Stator contact equipment

Abstract

The present invention relates to a contact device (5) for a stator (2), the contact device having an annular interconnection housing (11), which accommodates a certain number of busbars (16) for interconnecting the coil ends (10) of the stator winding (3) with a certain number of phase terminals (4), wherein the interconnection housing (11) has an annularly surrounding base section (21) and a number of carrier sections (18) corresponding to the number of phase terminals (4), the carrier sections extending axially from the base section (21), wherein the respective phase terminals (4) have an axially extending contact section (4a) and a connecting section (4b) extending orthogonally to the contact section, and wherein the respective phase terminals (4) are placed in the assigned carrier section (18) so that the axial movement of the contact section (4a) of the respective phase terminal (4) in the direction of the base section (21) is prevented, while axial movement in the opposite direction is allowed.

Description

Technical Field

[0001] The invention relates to a contact device for a stator. The invention also relates to a stator for an electric motor, in particular a stator for an electronically commutated steering motor of a motor vehicle, and to an electric motor having such a stator. Background Art

[0002] Nowadays, motor vehicles usually have a certain number of adjustable parts, such as steering, seat adjustment, actuable locks, window lifts, and an adjustable sliding roof, which can be adjusted or shifted between different adjustment positions by means of respectively assigned electric motor drives.

[0003] Electric motors, particularly brushless electric motors, as AC motors usually have a stator with a certain number of stator teeth, arranged, for example, in a star shape. The stator teeth carry a rotating field winding or stator electric winding in the form of individual coils, which are themselves wound from insulated wire. The coils are assigned with their coil ends (winding wire ends) to the individual branches or phases, are interconnected in a predetermined manner, and are routed to phase terminals for energizing the rotating field winding.

[0004] In the case of a brushless electric motor, which is a three-phase electronically commutated AC motor, the stator has three phases and therefore at least three phase conductors or phase windings, each of which is supplied with current in a phase-shifted manner to generate a rotating magnetic field in which a rotor or mover, usually equipped with permanent magnets, rotates. The phase ends of the phase windings are connected to the motor electronics for controlling the electric motor. The coils of the rotating field winding are interconnected in a star or delta connection and are electrically contacted with the three phase terminals.

[0005] To guide and interconnect the coil ends, contact devices are commonly used as interconnection systems or switching units, which are placed on the end faces of the stator or on the stator laminated core. Such contact devices are used, in particular, to electrically connect the coil ends of the winding wire segments that form the coil windings, thereby electrically connecting the individual coil ends to one another (short-circuiting) and thus enabling the coil windings or phase windings to be energized in series.

[0006] Such contact devices typically have a number of integrated or encapsulated conductor tracks or busbars as connecting conductors for connecting or contacting the coil ends. During assembly of the electric motor or stator, the coil ends are contacted with the busbars, thereby connecting the coil windings associated with a common phase to one another via the contact device. The contact between the coil ends and the busbars is typically achieved by a material-bonded connection, for example by soldering or welding, particularly laser welding.

[0007] DE 10 2016 121 119 A1 discloses a busbar unit for an electric motor having a stator with a number of coils. The busbar unit, provided at the end face of the stator, comprises a busbar support made of electrically insulating material, annularly arranged around a central (stator) axis, and a number of busbars connected to the coils, each having axially oriented phase terminals. The phase terminals are inserted into a carrier section having (axial) slots, through which the spring-loaded legs of the respective busbars are guided out of the carrier section. The phase terminals have punched and bent locks that engage with projections on the carrier section, so that while axial movement of the phase terminal toward the busbar support is permitted, axial movement of the phase terminal in the opposite direction is prevented. Summary of the Invention

[0008] The present invention is based on the object of specifying a particularly suitable contact device. The contact device is preferably designed to compensate for relative movements between the phase terminals of the contact device and the motor electronics, in particular due to temperature changes caused by operation. The phase terminals are preferably electrically connected to the power contacts of the motor electronics by means of clamping or insulation-piercing contacts. Undesired loosening of the contacts, preferably established by clamping or insulation-piercing connections, between the phase terminals and the associated contacts of the motor electronics should also be prevented in a suitable manner. Furthermore, a particularly suitable stator having such a contact device and a particularly suitable electric motor having such a stator should be specified.

[0009] This object is achieved by the contact device according to the invention, the stator according to the invention and the electric motor according to the invention. The advantages and configurations listed with respect to the contact device can also be transferred to the stator and / or the electric motor, and vice versa.

[0010] A contact device, in particular a contact device for a stator of an electric motor, comprises an annular interconnection housing that is placed or can be placed on an end side of a stator base body extending along the stator axis, preferably in the form of a stator laminated core. The contact device also comprises a number of busbars for interconnecting the coil ends of the stator winding with a number of phase terminals. The interconnection housing, in which the busbars are at least partially accommodated, consists of an electrically insulating material and is preferably embodied as a plastic encapsulation of the busbars.

[0011] The interconnection housing has an annularly circumferential base section and a number of carrier sections corresponding to the number of phase terminals, the carrier sections extending axially from the base section. Suitably, the carrier sections are molded onto the base section of the interconnection housing.

[0012] Each phase terminal includes an axially extending contact section and a strap-type or cantilevered connection section extending orthogonally to the contact section. The width of the contact section of each phase terminal is preferably greater than the width of the connection section, relative to the circumferential direction of the contact device or its interconnection housing. In other words, the cross-sectional area of the contact section is preferably greater than the cross-sectional area of the connection section. The contact sections of the phase terminals are particularly preferably configured as insulation-piercing contacts or have such insulation-piercing contacts at their free ends.

[0013] The respective phase terminal is inserted into the associated carrier section in such a way that an axial movement of the contact section of the respective phase terminal in the direction of the base section is blocked, while an axial movement in the opposite direction is permitted.

[0014] This allows for compensation of relative movements between the phase terminals of the contact device and the motor electronics, which may occur, for example, due to temperature changes caused by operation. This is particularly advantageous when the phase terminals and corresponding mating contacts of the motor electronics are preferably connected by means of clip-type or insulation-piercing contacts. Furthermore, after establishing this insulation-piercing connection, unintentional loosening of the contact connection is reliably prevented.

[0015] In one advantageous embodiment, the carrier segment has an axial longitudinal slot bounded on both sides by segment edges that partially enclose the contact section of the respective phase terminal. The connection section of the respective phase terminal is guided out of the carrier segment via the longitudinal slot. In other words, the contact section of the phase terminal is inserted into the carrier segment, in particular so that it can be moved in one axial direction, while the connection section is guided out of the carrier segment via the longitudinal slot at the base of the carrier segment, i.e., at the transition to the base section of the interconnection housing. The connection section of the respective phase terminal rests appropriately against the base section. This prevents axial movement of the phase terminal, housed in the carrier segment with the contact section, toward the base section of the interconnection housing of the contact device.

[0016] In a further advantageous embodiment, the busbar to be connected to the phase terminal has a connection end which extends through a corresponding, preferably rectangular, recess in the connecting section of the phase terminal. Advantageously, the busbar to be connected to the phase terminal has a connection end (fixed end) which extends through a corresponding recess in the connecting section of the phase terminal.

[0017] The joining end of the busbar is suitably deformed or reshaped during the connection (joint connection) with the phase terminal to form a fixing head, for example a mushroom head, which at least partially covers the recess. Particularly preferably, the connection is established as a welded connection, expediently by means of laser welding.

[0018] The stator according to the present invention is suitable and designed for use in an electric motor. The stator comprises a stator lamination stack with a number of radially oriented stator teeth, each of which is provided with coils of a multi-phase stator winding. Each coil has a first and a second coil end oriented in the axial direction. The aforementioned contact device is applied to the end faces of the stator lamination stack. The coil ends are interconnected to form phase legs or motor phases and contacted with the phase terminals by means of the contact device. The contact device significantly simplifies contacting and interconnecting the stator, resulting in a particularly suitable, cost-effective, and easy-to-manufacture stator.

[0019] In a preferred application, the above-mentioned stator is part of an electric motor of a motor vehicle. The electric motor according to the invention is preferably a steering motor for a steering system of a motor vehicle, which includes a transmission, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following is a more detailed explanation of the embodiments of the present invention with reference to the accompanying drawings, wherein:

[0021] Figure 1 A schematic and simplified illustration of an electric motor of a motor vehicle is shown;

[0022] Figure 2 A perspective view showing a stator and a contact device arranged on its end side, the contact device having an interconnection housing and contact tabs for phase terminals and busbars projecting from the interconnection housing;

[0023] Figure 3 shows a perspective view of a contact device without an interconnection housing but with a joint connection between the joint end of each busbar and the connecting section of the phase terminal; and

[0024] Figure 4 A perspective view of a detail of a contact device in the region of one of the phase terminals is shown.

[0025] Parts and dimensions that correspond to one another are always provided with the same reference symbols in all the figures. DETAILED DESCRIPTION

[0026] Figure 1 A schematic and simplified illustration of an electric motor 1 for use in a motor vehicle is shown. The electric motor 1 comprises a stator 2 having a multi-phase rotating field winding or stator winding 3 which is connected to the stator by means of a contact device 5 ( Figures 2 to 4 Phase terminals 4, also referred to below as phase contacts, of the electric motor 1 are connected to motor electronics 6 for current supply. In the energized state, stator winding 3 generates a rotating magnetic field that drives a rotor (not shown in detail) of electric motor 1. Electric motor 1 is, in particular, an electronically commutated steering motor of a motor vehicle.

[0027] In the exemplary embodiment shown, the stator winding 3 is in particular designed as a three-phase device with three (motor) phases U, V, W. Each phase U, V, W is formed by a phase winding, which is essentially formed by interconnecting at least one coil (coil winding) 7 of the stator winding 3. In this exemplary embodiment, the phases U, V, W are interconnected in a delta connection.

[0028] Figure 2 A perspective view of a contact device or switching unit 5 for a stator 2 is shown. In the assembled state, the contact device 5 is placed on the end face of the stator 2 or on the end face of a stator base body 8, which is embodied as a stator laminated core and extends along the stator axis A and therefore in the axial direction. This stator base body or the stator laminated core of the stator 2 comprises, for example, twelve inwardly pointing stator teeth, on which the stator winding or rotating field winding 3 of the electric motor 1 is mounted.

[0029] In the exemplary embodiment, the coils 7 are wound onto an insulating winding carrier or coil carrier 9 and placed together with the winding carrier or coil carrier on the stator teeth of the stator base body 8. Each frame-shaped winding carrier 9 carries a coil 7 as part of the stator winding 3. The coils 7 each have two axially oriented coil ends 10. The coils 7 and their coil ends 10 are arranged on the stator teeth. Figure 2 The reference numerals are provided therein only by way of example.

[0030] The coil ends 10 of the coils 7 are interconnected to the three-phase (3-phase) stator winding or rotating field winding 3 in this embodiment by means of contact devices 5 placed on the end side of the stator 2. In electric motor operation, the energized windings of the stator winding 3 generate a stator-side magnetic field that interacts with the permanent magnets of the rotor of the brushless electric motor 1, which rotates about the central stator or motor axis A.

[0031] The contact device 5 has an annular interconnection housing 11 made of an electrically insulating material. The coil ends 10 of the coil 7 are passed through an axial through-opening 12 on the radial inner side of the interconnection housing 11 and contact contact tabs 13 on the upper side of the interconnection housing 1 for interconnection. The through-opening 12 and the contact tabs 13 are provided with reference numerals in the figures merely for illustrative purposes.

[0032] The contact device 5 is secured or can be secured to the stator base body 8 by means of axial locking tongues 14 of the interconnection housing 11 in a form-fitting and / or force-fitting manner. The locking tongues 14 are distributed over the outer circumference and are arranged on the side (underside) of the interconnection housing 11 facing the stator base body 8. The stator base body 8 has axially extending grooves 15 on its outer circumference, into which the locking tongues 14 engage in a clamping manner for securing. The contact device 5, arranged on the corresponding end face of the stator 2, is releasably locked or clamped to the stator base body 8.

[0033] If combined Figure 3 As can be seen, the contact device 5 includes a number of busbars 16 as connecting conductors for interconnecting the coil ends 10 or their contact tabs 13 with the phase terminals 4. The interconnection housing 11 is designed as a plastic encapsulation for the busbars 16, which are accommodated in the interconnection housing, extending concentrically with one another, at least in sections. The end contact tabs 13 of the busbars 16 and the joint ends 17 of some of the busbars 16 intended for connection to the phase terminals 4 are accessible, i.e., are not enclosed by the interconnection housing 11, at least in sections. The six phase terminals 4 in the exemplary embodiment provide three terminal pairs for the phases U, V, and W of the three-phase stator winding or rotating field winding 3 formed by the coils 7 and their interconnections. Each terminal pair forms a stator winding 3 with the three phases U, V, and W, thereby making the stator winding redundant.

[0034] The axially oriented joint ends 17 are provided as contact points for connection to the associated phase terminals 4 and are integrally, i.e., integrally or integrally, molded onto the corresponding busbar 16. Similarly, the axially oriented contact tabs 13 are integral components of the busbar 16 as contact points for contacting or electrically conductively connecting the respectively associated coil ends 10. The contact tabs 13 are particularly designed as welding tabs for welding, preferably laser welding, connection to the insulated coil ends 10. The busbar 16, its joint ends 17, and the contact tabs 13 are, for example, punched and bent parts made of copper.

[0035] In this embodiment, the phase terminals 4 are designed as roughly rectangular contact tabs in the form of punched and bent parts. The longitudinal sides of the respective phase terminals 4 are oriented in the axial direction A, with the narrow sides oriented roughly radially. The respective phase terminals 4 stand axially on the stator end face of the supporting interconnection housing 11. For support and stability, when the electric motor 1 is in the assembled or connected state, the phase terminals 4 are placed in a retaining receptacle, hereinafter referred to as a carrier section 18, of the interconnection housing 11 of the contact device 5. The phase terminals 4 are designed as insulation-piercing contacts and, for this purpose, are provided with receiving slots 19 at their free ends for the respective blade contacts of the motor electronics 6.

[0036] As from Figure 3 and Figure 4As can be seen relatively clearly, each phase terminal 4 has an axially extending contact section 4a and a connecting section 4b extending orthogonally thereto, with a preferably rectangular recess (not specifically labeled) introduced into the connecting section. The busbar 16 to be connected to the respective phase terminal 4 extends through the corresponding recess in the connecting section 4b of the phase terminal 4 with its joint end 17. The joint end 17 of the respective busbar 16 to be connected to the respective phase terminal 4 is embodied as a cross-sectional reduction or narrowing 20 at the rail end or connecting end of the busbar 16 facing the respective phase terminal 4. The joint end 17 is preferably approximately L-shaped, with the vertical L side forming the narrowing 20. The cross-sectional area of the narrowing 20 is smaller than the cross-sectional area of the adjacent section of the joint end 17. The cross-sectional area of the joint end 17 in the region of the narrowing 20 is smaller than the cross-sectional area of the recess in the cantilevered connecting section 4b of the phase terminal 4.

[0037] In the illustrated joined state, a positive-locking and material-locking connection 23 is established between the joint end 17 of the busbar 16 and the connecting section 4b of the phase terminal 4, preferably by means of laser welding, in particular a welded connection. This connection is established after the joint connection has been established and the components of the contact device 5 (busbar 16 and / or phase terminal 4) have been encapsulated, i.e., after the interconnection housing 11 has been completed. The interconnection housing then has a preferably flat, annular base section 21. In this state, the joint end 17 is passed through an opening 22 in the interconnection housing 11 to the upper side of the interconnection housing formed by the base section 21. The joint end 17 of the busbar 16 or its narrowing 20 is deformed in the connection (positive-locking and material-locking joint connection) established with the phase terminal 4 by means of laser welding. These connections are accessible after the corresponding sections of the busbar 16 have been encapsulated.

[0038] The connecting section 4b of the phase terminal 4 extends in the circumferential direction or tangentially relative to the annular base section 21 of the interconnection housing 11, while the connecting end 17 of the busbar 16 to be connected to the phase terminal 4 is oriented axially. In this way, the connecting end 17 on the busbar side can be passed through the cutout 20 on the phase terminal side.

[0039] As from Figure 4 As can be seen more clearly in the figure, the through-opening 12 for the busbar-side contact web 13 has a keyhole-like geometry with a circular opening 12a for the coil end 10 and a guide slot 12b leading into the opening for guiding the coil end to the associated contact web 13, where the respective coil end 10 is welded to the associated contact web 13. The contact web 13 of the busbar 16 is positioned in a radially inner region of the interconnection housing 11 relative to the connecting section 4b of the phase terminal 4 and its connection to the busbar 16.

[0040] Figure 4 Shown on a larger scale Figure 1 A detail in the area of one of the phase terminals 4 is shown. The annular base section 21 of the interconnection housing 11 of the contact device 5 and the carrier section 18 extending axially therefrom can be seen. The phase terminal 4, together with its axially extending contact section 4a, is inserted into the carrier section 18. This carrier section has an axial longitudinal slot 23 that extends up to the base section 21. The carrier section 18 circumferentially surrounds the contact section 4a of the phase terminal 4, enclosing it at the rear and laterally and partially enclosed by slot edges or segment edges 24 that flank the axial longitudinal slot on both sides.

[0041] The clear width I within the circumferentially closed carrier section 18, excluding the longitudinal slit 23, corresponds to the width a of the contact section 4a of the phase terminal 4. The width b of the strap-type or cantilevered connecting section 4b of the phase terminal 4, which extends orthogonally to the contact section 4a, is smaller than the width of the contact section 4a (a > b). In other words, the cross-sectional area of the contact section 4a is larger than the cross-sectional area of the connecting section 4b. In an exemplary embodiment, the width b of the connecting section 4b is also at least slightly smaller than the gap width s of the longitudinal slit 23 of the carrier section 18.

[0042] In this way, the phase terminal 4 can be inserted into the carrier section 18 from above during its assembly process with the connecting section 4b guided therethrough, the connecting section 4b being guided along the longitudinal slot 23 and outside thereof until it abuts against the base section 21. On the other hand, the phase terminal 4 is securely positioned in the carrier section 18, but in a manner that allows it to be positioned along the longitudinal slot 23. Figure 4 The direction of the arrow marked with A (i.e. relative to Figure 4 Thus, the contact section 4 a of the phase terminal 4 is inserted into the carrier section 21 so as to be movable in one of the axial directions A, while the connecting section 4 b is led out of the carrier section 18 at the foot of the carrier section 18 , i.e., at the transition to the base section 21 of the interconnection housing 11 , via the longitudinal slot 23 .

[0043] In other words, the respective phase terminals 4 are inserted into the associated carrier section 18 in such a manner that axial movement of the contact section 4a toward the base section 21 is blocked, while axial movement in the opposite direction is permitted. This compensates for relative movements between the phase terminals 4 of the contact device 5 and the motor electronics 6, which may occur, for example, due to temperature changes caused by operation. This is particularly advantageous when the phase terminals 4 are connected to corresponding mating contacts (not shown) of the motor electronics 6 via clip-type or insulation-piercing contacts. Furthermore, when the connection between the phase terminals 4 of the contact device 5 and the contacts of the motor electronics 6 is preferably established via plug-type or insulation-piercing contacts, the phase terminals 4 can rebound (relax) if the (axial) joining forces acting on the corresponding contacts of the phase terminals 4 and motor electronics 6 during the establishment of the contact connection are reduced or completely eliminated, thereby reliably preventing undesirable loosening of the contact connection.

[0044] In summary, the contact device 5 according to the present invention of the stator 2 has an interconnection housing 11, which accommodates busbars 16 for interconnecting the coil ends 10 of the stator winding 3 with the phase terminals 4, wherein the interconnection housing 11 has an annular base section 21 and a number of carrier sections 18 corresponding to the number of phase terminals 4 and extending axially from the base section 21, wherein the respective phase terminals 4 have an axially extending contact section 4a and a connecting section 4b extending orthogonally to the contact section, and wherein the respective phase terminals 4 are placed in the assigned carrier section 18, so that axial movement of the contact section 4a of the respective phase terminal 4 in the direction of the base section 21 is prevented, while axial movement in the opposite direction is allowed.

[0045] The present invention is not limited to the above-described embodiments. On the contrary, other variants of the present invention can also be derived by those skilled in the art without departing from the subject matter of the present invention. In particular, all individual features described in connection with the embodiments can also be combined with one another in other ways without departing from the subject matter of the present invention.

[0046] Furthermore, the present invention can be used not only in the specifically shown application but also in a similar embodiment in other motor vehicle applications, such as door and tailgate systems, window regulators, locks, adjustable seats and interior systems, as well as electric drives, control units, sensors and their arrangement in the vehicle.

[0047] Reference Signs List

[0048] 1 electric motor

[0049] 2 stator

[0050] 3 Stator winding

[0051] 4-phase terminals / phase contacts

[0052] 4a Contact section

[0053] 4b Connecting section

[0054] 5. Contact equipment

[0055] 6 Motor Electronics

[0056] 7 Coils

[0057] 8 Stator base / stator lamination stack

[0058] 9 Coil carrier / winding carrier

[0059] 10 Coil end

[0060] 11 Interconnection housing

[0061] 12 Through opening

[0062] 12a Opening

[0063] 12b Guide Gap

[0064] 13 Contact tabs

[0065] 14 Lock tongue

[0066] 15 slots

[0067] 16 busbars

[0068] 17 Joint end

[0069] 18 Carrier section / holding receptacle

[0070] 19 Accommodate gaps

[0071] 20 Narrowing

[0072] 21 base section

[0073] 22 Opening

[0074] 23 longitudinal gap

[0075] 24 Gap edge / segment edge

[0076] a Width of the contact segment

[0077] b Width of the connecting section

[0078] I Clear width

[0079] s Gap width

[0080] A Stator axis / axial direction

[0081] U, V, W phase

Claims

1. A contact device (5) for a stator (2), comprising an annular interconnection housing (11) which is placed or can be placed on an end side of a stator base body (8) extending along the stator axis (A) and accommodates a number of busbars (16) for interconnecting the coil ends (10) of the stator winding (3) with a number of phase terminals (4), -in, The interconnection housing (11) comprises an annularly circumferential base section (21) and a number of carrier sections (18) corresponding to the number of the phase terminals (4), the carrier sections extending axially from the base section (21). wherein the respective phase terminal (4) has an axially extending contact section (4a) and a connecting section (4b) extending orthogonally to the contact section, and - wherein the respective phase terminal (4) is inserted into the associated carrier section (18) in such a way that an axial movement of the contact section (4a) of the respective phase terminal (4) in the direction of the base section (21) is blocked, while an axial movement in the opposite direction is permitted, With reference to the circumferential direction of the interconnection housing (11), the width (a) of the contact section (4a) is greater than the width (b) of the connection section (4b) of the respective phase terminal (4), The carrier segment (18) has an axial longitudinal slot (23) which is delimited on both sides by segment edges (24) which partially surround the contact segment (4a) of the respective phase terminal (4). The connecting section (4b) of the respective phase terminal (4) is led out of the carrier section (18) via the longitudinal slot (23), The busbar (16) to be connected to the phase terminal (4) has a connection end (17) which passes through a corresponding recess in the connection section (4b) of the phase terminal (4). The phase terminals (4) are configured as insulation displacement contacts.

2. The contact device (5) according to claim 1, It is characterized by: The carrier section (18) is molded onto a base section (21) of the interconnection housing (11).

3. The contact device (5) according to any one of claims 1 to 2, It is characterized by: The connection section (4b) of the respective phase terminal (4) rests on the base section (21) of the interconnection housing (11).

4. The contact device (5) according to claim 1 or 2, It is characterized by: The contact sections (4a) of the respective phase terminals (4) are designed as insulation-piercing contacts.

5. A stator (2) of an electric motor (1), comprising a stator base body (8) having a number of coils (7) of a multi-phase stator winding (3), wherein: Each coil (7) has a first and a second axially oriented coil end (10) and a contact device (5) according to any one of claims 1 to 4, which is arranged on an end side of the stator base body (8).

6. An electric motor (1) for a motor vehicle, comprising a stator (2) according to claim 5.

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