DE10037787B4 - Permanent magnet synchronous machine - Google Patents

Abstract

permanent-magnet Synchronous machine in external rotor design, including an outside one Rotor (1) which rotatably with a about an axis (3) rotatable Shaft (2) is connected and one between a rotor shell (5) the rotor (1) and the shaft (2) arranged stator (10), wherein Rotor (1) and stator (2) has a cylindrical tube-shaped gap (8) between them form, wherein on the inner circumference of the substantially bell-shaped Rotor shell (5) evenly distributed around the circumference, but in principle not necessarily equidistant, Yoke cores (6; 20; 25; 28) are aligned in the axial direction, on the inner circumference of which permanent magnets (9, 21, 27, 30) are arranged are and the return cores (6; 20; 25; 28) on the side of the gap (8) by one or more axially spaced circumferential carrier rings (7; 19; 24; 24) are supported.

Description

The The invention relates to a permanent magnet synchronous machine according to Transversal flow principle and in particular a special construction of the rotor in external rotor construction.

The This invention relates to general-purpose engines, in particular, a rotor diameter in the range 40 mm to 400 mm is to be used. However, the invention is not limited to these sizes limited; they are only examples of specified here the drive task.

transverse flux stand opposite each other other engines by a high torque density and moderate short-circuit currents. This makes them great for Direct drives suitable in wheel hub applications and are therefore with Advantage as external rotor machines built. Technologically, this construction is advantageous because the force application point further outside lies as an equal in size Internal rotor construction.

There but the magnetic flux in transverse flux guided essentially axially to the air gap, the problem arises that the Rotor not, as in conventional machines, from annular round sheets can be produced.

It is known to return the axial magnetic flux in the stator (also used in DE 196 14 862 ), which can be used in the rotor round sheets, which lead with a suitable external support to a per se stable structure of the active part of the rotor. However, this results in a Aktivteilgeometrie with considerable scattering thread, which completely negates the benefits of Transversalflußtechnologie.

The Technology described here therefore relies on an approximately axial River guidance in Rotor back. The The basic principle of such an arrangement has already been described by H.Weh (etzArchiv Bd.10 (1988) pp. 143-149) in general and by the active part an internal rotor machine illustrated; a mechanical construction that allows this However, building machines is not mentioned there.

By the machine according to the invention, this principle is realized for the first time in a meaningfully producible form:
The active part of the stator consists of juxtaposed phases, each of which consists of an annular coil which is inserted in a groove which is formed by p basically equidistantly distributed on the circumference U-shaped soft iron body. These U-cores face the rotor 2p I-shaped soft iron parts, which are provided with alternating polarized permanent magnets that excite an alternating current in the U-cores. This can be achieved either with axially parallel plates, in each case per phase complementary polarized flat permanent magnets or by a skew of rotor and / or stator plate to a pole pitch. The latter arrangement is mandatory when used between the rotor yokes permanent magnets are used.

There the relative position of the permanently excited field in the air gap to the teeth each enclosing a phase Winding the phase angle of the induced voltage of the corresponding phase determined, in a multi-phase machine, the average angular position the rotor magnet or the position of the stator teeth or both accordingly be offset, which by a corresponding inclination of the rotor or stator laminations or by appropriate offset of the U-cores or I-cores or can be achieved by a combination of these approaches.

Basically so machines can be realized with any number of phases; practically especially relevant are two- and three-phase arrangements. Prefers becomes an annular one per phase Coil used in a groove; but it can also be a phase on several annular Spools be distributed in several grooves and / or a groove with coils be energized by different phases. To have a machine with electric To obtain largely symmetrical phases, the phases must at least on Rotor or magnetically separated on the stator; you take asymmetric In phases, so can be apart from this separation.

In the mentioned DE 197 14 895 the rotor laminations are designed as blanks, ie, they are annular plates which are formed layered perpendicular to the axis of rotation.

disadvantage this solution is, however, that, as described above, form significant scattering paths, which is the maximum achievable torque significantly reduce the engine.

The DE 44 00 614 A1 shows a rotor for a transverse flux machine, in which the return parts 12 by axially spaced retaining rings 6 . 16 . 7 . 17 being held. The retaining rings are not only provided on the air-gap side, but themselves form a supporting part of the rotor construction. In the DE 43 25 740 A1 ( 3 ) are the components of the collector (permanent magnets and soft iron elements) by axially spaced Hal borders R1, R2 bordered. Again, the retaining rings are an integral part of the rotor design. From the EP 0 790 695 A1 is a generic transversal flux machine known ( 4 . 1 ). The return cores 48 be in this machine by a dovetail connection ( 1 , Part 48c in 4 ) fixed to the rotor shell. A carrier ring on the air gap side is not mentioned.

Of the The invention is therefore based on the object, a transversal flux machine be designed so that a stable construction is achieved and at the same time Scattering paths are substantially minimized, so that a significant volume per volume higher Torque can be generated.

to solution the task is the invention by the technical teaching of claim 1.

essential Feature of the invention is that the Inner circumference of a substantially bell-shaped rotor shell in principle evenly around the circumference distributed, but not necessarily exactly equidistant, in basically axial Direction aligned return cores arranged are, on the inner circumference of permanent magnets are arranged, and that the Return cores radially seen inward by one or more circumferentially spaced apart in the axial direction support rings supported are.

The solution shown here shows a rotor construction, which shows its basic strength a tubular Construction outside of the active part, in the the rod-shaped Conclusions Soft iron material is additional Support rings, which in particular the radially inwardly directed force component take up.

These carrier rings may extend outside the magnetic circuit of the phases (with magnetically separated phases, as in FIG 1 to 3 or with magnetically connected phases, as in 4 and 5 ). Alternatively, carrier rings of electrically poorly conductive material can be mounted inside the magnetic circuit ( 6 to 8th ). The radial fixation of the soft iron parts can be realized by a variety of methods, such as gluing, potting, injection molding and possibly also by prefabricated form-fitting spacers.

When Material for the carrier rings used here it is preferred to use a magnetically non-conductive material such as As aluminum, aluminum alloys, brass and other non-ferrous alloys as well as ceramics and ceramic composites.

In some applications can the carrier ring also made of iron material. Overall, the carrier ring consist of a solid material or of laminated layered materials from the material selection above.

According to the invention by this special concept the scattering paths are minimized by that it now possible for the first time is, aligned in the axial direction of individual and separate Return cores too use, which are arranged in the rotor bell and through the carrier rings according to the invention supported are. There are for the support structure according to the invention different designs, all of them be embraced by the spirit of the present invention should.

In a first, preferred embodiment is provided that in axial direction distributes several, along the circumference of the rotor bell extending and self-contained carrier rings are present, wherein the carrier rings carry the said return cores and the return cores in turn at the bottom carry the permanent magnets.

in this connection are the return cores in axial direction piecewise available, d. h., They form between them seen in the axial direction Interruptions, arranged in the region of the respective carrier ring is.

at This construction is thus in each case a return core at its front and Rear side (seen in the axial direction) of one support ring carried.

In however, it is another modified embodiment provided that the return cores themselves essentially over the entire axial length extend the rotor and have corresponding grooves, in which the carrier rings are arranged and thereby the return cores are worn.

In a modified embodiment thereof can it be provided that the radial expansion of the groove in the respective yoke core for receiving the carrier ring is minimized so that only the bottom of the respective yoke core the radially outer surface of the carrier ring seated.

In In another embodiment, it may also be provided that the recess for the holder of the carrier ring is also arranged in a groove of the permanent magnet itself.

In Another embodiment of the invention is the carrier ring arranged above the stator winding in a Gap between two continuous in the axial direction permanent magnets, wherein again the carrier ring either in a groove of the return core can be arranged and the height This groove can also receive the value 0 in the radial direction.

In a modification of this embodiment can it be provided that the Groove for receiving the carrier ring not arranged in the yoke core is but in the arranged on the underside of the yoke core permanent magnet.

In a further embodiment it is envisaged that a Variety of rotor teeth distributed evenly in principle is arranged on the inner circumference of the rotor bell. Between the rotor cores are in the radial direction, the permanent magnets attached. Basically these permanent magnets are in contrast to the previously mentioned ones embodiments oriented upright as it were, and also with this construction become the rotor teeth with the intermediate permanent magnets by appropriate inventive carrier rings carried.

in the The following is the invention with reference to several execution paths illustrative drawings closer explained. Here are more from the drawings and their description Features and advantages of the invention.

It demonstrate:

1 a longitudinal section through a Transversalflußmaschine showing the upper half;

2 : Perspective side view in the position of a yoke core in the rotor with its holder;

3 : one opposite 2 modified embodiment;

4 a second embodiment with representation of a longitudinal section through the upper half of a Transversalflußmaschine with a continuous yoke core in the axial direction;

5 : the embodiment according to 4 showing the holder of a single yoke core;

6 : one opposite 4 modified embodiment with a centrally arranged support ring, which is arranged directly opposite the stator winding;

7 : The perspective view of the embodiment according to 6 ;

8th : one opposite 7 illustrated modification;

9 : Another embodiment of a Transversalflußmaschine with lying between the reclosures permanent magnet.

In 1 is generally shown a half-section of a transverse flux machine, wherein an external rotor 1 non-rotatable with a shaft 2 connected to a rotation axis 3 can rotate. There are one or more camps 4 for the rotary bearing of the bell-shaped rotor 1 present, in the longitudinal direction of a rotor shell 5 formed.

According to the invention are now on the inner circumference of the rotor shell 5 in the axial direction in pieces one behind the other trailing cores 6a , b, c arranged, wherein in 2 the holder of a single yoke core is shown.

Every inference core 6 consists essentially of a magnetically conductive material, which may be a laminated sheet material or a solid material.

It is important that every inference nucleus 6a - 6c each end a recess 15 comprising, of a, circumferential in the circumferential direction and self-contained, carrier ring 7 is penetrated. In the embodiment of the 1 are a total of four such carrier rings 7a - 7b arranged in the axial direction with mutual distance from each other.

At the bottom of the respective yoke core 6 Here, each is a permanent magnet 9a . 9b . 9c arranged, in a manner not shown with return core 6 connected is.

Preferably, the entire assembly is cast, so it will be the return cores 6 , the associated and supporting carrier rings 7 and the permanent magnets 9 enclosed in a plastic material.

Instead of pouring, it may also be provided that the carrier rings 7 in their recesses 15 , in the area of the return cores 6 , glued, welded, soldered, mechanically clipped or otherwise positively connected to this part.

In a known manner is between the stator 10 and the rotating rotor 1 an air gap 8th educated.

The stator consists in the embodiment shown of a stator core 11 , seen on the axial length of a total of three windings 12 . 13 . 14 available. Of course, more or less than three such windings may be used 12 - 14 be provided.

The windings 12 - 14 In alternating mode, alternating currents of different phase angles flow through each one.

It is important in the embodiment of the 1 and 2 That now very high forces during operation of the engine on the return cores 6 in the direction of the arrow 16 are exercised, which act radially inward, and here are these return cores 6 by the carrier rings according to the invention 7a - 7d carried.

The height 17 the recesses 15 in which the carrier rings 7 lie, is variable. This height 17 can be up to the vicinity of the outer circumference of the return core 6 walk; the height 17 but can also be the value 0, in this case would - according to the embodiment according to 1 - The support ring directly to the bottom of the return core 6 rest.

In the 4 and 5 is shown a further embodiment, where it can be seen that not in the axial direction piecewise arranged one behind the other return cores 6 are present, but it is in each case a single, continuous in the axial direction yoke core 20 present, with such return cores 20 uniform in principle, but not necessarily equidistant, distributed over the circumference are arranged in the axial direction and with the carrier rings according to the invention 19a . 19b are worn.

In the return cores 20 are circumferential grooves in the circumferential direction 23 incorporated, in which the carrier rings 19a . 19b are included. In the illustrated embodiment according to 4 The carrier rings project with their lower edge over the lower edge of the respective yoke core 20 out and are approximately flush with the lower edge of the underlying permanent magnets 21a - 21f arranged. This is a preferred embodiment. However, the invention is not limited thereto.

Again, the same applies as regards height 17 the recess 15 Said that in fact the height of the groove 23 (according to the height 17 in 1 ) Is variable, so that in this embodiment, the groove 23 can completely be omitted and the carrier rings 19 then with its radially outer surface at the bottom of the return cores 20 rest.

The permanent magnets 21a - 21f each form recesses between them 22 , which opposite the respective winding 12 - 14 in the stator 10 is arranged.

The stator is in this case on a series of axially successively arranged, U-shaped stator cores 18 - 18c formed, each U-leg of the respective stator core 18a - 18c an associated permanent magnet 21a - 21b assigned.

The 5 shows again the representation in 4 in a perspective side view, where also shown that the height 17 the groove 23 can vary, so that so the groove 23 Can be omitted and the surface of the carrier rings 19 then immediately on the bottom of the trailing edge 20 rests.

The 6 and 7 show one opposite the 1 to 5 modified embodiment, which is characterized by a construction with centrally above the windings 12 - 14 arranged carrier rings 24 distinguished.

There is the stator 10 only with a single U-shaped stator core 18 shown that a winding 12 - 14 wearing. Such an arrangement can also in the axial direction, according to the 1 to 4 , be continued multiplied.

There is essential that the carrier ring 24 centrally in the inference core 25 in the area of a groove 26 is arranged and the opposite central stator side winding 12 - 14 is arranged.

Laterally on the outside, in contrast to the U-shaped legs of the stator core 18 are then the permanent magnets 27a . 27b arranged.

This situation is in again 7 shown in a perspective side view, in which case for the groove 26 the same statements regarding the height 17 as in the other embodiments apply.

In 8th a further embodiment is shown, which consists essentially of a combination of the embodiments in 3 and 6 equivalent.

There it can be seen that the permanent magnet 27 even a groove 26 through which the carrier ring 24 extends and thus the entire holder only through the groove 26 in the permanent magnet 27 for the inference core 25 he follows.

The 9 shows a further embodiment in which distributed around the circumference return cores are provided, of which only two return cores 28a . 28b are shown by way of example. Between each return core 28 is a distance 29 provided by a respective permanent magnet 30 is filled. In this way, at the periphery of an alternating order of a return core 28a , a permanent magnet 39 , a backsheet core 28b , another permanent magnet, etc. provided.

In this embodiment, it is essential that the permanent magnets 30 - Are arranged approximately upright compared to the previously described embodiments.

This example is only intended to show that it is provided according to the invention in such a rotor construction that carrier rings 19 are present, which the respective return cores 28 wear.

Here are near the end faces of the return cores 28 each opposing grooves 31 provided, each of a support ring 19 are penetrated.

Again, apply with respect to the groove 31 , which the respective return cores 28 goes through the same expositions as they do by height 17 with respect to the recess 15 and the groove 23 were made.

Essential in all embodiments is that so a circumferentially closed support member in the form of a carrier ring is present, which is now able to distributed around the circumference, axially extending return cores too wear and against radially inward directed forces support.

In order to is it possible for the first time Piecewise available Return cores too use that opposite a construction with annular Return plates result in a substantial minimization of the existing scattering paths.

2

rotor

3

wave

4

axis of rotation

5

camp

6

rotor casing

7

Inference core (rotor a, b, c)

8th

support ring a, b, c, d

9

air gap

10

permanent magnet a, b, c

11

stator

12

stator core

13

winding

14

winding

15

winding

16

recess

17

arrow

18

Height of the recess 15

19

stator core a, b, c

20

Carrier a, b

21

Yoke core

22

permanent magnet a - f

23

recess

24

groove

25

support ring

26

Yoke core

27

groove

28

permanent magnet a, b

29

Yoke core 28a , b

30

distance

31

permanent magnet

32

groove

Claims (16)

Permanent magnet synchronous machine in external rotor design, including an external rotor ( 1 ), which rotatably with one about an axis ( 3 ) rotatable shaft ( 2 ) and one between a rotor shell ( 5 ) of the rotor ( 1 ) and the wave ( 2 ) arranged stator ( 10 ), where rotor ( 1 ) and stator ( 2 ) a cylindrical tube-shaped gap ( 8th ) form between them, wherein on the inner circumference of the substantially bell-shaped rotor shell ( 5 ) distributed evenly around the circumference, but not necessarily equidistant, 6 ; 20 ; 25 ; 28 ) are arranged aligned in the axial direction, on whose inner circumference permanent magnets ( 9 ; 21 ; 27 ; 30 ) and the return cores ( 6 ; 20 ; 25 ; 28 ) on the side of the gap ( 8th ) by one or more, in the axial direction spaced, circumferential support rings ( 7 ; 19 ; 24 ; 24 ) are supported. A permanent magnet synchronous machine according to claim 1, wherein the support rings ( 7 ) outside the magnetic circuit of the windings ( 12 - 14 ). A permanent magnet synchronous machine according to claim 2, wherein the stator cores ( 18 ) of the windings ( 12 - 14 ) are separated from each other and thus the windings ( 12 - 14 ) are substantially magnetically decoupled from each other. A permanent magnet synchronous machine according to claim 2, wherein the stator cores ( 11 ) of the windings ( 12 - 14 ) and thus the windings ( 12 - 14 ) are substantially magnetically coupled together. Permanent magnet synchronous machine after Claim 1, wherein the carrier rings ( 7 ) within the magnetic circuit of the windings ( 12 - 14 ) and are formed from electrically poorly conductive material. Permanent magnet synchronous machine according to one of claims 1 to 5, wherein the permanent magnets ( 9 ; 21 ; 27 ; 30 ) through the return cores ( 6 ; 20 ; 25 ; 28 ) are worn. Permanent magnet synchronous machine according to claim 6, wherein the permanent magnets ( 9 ; 21 ; 27 ) in approximately radial direction at the bottom of the return cores ( 6 ; 20 ; 25 ) are mounted. Permanent magnet synchronous machine according to claim 6, wherein the permanent magnets ( 30 ) in each case between the return cores ( 28a . 28b ) are mounted. A permanent magnet synchronous machine according to any one of claims 1 to 8, wherein the cores ( 6 ; 28 ) at its axial ends by a respective carrier ring ( 7 ; 19 ) are worn. A permanent magnet synchronous machine according to claim 9, wherein carrier rings ( 7 ; 19 ) in recesses ( 15 ) of the return cores ( 6 ; 28 ) intervene. A permanent magnet synchronous machine according to any one of claims 1 to 8, wherein the cores ( 20 ; 25 ) substantially over the entire axial length of the rotor ( 1 ). A permanent magnet synchronous machine according to claim 11, wherein the cores ( 20 ; 25 ) corresponding grooves ( 23 ; 26 ), in which the carrier rings ( 19 ; 24 ) are arranged. A permanent magnet synchronous machine according to claim 11, wherein the cores ( 20 ) with their radial bottoms. the radially outer surface of the carrier rings ( 19 ) hang up. A permanent magnet synchronous machine according to claim 11, wherein the carrier rings ( 24 ) in grooves ( 26 ) of the permanent magnets ( 27 ) and thus the return cores ( 25 ). Permanent magnet synchronous machine according to one of claims 1 to 14, wherein the carrier rings ( 7 ; 19 ; 24 ) radially outside the stator windings ( 12 - 14 ) are arranged. Permanent magnet synchronous machine according to one of claims 1 to 15, wherein the carrier rings ( 7 ; 19 ; 24 ) in a gap between two axially spaced apart permanent magnets ( 9 ; 21 ; 30 ) are arranged.