JP2015192594A - Rotor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor which suppresses demagnetization of a magnet when embedding a magnet in a magnet hole and eliminates leakage flux, and a method for manufacturing the same. A rotor 10a of the present invention includes a rotor core 12, a fastening member 14, a magnet 16, an end plate 18, and a rotating shaft 20. The rotor core 12 has a magnet hole 22, a cutting portion 24, and a fastening hole 26a. The fastening member 14 is inserted into the fastening hole 26a, and the magnet 16 is embedded in the magnet hole 22. The cut portion 24 is formed from the end portion of the magnet hole 22 to the outer periphery of the core sheet 28. The cut portion 24 is a space and is a portion without an electromagnetic steel plate. The magnet 16 is fixed to the inner wall of the magnet hole 22 by brazing. [Selection diagram] Fig. 1

Description

  Conventionally, various rotating electrical machines 104 having an annular stator 102 around a cylindrical rotor 100 have been developed. When the rotating electrical machine 104 is applied to the compressor 106 as shown in FIG. 12, the stator 102 is disposed in the cylindrical pipe 108, and the rotor 100 is disposed therein. The compressor 106 is provided with a pipe 110 that supplies a refrigerant, a pipe 112 that discharges the refrigerant, a terminal 114 connected to a winding, and a compression mechanism 116. When the rotor 100 rotates, the refrigerant is sucked into the compression mechanism 116, compressed, and discharged.

  The rotor 100 includes a rotor core 120 in which a disk-shaped core sheet 118 shown in FIG. 13 is laminated, a magnet 124 embedded in a magnet hole 122 formed in the rotor core 120, and an end plate 126 disposed at the end of the rotor core 120. , And a rotating shaft 128 attached to the center of the rotor core 120. The magnet hole 122 does not reach the outer periphery of the rotor core 120, and a bridge portion 130 extends from the end of the magnet hole 122 to the outer periphery of the rotor core 120. In the following Patent Document 1, the magnet 124 is welded to the rotor core 120 using a pulse laser.

  However, since Patent Document 1 uses laser welding, the temperature during welding rises to about 1500 ° C. The magnet 124 may be demagnetized and the rotational performance may be reduced.

  In addition, leakage magnetic flux is generated in the bridge portion 130. Since the leakage magnetic flux does not contribute to the rotation of the rotor 100, it is necessary to eliminate the leakage magnetic flux. The following Patent Document 1 does not disclose countermeasures against leakage magnetic flux.

JP 2000-83334 A

  An object of this invention is to provide the rotor which suppressed the demagnetization of the magnet when embedding a magnet in a magnet hole, and eliminated the leakage magnetic flux, and its manufacturing method.

  The rotor of the present invention includes a rotor core in which a core sheet made of an electromagnetic steel plate is laminated, a magnet hole formed in the rotor core, a cutting part that forms a space from an end of the magnet hole to the outer periphery of the rotor core, and the magnet hole And a magnet brazed or soldered to the rotor core.

  The magnet hole includes a concave portion, a convex portion, or both, and the magnet includes a convex portion, a concave portion, or both, which are fitted into the concave portion, the convex portion, or both of the magnet hole, and at least the convex portion of the magnet, The recess or both are brazed or soldered to the rotor core.

  The convex part of the said magnet or the convex part of a magnet hole is provided with the part which hooks a magnet and a rotor core.

  The convex portions of the magnet, the concave portions, or the convex portions and the concave portions do not face each other. Convex portions and the like are provided on one surface and the other surface of the magnet so that the convex portions and the like on the one surface and the other surface do not face each other.

  The width of the magnet changes, and at least both ends of the magnet are brazed or soldered to the rotor core.

  When one surface of the magnet is disposed on the outer peripheral side of the rotor core, the width of one surface is Wo, the width of the center is Wc, and the width of the other surface is Wi, Wi ≧ Wo> Wc.

  A fastening hole provided in the rotor core, and a fastening member inserted into the fastening hole and fixing the core sheets to each other, wherein the fastening hole is provided inside a magnet hole in the core sheet, In the core sheet, caulking is provided outside the magnet hole.

  The method for manufacturing a rotor of the present invention includes a step of preparing an electromagnetic steel plate, a step of punching the electromagnetic steel plate to form a core sheet having magnet holes, and a step of forming the rotor core by stacking the core sheets. And a step of preparing a magnet and embedding it in the magnet hole, a step of fixing the magnet to the rotor core by brazing or soldering, and cutting the space from the end of the magnet hole to the outer periphery of the rotor core. Forming a cut portion.

  The magnet hole includes a concave portion, a convex portion, or both, and the magnet includes a convex portion, a concave portion, or both, which are fitted into the concave portion, the convex portion, or both of the magnet hole, and at least the convex portion of the magnet, The recess or both are brazed or soldered to the rotor core.

  The width of the magnet changes, and at least both ends of the magnet are brazed or soldered to the rotor core.

    In the present invention, the leakage magnetic flux can be eliminated by forming a cut portion that is a space from the end of the magnet hole to the outer periphery of the rotor core instead of the conventional bridge portion. Further, demagnetization when the magnet is fixed to the magnet hole by brazing or soldering can be suppressed, and the magnet and the rotor core can be integrated.

It is a figure which shows the rotor of this invention, (a) is a top view, (b) is the sectional view on the AA line of (a). (A) is a top view of the punched core sheet, and (b) is a diagram in which magnets are embedded in the rotor core. It is the figure which provided the convex part in the magnet, (a) is a top view, (b) is the enlarged view in the dotted line of (a). It is a figure which shows the convex part of various shapes to a magnet. It is a figure showing various magnets, (a) is a figure with a plurality of convex parts, (b) is a figure with concave parts, (c) is a figure with convex parts and concave parts, (D) is the figure which shifted the position of the convex part, (f) is the figure which shifted the recessed part. It is the figure which made the convex part of a magnet catch on a rotor core. It is the figure which made the convex part of a magnet catch on a rotor core. It is the figure which provided the protrusion part in the one surface and the other surface in the both ends of a magnet. It is a figure which defines the shape of a magnet, (a) is a top view, (b) is an enlarged view in the dotted line of (a). It is the figure which provided the crimp to the outer side rotor core. It is a figure which shows the rotor of an arc-shaped magnet hole. It is a figure which shows a compressor. It is a figure which shows the cross section of the conventional rotor.

  The rotor of the present invention will be described with reference to the drawings. The rotor is used for a rotating electric machine. The rotating electrical machine can be applied to a compressor or the like, as in the past. In the description of a plurality of embodiments, the same content as that described in one embodiment may be omitted in other embodiments.

  The rotor 10a of the present invention shown in FIG. 1 includes a rotor core 12, a fastening member 14, a magnet 16, an end plate 18, and a rotating shaft 20. The rotor core 12 has a magnet hole 22, a cutting portion 24, and a fastening hole 26 a, the fastening member 14 is inserted into the fastening hole 26 a, and the magnet 16 is embedded in the magnet hole 22.

  The rotor core 12 is a laminate of core sheets 28. The core sheet 28 can be formed by punching a magnetic steel sheet made of soft magnetic material. The thickness of the core sheet 28 is, for example, about 0.2 to 1 mm, and preferably about 0.3 to 0.5 mm. The surface of the core sheet 28 covers an insulating film and prevents eddy currents between the core sheets 28. The outer shape of the core sheet 28 is circular except for a cutting portion 24 described later.

  The core sheet 28 has a magnet hole 22 formed therein. As shown in FIG. 1A, in the plane of the core sheet 28, the magnet hole 22 has a band shape and is bent so as to have a U shape or a V shape. Both ends of the magnet hole 22 are disposed near the outer periphery of the core sheet 28. The magnet holes 22 of each core sheet 28 have the same shape and are symmetrical about the rotation axis 20. When the rotor core 12 is formed, the magnet hole 22 communicates from one end to the other end.

  A cut portion 24 is formed from the end of the magnet hole 22 to the outer periphery of the core sheet 28. The cutting part 24 is a space and is a part without an electromagnetic steel plate. The cutting part 24 has a shape in which the magnet hole 22 is extended to the outer periphery of the core sheet 28. The width of the cutting part 24 in FIG. 1 is the same as that of the magnet hole 22, but the width of the cutting part 24 may be different from that of the magnet hole 22. The conventional bridge portion 130 shown in FIG. 13 is eliminated, and the leakage magnetic flux can be made zero. In the rotor core 12, the outer side of the magnet hole 22 and the cutting part 24 is the outer rotor core 12 o, and the inner side is the inner rotor core 12 i. The outer rotor core 12 o and the inner rotor core 12 i are connected via a magnet 16.

  In this embodiment, a fastening hole 26a is provided in the outer rotor core 12o. When the core sheet 28 is laminated, the fastening member 14 is inserted into the fastening hole 26a, and the laminated core sheet 28 is fixed. Examples of the fastening member 14 include rivets, bolts and nuts, and their shafts enter the fastening holes 26a.

  Examples of the magnet 16 include sintered magnets such as ferrite magnets, neodymium magnets, samarium cobalt magnets, and alnico magnets. The magnet 16 has a plate shape and is fixed to the inner wall of the magnet hole 22 by brazing. The number of magnets 16 is an even number, and N poles and S poles are alternately arranged on the outer periphery of the rotor core 12.

  The magnet 16 is fixed to the inner wall of the magnet hole 22 by brazing. The brazing material 30 is melted, and the brazing material 30 melted in the gap between the inner wall of the magnet hole 22 and the magnet 16 is brazed. A surface facing the inner wall of the magnet hole 22 in the magnet 16 is defined as one surface m and the other surface n. In FIG. 1, the entire surface m and the other surface n of the magnet are brazed to form a thin film layer of the brazing material 30, but may be brazed to a plurality of locations. The outer rotor core 12o and the inner rotor core 12i are fixed via the magnet 16 by brazing.

  Examples of the brazing material include silver brazing, copper brazing, brass brazing, phosphorous copper brazing, and aluminum brazing, and it is preferable to use a material having a low melting point. Soft brazing (soldering) with a melting point of 450 ° C. or less may be used depending on the choice of brazing material. Brazing is performed at a relatively low temperature to make the magnet 16 difficult to demagnetize. For example, the Curie temperature of a ferrite magnet is about 450 ° C., the Curie temperature of a neodymium magnet is about 300 ° C., the Curie temperature of a samarium cobalt magnet is about 750 ° C., and the Curie temperature of an alnico magnet is about 860 ° C. By making it not exceed, demagnetization can be suppressed. Note that the Curie temperature changes somewhat depending on the selection of the magnet material.

  The end plates 18 are made of a nonmagnetic material and are disposed at both ends of the rotor core 12. Non-magnetic material prevents eddy current loss. As with the core sheet 28, a fastening hole 26b is provided so that the fastening member 14 can be passed therethrough. The shaft of the fastening member 14 is passed through the fastening hole 26b simultaneously with the fastening hole 26a of the core sheet 28, and is fixed by the fastening member 14 so that the rotor core 12 and the end plate 18 are integrated. Further, the end plate 18 is provided with a rotation shaft hole 32b through which the rotation shaft 20 passes. The end plate 18 does not have to be in contact with the rotary shaft hole 32b in order to prevent the end plate 18 from popping out when the magnet 16 is detached or to fix the outer rotor cores 12o to each other.

  The rotary shaft 20 is fitted into the rotary shaft hole 32a at the center of the rotor core 12 and fixed. When the rotating electrical machine including the rotor 10a is applied to a compressor, the rotating shaft 20 extends to the compression mechanism and also serves as the rotating shaft of the compressor. A stator is disposed so as to surround the side of the rotor core 12 to become a rotating electrical machine. The stator includes a coil, and the rotor 10a is rotated by a magnetic field generated by applying a current to the coil.

  Next, a method for manufacturing the rotor 10a will be described. (1) An electromagnetic steel sheet is prepared, punched into a predetermined shape, and the core sheet 28 is formed. When performing the punching process, as shown in FIG. 2A, the core sheet 28 is formed with a magnet hole 22, a fastening hole 26a, and a rotary shaft hole 32a. When the outer shape of the core sheet 28 is formed, the magnet hole 22 and the like are formed in the same process or another process. At this point, the cut portion 24 is not formed, and the bridge portion 34 extends from the end of the magnet hole 22 to the outer periphery of the core sheet 28.

  (2) The rotor core 12 is formed by laminating the core sheets 28. When the core sheet 28 is laminated, the magnet hole 22 and the fastening hole 26a penetrating the rotor core 12 are formed so that the positions of the magnet hole 22 and the fastening hole 26a coincide with each other. At this time, the rotation shaft hole 32 a is also formed so as to penetrate the rotor core 12.

  (3) The rotary shaft 20 is inserted into the rotary shaft hole 32a of the rotor core 12 and fixed. Examples of the fixing method include shrink fitting, cold fitting, press fitting, and welding. At this time, the fastening member 14 may be inserted into the fastening hole 26a of the core sheet 28, the core sheets 28 may be fixed to each other, and the fastening member 14 may be temporarily removed after the fixing.

  (4) As shown in FIG. 2B, the magnet 16 is embedded in the magnet hole 22 and fixed. The magnet 16 is fixed to the inner wall of the magnet hole 22 by brazing. The magnet 16 is inserted into the magnet hole 22, the brazing material 30 is melted, and the brazing material 30 poured into the gap between the inner wall of the magnet hole 22 and the magnet 16 is brazed. When inserting the magnet 16, the end plate 18 may be disposed at one end of the rotor core 12. At the stage of inserting the magnet 16 into the magnet hole 22, the magnet 16 is prevented from falling out of the magnet hole 22.

  (5) The bridge portion 34 is cut to form a cutting portion 24 that is a space. When cutting the bridge portion 34, the core sheet 28 is preferably fixed by the fastening member 14. The end plates 18 may be fixed to both ends of the rotor core 12 together with the core sheet 28. Since the magnet 16 is brazed to the inner wall of the magnet hole 22, the outer rotor core 12o and the magnet 16 and the inner rotor core 12i and the magnet 16 are fixed even after the bridge portion 34 is cut.

  Cutting from the outer periphery of the rotor core 12 toward the end of the magnet hole 22. If a space is provided from the end of the magnet hole 22 to the magnet 12, the cutting device does not reach the magnet 16 at the time of cutting, and the magnet 16 can be protected. Any cutting device such as a saw or a cutter can be used as long as it can cut.

  Since the bridge portion 34 is cut after the magnet 16 is embedded, it is not necessary to align the outer rotor core 12o with respect to the inner rotor core 12i. Each rotor core 12i, 12o is arrange | positioned in a desired position even if it does not align.

  In addition, the rotor 10a is arrange | positioned inside a cyclic | annular starter, and a rotary electric machine is comprised. A current is passed through a coil in the stator, and the rotor 10a rotates by a magnetic field generated by the current. When the rotating electrical machine is applied to a compressor, the rotating shaft 20 is connected to the compressor as shown in the prior art. The compressor is driven by the rotation of the rotor 10a.

  Since the bridge portion 34 is cut after the magnet 16 is embedded as described above, there is no need for relative alignment between the inner rotor core 12i and the outer rotor core 12o, and the outer periphery of the rotor core 12 is a perfect circle. The air gap with the stator can be made uniform. Since the air gap is uniform, the rotor 10a is easy to rotate.

  The one surface m and the other surface n of the magnet 16 are not limited to planes. As in the rotor 10b of FIG. 3, triangular convex portions 36 are provided on one surface m and the other surface n. The magnet hole 22 is provided with a triangular concave portion that is fitted to the convex portion 36. At least the convex portion 36 is brazed, and the brazed area between the magnet 16 and the rotor core 12 is expanded by the convex portion 36. By enlarging the brazing area, the brazing between the magnet 16 and the rotor core 12 can be strengthened.

  The shape of the convex portion 36 is not limited to a triangle, and may be a semicircular or quadrangular convex portion 36 as shown in FIGS. Even if it is the convex part 36 of a triangle, arbitrary triangles, such as a right-angled triangle, may be sufficient. A single magnet 16 may be provided with a combination of convex portions 36 having various shapes. The size of the convex portion 36 is not limited, and a convex portion 36 having an area of about 70% of one surface m and the other surface n may be provided as shown in FIGS.

  The number of the convex portions 36 is not limited, and a plurality of convex portions 36 such as three convex portions 36 may be provided on one surface as shown in FIG. By increasing the number of the convex parts 36, the brazing area of the magnet 16 and the rotor core 12 can be expanded, and fixation can be strengthened. You may make it the number of the convex parts 36 of each surface m and n differ.

  As shown in FIG. 5B, the magnet 16 may be provided with a recess 38. A convex portion is provided in the magnet hole 22, and the convex portion of the magnet hole 22 is fitted into the concave portion 38 of the magnet 16. At least the recess 38 of the magnet 16 is brazed. Moreover, you may provide the convex part 36 and the recessed part 38 in the magnet 16 like FIG.5 (c). The magnet hole 22 is also provided with a concave portion and a convex portion so that the respective convex portion and concave portion are fitted together.

  In the above-described embodiment, the magnet 16 is arranged such that the one surface m and the other surface n face each other, and the convex portion 36 on the one surface m and the convex portion 36 on the other surface n face each other. Further, as shown in FIG. 5D, the convex portion 36 on the one surface m and the convex portion 36 on the other surface n may be arranged at positions that do not face each other. Since the positions of the convex portions 36 do not face each other, the magnetic anisotropy is hardly disturbed when the magnet 16 is manufactured by sintering.

  When the concave portion 38 is provided in the magnet 16, the concave portions 38 may not be opposed to each other as in FIG. 5D (FIG. 5E). Moreover, when both the recessed part 38 and the convex part 36 are provided in the magnet, the recessed part 38 and the convex part 36 are made not to oppose. That is, when providing the convex part 36 and the recessed part 38 in order to increase an adhesion area, they do not oppose and it makes it difficult to disturb magnetic anisotropy.

  The inner rotor core 12i and the outer rotor core 12o may be firmly fixed using the convex portion 36 of the magnet 16 and the concave portion of the magnet hole 22. The convex portion 40 of FIG. 6 is configured such that the base portion 42 and the other portion 44 have a portion where the other portion 44 is wider than the width of the base portion 42. By fitting the convex portion 40 of the magnet 16 into the concave portion of the rotor core 12, the other portion 44 of the convex portion 40 is a portion that is caught by the concave portion. The rotor core 12 and the magnet 16 are fixed in a direction perpendicular to the rotating shaft 20 by the convex portion 40 being hooked on the rotor core 12.

  Moreover, you may provide the part hooked on the convex part 46 when the convex part 46 bends like the magnet 16 of FIG. In addition to the axial direction of the rotating shaft 20 of the rotor 10a, the convex portion 46 does not come off the concave portion. There is a possibility that the inner rotor core 12i, the magnet 16 and the outer rotor core 12o may be separated due to the centrifugal force at the time of rotation of the rotor 10a. Will remain.

  A convex portion having the same function as the convex portion 40 of the magnet 16 may be provided in the magnet hole 22, and a concave portion in which the convex portion is fitted may be provided in the magnet 16. Further, a convex portion having the same function as the convex portion 46 of the magnet 16 may be provided in the magnet hole 22, and a concave portion in which the convex portion is fitted may be provided in the magnet 16.

  As shown in FIG. 8, when the rotor 16 is viewed in plan, the magnet 16 has protrusions 48 on one surface m and the other surface n at both ends thereof, and a recess 50 is formed between the surface m and the other surface n. It may be. On one surface m and the other surface n, the protrusion 48 is flush with the other portions. The projections 48 are provided at both ends of the plate-like magnet 16, and both ends of the magnet 16 are recessed toward the center of the magnet 16. Unlike a rectangular plate, the area to be brazed is enlarged by the protrusion 48, and the brazing strength is increased.

  Moreover, if the width | variety of the magnet 16 changes between the one surface m of the magnet 16, and the other surface n and the protrusion part 48 is formed in the both ends of the one surface m and the other surface n, the shape of the protrusion part 48 will not be limited. As shown in FIG. 8, protrusions 48 such as arcs, quadrangles, triangles, and the like can be mentioned. Moreover, you may combine the protrusion part 48 of a different shape in one magnet.

  Like the rotor 10c shown in FIG. 9, the width of one surface m of the magnet 16 is Wo, and the width of the other surface n is Wi. The width of the center of the magnet 16 in the thickness direction is Wc. In this case, Wi ≧ Wo> Wc. This is because in the radial direction of the rotor 10c, if one surface side of the magnet 16 is increased, the centrifugal force is increased, and the brazing between the magnet 16 and the rotor core 12 may be released. If it is the structure of a present Example, the one surface m will not become larger than the other surface n, and a centrifugal force will not become large.

  When the fastening hole 26a is provided in the inner rotor core 12i as in the rotor 10d of FIG. 10, the outer rotor core 12o is not integrated with the fastening member 14, and therefore the caulking 52 is provided in the outer rotor core 12o. The core sheets 28 are fixed to each other by the caulking 52 so that the core sheets 28 hardly fly by centrifugal force. When the fastening hole 26a is provided in the outer rotor core 12o, the caulking 52 of the outer rotor core 12o is not essential. This is because the core sheet 28 of the outer rotor core 12o is integrated by the fastening member 14.

  The shape of the magnet hole 22 is not limited to a U shape or a V shape. An arcuate magnet hole 22 and a magnet 16 may be used as in the rotor 10e of FIG. Similar to the above embodiment, it has a cutting part 24 and fixes the magnet 16 to the rotor core 12 by brazing.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the gist thereof. Each embodiment is not an independent or exclusive embodiment, and may be implemented by appropriately combining all or a part of various embodiments.

10a, 10b, 10c, 10d, 10e: Rotor 12: Rotor core 12i: Inner rotor core 12o: Outer rotor core 14: Fastening member 16: Magnet 18: End plate 20: Rotating shaft 22: Magnet hole 24: Cutting portions 26a, 26b: Fastening Hole 28: Core sheet 30: Brazing material 32a, 32b: Rotating shaft hole 34: Bridge portions 36, 40, 46: Convex portion 38: Concavity 42: Base of convex portion 44: Other portion 48 of the convex portion 48: Protrusion Part 50: recessed part 52: caulking

Claims (11)

A rotor core in which core sheets made of electromagnetic steel sheets are laminated;
A fastening hole provided in the rotor core;
A fastening member that is inserted into the fastening hole and fixes the core sheets together;
Magnet holes formed in the rotor core;
A cutting part formed from the end of the magnet hole to the outer periphery of the rotor core;
A magnet embedded in the magnet hole and brazed or soldered to the rotor core;
With a rotor. The magnet hole includes a concave portion, a convex portion, or both;
The magnet includes a convex portion, a concave portion or both, which are fitted into the concave portion, the convex portion or both of the magnet hole,
The rotor according to claim 1, wherein at least convex portions, concave portions, or both of the magnets are brazed or soldered to the rotor core. The rotor according to claim 1, wherein the convex portion of the magnet or the convex portion of the magnet hole is a hooked portion that fixes the magnet and the rotor core. The rotor according to claim 2 or 3, wherein the convex portions of the magnet, the concave portions, or the convex portion and the concave portion do not face each other. The rotor according to claim 1, wherein the width of the magnet is changed, and at least both ends of the magnet are brazed or soldered to the rotor core. 6. The rotor according to claim 5, wherein one surface of the magnet is arranged on an outer peripheral side of the rotor core, and when the width of one surface is Wo, the width of the center is Wc, and the width of the other surface is Wi, Wi ≧ Wo> Wc. The fastening hole is provided inside the magnet hole in the core sheet,
The rotor according to any one of claims 1 to 6, wherein a caulking is provided outside the magnet hole in the core sheet. The rotor according to claim 1, wherein a surface of the magnet is roughened. Preparing a magnetic steel sheet;
Punching the electromagnetic steel sheet, forming a core sheet having a magnet hole and a fastening hole; and
Laminating the core sheets to form a rotor core;
Inserting a fastening member into the fastening hole and fixing the core sheets together;
Preparing a magnet and embedding it in the magnet hole;
Fixing the magnet to the rotor core by brazing or soldering;
Cutting from the end of the magnet hole to the outer periphery of the rotor core, and forming a cut portion;
A method for manufacturing a rotor comprising: The magnet hole has a concave portion, a convex portion or both,
The magnet includes a convex portion, a concave portion or both, which are fitted into the concave portion, the convex portion or both of the magnet hole,
The method for manufacturing a rotor according to claim 9, wherein at least the convex portion, the concave portion or both of the magnet are brazed or soldered to the rotor core. The method for manufacturing a rotor according to claim 9, wherein the width of the magnet is changed, and at least both ends of the magnet are brazed or soldered to the rotor core.

Images