JP5365991B2 - Method for manufacturing rotor, method for manufacturing axial gap type rotating electrical machine, rotor for axial gap type rotating electrical machine, and axial gap type rotating electrical machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent thermal demagnetization of a permanent magnet or the loss of magnetism in the permanent magnet by blocking or reducing heat conduction to the permanent magnet that constitutes a rotor, in assembling the rotor of an axial-gap-type rotating electrical machine by welding. <P>SOLUTION: The rotor 14 includes: a first pressing member 22 which supports a field part 20, a frame 26 which has a field part storing hole 24 and is welded to the first pressing member 22, a permanent magnet 28 stored in the field part storing hole 24, a magnetic substance 30 stored in the field part storing hole 24 in contact with the permanent magnet 28, and a second pressing member 32 which is welded to the frame 26 and fixes the permanent magnet 28 in the field part storing hole 24 by fixing the magnetic substance 30 in the field part storing hole 24. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a rotor using welding, a method for manufacturing an axial gap rotating electrical machine, a rotor for an axial gap rotating electrical machine, and an axial gap rotating electrical machine.

  An axial gap type rotating electrical machine includes a rotor arranged to be rotatable about a rotation axis, and a stator arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. It is a rotating electrical machine. This axial gap type rotating electrical machine is preferable to rotating electrical machines of other structures in that the structure can be reduced in thickness and the magnetic pole area can be increased to improve the torque density. The rotor of the axial gap type rotating electrical machine requires a fixing means for disposing a field portion mainly composed of a permanent magnet at a predetermined position and fixing the field portion to a rotating shaft. Patent Document 1 discloses a technique for fixing a core (cover portion 4) and a frame (disk 2) by welding in order to hold a field portion.

JP-A-2-262863

  However, according to Patent Document 1, when a core and a frame are welded, a magnetic body, specifically, a dust core or a laminated steel plate is used for the core as an electromagnetic material for reducing iron loss. The magnetic core cannot be joined by welding, and the laminated steel sheet needs to be welded on the entire laminated surface including the bond between the laminated layers. For this reason, there existed a possibility of the increase in the eddy current loss by the interlayer short circuit of the core by welding, and the deterioration of the magnetic characteristic by thermal stress. Further, since heat is applied to the core for welding, the heat conducted through the core is transmitted to the permanent magnet in contact with the core, and there is a possibility that the permanent magnet is demagnetized or loses its magnetism beyond the Curie point.

  Accordingly, an object of the present invention is to prevent or reduce heat transfer to the permanent magnets constituting the rotor when the rotor of the axial gap type rotating electrical machine is assembled by welding, The purpose is to prevent the permanent magnet from losing its magnetism.

The method of manufacturing a rotor according to the present invention includes a rotor arranged to be rotatable about a rotation axis, and a fixed arrangement arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. And a step of welding a frame having a plurality of field-portion housing holes to a first pressing member and fixing the frame to the first pressing member, A step of storing a magnet in the field portion receiving hole, a step of storing a plurality of magnetic bodies in the field portion storing hole in contact with the permanent magnet, and a second pressing member in the frame Fixing the permanent magnet in the field part accommodation hole in a state where the second pressing member is not in contact with the permanent magnet by welding and fixing to the field part accommodation hole. , only including, the heat capacity of the frame It is larger than the thermal capacity of the serial second pressing member.

The rotor manufacturing method of the present invention is characterized in that, in the rotor manufacturing method, the second pressing member is ring-shaped . In the method for manufacturing a rotor , the welding of the second pressing member to the frame is spot welding performed on a plurality of spots or circumferential welding generating a plurality of arc trajectories . In the method for manufacturing a rotor, the permanent magnet is closely attached to the first pressing member. Moreover, in the manufacturing method of the rotor, the first pressing member side of the permanent magnet is closely attached to the first pressing member. In the method for manufacturing a rotor, the frame and the second pressing member are made of nonmagnetic stainless steel.

  The manufacturing method of the axial gap type rotating electrical machine according to the present invention includes a rotor arranged to be rotatable about a rotation axis, and a gap on both sides or one side of the rotor in the direction of the rotation axis. A method of manufacturing an axial gap type rotating electrical machine including the stator thus formed, wherein the method of manufacturing the rotor is the method of manufacturing a rotor of the present invention.

The rotor of the axial gap type rotating electrical machine according to the present invention is provided with a rotor disposed so as to be rotatable about a rotation axis and a gap on both sides or one side of the rotor in the direction of the rotation axis. A rotor of an axial gap type rotating electrical machine comprising: a first pressing member that supports a field part; and a plurality of field part accommodation holes, wherein the first pressing part includes: A frame welded and fixed to the member, a plurality of permanent magnets housed in the field magnet housing hole,
A plurality of magnetic bodies housed in the field magnet housing holes so as to be in contact with the permanent magnets, and fixed by welding to the frame, and fixing the magnetic bodies in the field magnet housing holes, the a second pressing member for fixing the permanent magnet to the field magnet part accommodating hole saw including a heat capacity of the frame is greater than the thermal capacity of the second pressing member in a state not in contact with said permanent magnet It is characterized by.

  An axial gap type rotating electrical machine according to the present invention includes a rotor arranged to be rotatable around a rotation axis, and a fixed arrangement arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. An axial gap type rotating electric machine including the rotor, wherein the rotor is the rotor of the present invention.

  Further, the axial gap type rotating electrical machine of the present invention is characterized in that, in the axial gap type rotating electrical machine, the stator on the second pressing member side is disposed close to the magnetic body via a gap. To do.

  The rotor manufacturing method, the axial gap rotating electrical machine manufacturing method, the axial gap rotating electrical machine rotor, and the axial gap rotating electrical machine according to the present invention weld the second pressing member to the frame to bind the magnetic body to the boundary. By fixing in the magnetic part accommodation hole, the permanent magnet can be fixed in the magnetic part accommodation hole in a state where the second pressing member does not contact the permanent magnet. For this reason, since the frame is not welded to the magnetic body, and the member to be welded on the side having a small heat capacity does not directly contact the permanent magnet, the heat of welding is transmitted from the second pressing member to the permanent magnet via the magnetic body. The heat transfer to the permanent magnet can be reduced. Thereby, the thermal demagnetization or magnetism disappearance of a permanent magnet can be prevented.

It is side surface sectional drawing which shows the axial gap type rotary electric machine of this invention. It is a perspective view for demonstrating the manufacturing method of the axial gap type rotary electric machine of FIG. It is a figure for demonstrating the manufacturing method of the axial gap type rotary electric machine of FIG. 1, The figure (a) is a top view of a rotor, The figure (b) is a bottom view of a rotor. It is a figure for demonstrating the manufacturing method of the axial gap type rotary electric machine of FIG. 1, The figure (a) is a top view of a rotor, The figure (b) is a bottom view of a rotor. It is a perspective view which shows other embodiment of the rotor of the axial gap type rotary electric machine of this invention. It is side surface sectional drawing which shows other embodiment of the rotor of the axial gap type rotary electric machine of this invention. It is side surface sectional drawing which shows other embodiment of the axial gap type rotary electric machine of this invention. It is side surface sectional drawing which shows other embodiment of the axial gap type rotary electric machine of this invention. It is side surface sectional drawing which shows other embodiment of the rotor of the axial gap type rotary electric machine of this invention.

  The present invention will be described with reference to the drawings. In addition, the figure has shown typically and may differ from an actual magnitude | size.

  As shown in FIG. 1, the axial gap type rotating electrical machine 10 according to the present invention has a rotor 14 disposed rotatably around a rotating shaft 12 and gaps on both sides of the rotor 14 in the direction of the rotating shaft 12. It is an axial gap type rotary electric machine provided with a pair of stators 16 and 18 disposed apart from each other. That is, the axial gap type rotating electrical machine 10 has a configuration in which the rotor 14 is sandwiched between the stators 16 and 18.

  The rotor 14 of the present invention includes a first pressing member 22 that supports the field portion 20, a frame 26 that has six field portion receiving holes 24 and is welded to the first pressing member 22, Six permanent magnets 28 housed in the field magnet housing hole 24 so as to be in contact with the first pressing member 22 and six magnets housed in the field magnet housing hole 24 so as to be in contact with the permanent magnet 28 The magnetic body 30 and the frame 26 are welded, and the magnetic body 30 is fixed in the field magnet housing hole 24, thereby fixing the permanent magnet 28 in the field magnet housing hole 24 without contacting the permanent magnet 28. And a second pressing member 32.

  The first pressing member 22 is a short-circuited steel plate (electromagnetic steel plate) made of a soft magnetic material, and has a function of partially short-circuiting the magnetic flux on the stator 18 side of the field part 20 and supports the field part 20. Has the function of By having the function of partially short-circuiting the magnetic flux on the stator 18 side, the magnetic attraction force acting between the stator 18 and the rotor 14 becomes the magnetic attraction force acting between the stator 16 and the rotor 14. When it is stronger, the magnetic attractive force acting between the stator 18 and the rotor 14 can be weakened. If this function is not necessary, the first pressing member 22 may be made of a non-metallic plate. Moreover, the 1st holding | suppressing member 22 is not comprised integrally, and may be divided | segmented into plurality and comprised. For example, a method of dividing so that one pressing member 22 is provided per one field generating portion can be considered. Further, as the first pressing member 22, a ring-shaped second pressing member 32 may be used.

  Considering the weldability with the second pressing member 32, the frame 26 is preferably made of nonmagnetic stainless steel. For example, the frame 26 may be formed by punching a stainless steel plate, or may be a sintered body. Good. The six field portion accommodation holes 24 of the frame 26 are partitioned by six spokes 34.

  In order to increase the magnetic flux density, the permanent magnet 28 is preferably composed of a sintered rare earth magnet, particularly an Nd—Fe—B system (neodymium, iron, boron). On the other hand, rare earth magnets, particularly sintered rare earth magnets, have high electrical conductivity, and eddy current loss is likely to occur due to the rotating magnetic field generated from the stator 16. For this reason, the magnetic body 30 is made of a magnetic material having a lower conductivity than that of the rare earth magnet, and is disposed on the stator 16 side with respect to the permanent magnet 28, thereby reducing eddy current loss. In particular, when PWM (Pulse Width Modulation) control is performed, eddy current loss due to a change in high-frequency magnetic flux of the carrier component can be reduced. Further, if the magnetic body 30 is composed of a magnetic core having magnetic isotropy, eddy current loss can hardly occur in the magnetic body 30. On the other hand, since most of the field magnetic flux generated by the permanent magnet 28 on the stator 16 side passes through the magnetic body 30, the surface of the magnetic body 30 on the stator 16 side is substantially the pole of the field portion 20. It will function as a magnetic surface.

  The second pressing member 32 is composed of ring-shaped members 36 and 38. In consideration of weldability with the frame 26, the second pressing member 32 is preferably made of nonmagnetic stainless steel, and is formed by punching or sintering a stainless steel plate, for example.

  The stator 16 includes a back yoke 40, a tooth 42 disposed on the rotor 14 side of the back yoke 40, and a coil portion 44 wound around the tooth 42. The back yoke 40 has a disk shape having a hole 46 that passes through the central portion of the back yoke 40 without being constrained, and has, for example, a hole or groove into which the tooth 42 is fitted. . The coil unit 44 is composed of a three-phase coil. For example, if the rotor 14 has 6 poles, nine teeth 42 are provided, and each phase coil is configured by winding a coil around each tooth 42 in a concentrated winding manner. The back yoke 40 does not require the central hole 46 if the rotating shaft 12 does not penetrate therethrough.

  The stator 18 has a hole 48 in the center and is configured without a coil. The stators 16 and 18 are fixed in a container (not shown). The rotating shaft 12 of the rotor 14 passes through the hole 46 of the stator 16 and the hole 48 of the stator 18 in a rotatable manner.

  A method for manufacturing the rotor 14 having such a configuration will be described below.

  First, the first pressing member 22 is laser welded to the frame 26. The laser welding form R may be spot welding as shown in FIG. 3 (b) or circumferential welding as shown in FIG. 4 (b). Further, it may be welded to the spoke 34 of the frame 26.

  Next, as shown in FIG. 2, after the permanent magnet 28 is stored in the field magnet storage hole 24 of the frame 26, the magnetic body 30 is stored. At this time, the permanent magnet 28 may or may not be magnetized. The ring-shaped members 36 and 38 are laser-welded to the frame 26 in a state where the permanent magnet 28 and the magnetic body 30 are stored in the field magnet storage hole 24. This form R of laser welding may be spot welding as shown in FIG. 3 (a) or circumferential welding as shown in FIG. 4 (a). When the permanent magnet 28 is not magnetized, the magnet is magnetized by passing a current through the stator winding in a state where the rotor 14 is completed and assembled as a magnetizer or a motor.

  According to such a method of manufacturing a rotor, the second pressing member 32 is welded to the frame 26, so that the permanent magnet 28 is housed in the magnetic part in a state where the second pressing member 32 does not contact the permanent magnet 28. It can be fixed in the hole 24. Therefore, the frame 26 is not welded to the magnetic body 30. For this reason, heat transfer to the permanent magnet 28 can be reduced by contact resistance due to the heat of welding being transmitted from the second pressing member 32 to the permanent magnet 28 via the magnetic body 30. Although the frame 26 is in direct contact with the permanent magnet, the distance between the welded portion and the permanent magnet contact portion is large, and since the volume is larger than the second pressing member 32, the permanent magnet has a large heat capacity. The heat transferred to is extremely small. Also, heat transfer to the permanent magnet 28 can be reduced by heat radiation from the frame 26. By reducing the heat transfer to the permanent magnet 28 in this way, the thermal demagnetization or the disappearance of the magnet of the permanent magnet 28 can be prevented.

  Further, when the permanent magnet 28 is a rare earth that causes irreversible demagnetization and high temperature demagnetization, the irreversible demagnetization can be prevented by reducing the heat transfer to the permanent magnet 28, and a particularly advantageous effect is produced. Furthermore, when the magnetic body 30 is a dust core, it is impossible to perform a welding process on the magnetic body 30, and thus the rotor manufacturing method of the present invention has a particularly advantageous effect. In addition, when the magnetic body 30 is a laminated steel sheet, the laminated steel sheet is not directly heated by welding, and there is no short circuit between the laminations. Therefore, the magnetic characteristics are deteriorated due to thermal stress and the eddy current is increased due to the short circuit between the laminations. Can be prevented.

  As mentioned above, although this invention was demonstrated, this invention is not limited to said embodiment. For example, in the rotor 14 of the present invention, as shown in FIG. 5, holes 50 extending in the radial direction may be provided in the spokes 34 of the frame 26, and the magnetic body 52 may be fitted into the holes 50. The magnetic body 52 is made of an electromagnetic steel plate or a dust core provided in the radial direction or the circumferential direction. The magnetic body 52 is fixed by the first pressing member 22 and the second pressing member 32 in the fitting direction. In this case, the position of the magnetic body 52 in the circumferential direction avoids the field portion 20, particularly the magnetic pole surface, and increases the q-axis inductance to generate reluctance in proportion to the difference between the q-axis inductance and the d-axis inductance. This effectively contributes to an increase in torque.

  Further, in the rotor 14 of the present invention, as shown in FIG. 6, steps are provided on the outer periphery and inner periphery of the magnetic body 30, and ring-shaped members 36 and 38 are fitted to the steps to fix the field portion 20. May be. In this case, since the ring-shaped members 36 and 38 do not exceed the gap surface height of the magnetic body 30 and the spokes 34 are retracted from the gap surfaces, the magnetic flux passes through the ring-shaped members 36 and 38 and the spokes 34. Eddy current loss can be reduced.

  Further, in the axial gap type rotating electrical machine 10 of the present invention, as shown in FIG. 7, the stator 18 is not provided, and the thick back yoke 60 (first pressing member 60) is used instead of the first pressing member 22. May be provided. The first pressing member 22 as a short-circuit steel plate is thin for short-circuiting a part of the magnetic flux, but the back yoke 60 is for short-circuiting all of the magnetic flux of the field part 20, so that it is sufficient. Requires thickness. For example, it is comprised from the wound iron core wound centering around the rotating shaft, the electromagnetic steel plate etc. which were laminated | stacked by the rotating shaft direction. For assembly, the frame 26 is attached to the back yoke 60, for example, the contact surface between the frame and the back yoke is laser welded from the outer peripheral side, the permanent magnet 28 and the magnetic body 30 are accommodated in the frame 26, and the ring-shaped members 36 and 38 are attached to the frame. No. 26 is laser welded. In this case, heat is not directly transmitted to the permanent magnet 28 even if the outer peripheral portion or the inner peripheral portion of the frame 26 is small.

  Further, in the axial gap type rotating electrical machine 10 of the present invention, as shown in FIG. 8, armatures having coils in both of the stators 16 and 18 are used, and an equal magnetic field is generated on both surfaces of the rotor 14. Good. In the frame 26, the magnetic body 30, the permanent magnet 28, and the magnetic body 30 are accommodated in a three-layer state. When the rotor 14 is assembled, even if the first pressing member 22 is first welded to the frame 26 and the second pressing member 32 is finally welded, the second pressing member 32 is first welded. Finally, the first pressing member 22 may be welded.

  In the rotor 14 shown in FIG. 7, as shown in FIG. 9, the back yoke may be divided in the circumferential direction and stored in the frame. As the rotor shape, in the rotor 14 shown in FIG. 8, the thickness of one magnetic body 30 (a) is made smaller than the thickness of the other magnetic body 30 (b) (corresponding to the back yoke), and the permanent magnet 28 and One magnetic body 30 (a) is housed on the upper side of the frame 26, and the other magnetic body 30 (b) is housed on the lower side of the frame 26. The permanent magnet 28 and one magnetic body 30 (a) and the other The magnetic body 30 (b) may be configured to be housed so as to be alternately located in the circumferential direction. In this case, the frame 26 includes an upper spoke 70 (a) corresponding to the permanent magnet 28 and one magnetic body 30 (a), and a lower spoke 70 (b) corresponding to the other magnetic body 30 (b). Are provided alternately. If it is difficult to integrally mold the frame 26, after forming the portion corresponding to the permanent magnet 28 and one magnetic body 30 (a) and the portion corresponding to the other magnetic body 30 (b) separately, They may be integrated by welding or sintering. In the axial gap type rotating electrical machine 10 including the rotor 14, the stator does not face the other magnetic body 30 (b), and the magnetic body 30 (a) functions as a back yoke. The magnetic body 30 (b) is preferably configured integrally, but is divided for storage in the frame 26. In the case of dividing the structure, it is preferable that the magnetic flux of the permanent magnet 28 is divided at both sides at the pole center and is divided at the pole center. When the rotor 14 is assembled, even if the first pressing member 22 is first welded to the frame 26 and the second pressing member 32 is finally welded, the second pressing member 32 is first welded. Finally, the first pressing member 22 may be welded. Regardless of the assembly method, the magnetic body 30 (b) is interposed between the first pressing member 22 and the permanent magnet 28, and the magnetic body 30 ( Since a) is interposed, heat transfer to the permanent magnet 28 can be reduced.

  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 spirit of the present invention. For example, the welding of the second pressing member to the frame is preferably laser welding with little heat input, but may be other welding.

  According to the rotor manufacturing method, the axial gap rotating electrical machine manufacturing method, the axial gap rotating electrical machine rotor, and the axial gap rotating electrical machine of the present invention, heat generated by welding during assembly of the rotor The amount of heat transferred from the weld to the permanent magnet can be reduced, and the permanent magnet can be prevented from demagnetizing or disappearing. For this reason, it can be widely used as a motor. In particular, since the rotor is assembled by welding without using an adhesive or a mold, it is suitable for use in a hermetic compressor used in a refrigerant.

DESCRIPTION OF SYMBOLS 10: Axial gap type rotary electric machine 12: Rotating shaft 14: Rotor 16, 18: Stator 20: Field part 22: First pressing member 24: Field part accommodation hole 26: Frame 28: Permanent magnets 30, 52 : Magnetic body 32: Second pressing member 34: Spoke 60: Back yoke (first pressing member)

Claims (10)

Axial gap type rotation comprising: a rotor arranged to be rotatable around a rotation axis; and a stator arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. A method for manufacturing the rotor of an electric machine,
A step of welding and fixing a frame having a plurality of field part accommodation holes to the first pressing member;
Storing a plurality of permanent magnets in the field magnet storage hole;
Storing a plurality of magnetic bodies in the field magnet storage hole so as to be in contact with the permanent magnet;
A second pressing member is welded and fixed to the frame and fixed in the field portion receiving hole so that the second pressing member is not in contact with the permanent magnet and the permanent magnet is moved to the field portion. A step of fixing in the storage hole;
Only including,
A method for manufacturing a rotor, wherein the heat capacity of the frame is larger than the heat capacity of the second pressing member . The method for manufacturing a rotor according to claim 1, wherein the second pressing member has a ring shape . 3. The method for manufacturing a rotor according to claim 1, wherein the welding of the second pressing member to the frame is spot welding performed to a plurality of spots, or circumferential welding generating a plurality of arc trajectories . The method for manufacturing a rotor according to any one of claims 1 to 3, wherein the permanent magnet is in close contact with the first pressing member. The method for manufacturing a rotor according to any one of claims 1 to 4 , wherein the first pressing member side of the permanent magnet is closely attached to the first pressing member.   The method for manufacturing a rotor according to claim 1, wherein the frame and the second pressing member are made of nonmagnetic stainless steel. Axial gap type rotation comprising: a rotor arranged to be rotatable around a rotation axis; and a stator arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. A method of manufacturing an electric machine,
The manufacturing method of the axial gap type rotary electric machine whose manufacturing method of the said rotor is a manufacturing method of the rotor in any one of Claims 1-6. Axial gap type rotation comprising: a rotor arranged to be rotatable around a rotation axis; and a stator arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. The rotor of the electric machine,
A first pressing member that supports the field part;
A frame having a plurality of field part storage holes, welded and fixed to the first pressing member;
A plurality of permanent magnets housed in the field magnet housing holes;
A plurality of magnetic bodies housed in the field magnet housing holes so as to be in contact with the permanent magnets;
The frame is smaller than the frame and has a smaller heat capacity, and is fixed by welding. A second pressing member fixed in the magnetic part storage hole;
Only including,
The rotor of an axial gap type rotary electric machine in which the heat capacity of the frame is larger than the heat capacity of the second pressing member . Axial gap type rotation comprising: a rotor arranged to be rotatable around a rotation axis; and a stator arranged with a gap on both sides or one side of the rotor in the direction of the rotation axis. Electric
An axial gap type rotating electrical machine, wherein the rotor is a rotor according to claim 8.   The axial gap type rotating electrical machine according to claim 9, wherein the stator on the second pressing member side is disposed close to the magnetic body through a gap.

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