K and more than 10 W/m.Math.K.

22. The pump arrangement as claimed in claim 21, wherein the thermal conductivity of the coupling unit material is at least one of less than 250 W/m.Math.K, and more than 30 W/m.Math.K.

23. The pump arrangement as claimed in claim 14, wherein a thermal conductivity of the thermal conduction barrier is at least one of less than 20 W/m.Math.K and more than 0.1 W/m.Math.K.

24. The pump arrangement as claimed in claim 23, wherein the thermal conductivity of the thermal conduction barrier is at least one of less than 10 W/m.Math.K and more than 0.1 W/m.Math.K.

25. The pump arrangement as claimed in claim 16, wherein a width of the material recess is at least one of more than 0.5 mm and less than 30 mm.

26. The pump arrangement as claimed in claim 25, wherein the width of the material recess is at least one of more than 1.5 mm and less than 20 mm.

27. The pump arrangement as claimed in claim 14, wherein a material thickness of the coupling unit is at least one of more than 1 mm and less than 14 mm.

28. The pump arrangement as claimed in claim 27, wherein the material thickness of the coupling unit is at least one of more than 3 mm and less than 10 mm.

29. The pump arrangement as claimed in claim 14, wherein the coupling unit formed as one or both of a pressure cover at a pump side of the coupling unit and a bearing carrier at a motor side of the coupling unit.

30. The pump arrangement as claimed in claim 14, wherein a path for the thermal conduction includes a least one portion through which heat is conducted in a first axial direction and a circumferentially adjacent portion through which heat is conducted in a second axial direction opposite the first axial direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows a section through a centrifugal pump unit in accordance with an embodiment of the present invention,

[0024] FIG. 2 shows a perspective illustration of a coupling unit in accordance with an embodiment of the present invention,

[0025] FIG. 3 shows a perspective illustration of another coupling unit construction in accordance with an embodiment of the present invention,

[0026] FIG. 4 shows a perspective illustration of a third coupling unit construction in accordance with an embodiment of the present invention,

[0027] FIG. 5 shows a perspective illustration of another coupling unit construction in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

[0028] FIG. 1 shows a pump arrangement having a coupling unit 1 which connects a pump housing 3 and a motor housing 7 to each other. The centrifugal pump illustrated in the embodiment is used to convey fluids which under some circumstances may have high temperatures.

[0029] The fluid enters the pump housing 3 of the centrifugal pump through a suction nozzle 2. The impeller 4 is arranged inside the pump housing 3. The impeller 4 transmits kinetic energy to the fluid which leaves the centrifugal pump via pressure nozzles which are not shown in this illustration. The space which is filled with fluid and the impeller 4 is delimited by a pump housing 3 and a housing cover 5. The impeller 4 is connected in a rotationally secure manner to a shaft 9 which drives the impeller 4 by means of a motor arrangement 13. The motor arrangement 13 comprises a rotor 10, a stator 8, the shaft 9, a pump-side motor cover 6 and a motor housing 7. A bearing carrier which carries a bearing 11 is arranged in the motor cover 6.

[0030] With reference to the illustration of the coupling unit 1 in FIG. 1, it can clearly be seen that in all the central axial portions a thermal conduction barrier 12 is produced between the pump housing 3 and the motor housing 7. Such a thermal conduction barrier 12 is in such a form that no direct axial connection exists between the housing components, which in turn more powerfully thermally decouples the housings 3 and 7. In this advantageous manner, the path of the thermal conduction is extended significantly in a radial direction without increasing the axial structural length of the coupling unit 1.

[0031] FIG. 2 shows a perspective illustration of a coupling unit 1. The connection plate 15 for connection to the motor cover 6 which is not shown in this instance is connected by means of connection webs 14 to the connection plate 16 in order to connect to the housing cover 5 (which is also not shown) of the pump housing 3. The coupling unit 1 has a plurality of thermal conduction barriers 12 which in this embodiment are in the form of material recesses. In an alternative variant, the thermal conduction barrier could also be in the form of a material which has poor thermal conductivity. The connection webs 14 prevent engagement in the rotating shaft 9. The structural configuration of the connection webs 14 produces a coupling unit 1 which provides with the shortest possible axial structural space an extremely long circumferential path of the thermal conduction. The cooling air flow which is produced by the motor fan which is not illustrated and which flows via the cooling ribs of the motor housing 7 in the direction toward the coupling unit 1 can in addition to the thermal conduction barrier 12 discharge the heat which is conducted by the connection webs 14 from the pump housing 3 so that an extremely small thermal input arrives at the motor cover 6. As a result of the particularly advantageous construction of the coupling unit 1, the pump housing 3 and the motor arrangement 13 are more powerfully thermally decoupled.

[0032] FIG. 3 shows a perspective illustration of another embodiment of the coupling unit 1. The connection plate 15 for connection to the motor cover 6 which is not illustrated in this instance is connected by means of connection webs 14 to the connection plate 16 for connection to the housing cover 5 (which is also not illustrated) of the pump housing 3. The coupling unit 1 has a plurality of thermal conduction barriers 12 which in this embodiment are in the form of material recesses. In this variant of the invention, the connection webs 14 are in the form of a cylindrical component which by means of four small connection elements are in each case constructed integrally with the connection plates 15 and 16. The material recesses are in each case arranged between the small connection elements and between the cylindrical component and the connection plate 16 and the cylindrical component and the connection plate 15. Advantageously, by means of this variant of the connection unit 1, the motor arrangement 13 is thermally decoupled from the pump housing 3 and, at the same time, the coupling unit 1 is configured in a particularly stable and vibration-resistant manner.

[0033] FIG. 4 shows a perspective illustration of a third variant of the coupling unit 1 according to the invention. The connection plate 15 for connection to the motor cover 6 which is not illustrated here is connected by means of connection webs 14 to the connection plate 16 for connection to the housing cover 5 (which is also not illustrated) of the pump housing 3. The coupling unit 1 has a large number of thermal conduction barriers 12 which in this embodiment are in the form of material recesses. The coupling unit 1 of FIG. 4 corresponds to the coupling unit 1 of FIG. 3. In this instance, in addition, the cylindrical component is provided with additional axially arranged thermal conduction barriers 12 in the form of material recesses. The radial and/or axial extent of the thermal conduction from the pump housing 3 in the direction of the motor arrangement 13 is thereby extended without increasing the axial length of the coupling unit 1.

[0034] In this instance, the thermal conductivity of the coupling unit material is less than 400 W/m.Math.K, preferably less than 300 W/m.Math.K, in particular less than 250 W/m.Math.K, and/or more than 10 W/m.Math.K, preferably more than 20 W/m.Math.K, in particular more than 30 W/m.Math.K. The thermal conductivity of the thermal conduction barrier 12 is in this instance less than 20 W/m.Math.K, preferably less than 15 W/m.Math.K, in particular less than 10 W/m.Math.K, and/or more than W/m.Math.K, preferably more than 0.05 W/m.Math.K, in particular more than 0.1 W/m.Math.K.

[0035] The width of the thermal conduction barrier 12 which in this embodiment is in the form of a material recess is more than 0.5 mm, preferably more than 1 mm, in particular more than 1.5 mm, and/or less than 30 mm, preferably less than 25 mm, in particular less than 20 mm. The material thickness of the coupling unit 1 is more than 1 mm, preferably more than 2 mm, in particular more than 3 mm, and/or less than 14 mm, preferably less than 12 mm, in particular less than 10 mm.

[0036] FIG. 5 shows a perspective illustration of a coupling unit 1. The connection plate 15 for connection to the motor cover 6 which is not illustrated here is connected by means of connection webs 14 via a hollow-cylindrical sleeve 17 and additional connection webs 14 to the connection plate 16 for connection to the housing cover 5 (which is also not illustrated) of the pump housing 3.

[0037] The connection unit 1 has a plurality of thermal conduction barriers 12 which in this embodiment are in the form of material recesses. In an alternative variant, the thermal conduction barrier could also be made from a material with poor thermal conductivity. The connection webs 14 and the hollow-cylindrical sleeve 17 prevent an engagement in the rotating shaft 9 and direct from the motor housing 7 into the base of the pump the forces which act through the mass of the motor arrangement 13. To this end, the hollow-cylindrical sleeve 17 is additionally reinforced around two recesses 18 in the embodiment shown.

[0038] The thermal conduction barriers 12 which are arranged beside the connection webs 14 limit the thermal conduction to a minimum and extend the path of the thermal conduction from the connection plate 16 in the direction of the connection plate 15, in particular as a result of the radially inwardly orientated extent of the connection webs 14.

[0039] The parallelepipedal connection plate 16 is constructed with rounded edges, wherein the connection webs 14 begin in each case centrally and extend radially inward in the manner of a strut. The hollow-cylindrical sleeve 17 has additional thermal conduction barriers 12 in the form of material recesses which lead to an extended path of the thermal conduction and thereby virtually thermally decouple the pump housing 3 and the motor housing 7.

[0040] The cooling air flow which is produced by the motor fan which is not illustrated and which flows over the cooling ribs of the motor housing 7 in the direction toward the coupling unit 1 can in addition to the thermal conduction barriers 12 discharge the heat which is conducted by the connection webs 14 from the pump housing 3 so that an extremely low thermal input arrives at the motor cover 6.

[0041] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.