WO2007107136A1

WO2007107136A1 - Rotors for a permanently excited motor, in particular an ec motor

Info

Publication number: WO2007107136A1
Application number: PCT/DE2007/000073
Authority: WO
Inventors: Michael Bulatow; Andre Gornott
Original assignee: Temic Automotive Electric Motors Gmbh
Priority date: 2006-03-20
Filing date: 2007-01-18
Publication date: 2007-09-27
Also published as: DE112007000003A5; DE102006052772A1

Abstract

The rotor according to the invention for a permanently excited motor comprises a plate assembly (2), in which a rotor shaft (12) is positioned centrally in a cavity and which has a number of stacked individual plates (2.1 to 2.n), each plate having segments (4) distributed around its circumference, said segments being separated by grooves (6) facing radially inwards that are distributed around the circumference and being provided with a cavity (8), in which at least one magnet (10) is housed. The plate assembly (2) is axially sub-divided into groups (G1, G2) of identically stacked individual plates (2.1 to 2.k, 2.k+1 to 2.n) and said groups (G1, G2) are offset in relation to one another around the circumference. This feature of the rotor according to the invention for a permanently excited motor prevents splinter particles from the permanent magnets from blocking the motor.

Description

description

Rotor for a permanent-magnet motor, in particular EC motor

The invention relates to a rotor for a permanent-magnet motor, in particular an EC motor.

The EC motor (electronically commutated) is a brushless, permanent-magnet synchronous motor. The for this

Motor type also used designation "AC servomotor" can cause confusion, since it is also used for highly dynamically controlled asynchronous motors.To eliminate this, the electronically commutated motor is referred to below as EC motor

Internal rotor motors or be designed as external rotor motors. The invention relates primarily to

Internal rotor motors, on the basis of which below

Invention will be explained in more detail. Nevertheless, the invention is also applicable to external rotor motors.

Electric motors have a fixed part and a rotatably mounted part. The fixed part is called a stator or a stator. The rotatably mounted part is called rotor or rotor. In the following, the terms stator and rotor are to be used.

The motor housing of a permanent-magnet motor is often produced by continuous casting or deep drawing. In the motor housing, the stator is used, which includes the laminated stator core and windings as a plate pack. Grooves for receiving the three-phase windings are milled or punched into the sheets of the laminated stator core. The connection of the sheets to the laminated stator core takes place by means of a notch pronounced on one side of the sheet, which engages in the corresponding recess on the other side of the adjacent sheet metal. On the rotor shaft of the permanent-magnet motor, the rotor core stack is arranged as a plate pack, which usually has punch-outs for reducing weight. On the periphery of the rotor core or in the punched out permanent magnets are arranged, which are often permanently attached, for example, with two-component adhesive attached. In some permanent-magnet motors, grooves for receiving the permanent magnets are milled or punched into the sheets of the rotor lamination stack, which are circumferentially open or closed.

A disadvantage of the known EC motors is that magnetic splinters, which normally occur in known EC motors, can lead to a blockage of the motor.

The invention has for its object to provide a rotor for a permanent-magnet motor, in which the

Blocking of the motor is effectively prevented by chipped parts of the permanent magnets.

According to the invention the object is achieved by a rotor for a permanent-magnet motor with the features of claim 1. Advantageous embodiments of the invention are the subject of dependent claims.

The rotor according to the invention for a permanent-magnet motor comprises a disk set, in which centered in a recess a rotor shaft is arranged and which has a plurality of stacked individual slats, each with distributed over the circumference segments, which by radially inwardly distributed circumferentially distributed beads from each other are separated. Each 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 distributed over the circumference of the disk pack arranged Magnets. The disk pack is preferably divided axially into groups of identical stacked individual laminations, wherein the groups are arranged offset from each other in the circumferential direction. Such rotation of the groups or rotor parts on the rotor shaft to each other ensures that no chips from or in the Αusnehmungen of the magnets (also called magnet pockets) fall. The recesses are formed for example by punching. By an identical stacking of several individual slats and their grouping channels are formed, in which the magnets, for. B. permanent magnets are arranged. Due to the rotation of the groups in the circumferential direction relative to one another, in the permanent-magnet motor according to the invention, it is prevented that particles chipped off by the permanent magnets can lead to blockage of the motor. In addition, a rotation of the groups leads to a reduction of the cogging torque of the motor by the field energy remains largely constant by the rotation of the rotor parts and thus the poles of the rotor despite resulting different magnetic paths. In particular, the motor is an internal rotor motor in which the surface of the disk set of the rotor facing the stator is the outer surface of the essentially cylindrical rotor.

In an advantageous embodiment of the invention, a separating element is additionally arranged between the groups of individual lamellae. This additionally ensures that the magnets are protected in the magnetic pockets and no chips fall out or into the magnetic pockets. For this purpose, the separating element is preferably designed as a closed separating plate, which separates the groups of individual lamellae and completely closes the recesses for the magnets between two groups. Expediently, the outer dimensions of the separating element essentially correspond to the outer dimensions of the individual louvers. As a result, a largely circumferentially closed Construction of the rotor achieved, so that the flow loss occurring through the closed design is as low as possible.

In one possible embodiment, the groups are, in the circumferential direction at an angle α of 0 ° to a maximum angle, which is determined in dependence on the number of poles of the rotor. The maximum angle ctmax is determined according to:

cCmax = 0.5 x 360 ° / number of poles.

For example, the maximum angle α _{max is} 18 ° for a rotor comprising 10 poles.

In a further advantageous embodiment of the invention, in addition, the end faces of the disk set, ie the rotor laminated core, completely closed by ^' Rotorendscheiben. The Rotorendscheiben can be performed in an internal rotor motor, for example, as disks of non-magnetic material, which are centered on the rotor shaft and completely cover the front sides of the rotor to the outer diameter. As a result, a further improved protection of the motor is achieved against blocking.

In an advantageous embodiment of the invention, the magnets, z. B. permanent magnets, in the channels formed by the recesses _. held in a positive, force and / or material fit. For example, the magnets are glued, wherein the magnets are coated with adhesive. Alternatively, the magnets in the. Magnetic bags are mechanically jammed. In a further alternative embodiment, the magnets used in the recesses can be encapsulated with plastic. An advantage of the glued or plastic molded design is. ,, That the adhesive or the Plastic serves both as a noise-damping element, as well as for the fixation of magnetic splinters.

The advantages achieved by the invention are in particular that the blocking of the motor is effectively prevented by chipped parts of the permanent magnets. Furthermore, the invention makes it possible to produce groups of individual lamellae for the rotor lamination stack. The engine is cheaper to produce overall.

An embodiment of the invention will be explained in more detail with reference to figures. Show:

1 is a schematic perspective view of a rotor of a motor according to the invention,

Fig. 2 shows schematically in cross section the rotor according to Figure 1, and

3 shows a schematic longitudinal section through the rotor according to FIG. 2.

Corresponding parts are provided in all figures with the same reference numerals.

FIG. 1 shows a rotor 1 according to the invention for a permanent-magnet motor. The stator is not shown.

The rotor 1 has a disk pack 2, which is formed from a plurality of individual laminations 2.1 to 2.n. The individual lamellae 2.1 to 2.n are identical in size, dimension and shape. In detail, the respective lamella 2.1 to 2.n distributed over the circumference segments 4. The segments 4 are separated from each other by radially inwardly facing circumferentially distributed beads 6. In addition, the respective segment 4 is provided with a recess 8. ,In the Recess 8 (also called magnet pocket) is at least one magnet 10 (also called pocket magnet) arranged. The magnet 10 is, for example, a permanent magnet. The magnets 10 form the poles Pl to PlO of the rotor first

The individual laminations 2.1 to 2.n are, for example, thin metal sheets. The Einzellaraellen 2.1 to 2.n are connected to each other by form, friction and / or adhesion. In addition, the individual lamellae are 2.1 to 2.n in an identical position centered on each other. For centering the position of the individual blades 2.1 to 2.n, the shaft 12 of the rotor 1 is used.

Furthermore, the individual lamellae 2.1 to 2.n are stacked on top of each other. In this case, a plurality of identically stacked individual lamellae 2.1 to 2.k and 2.k + 1 to 2.n form a group Gl or G2. The groups Gl, G2 of

Single lamellae 2.1 to 2.n are arranged twisted in the initial direction to each other. This prevents particles splintered off from the permanent magnets 10 from forming into a

Blockade of the engine can lead. In addition, the cogging torque of the engine is reduced.

In a preferred embodiment, the groups Gl and G2 in the circumferential direction at an angle α of 0 ° to a maximum angle α ^ _x to each other about the shaft 12 is rotated. The maximum angle O _m3x is determined as a function of the number of poles Pl to PlO of the rotor 1 according to:

α _max = 0.5 x 360 ° / number of poles.

With ten poles Pl to PlO, this results in a maximum angle of rotation α ^ _x of 18 °. In the embodiment of Figure 1, the angle of rotation α is about 5 °. In the illustrated, belonging to an internal rotor motor rotor 1, the stator facing surface of the disk set 2 is the outer surface of the substantially cylindrical rotor first

FIG. 2 shows, in cross-section, the rotor 1 according to FIG. 1. In this case, between the groups G1 and G2 a separating element 14, for example, is provided. B. arranged a partition. The separating element 14 is completely closed and has to the outer dimensions of the individual lamellae 2.1 to 2.n substantially the same external dimensions. Due to the closed design, the motor is additionally protected, since no chips fall out of or into the recesses 8 for the magnets 10. FIG. 3 shows the rotor 1 according to FIG. 2 in longitudinal section with the separating element 14 between the groups E1 and G2 of the disk set 2. In this exemplary embodiment, the groups E1 and G2 of the disk set 2 are not rotated relative to one another in the circumferential direction. Conditioned ^'by the low distortion of the groups Gl and G2 with a very small angle α of approximately 5 ° in a longitudinal section just one. very small parallel displacement of the beads 6 of the groups Gl and G2 can be seen. For a sufficient protection against blocking of the motor by chips, it is advantageous to rotate the groups Gl and G2 in the circumferential direction to each other and to arrange the separating element 14 between the groups Gl and G2.

LIST OF REFERENCE NUMBERS

1 rotor

2 plate pack

2.1 to 2.n single lamellae

4 segment

6 beads

8 recess

10 magnet

12 wave

14 separating element

α twist angle α _max maximum twist angle

Gl, G2 groups of single lamellae

Pl to PlO Pole

Claims

claims

1. rotor (1) for a permanent-magnet motor, in particular EC motor, comprising a disk set (2) in which centered in a recess ^' a rotor shaft (12) is arranged and which a plurality of stacked individual laminations (2.1 to 2. n) each with circumferentially distributed segments (4) which are separated by radially inwardly extending over the circumference distributed beads (6) and which are each provided with a recess (8) in which at least one magnet (10 ), wherein the disk set (2) is divided axially into groups (G1, G2) of identically stacked individual lamellae (2.1 to 2.k, 2.k + 1 to 2.n) and the groups (G1, G2) are offset from one another in the circumferential direction.

2. Rotor according to claim T, wherein between the groups (Gl, G2) of individual lamellae (2.1 to 2. k, 2. k + 1 to 2.n) a

Separating element (14) is arranged.

3. Rotor according to claim 2, wherein the separating element (14) is formed as a closed separating plate which separates the groups (G1, G2) of individual lamellae (2.1 to 2.k _r 2. k + 1 to 2.n) from each other and the recesses (8) for the magnets (10) closes.

4. Rotor according to claim 2 or 3, wherein the outer dimensions of the separating element (14) substantially correspond to the outer dimensions of the individual lamellae (2.1 to 2.n).

5. Rotor according to one of the preceding claims, wherein the groups (Gl, G2) in the circumferential direction to each other with a

Angle α are offset from greater than 0 ° to a maximum angle O _m ^.

6. Rotor according to one of the preceding claims, wherein the end faces of the plate pack ^' (2) are completely closed by Rotorendscheiben.

7. Rotor according to one of the preceding ^'claims, wherein the magnets (10) positively in the recesses formed by the (8) channels, positive and / or are maintained cohesively. ■

8. Rotor according to claim 7, wherein the ^' magnets (10) are clamped in the recesses (8), glued or encapsulated by plastic.

9. Permanent-magnet motor with a rotor (1) according to one of the preceding claims 1 to 8.

10. Permanent-magnet motor according to claim 9, wherein the rotor (1) is designed as an internal rotor or external rotor.