Motor with circuit board

Abstract

The invention relates to an electric machine having a printed circuit board, wherein a first printed circuit board has a plurality of layers with conductor tracks, wherein the layers are separated from one another by a first covering layer, the first covering layer consisting of an insulating material, in particular a fiber-reinforced plastic, in particular an epoxy resin material, wherein an insulating covering layer is arranged between two of the layers.

Description

Technical Field

[0001] The invention relates to a motor with a circuit board. Background Art

[0002] It is well known that electric motors generate heat losses and thus high temperatures.

[0003] As the closest prior art, an electric power steering device is known from DE 10 2006 043 194 A1.

[0004] A method for producing a multilayer printed circuit board is known from DE 10 2018 100 139 A1.

[0005] A control unit is known from US 2013 / 0 301 229 A1.

[0006] A drive unit is known from DE 10 2011 056 365 A1.

[0007] A vehicle control unit is known from US 2010 / 0 314 192 A1.

[0008] WO 2009 / 069 103 A2 discloses a production method for an electric motor.

[0009] DE 10 2013 006 539 A1 discloses an electrical device having a cooling structure. Summary of the Invention

[0010] It is therefore an object of the present invention to improve an electric machine with integrated electronics.

[0011] According to the invention, this object is achieved by an electric machine according to the features specified in claim 1 .

[0012] An essential feature of the invention with respect to an electric machine having a printed circuit board is that the first printed circuit board has a plurality of layers with conductor paths / conductor tracks.

[0013] The layers are spaced apart from one another by a first covering layer consisting of an insulating material, in particular a fiber-reinforced plastic, in particular an epoxy resin material.

[0014] In this case, an insulating coating is arranged between two of the layers.

[0015] The advantage here is that simple production is possible, but this production results in an insulating coating that acts as a thermal barrier between the two sides of the first printed circuit board.

[0016] In an advantageous embodiment, the insulating coating has a greater coating thickness than the first coating. This has the advantage that a strong thermal resistance effect can be achieved.

[0017] In an advantageous embodiment, the insulating coating is made of the same material as the first coating, in particular so that the first printed circuit board is designed as a multilayer printed circuit board, the individual layers of which are spaced apart from one another unevenly, in particular irregularly.

[0018] Particularly wherein, this material is fiber reinforced plastic, particularly epoxy resin material. Advantage is here, can realize simple manufacturing.

[0019] In an advantageous embodiment, the insulating coating is made of a material different from that of the first coating.

[0020] In particular, the material of the insulating coating is a plastic, which in particular has closed bubbles, in particular gas volumes. The advantage here is that the insulating coating can be made of a material that is less thermally conductive than other materials of the first printed circuit board that are arranged between the layers.

[0021] In one advantageous embodiment, the electric motor comprises a stator housing in which the stator winding of the electric motor is accommodated, a cover, and a retaining ring arranged between the cover and the stator housing and in which the first printed circuit board is accommodated. This has the advantage that the space for the electronics, in particular the inverter, can be integrated into the electric motor.

[0022] In an advantageous embodiment, the first and second printed circuit boards are arranged in a space of the motor that is bounded, in particular surrounded, by the stator housing, the retaining ring, and the cover. Advantageously, the electronics are arranged in a protected manner in the space.

[0023] In an advantageous embodiment, the first circuit board and the second circuit board are parallel to each other and spaced apart from each other.

[0024] In particular, the rotation axis of the rotatably mounted rotor shaft of the electric motor is parallel to the normal direction of the first printed circuit board. This has the advantage that the electrical insulation distance can be maintained and an air gap is provided between the second printed circuit boards. The space is filled with air, thus enabling air circulation.

[0025] In an advantageous embodiment, the second printed circuit board is arranged on the side of the first printed circuit board facing away from the stator housing. This has the advantage that the second printed circuit board can be exposed to a lower temperature than the stator winding of the power module and / or the electric machine.

[0026] In one advantageous embodiment, the first printed circuit board is arranged between the stator housing part and the second printed circuit board. Advantageously, the first printed circuit board has power electronics on the side facing the stator housing part and signal electronics on the side facing away from the stator housing part, which generate the control signals for the controllable semiconductor switches of the power module. The signal electronics can also be arranged on the second printed circuit board.

[0027] In an advantageous embodiment, a power module connected to the stator housing part in a heat-conducting manner is mounted on the side of the first printed circuit board facing the stator housing part. This has the advantage that heat can be dissipated to the environment together with the heat losses generated by the stator winding.

[0028] In an advantageous embodiment, the power module and, in particular, the components mounted on the first printed circuit board on that side of the first printed circuit board which faces the stator housing part, can be operated up to a first temperature, in particular, the first temperature being the maximum permissible operating temperature for the power module.

[0029] wherein the components mounted on the first printed circuit board and the components mounted on the second printed circuit board on the side of the first printed circuit board facing away from the stator housing part are operable up to a second temperature, in particular the second temperature being a maximum permissible operating temperature for the components,

[0030] The second temperature is lower than the first temperature, in particular at least 10° C. lower. This has the advantage that the signal electronics can be operated at a lower temperature level and can dissipate heat independently to the environment.

[0031] In one advantageous embodiment, the second circuit board is accommodated in the cover. This has the advantage that the cover can be pre-assembled to the second circuit board and then to the retaining ring with the first circuit board. The electronics area can thus be connected to the stator housing part during assembly. Alternatively, however, the first circuit board can be fastened to the stator housing part, in particular by screwing it, before the cover, with the pre-assembled second circuit board arranged therein, is plugged onto the retaining ring. The power module can thus already be pressed against the stator housing part while the first circuit board is being attached, with thermal paste being applied between the power module and the stator housing part to improve heat transfer.

[0032] In an advantageous embodiment, the first printed circuit board is connected to a second printed circuit board that is closest to the first printed circuit board by means of an electrical plug-in device.

[0033] Each second printed circuit board is connected to the second printed circuit board closest to the second printed circuit board by means of a corresponding electrical plug-in device.

[0034] In an advantageous embodiment, the retaining ring is constructed as a single piece or in multiple pieces. The advantage here is that the circuit board can either be clamped between the two blocks or can be pressed against a step of the retaining ring in the case of a single-piece construction.

[0035] In an advantageous embodiment, the retaining ring is tightly connected to the stator housing part by means of a seal arranged in between, which also serves as a thermal barrier. This has the advantage that the thermal separation of the signal electronics and the power electronics can be improved.

[0036] In an advantageous embodiment, the retaining ring is tightly connected to the cover by means of a seal arranged in between, which also serves as a thermal barrier. This has the advantage that the thermal separation of the signal electronics and the power electronics can be improved.

[0037] In one advantageous embodiment, a fan is arranged in the spatial region. In another advantageous embodiment, each of the second printed circuit boards has two axially continuous openings, particularly arranged diametrically opposite one another with respect to the rotational axis of the rotor shaft. This has the advantage that the circulating air flow can be conveyed through the spatial region with minimal disruption.

[0038] In an advantageous embodiment, the stator housing part, the retaining ring and the cover are made of metal, in particular are designed as cast parts.

[0039] Particularly wherein, cover has cooling fins on its outside. Advantage is here that thermal conductivity is high, and therefore the efficiency of heat dissipation to the environment is high.

[0040] Further advantages are provided by the dependent claims. The invention is not limited to the feature combinations of the claims. Other suitable combinations of the claims and / or features of individual claims and / or features of the description and / or features of the drawings will appear to a person skilled in the art, particularly based on the objectives presented and / or from a comparison with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention is described in detail below according to the schematic diagram:

[0042] Figure 1 The first circuit board 40 is shown schematically in cross section.

[0043] Figure 2 The first printed circuit board 40 is schematically shown in a top view.

[0044] Figure 3 Show Figure 2 Alternative implementation scheme.

[0045] Figure 4A cross section through an axial end region of an electric machine is schematically shown with a first printed circuit board 40 .

[0046] Figure 5 Schematically shows the Figure 4 An oblique perspective view of a portion of the end region. DETAILED DESCRIPTION

[0047] like Figure 1 、 Figure 2 、 Figure 4 and Figure 5 As shown, a printed circuit board 40 has a plurality of layers 1 with conductor tracks, wherein these layers are separated from one another by a coating of an insulating material 2 , in particular a fiber-reinforced plastic, in particular an epoxy resin material.

[0048] Between two of the layers, an insulating coating 3 is arranged, which in a first embodiment is made of the same material as the coating, in particular so that the circuit board 40 resembles a multilayer circuit board, the layers 1 of which are unevenly spaced apart from one another. Thus, the material is a fiber-reinforced plastic, in particular an epoxy resin material.

[0049] The insulating coating 3 is thicker, ie has a greater wall thickness than the other coatings.

[0050] In a second embodiment, the insulating coating 3 is made of a material different from the coating. A suitable material for the insulating coating 3 is a plastic with closed bubbles, in particular a gas volume.

[0051] In both embodiments, the insulating coating 3 acts as a thermal barrier.

[0052] like Figure 2 As shown, the circuit board 40 has no plated through-holes in the central region 20, but only in the edge region 21 surrounding the central region 20. The plated through-holes arranged there are irregularly spaced apart from one another and impair the effect as a heat barrier in the edge region there.

[0053] replace Figure 2 In the circular embodiment of the circuit board, a rectangular circuit board 40 can also be used, such as Figure 3 As shown, the central region 20 is preferably also designed as a rectangle.

[0054] The circuit board is arranged in the motor. When the motor has a rectangular shape, the Figure 3 circuit board 40.

[0055] like Figure 4 As shown, in the case of a circular shape of the motor, the circuit board 40 is arranged according to Figure 2 The structure shown.

[0056] The printed circuit board 40 is accommodated in this case in a retaining ring 45 which is arranged between a stator housing 44 and a cover 46 of the electric motor.

[0057] The stator of the electric motor is arranged inside the stator housing 44 . On the B side, a space region for the electronics is provided on the stator housing 44 , which is surrounded by the stator housing 44 , the retaining ring 45 and the cover 46 .

[0058] Arranged in this spatial region are both the printed circuit board 40 as a first printed circuit board and a second printed circuit board 47 , which are likewise populated with components.

[0059] The first printed circuit board 40 and the further printed circuit board 47 are axially spaced apart from each other and are arranged parallel to each other.

[0060] The axial direction is parallel to the radial direction of the electric machine and is the rotation axis of the rotor shaft arranged inside the stator.

[0061] The second printed circuit board 47 is arranged on a side of the first printed circuit board 40 facing away from the stator housing 44 .

[0062] The electronic system comprises an inverter, whose controllable semiconductor switches are arranged in an integrated manner in the power module 42 .

[0063] To dissipate heat, the power module 42 is thermally connected to the stator housing 44 on its side facing away from the first printed circuit board 40. Thus, heat losses from the semiconductor switches, and therefore the power module, can be dissipated to the surroundings via the stator housing. However, heat losses from the stator windings of the motor are also dissipated to the surroundings via the stator housing.

[0064] The power module is mounted on a printed circuit board 40. On the same side of the printed circuit board 40, in particular the side facing the stator housing 44, further components 43 are also mounted, which can be operated up to a first temperature.

[0065] On the other side of the first circuit board 40 and on the second circuit board 47 , components 41 are mounted that can operate up to a second temperature, which is however lower than the first temperature. The heat dissipation of the spatial area, ie, in particular these components, is achieved via a cover 46 .

[0066] The stator housing 44 , the retaining ring 45 and the cover 46 are each made of metal, in particular are designed as cast parts. The retaining ring 45 is sealingly connected to the cover 46 and the stator housing part 44 by means of seals arranged in between.

[0067] The first printed circuit board 40 and the second printed circuit board 47 are connected to their respective nearest neighboring components by means of electrical plug-in connectors 48 .

[0068] The second printed circuit boards 47 are spaced apart from one another by means of spacer bolts or spacer sleeves.

[0069] Figure 5 Shows the Figure 4 An oblique view of a partial perspective.

[0070] The seals between the housing parts, ie between the stator housing 44, the retaining ring 45 and the cover 46, also serve as a thermal barrier, as does the insulating coating 3 of the circuit board 40. The B-side end region is thus thermally isolated from the rest of the motor.

[0071] The normal direction of the circuit board plane is parallel to the rotation axis of the rotor shaft.

[0072] In further embodiments according to the present invention, the retaining ring 45 can be constructed in two or more parts instead of in one piece, wherein the parts are respectively connected to one another in a sealing manner, in particular by means of corresponding seals.

[0073] In another embodiment according to the present invention, a fan is arranged inside the space region so that the air there can circulate and thus achieve thermal equilibrium.

[0074] To this end, the second circuit boards 47 have axially extending notches. These notches are designed to be sufficiently large so that the flow resistance is only negligible. Preferably, each of the second circuit boards 47 has two notches arranged diametrically opposite each other on the corresponding circuit board 47, thereby enabling simple circulation.

[0075] List of reference numerals:

[0076] 1 Layer with conductor paths

[0077] 2 Insulation materials, especially fiber reinforced plastics, especially epoxy resin materials

[0078] 3 Insulation coating

[0079] 20 Central Area

[0080] 21 Edge area with metallized through-holes

[0081] 40 First Circuit Board

[0082] 41 First structural element

[0083] 42 Power Module

[0084] 43 Second structural element

[0085] 44 stator housing

[0086] 45 retaining ring

[0087] 46 Cover

[0088] 47 Second circuit board

[0089] 48 plug-in device

[0090] 49 Second temperature zone

[0091] 50 First temperature area

Claims

1. A motor having a circuit board, the motor having: a stator housing in which the stator windings of the electric machine are accommodated, and - a cover, and a retaining ring which is arranged between the cover and the stator housing and in which the first printed circuit board is accommodated, It is characterized by: The first printed circuit board has a plurality of layers with conductor tracks, The layers are spaced apart from one another by a first coating consisting of an insulating material. wherein an insulating coating is arranged between two of the layers, A power module is mounted on the side of the first printed circuit board facing the stator housing part, wherein the power module is thermally connected to the stator housing part. The power module and the components (43) mounted on the first circuit board on the side of the first circuit board facing the stator housing part can be operated up to a first temperature, which is the maximum permissible operating temperature for the power module. wherein the structural element (41) mounted on the first circuit board and the structural element mounted on the second circuit board on the side of the first circuit board facing away from the stator housing part can be operated up to a second temperature, the second temperature being the maximum permissible operating temperature for the structural element (41), The second temperature is lower than the first temperature.

2. The motor according to claim 1, It is characterized by: The insulating coating has a coating thickness greater than that of the first coating.

3. The motor according to claim 1 or 2, It is characterized by: The insulating covering is made of the same material as the first covering, so that the first circuit board is constructed as a multilayer circuit board, the individual layers of which are unevenly spaced apart from each other, Said same material is fiber reinforced plastic.

4. The motor according to claim 1 or 2, It is characterized by: The insulating coating is made of a different material than the first coating, The material of the insulating coating is plastic having closed air bubbles.

5. The motor according to claim 1 or 2, It is characterized by: The first printed circuit board and the second printed circuit board are arranged in a spatial region of the electric machine that is delimited by the stator housing, the retaining ring, and the cover.

6. The electric motor according to claim 1 or 2, It is characterized by: The first circuit board and the second circuit board are parallel to each other and spaced apart from each other, The rotation axis of the rotatably mounted rotor shaft of the electric motor is parallel to the normal direction of the first printed circuit board.

7. The electric motor according to claim 1 or 2, It is characterized by: The second printed circuit board is arranged on a side of the first printed circuit board facing away from the stator housing. and / or The first printed circuit board is arranged between the stator housing part and the second printed circuit board.

8. The motor according to claim 1 or 2, It is characterized by: The second circuit board is received in the cover.

9. The electric motor according to claim 1 or 2, It is characterized by: The first circuit board is connected to the second circuit board closest to the first circuit board by means of an electrical plug-in device, Each second printed circuit board is connected to the second printed circuit board closest to the second printed circuit board by means of a corresponding electrical plug-in device.

10. The electric motor according to claim 1 or 2, It is characterized by: The retaining ring is constructed in one piece or in multiple pieces.

11. The electric motor according to claim 1 or 2, It is characterized by: The retaining ring is tightly connected to the stator housing part by means of a seal arranged in between, which also serves as a thermal barrier. and / or The retaining ring is tightly connected to the cover by means of a seal arranged in between, which also serves as a thermal barrier. And / or a fan is arranged in the spatial area, and / or each of the second printed circuit boards has two axially through-going notches that are arranged diametrically opposite to each other with respect to the rotation axis of the rotor shaft.

12. The electric motor according to claim 1 or 2, It is characterized by: The stator housing parts, retaining rings and cover are made of metal and are constructed as castings. The cover has cooling fins on its outer side.

13. The motor according to claim 1 or 2, characterized in that The insulation material is fiber reinforced plastic.

14. The motor according to claim 1 or 2, characterized in that The insulating material is epoxy resin material.

15. The motor according to claim 1 or 2, characterized in that The second temperature is at least 10° C. lower than the first temperature.

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