Electric motor with simplified wiring

Abstract

The present invention relates to an electric motor (1) comprising a stator (2) with at least one winding (3) having an electrically conductive coil wire (4), at least one pocket element (5) through which the coil wire (4) is guided, at least one contact element (6) extending along a longitudinal direction (100) and having, with respect to the longitudinal direction (100), an insulation displacement terminal (7) on one side and a contact pin (8) on an opposite side, wherein a first shoulder (10) extending in the transverse direction (200) and a second shoulder (11) formed in the transverse direction (200) opposite the first shoulder (10) are arranged between the contact pin (8) and the insulation displacement terminal (7), a wiring element (12) comprising at least one through-opening (13) through which the contact pin (8) is guided and electrically connected to the wiring element (12), wherein the insulation displacement terminal (7) is guided within the pocket element (5),to electrically contact the coil wire (4), wherein the first shoulder (10) bears against a first end face (14) of the pocket element (5) and the second shoulder (11) bears against a second end face (15) of the pocket element (5).

Description

State of the art

[0001] The present invention relates to an electric motor. This electric motor has a simplified winding configuration.

[0002] Insulation displacement connections, which cold-contact a conductor strip to a coil wire, are state-of-the-art for stators for small motors in motor vehicles. They have the advantage that the wire to be contacted does not need to be stripped beforehand, and the insulation displacement connection itself does not require a separate coating. Insulation displacement connections are predominantly used in so-called full-cut stators as a contact element between the coil wire and a stator interconnection plate. Disclosure of the invention

[0003] The electric motor according to the invention allows direct contacting without the need for a separately mounted circuit board, as is usually the case, since contact elements for direct contacting are very precisely aligned. This allows for fully automated placement and, if necessary, pressing into a circuit element, while preferably keeping the space required for the feedthrough / insertion hole in the circuit board as small as possible. To achieve this, a geometry for supporting the respective contact element on the insulation displacement connector and an associated pocket element are defined, enabling this precise alignment.

[0004] In addition to the preferred position, the insulation displacement connections can also be used rotated 180° around the axial axis or longitudinal direction. In particular, the contact elements can be rolled out continuously on a tape reel, which can then be individually picked up internally, automatically gripped, and pressed into the corresponding pockets with the connecting wire.

[0005] The electric motor has a stator with multiple windings, each of which has an electrically conductive coil wire. Furthermore, the stator has at least one pocket element and a contact element. The coil wire is guided through the pocket element. The contact element extends along a longitudinal direction and, with respect to the longitudinal direction, has an insulation displacement contact on one side and a contact pin on an opposite side.

[0006] A first shoulder and a second shoulder are formed between the contact pin and the insulation displacement connector. The first shoulder extends in a transverse direction, and the second shoulder is formed opposite the first shoulder. Thus, both shoulders, the first shoulder and the second shoulder, extend parallel to the transverse direction in opposite directions.

[0007] A wiring element is also provided, which has at least one through-hole through which the contact pin is guided and electrically connected to the wiring element. The wiring element is preferably part of a higher-level control electronics system. The contact elements enable direct contact between the coil wire and said electronics without the use of a wiring board or similar device.

[0008] The insulation displacement terminal is preferably routed inside the pocket element to electrically contact the coil wire. The coil wire does not need to be stripped for this purpose; the insulation displacement terminal ensures reliable mechanical and electrical contact. The electrical connection between the coil wire and the contact element is therefore simple and inexpensive to establish.

[0009] The first shoulder rests against a first end face of the pocket element. The second shoulder preferably rests against a second end face of the pocket element. This particularly aligns the contact element with the pocket element. The contact elements can thus be aligned very precisely with one another, since the pocket elements are usually firmly connected to the stator. This makes it easy and reliable to pass the contact pins through the through-openings of the interconnection element. The shoulders are, in particular, the only areas of the contacting element that rest against the pocket element along the longitudinal direction.

[0010] This creates an insulation displacement connection that contacts the coil wire of a stator using the contact element, which acts as a direct contacting element. This is achieved by combining the design of the pocket element with the design of the contact element to ensure that the contact pin is precisely aligned with the interconnection element after the insulation displacement connection has been pressed in, thus establishing the insulation displacement connection. This alignment is particularly precise enough when a connection to the interconnection element, in particular printed circuit board electronics and / or hybrid electronics, can be established without further alignment operations.

[0011] When the contact element is pressed into the pocket element, the shoulders of the contact element come into contact with the end faces of the pocket element. The dimensions of the insulation displacement terminal are preferably designed to compensate for any tolerances in the press-in direction for wire fixation.

[0012] A connection plate is no longer necessary and can be omitted, resulting in cost savings. Furthermore, the stiffening measures improve the alignment of the contact pin to the connection element when pressing the contact element into the pocket, in accordance with the flatness of the pocket's top edge and the punched-out shoulder geometry.

[0013] In particular, the contacting element achieves a positioning accuracy of less than + / - 0.2 mm per contact pin. Furthermore, the shape of the first shoulder and the second shoulder allows for easy separation of the individual contacting elements from an endless conductor strip of the contacting elements, which simplifies the production and provision of the contacting elements. The subclaims show preferred developments of the invention

[0014] The first shoulder and the second shoulder preferably have different dimensions along the longitudinal direction. In this way, the first end face and the second end face are formed at different locations with respect to the longitudinal direction. This prevents, in particular, tilting of the contact element within the pocket element. This difference in the longitudinal direction preferably increases with the fill factor or the number of winding layers per stator tooth, since one of the pocket walls guides the end wire emerging from the winding at the height of the highest winding layer. In contrast, the opposite wall only requires a minimum height to guide the terminal and is therefore not dependent on the number of turns. With a low copper fill level or few turns, the shoulders can both be at the same height, which then corresponds to the minimum height for guiding the terminal.

[0015] The contact element has a cut edge or separating edge at the outer shoulder ends of the first shoulder and the second shoulders in the transverse direction. The cut edge and / or separating edge is in particular formed with a burr. This is created in particular by separating the contact element from a strip, wherein the strip has several interconnected contact elements with a pre-formed geometry. The geometry is created, for example, at an earlier point in time using a different tool. A final cut or a final punching is carried out, for example, only later using a second tool, e.g. immediately before assembly. In this case, a piece of offcut can be removed between two contact elements arranged adjacently in the strip. A small burr or a sharp edge / corner then remains at the boundaries of the cuts and / or punches.

[0016] The pocket element advantageously has a first wall with the first end face and a second wall with the second end face. In addition, the pocket element has third walls connecting the first wall and second wall. A wall thickness of the first wall and / or second wall is preferably greater, at least in sections, than a wall thickness of the third walls. The wall thickness of the first wall and / or second wall is particularly preferably between twice and five times as great as the wall thickness of the third wall. The wall thickness of the first wall and / or second wall is preferably greater the longer the contact pin is in the longitudinal direction and the higher the positioning accuracy of the pin tip must be in the installed state.

[0017] Advantageously, the electric motor comprises a plurality of pocket elements, with a contact element arranged in each pocket element. Along a circumferential direction of the electric motor, adjacent pocket elements and / or contact elements are oriented similarly or in a mirror-inverted manner. Depending on the type of connection and winding direction of adjacent coils, the contact elements are pressed / contacted into the associated pocket elements at different positions and / or in a mirror-inverted manner relative to the adjacent connection element.

[0018] Particularly preferably, the first wall and / or the second wall and / or the third walls have wire guide elements for wrapping the coil wire around the pocket element. The wire guide elements are, in particular, groove-shaped to accommodate the coil wire. This ensures secure guidance of the coil wire.

[0019] The third walls, in particular, have a guide slot. The guide slot serves, in particular, to guide the coil wire through the pocket element. In this way, the insulation displacement terminal can be mechanically and electrically connected to the coil wire.

[0020] The pocket element advantageously has a rib. The insulation displacement connector in particular has a slot forming cutting edges, which is designed for mechanical and electrical connection to the coil wire. The insulation displacement connector is also designed to receive the rib in the slot. The rib is particularly advantageous for wires with a diameter of ≥0.5 mm. This reduces any deformation or pocket walls of the pocket element during winding of the coil wire, so that the alignment of the contact element is not negatively influenced or deformation can be deliberately prevented. Complex alignment after assembly or oversized recesses in the interconnection element for tolerance compensation are avoided. The shoulders of the contact element form the contact surface towards the top to a tool such as a press-in die for mounting the contact element in the pocket element.

[0021] The formation of the first shoulder and second shoulder also increases the width of the contact element, which improves the alignment of the contact element during assembly.

[0022] The outer surfaces of the first shoulder and the second shoulder located on the contact pin side preferably form a support surface for the interconnection element. This allows for easy installation and reliable support of the interconnection element.

[0023] Particularly preferably, when multiple contact elements are used, all ends of the contact pins and the outer surfaces of the first shoulder and the second shoulder located on the contact pin side are arranged at the same longitudinal level or at the same height in the installed state. The longitudinal level or height refers in particular to a dimension along the longitudinal direction. A deviation of a maximum of one contact element from the same longitudinal level or the same height is provided.

[0024] The contact pin is preferably a press-fit pin or a solder pin. In both cases, a reliable electrical connection is ensured. The contact pin thus has the appropriate detailed geometry for use as either a press-fit pin or a solder pin.

[0025] The interconnection element is preferably a circuit board. The circuit board is electrically connected to the contact pins. Conductor elements are mounted on the circuit board, enabling the interconnection of the contact elements and thus the interconnection of the windings.

[0026] The interconnection element includes control electronics for controlling the windings. This eliminates the need for a separate interconnection component. Instead, the interconnection can be done directly on the control electronics circuit board.

[0027] The pocket element is preferably designed in such a way that the pocket is not deformed as much as possible during winding and thus only the smallest possible tilting of the contact element occurs due to a significant deformation of the pocket element.

[0028] Particularly advantageously, individual pocket elements have clamping elements for clamping the start and end wires. Short description of the drawings

[0029] Embodiments of the invention will be described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 is a schematic diagram of an electric motor according to an embodiment of the invention, Fig. 2 a schematic view of a first variant of a contact element of the stator of the electric motor according to the embodiment of the invention, Fig. 3 a schematic view of a second variant of a contact element of the stator of the electric motor according to the embodiment of the invention, Fig. 4 a schematic view of the second variant of the contact element of the stator of the electric motor according to the embodiment of the invention when contacting a coil wire, Fig. 5 a schematic illustration of a partial area of ​​the electric motor according to the embodiment of the invention, Fig. 6 a schematic detailed view of the stator of the electric motor according to the embodiment of the invention, Fig. 7 is a schematic view of a first variant of a pocket element of the stator of the electric motor according to the embodiment of the invention, Fig. 8 is a schematic view of a second variant of a pocket element of the stator of the electric motor according to the embodiment of the invention, and Fig. 9 several contact elements after a first punching process. Embodiments of the invention

[0030] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0031] Fig. Figure 1 shows an electric motor 1 according to an embodiment of the invention. The electric motor 1 has a stator 2 with several windings 3, wherein the Windings 3 have an electrically conductive coil wire 4. In addition, the electric motor 1 has a rotor, which is not shown for the sake of clarity.

[0032] In addition, a circuit element 12 is provided, which is a circuit board. The circuit element 12 or the circuit board has control electronics 21 for controlling the windings 3. The circuit element 12 is also designed to connect the windings 3, in particular by means of corresponding conductor tracks on the circuit board. An additional, intermediate circuit part is not provided. Rather, the coil wires 4 are connected to the circuit element 12 via contact elements 6. Each contact element 6 is arranged in a pocket element 5, through which the coil wire 4 is guided. The circuit element 12 has through-openings 13, through which a contact pin 8 of the contact elements 6 is guided and electrically connected to the circuit element 12.

[0033] The Fig. 2 and Fig. 3 show different variants of the contact element 6. The contact element 6 extends along a longitudinal direction 100 and has, with respect to the longitudinal direction 100, on one side an insulation displacement terminal 7 and on an opposite side the contact pin 8. In Fig. 2, the contact pin 8 is a press-fit pin, in Fig. 3, the contact pin 8 is a solder pin. The insulation displacement terminal 7 is guided within the pocket element 5 to electrically contact the coil wire 4. The insulation displacement terminal 7 has a slot 7b forming cutting edges 7a.

[0034] Between the contact pin 8 and the insulation displacement terminal 7, a first shoulder 10 extending in the transverse direction 200 and a second shoulder 11 formed in the transverse direction 200 opposite the first shoulder 10 are arranged. The two shoulders 10, 11 are located in particular above the slot 7b of the insulation displacement terminal 7 and / or above claw elements 23, with which the contact elements 6 can be clawed into the pocket elements 5.

[0035] The first shoulder 10 is higher in the longitudinal direction 100 than the opposite second shoulder 11. Thus, a first dimension L1 of the first shoulder 10 along the longitudinal direction 100 is smaller than a second dimension L2 of the second shoulder 11 along the longitudinal direction 100. The tangential width of the shoulders 10, 11, i.e. the dimension in the transverse direction 200, is ideally the same. Different tangential widths are also possible. The height of the respective shoulder 10, 11 allows the shoulder geometry of the contact elements 6 to be adapted to the necessary press-in force or the wire diameter of the insulation displacement connection of the insulation displacement connection 7 and the coil wire 4. The contact pin 8 can be arranged symmetrically or asymmetrically between the shoulders 10, 11.

[0036] The outer surfaces 20 of the first shoulder 10 and the second shoulder 11 located on the side of the contact pin 8 form a support surface for the interconnection element 12. Furthermore, it is preferably provided that all outer surfaces 20 are at the same height with respect to the longitudinal direction 100. The interconnection element 12 is easy to install and reliably received. Preferably, all contact pins 8 have one end at the same height with respect to the longitudinal direction 100, so that contacting of the contact pins 8 with the interconnection element 12 is also easy and reliable. Preferably, the electric motor 1 is designed such that a maximum of one of the contact elements 6 deviates from the specification regarding the same height of outer surface 20 and contact pin 8.

[0037] In Fig. Figure 4 shows an example of how electrical and mechanical contact is made with the coil wire 4 using the insulation displacement terminal 7. For contacting using the insulation displacement terminal 7, the coil wire 4 does not need to be stripped; this is done by the insulation displacement terminal 7. The insulation displacement terminal 7 fixes the coil wire 4 above the cutting edge 7a in the slot 7b and below the recess or the slot end.

[0038] The contact elements 6 of the variant according to Fig. 3 and Fig. 4 have, in comparison to the contact elements 6 in the variant of Fig. 2 no claw elements 23 for fixing the contact element 6 in the longitudinal direction 100 in the pocket element 5 above the slot 7b in the insulation displacement terminal 7. The Fig. 2 The tips or hooks shown as claw elements 23 increase the axial clamping force of the contact element 6 in the pocket element 5 in the pressed-in state and prevent movements of the insulation displacement connection of the insulation displacement terminal 7 to the coil wire 4.

[0039] Fig. 5 shows a schematic representation of a partial region of the electric motor 1 according to the exemplary embodiment of the invention. It is provided that each contact element 6 is arranged in a respective pocket element 5, wherein the contact elements 6 establish an insulation displacement connection to the coil wire 4 guided through the respective pocket element 5 by means of the respective insulation displacement connection 7. When the contact element 6 is fully pressed into the pocket element 5, the first shoulder 10 rests against a first end face 14 of the pocket element 5 and the second shoulder 11 rests against a second end face 15 of the pocket element 5. The end faces 14, 15 have different positions with respect to the longitudinal direction 100 in order to be designed to correspond to the different heights of the shoulders 10, 11 of the contact element.

[0040] The Fig. 6 to 8 show schematic detailed views of the pocket elements 5 in different variants. Fig. 6 shows a pocket element 5 with winding 3 and coil wire 4 running through the pocket element 5. This is the state before assembly, i.e., before the contact element 6 is pressed with the insulation displacement terminal 7 side onto the coil wire. The pocket elements 5 are, in particular, injection-molded from PA materials, i.e., polyamide, e.g., PA66 GF30 or PA6 GF35; however, PBT materials, i.e., polybutylene terephthalate, and PEEK materials, i.e., polyetheretherketone, are also possible.

[0041] Each pocket element 5 has a first wall 16 with the first end face 14 and a second wall 17 with the second end face 15, as well as third walls 18 connecting the first wall 16 and second wall 17. The third walls 18 have a guide slot 9 for guiding the coil wire 4 through the pocket element 5, as shown in particular in Fig. 6 shown.

[0042] A wall thickness of the first wall 16 and second wall 17 is at least partially greater, in particular between two and five times greater, than a wall thickness of the third walls 18. This provides sufficient stability, which reduces or prevents deformation of the pocket element 5 and thus the risk of misalignment of the contact element 6. Preferably, insertion bevels 24 are provided, which serve to guide the contact element 6 into the pocket element 5. Preferably, stiffening ribs 25 are also provided.

[0043] The design of the pocket elements 5 is conceived so that the pocket element is not deformed as much as possible during winding of the windings 3 and, ideally, no or only very slight tilting of the contact element 6 occurs due to significant deformation of the pocket element in both the tangential and radial directions during winding. Preferably, the first wall 16 and / or the second wall 17 and / or the third walls 18 have wire guide elements 22 for wrapping the coil wire 4 around the pocket element 5. With a wiring plate, as provided in conventional designs, the pocket wall thickness would be less than half to one-fifth of the wall thicknesses described above.

[0044] In Fig. Figure 8 shows a variant in which the pocket element 5 has a rib 19. The insulation displacement terminal 7 of the contact element 6 is designed to receive the rib 19 in the slot 7b when the contact element 6 is inserted into the pocket element 5. This rib 19 is advantageous for coil wire 4 with a wire diameter ≥0.5 mm.

[0045] If a contact element 6 is inserted into pocket element 5, it is pressed in until the contact element 6 rests with its shoulders 10, 11 on the end faces 14, 15 of the thickened pocket wall areas of the pocket element 5. The slot length of the slot 7b of the insulation displacement terminal 7 and the cutting edge 7a in the slot 7b of the insulation displacement terminal 7 compensate for any tolerances in the longitudinal direction 100 for wire fixation.

[0046] In particular, the contact elements 6 are all located on one plane and have the same distance from a stator center point in order to make the assembly device as simple and cost-effective as possible.

[0047] The contact elements 6 are preferably produced by punching. Fig.9 shows a plurality of contact elements 6 after a first punching process, wherein the shoulders 10, 11 enable optimal connection to the adjacent element. The contact elements 6 can thus be delivered continuously on a strip roll. In this strip form, there is a piece of offcut 6a between the individual contact elements 6, which is removed in a second punching process. The contact element 6 can be processed automatically, e.g. for automated gripping, the contact element 6 can be gripped laterally over a broad surface and for pressing in, a punch is placed from the side of the contact pin 8 onto the shoulders 10, 11 and moved downwards in the longitudinal direction 100 into the pocket element. The pressing-in force is preferably monitored. The interconnection element 12 in the form of a circuit board or printed circuit board can be easily applied to the contact elements 6, in particular the contact pins 8.Depending on the design of the contact pins 8, this is done either by pressing on or soldering.

Claims

[1] Electric motor (1) comprising - a stator (2) with at least one winding (3) having an electrically conductive coil wire (4), - at least one pocket element (5) through which the coil wire (4) is guided, - at least one contact element (6) extending along a longitudinal direction (100) and having, with respect to the longitudinal direction (100), on one side an insulation displacement terminal (7) and on an opposite side a contact pin (8), wherein a first shoulder (10) extending in the transverse direction (200) and a second shoulder (11) formed in the transverse direction (200) opposite the first shoulder (10) are arranged between the contact pin (8) and the insulation displacement terminal (7), - a connection element (12) having at least one through-opening (13) through which the contact pin (8) is guided and electrically connected to the connection element (12), - wherein the insulation displacement terminal (7) is guided within the pocket element (5) in order to electrically contact the coil wire (4), - wherein the first shoulder (10) bears against a first end face (14) of the pocket element (5) and the second shoulder (11) bears against a second end face (15) of the pocket element (5). [2] Electric motor (1) according to claim 1, characterized by that the first shoulder (10) and the second shoulder (11) of the contact element (6) have different dimensions (L1, L2) along the longitudinal direction (100), so that the first end face (14) and the second end face (15) are formed at different locations with respect to the longitudinal direction (100). [3] Electric motor (1) according to one of the preceding claims, characterized by that the contact element (6) has a cutting edge or separating edge, in particular with a ridge, at the outer shoulder ends of the first shoulder (10) and the second shoulders (11) in the transverse direction (200). [4] Electric motor (1) according to one of the preceding claims, characterized by in that the pocket element (5) has a first wall (16) with the first end face (14) and a second wall (17) with the second end face (15) as well as third walls (18) connecting the first wall (16) and second wall (17), wherein a wall thickness of the first wall (16) and / or second wall (17) is at least partially greater, in particular between twice and five times as great, than a wall thickness of the third walls (18). [5] Electric motor (1) according to one of the preceding claims, characterized by that a plurality of pocket elements (5) are provided, wherein a contact element (6) is arranged in each pocket element (5), and wherein pocket elements (5) and / or contact elements (6) arranged adjacently along a circumferential direction of the electric motor (1) are oriented in the same way or in a mirror-inverted manner. [6] Electric motor (1) according to claim 4 or 5, characterized bythat the first wall (16) and / or the second wall (17) and / or the third walls (18) have wire guide elements (22) for wrapping the pocket element (5) with the coil wire (4). [7] Electric motor (1) according to one of claims 4 to 6, characterized by that the third walls (18) have a guide slot (9) to guide the coil wire (4) through the pocket element (5). [8] Electric motor (1) according to one of the preceding claims, characterized by in that the pocket element (5) has a rib (19), wherein the insulation displacement terminal (7) has a slot (7b) forming cutting edges (7a), and wherein the insulation displacement terminal (7) is designed to receive the rib (19) in the slot (7b). [9] Electric motor (1) according to one of the preceding claims, characterized by that the outer surfaces (20) of the first shoulder (10) and the second shoulder (11) located on the side of the contact pin (8) form a support surface for the interconnection element (12). [10] Electric motor (1) according to claim 9, characterized by that in the case of a plurality of contact elements (6), all ends of the contact pins (8) and the outer surfaces (20) of the first shoulder (10) and the second shoulder (11) located on the side of the contact pin (8) are arranged at the same longitudinal level or at the same height in the installed state, with the exception of a maximum of one contact element (6). [11] Electric motor (1) according to one of the preceding claims, characterized by that the contact pin (8) is a press-fit pin or a solder pin. [12] Electric motor (1) according to one of the preceding claims, characterized by that the interconnection element (12) is a circuit board which is electrically connected to the contact pins (8) [13] Electric motor (1) according to claim 7, characterized by that the interconnection element (12) has control electronics (21) for controlling the at least one winding (3).

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