Method for electrically contacting at least one enameled copper wire with a component and electric machine

Abstract

The invention relates to a method for electrically contacting at least one enamelled copper wire forming a winding carried by a first component (1) with a second component of an electric machine, generator, sensor or electromagnet, the method having the following steps: a) shaping at least one wire end (2) of the at least one enamelled copper wire to an electrical contact (3, 6, 8); b) positioning the electrical contact (3, 6, 8) in a shaping process, wherein a moulding compound (4) formed in the shaping process at least partially surrounds the first component (1) and the at least one wire end (2); c) bringing the electrical contact (3, 6, 8) into contact with the second component.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for electrically contacting at least one enameled copper wire with a component of an electric machine, generator, sensor or electromagnet, in particular by means of an electrical contact formed on the end of the enameled copper wire and an additional potting, and to an electric machine. BACKGROUND

[0002] In electrically contacting enameled copper wires arranged in a winding with a component of an electric machine, generator, sensor or electromagnet, it is known to insert a contact plug or to solder or weld the wire end. SUMMARY

[0003] It is the task of the invention to simplify and to carry out the electrical contacting in a process-reliable manner.

[0004] This task is solved by a method for electrically contacting at least one enameled copper wire with a component of an electric machine, generator, sensor or electromagnet having the features of the invention and by an electric machine having the features of the invention.

[0005] The term "enameled copper wire" is to be understood as a wire made of a copper alloy, which is surrounded by an electrically insulating enamel layer.

[0006] Thereby a method for electrically contacting at least one enameled copper wire with a second component of an electric machine, generator, sensor or electromagnet is proposed, the enameled copper wire forming a winding carried by a first component, the method having the following steps:

[0007] a) shaping at least one wire end of the at least one enameled copper wire to an electrical contact,

[0008] b) positioning the electrical contact in a shaping process, wherein a molding compound formed in the shaping process at least partially surrounds the first component and the at least one wire end,

[0009] c) contacting the electrical contact with the second component.

[0010] Thus, the contacting is particularly simple and space-saving. Furthermore, the heat can be dissipated efficiently by the molding compound formed in the shaping process. Furthermore, the winding wire is preferably heated in the shaping process, which is accompanied by a removal of the insulation layer of the wire, so that a process for removing the insulation can be saved.

[0011] The shaping process can be injection molding, classic potting, vacuum potting, but also transfer molding.

[0012] The electrical contact is preferably a plug-in contact. The plug-in contact is preferably a press-fit contact. However, it is also possible to use a round plug, a flat plug or another profile for electrical contacting inserted into the second component.

[0013] Advantageously, the at least one wire end is reinforced by mechanical reinforcement, in particular twisting or stranding, and / or by surface treatment, in order to be able to establish a reliable electrical connection to the second component. For the case of using both reinforcement methods, it is advantageous if the coated wire end is cold-pressed in order to achieve the required hardness and spring stiffness. Here, the cold hardening is preferably carried out by twisting and subsequently extruding and / or punching out a crimp profile.

[0014] In one embodiment, the method forms an electrical contact between an armature winding of an armature and a commutator of a brush motor, wherein the armature winding is formed by at least one enameled copper wire, the wire end of which is shaped to an electrical contact in step a), and in step b) the armature with the wire end is at least partially surrounded by the molding compound, and in step c) the electrical contact is contacted with the commutator.

[0015] In order to accumulate material for forming the contact, it is advantageous to fold the winding wire end back and thus to utilize a doubled wire cross section for shaping.

[0016] In another embodiment, the method forms an electrical contact between a stator of an electric motor and a printed circuit board, wherein the stator has a stator core and a coil formed from the enameled copper wire, wound on the stator core, and in step a) at least one wire end associated with a common phase is shaped to an electrical contact, and in step b) the electrical contact is connected with the stator, wherein the molding compound formed in the shaping process at least partially surrounds the at least one wire end and the stator, and in step c) the electrical contact is contacted with the printed circuit board.

[0017] This has the advantage that separate electrical wiring in the form of busbar units is no longer required.

[0018] Depending on the number of slots and the winding scheme, the winding wire ends can be associated with one common phase. For the case that two winding wire ends belong to one phase, the two winding wire ends are preferably stranded around a longitudinal axis and form a common electrical contact, which extends in the longitudinal direction of the stator.

[0019] If only one winding wire end is provided per phase, this winding wire end is preferably twisted around a longitudinal axis and forms one electrical contact, which extends in the longitudinal direction.

[0020] Preferably, in method step b) at least two guide pins extending in the longitudinal direction are formed on the upper side of the stator, which are used in method step c) to center the printed circuit board on the upper side of the stator.

[0021] Furthermore, an electric machine is proposed, which has a first component and a second component, the first component carrying a winding formed from enameled copper wire, with wire end portions, the second component being in electrical contact with the wire end portions of the winding, wherein at least one wire end portion is shaped as an electrical contact, which contacts the second component, wherein the electrical contact is held in its position on the first component by means of a shaping process.

[0022] The above-mentioned advantages can be derived from the above.

[0023] The electrical contact is preferably formed as described above.

[0024] In one embodiment, the electric machine comprises an armature body and a commutator having a through-hole extending in a longitudinal direction, the commutator being fixed against rotation on an armature shaft of the electric machine by means of the through-hole, the armature body being carried by the armature shaft, wherein a winding formed from enameled copper wire is arranged on the armature body. The electrical contact electrically contacts the winding with the commutator, and the electrical contact is held in its position on the armature body with the winding by means of a shaping process.

[0025] In another embodiment, the electric machine has:

[0026] a rotor, which is mounted rotatably about a rotation axis,

[0027] a stator, wherein the stator has a stator core and a coil wound on the stator core, the coil comprising a winding, and

[0028] a printed circuit board, wherein at least one wire end portion of each phase is shaped as an electrical contact, which contacts the printed circuit board, wherein the electrical contact is held in its position on the stator by means of a shaping process.

[0029] It is generally advantageous if the electrical contact protrudes from the molding compound formed in the shaping process. The sealing in the shaping process is preferably achieved in the tool itself or by means of a geometry on the winding wire end portion.

[0030] In the case of a brushless electric machine, the molding compound formed in the shaping process completely surrounds the stator surface in addition to the electrical contact. It is furthermore possible to provide at least two guide pins extending in the longitudinal direction on the upper side of the stator, which are formed in the shaping process. These guide pins serve to center the printed circuit board on the upper side of the stator. BRIEF DESCRIPTION OF DRAWINGS

[0031] Preferred embodiments of the present application are explained in greater detail below with reference to the drawings. Components of the same type or with the same function are denoted by the same reference signs in the figures. The figures show:

[0032] Figure 1: perspective view of a stator of a brushless motor;

[0033] Figure 2 : Figure 1 : detailed view with connection elements for connecting the winding wire end portions of the stator to a printed circuit board;

[0034] Figure 3 : spatial illustration of different connection elements; and

[0035] Figure 4 : perspective view of another stator of a brushless motor. DETAILED DESCRIPTION

[0036] Figure 1 A stator 1 is shown, which is part of a brushless DC motor. The stator 1 encloses a rotor, not represented, and extends coaxially to the axis of rotation of the rotor, which in the mounted state corresponds to the longitudinal axis of the stator 100. The stator 1 has stator core segments, not represented, around which coils are respectively wound. The windings of the coils are preferably wound in a three-phase manner, wherein the windings are formed from winding wires with winding wire end portions 2. The winding wire end portions 2 protrude from the end face on the upper side of the stator 1. In the case represented, one winding wire end portion 2 respectively belongs to one phase. The three winding wire end portions 2 are shaped on the end portion side such that they form a press contact 3, which is provided for forming an electrical connection to a printed circuit board. The press contact 3 extends in the longitudinal direction.

[0037] The stator 1 is surrounded by a molding compound 4 in a molding process. The formation in an injection molding process is represented here. The molding compound or potting material 4 is preferably formed from a plastic, in particular a thermoplastic, a thermoset, for example an epoxy resin. As represented in Figure 1 The upper side and the lower side of the stator are injection-molded all over. The retention of the windings, in particular the orientation of the winding wire end portions 2, is taken over by the potting material 4, which encapsulates the stator 1.

[0038] Figure 2 The stator 1 is shown in detail Figure 1 with the portion of the press contact 3. Only the press contact 3 protrudes upward from the potting material 4.

[0039] The potting achieves a better dissipation of the loss power of the windings, since the plastic conducts heat better than air. The sealing of the volume of the potting toward the press contact 3 can be achieved by a holding tool during the potting itself or by a geometry on the winding wire end portions. Preferably, one geometry is provided below the press contact 3, which can easily be gripped and encapsulated in the holding tool, so that the press contact 3 is not injection-molded together.

[0040] In order to achieve a reliable press-fit connection of the printed circuit board or the control unit, the press contact 3 requires a sufficient spring stiffness. In order to increase the strength of the winding wire end 2, the winding wire end can be additionally treated, for example by mechanical stiffening such as twisting and / or by a corresponding surface treatment, in particular by a coating with tin. In the case of the use of both stiffening methods, it is advantageous if the cold-formed winding wire end is coated with tin in order to achieve the required hardness and spring stiffness. Here, the press contact is preferably cold-work hardened in a twisted manner and subsequently punched out in the press-fit profile. The press contact thus obtained has good spring-back properties. Due to the temperature during forming, the insulation of the wire is removed, so that the process of removing the insulation can be saved.

[0041] It is additionally conceivable to influence the hardness of the plug-in contact by the material selection of the copper wire or by the selection of a copper alloy used for this purpose. The profile of the press contact can here be formed as a pinhole (as presented) or by slotted on both sides.

[0042] In order to accumulate material for forming the contact, it is advantageous to fold the winding wire end back and thus to use double the wire cross section for forming.

[0043] The plug-in contact formed is positioned in the forming tool.

[0044] Figure 3 Three embodiments of the electrical contact are shown. Depending on the number of slots and the winding scheme of the electrical machine, it is also possible to connect 2 or 3 wires and to form them as electrical contacts. In Figure 3 each case, two winding ends 2 are formed by plastic deformation (for example pressing, molding, stamping, etc.) as a common electrical contact.

[0045] The first two figures on the left show the plug-in contact in the form of a press contact 3 in two different views. The two winding wire ends 2 are twisted around a longitudinal axis. On the end, the press contact 3 is formed with a pinhole profile 5, which extends in the longitudinal direction. The press contact 3 can be inserted into the printed circuit board and establishes an electrical connection with the printed circuit board. No additional components or method steps (for example soldering) are required.

[0046] The two figures in the middle show a classic knife profile 6 for a solder contact on a printed circuit board. Here, too, the two winding wire ends 2 are twisted around a longitudinal axis and are formed on the end as a rectangular flat contact surface 7. This contact surface 7 can be fixed on the printed circuit board by means of a fusion welding process.

[0047] The last two diagrammatic illustrations on the right-hand side show a plug-in contact with a plug pin profile 8. The two winding wire end portions 2 are twisted around the longitudinal axis and are shaped in their end portions to pins which extend in the longitudinal direction. The pins can then be inserted, for example, into a corresponding soldered, preferably spring-loaded, socket of a printed circuit board and brought into contact therewith. In comparison with the crimp profile 3, the shaping of the winding wire end portions 2 is simplified and the connection is suitable for higher currents.

[0048] Figure 4 Another embodiment of the stator 1 is shown, in which, in contrast to the stator according to Figure 1 the stator, two guide pins 9 have additionally been formed in the injection-molding process on the upper side of the stator. The guide pins 9 serve to center the printed circuit board on the upper side of the stator. Thereby, the tolerance chain for positioning the printed circuit board can be reduced. The guide pins 9 can have a stop shoulder as axial stop. In one method step of the molding process, the guide pins 9 are formed together with the injection-molding of the winding wire end portions 2.

[0049] For the positioning of the printed circuit board, a stop shoulder is also formed on the contact as axial stop.

[0050] In another embodiment, the aforementioned type of electrical contact is used in a brush motor, which comprises a commutator which comprises in the usual manner a longitudinal axis with a through-hole which extends in the longitudinal direction, through which the commutator is fixed in a torque-proof manner on an armature shaft of the motor. The armature shaft carries an armature body or rotor body with an armature winding which is inserted in a slot of the rotor body, the armature winding having a plurality of wire windings. The wire windings are formed from enameled copper wire.

[0051] The commutator has a plurality of commutator segments on its peripheral surface which are arranged at an equal angular distance relative to one another, said commutator segments being arranged concentrically to the longitudinal axis of the commutator. On the side of the commutator segments which faces the armature winding, said commutator segments each have a contact element. In general, the contact elements serve to electrically conductively connect the armature winding with the commutator segments, in particular by means of a soldering process or a fusion welding process. On the side of the commutator segments which faces away from the armature winding, the commutator segments cooperate in a known manner with brush elements.

[0052] According to the invention, the contact elements are connected with the wire windings by means of the shaped wire end portions. For this purpose, the wire end portions are shaped as described above and an electrical contact is formed. Preferably, the winding wire end portions are folded back in order to accumulate material for forming the electrical contact, so that a doubled wire cross-section is available for the shaping. The electrical contact is preferably a crimp contact.

[0053] In the molding process, the armature winding is utilized and at least partially surrounded by the molding compound formed in the molding process. The electrical contacts are left bare as described previously and project from the molding compound. The electrical contacts can then be connected directly to the commutator. Depending on the type of electrical contact, it is conceivable that the contacts are soldered to the commutator or, for example in the case of press contacts, are inserted into the corresponding contact elements.

[0054] This type of electrical contact allows the wire ends of the armature winding to be mechanically contacted or connected to the contact elements, which is achieved safely and reliably. Furthermore, this type of connection is particularly space-saving.

[0055] The described electrical contact can also be used quite generally in generators, sensors or electromagnets.

Claims

1. A method for electrically contacting at least one enameled copper wire with a component, which is a second component of an electric machine, a generator, a sensor or an electromagnet, the enameled copper wire forming a winding carried by a first component, the method having the following steps: a) shaping at least one wire end (2) of the at least one enameled copper wire to an insertion electrical contact (3, 6, 8), b) forming a molding compound (4) in the shaping process, which at least partially surrounds the first component and the at least one wire end (2), the wire end (2) only having the insertion electrical contact (3, 6, 8) protruding from the molding compound (4), the molding compound (4) being able to fix the insertion electrical contact (3, 6, 8); forming at least two guide pins (9) extending in the longitudinal direction on the upper side of the stator (1) of the electric machine in the shaping process; c) inserting the insertion electrical contact (3, 6, 8) into the second component to electrically contact the second component; the method further comprising the following step before step a), strengthening the at least one wire end (2) by mechanical machining and / or surface treatment to improve the hardness and spring stiffness of the insertion electrical contact (3, 6, 8). The method is designed for electrically contacting an armature winding of an armature with a commutator of a brushed electric machine, wherein the armature winding is formed by at least one enameled copper wire, a wire end of which is shaped to an insertion electrical contact in step a) and in step b) the armature having the wire end is at least partially surrounded by the molding compound and in step c) the insertion electrical contact is contacted with the commutator. b) positioning the plug-in electrical contacts (3, 6, 8) in a molding process, wherein The method is designed for electrically contacting a stator (1) of an electric machine with a printed circuit board, wherein the stator (1) has a stator core and coils formed by the enameled copper wire, wound on the stator core, and in step a) at least one wire end (2) associated with a common phase is shaped to an insertion electrical contact and in step b) the insertion electrical contact is connected with the stator (1), wherein a molding compound (4) formed in the shaping process at least partially surrounds the at least one wire end and the stator (1) and in step c) the insertion electrical contact is contacted with the printed circuit board. At least two guide pins (9) extending in the longitudinal direction are formed on the upper side of the stator (1) in method step c), which are used to center the printed circuit board on the upper side of the stator (1) in method step d). At least one wire end (2) is strengthened by mechanical machining and / or surface treatment and shaped to an insertion electrical contact (3, 6, 8) to improve the hardness and spring stiffness of the insertion electrical contact (3, 6, 8), which contacts a second component, wherein the insertion electrical contact (3, 6, 8) is held in its position on the first component by means of a shaping process and is inserted into the second component to form an electrical contact; 2. The method of claim 1, wherein, ​ 3. The method of claim 1, wherein, ​ 4. The method of claim 3, wherein, ​ 5. An electric machine having a first member and a second member, the first member carrying a winding formed of enameled copper wire having wire end portions (2), the second member being in electrical contact with the wire end portions of the winding, characterized in that, ​ wherein the molding compound (4) formed in the molding process at least partially surrounds the at least one wire end (2), the wire end (2) protruding from the molding compound (4) only with the plug-in electrical contact (3, 6, 8), the molding compound (4) being able to fix the plug-in electrical contact (3, 6, 8); on the upper side of the stator (1) of the electric machine, at least two guide pins (9) extending in the longitudinal direction are formed in the molding process.

6. The electric machine of the previous claim 5, characterized in that, The electric machine comprises a commutator having a through-hole extending in the longitudinal direction and being fixed in a torque-proof manner on an armature shaft of the electric machine by means of the through-hole, and an armature body carried by the armature shaft, wherein the winding formed from the enameled copper wire is arranged on the armature body, and the plug-in electrical contact electrically contacts the winding with the commutator, and the plug-in electrical contact is held in its position on the armature body having the winding by means of the molding process.

7. The electric machine of the previous claim 5, characterized in that, The electric machine has: a rotor rotatably mounted about a rotation axis, a stator (1), wherein the stator (1) has a stator core and a coil wound on the stator core, the coil comprising the winding, and a printed circuit board, wherein at least one wire end (2) of each phase is shaped as a plug-in electrical contact (3, 6, 8) contacting the printed circuit board, wherein the plug-in electrical contact (3, 6, 8) is held in its position on the stator by means of a molding process.

8. The electric machine of claim 7, wherein, The plug-in electrical contacts (3, 6, 8) of all phases protrude from a molding compound (4) formed in the molding process.

9. The electric machine of claim 7 or 8, characterized in that The molding compound (4) formed in the molding process completely surrounds the surface of the stator in addition to the plug-in electrical contacts (3, 6, 8) of all phases.

10. The electric machine of any of the preceding claims 5 to 8, characterized in that The two wire ends (2) are twisted around a longitudinal axis and form the plug-in electrical contact (3, 6, 8) extending in the longitudinal direction.

11. The electric machine of the previous claim 9, characterized in that, The two wire ends (2) are twisted around a longitudinal axis and form the plug-in electrical contact (3, 6, 8) extending in the longitudinal direction.

12. The electric machine of any of the preceding claims 5 to 8, characterized in that The wire end (2) is twisted around a longitudinal axis and forms the plug-in electrical contact (3, 6, 8) extending in the longitudinal direction.

13. The electric machine of the previous claim 9, characterized in that, The wire end (2) is twisted around a longitudinal axis and forms the plug-in electrical contact (3, 6, 8) extending in the longitudinal direction.

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