JP6018815B2 - Rotor and electric motor - Google Patents

Description

  The present invention relates to a rotor and an electric motor.

  2. Description of the Related Art Conventionally, as one form of motor, an IPM (Interior Permanent Magnet) motor in which a permanent magnet is embedded in a rotor core of a magnetic material constituting a rotor is known. Since this type of motor has a magnetic body (rotor core) between permanent magnets adjacent in the circumferential direction, the amount of magnetic flux that detours to the rotor core out of the amount of magnetic flux from the permanent magnet increases. Leakage flux increases. For this reason, the magnetic flux linked to the winding around which the stator is wound is reduced, and the motor characteristics are deteriorated. In view of this, various techniques have been disclosed in IPM motors in order to prevent deterioration of motor characteristics.

For example, a substantially cylindrical rotor core (rotor main body) having an internal opening and a plurality of permanent magnets arranged in a plurality of slots formed in the rotor core, the slot extending from the internal opening to the main body A technique is disclosed in which each slot is formed with an end having an area in which the slot width is increased in the vicinity of the outer periphery of the rotor core (see, for example, Patent Document 1). .
According to Patent Document 1, the leakage magnetic flux in the vicinity of the outer periphery of the rotor core can be reduced by forming an end portion having an area in which the slot width is enlarged in the vicinity of the outer periphery of the rotor core in each slot. For this reason, the magnetic flux (flux) concentration in the space | gap between a stator and a rotor can be improved, and the fall of a motor characteristic can be prevented.

JP 2004-173491 A

  However, in the above-described prior art, the leakage magnetic flux inside the rotor core in the radial direction may not be reduced. That is, each slot is opened at the internal opening, and a rotation shaft (shaft) is inserted into the internal opening. When a magnetic body is used for the rotating shaft, there is a problem that the amount of magnetic flux that detours toward the rotating shaft increases and the leakage flux increases. For this reason, it is difficult to effectively prevent a decrease in motor characteristics.

  Further, for example, when the rotating shaft and the rotor core expand and contract due to a change in the environmental temperature, the fixing force between the rotating shaft and the rotor core may be reduced, and the rotating shaft and the rotor core may be relatively rotated. In such a case, there is a problem that the relative position between the rotation shaft and the rotor core is shifted, and it is difficult to perform rotation control with high accuracy.

  Therefore, the present invention has been made in view of the above-described circumstances, and suppresses an increase in leakage magnetic flux, prevents a decrease in motor characteristics, and prevents a relative position shift between the rotating shaft and the rotor core, A rotor and an electric motor capable of performing rotation control with high accuracy are provided.

In order to solve the above problems, a rotor according to the present invention is a rotor core formed by laminating a rotating shaft having a non-magnetic body at least on its outer peripheral surface and a plurality of magnetic metal plates that are externally fixed to the rotating shaft. And a plurality of permanent magnets radially arranged in the circumferential direction along the radial direction of the rotor core, and the metal plate has a shaft hole through which the rotating shaft can be inserted, and the permanent magnet is inserted A plurality of slits formed at equal intervals in the circumferential direction and the center between the two slits adjacent in the circumferential direction, and opposed to the shaft hole with the rotation axis as a center. formed in Rutotomoni, and a pair of tongue portions which are formed so as to extend radially inward, said tongue portion is arranged in the axial direction every predetermined number of the metal plate together are disposed between each of said slits, before Anti-rotation portions for preventing relative rotation of each other are formed on the outer peripheral surface of the rotating shaft and the inner peripheral surface of the rotor core, and the radially inner end surface of the permanent magnet is in contact with the outer peripheral surface of the rotating shaft. It is contacted.

By comprising in this way, the magnetic flux amount detoured to the rotating shaft side among the magnetic flux amount from a permanent magnet can be decreased, and a motor characteristic fall can be prevented.
Further, since the rotation preventing portions for preventing relative rotation of each other are formed on the outer peripheral surface of the rotating shaft and the inner peripheral surface of the rotor core, it is possible to prevent the relative position between the rotating shaft and the rotor core from shifting. It becomes possible to perform rotation control with high accuracy.

  In the rotor according to the present invention, a plurality of protrusions are formed at equal intervals in the circumferential direction on the outer peripheral surface of the rotating shaft, and the protrusions are formed at locations corresponding to the protrusions on the inner peripheral surface of the rotor core. A concave portion capable of receiving a strip portion is formed, and a radially inner end surface of the permanent magnet is brought into contact with the convex strip portion.

  With such a configuration, a simple structure suppresses an increase in leakage magnetic flux, prevents a decrease in motor characteristics, prevents a relative position shift between the rotating shaft and the rotor core, and controls rotation with high accuracy. A rotor that can be performed can be provided.

  The rotor according to the present invention is characterized in that a plurality of recesses are formed at equal intervals in the circumferential direction on the outer peripheral surface of the rotating shaft, and the radially inner ends of the permanent magnets are inserted into these recesses.

  With such a configuration, a simple structure suppresses an increase in leakage magnetic flux, prevents a decrease in motor characteristics, prevents a relative position shift between the rotating shaft and the rotor core, and controls rotation with high accuracy. A rotor that can be performed can be provided. Further, the length of the permanent magnet in the radial direction can be set long without changing the outer diameter of the rotor core. For this reason, it becomes possible to improve a motor characteristic.

  The rotor according to the present invention is characterized in that a gap is formed at a location corresponding to the radially outer end of the permanent magnet in the rotor core.

  By comprising in this way, the magnetic flux amount which detours to the outer peripheral surface side of a rotor core among the magnetic flux amounts from a permanent magnet can be reduced, and the fall of a motor characteristic can be prevented.

  An electric motor according to the present invention includes the rotor according to any one of claims 1 to 4 and a stator formed around the rotor and wound with a winding. It is characterized by that.

  With this configuration, it is possible to control the rotation of the rotating shaft and the rotor core with high accuracy by suppressing an increase in leakage magnetic flux and preventing a decrease in motor characteristics while preventing a relative position shift between the rotating shaft and the rotor core. An electric motor can be provided.

ADVANTAGE OF THE INVENTION According to this invention, the magnetic flux amount detoured to the rotating shaft side among the magnetic flux amounts from a permanent magnet can be decreased, and the fall of a motor characteristic can be prevented.
Further, since the rotation preventing portions for preventing relative rotation of each other are formed on the outer peripheral surface of the rotating shaft and the inner peripheral surface of the rotor core, it is possible to prevent the relative position between the rotating shaft and the rotor core from shifting. It becomes possible to perform rotation control with high accuracy.

It is a block diagram of the brushless motor in the 1st reference example of this invention. It is the A section enlarged view of FIG. It is a block diagram of the brushless motor in the 2nd reference example of this invention. It is a top view of the rotor in the 3rd reference example of the present invention. It is a top view of the rotor in the 4th reference example of the present invention. It is sectional drawing which follows the BB line of FIG. It is a top view of the rotor in the 5th reference example of the present invention. It is a top view of the rotor in the 6th reference example of the present invention. It is a top view of the rotor in the 7th reference example of the present invention. It is a top view of the rotor in the 8th reference example of the present invention. It is a perspective view of the rotor core in the 9th reference example of this invention. It is the C section enlarged view of FIG.

(First Reference Example )
(Brushless motor)
Next, a first reference example of the present invention will be described with reference to FIGS.
FIG. 1 is a configuration diagram of a brushless motor, and FIG. 2 is an enlarged view of a portion A in FIG.
As shown in FIGS. 1 and 2, the brushless motor 1 is a so-called inner rotor, and includes a stator 2 and a rotor 3 that is rotatably arranged on the radial inner side of the stator 2.

The stator 2 includes a substantially cylindrical stator housing 11 and a substantially cylindrical stator core 12 that is fitted and fixed to the stator housing 11.
The stator core 12 has an annular core body 15 that forms an outer peripheral portion, and the outer peripheral surface of the core main body 15 is fixed to the inner peripheral surface of the stator housing 11 by shrink fitting or the like. The core body 15 is a part that forms an annular magnetic path of the stator core 12.

A plurality (12 in this reference example ) of teeth portions 14 project from the core body 15 at equal intervals in the circumferential direction toward the inner side in the radial direction. Each tooth part 14 is formed in a substantially T shape in a plan view in the axial direction, and a winding 16 is wound around an insulator (not shown). A dovetail slot 17 is formed between the teeth 14 adjacent in the circumferential direction so as to extend in the axial direction, and the winding 16 is inserted into the slot 17.

A terminal portion of the wound winding 16 is electrically connected to an external power source via a substrate (not shown), and current is supplied to the coil.
The stator core 12 may be configured by joining a plurality of core units each having a tooth portion 14 divided in the circumferential direction, or may be integrally formed without being divided in the circumferential direction.

(Rotor)
The rotor 3 has a rotating shaft 21 formed of a nonmagnetic material such as an aluminum sintered material, for example. Splines 22 are formed on the outer peripheral surface of the rotating shaft 21 at locations corresponding to the stator core 12. The spline 22 is formed by arranging a plurality of protrusions 22a extending along the axial direction at equal intervals in the circumferential direction. That is, the outer peripheral surface of the rotating shaft 21 is alternately formed with protrusions 22a extending along the axial direction at positions corresponding to the stator core 12 and recesses 22b extending between the protrusions 22a and extending in the axial direction. It is in the state formed.

A rotor core 23 made of a magnetic material is fitted and fixed to a portion of the rotating shaft 21 where the spline 22 is formed. The rotor core 23 is formed by laminating a plurality of metal plates 6 made of magnetic material into a cylindrical shape, and a shaft hole 24 into which the rotary shaft 21 can be press-fitted is formed at the center in the radial direction. Further, slits 25 are formed in the rotor core 23 at positions corresponding to the ridges 22a of the rotating shaft 21, respectively.
The slit 25 is formed so as to extend along the radial direction from the shaft hole 24 to a position slightly ahead of the outer peripheral surface 23 a of the rotor core 23. A slit 25 is formed over the entire axial direction of the rotor core 23.

  Thereby, the rotor core 23 is formed with a thin portion 23 b at the radially outer end of the slit 25. On the other hand, the shaft holes 24 of the rotor core 23 are alternately formed with slits 25 and ridges 26 formed between the slits 25 and extending in the axial direction. Then, the ridges 26 of the rotor core 23 are fitted into the recesses 22b of the rotating shaft 21.

As a result, relative rotation between the rotating shaft 21 and the rotor core 23 is reliably prevented. That is, the spline 22 of the rotating shaft 21, the slit 25 of the rotor core 23 formed so as to correspond to the spline 22, and the ridge portion 26 are rotated to prevent relative rotation between the rotating shaft 21 and the rotor core 23. It functions as the stopper 5.
Here, the circumferential width W1 of the slit 25 and the circumferential width W2 of the convex portion 22a of the rotating shaft 21 are set substantially the same, and the rotor core 23 is fitted and fixed to the rotating shaft 21. Then, the slit 25 and the ridge 22a are flush with each other.

A permanent magnet 27 is inserted into the slit 25 of the rotor core 23. The permanent magnet 27 is formed in a flat plate shape so as to correspond to the space surrounded by the slit 25 of the rotor core 23 and the protruding strip portion 22a of the rotating shaft 21, and has a thickness direction (the circumferential direction of the rotor core 23). ) Different magnetic poles are magnetized on both sides. And the permanent magnet 27 is arrange | positioned in the slit 25 without gap, and it adheres in the slit 25 with the adhesive agent not shown. In addition, the radially inner end surface 27 a of the permanent magnet 27 is in contact with the protruding strip portion 22 a of the rotating shaft 21.
Under such a configuration, the rotor core 23 is formed with a magnetic flux interlinked with the winding 16 wound around the stator core 12.

Here, at both ends in the radial direction of each permanent magnet 27, the magnetic flux tends to wrap around from one surface in the thickness direction to the other surface in the thickness direction (see arrow Y1 in FIG. 2). However, since only the thin portion 23b is formed between the radially outer end of the permanent magnet 27 and the outer peripheral surface 23a of the rotor core 23, the magnetic flux hardly wraps around.
On the other hand, the radially inner end surface 27a of the permanent magnet 27 is in contact with the rotary shaft 21 made of a nonmagnetic material, and the magnetic path is cut off. For this reason, wraparound of the magnetic flux from one surface in the thickness direction of the permanent magnet 27 to the other surface in the thickness direction is prevented.

(effect)
Therefore, according to the first reference example described above, the amount of magnetic flux that detours toward the rotor core 23 out of the amount of magnetic flux from the permanent magnet 27 can be reduced. In particular, the radial inner end surface 27a of the permanent magnet 27 is in contact with the rotating shaft 21 made of a non-magnetic material, so that the magnetic flux can be reliably prevented from wrapping around. For this reason, the deterioration of the motor characteristics of the brushless motor 1 can be prevented.

  In addition, the spline 22 is formed on the outer peripheral surface of the rotating shaft 21, that is, the ridge 22a and the recess 22b are formed, while the slit 25 fitted into the ridge 22a or the recess 22b in the shaft hole 24 of the rotor core 23. Since the ridges 26 are formed, these can function as the rotation stoppers 5 for preventing relative rotation between the rotating shaft 21 and the rotor core 23. For this reason, it is possible to prevent the relative position between the rotating shaft 21 and the rotor core 23 from being shifted with a simple structure, and to perform rotation control with high accuracy.

(Second reference example )
Next, a second reference example of the present invention will be described with reference to FIG.
FIG. 3 is a configuration diagram of the brushless motor in the second reference example . Note that the same reference numerals are given to the same aspects as the first reference example (the same applies to the following reference examples and embodiments).
In the second reference example , the brushless motor 101 is a so-called inner rotor, and includes a stator 2 and a rotor 103 that is rotatably arranged on the radial inner side of the stator 2. The rotor 103 includes a rotating shaft 21 and a rotor core 23 that is externally fixed to the rotating shaft 21. The rotor core includes a stator core 12 having a plurality of teeth portions 14 projecting inward in the direction. 23, a flat permanent magnet 27 is inserted into a plurality of slits 25 that are formed radially so as to communicate with the shaft hole 24, and the radially inner end face 27a of the permanent magnet 27 is a rotational axis. The basic configuration such as the point of contact with the head 21 is the same as that of the first reference example described above (the same applies to the following reference examples and embodiments).

Here, as shown in FIG. 3, the difference between the second reference example and the first reference example is that the permanent magnet 27 is disposed in the slit 25 of the rotor core 23 of the first reference example without any gap. The gaps K1 and K2 are formed between the slit 25 and the permanent magnet 27 of the rotor core 23 of the second reference example .
In other words, the radially inner end surface 27 a of the permanent magnet 27 is in contact with the ridge 22 a of the rotating shaft 21, while the gap K 1 is formed between the radially outer end surface 27 b of the permanent magnet 27 and the slit 25. Is formed. Further, a gap K <b> 2 is formed between the thickness direction surface 27 c of the permanent magnet 27 and the slit 25.

The permanent magnet 27 arranged in this manner is fixed to the rotor core 23 by filling an adhesive (not shown) with the slit 25. The adhesive may be applied to the bonding surface of the permanent magnet 27, while the gaps K1 and K2 may be filled with resin or the like.
Under such a configuration, the magnetic path on the radially outer end face 27b side of the permanent magnet 27 is cut off by the gap K1. Further, the magnetic path on the surface 27c side in the thickness direction of the permanent magnet 27 is cut off by the gap K2.

Therefore, according to the second reference example described above, in addition to the same effects as those of the first reference example described above, the leakage magnetic flux can be more reliably reduced, so that the motor characteristics of the brushless motor 101 can be further improved. .

(Third reference example )
Next, a third reference example of the present invention will be described with reference to FIG.
FIG. 4 is a plan view of the rotor in the third reference example .
The difference between the third reference example and the first reference example is that the shape of the rotor 203 of the third reference example is different from the shape of the rotor 3 of the first reference example .
More specifically, as shown in FIG. 4, on the outer peripheral surface of the rotation shaft 221 of the third reference example, a protruding strip portion 222 a extending along the axial direction at a position corresponding to the stator core 12, and each protruding strip. Recesses 222b formed between the portions 222a and extending in the axial direction are alternately formed. The shapes of the ridges 222a and the recesses 222b are different from those of the first reference example .

Here, the circumferential width W3 of the convex portion 222a of the rotating shaft 221 is set wider than the circumferential width W1 of the slit 25 of the rotor core 223.
On the other hand, the shape of the shaft hole 224 of the rotor core 223 is formed to correspond to the shape of the rotation shaft 221. That is, the shaft hole 224 of the rotor core 223 is formed with slits 25 and convex portions 226 that are formed between the slits 25 and extend in the axial direction, and the rotor core 223 is externally fixed to the rotating shaft 221. The

Therefore, according to the third reference example described above, the circumferential width W3 of the convex portion 222a of the rotating shaft 221 is set wider than the circumferential width W1 of the slit 25. The wraparound of the magnetic flux in the direction inner end surface 27a can be reliably suppressed.

In the first and second reference examples described above, a case where twelve plate-like permanent magnets 27 along the radial direction are arranged on the rotor core 23 will be described. In the third reference example , the rotor cores 223 to 823 are described. In the above, a case where six flat permanent magnets 27 along the radial direction are arranged has been described. However, the present invention is not limited to this, and the number of permanent magnets 27 can be set arbitrarily. In this case, the shape of the rotating shaft 221 and the shape of the rotor core 223 may be changed according to the number of permanent magnets 27 (the same applies to the following reference examples and embodiments).
That is, for example, in the third reference example , the number of ridges 222 a of the rotating shaft 221 may be set according to the number of permanent magnets 27.

(4th reference example )
Next, a fourth reference example of the present invention will be described with reference to FIGS.
FIG. 5 is a plan view of the rotor in the fourth reference example , and FIG. 6 is a cross-sectional view taken along the line BB in FIG.
The difference between the fourth reference example and the third reference example is that the rotary shaft 321 of the fourth reference example has a double structure of a shaft main body 305 and a rib portion 306 that is externally fixed to the shaft main body 305. In contrast to this, in the third reference example , the rotating shaft 221 is not configured in a double structure.

Here, as shown in FIG. 5, the shaft body 305 is formed of a magnetic material such as iron. The shaft main body 305 has a diameter-expanded portion 305a where the diameter corresponding to the stator core 12 is the largest, and both ends in the axial direction are reduced in diameter by steps. A cylindrical rib portion 306 is fitted and fixed to the largest diameter portion 305a. The rib portion 306 is formed of a nonmagnetic material such as an aluminum sintered material, and its outer peripheral surface is formed in the same shape as the outer peripheral surface of the rotating shaft 221 in the third reference example described above. Yes. For this reason, description about the outer peripheral surface shape of the rib part 306 is abbreviate | omitted.

Therefore, according to the above-described fourth reference example , the same effects as in the above-described third reference example can be achieved. In addition to this, the rotating shaft 321 has a double structure of the shaft main body 305 and the rib portion 306, thereby suppressing the wraparound of the magnetic flux on the radially inner end surface 27 a of the permanent magnet 27, and the rotation shaft 321. Stiffness can be increased.

(5th reference example )
Next, a fifth reference example of the present invention will be described with reference to FIG.
FIG. 7 is a plan view of the rotor in the fifth reference example .
The difference between the fifth reference example and the first reference example described above is that the positions of the ridges 422a and the recesses 422b formed on the outer peripheral surface of the rotating shaft 421 of the rotor 403 in the fifth reference example are as follows. It is in the point which is reverse to the position of the protruding item | line part 22a formed in the outer peripheral surface of the rotating shaft 21 of 1 reference example , and the recessed part 22b.

That is, as shown in FIG. 7, concave portions 422 b are formed on the outer peripheral surface of the rotation shaft 421 of the fifth reference example at locations corresponding to the plurality of slits 425 formed radially on the rotor core 423. And the protruding item | line part 422a is formed between each recessed part 422b.
Further, the groove width W4 of the recess 422b is set to be substantially the same as the circumferential width W5 of the slit 425. For this reason, the slit 425 and the recess 422b are flush with each other in a state where the rotor core 423 is externally fixed to the rotating shaft 421.

  Under such a configuration, a substantially flat permanent magnet 427 is inserted in a space surrounded by the slit 425 of the rotor core 423 and the concave portion 422b of the rotating shaft 421, and is fixed by an adhesive (not shown). The In other words, the radially inner end surface 427 a of the permanent magnet 427 is inserted into the recess 422 b of the rotating shaft 421.

Therefore, according to the above-described fifth reference example , the same effects as those of the above-described first reference example can be achieved. In addition, since the permanent magnet 427 extends in the radial direction until reaching the recess 422b of the rotating shaft 421, a large cross-sectional area of the permanent magnet 427 can be ensured. As a result, the motor characteristics can be further improved.

(Sixth reference example )
Next, a sixth reference example of the present invention will be described with reference to FIG.
FIG. 8 is a plan view of the rotor in the sixth reference example .
The difference between the sixth reference example and the first reference example described above is that the shape of the protrusions 522a and the recesses 522b formed on the outer peripheral surface of the rotation shaft 521 of the rotor 503 in the sixth reference example is This is in the point different from the shape of the convex portion 22a and the concave portion 22b formed on the outer peripheral surface of the rotating shaft 21 of one reference example .

  That is, as shown in FIG. 8, the protrusion 522 a of the rotating shaft 521 is formed in a substantially dovetail cross section. For this reason, the recessed part 522b formed between each protruding item | line part 522a is also formed in cross-sectional substantially dovetail shape. On the other hand, the radially inner opening of the slit 525 formed in the rotor core 523 is also formed in a dovetail shape so as to correspond to the ridge 522a.

(Seventh reference example )
Next, a seventh reference example of the present invention will be described with reference to FIG.
FIG. 9 is a plan view of the rotor in the seventh reference example .
The difference between the seventh reference example and the first reference example is that the shape of the rotor 603 of the seventh reference example is different from the shape of the rotor 3 of the first reference example .
More specifically, as shown in FIG. 9, the rotation shaft 621 of the seventh reference example is formed in a substantially hexagonal cross section. On the other hand, the shaft hole 624 of the rotor core 623 of the seventh reference example is also formed in a substantially hexagonal cross section so as to correspond to the shape of the rotating shaft 621.

The rotating shaft 621 is formed so that the apex portion 621 a of the outer peripheral surface is located between the slit 25 and the slit 25 formed in the rotor core 623. As a result, the radially inner end surface 27 a of the permanent magnet 27 comes into contact with the flat portion 621 b on the outer peripheral surface of the rotating shaft 621.
Under such a configuration, the substantially hexagonal cross section of the rotation shaft 621 functions as a rotation preventing portion 605 that prevents relative rotation between the rotation shaft 621 and the rotor core 623.

Therefore, according to the seventh reference example described above, in addition to the same effects as those of the first reference example described above, it is not necessary to form the outer peripheral surface of the rotating shaft 621 in an uneven shape, so that the rotating shaft 621 and the rotor core 623 Stiffness can be increased.
The shape of the rotating shaft 621 is not limited to a substantially hexagonal cross section, and may be a polygonal shape so as to function as the rotation preventing portion 605. Further, it may be formed so that the radial inner end surface 27a of the permanent magnet 27 can come into contact with the flat portion 621b of the rotating shaft 621.

(Eighth reference example )
Next, an eighth reference example of the present invention will be described with reference to FIG.
FIG. 10 is a plan view of the rotor in the eighth reference example .
As shown in the figure, the difference between the eighth reference example and the first reference example is that the rotary shaft 721 of the rotor 703 in the eighth reference example is formed with three key grooves 721a on the outer peripheral surface. On the other hand, the spline 22 is formed on the outer peripheral surface of the rotary shaft 21 of the first reference example . Each key groove 721a is arranged at three positions at equal intervals in the circumferential direction so as to avoid a position corresponding to the slit 25 formed in the rotor core 723.

Therefore, according to the above-mentioned eighth reference example , in addition to the same effects as those of the above-described first reference example , the machining cost can be reduced compared to the rotating shaft 21 of the first reference example .

(Implementation form)
The following will describe a implementation form of the invention 11, in FIG. 12.
Figure 11 is a perspective view of the rotor core in the implementation form, FIG. 12 is a C part enlarged view of FIG. 11.
Differences of this implementation embodiment and the third reference example, a plurality of metal plates 806 constituting the rotor core 823 in the implementation form, a plurality of metal plates 206 constituting the rotor core 223 in the third reference example (see FIG. 4 ) And the shape is different.

That is, as shown in FIG. 11, FIG. 12, a rotor core 823 of the rotor 803 in the implementation form, is formed by a so-called rotating stack stacked while the metal plate 806 comprising a plurality of magnetic material is rotated by 60 ° Yes.
The metal plate 806 is formed in a substantially disc shape, and a shaft hole 824 into which the rotary shaft 221 can be press-fitted is formed at the center in the radial direction. The shaft hole 824 is formed with a pair of tongue pieces 824a and 824a extending radially inward so as to face each other about the rotation axis O.

  Further, six slits 825 are formed in the metal plate 806 so as to extend along the radial direction from the shaft hole 524 to a position slightly ahead of the outer peripheral surface 806a of the metal plate 806. The slits 825 are formed at equal intervals in the circumferential direction and so that the tongue pieces 824a are located at the centers of the adjacent slits 825.

  When the metal plates 806 configured in this manner are stacked while being rotated by 60 °, the tongue pieces 824a are arranged in the axial direction between the slits 825 every two of the metal plates 806. Become. The plurality of tongue pieces 824a arranged side by side in the axial direction form a ridge portion 826 to be inserted into the recess 222b (see FIG. 4) of the rotation shaft 221.

Therefore, according to the implementation described above, the pair of tongue portions 824a, since the metal plate 806 having 824a is rotated stacked to form a rotor core 823, is lighter compared to the rotor core 223 in the third reference example be able to.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
For example, in the first reference example described above, the case where the twelve tooth portions 14 are protruded from the core body 15 of the stator core 12 is not limited to this, and the number of the tooth portions 14 is not limited thereto. It is possible to set arbitrarily.

1,101 Brushless motor (electric motor)
2 Stator 3, 203, 303, 403, 503, 603, 703, 803 Rotor 5, 605 Non-rotating portion 21, 221, 321, 421, 521, 621, 721 Rotating shaft 22 Spline 22a, 222a, 422a, 522a Projection Part 22b, 222b, 422b, 522b recess 23, 223, 323, 423, 523, 623, 723, 823 rotor core
25,825 Slit 26 Projection 27,427 Permanent magnet 27a, 427a Radial inner end surface 721a Key groove 806 Metal plate 824 Shaft hole 824a Tongue piece K1, K2 Gap

Claims (5)

At least the outer peripheral surface of the non-magnetic rotating shaft,
A rotor core formed by laminating a plurality of metal plates made of a magnetic material, and fitted and fixed to the rotary shaft;
A plurality of permanent magnets arranged radially along the circumferential direction of the rotor core and in the circumferential direction,
The metal plate is
A shaft hole through which the rotating shaft can be inserted;
A plurality of slits formed by inserting the permanent magnets at equal intervals in the circumferential direction;
So as to be positioned at the center between two of said slits adjacent to each other in the circumferential direction, it is formed and so as to face each other with respect to the rotary shaft in the shaft hole Rutotomoni, to extend radially inward A pair of tongue pieces formed on
The tongue pieces are arranged in the axial direction for every predetermined number of the metal plates, and are arranged between the slits,
On the outer peripheral surface of the rotating shaft and the inner peripheral surface of the rotor core, a rotation preventing portion for preventing mutual relative rotation is formed,
A rotor characterized in that a radially inner end surface of the permanent magnet is in contact with an outer peripheral surface of the rotating shaft. A plurality of ridges are formed at equal intervals in the circumferential direction on the outer peripheral surface of the rotating shaft, and the ridges can receive the ridges at locations corresponding to the ridges on the inner peripheral surface of the rotor core. Form the
2. The rotor according to claim 1, wherein a radial inner end surface of the permanent magnet is brought into contact with the ridge portion.   2. The rotor according to claim 1, wherein a plurality of recesses are formed at equal intervals in the circumferential direction on the outer peripheral surface of the rotating shaft, and a radially inner end of the permanent magnet is inserted into these recesses.   The rotor according to any one of claims 1 to 3, wherein a gap is formed at a location corresponding to the radially outer end of the permanent magnet in the rotor core. The rotor according to any one of claims 1 to 4,
An electric motor comprising: a stator formed so as to surround the periphery of the rotor and wound with a winding.

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