JP5672149B2 - Rotating electric machine rotor and rotating electric machine using the same - Google Patents

Description

  The present invention relates to a rotor for a rotating electrical machine and a rotating electrical machine using the same, and more particularly to a rotor for a rotating electrical machine incorporating a magnet.

  2. Description of the Related Art Conventionally, a rotating electrical machine is known that includes a rotor in which a permanent magnet is embedded in a rotor core that is formed by stacking and integrating a large number of magnetic metal plates that are punched into a disk shape. Such a rotor is also called an IPM (Interior Permanent Magnet) rotor.

  In the IPM rotor, the rotor core embedded with permanent magnets may be fixed to the rotor shaft by being sandwiched between two end plates made of a nonmagnetic metal plate from both sides in the axial direction. These end plates have functions such as preventing permanent magnets embedded in the rotor core from jumping out in the axial direction.

  For example, an electromagnetic steel plate may be used as the magnetic metal plate constituting the rotor core, and a disc made of an aluminum alloy may be used as the end plate. On the other hand, it has been studied to abolish the end plate by filling a resin material in a gap between the rotor core and the permanent magnet and bonding and fixing the permanent magnet. In this case, if the relatively expensive end plate can be omitted, the cost of the IPM motor can be reduced accordingly.

  However, since the end plate also has a function of pressing the laminated steel sheet in the axial direction, when the end plate is eliminated, the outer peripheral part of the electromagnetic steel sheet located at the end in the axial direction is between the adjacent electromagnetic steel sheet. There is a problem of turning outward due to the repulsive force that acts. FIG. 8 shows the situation.

  FIG. 8 shows a part of a rotating electrical machine 80 that includes a rotor 82 from which an end plate is omitted, and a cylindrical stator 84 that is opposed to the outer periphery of the rotor 82 with a predetermined gap G therebetween. In the rotating electrical machine 82, both the rotor 82 and the stator 84 are configured by laminating and integrating electromagnetic steel plates.

  The cylindrical rotor 82 is inserted and fixed in a substantially cylindrical rotor core 86 formed by laminating electromagnetic steel plates 86 and integrated by caulking or the like, and a magnet insertion hole 88 formed in the rotor core 86. And a permanent magnet 90.

  The substantially cylindrical stator 84 includes a stator core 94 formed by laminating annular electromagnetic steel plates 92 and integrating them by caulking or the like. A plurality of teeth 96 project radially inward from the inner peripheral portion of the stator core 94 with an equal arrangement in the circumferential direction. A coil 98 is wound around the teeth 96.

  In such an IPM rotor, the magnetic flux emitted from the permanent magnet 90 advances in the in-plane direction through the electromagnetic steel plate 86 constituting the rotor core 82 and crosses the gap G from the outer periphery of the rotor to the end surface of the inner periphery of the teeth 96 of the stator core 94. Flow into.

  At this time, an axial repulsive force acts between the electromagnetic steel plates 86 due to the magnetic flux flowing inside. The electromagnetic steel sheet 86 positioned on the inner side in the axial direction is not displaced because the repulsive forces acting from both sides cancel each other, but the outer peripheral portion of the electromagnetic steel sheet 86a positioned on the end side in the axial direction, particularly on the outermost side, is shown in FIG. As indicated by a broken line inside, it is easily lifted or turned up from an adjacent magnetic steel sheet. When such deformation of the outer peripheral portion is repeatedly generated by being closed or opened, damage is likely to occur at the outer peripheral portion, particularly the bridge portion narrowed around the magnet insertion hole 88.

  In order to suppress the turning of the electromagnetic steel sheet at the end as described above, as shown in FIG. 9, the stator core 83 is formed longer in the axial direction than the stator core 94, and the end of the rotor core 83 is axially outward from the stator core 92. It is conceivable to provide an overhang portion 86b that protrudes. Here, an example in which the overhang portion 86b is constituted by three electromagnetic steel plates is shown.

  In this case, the magnet insertion hole 88 is also formed so as to penetrate the overhang portion 86b. However, the permanent magnet 90 has substantially the same length as the stator core 92, and the magnet insertion hole 88 located in the overhang portion 86b. For example, the end portion may be filled with a mold resin and closed.

  In the rotor 81 including the overhang portion 86b as described above, the electromagnetic steel plate 86 corresponding to the magnet end is pressed from the outside by the electromagnetic steel plate constituting the overhang portion 86b, and thus the turning of the outer peripheral portion as described above is suppressed. Is done.

  However, as shown in FIG. 9, the magnet magnetic flux F flowing from the end of the permanent magnet 90 to the outer peripheral portion of the overhang portion 86 b enters the tip end portion of the teeth 96 of the stator core 94 from the axial direction across the gap G. Will occur. Then, as shown in FIG. 10, in-plane eddy current EC flows in the electromagnetic steel sheet constituting the tooth 96, in particular, the electromagnetic steel sheet 92a located on the outermost side, and loss occurs. Output efficiency may deteriorate.

  In relation to this, for example, in Japanese Patent Application Laid-Open No. 2010-206952 (Patent Document 1), when the rotor is moved to a position protruding from the stator so as to include the overhang portion, the magnetic flux is axially outward to the stator. In order to reduce the eddy current loss caused by flowing from the stator, it is described that the end of the stator is made of a magnetic material compacted by compacting particles of a magnetic material covered with an electrical insulating film.

JP 2010-206952 A

  However, when the stator is configured by combining the magnetic steel sheet laminated portion and the compacted material as in the stator described in Patent Document 1, the cost increases due to an increase in manufacturing cost and manufacturing man-hours. In addition, since the mechanical strength of the green compact material is significantly lower than that of the steel sheet laminate, there is also a problem that it is difficult to employ a method of tightening and fixing by screwing, press-fitting, shrink fitting or the like.

  An object of the present invention is to reduce eddy current loss in an inner peripheral portion of a stator in a rotating electrical machine including a magnet built-in type rotor including an overhang portion, and to improve output efficiency of the rotating electrical machine.

  A rotor for a rotating electrical machine according to the present invention is a rotor for a rotating electrical machine comprising a magnetic metal plate laminate provided inside a cylindrical stator and having a magnet inserted and fixed in a magnet insertion hole. A rotor including an overhang portion that protrudes outward in the axial direction from the axial end surface of the stator, and a radial dimension between an outer periphery of the electromagnetic steel sheet in the overhang portion and an inner peripheral surface of the stator is other than the overhang portion. It is formed larger than the radial dimension between the outer periphery and the inner peripheral surface of the stator.

  In the rotor for a rotating electrical machine according to the present invention, the outer diameter of the electromagnetic steel sheet included in the overhang portion of the rotor may be formed so as to be gradually reduced toward the outside in the axial direction.

  Moreover, in the rotor for rotating electrical machines according to the present invention, the outer shapes of all the electromagnetic steel sheets included in the overhang portion of the rotor may be formed identically.

  Also, in the rotor for a rotating electrical machine according to the present invention, the magnet insertion hole is formed by extending in the axial direction of the rotor, and is blocked by a resin material filled in a hole end located in the overhang portion. It may be.

  A rotating electrical machine according to another aspect of the present invention includes the rotor having any one of the above-described configurations and a stator provided around the rotor with a predetermined gap therebetween.

  According to the present invention, in the overhang portion that protrudes outward in the axial direction from the end surface of the stator in the rotor, the dimension to the inner peripheral surface of the stator is formed to be relatively large. growing. Therefore, it can suppress that the magnetic flux which came out of the magnet embed | buried under the rotor flows into the inner peripheral part of a stator from the axial direction outer side through an overhang part. Therefore, in the rotating electrical machine including the magnet built-in type rotor including the overhang portion, the eddy current loss in the inner peripheral portion of the stator can be reduced, and the output efficiency of the rotating electrical machine can be improved.

It is sectional drawing of the axial direction which shows the rotary electric machine which is 1st Embodiment of this invention only by the radial direction half. They are radial direction sectional drawing in alignment with the AA in FIG. 1, and the arrow B direction arrow view in FIG. It is an enlarged view of the overhang part of a rotor. It is a figure which shows the modification of the step shape in the axial direction edge part outer peripheral part of a rotor. It is a figure which shows another modification of the step shape in the axial direction edge part outer periphery of a rotor. It is an axial direction sectional view showing the rotary electric machine of a 2nd embodiment only in the diameter direction half. It is sectional drawing which follows the AA line in FIG. 6, and sectional drawing which follows the CC line in FIG. It is a figure for demonstrating a mode that the edge part steel plate of the rotor core which does not use an end plate is turned up. It is a figure which shows an example of a rotary electric machine provided with the rotor which provided the overhang part with respect to the stator for the curling suppression of the said edge part steel plate. FIG. 10 is a diagram showing how eddy currents are generated in the teeth of the stator in FIG. 9.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like. In addition, when a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that these characteristic portions are used in appropriate combinations. Furthermore, in this specification, “axial direction” refers to a direction along the rotation center axis of the rotor, and “radial direction” refers to a direction orthogonal to the axial direction.

  FIG. 1 is an axial sectional view showing a rotating electrical machine 10 according to a first embodiment of the present invention. In FIG. 1, only half of the radial direction is shown. 2 is a radial cross-sectional view taken along line AA in FIG. 1 and a view taken in the direction of arrow B in FIG. 1, and FIG. 3 is an enlarged view of the overlap region of the rotor.

  As shown in FIG. 1, the rotating electrical machine 10 includes a rotor 12 and a stator 14. The rotor 12 is formed by laminating a large number of magnetic metal plates punched into a disk shape, for example, electromagnetic steel plates such as silicon steel plates in the axial direction, and being connected and integrated by a fixing method such as caulking, welding, and bonding. The rotor core 16 is formed.

  A shaft 18 is provided through the center of the rotor core 16 in the radial direction. Both ends of the shaft 18 are rotatably supported via bearing members attached to a motor case (not shown). Thereby, the rotor 12 is rotatable about the central axis X of the shaft 18 as a rotation axis.

  One end side of the rotor core 16 in the axial direction is in contact with a flange portion 20 provided on the outer periphery of the shaft 18. On the other hand, the other axial end of the rotor core 16 is pressed toward the flange portion 20 by a fixing member 22 fixed on the shaft 18 by a fixing method such as caulking. Thus, the rotor core 16 is fixed on the shaft 18 with its axial position determined.

  Here, in the rotor 12 of this embodiment, the end plates are not provided on both axial sides of the rotor core 16. Thus, by omitting the end plate, the number of parts, manufacturing cost, assembly man-hours, etc. can be reduced.

  In addition, although this embodiment demonstrates as what fixes the one side of the rotor core 16 with the fixing member 22, it is not limited to this, You may fix the both sides of the rotor core 16 with a fixing member. In this way, it is not necessary to form a flange portion on the shaft 18, the shaft can be formed of a thinner round bar steel material, and cost reduction can be achieved.

  The stator 14 is a cylindrical member provided around the rotor core 16 with a predetermined gap G therebetween. The stator 14 includes a stator core 24 and a coil 30. The stator core 24 includes a back yoke portion 26 that has an annular shape when viewed from the end in the axial direction, and a plurality of teeth portions 28 that protrude radially inward from the back yoke portion 26 and that are formed at equal intervals in the circumferential direction. The stator core 24 is also configured as a steel plate laminate in which, for example, electromagnetic steel plates punched into an annular shape are laminated in the axial direction and are integrally connected by a fixing method such as caulking.

  A coil 30 is wound around the teeth portion 28 of the stator core 24. When the rotating electrical machine 10 is, for example, a three-phase AC motor, the coil 30 is divided into U-phase, V-phase, and W-phase coils and is mounted in a winding manner such as distributed winding or concentrated winding. Thus, when a three-phase AC voltage is applied to the coil 30, a rotating magnetic field that rotates the rotor 12 is formed inside the stator 14.

  The rotor 12 in this embodiment is an IPM rotor in which a permanent magnet 32 is embedded in the rotor core 16. The rotor 12 is provided with a plurality of magnetic poles 33 arranged in a uniform manner in the circumferential direction, and two permanent magnets 32 are arranged in a substantially V shape on each magnetic pole 33.

  The permanent magnet 32 is inserted from the axial direction into a magnet insertion hole 34 that extends in the axial direction inside the vicinity of the outer peripheral surface of the rotor core 16 and is disposed in the rotor core 16. The permanent magnet 32 is fixed in the rotor core 16 by filling an adhesive thermosetting resin material such as epoxy resin or silicone resin between the permanent magnet 32 and the inner wall of the magnet insertion hole 34. ing.

  The permanent magnet 32 has substantially the same axial length as the stator core 24 and is provided in the rotor core 16 so as to face the stator core 24. Thereby, it is comprised so that a permanent magnet may not be located in the overhang part of the rotor core 16 mentioned later.

  In the rotor 12 of the present embodiment, the description will be made assuming that one magnetic pole 33 includes two permanent magnets 32. However, the present invention is not limited to this, and one magnetic pole includes only one permanent magnet. Alternatively, three or more permanent magnets may be included. Moreover, the thing of a thermoplastic resin material may be used for the adhesive agent which adheres and fixes the permanent magnet 32. FIG.

  In this embodiment, the axial length of the rotor core 16 is longer than the axial length of the stator core 24. As a result, the rotor core 16 has overhang portions 36 that protrude outward in the axial direction from both end surfaces of the stator core 24. A magnet insertion hole 34 is also formed through this overhang portion 36, but the hole end portion of the magnet insertion hole 34 corresponding to the overhang portion 36 is made of a resin material for bonding and fixing the permanent magnet 32. It is blocked by a filling material 38. Thereby, it is possible to reliably prevent the permanent magnet 32 from protruding from the rotor core 16 in the axial direction without using an end plate.

  In the overhang portion 36 of the rotor core 16, the radial dimension between the outer periphery of the electromagnetic steel plate constituting the rotor core and the inner peripheral surface of the stator 14 is between the outer periphery of the rotor other than the overhang portion 36 and the inner peripheral surface of the stator 14. It is formed larger than the radial dimension. Specifically, the outer diameter of the electromagnetic steel sheet included in the overhang portion 36 of the rotor core 16 is formed so as to be gradually reduced toward the outside in the axial direction.

  This will be described in more detail with reference to FIG. FIG. 3 is an enlarged view showing the overhang portion 36 of the rotor core 16. FIG. 3 shows an example in which the overhang portion 36 on one side in the axial direction is configured by six electromagnetic steel plates 17b, but the number of the electromagnetic steel plates 17b can be changed as appropriate.

  As shown in the arrow B diagram of FIG. 2 and FIG. 3, at the position corresponding to the magnetic pole 33 of the rotor core 16, that is, at the position where the magnet insertion hole 34 is formed, the electromagnetic steel plate 17 b that constitutes the overhang portion 36. Cutout portions 40a, 40b, 40c are formed in the outer peripheral edge portion so as to enter a substantially V shape inward in the radial direction. These notches 40a, 40b, and 40c are formed so as to have a greater depth of cutting inward in the radial direction as they go outward in the axial direction. As a result, the outer diameter dimensions (for example, radii) R2, R3, and R4 of the electromagnetic steel sheet 17b at the notch portion forming position are shorter than the outer diameter dimension R1 of the electromagnetic steel sheet 17 at the stator facing position. The outer shape of the portion 36 is gradually formed.

  Here, an example is shown in which the overhang portion 36 is constituted by six electromagnetic steel plates 17b, and the notch portions 40a, 40b, and 40c having the same size and shape are formed in every two electromagnetic steel plates 17b. Thus, if the size of the notch is changed for each of a plurality of sheets, there is an advantage that the types of punching dies for the electromagnetic steel sheet can be reduced and the manufacturing equipment cost can be reduced.

  However, the present invention is not limited to this, and as shown in FIG. 4, the outer diameter dimensions are set to R2 to R7 by changing the cut depth of the notch portion for each of, for example, six electromagnetic steel sheets constituting the overhang portion 36. It may be formed in a stepped shape for each thickness of each electromagnetic steel sheet.

  Moreover, the shape of the notches 40a, 40b, and 40c may be formed in a shape other than a substantially V shape, for example, an arc chord shape as shown in FIG.

  Furthermore, the above-described notch may be formed at a position between the magnetic poles 33 adjacent in the circumferential direction in the rotor core 16.

  As described above, in the rotating electrical machine 10 including the rotor 12 according to the present embodiment, in the overhang portion 36 that protrudes outward in the axial direction from the end surface of the stator core 24 in the rotor core 16, the outside of the electromagnetic steel plate 17 b included in the overhang portion 36 is removed. Since the diameter is formed so as to be gradually reduced toward the outer side in the axial direction, the radial dimension between the tip of the tooth portion 28 that is the inner peripheral surface of the stator 14 and the rotor 12 is the position at the stator core facing position. The overhang portion 36 is formed to be relatively larger than the gap G, thereby increasing the magnetic resistance between the inner periphery of the stator 14.

  Therefore, the magnetic flux emitted from the axial end portion of the permanent magnet 32 embedded in the rotor core 16 flows from the rotor core 16 to the stator core 24 toward the radially outer side without going to the overhang portion 36. As a result, it is possible to suppress the flow from the axially outer side to the teeth portion 28 of the stator 14 through the overhang portion 36 of the rotor core 16. Therefore, in the rotating electrical machine 10 including the IPM rotor 12 including the overhang portion 36, eddy current loss in the inner peripheral portion of the stator 14 can be reduced, and the output efficiency of the rotating electrical machine 10 can be improved.

  Further, in the rotating electrical machine 10 of the present embodiment, the electromagnetic steel plate 17a positioned at the axial endmost position can be pressed by the electromagnetic steel plate 17b constituting the overhang portion 36 so that the end plate is omitted. Moreover, it can suppress that the outer peripheral edge part of the electromagnetic steel plate 17a turns up.

  Furthermore, in the rotating electrical machine 10 of the present embodiment, since the end of the magnet insertion hole 34 located in the overhang portion 36 is blocked by the filler 38, the permanent magnet from the rotor core 16 is eliminated even if the end plate is omitted. 32 can be reliably prevented from popping out.

  Next, the rotating electrical machine 11 of the second embodiment will be described with reference to FIGS. FIG. 6 is an axial cross-sectional view showing the rotary electric machine according to the second embodiment only in a half in the radial direction. Moreover, FIG. 7 shows the cross section which follows the AA line in FIG. 6, and the cross section which follows the CC line in FIG. Here, differences from the first embodiment will be mainly described, and the same or similar components are denoted by the same or similar reference numerals, and redundant description will be omitted.

  As shown in FIGS. 6 and 7, in the rotating electrical machine 11 of this embodiment, the outer diameters of the electromagnetic steel plates 17 b constituting the overhang portion 36 of the rotor core 16 are all formed identically. Specifically, the electromagnetic steel plate 17b is formed as a disk having an outer radius R2 smaller than the outer radius R1 of the electromagnetic steel plate 17 located in the stator core facing region. Thereby, a step portion is formed in the rotor core 16 in the overhang portion 36, and the radial dimension between the inner periphery of the stator 14 is enlarged. Therefore, also in the rotating electrical machine 11 of the present embodiment, the magnet magnetic flux can be suppressed from flowing into the stator core 24 via the overhang portion 36, and the rotation is achieved by reducing the eddy current loss in the inner peripheral portion of the stator 14. The output efficiency of the electric machine 11 can be improved.

  Further, by making the shape of the electromagnetic steel sheet 17b constituting the overhang portion 36 in this way, it is possible to limit the number of press dies for manufacturing the rotor core to two types and to further reduce the manufacturing equipment cost.

  As shown in the CC cross section of FIG. 7, also in the present embodiment, in the same manner as in the case of the rotating electrical machine 10, inward in the radial direction toward the space between the two magnet insertion holes 34 in the overhang portion 36. You may form the notch 40c cut into the substantially V shape.

  Further, as shown in FIG. 7, in the electromagnetic steel sheet constituting the rotor core 16, the width W <b> 2 of the bridge portion 42 between the magnet insertion hole 34 in the overhang portion 36 and the outer periphery is set to the bridge portion 42 of the stator facing region 37. You may form narrower than width W1. Thus, even if the width of the bridge portion 42 in the overhang portion 36 is made as narrow as possible, the strength against centrifugal force is secured by being firmly bonded by the filler 38 filled in the magnet insertion hole 34. Therefore, no problem occurs.

  Although the rotary electric machines 10 and 11 of the first and second embodiments have been described above, the rotary electric machine according to the present invention is not limited to the configuration of the above embodiments, and does not depart from the gist of the invention. Various changes and improvements can be made.

  For example, in the above description, the stator core 24 is described as being made of a magnetic metal plate laminate. However, the rotor for a rotating electrical machine according to the present invention is a magnetic material obtained by compacting particles of a magnetic material covered with an electrical insulating film. You may use with the stator containing the stator core comprised only with material.

  10, 11 Rotating electric machine, 12 Rotor, 14 Stator, 16 Rotor core, 17, 17a, 17b Magnetic steel sheet, 18 Shaft, 20 Flange part, 22 Fixing member, 24 Stator core, 26 Back yoke part, 28 Teeth part, 30 Coil, 32 Permanent magnet, 33 magnetic pole, 34 Magnet insertion hole, 36 Overhang part, 37 Stator facing area, 38 Filler, 40a, 40b, 40c Notch part, 42 Bridge part, G clearance, R1, R2 outer diameter, W1, W2 width , X Center axis.

Claims (5)

A rotor for a rotating electrical machine comprising a magnetic metal plate laminate that is provided inside a cylindrical stator and has a magnet inserted and fixed in a magnet insertion hole,
The rotor includes an overhang portion that protrudes outward in the axial direction from an axial end surface of the stator, and a radial dimension between an outer periphery of the electromagnetic steel sheet in the overhang portion and an inner peripheral surface of the stator is the overhang. It is formed larger than the radial dimension between the outer periphery of the rotor other than the portion and the inner peripheral surface of the stator,
Rotor for rotating electrical machines. The rotor for a rotating electrical machine according to claim 1,
A rotor for a rotating electrical machine, wherein an outer diameter of the electromagnetic steel sheet included in an overhang portion of the rotor is formed so as to be gradually reduced toward an outer side in the axial direction. The rotor for a rotating electrical machine according to claim 1,
A rotor for a rotating electrical machine, wherein the outer shapes of all electromagnetic steel sheets included in the overhang portion of the rotor are formed to be the same. The rotor for a rotating electrical machine according to any one of claims 1 to 3,
The rotor for a rotating electrical machine, wherein the magnet insertion hole is formed by extending in the axial direction of the rotor, and is closed by a resin material filled in a hole end located in the overhang portion. The rotor according to any one of claims 1 to 4,
A stator provided around the rotor with a predetermined gap;
A rotating electrical machine.