Electric motor and method for manufacturing an electric motor

Abstract

electric motor, comprising a circuit ring and a stator with stator windings, wherein respective end regions (21), in particular end sections, of the stator winding wires of the stator of the electric motor are connected to contact sections (3) of the electrical conductors of a connecting ring, wherein each contact section (3) has grasping arms with which a respective end area (21) can be captured and held securely in a force-fit manner, in particular clamped between the grasping arms, the electrical conductors are designed as stamped and bent parts, wherein each contact section (3) is connected to a respective connecting bridge (2) which is connected to a busbar (80), wherein contact section (3), connecting bridge (2) and busbar (80) are manufactured in one piece, characterized by the fact that the interlocking ring has recesses on its radial outer side, into which respective engagement sections, projecting radially inwards and integrally formed on retaining sections of an end cap, engage, wherein means for snapping and / or clipping the stator winding wires, in particular the end regions (21), are arranged at the holding sections.

Description

[0001] The invention relates to an electric motor and a method for manufacturing an electric motor.

[0002] It is generally known that an electric motor has a stator winding, the end regions of which of the stator winding wires must be interconnected, for example in star connection or delta connection in a three-phase motor or in a suitably suitable connection of the individual tooth windings of a stator designed with wound individual teeth.

[0003] From EP 2139094 A1 a stator with a connection arrangement of an electrical machine is known.

[0004] A switching head for electric motors is known from DE 10 2010 033 699 A1.

[0005] From WO 2011 / 151692 A2 an electrical power distribution unit for a motor is known.

[0006] A melt structure for a motor is known from DE 10 2008 040 732 A1.

[0007] A rotating electric machine is known from US 2003 / 0 201 688 A1.

[0008] The invention is therefore based on the objective of making an electric motor easy and quick to manufacture.

[0009] According to the invention, the problem is solved in the electric motor according to the features specified in claim 1 and in the method according to the features specified in claim 15.

[0010] Important features of the invention in the electric motor are that it has a connecting ring and a stator with stator windings, wherein respective end areas, in particular end sections, of the stator winding wires of the stator of the electric motor are connected to contact sections of the electrical conductors of a connecting ring.

[0011] The advantage here is that it allows for simple and quick production.

[0012] In an advantageous embodiment, each contact section has grasping arms with which a respective end region can be captured and held securely in place, in particular clamped between the grasping arms. It is advantageous that the contact sections can be captured by a rotary movement of the connecting ring and then also connected in a force-fit manner and subsequently by a material bond, in particular by contact welding.

[0013] In an advantageous embodiment, each end region is electrically connected to one or more of the contact arms by means of contact welding. The advantage here is that a thermally stable connection can be achieved without solder.

[0014] In an advantageous embodiment, the electrical conductors are designed as stamped and bent parts, in particular as stamped and bent parts made from copper-containing sheet metal or copper sheet. An advantage of this is the low ohmic losses.

[0015] In an advantageous embodiment, each contact section is connected to a respective connecting bridge, which is connected to a busbar. In particular, the contact section, connecting bridge, and busbar are manufactured as a single piece. An advantage of this design is that the copper conductors can be easily and cost-effectively manufactured as a single stamped and bent component.

[0016] In an advantageous embodiment, the busbars are arranged in recesses, in particular recesses arranged at a constant radial distance, especially grooves, of the connecting ring. It is advantageous that the grooves can be arranged concentrically in the end face of the connecting ring, thus enabling simple manufacturing.

[0017] In a preferred embodiment, the connecting ring is made of plastic, in particular as a plastic injection-molded part. The advantage here is that simple and cost-effective manufacturing is possible.

[0018] In an advantageous embodiment, the stator has a laminated core composed of individual teeth, each of which is wound with a respective stator winding. wherein the stator winding wire of each stator winding has two end sections. An advantage of this is that while a single-tooth winding with many end sections is possible, the invention discloses an effective and inexpensive connection method for this purpose.

[0019] In an advantageous embodiment, the respective connecting web extends, particularly primarily, in a radial direction, and the busbars extend, particularly primarily, in a circumferential direction. It is advantageous that the conductors can be easily manufactured as stamped and bent parts.

[0020] In an advantageous embodiment, the capture area opening created by the capture arms of each contact section is oriented circumferentially. The advantage here is that synchronous capture of all end sections is possible.

[0021] In an advantageous embodiment, the busbars are arranged in four concentrically arranged grooves of the connecting ring. An advantage of this design is that it allows for simple manufacturing by inserting the busbars into the grooves.

[0022] In an advantageous embodiment, the grasping arms are open in a V-shape, U-shape, or C-shape, particularly where the grasping arms form the legs of the V. An advantage of this is that the contact sections are easy to manufacture.

[0023] In an advantageous embodiment, the grooves for receiving the busbars are arranged in the axially oriented end face of the connecting ring. An advantage of this is that potting with potting compound can be carried out in a simple manner.

[0024] Important features of the process for manufacturing an electric motor are that the electric motor has a circuit ring and a stator with stator windings, wherein respective end areas, in particular end sections, of the stator winding wires of the stator of the electric motor are connected to contact sections of a connecting ring, by arranging the end regions in an axial direction, in particular parallel to each other. and then the interconnection ring is rotated relative to the stator, so that the respective end areas enter the respective capture area formed by the grasping arms of the respective contact sections, wherein in a subsequent step the respective end sections are held in a force-fit manner, in particular clamped, by means of the respective grasping arms and are contact welded to the grasping arms of a respective contact section.

[0025] The advantage here is that capturing and contacting are made possible by means of a simple twist.

[0026] In an advantageous embodiment, a relative axial displacement, in particular a reduction of the axial distance, is also carried out before or during the relative rotation with respect to an end cap arranged on the stator lamination stack, so that an axially projecting retaining section with a radially widened head section engages in a corresponding recess on the outer surface of the connecting ring. It is advantageous that a mechanical connection of the connecting ring can be carried out simultaneously with the electrical connection of the contact section to the end regions.

[0027] Further advantages arise from the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, in particular from the problem statement and / or the problem arising from a comparison with the prior art.

[0028] The invention will now be explained in more detail with the help of illustrations: In the Fig. Figure 1 shows an oblique view of a connecting ring according to the invention for an electric motor, with connecting webs 2 only schematically indicated. In the Fig. Figure 2 shows a corresponding top view. In the Fig. Figure 3 shows a side view of another embodiment according to the invention. In the Fig. 4 is in contrast to the Fig. 1 and Fig. Figure 2 shows a wiring configuration executable according to the invention, wherein the connecting sections 2 always extend radially only to the respective assigned busbar 80. The end regions 21 are shown precisely as they enter the capture area of ​​the capture arms. In the Fig. Figure 5 shows the interconnection ring 1 in the state connected to the end cap 51. In the Fig. Figure 6 shows the stator lamination stack 50 with the end cap 51 attached to the axial end region of the stator lamination stack 50, the heads 60 on the retaining sections 61 also being shown, the heads 60 being provided for engaging in the recesses (5, 32). In the Fig. Figure 7 shows the connecting ring 1, with the recesses (5, 32) hidden, i.e., removed. The stamped and bent parts are also hidden, so that the grooves 4 for receiving the busbars 80 of the stamped and bent parts are clearly visible. Recesses 71 are visible at the axially upper edge region; these are regularly spaced from one another in the circumferential direction and are provided for determining the circumferential angular position of the stamped and bent parts by allowing the connecting sections 2 of the stamped and bent parts to be inserted into the recesses 71. In the Fig. Figure 8 shows an enlarged section of the interconnection ring 1, so that the tab-like contact sections 3 with the V-shaped arranged grasping arms are visible in enlarged detail. In the Fig. 9 is an alternative to the interconnection ring 1 of the Fig. 5 shown.

[0029] As in Fig. As shown in Figure 1, the connecting ring has a receiving part 1 made of plastic. Circular, coaxially aligned grooves 4 are arranged on its axially upper side, in which busbars can be received.

[0030] Connecting webs 2, spaced regularly apart in the circumferential direction, are arranged at the same radial distance. Each connecting web 2 is electrically connected to a respective busbar, in particular in one piece, with the connection being in Fig. 1 is not shown.

[0031] At the end of the respective connecting web 2 facing away from the respective busbar, a V-shaped bent, tab-shaped contact section 3 is electrically connected, in particular in one piece.

[0032] Preferably, the connecting webs 2 with the contact sections 3 and busbars are manufactured as a multi-piece stamped-bent part, i.e., as several stamped-bent parts.

[0033] The respective stamped and bent parts are inserted into the respective grooves 4 of the receiving part 1 and potted with potting compound, thus forming a material bond with the receiving part 1.

[0034] On the outer circumference of the receiving part, regularly spaced recesses 5, in particular radially directed depressions, are arranged in the circumferential direction, with which a connection of the interconnection ring to the stator can be carried out.

[0035] For this purpose, the stator has an end cap with retaining sections arranged at regular intervals around the circumference, each at the same radial distance from the rotor shaft axis. The head of each retaining section, which is wider in the radial direction, engages in a corresponding recess 5. When connected to the connecting ring, the retaining sections are slightly deflected in the radial direction, so that a radially directed elastic restoring force presses the heads into the recesses.

[0036] The recesses 5 are identical in design and have the same depth in the radial direction. They extend from the edge of the interlocking ring first in the axial direction and then also in the circumferential direction.

[0037] Therefore, when connecting the connecting ring to the end cap of the stator, a shift in the axial direction and a subsequent rotation in the circumferential direction must be performed.

[0038] The stator has a stator lamination stack which has individual teeth, each of which is provided with a stator winding.

[0039] The associated end regions 21 of the stator winding wire are oriented in an axial direction, as shown in Fig. Figure 2 shows that the end regions 21 are essentially parallel to each other and arranged at the same radial distance from the rotor shaft axis. They are also regularly spaced apart from each other in the circumferential direction.

[0040] In this way, a quick and simple electrical connection of the end sections 21 to the contact sections 3 is now possible, by capturing the end sections 21 in the inner area enclosed by the contact section when the connecting ring is rotated relative to the end cap, specifically in the inner area enclosed by the V of the V-shaped contact section. The respective contact section thus threads the respective end section 21 into place until it reaches the connection position at the inner tip of the V. Once the rotation is complete, a contact welding connection is made. For this purpose, the respective legs of the contact section, i.e., the contact section's arms, are first pressed together by bending them accordingly until the end section is held securely, in particular clamped, by the contact section's arms.Then contact welding is carried out so that the electrical connection between end area 21 and contact section can be made without solder.

[0041] The recesses 5 therefore have an L-shaped profile, so that the axial insertion must be carried out first and then the rotation.

[0042] In this way, a mechanical connection between the interconnection ring and the stator, in particular the end cap, can be achieved through a single process step of twisting, and the end areas can be captured by means of the respective associated contact sections, so that contact welding can be carried out in a simple manner.

[0043] Instead of a V, a U or C can also be used.

[0044] The interconnection ring 1 spans a ring plane whose normal is the axial direction, this normal direction being aligned parallel to the rotor axis. The circumferential direction runs along the ring, whose maximum radial distance is constant depending on the circumferential direction.

[0045] As in Fig. As shown in Figure 4, the connecting sections 2 extend radially outwards, i.e., from the transition to the respective contact section 3, radially inwards to the radial position of the busbar 80 to be contacted. The connecting ring 1 has already been rotated to such an extent that the end regions 21 are already within the capture area of ​​the V-shaped capture arms of the contact section 3.

[0046] As in Fig. As shown in Figure 5, the end cap 51 is placed on the axial end region of the stator lamination stack 50, which is wound with individual tooth windings. The end regions 21 are each located within the capture area of ​​the V-shaped grasping arms of the contact section 3, specifically almost at the apex of the V. In the subsequent process step, the grasping arms are moved towards each other, thus clamping the respective end region 21 between them. Contact welding can then be carried out, which requires no solder and creates a metallurgical electrical connection that can be used up to high operating temperatures.

[0047] As in Fig. As shown in Figure 6, the retaining sections 61, which are formed in one piece on the end cap 51, have radially inward projecting heads or pins which are provided as engagement sections, i.e. sections for engaging in the recesses (5, 32) on the radial outer wall of the interconnection ring 1.

[0048] To improve the connection between the end cap 51 and the connecting ring 1, adhesive is applied in the area of ​​the recesses (5, 32) so that the heads 60 are bonded together.

[0049] Fig. Figure 7 is shown without recesses 5 or 32, but can have both. The contact sections 3 rest on the recesses 71 and are thus defined in their circumferential angular position. The recesses 71 are arranged on the axially upper side of the interconnection ring 1, i.e., on the axial side facing away from the stator lamination stack 50.

[0050] As in Fig. As shown in Figure 8, the connecting section 2 extends radially to the respective associated busbar 80. For example, the front connecting section 2 extends radially to the second busbar 80, counting from the radial inside, and the one in Fig. The section 8 shown at the rear extends radially to the fourth busbar 80, counting radially from the inside. The busbars 80 are connected either to the three-phase current R, S, T or to the neutral conductor.

[0051] The electric motor can be operated as a preferably inverter-fed three-phase motor.

[0052] In a further embodiment according to the invention, instead of engaging the heads 60 in recesses (5, 32) and adhesively joining them, it is alternatively possible to clip the heads in or snap the heads into corresponding areas of the interconnection ring.

[0053] In a further embodiment of the invention, the recess 5 in the receiving part 1 has a screw-like shape instead of the L-shaped shape. This allows for simultaneous axial sliding and rotation, i.e., a screw motion, when connecting the connecting ring to the stator. [Figure 1] Fig. 3 a receiving part 31, in particular made of plastic, which is connected to the receiving part 1 made of Fig. 1 is identical except for the screw-like recesses 32, i.e., depressions, which correspond to the L-shaped depressions of the embodiment according to Fig. Replace 1. In this sense, the figure description for the other figures also refers to the curve 32, which can be used as an alternative to the L-shaped depression curve 5.

[0054] In a further embodiment of the invention, the respective end section 21 is held on the retaining section 61 by a clip connection. For this purpose, the retaining section has a corresponding receptacle that can be elastically deflected when the winding wire is inserted, so that a positive locking hold of the end section 21 is achieved after insertion.

[0055] As in Fig. Figure 9 shows that the outer and inner walls (91, 93) are higher in the axial direction than the intermediate walls 92. Thus, the potting compound is limited by the inner and outer walls (91, 93) and does not flow radially inwards or outwards before hardening.

[0056] The walls (91, 92, 93) each define the grooves 4. Preferably, the interlocking ring 1 is manufactured by plastic injection molding and the grooves are thus created by the injection molding process and therefore do not need to be machined.

[0057] To fix, and in particular limit, the connecting webs 2 in the circumferential direction, axially projecting, hump-like elevations 90 are arranged on the intermediate walls 92. These can be easily manufactured by injection molding. In addition, recesses 71 are also provided so that a connecting web 2 can also be fixed that is connected to the radially outermost busbar 80 and thus does not extend over an intermediate wall 92. Reference symbol list 1 Receiving part, especially made of plastic 2 connecting bridge 3 Contact section, tab-shaped 4 grooves for mounting the busbars 80 5. Recess, in particular deepening 21 End area of ​​a respective stator winding wire 31 Receiving part, especially made of plastic 32. Recess, in particular deepening 50 stator lamination stack 51 End cap 60 Head, Intervention Section 61 stopping sections 71 Recess, depression 80 busbar 90 elevations, hump-like elevations in the circumferential direction 91 outer wall 92 Partition wall 93 inner wall

Claims

Electric motor comprising a connecting ring and a stator with stator windings, wherein respective end regions (21), in particular end sections, of the stator winding wires of the stator of the electric motor are connected to contact sections (3) of the electrical conductors of a connecting ring, wherein a respective contact section (3) has grasping arms with which a respective end region (21) can be grasped and held securely, in particular clamped between the grasping arms, wherein the electrical conductors are designed as a stamped-bent part, wherein a respective contact section (3) is connected to a respective connecting web (2) which is connected to a busbar (80), wherein contact section (3), connecting web (2) and busbar (80) are designed in one piece, characterized in that the connecting ring has recesses on its radial outer side into which respective radially inwardly projectingintegrally formed engagement sections engage on the retaining sections of an end cap, wherein means for snapping and / or clipping the stator winding wires, in particular the end regions (21), are arranged on the retaining sections. Electric motor according to claim 1, characterized in that a respective end region (21) is electrically connected by means of contact welding to one or the grasping arms of the contact section (3). Electric motor according to at least one of the preceding claims, characterized in that the stamped-bent part is manufactured as a stamped-bent part made from a copper-containing sheet or copper sheet. Electric motor according to at least one of the preceding claims, characterized in that the busbars (80) are arranged in recesses, in particular recesses arranged at constant radial spacing, in particular grooves, of the connecting ring. Electric motor according to at least one of the preceding claims, characterized in that the interconnection ring is made of plastic, in particular as a plastic injection molded part. Electric motor according to at least one of the preceding claims, characterized in that the engagement sections are materially bonded and / or form-fitted and / or clipped to the connecting ring. Electric motor according to at least one of the preceding claims, characterized in that the locking means or clipping means are integrally formed with the retaining sections and / or the end cap. Electric motor according to at least one of the preceding claims, characterized in that recesses for receiving and / or for positively connecting a respective contact section (3) at least in the circumferential direction are arranged on the connecting ring, in particular for determining the circumferential angle position of a respective contact section (3). Electric motor according to at least one of the preceding claims, characterized in that the stator has a laminated core composed of individual teeth, wherein the individual teeth are each wound with a respective stator winding, wherein the stator winding wire of each stator winding has two end regions (21). Electric motor according to at least one of the preceding claims, characterized in that the respective connecting web (2) extends, in particular primarily, in the radial direction and that the busbars (80) extend, in particular primarily, in the circumferential direction. Electric motor according to at least one of the preceding claims, characterized in that the capture area opening generated by the capture arms of each contact section (3) is oriented in the circumferential direction. Electric motor according to at least one of the preceding claims, characterized in that the busbars (80) are arranged in four concentrically arranged grooves (4) of the connecting ring. Electric motor according to at least one of the preceding claims, characterized in that the grasping arms are V-shaped or U-shaped or C-shaped, in particular wherein the grasping arms form the legs of the V. Electric motor according to at least one of the preceding claims, characterized in that the grooves (4) for receiving the busbars (80) are arranged in the axially directed end face of the connecting ring. A method for manufacturing an electric motor according to at least one of the preceding claims, wherein the electric motor comprises a connecting ring and a stator with stator windings, wherein the connecting ring has recesses on its radial outer side into which respective engagement sections, projecting radially inwards and integrally formed on retaining sections of an end cap, engage, in particular and are materially bonded and / or positively bonded and / or clipped together, wherein respective end regions (21), in particular end sections, of the stator winding wires of the stator of the electric motor are connected to contact sections (3) of a connecting ring by arranging the end regions (21) in an axial direction, in particular parallel to each other, and then rotating the connecting ring relative to the stator so that the respective end regions (21) enter the respective capture area formed by the grasping arms of the respective contact sections.wherein in a subsequent step the respective end sections are held in a force-fit manner, in particular clamped, by means of the respective grasping arms and are contact-welded to the grasping arms of a respective contact section (3), wherein before or during the relative rotation a relative axial displacement, in particular a reduction of the axial distance, to an end cap arranged on the stator lamination stack (50) is also carried out, so that an axially projecting holding section with a radially widened head section engages in a corresponding recess on the outer surface of the interconnection ring.

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