DE102021209071A1 - Method of connecting wires of an electrical machine - Google Patents

Abstract

The invention relates to a method for connecting wires (1, 2) of an electrical machine, comprising the steps of: twisting parallel wire ends (11, 12) of two wires (1, 2) together, and cohesively connecting the twisted wire ends (11, 12 ) together by covering the twisted wire ends (11, 12) with an electrically conductive connecting means (3).

Description

State of the art

The present invention relates to a method for connecting wires of an electric machine and a method for manufacturing a stator of an electric machine.

Electrical machines with wires which form windings of the electrical machine, in particular in a stator, are known. To supply electrical energy, for example, several wires are led out of the stator. It is often necessary to connect wires to one another. The wires are usually connected by welding, such as resistance welding, for example.

Disclosure of Invention

• - Verdrillen von parallelen Drahtenden zweier Drähte miteinander, und
• - stoffschlüssiges Verbinden der verdrillten Drahtenden miteinander durch Überziehen der verdrillten Drahtenden mit einem elektrisch leitfähigen Verbindungsmittel.

In contrast, the method according to the invention for connecting wires of an electrical machine is characterized in that a connection of the wires is made possible which is mechanically reliable and at the same time ensures a particularly reliable electrical connection of the wires. In addition, the method can be carried out in a particularly simple and cost-effective manner. This is achieved by a method for connecting wires of an electric machine, comprising the following steps:

• - twisting parallel wire ends of two wires together, and
• - Cohesive connection of the twisted wire ends to one another by coating the twisted wire ends with an electrically conductive connecting agent.

In other words, in the method, the two wire ends of two wires arranged in parallel are first mechanically connected by twisting. Twisting is considered to mean twisting and/or helical winding of the wires around one another. "String" can also be seen as an alternative term for "twisting". The wire ends that are twisted together are then coated with the electrically conductive connecting agent in order to create an additional material bond between the two wire ends. In particular, the connecting means thus forms a coating, for example similar to a coating, on the twisted wire ends.

A connection of wires produced using the method is referred to below as a "Daifer connection". The establishment of this connection, i.e. the process, can also be referred to as "Daifer connection" in line with this designation.

The connection means has two effects: on the one hand, the connection means creates a particularly good electrically conductive connection between the two wire ends, in particular because the connection means, since it forms a coating, can cover the maximum possible surface of the two wire ends and thus for the electrical line may be available. On the other hand, the connecting means causes an additional increase in the strength of the mechanical connection of the two wire ends to one another, in particular since the connecting means can, for example, prevent the twist from loosening due to the additional material connection. The method thus allows a particularly robust and reliable mechanical and electrical connection of the wire ends of the two wires by means of the Daifer connection in a particularly simple and cost-effective manner.

The dependent claims relate to preferred developments of the invention.

The connecting means is preferably a solder. The solder is particularly preferably a metal. For example, the solder can be a mixture of different metals. The solder preferably comprises one or more of the following materials: copper, bronze, brass, zinc, aluminum, iron. As a result, a particularly cost-effective connecting means can be provided which can ensure the electrical conductivity of the connection.

The material connection is particularly preferably carried out by immersing the twisted wire ends in a solder bath. Preferably, the solder bath comprises a bath of liquid solder into which the wire ends twisted together are dipped to thereby form the coating of solder. This process can in particular also be referred to as dip soldering. As a result, the Daifer connection can be carried out particularly easily and quickly.

Preferably, each wire has a connection area adjacent to the wire end, the wire ends and the connection areas of each wire being arranged in an L-shape, in particular at right angles to one another, during twisting. In this case, the wires are also arranged in such a way that the connection areas of the two wires to be connected to one another extend in opposite directions. The twisting preferably takes place over the entire length of the respective wire ends. That is, the two wires are connected from the kink at the transition between area and wire end twisted together over the entire wire end. This makes the Daifer connection particularly easy to carry out.

Each wire preferably has a circular cross section. Alternatively, the wires may each have a rectangular or square cross-section.

More preferably, the twisting is performed using a clamping tool. The clamping tool has a first clamping jaw and a second clamping jaw. The Daifer connection of the wire pairs can be carried out in a particularly simple and precisely reproducible manner using the clamping tool.

The clamping tool is preferably in a clamping configuration during the twisting, with the two clamping jaws gripping the two wire ends in the clamping configuration, in particular in relation to a circumferential direction of the wire ends. For example, the jaws may be symmetrically constructed and arranged and sandwich the wire ends in the clamping configuration.

The two clamping jaws of the clamping tool particularly preferably form a rectangular guide opening in the clamping configuration, with the two wire ends being arranged inside the guide opening in the clamping configuration. As a result, the two wire ends can be held in a defined manner during the twisting, in order to be able to carry out the twisting easily and precisely.

Preferably, the twisting is performed such that the clamping tool is rotated about a central axis in the clamping configuration, the clamping tool being simultaneously, ie while rotating, moved along the central axis and relative to the wire ends. The central axis is arranged parallel to the wire ends and in the middle between the wire ends, in particular when considering a state of the wire ends before twisting. A gradient of the twisting can preferably be adjusted by a ratio of a rotational speed to a movement speed along the central axis.

More preferably, the wires are partially coated with an insulating varnish, with end regions of the wire ends being designed without insulation, ie without insulating varnish. For example, the end areas can extend over the entire wire ends. Alternatively, the end areas can only form a partial area of the wire ends, for example 70% or 50%. In the case of a material connection, the end areas are completely covered with the connection means. As a result, a particularly reliable mechanical and electrical Daifer connection can be provided.

• - Anordnen von Drähten in dem Stator der elektrischen Maschine, und
• - Verbinden der Drähte mittels des oben beschriebenen Verfahrens zum Verbinden von Drähten, also dem Daifer-Verbinden.

Furthermore, the invention leads to a method for producing a stator of an electrical machine, which comprises the steps:

• - arranging wires in the stator of the electric machine, and
• - Connecting the wires by means of the method for connecting wires described above, i.e. the Daifer connection.

For example, arranging the wires in the stator can be done by winding the wires into a stator core, or by inserting the wires into a stator core.

A plurality of wires are preferably arranged in the stator, with two wires being connected to one another to form a pair of wires by means of the method described for Daifer connecting wires. The material connection of the wire ends of all wire pairs is carried out simultaneously. This is possible in a particularly simple and efficient manner if the cohesive connection is made by immersing the twisted wire ends in a solder bath.

More preferably, the wire pairs form electrical phases of the electrical machine. In particular, three phases, ie three pairs of wires, are provided. For example, the twisted wire ends coated with the connecting means can be electrically contacted in order to provide an electrical energy supply for the stator.

The wires are particularly preferably arranged in the stator in such a way that, before twisting, the wire ends are arranged parallel to a stator axis of the stator and protrude beyond an axial end face of the stator. As a result, the Daifer connection can be produced and electrically contacted in a particularly simple manner.

The method preferably also includes the step, which is carried out after the Daifer connection of the wires: bending over the wire ends connected to one another Daifer in such a way that the wire ends are arranged in a plane in which the end face of the stator lies. In other words, the wire ends which are daifer-connected to one another, that is to say twisted and coated with the connecting means, are bent flat. As a result, a particularly compact stator with a small axial extent can be provided. The special Daifer connection of the wire ends ensures that even after the Bending reliably maintains the mechanical and electrical connection of the wire ends.

Each wire particularly preferably has a winding area adjoining the connection area, ie the Daifer connection. The effective area forms a winding of the stator of the electrical machine. Preferably, the winding portion is wound around a stator core of the stator.

character list

• 1 eine vereinfachte schematische Ansicht eines Verfahrensschritts eines Verfahrens zum Daifer-Verbinden von Drähten gemäß einem bevorzugten Ausführungsbeispiel der Erfindung,
• 2 einen weiteren Verfahrensschritt des Verfahrens zum Daifer-Verbinden von Drähten,
• 3 einen weiteren Verfahrensschritt des Verfahrens zum Daifer-Verbinden von Drähten,
• 4 eine Alternative Ansicht des in 3 dargestellten Verfahrensschritts,
• 5 eine vereinfachte schematische Ansicht eines Klemmwerkzeugs, welches bei der Durchführung des Verfahrens verwendet wird,
• 6 einen weiteren Verfahrensschritt des Verfahrens zum Daifer-Verbinden von Drähten,
• 7 einen weiteren Verfahrensschritt des Verfahrens zum Daifer-Verbinden von Drähten,
• 8 eine perspektivische Ansicht eines Stators einer elektrischen Maschine, in welchem die mittels des Verfahrens der 1 bis 7 verbundenen Drähte verwendet werden und,
• 9 den Stator der 8 in fertiggestelltem Zustand.

The invention is described below using exemplary embodiments in conjunction with the figures. In the figures, components that are functionally the same are each identified by the same reference symbols. It shows:

• 1 a simplified schematic view of a method step of a method for Daifer connection of wires according to a preferred embodiment of the invention,
• 2 a further process step of the method for connecting wires to Daifer,
• 3 a further process step of the method for connecting wires to Daifer,
• 4 an alternative view of the in 3 illustrated process step,
• 5 a simplified schematic view of a clamping tool used in carrying out the method,
• 6 a further process step of the method for connecting wires to Daifer,
• 7 a further process step of the method for connecting wires to Daifer,
• 8th a perspective view of a stator of an electrical machine, in which the means of the method of 1 until 7 connected wires are used and,
• 9 the stator of 8th in completed condition.

Preferred Embodiments of the Invention

A method for daifer-connecting wires 1, 2 of an electrical machine and a method for producing a stator 10 of the electrical machine are described below with reference to the figures. Based on 1 until 7 the method of daifer-connecting the wires 1, 2 will be described first.

The wires 1, 2 are copper wires, each of which has an insulating varnish 4 on its outside (cf 1 ) to provide electrical insulation. One end region 40 of each wire 1, 2 is uninsulated in order to enable an electrically conductive connection to another wire 1, 2.

In the method, two wires 1, 2 are connected to each other in order to create a so-called Daifer connection. In this case, wire ends 11, 12 of the two wires to be connected 1, 2 are twisted together, as follows using the 1 until 5 described. The wire ends 11, 12 each correspond to axial end sections of the wires 1, 2

Before twisting, the wires 1, 2 are each arranged in an L-shaped configuration. The two wire ends 11, 12 are arranged parallel to one another, i.e. parallel and symmetrical to a central axis 15 (cf 1 ). The wire ends 11, 12 can touch each other, or alternatively be arranged at a small distance from each other. The end regions 40 without insulation preferably extend over approximately 20% of an axial length of the wire ends 11, 12.

Adjacent to the wire ends 11, 12 are connection areas 21, 22, which are each arranged approximately perpendicularly to the wire ends 11, 12.

The connecting areas 21, 22 of the two wires 1, 2 extend in opposite directions, starting from the central axis 15.

When twisting, the wire ends 11, 12 are twisted together over their entire axial length.

The twisting is carried out by means of a clamping tool 5, which is 5 is shown. The clamping tool 5 has two clamping jaws 51,52. The jaws 51 can be placed against each other in the direction indicated by the arrows D. On the sides facing each other, each clamping jaw 51, 52 has a groove-like recess 57 with a rectangular cross section. As a result, the clamping jaws 51, 52 form a rectangular guide opening 55 when they are in contact with one another, as in particular in 4 shown. This condition is referred to below as the clamped configuration. the inside 5 The state shown is also referred to as the opening configuration.

For twisting the clamping tool 5 is first in the opening configuration as in FIG 1 shown pushed onto the wire ends 11, 12 along the central axis 15 in the direction of the arrow A, so that the wire ends 11, 12 are located between the two clamping jaws 51, 52.

in the in 2 position shown, ie when the clamping tool 5 rests against the connection areas 21, 22, the clamping tool 5 is brought into the clamping configuration. The wire ends 11, 12 are then twisted by rotating the clamping tool 5 about the central axis 15 (compare arrow C in 3 and 4 ) and at the same time displaced during rotation in the direction of arrow B along the central axis 15 towards the axial ends of the wire ends 11, 12 and away from the connection areas 21, 22, as in FIG 3 shown.

The wire ends 11, 12 are twisted together over their entire axial length. Alternatively, it can also be provided that the end regions 40 remain untwisted.

In particular, the clamping jaws 51, 52 are designed in such a way that they clamp the two wire ends 11, 12 with a slight clamping force in order to enable a precisely defined twisting. Alternatively, play between the wire ends 11, 12 and the clamping jaws 51, 52 can also be provided in the clamping configuration in order to enable a particularly slight relative movement of the clamping jaws 51, 52 and the wire ends 11, 12.

The method for Daifer-connecting the wires 1, 2 also includes the step of a material connection of the twisted together wire ends 11, 12, which below with respect to the 6 and 7 is described.

The end regions 40 of the twisted wire ends 11, 12 are coated with an electrically conductive connecting means 3 for the material connection. This is done in that the twisted wire ends 11, 12 are immersed in a solder bath 30, in which there is a liquid solder. That is, the twisted wire ends 11, 12 are, as in 6 shown, immersed in the direction of arrow E in the solder bath 30 and then, as in 7 shown, pulled out of the solder bath 30 in the opposite direction of the arrow F.

The resulting arrangement of wire ends 11, 12 twisted together and coated with the connecting means 3 thus form the Daifer connection.

The method for Daifer connection of the wires 1, 2 offers the advantage that a mechanical connection of the wire ends 11, 12 is first produced by twisting. The subsequent integral connection using the connecting means 3 strengthens this mechanical connection on the one hand, since the coating of the connecting means 3 causes additional mechanical strength of the connection, and on the other hand a good electrical connection of the end regions 40 is ensured.

The wires 1, 2 connected by means of the Daifer method are particularly advantageously suitable for use in a stator 10 of an electrical machine, as will be explained below with reference to FIG 8th and 9 described.

The 8th and 9 show perspective views of a stator 10 of an electric motor. In this case, a plurality of wires 1, 2 are wound around a stator core of the stator 10. In detail, winding areas 23 (cf 9 ) of the wires 1, 2, which respectively adjoin the connection area 21, 22 of the respective wire 1, 2, are wound around the stator core of the stator 10.

The winding regions 23 are preferably arranged at least partially within a large number of recesses 20 distributed around the circumference of the stator 10 . Preferably, the recesses 20 can each be lined with an insulating element 17, such as insulating paper.

The stator 10 comprises three electrical phases for supplying electrical energy, each phase being formed from a pair of wires 61, 62, 63. Each pair of wires 61, 62, 63 consists of two wires 1, 2 connected by means of the method described above, ie a Daifer connection in each case.

During the production of the stator 10, the wires 1, 2 are initially, i.e. before the Daifer connection, arranged in such a way that the connection areas 21, 22 and wire ends 11, 12 of the wires 1, 2 are arranged parallel to a stator axis 36 before twisting and project beyond an end face 35 of the stator 10 .

Before twisting, the connection areas 21, 22 are preferably first bent into the plane of the end face 35, and then the wire ends 11, 12 in the direction parallel to the stator axis 36.

Then the wire ends 11, 12 can be twisted together. For example, the wire ends 11, 12 of all wire pairs 61, 62, 63 can be twisted together simultaneously using several clamping tools 5, or alternatively one after the other using a single clamping tool 5.

A particularly quick and inexpensive production of the stator 10 can be achieved in that, after twisting, the wire ends 11, 12 of all wire pairs 61, 62, 63 are simultaneously immersed in the solder bath 30, for the material connection of the respective wire ends 11, 12.

After the material connection, the Daifer-connected wire ends 11, 12 are bent over so that they are arranged in a plane 50 of the end face 35 of the stator 10 in order to enable a particularly compact arrangement of the stator 10 in the axial direction.

Claims (15)

Method for connecting wires (1, 2) of an electrical machine, comprising the steps: - Twisting parallel wire ends (11, 12) of two wires (1, 2) together, and - Cohesively connecting the twisted wire ends (11, 12) to one another by coating the twisted wire ends (11, 12) with an electrically conductive connecting means (3). procedure after claim 1 , wherein the connecting means (3) is a solder. procedure after claim 2 , wherein the cohesive connection takes place by immersing the twisted wire ends (11, 12) in a solder bath (30). Method according to one of the preceding claims, in which the wires (1, 2) each have a connection area (21, 22) adjoining the corresponding wire end (11, 12), and in which the wire ends (11, 12) and the connection areas (21, 22 ) are arranged in an L-shape during twisting so that the connecting portions (21, 22) of the wires (1, 2) to be connected extend in opposite directions. Method according to one of the preceding claims, wherein the twisting is carried out by means of a clamping tool (5) which has a first clamping jaw (51) and a second clamping jaw (52). procedure after claim 5 , wherein the clamping tool (5) is in a clamping configuration during the twisting, in which the two clamping jaws (51, 52) embrace the two wire ends (11, 12). procedure after claim 6 , wherein the two clamping jaws (51, 52) in the clamping configuration form a rectangular guide opening (55) within which the wire ends (11, 12) are arranged. procedure after claim 6 or 7 , wherein the twisting is performed by rotating the clamping tool (5) in the clamping configuration about a central axis (15) and by simultaneously moving the clamping tool (5) along the central axis (15) and relative to the wire ends (11, 12), the Central axis (15) is arranged parallel to the wire ends (11, 12), and in particular centrally between the wire ends (11, 12). Method according to one of the preceding claims, in which the wires (1, 2) are partially coated with an insulating varnish (4), end regions (40) of the wire ends (11, 12) not being insulated, and the end regions (40) for materially bonded connection completely covered with the connecting means (3). Method for producing a stator (10) of an electrical machine, comprising the steps: - arranging wires (1, 2) in the stator (10) of the electric machine, and - connecting the wires (1, 2) by means of the method for connecting wires (1, 2) according to any one of the preceding claims. procedure after claim 10 , wherein a plurality of wires (1, 2) are arranged in the stator (10), wherein two wires (1, 2) are connected to each other to form a pair of wires (51, 52, 53), and wherein the material connection of the wire ends (11 , 12) of all wire pairs (61, 62, 63) is carried out simultaneously. procedure after claim 11 , wherein the pairs of wires (61, 62, 63) form electrical phases of the electrical machine. Procedure according to one of Claims 10 until 12 , wherein the wires (1, 2) are arranged in the stator (10) in such a way that the wire ends (11, 12) are arranged parallel to a stator axis (36) before twisting and are connected via an end face (35) of the stator (10 ) survive. Procedure according to one of Claims 10 until 13 , further comprising the step after connecting the wires (1, 2): - bending over the connected wire ends (11, 12) so that the wire ends (11, 12) are in a plane (50) of the end face (35) of the stator ( 10) are arranged. Procedure according to one of Claims 10 until 14 , wherein each wire (1, 2) has a winding area (23) adjoining the connection area (21, 22) and forming a winding of the stator (10) of the electrical machine, in particular wherein the winding area (23) is wound around a stator core of the stator (10).

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