DE102006058711A1 - Rotor for a motor, in particular for an electric motor - Google Patents

Abstract

The rotor according to the invention for a permanent-magnet motor comprises a disk pack (2) which has a multiplicity of identical individual laminations (2.1 to 2.n) stacked one above the other, each having outer segments (4) distributed over the circumference, which have an annular, radially inward direction facing outer yoke (8) are interconnected, in the inner circle (K1) a predetermined number of inner segments (6) is provided, which are interconnected via an annular inner yoke (10), wherein within the inner circle (K1) of the outer yoke (8) Wing elements are integrated so that upon rotation of the rotor (1) an axial air flow is generated.

Description

The The invention relates to a rotor for an electric motor, in particular a permanent-magnet motor or permanent-magnet synchronous motor, z. B. a radiator fan motor in a vehicle. Furthermore, the invention relates to a method for the production a plate pack for a rotor.

such Electric motors are particularly suitable for use in motor vehicles. In the automotive sector electric motors play as small engines are formed, due to the limited space a significant Role. Small motors are electric motors with small dimensions and usually have a power of up to 1 kW. The electric motor may preferably be a permanent magnet commutator or a brushless permanent-magnet DC or synchronous motor or another Be electric motor. The for This designation also used "AC servo motor" may cause confusion to lead, as she too for highly dynamically controlled asynchronous motors is used. To this ruled out the electronically commutated motor will subsequently become an EC motor designated.

electric motors can as an inner rotor or external rotor motors be educated. Internal rotor motors have an outer stator and an inner rotor. The rotor is coaxial with the stator inserted. at an external rotor motor surrounds the outer rotor the inner stator coaxial. The rotor or the rotor shaft is rotatably mounted in all variants. The invention relates primarily on internal rotor motors, on the basis of which the invention is explained in more detail below.

in the State of the art are stators or rotors of electric motors known, which formed from packages of single sheets or single lamellae and by so-called stamping-packaging or punching laser packaging. In detail, using a complex and elaborate punching laser plant the individual sheets or Slats punched within the stamping sequence and at the same time to packages welded. there The individual sheets or fins are in a very fast Followed by pressed out nubs of different designs (also called "Paketiernoppen") with each other connected. The Paketiernoppen hold the individual slats in the package together. additionally the disk pack can be overmoulded with plastic. Also, the Single lamellae are glued together.

Furthermore is in the rotors of electric motors with a number of pole pairs of p> 1, the range between Slot bottom and shaft at commutator armatures or between magnet inside and shaft in permanent magnet rotors are not complete for a magnetic river guide necessary and can be reduced to a defined yoke width. The area between the yoke and a remaining inner ring for fixing the Package on the rotor shaft is usually punched free except for a few remaining webs. The recovered area serves as additional Air passage area for cooling the engine components.

to better cooling Especially in open engines by special internal or external measures for one flow the engines were supplied with air. Even with closed engines is it is advantageous if a steady circulation of air takes place inside, so that the heat loss better from heat sources to heat sinks is transported. This can be achieved by additional fan wheels, which are mounted on the motor shaft or, to a limited extent, attached to the bankruptcy e.g. sprayed, wings done. This increases the axial length the engines. If one refrains from such additional measures, the cooling suffices Air turbulence is usually not enough and the permissible power the engines are dropping rapidly.

Of the Invention is therefore based on the object, a rotor for a Specify electric motor, which is sufficient even with small size well chilled becomes. About that In addition, a particularly suitable method for producing a Lamella packages for to specify a rotor.

Regarding of the rotor, the object is achieved by the features of claim 1. With regard to the manufacturing process, the object is achieved by the features of claim 15.

advantageous Further developments of the invention are the subject of the dependent claims.

In the rotor according to the invention for a drive unit, in particular an electric motor, in particular a permanent-magnet motor or a synchronous motor or EC motor, a disc pack is provided which comprises a plurality of stacked identical individual slats, each having over the circumference distributed outer segments over an annular, radially inward point the outer yoke are interconnected, in whose inner circle a predetermined number of inner segments is provided, which are interconnected via an annular inner yoke, wherein within the inner circle of the outer yoke wing elements are integrated so that upon rotation of the rotor, an axial air flow is generated. As a result, an engine cooling is possible without an axial installation space extension. The wing elements cause in the inner free area of the rotor laminated core in the form of blades of an axial fan an axial air flow, which is used for cooling the engine components.

In a possible embodiment are at least two of the individual lamellae in the circumferential direction to each other rotatable so that their outer segments identical to each other and their inner segments with a predetermined angle α to each other are arranged offset, wherein the mutually offset inner segments the wing elements form. In other words, by the angularly offset one another Inner segments of axially one behind the other arranged individual lamellae an integrated slightly curved wing element is formed, that during rotation of the shaft from the surrounding medium, here air, flows around obliquely and is deflected. Utilizing the principle of centrifugal force, the offset inner segments act like shovels of an axial fan. Upon rotation of the shaft creates an axial pressure difference and a The suction is generated, the axial flow as the interior of the rotor flows through.

Conveniently, can the inner segments in the simplest form when punching packages from the Single lamellae, z. B. laminations, are punched out. alternative or additionally can formed by molded to the inner segments or additionally introduced parts wing but they have extra parts or an additional one Require tool for overmoulding.

In a particularly simple embodiment are at least one of the suction side single fins and one of pressure-side individual slats arranged offset from one another. there become at least the first and the last single lamella of the rotor disk package according to the desired flow direction by a given circumferential division, z. B. Nutteilung at a commutator armature or pole pitch in a permanent magnet rotor, turned back or forth.

Around the outer segments identical on top of each other stack and the inner segments to form the integrated wing elements to arrange offset to each other, the number of predetermined Inner segments not equal to the number of outer segments. Preferably the number of outer segments unequal to a whole multiple of the number of predetermined inner segments, which form the integrated wing elements. That means, the predetermined number of inner segments, the fan wheel is not a divisor of the number of outer segments, i. no divider the slot or pole number. Any number of indoor and outer segments be specified. The number of inner and outer segments depends on the Type and structure of the engine.

In a further embodiment can several identical on top of each other stacked individual lamellae each form a group. There are preferably several groups in the circumferential direction rotatable to each other, wherein the inner segments of a single group are identical to one another are arranged and the inner segments of adjacent groups with a predetermined angle α to each other are arranged offset and form the wing elements.

Preferably, the least common multiple of the number of outer segments and the number of inner segments results in the number of circumferential divisions by which the individual lamellae and / or groups of individual lamellae are or can be rotated. This makes it possible in a simple manner to determine the degree of rotation for different types of engines with different number of poles or payloads. In detail, the predetermined angle α, by which the inner segments are arranged offset from each other during rotation of adjacent individual slats and / or adjacent groups of individual slats, can be determined according to: α = 360 ° / number of circumferential divisions.

In a further embodiment can additionally at least one of the wing elements suction side by a smaller radial outer diameter of the inner circle at least one suction side arranged single lamella, in particular the end plate or the end plate be formed. Furthermore In addition, at least one of the wing elements on the pressure side by a larger radial Inner diameter of the inner circle of at least one pressure side arranged Single lamellae, in particular the end lamella or the end plate formed be. Alternatively, an appropriately trained Stirnisolation be arranged on the suction and / or pressure side. The reduction of the suction or pressure side openings causes a corresponding deflection of the flow.

ever according to the type and design of the engine form the radially outward facing outer segments in a possible embodiment Poles of a permanent magnet rotor. These are in the outer segments, for example Recesses for receiving magnets provided. Every outer segment is provided with a recess in which at least one magnet is arranged. The magnets act as magnetic poles of the Rotor. The number of poles corresponds to the number of over the Scope of the disk pack distributed magnets arranged and outer segments. Alternatively you can through the outer segments Grooves separate, in particular mushroom-shaped webs of a commutator armature form. The grooves between the mushroom-shaped webs serve to accommodate from windings. The inner segments are formed as inner webs, the resulting freely stamped inner rotor area is used as air passage area for engine cooling. The motor is in particular an internal rotor motor, in which the stator facing surface of the plate pack of the Rotor the outer surface of the is essentially cylindrical rotor.

At the inventive method for producing a disk set for a rotor several Single louvers, especially metal sheets centered and in identical Stacked on each other and outer segments and inner segments stamped out, with one or more identically punched individual slats be rotated in the circumferential direction to each other that their outer segments identical on top of each other and their inner segments with a predetermined angle α to each other are arranged offset and the staggered inner segments in the inner circle integrated wing elements form, upon rotation of the rotor, an axial air flow in the Create interior of the rotor. Depending on the design of the rotor, the Single lamellae by form, material and / or friction with each other together. For example, these are mechanically interconnected by knobs connected. Alternatively you can the individual lamellae are mechanically clamped together. In a further alternative embodiment can these are encapsulated in plastic or bonded together with adhesive become.

The particular advantages of the invention are that for one possible small construction of the rotor and a sufficient engine cooling in the rotor inner area wing elements are integrated, which cause an axial flow of air during rotation of the rotor. Furthermore possible the invention the production of groups of individual lamellae for the rotor lamination stack. The engine is cheaper overall produced.

following becomes an embodiment of the invention explained in more detail with reference to figures. Show:

1 1 is a schematic perspective view of a rotor according to the invention with a freely stamped rotor inner region (prior art),

2 1 is a schematic diagram for the displacement of inner segments of the rotor blade package to form integrated wing elements,

3 3 is a perspective view of an alternative embodiment of a rotor according to the invention with a freely stamped rotor inner region and in this integrated wing elements,

4 1 is a schematic diagram for the displacement of inner segments of the rotor disk pack to form the integrated wing elements,

5 schematically in longitudinal section a further alternative embodiment of a rotor according to the invention with additionally modified end plates on the suction and pressure side.

each other corresponding parts are in all figures with the same reference numerals Mistake.

1 schematically shows a perspective view of the prior art for a rotor 1 a drive unit, for. B. a permanent-magnet motor. The rotor 1 is from a disk pack 2 formed, that a multiplicity of identically formed single lamellas 2.1 to 2.n includes, which are centered stacked. The plate or plate package 2 of the rotor 1 for an electric machine is usually produced by stamped packaging. Here are from individual sheets of individual slats 2.1 to 2.n outer segments 4 and inner segments 6 punched out. The outer segments 4 are formed as distributed over the circumference and radially outwardly facing webs, which are separated by grooves N from each other. The outer segments 4 Depending on the design of the engine, for example, as a mushroom-shaped webs for receiving windings of a commutator or as webs with recesses for receiving magnets of a Per Manentmagnetrotors trained. The outer segments 4 are radially inward via an annular outer yoke 8th connected with each other. In the inner ring circle K1 of the outer yoke 8th that covers the interior of the rotor 1 forms are the inner segments 6 punched out. The inner segments 6 are over an annular inner yoke 10 connected to each other, in whose inner circle K2 a shaft 12 of the rotor 1 centered can be arranged.

In order to compensate for any skewed edge of the starting material during punching packetization and thus the balancing quality of the rotor 1 To improve, are provided in stamping package tools turning stations, the rotation of the individual slats 2.1 to 2.n or make sheets during packaging. The symmetries in the structure of the sheet or the individual lamellae 2.1 to 2.n to be observed, so that the smallest possible rotation step corresponds to a slot pitch in Kommutatorankern or a pole pitch in permanent magnet rotors. In general, the individual slats 2.1 to 2.n rotated by a multiple of a slot pitch, eg 90 °, since the inner area has a different pitch. For example, the number of outer segments 4 unequal, in particular larger than the number of inner segments 6 ,

To form integrated wing elements in through the inner segments 6 freely stamped rotor inner region, the known rotational function of the punching package is used. As in 2 shown in detail, this is the first single lamella 2.1 and the last single lamella 2.n according to the desired flow direction by a slot pitch before or turned back. By such an angular offset arrangement of axially adjacent individual slats 2.1 to 2.n is in the free-punched rotor inner region by a resulting offset arrangement of the inner segments 6 at least one wing element formed by an angle α of about 18 °, which upon rotation of the rotor 1 generates an axial air flow through the inner circle K2. This only end-side, in particular suction and pressure side rotation of the individual lamellae 2.1 and 2.n represents a very simple wing element. The resulting wing profile is not very effective. In order to obtain a meaningful profile and not to re-interlock the obtained air passage area, the angular step for the rotation of the individual louvers may 2.1 to 2.n to each other and the resulting angular displacement of the inner segments 6 , z. B. webs, not too big. A possible angle α of <10 °, as for rotors 1 with a groove or pole number of> = 36 is possible, allows the formation of integrated wing elements. For smaller motors with common payloads of 12, 16 or 20 slots or for pole wheels with 8 or 10 magnet segments, the possible turning step of a slot or pole pitch is too large.

But still the smallest possible angular displacement of the inner segments 6 from adjacent individual slats 2.1 to 2.n to get each other, the number of the wing elements forming on the circumference uniformly distributed inner segments 6 chosen such that it does not divide the number of slots or poles and thus the number of outer segments 4 is. The smallest common multiple KgV from the number of outer segments 4 , ie groove or pole number, and the number of inner segments 6 then gives the number of divisions on the circumference around which the inner segments 6 adjacent and twisted individual slats 2.1 to 2.n can be offset. The angle α around which the inner segments 6 with rotation of adjacent individual slats 2.1 to 2.n is arranged offset from one another, can therefore be determined according to: α = 360 ° / number of divisions on the circumference.

For example, a 20-groove rotor 1 with 20 outer segments 4 gives, for example, the choice of three or six inner segments 6 inside a possible smallest angle of rotation α of the inner segments 6 of 6 °, ie 60 divisions on the circumference. To do this, the individual slats must each be rotated by 7 slot pitches (7 · 360/20 = 126 °).

Tabelle 1: Teilung und Winkel α für verschiedene Nut- bzw. Polzahlen und Stegzahlen Table 1 shows examples of different groove or pole numbers (= number of outer segments 4 ), their possible number of bars (= number of inner segments 6 ) and the associated rotation angles α:

Table 1: Graduation and angle α for different groove or pole numbers and ridge numbers

Will now the rotation of the individual slats 2.1 to 2.n with the number of individual slats rotated in the same position 2.1 to 2.n combined, a wing profile similar to the known axial fan can be generated.

As an example, here is a rotor 1 with N = 20 (= outer segments 4 ) and x = 6 webs (= inner segments 6 ) to be viewed as. The slat package 2 is made of 17 single lamellae 2.1 to 2.17 formed, each having a sheet thickness of 0.65 mm. By twisting the individual louvers 2.1 to 2.17 each 7 slot pitches results in a 6 ° gradation of the inner segments 6 in the rotor inner region, ie in the inner circle K1 of the outer yoke 8th , In nine stages or groups G1 to G9 with different numbers of identical stacked single lamellae 2.1 to 2.17 this results in the 3 and 4 shown fan profile from the mutually offset inner segments 6 that form the integrated wing elements.

By variance of the number of groups G1 to Gx and the number of individual slats 2.1 to 2.x in each group G1 to Gx a variety of profiles can be displayed, so that the sash profile the respective pressure or flow conditions in the rotor 1 and thus can be adapted in the engine.

Tabelle 2: Verdrehung und Blechanzahl für ein Flügelprofil In Table 2 is the rotation of the axially successively arranged individual lamellae 2.1 to 2.17 in number of slot pitches as well as the grouping of the single louvers 2.1 to 2.17 into the groups G1 to G9 and the respective number of individual lamellae 2.1 to 2.17 in the respective group G1 to G9 dargstellt.

Table 2: Twist and number of plates for a sash profile

In 4 is the associated unrolled profile of the integrated wing elements shown, from the offset inner segments 6 are formed.

Another solution to an axial flow in the disk pack 2 to generate, based on the centrifugal force principle. Ideally, this will be the inner segments 6 designed in the interior of the rotor assembly as the blades of a centrifugal fan. During rotation, the molecules of the flowing medium are accelerated and pushed outward. This creates a radial pressure difference. If now the radially outer area and on the pressure side of the radial inner area at least partially covered by an end plate or alternatively by a Stirnisolation on the Sauseite, creates a corresponding flow that can be used to cool the engine components. In 5 an example of this is shown. The suction side has the first single lamella 2.1 a smaller radial outer diameter Da of the inner ring circle K1 than the other single louvers 2.2 to 2.16 on. On the pressure side, the last individual lamella points 2.17 a larger radial inner diameter Di of the inner ring circle K1 than the other individual lamellae 2.1 to 2.16 ,

In the production of the lamella package 2 become the single lamellae 2.1 to 2.n For example, thin metal sheets centered stacked. In addition, the individual slats are 2.1 to 2.n centered in identical position one above the other. For centering the position of the individual louvers 2.1 to 2.n is a centered recess 14 for receiving the shaft 12 of the rotor 1 in the individual slats 2.1 to 2.n punched. Subsequently, the outer segments 4 and the inner segments 6 punched out. Single or several of the identically punched single lamellae 2.1 to 2.n are then rotated in the circumferential direction to each other such that their outer segments 4 arranged identically one above the other and their inner segments 6 are arranged offset to each other with the predetermined angle α. The single lamellae 2.1 to 2.n are subsequently connected to each other by form, friction and / or adhesion.

Also can single lamellae 2.1 to 2.n grouped on top of each other. In this case, several identical stacked single lamellae form 2.1 to 2.n a group G1 to G9. Groups G1 to G9 of single lamellae 2.1 to 2.n are arranged rotated in the circumferential direction to each other.

In the illustrated, belonging to an internal rotor motor rotors 1 is the stator facing surface of the disk pack 2 the outer circumferential surface of the substantially cylindrical rotor 1 ,

Claims (16)

Rotor ( 1 ) for a drive unit, in particular an electric motor, comprising a disk pack ( 2 ), which has a multiplicity of identical individual laminations stacked on top of each other ( 2.1 to 2.n ), the outer segments distributed over the circumference ( 4 ), which via an annular, radially inwardly facing outer yoke ( 8th ) are interconnected, in whose inner circle (K1) a predetermined number of inner segments ( 6 ) is provided, which via an annular inner yoke ( 10 ) are interconnected, wherein within the inner circle (K1) of the outer yoke ( 8th ) Wing elements are integrated so that upon rotation of the rotor ( 1 ) an axial air flow is generated. Rotor according to claim 1, wherein at least two of the individual blades ( 2.1 . 2.17 ) are rotatable in the circumferential direction to each other that their outer segments ( 4 ) identical to each other and their inner segments ( 6 ) are offset from each other at a predetermined angle (α), wherein the mutually offset inner segments ( 6 ) form the wing elements. Rotor according to claim 2, wherein at least one of the suction-side individual blades ( 2.1 ) and one of the pressure-side individual slats ( 2.17 ) are arranged offset from each other. Rotor according to one of claims 1 to 3, wherein the number of predetermined inner segments ( 6 ) not equal to the number of outer segments ( 4 ). Rotor according to one of claims 1 to 4, wherein the number of outer segments ( 4 ) not equal to a whole multiple of the number of predetermined inner segments ( 6 ). Rotor according to one of claims 1 to 5, wherein a plurality of identical individual laminations ( 2.1 to 2.n ) each form a group (G1 to G9) and a plurality of groups (G1 to G9) are rotatable relative to each other in the circumferential direction and their associated inner segments ( 6 ) are offset from each other with a predetermined angle (α) and form the wing elements. Rotor according to one of claims 1 to 6, wherein the least common multiple of the number of outer segments ( 4 ) and the number of inner segments ( 6 ) gives the number of circumferential divisions around which the individual lamellae ( 2.1 to 2.n ) and / or groups (G1 to G9) of individual lamellae ( 2.1 to 2.n ) are rotatable or is. Rotor according to one of claims 2 to 7, wherein the predetermined angle (α) around which the inner segments ( 6 ) with rotation of adjacent individual slats ( 2.1 to 2.n ) and / or of adjacent groups (G1 to G9) of individual lamellae ( 2.1 to 2.n ) are arranged offset from each other, can be determined according to α = 360 ° / number of circumferential divisions. Rotor according to one of claims 1 to 8, wherein in addition at least one of the wing elements on the suction side by a smaller radial outer diameter (Da) of the inner circle (K1) at least one suction side arranged single lamella ( 2.1 ) is formed. Rotor according to one of claims 1 to 9, wherein additionally at least one of the wing elements on the pressure side by a larger radial inner diameter (Di) of the inner circle (K1) at least one pressure side arranged individual lamella ( 2.17 ) is formed. Rotor according to one of claims 1 to 10, wherein the radially outwardly facing outer segments ( 4 ) Form poles of a permanent magnet rotor. Rotor according to one of claims 1 to 10, wherein the outer segments ( 4 ) separated by grooves, in particular mushroom-shaped webs of a commutator anchor. Rotor according to one of claims 1 to 12, wherein the inner segments ( 6 ) are formed as inner webs with lateral air passage surfaces. Electric motor with a rotor ( 1 ) according to one of the preceding claims 1 to 13. Method for producing a disk pack ( 2 ), in particular for a rotor ( 1 ) of an electric motor, in particular according to one of claims 1 to 14, wherein a plurality of individual blades ( 2.1 to 2.n ) and stacked in an identical position and outer segments ( 4 ) and inner segments ( 6 ) are punched out, wherein individual or several identically punched individual slats ( 2.1 to 2.n ) are rotated in the circumferential direction to each other such that their outer segments ( 4 ) identical to each other and their inner segments ( 6 ) are offset from each other at a predetermined angle (α), wherein the mutually offset inner segments ( 6 ) in the inner circle (K1) form integrated wing elements, which upon rotation of the rotor ( 1 ) generate an axial flow of air. Method according to claim 15, wherein the individual lamellae ( 2.1 to 2.n ) are joined together by form, material and / or friction.