DE2538320A1 - PERMANENT MAGNETIC RUNNER FOR DYNAMOELECTRIC MACHINERY AND PROCESS FOR THEIR PRODUCTION - Google Patents

Description

Meinig · Lemke · ridicule

Patent attorneys office Berlin:

! Berlin 19. Oldenburgallee 10

Meinig · Lemke · ridicule

Patent attorneys office Berlin: ² 6. August 1975

Inland 11 PERMANENT MAGNETIC RUNNER FOR DYNAMOELECTRIC

MACHINERY AND METHOD FOR MANUFACTURING THEREOF

The invention relates to rotors for DC machines of the inverted design, in which the Stator is provided with a plurality of winding units ("coils") and thus magnetic poles and their rotors contains permanent magnets to generate magnetic fields.

It relates in particular to such runners, which are permanent magnetic material with a high energy product and high coercive force (hereinafter collectively referred to as "rare earth-containing magnetic material") Find use, as well as for the production of such runners.

Permanent magnets made from a material that contains rare earths are recommended because of their high energy product and their high coercive force evidently to the construction of such rotors. It has also already been suggested to use in addition to such magnetic material Alnico magnets or other known magnetic materials, and by the combination of these materials in conjunction with appropriately shaped pole pieces ensure the highest possible magnetic flux to generate in the working air gap.

609812/0701

Magnetic materials that contain rare earths (hereinafter referred to as "rare earth magnets"), however, lead Because of their special properties, they lead to difficulties in the manufacture of a runner. Because of the extraordinary high magnetic field of such permanent magnets, it is practically impossible to process to be carried out in the magnetized state, since the chips and particles released during machining are made of ferromagnetic Adhere material extremely firmly and, if at all, only in an extremely tedious and uneconomical manner Way can be removed. On the other hand, it succeeds with the conventional rotor and pole shoe designs not, sufficient magnetization field strengths on fittings made of rare earth-containing magnetic materials bring them up to magnetize them in situ, i.e. as part of an assembled rotor, like this usually happens with Alnico magnets.

known rotor constructions with permanent magnetic material, for example Alnico magnets, it is state of the art to dimension the pole pieces made of magnetically soft material so that the of the Magnetic flux emanating from permanent magnets does not lead to saturation in the pole pieces at any point.

As investigations by the applicant have shown, such a construction does not allow a magnetic The field to the fittings containing rare earths

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spend that would be sufficient to magnetize this material accordingly.

Fittings made of rare earths containing magnetic materials are usually according to the current state the technology produced only in relatively small dimensions. Typical sizes are approximately 12.5 12.5 χ 0.25 mm or smaller. In order to get to DC motors with greater power, it is therefore necessary to have a larger number of such fittings and to anchor them geometrically in a suitable manner in the rotor construction. It was already proposed to use a bonding process with appropriate synthetic resins for this purpose. Has such a procedure however, proved to be unsuitable for the economical and technically perfect manufacture of such rotors .

The aim of the present invention is the construction of runners in which the disadvantages mentioned in full Scope are avoided or processes for their economical and simple production.

Rotor according to the invention for DC motors with an inverted structure have pole pieces made of laminated, magnetically soft material, the cross-section of which is at least 1.5 times larger than that required is to supply the rare earth material contained in the permanent magnets in the magnetized state to absorb magnetic flux without saturation phenomena

253Β32Π

and forward and that is enough to keep that in the virgin or pseudo-virgin state built-in permanent magnetizable material using the pole pieces to pass on the magnetizing flux and to magnetize in situ without being hindered by saturation phenomena.

The cross-section of the pole pieces is advantageously dimensioned approximately 2 to 3 times larger or selected so that that it is sufficient to remove the fittings that are in the virgin or pseudo-virgin state permanently magnetizable material in situ with 12,000 oersteds and magnetize a field of 10,000 Gauss without causing the magnetization process in the pole pieces by saturation is limited.

According to the method according to the invention for producing such rotors, the soft magnetic part is first of all of the runner composed of blanks of laminated, magnetically soft material, these blanks contain first openings for receiving the permanently magnetizable material and with a second set of openings are equipped; and that

then the molded pieces made of permanently magnetizable material, which is in the virgin or pseudo-virgin state is located in the set of first openings is used to then non-magnetic, pourable material to pour into the set of second openings intended for this and to solidify, whereupon the thus formed runner

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The blank is mechanically processed in order to be brought into its final shape with the formation of discrete pole pieces will; and that

then the permanently magnetizable material of the Rotor is magnetized in situ and using the pole pieces or the soft magnetic material of the rotor, in order to produce the desired strength using permanent magnets,

According to a preferred embodiment of the invention the rotor axis is inserted before potting and thus anchored during the potting process.

This axis is advantageously made of magnetically conductive material. Has as a pourable material Molten aluminum proved particularly beneficial.

The casting process creates a geometrically clear and reliable anchoring of the molded pieces made of magnetizable Material achieved; because this material is in its virgin or pseudo-virgin state for installation reached, all difficulties in the subsequent mechanical processing are also avoided. Finally allowed the dimensioning of the material of the pole pieces in combination with its lamination the desired magnetization of the magnetic material without being hindered by saturation phenomena.

To ensure that the magnetisable material of the fittings is prior to mechanical processing

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in the unmagnetized or pseudo-virgin state is located, these or the blank rotor are in a magnetically conductive material before mechanical processing free environment is heated for a sufficient time to a temperature which is suitable for an existing magnetization dismantle.

According to one embodiment of this inventive step, after magnetization, the rotor can move to a exactly predetermined value of magnetization can be brought by placing it in a free of magnetically conductive material The surrounding area is heated for a time sufficient to pre-magnetize the permanent magnets to bring a certain value, with it possibly a magnetization in the original direction and on can connect a likewise predetermined value.

In the following the invention is explained in more detail with reference to the drawings in an exemplary manner.

Fig. 1 shows in cross section a DC machine with an inverted structure and an iron rotor according to the invention.

Fig. 2a is a plan view of a lamella made of soft, magnetic material in an exemplary embodiment.

Fig. 2b is the cross-sectional representation of a rotor according to the invention, which by means of the lamellae according to 2a is constructed.

609812/0701

Fig. 1 shows an embodiment of a DC machine with an inverted structure and a permanent magnet rotor. Here 11 and 12 are housing parts with openings 11a and 12a for receiving the rotor axis 15. The stator 16 consists of a core made of soft magnetic sheet metal and a plurality of stator winding coils 17, which are not shown in detail for reasons of clarity. The stator coil winding ends are connected in a known manner to the commutator bars 19 of a switching device 18, which advantageously (according to domestic patent application 9/10). In the simplified representation in Fig. 1 mean

21 a sleeve fastened on the axis 15 on which the support piece 30 is located, which in turn is the holder

22 for the contact rollers 35 carries. On the same sleeve 21 there are isolated slip rings 23 and 24, which are connected via lines 37 and 37a. Power supply brush assemblies slide on the slip rings 25 and 26, which in turn are stationarily connected to the stand structure and (not shown) the electrical connection each with one of the poles of the direct current source. Also anchored in a stationary manner on the carrier 20 is the commutator with the commutator bars 19. Openings 11a and 12a in the housing serve as a holder for the Bearings 13 and 14 of the rotor axis 15.

The rotor 44 contains pole pieces made of magnetically soft, laminated material, as well as permanent magnets Rare earth material and other appropriate materials

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Components that are also not for reasons of simplification are shown.

Fig. 2a shows a cut of a lamella made of soft magnetic material 200. This has a set openings 201 for receiving fittings 203 made of perv magnetic material, as well as a further set of openings 202 and a central opening 206.

Fig. 2a is the area of the blank 201 ', that which is omitted during the completion of the rotor for the formation of the individual pole shoes 201 ″.

Fig. 2b shows a cross section through a finished runner according to the invention. Here are the Pole shoes made of laminated magnetically soft material with 201 "and the permanent magnetic fittings with 203 as well the rotor axis is designated by 204. The space of the openings 201 which is not filled in and the space provided for this purpose Openings 202 and the space 205 between the rotor axis and the inner opening of the actual rotor are filled, preferably by pouring molten aluminum.

The blanks made of magnetically suitable material have a thickness of 0.5 mm; the fittings from rare Permanently magnetizable material containing earths typically have the dimensions 12 × 20 × 10 mm.

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For a runner length of 10 cm are therefore for
each slot 10 such fittings required. These preferably consist of cobalt / rare earth magnet material of known composition. Suitable steel is used as the material for the rotor axis.

As described, the fittings are made from permanent magnets! manageable material in the virgin or pseudo-virgin state in the slots, and only
magnetized after pouring and mechanical treatment by applying suitable fields.

609812/0701

Claims (10)

-PATENT CLAIMS: - ΐ \ Rotor for direct current motors with an inverted construction, the pole pieces of which are made of laminated, magnetically soft material and whose magnetic field is generated by means of permanent magnets from the class of rare earths containing magnetic materials, possibly in cooperation with magnets made of other known magnetic materials, characterized in, that the cross-section of the pole pieces is at least 1.5 times larger than that required to absorb and pass the magnetic flux supplied by the permanent magnets in the magnetized state without saturation phenomena; and that is sufficient to do so in the virgin or pseudo-virgin state built-in permanently magnetizable material using the pole pieces to pass on the magnetizing flux and to magnetize it in situ without being hindered by saturation phenomena. 2. Runner according to claim 1, characterized in that that the cross-section of the pole pieces is two to three times larger than that which is required to the to absorb and pass on the flux supplied by the permanent magnets without saturation phenomena. 609812/07 0 ? 5383? 0 3. Rotor according to claim 1, characterized in that the cross section of the pole pieces is sufficiently dimensioned to magnetize the permanently magnetized material in the virgin or pseudo-virgin state in situ with 12,000 Oersteds and a field of 10,000 Gauss magnetize. 4. A method for producing a rotor according to at least one of claims 1 to 3, characterized in that that the soft magnetic part of the runner is made from blanks of laminated, magnetically soft material is assembled, the first opening for receiving the permanently magnetized material and a second Own set of openings; and that Fittings made of permanently magnetizable material, the sicn is in the virgin or pseudo-virgin state, are inserted into the first openings; and dais non-magnetic, pourable material in the second sentence Openings are poured and solidified; and aa the rotor blank formed in this way is mechanically processed, to form discrete pole pieces into its eno shape to be brought; and that then the permanently magnetizable material of the rotor is magnetized in situ and using the pole pieces or the soft magnetic material of the rotor, in order to produce permanent magnets of the desired strength. 609812/0701 _ 2538370 5. The method according to claim 4, characterized / that the rotor axis is used before potting. 6. The method according to claim 5, characterized in that that the axis is made of magnetically conductive material. 7. The method according to at least one of claims 4 to 6, characterized / that as a pourable Material molten aluminum is used. 8. The method according to at least one of claims 4 to 7, characterized in that the shaped pieces made of permanently magnetizable material before or after installation, but preferably before mechanical Machining of the rotor blank and thereby brought into the pseudo-virgin state before magnetization, that they are in an environment free of magnetically conductive material for a sufficient time at a temperature are heated, which is suitable to reduce an existing magnetization. 9. The method according to at least one of claims 1 to 8, characterized / that the rotor R09812 / 0701 r 25383? 0 after magnetization is heated in an environment free of magnetically conductive material for a time that is sufficient to reduce the magnetization of the permanent magnets to a predetermined value, taking care of it possibly connect a magnetization in the original direction and to a likewise predetermined value can. 10. The method according to at least one of claims 4 to 9, characterized in that the blanks made of soft magnetic material a set of openings 201 for receiving molded pieces made of permanent magnetic material Have material 203 and have another set of openings 202 and a central opening 206; and that the space of the openings 202 and the opening 206, if applicable after the axle 204 has been installed, it is filled with castable material, for example molten aluminum, wherein the pourable material also fills the space of the openings 201 that is not occupied by the molded pieces 203. 60981 2/0701