DE102016123064A1 - Rotor for an internal rotor electric motor - Google Patents

Abstract

The invention relates to a rotor (1) for an electric motor, wherein the rotor (1) comprises a laminated core (2) which is formed from a stack of mutually insulated sheets (20) and wherein in the laminated core (2) a plurality of permanent magnets (3) introduced are and wherein the laminated core (2) with a metallic rotor casting (4) encapsulated and / or partially poured, characterized in that the laminated core with 40 - 70 mass%, the permanent magnets (3) with 10 - 50 mass% and the rotor casting (4) with 8 - 25 mass% of the total mass of 100% formed from the laminated core (2), the permanent magnet (3) and the rotor casting (4) are involved.

Description

The invention relates to a rotor for an internal rotor electric motor.

Rotors for electric motors are known in various embodiments for synchronous motors and asynchronous motors, depending on the engine concept permanent magnets are used in the rotor.

So z. As EC motors, in which permanent magnets are located on the rotor surface known. These permanent magnets are realized in various embodiments. In the arrangement of such permanent magnets on the rotor surface, a return body is provided between the rotor shaft and the permanent magnets, which is fixedly connected to the rotor shaft. For example, annularly realized permanent magnets are glued to this return body, so that a torque can be transmitted via the return body to the rotor shaft.

From the DE 103 14 394 A1 For example, a rotor for an EC motor and a method for mounting such a rotor are known. This known rotor has a shaft, a yoke body arranged on the shaft and a ring magnet surrounding the yoke body. Furthermore, a jacket is preferably provided which surrounds the ring magnet. The holding element and the jacket are integrally formed as a sleeve, wherein the ring magnet is also connected by pressing into the sleeve with this non-positively.

For EC motors, there are also efforts using plastic encapsulation method to encase the laminated core with the shaft. As a result, however, typically only torque ranges for an EC motor with a realizable torque of less than 10 Nm can be realized. However, it is desirable to cover significantly higher torque ranges with the engines, which are in the range of 10Nm - 200 Nm. However, such aforementioned motors do not tolerate high process temperatures in the Umgussverfahren after the permanent magnets are mounted, as it would lead to unwanted demagnetization of the permanent magnets at high process temperatures, which previously restricted the material selection for the Umgussverfahren on non-metallic materials, such as plastics Plastics typically have a significantly low melting point of about 220 - 270 ° C compared to the process temperature of z. B. aluminum die casting of about 700 ° C.

In a known motor-type special - called line-start engine - pockets are provided in the rotor to press permanent magnets into the pockets. A Line Start Permanent Magnet (LSPM) motor is a three-phase synchronous motor with asynchronous start-up, which additionally contains permanent magnets in the rotor with squirrel-cage rotor. Therefore, such motors also do not tolerate high process temperatures after the permanent magnets are mounted, as it would also lead to an undesirable demagnetization of the permanent magnets at the high process temperatures.

According to the current state of the art, therefore, permanent magnets in motor types in which the laminated core is exposed to high temperatures of the order of about 650 ° C. and higher can only be used in a subsequent production step. A disadvantage of the line-start engines also the fact that the existing space for the front side to be arranged rings and thus their effective cross-section is limited, which prevents minimizing the electrical resistance of the short-circuit cage and thus adversely affect the performance of the engine effect.

The invention is therefore an object of the invention overcome above-mentioned disadvantages and on the one hand to provide a solution for manufacturing an EC motor and on the other hand a line-start motor, which is inexpensive to manufacture and in which the problem of demagnetization of permanent magnets is bypassed.

This object is achieved by the feature combination according to claim 1.

A basic idea of the present invention is to provide a specific material combination in a defined mass ratio in the rotor. It has been recognized by studies that at a certain weight ratio of the laminated core, the magnets and the potting the problem of demagnetization of the magnets when encapsulating with a metallic potting compound such. B. cast aluminum no longer or almost no longer occurs.

• - Blechpaket: 40 - 50 Masse-%,
• - Permanentmagnete 40 - 50 Masse-%
• - Rotorguss 8 - 20 Masse-%.

According to the invention, a rotor is provided with respect to an EC motor with internal rotor, which has a laminated core, which is formed from a stack of mutually insulated sheets and wherein in the laminated core several permanent magnets are radially introduced and wherein the laminated core with a metallic rotor casting and / or is partially poured out and wherein the following mass ratios in mass% based on a total mass of 100% (formed from the laminated core, the permanent magnet and the rotor casting) are used:

• - Laminated core: 40 - 50 mass%,
• - permanent magnets 40 - 50 mass%
• - rotor casting 8 - 20 mass%.

• - Blechpaket: 65 - 70 Masse-%,
• - Permanentmagnete 10 - 20 Masse-%
• - Rotorguss 10 - 30 Masse-%.

Thus, in a preferred embodiment of the invention, it has been shown that in an internal rotor rotor of a line-start engine, the following mass ratios have been shown as preferred embodiments:

• - laminated core: 65 - 70 mass%,
• - permanent magnets 10 - 20 mass%
• - Rotor casting 10 - 30 mass%.

The sum of the components is to be taken into account with 100%, so that each selection of a value of weight% for one ingredient limits the choice for the other two ingredients and vice versa.

The permanent magnets are designed as magnetized ferrite elements. In an EC motor, it is advantageous if the rotor casting is a casting of aluminum or an aluminum alloy and wherein the permanent magnets are held by the respective rotor casting directly in position.

In a likewise advantageous embodiment of the invention in the EC motors is provided that in the rotor by means of Rotorgusses a rotor shaft is cast.

In preferred embodiments of the invention it is further provided that the permanent magnets are introduced either in intermediate spaces between wedge-shaped radially outwardly extending teeth of the laminated core or in correspondingly shaped axially extending pockets.

It is also advantageous if the sheets and thus the laminated core are fixed by an inner bore filled with the rotor casting or is.

1. a. Bereitstellen von gegeneinander isolierten Blechen zur Bildung eines Blechpakets mit Zwischenräumen und/oder Taschen zur Aufnahme von Permanentmagneten innerhalb des Blechpakets;
2. b. Einbringen von magnetisierten Ferritelementen oder Permanentmagneten in die Zwischenräumen und/oder Taschen und
3. c. Um- und oder Ausgießen des Blechpaketes mit einem metallischen Gussmaterial zur Herstellung eines Rotorgusses, wobei

die Massenverhältnisse wie folgt gewählt werden: das Blechpaket ist mit 40 - 50 Masse-%, die Permanentmagnete (3) sind mit 40 - 50 Masse-% und der Rotorguss (4) ist mit 8 - 20 Masse-% an der Gesamtmasse von 100% beteiligt.A further aspect of the invention relates to a method for producing a rotor as above, in particular a rotor for an internal rotor of an electric motor, comprising the following steps:

1. a. Providing mutually insulated sheets to form a lamination stack having spaces and / or pockets for receiving permanent magnets within the lamination stack;
2. b. Introducing magnetized ferrite elements or permanent magnets into the spaces and / or pockets and
3. c. Um- and or pouring the laminated core with a metallic casting material for producing a rotor casting, wherein

the mass ratios are chosen as follows: the laminated core is 40 - 50 mass%, the permanent magnets (3) are 40 - 50 mass% and the rotor casting (4) is 8 - 20 mass% of the total mass of 100 % involved.

It is also advantageous if the rotor casting is cast between or around the laminated core such that both the laminated core and the permanent magnets are fixed by the rotor casting and the shaft and are preferably held in position.

In an advantageous embodiment of the invention in line-start motors is provided that the rotor is further penetrated by rods, which are predominantly or completely formed from the rotor casting. For electrical connection of the rods, these can be realized by means of end rings also made of the rotor casting material.

The permanent magnets are arranged in a preferred embodiment in each rotor pole of the laminated core in a substantially U-shaped arrangement to each other, wherein the laminated core is preferably formed as an externally grooved laminated core.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to FIGS.

• 1 eine Schnittansicht durch ein erstes Ausführungsbeispiel eines EC-Rotors;
• 2 eine Schnittansicht durch ein zweites Ausführungsbeispiel eines EC-Rotors;
• 3 eine perspektivische Ansicht sowie eine Schnittansicht durch ein Blechpaket eines Line-Start-Rotors mit in Taschen eingefügten Permanentmagneten;
• 4 ein Druckguss-umspritzter Rotor eines Line-Start-Motors.

Show it:

• 1 a sectional view through a first embodiment of an EC rotor;
• 2 a sectional view through a second embodiment of an EC rotor;
• 3 a perspective view and a sectional view through a laminated core of a line-start rotor with inserted in pockets permanent magnet;
• 4 a die-cast over-molded rotor of a line-start engine.

The invention will be described below with reference to FIGS 1 to 4 explained in more detail, wherein like reference numerals refer to the same structural and / or functional features. In the 1 and 2 are each sectional views of Embodiments of a rotor 1 of an EC motor according to the present invention for internal rotor motors and in the 3 and 4 Views of a line-start engine.

The rotor 1 in 1 has a segmented laminated core 2 with radial segment arrangement, which consists of a stack of mutually insulated sheets 20 is trained. The sheets 20 are designed as wedge-shaped sheets. In the laminated core 2 are each permanent magnets between the segments 3 brought in. The laminated core 2 is with a metallic rotor casting 4 as well as in the axially continuous openings 25 poured out with the rotor casting material.

The rotor 1 is with bars 42 from the rotor casting 4 be formed, interspersed, through the openings 25 in the axial direction of the one end of the laminated core 2 to the opposite end of the laminated core 2 run. The bars 42 connect the front flanges of the rotor 1 and ensure high rotor stability. The end flanges are additionally equipped with cooling vanes for improved engine cooling.

The laminated core 2 is with the rotor casting 4 fixed inside, the one inside bore 40 for a cast-rotor shaft W, wherein the rotor casting 4 with a groove 26 is formed for the rotor shaft W. In detail 1 of the 1 this can be seen in an enlarged view. By this configuration, in which the segments of the sheets 20 , the permanent magnets 3 and the rotor shaft W are cast, desired torques between about 10 Nm and 200 Nm can be realized, depending on the specific design.

The rotor casting 4 is formed in this embodiment of aluminum or alternatively of an aluminum alloy.

In the 2 is a similar design as in 1 shown here, wherein the teeth are fixed in a star shape and between the formed as an inner ring rotor casting 4 , another ring-shaped section 2a the laminated core 2 is formed. Between the inside end faces 3a the permanent magnets 3 and the annular portion 2a the laminated core 2 is also the rotor casting 4 poured, causing the laminated core 2 is fixed. In detail 2.1 of the 2 this can be seen in an enlarged view. In the possible embodiment, the laminated core 2 partially punched to reduce stray flux, which in detail 2.2 of the 2 is shown.

The 3 shows a perspective view of a line-start motor and including a sectional view through a laminated core 2 a rotor 1 , in the cuboid permanent magnets 3 in bags 23 in an approximately U-shaped arrangement, each formed from three permanent magnets 3 for the two or four rotor poles are arranged. This version also shows a rotor 1 for an internal rotor motor. Outside on the laminated core 2 are additional grooves in this design 21 introduced, with the rotor casting 4 fill out.

In the 4 is the rotor 1 , like in the 3 shown, with the grooves 21 with rotor casting 4 are filled and a die-cast with a rotor casting 4 is provided.

The rotor casting 4 fixes the permanent magnets 3 in the pockets 23 and closes these frontally. The frontal rings 27 serve to contact the rods 42 in the grooves 21 and can, as shown in the cross section in the circumferential direction are dimensioned correspondingly large.

• Blechpakete aus Dynamoblechen: 46 Masse-%,
• Permanentmagnete: 42 Masse-%
• Rotorguss: 12 Masse-%

von der Gesamtmasse von 100%.As a practical embodiment, the rotor components for an EC motor consisting of laminated core, permanent magnets and cast aluminum for the internal rotor rotor were formed as follows:

• Laminated cores of dynamo sheets: 46% by mass,
• Permanent magnets: 42 mass%
• Rotor casting: 12% by mass

of the total mass of 100%.

• Blechpakete aus Dynamoblechen: 66 Masse-%,
• Permanentmagnete: 14 Masse-%
• Rotorguss: 20 Masse-%

von der Gesamtmasse von 100%.As a further practical embodiment, the rotor components of a line-start engine consisting of laminated core, permanent magnets and cast aluminum were formed as follows:

• Laminated cores of dynamo sheets: 66 mass%,
• Permanent magnets: 14 mass%
• Rotor casting: 20% by mass

of the total mass of 100%.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10314394 A1 [0004]

Claims (13)

Rotor (1) for an internal rotor synchronous motor, wherein the rotor (1) has a laminated core (2) which is formed from a stack of mutually insulated sheets (20) and wherein in the laminated core (2) a plurality of permanent magnets (3) are introduced and wherein the laminated core (2) with a metallic rotor casting (4) encapsulated and / or partially poured, characterized in that the laminated core with 40 - 70 mass%, the permanent magnets (3) with 10 - 50 mass% and the rotor casting (4) with 8 - 25 mass% of the total mass of 100% formed from the laminated core (2), the permanent magnet (3) and the rotor casting (4) are involved. Rotor (1) to Claim 1 , characterized in that the rotor is designed for a EC synchronous motor, wherein the laminated core with 40 - 50% by mass, the permanent magnets (3) with 40 - 50% by mass and the rotor casting (4) with 8 - 25 mass -% of the total mass of 100% formed from the laminated core (2), the permanent magnet (3) and the rotor casting (4) are involved. Rotor (1) to Claim 1 , characterized in that the rotor is designed for a line-start motor, in which the laminated core with 60 - 70 mass%, the permanent magnets (3) with 10 - 20 mass% and the rotor casting (4) with 15 - 25 mass% of the total mass of 100% formed from the laminated core (2), the permanent magnet (3) and the rotor casting (4) are involved. Rotor (1) according to one of the preceding claims, characterized in that the permanent magnets (3) are designed as magnetized ferrite elements. Rotor (1) according to one of the preceding claims, characterized in that the rotor casting (4) is a casting of aluminum or an aluminum alloy. Rotor (1) to Claim 2 , characterized in that in the rotor (1) by means of the rotor casting (4) a rotor shaft (W) is cast. Rotor (1) according to one of the preceding Claims 1 to 6 , characterized in that the permanent magnets (3) are introduced either in intermediate spaces (21) between wedge-shaped radially outwardly extending teeth (22) of the laminated core (2) or in correspondingly formed axially extending pockets (23). Rotor (1) according to one of the preceding claims, characterized in that the laminated core (2) by an with the rotor casting (4) filled inner bore (40) are fixed. Rotor (1) according to one of the preceding claims, characterized in that the rotor (1) is further formed with rods (42) from the rotor casting (4) interspersed. Rotor (1) to Claim 3 characterized in that the permanent magnets (3) in each rotor pole of the laminated core (2) are arranged in a substantially U-shaped arrangement to each other, wherein the laminated core (2) is preferably formed as an externally grooved laminated core. Rotor (1) according to one of the preceding claims, characterized in that the permanent magnets (3) are held in position by the rotor casting (4). Method for producing a rotor (1), in particular a rotor (1) for an internal rotor of a synchronous motor, comprising the following steps: a. Providing a laminated core (2) of mutually insulated sheets (20) with intermediate spaces (21) and / or pockets (23) for receiving permanent magnets (3); b. Introducing magnetized ferrite elements or permanent magnets (3) into the intermediate spaces (21) and / or pockets (23) and c. Umgießen and / or pouring the laminated core (2) with a metallic casting material for producing the rotor casting (4), wherein the mass ratios are selected as follows: the laminated core is with 40 - 70 mass%, the permanent magnets (3) are 10 - 50% by weight and the rotor casting (4) is involved with 8 - 25% by mass of the total mass of 100%. Method according to Claim 12 , characterized in that the rotor casting (4) is poured between or around the laminated core (2), that both the laminated core (2) and the permanent magnets (3) of the rotor casting (4) are fixed.

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