ELECTRONIC UNIT AND ELECTRIC FLUID PUMP, AND CLOSURE ELEMENT

Abstract

An electronic unit, in particular for an electric fluid pump of a motor vehicle, having a functional element for holding electronics, and a heat sink arranged on the functional element, wherein the functional element and the heat sink are sealed from one another in fluid-tight fashion by means of a cured sealing compound of a liquid seal, and wherein the functional element has at least one ventilation opening, which is open in the course of a curing process for the sealing compound, and which, after the curing process, is sealed in fluid-tight fashion by means of a closure element.

Claims

1. An electronic unit for use in an electric fluid pump for a motor vehicle, the electronic unit comprising: an electronic assembly; a function carrier retaining the electronic assembly and including a ventilation opening; a cooling member disposed on the function carrier, wherein the function carrier and the cooling member are sealed with respect to each other in a fluid-tight manner by means of a fluid seal formed of a hardened sealing compound; and a closure element wherein during a hardening process to harden the sealing compound, the ventilation opening is open and wherein after the hardening process, the closure element closes the ventilation opening.

2. The electronic unit of claim 1, wherein the closure element is configured to permanently close the ventilation opening in a fluid-tight manner.

3. The electronic unit of claim 1, wherein function carrier includes an outer face and an inner face and the closure element extends through the outer face and the inner face and engages a region of the inner face covered by the ventilation opening.

4. The electronic unit of claim 1, wherein the closure element is formed of a plastic material and includes a sealing ring configured to seal the closure element in a fluid-tight manner with respect to an inner wall of the ventilation opening.

5. The electronic unit of claim 1, wherein the closure element has a substantially T-shaped cross section and includes a vertical T leg and a horizontal T leg, wherein a free end of the vertical T leg defines a tool receiving member, and wherein the horizontal T leg engages in a positive-locking manner an inner surface of the function carrier spaced apart from the ventilation opening.

6. The electronic unit of claim 5, wherein the inner surface defines two introduction ramps and two stops extending axially from the inner surface and collectively arranged in an alternating manner about the ventilation opening and configured to engage for the horizontal T leg.

7. The electronic unit f claim 6, wherein the closure element extends along a longitudinal axis and is configured to be rotated about the longitudinal axis thereof so that the horizontal T leg slides over the introduction ramps and engages the stops in a positive-locking manner.

8. The electronic unit of claim 1, wherein the closure element includes a free end and two flexible snap-fit members extending therefrom, wherein each of the two flexible snap-fit members include a snap hook head that engage an inner surface of the function carrier.

9. An electric fluid pump for use in a motor vehicle transmission, the electric fluid pump comprising: electric motor; and an electronic unit coupled to the electric motor and including, a function carrier defining a ventilation opening, a cooling member fixed to the function carrier by a sealing compound, wherein the sealing compound is configured to harden after a period, and a closure element provided with a sealing ring, wherein the closure element is inserted into the ventilation opening so that the ventilation opening is closed after the sealing compound hardens.

10. (canceled)

11. The electronic unit of claim 4, wherein the closure element is formed by injection molding.

12. The electric fluid pump of claim 9, wherein the closure element is formed of a plastic material.

13. The electric fluid pump of claim 9, wherein the function carrier includes an outer face and an inner face opposing the inner face and fixed to the cooling member, wherein the closure element extends through the outer face and the inner face.

14. The electric fluid pump of claim 13, wherein the closure element includes a first end and a second end provided with a retention member configured to engage a portion of the inner surface of the function member.

15. The electric fluid pump of claim 14, wherein the function carrier includes a protrusion extending from the outer face, wherein the protrusion defines a first axial portion of the ventilation opening and the sealing ring is disposed in the first axial portion.

16. The electric fluid pump of claim 15, wherein the first end of the closure element includes a head and the sealing ring lies against the head.

17. The electric field pump of claim 16, wherein the first head defines a socket configured to receive a tool.

18. The electric fluid pump of claim 13, wherein the retention member includes a tapered locking tab.

19. An electric fluid pump for use in a motor vehicle transmission, the electric fluid pump comprising: electric motor; and an electronic unit coupled to the electric motor and including, a function carrier including an inner side and an outer side collectively defining a ventilation aperture, a cooling member fixed to the function carrier by a sealing compound, wherein the sealing compound is configured to harden after a period, and a closure element extending through the ventilation aperture and including a body provided with first end and a second end, wherein a portion of the second end engages the inner side of the function carrier to fix the closure element to the function carrier.

20. The electric fluid pump of claim 19, wherein the closure element is configured to rotate about a longitudinal axis and the second end includes a leg extends from the body in a direction transverse to the longitudinal axis.

21. The electric fluid pump of claim 20, wherein a portion of the inner surface includes a ramp and a stop, wherein the leg is configured to move along the ramps to clamp the body towards the inner surface and engage the engage the stop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the invention are explained in greater detail below with reference to the drawings, in which:

[0034] FIG. 1 is a schematic and simplified illustration of an oil circuit of a motor vehicle having an electromotive oil pump,

[0035] FIG. 2 is a perspective illustration of the oil pump with a pump mechanism and with an electric motor and with an electronic unit,

[0036] FIG. 3 is a perspective illustration of a function carrier of the electronic unit,

[0037] FIG. 4 is a perspective section of the electronic unit along the line IV-IV according to FIG. 3,

[0038] FIG. 5 is a sectioned illustration of a ventilation opening of the function carrier in a first embodiment,

[0039] FIG. 6 is a sectioned illustration of the ventilation opening with an inserted closure element in a first embodiment,

[0040] FIG. 7 is a perspective illustration of the closure element,

[0041] FIG. 8 is a perspective illustration of the closure element with a sealing ring,

[0042] FIG. 9 is a perspective illustration of a second embodiment of a closure element,

[0043] FIG. 10 is a perspective illustration of the closure element according to FIG. 9 with three sealing rings,

[0044] FIG. 11 is a perspective cut-out of the function carrier in the region of the ventilation opening according to a second embodiment,

[0045] FIG. 12 is a perspective cut-out of the region of the ventilation opening,

[0046] FIG. 13 is a sectioned illustration of the ventilation opening,

[0047] FIG. 14 is a plan view of the ventilation opening,

[0048] FIG. 15 is a sectioned illustration of the ventilation opening with the inserted closure element in the second embodiment,

[0049] FIG. 16 shows in successive individual illustrations a securing of the closure element in the ventilation opening in the manner of a bayonet closure, and

[0050] FIG. 17 is a perspective illustration of a third embodiment of the closure element.

[0051] Components and dimensions which mutually correspond are always given the same reference numerals in all the Figures.

DETAILED DESCRIPTION

[0052] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0053] In order to seal a function carrier with respect to a cooling member and in order to prevent leakages, for example, it is possible to use a fluid seal (surface seal). With such a fluid seal, a fluid sealing or casting compound is applied to the abutment or contact faces between the function carrier and the cooling member. As a result of the fluid form of the sealing compound, roughness depths and structural deviations of the contact faces are filled and compensated for. The sealing compound is subsequently hardened in a hardening process, for example, in a climate chamber in the case of thermal hardening, that is to say, solidified, whereby a complete material engagement is brought about between the contact faces.

[0054] A “material engagement” or a “materially engaging connection” between at least two components which are connected to each other is intended to be understood in this instance and below in particular to mean that the components which are connected to each other are held together at their contact faces by means of material association or cross-linking (for example, as a result of atomic or molecular bonding forces), where applicable under the action of an additive.

[0055] The material engagement consequently prevents the penetration of fluids into the electronic unit and ensures a reliable sealing. In addition, the seal which is thereby formed bonds on both contact faces, whereby a fixed (adhesive) connection between the function carrier and the cooling member is brought about. That is to say, such a fluid seal serves both to seal and to join the electronic unit.

[0056] In the case of a completely closed electronic unit, however, the problem occurs in this instance that the sealing compound after a hardening process does not fully or completely harden. Both the sealing and the joining properties of the material engagement or the adhesive connection are thereby reduced in a disadvantageous manner, whereby the risk of leakages of the electronic unit is significantly increased.

[0057] FIG. 1 is a schematic and simplified illustration of a part-region of an oil circuit 2 of a motor vehicle which is not shown in greater detail. The oil circuit 2 comprises an electrical or electromotive fluid pump 4 as a combined main oil pump and an auxiliary or supplementary pump for conveying a fluid 6, in particular a (lubricant) oil to gear components of a vehicle transmission.

[0058] The fluid pump 4 which is also referred to below as an oil pump has an electric motor 8 as an electric drive machine. During operation of the electric motor 8 or the oil pump 4, the oil 6 is drawn by means of a reduced pressure line 10 from an oil sump 12 via a (pump) inlet 14 and pumped via a (pump) outlet 16 into an oil line 18 which is divided into a main oil line 20 and an auxiliary or additional line 22.

[0059] The main oil line 20 forms a main oil circuit of the oil circuit 2 and may be provided to supply and activate hydraulic transmission actuators 24 by means of which, for example, the gears of a transmission arrangement 26 of a vehicle transmission which may be an automatic transmission or as a dual coupling transmission are engaged or shifted. The auxiliary or supplementary line 22 is accordingly in particular a component of an auxiliary or supplementary circuit for at least occasional lubrication or additional lubrication of gear components, such as, for example, of the transmission arrangement 26.

[0060] The oil pump 4 is shown in FIG. 2 in a comparatively detailed manner. The oil pump 4 comprises a pump housing 28 having a pump mechanism which is not shown in greater detail for conveying the oil 6. The pump mechanism is coupled to the electric motor 8 in technical drive terms. To this end, the electric motor 8 is secured at a first end side to the pump housing 28. At the end side of the electric motor 8 opposite the pump housing 28, an electronic unit 30 is provided.

[0061] The electronic unit 30 has a function carrier 32 which is illustrated in detail in FIGS. 3 and 4 and which carries a (motor, pump) electronic assembly 34 for operating the machine 8. The electronic assembly 34 is shown only as a cut-out in FIG. 4 in the form of current paths (lead frames) which are integrated in the function carrier 32 and, for example, provided with reference numerals. In order to cool and protect the electronic assembly 34, it is covered with a cover-like cooling member (cooling lid) 36 in a fluid-tight manner. That is to say, the function carrier 32 and the cooling member 36 form the electronic unit 30 of the oil pump 4 which is closed in a substantially completely fluid-tight manner.

[0062] In this embodiment, the function carrier 32 is constructed as an injection-molded component from a plastics material, wherein the cooling member 36 is constructed as a metal die-cast component, for example, from an aluminum material. As an example, the cooling member 36 which acts as a heat sink has a higher thermal conductivity than the function carrier 32. For improved and effective cooling of the function carrier 32, it has two recesses 32a, 32b.

[0063] In order to ensure the highest possible level of fluid-tightness, the function carrier 32 and the cooling member 36 are joined together in a materially engaging manner by means of a fluid seal which is not shown in greater detail. To this end, a sealing compound (grouting) of the fluid seal which is constructed, for example, as an adhesive, is applied to the mutually facing, such as edge-side, that is to say, arranged on the respective external periphery, contact or abutment faces of the cooling member 32 and/or the function carrier 36. Subsequently, the cooling member 32 and the function carrier 36 are joined and the sealing compound is hardened by means of a hardening process. The material of the sealing compound is fluid or oil-resistant in this instance at least in the hardened state of the fluid seal, this means that the sealing compound with respect to contact with the oil 6 is chemically inert, that is to say, non-reactive.

[0064] In order to ensure the most complete hardening of the sealing compound during the hardening process, the function carrier 32 has a ventilation opening 38. As can be seen in the sectioned illustration of FIG. 4, the ventilation opening 38 is in this instance constructed as a channel-like through-opening or through-hole which extends through the function carrier 32 from an inner face 40 facing the cooling member 36 to an opposing outer face 42.

[0065] The ventilation opening 38 which is illustrated in detail in FIG. 5 has a collar or pipe portion which protrudes axially in an upward direction from the outer face 42 and which is not shown in greater detail. The ventilation opening 38 has an introduction region 38a and a retention region 38b which opens therein and which leads to the inner face 40. The introduction region 38a is provided at the upper, that is to say, the outer end thereof with a chamfered introduction member 44. The retention region 38b has in comparison with the introduction region 38a a reduced clear width, that is to say, a smaller radial diameter.

[0066] The ventilation opening 38 is open during the hardening process, this means that the electronic unit 30 is not completely closed during the hardening process of the fluid seal. For subsequent complete fluid-tight sealing of the electronic unit 30 and in order to prevent leakages, the ventilation opening 38 is connected in a fluid-tight manner to a closure element 46 after the hardening process.

[0067] As can be seen in the sectioned illustrations of FIG. 4 and FIG. 6, the closure element 46 is located in this instance substantially completely in the ventilation opening 38.

[0068] The closure element 46 illustrated in detail in FIG. 7 and in FIG. 8 has a closure head 48 and a retention seat 50 and two snap-fit members 52 which are constructed as a one-piece, that is to say, integral or monolithic injection molded component. The closure element 46 is in this may be produced from the same plastics material as the function carrier 32.

[0069] The cylindrical retention seat 50 is formed on the substantially annular closure head 48, wherein the closure head 48 protrudes radially beyond the retention seat 50 toward the outer periphery thereof. As can be seen, for example, in FIG. 6, the closure head 48 has a diameter which substantially corresponds to the clear width of the introduction region 38a of the introduction opening 38.

[0070] As shown, for example, in FIG. 6 and FIG. 8, a resilient sealing ring (O-ring) 54 is fitted to the retention seat 50. In the assembled or joined state (FIG. 6, FIG. 8) of the closure element 46 in the ventilation opening 38, the sealing ring 54 is in abutment in a fluid-tight manner with an inner wall 56 of the introduction region 38a which is also referred to below as a sealing seat. The sealing ring 54 may be produced from a fluid or oil-resistant material so that in the assembled state of the closure element 46 a dependable and operationally reliable fluid-tight sealing of the ventilation opening 38 is ensured.

[0071] The sealing ring 54 which is placed on the retention seat 50 is oversized with respect to the sealing seat 38a of the introduction opening 38. As an example, the sealing ring 54 has a greater radial width than the plug-like closure head 48. When the closure element 46 is inserted into the ventilation opening 38, as a result of the resilience of the sealing ring 54, a clamping and sealing abutment of the sealing ring 54 against the retention seat 50, on the one hand, and the inner wall 56 of the sealing seat 38a, on the other hand, is ensured. The ventilation opening 38 is thereby closed in a reliable fluid-tight manner by the closure element 46.

[0072] In order to prevent the closure element 46 from sliding out of the ventilation opening 38 in an undesirable manner, the two snap-fit or joining members 52 are formed on the retention seat 50 of the closure element 46. The snap-fit members 52 are as a result of their shape and/or material constructed to be at least partially flexible, that is to say, at least to some degree resilient. The snap-fit members 52 are provided in each case at the free end side, that is to say, at a member end or free end facing away from the retention seat 50, with a projection-like snap hook head 58.

[0073] In order to facilitate the insertion or pressing of the closure element 46 into the ventilation opening 38, the closure element 46 has a blind-hole-like receiving member 60. The receiving member 60 is in this instance introduced as a central annular opening in the closure head 48 and extends at least partially axially into the retention seat 50. During assembly, for example, it is possible for a stamp to engage in the receiving member 60 and to thereby press the closure element 46 axially into the ventilation opening 38, wherein the chamfered introduction member 44 of the sealing seat 38a in this instance may enable a relatively simple and reliable introduction of the closure element 46.

[0074] As a result of the application of the pressing or joining pressure, the snap-fit members 52 are guided along an inner wall of the retention region, and in this instance at least partially bent toward each other. As a result of the restoring forces which are consequently active, the snap hook heads 58 when emerging at the inner face 40 in the region of the ventilation opening 38 are independently moved into a locking position. That is to say, the snap hook heads 58 engage in the joined or assembled state behind the function carrier 32 in the region of the ventilation opening 38 in a positive-locking manner (FIG. 6). A plug-type securing of the closure element 46 with reduced complexity is thereby produced and closes the ventilation opening in a fluid-tight manner permanently, that is to say, in a manner which cannot be released without being destroyed.

[0075] With reference to FIGS. 9 to 16, a second embodiment of the closure element 46′ with a second embodiment of the ventilation opening 38′ which is adapted thereto is illustrated in greater detail below.

[0076] In this embodiment, the closure element 46′ which is illustrated in detail in FIG. 9 and in FIG. 10 is constructed to be substantially T-shaped in a longitudinal section (FIG. 15).

[0077] The vertical T leg 62 extends in this instance in the joined or assembled state in the axial direction, that is to say, along the center axis, of the ventilation opening 38′. The closure head 48′ in which a central tool receiving member 64 is formed is formed on the free end of the T leg 62. The tool receiving member 64 is in this instance constructed as a hexalobular socket.

[0078] At the end of the T leg 62 opposite the tool receiving member 64, the horizontal T leg 66 of the closure element 46′ which extends transversely relative thereto is formed. The T leg 66 has a substantially cylindrical center region 66a which is constructed as a continuation of the T leg 62. At the central region 66a, two transversely orientated and mutually diametrically opposed arms 66b are arranged. The two arms 66b of the T leg 66 which protrude over the T leg 62 are in this instance constructed to engage behind the function carrier 32 in the region of the ventilation hole 38′ in a positive-locking manner.

[0079] As shown in FIG. 9, the closure element 46′ has two retention plates 68 which are formed in an axially distributed manner in the T leg 62. As a result of the retention plate 68. three retention seats 50′ are formed along the T leg 62, wherein a sealing ring 54 is provided in each case for the respective retention seat 50′ (FIG. 10).

[0080] With reference to FIGS. 11 to 14, the structure of the ventilation opening 38′ which is constructed to complement the closure element 46′ is explained in greater detail below.

[0081] FIG. 11 shows a cut-out of the function carrier 32 in the region of the ventilation opening 38′, with a view of the inner face 40, wherein this region is illustrated to a larger scale in FIG. 12.

[0082] The opening of the retention region 38b′ of the ventilation opening 38′ facing the inner face 40 has in this embodiment—as can be seen in particular in FIG. 12 and FIG. 14—a cross-sectional shape which is adapted to the outer contour of the T leg 66. That is to say, the T leg 66 during an assembly or joining method can be guided substantially in a precisely fitting manner through the retention region 38b′ to the inner face 40.

[0083] The inner face 40 of the function carrier 32 has in this region, behind which the arms 66b of the T leg 66 engage in the assembly or joined state, two introduction ramps 70 and two stops 72 which are arranged alternately, that is to say, in turn, about the ventilation opening 38′.

[0084] The introduction ramps 70 and the stops 72 protrude axially in an upward direction from the inner face 40 of the function carrier 32, wherein the stops 72 have a greater axial height than the introduction ramps 70. The introduction ramps 70 have a running face which is not depicted in greater detail and which extends at an angle inclined with respect to the inner face 40. The introduction ramps 70 and the stops 72 are in this instance arranged in the region of the (shaping) opening of the ventilation opening 38′ which corresponds to the arms 66b.

[0085] As shown in particular in FIGS. 15 and 16, in order to assemble or join the closure element 46′ in the ventilation opening 38′ there is provision for the closure element 46′ to be pressed into the ventilation opening 38′ and subsequently rotated about the longitudinal axis thereof. In order to rotate the closure element 46′, in this instance in particular a tool which is not illustrated in greater detail and which engages in the tool receiving member 64 is used.

[0086] The closure element 46′ is in this instance rotated through 90°, wherein the arms 66b of the T leg 66 are guided over the introduction ramps 70. The T leg 66 and consequently the closure element 46′ is thereby axially raised with respect to the inner face 40, the closure element 46′ is thus drawn to some degree further into the ventilation opening 38′. In this instance, in particular the sealing ring 54 which is arranged next to the T leg 66 brings about an axial pretensioning of the closure element 46′. At the end of the respective introduction ramp 70, the T leg is moved back to the inner face 40 as a result of this pretensioning.

[0087] The rotational movement is blocked by the stops 72 so that the T leg 66 engages or locks in a positive-locking manner in the manner of a bayonet closure between the introduction ramps 70 and the stops 72. As an example, the T leg 66 and consequently the closure element 46′ is consequently permanently fixed in a positive-locking manner to the function carrier 32.

[0088] FIG. 17 shows a third embodiment of the closure element 46″. The closure element 46″, which is configured in a substantially T-shaped manner in an axial section, has a closure head 48″ having a central tool receiving member 64. A retention seat 50″ for a sealing ring 54 is formed on the closure head 48″.

[0089] In contrast to the above-described embodiments of the closure elements 46 and 46′, the closure element 46″ has no additionally formed fixing elements (snap hooks, bayonet). In other words, it is constructed without fixing elements and consequently has a particularly simple and cost-effective structure. The securing of the closure element 46″ in order to close a corresponding ventilation opening in a fluid-tight manner is carried out in this instance only by means of the resilient pretensioning of the sealing ring 54 which is fitted to the retention seat 50″.

[0090] The invention is not limited to the embodiments described above. Instead, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject-matter of the invention. In particular, all individual features described in connection with the embodiments can also be combined with each other in another manner without departing from the subject-matter of the invention.

[0091] The following is a list of reference numbers shown in the Figures. However, it should be understood that the use of these terms is for illustrative purposes only with respect to one embodiment. And, use of reference numbers correlating a certain term that is both illustrated in the Figures and present in the claims is not intended to limit the claims to only cover the illustrated embodiment.

LIST OF REFERENCE NUMERALS

[0092] 2 Oil circuit [0093] 4 Fluid pump/oil pump [0094] 6 Fluid/oil [0095] 8 Electric motor [0096] 10 Reduced pressure line [0097] 12 Oil sump [0098] 14 Inlet [0099] 16 Outlet [0100] 18 Oil line [0101] 20 Main oil line [0102] 22 Auxiliary line/supplementary line [0103] 24 Transmission actuator [0104] 26 Transmission arrangement [0105] 28 Pump housing [0106] 30 Electronic unit [0107] 32 Function carrier [0108] 32 a, 32b Recess [0109] 34 Electronic assembly [0110] 36 Cooling member [0111] 38, 38′ Ventilation opening [0112] 38a, 38a′ Introduction region/sealing seat [0113] 38b, 38b′ Retention region [0114] 40 Inner face [0115] 42 Outer face [0116] 44 Chamfered introduction member [0117] 46, 46′, 46″ Closure element [0118] 48, 48′, 48″ Closure head [0119] 50, 50′, 50″ Retention seat [0120] 52 Snap-fit member [0121] 54 Sealing ring [0122] 56 Inner wall [0123] 58 Snap hook head [0124] 60 Receiving member [0125] 62 T leg [0126] 64 Tool receiving member [0127] 66 T leg [0128] 66a Central region [0129] 66b Arm [0130] 68 Retention plate [0131] 70 Introduction ramp [0132] 72 Stop

[0133] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.