JP2006296045A - Embedded magnet type motor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an embedded magnet type motor that can easily be arranged so that an air gap between a magnet and a rotor core is not formed and the motor is not broken. <P>SOLUTION: The embedded magnet type motor comprises a rotor 2 in which a plurality of the V-shaped permanent magnets 12 are arranged in the rotor core 11 in the circumferential direction. The rotor core 11 comprises an inner core part 21 and an outer core part 22 having shapes divided in the radial direction with a part wherein the V-shaped permanent magnets 12 are arranged as a boundary, and the inner core part 21 is composed of circumferentially divided core parts 24 that are divided in the circumferential direction. After assembling each V-shape constituting magnet 23 that constitutes the V-shaped permanent magnet 12 to the circumferentially divided core part 24 in an independent state from an axis orthogonal direction, the circumferential core part 24 is assembled together with the outer core part 22 from the inside of the radial direction so as to sandwich the V-shaped constituting magnet 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an embedded magnet type motor in which a magnet is disposed inside a rotor core and a method for manufacturing the same.

2. Description of the Related Art Conventionally, some embedded magnet type motors include a rotor core in which a plurality of housing holes penetrating in the axial direction are formed in the circumferential direction, and a magnet is disposed in each housing hole. In such a rotor in an embedded magnet type motor, a magnetized magnet is inserted into the accommodation hole from the axial direction and assembled to the rotor core. Moreover, as such an embedded magnet type motor, there is a motor provided with a spring (elastic means) that presses the magnet in the axial direction in order to prevent the magnet from rattling against the rotor core (see, for example, Patent Document 1).
JP 2003-70195 A

  However, in the above-described embedded magnet type motor, when the magnet is inserted into the accommodation hole from the axial direction, the magnet has already been magnetized, and the magnet tends to be attracted to the rotor core. Further, if the accommodation hole is made slightly larger than the magnet in order to make insertion relatively easy and prevent damage such as cracking or chipping of the magnet, an air gap between the magnet and the rotor core is generated. In addition, it is difficult to prevent the occurrence of the air gap while increasing the number of parts in the device including the spring.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to embed a magnet that can be easily arranged so that an air gap with the rotor core does not occur and is not damaged. The object is to provide a magnet type motor and a method of manufacturing the same.

  According to the first aspect of the present invention, there is provided an embedded magnet type motor including a rotor in which a plurality of magnets are arranged in a circumferential direction inside the rotor core, and the rotor core has a boundary at a portion where the magnet is arranged. The inner core portion and the outer core portion are divided in the radial direction, and the inner core portion or the outer core portion has a circumferential divided core portion shaped in the circumferential direction.

  According to a second aspect of the present invention, in the interior magnet type motor according to the first aspect, the magnet has a V-shape in which a pair of V-shaped magnets are arranged in a substantially V shape projecting radially inward. It is a permanent magnet, The said circumferential direction division | segmentation core part is a shape by which the said inner core part was cut | disconnected for every intermediate part of the circumferential direction in the said V-shaped permanent magnet.

According to a third aspect of the present invention, in the interior magnet type motor according to the first or second aspect, a holding groove for holding the magnet is formed in the inner core portion.
According to a fourth aspect of the present invention, in the interior magnet type motor according to the first or second aspect, a holding groove for holding the magnet is formed in the outer core portion.

  According to a fifth aspect of the present invention, there is provided a method of manufacturing an embedded magnet type motor including a rotor in which a plurality of magnets are arranged in a circumferential direction inside the rotor core, wherein the magnet is arranged on the rotor core. Having an inner core portion and an outer core portion having a shape that is divided in a radial direction with a portion as a boundary, and the inner core portion or the outer core portion having a circumferentially divided core portion having a shape that is divided in a circumferential direction The magnet is assembled to the inner core portion or the outer core portion from the direction perpendicular to the axis, and the magnet is sandwiched with the outer core portion or the inner core portion after the magnet assembly step. Thus, a core assembling step for assembling the circumferentially divided core portion from the radial direction was provided.

(Function)
According to invention of Claim 1, a rotor core has an inner core part and outer core part of the shape divided | segmented into radial direction on the boundary where the magnet is arrange | positioned. And since an inner core part or an outer core part has the circumferential direction division | segmentation core part of the shape divided | segmented into the circumferential direction, after attaching a magnet to an inner core part or an outer core part from an axial orthogonal direction, an outer core part or inner A circumferentially divided core part can be assembled | attached from radial direction so that a magnet may be pinched | interposed with a core part. Therefore, it is possible to easily dispose the magnet so that an air gap with the rotor core does not occur and is not damaged.

  According to the invention described in claim 2, the circumferentially divided core portion has a shape in which the inner core portion is separated at each intermediate portion in the circumferential direction of the V-shaped permanent magnet. Corresponding to the V-shaped constituent magnets on the side close to each other in the permanent magnet, the shape becomes narrower toward the outside in the radial direction. Therefore, the circumferentially divided core portion can be easily assembled from the radially inner side so as to sandwich each V-shaped magnet together with the outer core portion. Further, the V-shaped constituent magnets adjacent to each other in the V-shaped permanent magnets adjacent to each other in the circumferential direction have magnetic poles set in opposite directions and require a magnetic path inside the rotor core (inner core portion). By separating the core part as described above, it is possible to satisfactorily configure the magnetic path in the circumferentially divided core part.

  According to the invention described in claim 3, since the holding groove for holding the magnet is formed in the inner core portion (circumferentially divided core portion), for example, before assembling the inner core portion and the outer core portion. Further, the magnet can be easily held by being assembled to the inner core portion (circumferentially divided core portion) from the direction perpendicular to the axis. Therefore, assembly becomes easy. In particular, when this configuration is applied to the configuration according to claim 2, the V-shaped constituent magnets adjacent to each other in the circumferentially adjacent V-shaped permanent magnet are held so as to sandwich one circumferential-direction divided core portion. As a result, the holding force can be increased, and the circumferentially divided core portion holding the V-shaped magnet can be easily assembled to the outer core portion.

  According to the invention described in claim 4, since the holding groove for holding the magnet is formed in the outer core portion, for example, before assembling the inner core portion and the outer core portion, the magnet is attached to the outer core portion. Can be easily assembled and held from the direction perpendicular to the axis. Therefore, assembly becomes easy.

  According to invention of Claim 5, a magnet is assembled | attached to an inner core part or an outer core part from an axial orthogonal direction in a magnet assembly | attachment process, and an outer core part or an inner core part is combined in a subsequent core assembly process. The circumferentially divided core portion is assembled from the radial direction so as to sandwich the magnet. Therefore, it is possible to easily dispose the magnet so that an air gap with the rotor core does not occur and is not damaged.

  According to the first to fourth aspects of the present invention, it is possible to provide an embedded magnet type motor in which a magnet can be easily arranged so that an air gap with a rotor core does not occur and is not damaged.

  According to the fifth aspect of the present invention, there is provided a method for manufacturing an embedded magnet type motor in which a magnet can be easily disposed so as not to cause an air gap with a rotor core and to prevent damage. Can do.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the embedded magnet type motor includes a stator 1 and a rotor 2 that is rotatably supported inside the stator 1.

  The stator 1 is formed in a substantially cylindrical shape as a whole, and includes a stator core 3 and a winding 4 (partially shown by a two-dot chain line in FIG. 1). The stator core 3 includes an annular core 5 and a plurality of (12 in this embodiment) teascores 6 in the circumferential direction fixed to the annular core 5 so as to extend radially inward from the annular core 5. A winding 4 is wound around the tee score 6 (concentrated winding) via an insulator (not shown).

  The rotor 2 is formed in a substantially cylindrical shape as a whole, the rotor core 11, a plurality of (eight) V-shaped permanent magnets 12 disposed in the circumferential direction inside the rotor core 11, and the inner peripheral surface of the rotor core 11. And a rivet 15 that fastens the rotor core 11 and the cover 14 in the axial direction. The cover 14 is disposed on both end faces of the rotor core 11 (see FIG. 2). The rotor core 11 includes an inner core portion 21 and an outer core portion 22 having a shape that is divided in a radial direction with a portion where a plurality of V-shaped permanent magnets 12 are disposed as a boundary. The inner core portion 21 and the outer core portion 22 of the present embodiment are each formed by stacking core sheets in the axial direction.

  More specifically, each of the V-shaped permanent magnets 12 has a quadrangular prism shape, and a pair of substantially straight V-shaped constituent magnets 23 as viewed from the axial direction has a substantially V-shape projecting radially inward. It is arranged.

  Further, the outer core portion 22 has a shape that is disposed radially outward from the V-shaped permanent magnet 12 and has a shape having an outer peripheral surface of the rotor core 11. That is, the outer core portion 22 has a V-shaped receiving portion 22a having a shape that becomes narrower toward the inner side in the radial direction so as to be disposed inside the two sides constituting the V-shape of the V-shaped permanent magnet 12, and the plurality of these It has the connection part 22b which connects the radial direction outer side edge part of the V-shaped accommodating part 22a with what adjoins in the circumferential direction. Further, a through hole 22c penetrating in the axial direction is formed in the V-shaped receiving portion 22a of the outer core portion 22 of the present embodiment.

  The inner core portion 21 has a shape that is disposed radially inward from the V-shaped permanent magnet 12 and has a shape having an inner peripheral surface of the rotor core 11. The inner core portion 21 includes a circumferentially divided core portion 24 having a shape divided in the circumferential direction (eight). The circumferentially divided core portion 24 of the present embodiment has a shape in which the inner core portion 21 is separated at each intermediate portion (between a pair of V-shaped constituent magnets 23) in the V-shaped permanent magnet 12 in the circumferential direction. That is, the circumferentially-divided core portion 24 generally goes outward in the radial direction corresponding to the V-shaped constituent magnets 23 on the adjacent sides of the V-shaped permanent magnets 12 adjacent to each other in the circumferential direction as viewed from the axial direction. It becomes a narrow shape. A pair of press-fit grooves 24a as holding grooves for holding the V-shaped magnets 23 are formed in each circumferentially divided core portion 24 of the inner core portion 21 (see FIG. 3). In the press-fitting groove 24a, the distance between both walls as viewed from the axial direction is set so that the longitudinal end of the V-shaped constituent magnet 23 can be press-fitted (in the concave direction of the groove). That is, the circumferentially divided core portion 24 extends in a substantially circumferential direction at a radially outer end portion and extends in a substantially circumferential direction at a distal end side extending portion 24b that forms one of the two walls. A proximal end extending portion 24c forming the other of the two walls. Note that the distal end side extending portion 24b and the proximal end side extending portion 24c extend in the substantially circumferential direction by about half or one third of the length of the V-shaped magnet 23 in the short direction.

  The V-shaped magnet 23 is press-fitted and held in each press-fit groove 24 a of each circumferentially divided core part 24 and is disposed so as to be sandwiched between the outer core part 22 and the circumferentially divided core part 24. In this state (see FIG. 1), a gap is formed between the circumferentially divided core portions 24 in the circumferential direction. In this state (see FIG. 1), a gap is set between the radially outer end of the circumferentially divided core portion 24 and the connecting portion 22 b of the outer core portion 22. And the rotating shaft 13 is internally fitted by the inner peripheral surface of the inner core part 21 (circumferential division | segmentation core part 24). Further, as shown in FIG. 2, resin-made covers 14 are arranged on both end surfaces in the axial direction of the rotor core 11, and these are fastened by rivets 15 penetrating the rotor core 11 (through hole 22 c) and the cover 14. Yes. In FIG. 1, the cover 14 and the rivet 15 are not shown.

Here, the manufacturing method of the interior magnet type motor (rotor 2) comprised as mentioned above is demonstrated.
First, the inner core part 21 (that is, the plurality of circumferentially divided core parts 24), the outer core part 22, and the V-shaped constituent magnet 23 are manufactured independently. Note that the V-shaped magnet 23 is already magnetized at this point.

  Next, in the “magnet assembly step”, the V-shaped magnet 23 is assembled to the circumferentially divided core portion 24 (in an independent state) from the axis orthogonal direction (the axis orthogonal direction in the rotor 2). Specifically, in the present embodiment, the V-shaped constituent magnets 23 are press-fitted and held in the press-fitting grooves 24a of the circumferentially divided core portion 24, respectively. At this time, the two V-shaped constituent magnets 23 held in the pair of press-fit grooves 24a of one circumferentially divided core portion 24 are V-shaped on the side close to each other in the V-shaped permanent magnet 12 adjacent in the circumferential direction. In the constituent magnet 23, the magnetic poles are set in opposite directions, more specifically, the magnetic poles on the side fitted in the press-fit groove 24a are set to be opposite to each other (N pole and S pole).

  Next, in the “core assembly step”, the circumferentially divided core portion 24 is assembled from the radial direction (inner side) so as to sandwich the V-shaped magnet 23 together with the outer core portion 22 (see FIG. 3). Specifically, first, as shown in FIG. 3 (see a partially enlarged view in the figure), a circumferentially divided core portion 24 holding a V-shaped magnet 23 inside the outer core portion 22 is inserted from the axial direction. At this time, as shown in the partially enlarged view of FIG. 3, the V-shaped constituent magnet 23 is inserted so as not to come into contact with the outer core portion 22 (with the circumferentially divided core portion 24 disposed slightly inward in the radial direction). Then, the circumferentially divided core part 24 holding the V-shaped magnet 23 is moved radially outward so that the V-shaped magnet 23 is sandwiched between the outer core part 22 and the circumferentially divided core part 24. Assemble to. This step is performed for each circumferentially divided core portion 24.

  Next, the rotating shaft 13 is fitted into all the circumferentially divided core portions 24 arranged, that is, the inner peripheral surface of the inner core portion 21. Further, covers 14 are arranged on both end surfaces in the axial direction of the rotor core 11 (including the V-shaped permanent magnet 12) and fastened with rivets 15. In this way, the manufacture of the rotor 2 is completed.

Next, characteristic effects of the above embodiment will be described below.
(1) The rotor core 11 has an inner core portion 21 and an outer core portion 22 that are divided in the radial direction from the portion where the V-shaped permanent magnet 12 is disposed, and the inner core portion 21 is in the circumferential direction. It consists of the circumferentially divided core part 24 of the shape divided | segmented into. Therefore, after assembling each V-shaped component magnet 23 constituting the V-shaped permanent magnet 12 to the circumferentially divided core portion 24 from the direction orthogonal to the axis, the circumferentially divided core is sandwiched between the outer core portion 22 and the V-shaped configured magnet 23. The part 24 can be assembled from the radial direction. Therefore, the V-shaped permanent magnet 12 (V-shaped magnet 23) can be easily disposed so as not to generate an air gap with the rotor core 11 and to be damaged. As a result, an embedded magnet motor that can effectively use the magnetic flux of the V-shaped permanent magnet 12 (V-shaped magnet 23) can be easily obtained.

  (2) The magnet disposed inside the rotor core 11 is a V-shaped permanent magnet 12 in which a pair of V-shaped constituent magnets 23 are disposed so as to have a substantially V-shape convex radially inward. The circumferentially divided core portion 24 has a shape in which the inner core portion 21 is separated at every circumferential intermediate portion (between the pair of V-shaped constituent magnets 23) in the V-shaped permanent magnet 12, so that it is viewed from the axial direction. Overall, the shape becomes narrower toward the outside in the radial direction. Accordingly, the circumferentially divided core portion 24 can be easily assembled from the radially inner side (toward the radially outer side) so as to sandwich the V-shaped magnets 23 together with the outer core portion 22. In addition, the V-shaped constituent magnets 23 on the sides close to each other in the V-shaped permanent magnets 12 adjacent to each other in the circumferential direction have the magnetic poles set in opposite directions and require a magnetic path inside the rotor core 11 (inner core portion 21). By separating the circumferentially divided core part 24 as described above, it is possible to satisfactorily configure the magnetic path in the circumferentially divided core part 24.

  (3) Since the press-fit groove 24a for holding the V-shaped magnet 23 is formed in the circumferentially divided core part 24 of the inner core part 21, the circumferentially divided core part 24 and the outer core part 22 are assembled. Before, the V-shaped magnet 23 can be easily held by being assembled to the circumferentially divided core portion 24 from the direction perpendicular to the axis. Therefore, assembly becomes easy. Further, in the present embodiment, the V-shaped constituent magnets 23 (the magnetic poles are opposite to each other) in the V-shaped permanent magnets 12 adjacent in the circumferential direction are held so as to sandwich one circumferential-direction divided core portion 24. As a result, the holding force increases, and the circumferentially divided core portion 24 holding the V-shaped magnet 23 can be easily assembled to the outer core portion 22.

The above embodiment may be modified as follows.
In the above embodiment, the press-fit groove 24a (holding groove) for holding the V-shaped magnet 23 is formed in the inner core portion 21 (circumferentially divided core portion 24). A holding groove may be formed in the part. For example, you may change as shown in FIG.4 and FIG.5. Specifically, the rotor core 31 includes an inner core portion 41 and an outer core portion 42 having a shape divided in the radial direction with a portion where the plurality of V-shaped permanent magnets 12 are disposed as substantially the same as in the above embodiment. Become.

  The outer core portion 42 has a V-shaped receiving portion 42a and a connecting portion 42b in substantially the same manner as in the above embodiment, and the V-shaped magnets 23 are provided on the V-shaped receiving portions 42a (both sides in the circumferential direction). A pair of press-fit grooves 42c are formed as holding grooves for holding.

  Moreover, the inner core part 41 consists of the circumferential direction division | segmentation core part 43 of the shape divided | segmented into the circumferential direction similarly to the said embodiment. And the circumferential direction division | segmentation core part 43 has a shape which becomes so narrow that it goes to radial direction outer side substantially like the said embodiment, The front end side extension part 24b and the base end side extension part of the said embodiment. 24c is not provided.

  In the “magnet assembly step” in this example, the V-shaped magnet 23 is assembled to the outer core portion 42 from the direction perpendicular to the axis. Specifically, the V-shaped magnet 23 is press-fitted and held in each press-fitting groove 42c.

  In the next “core assembling step”, the circumferentially divided core portion 43 is assembled from the radial direction (inner side) so as to sandwich the V-shaped magnet 23 together with the outer core portion 42 (see FIG. 5). Specifically, first, as shown in FIG. 5 (see a partially enlarged view in the drawing), the circumferentially divided core portion 43 is inserted from the axial direction inside the outer core portion 42 holding the V-shaped magnet 23. At this time, as shown in the partially enlarged view of FIG. 5, the V-shaped magnet 23 is inserted so as not to contact the circumferentially divided core part 43 (with the circumferentially divided core part 43 disposed slightly inward in the radial direction). . Then, the circumferentially divided core part 43 is moved radially outward so that the outer core part 42 and the circumferentially divided core part 43 are assembled so as to sandwich the V-shaped magnet 23. Even in this case, the V-shaped permanent magnet 12 (V-shaped composing magnet 23) can be easily disposed so that an air gap with the rotor core 31 does not occur and is not damaged.

  In the above embodiment and other examples, the holding grooves are the press-fit grooves 24a and 42c. However, the present invention is not limited to this, and the holding grooves may be changed to other holding grooves for holding the V-shaped magnet 23 (magnet). Good. For example, it is a holding groove having a shape substantially the same as that of the press-fit grooves 24a and 42c, and a space between both walls slightly wider than the press-fit grooves 24a and 42c. It is good also as a holding groove hold | maintained by restricting the movement of the direction orthogonal to a direction. In such a case, the V-shaped magnet 23 and the holding groove may be fixed with an adhesive. Alternatively, the V-shaped magnet may be fixed only with an adhesive without forming the holding grooves in the inner core portion and the outer core portion.

  In the above embodiment and other examples, the circumferentially divided core parts 24 and 43 have a shape obtained by dividing the inner core parts 21 and 41 in the circumferential direction, but conversely, the inner core part is divided in the circumferential direction. Without changing (assuming a continuous annular shape), the outer core portion may be changed to include a circumferentially divided core portion having a shape divided in the circumferential direction. Even if it does in this way, after assembling a magnet to an inner core part or an outer core part (circumferential division | segmentation core part) from an axis orthogonal direction, a circumferential direction division | segmentation core part is assembled | attached from a radial direction so that a magnet may be pinched | interposed with an inner core part. be able to. Therefore, it is possible to easily dispose the magnet so that an air gap with the rotor core does not occur and is not damaged.

  In the above embodiment, the magnet is the V-shaped permanent magnet 12 in which the pair of V-shaped magnets 23 are arranged so as to have a substantially V-shape projecting radially inward. However, the present invention is not limited to this. Other shape magnets may be used. For example, the V-shaped permanent magnet 12 may be changed to a linear magnet substantially along the outer periphery of the rotor core. In this case, it is necessary to appropriately change the shape of the inner core portion and the outer core portion and the shape of the circumferentially divided core portion.

  In the present embodiment, the inner core portion 21 (circumferentially divided core portion 24) and the outer core portion 22 are each formed by laminating core sheets, but may have any similar shape, for example, magnetic powder It may be formed by sintering.

The top view of the stator and rotor of an embedded magnet type motor in this Embodiment. Sectional drawing of the stator and rotor of an embedded magnet type motor in this Embodiment. Explanatory drawing for demonstrating the manufacturing method of the rotor in this Embodiment. The top view of the stator and rotor of an embedded magnet type motor in another example. Explanatory drawing for demonstrating the manufacturing method of the rotor in another example.

Explanation of symbols

  2 ... rotor, 11, 31 ... rotor core, 12 ... V-shaped permanent magnet (magnet), 21, 41 ... inner core, 22, 42 ... outer core, 23 ... V-shaped magnet, 24, 43 ... circumferential division Core part, 24a, 42c ... press-fit groove (holding groove).

Claims (5)

An embedded magnet type motor including a rotor in which a plurality of magnets are arranged in a circumferential direction inside a rotor core,
The rotor core has an inner core portion and an outer core portion that are divided in a radial direction with a portion where the magnet is disposed as a boundary,
The inner magnet part or the outer core part has a circumferentially divided core part having a shape divided in a circumferential direction. The interior magnet type motor according to claim 1,
The magnet is a V-shaped permanent magnet in which a pair of V-shaped magnets are arranged in a substantially V shape protruding radially inward,
The circumferentially divided core portion has a shape in which the inner core portion is separated at each intermediate portion in the circumferential direction of the V-shaped permanent magnet. The interior magnet type motor according to claim 1 or 2,
An embedded magnet type motor, wherein a holding groove for holding the magnet is formed in the inner core portion. The interior magnet type motor according to claim 1 or 2,
An embedded magnet type motor, wherein a holding groove for holding the magnet is formed in the outer core portion. A method of manufacturing an embedded magnet type motor including a rotor in which a plurality of magnets are arranged in a circumferential direction inside a rotor core,
The rotor core has an inner core portion and an outer core portion having a shape divided in a radial direction with a portion where the magnet is disposed as a boundary,
The inner core part or the outer core part has a circumferentially divided core part having a shape divided in the circumferential direction,
A magnet assembling step for assembling the magnet to the inner core portion or the outer core portion from the direction perpendicular to the axis;
And a core assembling step for assembling the circumferentially divided core portion from the radial direction so as to sandwich the magnet together with the outer core portion or the inner core portion after the magnet assembling step. Manufacturing method of magnet type motor.

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