DE102020204467A1 - Rotor for an electrical machine and sheet metal cutting for an electrical machine - Google Patents

Abstract

In order to enable improved cooling in a rotor for an electrical machine, comprising a rotor shaft and a laminated core fastened to the rotor shaft, whereby the cooling takes place closer to the heat sources, a rotor (100) for an electrical machine, comprising a rotor shaft ( 10) and a laminated core (11) fastened to the rotor shaft (10) is proposed, the laminated core (11) comprising a plurality of sheet metal cuts (12, 12a, 12b, 12c), each sheet metal cut (12, 12a, 12b, 12c ) Has pole segments (20) comprising cavities, in particular magnetic cavities (21) and / or air cavities (22), for receiving magnets (26) and / or for guiding a magnetic flux, cooling channels (14) being arranged within the laminated core (11) are, wherein the cooling channels (14) are arranged from the rotor shaft (10) essentially in a radial direction (15), preferably up to the axial return channels, extending outwards, wherein it is further provided that the cooling channels (14 ) are meandering along their course in the radial direction (15) and have alternating sections (17) running in the radial direction (15) and sections (19) running in an axial direction (18).

Description

The present invention relates to a rotor for an electrical machine, comprising a rotor shaft and a laminated core fastened to the rotor shaft, the laminated core comprising a plurality of sheet metal sections, each sheet metal section comprising pole segments including cavities, in particular magnetic cavities and / or air cavities, for receiving magnets and / or has for guiding a magnetic flux, cooling channels being arranged within the laminated core, the cooling channels being arranged to run from the rotor shaft essentially in a radial direction outward, preferably up to axial return channels. The present invention further relates to a sheet metal section for a rotor for an electrical machine, an electrical machine with a rotor and a motor vehicle with an electrical machine.

Electrical machines are used in many technical areas. Electric machines used in electric vehicles or hybrid electric vehicles in particular in the field of electric mobility are designed for high performance. During operation, electrical machines and in particular the rotors of electrical machines can become very hot. This can lead to the temperature exceeding a limit temperature above which the magnets of the electrical machine demagnetize, with the result that the power, in particular the continuous power, of the electrical machine and the achievable torque are reduced.

Methods for cooling electrical machines are known in the prior art. One way of cooling electrical machines is what is known as internal rotor cooling, with oil being used as the coolant. Another known possibility for cooling electrical machines is the use of axial compressors for convective cooling via holes within the rotor. Purely convective cooling without an axial compressor is also known in the prior art. Spray cooling methods using oil-air mixtures are also known.

From the DE 10 2016 209 173 A1 A rotor for an electrical machine is known to the applicant, consisting of a rotor shaft and a rotor body arranged non-rotatably on the rotor shaft. The rotor shaft is designed at least in sections as a hollow shaft, with a delivery spindle being non-rotatably arranged in the hollow shaft, by means of which a cooling fluid can be guided through the hollow shaft in a first direction. In order to provide improved cooling of the rotor, it is provided that the rotor body has at least one cooling channel extending in the axial direction with an end-side inlet opening and an opposite end-side outlet opening for the cooling fluid. The cooling fluid guided through the hollow shaft in the first direction can at least partially be introduced into the cooling channel through the inlet opening and can be guided to the outlet opening in a second direction opposite to the first direction.

the DE 10 2011 054 250 A1 discloses a ventilated rotor and stator for a dynamoelectric machine. A laminated rotor of the dynamoelectric machine comprises at least one end flange with a group of cooling openings and at least one inner rotor web plate with a group of cooling openings. At least one outer rotor web plate has a group of cooling openings which is connected to a first group of radially aligned ventilation slots. End flange, inner rotor web plate and outer rotor web plate are combined to form a rotor laminated core, and the group of cooling openings forms an essentially axial cooling channel through which a cooling medium can flow.

From the CN 109 742 883 A an electrical machine with a rotor shaft and a laminated rotor core fixedly attached to the rotor shaft is known. A sheet metal section of the laminated rotor core has incisions running in the radial direction, through which a cooling medium can be guided outwards from the rotor shaft in the radial direction. Cooling channels run through the laminated rotor core in an axial direction, through which the cooling medium, which is guided to the outside in the incisions, can flow out of the laminated rotor core.

In the known solutions, the heat dissipation usually takes place on the rotor shaft. However, the heat losses occur in the magnets or on the outer edge of the rotor. The cooling is therefore determined by the thermal conductivity of the sheet metal sections of the rotor. The cooling takes place away from the heat sources.

The object of the present invention is to provide a rotor for an electrical machine comprising a rotor shaft and a laminated core fastened to the rotor shaft, which has improved cooling and in which the cooling takes place closer to the heat sources. A further object of the present invention is to provide a sheet metal section for a rotor for an electrical machine, an electrical machine with a rotor and a motor vehicle with an electrical machine, with which these advantages are achieved.

To solve the problem on which the invention is based, a rotor for an electrical machine comprising a rotor shaft and a laminated core attached to the rotor shaft is proposed, the laminated core having a plurality of Includes sheet metal sections, each sheet metal section having pole segments comprising cavities, in particular magnetic cavities and / or air cavities, for receiving magnets and / or for guiding a magnetic flux, cooling channels being arranged within the laminated core, the cooling channels from the rotor shaft essentially in a radial direction , preferably up to axial return ducts, are arranged running outwards, it is further provided that the cooling ducts are meandering along their course in the radial direction and have alternating sections running in the radial direction and sections running in an axial direction.

The laminated core comprises a multiplicity of sheet metal cuts which are arranged parallel and adjacent to one another and in contact with one another. The laminated core is built up by the large number of sheet metal cuts. The rotor or the laminated core comprises several, preferably four, more preferably six, particularly preferably eight, magnetic poles which, viewed in an axial direction of the laminated core, each occupy an angular segment of the laminated core. To form the magnetic poles, each sheet metal section has a pole segment, with at least one cavity, in particular a magnetic cavity, preferably being present in each pole segment. A magnet, in particular a permanent magnet, can be arranged in the magnet cavity. A magnet does not have to be arranged in each cavity. Air cavities can also be arranged in the pole segments, which are separated from one another and / or the magnetic cavities by material webs. Furthermore, the air cavities can be designed as partial areas of the magnetic cavities, i.e. the air cavities are those areas of the cavities which are not filled by a magnet. In this case, magnetic cavities and air cavities merge directly into one another without a separating material web and together form a larger cavity. By means of the air cavities and in particular the remaining material webs, the magnetic flux can be guided or directed in the sheet metal section and in particular in the laminated core to optimize the performance of the electrical machine. In an exemplary eight-pole laminated core, each sheet metal section has eight pole segments, with each pole segment occupying an angular range of 45 °.

The cooling channels arranged in the laminated core run, starting from the rotor shaft, essentially in a radial direction outwards. A course running outwards essentially in a radial direction is understood to mean that the cooling channels have a main orientation in the radial direction, so that a cooling medium can flow into the cooling channels at an inner edge of the laminated core and is conducted outward in the radial direction. As a result of this measure, the cooling medium can be conducted to the heat sources located on the outer edge, in particular the magnets. The cooling channels preferably do not extend to the outside of the laminated core. Instead, it is preferably provided that the cooling channels open into axial return channels, the axial return channels running within the laminated core.

According to the invention, it is provided that the cooling channels are meandering along their course in the radial direction and have alternating sections running in the radial direction and sections running in an axial direction of the laminated core. For this purpose, the cooling channels have turns or turns. The individual turns or turns are dimensioned so small that the axial deviations of the cooling channels from the radial alignment are small compared to the radial length of the cooling channels, and are, for example, less than 10%, preferably less than 5%, of the radial length.

A coolant introduced into the cooling channels from an inner edge of the laminated core is preferably carried to the outside by the rotation of the rotor in the stator of the electrical machine, and flows alternately in the sections extending in the radial direction further outwards in the radial direction and in the between the Sections extending in the radial direction and sections extending in the axial direction are respectively forward and backward in the axial direction. As a result of the sections running alternately in the radial direction and in the axial direction, the cooling ducts, viewed in the radial direction, have a multiplicity of steps over which the cooling medium flows. In this case, turbulence advantageously occurs in the cooling medium, so that the cooling medium is effectively mixed and, overall, more heat can be absorbed and dissipated by the cooling medium. The heat dissipation is thus improved.

The cooling medium can preferably be oil, air, an oil-air mixture or another suitable cooling medium.

Through the cooling channels running essentially in the radial direction, the cooling medium is preferably guided outwards into the area of the edge of the laminated core and thus into the area of the heat sources, in particular into the area of the magnets arranged in the magnet cavities. In this way, more effective cooling is provided, so that higher powers and higher torques can be achieved with an electrical machine.

It is preferably provided that the rotor shaft is a hollow shaft and has cooling medium openings in a circumferential direction, the Cooling channels are in a fluidic connection with the cooling medium openings.

The cooling medium, for example the air or the oil, exits through the cooling medium opening of the hollow shaft and enters the cooling channels in the laminated core.

With a further advantage it can be provided that the sections of the cooling channels running in the axial direction each have a length which corresponds to the thickness of at least two, preferably of at least five, particularly preferably of at least ten, sheet metal cuts.

Since the axial thickness of a sheet metal section is significantly smaller than the radius of the sheet metal section viewed in the radial direction, the length of the sections of the cooling channels running in the axial direction is small compared to the radial length of the cooling channels.

The sections running in the axial direction can also each have a length which corresponds to the thickness of three, four or more sheet metal cuts.

Depending on the choice of the length of the sections running in the axial direction, a desired flow of the cooling medium and a desired cooling capacity can thus be set.

With a further advantage it can be provided that the plurality of sheet metal cuts comprises perforated sheet metal cuts, the perforated sheet metal cuts having openings, in particular holes, the openings being arranged in rows aligned in the radial direction, with at least a first perforated sheet metal cut and at least a second perforated Sheet metal section are arranged next to one another in such a way that the openings of the first perforated sheet metal section and the openings of the second perforated sheet metal section are offset from one another, viewed in the radial direction, and are arranged partially overlapping one another and together form the cooling channels.

In the following, a first perforated sheet metal cut can also be understood to mean a perforated sheet metal cut in a first alignment variant. In the following, a second perforated sheet metal cut can also be understood to mean a perforated sheet metal cut in a second alignment variant. Insofar as several first or second perforated sheet metal cuts are mentioned in the following, this can be understood to mean that several perforated sheet metal cuts are provided in a first alignment variant or several perforated sheet metal cuts are provided in a second alignment variant.

If the sections of the cooling channels running in the axial direction each have a length which corresponds to the thickness of more than two sheet metal cuts, several first and several second perforated sheet metal cuts can be arranged next to one another in such a way that the openings of the several first perforated sheet metal cuts and the openings of the a plurality of second perforated sheet metal cuts are offset from one another, viewed in the radial direction, and are arranged partially overlapping one another and together form the cooling channels.

If the sections of the cooling channels running in the axial direction have, for example, a length which corresponds to the thickness of ten sheet metal cuts, then five first perforated sheet metal cuts and five second perforated sheet metal cuts can be arranged next to one another. The five first perforated sheet metal cuts are aligned congruently with one another and the five second perforated sheet metal cuts are aligned congruently with one another.

A "perforated" sheet metal cut does not necessarily have to have circular holes, but it is possible that the perforations of the perforated sheet metal cuts are designed as circular holes.

In general, a perforated sheet metal cut is understood in the following to mean a sheet metal cut which has openings that penetrate the entire axial thickness of the sheet metal cut. The perforations are to be distinguished from the magnet and / or air cavities. In a plan view of a perforated sheet metal section, openings, in particular holes, are thus provided in the sheet metal section, the openings, in particular the holes, being arranged in rows aligned in the radial direction. The material of the sheet metal section remaining there forms webs between adjacent holes, seen in the radial direction.

If a first perforated sheet metal section and a second perforated sheet metal section are arranged next to one another in such a way that the perforations of the first perforated sheet metal section and the perforations of the second perforated sheet metal section are offset from one another as seen in the radial direction and are arranged partially overlapping one another, then the offset overlapping perforations form the Cooling channels off. If a cooling medium, for example oil, flows into a first opening of the first perforated sheet metal section, the cooling medium cannot flow directly into an adjacent second opening of the first perforated sheet metal section due to the material webs arranged between the perforations. However, the cooling medium then flows into a first opening of the second perforated sheet metal section, which is arranged overlapping the first opening of the first perforated sheet metal section and offset from this in the radial direction. Since the second perforated sheet metal section is arranged adjacent to the first perforated sheet metal section in the axial direction, the cooling medium flows a little in the axial direction in a section extending in the axial direction. In the first opening of the second perforated sheet metal section, the cooling medium can continue to flow outward in the radial direction, corresponding to the length of the first opening of the second perforated sheet metal section, in a section running in the radial direction, until the cooling medium hits the material web between the first opening of the second perforated sheet metal section and meets an adjacent second opening of the second perforated sheet metal section. The first opening of the second perforated sheet metal section overlapping and offset outward in the radial direction, however, a second opening of the first perforated sheet metal section is arranged so that the cooling medium in a section running in the axial direction back in the axial direction and into the second opening of the first perforated sheet metal section can flow. From the second opening of the first sheet metal section, the cooling medium will flow in an analogous manner into the next, namely the second, opening of the second perforated sheet metal section, and then into the third opening of the first sheet metal section and so on. In this way, the cooling medium is successively carried to the outside in the cooling channels, the cooling channels being designed to be serpentine along their course in the radial direction.

It is preferably provided that the at least one first perforated sheet metal cut, preferably the several first perforated sheet metal cuts, and the at least one second perforated sheet metal cut, preferably the several second perforated sheet metal cuts, are arranged between two further sheet metal cuts, the two further sheet metal cuts being perforated sheet metal cuts or not are perforated sheet metal cuts, the two further sheet metal cuts being designed and / or aligned in such a way that they have no opening, in particular holes, which overlap the openings of the first perforated sheet metal cut and / or the second perforated sheet metal cut.

The two further sheet metal cuts, which are arranged adjacent to the first perforated sheet metal cut, preferably to the several first perforated sheet metal cuts, and the second perforated sheet metal cut, preferably to the several second perforated sheet metal cuts, delimit the cooling channels in the axial direction, since the further sheet metal cuts do not Have openings which are arranged to overlap with an opening of the first perforated sheet metal section and / or the second perforated sheet metal section. The cooling channels, which are arranged to run in the radial direction and are designed to be serpentine along their course in the radial direction, thus each run between such a pair of further sheet metal cuts. The first perforated sheet metal section and the second perforated sheet metal section are, as it were, sandwiched between the further sheet metal sections in the form of a partial laminated core. The laminated core can comprise several of these partial laminated cores.

The further sheet metal cuts can be non-perforated or unperforated sheet metal cuts which, with the exception of the magnet or air cavities, have no further openings. In such a case, the laminated core, viewed in the axial direction, can consist of a sequence of partial laminated cores, each partial laminated core having two perforated sheet metal cuts which are arranged between two further sheet metal cuts. Each of the further sheet metal cuts can belong to two adjacent sheet metal bundles, so that on a first side of the further sheet metal cut a perforated sheet metal cut, for example the first perforated sheet metal cut, of a first partial sheet metal packet and on the opposite second side of the further sheet metal cut another perforated sheet metal cut, for example the second perforated sheet metal section, a second partial laminated core is arranged.

It can also be provided that the further sheet metal cuts, between which the first perforated sheet metal cut and the second perforated sheet metal cut are arranged, are also perforated sheet metal cuts. These further perforated sheet metal cuts are then designed or aligned in such a way that their openings are not arranged so as to overlap the openings in the first perforated sheet metal cut or the second perforated sheet metal cut arranged directly adjacent. The other perforated sheet metal cuts can have a double function and on the one hand be arranged adjacent to the first perforated sheet metal cut or the second perforated sheet metal cut of a first partial sheet stack and delimit a cooling channel in the axial direction, and at the same time themselves as a first perforated sheet metal cut or as a second perforated sheet metal cut be formed of a second partial laminated core.

If several cooling channels are provided, the arrangement of the cooling channels in the laminated rotor core can be designed analogously to the steps of a spiral or spiral staircase, that is, in a plan view of the laminated rotor core, adjacent cooling channels in the axial direction are offset from one another in the circumferential direction of the laminated rotor core.

It can advantageously be provided that the distances between two adjacent ones Openings in a series of openings in a perforated sheet metal section are smaller than the diameter of the openings measured in the radial direction.

In other words, the width of the webs between two openings of a perforated sheet metal section arranged adjacently in the radial direction is less than the diameter of the openings measured in the radial direction. If a second perforated sheet metal section is thus arranged adjacent to a first perforated sheet metal section in such a way that the openings of the second perforated sheet metal section are offset in the radial direction with respect to the openings of the first perforated sheet metal section, the choice of the distances ensures that alternating in the radial direction always an opening of the second perforated sheet metal section overlaps an opening of the first perforated sheet metal section and vice versa.

Furthermore, it can be provided that the perforated sheet metal cuts have identical hole patterns.

This has the advantage that only one configuration of perforated sheet metal cuts has to be provided, as a result of which the production and manufacturing costs of the entire laminated core of the rotor are reduced.

Furthermore, it can preferably be provided that all sheet metal cuts of the laminated core, optionally with the exception of end sheet metal cuts forming the end faces of the sheet metal core, are perforated sheet metal cuts.

It can preferably be provided that each perforated sheet metal cut has two types of rows of perforations aligned in the radial direction, the perforations of the rows of the first type being arranged offset from the perforations of the rows of the second type, viewed in the radial direction.

Each perforated sheet metal section can have at least one row of the first type and at least one row of the second type. If two of these perforated sheet metal cuts are thus arranged next to one another, the rows of the second type can be arranged in relation to the rows of the first type by rotating the second sheet metal section around the axial direction or by turning or mirroring the second sheet metal section about an axis running in the radial direction, that the openings in the rows of the first type and the openings in the rows of the second type are offset in the radial direction and partially overlapping one another and together form the cooling channels.

It is preferably provided that each pole segment has one or two rows of openings aligned in the radial direction.

If a pole segment has two rows of openings aligned in the radial direction, the two rows can both be rows of the first type or the second type, or a first of the rows can be a row of the first type and the second of the rows can be a row of the second kind.

Preferably, it can furthermore be provided that pole segments of each perforated sheet metal section that are adjacent in a circumferential direction have different types of rows of perforations aligned in the radial direction.

It is preferably provided that the second perforated sheet metal section is obtained by rotating a perforated sheet metal section identical to the first perforated sheet metal section about the axial direction and / or by rotating or mirroring about an axis in the radial direction by 180 °.

If each pole segment has only one type of rows of openings aligned in the radial direction, then it is preferably provided that adjacent pole segments of each perforated sheet metal section have different types of rows of openings aligned in the radial direction. Thus, a first pole segment can have two rows of a first type, and the pole segments adjacent to the first pole segment in the circumferential direction have two rows of a second type. By rotating the second sheet metal section by a sector angle, which depends on the number of pole pairs of the electrical machine, the openings in the rows of the second type of Corresponding pole segments are arranged opposite the openings of the rows of the first type in such a way that the openings of the first perforated sheet metal section and the openings of the second perforated sheet metal section are offset from one another when viewed in the radial direction and are arranged partially overlapping one another and together form the cooling channels. In the case of an eight-pole rotor, the sector angle is 45 °, for example.

It can also be provided that each pole segment has only one row of a first type, and that the pole segments that are respectively adjacent in the circumferential direction each have only one row of a second type. In this case, the second perforated sheet metal cut can be obtained by turning around or mirroring a perforated sheet metal cut identical to the first sheet metal cut about an axis running in the radial direction, so that the openings in the rows of the second type of the corresponding pole segments are opposite to the openings in the rows of the first Art are arranged that the openings of the first perforated sheet metal section and the openings of the second perforated sheet metal section, viewed in the radial direction, are offset from one another and partially overlapping one another and together form the cooling channels.

It is particularly advantageous that the cooling channels open into the cavities, in particular into the magnetic cavities and / or into the air cavities.

The cavities, in particular the magnetic cavities or the air cavities, of the sheet metal sections of the laminated core are arranged so as to overlap in the axial direction of the laminated core. Areas of the cavities that are not filled by magnets thus form an axial return channel for the cooling medium. One advantage of using the cavities, in particular the magnetic cavities or the air cavities, as return channels is that the cooling medium is brought close to the magnets.

If the cooling channels open into magnetic cavities, sealing elements can also be provided in the magnetic cavities, which seal the magnets arranged in the magnetic cavities from the cooling medium flowing through the cavities.

It can also preferably be provided that each sheet metal section has at least one, preferably two return openings per pole segment, the return openings forming return channels in the laminated core.

In other words, the return openings of the sheet metal cuts, regardless of whether the sheet metal cuts are perforated sheet metal cuts or non-perforated sheet metal cuts and / or how the perforated sheet metal cuts are rotated or aligned with one another, are arranged so that they overlap in the axial direction so that the return openings form an axial return channel.

The cooling channels then each end in one of the return channels formed by the return openings. The return openings can also be designed as perforations, in particular as holes, in the sheet metal cuts.

It can particularly preferably be provided that at least some of the return openings are in fluidic connection with the openings in the perforated sheet metal cuts.

Another solution to the problem on which the invention is based is to provide a sheet metal section for a previously described rotor for an electrical machine.

Yet another solution to the problem on which the invention is based consists in providing an electrical machine comprising a rotor as described above.

Another solution to the problem on which the invention is based is to provide a motor vehicle, in particular an electric vehicle or an electric hybrid motor vehicle, comprising an electrical machine as described above.

• 1 einen Rotor für eine elektrische Maschine mit einer Rotorwelle und einem Blechpaket,
• 2 einen Querschnitt durch einen Rotor mit Kühlkanälen,
• 3 eine Rotorwelle mit Kühlmediumsöffnungen,
• 4 einen Querschnitt durch einen Kühlkanal,
• 5a eine erste Ausgestaltung eines ersten gelochten Blechschnitts,
• 5b eine erste Ausgestaltung eines zweiten gelochten Blechschnitts,
• 5c eine Aufsicht auf durch Aufeinanderlegen eines ersten und eines zweiten gelochten Blechschnitts gebildete Kühlkanäle,
• 5d einen weiteren Blechschnitt,
• 6 ein Polsegment mit Magneten in Magnetkavitäten mit Abdichtelementen,
• 7a eine zweite Ausgestaltung eines ersten gelochten Blechschnitts,
• 7b eine zweite Ausgestaltung eines zweiten gelochten Blechschnitts,
• 8a eine dritte Ausgestaltung eines ersten gelochten Blechschnitts,
• 8b eine dritte Ausgestaltung eines zweiten gelochten Blechschnitts, und
• 9 einen weiteren Querschnitt durch einen Rotor mit Kühlkanälen.

The invention is explained in more detail below with reference to the accompanying figures. Show it

• 1 a rotor for an electrical machine with a rotor shaft and a laminated core,
• 2 a cross section through a rotor with cooling channels,
• 3 a rotor shaft with cooling medium openings,
• 4th a cross section through a cooling channel,
• 5a a first embodiment of a first perforated sheet metal section,
• 5b a first embodiment of a second perforated sheet metal cut,
• 5c a plan view of cooling channels formed by laying a first and a second perforated sheet metal section on top of one another,
• 5d another sheet metal cut,
• 6th a pole segment with magnets in magnet cavities with sealing elements,
• 7a a second embodiment of a first perforated sheet metal cut,
• 7b a second embodiment of a second perforated sheet metal cut,
• 8a a third embodiment of a first perforated sheet metal cut,
• 8b a third embodiment of a second perforated sheet metal cut, and
• 9 another cross-section through a rotor with cooling channels.

1 shows a rotor 100 for an electrical machine not shown in detail. The rotor 100 includes a rotor shaft 10 and one on the rotor shaft 10 attached laminated core 11 . The sheet metal package 11 is made from a variety of sheet metal cuts 12th constructed, which are arranged adjacent and contiguous to each other.

2 shows a cross section through the rotor 100 after 1 . The rotor shaft 10 is as a hollow shaft 13th educated. In the sheet metal package 11 or the sheet metal cuts 12th are cooling channels 14th arranged, of which in 2 only two are shown by way of example. The cooling channels 14th run from the rotor shaft 10 essentially in a radial direction 15th outward. The rotor shaft 10 points, as well as in 3 shown, cooling medium openings 16 on, through which a cooling medium enters the cooling channels 14th can flow.

As in the detailed representation of the 4th the cooling channels are shown 14th along their course in the radial direction 15th meandering and pointing alternately in the radial direction 15th running sections 17th and in an axial direction 18th running sections 19th on. The cooling channels 14th are made by arranging a first perforated sheet metal cut next to one another 12a and a second perforated sheet metal cut 12b educated. The two perforated sheet metal cuts 12a , 12b are between two more sheet metal cuts 12c arranged.

5a shows a first perforated sheet metal section 12a for the sheet metal package 11 of the rotor 100 . The sheet metal cut 12a has a total of eight pole segments 20th on, with each pole segment 20th Magnetic cavities 21 as well as air cavities 22nd having. Between the cavities 21 , 22nd are material bars 23 arranged, which are designed to guide the magnetic flux. Furthermore, each pole segment 20th two rows 24a , 24b of in the radial direction 15th adjacent openings 25th on. One half of the pole segments 20th shows rows of a first kind 24a on which three breakthroughs each 25th include. The radially innermost perforations 25th are to the inner edge 29 of sheet metal cutting 12a open minded. Thus, a cooling medium can flow out of the cooling medium openings 16 the rotor shaft 10 into the breakthrough 25th pour in. The other half of pole segments 20th has rows of a second kind 24b on, which also have three breakthroughs 25th include, but these in the radial direction 15th towards the breakthroughs 25th of the first kind 24a are staggered from rows. The ones in the radial direction 15th seen extreme breakthroughs 25th are to the magnetic cavities 21 open to.

5b shows a second perforated sheet metal section 12b . The second perforated sheet metal cut 12b has the same hole pattern as the first perforated sheet metal cut 12a the 5a and is opened by rotating the first perforated sheet metal cut 12a by 45 ° around the axial direction perpendicular to the plane of the figure 18th obtain.

Will be the second punched sheet metal cut 12b the 5b at first perforated sheet metal cut 12a the 5a placed, the hole pattern results 5c , being in the radial direction 15th offset to each other and overlapping arranged perforations 25th of the first perforated sheet metal cut 12a and the second perforated sheet metal cut 12b those in the radial direction 15th running cooling channels 14th form which, as in 4th shown along its course in the radial direction 15th are formed serpentine and alternating in the radial direction 15th running sections 17th and in the axial direction 18th running sections 19th exhibit.

To the cooling ducts 14th after 4th and 5c in the axial direction 18th further sheet metal cuts are to be limited 12c provided which, as in 5d shown, although magnetic cavities 21 and air cavities 22nd have, but also do not include any breakthroughs. To 4th and 5c the cooling medium flows through the cooling medium openings 16 the rotor shaft 10 in the cooling channels 14th and is made by the rotation of the rotor 100 in the radial direction 15th carried outwards. Because the cooling channels 14th in the magnet cavities 21 or air cavities 22nd open out, the cooling medium is applied to the magnets that represent the heat sources 26th ( 5c ) brought up. The magnetic cavities 21 or the air cavities 22nd of sheet metal cuts 12th , 12a , 12b , 12c form return channels 27 through which the cooling medium, as in 2 and 4th shown in the axial direction 18th again from the rotor 100 can flow out.

To prevent the cooling medium, especially the oil, from continuing in the radial direction 15th to the outside of the magnet 26th can, as in 6th shown sealing elements 28 in the magnet cavities 21 or the air cavities 22nd be arranged.

7a shows a further embodiment of a first perforated sheet metal cut 12a . Each pole segment 20th this first perforated sheet metal cut 12a has only one row 24a , 24b from in radial direction 15th aligned breakthroughs 25th on. One half of the pole segments 20th each has a row of a first type 24a comprising three breakthroughs. The radially innermost opening 25th is to the inner edge 29 of sheet metal cutting 12a open minded. The other half of pole segments 20th each has a row of a second type 24b on, which also have three breakthroughs 25th includes, but this in the radial direction 15th towards the breakthroughs 25th of the first kind 24a are staggered from rows. The ones in the radial direction 15th seen extreme breakthroughs 25th are to the magnetic cavities 21 and air cavities 22nd open to.

By turning the first perforated sheet metal cut 12a after 7a about an axis in the radial direction 15th a second perforated sheet metal cut is made by 180 ° 12b according to 7b obtain. Will this second sheet metal cut 12b on the first sheet metal cut 12a after 7a placed, so form the Breakthroughs 25th of the first sheet metal cut 12a and the breakthroughs 25th of the second sheet metal cut 12b in the radial direction 15th outward meandering cooling channels 14th . Each pole segment 20th points to the configuration according to the 5a until 5d only one cooling channel 14th on. The magnet cavities also form in this embodiment 21 or the air cavities 22nd axial return channels 27 for the cooling medium.

Will be two more punched sheet metal cuts 12a , 12b the 7a and 7b As described above, placed one on top of the other to form a second partial laminated core and as a whole opposite the first partial laminated core of the first two perforated sheet metal cuts 12a , 12b Rotated 45 ° and then placed on the first partial laminated core, this is how the cooling channels are 14th twisted against each other in the two laminated cores and not connected in terms of flow. The perforated sheet metal cuts 12a , 12b different partial sheet stacks then serve as further sheet metal cuts at the same time 12c to the cooling ducts 14th in the axial direction 18th to limit. With the sheet metal cuts 12a and 12b In this embodiment, there are no non-perforated sheet metal cuts like after 5d needed.

Yet another embodiment of a first perforated sheet metal cut 12a is in 8a shown. In this case, too, each have two adjacent pole segments 20th two different configurations 24a , 24b of rows of adjacently arranged perforations 25th on. However, this is the radially outermost opening 25a the second row 24b in the radial direction 15th extended trained. Furthermore is in the pole segments 20th with the ranks 24b the second type has a return opening 30th intended. By turning the first perforated sheet metal cut 12a after 8a about an axis in the radial direction 15th a second perforated sheet metal cut is made by 180 ° 12b according to 8b obtain. The return openings 30th and the extreme breakthroughs 25a form when arranging the sheet metal cuts 12a , 12b according to the pattern of sheet metal cuts 12a , 12b the 7a and 7b axial return channels 27 the end. With one of the sheet metal cuts 12a , 12b the 8a and 8b formed laminated core 11 the cooling medium is therefore not in the magnet cavities 21 or air cavities 22nd guided. Instead, the cooling medium is used, as in 9 shown through the out of the return ports 30th and the outermost breakthroughs 25a formed axial return channels 27 discharged.

List of reference symbols

100

rotor

10

Rotor shaft

11

Laminated core

12th

Sheet metal cut

12a

First sheet metal cut

12b

Second sheet metal cut

12c

Another sheet metal cut

13th

Hollow shaft

14th

Cooling duct

15th

Radial direction

16

Cooling medium opening

17th

Section extending in the radial direction

18th

Axial direction

19th

Section extending in the axial direction

20th

Pole segment

21

Magnetic cavity

22nd

Air cavity

23

Material bar

24a

Row of the first kind

24b

Row of the second kind

25th

Breakthrough

25a

Breakthrough

26th

magnet

27

Return duct

28

Sealing element

29

Inner edge

30th

Return opening

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016209173 A1 [0004]
• DE 102011054250 A1 [0005]
• CN 109742883 A [0006]

Claims (12)

A rotor (100) for an electrical machine, comprising a rotor shaft (10) and a laminated core (11) fastened to the rotor shaft (10), the laminated core (11) comprising a plurality of sheet metal cuts (12, 12a, 12b, 12c), each sheet metal section (12, 12a, 12b, 12c) having pole segments (20) comprising cavities, in particular magnetic cavities (21) and / or air cavities (22), for receiving magnets (26) and / or for guiding a magnetic flux, wherein cooling ducts (14) are arranged within the laminated core (11), the cooling ducts (14) extending outwards from the rotor shaft (10) essentially in a radial direction (15), preferably up to the axial return ducts, characterized in that the cooling channels (14) are meandering along their course in the radial direction (15) and have alternating sections (17) running in the radial direction (15) and sections (19) running in an axial direction (18). Rotor (100) Claim 1 , characterized in that the rotor shaft (10) is a hollow shaft (13) and has cooling medium openings (16) in a circumferential direction, the cooling channels (14) being in fluidic connection with the cooling medium openings (16), and / or that the in the axial direction (18) extending sections (19) of the cooling channels (14) each have a length which corresponds to the thickness of at least two, preferably of at least five, particularly preferably of at least ten, sheet metal cuts (12, 12a, 12b, 12c). Rotor (100) Claim 1 or 2 , characterized in that the plurality of sheet metal cuts (12, 12a, 12b, 12c) comprises perforated sheet metal cuts (12a, 12b), the perforated sheet metal cuts (12a, 12b) having openings (25, 25a), in particular holes, the Openings (25, 25a) are arranged in rows (24a, 24b) aligned in the radial direction (15), at least one first perforated sheet metal cut (12a) and at least a second perforated sheet metal cut (12b) being arranged next to one another that the openings ( 25, 25a) of the first perforated sheet metal section (12a) and the openings (25, 25a) of the second perforated sheet metal section (12b), viewed in the radial direction (15), are offset from one another and partially overlapping one another and together form the cooling channels (14). Rotor (100) Claim 3 , characterized in that the at least one first perforated sheet metal cut (12a), preferably the several first perforated sheet metal cuts (12a), and the at least one second perforated sheet metal cut (12b), preferably the several second perforated sheet metal cuts (12b), between two further sheet metal cuts (12c), the two further sheet metal cuts (12c) being perforated sheet metal cuts (12a, 12b, 12c) or non-perforated sheet metal cuts (12c), the two further sheet metal cuts (12c) being designed and / or aligned in such a way that they have no openings (25, 25a), in particular holes, which are arranged to overlap the openings (25, 25a) of the first perforated sheet metal section (12a) and / or of the second perforated sheet metal section (12b). Rotor (100) Claim 3 or 4th , characterized in that the perforated sheet metal cuts (12a, 12b) have identical hole patterns, and / or that all sheet metal cuts (12, 12a, 12b, 12c) of the laminated core (11), possibly with the exception of the end faces of the laminated core (11) forming end sheet metal cuts , perforated sheet metal cuts (12, 12a, 12b). Rotor (100) according to one of the Claims 3 until 5 , characterized in that each perforated sheet metal cut (12, 12a, 12b) has two types of rows (24a, 24b) of openings (25, 25a) aligned in the radial direction (15), the openings (25, 25a) of the rows (24a) of the first type, viewed in the radial direction (15), are arranged offset from the openings (25, 25a) of the rows (24b) of the second type. Rotor (100) according to one of the Claims 3 - 6th , characterized in that each pole segment (20) has one or two rows (24a, 24b) of openings (25, 25a) aligned in the radial direction (15), and / or that adjacent pole segments (20) of each perforated sheet metal section in a circumferential direction (12, 12a, 12b, 12c) have mutually different types of rows (24a, 24b) of perforations (25, 25a) aligned in the radial direction (15). Rotor (100) according to one of the Claims 3 until 7th , characterized in that the second perforated sheet metal section (12, 12b) by rotating a perforated sheet metal section (12, 12a, 12b) identical to the first perforated sheet metal section (12, 12a) about the axial direction (18) and / or by rotating about an axis is obtained by 180 ° in the radial direction (15). Rotor (100) according to one of the preceding claims, characterized in that the cooling channels (14) open into the cavities, in particular into the magnet cavities (21) and / or into the air cavities (22), and / or that each sheet metal cut (12 , 12a, 12b) has at least one, preferably two, return openings (30) per pole segment (20), the return openings (30) forming return channels (27) in the laminated core (11). Sheet metal cut (12, 12a, 12b) for a rotor (100) for an electrical machine according to one of the Claims 1 until 9 . Electric machine with a rotor according to one of the Claims 1 until 9 . Motor vehicle, in particular electric vehicle or hybrid electric vehicle, with an electric machine Claim 11 .

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