RU2801142C1 - Active part of electric machine with printing wire - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the active part of an electrical machine manufactured using additive technology. The active part (1) of the electrical machine (10) comprises electrical wires (3, 3', 3ʺ, 3'ʺ) printed additively. Between the electrical wires (3, 3', 3ʺ, 3'ʺ) there are additively printed intermediate elements (4, 4', 4ʺ, 4'ʺ). A feature of the invention is the printing of electrical wires (3, 3', 3ʺ, 3'ʺ) so that they alternate with the intermediate element (4, 4', 4ʺ, 4'ʺ), increasing radially. At the same time, a contact layer (5, 5', 5ʺ, 5'ʺ) is applied between at least one of the electrical wires (3, 3', 3ʺ, 3'ʺ) and at least one of the printed intermediate elements (4, 4', 4ʺ, 4'ʺ)≤ 300 mcm of the third material, through which a diffusion zone is formed using heat treatment.

EFFECT: increased reliability of the design.

13 cl, 13 dwg

Description

The invention relates to an active part of an electric machine and a method for its manufacture.

An electrical machine has a stator and a rotor. If the electrical machine is an asynchronous machine, both the stator and the rotor are supplied with current during operation of the electrical machine. In this case, the rotor is also an active part of the electric machine, since it has a short-circuited cage with wires through which electric current flows during operation of the electric machine.

The rotor of an electrical machine, that is, the active part of an asynchronous machine that rotates during operation, is subject to centrifugal forces during operation. The wires of the active part, that is, in particular the wires of the short-circuited cage, must be made or, accordingly, designed so that they withstand these centrifugal forces. One of the specific problems is, for example, to stably make a connection (for example, for the manufacture of components for electrical machines, such as, for example, the rotor of an induction machine as its active part) using different materials (for example, copper/iron or copper/steel or iron/steel). This can be achieved, for example, by means of material connections. One of these connections by means of a material has been made up to now, for example, for squirrel-cage rotors of asynchronous machines. These rotors require squirrel-cage rotor windings to perform their function. The energized stator induces currents in the rotor, which generate a torque with the stator field and thus set the load in motion. For high-frequency drives, the rotor, for mechanical strength, consists of massive, high-strength steel with an integrated squirrel-cage rotor winding. To integrate the rotor winding, grooves are first milled or machined in solid forgings for the rods or ring segments of the rotor winding, and then massive, nickel-plated copper rods/ring segments are inserted there. As a result of the subsequent application of the method of hot isostatic pressing (HIP: Hot Isostatic Pressing) between the copper rods and the nickel coating, and between the nickel coating and the steel of the massive rotor, a diffusion zone occurs. This high-strength connection is required to withstand centrifugal forces at the highest speeds. The HIP process requires high temperatures and pressures. The described method is very laborious and expensive.

The object of the invention is to make the active part of the electrical machine, in particular the rotor of the electrical machine, simple and stable. In this case, it is necessary to ensure that the active part does not collapse during rotation.

The solution to the problem is obtained from the active part according to claim 1 of the claims. Another solution to the problem is obtained with the method according to claim 8 of the claims. Other embodiments are obtained according to claims 2-7 and 9-12 of the claims.

An active part of an electrical machine having electrical wires has electrical wires that are printed. These printed electrical wires are, in particular, additively printed. This means that for the printing of electrical wires, an additive printing method is applied, applied or, accordingly, was applied. The active part of the electrical machine is, in particular, the rotor of the electrical machine. The electric machine is in particular an asynchronous machine. The printed electrical wire is, in particular, the wire of a short-circuited cage of an asynchronous machine, and here further under printing, that is, something printed, should also be understood as additive printing. That is, this printing is in particular 3D printing, such as, for example, selective laser melting (SLM), selective laser sintering (SLS), electron beam melting (EBM), laser deposition welding (LMD), cold gas dynamic spraying etc. There is an intermediate element between the printed wires. These intermediate elements have a different and lower conductivity than electrical wires. That is, the intermediate element is in particular an insulator. The intermediate element isolates, in particular, two adjacent electrical wires from each other if the intermediate element is placed between adjacent electrical wires. The intermediate element in particular consists of or at least also contains an insulating material. By printing electrical wires, a strong connection can be made. Printed electrical wires have a longitudinal orientation parallel to the axis of rotation of the rotor. That is, the electric machine is, in particular, a rotary electric machine which has a rotation axis. From the distance to the axis of rotation for the rotor or, respectively, the stator of the electrical machine, a radial base area is obtained. That is, the regions or respectively the points of the rotor or, respectively, the stator of the electric machine have a certain radial base or, respectively, can be described by their radial position or, respectively, orientation. The electric machine may, for example, also be a linear motor. For the printed electrical wire, for example, copper and/or aluminum can be used.

Electrical wires are printed, in particular, in layers, that is, in layers (additively printed). These layers extend, in particular, along the axis of rotation of the electric machine, have an arc section and have a certain radial height, the radius always referring to the distance to the axis of rotation. Also, the intermediate elements are printed, in particular, in layers, that is, in layers (printed additively). And these layers extend, in particular, along the axis of rotation of the electric machine, have an arc section and have a certain radial height, the radius always referring to the distance to the axis of rotation.

In one of the embodiments of the active part, the additive printing of various materials in contact with each other is carried out with a shift in time. This makes building layers easier.

That is, in one of the embodiments of the active part, the electrical wires are printed, as are the intermediate elements between the electrical wires are printed. And it increases durability. In particular, also the sheet pack can be wholly or partially printed.

In one of the embodiments of the active part, the electrical wires are placed symmetrically around the perimeter of the rotor (active part).

In one of the embodiments of the active part, at least one of the electrical wires in some area has a cross section that narrows as the radius increases. In this case, the radius refers to the axis of rotation of the active part (rotor). Electrical wires, like intermediate elements, have some volume. This volume is obtained in particular from the length along or, respectively, parallel to the axis of rotation, the width, which is obtained from the size of the circle segment occupied, and the height, which is obtained from the radial extension. That is, in one of the embodiments of the active part, at least one of the electrical wires in some area has a cross section that narrows as the height increases. In this case, the height increases as the radial distance increases.

As the cross section tapers radially outward, the printed electrical wire can be held by adjacent intermediate members. This is obtained from the geometric shape, when the intermediate elements in the circumferential direction are each indirectly or directly connected to the electric wires. Indirect connection is obtained, for example, when there is still some intermediate layer between the electrical wires and the intermediate element. It consists, for example, of a material that contains means. The intermediate elements consist, for example, of a material which contains steel and/or iron. When the cross section of the printed electrical wire narrows, it narrows, in particular in the tangential direction. The cross section is obtained from the end view of electrical wires or, respectively, intermediate elements.

In one embodiment of the active part, the cross-section in its tangential extent alternately increases and decreases, or, respectively, decreases and increases radially outward. Similarly, this applies to the cross section along the tangential extent of the intermediate elements. Thus, in one embodiment, it turns out that where the cross section of the printed electrical wire in the radial direction narrows, the cross section of the intermediate element increases accordingly, and vice versa. In this case, in particular, a gearing of electrical wires and intermediate elements is obtained, while also the intermediate elements can be printed.

In one of the embodiments of the active part, it can therefore be performed in such a way that at least one of the electrical wires has a plurality of sections having cross-sections that taper as the radius increases. That is to say, the active part can be configured in particular such that at least one of the electrical wires has a plurality of sections having cross sections that become narrower as the height increases.

Moreover, these areas, for example, at least partially correspond to the areas of printing of electrical wires, and these electrical wires are printed alternately with intermediate elements, increasing radially.

In one of the embodiments of the active part between at least one of the printed electrical wires and the printed intermediate element is a three-dimensional structure. That is to say, the active part can be configured in particular such that a three-dimensional structure is formed between at least one of the printed electric wires and at least one of the printed intermediate elements.

This three-dimensional structure is, for example, zigzag or wavy in cross section. In this way, a mutual adaptation of the shape of the intermediate elements and the electric wires is obtained, so that they can better be held in their position even when forces act on them radially outward.

That is, in one embodiment of the active part, the three-dimensional structure has a zigzag pattern or a wavy pattern in cross section.

In one of the embodiments of the active part, the electrical conductivity of the electrical wires is radially different. That is, the active part can be designed in particular in such a way that the electrical conductivity of the electrical wires varies depending on the height. The height is obtained from the radial extent. The electrical conductivity is greater, in particular in areas that have a larger radius, i.e. greater distance to the axis of rotation. In this way, the resistance of electrical wires can be adjusted, and the skin effect can also be taken into account. For example, the electrical conductivity may also decrease radially outward.

In one of the embodiments of the active part between at least one of the electrical wires and at least one of the printed intermediate elements is a contact layer, which, in particular, contains Nickel. With this contact layer it is possible, in particular, to promote diffusion in the case of an electrical wire and/or in the case of an intermediate element. In this way, the connection between the electric wire and the intermediate element can be improved. This is advantageous in particular when high centrifugal forces occur.

In one embodiment of the active part, the electrical wires and/or in particular the printed intermediate elements between two electrical wires have layers which end or respectively begin radially where the thickness of one of the electrical wires or, respectively, the intermediate element has a local minimum or maximum. The lamination is obtained because the electrical wires or, respectively, the intermediate elements are printed in layers radially outwards. That is, the radial thickness of the electrical wires and intermediate elements increases in turn (alternately). In this case, it is possible to produce a wavy shape or, respectively, a zigzag shape, which gives additional resistance.

In a method for manufacturing an active part, in particular a rotor having a short-circuited cage, of an electrical machine, electrical wires are printed, while an intermediate element is printed between the electrical wires, while printing at least one electrical wire and an intermediate element alternates. This results in a layered construction of electrical wires or, accordingly, intermediate elements. That is, electrical wires are printed, in particular, in layers. And intermediate elements are printed, in particular, in layers. Layers of electrical wires and intermediate elements are printed, in particular, alternating. Said printing is in particular additive printing. Additive printing is often referred to as 3D printing as well. The short-circuited cage of the active part (rotor) of an asynchronous machine can be produced, in particular, additively, so that a material-to-material connection occurs between the materials. Bonding by means of a material is necessary so that high strengths can be achieved at the junction of the joint and at the same time between substances. This can be achieved, for example, by means of a cold gas-dynamic spraying method. By means of the cold vapor deposition method, an electrically conductive material such as copper or aluminum as well as a magnetizable material such as iron can be printed. That is, the squirrel-cage cage of the asynchronous machine may be partially or wholly manufactured by an additive printing process such as "cold gas dynamic spraying". To do this, the wire material (eg copper or aluminum) for the winding and the soft magnetic material (eg FeSi2.9) for the teeth are printed in layers on the shaft so that the wires and teeth are built in parallel. Additionally, for example, parallel to them between the electrical wire and the intermediate element, that is, in particular, between the material of the wire, tooth and / or wave, is printed and / or applied by spraying, etc. a relatively very thin layer (≤ 300 μm) of some or a third material such as nickel. This additional layer (hereinafter also referred to as the diffusion layer or the contact layer) serves to form the diffusion zone. This contact layer results in improved diffusion, that is to say an improved diffusion zone, which enhances or improves the bond between adjacent materials. A tooth is an example of an intermediate element between electrical wires that form short-circuited windings. Then, during a possible subsequent heat treatment (for example, 6 h at 400°C), in particular, between the wire material and the diffusion layer, between the diffusion layer and the magnetically soft material, as well as between the diffusion layer and the steel of the massive rotor, a diffusion zone is formed and, at the same time, high-strength connection between different materials.

In some cases, for technological and/or accuracy reasons, it may be necessary to perform subtractive intermediate processing between additively built materials. The described method or, respectively, the described methods are not limited exclusively to asynchronous machines having massive rotors. The rotors can, for example, also be partially massive.

In one of the embodiments of the method, at one of the stages of the method, the first electrical wire and the second, adjacent electrical wire are printed, while their width is reduced, while at the next stage of the method, an intermediate element is printed between the first electrical wire and the second electrical wire, while its width increases. This results in different thicknesses of the cross sections of the printed elements.

In one embodiment of the method, electrical wires and/or intermediate elements are printed on the shaft housing. This housing is built, in particular, massive in such a way that it is not affected by the resulting centrifugal forces.

In one of the embodiments of the method, the printing of at least some part of one of the electrical wires, which is the first object of printing, and the printing of at least some part of the intermediate elements, which are the second object of printing, are alternated, so that before the alternation, a radial an increase in the thickness of an electrical wire or an intermediate element that lies between greater than or equal to 50% and less than or equal to 200% of the subsequent radial increase in the thickness of each other print object. Radial thickness gain may also be referred to as radial height gain. The height is obtained from the difference of various radial distances from the printed material to the axis of rotation.

The described method includes a simplification of production and a clear increase in the degree of automation (perhaps ˃80%) compared to the existing docking/HIP method. In addition, it includes the possibility of realizing individual rotor geometries adapted to special customer requirements (rotor shaft geometries) which cannot or can only be produced at extremely high cost by conventional methods. In addition to the rotor shaft, ie the electrical wire of the active part, locally specific electrical properties of the material, such as, for example, different electrical conductivities, can be imparted.

In one of the embodiments of the method, when printing, the difference between the first height of the layers of the electrical wire and the second height of the layers of the adjacent intermediate element does not exceed a maximum of two layers. In particular, the difference between adjacent layers is equal to only one layer. This means that the difference has, in particular, the height of only one layer.

In the following, the invention will be described and explained in more detail by way of examples with the help of figures. The features shown in the figures can also be combined with new embodiments without departing from the scope of the invention. Like reference numerals designate like elements. Shown:

figure 1: electric machine;

figure 2: grooves;

figure 3: shape of the grooves;

figure 4: the first form of printed electrical wires;

figure 5: the second form of printed electrical wires;

Fig.6-Fig.9: the first sequence of the printing process; And

Fig.10-Fig.13: the second sequence of the printing process.

The image in figure 1 shows an electrical machine 10, which has an active part 1 and a stator 2. In this figure, the active part 1 represents the rotor of the electrical machine 10. In another way, the rotor may be called the first active part, and the stator the second active part. The stator 2 has windings having end windings 13. The rotor, ie in the present example the active part 1, is a squirrel-cage rotor. There is an air gap 15 between the stator and the rotor. The active part 1 has a first short-circuited ring 11 and a second short-circuited ring 11ʽ. The active part 1 is supported with the possibility of rotation around the axis 14 of rotation. The short-circuited cage has electrical wires that lie in the printed layer 22. These electrical wires are printed on the shaft body 6 . The active part 1 has a radial extension having a radius of 7. The printed layer 22 is located in the radially outer region of the active part 1. The electrical wires of the short-circuited cage are not explicitly shown in FIG. 1, but run axially approximately parallel to the axis 14 of rotation.

The image of figure 2 shows different embodiments of the electrical wires 3, 3', 3'' in the grooves. Figure 2 shows an electrical wire 3 containing a permanent copper alloy. It is suitable for starting an electric machine without special requirements. Figure 2 also shows an electrical wire 3', in which the arrow 8 indicates that the conductivity decreases radially outward. This can be achieved, for example, with an alloy containing CuSi. Higher conductivities can be obtained, for example, with an E-Cu alloy. By changing the conductivity, it is possible to respond to increased requirements in relation to the start-up of an electric machine. The transition of the alloy need not be gradual. It is also possible, for example, to change the conductivity abruptly, as symbolized in the electric wire 3'' by the dotted line 12.

The image of figure 3 shows different cross-sectional shapes of electrical wires. Figure 2 selected rectangular cross-section. Figure 3 from left to right shows the following cross-sections: a cross-section of a round rod, a cross-section of a deep-groove rod, a cross-section of a trapezoidal rod and a cross-section of two rods of a starting and working cage. The Coldspray method can be used to produce various standard rod shapes with locally different electrical conductivity.

In the image of Fig.4, a fragment of the active part similar to a piece of cake in the end cross section shows the placement of electrical wires and intermediate elements. Between the electric wires 3, 3ʽ, 3ʽʽ, 3ʽʽʽ there are intermediate elements 4, 4ʽ, 4ʽʽ, 4ʽʽʽ. The electrical wires are layered, with FIG. 4 showing only the layers 19 and 19' for the 3' electrical wire so as not to clutter the image. The intermediate elements also have layers, with Figure 4 showing only the layers 19, 19' and 19'' for the 3' intermediate element so as not to clutter the image. Electrical wires, like intermediate elements, have a certain radial thickness. This radial thickness may also be referred to as height. Figure 4 shows, by way of example, a height 23 for an electrical wire 3'' and a height 24 for an intermediate element 4''.

Electrical wires contain, in particular, copper. The intermediate elements contain, in particular, iron and/or steel. Both of them are printed. Between the electrical wires and the intermediate elements are contact layers 5, 5', 5'', 5'', which contain, in particular, nickel. These contact layers have a zigzag pattern 16, 16ʽ. Electric wires and intermediate elements are printed on the shaft body. Printing is from the inside to the outside, which is explained by the radial direction 17. Outwardly, the width 9, 9', 9'', 9'' of the electrical wires varies in the circumferential direction. Alternating with it, the width of the intermediate elements in the same radial position also changes. Due to the zigzag shape, particularly good fastness is obtained within the printed layer 22.

The image in accordance with Fig.5 similarly to Fig.4 shows a cross-section of a fragment of the active part, while the boundary region between the electric wires and the intermediate elements is not shown, but passes in a wave-like manner.

The image in accordance with Fig.6-9 shows the sequence of printing processes. At the first stage, a layer of electrical wires 3, 3ʽ, 3ʽʽ, 3ʽʽʽ is printed on the shaft body 6. These electrical wires are at a distance from each other. In the next step, layers of intermediate elements 4, 4', 4'', 4''' are printed, with them being radially outward above the first layer of electrical wires. Then, according to Fig. 8, in the next step, the electrical wires are again printed layer-by-layer, so that they also end up radially outward above the intermediate elements. Steps 20 are thus obtained. Then, in the following steps, which are shown in Fig. 9, the intermediate elements continue to be printed radially outwards first, then the electrical wires are printed outwards so that there are no more steps. Due to this step-by-step procedure, layers 19, 19' are formed. Layers 19, 19' and 19' also have radial thicknesses, ie heights. In the drawing of FIG. 9, for the respective layers, heights of 23', 23'' and 23'' or 24'' and 24'', respectively, are shown as an example.

The image in accordance with Fig.10-13 shows the sequence of printing processes, corresponding to the sequence already shown in Fig.6-9. In contrast, electrical wires are round in shape and reflect how electrical wires and intermediate elements can be connected to each other due to their shape in order to absorb centrifugal forces. Here, too, it is shown that here, too, the width 18 of the completed electric wire changes radially outwards, i.e. either increases, then decreases again, and increases again, or vice versa.

Claims (13)

1. An active part (1) of an electrical machine (10) that has electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ), wherein the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are additively printed, while between the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) there is an intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), and the intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) is printed additively, while electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are printed in layers ( 19, 19ʽ), while the intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) are printed in layers (19, 19ʽ), while the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are printed alternating with the intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), increasing radially, with a contact layer (5 , 5ʽ, 5ʽʽ, 5ʽʽʽ) ≤ 300 µm of the third material, whereby a diffusion zone is formed by this layer and heat treatment. 2. The active part (1) according to claim 1, wherein at least one of the electrical wires (3, 3', 3'', 3''') in the area has a cross section that narrows as the radial height increases. 3. The active part (1) according to claim 1 or 2, wherein at least one of the electrical wires (3, 3', 3'', 3''') has a plurality of sections having cross sections that taper as the radial height increases. 4. The active part (1) according to any one of claims 1 to 3, wherein between at least one of the printed electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) and at least one of the printed intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) has a three-dimensional structure (5). 5. The active part (1) according to claim 4, wherein the three-dimensional structure (5) has a zigzag pattern (16, 16') or a wavy pattern in cross section. 6. Active part (1) according to any one of claims 1 to 5, wherein the electrical conductivity of the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) varies depending on the radial height. 7. Active part (1) according to any one of claims 1 to 6, wherein the contact layer (5, 5', 5'', 5''') contains nickel. 8. A method for manufacturing an active part (1) of an electrical machine, wherein the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are printed additively, while between the electrical wires, the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) print an intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), while printing alternately at least one electrical wire (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) and at least one intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), while the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are printed in layers, while the intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) are printed in layers, while the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) are printed alternating with the intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), increasing radially, while printing the difference between the first height (23, 23ʽ, 23ʽʽ, 23ʽʽʽ) of the layers of electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) and the second height of the layers of adjacent intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) does not exceed a maximum of two layers, in particular not more than one layer, while between at least one of the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) and at least one of the printed intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) a contact layer (5, 5ʽ, 5ʽʽ, 5ʽʽʽ) ≤ 300 µm of the third material is applied, with this layer and heat treatment forming a diffusion zone. 9. The method according to claim 8, while at one of the stages of the method the first electrical wire (3') and the second, adjacent electrical wire (3'') are printed, while their width decreases, while at the next stage of the method between the first electrical wire (3') ) and the second electric wire (3ʽʽ) print an intermediate element, while its width increases. 10. Method according to claim 8 or 9, wherein electrical wires (3, 3', 3'', 3''') and/or intermediate elements (4, 4', 4'', 4''') are printed on the shaft housing (6). 11. The method according to any one of claims 8-10, wherein the printing of at least one part of one of the electrical wires (3, 3ʽ, 3ʽʽ, 3ʽʽʽ), which represent the first print object, and the printing of at least one part of the intermediate elements (4, 4ʽ, 4ʽʽ, 4ʽʽʽ), which represent the second print object, so that before interleaving, an increase in the radial height of the electric wire (3, 3ʽ, 3ʽʽ, 3ʽʽʽ) or intermediate element (4, 4ʽ, 4ʽʽ, 4ʽʽʽ) ) that lies between greater than or equal to 50% and less than or equal to 200% of the subsequent radial height increment of every other print object. 12. Method according to any one of claims 8 to 11, wherein the active part (1) is subjected to heat treatment. 13. A method according to any one of claims 8 to 12, wherein the active part (1) is manufactured according to one of claims 1 to 7.