Electric motor

Abstract

The invention relates to an electric motor having a stator-side rod winding, comprising a plurality of inverters for control rods, the power parts of the inverters being arranged on one or more circuit boards, the circuit boards forming at least two circular or annular structures that are axially displaced relative to one another, the circuit boards being electrically connected by means of a connecting plate, the connecting plate extending axially, and the connecting plate being electrically connected to the circuit boards. And the circuit board with the circular or annular structure is inserted on the outer circumference or the inner circumference of the circular or annular structure.

Description

Technical Field

[0001] The invention relates to an electric motor with a stator-side bar winding. Background Art

[0002] Electric motors can have a rod winding on the stator side. In this case, the stator has a series of rods instead of wound wire conductors as field conductors. Compared to conventional windings, the rods have a low inductance. Therefore, relatively large currents are required to generate a predetermined magnetic field.

[0003] Such a large current requires only a relatively low voltage of, for example, 12 V. The low voltage enables the components of the inverter for controlling the rods to be arranged at small intervals relative to each other. Thus, for example, the components of the power electronics can be arranged on one or more circuit boards arranged close to the motor.

[0004] It is particularly advantageous that such an electric motor can be designed in a compact manner so that each field conductor is controlled by its own power section, so that each field conductor can be controlled with its own phase. Thus, electric motors with 48, 72 or even 120 field conductors and phases can be compactly constructed.

[0005] The problem here is that a large number of power parts must be connected to the central controller. The cable connection between the central controller and the plurality of power components disadvantageously results in a very complicated construction. Summary of the invention

[0006] The object of the present invention is to specify an electric motor which eliminates the disadvantages mentioned at the outset and in particular has an effective connection between the control unit and the power section.

[0007] This object is achieved by an electric motor having the features specified in claim 1 .

[0008] The electric motor according to the invention comprises a stator having a plurality of field conductors designed as rods. The electric motor further comprises an inverter having one or more parallel-connected power sections for each field conductor for controlling the field conductors, wherein the inverter comprises a controller for generating control signals for the power sections.

[0009] Here, the output stage of the inverter is arranged on a plurality of circuit boards. These circuit boards are arranged in turn so that they form at least two circular or annular structures. These circular or annular structures are arranged parallel to each other and axially offset relative to each other so that their centers are located on a common central axis.

[0010] One or more plug connectors are arranged on each circuit board for contacting the output stage. The connecting plate is plugged into the plug connectors of the circuit boards of different circular or ring structures with the same orientation about the central axis.

[0011] For circular or annular structures, parallelism means that their circular or annular planes are parallel, or expressed in another mathematical way, that their surface normals have the same direction.

[0012] For circular or annular structures, axial offset means that they are displaced relative to each other (only) along a coincident axis, wherein this axis corresponds to the central axis, ie the surface normal through the center of the circle or ring.

[0013] Because the circular or annular structures are formed from a plurality of circuit boards, it should be understood that they are not geometrically accurate and the circular or annular area does not have to be completely filled. Instead, gaps are left between the circuit boards.

[0014] If polar coordinates are placed in each circular or annular structure, the orientation refers to the angle in these polar coordinates. This means that plug connectors with the same orientation are located in the same direction from the central axis. This means that such plug connectors in different circular or annular structures form a line parallel to the central axis.

[0015] The plug connector can be, for example, a spring contact or a direct circuit board plug connector. Here, it can be a socket or a (built-in) plug, wherein the corresponding reverse side is arranged on the connecting plate.

[0016] In the context of this document, the output stage is to be understood essentially as the power semiconductor switches at the AC voltage output of the power section. Since in some embodiments of the invention the gate drive circuits belonging to the power semiconductor switches are partially separated from the power semiconductor switches, they are not counted as the output stage. The power section is to be understood as the power semiconductor switches and their respective gate drive circuits. The power section and the controller as a whole are referred to as an inverter.

[0017] The invention advantageously enables a particularly simple contacting of electronic components on a circuit board, wherein a plurality of cables between the controller and the circuit board (at least one cable per circuit board of the same orientation) are replaced by a single connection plate per phase or even a connection plate for a plurality of phases. For example, if six circuit boards are connected in parallel for one phase in an electric motor of this type, then one connection plate with a single cable is sufficient to control the contacting of all six circuit boards.

[0018] It is advantageous if there is one connection plate for all plug connectors. For example, the plug connectors can be distributed in position on the outer edge or inner edge of each annular structure. Then, there is one connection plate for each position. It then forms a shape corresponding to a cylindrical housing with a gap.

[0019] Furthermore, it is expedient that each connection plate is connected to all the plug connectors in the same orientation, that is, if there are four circular or annular structures, then preferably all circular or annular structures have plug connectors in the same orientation, and each connection plate is in contact with all the plug connectors in one orientation, i.e. forming a line parallel to the central axis.

[0020] The connection board advantageously establishes an indirect connection between the controller on the one hand and the output stage, i.e. the power semiconductor switch, on the other hand on the circuit board. Indirect here means that the gate drive circuit of the power semiconductor switch is located in the middle of the connection, regardless of how they are physically arranged. The gate drive circuit can be arranged in different ways.

[0021] Advantageous embodiments of the electric motor according to the invention are derived from the dependent claims. Here, the embodiments of the independent claim can be combined with the features of one of the dependent claims or the features of several dependent claims. Thus, the following features can also be provided in addition:

[0022] The center axis of the circular or annular structure may correspond to the motor axis. In other words, this means that the center of each circular or annular structure is located on the motor axis and each circular or annular structure is arranged perpendicular to the motor axis.

[0023] In this arrangement of a circular or annular structure, the field conductor or the current conductor which continues the field conductor penetrates the circular or annular structure in a rotationally symmetrical manner when continuing along a straight line. This results in a well-modularized construction in which the same type of printed circuit boards can be used and the contacting of the corresponding field conductors is particularly simple.

[0024] Furthermore, the field conductor or the current conductor which continues the field conductor can even serve as a mechanical carrier for the printed circuit board, whereby the construction is further simplified.

[0025] The circular or annular structures can have the same diameter. This design is suitable because the spring contacts can form a line extending in the axial direction when they are arranged on the circuit board in the same way. This makes it possible to easily install the connecting plate.

[0026] The connecting plate preferably extends in the axial direction parallel to the motor axis. Here, extension refers to the orientation of the longest edge of the preferably rectangular connecting plate.

[0027] The number of connecting plates can correspond to the number of field conductors. That is, in this design, one connecting plate is used for each phase of the motor. As a result, the construction of the connecting plates is simplified and the wiring overhead on the circuit board is reduced.

[0028] In an alternative embodiment, a smaller number of connection plates than the number of field conductors can also be used. For example, two, three or more phases, i.e. the power parts of the field conductors, can be arranged on one circuit board, and the circuit board can be designed so that the power parts can be connected to a single connection plate for control. In this case, the number of connection plates corresponds to the number of field conductors or phases divided by the number of power parts per circuit board.

[0029] If a large number of field conductors are used, for example 48, 72 or even 120 field conductors, this design of the electric motor is particularly advantageous. In this electric motor, the number of circuit boards and connection plates is advantageously reduced compared to a simpler variant with one connection plate per phase.

[0030] The connection board can include a gate drive circuit for the power section. This means that the gate drive circuit no longer requires a dedicated space on the circuit board. For the power section, more space is reserved on the circuit board, which simplifies the design of the circuit board. In addition, the waste heat generated by the gate drive circuit is also kept away from the circuit board, thereby simplifying heat dissipation.

[0031] In addition, the connection board may also include one or more local control chips, which perform control tasks, such as current measurement for the corresponding output stage. The local control chip is correspondingly associated with one or more gate drive circuits and connected to the one or more gate drive circuits.

[0032] Alternatively, the gate drive circuits themselves can be arranged on the circuit board together with the corresponding power semiconductor switches. As a result, it is easier to construct the connection boards, since they only have to establish a connection between the controller and the circuit board, and thus between the controller and the gate drive circuits, but can still contain additional circuits, such as monitoring circuits, control circuits, amplifier / buffer circuits or communication interfaces. For this purpose, the connection board can advantageously include a multiplexer.

[0033] In a further alternative, the gate drive circuit can also be arranged on its own driver board. Preferably, these driver boards are plugged onto the circuit board with the power semiconductor switch, wherein the circuit board is arranged in this case in a sandwich-like manner, i.e. the driver board at least partially covers the circuit board. In this case, the connection board can be plugged onto the driver board, the output stage board or both, i.e. it can be connected to one or both types of circuit boards, via which connection the signals are transmitted.

[0034] For this purpose, each phase controlled on the circuit board has a half-bridge consisting of two logic switches. In this case, a logic switch can consist of just one single power semiconductor switch. However, in order to allow switching of larger currents, a logic switch can also consist of a plurality of power semiconductor switches connected in parallel, for example two, three, five or even more power semiconductor switches.

[0035] The gate driver circuit is preferably designed so that it controls the control connections (eg gate connections) of the two logic switches of the half bridge, i.e. supplies them with current / voltage in such a way that the switching actions required by the controller are performed and the switches are switched on and off in the manner required by the controller.

[0036] If the logic switch of the half-bridge accordingly comprises more than one power semiconductor switch connected in parallel, the gate drive circuit can be designed to control all power semiconductor switches. However, more than one gate drive circuit can also be provided for the control. For example, the number of gate drive circuits can correspond exactly to the number of power semiconductor switches connected in parallel. That is, if the half-bridge comprises five high-side MOSFETs and five low-side MOSFETs, there may be up to ten gate drive circuits for it. In this case, in order to save space, it is very advantageous to arrange the gate drive circuit on the driver board or the connection board.

[0037] The connecting board may include a multiplexer, and the connecting board may be designed so that a control signal for the first power part input by the controller on the first signal line is guided by the multiplexer to a second signal line among multiple second signal lines, which is connected to the first power part via a spring contact.

[0038] By means of a multiplexer on the connection board, it is achieved that the controller only has to be connected to the connection board using a single signal line, which simplifies the construction. This is particularly advantageous if the connection board connects a plurality of power sections on a single circuit board and a plurality of power sections connected in parallel to the controller, since in this case, without a multiplexer, a large number of parallel control lines would be required from the controller to the connection board. In this case, the single signal line can be a direct electrical line or also a connection operating in accordance with a communication standard, for example an optical connection, a USB connection or a LAN connection.

[0039] The connecting plate may include one or more threaded connections with one or more of the circular or annular structures. The threaded connections prevent the connecting plate from falling off due to vibrations and other external influences.

[0040] The connecting plate can be bent, for example, it can be bent in the tangential direction. In this case, the connecting plate has the shape of a flat saddle roof, the ridge of which extends axially. If the connecting plate has multiple, preferably parallel bending lines, a more complex shape will be obtained. Such a connecting plate is suitable for contacting plug-in connectors of multiple circuit boards arranged side by side with multiple circular or annular structures, even if these plug-in connectors are no longer located in a plane, but are oriented radially, that is, they are not oriented parallel to each other, but are inclined relative to each other. More precisely, the unbent connecting plate produces a shape that approximately forms a cylindrical shell with a gap, and this bent connecting plate is a combination of multiple unbent connecting plates, thereby reducing the gap in the cylindrical shell. A connecting plate with one bend is suitable for contacting two circuit boards arranged side by side. A connecting plate with two bends is suitable for contacting three circuit boards arranged side by side.

[0041] The connection plate can be a flexible printed circuit board. The flexible printed circuit board can be deformed under mechanical stress. In this case, the conductor tracks and other electronic components on such a printed circuit board retain their electrical function. The use of a flexible printed circuit board as a connection plate simplifies the construction and installation, since the circular or annular structures do not need to have a fixed defined distance relative to one another and can also be displaced relative to one another together with the connection plate in the installed state.

[0042] The electric motor may include a second connection plate. Each second connection plate is then plugged onto a plurality of connection plates. Each connection plate is in turn plugged onto a single second connection plate. Here, the second connection plates each include a cable connection to the controller. This advantageously eliminates the need for a cable connection from each connection plate to the controller and reduces the number of cable connections.

[0043] The second connecting plate can be designed as an annular sector or a circular sector, for example. Here, the center angle is selected so that at least two connecting plates can contact. The second connecting plate can also be designed as a substantially rectangular but bent plate.

[0044] The current conductor can be designed to extend the field conductor in the axial direction. In this case, the current conductor is designed similarly to the field conductor of the electric motor, but can have different cross-sectional shapes, for example. For example, the current conductor can have a circular cross section, while the field conductor has an elongated rectangular cross section. It is suitable that the current conductor can carry at least the same current as the field conductor. The current conductor and the field conductor can be connected by means of ferrules designed for this purpose, which ensure the mechanical and electrical connection.

[0045] The circuit board can be arranged on at least one cooling plate. In this case, the cooling plate can be covered with circuit boards on both sides to achieve a high density of electrical components. The cooling plate is preferably a metal, essentially circular or annular plate. In this case, the cooling plate can have heat pipes or cooling channels for the flow of air or fluid for heat dissipation. The cooling plate can also be composed of two parallel annular plates, which are connected to each other in a threaded manner so that a certain distance is maintained between them. Then, an active ventilation device can be arranged to suck air between the plates.

[0046] The cooling plate can be arranged in such a way that the field conductor or the current conductor electrically connected to the field conductor is mechanically operatively connected to the cooling plate. For example, the current conductor or the field conductor can be designed as a mechanical carrier for the cooling plate. For this purpose, the cooling plate is preferably arranged perpendicular to the axis of the electric machine. In this way, the cooling plate with the circuit board can be arranged at the axial end of the electric machine in a space-saving manner.

[0047] The circuit board can be designed as a circular sector or annular sector. Circuit boards with such a shape can be combined particularly well into a circle or ring, and thus arranged at the axial end of the motor in a manner optimally matched to the shape of the motor, wherein a high degree of modularity is simultaneously achieved.

[0048] The power section is preferably designed to generate an AC voltage with an amplitude of 200 V or less, in particular 100 V or less, in particular 50 V or less. This allows the components of the power electronics, in particular the power semiconductor switches, to be arranged at small distances in the millimeter range relative to one another, so that a considerable number of power semiconductor switches can be arranged in a relatively small space. This makes it possible to provide large currents without requiring too much space and to generate a plurality of phases, for example 6, 12, 24, 48, 72 or even 120 phases at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will be described and explained in detail below with the aid of the embodiments shown in the accompanying drawings. In the accompanying drawings:

[0050] Figure 1 An oblique view shows an electric motor having a power section arranged on circuit boards which are carried by a cooling plate.

[0051] Figure 2 The circuit board arranged on the cooling plate is shown in a front view,

[0052] Figure 3 A detail of an electric motor is shown in an oblique view, the detail having a cooling plate with a printed circuit board.

[0053] Figure 4A section of an electric motor is shown in a side view, which has a cooling plate with a printed circuit board and a connecting plate plugged in via spring contacts.

[0054] Figure 5 shows a front view of an electric motor having a cooling plate with a circuit board and a connection plate,

[0055] Figure 6 A second solution of a spring contact as a connection part between a connection plate and a circuit board is shown,

[0056] Figure 7 The structure with the gate drive circuit on the drive board is shown.

[0057] Figure 8 A first embodiment of a connecting plate is shown,

[0058] Fig. 9 A second embodiment of the connecting plate is shown,

[0059] Fig.10 A third embodiment of a connection board with a gate drive circuit is shown.

[0060] Fig.11 A configuration with an additional second connecting plate is shown. DETAILED DESCRIPTION

[0061] Figure 1 FIG. 1 shows an isometric view of an electric motor 10 as one embodiment of the present invention. The electric motor 10 includes a stator 11 and a rotor substantially arranged in the stator 11. Figure 1 The rotor is connected to the shaft in a rotationally fixed manner, which is also Figure 1 The rotor is rotated around the axis 9 by electromagnetic interaction between the rotor and the energized stator 11. Here, the rotor is isolated from the stator 11 by an air gap. In other embodiments, the motor 10 may also be an outer rotor motor or a bell armature motor.

[0062] The stator 11 includes a plurality of rigid straight conductor bars 12 as field conductors. Figure 1 The conductor bars 12 are connected to each other via short-circuit rings on the end faces 13 that are far away from each other. On the back side 14 of the motor 10, the conductor bars 12 are fed individually through the corresponding inverter modules. Because the motor 10 is a motor 10 that operates at a low voltage due to the conductor bars 12, the inverter module can be arranged relatively closely on the circuit board 15 together with other components of the electronic device (DC voltage converter, rectifier). Here, in this example, the circuit board 15 is annular sector-shaped, and many individual circuit boards 15 together form an annular circuit board structure.

[0063] Although it is assumed in this example that the circuit board 15 carries at least the power part of the inverter, a part of the circuit board 15 may also carry a rectifier and a DC / DC converter.

[0064] Figure 2 Here, for greater clarity, the plan view of the circuit board structure is shown. Figure 1 Compared with the diagram in Figure 2 The number of circuit boards shown in the figure is reduced and is shown in a greatly simplified manner. The specific number of such circuit boards 15 depends on the specific design of the electric motor 10, in particular the number of conductor bars 12. Each circuit board 15 includes a plurality of semiconductor switches 422. These semiconductor switches 422 together form the power part of the inverter, which provides the conductor bars 12 with an AC voltage.

[0065] In addition, part of the circuit board 15 or the entire circuit board 15 may include a drive circuit and other electronic components, such as capacitors, which are not shown in the drawings. The semiconductor switch 422 is a power semiconductor, such as an IGBT, a MOSFET or a JFET, and may additionally include a diode, which is not shown, depending on the wiring. The semiconductor switch 422 is connected to form a half bridge, for example. The capacitor, which is not shown, may be, for example, an intermediate circuit capacitor of the half bridge. Here, the semiconductor switch 422 of a circuit board 15 can be assigned to a single phase. In the case where the motor 10 has a large number of field conductors 12 and a corresponding number of phases, it is advantageous that a circuit board 15 carries the power section for multiple phases.

[0066] Furthermore, the printed circuit board 15 comprises contact points 421 which are connected to the conductor bars 12. The printed circuit board 15 is supported by a disk-shaped cooling plate 16, wherein the cooling plate 16 can be covered on both sides with the printed circuit board 15 for better utilization of space.

[0067] Since relatively large currents are required in the conductor bars of the electric motor 10, it is preferred that a plurality of power sections are connected in parallel for energization. This can be achieved, for example, by Figure 1 All six circuit board structures on three cooling plates 16 shown in FIG. 1 are connected to the conductor bars 12 in the same manner, thereby realizing a parallel electrical connection. Here, the following situation is utilized, that is, the conductor bars 12 or the connecting elements 18 to the conductor bars 12 penetrate the cooling plates 16 at the contact points in the same manner, thereby also penetrating the circuit boards 15, or in the case of the outermost cooling plates 16, at least contact the cooling plates 16, thereby also contacting the circuit boards 15.

[0068] Figure 3The cross-section of the electric motor 10 is shown in an oblique view. It can be seen here that the connecting element 18 mechanically supports and penetrates three cooling plates 16. The connecting element 18 is connected to the conductor bar 12 via a ferrule 17. The output stages are connected in parallel and jointly supply the conductor bar 12 with current, which are located on the printed circuit board 15 in the areas in which one of the connecting elements 18 penetrates the cooling plate 16. Figure 3 As can be seen in the configuration shown in FIG, two of the connecting elements 18 pass through one circuit board 15, respectively. Therefore, each circuit board carries the output stages of two phases of the motor 10. In other variants of the motor 10, a single circuit board 15 can also carry only one phase or three or more phases, wherein the same number of connecting elements 18 pass through the circuit board 15.

[0069] Figure 4 A side view of a fragment of the electric motor 10 is shown. Figure 4 , eight circuit boards 15 are shown, which are arranged on two cooling plates 16. In addition, Figure 4 Two connecting plates 32 are shown, each connecting plate 32 connects four circuit boards 15. The connecting plates 32 extend in the axial direction and are connected to the sockets 34 of the corresponding circuit boards 15 by means of spring contacts 33. In addition, each of the connecting plates 32 has a socket 35 for connecting a cable to the control board 31.

[0070] Figure 4 The arrangement in corresponds to Figures 1 to 3 Therefore, in the four ring structures forming the circuit board 15, Figure 4 The cross-sectional view of FIG. 1 covers eight circuit boards 15. The cross-sectional view also covers only two connecting boards 32 plugged into the eight circuit boards 15. Figure 4 In addition to the two connecting plates 32 shown in the figure, the electric motor 10 also includes other connecting plates 32 not shown. These connecting plates 32 are plugged into the circuit board 15 not shown, thus surrounding the structure shown and forming the shape of a loose cylindrical shell in a geometrically greatly simplified manner.

[0071] Figure 5 The same construction is shown in a greatly simplified manner in a front view. Figure 5 As can be seen in the figure, the circuit board 15 forms a ring structure. For each circuit board 15, there is a connecting plate 32, which is connected to the corresponding circuit board 15 through a spring contact 33 and a socket 34. Figure 5 , eight circuit boards 15 are arranged on the front side of the cooling plate 16, that is, when Figure 4The cooling plate 16 shown is covered on both sides and when two cooling plates are used, the electric motor 10 includes 32 circuit boards 15 which are connected to the control board 31 by means of eight connecting plates 32 .

[0072] In this case, the number of phases, and therefore the number of current bars 12 , does not necessarily have an influence on the number of connection plates 32 . Figure 5 It is not shown how many phases the electric motor 10 has and how many current bars 12 it has. Each circuit board 15 can control one phase, two phases, three phases or more phases. The same number of current bars 12 or connecting conductors 18 then leads to each circuit board 15. However, the connecting board 32 is adapted to the number of phases to be controlled, since a corresponding number of signal lines must be present.

[0073] The accompanying drawings show each spring contact 33 and socket 34 in a simplified manner. However, in any case, this can also refer to a plurality of actual signal lines accordingly. That is to say, the socket 34 can actually be a socket connection strip, and the spring contact 33 can be a corresponding plug connection strip.

[0074] Figure 6 An alternative design of a spring contact 33 and a socket 34 is shown, which is suitable for an electric motor 10 in which the cooling plate 16 is covered with a circuit board 15 only on one side. For the sake of clarity, Figure 6 is greatly simplified. In this case, the socket 34 can have an axial orientation instead of a radial orientation. In this example, the insertion of the connecting plate 32 is carried out by movement in the axial direction instead of the radial direction.

[0075] Other orientations of the plug connector, for example a tangential orientation, are also possible.

[0076] In another variant of the construction of the electric motor 10, which is not shown in the drawings, the control board 31 is arranged concentrically with the cooling plate and axially displaced relative to the cooling plate and has the same outer diameter as the circuit board 15. In this possible embodiment, the connection board 32 can also be plugged onto the control board 31 and the signal connection can be established via it. Therefore, a cable connection between the connection board 32 and the control board 31 is omitted.

[0077] exist Fig.11 In another variant of the construction of the electric motor 10 shown in , a plurality of the connecting plates 32 are correspondingly plugged into the second connecting plate 110. For this purpose, the second connecting plate 110 can be designed to be annular sector-shaped, for example. It is suitable that the connecting plate 32 is designed to protrude from the cooling plate 16 farthest from the stator / rotor block 8 and have an additional plug connector 111 toward its end. The additional plug connector 111 can be oriented axially or radially. Accordingly, the second connecting plate 110 is then plugged into the end face or the inner side or the outer side of the connecting plate 32.

[0078] Here, the second connecting plate 110 is designed so that it can be plugged onto a plurality of the connecting plates 32. Fig.11 In the example of , the second connecting plate 110 has a center angle of approximately 90°, i.e. approximately a quarter of a ring. In the case of a large electric motor 10, for example with 72 phases or 120 phases, the radius of the ring can be in the meter range, and it is convenient here to connect only two, three or four of the connecting plates 32. In this case, the center angle of each second connecting plate 110 is then, for example, only 9°, and three connecting plates 32 are plugged onto each second connecting plate 110. In this case, the electric motor 10 then includes 40 second connecting plates 110.

[0079] The second connection board 110 includes a connection to the controller, for example as a LAN connection, a USB connection or an optical connection via a socket 112 on the second connection board. This can save the connection of the connection board 32 to the controller, i.e. the socket 35 on the connection board 32. That is, from an electrical point of view, the second connection board 110 combines the connection boards 32 again, reducing the number of required cable connections to the controller.

[0080] For example, the motor 10 may have three double-sided covered cooling plates 16, each with twelve circuit boards 15, i.e., 72 circuit boards 15. The circuit boards 15 are axially connected via twelve connecting plates 32, which are correspondingly plugged into six circuit boards 15 with the same orientation. Then, four annular sector-shaped second connecting plates 110 are respectively plugged into three of the connecting plates 32. Therefore, each second connecting plate 110 is directly connected to 18 circuit boards 15, i.e., without cables, and the number of cable connections to the controller is reduced to 4, one for each second connecting plate 110.

[0081] Except in Fig.11 In addition to the elements shown in FIG. 1 , the second connection board 110 further includes at least one multiplexer 93 for signal distribution and matching line connection between the socket 35 , the multiplexer 93 and the plug connector 111 .

[0082] In all the examples given, it is assumed that the connecting plate 32 is plugged radially from the outside onto the circuit board 15. Alternatively or additionally, however, the connecting plate 32 can also be plugged from the inside. In other words, for this purpose, the connecting plate 32 is arranged on the annular structure formed by the circuit board 15 at the inner edge, i.e., at the edge belonging to the inner diameter of the ring.

[0083] In addition to the possibility of plugging the connection plate 32 directly onto the circuit board 15 carrying the output stage, there is also the possibility of plugging the connection plate 32 directly onto the circuit board 15 carrying the output stage. Figure 7Another embodiment is shown in FIG. Here, the circuit board 15 arranged on the cooling plate 16 carries the output stage of the inverter shown in a simplified manner as a power semiconductor switch 71. The driver board 70 carries the gate drive circuit 72 and the local control chip 73. The plug connector 74 transmits signals between the circuit board 15 and the driver board 70. In this embodiment, the spring contact 33 is arranged on the driver board 70. That is, in this embodiment, the connecting plate 32 is plugged into the driver board 70.

[0084] The above-described possible embodiments of arranging the connection plate 32 on the printed circuit board 15 can be combined with different embodiments of the connection plate 32 itself, which will be described below by way of example.

[0085] exist Figure 8 , an exemplary first connecting plate 81 is shown in more detail in FIG. The connecting plate 81 is rectangular, wherein, as shown in the previously described figures, the long sides extend axially in the installed state. In this first variant, the connecting plate 81 includes only four signal lines 82.

[0086] These signal lines 82 lead to a first end in the socket 35. The socket 35 is provided for connection to the control board 31. It can lead the signal lines out in parallel, for example as a socket connection strip for a direct circuit board connector or as a socket for a parallel interface cable. Another possibility is that the socket 35 is a USB or LAN (RJ45) socket. In this case, the connection board 81 also includes a Figure 8 The electronic components for controlling the socket 35 are not shown.

[0087] That is, in this embodiment, the connecting board 81 is responsible for transmitting the signal. The premise is that the gate drive circuit of the power semiconductor switch is arranged on the circuit board 15 together with the power semiconductor switch or on its own driver board, for example, these driver boards are plugged into the circuit board 15 so that the driver board partially covers the circuit board 15 (circuit boards stacked in a sandwich manner). The control signal of the gate drive circuit is guided through the connecting board 81. In addition, the premise is that the four circuit boards 15 located at the same position in the axial direction but arranged on the front and back sides of the two cooling plates 16 each control only one phase, and only one control signal of the gate drive circuit is also required.

[0088] In addition to the elements shown, the connecting board 81 and the other embodiments shown may also have further circuits, for example monitoring circuits, control circuits, amplifier / buffer circuits or communication interfaces.

[0089] exist Fig. 9A more complex connection board 91 is shown in FIG. In this example, the socket 35 is a LAN connector with a control chip 36. The control signal inputted therethrough is divided into a plurality of signal lines 92 by a multiplexer 93. Fig. 9 In FIG. 4 , three signal lines 92 are shown for each spring contact 33 , but in actual implementation there may be significantly more signal lines 92 , for example 10 or even 30 signal lines 92 , which are led to each plugged-in circuit board 15 .

[0090] That is, in this embodiment of the connecting board 91 , the gate drive circuit of the power semiconductor switch is also located on the circuit board 15 or on its own drive board together with the power semiconductor switch. The control signal of the gate drive circuit is guided through the connecting board 91 .

[0091] The gate drive circuit of the power semiconductor switch can also be arranged on the connection board. Fig.10 As shown in ( Fig.10 1041 . 1044 . ...

[0092] In principle, the connected circuit boards 15 can be controlled completely individually by means of the connecting plate 101. That is, even between the circuit boards 15 in the same orientation, there is no necessarily a relationship. However, in the motor 10 shown here, the circuit boards 15 in the same orientation always control the same phase or the same phase. Therefore, it is suitable for the motor 10 shown here to control a single phase of the motor 10 by means of the connecting plate 101 shown, which single phase includes a plurality of output stages connected in parallel on the circuit boards 15 connected by the connecting plate 101.

[0093] In the case where the printed circuit board 15 carries the output stages of a plurality of phases of the electric motor 10, it is expedient to Fig.10 A connection board in the form of a connection board 101 shown in FIG. 1 carries a corresponding number of gate drive circuits 1031 . . . 1034 and local control chips 1041 . . . 1044 and transmits their signals to the circuit board 15 via the spring contacts 33 .

[0094] Because according to Fig.10 The connection board 101 already carries the gate drive circuit, so it is consistent with the Figure 7However, it is possible to connect the connecting plate 101 and the Figure 7 The required number of gate drive circuits are divided between the drive boards 70. Compared with the drive boards 70 arranged parallel to the circuit boards 15, the advantage of the connection board 101 is that it enables all circuit boards 15 with the same orientation to be connected using a single cable connection for control.

[0095] Reference numerals list

[0096] 9 Motor axis

[0097] 10 Electric Motor

[0098] 11 Stator

[0099] 12 conductor rods

[0100] 13 End face

[0101] 14 Back

[0102] 15 Circuit Board

[0103] 16 Cooling Plate

[0104] 17 Baotou

[0105] 18 Connecting elements

[0106] 32, 81, 91, 101 connecting plates

[0107] 33 Spring contact

[0108] 34, 35 sockets

[0109] 36 control chip

[0110] 70 driver board

[0111] 71 Power semiconductor chips

[0112] 72 Gate drive circuit

[0113] 73 local control chip

[0114] 82, 92 signal lines

[0115] 93 Multiplexer

[0116] 1031...1034 gate drive circuit

[0117] 1041...1044 local control chip

[0118] 110 second connecting plate

[0119] 421 Contact Location

[0120] 422 semiconductor switch

Claims

1. An electric motor (10), comprising: - a stator (11) having a plurality of field conductors (12) designed as rods, - an inverter having one or more parallel-connected power sections for each of the field conductors (12) for controlling the field conductors, wherein: The inverter comprises a controller for generating a control signal for the power section, in, - the output stage of the inverter is arranged on a plurality of circuit boards (15), - the circuit boards (15) are arranged so that they form at least two circular or annular structures, - the circular or annular structures are arranged parallel to each other and axially offset relative to each other so that their centers lie on a common central axis, - one or more plug connectors (33) are arranged on each of the circuit boards (15) for contacting the output stages, The connecting plates (32, 81, 91, 101) are plugged into plug connectors (33) of circuit boards (15) of different circular or annular structures and have the same orientation with respect to the central axis.

2. The electric motor (10) according to claim 1, wherein: The axis of the circular or annular structure corresponds to the motor axis (9).

3. The electric motor (10) according to claim 1, wherein: The circular or annular structures have the same diameter.

4. The electric motor (10) according to claim 1, wherein: The connecting plate (32, 81, 91, 101) extends in an axial direction parallel to the motor axis (9).

5. The electric motor (10) according to claim 1, wherein: The number of the connecting plates (32, 81, 91, 101) corresponds to the number of the field conductors (12).

6. The electric motor (10) according to claim 1, wherein: The connection board (32, 81, 91, 101) comprises a gate drive circuit (72) for the power section.

7. The electric motor (10) according to claim 1, wherein: The connection board (32, 81, 91, 101) includes a multiplexer (93), and is designed to guide the control signal input from the controller to one of a plurality of signal lines, thereby guiding the control signal to the power part addressed by the control signal.

8. The electric motor (10) according to claim 1, wherein: The connecting plate (32, 81, 91, 101) comprises one or more threaded connections with one or more of the circular or annular structures.

9. The electric motor (10) according to claim 1, wherein: The connecting board (32, 81, 91, 101) is a flexible circuit board.

10. The electric motor (10) according to claim 1, wherein: The current conductor (18) axially lengthens the field conductor (12).

11. The electric motor (10) according to claim 1, wherein: The printed circuit board (15) is arranged on at least one cooling plate (16).

12. The electric motor (10) according to claim 1, wherein: The cooling plate (16) is arranged such that the field conductor (12) or a current conductor (18) electrically connected to the field conductor (12) is mechanically operatively connected to the cooling plate (16), in particular is designed as a mechanical support for the cooling plate (16).

13. The electric motor (10) according to claim 1, wherein: The circuit board (15) is designed to be in the shape of a circular sector or an annular sector.

14. The electric motor (10) according to claim 1, which is designed for controlling field conductors (12) of at least 6 phases.

15. The electric motor (10) according to claim 1, wherein: The inverter is designed to generate an AC voltage having an amplitude of 200 V or less, in particular 100 V or less, in particular 50 V or less.

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