Housing device for a fluid pump

Abstract

The present invention relates to a housing device (10) for an electric fluid pump, in particular a cooling pump or oil pump, comprising a pump (20) having a pump housing (150), comprising an electric motor (30) having a motor housing (90) and comprising an electronics module (40) having an ECU housing (50, 60) with a housing. The latter consists of a housing body cover and a housing body lower part (60), and a printed circuit board (170) arranged therein. The printed circuit board (170) has an electrical circuit arrangement (220) on one side and is arranged on the housing body lower part (60) using a sealing adhesive (180). At least one opening (190) through which oil can pass is provided in the housing body lower part (60), and the housing body cover (50) and the housing body lower part (60) are sealingly fitted to each other.

Description

[0001] The present invention relates to an electric fluid pump. It shows structural and connection concepts for such an electric fluid pump.

[0002] Electric fluid pumps, especially oil pumps with brushless DC motors (BLDC) and integrated control units, particularly those used in automotive applications for cooling, lubrication, and actuation, must dissipate the heat generated by the control units to maintain their temperature below critical component-specific values. Typically, the control unit's circuit board is mounted to a heat sink with good thermal conductivity, such as aluminum, which transfers heat to the ambient air or the oil being pumped. Furthermore, the circuit board is sealed to isolate the electronic components from the oil, which could otherwise chemically attack and damage them.

[0003] The problems with state-of-the-art printed circuit board (PCB) cooling include the relatively high cost of aluminum heat sinks, thermal paste, and a reliable seal to separate the fluid (e.g., oil) from the electronic components. Solutions using plastic heat sinks typically have limitations in heat dissipation and restrict pump applications. Another difficulty is that the heat source on the PCB is typically not uniformly distributed. There are several specific hot spots (i.e., transistors, controllers, and traces) on the PCB that require heat sinks to dissipate heat over an increased surface area. Furthermore, there is a conflict between establishing an electrical connection between the control unit and the motor phases and achieving a cost-effective design with a small number of parts and seals, as well as cost-effective pump assembly.Generally, reducing the size and weight of the pump is preferable for reasons of cost and installation space. The state of the art is known from US2021 / 003147.

[0004] It is therefore an object of the present invention to eliminate the aforementioned disadvantages and to provide a compromise between the quantity of parts required, part costs and the cooling capabilities of the pump control units.

[0005] According to the invention, this problem is solved by an electric fluid pump according to claim 1, wherein the housing device comprises a printed circuit board (PCB) which has SMT components on one side, the PCB being arranged on the lower part of the housing with a sealant adhesive, wherein at least one opening is provided in the lower part of the housing through which fluid or oil can pass, and wherein the housing cover and the lower part of the housing are fluid-tightly connected. The PCB is attached to the lower part of the housing and simultaneously sealed against oil in the wet area. Fluid or oil can reach the underside of the PCB through the at least one opening. This enables direct cooling of the PCB by the fluid. The prerequisite for cooling is the presence of fluid in the motor compartment, which is achieved by appropriately directing the pump's leakage flow.The housing cover and lower housing part are thus tightly sealed against environmental influences. The aim is to use the same sealant for the individual housing parts, as well as for the circuit board seal against oil and wet environments, and to apply it in a single process step.

[0006] In one embodiment, the circuit board has contact elements on the side facing away from the housing cover for contact with contact elements emanating from the electric motor, which extend through the at least one opening in it. Since the electrical contact elements are designed as SMT contacts, they do not require a through-hole in the circuit board. Because the circuit board is made of epoxy material and no through-holes are required, the circuit board can function as a separating and sealing layer against fluid / oil or the wet environment.

[0007] It is advantageous if the circuit board can be connected via an electrical connector.

[0008] In another embodiment, the housing body cover is an ECU housing upper part and the housing body lower part is an ECU housing lower part.

[0009] An advantageous embodiment provides that the lower part of the ECU housing is arranged on the motor housing of the electric motor and forms the upper part of the motor housing.

[0010] One possible arrangement is to mount the pump housing on the side of the engine housing facing away from the lower part of the ECU housing.

[0011] It is advantageous if the ECU housing base, the motor housing and the pump housing are screwed together.

[0012] According to the invention, seals are provided between the respective housing parts arranged next to each other. This eliminates the need for a geometrically complex seal or one consisting of several parts.

[0013] In one embodiment, the housing body cover is an ECU housing top and the housing body bottom is a housing top of the motor housing of the electric motor.

[0014] Preferably, a pump is arranged in the pump housing on the side of the engine housing facing away from the upper part of the ECU housing.

[0015] In one embodiment, the upper part of the ECU housing, the motor housing and the pump housing are sealed together.

[0016] According to the invention, the housing body cover can be an ECU housing top part and the housing body bottom part can be a housing top part of a pump housing.

[0017] In another embodiment, an electric motor is arranged on the side of the pump housing facing away from the upper part of the ECU housing.

[0018] Preferably, the ECU housing upper part, the pump housing and the motor housing are sealed together. This seals them against environmental influences.

[0019] Preferably, the lower part of the ECU housing, the motor housing and the pump housing are screwed together.

[0020] The housing device is preferably made of plastic.

[0021] The invention will now be described in more detail with reference to the attached figures. These show: Figure 1 a sectional view of a first embodiment of the housing device according to the invention; Figure 2 a sectional view of a second embodiment of the housing device according to the invention; and Figure 3a sectional view of a third embodiment of the housing device according to the invention.

[0022] Corresponding parts are marked with the same reference symbols in all figures.

[0023] Figure 1 Figure 1 shows an embodiment of a housing device 10 according to the invention, such as that used for an electric oil pump. The housing device 10 comprises a pump 20, a motor 30 and an electronic control unit, ECU, 40.

[0024] In this embodiment, the housing device 10 further comprises a housing body cover 50, which simultaneously constitutes the ECU housing upper part 50, and a housing body lower part 60, which simultaneously constitutes the ECU housing lower part 60. The ECU housing upper part 50 and the ECU housing lower part 60 are connected to each other by means of a seal 70 and screwed onto a motor housing 90 of the electric motor 30 by means of a sealing element 100 as the housing upper part 80.

[0025] The electric motor 30 comprises a shaft 110, a rotor 120, and a stator 130, here a brushless DC motor with the motor housing 90, and is constructed in a known manner. On the side facing away from the ECU housing 50, 60, the pump 20 is arranged on the motor housing 90 of the electric motor 30 with a pump housing 150. The shaft 110 of the motor 30 and the pump 20 is a single piece and extends from the pump housing 150 into the motor housing 90. The pump housing 150, the motor housing 90, and the lower part of the ECU housing 60 are connected to each other by means of a screw connection 160, with sealing material 100, 0160 being provided between the pump housing 150 and the motor housing 90 and between the motor housing 90 and the lower part of the ECU housing 60.

[0026] In Figure 1Furthermore, a printed circuit board 170 is arranged inside the ECU housing 50, 60 and is bonded to the lower part of the ECU housing 60 by means of a sealant 180, e.g., epoxy adhesive. The lower part of the ECU housing 60 has openings 190 through which cooling media (typically the fluid pumped by the pump 20) can pass and cool heat sources through direct contact of the fluid, e.g., oil, with the printed circuit board 170 in the area of ​​the openings 190. The design of the pump 20 ensures a certain amount of oil exchange of the oil that touches the hot spots (i.e., transistors, controllers, current conductors) of the printed circuit board 170, in order to transfer the heat also through oil movement. Preferably, the pump's internal leakage oil is used to ensure oil exchange in the required cooling volumes.

[0027] The circuit board 170 can be electrically connected by means of a connecting pin 200, which extends through the ECU housing base 60 in the direction from the housing base 60 into a connection area 210.

[0028] On the side of the circuit board 170 facing away from the motor housing 90, circuit assemblies 220 and SMT components, e.g., MOSFETs, are arranged. It is also possible, although not shown here, to mount the components on the side of the circuit board 170 that is bonded to the lower part of the ECU housing 60 by creating pockets in the housing to accommodate the electronic components. These circuit assemblies 220, which are designed as SMT components, do not require through-holes on the circuit board 170. Since the circuit board 170 is made of epoxy material and no through-holes are required, it can act as a separating or sealing layer against the oil or wet area.

[0029] On the side of the circuit board 170 facing the motor housing 90, SMT male pins 230 are provided, which are in contact with SMT female pins 240 extending from the stator 130 of the motor 30 for electrical contact with the motor 30. The SMT male pins 230 can also extend from the stator 130 for electrical contact with SMT female pins 240 located on the circuit board 170. In both cases, the motor phases are connected through the openings 190 formed in the lower part 60 of the ECU housing. The motor phase contacts are typically contacts that can be connected to the circuit board 170 without special mounting force or entirely without any force at all.

[0030] Figure 2 A second embodiment of the housing device 10 according to the invention is shown, with the sole focus being on how the housing devices 10 differ.

[0031] In this embodiment, the housing device 10 comprises a housing body cover 250, which represents an ECU housing 250 that is completely open on the side facing the motor housing 90. The ECU housing 250 is arranged on the adjacent motor housing 90 by means of screws, with the ECU housing 250 and the motor housing 90 being tightly sealed by means of a seal 260.

[0032] The electric motor 30 incorporated in the motor housing 90 corresponds to the one from Figure 1 , to whose description reference is made. The pump 20 with the pump housing 150 connects to the motor housing 90 in the same way as in the design according to Figure 1 .

[0033] The embodiment according to Figure 2 differs from the one in Figure 1by the fact that the circuit board 170 is also located inside the ECU housing 250, but is glued to the upper housing section 270 of the motor housing 90 by means of sealing adhesive 180. In The upper housing section 270 of the motor housing 90 has openings 280 through which the cooling medium can reach the back of the circuit board 170, and the required cooling of the circuit board is achieved through the oil exchange.

[0034] The connecting pin 200 extends from the circuit board 170 through the ECU housing 250 to the connection area 210 for the electrical connection.

[0035] Just like in the embodiment in Figure 1 Circuit arrangements 220 are provided on the side of the circuit board 170 facing away from the motor housing 90. Reference is made to the description there.

[0036] The motor phase contacts 230, 240 are also identical to those of the Figure 1 trained.

[0037] Figure 3 Figure 10 shows a housing device in which the arrangement of pump 20 with pump housing 150, electric motor 30 with motor housing 90 and electrical control unit 40 with ECU housing 250 differs from the arrangement of the same in the Figure 1 and 2 differs.

[0038] The housing assembly 10 of this embodiment comprises the housing body cover 250, which also forms the ECU housing 250. The ECU housing 250 is completely open on the side facing the pump housing 150. Adjacent to the ECU housing 250 is the pump housing 150 with the pump 20, onto which the ECU housing 250 is attached by means of a screw connection. On the side facing away from the ECU housing 250 is the motor housing 90 with electric motor 30. The ECU housing, the pump housing 150, and the motor housing 90 are connected to each other by screws 290. Seals 260, 300 are arranged between the ECU housing 250 and the pump housing 150 and between the pump housing 150 and the motor housing 90 to seal the interior of the housing device fluid-tight and to the outside towards the wet room.

[0039] The circuit board 170 is glued to the upper housing area 310 of the pump housing 150 using a sealant 160. InOpenings 320 are formed in the upper housing area 310 of the pump housing 150, through which cooling medium from inside the pump housing 150 can reach the back of the circuit board 170. This oil exchange cools the circuit board 170. The heat from the circuit board 170 is thus dissipated close to its source. This allows for very small cooling surfaces with good heat dissipation. Due to this direct cooling of the circuit board 170, the housing material is no longer the primary factor determining the circuit board cooling. Therefore, more cost-effective materials, such as plastic, can be used for the housing, and the size of the pump can be reduced.

[0040] On the side of the circuit board 170 facing away from the pump housing 150, namely on the side that is not glued to the pump housing 150, circuit arrangements 220 and SMT components, e.g., MOSFETs, are also arranged in this embodiment. Here, too, as in the embodiment of the Figure 1 , to provide the components on the side of the circuit board 170 that is bonded to the pump housing 150.

[0041] On the side of the circuit board 170 facing the pump housing 150, SMT female pins 240 are provided, which are in contact with SMT male pins 230 for electrical contact with the motor 30. The SMT male pins 230 extend from the stator 130 of the motor 30 through the pump 20, through the openings in the upper housing area 310 of the pump housing 150, and contact the SMT female pins 240 provided on the circuit board 170 in the area of ​​the openings 320. In this embodiment as well, the number of parts and the sealing effort for the housing assembly are reduced due to the low insertion forces of the motor phase contacts. Easy assembly is also ensured.

[0042] Housing devices of the type described above can be used, for example, in automotive hydraulic systems, electric drives for electric and hybrid vehicles, automatic transmissions, commercial vehicles, oil supply systems, in nautical applications, battery cooling systems and lubrication systems. Reference symbol list

[0043] 10 Housing assembly 20 Pump 30 Motor 40 Electrical control unit, ECU 50 ECU housing top 60 ECU housing bottom 70 Gasket 80 Housing body cover 90 Motor housing 100 Sealing element 110 Shaft 120 Rotor 130 Stator 140 Pump 150 Pump housing 160 Sealant 170 Printed circuit board 180 Sealing adhesive 190 Openings 200 Connecting pin 210 Connection area 220 Circuit arrangement 230 SMT male pins 240 STM female pins 250 Housing body cover 260 Gasket 270 Upper housing area of ​​the motor housing 90 280 Openings in the motor housing 90 290 Screw connection 300 Sealing element 310Upper housing area of ​​the pump housing 150 320Openings

Claims

1. Fluid pump, in particular cooling pump or oil pump, comprising a pump (20) with a pump housing (150), an electric motor (30) with a motor housing (90), and an electronics module (40) with an ECU housing (50, 60), having a housing which consists of a housing-body cover (50) and a housing-body bottom part (60, 90, 150), a printed circuit board (170) arranged therein, which printed circuit board (170) has an electrical circuit arrangement (220) on one side, wherein the printed circuit board (170) is arranged on the housing-body bottom part (60) by way of a sealing adhesive (180), characterized in that provision is made in the housing-body bottom part (60) of at least one opening (190) through which oil can pass and reach the printed circuit board (170), and wherein the housing-body cover (50) and the housing-body lower part (60, 90, 150) are fitted tightly together, wherein, on the side facing away from the housing-body cover (50), the printed circuit board (170) has contacting elements (230, 240) for contact with contact elements (240, 230) departing from the electric motor (30), which extend into them through the at least one opening (190), wherein the printed circuit board (170) is connectable via an electrical connecting element (200).

2. Fluid pump according to Claim 1, wherein the housing-body cover (50) is an ECU-housing top part (50) and the housing-body bottom part is an ECU-housing bottom part (60).

3. Fluid pump according to Claim 2, wherein the ECU-housing bottom part (60) is arranged on the motor housing (90) of the electric motor (30) and forms the housing top part of the motor housing (90).

4. Fluid pump according to Claim 3, wherein the pump housing (150) is arranged on that side of the motor housing (90) which faces away from the ECU-housing bottom part (60).

5. Fluid pump according to Claim 6, wherein the ECU-housing bottom part (60), the motor housing (90) and the pump housing (150) are screwed together.

6. Fluid pump according to Claim 5, wherein provision is made between the respective housing parts (60, 90, 150) arranged one on the other of seals (70, 100, 160).

7. Fluid pump according to Claim 1, wherein the housing-body cover is an ECU-housing top part (250) and the housing-body bottom part is a housing top part of the motor housing (90) of the electric motor (30).

8. Fluid pump according to Claim 7, wherein the pump (20) in the pump housing (150) is arranged on that side of the motor housing (90) which faces away from the ECU-housing top part (250).

9. Fluid pump according to Claim 8, wherein the ECU-housing top part (250), the motor housing (90) and the pump housing (150) are connected sealingly to one other.

10. Fluid pump according to Claim 1, wherein the housing-body cover is an ECU-housing top part (250) and the housing-body bottom part (310) is a housing top part of a pump housing (150).

11. Fluid pump according to Claim 10, wherein an electric motor (30) is arranged on that side of the pump housing (150) which faces away from the ECU-housing top part (250).

12. Fluid pump according to Claim 11, wherein the ECU-housing-body top part (250), the pump housing (150) and the motor housing (90) are connected sealingly to one other.

13. Housing device (10) according to one of Claims 1 to 12, wherein the housing body is made of plastic.

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