Interconnection assemblies and stators for electric machines

Abstract

The invention relates to an interconnection assembly (10) for a stator (100) of an electric machine. The interconnection assembly (10) comprises a shaped busbar (12) having a first region (14) comprising connection points (16) for external connection (23) of the interconnection assembly (10), a second region (18) in which connection points (20) for forming a connection of the busbar (12) to a stator winding (102) are formed, and an intermediate region (22) connecting the first region (14) and the second region (18). The first region (14) and the second region (18) are arranged in parallel planes (30, 31). The intermediate region (22) is oriented so that the angle (α) of the transition between the first region (14) and the intermediate region (22) and the angle of the transition between the second region (18) and the intermediate region (22) deviate from a right angle. The invention also relates to a stator (100) having the interconnection assembly (10).

Description

[0001] The present invention relates to an interconnection mechanism for a stator of an electric machine. Other aspects of the present invention relate to a stator for an electric machine having the inventive interconnection mechanism.

[0002] According to known concepts, the stator coils or stator windings of an electric machine may be contacted with an external connection point or power connection via an interconnection mechanism to apply a corresponding voltage to the individual phases of the winding via an electrical circuit or power electronics.

[0003] Known interconnection mechanisms have, for example, three connector rings received in a carrier. At the same time, the carrier ensures the positioning of the rings and the electrical insulation of the connector rings from one another. The connector rings are securely fastened in the carrier.

[0004] The connector ring has, for example, a coil connection area for connecting the interconnection means to the stator windings and an external connection area for connecting the interconnection means to external connections. The individual stator windings are each contacted with external connections, for example with power supply cables of power electronics, via the external connection area.

[0005] US2003 094 879A1 discloses a centralized power distribution unit for a thin brushless motor for a vehicle, which has a plurality of bus bars, a resin insulation layer covering the bus bars, and an insulation holder having a plurality of holding grooves for holding the bus bars. The bus bars are pre-bent in the thickness direction to form a substantially annular shape. The connection portion of the bus bar protrudes at right angles to the embedding area of ​​the bus bar.

[0006] US2005 082 923A1 discloses a stator of a rotating electric machine, the stator having a stator core, a plurality of coil pairs and a plurality of conducting wires. The stator core comprises a laminated core assembly formed by laminating thin steel plates into a cylindrical shape. The stator core has a plurality of slots spaced apart in a circumferential direction.

[0007] In the known interconnection concept, the high stiffness of the elements of the interconnection can lead to mechanical stresses at the electrical contact points in the installed state of the interconnection, which can, for example, impair the mechanical contact between two electrical conductors and thus also the electrical contact between the electrical conductors.

[0008] A flexible design of the connection element, such as an extension of the wound flexible wire winding of the coil, can prevent mechanical stresses in the installed state of the interconnection mechanism, however, the assembly effort involved may increase for such a concept. For such a connection, the individual flexible conductors (e.g. wires or laminates) must be precisely prepositioned individually, which may be made more difficult due to the easy deformability of the winding wire.

[0009] The object of the present invention is to provide an improved interconnection mechanism for a stator of an electric machine which prevents mechanical stresses at the respective contact points in the installed state and / or which can be assembled in a simple manner.

[0010] This object is achieved according to the subject matter of the invention. Further aspects and developments of the invention, which may achieve additional advantages, are described in the following description and in conjunction with the illustrated drawings.

[0011] Accordingly, an interconnection mechanism for a stator of an electric machine is proposed. The interconnection mechanism comprises at least one shaped busbar having a plurality of regions. A first region of the busbar comprises connection points of the interconnection mechanism for external connection, for example for establishing contact between the interconnection mechanism and power electronics controlling a stator winding of the stator. The busbar comprises a second region, in which connection points for establishing a connection between the busbar and the stator winding are formed. An intermediate region of the busbar connects the first region to the second region.

[0012] In a first portion of the busbar, the interconnection mechanism can thus be in contact with the supply electronics. In a second portion of the busbar, which is for example formed in a connector ring segment formed by the busbar (for example in a common plane with the second region of the busbar), the interconnection mechanism can be in contact with the windings of the stator. The connector ring segment can be received and fixed in a housing of the interconnection mechanism.

[0013] According to the invention, the intermediate region is oriented so that the respective angles of the transitions between the first region and the intermediate region and between the second region and the intermediate region deviate from a right angle. In other words, the angles of the transitions between mutually adjacent regions are not equal to 90°. In this case, the angles between the regions can be measured between the region segments that are located outside the bending radius of the bend of the shaped busbar.

[0014] For example, the angle of the transition portion deviates from the right angle and exceeds the value related to the tolerance. The right angle affected by the tolerance can include, for example, 90 ° + / - 1 ° (or + / - 2 °). However, according to the present invention, the angle of the transition portion is formed so that it is planned or intended to deviate from the right angle. This deviation can include, for example, greater than 3 ° (or greater than 5 °, greater than 10 °, greater than 20 °, greater than 30 °, greater than 40 °; greater than 50 ° or greater than 60 °) and / or less than 70 ° (or less than 60 °, less than 50 °, less than 40 °, less than 30 °, less than 20 ° or less than 15 °). For example, this deviation includes a value of 3 ° (or a value of 4 °; a value of 5 °, a value of 7 °; a value of 10 °, a value of 15 °; a value of 20 ° or a value of 25 °).

[0015] Due to the proposed choice of the transition section angle, a slight, in other words slight elasticity of the intermediate region can be produced. As a result, for example, the first region can be displaced relative to the second region by a certain distance (for example up to 1 mm, up to 2 mm or up to 3 mm), wherein the resulting mechanical loading or deformation of the busbar occurs mainly in the intermediate region. In other words, the intermediate region can provide a spring effect over a small displacement path.

[0016] The value of the angle of the transition portion can be selected based on the distance between the first area and the second area. For example, a larger angle deviating from a right angle can be selected for a smaller distance than for a larger distance, so as to still achieve sufficient elasticity of the intermediate area. By way of example, for a distance less than 5 times the thickness of the busbar, the angle of the transition portion can deviate from a right angle by at least 20°, for a distance greater than 5 times the thickness of the busbar and less than 10 times the thickness of the busbar, the angle of the transition portion can deviate from a right angle by more than 8° and less than 20°, and / or for a distance greater than 10 times, the angle of the transition portion can deviate from a right angle by less than 8°. Thus, an interconnection mechanism with a variety of different busbars can always obtain the required length compensation during assembly of the interconnection mechanism.

[0017] For example, the first region and the second region are arranged in parallel planes. By way of example, the first region is located in a plane which is inclined by less than 1° (or at least less than 2, or less than 5°) relative to the plane of the second region. In the state in which the interconnection mechanism is mounted in the stator, these planes can be oriented in the radial direction of the stator, so that, for example, contacting of the interconnection mechanism with an external connection can be achieved in a particularly simple manner. In this case, the second region can be extended or compressed in the axial direction to compensate for tolerance gaps, for example between the first region of the busbar and the power connection.

[0018] For example, at least one sub-region of the middle region is oriented in the connection plane, wherein the angle between the connection plane and the plane of the first region deviates from a right angle. The range of values ​​of the angle can be defined as described above. For example, the sub-region comprises at least 50% of the area of ​​the middle region. For example, a middle area of ​​the middle region (e.g. less than 50% of the area of ​​the middle region) can be arranged at an angle of 90° relative to the plane of the first region or the second region, and the interconnection mechanism can still achieve length compensation.

[0019] According to the development of the interconnection mechanism, the busbar has at least one bend in the middle region. In other words, the middle region can be formed, for example, with one or more further bends or kinks. Thus, for example, the elasticity of the middle region can be influenced more precisely. For example, the bend can increase the elasticity of the middle region in the case of low expansion. It is possible that the busbar is formed at least partially arched in the middle region.

[0020] For example, the busbar has a thickness of less than 20 mm (or less than 10 mm, less than 5 mm, less than 4 mm, less than 3 mm, or less than 2 mm) and / or greater than 1 mm (or greater than 3 mm or greater than 5 mm). Alternatively or additionally, the ratio of the width of the busbar to the thickness of the busbar may be at least 2 times (or at least 2.5 times; at least 3 times; at least 4 times; or at least 5 times). For example, the geometry of the busbar affects the elasticity of the busbar in the middle region.

[0021] By way of example, the second region of the busbar forms at least a part of a connector ring or a connector ring segment for the stator.The second region can extend circumferentially and adjoin the middle region in a region radially outside the connector ring segment.

[0022] It is possible that the interconnection mechanism has a single busbar or two busbars. According to an embodiment, the interconnection mechanism has three busbars formed to be electrically insulated from each other for contacting the three phases of the stator winding. For example, an interconnection mechanism for contacting a four-phase or five-phase winding may have 4 or 5 busbars, respectively.

[0023] The interconnection mechanism can, for example, have three busbars formed to be electrically insulated from one another for contacting three phases of the stator winding, wherein the respective middle regions of the busbars are arranged in different, non-parallel planes. As described, manufacturing tolerances and the like can be compensated by the middle regions, since the middle regions are correspondingly deformed in the axial and / or radial direction. Due to this deformation, forces acting on the interconnection mechanism or the stator can thus be generated. In order to keep these forces low, in the case of a plurality of busbars, the middle regions are therefore advantageously arranged in different planes, wherein these planes preferably do not extend in parallel. An increase in forces that could occur at the individual busbars, in particular in the radial direction, is thus prevented; instead, these forces remain low and can counteract or weaken each other.

[0024] For example, in the case of an interconnection mechanism having a plurality of bus bars, at least two bus bars are formed differently. For example, a middle region of a first bus bar has a bend, while a middle region of a second bus bar is formed linearly or flatly. For example, first regions of two bus bars are formed in a common plane, while a second region of the first bus bar is arranged closer to the common plane than a second region of the second bus bar.

[0025] The busbar is formed of, for example, an electrically conductive material, in particular a metal. The busbar may include, for example, copper, a copper alloy, aluminum or an aluminum alloy.

[0026] One aspect of the invention relates to a stator for an electric machine. The stator has an interconnection mechanism according to the interconnection mechanism described above or below for establishing contact between a winding of the stator (stator winding) and a connector device supplying a voltage to the stator winding. The invention further relates to an electric machine with a stator comprising a corresponding interconnection mechanism, which interconnection mechanism is for example in contact with an electric power connection.

[0027] In this case, it is possible that the connection of the connection point associated with the second area of ​​the busbar to the winding of the stator winding is formed as non-detachable (e.g. a welded connection). The connection of the power connection to the first area of ​​the busbar can be formed, for example, by a detachable connection (e.g. a screw or plug connection).

[0028] According to a development of the stator, a first region of the busbar of the interconnection means is arranged in a normal plane to a main axis of the stator (e.g. a rotor axis). In other words, the normal vector of the plane of the first region is parallel to the main axis. In this case, for example, the elasticity of the middle region of the busbar enables an axial displacement of the first region of at least 1 mm. For example, at a displacement of the first region of 3 mm, substantially only the middle region is deformed.

[0029] Thus, for example, the first region can be directed towards the power connection of the electric machine, for example to compensate for assembly tolerances, without generating mechanical stresses (or only generating insignificant mechanical stresses) between the interconnection mechanism and the power connection and / or the stator winding. For example, the reliability of the electrical contact between the contact points can thus be improved.

[0030] As a result of the invention, for example, an interconnection with length compensation is provided for an electric machine. The intermediate region allows slight variations in the length of the busbars to compensate for tolerance-related play during assembly of the interconnection.

[0031] The development of the stator and the electric machine involves the development features already described in connection with the interconnection mechanism. A repeated description is therefore omitted and the corresponding features also apply to the proposed stator and electric machine.

[0032] Several examples of the apparatus are explained in more detail below, by way of example only, with reference to the accompanying drawings, in which:

[0033] Figure 1 An exemplary embodiment of an interconnection mechanism for contacting stator windings is shown;

[0034] Figure 2 An exemplary embodiment of an interconnect mechanism with an assembled supply connection is shown;

[0035] Figure 3 An interconnection mechanism with supply connections is shown in cross-section; and

[0036] Figure 4 An example of a stator of an electric machine having an interconnection mechanism is shown.

[0037] Figure 1 An exemplary embodiment of an interconnection mechanism 10 for establishing contact between a coil winding and its power electronics is shown. The circuit arrangement 10 has three busbars 12, 12a, 12b which are each electrically insulated from one another and fixed in place by a retaining device or housing 13 of the interconnection mechanism 10.

[0038] The busbar 12 has a first region 14 with connection points 16 for connecting the busbar to an external connection. The connection points 16 are formed, for example, to connect an external connection cable or a further busbar to the busbar 12 by means of a screw connection or a plug connection. The first region 14 with the connection points 16 is formed, for example, as an external connection lug.

[0039] The bus bar 12 further has a second region 18 at which a connection point 20 is formed to connect the bus bar 12 to the stator winding. The connection point can be formed as a flat, continuous surface for connecting a corresponding winding of the coil winding to a corresponding connection point 20. The connection can be formed as a non-detachable (or only detachable by destruction) connection, for example, by a welding connection or a solder connection. For example, the connection point 20 is a coil connection lug.

[0040] The bus bar 12 further has an intermediate region 22 that connects the first region 14 and the second region 18 to each other. An angle α that deviates from a right angle is formed at the transition portion between the first region 14 and the intermediate region 22 (i.e., the bend of the bus bar 12 between the two regions). For example, Figure 1 The value of the angle α in the example shown is 100° and therefore deviates from a right angle by 10°. Figure 1 In the example shown, the value of the angle β of the transition between the second region 18 and the intermediate region 22 is also 100°. In this case, the angles α and β can be selected to be the same or different. For example, one of the two angles can be an acute angle and the other a straight angle.

[0041] By way of example, the value of the thickness D of the busbar 12 is 3 mm. In combination with the specific form of the angles α and β, a slight elasticity of the intermediate region is thereby generated, for example. The intermediate region 22 can have a slight spring effect, so that a small movement of the first region 14 into a plane parallel to the first region 14 in the direction of the normal vector of the first region 14 (for example 1 mm or 2 mm) is obtained, while there are no significant mechanical stresses (for example shear forces or forces in the direction of the normal vector of the parallel plane) in the first region 14 and / or the second region 18. In this case, for example, the thickness D simultaneously achieves sufficient rigidity of the busbar 12, so that the first region 14 remains positioned in a predetermined position without being affected by pressure or tension, and can therefore be easily contacted.

[0042] The interconnection mechanism 10 has, for example, three connector rings and a carrier such as a housing 13. Figure 1 As shown, the connector ring can be designed as a connector ring segment. The connector ring segment is formed, for example, by the second region 18 of the busbar 12 in the housing 13.

[0043] Figure 1 The interconnection mechanism 10 shown is provided for a three-phase stator winding. A voltage can be applied to the respective phase in each case via three busbars 12, 12a, 12b. In this case, the two further busbars 12, 12b also have respective first, second and intermediate regions, wherein the angle of the transition section each deviates from an angle of 90°.

[0044] The carrier can be formed as a separate carrier part and can have a U-shaped profile with a partition wall in which the connector rings are received such that the connectors are insulated from one another. The carrier can be designed, for example, as a plastic overmolding in one piece with the connector rings.

[0045] The coil connection lug is connected to the coil in a first plane. The external connection lug is connected to the external connection piece in a second plane. The two planes are at an axial distance from each other. In order to bridge this axial distance, the external connection lug (e.g., including a first area, a second area and an intermediate area) is designed so that they are bent multiple times and have, for example, three areas in three planes.

[0046] One region (e.g., the second region 18) is mainly arranged in the same plane as the coil connection lug and forms a circumferential portion protruding in the radial direction (e.g., protruding from the connector ring segment). Another region (e.g., the intermediate region 22) is a portion of an outer connection lug, which is bent in the axial direction, for example, starting from this region, and then bent to form a final region, such as the first region 14. For example, the planes of this region and the final region are substantially parallel to each other. The plane of the other region intersects the planes of the other two regions at a predetermined angle.

[0047] Advantages can be achieved, for example, in that the predetermined angle (e.g., angle α) is not an angle of 90°, but is greater or less than 90° (e.g., at least 95° or at most 85°). For example, length compensation during assembly is achieved by the inclined form of the other region. When the power connection screw is connected to the external connection of the interconnection mechanism 10, the first region used as the connection region can be moved out of the plane associated with the first region, for example, in the direction of the plane of the second region, so that length compensation is achieved. In this case, for example, due to the already existing angular position, only the second region is deformed.

[0048] In the case of other interconnections, on the other hand, when the intermediate region is arranged perpendicular to the other two regions, the entire interconnection may deform during the tightening process for establishing contact, thereby also introducing forces at the welding points of the coils, which may, for example, lead to splitting during operation.

[0049] Therefore, according to the inventive interconnection mechanism 10, a predetermined angular position of the intermediate region is proposed, so that, for example, a slight spring effect of the busbar is produced.

[0050] Figure 2 An exemplary embodiment of an interconnection mechanism 10 is shown with an assembled supply connection 23. The supply connection 23 has a busbar 24 which makes electrical contact with the first area 14. In this case, the mechanical connection of the busbar 24 to the busbar 12 is produced by means of two-piece fastening means 26a, 26b. The connection can be produced by a screw connection.

[0051] The further supply connections 23, which are in contact with the further busbars 12a, 12b, have corresponding busbars 24a, 24b, which are assembled on the interconnection mechanism using corresponding fastening means. In the present example, the connections of the power electronics, such as the supply connections 23, are inserted into the external connection lugs of the interconnection mechanism 10 from the side opposite to or facing the connector ring.

[0052] Further in Figure 2 The width B of the busbar 12 is shown in . In this case, the ratio of the width B to the thickness D of the busbar is greater than 2 times. Thus, for example, a screw connection of the busbar 12 to an external connection can be realized.

[0053] Figure 3 The interconnection mechanism 10 is shown in a cross-sectional view with an assembled supply connection 23. In this case, it can be seen that the first region 14 and the second region 18 are oriented or arranged in parallel planes 30, 31. Between the first region 14 and the second region 18 there is provided a distance 32 defined by the extent of the intermediate region 22. For example, in the state in which the interconnection mechanism 10 is assembled on the stator, the distance 32 is an axial distance.

[0054] exist Figure 3 It can be further seen in FIG. 1 that the middle region 22 of the busbar 12 has a bend 34, such as a twist or bend. For example, due to the bend 34, the flexibility of the middle region 22 can be increased, so that when the distance 32 changes, only the middle region 22 is deformed, while at the connection between the first region 14 of the busbar 12 and the busbar 24 supplying the connection or at the second region 18 of the busbar 12 and the assembled stator winding (see FIG. 1 ). Figure 4 ) do not generate mechanical stress at the connection between them. For example, the middle region 22 can compensate for the axial change of the length by extending or compressing the extension of the middle region in the radial direction.

[0055] Further in Figure 3 , the further intermediate region 22a is formed completely in a connection plane 36, which is arranged at an angle α relative to the plane 30a of the further first region 14a. The elasticity of the intermediate region can also be achieved, for example, by a linear extension of the intermediate region. The first regions 14, 14a, 14b are arranged in a common plane, while the second regions 18, 18a, 18b are each arranged in a different plane in order to achieve simple contacting of the respective phases of the stator winding, for example, by means of the corresponding busbars 12, 12a, 12b of the interconnection mechanism.

[0056] Figure 4 A stator 100 of an electric machine (not shown) is shown with the connector arrangement 10. The stator 100 comprises a stator winding 102. Respective windings or winding ends 104 of the stator winding 102 are securely connected to the connection points 20 of the respective busbars 12, 12a, 12b.

[0057] In order to electrically contact the phases of the stator winding 102, the power connection can be screwed to the busbar 12. In this case, the tolerance-related axial distance between the first region 14 and, for example, the busbar of the power connection can be compensated by the flexibility of the middle region 22 of the busbar 12. By way of example, the distance between the first region 14 and the second region 18 can be reduced by compression of the middle region 22 or increased by lengthening of the middle region 22. The angle of the transition between the regions and / or the thickness of the busbar 12 can be selected such that a distance variation between the first region 14 and the second region 18 of, for example, more than 1 mm (or more than 2 mm) and / or less than 3 mm (or less than 2 mm) can be achieved without generating mechanical stresses at the connection points of the interconnection mechanism.

[0058] Due to the slight flexibility or elasticity of the intermediate region 22, for example, tolerance-related play can be compensated when establishing contact between power electronics and the interconnection mechanism 10. In this case, however, the elasticity is chosen to be small enough that the outer connection points of the interconnection mechanism 10 can still be held in a predetermined position and simple assembly of the power connection is achieved.

[0059] In some applications, the electric machine is mounted, for example, in a housing, so that the connection points of the electric machine or the interconnection means for establishing contact with the external connections of the power electronics cannot be displaced or oriented relative to each other. In this case, for example, the external connections of the power electronics are also fixed with respect to their mounting position. Thus, for example, an orientation of two connection points is not possible. In this case, for example, due to the tolerance chain, an axial distance of about 1 mm may occur between the connection points of the electric machine and the power electronics.

[0060] The concept proposed according to the invention provides an interconnection mechanism that can compensate for such assembly tolerances between the stator or the external connection of the interconnection mechanism and the power connection. Thus, for example, axial screw forces between the connection point of the electric machine and the power electronics do not negatively affect the contact points with the stator coils.

[0061] List of Reference Numerals

[0062] 10 Interconnection institutions

[0063] 12 Busbar

[0064] B Busbar width

[0065] D Busbar thickness

[0066] 13 Housing

[0067] 14 First area of ​​busbar

[0068] 16 Connection points for external connections

[0069] 18 Second area of ​​busbar

[0070] 20 Connection point for stator connection

[0071] 22 Middle Area

[0072] Angle of transition between α and β

[0073] 23 Supply Connections

[0074] 24 Supply connection busbars

[0075] 26a, 26b fastening device

[0076] 30, 31 Parallel planes

[0077] 32 Distance

[0078] 34 Bend

[0079] 36 Connection plane

[0080] 100 Stator

[0081] 102 stator winding

[0082] 104 Winding end

Claims

1. An interconnection mechanism (10) for a stator (100) of an electric machine, the interconnection mechanism (10) comprising at least one shaped bus bar (12), the shaped bus bar (12) comprising: a first region (14) having a connection point (16) of the interconnection mechanism (10) for an external connection (23); a second region (18) in which connection points (20) for forming a connection of the busbar (12) to the stator winding (102) are formed; as well as an intermediate region (22) connecting the first region (14) and the second region (18), wherein the intermediate region (22) is oriented such that the respective angles (α) of the transitions between the first region (14) and the intermediate region (22) and between the second region (18) and the intermediate region (22) deviate from a right angle, The second region is located below the first region, thereby forming a substantially C-shape.

2. The interconnection mechanism (10) according to claim 1, in, The first region (14) and the second region (18) are arranged in parallel planes (30, 31).

3. The interconnection mechanism (10) according to claim 1, in, At least one sub-region of the intermediate region (22) is oriented in a connecting plane (36), wherein an angle (α) between the connecting plane (36) and the plane (30) of the first region deviates from a right angle.

4. The interconnection mechanism (10) according to any one of claims 1 to 3, in, The busbar (12) has at least one bend (34) in the middle region (22).

5. The interconnection mechanism (10) according to any one of claims 1 to 3, in, The busbar (12) is formed at least partially in an arcuate shape in the middle region (22).

6. The interconnection mechanism (10) according to any one of claims 1 to 3, in, The thickness (D) of the busbar (12) is less than 5 mm.

7. The interconnection mechanism according to any one of claims 1 to 3, in, The ratio of the width (B) of the bus bar to the thickness (D) of the bus bar (12) is at least 2 times.

8. The interconnection mechanism (10) according to any one of claims 1 to 3, wherein: The interconnection mechanism (10) has three busbars (12, 12a, 12b) formed to be electrically insulated from each other for contacting three phases of the stator winding (102), wherein respective middle regions (22, 22a, 22b) of the busbars (12, 12a, 12b) are arranged in different non-parallel planes.

9. The interconnection mechanism (10) according to any one of claims 1 to 3, wherein: The interconnection mechanism (10) has three busbars (12, 12a, 12b) formed to be electrically insulated from each other for contacting three phases of the stator winding (102), wherein respective first regions (14, 14a, 14b) of the busbars (12, 12a, 12b) are arranged in a common plane.

10. A stator (100) for an electric machine, in, The stator (100) has an interconnection mechanism (10) as defined in one of the preceding claims 1 to 9 for establishing contact between a stator winding (102) and an electrical connector device supplying a voltage to the stator winding (102).

11. The stator (100) according to claim 10, in, A first region (14) of a busbar (12) of the interconnection mechanism (10) is arranged in a normal plane to a main axis of the stator (100), wherein the elasticity of a middle region (22) of the busbar (12) enables the first region (14) to be displaced axially by at least 1 mm.

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