DE102010052217A1 - Electric motor e.g. line start permanent magnet (LSPM) motor has circlip that is arranged inside short circuit cage, such that radial region of circlip is partially covered in recesses in laminated core of rotor - Google Patents

Abstract

The electric motor has rotor with laminated core (1) comprising bundle of metal sheets, and short circuit rod (3) to which short circuit ring (2) is connected, so as to form a short circuit cage. The permanent magnets (30) are arranged in the recesses in the laminated core. A circlip (4) is arranged inside the short circuit cage, such that the circlip inside the short circuit ring. A rotating groove is formed along circumferential direction in the short circuit cage. The radial region of the circlip is partially covered in the recesses.

Description

The invention relates to an electric motor with a rotor and method for producing an electric motor.

It is well known that a rotor of an asynchronous machine has a laminated core arranged on a rotor shaft.

The invention is therefore the object of developing an electric motor with a rotor and method for producing an electric motor, with high stator currents should be allowed

According to the invention, the object is achieved in the electric motor according to the features indicated in claim 1.

Important features of the invention in the electric motor with a rotor are that the rotor has a composite of single sheet metal parts laminated core to which a short-circuiting cage is integrally connected, in particular is cast,
wherein permanent magnets are arranged in recesses of the laminated core,
wherein at least one securing ring is arranged in a circumferential groove on the inside of a region of the shorting cage, in particular on the inside of a shorting ring of the shorting cage,
wherein the securing ring at least partially covers the radial area covered by the recesses.

The advantage here is that the magnets are axially secured. Thus, therefore, high stator currents are allowed, in particular stator short-circuit currents, which make an axially acting force on the permanent magnet.

In an advantageous embodiment, the retaining ring is arranged on a first end face of the laminated core and a second retaining ring is likewise arranged in a circumferential groove on the inside of a region of the shorting cage, in particular on the inside of a shorting ring of the shorting cage,
wherein the second securing ring at least partially covers the radial area covered by the recesses. The advantage here is that a double-sided fuse can be reached and also the imbalance by a mutual rotation by 180 ° with otherwise similar design can be achieved.

In an advantageous embodiment, the first and the second locking ring each have a slot extending in the radial direction, in particular continuous slot, and the retaining rings are arranged rotated in the circumferential direction to each other, in particular by about 180 ° to each other. The advantage here is that the imbalance can be reduced or even prevented.

In an advantageous embodiment, the retaining ring on a bias, in particular so not completely relaxed in the groove is arranged. The advantage here is that even with thermally induced changes in length, a secure fit of the locking ring in the circumferential groove is reached.

In an advantageous embodiment, the circumferential groove has a conical wall, in particular a conically shaped groove wall, so that a bias voltage is generated in the locking ring. The advantage here is that a bias in a simple and cost-effective manner by making a skew is effected.

In an advantageous embodiment, a respective securing ring at least partially covers the radial area covered by the permanent magnets and / or recesses. The advantage here is that an axial securing of the magnets can be achieved, in particular even on both sides of the laminated core.

In an advantageous embodiment, a respective locking ring on its inner periphery radially inwardly outstanding tabs. The advantage here is that with less mass still secure coverage and thus securing the permanent magnets can be achieved.

In an advantageous embodiment, the number of tabs is greater than the number of permanent magnets and / or that the number of tabs is an odd number. The advantage here is that at each rotation angle of the locking ring is a fuse of the permanent magnets - even if each permanent magnet is arranged tangentially, ie perpendicular to a radial direction, in particular by its center of gravity, oriented.

In an advantageous embodiment, a respective retaining ring has an annular hole, the edge of which has a radial distance from the rotor shaft axis which is smaller than the radial area covered by the permanent magnets or which is at least smaller than the greatest radial distance of the radial area covered by the permanent magnets. The advantage here is that by means of the overlap, the axial fuse can be produced.

In an advantageous embodiment, the short-circuit cage has at least two Short-circuit rings, which are connected to each other by means of extending in the axial direction, ie Rotorachsrichtung, extending shorting bars. The advantage here is that the cage is easy to produce.

In an advantageous embodiment, the laminated core is composed of loose juxtaposed, stanzpaketiert connected and / or welded together single sheet metal parts and is held together by means of the short-circuit cage. The advantage here is that holding together in a simple manner is feasible.

In an advantageous embodiment, permanent magnets are arranged in recesses of the laminated core. The advantage here is that the engine is executable as LSPM engine.

In an advantageous embodiment, the recesses extend in the axial direction and / or are formed continuously. The advantage here is that a simple insertion of the permanent magnets is made possible in the magnetic pockets of the laminated core thus formed.

In an advantageous embodiment, the recesses are cuboid and / or that the permanent magnets formed cuboid. The advantage here is that easily manufacturable permanent magnets are used.

In an advantageous embodiment, the tabs in the circumferential direction are regularly spaced from each other. The advantage here is that imbalance or higher moments of imbalance, such as quadrupole moment, are avoidable.

In an advantageous embodiment, the number of tabs on a retaining ring is an odd number, whereas the number of magnets is even. Alternatively, the reverse, that is, an odd number of magnets and an even number of tabs. The advantage here is that the retaining ring with the least possible mass is executable.

In an advantageous embodiment, the securing ring has a hole whose edge has a radial distance which is smaller than the radial area covered by the permanent magnets or which is at least smaller than the greatest radial distance of the radial area covered by the permanent magnets. The advantage here is that a sufficient assurance can be ensured.

In an advantageous embodiment, the short-circuit cage has a light metal, such as aluminum or copper, and the retaining ring is made of steel. The advantage here is that a high conductivity is achievable.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination options of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task.

The invention will now be explained in more detail with reference to figures:

In the 1 is shown an oblique view of the rotor of an electric motor with shorting cage. The electric motor is preferably designed as LSPM engine. The electric motor has a short-circuit cage on the rotor and permanent magnets. Thus, when starting the engine, a predominantly asynchronous mode of operation and upon reaching the setpoint speed a predominantly synchronous mode of operation can be achieved. In particular, a network operation of the engine is thus feasible. An inverter feeding the motor is thus dispensable.

In the 2 is shown a plan view in Rotorwellenachsrichtung, the position of the magnetic pockets 30 is indicated by permanent magnets

In the 3 an axial longitudinal section is shown.

In the 4 is an enlarged section of the 3 shown so that the groove with groove wall 40 it is better recognizable which the circlip 4 receives.

According to the embodiment 1 is a laminated core 1 formed of individual sheet packages, which are preferably stanzpaketiert or held together by means of axially extending weld.

After production of the laminated core, the short-circuit cage is cast. This liquid aluminum is in axially extending recesses in the laminated core 1 injected so that shorting bars 3 arise. In addition, at the axial end portion of the shorting bars 3 a short-circuit ring 2 molded so that this with the shorting bars 3 forms a short circuit cage.

The short-circuit cage holds the laminated core 1 together, in particular in addition to a stamped package, weld or other connection force generating connection.

After making the short-circuit cage magnets are in the laminated core 1 axially extending magnetic pockets 30 introduced. For this purpose, four parallelepiped permanent magnets are provided in the circumferential direction regularly spaced arrangement.

For axial securing of the magnets is at both axial end portions of the laminated core 1 one retaining ring each 4 arranged, that of the permanent magnets or magnetic bags 30 covered radial region at least partially covered and in a circumferentially circumferential groove on the inside of the shorting ring 2 sitting.

Before the circlip is inserted into the groove, this groove is screwed or milled into the short-circuit ring.

The groove wall 40 the circumferential groove is beveled so conically shaped so that one of the retaining ring can not relax completely, since it is prevented from its radial expansion. The circlip 4 So it's more relaxed than during the insertion into the groove, but not completely relaxed yet.

Inserting the locking ring 4 Only after inserting the permanent magnets in the magnetic pockets 30 executed by the ring opening of the shorting ring 2 and then with the laminated core, in particular with the first or last single sheet of the laminated core 1 , materially connected, in particular so glued to the front side of the laminated core.

The circlip 4 is preferably made of steel, whereas the shorting cage is made of a light metal, such as aluminum or copper, or of an alloy containing the light metal.

The circlip 4 is annular and has a slot so that it by compressing the two, spaced apart by the slot end portions of the locking ring 4 is tensionable.

The arranged on the first end side circlip 4 and at the other end of the laminated core 1 arranged circlip 4 arranged rotated in the circumferential direction to each other, in particular in the circumferential direction to each other by 180 ° twisted. Thus, imbalance is avoidable or at least reducible.

In a further embodiment of the invention, the retaining ring 4 at its diametrically opposite the slot a larger radial extent than in the slot adjacent or less distant areas. The radial expansion then increases with the distance from the slot.

In a further embodiment of the invention, the retaining ring 4 at its inner periphery extending in radially inwardly directed direction tabs, said tabs 20 are spaced apart in the circumferential direction, in particular regularly. The tabs 20 rise in the radial direction over the otherwise round, in particular circular, inner edge of the locking ring 4 , The survey is at least ten times smaller than the outer diameter of the locking ring 4 ,

By means of the tabs, an improved coverage of the radial area covered by the permanent magnets is achieved.

In a further embodiment of the invention, the number of tabs is greater than the number of permanent magnets.

In a further embodiment of the invention, the number of tabs is an odd number, in particular, this number 5 . 7 or 9 , In contrast, the number of permanent magnets is even, in particular, this number 2 . 4 . 6 or 8th Thus, the retaining ring radially as narrow as possible and still allows a secure holding the permanent magnets.

In a further embodiment of the invention, the laminated core is formed of only loosely arranged one behind the other individual sheets, wherein the compound is formed during spraying of the short-circuit cage.

LIST OF REFERENCE NUMBERS

1

laminated core

2

Shorting ring

3

Shorting bar

4

circlip

30

Magnetic bags with permanent magnets

40

conical groove wall

Claims (15)

Electric motor with a rotor, wherein the rotor has a composite of single sheet metal plate package to which a short-circuiting cage is integrally connected, in particular is cast, being arranged in recesses of the laminated core permanent magnets, characterized in that at least one locking ring in a on the inside of a range the short-circuit cage, in particular on the inside of a short-circuit ring of the short-circuit cage, circumferential groove is arranged in the circumferential direction, wherein the locking ring at least partially covers the area covered by the recesses radial region. Electric motor according to at least one of the preceding claims, characterized in that the securing ring is arranged on a first end face of the laminated core and a second securing ring is likewise arranged in a circumferential groove on the inside of a region of the short-circuiting cage, in particular on the inside of a shorting ring of the shorting cage, wherein the second securing ring at least partially covers the radial area covered by the recesses. Electric motor according to at least one of the preceding claims, characterized in that the first and the second locking ring each have a radially extending slot, in particular continuous slot, and the retaining rings are arranged in the circumferential direction to each other twisted, in particular by about 180 ° to each other are. Electric motor according to at least one of the preceding claims, characterized in that the short-circuit cage has at least two short-circuit rings, which are connected to each other by means of extending in the axial direction, so Rotorachsrichtung, extending short-circuit bars. Electric motor according to at least one of the preceding claims, characterized in that the laminated core of loosely juxtaposed, stanzpaketiert connected and / or welded together single sheet metal parts is assembled and held together by means of the short-circuit cage. Electric motor according to at least one of the preceding claims, characterized in that the securing ring has a bias, in particular so is not completely relaxed in the groove. Electric motor according to at least one of the preceding claims, characterized in that the circumferential groove has a conical wall, in particular a conically shaped groove wall, so that in the circlip, a bias voltage is generated. Electric motor according to at least one of the preceding claims, characterized in that the recesses extend in the axial direction and / or are formed continuously. Electric motor according to at least one of the preceding claims, characterized in that the recesses are cuboid and / or that the permanent magnets are cuboidal. Electric motor according to at least one of the preceding claims, characterized in that a respective securing ring at least partially covers the area covered by the permanent magnets and / or recesses radial region. Electric motor according to at least one of the preceding claims, characterized in that a respective retaining ring has on its inner periphery radially inwardly projecting tabs. Electric motor according to at least one of the preceding claims, characterized in that the tabs in the circumferential direction are regularly spaced from each other. Electric motor according to at least one of the preceding claims, characterized in that the number of tabs is greater than the number of permanent magnets and / or that the number of tabs is an odd number. Electric motor according to at least one of the preceding claims, characterized in that a respective retaining ring has an annular hole whose edge has a radial distance which is smaller than the radial area covered by the permanent magnet or which is at least smaller than the greatest radial distance of the radial area covered by the permanent magnet , Electric motor according to at least one of the preceding claims, characterized in that the short-circuit cage has a light metal, such as aluminum or copper, and the respective retaining ring is made of steel.

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