CN107565723B

CN107565723B - Rotor

Info

Publication number: CN107565723B
Application number: CN201710499211.8A
Authority: CN
Inventors: R.赫尔默; G.斯托尔
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2016-07-01
Filing date: 2017-06-27
Publication date: 2020-10-02
Anticipated expiration: 2037-06-27
Also published as: DE102016212022A1; CN107565723A

Abstract

In order to reduce the manufacturing costs while maintaining power and torque, the rotor of an IPM machine with a magnetically conductive rotor core comprises in each pole of the rotor a first, a second, a third and a fourth indentation in which at least one first, second, third or fourth permanent magnet is provided, wherein-the first and second indentations are mutually arranged in a first "V" shape opening towards the outer surface of the rotor core and the third and fourth indentations are mutually arranged in a second "V" shape opening towards the outer surface of the rotor core, -the second "V" shape is located between and mutually nested with the indentations of the first "V" shape, -the permanent magnets are configured with ferrite material, preferably formed entirely of ferrite material, -in particular, the size of the indentations along the sides of the "V" shape is larger than, preferably many times larger than, Particularly preferably at least three times the dimension perpendicular to the sides, -more particularly, the permanent magnet is magnetized at least to a large extent, preferably at least almost completely, along the minor dimension of the indentation.

Description

Rotor

Technical Field

The invention relates to a rotor of a permanent-magnet excited machine. The invention also relates to a permanent magnet excited machine. The invention further relates to a vehicle, in particular a road vehicle.

Prior Art

As disclosed in DE 102014102411 a1, machines with built-in permanent magnets, abbreviated as: the IPM machine includes a rotor having a plurality of magnets of alternating polarity arranged around an outer circumference of the rotor. The rotor is rotatable within a stator containing a plurality of windings. The rotor magnetically interacts with the stator to produce rotation of the rotor about an axis of rotation. IPM machines can use either ferrite magnets or rare earth magnets, for example composed of neodymium-iron-boron (NdFeB), in the rotor. Ferrite magnets are less expensive than rare earth magnets, but produce lower power when used in IPM machines of the same design.

DE 102014102411 a1 discloses a rotor core for a machine with built-in permanent magnets, which comprises at least one ferrite pole and at least one rare earth pole, which are arranged in a radial direction in an alternating relationship about an axis. The ferrite pole defines a plurality of first pole cavities and the rare earth pole defines a plurality of second pole cavities. One of the plurality of ferrite magnets is disposed in each first pole cavity of the ferrite pole and one of the plurality of rare earth magnets is disposed in each second pole cavity of the rare earth pole.

The rotor core is thus designed for a hybrid assembly of magnets with different materials. Wherein the second pole cavities for the rare earth magnets are arranged in an interdigitated V-shape with the smaller magnets forming the inner "V" and the larger magnets forming the outer "V". The rare earth magnets may completely fill the second pole cavities, or they may leave one or more air gaps between the rare earth magnets and the respective second pole cavities. It is thus shown that one air chamber each is arranged on the root and the end of the sides of the large "V" as well as the small "V". These air cavities are directly adjacent to the rare earth magnets and are substantially triangular.

The rotor arrangement of DE 102014102411 a1 therefore contains ferrite magnets and rare earth magnets arranged in alternating magnetic poles in order to minimize the volume of the rare earth magnets, while the power of an equivalent rotor arrangement consisting of only rare earth magnets is substantially retained. Minimizing the volume of the rare earth magnets reduces the manufacturing cost of the rotor assembly compared to a rotor assembly constructed only of rare earth magnets.

DE 102010002786 a1 also shows IPM machines of this type, for example for driving electric machines and hybrid electric vehicles. The machine includes a rotor having a plurality of ferrite magnets arranged in one or more layers, wherein at least one layer of rare earth magnets (e.g., NdFeB magnets) abuts the ferrite magnets to avoid or reduce demagnetization. In the spatial arrangement of the magnets, the "V" -shape-the "inner V" and the arc-the "outer V" are combined with each other. In such a spatial arrangement, each adjacent pair of "V" shaped magnets (in the "V" shape on the one hand and in the arc shape on the other hand) are separated from each other by an air gap or other non-magnetic material (e.g., plastic or similar material).

Disclosure of Invention

The object of the invention is to reduce the production costs of IPM machines (in particular due to the rare earth magnets used in the rotor) while maintaining the power and torque as far as possible.

The object is achieved by a rotor of a permanently excited electrical machine having a magnetically conductive rotor core, comprising at each pole of the rotor:

a first indentation in which at least one first permanent magnet is arranged,

a second indentation in which at least one second permanent magnet is arranged,

a third indentation in which at least one third permanent magnet is arranged,

a fourth indentation in which at least one fourth permanent magnet is arranged,

wherein the content of the first and second substances,

the first and second recesses are mutually arranged in a first "V" shape open towards the outer surface of the rotor core, and

the third and fourth recesses are mutually arranged in a second "V" shape opening towards the outer surface of the rotor core,

the first and second "V" -shaped shapes are nested in each other such that the second "V" -shaped shape is located between the indentations of the first "V" -shaped shape,

the permanent magnet is constructed with a ferrite material, preferably entirely of ferrite material (Ferritwerkstoff),

in particular, the extension of the indentation along the side of the "V" shape is greater than, preferably more than, particularly preferably at least three times, the dimension perpendicular to the side of the "V" shape,

more particularly, the magnetization direction of the permanent magnet is oriented at least to a large extent, preferably at least almost completely, along the smaller dimension of the indentation.

In this arrangement, a permanent magnet is arranged individually in each recess. Optionally, two or more permanent magnets may be arranged side by side and/or in succession in each recess. The side-by-side arrangement means: two or more permanent magnets are arranged with their magnetic north poles on one side and their magnetic south poles on the other side adjacent to each other; that is to say the like poles of the permanent magnets abut each other. The successive arrangement means that: one magnetic pole of the first permanent magnet is connected with the opposite magnetic pole of the adjacent second permanent magnet along the magnetization direction of the permanent magnet; for example, the magnetic north pole of the first permanent magnet is connected to the magnetic south pole of the second permanent magnet.

The rotor core outer surface is equal to the rotor outer surface, i.e. corresponds to the at least substantially cylindrical outer side surface of the rotor. The direction statement "towards the outer surface of the rotor core" here denotes a direction pointing outwards in the radial direction from the axis of rotation of the rotor and the rotor core. Furthermore, the indentation extends in the axial direction of the rotor and thus of the rotor core, i.e. in the direction of the axis of rotation, at least partially, preferably completely, over at least one axial section of the rotor or of the rotor core. The rotor may preferably be constructed with several such axial sections, which are also referred to as segments. Particularly preferably, the individual segments are twisted about the axis of rotation at a predetermined angle to one another — the angle of inclination. For example, six segments are provided, wherein two segments directly adjacent to one another in the axial direction are rotated by 1 degree relative to one another. The twisted arrangement, known as the skewed, serves to reduce the so-called cogging torque (nuttrastmement) of the motor.

By the shaping of the notches and thus of the first and second "V" shapes of the permanent magnets arranged therein, and by the nested arrangement of the first and second "V" shapes (wherein the first and second notches of the first "V" shape are located outside and the third and fourth notches of the second "V" shape are embedded inside the first "V" shape), both the base torque of the electric machine and in particular the reluctance torque of the electric machine are increased; this improvement is particularly great compared to arrangements in which only a single "V" shape is provided for each pole of the rotor. This is achieved in that permanent magnets made of ferrite material are used in the rotor instead of rare earth magnets, and that a higher power of the electric machine is achieved despite the lower susceptibility of permanent magnets made of ferrite material (i.e. a smaller permanent magnetic flux than rare earth magnets). Preferably, in such a configuration, all the permanent magnets in the rotor may be formed of only ferrite material, while the power of the motor is high. Therefore, the present invention can realize inexpensive manufacture of a motor with high power efficiency.

The preferred embodiment enables the use of flatter, space and material saving permanent magnets and thus a compact, power efficient rotor arrangement, wherein the extension of the indentation along the side of the "V" shape is preferably a multiple of the extension perpendicular to the "V" shape, and wherein the magnetization of the permanent magnets is oriented along the smaller dimension of the indentation.

Advantageous embodiments of the invention are described in the dependent claims.

According to a preferred development of the rotor according to the invention,

the radially inward ends of the first and second recesses are spaced from the rotor core inner surface only by the radial dimension of an at least almost annular inner rotor core carrying area extending along the rotor core inner surface in the circumferential direction of the rotor core and thus of the rotor,

and/or

The radially outward ends of the first, second, third and fourth recesses are spaced from the rotor core outer surface only by the radial extent of an at least substantially annular outer rotor core bearing area, the radial extent of the rotor core bearing area spacing being the radial extent of an at least substantially annular outer rotor core bearing portion, the rotor core bearing area extending along the rotor core outer surface in the circumferential direction of the rotor core.

The rotor core inner surface is here preferably a boundary of the circularly cylindrical or at least approximately cylindrical rotor core to a rotor shaft, which is preferably arranged in the rotor core in a rotationally symmetrical manner in a centered manner; the rotor shaft is preferably constructed of a non-magnetic material. The rotor core inner surface is formed as an inner surface of a spatial region of the rotor core, which is preferably, but not necessarily, formed in one piece from a rotor core material, i.e. in particular a magnetically conductive material, but which serves firstly for transmitting mechanical forces between the rotor core and the rotor shaft. This spatial region of the rotor core surrounds the rotor shaft at least almost circularly, i.e. is at least almost cylindrical, and is referred to herein as the inner rotor core carrying region. In particular, the inner rotor core carrying area is intended to withstand mechanical stresses caused by centrifugal forces and torques acting on the rotor during operation, but may also withstand mechanical stresses acting on the rotor core from the manufacturing, for example by being press-fitted on the rotor shaft. The radial dimension of the inner rotor core bearing area is chosen to be so small that it is possible to achieve the mechanical load, so that the first and second recesses and thus the permanent magnets arranged therein extend as close as possible to the inner surface of the rotor core.

The outer rotor core support region corresponds in material, shape and purpose to the inner rotor core support region and defines the rotor core along the outer rotor core surface. The outer rotor core bearing region extends in the circumferential direction of the rotor and thus of the rotor core and along the outer surface of the rotor core and serves primarily for receiving centrifugal forces in the rotor, in particular the centrifugal forces exerted on the permanent magnets in the recesses. The radial dimension of this outer rotor core support area is also chosen to be so small that it is possible to achieve said mechanical load, whereby the first and second recesses and thus the permanent magnets arranged therein extend as close as possible to the outer surface of the rotor core.

Overall, it is thus achieved that the recess and the permanent magnets arranged therein extend radially over as large a portion of the rotor core as possible. In particular in the case of an orientation of the magnetization of the permanent magnet transverse to the sides of the "V" shape, the permanent magnet obtains as large a dimension as possible transverse to its magnetization by means of the recess and the extension of the permanent magnet arranged therein, whereby the permanent magnetic flux is increased. In the case of a predetermined pole pitch of the magnetic poles of the rotor, this extension of the indentations also results in the sides of the "V" shape being arranged as steeply as possible within the pole pitch, i.e. at an angle to one another that is as small as possible.

In a further preferred embodiment of the rotor according to the invention, the at least one permanent magnet extends at least almost completely over the associated indentation, at least almost completely filling the associated indentation. Optionally, the at least one indentation has at least one air pocket at the radially inwardly and/or radially outwardly directed end.

In general, the non-magnetically conductive spatial region of the rotor core that is free of rotor core material and permanent magnets is referred to herein as an air pocket. A spatial region whose relative permeability is at least almost equal to 1 (i.e., almost equal to vacuum) is referred to as a non-permeable spatial region.

In order for the recess and the permanent magnet accommodated therein to extend as far as possible in the radial direction, i.e. here along the sides of the "V" shape, the air pocket of said form has as small a size as possible; on the other hand, leakage flux is avoided by the air pockets and the power of the electric machine is thus increased. However, the air pocket preferably has a very small size here, preferably smaller than the smallest size of the permanent magnet, since thereby a permanent magnet with a correspondingly higher permanent magnetic flux can be achieved.

Another preferred embodiment of the rotor according to the invention

The dimensions of the first and second recesses along the sides of the first "V" shape are greater than, preferably at least almost twice as great as, the dimensions of the third and fourth recesses along the sides of the second "V" shape,

and/or

The dimension of the first and second recesses perpendicular to the side of the first "V" shape is larger than the dimension of the third and fourth recesses perpendicular to the side of the second "V" shape, preferably at least almost 10%,

and/or

The opening angle of the side of the second "V" shape is greater than the opening angle of the side of the first "V" shape, preferably at least almost 20% greater.

Thus, for a preferred magnetization direction of the permanent magnet (which is perpendicular to the sides of the "V" shape), the first and second notches are configured for a permanent magnet that is thicker along the magnetization direction and wider perpendicular to the magnetization direction than the third and fourth notches.

Advantageously, the third and fourth recesses are also adjacent to one another as close as possible at their radially inwardly directed ends, separated only by a supporting beam of the rotor core material, which is intended to withstand centrifugal forces and is selected to be so narrow that the stated object is achieved. Leakage flux can thereby also be avoided or reduced.

According to a preferred embodiment of the rotor according to the invention, the first recesses of the first magnetic pole belonging to the rotor extend at least approximately parallel to the second recesses of the second magnetic pole of the rotor directly adjacent to the first magnetic pole of the rotor in the circumferential direction and directly adjacent in the circumferential direction. The opening angle of the first "V" shape is at least almost equal to the angle of the pole pitch of the magnetic poles of the rotor. The sections of rotor material between the individual poles of the rotor have an at least almost uniform width in the circumferential direction of the rotor in the radial direction thereof.

In another preferred embodiment of the rotor according to the invention

At least one magnetically non-conductive, preferably quadrangular, flux-deflecting notch extends in the circumferential direction of the rotor core between the radially inner ends of the first and second grooves,

in particular, a plurality of such magnetically non-conductive, preferably quadrangular, flux-deflecting recesses are arranged in succession in the circumferential direction between the radially inner ends of the first and second recesses and are separated from one another by a supporting beam, preferably formed from the rotor core material in one piece with the rotor core.

The at least one flux-deflecting recess, which is preferably likewise designed as an air pocket, serves in particular to reduce or prevent leakage of magnetic flux from the permanent magnets in the first or second recess into the inner rotor core-carrying region and towards the rotor shaft, which could impair the base torque of the electrical machine. The at least one flux-deflecting recess is separated from the first and second recesses by a support beam, which is used, in particular, to absorb centrifugal forces and is as thin as possible for effective flux deflection; further support beams are arranged between two or more such flux deflecting recesses. If a plurality of such flux-deflecting recesses are provided, they can be connected in succession in the circumferential direction and also in the radial direction (separated from one another by the supporting beam).

Due to the above-described design features of the rotor according to the invention, an ideal design of the high torque of the electric machine is achieved, i.e. both a high base torque and a high reluctance torque are achieved, wherein the rotor core is designed for an ideal force acceptance and a maximum reduction of leakage flux.

According to a further development of the rotor according to the invention, at least one recess for accommodating at least one fastening element is provided in the rotor core in the region of the space between the first and second recesses, in particular between the radially inwardly directed ends of the first and second recesses. Preferably, the at least one fastening element is designed to connect the rotor core elements, in particular the rotor discs, at least one section of the rotor to one another in the rotor (the rotor core of which is formed from two or more rotor core elements, in particular rotor discs). Particularly preferably, the at least one fastening is designed to connect at least almost all rotor core elements, in particular rotor discs, of all sections of the rotor to one another. Advantageously, the at least one fastening element is designed as a screw connection, preferably as a pin; alternatively, rivets, clamps, etc. may be used. In order to obtain the aforementioned inclination in a simple manner, at least one recess for accommodating at least one fastening element is positioned in the rotor core element, in particular in the rotor plate section, in a manner that it is rotatable in the circumferential direction about the rotational axis relative to the next section in the axial direction at the inclination angle. In this way, a desired sequence of inclinations can be achieved when stringing up the rotor core element, in particular the rotor disk, on at least one fixing element, in particular a pin.

The recesses are superfluous when the rotor core elements, in particular the rotor disks, are connected by other means, for example by means of adhesive, in particular by means of electrically insulating adhesive material or the like.

The above-mentioned object is also achieved by a rotor core element, in particular a rotor disk, which is characterized by the features of a rotor of the type described above.

The rotor core element according to the invention, in particular the rotor disk according to the invention, of the magnetically conductive rotor core of the rotor according to the invention of a permanently excited electrical machine comprises, at each pole of the rotor:

a first indentation in which at least one first permanent magnet is arranged,

a second indentation in which at least one second permanent magnet is arranged,

a third indentation in which at least one third permanent magnet is arranged,

a fourth indentation in which at least one fourth permanent magnet is arranged,

wherein the content of the first and second substances,

the first and second "V" shapes are nested such that the second "V" shape is located between the indentations of the first "V" shape.

In a preferred development of the rotor core element according to the invention, the extension of the recess along the side of the "V" shape is greater than, preferably more than, particularly preferably at least three times, the dimension perpendicular to the side of the "V" shape.

According to a preferred embodiment of the rotor core element according to the invention, in particular of the rotor disk according to the invention, of the rotor according to the invention,

the radially inward ends of the first and second recesses are spaced from the rotor core inner surface only by the radial dimension of an at least almost annular inner rotor core carrying area, which extends along the rotor core inner surface in the circumferential direction of the rotor core and thus of the rotor,

and/or

The radially outward ends of the first, second, third and fourth recesses are spaced from the rotor core outer surface only by the radial dimension of an at least almost annular outer rotor core carrying area extending along the rotor core outer surface in the circumferential direction of the rotor core.

In a preferred embodiment of the rotor core element according to the invention, the recesses are designed such that the at least one permanent magnet extends at least almost completely over the relevant recess and fills the relevant recess at least almost completely. Optionally, the at least one indentation has at least one air pocket at the radially inwardly and/or radially outwardly directed end.

In another preferred embodiment of the rotor core element according to the invention,

and/or

Furthermore, in the rotor core element according to the invention, the first recesses belonging to the first magnetic poles of the rotor are at least almost parallel to the second recesses of the second magnetic poles of the rotor directly adjacent in the circumferential direction to the first magnetic poles of the rotor directly adjacent in the circumferential direction.

Finally, according to a preferred development of the rotor core element according to the invention, at least one recess for accommodating at least one fastening element is provided in the rotor region between the first and second recesses, in particular in the region of the space between the radially inwardly directed ends of the first and second recesses.

The rotor core element according to the invention, in particular the rotor disk, can be produced inexpensively in a simple manner, since it can be formed with a simple contour, can be produced simply by conventional machining methods, and can be fed through a stamping or the like. It is also simple to manufacture a rotor core for a rotor and the entire rotor with the features and advantages described with the aid of the rotor core element according to the invention, in particular the rotor disk.

The above object is also achieved by a permanently excited electrical machine having a rotor of the type described above and/or a rotor core element of the type described above, in particular a rotor disk. The machine constructed according to the invention can be produced from inexpensive materials, in particular inexpensive permanent magnets made of ferrite material, and has a high power, in particular a high power density. The motor no longer requires the use of expensive rare earth magnets.

The above-mentioned object is finally achieved by a vehicle, in particular a road vehicle, having a permanently excited electric machine of the type described above and/or being equipped with an electric machine which is constructed with an electric machine of the type described above and/or having a rotor core element of the type described above, in particular a rotor disk. In this way, the vehicle can be equipped with an inexpensive and power-efficient drive, in particular a traction drive.

Drawings

Embodiments of the invention are illustrated in the drawings and will be described below in detail, wherein corresponding elements are designated by the same reference numerals throughout the drawings and repeated description of the elements is omitted. In the drawings:

fig. 1 shows a top view in the axial direction of an embodiment of a rotor disk constructed according to the invention of a magnetically conductive rotor core of a rotor according to the invention of a permanently excited electrical machine according to the invention,

fig. 2 shows a detail of fig. 1 with a secondary profile for a rotor with the rotor disk according to fig. 1

Fig. 3 shows an embodiment of a preferred dimensioning of the shaping according to fig. 2.

Detailed Description

In fig. 1, reference numeral 101 denotes an example of a rotor disk according to the present invention, which is a rotor core element of a magnetically permeable rotor core 102 of an example of a rotor 100 according to the present invention, and is shown in a top view in the axial direction, i.e., in the direction of the rotational axis 103 of the rotor 100. The rotor core 102 and thus the rotor 100 extend axially into the plane of the drawing. The rotor 100 is provided for a permanently excited electrical machine according to the invention, in particular a rotating field machine. The rotor 100 according to the example of fig. 1 has ten poles, the central position of which is indicated in the circumferential direction 104 by pole shafts 105 pointing radially outwards from the axis of rotation 103, but any other number of poles is also possible. Every two adjacent magnetic poles, i.e. their pole axes 105, are spaced apart from each other in the circumferential direction 104 by a pole angle W1. Due to the axial extension, the pole shaft 105 defines exactly an axially extending face and the poles form an axially oriented strip. Each magnetic pole in the rotor disk 101 and the rotor core 102 has the form of a recess, which likewise extends in the axial direction and is shown in detail in fig. 1, and which is shown in detail in the associated labeled embodiment in fig. 3 in the detail view according to fig. 2, which depicts the detail in fig. 1 and is indicated by Z.

Such a shaping according to fig. 2 comprises, for each pole, a first notch 106 and a second notch 107, the first notch 106 and the second notch 107 being mutually arranged in a first "V" shape 108 open towards the outer surface 109 of the rotor core. The rotor core outer surface 109 forms a radially outward edge of the rotor core 102, and thus also the rotor 100, and is preferably cylindrical and rotationally symmetric with the rotational axis 103. At the rotor core outer surface 109, the rotor core 102, and thus the rotor 100, has a first diameter D1. The first and

second notches

106, 107 and the first "V" shaped configuration 108 are designed to correspond to the respective pole axes 105. Each pole in fig. 2 comprises a third indentation 110 and a fourth indentation 111, the third indentation 110 and the fourth indentation 111 being arranged in a second "V" shape 112 opening towards the rotor core outer surface 109. The third and

fourth notches

110, 111 and the second "V" shape 112 are also symmetrical with respect to said polar axis 105. The first and second "V" shapes 108, 112 are nested such that the second "V" shape 112 is located between the first and

second notches

106, 107 of the first "V" shape.

The first, second, third and

fourth recesses

106, 107, 110, 111 have radially outwardly directed ends 113, 114, 115 and 116 which are spaced apart from the rotor core outer surface 109 only by an at least almost annular outer rotor core bearing area 117, which rotor core bearing area 117 extends along the rotor core outer surface 109 in the circumferential direction 104 of the rotor core 102. The rotor core bearing region 117 has a radial dimension, indicated by D8, in the radial direction of the rotor core 102, equal to half the difference between the first diameter D1 and the second diameter D2; the second diameter D2 describes the radial position of the radially outwardly directed ends 113, 114, 115 and 116. The radial dimension D8 is sized as small as possible, as it can account for mechanical loads occurring in the rotor core 102.

The rotor core 102 is delimited radially inwards, i.e. towards the steering axis 103, by a rotor core inner surface 118, which rotor core inner surface 118, like the rotor core outer surface 109, is also cylindrical and rotationally symmetric with respect to the rotation axis 103 and has a seventh diameter D7. Rotor core 102 is connected to a rotor shaft arranged rotationally symmetrically to rotational axis 103 by way of rotor core surface 118 in a non-positive and/or positive-locking manner; the latter are preferably designed with non-magnetic material, but not explicitly shown in the figures.

The first and

second recesses

106, 107 have radially inwardly directed ends 119 and 120 which are spaced from the rotor core inner surface 118 only by an at least almost annular inner rotor core carrying area 121 which extends along the rotor core inner surface 118 in the circumferential direction 104 of the rotor core. The radial position of the radially inwardly directed ends 119, 120 of the first and

second recesses

106, 107 is described by a sixth diameter D6. The inner rotor core carrying area 121 has a radial dimension in the radial direction of the rotor core 102, denoted by D9, which is equal to half the difference between the sixth diameter D6 and the seventh diameter D7, and which is dimensioned as small as possible, as it can take into account the mechanical loads occurring in the rotor core 102.

In contrast, the third and

fourth recesses

110, 111 have radially inward ends 122 and 123, respectively, which are not separated from the inner rotor core surface 118 only by the inner rotor core bearing area 121. The radial position of the radially inward ends 122 and 123 of the third and

fourth recesses

110, 111, respectively, is described by a third diameter D3. The difference between the second diameter D2 and the sixth diameter D6 is preferably at least almost twice the difference between the second diameter D2 and the third diameter D3, with a deviation of about 5% and a maximum of 10%. In other words, the first and

second recesses

106, 107 have a larger dimension in the radial direction or in their extension along the side of the first "V" shape 108 than the third and

fourth recesses

110, 111 in the radial direction or in their extension along the side of the second "V" shape 112, preferably at least almost twice as large. A spatial region 124 with rotor core material, the shape of which is described in more detail below, is thus formed in the rotor core 102 between the first and

second recesses

106, 107 and the third and sixth diameters D3, D6.

In the rotor core 102 shown as an example, the dimensions of the

indentations

106, 107, 110, 111 on their extension along the sides of the "V"

shape

108, 112, i.e. between the radially inwardly directed ends 119, 120, 122 and 123 (on one side) and the radially outwardly directed ends 113, 114, 115 and 116 (on the other side), are preferably many times larger than the dimensions perpendicular to the sides of the "V"

shape

108, 112. If the radial extension of the

recesses

106, 107, 110, 111 is described in another way, namely by the difference D2-D3 between the second D2 and the third D3 diameter or by the difference D2-D6 between the second D2 and the sixth D6 diameter, this applies in particular to the

recesses

106, 107, 110, 111 which are connected in a rotationally fixed manner in the radial direction

-first and

second notches

106, 107, the difference D2-D6 being at least five times the dimension a1 of the first and

second notches

106, 107 perpendicular to the first "V" shape 108, noted as the first dimension, and

third and

fourth recesses

110, 111, the difference D2-D3 being at least three times the dimension a2 of the third and

fourth recesses

110, 111 perpendicular to the second "V" shape 112, labelled the second dimension.

Also in the example shown, the first dimension a1 is preferably at least nearly 10% greater than the second dimension a 2.

Furthermore, the opening angle W4 of the sides of the second "V" shaped structure 112, i.e. the third and

fourth recesses

110, 111, is preferably at least about 20% greater than the opening angle W3 of the sides of the first "V" shaped structure 108, i.e. the first and

second recesses

106, 107.

The first, second, third and

fourth recesses

106, 107, 110 and 111 are used to accommodate the first, second, third and fourth permanent magnets, respectively. This is shown in fig. 3 by means of a first recess 106 arranged with a first permanent magnet 125 and a fourth recess 111 arranged with a fourth permanent magnet 126. Here the first 125 and second permanent magnets are identical; likewise, the third and fourth permanent magnets are identical. In the illustrated example, the

permanent magnets

125, 126 are integrally designed in a rectangular parallelepiped shape having rounded edges and corners. Instead, a plurality of permanent magnets, preferably of the same rectangular parallelepiped shape, can be arranged in each

recess

106, 107, 110 and 111, respectively. In a rotor 100 with several axially consecutively arranged segments (in which the poles are offset from one another in the circumferential direction 104 by a predetermined angle of inclination from one segment to the other, i.e. arranged rotationally), the individual permanent magnets extend in the axial direction over at most only one segment; otherwise, each permanent magnet may also extend at least over almost the entire axial dimension of the rotor 100 or the rotor core 102.

The permanent magnets, i.e. the first and fourth

permanent magnets

125, 126 according to fig. 3, are constructed in a rotor 100 constructed according to the invention with a ferrite material, preferably completely made of ferrite material. This allows the rotor to be manufactured inexpensively. Furthermore, the magnetization directions of the permanent magnets, i.e. the magnetization directions of the first and fourth

permanent magnets

125, 126 shown in fig. 1, as shown in fig. 3, are oriented at least to a large extent, preferably at least almost completely, along the smaller dimension a1, a2 of the

indentations

106, 107 or 110, 111, i.e. perpendicular to the sides of the "V" -shaped

shapes

108, 112.

The magnetization directions of the permanent magnets, i.e. of the first and fourth

permanent magnets

125, 126 according to the exemplary illustration in fig. 3, are oriented from one magnetic pole of the rotor 100 alternately toward the magnetic poles lying next to one another in the circumferential direction 104, pointing away from the pole axis 105 of the relevant magnetic pole and pointing toward the pole axis 105 of the relevant magnetic pole. The magnetic poles of the rotor 100 are thus at least almost located in the pole axis 105, and the magnetic north and south poles alternate in the circumferential direction 104.

In the exemplary embodiment shown, the

permanent magnets

125, 126 do not extend completely over the associated

recesses

106, 107, 110 or 111. Only the first and

second recesses

106, 107 are at least almost completely filled with the first and second permanent magnets, respectively, at the radially inward ends 119, 120. Air pockets 127, 128 and 129, 130 and 131, 132 are provided at the radially outwardly directed ends 113, 114 of the first and

second recesses

106, 107 and at the radially inwardly and radially outwardly directed ends 122, 123 and 115, 116 of the third and

fourth recesses

110 and 111, respectively. The air pockets 127, 128 and 129, 130 and 131, 132 are preferably formed in such a way that the ends 113, 114, 115, 116, 122 or 123 of the

recesses

106, 107, 110 or 111 are oriented at an acute angle or at an obtuse angle (i.e. not at right angles) to the extent of the

recesses

106, 107, 110 or 111 along the sides of the "V" shapes 108 and 112, and the opposing

permanent magnets

125, 126 have mutually perpendicular surfaces. For example, the radially inward end 122 of the third recess 110 is oriented at an obtuse angle relative to the direction of the side of the second "V" shape 112 formed by the third recess 110; the right angle W6, which is formed opposite the right angle surface through the third permanent magnet, thus leaves room for the air pocket 129. In contrast, for example, the radially inwardly directed end 120 of the second recess 107, when forming the right angle W5, is apparent in the direction of the side of the first "V" shape 108 formed by the second recess 107, so that no air pocket is formed here.

In the magnetization direction of the permanent magnet described above, the air pockets prevent magnetic short-circuiting or magnetic leakage at the

end portions

113, 114, 115, 116, 122 and 123.

The suppression of leakage flux also serves to ensure that the radially inwardly directed ends 122, 123 of the third and

fourth recesses

110, 111 are pressed against each other as tightly as possible; they are separated from each other only by the first support beams 133 made of the rotor core material for receiving the centrifugal force, and the width T1 of the first support beams is selected to be as narrow as possible as long as the object can be achieved.

Instead of air pockets directly adjoining the first 125 and second permanent magnets, in the exemplary embodiment shown, two magnetically non-conductive, quadrangular, flux-deflecting

recesses

134, 135 extending in the circumferential direction 104 of the rotor core 102 are provided between the radially inwardly directed ends 119 and 120 of the first and

second recesses

106, 107. The flux-deflecting

recesses

134, 135, which preferably form air-filled cavities, are arranged one after the other in the circumferential direction 104 between the radially inwardly directed ends 119, 120 of the recesses of the first 106 and second 107 and are separated from each other by supporting

beams

136, 137, 138 of rotor core material integral with the rotor core 102. Specifically, a first one 134 of the

flux deflecting notches

134, 135 abuts the first notch 106 and is separated by a second one 136 of the support beams 136, 137, 138. A second one 135 of the flux-deflecting

notches

134, 135 adjoins the first one 134 of the flux-deflecting

notches

134, 135 in the circumferential direction 104 and is separated by a third one 137 of the support beams 136, 137, 138. The second recess 107 adjoins the second recess 135 of the flux-deflecting

recesses

134, 135 in the circumferential direction 104 and is separated by a fourth support beam 138 of support beams 136, 137, 138. The flux-deflecting

recesses

134, 135 are closed radially on the inside by edges which extend along the sixth diameter D6. The flux-deflecting

recesses

134, 135 are closed radially on the outside by edges extending along a fifth diameter D5.

The fifth diameter D5 is greater than the sixth diameter D6 but smaller than the third diameter D3 and is selected to be as small as possible, so that the

recesses

134, 135 deflected by the magnetic flux, on the one hand, effectively suppress magnetic flux leakage at the radially inwardly directed ends 119, 120 of the first and

second recesses

106, 107, while the magnetic flux for generating a torque on the rotor 100 is not or as little disturbed. Preferably, the fifth diameter D5 is selected to be at most 8% to 10% larger than the sixth diameter D6. Further, the second, third, and fourth support beams 136, 137, 138 are also formed of a rotor core material integrally with the rotor core 102, and are used to withstand centrifugal force. Further, the width T3 of the third support beam 137 and the width T2 of the second and fourth support beams 136 or 138 are selected to be as narrow as possible as long as the object can be achieved.

In the exemplary embodiment shown, all corners of all

recesses

106, 107, 110, 111, 134 and 135 are rounded with a radius R1. All angles for all

indentations

106, 107, 110, 111, 134 and 135 are preferably the same. The rounding is used in particular for a more uniform distribution of mechanical stresses in the rotor core 102.

Furthermore, the first recesses 106 belonging to the first magnetic pole of the rotor 100 are at least almost parallel to the second recesses 107 of the second magnetic pole of the rotor 100 directly adjacent to the first magnetic pole of the rotor 100 in the circumferential direction 104, which second recesses are directly adjacent to the first magnetic pole of the rotor 100 in the circumferential direction 104. In the rotor core 102, therefore, radially oriented plates of rotor core material having a width measured in the circumferential direction 104 are arranged between a first recess 106 belonging to a first magnetic pole of the rotor 100 and a second recess 107 of a second magnetic pole of the rotor 100 directly adjacent in the circumferential direction 104, which plates have at least largely the same shape in the radial direction. The at least almost uniform flux condition thus achieved in the plates over the entire radial extension of the rotor core 102, the lines of force of which extend from the first permanent magnet 125 in the first recess 106 of the first pole of the rotor 100 to the second magnet in the second recess 107 of the second pole of the rotor 100 directly adjacent in the circumferential direction 104. Accordingly, the pole angle W1 between each two poles of the rotor 100 or the pole axis 105 thereof is at least almost identical to the opening angle W3 of the side of the first "V" shape 108, i.e. between the first and

second recesses

106, 107.

At least one recess 139 is provided in the rotor core 102 in the rotor region 124 between the first 106 and second 107 recesses, in particular between the sections of the first 106 and second 107 recesses which are close to the ends of the first 106 and second 107 recesses which are radially inside, for accommodating at least one fastening element. The at least one fastener is preferably constituted by a bolt connection, a rivet or the like. The indentations 139 are arranged along a circle having a fourth diameter D4 concentric with the rotation axis 103; the fourth diameter D4 determines the radial position of the recess 139 for at least one fastener. In the circumferential direction 104, the position of the indentation 139 for the at least one fastener is determined by an angle W2, the angle W2 representing the angular position of the indentation 139 for the at least one fastener relative to the pole shaft 105. A recess 139 for at least one fastener is provided for each pole of the rotor 100, so that the recesses 139 of two poles adjacent in the circumferential direction 104 are rotated relative to one another in the circumferential direction 104 by a pole angle W1.

The recess 139 for the at least one fastener is constituted in the example shown by a circular hole having a diameter D10 determined by the type and size of the at least one fastener. The recesses 139 for the at least one fastener are spaced a third dimension A3 relative to the third diameter D3 and the radially inwardly directed ends 122, 134 of the third and

fourth recesses

110, 111. The recesses 139 for the at least one fastener are spaced a fourth dimension a4 relative to the fifth diameter D5, and thus, relative to the radially outward edges of the flux-deflecting

recesses

134, 135. The dimensions A3 and a4 are preferably selected to be the same.

In the structure of the rotor 100 having two or more axially aligned sections, the angle W2, i.e., the angular position of the notches 139 for at least one fastener with respect to the pole shaft 105, varies from one section to another at a desired inclination angle, so that all the notches 139 for at least one fastener of the magnetic poles arranged one after another in the axial direction of the rotor 100 are aligned in the rotor 100. Thus, the at least one fastening element can be guided very simply linearly through the entire axial extension of the rotor 100.

Preferred dimensional embodiments for the rotor core 102 of the rotor 100 according to the invention are given in the following table.

In summary, the present invention provides a rotor of an IPM machine having a magnetically conductive rotor core including first, second, third and fourth notches in each magnetic pole of the rotor in which at least one first, second, third and fourth permanent magnet is disposed, in order to reduce manufacturing costs while maintaining power and torque, wherein

The first and second notches are mutually arranged in a first "V" shape (108) opening towards the outer surface of the rotor core, and the third and fourth notches are mutually arranged in a second "V" shape opening towards the outer surface of the rotor core,

the second "V" shape is located between the notches of the first "V" shape, and is nested with it,

the permanent magnet is formed of a ferrite material, preferably entirely formed of a ferrite material,

in particular, the dimension of the indentation along the side of the "V" shape is greater than, preferably more than, particularly preferably at least three times, the dimension perpendicular to the side,

more particularly, the permanent magnet is magnetized at least to a large extent, preferably at least almost completely, along the smaller dimension of the indentation.

List of reference numerals

100 rotor

101 rotor disk as a rotor core element of 102

102100 rotor core

103100 rotary shaft

104100 and 102 in the circumferential direction

105100 pole shaft

106 first indentation in 101 or 102

107 second recesses in 101 and 102

108 a first "V" shape comprising 106, 107

109 rotor core outer surface: 102 radially outwardly directed edge

110 third recess in 101 or 102

111 fourth indentation 112 in 101 or 102

112 second "V" shape, including 110, 111

113106 radially outwardly directed ends

114107 radially outwardly directed end

115108 radially outwardly directed end

116109 radially outwardly directed end

117101 or 102, and a rotor core carrying region

118102 rotor core inner surface

119106 radially inwardly directed end

120107 radially inwardly directed end

121101 or 102 in the inner rotor core carrying area

122110 radially inwardly directed end

123111 radially inwardly directed end

124 between 106, 107 and between D3, D6 have regions of space for the rotor core material

125106 first permanent magnet

126111 fourth permanent magnet

127 air pocket 113 at 106

128 cavitation at 114 of 107

129 air pocket at 122 of 110

130 cavitation at 116 of 110

131 at 115 of 110

132 cavitation at 116 of 111

133 first support beam between 122 of 110 and 123 of 111

134 first flux deflection notch in 101 or 102

135 in 101 or 102

136106 and 134 between the first and second support beams

137134 and 135 between the third support beam

138135 and 107 between the fourth support beam

139 recesses for fasteners, e.g. screw connections, rivets

A1 first size: 106. 107 perpendicular to 108

A2 second size: 110. 111 dimension perpendicular to the sides 112

A3 third dimension: distance from 139 to D3

A4 fourth dimension: distance from 139 to D5

D1 first diameter: 102, i.e. 100 at 109

D2 second diameter: 113. 114, 115, 116, and a radial position

D3 third diameter: 122. 123 radial position

D4 fourth diameter: 139 radial position

D5 fifth diameter: 134. 135 of the radially outwardly directed edge

D6 sixth diameter: 119, 120 radial position

D7 seventh diameter: 118 diameter of

Radial dimension of D8117 in radial direction of 101 or 102

Radial dimension of D9121 in radial direction of 101 or 102

Diameter of D10139

Radius of rounding of the corners of R1106, 107, 110, 111, 134, 135

Width of T1133

Width of T2136 and 138

Width of T3137

W1 polar angle between each two adjacent poles or their polar axes 105

Angular position of W2139 with respect to 105

Opening angle of the sides of W3108, i.e. 106, 107

Opening angle of the sides, i.e., 110, 111, of W4112

W5 Right Angle from 120 to 107

W6 Right Angle of second permanent magnet at 122 in 110

Z partial of FIG. 1: detail view according to fig. 2 and 3

Claims

1. A rotor (100) of a permanent-magnet excited electrical machine with a magnetically conductive rotor core (102), comprising on each pole of the rotor (100):

a first recess (106) in which at least one first permanent magnet (125) is arranged,

a second indentation (107) in which at least one second permanent magnet is arranged,

-a third recess (110) in which at least one third permanent magnet (126) is arranged,

-a fourth indentation (111) in which at least one fourth permanent magnet is arranged,

wherein the content of the first and second substances,

-the first and second recesses (106, 107) are mutually arranged in a first "V" shape (108) opening towards the rotor core outer surface (109), and

-the third and fourth recesses (110, 111) are mutually arranged in a second "V" -shape (112) opening out towards the rotor core outer surface (109),

-the first and second "V" -shaped shapes (108; 112) are nested one inside the other in such a way that the second "V" -shaped shape (112) is located between said notches (106, 107) of the first "V" -shaped shape (108),

-the permanent magnets (125, 126) are configured with ferrite material,

-the extension of said notches (106, 107, 110, 111) along the sides of the "V" shape is greater than the dimension perpendicular to the sides of the "V" shape,

-the magnetization direction of the permanent magnets (125, 126) is oriented along the smaller dimension of the indentations (106, 107, 110, 111),

-wherein the opening angle (W4) of the side of the second "V" shape (112) is larger than the opening angle (W3) of the side of the first "V" shape (108), and wherein a first notch (106) belonging to a first pole of the rotor (100) extends parallel to a second notch (107) of a second pole of the rotor (100) directly adjacent to the first pole of the rotor (100) in the circumferential direction (104), directly adjacent in the circumferential direction (104).

2. The rotor (100) of claim 1, wherein the permanent magnets (125, 126) are comprised entirely of ferrite material.

3. The rotor (100) according to claim 1, characterized in that the extension of the recesses (106, 107, 110, 111) along the sides of the "V" shape is a multiple of the dimension perpendicular to the sides of the "V" shape.

4. The rotor (100) of claim 1, characterised in that the extension of said notches (106, 107, 110, 111) along the sides of the "V" shape is at least three times greater than the dimension perpendicular to the sides of the "V" shape.

5. The rotor (100) of claim 1, wherein the opening angle (W4) of the side of the second "V" shape (112) is at least 20% greater than the opening angle (W3) of the side of the first "V" shape (108).

6. The rotor (100) of claim 1,

-the radially inward ends (119, 120) of the first and second recesses (106, 107) are spaced from the rotor core inner surface (118) only by the radial dimension (D9) of an annular inner rotor core carrying area (121) extending along the rotor core inner surface (118) in the circumferential direction (104) of the rotor core (102),

and/or

The radially outward ends (113, 1114, 115, 116) of the first, second, third and fourth recesses (106, 107, 110, 111) are spaced from the rotor core outer surface (109) only by the radial dimension (D8) of an annular outer rotor core carrying region (117) which extends along the rotor core outer surface (109) in the circumferential direction (104) of the rotor core (102).

7. The rotor (100) according to claim 1, characterized in that at least one permanent magnet (125, 126) extends completely over the associated indentation (106, 107, 110, 111) and completely fills the associated indentation (106, 107, 110, 111).

8. The rotor (100) according to claim 1, characterized in that at least one recess (106, 107, 110, 111) has at least one air pocket (127, 128, 129, 130, 131, 132) at a radially inwardly and/or radially outwardly directed end (113, 114, 115, 116, 119, 120, 122).

9. The rotor (100) of claim 1,

-the dimensions of the first and second recesses (106, 107) along the sides of the first "V" -shape (108) are greater than the dimensions of the third and fourth recesses (110, 111) along the sides of the second "V" -shape (112),

and/or

The dimensions (A1) of the first and second recesses (106, 107) perpendicular to the sides of the first "V" shape (108) are greater than the dimensions of the third and fourth recesses (110, 111) perpendicular to the sides of the second "V" shape (112).

10. The rotor (100) of claim 9, characterised in that the dimensions of the first and second recesses (106, 107) along the sides of the first "V" shape (108) are at least twice as large as the dimensions of the third and fourth recesses (110, 111) along the sides of the second "V" shape (112).

11. The rotor (100) of claim 9, characterised in that the dimension (a1) of the first and second recesses (106, 107) perpendicular to the side of the first "V" shape (108) is at least 10% greater than the dimension of the third and fourth recesses (110, 111) perpendicular to the side of the second "V" shape (112).

12. The rotor (100) of claim 1,

-at least one magnetically non-conductive, flux-deflecting indentation (134, 135) extending in a circumferential direction (104) of the rotor core (102) between radially inward ends (119, 120) of the first and second grooves (106, 107),

-a plurality of such magnetically non-conductive, flux-deflecting recesses (134, 135) are arranged consecutively in circumferential direction between the radially inward ends (119, 120) of the first and second recesses (106, 107) and are separated from each other by support beams (136, 137, 138).

13. The rotor (100) as recited in claim 12, characterized in that the magnetically non-conductive, flux-deflecting recesses (134, 135) are of quadrilateral configuration.

14. The rotor (100) of claim 12, wherein the support beams (136, 137, 138) are integrally formed with the rotor core (102) from a rotor core material.

15. The rotor (100) of claim 1,

in the rotor core (102), at least one recess (139) for receiving at least one fastening element is provided in the spatial region (124) between the first and second recesses (106, 107).

16. The rotor (100) as claimed in claim 15, characterized in that a recess (139) for accommodating at least one fixing element is arranged in the spatial region (124) between the radially inwardly directed ends (119, 120) of the first and second recesses (106, 107).

17. A rotor core element (101), characterized in that the rotor core element (101) is configured as a rotor core element for a magnetically conductive rotor core (102) of a rotor (100) according to any of the preceding claims 1 to 16.

18. A rotor core element (101) according to claim 17, wherein said rotor core element (101) is a rotor disc (101).

19. A permanent magnet excited machine, characterized in that the machine has a rotor (100) according to one of claims 1 to 16 and/or a rotor core element (101) according to claim 17.

20. The pm excited machine according to claim 19, wherein said rotor core element (101) is a rotor disc (101).

21. A vehicle, characterized in that it has a permanent magnet excited machine according to claim 19 and/or has a machine with a rotor (100) according to one of claims 1 to 16 and/or has a machine with a rotor core element (101) according to claim 17.

22. The vehicle of claim 21, wherein the vehicle is a road vehicle.

23. A vehicle according to claim 21, characterized in that the rotor core element (101) is a rotor disc (101).