Method for producing winding pad for stator or rotor of electric motor

Abstract

The invention relates to a method for producing a winding pad for a stator or a rotor of an electric motor. The method according to the invention comprises providing two conductor strands (1), each having at least one conductor in each case; transporting the conductor strands (1) in each case along the x-direction of the Cartesian coordinate system to a receiving device (2); winding ends (11) arranged opposite each other are simultaneously formed on the two conductor strands (1), each forming a sharp corner (111). Preferably, the cross-layer part (5) is punched in the sharp corner part (111) at the same time. A connecting strip (12) extending in the opposite direction is then formed before releasing the receiving device (2) from the conductor strand (1) and transferring the conductor strand (1) for a transport cycle. The above steps are repeated until a winding pad (8) having a defined number of windings is produced, each winding comprising two winding ends (11) and four connecting strips (12).

Description

Technical Field

[0001] The importance of electric motors has increased significantly due to the energy transition and the transport transition, as the demand for drives that do not require fossil fuels continues to increase. Conventional electric motors consist of a stator and a rotor. When current flows through the conductor wound around the rotor, north and south poles are formed and the rotor begins to rotate due to the external magnetic field of the stator. The winding type of the stator and rotor plays an important role in the efficiency of the electric motor. Background Art

[0002] When the conductor is wound into a winding mat which is fixed around or at the stator or rotor, the conductor is subjected to mechanical stress. In order to be able to ensure high efficiency, very smooth running, low noise levels and high robustness of the electric motor, the winding process must be reproducible and the conductor be subjected to as little mechanical stress as possible. In addition, high stresses of the conductor material during winding are also disadvantageous, since this leads to increased material costs during production.

[0003] There are different methods for manufacturing winding mats for stators or rotors. Usually, one or more winding wires or conductors, which can be round wires or flat wires, are fed to a winding plate or terminal block via a feeding device and wound thereon.

[0004] Patent document WO 2019 / 130232 A1 discloses winding around a terminal block. For this purpose, a conductor and a terminal block are prepared. The latter has a slot for accommodating the conductor. The conductor is provided with the aid of one or more wire guides. The conductor is introduced into the slot of the terminal block so that some parts of the conductor are located in the slot and other parts of the conductor extend beyond the slot. A connection (winding end) connected to the part of the conductor to be placed in the nearest slot (connecting strip) is formed from the part of the conductor that extends beyond the slot.

[0005] Patent document DE 10 2004 035 084 A1 describes a winding method for multiple windings around a winding plate. The winding method requires a template on which, in a first step, connecting strips located on the template and winding ends projecting beyond the template are produced from n parallel wires. The winding ends are produced preferably in a V-shaped or pointed shape by means of shaped bodies placed on the template. After the connecting strips and winding ends have been produced, they are displaced along the axis of rotation of the template by n times the spacing in a second step. The first two steps are repeated until the number of windings produced corresponds to the number of rotor slots or stator slots.

[0006] Patent document US 7 281 312 B2 describes another winding method using a winding plate. This method is similar to the previously described method, but additionally includes transferring the resulting winding mat into a transfer tool, a rotor or a stator.

[0007] An important problem with the method described is that, in particular when the length of the winding mat is large, an adaptation of the dimensions and (removal) transfer is not possible or is only possible at considerable expense, since the length of the terminal block or the length of the winding plate essentially corresponds to the length of the winding mat to be produced.

[0008] Patent document EP 3 182 568 B2 also describes a method for manufacturing a winding mat using a winding plate. In the described method, a single or multiple wires are wound several times around a winding plate. For this purpose, a holding mechanism may be provided, which holds a portion of the wire during winding, while another portion of the wire moves relative to it. However, winding is not performed until the number of windings reaches a value that corresponds to the number of rotor slots or stator slots, and the wound wire is transported away directly after winding via a transport device that rotates with the winding device, the transport device being configured as a belt conveyor or a toothed belt conveyor. This has the advantage that the length of the winding mat to be manufactured can be flexibly adapted to the stator or rotor.

[0009] In the described winding method, the conductor is removed from the winding plate or terminal block after winding and is subsequently pressed together flat. The squeezing of the winding mat or conductor causes great stresses on the insulation of the conductor. When using rotating terminal blocks or winding plates, the step width can also only be changed to a limited extent. As a result, the conductors wound in parallel are not symmetrical to each other and circular currents can form. This leads to losses in the conductor during operation and does not contribute to the formation of torque. Summary of the invention

[0010] The object of the present invention is to provide a winding method for manufacturing a winding mat for a stator or rotor of an electric motor, which method produces less mechanical load on the conductor without using a winding plate and allows a higher design flexibility of the winding mat.

[0011] According to the present invention, this object is achieved by a method for manufacturing a winding for a stator or rotor of an electric motor, in which two conductor strands are provided, each of which has at least one conductor; and the conductor strands are respectively conveyed to a receiving device along the x direction of a Cartesian coordinate system; the winding ends arranged opposite to each other are formed, wherein the conductor strands are pushed (pressed) onto a second forming tool having a pointed protrusion using a first forming tool having a pointed recess to form a pointed corner, whereby the conductor strands are bent in the xz plane, and cross-layer portions are respectively punched out in the two pointed corners in opposite directions in the y direction; for each The invention relates to a method for forming a conductor strand into a connecting strip extending in an xz plane perpendicular to the x direction, wherein the connecting strip is bent by connecting a receiving device to a first axis and the first axis moves in opposite directions toward each other in the z direction, and the conductor strand is transferred to a second axis and the second axis moves in opposite directions away from each other in the z direction; releasing the receiving device and conveying the conductor strand in the x direction for one conveying cycle; and repeating conveying, shaping the winding ends, shaping the connecting strips, releasing the receiving device and conveying the conductor strands until a winding mat with a defined number of windings is produced, wherein each winding includes two winding ends and four connecting strips.

[0012] In order to protect the conductor material, it is reasonable not to use terminal strips or winding strips. This has the advantage that winding mats of almost any length and shape can be produced, while the mat width and mat height are relatively small, and the conductors can be inserted and removed flexibly in the method.

[0013] It is advantageous if the layer jump is punched out in the corner-forming section of the conductor strand during the bending of the conductor strand in the xz plane. The method can thereby be accelerated.

[0014] For punching out the layer crossovers, an additional punching device can be used or the punching can be carried out using a correspondingly designed first forming tool 3 and a second forming tool 4 .

[0015] When forming the connecting strip, each conductor strand can advantageously be pushed against the third forming tool individually, and the conductor strands can be bent around the third forming tool to form the connecting strip.

[0016] During the method, the first forming tool and the second forming tool can be replaced according to the requirements of the winding mat in order to change the step width of the windings in the produced winding mat.

[0017] Advantageously, the winding is transferred to a winding table which, during the entire method, performs an oscillating movement about the z-axis in order to punch the layer jumps into the pointed corners of the winding ends. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described in more detail below by way of embodiments with reference to the accompanying drawings.

[0019] Figure 1 A diagram showing an apparatus for carrying out the method,

[0020] Figure 2a to Figure 2h The various method steps for producing a winding mat are shown in top view,

[0021] Figure 3 A plurality of windings with winding pads of different step widths are shown in a top view,

[0022] Figure 4 A view showing a first forming tool and a second forming tool for forming a winding end using a conductor strand,

[0023] Figure 5 A view showing the conductor strands, the receiving device and the first shaft, and

[0024] Figure 6a to Figure 6b A detailed view of the stamping of the winding heads is shown. DETAILED DESCRIPTION

[0025] Figure 1 A view of a device for carrying out the method is shown. Two conductor strands 1 are respectively conveyed along the x direction of a Cartesian coordinate system to one of two receiving devices 2 in which the conductor strands 1 are fixed. The conductor strands 1 each have at least one conductor, and the receiving devices 2 each receive all the conductors of the conductor strands 1. Two first shafts 6 and two second shafts 7 can be moved in opposite directions in the z direction and can be connected to the receiving devices 2. Figure 1 In the embodiment shown, the first axis 6 is arranged above the conductor strand 1, and the second axis 7 is arranged below the conductor strand 1. The two first forming tools 3 are arranged to be movable in opposite directions in the z direction, and the second forming tool 4 is arranged to be stationary. The advantageously provided third forming tool 9 is designed to be adjustable along all axes of the Cartesian coordinate system.

[0026] Figure 2a to Figure 2h The figure shows a method for winding a conductor strand 1. Another conductor strand 1 is wound similarly at the same time, wherein the winding ends 11 are arranged opposite each other. In order to shape the winding ends 11, the conductor strand 1 shown by way of example by a conductor is pushed onto a second shaping tool 4 having a pointed protrusion using a first shaping tool 3 having a pointed recess, thereby bending the conductor strand 1 in the xz plane to form a pointed portion 111. Afterwards or at the same time, a cross-layer portion 5 is punched out in the pointed portion 111 of the winding end 11. Figure 2a In the embodiment shown in FIG. 1 , the winding head 11 is already formed and the receiving device 2 has already received the conductor strand 1 . Figure 2b to Figure 2dThe forming of the connecting strip 12 is shown. The receiving device 2 is connected to the first shaft 6 (not shown) and the first shaft 6 is moved in the z direction, whereby the conductor strand 1 is bent in the xz plane. Then, the receiving device 2 with the conductor strand 1 is transferred to the second shaft 7 (also not shown), and the third forming tool 9 is pushed at the conductor strand 1. The second shaft 7 is also moved in the z direction, whereby the conductor strand 1 is further bent in the xz plane, the connecting strip 12 is formed and the conductor strand 1 is bent around the third forming tool 9.

[0027] The receiving device 2 is then released and the conductor strand 1 is moved in the x direction by one conveying cycle. This conveying cycle advantageously corresponds to the step width SW of the respective winding. The conductor strand 1 is now received by another receiving device 2 and the winding end 11 is formed again, as shown in FIG. Figure 2e As shown. Figure 2b to Figure 2d similar, Figure 2f to Figure 2h The shaping of the second connecting strip 12 is shown.

[0028] The described method steps are repeated until a winding mat 8 with a defined number of windings has been produced, each winding comprising two winding ends 11 and four connecting bars 12. With the exception of the first and last connecting bar 12 of the winding mat 8, each connecting bar 12 is associated with two windings.

[0029] Figure 3 A total of four windings are shown, each of which consists of two opposite winding ends 11 and four connecting strips 12, wherein every two connecting strips 12 overlap each other. The first step width SW1 of the two lower windings is different from the second step width SW2 of the two upper windings. The step width SW is the distance between the two connecting strips 12 of a winding. Like the shape of the pointed portion 111, the step width SW depends on the first forming tool 3 and the second forming tool 4 used in the winding method. The first forming tool and the second forming tool can be replaced during the operation of the method, so that the manufactured winding mat 8 can have windings with different step widths SW.

[0030] Figure 4 The shaping of the winding head 11 is shown in detail. The first shaping tool 3 is movable and pushes the conductor strand 1 shown toward the second shaping tool 4 which is fixed in position and presses the conductor strand 1 onto the second shaping tool 4. As a result, the pointed winding head 11 is formed.

[0031] Figure 5 The connection of a receiving device 2, which has received one of the conductor strands 1, to a first shaft 6 is shown by way of example. For this purpose, additional connecting means may be provided on the receiving device 2 and / or on the first shaft 6. Similar to the first shaft 6, the receiving device 2 can also be connected to a second shaft 7. Whether the shaft is arranged above or below the receiving device 2 is not important for the invention.

[0032] Figure 6a and Figure 6b The punching of the cross-layer section 5 in each winding head 11 is shown in detail. To punch the cross-layer section 5, an additional punching device can be used or the punching can be performed using a first forming tool 3 and a second forming tool 4 of corresponding design. The cross-layer section 5 indicates that the conductor strand 1 crosses over into different layers. Each wound conductor strand is located in two layers. Punching can advantageously ensure that the thickness of the conductor strand 1 or the individual conductors of the conductor strand 1 is also reduced. By punching, a plurality of conductor strands 1 or windings can be interwoven with each other to form a winding mat 8.

[0033] List of reference numerals:

[0034] 1 conductor strand

[0035] 2. Accommodation device

[0036] 3. First forming tool

[0037] 4 Second molding tool

[0038] 5 Cross-layer department

[0039] 6 First axis

[0040] 7 Second axis

[0041] 8 Winding pads

[0042] 9 Third forming tool

[0043] 10 Winding table

[0044] 11 Winding ends

[0045] 12 Connecting strip

[0046] 111 Sharp corner

[0047] SW step width

[0048] SW1 First step width

[0049] SW2 Second step width.

Claims

1. A method for manufacturing a winding pad for a stator or rotor of an electric motor, the method comprising the following steps: A. providing two conductor strands (1), each of which has at least one conductor, B. transporting the conductor strands (1) to the receiving device (2) respectively along the x direction of the Cartesian coordinate system, C. forming winding ends (11) arranged opposite to each other, wherein the conductor strands (1) are pushed onto a second forming tool (4) having a pointed protrusion by using a first forming tool (3) having a pointed recess, thereby the conductor strands are bent in the xz plane to form a pointed corner (111), and cross-layer portions (5) are punched out in the two pointed corners (111) in opposite directions in the y direction, D. forming a connecting strip (12) for each conductor strand (1) and extending in the xz plane perpendicular to the x direction, wherein the connecting strip (12) is bent by connecting the receiving device (2) to a first shaft (6) and moving the first shaft (6) in opposite directions towards each other in the z direction, and by transferring the conductor strands (1) to a second shaft (7) and moving the second shaft (7) in opposite directions away from each other in the z direction, E. releasing the receiving device (2) from the conductor strand (1) and conveying the conductor strand (1) in the x direction by one conveying cycle respectively, and F. Repeating steps B to E until a winding mat (8) having a defined number of windings is produced, each of which is formed by two conductor strands and each comprises two winding ends (11) and four connecting bars (12).

2. The method according to claim 1, characterized in that In step C, the layer span (5) is punched out in the corner (111) during bending of the conductor strand (1) in the xz plane.

3. The method according to claim 1 or 2, characterized in that: In step D, a third shaping tool (9) is respectively pushed onto the conductor strand (1) and the conductor strand (1) is bent around the third shaping tool (9).

4. The method according to any one of the preceding claims, characterized in that During the method, the first forming tool (3) and the second forming tool (4) are replaced in order to change the step width (SW) of the winding.

5. The method according to any one of the preceding claims, characterized in that The winding is transferred to a winding table (10) which performs a swiveling movement about the z-axis during the entire method in order to punch out the layer jump (5) in the pointed corner (111) of the winding head (11).

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