PUMP MOTOR WITH COOLED TWO-PART ELECTRONIC MODULE

Abstract

A pump motor (1) includes a rotor (2) mounted to a drive shaft (3) extending along a rotor axis (L). The rotor (2) is circumferentially embraced by a stator. A stator housing (5), encloses the stator. The stator housing includes a first axial end and a second axial end. Electronics for powering and controlling the motor operation include a first portion, arranged on a first PCB, and a second portion, arranged on a second PCB (51). A first electronics housing (11) accommodates the first PCB. The first electronics housing (11) is arranged at a perimeter of the stator housing (5). A second electronics housing (47) accommodates the second PCB (51). The second electronics housing (47) is arranged at the second axial end of the stator housing (5). The second electronics housing (47) at least partially rings the drive shaft (3).

Claims

1. A pump motor comprising: a rotor; a stator; a drive shaft extending along a rotor axis, wherein the rotor is mounted to the drive shaft and the rotor is circumferentially embraced by the stator; a stator housing enclosing the stator, wherein the stator housing comprises a first axial end and a second axial end; electronics for powering and controlling motor operation, wherein a first portion of the electronics are arranged on a first PCB and a second portion of the electronics are arranged on a second PCB; a first electronics housing accommodating the first PCB, wherein the first electronics housing is arranged at a perimeter of the stator housing; and a second electronics housing accommodating the second PCB, wherein the second electronics housing is arranged at the second axial end of the stator housing, wherein the second electronics housing at least partially rings the drive shaft.

2. The pump motor according to claim 1, wherein the first portion of the electronics comprises power electronics, and wherein the second portion of the electronics comprises a line filter.

3. The pump motor according to claim 1, wherein the drive shaft protrudes out of the first axial end of the stator housing for driving a pump, and wherein the drive shaft protrudes out of the second axial end of the stator housing for driving a cooling fan.

4. The pump motor according to claim 1, further comprising a cooling fan being mounted to the drive shaft, wherein the second electronics housing is arranged axially between the cooling fan and the second axial end of the stator housing.

5. The pump motor according to claim 1, further comprising: a cooling fan; and a fan cover, wherein the cooling fan is a radial fan that is arranged axially between the fan cover and the second electronics housing, wherein the fan cover is configured to guide a cooling fan outlet flow axially along lateral sides of the second electronics housing towards axially extending lateral cooling ribs of the stator housing.

6. The pump motor according to claim 5, wherein the fan cover comprises a fully closed axial front face.

7. The pump motor according to claim 1, wherein the second electronics housing defines a central axial channel through which the drive shaft extends.

8. The pump motor according to claim 7, wherein the channel defines a cooling fan suction inlet for a cooling fan that is mounted to the drive shaft .

9. The pump motor according to claim 1, wherein the second electronics housing comprises an output connection, wherein the output connection faces towards the first electronics housing.

10. The pump motor according to claim 1, wherein the second electronics housing is mountable to the second axial end of the stator housing as a pre-assembled unit.

11. The pump motor according to claim 1, wherein the second PCB extends in a plane perpendicular to the rotor axis and comprises a hole through which the drive shaft extends.

12. The pump motor according to claim 1, wherein inlet flow paths are defined between the first electronics housing and the stator housing.

13. The pump motor according to claim 1, wherein the first electronics housing comprises a first housing part and a second housing part, wherein the first housing part is thermally coupled to the stator housing, and wherein the second housing part, comprising the first PCB, is thermally decoupled from the first housing part and thermally decoupled from the stator housing.

14. The pump motor according to claim 13, wherein the first housing part is arranged closer to the rotor axis than the second housing part.

15. The pump motor according to claim 13, wherein the first housing part comprises a first material having a first thermal conductivity, and wherein the second housing part comprises a second material having a second thermal conductivity, wherein the first thermal conductivity is significantly higher than the second thermal conductivity.

16. The pump motor according to claim 1, wherein the first PCB is thermally coupled to a heat sink that is arranged between the first PCB and the stator housing, wherein the heat sink comprises heat sink cooling ribs facing towards the stator housing, wherein the stator housing comprises stator housing cooling ribs facing towards the heat sink, wherein the heat sink cooling ribs and the stator housing cooling ribs complement each other to define inlet flow paths towards a cooling fan suction inlet defined by the second electronics housing.

17. The pump motor according to claim 16, wherein the heat sink cooling ribs and the stator housing cooling ribs are thermally decoupled from each other by a distance.

18. The pump motor according to claim 16, wherein the heat sink cooling ribs and the stator housing cooling ribs define curved inlet flow paths from a lateral flow path inlet towards the second axial end of the stator housing.

19. The pump motor according to claim 1, wherein the first electronics housing comprises a projecting portion projecting axially beyond the second axial end of the stator housing, wherein the projecting portion receives at least a portion of the second electronics housing.

20. The pump motor according to claim 1, wherein the first electronics housing defines a lateral flow path inlet and a flow path outlet directed towards the second electronics housing.

21. The pump motor according to claim 1, wherein the second electronics housing is fixed to the stator housing by at least one electrically conducting screw, wherein said at least one screw electrically connects a ground of the second PCB to the stator housing.

22. The pump motor according to claim 21, wherein the second PCB comprises at least one hole through which the at least one screw protrudes, wherein the second PCB comprises a ground contact around the hole.

23. The pump motor according to claim 22, wherein the second electronics housing comprises at least one pilot hole for receiving the at least one screw, wherein the second electronics housing comprises an electrically conducting element at the pilot hole for providing a ground connection for the ground contact of the second PCB, wherein tightening the at least one screw presses the electrically conducting element onto the ground contact of the second PCB.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In the drawings:

[0044] FIG. 1 is a perspective view of an embodiment of a pump according to the present disclosure;

[0045] FIG. 2 is a partial sectional perspective view of the embodiment shown in FIG. 1;

[0046] FIG. 3 is a partial sectional view of the embodiment shown in FIGS. 1 and 2, showing an enlarged portion;

[0047] FIG. 4 is an exploded view of components of the embodiment shown in FIGS. 1-3;

[0048] FIG. 5 is an exploded view of the second electronics housing according to the present disclosure; and

[0049] FIGS. 6a, 6b and 6c are exploded views of embodiments of a power plug according to the present disclosure in different configurations.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0050] Referring to the drawings, FIG. 1 shows a compact pump motor 1 according to the present disclosure. In order to facilitate the technical description of the present disclosure, the figures show a local right-handed Cartesian coordinate system, wherein a rotor axis L of the pump motor 1 extends along the z-axis, a lateral axis extends along the x-axis and a vertical axis extends along the y-axis. Please note that the local Cartesian coordinate system can have any spatial orientation depending on how the pump motor 1 is actually arranged. However, to facilitate the technical description of the present disclosure, spatial terms like “vertical”, “upper”, “lower”, “forward”, “backward”, “front”, “rear”, “left” or “right” refer to a view on the pump motor 1 in negative z-direction. Therefore, the positive z-axis is denoted as a forward direction, the positive x-axis is denoted as a lateral direction to the right, and the positive y-axis is denoted as an upward direction.

[0051] The pump motor 1 comprises a rotor 2 (see FIG. 4) mounted to a drive shaft 3 extending along the rotor axis L. The rotor 2 is circumferentially embraced by a stator (not visible) being enclosed by a stator housing 5. The stator housing 5 comprises a forward facing first axial end and a rearward facing second axial end. The pump motor 1 further comprises a mounting bracket 7 or foot for mounting the pump motor 1 to an external body, e.g. a ground floor, wall or ceiling. The mounting bracket 7 is fixed to a lower side of the stator housing 5. A left lateral side of the stator housing 5 comprises lateral stator housing cooling ribs 9 extending essentially parallel to the rotor axis L. A right lateral side of the stator housing 5 is not visible in FIG. 1, but comprises analogously lateral stator housing cooling ribs 9 extending essentially parallel to the rotor axis L.

[0052] The pump motor 1 further comprises a first electronics housing 11 at an upper side of the stator housing 5. The electronics housing 11 comprises an opening 13 through which a power plug 15 is plugged in. The opening 13 is arranged at a left lateral side of a rear portion 35 of the first electronics housing 11. Slightly more forward next to the opening 13, a signal connector 17 is arranged at the left lateral side of the electronics housing 11. In a forward section of the electronics housing 11, the left lateral side of the electronics housing 11 further defines a cooling flow inlet 19, into which cooling air is sucked in by a cooling fan 39 (see FIG. 4). The axial rear end of the pump motor 1 is defined by a fan cover 21 comprising a fully closed axial front face 23. The fan cover 21 guides the air flow towards cooling flow outlets 25 directed at the left and right lateral sides of the stator housing 5 guiding the cooling air outflow forward along the lateral stator housing cooling ribs 9.

[0053] FIG. 2 describes the cooling air flow in more detail. The cooling air flow enters the pump motor 1 at the lateral cooling flow inlet 19 defined by the first electronics housing 11. The first electronics housing 11 accommodates a first printed circuit board (PCB) (not shown) that is thermally coupled to an internal heat sink 27 being arranged between the first PCB and an upper side of the stator housing 5. The first PCB extends in the horizontal xz-plane and the heat sink 27 comprises heat sink cooling ribs 29 extending in the horizontal xz-plane and facing towards the upper side of the stator housing 5. The upper side of the stator housing 5 comprises stator housing cooling ribs 31 facing towards the heat sink 27. The heat sink cooling ribs 29 and the stator housing cooling ribs 31 complement each other to define inlet flow paths 33. The inlet flow paths 33 follow a curved path from the lateral cooling flow inlet 19 towards a rear portion of the first electronics housing 11. The rear portion of the first electronics housing 11 defines a projecting portion 35 of the first electronics housing 11 projecting axially beyond the rear axial end of the stator housing 5. The projecting portion 35 comprises a radially inward, i.e. downward, facing opening 37 through which the cooling air flow passes radially inward towards the drive shaft 3 projecting backwardly out of the rear axial end of the stator housing 5. A cooling fan 39 is mounted to the rear axial end of the drive shaft 3 and sucks the cooling air flow through a central axial channel 41 extending axially between the axial rear end of the stator housing 5 and the cooling fan 39 and circumferentially about drive shaft 3. The cooling fan 39 is a radial fan driving the cooling air radially outward. The fan cover 21 then redirects the cooling air flow forward along the left and right lateral sides of the stator housing 5, where the cooling air flow leaves the pump motor 1 at the cooling flow outlets 25 for passing along the lateral stator housing cooling ribs 9. It should be noted that the cooling air flow though the pump motor 1 is fully internal between the cooling flow inlet 19 and the cooling flow outlet 25.

[0054] The first electronics housing 11 comprises a radially inner, i.e. lower, first housing part 43 and a radially outer, i.e. upper, second housing part 45. The first housing part is thermally coupled to the stator housing 5. In fact, the first housing part 43 is integrally moulded as part of the stator housing 5 and thus made of the same metallic material. In contrast to that, the second housing part 45 is made of plastic and is thermally decoupled from the first housing part 43 and from the stator housing 5. The second housing part 45 comprises the first PCB with the power electronics and the heat sink 27. The second housing part 45 comprises a base part 46 and a lid part 48, wherein the base part 46 acts as a thermal barrier between the first housing part 43 and the lid part 48. The first PCB and the heat sink 27 are mounted to the base part 46, whereas the lid part 48 covers the electronics on the first PCB. As can be seen in FIG. 3, the heat sink cooling ribs 29 and the stator housing cooling ribs 31, which define together the inlet flow paths 31, are thermally decoupled from each other by a distance R. The distance R is preferably smaller than 20% of a height H.sub.1 of the heat sink cooling ribs 29, i.e. R ≤ 0.2 .square-solid. H.sub.1. The corresponding stator housing cooling ribs 31 have a height H.sub.2 that is significantly smaller than the height H.sub.1 of the heat sink cooling ribs 29, i.e. H.sub.2 ≤ H.sub.1. In fact, the stator housing cooling ribs 31 are optional, so that the inlet flow paths 31 may be defined by the heat sink cooling ribs 29 alone. However, it is important to note that there is a very limited or no thermal flow between the heat sink 27 and the stator housing 5 due to the distance R. Therefore, the heat sink 27 and the stator housing 5 are cooled independently by certain fractions of the cooling air flow along the curved inlet flow paths 31. This prevents an undesirable thermal transfer from a hot stator housing 5 to the heat sink 27, which would reduce the capacity of the heat sink 27 to cool the power electronics on the first PCB. Due to the larger height H.sub.1 of the heat sink cooling ribs 29, a larger fraction of the cooling capacity of the cooling air flow along the curved inlet flow paths 31 is used for cooling the heat sink 27, and thus the power electronics on the first PCB.

[0055] The exploded view shown in FIG. 4 shows a second electronics housing 47 being arranged at the rear axial end of the stator housing 5 below the projecting portion 35 of the first electronics housing 11. The second electronics housing 47 accommodates a second PCB 51 (see FIG. 5) and fully rings the drive shaft 3. The second electronics housing 47 defines a central axial channel 41 through which the drive shaft 3 extends. The diameter of the central axial channel 41 is significantly larger than the diameter of the drive shaft 3 extending through the central axial channel 41. Thereby, the central axial channel 41 defines a cooling fan suction inlet for the cooling fan 39. When fully assembled, the second electronics housing 47 protrudes at least partially with an upper portion of the second electronics housing 47 into the protruding portion 35 of the first electronics housing 11. The second electronics housing 47 further comprises a power socket 49 being located at a left lateral side of the upper portion of the second electronics housing 47 protruding into the first electronics housing 11. When fully assembled, the power socket 49 is located at the opening 13 of the first electronics housing 11, so that the power plug 15 can be plugged into the power socket 49 through the opening 13 of the first electronics housing 11. The second electronics housing 47 further defines a vertical cooling air flow path from the lower opening 37 in projecting portion 35 of the first electronics housing 11 towards the central axial channel 41. The second electronics housing 47 is a pre-assembled unit that is mountable to the rear axial end of the stator housing 5 as shown in FIG. 4.

[0056] FIG. 5 shows the second electronics housing 47 in an exploded view in more detail. The second electronics housing 47 defines a donut-shaped inner volume ringing the central axial channel 41, wherein the second PCB 51 is arranged in said inner volume. The second PCB 51 extends in the xy-plane perpendicular to the rotor axis L. The second PCB 51 further comprises a hole 56 through which the central axial channel 41 and, when the pump motor 1 is fully assembled, the drive shaft 3 extends. The second PCB 51 comprises bulky electronics components 52 of a line filter or EMI filter for reducing electromagnetic interference. The line filter electronics of the second PCB 51 is connected to the power plug via input line cables 53. The second PCB 51 further comprises output connectors 54 at an upper end of the second PCB 51 facing towards the projecting portion 35 of the first electronics housing 11. The electronics on the first PCB in the first electronics housing 51 is powered by a connection with the output connectors 54 of the second PCB 51. A ground connector element 55 provides a ground connection between a ground of the power socket 49 and both the ground of the second PCB 51 and the stator housing 5.

[0057] FIG. 4 shows four axially extending mounting screws 57 for fixing the second electronics housing 47 to the rear axial end of the stator housing 5. The longer one of the four mounting screws 57 provides for the ground connection between the second PCB 51 and the stator housing 5. A pilot hole 61 of the second electronics housing 47 receives the screw 57 when the second electronics housing 47 is mounted to the rear axial end of the stator housing 5. The mounting screw 57 also passes through a hole 63 in the second PCB 51. An annular connecting surface 65 is provided around the hole 63 at both the forward and backward side of the second PCB 51. The second electronics housing 47 further comprises a lid element 67 also comprising holes 69 through which the mounting screws 57 extend. The holes 69 of the lid element 67 are surrounded by connectors sleeves 71 for establishing an electrical contact between a head of the mounting screw 57 and the annular contact surface 65 around the hole 63 at the backward side of the second PCB 51. The connector element 55 is an angled rigid metallic structure having a first end 73 defining a ground of the power socket 49 and having a second end 75 comprising a hole 77 through which the mounting screw 57 extends. The second end 75 of the connector element 55 connects to the annular connector surface 65 around the hole 63 at the front side of the second PCB 51. A forward end of the mounting screw 57 is screwed into a metallic thread of the stator housing 5. Thereby, when the second electronics housing 47 is fully assembled and mounted to the rear axial end of the stator housing 5, the mounting screw 57 presses all connecting elements 71, 65, 75 together in a sandwiched manner for providing an electrical ground contact.

[0058] FIGS. 6a-c show the power plug 15 in more detail and in two different configurations. The power plug 15 comprises an angled plug housing 79, wherein a cable (not shown) extends essentially vertically out of the power plug housing 79. An isolation element 81 of the power plug 15 separates the different phases and defines a pin structure for plugging the power plug 15 into the correspondingly shaped power socket 49. For each phase of the power plug 15, i.e. four phases including ground in this example, the power plug 15 comprises a crimp connection 83 having a plugging end 85 facing towards the power socket 49 and a crimping end 87 opposite the plugging end 85. The plugging end is fed into an associated opening in the isolation element 81. The power plug 15 provides two selectable configuration options for connecting wires of the power cable to the crimping end 87 of the crimp connector 83.

[0059] As shown in FIG. 6a, the cable wires (not shown) may be directly crimped to the crimping end 87 of the crimp connector 83. The power plug 15 provides a further option by comprising a screw terminal element 89 having a first receptable 91 and a second receptable 93. Therefore, in a second configuration ay shown in FIGS. 6b,c, the cable wires can be indirectly connected to the crimp connector 83 via the screw terminal element 89, wherein the crimping end 87 of each crimp connector 83 is inserted into the first receptable 91 of the screw terminal element 89, and wherein each cable wire is inserted into the second receptable 93 of the screw terminal element 89. This facilitates maintenance tasks to be performed by service personnel.

[0060] The different aspects of the present disclosure contribute alone or in any combination with each other to providing a more compact and less noisy pump motor that is quicker and cheaper to assemble.

[0061] Where, in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present disclosure, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the disclosure that are described as optional, preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims.

[0062] The above embodiments are to be understood as illustrative examples of the disclosure. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. While at least one exemplary embodiment has been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art and may be changed without departing from the scope of the subject matter described herein, and this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0063] In addition, “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, characteristics or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other characteristics or steps of other exemplary embodiments described above. Method steps may be applied in any order or in parallel or may constitute a part or a more detailed version of another method step. It should be understood that there should be embodied within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of the contribution to the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the disclosure, which should be determined from the appended claims and their legal equivalents.

[0064] 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.

TABLE-US-00001 List of reference numerals 1 pump motor 2 rotor 3 drive shaft 5 stator housing 7 mounting bracket 9 stator housing cooling ribs 11 first electronics housing 13 opening 15 power plug 17 signal connector 19 cooling flow inlet 21 fan cover 23 front face 25 cooling air outlets 27 internal heat sink 29 heat sink cooling ribs 31 stator housing cooling ribs 33 inlet flow paths 35 projecting portion 39 cooling fan 41 central axial channel 43 first housing part 45 second housing part 46 base part of second housing part 47 second electronics housing 48 lid part of second housing part 49 power socket 51 second PCB 52 electronic components of line filter 54 output connector 55 connector element 56 hole in second PCB 57 mounting screw 61 pilot hole 63 holes in second PCB 65 connecting surface 67 lid element 69 holes in lid element 71 connector sleeves 73 first end of connector element 75 second end of connector element 77 hole in connector element 79 power plug housing 81 isolation element 85 plugging end 89 screw terminal element 91 first receptable 93 second receptable L rotor axis R distance H.sub.1 height of heat sink cooling ribs H.sub.2 height of stator housing cooling ribs