DE102020129142B4 - Rotor for a rotating electrical machine - Google Patents

Abstract

The invention relates to a rotor (40) for a synchronous machine (70) without permanent magnets, having a magnetic unit (42) which has a base body (44) and is designed to provide magnetic poles (16) alternating in the circumferential direction on the air gap side, with each magnetic pole (16) a winding section (48, 50) arranged on the base body (44) is associated with an excitation winding of the rotor (40). According to the invention, each winding section (48, 50) is arranged in at least two winding chambers (52, 54) assigned to this respective magnetic pole (16), which are formed by respective through-openings (58) formed in the base body (44), the through-openings (58) provide respective flux blocking sections which are designed to block a magnetic flux during normal operation, the through-openings (58) being separated from one another by a respective flux-conducting section (56) which is designed to conduct the magnetic flux during normal operation, the through-openings (58 ) are arranged at a distance from an axis of rotation (22) of the rotor (40) and extend in an axial direction parallel to the axis of rotation (22), the base body (44) at least partially providing a rotor surface (28) of the rotor (40) and between two magneti provided immediately adjacent in the circumferential direction rule poles (16) has a radial recess (64) which extends in the axial direction and in which a coupling element (46) is arranged, wherein the coupling element (46) is formed from a grain-oriented magnetizable material.

Description

The invention relates to a rotor for a synchronous machine without permanent magnets, with a magnetic unit that has a base body and is designed, during normal operation, to provide magnetic poles on the air gap side in the circumferential direction with respect to an axis of rotation of the rotor in such a way that the magnetic poles have alternating polarities in the circumferential direction , Each magnetic pole being assigned a winding section, arranged on the base body, of an excitation winding of the rotor. Furthermore, the invention relates to a synchronous machine without permanent magnets, having a stator and a rotor which is arranged such that it can rotate with respect to the stator. Furthermore, the invention relates to a motor vehicle with a synchronous machine without permanent magnets. Finally, the invention also relates to a method for producing a rotor for a synchronous machine without permanent magnets, wherein a magnetic unit of the rotor, which has a base body, is designed in order to have magnetic poles on the air gap side in the circumferential direction in relation to an axis of rotation of the rotor during normal operation to provide that the magnetic poles have alternating polarities in the circumferential direction, with each magnetic pole being assigned a winding section, arranged on the base body, of an excitation winding of the rotor.

Rotors with magnetic units, synchronous machines without permanent magnets, in particular externally excited synchronous machines, and motor vehicles as well as methods for their production are extensively known in the prior art, so that there is basically no need for separate printed evidence in this regard. Generic synchronous machines are not only, but are now often used in electrically driven motor vehicles such as hybrid vehicles, electric vehicles or the like in the area of a respective drive device. In addition, however, they can be used not only in the drive device of the motor vehicle but also in other drive functions, for example in a window winder, a starter and/or the like.

The synchronous machine is a rotating electrical machine that converts electrical energy into mechanical energy, in particular kinetic energy in the form of a rotation and/or mechanical energy into electrical energy in generator operation. The movement is usually a rotary movement performed by the rotor relative to the stator. In contrast to the rotor, the stator is generally arranged in a rotationally fixed manner, that is to say that a rotary movement involves a rotary movement of the rotor relative to the stator.

The stator and the rotor are linked by means of a magnetic flux, whereby the force effect, namely the torque, is generated during motor operation, which drives the rotor to rotate in relation to the stator. In generator operation, on the other hand, mechanical energy supplied to the rotor can be converted into electrical energy in the form of torque. For this purpose, the stator and also the rotor generally have a magnetic unit, which in turn comprises a winding through which an electric current flows. Rotating electrical machines of the generic type are in particular, for example, induction machines that can be connected to a multi-phase, in particular three-phase, electrical power supply network, specifically synchronous machines, synchronous reluctance machines, synchronous machines with a damper cage or the like. The rotating electrical machine can be designed both as an internal rotor and as an external rotor.

In an electrically drivable motor vehicle, the rotating electrical machine is often used to drive the motor vehicle during normal driving operation of the motor vehicle. In addition, it can also be provided for other drive functions, for example in a window winder, in an oil and/or water pump and/or the like.

Magnetic units, which are arranged both in the stator and in particular in the rotor, serve, among other things, to provide and/or guide the magnetic flux that occurs in a predetermined manner, in particular during normal operation of the rotating electrical machine, in order to achieve the desired force effect or to achieve the desired torque. It should be borne in mind here that a magnetic flux density and also the direction of the magnetic flux density or a magnetic flux in the magnetic unit can be very different. In the prior art, a stack of laminations consisting of individual laminations arranged one after the other in the axial direction in relation to the axis of rotation of the rotor and electrically insulated from one another, or a body element made of a magnetizable material that is electrically poorly conductive, is often used for the magnetic unit. Such a magnetic unit usually has almost isotropic flux-guiding properties for the magnetic flux.

In this context, for example, disclosed EP 3 629 447 A1 an arrangement for an electric machine with reduced rotor-post loss. Furthermore, the U.S. 8,618,708 B2 an electric machine. Finally revealed the EP 3 018 802 A2 a method of making a runner.

In addition, the DE 10 2007 040 750 A1 a current-excited synchronous motor, in particular for vehicle drives. the DE 10 2016 204 154 A1 discloses a rotating electric machine. the US 2018/0166937 A1 discloses a synchronous reluctance machine. Furthermore, WO 2014/024 023 A2 discloses a rotor of a rotating electrical machine. Furthermore, the JP 2016-59099 A a rotating electrical machine.

Even if the aforementioned prior art has proven itself, there still remains a need for improvement. Permanently excited synchronous machines are often more efficient than separately excited synchronous machines. At the same time, however, the separately excited synchronous machine can be controlled more favorably with regard to the intended operation, because the separately excited rotor provides an additional degree of freedom for controlling the electrical machine.

The object of the invention is to achieve an improvement here.

To achieve the object, the invention proposes a rotor, a synchronous machine without permanent magnets, a motor vehicle and a method for producing a rotor according to the independent claims.

Advantageous developments result from the features of the dependent claims.

With regard to a generic rotor, the invention proposes in particular that each winding section be arranged in at least two winding chambers assigned to this respective magnetic pole, which are formed by respective through-openings formed in the base body, with the through-openings providing respective flux blocking sections which are used to block a magnetic Flux are formed in normal operation, the through-openings being separated from one another by a respective flux-guiding section, which is designed to guide the magnetic flux in normal operation, the through-openings being arranged at a distance from the axis of rotation of the rotor and extending in an axial direction parallel to the axis of rotation of the runner.

With regard to a generic synchronous machine without permanent magnets, the invention proposes in particular that the rotor be designed according to the invention.

With regard to a generic motor vehicle, the invention proposes in particular that the synchronous machine without permanent magnets be designed according to the invention.

With regard to a generic method for producing a rotor, the invention proposes in particular that the winding section be arranged in at least two winding chambers assigned to this respective magnetic pole, which are formed by respective through-openings formed in the base body, the through-openings providing respective flux blocking sections which are designed to block a magnetic flux during normal operation, with the through-openings being separated from one another by a respective flux-guiding section, which is designed to conduct the magnetic flux during normal operation, with the through-openings being arranged at a distance from the axis of rotation of the rotor and being in an axial Extend direction parallel to the axis of rotation of the rotor.

The invention uses, among other things, the idea that the efficiency of a separately excited synchronous machine can be increased, particularly in a partial load range, by additionally achieving a drive effect using the reluctance effect in the manner of a reluctance synchronous machine. The inventive design of the magnetic unit of the rotor can namely ensure that the rotor winding can not only be magnetized in accordance with a separately excited synchronous machine, but can also additionally use the reluctance effect for drive purposes. In order to utilize these effects, the invention proposes that through-openings are formed in the magnetic unit, which extend in the axial direction to the axis of rotation of the rotor, with part of the excitation winding of the rotor being able to be arranged in at least some of the through-openings. As a result, in addition to the typical excitation of the rotor and the use of the drive effect of a separately excited synchronous machine, the use of the reluctance effect can also be achieved, whereby the effort for the separate excitation can be reduced in normal operation, especially in a partial load range of the synchronous machine. Basically, a drive function can even be implemented without external excitation, so that the drive radio tion can be achieved by the synchronous machine, especially with smaller powers, under certain circumstances even without any external excitation. The external excitation then only needs to be activated accordingly when required, for example to be able to provide large outputs. Overall, this results in an improved synchronous machine, which can also have a higher degree of efficiency compared to the corresponding synchronous machines of the prior art. It can also be taken into account that the use of a drive device of a motor vehicle takes place predominantly with partial performance. The maximum performance is usually only rarely accessed. The invention makes it possible to increase the efficiency of the drive device, particularly in a partial power range, so that the range of a correspondingly driven electrically drivable motor vehicle can also be correspondingly increased. This can be achieved in that reluctance effects, such as in a synchronous reluctance machine, are caused or increased by means of the through-openings, among other things.

The through openings are formed with a substantially constant inner diameter in the axial direction. The passage openings at least partially form the flow blocking sections, which can have a correspondingly suitable cross-sectional shape for the predetermined impeding of the flow. The flux-guiding sections, in which the magnetic flux is guided through the magnetic unit, are at least partially formed between adjacently arranged through-openings. Due to the fact that at least one electrical conductor of the rotor winding is also arranged in the through-openings, the through-opening can also be used to implement external excitation at the same time. For this purpose, the electrical conductor can be subjected to a suitable electrical direct current depending on a respective external excitation. The electrical conductor is usually formed by an electrically highly conductive material that is not or at most hardly magnetizable.

The through-openings can thus at least partially accommodate an excitation winding of the rotor. The field winding is preferably arranged completely in the through-openings. In order to be able to largely maintain the flux blocking properties of the passage openings, the electrical conductor of the rotor winding is formed from a non-magnetizable material such as copper, aluminum, alloys thereof and/or the like. Of course, the electrical conductor can also have electrical insulation in the form of a coating or the like.

If a cross-section of the through-openings is larger than the at least one electrical conductor or multiple electrical conductors arranged in them, the area of the cross-section of the through-opening that is not acted upon by the at least one electrical conductor or multiple electrical conductors can be filled with a suitable material, for example a plastic also a gas such as air or the like which is essentially non-magnetizable.

The flux-conducting sections can be designed to at least partially provide the magnetic poles on a rotor surface of the rotor on the air-gap side. The magnetic poles are preferably formed in such a way that the polarity of the magnetic pole alternates in the circumferential direction. For this purpose, it can also be provided that in the area of a respective magnetic pole, narrow through openings can also be formed in the axial direction in order to be able to achieve a specific flux guidance in this way in the area of the magnetic pole. A cross section of these through-openings can, for example, be in the form of a slot or the like in the radial direction. In addition, a plurality of such through openings can be arranged adjacent to one another in the circumferential direction within a respective pole. The through-openings can have cross-sectional areas that differ from one another.

The base body at least partially provides a rotor surface of the rotor and has a radial recess between two magnetic poles provided immediately adjacent in the circumferential direction, which extends in the axial direction and in which a coupling element is arranged. For the production of the magnetic unit, the coupling element can provide access to the through-openings in which at least some of the field winding is to be arranged. If the field winding is arranged in the respective through-openings, arranging the coupling element in the recess can result in the through-openings being closed again radially. In addition, additional stability can be achieved in the area of the slider surface. The recess can also serve to improve the provision of the magnetic poles. However, in contrast to this, the coupling element can also at least partially provide a part of the rotor surface in the circumferential direction. As a result, an undesired leakage flux can be further reduced. At the same time, the coupling element makes it possible to facilitate the arrangement of the electrical conductor in the respective through-opening if the recess is in at least one respective through-opening opens out. It is thus possible first to insert the electrical conductor axially through the recess into the through-opening which is still open and then to close the through-opening by inserting the coupling element in the radial recess.

The coupling element is formed from a grain-oriented, magnetizable material. A further improvement in the guidance of the magnetic flux by means of the coupling element can thereby be achieved. The grain orientation is preferably chosen to be adapted to a direction of the magnetic flux in normal operation.

According to a development, it is proposed that the magnetic unit has salient poles on which the rotor winding is at least partially arranged. As a result, a particularly simple construction can be achieved. The through openings of the invention can of course also be arranged in the area of the salient poles. Provision can thus be made, for example, for immediately adjacent salient poles to provide a common through-opening in which the respective electrical conductors of the rotor winding are arranged. A flux blocking element can also be arranged particularly advantageously between the two respective electrical conductors of the respective rotor winding. As a result, the electrical conductor can also be fixed well in its position at the same time.

In addition, it is proposed that at least in some of the passage openings, in addition to the respective winding section, a flux blocking element extending in the axial direction and made of a non-magnetizable material be arranged. The flux blocking element can be designed to match the electrical conductor and can preferably be designed to completely fill the cross section of the through-opening. The flux blocking element can be made of a plastic, a ceramic material or the like, for example, and can be inserted axially into the through-opening as part of the manufacture of the rotor. Of course, the flow blocking element can also be formed by a fluid, for example an oil, air, a gas or the like. In addition, the flux blocking element can of course also be formed by a coolant, so that a cooling effect can also be achieved at the same time during normal operation of the rotating electrical machine.

At least one winding-free passage opening is preferably additionally formed for each of the magnetic poles. The at least one winding-free through-opening can extend in the basic body in the manner of a through-opening that is elongated in the radial direction. It is preferably designed to be closed in the circumferential direction of its cross section. It can have a shape in cross section that is adapted to the desired flux guidance of the magnetic flux. For example, the cross section can be selected depending on the radial distance from the axis of rotation. Thus, the cross section in the circumferential direction can be larger at a small pitch than at a large pitch. The through-opening can, for example, have an essentially approximately triangular cross-sectional area. Of course, several additional through-openings without windings can also be provided for a respective magnetic pole. They need not have the same cross-sectional area and/or cross-sectional shape.

In addition, it is proposed that the recess and the coupling element each have form-fitting elements which engage with one another in order to keep the coupling element secured in its position when it is arranged in the recess. This development uses the idea that the secure holding of the coupling element in its position in the recess allows the direction of the coupling element relative to the magnetic unit, i.e. relative to the laminated core or the body element of the rotor, especially for the rotor during normal operation , is essentially constant and thus the flow guidance properties, in particular because the coupling element is formed from a grain-oriented material, can be maintained essentially unchanged during normal operation.

The position of the coupling element in the recess can be securely held in a particularly simple and reliable manner by the positive-locking elements, which are in engagement with one another. The positive-locking elements can be formed, for example, by projections that are formed on an inner contour of the recess and/or on the outer contour of the coupling element, which engage in corresponding, opposite recesses on the inner contour of the recess or the outer contour of the coupling element. The positive-locking elements can be designed, for example, in the manner of teeth, mushrooms or the like, but can also have other angular and/or round structures. The recesses are then preferably designed to be appropriately adapted, so that a form-fitting connection can be implemented. The positive-locking elements can be designed, for example, in the manner of a jigsaw puzzle piece. The form-fitting elements extend at least partially over the circumference of the inner contour or the outer contour. preferred As they are essentially completely formed.

With regard to the method, it is also proposed that a radial recess is first formed in the rotor surface between two magnetic poles provided immediately adjacent in the circumferential direction, which extends in the axial direction, then the rotor winding is arranged on the magnetic unit and then in the recess a coupling element is arranged. In this way, the rotor according to the invention can be manufactured easily. It has proven to be particularly advantageous if the radial recess is connected to one or more of the through-openings in which the winding sections or partial winding sections are to be arranged. In this case, the coupling element can preferably close off the through-opening in the radial direction in the fully assembled state. This creates closed through openings in the circumferential direction.

The advantages and effects specified for the rotor according to the invention naturally also apply equally to the synchronous machine equipped with the rotor according to the invention and the motor vehicle equipped with the synchronous machine according to the invention as well as the method for producing the rotor and vice versa. In this respect, device features can also be formulated as method features and vice versa.

The invention also includes developments of the method according to the invention, which have features as have already been described in connection with the developments of the runner according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.

The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

The invention also includes the combinations of features of the described embodiments. The invention also includes implementations that each have a combination of the features of several of the described embodiments, unless the embodiments were described as mutually exclusive.

• 1 eine schematische Schnittansicht einer magnetischen Einheit eines Läufers einer fremderregten Synchronmaschine nach dem Stand der Technik;
• 2 eine schematische Schnittansicht nach dem Stand der Technik wie 1, bei der im Bereich jeweiliger magnetischer Pole radiale Langlöcher ausgebildet sind;
• 3 eine schematische Schnittansicht nach dem Stand der Technik wie 2, bei der in einem jeweiligen magnetischen Pol jeweils zwei Langlöcher ausgebildet sind, die in Umfangsrichtung beabstandet zueinander sind und die in einem radial innenliegenden Bereich mit jeweiligen Ringabschnittsöffnungen mit benachbarten Langlöchern von benachbarten Polen verbunden sind;
• 4 eine schematische Schnittansicht einer magnetischen Einheit eines Läufers einer fremderregten Synchronmaschine gemäß der Erfindung, bei der Wicklungsabschnitte einer Erregerwicklung, die einem jeweiligen magnetischen Pol zugeordnet sind, in zwei diesem jeweiligen magnetischen Pol zugeordneten Wicklungskammern angeordnet sind;
• 5 eine schematische Schnittdarstellung wie 4, bei der im Bereich eines jeweiligen Pols zusätzliche wicklungslose Durchgangsöffnungen ausgebildet sind;
• 6 eine vergrößerte Darstellung eines Bereichs VI in 5, wobei zwischen zwei benachbarten Polen eine weitere Ausgestaltung für ein Koppelelement in einer Ausnehmung eines Grundkörpers der magnetischen Einheit angeordnet ist;
• 7 eine schematische Darstellung wie 6, jedoch mit einer weiteren Ausgestaltung für ein Koppelelement;
• 8 eine schematische Darstellung wie 6, jedoch mit einer weiteren Ausgestaltung für ein Koppelelement;
• 9 eine schematische Schnittdarstellung wie 5, bei der nunmehr zwischen benachbarten Polen jeweils eine Durchgangsöffnung ausgebildet ist;
• 10 eine vergrößerte Darstellung eines Bereichs X in 9;
• 11 eine schematische Schnittdarstellung eines Koppelelements aus einem kornorientierten Werkstoff gemäß 10;
• 12 eine schematische Schnittdarstellung wie 9, bei der in einem radial innenliegenden Bereich eines jeweiligen Pols eine zusätzliche Durchgangsöffnung ausgebildet ist;
• 13 eine schematische Schnittansicht eines Grundkörpers der magnetischen Einheit des Läufers gemäß 9;
• 14 eine schematische Schnittansicht wie 13, bei der im Grundkörper nunmehr die entsprechenden Wicklungsabschnitte in den Durchgangsöffnungen angeordnet gemäß einem ersten Herstellungsschritt des Läufers sind;
• 15 eine schematische Schnittdarstellung wie 14, bei der in jeweiligen Ausnehmungen des Grundkörpers jeweilige Koppelelemente gemäß einem zweiten Herstellungsschritt des Läufers angeordnet sind;
• 16 eine schematische Schnittdarstellung wie 15, bei der in den Durchgangsöffnungen zusätzlich Flusssperrelemente gemäß einem dritten Herstellungsschritt des Läufers angeordnet sind; und
• 17 in einer schematischen Seitenansicht ein Elektrofahrzeug mit einer elektrischen Antriebseinrichtung, die eine fremderregte Synchronmaschine umfasst.

Exemplary embodiments are described below in connection with the invention. For this shows:

• 1 a schematic sectional view of a magnetic unit of a rotor of a separately excited synchronous machine according to the prior art;
• 2 a schematic sectional view according to the prior art as 1 in which radial slots are formed in the region of respective magnetic poles;
• 3 a schematic sectional view according to the prior art as 2 in which two elongated holes are formed in a respective magnetic pole, which are spaced apart from one another in the circumferential direction and which are connected in a radially inner area with respective ring section openings to adjacent elongated holes of adjacent poles;
• 4 a schematic sectional view of a magnetic unit of a rotor of a separately excited synchronous machine according to the invention, in which winding sections of an exciter winding which are assigned to a respective magnetic pole are arranged in two winding chambers assigned to this respective magnetic pole;
• 5 a schematic sectional view as 4 , in which additional winding-free passage openings are formed in the region of a respective pole;
• 6 an enlarged view of an area VI in 5 , wherein a further configuration for a coupling element is arranged in a recess of a base body of the magnetic unit between two adjacent poles;
• 7 a schematic representation of how 6 , but with a further configuration for a coupling element;
• 8th a schematic representation of how 6 , but with a further configuration for a coupling element;
• 9 a schematic sectional view as 5 , in which a through hole is now formed between adjacent poles;
• 10 an enlarged view of an area X in 9 ;
• 11 a schematic sectional view of a coupling element made of a grain-oriented material according to 10 ;
• 12 a schematic sectional view as 9 , in which an additional through opening is formed in a radially inner region of a respective pole;
• 13 a schematic sectional view of a base body of the magnetic unit of the rotor according to FIG 9 ;
• 14 a schematic sectional view as 13 in which the corresponding winding sections are now arranged in the passage openings in the base body according to a first manufacturing step of the rotor;
• 15 a schematic sectional view as 14 in which respective coupling elements are arranged in respective recesses of the base body according to a second manufacturing step of the rotor;
• 16 a schematic sectional view as 15 , in which flow blocking elements are additionally arranged in the passage openings according to a third manufacturing step of the rotor; and
• 17 in a schematic side view, an electric vehicle with an electric drive device that includes a separately excited synchronous machine.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that each also develop the invention independently of one another. Therefore, the disclosure is also intended to encompass combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.

In the figures, the same reference symbols designate elements with the same function.

1 shows a schematic sectional view of a rotor 10 of a not shown, separately excited synchronous machine according to the prior art. The rotor 10 has a magnetic unit 12 , a base body 14 and an excitation winding with winding sections 20 . The base body 14 is formed as a laminated core of magnetizable individual laminations, which are arranged adjacent to one another and electrically insulated from one another in an axial direction parallel to an axis of rotation 22 of the rotor 10 . In this embodiment, the winding sections 20 are electrically connected in series. In alternative configurations, however, a series connection can also be provided, at least in part. A rotor shaft 18 of the rotor 10 is connected to the base body 14 or the magnetic unit 12 of the rotor 10 in a rotationally fixed manner. In accordance with the design 1 the rotor 10 is designed in the manner of an internal rotor.

The base body 14 is designed to provide magnetic poles 16 on the air gap side in the circumferential direction in relation to the axis of rotation 22 in the intended operation in such a way that the magnetic poles 16 have alternating polarities in the circumferential direction. For this purpose, each magnetic pole 16 is assigned one of the winding sections 20 of the field winding of the rotor 10 arranged on the base body 14 .

Recesses (not designated) are formed between immediately adjacent magnetic poles 16 in the circumferential direction, so that the winding sections 20 for a respective pole 16 can be arranged on the base body 14 . After the winding sections 20 have been arranged, the remaining recesses are closed by means of respective plastic bodies 24, which at the same time also serve to fix the winding sections 20 in the respective recesses. Finally, a terminating element 26 is attached to each plastic element 24 radially on the outside, which terminates in the circumferential direction and in the axial direction with a runner surface 28 that is at least partially provided by the base body 14 .

The function of the separately excited synchronous machine is basically known to the person skilled in the art, which is why further detailed explanations in this regard are dispensed with. In normal operation, the winding sections 20 are supplied with a direct current, so that the corresponding magnetic polarities can be provided at the magnetic poles 16 . These alternate in the circumferential direction.

2 shows a sectional view like 1 , in which it is shown that in the region of each pole 16 there is also an internal radial opening which also extends in the axial direction and is designed as a through-opening 30 . The through-opening 30 is intended to make it possible to achieve improved utilization of a reluctance torque. As a result, the efficiency of the separately excited synchronous machine can be improved.

3 FIG. 1 shows a further corresponding embodiment according to the prior art, which is based on the embodiment according to FIG 2 based and at the im Area of each of the poles 16 not only a through-opening 30, but in the circumferential direction adjacent two through-openings 30 are formed. In a radially inner region, two through-openings 30 of two immediately adjacent magnetic poles 16 are connected to one another via a respective annular section 32, which is also designed as a through-opening.

The winding sections 20 are arranged in respective winding chambers 34 which also extend in the axial direction and are designed in the manner of a recess which is open on the air gap side. The winding chambers of two adjacent magnetic poles 16 can merge into one another.

4 shows an embodiment for a rotor for a synchronous machine without permanent magnets 70 ( 17 ) according to the invention. This embodiment is based on the embodiment according to FIG 1 , which is why reference is also made to the explanations above. The rotor 40 has a magnetic unit 42 which has a base body 44 . The magnetic unit 42 is designed, during normal operation, to provide magnetic poles 16 on the air gap side in the circumferential direction in relation to a rotational axis 22 of the rotor 40 such that the magnetic poles 16 have alternating polarities in the circumferential direction. Each magnetic pole 16 is assigned a winding section which is arranged on the base body 44 and has two partial winding sections 48, 50, an excitation winding of the rotor 40 which is not shown in any more detail. The partial winding sections 48, 50 can be electrically connected in series or else in parallel in order to form the respective winding section. In normal operation, the field winding and thus each of the winding sections and partial winding sections 48, 50 can be supplied with a direct current in order to enable or support the provision of the magnetic poles 16 in normal operation.

Each partial winding section 48, 50 is thus also assigned to a respective one of the magnetic poles 16. In addition, each winding section is divided into partial winding sections 48, 50, with each partial winding section 48, 50 being arranged in a respective winding chamber 52, 54. The winding section is - contrary to the prior art - not in a single winding chamber - as in the rotor 10 according to 1 - Arranged, but each winding section is arranged in two, the respective magnetic pole 16 associated winding chambers 52, 54.

The winding chambers 52, 54 are formed by respective through openings 58 formed in the base body 44. As a result, respective flux blocking sections are provided by the through-openings 58, which at the same time serve to block a magnetic flux during normal operation of the synchronous machine 70. Compared to the base body 44, the flux blocking sections are characterized in that they provide a significantly lower relative magnetic permeability and thus a correspondingly lower magnetic conductivity and thus provide a correspondingly large magnetic resistance for the magnetic flux compared to the base body 44. In the present case, the base body 44 is otherwise like the base body 14 of the rotor 10 according to FIG 1 formed, although the invention is not limited thereto.

However, it is not essential for the invention that the base body 14 or 44 is designed as a laminated core. Basically, another suitable material can also be provided here, which provides the greatest possible magnetizability with the lowest possible electrical conductivity. This can also be done, for example, using a suitable ferrite or the like.

In addition, the through openings 58 associated with each of the poles 16 are separated from each other by a respective flux guide section 56 . The flux-conducting section 56 is used to guide the magnetic flux during normal operation. In accordance with the design 4 the partial winding sections 48, 50 are separated from one another in the radial direction by the flux-conducting section 56.

The through openings 58 are arranged at a distance from the axis of rotation 22 of the rotor 40 and extend in an axial direction parallel to the axis of rotation 22 of the rotor 40.

A part of a respective winding section, namely a respective partial winding section 48, 50, is arranged in each of the winding chambers 52, 54, with these winding chambers 52, 54 being separated from one another in the circumferential direction. Plastic elements extending in the axial direction are arranged as flow blocking elements 24, 60 in the intermediate space formed in this way. As a result, the respective winding chambers 52, 54 are closed and hold the respective partial winding sections 48, 50 in their respective positions.

Each of the winding sections or partial winding sections 48, 50 thus encloses a respective one of the magnetic Poles 16 of the magnetic unit 42. The excitation winding of the rotor 40 is therefore part of the magnetic unit 42.

A respective coupling element 46 is arranged between a respective flow blocking element 24 and a respective flow blocking element 60 , which in the present case is made of the same material as the base body 44 . In alternative configurations, a different material can also be used here, as is the case, for example, with reference to the further exemplary embodiments in relation to FIG 9 until 11 will be explained later. A respective cover element 26 is arranged radially on the outside of the respective flux blocking element 24 and terminates with the rotor surface 28 provided by the base body 44 . As a result, an almost homogeneous rotor surface 28 can be achieved in the circumferential direction. At the same time, the flux blocking element 24 can be protected from the effects of the air gap during normal operation.

By designing the excitation winding according to 4 can compared to that of the runner 10 according to 1 a significant increase in the reluctance torque can be achieved. In the fully assembled state, the flux blocking elements 24, 60 also separate the corresponding winding chambers 52, 54 from adjacent magnetic poles 16.

5 now shows a sectional view of a development of the embodiment according to FIG 4 . The above explanations for the design according to 4 basically also apply to the design 5 , which is why in addition to the statements on the rotor 40 according to 4 is referenced. Only the differences are explained below.

The runner 40 according to 5 differs from the runner 40 according to 4 in that in the area of the magnetic poles 16 additional through-openings 62 without windings are formed. The reluctance torque can be further increased by the through-openings 62, which essentially extend in an axial direction and a radial direction and which are separated from one another by flux-conducting sections of the base body 44. The through-openings 62 are shown in the sectional view according to FIG 5 recognizable as slot openings, the radial direction of extension of which is essentially linear. For each of the magnetic poles 16 , five through openings 62 are provided which are spaced apart from one another in the circumferential direction and extend into a region of the rotor surface 28 . They also extend radially inward, with the circumferentially middle one of the through openings 62 extending beyond the respective winding chambers 52 and 54 . The through-openings 62 that are adjacent to this in the circumferential direction, on the other hand, only extend inward beyond the radially outer winding chambers 52 , whereas the outermost of the through-openings 62 only extend radially inward to approximately the respective winding chamber 52 .

In 5 a region VI is shown, which in 6 is shown enlarged. In 6 is also an alternative embodiment in relation to the coupling element 46 according to 5 shown. How out 6 As can be seen, in this embodiment a coupling element 84 is provided, which instead of the coupling element 46 in 5 is used. The coupling element 84 consists of a material like the coupling element 46, but it extends through between two adjacent winding chambers 54 in the radial direction. In addition, the flow blocking element 60 of 5 replaced here by two flow blocking elements 86 . The flux blocking elements 86 are each arranged between the respective partial winding section 50 and a corresponding area of the coupling element 84 . Flow blocking elements 86 may be formed from the same material as flow blocking element 24 or flow blocking element 60 .

7 shows in a representation like 6 a third embodiment for a coupling element 80, which instead of the coupling element 46 according to 5 can be provided. In this embodiment, based on the embodiment 6 is based, which is why reference is also made to the relevant explanations, the coupling element 80 also protrudes radially outwards into an area that separates the two adjacent winding chambers 52 from one another. In this respect, in this embodiment, the flux blocking element 24 is now in accordance with the embodiment 5 replaced by two flux blocking elements 88 which, like the flux blocking elements 86, are arranged between the coupling element 80 and the respective partial winding section 48 in order to fill the respective passage opening 58. As a result, the cover element 26 also no longer needs to be provided. The coupling element 80 can thus also replace this element.

8th now shows a further configuration for a coupling element 82, which is based on the configuration according to FIG 7 is based, which is why reference is also made to the relevant statements. In contrast to the configuration of the coupling element 80 according to FIG 7 protrudes the coupling element 82 according to 8th radially not beyond the radially inner of the winding chambers 54, but only up to the radial position. Regarding the radial In the outer region of the coupling element 82, the configuration thus essentially corresponds to the configuration of the coupling element 80 7 . However, since the coupling element 82 does not protrude into a radial region of the winding chambers 54, the flux blocking element 60 is again arranged there in this embodiment. Basically, this corresponds to what is already to 4 and 5 was explained.

In the present case, the coupling elements 46, 80, 82, 84 are designed in the manner of elongated profiles, so that during the production of the rotor 40 they can be pushed axially from one of its end faces of the rotor 40 into a respective recess 64 of the base body 44. With regard to the manufacture of the rotor 40, reference is made to the following further explanations.

The above configurations of the coupling elements 46, 80, 82, 84 show that the realization of at least two winding chambers for a respective winding section can be used using easily manageable different manufacturing methods. In addition, a need-based adaptation to the functionality of the synchronous machine 70 can also be achieved. Depending on the design of the through openings 58, 62 and the positioning of the winding sections, the function can be further influenced.

9 shows a further configuration for a rotor 40, which is based on the previous configurations, which is why reference is also made to the relevant statements. The design according to 9 differs from the previous configurations, among other things, in the arrangement and design of the winding chambers 52, 54. These are formed by corresponding through-openings 58. With regard to their cross-section and their position and their cross-sectional shape, the through openings 58 are based on reluctance openings as are provided in rotors of synchronous reluctance machines. The through-openings 58 therefore divide the main body 44 into corresponding flow-guiding sections 56 and flow-blocking sections, which are formed by the through-openings 58 . This makes it possible to achieve a large reluctance torque without activating an excitation. In addition, the passage openings 58 now provide correspondingly shaped winding chambers 52, 54, in which the respective partial winding sections 48, 50 of the field winding of the rotor 40 are arranged. In this regard, reference is made to the corresponding previous statements. In addition, corresponding flow blocking elements 86 , 88 are additionally arranged in the through-openings in order to completely fill out a cross-section of the through-openings 58 . With regard to the flux blocking elements 86, 88, the explanations are also provided 6 and 7 referred.

10 now shows an enlarged section X 9 . Visible is off 10 that a coupling element 90 is provided, which is formed from a grain-oriented material. This coupling element 90 is shown in a sectional view in 11 shown as a separate part. Out of 11 it can be seen that the coupling element 90 is formed from a grain-oriented magnetizable material. The present case is a grain-oriented electrical steel sheet. The grain orientation is indicated by horizontal lines in 11 shown. Beyond that is off 11 It can be seen that the coupling element 90 has form-fitting elements 66 which, with correspondingly designed form-fitting elements of the recess 64 ( 14 ) are engaged to keep the coupling element 90 secured in position when arranged in the recess 64 . In the present embodiment, the coupling element 90 is thus firmly connected to the base body 44 by means of the positive-locking elements 66 . The coupling element 90 is designed as an elongated line part, so that it can be pushed in axially from one of the end faces of the rotor 40 during production. This refinement preferably also applies to the coupling elements described above.

12 shows a further configuration for a rotor 40, which is based on the configuration according to FIG 9 is based, which is why reference is also made to the relevant statements. Only the differences are explained further below.

The design according to 12 differs on the one hand from the design of the rotor according to 9 that in the area of the poles 16 centrically with respect to a respective magnetic pole 16 according to the sectional view 12 approximately triangular winding-free passage opening 100 is arranged. In addition, instead of the coupling element 90 according to 9 provided that two coupling elements 92, 94 are arranged in the respective recess 64. Furthermore, the flow blocking elements 86,88 are replaced by one-piece flow blocking elements 96,98. As a result, the coupling element 90 no longer needs to be provided, which protrudes through the winding chambers 52, 54 in the radial direction. Rather, the winding chambers 52, 54 of adjacent magnetic poles 16 are now separated from one another by the flux blocking elements 96, 98. To improve the stability, the flow blocking elements 96, 98 also have form-fitting elements 66 like the coupling elements 92, 94. This allows good stability even with large Speeds of the rotor 40 can be reached, although the coupling element 92 protrudes radially inwards only as far as the first through-opening 58 viewed from radially outside. With this construction, the reluctance torque can be further significantly increased.

The following 13 until 16 refer to the manufacture of the rotor 40 according to 9 . 13 shows the base body 34, which is already connected to the rotor shaft 18, in a schematic sectional view. It can be seen that the base body 44 has the through openings 58 which are connected to one another between two adjacent magnetic poles 16 via the recess 64 . The recess 64 is open radially outwards. The recess 64 includes the form-fitting elements 66, as already explained above.

14 now shows in a schematic sectional view how 13 the arrangement of the excitation winding on the base body 44 to form the magnetic unit 42. Because the through-openings 58 are accessible from the outside via the recess 64, an electrical conductor of the respective partial winding sections 48, 50 can be inserted into the respective through-openings 58 in a simple manner. The corresponding electrical conductors are introduced into the respective through-openings 58 from radially outside to radially inside. As soon as the partial winding sections 48, 50 have been introduced into the respective passage openings 58, the corresponding coupling elements 90 are pushed into the corresponding recesses 64 from one end. This isolates the winding chambers 52, 54 from each other and also from the corresponding winding chambers of the adjacent poles 16. This is according to the schematic sectional view 15 shown.

The blocking elements 86 , 88 are then also pushed from an axial end face of the rotor 40 into cross-sectional areas of the through bores 58 which are not acted upon by partial winding sections 48 , 50 . As a result, the partial winding sections 48, 50 are fixed in the respective through-openings 58. this is in 16 shown. As a result, the runner 40 is now made.

17 FIG. 12 shows an electrically drivable motor vehicle in a schematic side view, which is embodied here as an electric vehicle 76. The electric vehicle 76 has an electric drive device 72 which, as a rotating electric machine, has an externally excited synchronous machine 70 for driving the electric vehicle 76 in normal driving operation. The synchronous machine 70 has a stator 78 which has a through opening, not shown, in which a rotor 40 is rotatably arranged. In the present case, the rotor 40 is designed as an internal rotor. In alternative configurations, the runner 40 can of course also be designed as an external runner. The electric drive device 72 is also connected to a high-voltage battery 74, which is used to supply electric energy to the drive device 72, by means of an inverter 68 of the electric drive device 72, which is used as an energy converter.

Overall, the examples show how the reluctance torque can be provided in an improved manner by means of suitable arrangements of the field winding of a rotor. With the invention it is possible to make greater use of the reluctance effect in a synchronous machine. As a result, with a separately excited synchronous machine, less excitation current needs to be made available, as a result of which the efficiency can be increased and the energy consumption can be reduced. This is particularly advantageous in the low-power range. This can result in an advantage in particular in the partial load range, in which the motor vehicle is mostly operated. In this way, a range can be increased because full power is usually only rarely required. This also applies to most driving cycles, in which drive devices in motor vehicles often only need to provide a comparatively small amount of torque.

Overall, the examples also show how magnetic and strength-related coupling components can be used in a rotor of a separately excited synchronous machine. The coupling components allow the excitation winding of the rotor to be placed in multiple reluctance openings instead of being placed in just a single slot per magnetic pole. As a result, an increased reluctance torque can be achieved with the rotor constructed in this way. The number, shape and/or size of the reluctance openings can be optimized in order to be able to achieve the greatest possible reluctance torque. The coupling components or coupling elements are preferably inserted in an axial direction of the rotor only after the field winding has been wound or completed. The coupling elements have two particular tasks, namely, firstly, they magnetically couple two flux paths in the laminated rotor core or base body 44 and, secondly, they have positive-locking contours, as a result of which a good, firm connection can be achieved in the rotor. This makes it possible to also be able to transmit large forces at high speeds of the rotor, for example tensile forces that arise from magnetic torque formation, or corresponding torsional forces. In alternative configurations, the coupling elements can of course also provide a form-fitting connection with the flow blocking elements, which can also be formed by a plastic filling, for example.

The advantage of the invention results, among other things, from the fact that the rotor requires less excitation current for the same power because of the additional provision of reluctance torque. This results in fewer rotor losses and less heat build-up, as well as a longer range for electrically driven motor vehicles. In addition, a maximum torque that can be achieved with the same excitation current and the same maximum temperature can also be increased. This can also increase the power density.

The exemplary embodiments serve exclusively to explain the invention and are not intended to limit it.

Claims (8)

Rotor (40) for a synchronous machine (70) without permanent magnets, with a magnetic unit (42), which has a base body (44) and is designed, in normal operation, on the air gap side in the circumferential direction in relation to an axis of rotation (22) of the rotor (40) to provide magnetic poles (16) in such a way that the magnetic poles (16) have alternating polarities in the circumferential direction, with each magnetic pole (16) being assigned a winding section (48, 50) arranged on the base body (44) of an excitation winding of the rotor (40). , wherein each winding section (48, 50) is arranged in at least two winding chambers (52, 54) assigned to this respective magnetic pole (16), which are formed by respective through-openings (58) formed in the base body (44), the through-openings (58 ) Provide respective flux blocking sections, which are designed to block a magnetic flux during normal operation, the passages ng openings (58) are separated from one another by a respective flux-conducting section (56), which is designed to conduct the magnetic flux during normal operation, the through-openings (58) being arranged at a distance from the axis of rotation (22) of the rotor (40) and being located in in an axial direction parallel to the axis of rotation (22) of the rotor (40), the base body (44) at least partially providing a rotor surface (28) of the rotor (40) and between two magnetic poles (16) provided immediately adjacent in the circumferential direction a radial one Has a recess (64) which extends in the axial direction and in which a coupling element (46) is arranged, the coupling element (46) being formed from a grain-oriented magnetizable material. runner after claim 1 , characterized in that a flux blocking element (24, 60) extending in the axial direction and made of a non-magnetizable material is arranged in at least some of the passage openings (58) in addition to the respective winding section (48, 50). Rotor according to one of the preceding claims, characterized in that at least one winding-free passage opening (62) is additionally formed for each of the magnetic poles (16). Runner according to one of the preceding claims, characterized in that the recess (64) and the coupling element (46) each have form-fitting elements (66) which engage with one another in order to hold the coupling element (46) in the state arranged in the recess (64). to keep it secured in place. Synchronous machine (70) without permanent magnets, with a stator and a rotor (40) arranged rotatably relative to the stator (78), characterized in that the rotor (40) is designed according to one of the preceding claims. Motor vehicle (76) with a permanent magnet-free synchronous machine (70), characterized in that the permanent magnet-free synchronous machine (70) according to claim 5 is trained. Method for producing a rotor (40) for a synchronous machine (70) without permanent magnets, wherein a magnetic unit (42) of the rotor (40), which has a base body (44), is designed so that, during normal operation, it is positioned on the air gap side in the circumferential direction with respect to an axis of rotation (22) of the rotor (40) to provide magnetic poles (16) in such a way that the magnetic poles (16) have alternating polarities in the circumferential direction, each magnetic pole (16) having a winding section (48, 50 ) is assigned to an excitation winding of the rotor (40), the winding section (48, 50) being arranged in at least two winding chambers (52, 54) assigned to this respective magnetic pole (16), which are formed through respective through-openings (44) in the base body (44). 58) are formed, wherein the through openings (58) provide respective flux blocking portions which are intended for blocking a magnetic flux in the improper operation are formed, the through-openings (58) being separated from one another by a respective flux-conducting section (56) which is designed to conduct the magnetic flux during normal operation, the through-openings (58) being spaced apart from the axis of rotation (22) of the rotor (40) are arranged and extend in an axial direction parallel to the axis of rotation (22) of the rotor (40), the base body (44) at least partially providing a rotor surface (28) of the rotor (40) and between two magnetic poles provided immediately adjacent in the circumferential direction (16) has a radial recess (64) which extends in the axial direction and in which a coupling element (46) is arranged, the coupling element (46) being formed from a grain-oriented magnetizable material. procedure after claim 7 , characterized in that first a radial recess (64) is formed in a rotor surface (28) between two magnetic poles (16) provided immediately adjacent in the circumferential direction, which extends in the axial direction and into the through-openings (58), then the field winding is arranged on the base body (44) and then a coupling element (46) is arranged in the recess (64).

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