JP2007282301A - Method of manufacturing rotor of rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a rotor of a rotating electric machine which can magnetize a magnet by a simple process. <P>SOLUTION: The rotor of the rotating electric machine is equipped with a core whereon an exciting coil 21 is wound, a pair of discs which are extended in the diametrical direction from both ends of the core, claw-shaped magnetic poles which are formed between the discs and form N and S poles alternately in the circumferential direction of rotation, and magnets 29 which are arranged on one side in the circumferential direction of the claw-shaped magnetic poles beside between adjacent two claw-shaped magnetic poles each. The manufacturing method therefor is equipped with a magnetizing process for letting a magnetizing current which passes the core and can change properties of the magnet flow after a magnet assembling process for assembling the magnets 29 between the claw-shaped magnetic poles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a rotor of a rotating electrical machine such as a vehicular AC generator driven by an internal combustion engine of a vehicle.

  A vehicular AC generator generally has a pair of opposed claw-shaped magnetic poles each having a claw portion having a plurality of N poles and S poles at a tip portion, and a claw shape wound around the claw-shaped magnetic poles. The rotor includes an excitation winding that generates a magnetizing force in the magnetic pole. The AC generator for vehicles has a stator magnetic pole arranged with a certain gap from this rotor.

  The magnetic flux generated from the claw portion of the N-pole claw-shaped magnetic pole forms a magnetic circuit that passes through the stator magnetic pole and returns to the claw portion of the S-pole claw-shaped magnetic pole. A stator winding is wound around the stator magnetic pole, and when the magnetic flux of the magnetic circuit crosses the stator winding, an induced electromotive force is generated in the stator winding to operate as an AC generator.

In the above configuration, the magnetic flux that crosses the stator windings affects the generated voltage as an effective magnetic flux. However, a part of the magnetic flux emitted from the claw portion of the claw-shaped magnetic pole leaks between the claw-shaped magnetic poles without entering the stator magnetic pole, which causes a reduction in power generation efficiency. Therefore, conventionally, a vehicular AC generator has been known in which permanent magnets are arranged between claw-shaped magnetic poles to reduce leakage magnetic flux and improve power generation efficiency (see, for example, Patent Documents 1 to 3). ).
JP 7-31854 A (page 4-7, FIG. 1-17) Japanese Patent No. 3340259 (page 4-7, FIG. 1-16) JP-A-11-98787 (page 3-7, FIGS. 1-4)

  By the way, in the rotor with a magnet as disclosed in Patent Documents 1 to 3, when a foreign material such as chips is generated in the middle of the process of manufacturing the rotor, it adheres to the rotor and is removed. Is not easy. For this reason, a method for preventing foreign matter from adhering to the rotor has been known for some time by magnetizing the magnet in the final process. However, when a magnetizing magnetic field is applied from the outside, the magnetizing magnetic flux passes through the iron core portion around which the exciting coil is wound, so that the magnetic field is not easily applied to the magnet. Therefore, it is necessary to apply a very strong magnetic field from the outside. To that end, it is necessary to arrange a large energizing current and a magnetizing coil that can withstand such a large amount of equipment, including a power source, There was a problem of increasing complexity.

  The present invention has been made in view of such a point, and an object thereof is to provide a method of manufacturing a rotor of a rotating electrical machine capable of magnetizing a magnet by a simple process.

  In order to solve the above-described problems, a method of manufacturing a rotor of a rotating electrical machine according to the present invention includes an iron core portion around which an exciting coil is wound, a pair of disk portions that are radially extended from both ends of the iron core portion, and a disk Between the two claw-shaped magnetic pole portions and one claw-shaped magnetic pole portion in the circumferential direction between the claw-shaped magnetic pole portions formed between the two claw-shaped magnetic pole portions and alternately forming NS poles along the rotation circumferential direction. A method of manufacturing a rotor of a rotating electrical machine comprising a magnet and a magnet that can pass through the iron core and change the characteristics of the magnet after the magnet assembly step of assembling the magnet between the claw-shaped magnetic poles It has a magnetizing step for passing an electric current. As a result, a magnetizing coil is arranged in the vicinity of each magnet, and a magnetic field is generated by flowing a magnetizing current in the axial direction in the iron core portion without using a complicated and magnetic device for generating a large magnetic field as a whole. Thus, the magnet can be magnetized, and the process can be simplified. Further, since it can be magnetized at the final stage, it is possible to prevent adhesion of metal chips or the like during cutting or transfer.

  The rotor described above preferably includes a fan welded to the disk portion, and it is desirable to use a welding current required for fan welding as the magnetizing current in the magnetizing step. In a rotor that uses both an excitation coil and a magnet, a structure including a cooling fan is known to eliminate the temperature rise due to heat generation, and a structure in which an iron plate is resistance-welded for simplification of the structure is also known. . In such a configuration, by setting the fan welding current to an appropriate value and setting the welding shape and welding conditions suitable for the current, the welding current can also serve as the magnetizing current in the magnetizing process. . Therefore, the magnet can be magnetized without providing a magnetizing step separately from the welding step, and the process can be further simplified.

  Moreover, as for the magnetization current mentioned above, it is desirable that the direction in which the maximum current flows is a fixed direction corresponding to the arrangement of the magnets. As a result, the magnet is always magnetized in a constant direction corresponding to the maximum current direction and the magnet arrangement direction, so that the exciting current of the exciting coil may be formed in a certain direction, and the manufacture of the rotor is facilitated.

  The magnetizing current described above is preferably a direct current. Thereby, an error in the magnetization direction due to an error in the current direction can be prevented.

  The magnetizing current described above is desirably 2 KA or more and 200 KA or less. Thereby, a magnet can be magnetized reliably.

  Further, it is desirable that the above-described magnetizing current flow in such a direction that the polarity of the magnet disposed between the claw-shaped magnetic pole portions is the same as that of the claw-shaped magnetic pole portion facing this magnet. Thereby, while simplifying the process, the leakage of magnetic flux between the claw-shaped magnetic pole portions, which is the purpose of magnet arrangement, can be prevented and the output can be improved.

  Hereinafter, an AC generator for a vehicle according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall structure of an automotive alternator according to an embodiment. As shown in FIG. 1, the vehicle alternator 1 of this embodiment includes a rotor 2, a stator 3, a front side housing 4, a rear side housing 5, a brush device 6, a rectifier 7, a voltage regulator 8, It includes a pulley 9 and the like.

  The rotor 2 is disposed between a pair of pole cores 22 and 23 having a plurality of claw-shaped magnetic poles bent in the axial direction alternately forming NS magnetic poles along the rotation direction, and the pair of pole cores 22 and 23. A magnet 29, an exciting coil 21 in which an insulated copper wire is wound cylindrically and concentrically, and a rotating shaft 24. Further, on the end face of the pole core 22 on the front side (pulley 9 side), a cooling fan 25 that mixes the axial flow type or the axial flow type and the centrifugal type in order to discharge the cooling air sucked from the front side in the axial direction and the radial direction. Are fixed by welding (for example, projection welding). Similarly, a centrifugal cooling fan 26 for discharging the cooling air sucked from the rear side in the radial direction is attached and fixed to the end face of the pole core 23 on the rear side by welding or the like. A specific arrangement of the magnets 29 and a method for manufacturing the rotor 2 will be described later.

  Slip rings 27 and 28 that are electrically connected to both ends of the exciting coil 21 are formed on the rear side of the rotating shaft 24, and the brushes 61 and 62 in the brush device 6 are pushed against the slip rings 27 and 28, respectively. By assembling in the applied state, an exciting current flows from the rectifier 7 to the exciting coil 21.

  In the stator 3, three-phase stator windings 32 are wound at a predetermined interval in a plurality of slots formed in a stator core 31 disposed to face the rotor 2. The rectifier 7 is for rectifying the three-phase alternating current that is the output voltage of the three-phase stator winding 32 of the stator 3 to obtain a direct current output, and is a positive-side heat radiating plate fixed at a predetermined interval. And a negative-side heat radiating plate and a plurality of rectifying elements attached to the respective heat radiating plates by soldering or the like.

  The front-side housing 4 and the rear-side housing 5 accommodate the rotor 2 and the stator 3 described above, and the rotor 2 is supported so as to be rotatable around the rotation shaft 24. The stator 3 is disposed outside the pole cores 22 and 23 via a predetermined gap. The stator 3 is fixed by tightening bolts 34 to four support portions 420 provided at equal intervals along the rotation direction of the rotor 2.

  The voltage regulator 8 is for adjusting the output voltage of the vehicle alternator 1 by controlling the exciting current flowing through the exciting coil 21. The voltage regulator 8 adjusts the output voltage that changes according to the electric load and the amount of power generation. Keep almost constant. The pulley 9 is for transmitting the rotation of an engine (not shown) to the rotor 2 in the vehicular AC generator 1, and has a nut 91 at one end of the rotating shaft 24 (on the side opposite to the slip ring 27 and the like). It is fixed by tightening. A rear cover 92 that protects the brush device 6, the rectifying device 7, and the voltage regulator 8 is attached.

  In the vehicle alternator 1 having the above-described structure, the rotor 2 rotates in a predetermined direction when rotation from the engine is transmitted to the pulley 9 via a belt or the like. At this time, by applying an excitation voltage to the excitation coil 21, the respective claws of the pole cores 22 and 23 are excited, and a three-phase AC voltage can be generated in the stator winding 32. A predetermined direct current is taken out from.

  Further, since the cooling fan 25 attached to the end face of one pole core 22 rotates with the rotation of the rotor 2 described above, the cooling is performed via the suction port 440 of the front side housing 4 provided on the pulley 9 side. Wind is sucked into the AC generator 1 for the vehicle, the exciting coil 21 is cooled by the axial component of the cooling air, and the coil end in front of the stator winding 32 is cooled by the radial component. The cooling air is then discharged from the discharge port 450 of the front housing 4.

  Similarly, the cooling fan 26 attached to the end face of the other pole core 23 also rotates with the rotation of the rotor 2 described above, so that the cooling air sucked through the suction port of the rear cover 92 is supplied to the rectifier 7. Alternatively, after the voltage regulator 8 is cooled, it is guided to the cooling fan 26 through the suction port 540 of the rear side housing 5, and this cooling air is discharged in the radial direction so that the coil end behind the stator winding 32 is To be cooled. The cooling air is then discharged from a discharge port (not shown) of the rear housing 5.

  Next, details of the magnet 29 provided in the rotor 2 will be described. FIG. 2 is a partial cross-sectional view of the rotor 2 and shows a state where the magnet 29 is attached. FIG. 3 is a partial cross-sectional view of the rotor 2. FIG. 4 is a perspective view after the rotor 2 is assembled.

  One pole core included in the rotor 2 of the present embodiment includes a cylindrical iron core portion 22A around which the exciting coil 21 is wound, and a disk portion 22B extending in the radial direction from the axial end of the iron core portion 22A. It has claw-shaped magnetic pole portions 22C that extend in the axial direction from the disk portion 22B and alternately form NS magnetic poles with the other pole core 23. The same applies to the other pole core 23, which includes an iron core portion 23A, a disk portion 23B, and a claw-shaped magnetic pole portion 23C. The magnets 29 are arranged between every two adjacent claw-shaped magnetic pole portions 22C and 23C and on every other side of the claw-shaped magnetic pole portions 22C and 23C (see FIG. 4). The magnetic circuit portion on the rotor 2 side is formed by the portions of the two pole cores 22 and 23 and the exciting coil 21.

  The magnet 29 is arranged so that NS poles are arranged in parallel with the direction of the magnetic flux leakage between the claw-shaped magnetic pole portions 22C and 23C, that is, in parallel with the direction of the magnetic flux generated by the exciting coil 21 and flowing in the magnetic circuit portion. Yes. A magnet protection member 29A made of a non-magnetic material (for example, a stainless steel plate) is attached to the outer periphery of the magnet 29. As shown in FIG. 2, the magnet protection member 29 </ b> A extends so as to contain the magnet 29 radially inward at both ends along the axial direction, and the tip of the magnet protection member 29 </ b> A protects the exciting coil 21 from winding or protection. The protective member (bobbin or the like) provided for the purpose or the disk portions 22B and 23B of the pole cores 22 and 23 are locked with elastic deformation. Thereby, it is possible to protect the magnet 29 and to perform positioning in the axial direction. Movement of the magnet 29 in the radial direction (direction in which centrifugal force acts) is prevented by forming the claw-shaped magnetic pole portions 22C and 23C of the pole cores 22 and 23 wider on the outer diameter side. Further, the surface of the magnet protection member 29A on the side of the magnet 29 (inner peripheral surface) is coated with resin so that it is difficult to be damaged.

  FIG. 5 is a diagram illustrating a manufacturing process of the rotor 2. The rotor 2 is manufactured according to the following procedure. First, the pole cores 22 and 23 and the exciting coil 21 are assembled (step S1). These assemblies are performed by press-fitting the rotary shaft 24 into the through-holes of the iron core portions 22A and 23A of the pole cores 22 and 23 in a state where the pole cores 22 and 23 and the exciting coil 21 are combined.

  Next, the magnet 29 is assembled by inserting the magnet 29 between the claw-shaped magnetic pole portions 22C and 23C of the pole cores 22 and 23 (step S2). Thereafter, welding of the cooling fans 25 and 26 and joining to the slip rings 27 and 28 at both ends of the exciting coil 21 are performed (step S3).

  Next, impregnation processing of the exciting coil 21 is performed for the purpose of fixing and protecting the exciting coil 21 (step S4). Further, the outer diameter cutting of the pole cores 22 and 23, the slip rings 27 and 28, etc. is performed (step S5), and the chips generated by the cutting are removed (step S6). Then, after the balance of rotation is corrected (step S7) and the rotor 2 is inspected (step S8), the rotor 2 is recovered (step S9).

  In the present embodiment, thereafter, a magnetizing step for the magnet 29 is performed (step S10). As shown in FIG. 4, this magnetizing step is performed by supplying a magnetizing current that can change the characteristics of the magnet 29 from one pole core 23 side to the other pole core 22 side. The magnetizing current indicated by the arrow A mainly flows through the iron core portions 22A and 23A of the pole cores 22 and 23. Since the magnetic field is generated in the clockwise direction (arrow M) along the circumference of the energizing direction by the energization of the magnetizing current, the magnet 29 is magnetized in one direction by the magnetic field. In order to reliably perform this magnetization, for example, it is desirable to flow a magnetization current in the range of 2 KA to 200 KA. Further, the magnet 29 needs to be magnetized in a direction corresponding to an exciting magnetic field generated by energizing the exciting coil 21. There are two directions for this. One of them is a method for uniquely determining the winding direction of the exciting coil 21, the direction of connection with the slip rings 27 and 28, and the direction of magnetization current. In this case, the lead portions of the slip rings 27 and 28 and the lead portion of the exciting coil 21 must be connected in the correct combination. Therefore, it is necessary to distinguish according to the shape, color, length, and the like. In order to make a distinction, it takes time to form parts such as shape, color, and length, but the magnetizing current may flow in a certain direction. The other is a method of providing a step of detecting the connection direction with a magnetometer or the like after arbitrarily connecting and a step of changing the magnetization direction correspondingly. When the direction of the magnetic pole of the magnet 29 is opposite, a magnetizing current may be passed from the pole core 22 toward the pole core 23. Although a means for detecting is necessary, it is not necessary to form the parts separately.

  As described above, in the method for manufacturing the rotor 2 according to the present embodiment, the iron core portion is used without arranging a magnetizing coil in the vicinity of each magnet 29 and using a magnetizing device for generating a complicated and large magnetic field as a whole. The magnet 29 can be magnetized simply by passing a magnetizing current in the axial direction through 22A and 23A to form a magnetic field, and the process can be simplified. Further, since it can be magnetized at the final stage, it is possible to prevent adhesion of metal chips or the like during cutting or transfer.

  Further, since the direction in which the maximum current flows is set in a certain direction corresponding to the arrangement of the magnet 29, the magnetization current is always magnetized in a certain direction corresponding to the arrangement direction of the magnet 29. . For this reason, the exciting current of the exciting coil 21 may be formed in a certain direction, and the manufacture of the rotor 2 becomes easy. In addition, the magnetizing current is a direct current, so that an error in the magnetizing direction due to an error in the current direction can be prevented. By setting the magnetizing current in the range of 2 KA to 200 KA, the magnet 29 can be surely magnetized.

  Further, the magnetizing current flows in a direction in which the polarity of the magnet 29 arranged between the claw-shaped magnetic pole portions 22C and 23C becomes the same polarity as that of the claw-shaped magnetic pole portions 22C and 23C facing the magnet 29. That is, as shown in FIG. 3, the magnet 29 is attached so that the N pole of the magnet 29 and the N pole of the claw-shaped magnetic pole portion face each other, and the S pole of the magnet 29 and the S pole of the claw-shaped magnetic pole portion face each other. The direction of the magnetizing current is set in the direction in which it is magnetized. Thereby, while simplifying the process, the leakage of magnetic flux between the claw-shaped magnetic pole portions, which is the purpose of magnet arrangement, can be prevented and the output can be improved.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the magnetizing step (step S10 in FIG. 5) is provided only for magnetizing the magnet 29, but the end faces in the axial direction of the pole cores 22 and 23 like the rotor 2 of the present embodiment. When the cooling fans 25 and 26 are attached by welding, the welding current that flows when welding is used may be used as the magnetizing current.

  FIG. 6 is a view showing a modification of the manufacturing process of the rotor 2. The manufacturing process shown in FIG. 6 replaces the fan welding and excitation coil joining process in step S3 included in the manufacturing process shown in FIG. 5 with the excitation coil joining process in step S3 ′, and the magnetization process in step S10 is step S10. It is different in that it is replaced with 'fan welding process'. The fan welding process in step S <b> 10 ′ also serves as a magnetizing process for the magnet 29. That is, by setting the fan welding current to an appropriate value and setting the welding shape and welding conditions suitable for the current, the welding current can also serve as the magnetization current in the magnetization process. Thereby, the magnet 29 can be magnetized without providing a magnetizing process separately from the welding process, and the process can be further simplified.

  In the above-described present invention, the configuration is focused on simplification, but it is also possible to aim for reliable magnetization. In parallel with the configuration of the present invention, a step of forming a magnetic field by flowing a magnetization current in the axial direction through the iron core, and a step of forming a large magnetic field by arranging a magnetizing coil in the vicinity of each magnet. The magnet can be surely magnetized.

It is sectional drawing which shows the whole structure of the alternating current generator for vehicles of one Embodiment. It is a fragmentary sectional view of a rotor. It is a partial cross-sectional view of a rotor. It is a perspective view after the assembly | attachment of a rotor. It is a figure which shows the manufacturing process of a rotor. It is a figure which shows the modification of the manufacturing process of a rotor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Rotor 3 Stator 4 Front side housing 5 Rear side housing 6 Brush device 7 Rectifier 8 Voltage regulator 9 Pulley 20A Magnet protection member 21 Excitation coil 22, 23 Pole core 22A, 23A Iron core part 22B, 23B Disk part 22C, 23C Claw-shaped magnetic pole part 24 Rotating shaft 25, 26 Cooling fan 29 Magnet

Claims (6)

An iron core portion around which an exciting coil is wound, a pair of disk portions extending in the radial direction from both ends of the iron core portion, and NS poles are formed alternately between the disk portions and along the rotational circumferential direction. In a method of manufacturing a rotor of a rotating electrical machine, comprising: a claw-shaped magnetic pole portion to be arranged; and a magnet disposed between two adjacent claw-shaped magnetic pole portions and arranged on one circumferential side of the claw-shaped magnetic pole portion.
A magnetizing step of passing a magnetizing current that passes through the iron core and can change the characteristics of the magnet is provided after the magnet assembling step of assembling the magnet between the claw-shaped magnetic pole portions. A method for manufacturing a rotor of a rotating electrical machine. In claim 1,
The rotor includes a fan welded to the disk portion,
A method for manufacturing a rotor of a rotating electrical machine, wherein a welding current required for welding the fan is used as a magnetizing current in the magnetizing step. In claim 1 or 2,
The method of manufacturing a rotor of a rotating electrical machine, wherein the magnetizing current has a direction in which a maximum current flows in a certain direction corresponding to the arrangement of the magnets. In claim 3,
The method for manufacturing a rotor of a rotating electrical machine, wherein the magnetizing current is a direct current. In any one of Claims 1-3,
The method for manufacturing a rotor of a rotating electrical machine, wherein the magnetizing current is 2 KA or more and 200 KA or less. In any one of Claims 1-3,
In the rotating electrical machine, the magnetizing current is caused to flow in a direction in which a polarity of the magnet disposed between the claw-shaped magnetic pole portions is the same as that of the claw-shaped magnetic pole portion facing the magnet. A method for manufacturing a rotor.

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