Bearing arrangement for inverter module

Abstract

The present invention relates to a bearing arrangement (10) for supporting four electrical components of an inverter module (33) for an electric drive motor of a motor vehicle, comprising: two bearings (22, 24), each connected to a support plate (26) at a predefined distance from one another; wherein the first bearing (22) is designed as a fixed bearing to arrange the components at a predefined axial distance from one another and to mount them immutably with respect to this axial distance; the second bearing (24) is designed as a floating bearing to align the components in predefined orientations relative to one another; wherein the bearing arrangement (10) provides a common reference system for the manufacture of the inverter module (33) and remains in the inverter module (33) after manufacture.The present invention further relates to the use of such a bearing arrangement (10) for centering and supporting at least four different components of an inverter module (33). The present invention further relates to an inverter module (33) and a method for manufacturing an inverter module (33).

Description

[0001] The present invention relates to a bearing arrangement for supporting at least four electrical components of an inverter module for an electric drive motor of a motor vehicle, and to the use of such a bearing arrangement for centering and supporting at least four different components of an inverter module. Furthermore, the present invention relates to an inverter module and a method for manufacturing an inverter module.

[0002] The power electronics of electric and hybrid vehicles transfer traction energy from the battery to the electric motor or drive unit, converting direct current (DC) into alternating current (AC). This is accomplished using an AC converter, also known as an inverter or traction converter. Typically, this involves the use of multiple transistors or other power semiconductors, which are combined into a power semiconductor module and switch at short, regular intervals. In this context, MOSFETs (metal-oxide-semiconductor field-effect transistors) and IGBTs (insulated-gate bipolar transistors) are commonly used as switches. When switched on, the battery current is passed to the motor (conducting phase). These high-frequency switching operations create an AC voltage waveform that can then be converted into traction energy in the electric motor.To increase the current-carrying capacity, several power semiconductors are usually connected in parallel.

[0003] Using such power semiconductor modules or power semiconductors in this or other applications, comparatively high currents are switched, and the switching power semiconductors generate high temperatures in the process. Especially in sandwich-structure designs, pins can become very long. The length of the pins or contact lines poses a challenge for module manufacturing as well as for assembly in an inverter system.

[0004] In the assembly and manufacturing of electrical components, it is known to align electrical components for manufacturing and connection to one another. In particular, it is known that a further technical component arranged above a technical component contacts the underlying technical component at predefined points or detects it with sensors.

[0005] Individual components must therefore be precisely aligned with respect to the components below or above them.

[0006] It is known to manufacture components in a sandwich construction and then add them to other components to ultimately create a final module.

[0007] This approach is time-consuming, as some components must first be partially prefabricated. Furthermore, it is prone to errors and very time-consuming, since various module parts must be repeatedly processed, aligned, and arranged during manufacturing until the final module is complete.

[0008] The considerable length of the pins makes module production more complex. Furthermore, the length of the individual pins complicates assembly in power electronics. Positioning precision is limited by the inherent stability of the pins.

[0009] US 2017 / 0359906 A1 discloses an electronic device comprising a first printed circuit board, a second printed circuit board and a support pin.

[0010] US 2017 / 0118858 A1 discloses an integrated power semiconductor structure comprising a housing, a first printed circuit board, a second printed circuit board, a first pin, a second pin and a third pin.

[0011] US 10,043,717 B2 shows an electronic device comprising at least two circuit boards and a support pin.

[0012] In DE 10 2018 203 103 A1 a power semiconductor module and a power semiconductor device are shown.

[0013] US 2005 / 0212122 A1 describes a power arrangement with a large number of FET power semiconductors.

[0014] US 2006 / 0081065 A1 discloses a connection system comprising a sensor, at least one substrate, at least one contact device between sensor and substrate and optionally a sensing pin, connected to the sensor and extending through the substrate.

[0015] US 8,929,093 B2 shows a distribution box with an electrical circuit, manufactured by laminating a variety of resin sheets.

[0016] Based on this, the present invention aims to provide an approach for the improved manufacturing of an inverter module. In particular, it seeks to provide a cost- and time-efficient as well as mechanically robust method.

[0017] This problem is solved by a bearing arrangement for supporting at least four electrical components of an inverter module for an electric drive motor of a motor vehicle, comprising: two bearings, each connected to a support plate at a predefined distance from one another, wherein the first bearing is designed as a fixed bearing to arrange the components at a predefined axial distance from one another and to mount them immutably with respect to this axial distance. The second bearing is designed as a floating bearing to align the components in a predefined orientation relative to one another, particularly in conjunction with the fixed bearing. The bearing arrangement creates a common reference system for the manufacturing of the inverter module and can preferably remain in the inverter module after manufacturing.

[0018] In another aspect, the above task is solved by using the bearing arrangement as defined above to center and support at least four different components of an inverter module.

[0019] Finally, the above task is solved by an inverter module comprising a bearing arrangement as defined above and at least four different components in sandwich construction or in a sandwich composite.

[0020] In another aspect, the invention relates to a method for manufacturing an inverter module, in particular an inverter module as defined above, comprising the steps: Provide a storage arrangement as previously defined; Sliding a power semiconductor module, a busbar for AC supply of an electric drive motor of a motor vehicle, a busbar for DC supply of the power semiconductor module, and a printed circuit board with a current sensor onto the bearing arrangement. Preferably, laser welding is performed on the power semiconductor module, the busbar for AC supply and / or the busbar for DC supply of the power semiconductor module. The bearing arrangement is particularly preferred to remain in the module after manufacturing.

[0021] By using preferably only two bearings, one a fixed bearing and the other a floating bearing, an efficient arrangement of four or more components can be achieved with a small number of parts. Because the bearing arrangement creates a common, fixed reference system for all four components during the manufacturing of the inverter module, the bearing arrangement allows for the preparation and finalization of all four components in a single assembly. In particular, it ensures that the current sensors are correctly positioned. Contact pins can preferably be routed through all four components. Furthermore, various components can be correctly positioned for subsequent processing steps, such as laser welding. Since the bearing arrangement can remain in the finalized inverter module even after manufacturing, rapid production completion is possible.Furthermore, the bearing arrangement can ensure additional mechanical stability even during operation of the inverter module. In particular, it effectively counteracts the risk of weld breakage or subsequent bending of the pins.

[0022] In an advantageous embodiment, the predefined orientation and the predefined distance are chosen such that the bearings are arranged on opposite sides of the components, centered on those sides of the components.

[0023] This allows for efficient storage using only two bearings. Preferably, the four components are essentially rectangular and each has two long and two short sides. The bearings are preferably positioned centrally on the short sides, thus achieving a large leverage effect during storage.

[0024] In another preferred embodiment, the bearings extend essentially perpendicularly from an inner surface of the carrier plate. This creates vertical webs onto which the individual components can be easily slid. This bearing arrangement can contribute to the efficient manufacturing of the inverter module.

[0025] In a particularly preferred embodiment, the bearings are designed as metal pins, especially stainless steel. The carrier plate is made of aluminum. The bearings are preferably pressed into recesses in the carrier plate. This allows the bearing arrangement to be manufactured efficiently and quickly. In particular, pressing harder steel into softer aluminum enables a mechanically stable form-fit and force-fit connection between the carrier plate and the bearing pins. The bearing arrangement can be manufactured quickly and preferably in a single step, namely pressing in the pins. Further joining processes are not necessarily required.

[0026] In an advantageous embodiment, the bearings are designed and configured so that the individual components can be slid onto them axially. This allows the bearing arrangement to be created first during manufacturing, and then the individual components to be slid onto this arrangement. This offers the particular advantage that mechanically demanding manufacturing steps, such as pressing in the bearing pins, can be carried out independently of sensitive electronics. The failure rate of the inverter modules produced in this way is reduced.

[0027] In a preferred embodiment of the inverter module, the at least four components comprise a printed circuit board with current sensors, a busbar for the DC supply of a power semiconductor module, a busbar for the AC supply of an electric drive motor of a motor vehicle, and / or the power semiconductor module itself. This allows for the creation of a self-contained inverter that includes all components required for converting a DC voltage or DC current. A fully functional component can be created, enabling the inverter module to also be used as a spare part.

[0028] In a particularly preferred embodiment of the inverter module, the circuit board with current sensors is arranged above or below the AC supply busbar, wherein the power semiconductor module comprises pins that extend from the power semiconductor module through the uppermost component of the sandwich assembly. Additionally or alternatively, the power semiconductor module forms the lowermost component of the sandwich assembly, with the DC supply busbar arranged above the power semiconductor module and below the AC supply busbar. Finally, the circuit board with current sensors is the uppermost component of the sandwich assembly. This advantageous arrangement allows for a compact design of the sandwich assembly and ultimately of the inverter module.In particular, the power semiconductor module can be arranged at an edge of the inverter module, so that waste heat from the power semiconductor module can be advantageously dissipated and, in particular, does not penetrate deep into the sandwich structure in which sensitive electronics may be located. It is especially preferred that the power supplies for and from the power semiconductor module can be arranged as a kind of buffer above the power semiconductor module, so that the circuit board has a large distance to the main heat source of the inverter module.

[0029] In this process, the pins for controlling the power semiconductor module must pass through the entire sandwich assembly. By advantageously designing the geometry of the individual components of the sandwich assembly, the pins can be centered and stabilized. For example, one or more components can have a funnel-shaped geometry that centers and supports the pins as the subsequent components are slid on top.

[0030] In this context, a power semiconductor module is understood to be, in particular, an assembly for use in an inverter design. A power semiconductor module typically comprises several individual power semiconductors or chips. A power semiconductor is, in particular, an electronic chip that incorporates one or more integrated circuit components. For example, insulated-layer bipolar transistors or other semiconductors can be used.

[0031] A bus, busbar, or bus panel is preferably understood as an electrical conductor. This conductor enables efficient current and / or voltage transmission and preferably control within a system, in particular an inverter module.

[0032] An inverter is preferably essentially a converter and is designed to convert stored direct current into the alternating current required for the electric drive motor.

[0033] The power semiconductor module can be designed in a planar form and may comprise several power semiconductors that are also designed in a planar form.

[0034] The invention is described and explained in more detail below with reference to some selected embodiments in conjunction with the accompanying drawings. These show: Fig. 1 a schematically simplified representation of a storage arrangement for storing four components; Fig. 2 an inverter module with a bearing arrangement; Fig. 3 a detailed sectional view of a section through a first bearing; Fig. 4 a perspective schematically detailed representation of a second camp; Fig. 5 a detailed cross-section through an inverter module; and Fig. 6 schematically the steps of a method for manufacturing a device according to Fig. 2.

[0035] In Fig. Figure 1 schematically shows a bearing arrangement 10 with four components in sandwich construction 12, which are supported by the bearing arrangement 10.

[0036] A first component comprises a printed circuit board 14. A second component comprises a busbar for the DC supply 16 of a power semiconductor module 20, which forms the fourth component. A third component comprises a busbar for the AC supply 18 of an electric drive motor (not shown) of a motor vehicle.

[0037] The circuit board 14 includes current sensors 28, which are designed to monitor or detect the current flow of the busbar to the DC supply 16 of the power semiconductor module 20.

[0038] The bearing arrangement 10 comprises a first bearing 22 and a second bearing 24, both of which are pressed into a carrier plate 26.

[0039] The first bearing 22 is designed as a fixed bearing. In the embodiment shown, it is designed as a round metal pin onto which the individual components 14, 16, 18, 20 can be slid.

[0040] For this purpose, components 14, 16, 18, and 20 each have a through-hole whose diameter essentially corresponds to the diameter of the pin of the first bearing 22. This allows the functionality of a fixed bearing to be established.

[0041] The second bearing 24 also includes a metal round pin that is pressed into the carrier plate 26. To implement the functionality of a floating bearing, the components 14, 16, 18, 20 have a through-hole whose diameter is slightly larger than the diameter of the pin of the second bearing 24. This allows the second bearing 24 to function as a floating bearing.

[0042] The power semiconductor module 20 also has various pins 30, which are required for controlling the power semiconductor module 20. These pins 30 are routed through the four components 14, 16, 18, 20 for improved contact, so that contact can be made above the first component, i.e., the circuit board 14 with the current sensors 28.

[0043] Furthermore, the power semiconductor module 20, the DC supply busbar 16, and / or the AC supply busbar 18 can be processed by laser welding 32. In particular, the aforementioned components 16, 18, and 20 can be at least partially connected to one another by laser welding 32 and / or electrically contacted.

[0044] In Fig. Figure 2 shows an inverter module 33 with a bearing arrangement 10 and sandwich-construction components 12 in detail. Identical reference numerals refer to identical features and are not explained again.

[0045] Additionally, in Fig. Figure 2 shows the position of the individual bearings 22, 24. A first position 34 of the first bearing 22 is located on an end face of the inverter module 33, approximately in the middle.

[0046] A second position 36 of the second bearing 24 is located on the side of the inverter module 33 opposite the front face and is also arranged approximately in the middle with respect to this side.

[0047] In Fig. Figure 3 shows a detailed section through the first storage area 22.

[0048] The bearing pin of the first bearing 22 is pressed into the carrier plate 26, with the power semiconductor module 20 being arranged above the carrier plate 26.

[0049] The power semiconductor module 20 has a heat sink 38 to dissipate waste heat from the power semiconductor module 20.

[0050] Above the heat sink 38 a busbar for AC supply 18 of an electric drive motor of a motor vehicle (not shown) is arranged.

[0051] Above the busbar for the AC supply 18 is a busbar for the DC supply 16 of the power semiconductor module 20.

[0052] Above the busbar for the DC supply 16, a circuit board with current sensors (not shown) is arranged. The circuit board 14 is precisely positioned by means of the first bearing 22 and the second bearing 24 (not shown) so that the current sensors can detect a current flow from the busbar to the DC supply 16.

[0053] It is understood that in an alternative embodiment the order of the various components may be different and, in particular, the position of the busbar for the AC supply 18 may be exchanged with the position of the busbar for the DC supply 16.

[0054] In Fig. Figure 4 shows a perspective schematically detailed representation of the second camp 24.

[0055] Based on the representation according to the Fig. Figure 4 illustrates a bore 40 which is oversized. Consequently, it has a larger diameter than the bearing pin of the second bearing 24.

[0056] It is understood that such a bore is included in each of the components to be supported by means of the second bearing24 in order to establish a functionality of a floating bearing by interaction of the bearing pin with the bore.

[0057] In Fig. Figure 5 shows a detailed section through an inverter module 33.

[0058] Using this cut as an example, according to the Fig. 5 can illustrate the centering function of the individual components 14, 16, 18 with respect to the pins 30 of the power semiconductor module 20.

[0059] The busbar for the DC supply 16 of the power semiconductor module 20 has a through-hole with a funnel-shaped or conical bore profile. This profile serves to center the pins 30. In this respect, this bore profile acts like a funnel.

[0060] The pins 30 may therefore have certain manufacturing tolerances, which are compensated for by this advantageous geometry of the bore or funnel in the busbar for the DC supply 16.

[0061] The circuit board 14 has simple through-holes to allow the pins 30, after alignment through the funnel-shaped geometry, to pass through the circuit board 14 and over its surface. This allows for advantageous contact of the pins 30 above the circuit board 14.

[0062] Furthermore, advantageous storage and manufacturing of the inverter module 33 can be achieved through advantageous interaction of the individual components 14, 16, 18, 20 and through centering by means of the bearings not shown.

[0063] In Fig. Figure 6 schematically illustrates the steps of a method according to the invention.

[0064] In the first step S10, a storage arrangement is provided as described above.

[0065] In a second step S20, a power semiconductor module, a busbar for AC supply of an electric drive motor of the motor vehicle, a busbar for DC supply of the power semiconductor module and a circuit board with current sensors are slid onto the bearing arrangement.

[0066] In an optional third step S30, laser welding is performed, particularly on the power semiconductor module 20, the busbar for AC supply 18 and / or the busbar for DC supply 16.

[0067] The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as examples and not as limiting. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to a person skilled in the art when using the present invention and upon a detailed analysis of the drawings, the disclosure, and the subsequent claims.

[0068] In the claims, the words "comprise" and "with" do not preclude the presence of further elements or steps. The undefined article "a" or "an" does not preclude the presence of multiple elements. A single element, module, or unit can perform the functions of several of the units mentioned in the claims. The mere mention of some measures in several different dependent claims is not to be understood as precluding the advantageous use of a combination of these measures. Reference numerals in the claims are not to be interpreted restrictively. Reference sign 10 Storage arrangement 12 Sandwich construction 14 circuit board 16 busbars for DC power supply 18 busbars for AC supply 20 Power semiconductor module 22 first camp 24 second camp 26 Carrier plate 28 Current sensor 30-pin 32 Laser welding 33 Inverter module 34 first position 36 second position 38 heat sinks 40 bore S10-S30 Procedure steps

Claims

[1] Bearing arrangement (10) for supporting four electrical components of an inverter module (33) for an electric drive motor of a motor vehicle, comprising: two bearings (22, 24), each of which is connected to a support plate (26) at a predefined distance from each other; wherein the first bearing (22) is designed in the form of a fixed bearing in order to arrange the components at a predefined axial distance from each other and to mount them in a manner that does not change with respect to this axial distance; the second bearing (24) is designed in the form of a sliding bearing to align the components in predefined orientations to each other; wherein the bearing arrangement (10) creates a common reference system for the manufacture of the inverter module (33) and remains in the inverter module (33) after manufacture. [2] Bearing arrangement (10) according to claim 1, wherein the predefined orientations and / or the predefined distance are selected such that the bearings (22, 24) are arranged on opposite sides of the components centrally with respect to the sides. [3] Bearing arrangement (10) according to one of the preceding claims, wherein the bearings (22, 24) each extend perpendicularly away from an inner surface of the support plate (26). [4] Storage arrangement (10) according to one of the preceding claims, wherein the bearings (22, 24) are designed as pins made of metal, in particular stainless steel; the carrier plate (26) is made of aluminium; and preferably the bearings (22, 24) are pressed into recesses in the carrier plate (26). [5] Bearing arrangement (10) according to one of the preceding claims, wherein the bearings (22, 24) are designed and configured so that the components can be slid onto the bearings (22, 24) in an axial direction. [6] Use of a bearing arrangement (10) according to any of the preceding claims for centering and supporting at least four different components. [7] Inverter module (33) comprising a bearing arrangement (10) according to one of claims 1-5 and at least four different components in sandwich construction (12). [8] Inverter module (33) according to the preceding claim, wherein the at least four components a circuit board (14) with current sensors (28); a busbar for DC supply (16) of the power semiconductor module (20); a busbar for AC supply (18) to an electric drive motor of a motor vehicle; and / or comprise a power semiconductor module (20). [9] Inverter module (33) according to claim 8, wherein the circuit board (14) with current sensors (28) is arranged above or below the busbar for the AC supply (18); the power semiconductor module (20) comprises pins (30) which extend from the power semiconductor module (20) through the uppermost component of the sandwich assembly; and / or the power semiconductor module (20) forms the lowest component of the sandwich assembly, the busbar for DC supply (16) is arranged above the power semiconductor module (20) and below the busbar for AC supply (18); and the circuit board (14) with current sensors (28) forms the uppermost component of the sandwich assembly. [10] Method for manufacturing an inverter module (33), preferably an inverter module (33) according to any one of claims 7 to 9, comprising the steps: Providing (S10) a storage arrangement (10) according to one of claims 1 to 5; Slide (S20) a power semiconductor module (20); a busbar for AC supply (18) of an electric drive motor of a motor vehicle; a busbar for DC supply (16) of the power semiconductor module (20) and a printed circuit board (14) with current sensors (28) onto the bearing arrangement (10); and preferably laser welding (32, S30) on the power semiconductor module (20), the AC supply busbar (18) and / or the DC supply busbar (16) of the power semiconductor module (20).

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