Electric motor having stator with hairpin winding system and vehicle

Abstract

The utility model relates to an electric motor with a stator with a hairpin winding system and a vehicle, the stator is also provided with an interconnection assembly, the interconnection assembly comprises a support (6) and at least three busbars (1, 2, 3), the busbars are respectively provided with three areas, that is, the at least three busbars (1, 2, 3) are arranged in the support (6), and the at least three busbars (1, 2, 3) are arranged in the support (6). The utility model relates to an electrical connector comprising a plurality of connection pins, a first region having connection points for electrical connection, a second region having connection points for contact with one of the connection pins, and a third region, the third region connecting the first region and the second region, and the second region being formed at least partially by annular sections having the same radius. The connection point is formed by a groove (8) introduced at the annular section or at an inwardly directed radial projection of one of the annular sections, and the connection point (4) of at least one of the busbars is arranged at the same axial height with respect to the stator as the groove (8).

Description

Field of the Invention

[0001] The present invention relates to an electric motor having a stator with a hairpin winding system, wherein the connection pins of the coils are connected via an interconnecting assembly to establish electrical contact with a power electronics device. The present invention also relates to an electric motor having such a stator and a vehicle having such an electric motor. The present invention is particularly applicable in vehicle technology. Background Art

[0002] A hairpin winding is formed by a plurality of shaped strips (also referred to as hairpins) having a generally rectangular cross-section, the end portions of which are located at the winding heads and are conductively connected to each other, whereby they form a winding in the form of a series of hairpins. One or more parallel-connected windings form a coil. The hairpin winding system of a stator typically includes three or six coils, each of which is associated with a phase of a power supply. The ends of the windings, which are respectively formed by the ends of the hairpins defining the windings, are referred to as connection pins. For a hairpin winding inserted into a stack of stator laminations, the hairpins are located in grooves that are parallel to each other and axially extending, wherein the winding heads are arranged at the end sides of the stack of laminations. Here, the connection pins are preferably located at the same end side of the stack of laminations. To control the electric motor, the connection pins are connected to a power supply phase or a neutral conductor. This is typically accomplished by a power electronics device.

[0003] In order to enable the power electronics device to supply power to a plurality of windings of a coil, i.e., more than two connection pins, via a common contact, or in order to be able to connect the connection pins to each other to form a delta connection or a star connection, connection elements are typically provided. For a delta connection, the connection pins associated with one phase are typically wired via a connection ring. Each connection ring is connected to a phase, more precisely a neutral conductor, of the power electronics device. Here, the connection ring does not necessarily refer to a closed ring, but typically refers to an annular section covering a certain angular range, within which all the connection pins to be connected to the same phase are located. The connection ring, also referred to as an annular busbar, has contact sites, the number of which is the same as the number of connection pins that contact the connection ring accordingly. In addition, the connection ring also has an interface for electrical contact with a phase of the power electronics device. These connection rings together form an interconnecting assembly.

[0004] In the prior art of powerful electric drives based on hairpin technology, solutions for the interconnecting assembly are known, in particular, which ensure a durable and reliable contact of the connection pins of the hairpin winding system despite the mechanical and thermal alternating loads of the electric drive. This solution is particularly suitable for the spatial arrangement of the power electronics device and the electric motor and the site conditions therebetween.

[0005] For example, a centralized power distribution unit for a brushless vehicle motor is known from patent document US2003 / 0094879 A1, which has a plurality of busbars and an insulating holder with a plurality of holding grooves that hold the busbars. These busbars are pre-bent in one direction to form an annular shape. The bent connecting sections of the busbars protrude radially outward at a right angle from the embedding area of the busbars.

[0006] A similar solution is disclosed in patent document DE 10 2018 219 539 A1, which describes an interconnection assembly for an electric motor that has a plurality of connecting rings located in a common carrier, wherein a line connection is rigidly arranged at the connecting rings directly at a locally tangentially oriented area of the connecting rings. Here, the rigid connection is carried out indirectly by a connecting piece called a busbar there, which advantageously surrounds the respective connecting ring from three sides in order to produce a large contact area, and the line connection lies on the connecting piece over the entire end face.

[0007] Furthermore, an interconnection assembly for an external connection of a stator is disclosed in patent document DE 10 2019 202 911 A1, which includes a bracket and a formed busbar. In the bracket, the busbars are arranged relative to each other and kept electrically insulated from each other. The busbar is a bent piece having three different regions. The first region has a connecting site for connection to the external connection for the purpose of making electrical contact with the busbar. A connection site for connecting the busbar to the stator winding is located in the second region. This connection site is formed by a singly bent leg, the width and distance of which are predefined by the width and distance of the connection pins. The first region and the second region are preferably located in planes parallel to each other and are integrally connected to each other via the third region. The busbar described here is characterized in that the angle between the first region and the third region or between the second region and the third region is not a right angle, whereby the busbar has slight elasticity. Due to the plurality of bent sites, the production of the busbar is relatively troublesome and it is vulnerable to vibrations. Summary of the Utility Model

[0008] The object of the present utility model is to provide an electric motor having a stator with a hairpin winding system and an interconnection assembly, wherein the busbar can be manufactured with little bending effort.

[0009] For an electric motor having a stator with a hairpin winding system, wherein annularly arranged connection pins of the hairpin winding system protrude from an end face of the stator in an axial direction of the stator, the stator further having an interconnecting assembly including a bracket and at least three busbars, each of the busbars having three regions, namely, a first region, a second region, and a third region, the first regions respectively being for connection sites for making electrical contact, the second regions having connection sites for respectively contacting one of the connection pins, wherein the third regions respectively connect the first regions and the second regions, and the second regions are at least partially formed by annular segments having the same radius, this object is achieved in that the connection sites are formed by grooves introduced at the annular segments or at inwardly directed radial protrusions of one of the annular segments, and the connection sites of at least one of the busbars are arranged relative to the stator at the same axial height as the grooves. Thereby, the busbars can be manufactured with little bending effort.

[0010] Advantageously, the three regions of the second busbar are in one plane, and the first region of the first busbar and the first region of the third busbar are bent in opposite directions relative to their third regions. Thereby, the connection sites are at different axial heights relative to the stator, thereby providing more space in the axial direction for a conductor that is to contact the connection sites.

[0011] In order to space the connection sites at a certain distance from the rotor, the third region and the second region are advantageously formed by radially outwardly directed protrusions at the annular segments, wherein the protrusions are in one plane with the annular segments in the second region.

[0012] Herein, if the protrusions preferably have different lengths in the radial direction, more space is provided in the radial direction for a conductor that is to contact the connection sites, which results in different lengths in the third region.

[0013] Preferably, the annular segment of the second busbar has a length in the circumferential direction that is greater than the sum of the lengths of the annular segments of the first busbar and the third busbar, wherein the first busbar and the third busbar are arranged electrically insulated from the second busbar such that their annular segments overlap the annular segment of the second busbar. Due to the overlap of the busbars, the wiring gains stability.

[0014] If the third region of the second busbar is arranged between the third region of the first busbar and the third region of the third busbar, the stability can also be improved.

[0015] It is likewise advantageous if the annular segments of the first busbar and the third busbar are arranged at opposite end sides of the annular segment of the second busbar.

[0016] If the bracket covers at least all the annular segments directly or indirectly on the covering surface facing away from the stator, as well as on the inner and outer circumferential surfaces, it also has a positive impact on stability.

[0017] To compensate for the positional tolerance of the connection pins, the groove width of the groove is preferably greater than the pin width of the connection pins by more than the clearance.

[0018] It is also advantageous that the groove depth is greater than the pin thickness of the connection pins, whereby the connection pins are respectively connected to one of the busbars through three sides. This connection is preferably a welded connection.

[0019] Advantageously, the vehicle is equipped with an electric motor according to the present utility model. Description of the Drawings

[0020] The present utility model will be further elaborated below with reference to the embodiments using the drawings. Among them:

[0021] Figure 1 A cut-away part of an electric motor having a stator and a connection assembly according to the present utility model is shown in a three-dimensional top view,

[0022] Figure 2 Shows the connection group according to Figure 1 Three busbars arranged relative to each other, and

[0023] Figure 3 The three busbars are respectively shown from the perspective A. Detailed Description of the Embodiment

[0024] In Figure 1 , an embodiment of an electric motor having a stator is shown in a partial view. The stator has a hairpin winding system and a flat interconnect assembly. The stator with the hairpin winding system can be seen, wherein the annularly arranged connection pins of the hairpin winding system protrude from the end face of the stator in the axial direction of the stator. On one side of this end face, there is an interconnect assembly, which includes a bracket 6 and three busbars 1, 2, 3, which can be seen in Figure 2 and Figure 3It can be seen more clearly in [description]. The busbars 1, 2, 3 each have three regions, namely, a first region 11, 21, 31 respectively for the connection part 4 used for electrical contact, a second region 12, 22, 32 having a connection part 5 for contacting one of the connection pins respectively, and a third region 13, 23, 33, wherein the third regions 13, 23, 33 are respectively connected to the first regions 11, 21, 31 and the second regions 12, 22, 32. The second regions 12, 22, 32 respectively include annular sections 121, 221, 321 having the same radius r. All have third regions 13, 23, 33. In addition, radially outwardly pointing protrusions are respectively formed at the annular sections 121, 221, 321, and the protrusions are in the same plane as the corresponding annular sections 121, 221, 321, and the annular sections are formed at the plane. In this specification, it is simply assumed that the thickness of the annular section is zero, so the annular section is located in the plane. The radially outwardly pointing protrusions have different lengths with a stepped change, whereby the first regions 11, 21, 31 and thus the connection part 4 are located at different distances from the stator in the radial direction. When the three regions 21, 22, 23 of the second busbar are in a plane, the first region 11 of the first busbar and the first region 31 of the third busbar are bent in opposite directions relative to their third regions 13, 33. Thus, the connection part 4 is located at different heights in the axial direction of the stator. The above two measures are not conditional on each other, but especially in the form of their combination, they can cause easily accessible connection parts and sufficient structural space for arranging conductors (such as cables or busbars) at the connection parts of the flat connection assembly with less technical cost during the manufacture of the connection assembly.

[0025] In this first embodiment, the annular section 221 of the second busbar has a length in the circumferential direction R that is greater than the sum of the lengths of the annular section 121 of the first busbar and the annular section 321 of the third busbar. Therefore, the first busbar 1 and the third busbar 3 can be arranged to be electrically insulated from the second busbar such that their annular sections 121, 321 overlap with the annular section 221 of the second busbar. Here, the annular section 121 of the first busbar and the annular section 321 of the third busbar are arranged at opposite end sides of the annular section 221 of the second busbar. The third region 23 of the second busbar is located between the third region 13 of the first busbar and the third region 33 of the third busbar.

[0026] At the second busbar 2, there is a radially inwardly directed protrusion 7, and a groove 8 is formed at the protrusion, and the groove forms a connection part 5. The connection part 5 of the second regions of the first busbar and the third busbar is provided by the groove 8 formed at the annular sections 121, 321, wherein the annular sections 121, 321 have a width in the radial direction corresponding to the sum of the annular width of the second annular section and the width of the radially inwardly directed protrusion 7 formed thereon, so that the grooves 8 of all the busbars are located on a virtual circular ring. The connection part 4 of the second busbar is arranged at the same axial height as the groove 8 relative to the stator.

[0027] The bracket 6 directly or indirectly covers the covering surfaces facing away from the stator and the inner peripheral surface and the outer peripheral surface existing at the annular sections 121, 221, 321, whereby the busbars are fixed and arranged stably relative to each other.

[0028] The groove 8 has a groove width b, which is much larger than the pin width of the connection pin by more than the clearance. In addition, the groove depth t of the groove is greater than the pin thickness of the connection pin. Thereby, the positional tolerance between the connection pins to be connected to the busbar can be compensated during assembly, and a three-sided connection can be established. Therefore, the contact area between the busbar and the connection pin is significantly larger than the case when the connection pin is fixed only on one side, whereby a more stable connection can be established. This connection is preferably a welded connection.

[0029] The connection assembly is understood as a flat connection assembly because the connection assembly has a much smaller extension in the axial direction of the stator than the radial extension due to its characteristics.

[0030] Reference numerals

[0031] 1 First busbar

[0032] 11 First region of the first busbar

[0033] 12 Second region of the first busbar

[0034] 121 Annular section of the first busbar

[0035] 13 Third region of the first busbar

[0036] 2 Second busbar

[0037] 21 First region of the second busbar

[0038] 22 Second region of the second busbar

[0039] 221 Annular section of the second busbar

[0040] 23 Third region of the second busbar

[0041] 3 Third Busbar

[0042] 31 First Region of the Third Busbar

[0043] 32 Second Region of the Third Busbar

[0044] 321 Annular Section of the Third Busbar

[0045] 33 Third Region of the Third Busbar

[0046] 4 Connecting Part

[0047] 5 Connection Site

[0048] 6 Bracket

[0049] 7 Inwardly Directed Radial Protrusion

[0050] 8 Groove

[0051] r Radius

[0052] R Circumferential Direction

[0053] b Groove Width

[0054] t Groove Depth.

Claims

1. An electric motor having a stator with a hairpin winding system, wherein: The hairpin winding system has an annularly arranged connection pins protruding from the end face of the stator in the axial direction of the stator, and the stator also has an interconnection component, which includes a bracket (6) and at least three busbars (1, 2, 3), each of which has three regions, namely a first region (11, 21, 31), a second region (12, 22, 32) and a third region (13, 23, 33), the first region is used for a connection position (4) for electrical contact, the second region has a connection position (5) for contacting one of the connection pins, wherein the third region (13, 23, 33) respectively connects the first region (11, 21, 31) and the second region (12, 22, 32), and the second region (12, 22, 32) is at least partially formed by annular segments (121, 221, 321) with the same radius (r), It is characterized in that The connection point (5) is formed by a groove (8) introduced into the annular segment (121, 221, 321) or into an inwardly directed radial projection (7) of one of the annular segments, and the connection point (4) of at least one of the busbars is arranged at the same axial height as the groove (8) relative to the stator.

2. The electric motor having a stator with a hairpin winding system according to claim 1, characterized in that The interconnection assembly comprises a first busbar, a second busbar and a third busbar, wherein three regions (21, 22, 23) of the second busbar are located in one plane, and a first region (11) of the first busbar and a first region (31) of the third busbar are bent in opposite directions relative to their third regions (13, 33).

3. An electric motor having a stator with a hairpin winding system according to claim 2, characterized in that The second region (12, 22, 32) and the third region (13, 23, 33) are formed by a protrusion pointing radially outward at the annular segment (121, 221, 321), and the protrusion is located in the same plane as the annular segment (121, 221, 321) in the second region (12, 22, 32).

4. An electric motor having a stator with a hairpin winding system according to claim 3, characterized in that The outwardly directed projections have different lengths in the radial direction.

5. The electric motor having a stator with a hairpin winding system according to claim 2, characterized in that The annular segment (221) of the second busbar has a length in the circumferential direction (R) that is greater than the sum of the length of the annular segment (121) of the first busbar and the length of the annular segment (321) of the third busbar, wherein the first busbar (1) and the third busbar (3) are arranged to be electrically insulated from the second busbar (2) so that their annular segments (121, 321) overlap with the annular segment (221) of the second busbar.

6. An electric motor having a stator with a hairpin winding system according to claim 5, characterized in that The third region (23) of the second busbar is arranged between the third region (13) of the first busbar and the third region (33) of the third busbar.

7. An electric motor having a stator with a hairpin winding system according to claim 5 or 6, characterized in that The annular section (121) of the first busbar and the annular section (321) of the third busbar are arranged on opposite end sides of the annular section of the second busbar.

8. An electric motor having a stator with a hairpin winding system according to any one of claims 1 to 6, characterized in that The support (6) directly or indirectly at least partially covers the cover surface facing away from the stator as well as the inner and outer circumferences present on the annular section (121, 221, 321).

9. An electric motor having a stator with a hairpin winding system according to any one of claims 1 to 6, characterized in that The groove width (b) is greater than the pin width of the connection pin beyond the clearance.

10. An electric motor having a stator with a hairpin winding system according to any one of claims 1 to 6, characterized in that The groove depth (t) is greater than the pin thickness of the connecting pin.

11. A vehicle, characterized in that An electric motor according to any one of claims 1 to 10 is provided.

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