JP5917193B2 - Rotor, motor and method of manufacturing rotor - Google Patents

Description

  The present invention relates to a rotor, a motor, and a method for manufacturing the rotor.

  Conventionally, as shown in Patent Document 1, for example, a so-called continuous pole type rotor (also called a half magnet type rotor) in which a plurality of magnets are arranged in the circumferential direction of the outer peripheral surface of the rotor core and the iron core portion between the magnets functions as a pseudo magnetic pole. A motor equipped with the above has been devised. The pseudo magnetic pole functions as a magnetic pole opposite to the magnet by the magnetic action of the magnet. Thereby, the N pole and the S pole are alternately formed in the circumferential direction on the outer peripheral surface of the rotor. In such a configuration, the number of magnets can be reduced with respect to a rotor (full magnet type rotor) having the same number of magnetic poles and magnets, which is advantageous in terms of the number of parts and cost. In addition, as the number of magnets is reduced, the magnet can be easily assembled.

JP 9-327139 A

  By the way, as a method of fixing the magnet of the continuous pole type rotor, for example, adhesive fixing can be considered. However, in the case of adhesive fixing, since the adhesive material between the rotor core and the magnet becomes a magnetic resistance, there is a possibility that the way of magnetic flux will be different at each magnet magnetic pole part, which will cause the quality of the rotor and thus the motor to deteriorate. I will invite you.

  Therefore, as a fixing method that does not require an adhesive, press-fitting or caulking is considered. However, since the metal rotor core and the magnet (sintered magnet) are composed of relatively hard members, the press-fitting allowance is not large when the magnet is press-fitted and fixed to the rotor core, and fixing is difficult. Also, in the case of caulking, after inserting the magnet into the magnet housing hole formed in the rotor core, it is fixed by caulking part of the rotor core, but caulking fixing requires advanced dimensional design, and what is an easy fixing method? I can not say.

  The present invention has been made in order to solve the above-described problems, and the object thereof is to eliminate the need for an adhesive material and prevent a deterioration in quality due to the adhesive material, and to easily provide a magnet. It is providing the manufacturing method of a rotor, a motor, and a rotor.

In order to solve the above problems, the invention according to 請 Motomeko 1, together with a magnet in the circumferential direction of the rotor core are more disposed, as opposed magnetic poles and the magnet by magnetic action of the magnet between each magnet A rotor having a functioning pseudo magnetic pole, wherein each magnet is composed of a plastic magnet made of a resin material including a magnetic material, and each plastic magnet is separated from each other and has an outer periphery of the rotor core. Each plastic magnet has a radial engagement portion that engages with the rotor core in the outer radial direction on the radially inner side of each plastic magnet fixed to the outer peripheral surface of the rotor core. It is characterized by that.

In this invention, since a plastic magnet rotor magnet, it is possible to integrally mold the plastic magnet against the rotor core. Thereby, since it is not necessary to adhere and fix the plastic magnet to the rotor core, it is possible to prevent quality deterioration due to the adhesive. In addition, since the plastic magnet is integrally formed with the rotor core, the magnet fixing work is not required, so that the magnet can be easily provided.

  In addition, even when the plastic magnet is press-fitted and fixed to the rotor core, it is possible to eliminate the need for an adhesive, and to prevent deterioration in quality due to the adhesive. In addition, since the press-fitting allowance can be increased by the elasticity of the plastic magnet, the magnet can be press-fitted and fixed more easily than in the case of press-fitting a hard sintered magnet.

In addition , it is possible to suppress the plastic magnet from falling out in the radial direction by the engagement between the radial engagement portion and the rotor core.

In addition , it is possible to provide an SPM (Surface Permanent Magnet) type rotor in which a magnet can be easily provided while preventing the deterioration of quality due to the adhesive by making the adhesive unnecessary.

The invention according to claim 2 is a motor including the rotor according to claim 1 .
In this invention, it becomes possible to easily provide a magnet while preventing the deterioration of the quality due to the adhesive by eliminating the need for the adhesive, and as a result, it is possible to provide a motor of high quality and easy to manufacture. .

The invention according to claim 3, a rotor manufacturing method according to claim 1, wherein the magnets are those composed of a plastic magnet made of a resin material containing a magnetic material, wherein each plastic A magnet is integrally formed with the rotor core.

  In this invention, since it is not necessary to adhere and fix the plastic magnet to the rotor core, it is possible to prevent quality deterioration due to the adhesive. In addition, since the plastic magnet is integrally formed with the rotor core, the magnet fixing work is not required, so that the magnet can be easily provided.

  Therefore, according to the above-described invention, it is possible to easily provide the magnet while preventing the deterioration of the quality due to the adhesive by eliminating the need for the adhesive.

Sectional drawing of the motor of embodiment. (A) The top view which looked at the rotor of the same form from the axial direction one side, (b) The top view which looked at the rotor from the axial direction other side. (A) Sectional drawing of the rotor of another example, (b) The top view of the rotor. (A) Sectional drawing of the rotor of another example, (b) The top view of the rotor.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the motor 10 of the present embodiment includes an annular stator 12 supported by a motor case 11 and a rotor 13 disposed inside the stator 12. The rotating shaft 14 of the rotor 13 is supported by a pair of bearings 15 and 16 provided in the motor case 11. The stator 12 includes a substantially cylindrical stator core 17 fixed to the inner surface of the motor case 11 and a coil 18 wound around the stator core 17. When a current is supplied to the coil 18, the rotor 13 rotates according to the rotating magnetic field generated by the stator 12.

  The rotor 13 includes a rotating shaft 14 and a rotor core 21 provided on the rotating shaft 14 so as to be integrally rotatable. The rotating shaft 14 is made of a magnetic material and has a cylindrical shape. The rotor core 21 has a cylindrical shape, and a fixing hole 21a into which the rotary shaft 14 is press-fitted and fixed is formed at the center thereof. The rotor core 21 is formed by laminating a plurality of thin plate-like core sheets 21b made of a magnetic material such as metal in the axial direction of the rotary shaft 14 and integrating them.

  Four pseudo magnetic poles 22 projecting radially outward are integrally formed on the outer peripheral portion of the rotor core 21 at equal intervals in the circumferential direction (90-degree intervals). Each pseudo magnetic pole 22 is formed over the entire axial direction. The rotor core 21 is integrally formed with a resin molded member 23 made of a resin material containing magnetic powder. The resin molded member 23 is formed by insert molding using the rotor core 21 as an insert product.

  As shown in FIGS. 1 and 2A and 2B, the resin molding member 23 includes a plastic magnet 24 (hereinafter simply referred to as a magnet 24) disposed between the pseudo magnetic poles 22 in the circumferential direction, and each of the magnets 24. Are integrally provided with an annular connecting portion 25 that connects one end portion in the axial direction (the lower end portion in FIG. 1). As shown in FIG. 2B, the connecting portion 25 has an annular shape centered on the axis of the rotor core 21 (coincident with the axis of the rotary shaft 14), and one end surface in the axial direction of the rotor core 21 (lower in FIG. Side end face). Thereby, it is suppressed that the resin molding member 23 falls off to the axial direction one side (the axial direction edge part side in which the connection part 25 is not formed).

  Each of the four magnets 24 slightly protrudes radially outward from the connecting portion 25 and extends along the axial direction of the rotary shaft 14 therefrom. Each magnet 24 extends in the axial direction from one axial end to the other end of the rotor core 21. Further, the radially inner end surface 24 a of each magnet 24 is in close contact with the outer peripheral surface of the rotor core 21. That is, the rotor 13 is configured as an SPM (Surface Permanent Magnet) type rotor in which each magnet 24 is fixed to the outer peripheral surface of the rotor core 21. The connecting portion 25 that connects the magnets 24 at the end portions in the axial direction is formed radially inward from the radially inner end surface 24a of each magnet 24.

  The magnets 24 are formed at equal intervals in the circumferential direction (90 degree intervals). The magnets 24 are arranged with a gap between the pseudo magnetic poles 22 adjacent in the circumferential direction, and the magnets 24 and the pseudo magnetic poles 22 are arranged at equal intervals in the circumferential direction. That is, on the outer peripheral portion of the rotor core 21, the magnets 24 and the pseudo magnetic poles 22 are alternately arranged in the circumferential direction at equal intervals (45 degree intervals). A gap is provided between the magnet 24 and the pseudo magnetic pole 22 in the circumferential direction. In addition, the circumferential width of the magnet 24 and the circumferential width of each pseudo magnetic pole 22 are set to be substantially equal, and the outer circumferential surface of each magnet 24 and the outer circumferential surface of each pseudo magnetic pole 22 are aligned with the axis of the rotary shaft 14 when viewed from the axial direction. Located on the same circle as the center.

  In the present embodiment, each magnet 24 is magnetized so that the radially outer side is an N pole and the radially inner side is an S pole. That is, each magnet 24 functions as an N-pole magnetic pole. The pseudo magnetic pole 22 functions as an S pole by the magnetic action of the magnet 24. As a result, the magnetic poles on the outer peripheral portion of the rotor core 21 are configured so that N poles and S poles are alternately eight poles in the circumferential direction.

Next, a method for manufacturing the rotor 13 will be described together with the operation of this embodiment.
The rotor core 21 formed from a plurality of core sheets 21b is placed in a mold (not shown), and then a resin containing magnetic powder is injected into the mold. Thereby, the resin molding member 23 is integrally molded with the rotor core 21. Since this resin molding member 23 has a connecting portion 25 that connects each magnet 24 in the circumferential direction, the diameter of each magnet 24 and the outer peripheral surface of the rotor core 21 due to resin shrinkage inward in the radial direction of the connecting portion 25. Directional adhesion (integration) is improved. In particular, in the continuous pole type rotor 13 (half magnet type rotor) as in this embodiment, since the pseudo magnetic pole 22 is arranged between the magnets 24 in the circumferential direction, the connecting portion 25 becomes long. And since the amount of contraction becomes large, so that the connection part 25 is long, the integrity of the resin molding member 23 and the rotor core 21 by resin contraction is improved further.

  Next, each magnet 24 of the resin molding member 23 integrally molded with the rotor core 21 is magnetized in the radial direction. Thereafter, the rotary shaft 14 is press-fitted and fixed to the rotor core 21 to complete the rotor 13. In the rotor 13 of the present embodiment, the rotor core 21 is integrally formed with the resin molding member 23 and the integrity thereof is improved. As a result, the vibration of the rotor 13 is suppressed.

Next, characteristic effects of the present embodiment will be described.
(1) Since the plastic magnet 24 is used as the magnet of the rotor 13, the magnet 24 can be integrally formed with the rotor core 21. Thereby, since it becomes unnecessary to adhere and fix the magnet 24 to the rotor core 21, it is possible to prevent the quality from being deteriorated by the adhesive. In addition, since the magnet 24 is integrally formed with the rotor core 21, it is not necessary to fix the magnet 24, so that the magnet 24 can be easily provided. As a result, it is possible to provide a motor 10 that is high quality and easy to manufacture.

  (2) The magnet 24 integrally includes the rotor core 21 and a connecting portion 25 (axially engaging portion) that abuts in the rotational axis direction (axial direction of the rotational shaft 14). For this reason, it is possible to prevent the magnet 24 from dropping off in the axial direction by engagement (contact) between the rotor core 21 and the connecting portion 25.

  (3) A connecting portion 25 is formed integrally with the magnet 24 so as to connect the magnets 24 in the circumferential direction. Thereby, since each magnet 24 is mutually connected by the connection part 25 in the circumferential direction, it becomes possible to suppress that each magnet 24 falls out separately.

  (4) The connecting portion 25 is formed on the radially inner side than each magnet 24. That is, since each magnet 24 is integrally connected to the connecting portion 25 at its radially inner end face 24a, it is possible to make a configuration in which the magnetic poles on both sides in the radial direction of each magnet 24 are not short-circuited by the connecting portion 25. Thereby, a leakage magnetic flux can be suppressed and the fall of the effective magnetic flux (magnetic flux for generating the rotational force of the rotor 13) among the magnetic flux of each magnet 24 can be suppressed.

  (5) An integrally molded product (resin molding member 23) of each magnet 24 and the connecting portion 25 is formed on the rotor core 21 by integral molding. For this reason, the resin shrinkage of the resin molded member 23 toward the inside in the radial direction can improve the integrity of the resin molded member 23 and the rotor core 21 particularly in the radial direction.

In addition, you may change embodiment of this invention as follows.
The configuration such as the shape of the resin molded member 23 is not limited to the above embodiment, and may be changed as appropriate. For example, in the above embodiment, the connecting portion 25 is provided only on one end side in the axial direction of the magnet 24 (lower side in FIG. 1), but not only on one end side in the axial direction of the magnet 24 but on the other end side (upper side in FIG. 1). ) May also be provided with a connecting portion 25. Further, for example, as shown in FIGS. 3A and 3B, the connecting portion 25 may be omitted and the magnets 24 may be separated from each other. In the rotor 13A shown in the figure, the magnets 24 are not connected to each other in the circumferential direction. Both end portions in the axial direction of each magnet 24 extend radially inward, and a radial engagement portion 24c that protrudes inward in the axial direction (rotor core 21 side) from the tip of each extending portion 24b is formed. . Each radial engagement portion 24c is filled in a recess 21c formed on the axial end surface of the rotor core 21, and is in contact with the rotor core 21 in the outer diameter direction. According to such a configuration, it is possible to prevent the magnet 24 from dropping out in the radial direction by the engagement between the radial engagement portion 24 c and the rotor core 21. In addition, you may add this radial direction engaging part 24c to the said embodiment.

  In the above embodiment, the present invention is applied to the SPM type rotor 13 in which each magnet 24 is fixed to the outer peripheral surface of the rotor core 21. However, the present invention is not limited to this, and an IPM in which each magnet is embedded in the rotor core. You may apply to the (Interior Permanent Magnet) type rotor. For example, in the rotor 13B shown in FIGS. 4A and 4B, the cylindrical rotor core 41 to which the rotary shaft 14 is press-fitted and fixed has four through holes 41a formed at equal intervals in the circumferential direction. . Each through hole 41 a is formed slightly inside the outer peripheral surface of the rotor core 41 and penetrates the rotor core 41 in the axial direction. Each through hole 41a is filled with a plastic magnet 42 (hereinafter referred to as magnet 42) made of a resin material containing magnetic powder.

  Each magnet 42 is integrally formed with the rotor core by insert molding. Each magnet 42 has a rectangular parallelepiped shape that is long in the axial direction of the rotor core 41, and the axial length thereof is equal to the axial length of the rotor core 41. A protruding portion 43 (an axial engagement portion) that protrudes radially inward and outward is formed at one axial end portion (lower end portion in FIG. 4) of each magnet 42. The protrusion 43 of each magnet 42 is in contact with the stepped portion of the inner surface of each through hole 41 a in the axial direction of the rotary shaft 14.

  In the rotor core 41, pseudo magnetic poles 44 are formed between the circumferential directions of the through holes 41a. The pseudo magnetic poles 44 are portions that do not have the through holes 41 a in the outer peripheral portion of the rotor core 41, and are formed at four circumferentially equal intervals (intervals of 90 degrees). That is, on the outer peripheral portion of the rotor core 41, the magnets 42 and the pseudo magnetic poles 44 are alternately arranged in the circumferential direction at equal intervals (45 degree intervals). Each pseudo magnetic pole 44 functions as a magnetic pole opposite to the magnet 42, similarly to the pseudo magnetic pole 22 of the above-described embodiment, whereby the N pole and the S pole are circumferential in the circumferential direction of the rotor core 41. It is composed of 8 poles alternately.

  Even with such a configuration, the same effects as the effects (1) and (2) of the above embodiment can be obtained. In the rotor 13B, the magnets 42 are not connected to each other. However, for example, a connecting portion 25 similar to that of the above embodiment may be integrally formed with each magnet 42. In the rotor 13B, each magnet 42 is integrally formed with the rotor core 41 by insert molding. For example, each magnet 42 is press-fitted and fixed in the through hole 41a of the rotor core 41. It is good. Even in the case of press-fitting and fixing, an adhesive for fixing each magnet 42 is unnecessary, and deterioration of quality due to the adhesive can be prevented. Further, since the press-fitting allowance can be increased by the elasticity of the magnet 42, the magnet 42 can be easily press-fitted and fixed as compared with the case where a hard sintered magnet is press-fitted.

  In the above embodiment, each magnet 24 is magnetized so that the radially outer side is the N pole and the radially inner side is the S pole, but on the contrary, the radially outer side is the S pole and the radially inner side is the N pole. You may magnetize so that it may become. In this case, the pseudo magnetic pole 22 functions as an N pole.

  In the above embodiment, the number of the magnets 24 and the pseudo magnetic poles 22 is four, but the number of the magnets 24 and the pseudo magnetic poles 22 may be appropriately changed according to the configuration. .

  In the above embodiment, the present invention is applied to the inner rotor type motor 10, but the present invention is not particularly limited thereto, and may be applied to an outer rotor type motor.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 12 ... Stator, 13, 13A, 13B ... Rotor, 14 ... Rotary shaft, 21, 41 ... Rotor core, 22, 44 ... Pseudo magnetic pole, 24, 42 ... Plastic magnet, 24c ... Radial engagement part, 25 ... connecting part (axially engaging part), 43 ... projecting part (axially engaging part).

Claims (3)

A plurality of magnets are arranged in the circumferential direction of the rotor core, and between each magnet, a pseudo magnetic pole that functions as a magnetic pole opposite to the magnet is formed by the magnetic action of the magnet,
Each of the magnets is composed of a plastic magnet made of a resin material containing a magnetic body, and each plastic magnet is separated from each other and fixed to the outer peripheral surface of the rotor core.
Each of the plastic magnets has a radial engagement portion that engages with the rotor core in the outer diameter direction on the radially inner side of each plastic magnet fixed to the outer peripheral surface of the rotor core. A motor comprising the rotor according to claim 1 . It is a manufacturing method of the rotor according to claim 1, Comprising:
Each of the magnets is composed of a plastic magnet made of a resin material containing a magnetic material,
A method of manufacturing a rotor, wherein the plastic magnets are formed integrally with the rotor core.