JP2014187750A - Rotor and permanent magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor which allows for enhancement in the material yield of an end plate, while reducing the amount of a nonmagnetic material used in the end plate, and to provide a permanent magnet motor using that rotor.SOLUTION: A rotor 1 includes a rotor core 10, and a plurality of end plate pieces 20 of nonmagnetic material arranged on the upper end face 120 and the lower end face 130 of the rotor core 10 in the rotation axis direction, where a permanent magnet 40 is embedded, respectively, in a plurality of magnet embedding holes 100 elongating in the rotation axis direction of the rotor core 10. The end plate piece 20 has a magnet falling-off prevention part 200 for preventing a permanent magnet 40 embedded in the magnet embedding hole 100 from falling off, and the magnet falling-off prevention part 200 is abutted against the rotor core 10 so as to cover the adjacent corners 101 of the magnet embedding holes 100.

Description

  The present invention relates to a rotor and a permanent magnet electric motor using the rotor.

  Conventionally, a permanent magnet motor mounted on a compressor or the like includes a cylindrical stator and a columnar rotor arranged to face the inner diameter side of the stator with a predetermined interval. Each of the permanent magnets is embedded in a magnet embedding hole extending in the direction of the rotation axis and formed in a plurality at predetermined intervals in the circumferential direction inside the rotor core. The permanent magnet is prevented from falling off in the direction of the rotational axis from the magnet core hole of the rotor core by an annular end plate made of a magnetic material such as an electromagnetic steel plate disposed on both end surfaces of the rotor core in the direction of the rotational axis. It has become. Since the end plate is in contact with the rotor core so as to cover the openings of all the magnet embedding holes, when the permanent magnet moved in the direction of the rotation axis when the rotor core rotates, it is adjacent to the end plate. Magnetic flux that leaks between different magnetic poles of the permanent magnet that passes through the end plate causes eddy currents to occur in the end plate due to the leaked magnetic flux, resulting in eddy current loss. When an eddy current is generated in the end plate, the end plate generates heat, and the heat energy is lost to reduce the motor efficiency.

  As a rotor that solves the problem that such eddy current is generated in the end plate, non-magnetic end plates are arranged on both end surfaces in the rotation axis direction of the rotor core instead of the magnetic end plates. There is something. As a result, since the end plate is made of a non-magnetic material, leakage magnetic flux does not pass through the end plate, making it difficult to generate eddy currents. However, the non-magnetic material is a conventional magnetic material. There is a problem in that the electrical conductivity is lower than that of the electromagnetic steel sheet (eddy current is difficult to be generated) and the strength is hard, for example, stainless steel is used, but the manufacturing cost is high and expensive.

  As a rotor that can be made inexpensive even if such a non-magnetic end plate is used, end plates respectively disposed on both end faces of the rotor core are connected to the outer diameter side of the rotor core and a permanent magnet. An annular first end plate made of a non-magnetic material that comes into contact with the rotor core so as to cover the rotor, and a magnet that comes into contact with the rotor core so as to cover the inner diameter side of the rotor core and the inner peripheral side of the first end plate There exists what comprised from the annular | circular shaped 2nd end plate which consists of a body (for example, refer patent document 1). The end plate of the rotor is composed of two first end plates and a second end plate which are divided into the outer diameter side and the inner diameter side of the rotor core, so that the rotation with less leakage magnetic flux causing eddy currents is generated. By not using a non-magnetic material for the second end plate that contacts the inner diameter side of the core, it is possible to reduce the amount of non-magnetic material used for the end plate and reduce the manufacturing cost.

  However, since the first end plate made of a non-magnetic material is formed in an annular shape so as to cover the outer diameter side of the rotor core, the end material discarded when the first end plate is cut off by punching. There is a problem that the material yield is poor.

JP 2005-304177 A

  In view of the above problems, the present invention provides a rotor capable of improving the material yield of an end plate while reducing the amount of non-magnetic material used for the end plate, and a permanent magnet motor using the rotor. With the goal.

  In order to solve the above problems, a rotor according to the present invention includes a rotor core and a plurality of non-magnetic end plate pieces arranged on an end surface in the rotation axis direction of the rotor core, and the rotor core rotates. Permanent magnets are embedded in a plurality of magnet embedded holes extending in the axial direction, respectively, and the end plate piece has a magnet drop-off preventing portion for preventing the permanent magnets embedded in the magnet embedded holes from falling off. The magnet drop-off prevention portion is in contact with the rotor core so as to cover adjacent corner portions of the magnet embedding hole.

  The permanent magnet motor of the present invention includes the above-described rotor and a stator that is arranged to face the outer diameter side of the rotor at a predetermined interval.

  According to the rotor of the present invention and the permanent magnet motor using the rotor, the magnet drop-off prevention portion provided on the non-magnetic end plate piece covers the adjacent corners of the magnet embedding hole respectively. Since it is in contact with the iron core, the material yield of the end plate can be improved while reducing the amount of non-magnetic material used as the end plate.

It is a disassembled perspective view which shows the rotor of this invention. It is an external appearance perspective view which shows the rotor of this invention. It is a top view which shows the permanent magnet electric motor using the rotor of this invention. It is explanatory drawing which shows 2nd Embodiment of the end plate piece with which the rotor of this invention was equipped, (a) is a top view of an end plate piece, (b) is an end plate piece of (a) on a rotor core. The top view of the arrange | positioned rotor, (c) is explanatory drawing which shows the planing at the time of stamping the end plate piece of (a). It is explanatory drawing which shows 3rd Embodiment of the end plate piece with which the rotor of this invention was equipped, (a) is a top view of an end plate piece, (b) is an end plate piece of (a) on a rotor core. The top view of the arrange | positioned rotor, (c) is explanatory drawing which shows the planing at the time of stamping the end plate piece of (a). It is explanatory drawing which shows 4th Embodiment of the end plate piece with which the rotor of this invention was equipped, (a) is a top view of an end plate piece, (b) is an end plate piece of (a) on a rotor core. The top view of the arrange | positioned rotor, (c) is explanatory drawing which shows the planing at the time of stamping the end plate piece of (a).

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1 to 6 are views for explaining a permanent magnet motor mounted on a rotor and a compressor using the rotor in the present embodiment. As shown in FIGS. 1 and 2, the rotor 1 includes a rotor core 10, end plate pieces 20, rivets 30, and permanent magnets 40. The rotor core 10 is formed in a cylindrical shape by laminating a plurality of thin magnetic steel plates, and a rotation shaft (not shown) is inserted and fixed at the center thereof. In the rotor core 10, six rectangular magnet embedding holes 100 are formed in an annular shape at predetermined intervals so as to form hexagonal sides around the rotation axis. In addition, six circular through-holes 110 are annularly formed at predetermined intervals near the inner periphery.

  The magnet embedding hole 100 is a through hole having a side extending in the circumferential direction longer than a side extending in the radial direction of the rotor core 10 and extending in the rotation axis direction, and has six plate-like permanent shapes extending in the rotation axis direction. Magnets 40 are respectively embedded. The six permanent magnets 40 embedded in the magnet embedding hole 100 are magnetized so that adjacent magnetic poles are different from each other. The through hole 110 is a hole formed between adjacent magnet embedding holes 100 and extending in the rotation axis direction, and three of them are inserted with rod-like rivets 30 formed of carbon steel extending in the rotation axis direction. Is done. The other three through holes 110 are used, for example, when fixing the position of the rotor core 10 to a magnetizing jig (not shown) for magnetizing the rotor core 10.

  The end plate piece 20 is formed by punching a thin non-magnetic metal plate, for example, a stainless steel plate having a thickness of 1 mm, into a circular shape, and has an upper end surface 120 that is an end surface in the rotation axis direction of the rotor core 10 and a lower surface. Three each are arranged on the end face 130. Each of the end plate pieces 20 has the same structure and includes a magnet dropout prevention unit 200.

  The magnet drop-off prevention unit 200 abuts on the rotor core 10 so as to cover the corner portion 102 of the opening 101 of the magnet embedding hole 100 provided on the upper end surface 120 and the lower end surface 130 of the rotor core 10 in the rotation axis direction. . The magnet dropout prevention unit 200 prevents the permanent magnet 40 from dropping out from the magnet embedding hole 100 of the rotor core 10 in the rotation axis direction. The magnet dropout prevention unit 200 is formed with a circular through hole (rivet through hole 201).

  The procedure for assembling the rotor 1 configured as shown in FIG. 2 will be described with reference to FIG. As shown in FIG. 1, each end has a through hole 110 visible from the upper end surface 120 of the rotor core 10 into which the permanent magnet 40 before magnetization is inserted, and a through hole 110 visible from the lower end surface 130 of the rotor core 10. The rivet through-hole 201 formed in the magnet drop-off prevention part 200 of the plate piece 20 is aligned. Thereafter, the three rivets 30 are inserted from the rivet through holes 201 of the three end plate pieces 20 arranged on the lower end surface 130 of the rotor core 10. Next, each rivet 30 is passed through the through hole 110 of the rotor core 10 and the tip of each rivet 30 from the rivet through hole 201 of the three end plate pieces 20 disposed on the upper end surface 120 of the rotor core 10. The part 300 is protruded.

  Next, the tip 300 of the rivet 30 is caulked and plastically deformed (collapsed) by repeatedly pressing and rotating the head pin (not shown) of the rivet 30 with a head pin (not shown). As a result, as shown in FIG. 2, the rotor 1 in which the three end plate pieces 20 are fixed to the upper end surface 120 and the lower end surface 130 of the rotor core 10 is assembled. Since the through hole 110 is provided between the adjacent magnet embedding holes 100, the magnet dropout prevention unit 200 covers both the corners 102 of the adjacent magnet embedding holes 100.

  As shown in FIG. 3, the permanent magnet motor M includes the rotor 1 and the stator 5 described above. The stator 5 includes a stator core 50, an insulator 60, and a stator winding 70. The stator core 50 is formed on a cylinder by laminating a plurality of thin steel plates, and includes an annular back yoke portion 500 and a plurality of teeth portions 510 extending from the back yoke portion 500 to the inner diameter side. An insulator 60 is integrally formed on the stator core 50 by molding, and the stator winding 70 is wound around the tooth portion 510 via the insulator 60. The stator 5 configured as described above is arranged such that the tip surface of the tooth portion 510 faces the outer diameter side of the rotor 1 with a predetermined interval (so-called air gap).

  According to the rotor 1 and the permanent magnet motor M using the rotor 1 according to the embodiment described above, the magnet drop-off prevention unit 200 provided in the non-magnetic end plate piece 20 is adjacent to the magnet embedding hole 100. It abuts on the rotor core 10 so as to cover the matching corners 102 respectively. As a result, as shown in the background art, the amount of non-magnetic material used is significantly greater than that of a single non-magnetic end plate formed in an annular shape so as to cover the entire outer diameter side of the rotor core 10. The cost can be reduced and the material yield can be improved. Furthermore, since the contact area of the permanent magnet 40 with the end plate piece 20 is small, the generation of eddy currents in the end plate piece 20 can be reduced.

  Next, an end plate piece 80 according to the second embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same structure as the above-mentioned embodiment, and the description is abbreviate | omitted. As shown in FIG. 1 and FIG. 4, the end plate piece 80 includes a magnet dropout prevention portion 800, a connecting portion 810, and a bent portion 820. The magnet dropout prevention portion 800 abuts on the rotor core 10 so as to cover the corner portion 102 of the opening 101 of the magnet embedding hole 100 provided on the upper end surface 120 and the lower end surface 130 of the rotor core 10 in the rotation axis direction. . The magnet dropout prevention unit 800 prevents the permanent magnet 40 from dropping out from the magnet embedding hole 100 of the rotor core 10 in the rotation axis direction. A circular rivet through hole 801 is formed in the magnet dropout prevention portion 800.

  As shown in FIGS. 4A and 4B, a plurality (three in this embodiment) of the end plate pieces 80 are connected to each other so as to be bent in a ring shape by a connecting portion 810. The first connecting portion 811 extends in the radial direction of the rotor core 10 from the magnet dropout prevention portion 800 and the second connecting portion 812 extends in the circumferential direction of the rotor core 10 from the first connecting portion 811. As shown in FIG. 4C, a thin bent portion 820 that connects the second connecting portions 812 of the connecting portions 810 is formed between the adjacent connecting portions 810, and can be bent in an annular shape. ing. The three end plate pieces 80 are integrally formed by punching a rectangular stainless steel sheet S so as to be connected side by side. The three end plate pieces 80 which are bent into a ring at the bent portion 820 between the connecting portions 810 to form one part are inserted into the rivet through-holes 801 of the magnet drop-off prevention portion 800 so that each end plate piece 80 80 is fixed to the stator core 10.

  Thus, according to the end plate piece 80 according to the second embodiment, the amount of nonmagnetic material used as the end plate can be greatly reduced and the cost can be reduced, as in the above-described embodiment, and the punching can be performed. Since the three end plate pieces 80 are lined up side by side from the rectangular stainless steel sheet metal S by processing, there are few end materials discarded and the material yield can be improved. Furthermore, the three end plate pieces 20 according to the first embodiment described above are separate parts, whereas the three end plate pieces 80 according to the second embodiment are provided with a connecting portion 810 and a bent portion 820. Since it is connected, the workability at the time of fixing the three end plate pieces 80 to the stator core 10 can be improved.

  Next, an end plate piece 90 according to a third embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same structure as the above-mentioned embodiment, and the description is abbreviate | omitted. As shown in FIGS. 1 and 5, the end plate piece 90 includes a magnet drop-off prevention portion 900, a connecting portion 910, and a bent portion 920, and the end plate pieces 90 are connected to each other so as to be bent in an annular shape by the connecting portion 910 and the bent portion 920. Has been. The magnet dropout prevention unit 900 abuts on the rotor core 10 so as to cover the corners 102 of the opening 101 of the magnet embedding hole 100 provided on the upper end surface 120 and the lower end surface 130 of the rotor core 10 in the rotation axis direction. . The magnet dropout prevention unit 900 prevents the permanent magnet 40 from dropping out from the magnet embedding hole 100 of the rotor core 10 in the rotation axis direction. A circular rivet through hole 901 is formed in the magnet dropout prevention portion 900.

  As shown in FIGS. 5A and 5B, a plurality (six in this embodiment) of the end plate pieces 90 are connected to each other by a connecting portion 910 so as to be bent in an annular shape. The first connecting portion 911 extends from the magnet dropout prevention portion 900 in the radial direction of the rotor core 10 and the second connecting portion 912 extends from the first connecting portion 911 in the circumferential direction of the rotor core 10. As shown in FIG. 5C, a thin bent portion 920 that connects the second connecting portions 912 of the connecting portions 910 is formed between the adjacent connecting portions 910 so that it can be bent in an annular shape. ing. The six end plate pieces 90 are integrally formed by punching a rectangular stainless steel sheet S so as to be connected side by side. The six end plate pieces 90 that are bent into an annular shape at the bent portion 920 between the connecting portions 910 to form one part have the rivets 30 in the rivet through-holes 901 of the magnet drop-off preventing portion 900 of the three end plate pieces 90. The end plate pieces 90 are fixed to the stator core 10 through the stator core 10.

  Thereby, according to the end plate piece 90 by 3rd Embodiment, the effect similar to 2nd Embodiment can be acquired. Further, as in the second embodiment, six end plate pieces 90 are connected by a connecting portion 910 and a bent portion 920 as compared with the case where the three end plate pieces 80 are one component. Therefore, the force applied to one magnet dropout prevention portion 900 is reduced (dispersed), and no excessive force is applied only to one corner portion 102 of the magnet embedding hole 100, and each end plate piece 90 is attached to the stator core 10. It can be fixed in a stable state.

  Next, an end plate piece 90 according to a fourth embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same structure as the above-mentioned embodiment, and the description is abbreviate | omitted. As shown in FIG. 1 and FIG. 6, the end plate piece 90 includes a magnet dropout prevention part 900, a connecting part 930, and a bent part 940. The magnet dropout prevention unit 900 abuts on the rotor core 10 so as to cover the corners 102 of the opening 101 of the magnet embedding hole 100 provided on the upper end surface 120 and the lower end surface 130 of the rotor core 10 in the rotation axis direction. . The magnet dropout prevention unit 900 prevents the permanent magnet 40 from dropping out from the magnet embedding hole 100 of the rotor core 10 in the rotation axis direction. A circular rivet through hole 901 is formed in the magnet dropout prevention portion 900.

  As shown in FIGS. 6A and 6B, a plurality (six in this embodiment) of end plate pieces 90 are connected to each other by a connecting portion 930 so as to be bent in an annular shape. It extends in the circumferential direction of the rotor core 10 from both sides of the magnet dropout prevention part 900. Between the adjacent connection parts 930, as shown in FIG.6 (c), the thin-shaped bending part 940 which connects the connection parts 930 is formed, and it can be bent cyclically | annularly. The six end plate pieces 90 are integrally formed by punching a rectangular stainless steel sheet S so as to be connected side by side. The six end plate pieces 90 that are bent into an annular shape at the bent portion 940 between the connecting portions 930 to form one part have the rivets 30 in the rivet through holes 901 of the magnet fall-off prevention portions 900 of the three end plate pieces 90. The end plate pieces 90 are fixed to the stator core 10 through the stator core 10.

  Thereby, according to the end plate piece 90 by 4th Embodiment, the effect similar to 3rd Embodiment can be acquired. Moreover, since the 1st connection part 911 extended in the radial direction of the rotor core 10 from the magnet fall-off prevention part 900 of the six end plate pieces 90 is not formed like 3rd Embodiment, use of a nonmagnetic material is used. The amount can be further reduced to reduce costs. Furthermore, as in the third embodiment, the three end plate pieces 90 that are not fixed by the rivets 30 are not formed with the first connecting portions 911 that extend in the radial direction of the rotor core 10. Due to the action of centrifugal force during rotation of 1, the connection portion 930 of the three end plate pieces 90 that are not fixed by the rivet 30 is hardly excessively applied, and the connection portion 930 of the end plate piece 90 is not likely to be deformed. .

DESCRIPTION OF SYMBOLS 1 Rotor 10 Rotor core 100 Magnet embedding hole 101 Opening 102 Corner | angular part 110 Through-hole 120 Upper end surface 130 Lower end surface 20, 80, 90 End plate piece 200, 800, 900 Magnet drop-off prevention part 201, 801, 901 Through rivet Holes 810, 910, 930 Connecting portions 811, 911 First connecting portions 812, 912 Second connecting portions 820, 920, 940 Bending portions 30 Rivets 300 Tip portions 40 Permanent magnets 5 Stator 50 Stator core 500 Back yoke portion 510 Teeth 60 Insulator 70 Stator winding M Permanent magnet motor S Stainless steel sheet metal

Claims (4)

A rotor core, and a plurality of non-magnetic end plate pieces disposed on the end surface in the rotation axis direction of the rotor core, and a plurality of magnet embedded holes extending in the rotation axis direction of the rotor core, respectively. A rotor in which a permanent magnet is embedded,
The end plate piece has a magnet dropout prevention portion that prevents the permanent magnet embedded in the magnet embedding hole from falling out,
The rotor, wherein the magnet drop-off prevention part is in contact with the rotor core so as to cover adjacent corners of the magnet embedding hole.   The rotor according to claim 1, wherein each of the plurality of end plate pieces has a connecting portion and is connected to each other so as to be bent in an annular shape.   The rotor according to claim 2, wherein a thin bent portion is formed between the adjacent connecting portions.   A permanent magnet electric motor comprising: the rotor according to any one of claims 1 to 3; and a stator arranged to face the outer diameter side of the rotor at a predetermined interval.

Images