EP1850010A2 - Centrifugal pump - Google Patents

Abstract

The pump (100) has a pump housing (102) formed from an injection molding-plastic material. An electronically commutated direct current motor housing part closes a drying room, which separates a separating can (116) of a housing part (104) from a wet area. An electronic system is arranged on a printed circuit board (61), where conducting paths of the circuit board are in heat-conducive contact with a base (117) of the separating can. A heat-conducting foil (67) is arranged between the base and the plate and couples electronic components, particularly, transistors over the conducting paths.

Description

The invention relates to a centrifugal pump (100) comprising a pump housing (102) made of plastic material that can be processed by injection molding, comprising a first housing part (103) having a suction nozzle (105) and a discharge nozzle (106) and a second, an electronically commutated DC motor (10) receiving and a containment shell (116) having the second housing part (104), a motor housing part (44) having a drying space, which separates the containment shell (116) from a wet room and in which a stator (40) and an electronics ( 60), and a permanent magnet rotor (50) rotatably supported in the wet space and driving a pump impeller (59) extending into the pump chamber 109, the electronics being mounted at a right angle to an axis (49) and parallel arranged to a bottom (117) of the can (116) aligned printed circuit board (61) and the circuit board (61) in heat-conducting contact with the bottom (117).

From the US 6,524,083 B2 a generic centrifugal pump is known in which a plurality of transistors is thermally coupled to the bottom of a pump chamber. A disadvantage of this design, the low thermal conductivity of the component housing and the hardly be guaranteed flat support of the components with the ground.

The object of the invention is to cool heat-sensitive electronic components in a simple manner and with high efficiency, with a simple installation of the electronics is guaranteed and only a small number of parts is needed and the space is as small as possible.

This object is achieved in that one or more tracks (66) of the circuit board (61) in heat-conducting contact with the bottom (117). Since electronic components first conduct the heat generated in them to the immediately adjacent printed conductors, it is particularly effective to bring these printed conductors (66) into heat-conducting contact with a heat sink. As a heat sink here comes the bottom (117) of the split pot (116) in question. As a result, no additional heat sinks are needed.

In order to produce a good thermal coupling between the surface of the printed circuit board (61) and the bottom (117), it is expedient to arrange a surface-adaptable heat-conducting medium between the printed circuit board (61) and the bottom (117). In this case, it is particularly advantageous if a heat-conducting means which adjusts to the surface of the conductor tracks (66) and base (117) is arranged between the base (117) and the conductor tracks (66).

In this arrangement, excellent heat-dissipating effect is provided by heat generated in an electronic component (70) via traces (66) of the circuit board (61), the heat-conducting agent and the bottom (117) of the can (116) Delivery medium of the centrifugal pump is discharged.

If one uses several components, then a correspondingly larger area is available for the heat conduction. In one variant, therefore, at least three transistors as electronic components (70) are thermally coupled to the bottom (117).

The heat-conducting agent is preferably a heat-conducting foil (67). Wärmeleitfolien are compared to thermal paste easy and reliable to install.

In a preferred further development of the centrifugal pump, it is provided that the printed circuit board (61) has conductor tracks (66) whose cross-sections are selected differently depending on the components (70) or component terminals electrically and thermally connected thereto, the cross-section being larger at a higher heat development to be expected is selected. More heat can be dissipated to the environment via the larger cross sections. As a rule, printed circuit boards are provided with a copper lamination. On a printed circuit board, which is arranged within a housing, there is normally only very little surface which could serve as cooling surfaces, therefore the printed conductor surfaces are designed as required and for those components or component connections which are known to have a high heat development, this is usually winding current carrying parts to equip with the largest possible conductor cross-section, so that the heat can be dissipated quickly.

In the same way, it is preferred that the printed circuit board (61) has printed conductors (66) whose surface area on the printed circuit board is selected differently depending on the components or component connections electrically and thermally connected thereto, wherein the surface area is chosen to be larger with higher expected heat development. Here, the same applies as mentioned above, wherein in addition to the cross sections and the areal extent of the tracks is taken into account. In the optimal case, large conductor cross-sections are provided over a large conductor track length.

The inventive direct thermal coupling of the tracks (66) to the bottom (117) is only possible if components do not interfere on the circuit board, so it is provided in an advantageous development of the invention that at least one electronic component to be cooled (70) on the Bottom (117) facing away from the circuit board (61) is arranged and connected via at least one thermally conductive via with the interconnects (66) on the opposite side of the circuit board (61).

In order to achieve optimum heat coupling between the two sides of the circuit board, a plurality of plated-through holes are provided. Vias of this type are known from RF technology. There, an electromagnetic shield for high frequencies is maintained through the use of a plurality of small size vias.

In an alternative embodiment, a recess (107) is provided in the bottom (117), which serves as a cutout for an electronic component (70) arranged on the printed circuit board (61) and electrically and thermally connected to printed conductors (66) of the printed circuit board. As a rule, a depression can be realized only in the middle of the bottom (107). There is sufficient axial space available, which is for the electronic component (70) and the recess (107) can be used. A direct thermal coupling of the electronic component (70) in the recess (107) would be desirable, but is not provided due to the component tolerances.

A space-saving electronics is known to be achieved in that electronic components (70) are formed as an SMD component and is soldered to the surface of printed conductors (66) of the circuit board (61) without connecting wires. Due to the low height of the SMD components and the recess (107) can be chosen correspondingly flatter.

The component (70) is, for example, an integrated circuit (IC) which switches the stator winding (41).

An embodiment of the present invention will be explained in more detail with reference to the drawing.

• Fig. 1 eine Schnittansicht durch eine erfindungsgemäße Kreiselpumpe,
• Fig.2 ein Leiterplattenlayout,
• Fig.3 ein teilweise bestücktes Leiterplattenlayout,
• Fig. 4 eine Explosionsdarstellung eines Gehäuses der Kreiselpumpe,
• Fig. 5 eine Explosionsdarstellung mit einem Stator eines bürstenlosen Gleichstrommotors,
• Fig. 6 eine Darstellung des montierten Stators,
• Fig. 7 eine Darstellung nach Fig. 5 mit ausgeblendeter Leiterplatte
• Fig. 8 eine Darstellung des Stators mit ausgeblendetem Isolierstoffkörper,
• Fig. 9 eine zweite Darstellung des Stators mit ausgeblendetem Isolierstoffkörper,
• Fig. 10 eine Schnittansicht durch eine zweite Ausführungsform der Kreiselpumpe,
• Fig.11 eine Leiterplatte der zweiten Ausführungsform und
• Fig. 12 eine Leiterplatte mit Wärmeleitfolie.

Show it:

• 1 is a sectional view through a centrifugal pump according to the invention,
• 2 a circuit board layout,
• 3 shows a partially populated printed circuit board layout,
• 4 is an exploded view of a housing of the centrifugal pump,
• 5 shows an exploded view with a stator of a brushless DC motor,
• 6 is an illustration of the mounted stator,
• Fig. 7 is an illustration of FIG. 5 with blanked circuit board
• 8 is an illustration of the stator with blanked insulating material,
• 9 is a second view of the stator with blanked insulating material,
• 10 is a sectional view through a second embodiment of the centrifugal pump,
• 11 is a circuit board of the second embodiment and
• Fig. 12 is a circuit board with heat conducting foil.

FIG. 1 and FIG. 10 show a sectional view through a centrifugal pump 100 according to the invention, comprising a pump housing 102, comprising a first housing part 103 and a second housing part 104 adjoining it. A motor housing part 44 delimits a drying space provided by a stator (40) of a motor housing electronically commutated DC motor and its control electronics is filled. The motor housing part 44 connects to the second housing part 102 and. The first and the second housing part 103, 104 define a wet space 101 of the centrifugal pump. The second housing part 104 is formed integrally with a split pot 116 which separates the wet room 101 from a drying room 99.

The wet room 101 includes an axle 49 which is fixedly installed between a cradle-side axle receptacle 48 and an intake-side axle receptacle 47. A knurling at the axis end prevents rotation of the axis 49 during pump operation. On the axis 49, a fixed bearing 54 is rotatably mounted, which is pressed in a hollow shaft 51 of the rotor 50. The shaft 51 is integral with a pump impeller 59 which includes a plurality of approximately spirally shaped wings 591 for the fluid delivery. The end faces of the fixed bearing 54 can be supported axially with the interposition of thrust washers against the gap-side axle receptacle 48 and against the intake-side axle receptacle 47. A hollow cylindrical ferrite magnet 52 is adhered to the hollow shaft 51, using an elastic adhesive which is inserted into three, four or five axially parallel grooves 511 formed in the hollow shaft.

The drying space 99 contains the stator 40 of the electronically commutated DC motor 10, which is formed in the form of a hollow cylindrical stator winding 41, wherein the magnetic field is guided in operation via claw poles in an alternating manner to the periphery of the can 116 and the hollow cylindrical permanent magnet 52 in the wet space 101st interacts. The magnetic circuit is closed by a return ring 43, which is connected to the claw poles 42. The claw poles 42 are provided by encapsulation with an insulating body 46 which connects the claw poles 42 mechanically but not magnetically. The stator 40 has four pole pairs in the present example. The Isolierstoffkörper 46 is geometrically shaped so that the winding wires of the stator winding 41 with Klemmschneidkontakte having contact pins 62 are connected, said Klemmschneidkontakte are mechanically fastened in Isolierstoffkörper 46. The contact pins 62 are formed as combination contacts and pressed at its end opposite the clamping cutting contact 63 in a printed circuit board 61 and thereby contacted with this. The contact pins 62 contain one or two deformable press-fit zones for this purpose. The printed circuit board 61 is equipped with a Hall sensor 71, at least one electronic component 70 for the winding circuit and a PTC for the winding protection, and connector pins 64 for the power supply. The motor housing part 44 includes a connector housing 65 in which the connector pins 64 are arranged.

In the printed circuit board 61, heat is generated, therefore, why it is thermally coupled to the bottom 117 of the containment shell 116 to heat loss to the fluid of the Remove centrifugal pump. A first embodiment of this heat dissipation is shown in FIG. An electronic component 70 in the form of an integrated circuit (IC) would hinder this direct coupling to the ground, therefore, a depression 107 is provided in the containment shell in the the component can dip. The embodiment of FIG. 1 is not optimized space. However, it is possible to provide in the shaft 51 recesses for the recess 107 of the bottom 117, so that no space loss occurs by the described first embodiment of the invention. The position of the electronic component 70 is then fixed on the PCB center. The conductor tracks 66, which serve to make contact with components 70 to be cooled, are dimensioned such that the broadest possible conductor tracks 66 on the printed circuit board 61 are provided for easier heat dissipation. In order to achieve a particularly good utilization of the printed circuit board 61 and optimum heat dissipation, the different conductor tracks 66 are of different widths, depending on how much heat is generated in the component connection to be contacted. The conductor tracks 66 can be thermally coupled well to the floor 117 over their large area.

In the shaft 51 of the rotor 50, a longitudinal groove is formed as a cooling channel between a bottom 117 of the containment shell 116 and the pump impeller 59, which forces a continuous circulation of the fluid also in the interior of the containment shell 116. The printed circuit board is arranged between an end face 45 of the motor housing 44 and the bottom 117 of the can 116 and held in heat-conducting contact with the bottom 117 via the heat-conducting film 67.

The first housing part 103 has a first flange 130 and a first adjoining ring 131. The second housing part 104 has a second flange 140 and a second adjoining ring 141. The motor housing part has a third ring 441. The second flange 140 and the second ring 141 together form a T-shape in cross-section. There are four sealing areas 133, 144, 145 and 444 provided. The first sealing region is located on the radially outer side of the first ring 131 on the first housing part 103. Opposite on the radially inner side of the second ring 141 and the second housing part 104 is the second sealing region 144. Also on the radially inner side The third sealing region 145 is located on the radially outer side of the third ring 441 and the motor housing part 44. The second housing part 104 consists of one for laser light of one wavelength or a wavelength range permeable material. The first housing part 103 and the motor housing part 44 are made of a material absorbing the same laser light. This allows a laser beam without heating the transparent material to a seam lead. There, the beam encounters material that absorbs the light and converts it to heat, causing the plastic to melt and intimately bond with the adjacent material.

Since the two sealing regions to be welded are close to each other, it is possible without difficulty to produce the two seams in one device and in one operation. The welding apparatus may comprise two individual lasers, one weld being made with one laser beam at a time, or may comprise a single laser whose output beam is split by a beam splitter into two beams, each of which produces one of the welds. In the present example, the laser beams are directed radially onto the pump housing.

2 shows a printed circuit board layout for the printed circuit board 61, with printed conductors 66.

3 shows a partially populated printed circuit board layout of the printed circuit board 61, with the integrated circuit 70 (IC), whose connection contacts are electrically and thermally connected to different conductor track regions 66 having different surface expansions. Next plug pins 64 and contact pins 62 are shown.

4 shows an exploded view of the housing of the centrifugal puddle 100 with the first housing part 103, the second housing part 104 and the motor housing part 44. The first housing part 103 has an intake nozzle 105, a discharge nozzle 106, the first flange 130 and the first ring 131 connects to the first flange and has a first sealing region 133. The second housing part comprises the containment shell 116, which has at its bottom 117 a recess 107 for an electronic component, the second flange 140 and the second ring 141, on its inside the second sealing region 144 (not visible here) and the third sealing region 145th having. The motor housing part 44 includes the third ring 441, the fourth sealing area 444, and a plug housing 65.

5 shows an exploded view with a stator 40 of a brushless DC motor 10 with a first housing part 103, the second housing part 104 and the motor housing part 44. The second housing part carries the stator 40 with a wound on an insulating body 46 stator winding 41st On the Isolierstoffkörper There are fasteners 463, consisting of a stop means 464 and a Snap means 465, wherein the stop means 464 and the snap means 465 project from the Isolierstoffkörper 46. The fastening means 463 serve for fastening the printed circuit board 61. The insulating body 46 has holders 467 which serve exclusively for the mechanical support of plug pins 64. The connector pins are electrically connected to the circuit board 61. An electrical connection between the printed circuit board 61 and the stator winding 41 is made by contact pins 62, wherein the contact pins 62 on the one hand have insulation displacement contacts and on the other hand Einpresskontakte.

6 shows an illustration of the assembled stator 40 with the second housing part 104, the insulating body 46, the stops 464 and snap means 465 as fastening means 463 of the printed circuit board 61, the holders 467 for the connector pins 64 and the contact pins 62, which are in the circuit board are pressed and electrically connected via insulation displacement contacts with the stator winding 41.

FIG. 7 shows an illustration according to FIG. 6 with the printed circuit board 61 hidden, wherein the Hall sensor 71 and the integrated circuit (IC) with the heat conducting film are shown in the correct position. Clearly here are the contact pins 62 can be seen, which are inserted in the projections 466 and connected there via the insulation displacement contact with a winding wire, wherein the winding wire is inserted in slots 461 of the projection. Further, the stops 464, which are provided in duplicate per fastener 463 and slotted snap means 465 can be seen.

8 and 9 show the stator 40 with annular disk-shaped stator laminations 420, to which claw poles 42 connect, the stator winding 41, the printed circuit board 61, the connector pins 64, which are provided with projections 641, with the help of which they are mechanically fixed in the insulating body hidden here , the integrated circuit (IC) 70 with heat conducting film 67 and the Hall sensor 71. In FIG. 8, the insulation displacement contacts 63 of the contact pins 62 are clearly visible. The circuit board 61 has recesses 611, which serve to receive the above-mentioned snap means.

FIG. 10 shows a second embodiment of the invention, wherein the electronic components are arranged on the side opposite the bottom 117. As a result, it is also possible to form the components 70 as discrete transistors, because the transistors are not located in depressions and can therefore be distributed over the entire printed circuit board. In order to direct the heat generated in the components 70 on the floor 117, a plurality of plated-through holes 612 are provided in the printed circuit board 61. In sum, the vias form a large conductor cross section and can the Heat on the traces 66 of the components opposite side of the circuit board 61 and forward over this on the floor 117.

11 shows a printed circuit board 61 according to the second embodiment of the invention, with electronic components 70 in the form of transistors, with recesses 611 for receiving the printed circuit board 61, printed conductors 66 and a multiplicity of plated-through holes 612, which occupy the majority of the components 70 resulting heat to the opposite side of the circuit board and there via the traces 66 in the bottom of the centrifugal pump and from there into the pump medium.

FIG. 12 shows a printed circuit board 61 according to the second embodiment, in which the electronic components 70 face away from the floor. In order to improve the thermal coupling between the conductor tracks and the bottom 117, a heat-conducting foil is glued onto the conductor tracks.

LIST OF REFERENCE NUMBERS

10

electric motor

20

air gap

40

stator

41

stator

42

claw

420

annular disk-shaped stator laminations

421

The End

422

recess

423

web

424

air gap

43

Return ring

430

sheet metal bridge

431

slot

432

connecting slot

433

open slot

434

cutout

435

first edge

436

second edge

437

join

438

connecting means

439

sheet metal tongue

44

motor housing

45

Front side (of the motor housing)

46

insulating

461

receiving slot

462

mounting recess

463

fastener

464

attack

465

snap means

466

head Start

467

Bracket (for connector pin)

47

intake-side axle receptacle

48

gap pot-side axle mount

49

axis

50

rotor

51

wave

511

groove

512

disc

52

hollow cylindrical permanent magnet

521

working magnetization

522

Sensor trace magnetization

523

Front side (of the permanent magnet)

524

security gap

53

elastic connecting means

531

first area (wide)

532

second area (narrow)

54

fixed bearing

58

Longitudinal groove (for secondary fluid circuit)

59

pump impeller

591

wing

60

electronics

61

circuit board

611

recesses

612

vias

62

contact pin

63

Insulation displacement contact

64

Connector pin

641

projections

65

plug housing

66

conductor path

67

Heat conducting

70

Integrated circuit (IC)

71

Hall sensor

99

drying room

100

rotary pump

101

wet room

102

pump housing

103

first housing part

104

second housing part

105

suction

106

pressure port

107

deepening

109

pump room

111

round contour

112

spur

113

Transition area

114

peripheral

115

sharp edge

116

containment shell

117

ground

118

rotor chamber

119

deepening

120

spiral-shaped inner contour

121

admission

122

Pumps fasteners

123

rounding

130

first flange

131

first ring

133

first sealing area

140

second flange

141

second ring

144

second sealing area

145

third sealing area

150

dovetail contour

151

complementary contour

152

V-shaped recess

441

third ring

444

fourth sealing area

Claims (14)

Centrifugal pump (100) with a pump housing (102) made of plastic material that can be processed by injection molding, which housing a first, a suction nozzle (105) and a discharge nozzle (106), housing part (103), and a second, an electronically commutated DC motor (10) receiving and a second housing part (104) having a containment shell (116), a motor housing part (44) having a drying space which the containment shell (116) separates from a wet space and in which a stator (40) and electronics (60) are arranged and a permanent magnet rotor (50) rotatably supported in the wet space and driving a pump impeller (59) extending into the pump chamber 109, the electronics being mounted at a right angle to an axis (49) and parallel to a bottom (49). is aligned 117) of the gap pot (116) printed circuit board (61) arranged and the printed circuit board (61) (in thermally conductive contact with the bottom 117), characterized in that one or me More conductive tracks (66) of the printed circuit board (61) in heat-conducting contact with the bottom (117). Centrifugal pump according to claim 1, characterized in that a to the surface of the printed circuit board (61) and bottom (117) adapting heat conduction between the bottom (117) and the circuit board (61) is arranged. Centrifugal pump according to claim 1 or 2, characterized in that a to the surface of the conductor tracks (66) and bottom (117) adapting heat conduction between the bottom (117) and the conductor tracks (66) is arranged. Centrifugal pump according to claim 2 or 3, characterized in that heat generated in an electronic component (70) via conductor tracks (66) of the printed circuit board (61), the heat-conducting means and the bottom (117) of the split pot (116) to a pumped medium the centrifugal pump (100) is discharged. Centrifugal pump according to claim 4, characterized in that the heat-conducting means thermally coupled via at least three transistors as electronic components (70) via the conductor tracks to the bottom (117). Centrifugal pump according to claim 2, 3, 4 or 5, characterized in that the heat conducting means is a heat conducting foil (67). Centrifugal pump according to at least one of the preceding claims, characterized in that the printed circuit board (61) conductor tracks (66) whose cross-sections are chosen differently depending on the thus electrically and thermally connected components (70) or component connections, the cross-section at higher expected Heat development is chosen larger. Centrifugal pump according to at least one of the preceding claims, characterized in that the printed circuit board (61) conductor tracks (66) whose surface extension on the circuit board (61) are chosen differently depending on the thus electrically and thermally connected components or component connections, wherein the surface area at higher expected heat development is chosen larger. Centrifugal pump according to at least one of the preceding claims, characterized in that at least one electronic component (70) to be cooled is arranged on the side of the printed circuit board (61) facing away from the bottom (117) and via at least one thermally conductive via (612) with the printed conductors ( 66) is connected on the opposite side of the printed circuit board (61). Centrifugal pump according to claim 9, characterized in that a plurality of plated-through holes (612) is provided. Centrifugal pump according to at least one of the preceding claims, characterized in that the bottom (117) has a recess (107) arranged as a cutout for a on the printed circuit board (61) and with printed conductors (66) of the printed circuit board electrically and thermally connected electronic component (70) serves. Centrifugal pump according to claim 11, characterized in that the recess (107) in the middle of the bottom (117) is arranged. Centrifugal pump according to at least one of the preceding claims, characterized in that the electronic component (70) is designed as an SMD component and is soldered to the surface of printed conductors (66) of the printed circuit board (61) without connecting wires. Centrifugal pump according to at least one of the preceding claims, characterized in that the electronic component (70) is an integrated circuit (IC).

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