JP6380640B2 - Rotating electric machine and manufacturing method thereof - Google Patents

Description

The present invention relates to a rotor in which a plurality of permanent magnets are embedded in a rotor core and a method for manufacturing the same, and more particularly to a technique for correcting the rotational balance (rotational direction uniformity) of the rotor.

As techniques for correcting the rotational balance of the rotor, (i) a drill correction method (removal processing method) for forming a drill hole in a part of the rotor, and (ii) a putty correction method for adding putty to a part of the rotor (weight addition) Law).

The above technique (i) (drill correction method) has the following problems.
-A rotation balance correction process is required in which a drill hole is formed in a rotor once manufactured (a rotor having a permanent magnet fixed).
・ After drill holes are formed, it is necessary to perform cleaning to remove shavings.
・ It is necessary to dry after washing.
・ There is a concern that the rotor may rust due to cleaning.
-It is necessary to secure parts such as end plates for drilling holes.

On the other hand, the above technique (ii) (putty correction method) has the following problems.
・ A rotation balance correction process is required to add putty to the rotor once manufactured (rotor with a permanent magnet fixed).
-A heating process is required to cure the putty.
-Adding a putty (resin) to the inner diameter, outer diameter or axial end face of the rotor increases the rotor dimensions.
・ Use of putty (resin) increases the number of materials, which increases costs.

US Patent Application Publication No. 2012/0139378

The present invention has been made in view of the above problems, its object is to provide a rotor and a manufacturing method thereof can be corrected rotational balance of the "rotor embedded a plurality of permanent magnets in the rotor core."

According to the present invention (the rotor and the manufacturing method thereof), the rotor (1) is obtained by changing the “amount of resin (α) used when fixing the plurality of permanent magnets (4) to the rotor core (3)” in the rotation direction. The rotation balance is corrected.
According to the present invention, the rotational balance of the “rotor (1) having a plurality of permanent magnets (4) embedded in the rotor core (3)” can be finely corrected.

Specifically, since a plurality of magnet holes are provided in the circumferential direction, it is possible to increase the variety of selection of the magnet hole positions to which the resin is applied. Furthermore, since a plurality of surplus spaces β are formed in the magnet holes, the diversity of selection of the surplus spaces β for applying resin in the magnet holes can be increased. Since the vacant space is provided in the surplus space β when viewed from the axial direction with the imparting portion, the diversity of selection of the location of the imparting portion in the surplus space β can be increased. Therefore, in the balance correction method in the resin application to the magnet hole where the number of rotation balance correction points is finite, the rotation unbalance correction amount determined by the position of the application part and the empty space and the weight of the resin in the application part can be set finely.

It is explanatory drawing of the provision condition of resin amount. It is explanatory drawing which dripping resin to a magnet hole. It is explanatory drawing of the location which implements balance correction by increase / decrease in resin amount. It is explanatory drawing which shows the relationship between the resin amount and the balance correction amount. It is a comparison figure of the manufacturing process of an Example, and the manufacturing process of the prior arts 1 and 2. FIG. It is explanatory drawing of a rotor core. It is explanatory drawing of the adhesive force by resin. It is explanatory drawing of the shape of another magnet hole. It is explanatory drawing which provided the resin injection | pouring part in the other magnet hole.

[Description of Embodiments] [Mode for carrying out the invention] will be described below with reference to the drawings.

A specific example (example) of the present invention will be described with reference to the drawings. It should be noted that the following examples are merely examples, and the present invention is not limited to the examples.

[Example 1]
Embodiment 1 will be described with reference to FIGS.
The rotating electrical machine of this embodiment is a motor generator mounted on a vehicle, and operates as an electric motor that generates power for driving the vehicle and power for starting the engine, and generates a generator by receiving rotational torque. Also works.
This rotating electrical machine includes a stator (stator) and a rotor (rotor) 1 as in the case of ordinary electric motors and generators.

The stator is not limited in configuration, and adopts, for example, a well-known structure, and a stator core that is fixedly supported directly or indirectly to the vehicle, and a plurality of phases that are wound around the slots of the stator core. (U, V, W phase, etc.) stator coils.

The rotor 1 is an embedded magnet type (IPM type), and includes a rotating shaft (shaft) 2 that is rotatably supported at the center of the stator, a rotor core 3 coupled to the rotating shaft 2, and embedded in the rotor core 3. A plurality of permanent magnets 4 to be fixed are provided.
The rotor core 3 is provided by laminating a large number of ring disk-shaped electromagnetic steel plates (soft iron plate, silicon steel plate, amorphous metal plate, etc.) having an insulating film formed on the surface thereof.

The rotor core 3 is provided with a plurality of magnet holes (core slots) 5 independently for embedding a plurality of permanent magnets 4 in the circumferential direction.
Each magnet hole 5 is a through hole penetrating in the axial direction in the rotor core 3, and the permanent magnet 4 is inserted therein, and the inserted permanent magnet 4 is fixed to the rotor core 3 by a resin (adhesive) α.

The permanent magnet 4 has substantially the same length as the axial dimension of the rotor core 3 (the axial dimension of the magnet hole 5 in the rotor core 3), and has a plate shape that can be inserted into the magnet hole 5. The permanent magnet 4 employs a rare earth magnet (for example, a neodymium magnet). Of course, the type of the permanent magnet 4 is not limited to the rare earth magnet, and is appropriately selected according to the purpose of use, the temperature rise state, the cost, etc., such as a ferrite magnet and an alnico magnet.

As an example, each permanent magnet 4 is arranged in a V shape when the rotor core 3 is viewed from the axial direction. The V-shaped magnet arrangement structure is a V-shape formed by two permanent magnets 4. When the 4-pole rotor 1 is formed, four permanent magnets 4 are used to form four V-shapes. When creating the 6-pole rotor 1, 6 V-shapes are formed using 12 permanent magnets 4. When creating the 8-pole rotor 1, 8 V-shapes are formed using 16 permanent magnets 4. Is formed. Of course, the arrangement structure of the permanent magnets 4 is not limited to the V shape, and various arrangements such as a single character shape can be applied.

The resin α (adhesive for fixing the permanent magnet 4 to the rotor core 3) of this embodiment is a non-magnetic resin, has an appropriate viscosity during the manufacturing process, and exhibits a strong adhesive force and high durability after curing. Use epoxy resin. Of course, the type of the resin α is not limited, and can be appropriately selected according to the purpose of use, such as polypropylene, polyethylene naphthalate, polyphenylene sulfide, and polyimide. Of course, a resin α containing a filler may be used for the purpose of enhancing heat dissipation or increasing strength.

As described above, the plurality of permanent magnets 4 are inserted into the plurality of magnet holes 5 formed in the circumferential direction in the rotor core 3 and fixed to the rotor core 3 by the resin α.
In the rotor 1, the rotation balance is corrected by having different distributions of the resin amount given to the plurality of magnet holes 5 in each of the “circumferential direction of the rotor core 3” and the “axial direction of the rotor core 3”. Yes.
1 shows an example of a specific difference in the amount of resin applied to the magnet hole 5, and FIGS. 1A and 1B are examples of a case where the amount of resin applied to the magnet hole 5 is small. The resin application portion is formed to include both a part of the short side of the permanent magnet and a part of the curve that closes in contact with two parallel sides of the magnet hole. On the other hand, the empty space excluding the resin application portion is formed to include a part of the short side of the permanent magnet and a part of the curve that closes in contact with two parallel sides of the magnet hole.
FIGS. 1C and 1D are examples when the amount of resin applied to the magnet hole is large, and FIG. 1E shows the case where the amount of resin applied to the magnet hole is maximum.

The correction of the rotational balance due to the difference in the resin amount includes the “adhesion step of fixing the permanent magnet 4 to the rotor core 3 using the resin α” and the “resin amount applied to the plurality of magnet holes 5 in the circumferential direction and the axial direction”. A balance correction step of correcting the rotational balance by having different distributions in both ”is performed simultaneously, and a specific example in which the resin α is dropped into the magnet hole 5 is shown in FIG.

The “location where the rotational balance of the rotor 1 is corrected by the amount of resin” is performed at the location indicated by the range A in FIG. 3 (both sides in the axial direction of the rotor core 3). Thereby, the dynamic imbalance in the axial direction is corrected by the resin amount.
Here, the relationship between the resin amount and the balance correction amount will be described with reference to FIG. When the amount of resin applied to one magnet hole 5 is changed, as shown in FIG. 4, the correction amount of the rotation balance changes according to the increase or decrease of the resin amount. For this reason, in this embodiment, the rotational balance is corrected by the difference in the amount of resin applied to each of the plurality of magnet holes 5.

The manufacturing process of the rotor 1 is compared between “Prior Art 1 (Drill Correction Method)”, “Prior Art 2 (Putty Correction Method)”, and “Example 1”.
First, the manufacturing process of “Prior Art 1 (Drill Correction Method)” will be described with reference to FIG. Step S1: The permanent magnet 4 before magnetization is assembled in each magnet hole 5 formed in the rotor core 3.
Step S2: The rotary shaft 2 is press-fitted into the center of the rotor core 3.
Step S3: Resin α is dropped into each magnet hole 5 and the permanent magnet 4 is adhered and fixed to the rotor core 3.
Step S4: The rotor 1 to which the permanent magnet 4 is fixed is rotated, and the rotational balance of the uncorrected rotor 1 is measured.
Step S5: A drill hole is formed in the rotor 1 to correct the rotation imbalance based on the measurement result (execution of the correction process using the drill hole).
Step S6: Perform cleaning to remove shaving residue (execution of cleaning process).
Step S7: Drying is performed to remove the cleaning liquid from the rotor 1 (execution of the drying process).
Step S8: The rotor 1 whose rotational balance is corrected by the drill hole is rotated, and it is inspected that the rotational balance is within a specified range.
Step S9: The permanent magnet 4 is magnetized.

As described above, in the manufacturing process of the rotor 1 according to “Prior art 1 (drill correction method)”, as shown in steps S5 to S7 above, a correction process using a drill hole, a cleaning process, and a drying process are required. There is a problem that costs increase due to an increase in man-hours. Moreover, it leads to the increase in the parts which provide a drill hole, such as an end plate (refer "background art" mentioned above).

Next, the manufacturing process of “Prior Art 2 (Putty Correction Method)” will be described with reference to FIG.
Step S1: The permanent magnet 4 before magnetization is assembled in each magnet hole 5 formed in the rotor core 3.
Step S2: The rotary shaft 2 is press-fitted into the center of the rotor core 3.
Step S3: Resin α is dropped into each magnet hole 5 and the permanent magnet 4 is adhered and fixed to the rotor core 3.
Step S4: The rotor 1 to which the permanent magnet 4 is fixed is rotated, and the rotational balance of the uncorrected rotor 1 is measured.
Step S5: Putty is applied to the rotor 1 in order to correct the rotation imbalance based on the measurement result (execution of correction process using putty).
Step S6: A heat treatment for curing the putty is performed (implementing a heating step).
Step S7: The rotor 1 is cooled (implementation of a cooling process).
Step S8: The rotor 1 whose rotational balance is corrected by the putty is rotated to check that the rotational balance is within a specified range.
Step S9: The permanent magnet 4 is magnetized.

Thus, in the manufacturing process of the rotor 1 according to “Prior art 2 (putty correction method)”, as shown in steps S5 to S7, the correction process by applying putty, the heating process, and the cooling process are necessary. There is a problem that costs increase due to an increase in man-hours. Moreover, since the addition of putty is required, there are problems that the number of materials increases and the size of the rotor becomes large (refer to “Background Art” described above).

Next, the manufacturing process of “Example 1” will be described with reference to FIG.
Step S1: The permanent magnet 4 before magnetization is assembled in each magnet hole 5 formed in the rotor core 3.
Step S2: The rotary shaft 2 is press-fitted into the center of the rotor core 3.
Step S3: The rotor 1 to which the permanent magnet 4 is assembled is rotated, and the rotational balance of the uncorrected rotor 1 is measured.
Step S <b> 4: Resin α is dropped into each magnet hole 5 and the permanent magnet 4 is bonded and fixed to the rotor core 3. At this time, the rotational balance of the rotor 1 is corrected by increasing or decreasing the amount of resin applied to each of the plurality of magnet holes 5 in order to correct the rotational balance based on the measurement result of step S3. That is, the permanent magnet 4 adhesion step and the balance correction step are performed simultaneously. Of course, the resin amount (increase / decrease amount of the balance correction resin) to be given to each magnet hole 5 is obtained by feedforward from the measurement result of the rotation balance of the uncorrected rotor 1.
Step S5: The rotor 1 whose rotational balance is corrected by the difference in the resin amount is rotated, and it is inspected that the rotational balance is within a specified range.
Step S6: The permanent magnet 4 is magnetized.

(Effect 1 of Example 1)
As described above, the rotor 1 of the first embodiment changes the “amount of resin α used when the permanent magnet 4 is fixed to the rotor core 3” between the rotation direction and the axial direction, thereby changing the “rotation balance of the rotor 1. The correction is performed, and the “permanent magnet 4 adhesion step” and the “rotation balance correction step” are performed simultaneously.
For this reason, the rotational balance of the “rotor 1 in which a plurality of permanent magnets 4 are embedded in the rotor core 3” can be corrected with a smaller number of processes than in the prior art. Thereby, the productivity of the rotor 1 can be increased, and as a result, the cost of the rotating electrical machine can be suppressed.

(Effect 2 of Example 1)
In each magnet hole 5 formed in the rotor core 3, in addition to the magnet space occupied by the permanent magnet 4, an extra space β capable of adjusting the amount of resin is provided at the end. As a specific example, the rotor core 3 of this embodiment is provided with a magnetic barrier on the inner diameter side of the magnet hole 5, and this magnetic barrier is shared as an extra space β for adjusting the amount of resin.
As described above, the rotor core 3 of this embodiment includes the excess space β for adjusting the resin amount, thereby increasing or decreasing the resin amount (correcting the rotational balance due to the difference in the resin amount in the circumferential direction). Can do.

(Effect 3 of Example 1)
In this embodiment, as described above, the “location where the rotational balance of the rotor 1 is corrected by the amount of resin” is performed at the end of the rotor core 3 in the axial direction. Thereby, the dynamic imbalance in the axial direction can be corrected with the minimum amount of resin required. That is, when it is desired to intensively correct the dynamic imbalance, the amount of resin α used can be reduced and the yield can be suppressed, and as a result, the cost of the rotating electrical machine can be suppressed.

(Effect 4 of Example 1)
Further, when the rotor 1 has a skew structure and the rotor core 3 and the permanent magnet 4 are divided in the axial direction as shown in FIG. 6, the permanent magnet 4 located at the center in the axial direction is sandwiched between the adjacent divided cores. Take the structure. This structure increases the mechanical reliability of the permanent magnet 4 with respect to the axial omission, but there is a concern that the permanent magnets 4 arranged at both ends in the axial direction may escape in the axial direction.
Therefore, by adopting this embodiment, by giving a large amount of resin for fixing the permanent magnets 4 at both ends in the axial direction, the bonding area between the rotor core 3 and the permanent magnets 4 can be increased. It is possible to increase the mechanical reliability involved, that is, it is possible to widen the range of material design, and it is possible to select an inexpensive resin α with poor adhesion, resulting in cost reduction of the rotor 1. Can be achieved.

(Effect 5 of Example 1)
The resin α that fixes the permanent magnet 4 to the rotor core 3 is in direct contact with the metal. That is, the resin α is in direct contact with both the “metal surface of the permanent magnet 4” and the “metal surface of the rotor core 3 (substrate of the rotor core 3)”.
In this way, since the resin α and the metal (the permanent magnet 4 and the rotor core 3) are in direct contact, the adhesive force by the resin α can be strengthened. For this reason, even if rotational vibration etc. are added, the malfunction which the permanent magnet 4 peels from the rotor core 3 can be avoided. That is, the reliability of the rotating electrical machine can be improved.

(Effect 6 of Example 1)
The bonding step of bonding the permanent magnet 4 to the rotor core 3 with the resin α is performed before the permanent magnet 4 is magnetized. Thereby, “between the inner surface (inner diameter side surface) of the permanent magnet 4 and the inner surface (inner diameter side surface) of the magnet hole 5” and “the outer surface (outer diameter side surface) of the permanent magnet 4 and the outer surface of the magnet hole 5. The resin α can be applied to both of the “between (surface on the outer diameter side)”. That is, both the inner and outer surfaces of the permanent magnet 4 can be bonded to the rotor core 3 with the resin α.
Specifically, the resin α can be applied to “the entire inner surface of the permanent magnet 4” and “the entire outer surface of the permanent magnet 4”, and the adhesive force of the permanent magnet 4 by the resin α can be increased.

(Effect 7 of Example 1)
In the prior art 1 (drill correction method), a part for making a drill hole is required. However, in Example 1, a part for making a drill hole can be omitted. Moreover, since it is not necessary to provide a drill hole in the rotor 1, the mechanical reliability of the rotor 1 can be maintained.
On the other hand, in the prior art 2 (putty correction method), the number of materials increases due to putty applied to the rotor 1, but in this embodiment, another material such as putty can be made unnecessary for balance correction. Further, since putty is not added to the surface (outer peripheral surface, axial end surface, etc.) of the rotor 1, the rotor dimensions are not increased by the material for balance correction. Thereby, size reduction of a rotary electric machine is realizable.

(Supplementary explanation 1 of Example 1)
Unlike the above embodiment, the case where the “permanent magnet 4 adhesion step” and the “rotation balance correction step” are performed separately will be described.
After the “permanent magnet 4 bonding step” is performed, when the resin α is applied and the “rotation balance correcting step” is performed, the resin α used for bonding the permanent magnet 4 and the resin α used for balance correction are bonded. An interface is formed on the surface. As a result, interface peeling or the like occurs, and the adhesive strength is weakened.

As shown in FIG. 7A, this is a strong hydrogen bond with the hydroxide layer (oxide, water absorption) on the surface in the metal bonding in which the resin α is directly bonded to the metal, whereas in FIG. This is because, as shown in (b), in the adhesion between the resin α and the resin α, the adhesion between the resin α and the resin α is inferior because the intermolecular force with some electron clouds such as an aromatic ring is dominant.
On the other hand, in this embodiment, the “permanent magnet 4 adhesion step” and the “rotation balance correction step” are performed at the same time, and therefore, the permanent magnet 4 adhesion resin α and the balance correction resin α include Because of the same integrated structure without distinction, there is no problem that the balance correcting resin α is peeled off from the bonding resin α. For this reason, even if mechanical vibration is applied to the rotor 1, there is no problem that the resin α is peeled off, and the reliability of the rotating electrical machine can be improved.

(Supplementary explanation 2 of Example 1)
Unlike the above embodiment, when the “permanent magnet 4 bonding step” and the “rotation balance correction step” are performed separately, the magnet hole 5 is blocked when the resin α for bonding the permanent magnet 4 is cured. . As a result, there is no path through which the resin α necessary for correcting the rotation balance flows into the rotor core 3, and the rotation balance cannot be corrected.
In contrast, in this embodiment, since the “permanent magnet 4 bonding step” and the “rotation balance correction step” are performed simultaneously, the resin for correcting the rotation balance can be poured from the magnet hole 5.

(Supplementary explanation 3 of Example 1)
Unlike the above embodiment, when the resin α is applied after the permanent magnet 4 is magnetized, one of the inner surface and the outer surface of the permanent magnet 4 sticks to the magnet hole 5 with a magnetic force. Then, resin (alpha) is no longer provided in the meantime (bonding location by magnetic force). As a result, the adhesive area between the permanent magnet 4 and the rotor core 3 is reduced, and the adhesive force is weakened.
In contrast, in this embodiment, as described above, both the inner and outer surfaces of the permanent magnet 4 can be bonded to the rotor core 3 by the resin α, so that the adhesion of the permanent magnet 4 can be improved. Thereby, even if rotational vibration etc. are added, the malfunction which the permanent magnet 4 peels can be avoided, and the reliability of a rotary electric machine can be improved.

In the above-described embodiment, an example in which the shaft press-fitting process is performed before the magnet fixing process is shown, but the shaft press-fitting process may be performed after the magnet fixing process.

In the above-described embodiment, the “location where the rotational balance of the rotor 1 is corrected by the amount of resin” is implemented on both sides of the rotor core 3 in the axial direction, but may be implemented in the central portion in the axial direction.
In this case, it is possible to correct the static unbalance, which means the unbalance of the entire rotor, with the minimum amount of resin. That is, when the static unbalance is to be corrected in a concentrated manner, the dynamic unbalance on both sides of the rotor core 3 is corrected to concentrate on the static unbalance angle rather than to suppress the static unbalance. Can do. Thereby, the yield of the resin α used for balance correction can be suppressed, and the cost of the rotating electrical machine can be suppressed.
Furthermore, the heat of the rotor core 3 can be efficiently radiated. Specifically, the heat dissipation performance of the rotor core 3 is improved by moving the heat stored in the central portion of the rotor core 3 using heat conduction of the resin α to both axial ends of the rotor core 3 having a large contact area with air. Can be increased. As a result, since the heat resistance performance of the permanent magnet 4 can be lowered, the cost of the rotating electrical machine can be suppressed.

In the above embodiment, the example using the magnet hole 5 having the function of a magnetic barrier in which the permanent magnet 4 is arranged in a V shape has been shown. However, as shown in FIG. As shown in FIG. 9, the present invention may be applied to the rotor 1 using the magnet hole 5 having no magnetic barrier function.
8 shows an example of a specific difference in the amount of resin applied to the single-letter-shaped magnet hole 5, and FIGS. 8A and 8B show a small amount of resin applied to the magnet hole 5. FIG. 8 (c) and 8 (d) are examples when the amount of resin applied to the magnet hole is large, and FIG. 8 (e) is the case where the amount of resin applied to the magnet hole is maximum. .
FIG. 9 shows a single-letter-shaped magnet hole 5 provided with a resin injection portion γ (a hole functioning as a surplus space β in which the resin amount can be adjusted). FIG. FIG. 9B shows an example when the amount of resin applied to the magnet hole is large.

In the above embodiment, the example in which the present invention is applied to the motor generator has been described. However, the present invention may be applied to an electric motor (electric motor) that generates rotational torque by energization, and power generation is performed by the rotation of the rotor 1. You may apply this invention to the generator (generator) to perform.

In the above embodiment, the inner rotor type is shown, but the present invention may be applied to an outer rotor type.

In the above embodiment, an example in which the present invention is applied to a rotating electrical machine mounted on a vehicle has been shown. However, the present invention can be applied to other than a vehicle, and for example, a rotating electrical machine used for industrial equipment, household equipment, and the like. You may apply to.

1 rotor
3 Rotor core
4 Permanent magnet
5 Magnet hole
α resin

Claims (4)

A rotor in which a plurality of permanent magnets are embedded in a rotor core, wherein a plurality of magnet holes are formed in the circumferential direction, the permanent magnets are inserted in the center of the magnet holes, and the magnet holes occupy the permanent magnet (4). In addition, a plurality of excess spaces β are formed at the end,
A part of one surplus space β viewed from the axial direction is provided with an imparting part, and each of the imparting parts is provided with a resin that corrects the rotational balance by having a different distribution in the circumferential direction. A rotor characterized in that an empty space is formed in the remaining part of β when viewed from the axial direction. The magnet hole is formed of two sides extending in the longitudinal direction and a curve that closes in contact with the two sides, the permanent magnet has a rectangular shape, and the empty space includes a part of a short side of the permanent magnet and a magnet hole. The rotor according to claim 1, wherein the rotor is formed so as to include a part of the curve that closes in contact.   The rotor according to claim 2, wherein the resin is an adhesive, and the application portion includes both the remaining part of the short side of the permanent magnet and the part of the curve that closes in contact with the permanent magnet. A magnet hole forming step of forming a plurality of magnet holes in the circumferential direction inside the rotor core;
A surplus space forming step in which a permanent magnet is inserted into the central portion of the magnet hole obtained in the magnet hole forming step and a plurality of surplus spaces β are formed at the end in addition to the magnet space occupied by the permanent magnet (4);
A measuring step of measuring the rotational balance by rotating the rotor obtained in the press-fitting step and the press-fitting step to press the rotary shaft into the rotor core obtained in the surplus space forming step;
The measurement obtained in the measurement step so as to correct the rotation balance by having a distribution different in the circumferential direction with respect to the amount of resin applied to the applying portion which is a part of one surplus space β viewed from the axial direction. A resin amount calculation step determined from the result; and
A method for manufacturing a rotor, comprising: a resin application step in which a determined resin amount is applied to the application portion, and a free space is formed in the remaining portion of one surplus space β when viewed from the axial direction.

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