JP5275686B2 - Rotor and motor - Google Patents

Description

  The present invention relates to a rotor having a magnet and a motor including the rotor.

Conventionally, there is a motor rotor in which an annular magnet is fixed to the outer peripheral surface of a rotor body. In such a rotor, it is necessary to rotate the magnet and the rotor body integrally. As a method, for example, as shown in Patent Document 1, an engagement recess (patent) is provided at the end of the magnet in the axial direction. It is conceivable to engage in a circumferential direction a notch in Document 1 and an engaging projection (claw in Patent Document 1) provided on an annular fixing member fixed to the rotor body. That is, by such an uneven connecting portion, the rotor main body and the magnet can be engaged with each other in the circumferential direction so as to be integrally rotatable.
JP 2004-312876 A

  By the way, in the above rotor, when the magnet is fixed to the rotor main body, the engaging convex portion of the fixing member fixed to the rotor main body and the engaging concave portion of the magnet are engaged in the circumferential direction. As a result of the rotation, stress is inevitably generated at the engaging portions of the engaging convex portion and the engaging concave portion. Therefore, for example, when the rigidity of the fixing member having the engaging convex portion is high, the stress generated in the engaging concave portion of the magnet is increased, and there is a possibility of damaging the magnet. In addition, the problem is that, as the number of the engagement concave portions and the engagement convex portions is reduced, the stress generated in the concave / convex connecting portion is concentrated and increased, so that the possibility of damage to the magnet is increased. is there.

  The present invention has been made in order to solve the above-described problems, and its purpose is to damage a magnet due to stress concentration in the concave-convex connecting portion in the concave-convex connecting portion that integrally rotates the rotor body and the magnet in the circumferential direction. It is in providing the rotor and motor which can suppress this.

In order to solve the above-mentioned problem, the invention according to claim 1 is a rotor in which a rotor main body having a rotation shaft and an annular magnet provided on the outer periphery of the rotor main body are fixed so as to be integrally rotatable by a concave-convex connecting portion. The magnet is magnetized so that N poles and S poles are alternately arranged at equal intervals in the circumferential direction, and the concave / convex connecting portion is a concave / convex shape provided at an axial end of the magnet. A first engaging portion, an uneven second engaging portion formed on the rotor body, and an uneven third engaging portion that presses and engages with the first engaging portion are annular main bodies. And an intermediate member formed on the other end surface in the axial direction of the main body portion with a concave and convex fourth engagement portion that is formed on one axial end surface of the main body portion and press-engaged with the second engagement portion. said first and said rotor body and the magnet in the second engaging portion and the intermediate member Indirectly that engagement elastically pressed against the circumferential direction as its gist.

In the present invention, the concavo-convex connecting portion includes a concavo-convex first engagement portion provided at an axial end of the magnet, a concavo-convex second engagement portion formed in the rotor body, and a first engagement portion. the fourth engaging portion uneven third engaging portion uneven engaging in pressure contact is engaged in pressure contact with the second engagement portion is formed in a axial end surface of the main body portion of the annular And an intermediate member formed on the other end surface in the axial direction of the main body, and the magnet and the rotor main body are indirectly elastically pressed and engaged in the circumferential direction by the first and second engaging portions and the intermediate member. Therefore, the stress generated at the time of engagement in the circumferential direction at the concave-convex connecting portion can be absorbed by the elastic pressure contact engagement, and damage to the magnet can be suppressed.

According to a second aspect of the present invention, in the rotor according to the first aspect , the third engaging portion of the intermediate member is an engaging convex portion, and the first engaging portion of the magnet is an engaging concave portion. there, the intermediate member causes abutting directly with said first engaging portion of the said third engaging portion of its magnet in the circumferential direction, so as to be deflectable to the third engagement portion is circumferentially and Turkey, such being formed as its gist.

In this invention, the intermediate member, the third engagement portion of itself (engaging portion) and the first engaging portion of the magnet with (engagement recess) are in direct contact in the circumferential direction, the third engagement The joint portion is formed to be able to bend in the circumferential direction. In other words, the third engagement portion that is in direct contact with and connected to the first engagement portion of the magnet is formed so as to be able to bend in the circumferential direction, and thus is generated at the time of contact engagement with the first engagement portion in the circumferential direction. The stress to be absorbed can be absorbed by the elastic deformation of the third engaging portion, and an increase in the number of components can be suppressed.

The invention described in claim 3 is the rotor according to claim 2, wherein the third engagement portion of the intermediate member, and its gist in that it is resiliently deformable by holes and notches formed.
In the present invention, the third engagement portion of the intermediate member can be bent by the formation of the hole and the notch, so that the elastic deformation of the hole and the notch can be easily used in the circumferential direction with the first engagement portion. It is possible to absorb the stress generated at the time of contact engagement.

Invention according to claim 4, in the rotor according to any one of claims 1 to 3, wherein the third engagement portion of the intermediate member that engages the first engaging portion of said magnet, The gist is that the circumferential end has an R shape.

The gist of the invention described in claim 5 is that it is provided with the rotor according to any one of claims 1 to 4 and a stator arranged opposite to the outer periphery of the rotor.
In this invention, the motor which can show | play the effect of Claims 1-4 can be provided.

  Therefore, according to the above-described invention, there is provided a rotor and a motor capable of suppressing damage to the magnet due to stress concentration in the concave-convex connecting portion in the concave-convex connecting portion that integrally rotates the rotor body and the magnet in the circumferential direction. be able to.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
FIG. 1 shows a cross section of a motor 1 in the present embodiment. For example, the motor 1 is assembled in an electric power steering apparatus for a vehicle whose main purpose is to assist a driver's steering operation.

  As shown in FIG. 1, the motor 1 is fixed to a motor case 4 including a case body 2 having a bottomed cylindrical shape, an end frame 3 that closes an opening of the case body 2, and an inner peripheral surface of the case body 2. The brushless motor includes the stator 5 that is made, the rotor 6 disposed inside the stator 5, and the resolver 7.

  The stator 5 has a substantially cylindrical shape and includes a stator core 8 and a winding 9. The stator core 8 includes a plurality of tooth portions 8a (only two are shown) provided along the circumferential direction, and these tooth portions 8a are integrally formed by being connected on the outer peripheral side of the stator core 8. A winding 9 is wound around each tooth portion 8 a via an insulator 10.

  The rotor 6 is arranged with a certain gap between it and the inner peripheral surface of the stator core 8. The rotor 6 includes a rotating shaft 11, a rotor body (rotor body) 12 fixed to the rotating shaft 11, an annular ring magnet 14 disposed on the outer periphery of the rotor body 12 via an intermediate member 13, a rotor The cover member 15 covers the main body 12 and the ring magnet 14.

  The rotary shaft 11 is supported by a bearing 16 provided at the base end of the case body 2 at the base end and supported by a bearing 17 provided at the center of the end frame 3 at the tip end. It is rotatably supported.

  As shown in FIGS. 1 and 4, the rotor body 12 has a substantially cylindrical shape, and an annular flange portion 20 that extends radially outward is integrally formed on the base end side of the rotor body 12. The flange portion 20 is formed with an engagement recess 21 as a pair of second engagement portions that are recessed inward in the radial direction. Two engaging recesses 21 are provided on the outer periphery of the rotor body 12 at regular intervals of 180 degrees in the circumferential direction (only one is shown in FIG. 4).

  A through hole 22 penetrating in the axial direction is formed in the radial center of the rotor body 12. A portion of the through hole 22 from the end on the end frame 3 side to the center in the axial direction of the rotor body 12 is a fixing hole 23 having a diameter equal to or slightly smaller than the outer diameter of the rotating shaft 11. . Further, a portion of the through hole 22 from the center in the axial direction of the rotor body 12 to the end portion on the bottom side of the case body 2 is an insertion hole 24 having a diameter larger than the outer diameter of the rotating shaft 11. Yes. The rotor body 12 is fixed to the rotating shaft 11 fitted in the through hole 22 by a fixing hole 23 and can rotate integrally with the rotating shaft 11.

  As shown in FIGS. 2 and 4, the intermediate member 13 is made of a rigid material such as resin, and is for engaging the ring magnet 14 and the rotor body 12 in the circumferential direction. The intermediate member 13 includes an annular main body portion 13a, an engagement convex portion 13b as a fourth engagement portion, and a third engagement portion that extend in the axial direction from both end surfaces at substantially the same circumferential position of the main body portion 13a. It is comprised from this engagement convex part 13c.

  The engagement protrusions 13b and 13c are formed two by two at 180 ° intervals in the circumferential direction, the engagement protrusion 13b extends in one axial direction, and the engagement protrusion 13c extends in the other axial direction. ing. The engaging convex portion 13b is engaged (fixed) with the engaging concave portion 21 by, for example, light press fitting in a state where the main body portion 13a of the intermediate member 13 is fitted into the rotor main body 12. In addition to the above-described fixing method, the engaging convex portion 13b and the engaging concave portion 21 may use, for example, an elastic fixing method or other fixing methods. Further, as shown in FIG. 3, the engagement convex portion 13c is formed so as to form an R shape in which two circumferential end portions 13x are convex in the circumferential direction.

  The ring magnet 14 is magnetized so that N poles and S poles are alternately arranged at equal intervals in the circumferential direction of the outer peripheral surface thereof, and is engaged with the engagement convex portion 13c at the base end in the axial direction. Two engaging recesses 14a as first engaging portions are formed at regular intervals of 180 degrees in the circumferential direction. The engagement recess 14a of the ring magnet 14 is engaged with the engagement protrusion 13c of the intermediate member 13 via an elastic adhesive 30 as an elastic engagement portion as shown in FIG. The ring magnet 14 and the rotor main body 12 are provided so as to be integrally rotatable in the circumferential direction via the engagement convex portion 13b of the intermediate member 13 by engaging the 13c and the engaging concave portion 14a in the circumferential direction. . That is, since the ring magnet 14 is engaged with the rotor body 12 in the circumferential direction by the elastic adhesive 30 having elasticity, the stress generated when the engagement convex portion 13c and the engagement concave portion 14a are engaged in the circumferential direction is elastic. It can absorb by the elastic adhesive 30 which has, and can suppress the damage of the ring magnet 14.

  Further, as described above, since the circumferential end portion 13x is formed in an R shape, the engagement convex portion 13c can apply a relatively large amount of the elastic adhesive 30, and the peripheral portions of the elastic adhesive 30 on both ends in the radial direction can be applied. The directional thickness can be made thick. The outer peripheral surface 12a of the rotor main body 12 and the inner peripheral surface 14b of the ring magnet 14 are bonded and fixed by an adhesive 31 (regardless of elasticity), and the rotor main body 12 and the ring magnet 14 are related to the bonding. It is fixed by concavity and convexity connection by the joint recesses 14a and 21 and the engagement protrusions 13b and 13c.

  As shown in FIG. 1, the cover member 15 includes a cylindrical portion 15a, a bottom portion 15b, and a bent portion 15c. The cylindrical portion 15 a has an axial length that is substantially the same as the axial length of the rotor body 12. Therefore, the outer peripheral surface of the intermediate member 13, the outer peripheral surface of the flange portion 20, and the outer peripheral surface of the ring magnet 14 are covered with the cylindrical portion 15a.

  The bottom portion 15b of the cover member 15 extends radially inward from one axial end of the cylindrical portion 15a, and abuts on the end surface 12b of the rotor body 12 and the end surface 14c of the ring magnet 14. The bent portion 15c extends from one end in the axial direction on the opposite side of the bottom portion 15b of the cylindrical portion 15a. After the ring magnet 14 is disposed on the outer periphery of the rotor main body 12 via the intermediate member 13 and the cover member 15 is mounted on the rotor main body 12, the bent portion 15c has the flange portion 20 shown in FIG. It is bent radially inward to be locked. When the bent portion 15c is bent, the bent portion 15c locks the flange portion 20 of the rotor main body 12 and the engaging convex portion 13b of the intermediate member 13 in the axial direction, and the rotor main body 12 and the intermediate member 13 and the ring magnet 14 are prevented from falling off.

  The resolver 7 includes a resolver rotor 7a and a resolver stator 7b. The resolver 7 is for detecting the rotational position of the rotor 6 (rotating shaft 11). The resolver rotor 7 a is fixed to the end frame 3 side of the rotating shaft 11 of the rotor 6. The resolver stator 7b is fixed to the end frame 3 so as to face the resolver rotor 7a on the outer peripheral side of the resolver rotor 7a. The resolver 7 outputs the rotational position information of the rotor 6 to a control device (not shown), and a voltage is appropriately supplied to the stator 5 by the control device.

  In the motor 1 configured as described above, the ring magnet 14 constituting the rotor 6 is rotated by receiving the rotating magnetic field of the stator 5, and the rotational force of the ring magnet 14 is transmitted to the intermediate member 13 and the rotor body 12 to rotate. The shaft 11 is rotated.

Next, characteristic actions and effects of the present embodiment will be described.
(1) The engaging convex portion 13 c of the intermediate member 13 and the engaging concave portion 14 a of the ring magnet 14 constituting the concave-convex connecting portion are provided with an elastic adhesive 30 having elasticity, and the ring is interposed via the elastic adhesive 30. Since the magnet 14 and the rotor body 12 are indirectly elastically engaged with each other in the circumferential direction, stress generated during circumferential engagement in the engagement convex portion 13c and the engagement concave portion 14a constituting the concave-convex connecting portion is elastic adhesive. It can be absorbed by the elastic force of 30, and damage to the ring magnet 14 can be suppressed.

  (2) Since the engagement protrusion 13c of the intermediate member 13 that engages with the engagement recess 14a of the ring magnet 14 has an R shape with its circumferential end 13x protruding in the circumferential direction, the engagement of the ring magnet 14 A portion that widens the circumferential interval with the combined recess 14a can be formed, and by forming the elastic engagement portion with the elastic adhesive 30, the circumferential thickness can be increased. Thereby, stress can be absorbed effectively. Furthermore, since the circumferential interval between the ring magnet 14 and the engagement recess 14a can be partially narrowed, the engagement recess 14a of the ring magnet 14 and the engagement protrusion 13c that engages with the engagement recess 14a. Can be prevented from greatly shifting in the circumferential direction, and positioning in the circumferential direction can be facilitated in a state before the elastic adhesive 30 is interposed.

The embodiment of the present invention may be modified as follows.
-In above-mentioned embodiment, although the engaging recessed part 14a as a 1st engaging part and the engaging recessed part 21 as a 2nd engaging part were comprised so that it might become concave shape to an axial direction, it is not restricted to this. For example, one may be formed in a convex shape, or both may be formed in a convex shape. In this case, the engaging projections 13b and 13c of the intermediate member 13 are formed in a concave shape.

In the above embodiment, the engagement recess 14a, the engagement recess 21 and the engagement protrusions 13b and 13c of the intermediate member 13 are each formed two, but one or three or more may be formed.
In the above embodiment, the elastic adhesive 30 having elasticity is applied only to the engagement convex portion 13 c side of the intermediate member 13, but not limited thereto, the intermediate member 13 is engaged with the engagement concave portion 21 of the rotor body 12. An elastic adhesive 30 having elasticity may be applied to the engaging convex portion 13b. With such a configuration, the rotor main body 12 and the intermediate member 13 are engaged via the elastic adhesive 30, so that damage to the ring magnet 14 can be further suppressed.

  In the above embodiment, the intermediate member 13 is provided between the ring magnet 14 and the rotor body 12, but the present invention is not limited to this, and may not be provided. Specifically, as shown in FIGS. 5 and 6, the rotor body 12 is provided with a flange portion 40 that extends radially outward over the entire circumference of the base end (right side in the drawing). The flange portion 40 is provided with two engagement convex portions 41 extending in the axial direction from the end surface 40a on the bottom portion 15b side of the cover member 15 in the flange portion 40 at regular intervals of 180 degrees in the circumferential direction. 41 is engaged with the engaging recessed part 14a formed in the ring magnet 14 through the elastic adhesive 30 which has elasticity in the circumferential direction. By adopting a configuration in which the ring magnet 14 and the rotor main body 12 are directly engaged in the circumferential direction in this way, it is not necessary to provide the intermediate member 13 and the elastic adhesive 30 having elasticity while suppressing the number of members. Thus, damage to the ring magnet 14 and the rotor body 12 can be suppressed.

In the above embodiment, the elastic engagement portion is configured by the elastic adhesive 30, but is not limited thereto, and for example, a potting agent or rubber may be used.
Moreover, you may comprise an elastic engaging part with a mechanical structure. For example, as shown in FIGS. 7 and 8, an engagement convex portion 50 is provided as a third engagement portion extending in the axial direction from the main body portion 13 a of the intermediate member 13, and the circumferential side surface 51 of the engagement convex portion 50 is provided. Are provided with protrusions 54 that press in circumferential contact with the circumferential side surface 52 of the engagement recess 14 a of the ring magnet 14 and the circumferential side surface 53 of the engagement recess 21 of the rotor body 12. Is provided with a bending allowance hole 55 formed so as to be bent in a radial direction. With such a configuration, the stress transmitted by the protrusion 54 can be absorbed by elastic deformation by the bending allowance hole 55. Therefore, damage to the ring magnet 14 and the rotor body 12 can be suppressed. Moreover, since it is not necessary to use the elastic adhesive 30 (refer FIG. 1) as an elastic engaging part like the said embodiment, the drying process of an adhesive agent is not required. As a result, the manufacturing time can be shortened.

  Further, as shown in FIG. 9, the ring magnet 14 is engaged with the engagement recess 14 a of the ring magnet 14 and the engagement recess 21 of the rotor body 12 in the circumferential direction, and is cut out from both end surfaces of the body portion 13 a of the intermediate member 13. It is good also as a structure which provides the bending pieces 60 and 61 as a 3rd engaging part formed so that it may extend in an axial direction, and provides the hollow part 62 of the shape depressed in the circumferential direction at the base end of these bending pieces 60 and 61. . Two bending pieces 60 are formed with a predetermined gap in the circumferential direction from the end surface on the flange portion 20 side of the rotor body 12 in the axial direction of the intermediate member 13, and the bending pieces 61 are formed in the axial direction of the intermediate member 13. Two pieces are formed with a predetermined gap in the circumferential direction from the end surface on the ring magnet 14 side, and the bending pieces 60 and 61 are pressed against the circumferential side surfaces 14x and 21x of the engaging recesses 14a and 21 in the circumferential direction, respectively. It is formed to touch. With such a configuration, the bending pieces 60 and 61 can be easily bent in the circumferential direction, and damage to the ring magnet 14 and the rotor main body 12 can be suppressed, and the elastic engagement portion is elastic as in the above embodiment. Since it is not necessary to use the adhesive 30 (refer FIG. 1), the drying process of an adhesive is not required. As a result, the manufacturing time can be shortened.

  -In above-mentioned embodiment, although the circumferential direction edge part 13x of the engagement convex part 13c of the intermediate member 13 was formed in the R shape which becomes convex in the circumferential direction, it is not restricted to this. For example, as shown in FIG. 10, the circumferential end 13x of the engaging projection 13c of the intermediate member 13 may be formed in an R shape that is concave in the circumferential direction, that is, an R shape that is opposite to the above embodiment. These configurations can also be applied to the configuration described above with reference to FIGS. 5 and 6, for example. In this case, the axial end of the engagement convex portion 41 of the rotor body 12 is concave or convex in the circumferential direction. R shape may be used.

In the above embodiment, the cover member 15 is provided on the outer periphery of the ring magnet 14, but the present invention is not limited thereto, and the cover member may not be provided.
In the above embodiment, the motor is embodied as an electric power steering motor, but may be applied to other motors.

It is a schematic block diagram of the brushless motor in this Embodiment. It is the perspective view which showed a part of rotor in the same as the above. It is an end view of a ring magnet and an intermediate member in the same as above. It is a disassembled perspective view of a part of rotor in the same as the above. It is sectional drawing of the rotor in another example. It is the perspective view which showed a part of rotor in the same as the above. It is the perspective view which showed a part of rotor in another example. It is explanatory drawing for demonstrating the structure of the edge part of the rotor in the same as the above. It is explanatory drawing for demonstrating the structure of the edge part of the rotor in another example. It is an end view of the ring magnet and intermediate member in another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Motor, 5 ... Stator, 6 ... Rotor, 11 ... Rotating shaft, 12 ... Rotor main body, 13 ... Intermediate member, 13a ... Main body part, 13b ... Engaging convex part (4th engaging part and uneven | corrugated connection part), 13c ... engaging convex part (third engaging part and concave-convex connecting part), 13x ... circumferential end, 14 ... ring magnet (magnet), 14a ... engaging concave part (first engaging part and concave-convex connecting part), 21 ... engaging recess (second engaging portion and concave / convex connecting portion), 30 ... elastic adhesive (elastic engaging portion) 50 ... engaging convex portion (third engaging portion and concave / convex connecting portion), 51 ... side surface, 52, 53 ... circumferential side surface, 54 ... projection, 55 ... deflection allowance hole, 60, 61 ... flexure piece (third engagement portion).

Claims (5)

A rotor body having a rotating shaft and an annular magnet provided on the outer periphery of the rotor body fixed to be integrally rotatable by an uneven connecting portion,
The magnet is magnetized so that N poles and S poles are alternately spaced in the circumferential direction,
The concavo-convex connecting portion includes a concavo-convex first engagement portion provided at an axial end of the magnet, a concavo-convex second engagement portion formed in the rotor body, and the first engagement portion. A concavo-convex fourth engaging portion is formed on one end surface in the axial direction of the annular main body portion and is engaged with the second engaging portion while being pressed and engaged. An intermediate member formed on the other axial end surface of the main body,
The rotor, wherein the magnet and the rotor body are indirectly elastically pressed and engaged in the circumferential direction by the first and second engaging portions and the intermediate member . The rotor according to claim 1 , wherein
The third engaging part of the intermediate member is an engaging convex part, and the first engaging part of the magnet is an engaging concave part;
The intermediate member, as well is in direct contact with said first engaging portion of the said third engaging portion of its magnet in the circumferential direction, the third and the engaging portion is formed to be deflectable in the circumferential direction rotor, wherein the a Turkey. The rotor according to claim 2 , wherein
The rotor, wherein the third engagement portion of the intermediate member can be bent by forming a hole and a notch. The rotor according to any one of claims 1 to 3 ,
Wherein the third engagement portion of the intermediate member, the rotor, characterized in that the circumferential end portion is the R-shape to be engaged with the first engaging portion of the magnet. A motor comprising the rotor according to any one of claims 1 to 4 and a stator arranged to face the outer periphery of the rotor.

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