Electric motor, comprising stator windings encased in potting compound

Abstract

Electric motor, comprising stator windings encased in potting compound, wherein each stator winding is assigned a rail section (1), wherein, for the purpose of contacting the stator windings, an end region of each stator winding wire of the respective stator winding is electrically connected to the associated rail part (1), in particular by crimp connection, weld connection, solder connection, screw connection and / or connection by means of a rivet, wherein each rail part (1) encased in potting compound has a bent, in particular upward-bent, tab (2) which protrudes from the potting compound, wherein the tabs of the rail parts (1) of the respective stator windings are arranged offset from each other in the circumferential direction, in particular spaced apart from each other in the circumferential direction, wherein the rail parts (1) are arranged axially spaced apart from each other, wherein the end regions of the winding wires are contacted at different axial positions, wherein the rail part (1) has recesses (3) to which a stator winding wire end area is electrically connected, characterized by the fact that the recesses (3) are arranged on a radial inside of the rail part (1), wherein the rail parts (1) are at a smaller radial distance than the winding head (23) and are thus protected by it and the associated stator housing.

Description

[0001] The invention relates to an electric motor comprising stator windings encased in potting compound.

[0002] It is known that the end sections of the stator winding wires of an electric motor are connected to electrical supply lines.

[0003] From DE 11 2008 001 219 T5 an electric motor for a hybrid vehicle is known in which an arc-shaped curved busbar arrangement is disclosed for connecting the windings.

[0004] From FR 2 837 993 A1, a stator is known as the closest prior art in which connecting parts designed as a busbar are each provided in the same axial range.

[0005] An actuator for a wheel control system is known from EP 0 667 279 A1.

[0006] An electric motor is known from DE 10 2004 036 368 A1.

[0007] The invention is therefore based on the objective of further developing an electric motor with regard to its stator contacting in a simple and cost-effective manner.

[0008] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0009] A key advantage is that electrical contact can even be made using a supply line insulated with silicone. This is because the silicone is not subject to thermal stress, preventing it from spreading and potentially soiling the housing or contaminating the potting compound. This ensures a reliable electrical connection. Furthermore, the remaining rail section is potted, protecting it from corrosion and surrounded by the heat-dissipating potting compound. This allows for the conduction of very high currents through the rail section. The circumferential offset provides particularly easy contacting, as ample space is available for the connection.

[0010] According to the invention, the rail sections are arranged axially spaced apart from one another. An advantage of this is that simple assembly and a large insulation distance can be maintained.

[0011] In an advantageous embodiment, the axial area covered by the rail sections at least partially overlaps the area covered by a winding head, particularly a deflection area, of a stator winding. The advantage here is that no additional axial installation space is required, and the contact areas are located at a smaller radial distance than the winding head and are thus protected by it and the associated stator housing. This also increases safety.

[0012] In an advantageous embodiment, an electrical supply line is electrically connected to the tab, in particular by crimp connection, welding connection, soldering connection, screw connection and / or by means of a rivet. The advantage here is that a simple and cost-effective connection technique can be used and high currents can be conducted.

[0013] In an advantageous embodiment, two or more stator winding wires are electrically connected to the busbar section, in particular by crimp connection, welding connection, soldering connection, screw connection and / or by means of a rivet. An advantage of this is that the stator winding wires can be interconnected, for example, a star point connection of the three stator windings U, V, W.

[0014] In an advantageous embodiment, the rail section has at least one recess, in particular at least one slot opening into the edge region of the rail section, for electrical connection to each stator winding wire end. The advantage here is that a particularly simple connection is enabled, since the end section can be threaded into the slot and then connected, for example by welding or crimping.

[0015] In an advantageous embodiment, the rail section is curved, in particular arc-shaped, with the tab projecting out of the plane of curvature. It is advantageous that the rail section can be surrounded with potting compound, with the tab protruding from the potting compound.

[0016] According to the invention, the recess(s) are arranged on the radial inner side of the rail section. An advantage of this is that particularly simple contacting is possible, since the rail section can be arranged at a large radial distance and thus far away from the motor rotor.

[0017] In an advantageous embodiment, the tab is oriented axially, i.e., parallel to the rotor axis of the motor, and in particular the remaining rail section is oriented circumferentially. An advantage of this is that contact can be made in the axial direction.

[0018] In an advantageous embodiment, several identical rail sections are arranged in the potting compound, wherein the respective tabs are arranged offset from each other in the circumferential direction and protrude from the potting compound surrounding the stator windings.

[0019] In particular, each rail section has a tab bent outwards from the plane of curvature of the curved rail section. An advantage of this is that it enables a space-saving contact that requires very little installation space.

[0020] In an advantageous embodiment, the rail section is formed in the shape of a circular segment, with the tab bent out of the plane of the circular ring, in particular bent upwards. It is advantageous that the rail section can be manufactured as a stamped-bent part or as a cast part, and that the tab can be bent out or formed by casting.

[0021] In a favorable design, the rail component is a stamped and bent part. The advantage here is that cost-effective manufacturing is possible.

[0022] In a preferred embodiment, the rail section is made of copper-containing material, in particular copper. An advantage of this is the low ohmic losses.

[0023] In a preferred embodiment, the potting compound is thermally conductive and electrically insulating. A further advantage is that the rail section can withstand a high current.

[0024] In an advantageous embodiment, the rail section is designed to permanently conduct more than 100 amperes, in particular more than 400 amperes. The ability to conduct high currents is advantageous in this case.

[0025] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0026] The invention will now be explained in more detail using schematic illustrations: In the Fig. Figure 1 shows a rail section 1 that is bent in a semicircle and has a tab 2 bent upwards out of the plane of the semicircle.

[0027] In the Fig. Figure 2 shows a cross-section through a section of the electric motor.

[0028] Furthermore, spaced-apart recesses 3 are arranged in the circumferential direction of the semicircle on the rail section 1.

[0029] The rail section is used for stator contact in an electric motor. The stator winding wires are brought to the rail section 1, preferably to its recesses 3, and electrically connected, for example by crimping, welding, soldering, screwing and / or riveting.

[0030] Several winding wires, for example of the stator winding U, V and / or W, can be connected to the rail section 1.

[0031] In this way, an electrical connection of two stator winding wires is made possible.

[0032] The connection of an electrical supply line is made possible by connecting it to the tab. Here, the electrical supply line is again connected to tab 2 by crimping, welding, soldering, screwing, and / or riveting, as examples.

[0033] The stator winding of the electric motor is potted with an electrically insulating potting compound. The rail section 1, including the electrical connection areas with the stator winding wires, is also potted, but the bent-up tab 2 protrudes from the potting compound. This ensures that electrical contact via tab 2 is possible even after potting.

[0034] The potting compound also allows heat, for example from the stator winding or ohmic heat generated in the rail section 1 or at the connection points, to be dissipated to the stator lamination stack in which the stator winding is provided.

[0035] The electrical supply line can therefore be installed using a silicone sealant. This is because, during the potting process, no interfering silicone evaporates, and / or when welding the electrical supply line to the bent-up tab 2, the evaporating silicone does not interfere with the potting compound insulation.

[0036] Preferably, the rail part 1 is made of copper-containing material, in particular copper.

[0037] As in Fig. As shown in Figure 2, the motor has a shaft 20, in particular a rotor shaft, on which a rotor lamination stack 21 is arranged. The rotor shaft is mounted in a housing 24, which protects the stator lamination stack 22 by forming a housing.

[0038] The stator windings are arranged in the stator lamination stack 22, with their respective winding heads 23 projecting axially out of the stator lamination stack 22 and connected to Fig. 2 are cast with potting compound not shown.

[0039] The end sections of the stator winding wires are guided onto the rail sections 1, each of whose upwardly bent tabs 2 project axially in the rotor axis direction. Fig. 2 shows a prominent tab 2 for this purpose.

[0040] Preferably the tabs 2 of the other rail parts 1 are designed in the same way and the rail parts 1 are arranged offset from each other in the circumferential direction, so that the tabs 2 protrude from the potting compound at different angular ranges in the circumferential direction and can thus be easily contacted there and well spaced apart from each other.

[0041] The rail sections are therefore spaced apart from each other in the axial direction, so that the end areas of the winding wires are contacted at different axial positions.

[0042] The end regions of the stator winding wires and the rail parts 1 with tabs 2 are arranged in the axial region in which the protruding winding heads 23 extend, being arranged at a smaller radial distance than the winding heads.

[0043] The potting compound, which is positioned between the stator winding and the busbars, is electrically insulating and conducts heat from the busbars and / or the stator winding to the motor's stator housing. Thus, the potting compound improves not only mechanical stability against vibrations but also heat dissipation. List of reference symbols 1 rail section 2 tabs 3 Exclusion 20 Wave 21 Rotor lamination package 22 Stator lamination stack 23 winding head

Claims

[1] Electric motor, having stator windings encapsulated with potting compound, wherein each stator winding is assigned a rail part (1), wherein, for contacting the stator windings, an end region of a respective stator winding wire of the respective stator winding is electrically connected to the associated rail part (1), in particular crimped, welded, soldered, screwed and / or connected by means of a rivet, wherein each rail part (1) encapsulated by casting compound has a bent, in particular upwardly bent, tab (2) which protrudes from the casting compound, wherein the tabs of the rail parts (1) of the respective stator windings are arranged offset from one another in the circumferential direction, in particular spaced apart from one another in the circumferential direction, wherein the rail parts (1) are arranged axially spaced from one another, wherein the end regions of the winding wires are contacted at different axial positions, wherein the rail part (1) has recesses (3) to each of which a stator winding wire end region is electrically connected, characterized by , that the recesses (3) are arranged on a radial inner side of the rail part (1), wherein the rail parts (1) are surrounded at a smaller radial distance than the winding head (23) and are thus protected by the latter and the associated stator housing. [2] Electric motor according to claim 1, characterized bythat the axial region covered by the rail parts (1) at least partially covers the region covered by a winding head (23), in particular a deflection region, of a stator winding, in particular at least partially covers the region covered by winding heads (23), in particular a deflection region, of the stator windings. [3] Electric motor according to at least one of the preceding claims, characterized by that an electrical supply line is electrically connected to the tab (2), in particular crimped, welded, soldered, screwed and / or connected by means of a rivet. [4] Electric motor according to at least one of the preceding claims, characterized by that two or more stator winding wires are electrically connected to the rail part (1), in particular crimped, welded, soldered, screwed and / or connected by means of a rivet. [5] Electric motor according to at least one of the preceding claims, characterized by that the recesses (3) are each designed as a slot opening into the edge region of the rail part (1). [6] Electric motor according to at least one of the preceding claims, characterized by that the rail part (1) is curved, in particular curved in an arc shape, wherein the tab (2) protrudes from the plane of curvature. [7] Electric motor according to at least one of the preceding claims, characterized by that the tab (2) is oriented in the axial direction, i.e. parallel to the rotor axis of the motor, in particular and the remaining rail part (1) in the circumferential direction. [8] Electric motor according to at least one of the preceding claims, characterized bythat several similar rail parts (1) are arranged in the casting compound, wherein the respective tabs are arranged offset from one another in the circumferential direction and protrude from the casting compound surrounding the stator windings, in particular wherein each rail part (1) has a tab (2) bent out of the plane of curvature of the curved rail part (1). [9] Electric motor according to at least one of the preceding claims, characterized by that the rail part (1) is designed in the shape of a circular ring section, wherein the tab (2) is bent out of the plane of the circular ring, in particular bent upwards. [10] Electric motor according to at least one of the preceding claims, characterized by that the rail part (1) is a stamped and bent part or is manufactured in one piece as a cast part together with the upwardly bent tab (2), in particular wherein a very high current intensity can be conducted in the bending area. [11] Electric motor according to at least one of the preceding claims, characterized by that the rail part (1) is made of copper-containing material, in particular copper. [12] Electric motor according to at least one of the preceding claims, characterized by that the casting compound is thermally conductive and electrically insulating. [13] Electric motor according to at least one of the preceding claims, characterized by that the rail part (1) is designed to be suitable for the permanent conduction of more than 100 amperes, in particular more than 400 amperes.

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