DE102020132449A1 - Electric centrifugal pump - Google Patents

Abstract

The invention relates to an electric centrifugal pump that has a housing that includes a volute housing 4 , a bearing housing 2 , and a housing cover 9 . A pump wheel 8 is housed in a volute housing 4 which has an inlet 5 and an outlet 6 , with the pump wheel 8 conveying a medium from the inlet 5 to the outlet 6 . The impeller 8 is driven via a shaft 7 by an electric motor which is mounted in the bearing housing 2 . The electric motor is using electronic components 10a, 10b, 10c, 10d, which is arranged on a printed circuit board 3a in the bearing housing 2; 3b attached are powered. The circuit board 3a; 3b is at least partially ring-shaped and is formed with a tongue 3'. The electric motor and the circuit board 3a; 3b are in heat-transferring contact with the funding. The bearing housing 2 comprises an inner ring 2a with a bearing for the shaft 7 and an outer border 2b. The inner ring 2a and the outer skirt 2b extend from the circuit board 3a; 3b in the direction of the housing cover 9. The electronic components 10a, 10b, 10c, 10d are dependent on their respective heat loss on the printed circuit board 3a; 3b arranged.

Description

The invention relates to an electric centrifugal pump, a use of the electric centrifugal pump for conveying a delivery medium, in particular a coolant, in a vehicle such as an automobile, a truck, an aircraft, a watercraft, a robot, a machine or the like and a device, in particular a vehicle such as an automobile, truck, aircraft, watercraft, robot, machine or the like with the electric centrifugal pump.

An electric centrifugal pump has a number of electronic components that are required to operate the pump. During operation of the pump, these electronic components generate heat, also known as heat loss. If too much heat accumulates in the electronic components, proper operation of the pump can no longer be guaranteed. It is common practice to dissipate lost heat via the pumped medium.

the DE 10 2018 123 565 A1 , U.S. 2001/0033800 A1 , U.S. 2015/0004032 A1 and U.S. 2019/0234425 A1 show such electric centrifugal pumps in which heat loss is dissipated via the pumped medium.

Especially with regard to vehicles with an electric motor as the drive unit, there are different battery, operating or on-board voltages in vehicles, such as between 12V and 48V. When a higher operating voltage is used for a pump, more electronics are required to operate the pump. These also generate more heat loss, which can make it difficult to dissipate the heat loss.

In order to be able to dissipate more heat loss, the area by means of which heat loss is transferred to a pumped medium can be increased. One solution is therefore pump housings of different sizes, which, however, are associated with higher development and production costs. Furthermore, the mounting space, for example in vehicles, is limited. Any enlargement of the housing is therefore not possible.

Ultimately, vehicle manufacturers prefer to work with components of the same size in order not to increase design and development costs. Suppliers are also striving to find design solutions that contain a large number of identical parts and can be used across projects in order to be able to meet the vehicle manufacturers' cost specifications. On the other hand, if a pump manufacturer uses a large number of customer-specific housing geometries, this results in a considerable cost disadvantage in competition.

From the above, one object of the invention is to provide an electric centrifugal pump that has a housing in which different power configurations can be installed with good heat dissipation.

This problem is solved by the electric centrifugal pump according to the main claim, with the dependent claims showing further developments according to the invention and the subordinate claims showing further aspects according to the invention.

The electric centrifugal pump mentioned above has: a housing that includes a volute housing, a bearing housing, and a housing cover, with an impeller being enclosed by the volute housing, which has an inlet and an outlet, with the impeller conveying a delivery medium from the inlet to the outlet the impeller is driven via a shaft by an electric motor which is mounted in the bearing housing, the electric motor being supplied with power by means of electronic components which are mounted on a printed circuit board arranged in the bearing housing, the printed circuit board being at least partially annular and having is formed of a tongue, the electric motor and the circuit board are in heat-transferring contact with the conveying means, the bearing housing comprises an inner ring with a bearing for the shaft and an outer border, and the inner ring and the outer border extend from the circuit board towards the Cover cover extend.

This invention provides for the first time that the electronic components are arranged on the printed circuit board depending on their respective heat loss.

The dissipation of heat can be optimized by arranging the electronic components depending on their respective heat loss. For example, electronic components with high heat loss can then transfer the resulting heat to the pumped medium at a position where the pumped medium is warmer than at other positions and/or at which a relatively higher volume flow flows.

An advantage of the invention is that the same pump housing can be used for a variety of power configurations with different operating voltages without heat build-up occurring. Heat damage to electronic components can thus be avoided.

Another advantage of the invention is that the power configuration of the electronic components of the pump is more independent of the installation space in the pump. Thus, in the case of the centrifugal pump according to the invention, configurations for lower and higher operating voltages can be installed in the same bearing housing. The bearing housing therefore acts as a common part on which all other components are mounted. This design enables a universal assembly line. The assembly line can thus be used for several projects, which increases the utilization of the assembly line and the cost-effectiveness. For pumps with different housing structures, the assembly line would have to be expanded accordingly in order to cover different projects with one assembly line. Depending on the design, this would entail increased investment costs and possibly a greater space requirement for the machine park. Furthermore, the susceptibility to errors when assembling the pump is reduced since only one bearing housing is available. A fully assembled printed circuit board can therefore not be used in the "wrong" housing.

Specifically, the bearing housing is designed in such a way that the same bearing housing can be used without changes, e.g. for 12V and 48V electronics / motors. The different power requirements, such as 12V / 400W or 48V / 900W, are primarily set using the following parameters: motor length, stator wire thickness, stator winding density and motor speed. The electrical contacts can vary depending on the power and the required line cross-section for the electrical current. In order to use the bearing housing as a common part, the housing is designed according to the longest engine to be installed. For example, a 48V/900W motor is longer than a 12V/400W motor.

In one embodiment, the electronic components are arranged in such a way that the heat loss increases with the direction of rotation of the impeller.

This results in the advantage that electronic components with a high level of heat loss then give this to the conveyor when it is already heated. The reason for this is that a heat flow only occurs at a differential temperature. The electronic component with a large amount of heat loss can therefore transfer this to a funding device that has already absorbed heat loss from other electronic components with less heat loss. In the opposite case, electronic components with low heat loss would absorb the already heated conveying means and be heated further. There is also the possibility that electronic components give off only a small amount of the heat loss to the fluid because of a small difference in temperature between the electronic component and the conveyor.

In another embodiment, the electronic components with the greatest loss of heat are arranged on the printed circuit board in the immediate vicinity of the outlet. The conveyor absorbs most of the heat from the electronic components with the greatest loss of heat and is then discharged.

This is advantageous because in this way other electronic components may no longer absorb any heat, or only absorb it to a small extent, from the heavily heated conveying means. The cooling is more efficient.

In another embodiment, the inner ring and the outer border of the bearing housing are connected by ribs, with at least one rib bearing against the printed circuit board.

Due to the at least one rib lying against the printed circuit board, heat is dissipated from the printed circuit board to the bearing housing. This results in the advantage that the printed circuit board is cooled. Furthermore, the effect that electronic components transfer heat to other electronic components via the circuit board is reduced. Consequently, having more or fewer fins in certain locations can better control the heat flow on the circuit board.

Another benefit of the ribs is that they provide support for the shaft bearing seat. The connection allows forces to be transferred from the mount to the ribs to the outer edge. These forces are distributed and do not only act on the inner ring or the mount for the bearing. The mount for the shaft bearing is therefore more stable and stiffened. Consequently, the service life of the pump is increased and the shaft runs more smoothly. This also has a positive effect on the acoustic behavior of the pump.

In another embodiment, the angle between the ribs is between 25° and 150° and the number of ribs is between 3 and 14.

In this embodiment, the ribs are specified with respect to their mutual position. Designing the ribs according to the specifications of this embodiment ensures that there is sufficient free space on the circuit board for different power configurations. Suitability for different power configurations is improved.

In another embodiment, the bearing housing includes a stator seat, wherein a stator of the electric motor is housed in the stator seat, and the stator is connected to the printed circuit board via contacts.

In this embodiment, the stator seat is arranged in the bearing housing. The stator is housed in this with a corresponding insulation distance between the stator wires or winding heads and the bearing housing. The insulation distance depends mainly on the material of the bearing housing and the voltage applied to the stator wires. So that the stator is held in its position, the stator is fixed in the bearing housing by means of a transverse interference fit. Furthermore, the electrical contact between the printed circuit board and the stator is established via the contacts. Advantageously, these contacts are designed as plug-in contacts according to the prior art in order to keep assembly simple and inexpensive.

In another embodiment, the previous embodiment is specified. The contacts between the ribs extend from the printed circuit board to the stator. This specification deepens the above aspect of bearing housing-to-stator clearance.

In another embodiment, at least two centering pins and/or at least two sockets for receiving the at least two centering pins are arranged on or in the printed circuit board, these being fastened between ribs on or in the printed circuit board. The centering pins represent a mountable part of a stator busbar or a stator busbar, which is assigned to a stator assembly, or are integral with the stator busbar. The centering pins align the circuit board directly to/to the stator busbar and its electrical contacts, so that the contacts can grip into the associated contact points on the circuit board. Alignment of the printed circuit board using design elements in other components, e.g. the bearing housing, would lengthen the chain of production-related form and position tolerances. As a result, there would be a risk that the contacts would not interlock or would be damaged in such a way that there was no electrical contact that was compatible with the system. A stator busbar can now be aligned on the circuit board using the centering pins. Due to the position on the printed circuit board, a problem-free and simple connection with other components is also possible.

In another embodiment, the bearing for the shaft is a roller bearing or a plain bearing.

In another embodiment, the bearing housing is made of aluminum or an aluminum alloy. Aluminum and its alloys have good thermal conductivity. Furthermore, aluminum and its alloys have a lower density than other metallic materials such as steel. Aluminum and its alloys are also sufficiently chemically resistant for use as bearing housings.

A further aspect discloses the use of the electric centrifugal pump according to the invention for delivering a delivery medium, in particular a coolant, in a vehicle such as an automobile, a truck, an aircraft, a watercraft, a robot, a machine or the like. The use of the centrifugal pump according to the invention in one of the above devices has the advantage that the same space is required for the pump, regardless of the existing operating voltage. The housing of the pump remains the same size with operating voltages of e.g. 12 V and 48 V.

A further aspect discloses a device, in particular a vehicle such as an automobile, a truck, an aircraft, a watercraft, a robot, a machine or the like, with an electric centrifugal pump according to the invention for delivering a delivery medium, in particular a coolant.

Elements of different aspects or embodiments can be arbitrarily combined as long as there is no technical reason to prevent the combination. It is also noted that the terms used or examples given are not meant to be limiting, which also does not exclude other examples not given. Furthermore, elements common to multiple embodiments or aspects may have the same specifications and/or variations.

It is conceivable that the housing consists of a greater number of parts than is described. For example, the bearing housing can consist of a bearing housing and a motor housing, the motor housing can consist of a motor housing and a housing cover, or there can be an additional or additional housing part for attachment to a device. Alternatively, the housing can also consist of fewer parts. It is conceivable that partial areas of the housing are designed in one piece. Furthermore, the shape of the outer border is not fixed. An oval, round or rectangular shape or a combination of these is possible.

The electronic components include, for example, capacitors, MOSFETs, shunts, plug contacts, microcontrollers, centering sockets, com communication devices or the like. The electronic components mounted on the circuit board are not limited to those shown. More, fewer or different electronic components can be mounted. In addition, the positioning of an electronic component is not limited to the positioning shown in the figures.

The heat-transferrable contact of the electric motor and the printed circuit board with the conveying means can be designed in different ways.

According to one embodiment, the stator is connected to the printed circuit board via appropriate contacts. The contacts can be designed differently. The contacts can be made entirely of metal. However, the contacts can also be made of plastic with inserted connecting wires or can be made of other elements, as long as there is proper electrical contact between the printed circuit board and the stator and the printed circuit board is correctly positioned relative to the stator.

Any type of bearing can be used as long as the bearing allows the shaft to rotate according to use.

Furthermore, materials other than aluminum or aluminum alloys can be used for the bearing housing. For example, steel, a plastic, or a hybrid material such as a composite of a metallic bearing support with a thermally conductive (fibre-reinforced) plastic housing in which the stator is injected can be used. The same goes for the ribs.

• 1 zeigt eine Gesamtdarstellung einer erfindungsgemäßen Kreiselpumpe.
• 2a zeigt beispielhaft eine Leiterplatte in einer Konfiguration für eine Betriebsspannung von 12V.
• 2b zeigt beispielhaft eine Leiterplatte in einer Konfiguration für eine Betriebsspannung von 48V.
• 3 ist eine Schnittansicht des Lagergehäuses mit montierter Leiterplatte.
• 4 ist eine Schnittansicht der Kreiselpumpe entlang einer Längsachse der Welle mit montiertem Elektromotor.

The invention is explained in more detail below by way of example with reference to the drawing.

• 1 shows an overall representation of a centrifugal pump according to the invention.
• 2a shows an example of a printed circuit board in a configuration for an operating voltage of 12V.
• 2 B shows an example of a printed circuit board in a configuration for an operating voltage of 48V.
• 3 Fig. 12 is a sectional view of the bearing housing with the circuit board mounted.
• 4 13 is a sectional view of the centrifugal pump along a longitudinal axis of the shaft with the electric motor mounted.

In 1 an overall representation of a centrifugal pump 1 according to the invention can be seen. The housing includes a volute housing 4, a bearing housing 2 and a housing cover 9. The volute housing 4 includes an inlet 5 and an outlet 6 for a conveyor. In the volute 4 is also an in 4 shown impeller 8 housed, which has an in 4 shown shaft 7 is driven by an electric motor. The electric motor is housed in the bearing housing 2 . The shaft 7 is guided from the bearing housing 2 to the impeller 8 in the volute housing 4 .

Furthermore, in 1 a holder on the bearing housing 2 is shown as an example. This bracket is suitable for attaching the pump to a device or similar. The holder is provided with vibration-damping elements, in particular rubber elements, at fastening holes. The printed circuit board of the pump can be connected to a control unit, for example a vehicle, via a connection area 11 .

2a shows a printed circuit board 3a and the volute housing 4. The direction of rotation of the impeller 8 is counterclockwise, for example. The position of the outlet 6 can also be seen. The printed circuit board 3a is fitted with electronic components 10a, 10b, 10c, 10d, for example, in order to be able to operate the pump with an operating voltage of 12V.

In pump operation, the electronic components 10a, 10b, 10c, 10d each produce different heat losses. Electronic components 10a generate the lowest heat loss, electronic components 10b generate greater heat loss than electronic components 10a, electronic components 10c generate greater heat loss than electronic components 10b and electronic components 10d generate the greatest heat loss in relation to the other electronic components. The electronic components 10a, 10b, 10c, 10d transfer generated heat loss via the printed circuit board 3a and an intermediate layer (not shown) to the conveyor.

like it in 2a can be seen, the electronic components 10a are furthest away from the outlet 6 in the direction of rotation of the impeller 8 . At the same time, the electronic components 10a generate the least heat loss. The funding is thus only slightly heated by the heat transfer of the heat loss of the electronic components 10a. The electronic components 10b, 10c are now arranged along the direction of rotation of the impeller 8, which generate relatively average heat loss. Finally, the electronic components 10d are arranged adjacent to the outlet 6 of the volute. In this way, the heated conveying medium is conveyed out of the outlet directly after the heat transfer. Thus, the electronic components 10a, 10b, 10c with less heat loss are not heated by the conveyor, which has a higher heat due to the transfer of the heat loss of the electronic components 10d.

In 2 B an alternative circuit board 3b mounted on the volute 4 is shown. The direction of rotation of the impeller 8 is counterclockwise, for example. The printed circuit board 3b is fitted with electronic components 10a, 10b, 10c, 10d, for example, in order to be able to operate the pump with an operating voltage of 48V. The electronic components 10a, 10b, 10c, 10d on the printed circuit board 3b are comparable with the electronic components on the printed circuit board 3a in terms of the generated heat loss.

When comparing circuit board 3b in 2 B with the circuit board 3a in 2a clear that a larger number of electronic components is mounted on the printed circuit board 3b. It is also clear that there is sufficient space for electronic components for both exemplary configurations for operating voltages in the centrifugal pump according to the invention.

You can also see in 2 B that the arrangement of the electronic components 10a, 10b, 10c, 10d is still given according to the heat loss. For example, the electronic components 10d with the highest heat loss generated are arranged adjacent to the outlet 6 . From the positions of the electronic components 10a, 10b, 10c, 10d arise the same consequences as in the description of 2a described.

3 shows a sectional view of the bearing housing with mounted circuit board 3a; 3b. In 3 contacts 18 are visible, extending between two ribs 12 of the printed circuit board 3a; 3b extend. The contacts 18 protrude beyond the bearing housing to such an extent that there is a gap between a mounted stator 16 and the bearing housing 2 . The gap is large enough to prevent sparks from passing between the stator 16 and the bearing housing 2 .

4 13 is a sectional view of the centrifugal pump along a longitudinal axis of the shaft with the electric motor mounted. In addition to the electric motor, the shaft 7 and the impeller 8 are shown. The shaft 7 is mounted with a plain bearing in the inner ring 2a. The impeller 8 is rotatably connected to the shaft 7. In this exemplary representation is on the printed circuit board 3a; 3b shows a capacitor as an electronic component 10a. Furthermore shows 4 clearly the insulation distance between winding and bearing housing. This distance is between the stator 16 and the bearing housing 2, and the bearing housing 2 and the circuit board 3a; 3b to see.

In 4 it is also shown that in the area of the tongue 3' of the printed circuit board 3a; 3b the bearing housing 2 a defined distance from the printed circuit board 3a; 3b has. This is defined according to the height of the tallest component plus a safety distance that is in the area of the tongue 3' of the printed circuit board 3a; 3b is installed. In 4 a transformer is mounted there as an example.

Reference List

1

centrifugal pump

2

bearing housing

2a

inner ring

2 B

Outer border

3a; 3b

circuit board

3'

Tongue

4

volute casing

5

inlet

6

outlet

7

Wave

8th

impeller

9

housing cover

10a, 10b, 10c, 10d

electronic component

11

connection area

12

rib

16

stator

18

Contact

24

center pin

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102018123565 A1 [0003]
• US 2001/0033800 A1 [0003]
• US 2015/0004032 A1 [0003]
• US 2019/0234425 A1 [0003]

Claims (12)

Electric centrifugal pump, having: a housing, which comprises a spiral housing (4), a bearing housing (2), and a housing cover (9), wherein an impeller (8) is enclosed by the spiral housing (4), which has an inlet (5) and has an outlet (6), with the pump wheel (8) conveying a delivery medium from the inlet (5) to the outlet (6), the pump wheel (8) being driven via a shaft (7) by an electric motor which is in the bearing housing (2), the electric motor being supplied with power by means of electronic components (10a, 10b, 10c, 10d) which are mounted on a printed circuit board (3a; 3b) arranged in the bearing housing (2), the printed circuit board (3a ; 3b) is at least partially ring-shaped and has a tongue (3'), the electric motor and the printed circuit board (3a; 3b) are in heat-transferring contact with the conveying means, the bearing housing (2) has an inner ring (2a) with a bearing for comprising the shaft (7) and an outer border (2b), and the i Inner ring (2a) and the outer border (2b) from the circuit board (3a; 3b) extend in the direction of the housing cover (9), characterized in that the electronic components (10a, 10b, 10c, 10d) are arranged on the printed circuit board (3a; 3b) depending on their respective heat loss. Electric centrifugal pump after claim 1 , characterized in that the electronic components (10a, 10b, 10c, 10d) are arranged such that the heat loss increases with the direction of rotation of the impeller (8). Electric centrifugal pump after claim 1 or 2 , characterized in that the electronic components (10d) with the greatest loss of heat on the printed circuit board (3a; 3b) are arranged in the immediate vicinity of the outlet (6). Electric centrifugal pump according to one of the preceding claims, characterized in that the inner ring (2a) and the outer border (2b) of the bearing housing (2) are connected by ribs (12), with at least one rib (12) on the printed circuit board (3a ; 3b) is present. Electric centrifugal pump after claim 4 , characterized in that the angle between the ribs (12) is between 25° and 150°, and the number of ribs (12) is between 3 and 14. Electric centrifugal pump according to one of the preceding claims, characterized in that the bearing housing (2) comprises a stator seat, with a stator (16) of the electric motor being accommodated in the stator seat, and the stator (16) with the printed circuit board (3a; 3b) via contacts (18) is connected. Electric centrifugal pump after claim 7 , characterized in that the contacts (18) extend between the ribs (12) from the circuit board (3a; 3b) to the stator (16). Electric centrifugal pump according to one of the preceding claims, characterized in that on or in the circuit board (3a; 3b) at least two centering pins (24) and / or sockets for receiving the at least two centering pins (24) for a stator Busbar are arranged, these between ribs (12) on the printed circuit board (3a; 3b) are attached. Electric centrifugal pump according to one of the preceding claims, characterized in that the bearing of the shaft (7) is a roller bearing or a plain bearing. Electric centrifugal pump according to one of the preceding claims, characterized in that the bearing housing (2) is made of aluminum or an aluminum alloy. Use of the electric centrifugal pump according to one of the preceding claims for conveying a conveying medium, in particular a coolant, in a vehicle such as an automobile, a truck, an aircraft, a watercraft, a robot, a machine or the like. Device, in particular a vehicle, such as an automobile, a truck, an aircraft, a watercraft, a robot, a machine or the like, with an electric centrifugal pump according to one of Claims 1 until 11 .

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