Electric motor, comprising stator windings encased in potting compound

Abstract

electric motor comprising stator windings, wherein an end region of a stator winding wire of the stator windings is electrically connected to a rail part (1), namely by welding, wherein the rail part (1) encased in potting compound has a bent, in particular upward-bent, tab (2) which protrudes from the potting compound, wherein an electrical supply line is electrically connected to the tab (2), namely by welding, wherein the rail part (1) has at least one slot opening in the edge region of the rail part (1) as a recess (3) to which a respective stator winding wire end region is electrically connected, wherein the recess (3) or recesses (3) are arranged on the radial inside of the rail part (1), wherein the rail part (1) is formed in the shape of a circular ring segment, wherein the tab (2) is bent out of the plane of the circular ring in the rotor axis direction, in particular bent upwards, where the normal direction of the plane is parallel to the rotor axis of the electric motor, the stator windings are encased in potting compound, wherein the tab (2) is oriented in the axial direction, i.e. parallel to the rotor axis of the motor, and the remaining rail part (1) in the circumferential direction, wherein several identical rail parts (1) are arranged in the potting compound, wherein each rail section (1) has a respective tab (2) bent out of the plane of curvature of the curved rail section (1), wherein the respective tabs (2) are arranged circumferentially offset from each other and protrude from the potting compound surrounding the stator windings, the potting compound is thermally conductive and electrically insulating, wherein three stator winding wires are electrically connected to the rail part (1), thereby creating a connection of the stator winding wires, namely a star point connection of three stator windings (U, V, W), wherein the rail part (1) is made of copper-containing material, in particular copper, the electrical supply line is siliconized, wherein the electrical supply line is welded to the upturned tab (2).

Description

[0001] The invention relates to an electric motor having stator windings encapsulated with potting compound.

[0002] It is known that the end portions of 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 arcuately curved busbar arrangement is disclosed for connecting the windings.

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

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

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

[0007] EP 1 921 635 A1 discloses an electrical connection cable for an electrical unit of a motor vehicle.

[0008] From JP 2000 - 333 400 A, an interconnection ring with recesses for connecting stator winding wires is known.

[0009] From US 2010 / 0187918 A1 a stator with connecting cables cast in the winding head area is known. DE 10 2009 020 610 A1 also shows an interconnection ring.

[0010] The invention is therefore based on the object of developing an electric motor with regard to its stator contact in a manner that can be produced simply and cost-effectively.

[0011] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0012] Important features of the invention in the device and a method are that the electric motor has stator windings encapsulated with potting compound, wherein, for contacting the stator windings, an end region of a stator winding wire is electrically connected to a rail part, in particular crimped, welded, soldered, screwed and / or riveted, wherein the rail part cast in casting compound has a bent, in particular upwardly bent, tab which protrudes from the casting compound,

[0013] An advantage here is that electrical contact can even be made with a supply line insulated with silicone. This is because the silicone is not subjected to thermal stress, which could cause it to spread and soil the housing or contaminate the potting compound. This ensures a secure electrical connection. Furthermore, the remaining rail section is potted, thus protecting it from corrosion and also surrounded by the heat-dissipating potting compound. This allows very high currents to pass through the rail section.

[0014] According to the invention, an electrical supply line is electrically connected to the tab, in particular by crimping, welding, soldering, screwing, and / or riveting. This is advantageous in that a simple and cost-effective connection technology can be used and high currents can be conducted.

[0015] In an advantageous embodiment, two or more stator winding wires are electrically connected to the rail part, in particular by crimping, welding, soldering, screwing, and / or riveting. This advantageously allows for interconnection of the stator winding wires, for example, including a star point connection of the three stator windings U, V, and W.

[0016] According to the invention, the rail part has at least one recess, in particular at least one slot opening into the edge region of the rail part, for electrical connection to a respective stator winding wire end region. This is advantageous in that a particularly simple connection is possible, since the end region can be threaded into the slot and then connected, for example, by welding or crimping.

[0017] According to the invention, the rail part is curved, in particular arcuately curved, with the tab protruding from the plane of curvature. Advantageously, the rail part can be surrounded by casting compound, with the tab protruding from the casting compound.

[0018] According to the invention, the recess(es) are arranged on the radial inner side of the rail part. This allows for particularly simple contacting, as the rail part can be arranged at a large radial distance and thus far away from the motor rotor.

[0019] According to the invention, the tab is oriented in the axial direction, i.e., parallel to the rotor axis of the motor, and the remaining rail section is oriented in the circumferential direction. This is advantageous because the contact can be made in the axial direction.

[0020] According to the invention, several similar rail parts are arranged in the potting compound, with the respective tabs being offset from one another in the circumferential direction and protruding from the potting compound surrounding the stator windings. In particular, each rail part has a tab bent out from the plane of curvature of the curved rail part. This is advantageous in that it enables space-saving contacting, i.e., requiring only a small amount of installation space.

[0021] According to the invention, the rail part is designed in the shape of a circular ring, with the tab being bent out of the plane of the circular ring, in particular bent upwards. Advantageously, the rail part can be manufactured as a stamped and bent part or as a cast part, and the tab can be bent out or formed by casting.

[0022] In an advantageous embodiment, the rail part is a stamped and bent part. This allows for cost-effective production.

[0023] According to the invention, the rail part is made of copper-containing material, in particular copper. The advantage here is that low ohmic losses occur.

[0024] In an advantageous embodiment, the casting compound is thermally conductive and electrically insulating. This is advantageous because the rail component can be subjected to high currents.

[0025] In an advantageous embodiment, the rail section is designed to permanently conduct more than 100 amperes, in particular more than 400 amperes. This is advantageous because it allows for high currents to be conducted.

[0026] 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.

[0027] The invention will now be explained in more detail using schematic illustrations: In the Fig. 1 shows a rail part 1 which is bent in a semicircle shape and has a tab 2 which is bent upwards from the plane of the semicircle.

[0028] In addition, recesses 3 spaced apart from one another are arranged in the circumferential direction of the semicircle on the rail part 1.

[0029] The rail part is used for stator contact in an electric motor. The stator winding wires are brought to the rail part 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 the stator winding U, V and / or W, can be connected to the rail part 1.

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

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

[0033] The stator winding of the electric motor is encapsulated with an electrically insulating potting compound. The rail section 1, including the electrical connection areas with the stator winding wires, is also encapsulated, but the raised tab 2 protrudes from the potting compound. This allows for electrical contact with the tab 2 even after encapsulation.

[0034] Heat, for example from the stator winding or ohmic heat generated in the rail part 1 or at the connection points, can also be dissipated via the casting compound to the stator laminated core in which the stator winding is provided.

[0035] The electrical supply cable can thus be implemented with a silicon coating. This is because no disruptive evaporating silicone is present during the potting process, and / or the evaporating silicone does not interfere with the potting compound insulation when welding the electrical supply cable to the upturned tab 2.

[0036] Preferably, the rail part 1 is made of copper-containing material, in particular copper. List of reference symbols 1 rail section 2 tabs 3 recess

Claims

[1] Electric motor, comprising stator windings, wherein an end region of a stator winding wire of the stator windings is electrically connected to a rail part (1), namely welded, wherein the rail part (1) encapsulated by casting compound has a bent, in particular upwardly bent, tab (2) which protrudes from the casting compound, wherein an electrical supply line is electrically connected to the tab (2), namely welded, wherein the rail part (1) has at least one slot opening into the edge region of the rail part (1) as a recess (3), to which a respective stator winding wire end region is electrically connected, wherein the recess (3) or the recesses (3) are arranged on the radial inside of the rail part (1), wherein the rail part (1) is designed in the shape of a circular ring, wherein the tab (2) is bent out of the plane of the circular ring in the direction of the rotor axis, in particular bent upwards, where the normal direction of the plane is parallel to the rotor axis of the electric motor, where the stator windings are encapsulated with potting compound, wherein the tab (2) is oriented in the axial direction, i.e. parallel to the rotor axis of the motor, and the remaining rail part (1) in the circumferential direction, wherein several similar rail parts (1) are arranged in the casting compound, wherein each rail part (1) has a respective tab (2) bent out of the plane of curvature of the curved rail part (1), wherein the respective tabs (2) are arranged offset from one another in the circumferential direction and protrude from the casting compound surrounding the stator windings, the casting compound is thermally conductive and electrically insulating, wherein three stator winding wires are electrically connected to the rail part (1), whereby a connection of the stator winding wires is carried out, namely a star point connection of three stator windings (U, V, W), wherein the rail part (1) is made of copper-containing material, in particular copper, the electrical supply cable is siliconized, wherein the electrical supply line is welded to the bent-up tab (2). [2] Electric motor according to claim 1, 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. [3] Electric motor according to claim 1 or 2, characterized bythat 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.

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