JP2021197880A - Rotor and motor - Google Patents

Abstract

To provide a rotor having a structure which enables reduction of manufacturing costs, and to provide a motor.SOLUTION: A rotor 20 includes: a shaft 21 which may rotate around a center axis J extending in an axial direction; a rotor core 30 which is fixed to the shaft 21 and formed by laminating plate members in the axial direction; magnets 40 fixed to the rotor core 30; and fixing members 50 each of which fixes the magnet 40 to the rotor core 30. The rotor core 30 has housing holes 33 penetrating through the rotor core 30 in the axial direction. Each magnet 40 is housed in the housing hole 33. The fixing member 50 has: a base part 51 which contacts with one axial surface of the rotor core 30; and an extension part 52 which extends from the base part 51 to the other axial side and is inserted into the housing hole 33. The extension part 52 has: a magnet support part 53 which is located in the housing hole 33 and presses the magnet 40 to an inner surface of the housing hole 33; and a rotor core support part 54 which contacts with the other axial side surface of the rotor core 30.SELECTED DRAWING: Figure 3

Description

The present invention relates to a rotor and a motor.

A motor having a structure in which a magnet is held in a hole provided in a rotor core is known. For example, Patent Document 1 describes a motor used for electric power steering as such a motor.

Japanese Unexamined Patent Publication No. 2019-115121

The rotor core of a motor as described above may be configured by laminating a plurality of plate members. In this case, there is a risk that a part of the laminated plate members will be turned over. On the other hand, if a member that presses a plurality of plate members is attached to the rotor core, it is possible to prevent the plate members from turning over. However, in this case, the number of parts of the rotor increases, and the man-hours for assembling the rotor increase. Therefore, there is a problem that the manufacturing cost of the rotor and the manufacturing cost of the motor increase.

In view of the above circumstances, one of the objects of the present invention is to provide a rotor and a motor having a structure capable of reducing manufacturing costs.

One aspect of the rotor of the present invention is a shaft that is rotatable around a central axis extending in the axial direction, a rotor core that is fixed to the shaft and is configured by laminating a plurality of plate members in the axial direction, and the rotor core. It includes a fixed magnet and a fixing member for fixing the magnet to the rotor core. The rotor core has an accommodation hole that penetrates in the axial direction. The magnet is housed in the housing hole. The fixing member has a base portion that contacts one side surface of the rotor core in the axial direction, and an extension portion that extends from the base portion to the other side in the axial direction and is passed through the accommodating hole. The stretched portion is located in the accommodating hole and has a magnet support portion that presses the magnet against the inner surface of the accommodating hole and a rotor core support portion that contacts the other surface of the rotor core in the axial direction.

One aspect of the motor of the present invention includes the rotor and a stator facing the rotor with a gap.

According to one aspect of the present invention, the manufacturing cost of the rotor and the manufacturing cost of the motor can be reduced.

FIG. 1 is a cross-sectional view showing a motor of the first embodiment. FIG. 2 is a view of the rotor of the first embodiment as viewed from above. FIG. 3 is a cross-sectional view showing a part of the rotor of the first embodiment, and is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a perspective view showing a part of the rotor core of the first embodiment. FIG. 5 is a perspective view showing the fixing member of the first embodiment. FIG. 6 is a diagram showing a state in which the fixing member of the first embodiment is being manufactured. FIG. 7 is a cross-sectional view showing a part of the rotor in the modified example of the first embodiment. FIG. 8 is a cross-sectional view showing a part of the rotor of the second embodiment. FIG. 9 is a perspective view showing a part of the rotor of the third embodiment.

The Z-axis direction appropriately shown in each figure is a vertical direction in which the positive side is the "upper side" and the negative side is the "lower side". The central axis J appropriately shown in each figure is a virtual line that is parallel to the Z-axis direction and extends in the vertical direction. In the following description, the axial direction of the central axis J, that is, the direction parallel to the vertical direction is simply referred to as "axial direction", and the radial direction centered on the central axis J is simply referred to as "radial direction". The circumferential direction centered on is simply called the "circumferential direction". In each of the following embodiments, the lower side corresponds to "one side in the axial direction" and the upper side corresponds to "the other side in the axial direction".

In addition, the vertical direction, the upper side, and the lower side are simply names for explaining the arrangement relations of each part, and the actual arrangement relations, etc. are the arrangement relations, etc. other than the arrangement relations, etc. indicated by these names. There may be.

<First Embodiment>
The motor 10 of the present embodiment shown in FIG. 1 is an inner rotor type motor. As shown in FIG. 1, the motor 10 of the present embodiment includes a housing 11, a rotor 20, a stator 12, a bearing holder 13, and bearings 14 and 15. The housing 11 internally houses the rotor 20, the stator 12, the bearing holder 13, and the bearings 14 and 15. The bottom of the housing 11 holds the bearing 14. The bearing holder 13 holds the bearing 15. The bearings 14 and 15 are, for example, ball bearings.

The stator 12 faces the rotor 20 via a gap. In this embodiment, the stator 12 is located radially outside the rotor 20. The stator 12 is an annular shape surrounding the rotor 20. The stator 12 has a stator core 12a, an insulator 12b, and a plurality of coils 12c. Although not shown, the stator core 12a has an annular core back surrounding the rotor core 30, which will be described later, and a plurality of teeth extending radially inward from the core back. The plurality of coils 12c are attached to each of the plurality of teeth of the stator core 12a via the insulator 12b.

The rotor 20 can rotate about the central axis J. As shown in FIG. 2, the rotor 20 includes a shaft 21, a rotor core 30, a magnet 40, and a fixing member 50. The shaft 21 is rotatable around a central axis J extending in the axial direction. The shaft 21 is, for example, a columnar shape extending in the axial direction about the central axis J. As shown in FIG. 1, the shaft 21 is rotatably supported around the central axis J by bearings 14 and 15.

The rotor core 30 is a magnetic material. The rotor core 30 is fixed to the shaft 21. As shown in FIG. 2, the rotor core 30 is, for example, a substantially cylindrical shape centered on the central axis J. The rotor core 30 has a central hole 32, an accommodating hole 33, and a through hole 34. The central hole 32 penetrates the rotor core 30 in the axial direction. The central hole 32 is, for example, a circular hole centered on the central axis J. A shaft 21 is passed through the central hole 32 in the axial direction. The shaft 21 is fixed in the central hole 32 by, for example, press fitting or the like. As a result, the rotor core 30 is fixed to the outer peripheral surface of the shaft 21.

The accommodating hole 33 penetrates the rotor core 30 in the axial direction. In the present embodiment, a plurality of accommodating holes 33 are provided along the circumferential direction around the central axis J. The plurality of accommodating holes 33 are arranged at equal intervals, for example, along the circumferential direction. Eight accommodating holes 33 are provided, for example. The accommodating hole 33 is provided, for example, at the radial outer edge of the rotor core 30. The accommodating hole 33 extends linearly along the circumferential direction, for example, when viewed in the axial direction. Each of the plurality of accommodating holes 33 extends along each side of a regular polygonal shape centered on the central axis J, for example, when viewed in the axial direction. That is, each of the eight accommodating holes 33 extends along each side of the regular octagonal shape centered on the central axis J, for example, when viewed in the axial direction. The accommodating hole 33 is, for example, substantially rectangular when viewed in the axial direction.

The through hole 34 penetrates the rotor core 30 in the axial direction. The through hole 34 is, for example, a circular hole. A plurality of through holes 34 are provided along the circumferential direction. The plurality of through holes 34 are arranged at equal intervals, for example, along the circumferential direction. For example, eight through holes 34 are provided. The plurality of through holes 34 are arranged, for example, inside the plurality of accommodating holes 33 in the radial direction. By allowing air to flow in the through hole 34 in the axial direction, the rotor 20 can be cooled by the air.

The plurality of through holes 34 include a plurality of large-diameter holes 34a and a plurality of small-diameter holes 34b. The large-diameter holes 34a and the small-diameter holes 34b are arranged alternately along the circumferential direction, for example. For example, four large-diameter holes 34a and four small-diameter holes 34b are provided. The inner diameter of the small diameter hole 34b is smaller than the inner diameter of the large diameter hole 34a.

As shown in FIG. 3, the rotor core 30 is configured by laminating a plurality of plate members 31 in the axial direction. The plate member 31 has a plate shape in which the plate surface faces the axial direction. The plate surface of the plate member 31 is, for example, orthogonal to the axial direction. Although not shown, the plate members 31 adjacent to each other in the axial direction are connected to each other by, for example, being partially crimped to each other. The plate member 31 is, for example, an electromagnetic steel sheet. In the present embodiment, the plurality of plate members 31 include one first plate member 31a and a plurality of second plate members 31b.

In the present embodiment, the first plate member 31a is a plate member 31 located on the uppermost side of the plurality of plate members 31. As shown in FIG. 4, the first plate member 31a has a retaining portion 35. That is, in the present embodiment, the rotor core 30 has a retaining portion 35. The retaining portion 35 projects, for example, from the inner edge of the upper end of the accommodating hole 33 in a direction orthogonal to the axial direction. In the present embodiment, two retaining portions 35 are provided for each accommodating hole 33. In each accommodating hole 33, two retaining portions 35 are provided at the inner edges of both ends in the circumferential direction at the upper end portion of the accommodating hole 33, respectively. The retaining portion 35 closes a part of the upper opening of the accommodating hole 33.

As shown in FIG. 2, the retaining portion 35 is arranged so as to face the upper side of the magnet 40. In each accommodating hole 33, the two retaining portions 35 are arranged, for example, facing each upper side of both ends in the circumferential direction at the inner end in the radial direction of the magnet 40. The lower surface of the retaining portion 35 may be in contact with the upper surface of the magnet 40, or may be axially opposed to the upper surface of the magnet 40 via a gap.

The second plate member 31b has the same shape as the first plate member 31a except that the retaining portion 35 is not provided. The plurality of plate members 31 constituting the rotor core 30 are all the second plate members 31b except for the first plate member 31a arranged on the uppermost side, for example. As shown in FIG. 3, the lower surface 30a of the rotor core 30 is the lower surface of the second plate member 31b arranged on the lowermost side among the plurality of plate members 31. The upper surface 30b of the rotor core 30 is the upper surface of the first plate member 31a arranged on the uppermost side of the plurality of plate members 31. In the present embodiment, the lower surface 30a corresponds to one surface of the rotor core 30 in the axial direction, and the upper surface 30b corresponds to the other surface of the rotor core 30 in the axial direction.

The magnet 40 is fixed to the rotor core 30 by the fixing member 50. The magnet 40 is housed in the housing hole 33. As shown in FIG. 2, in the present embodiment, the magnet 40 is provided for each accommodating hole 33. That is, in this embodiment, a plurality of magnets 40 are provided along the circumferential direction. For example, eight magnets 40 are provided. As shown in FIGS. 2 and 3, the magnet 40 has, for example, a rectangular parallelepiped shape extending in the axial direction. As shown in FIG. 2, the magnet 40 has, for example, a rectangular shape that is long in the direction in which the accommodating hole 33 accommodating the magnet 40 is extended when viewed in the axial direction. That is, the plurality of magnets 40 have a shape that extends linearly along the circumferential direction, for example, when viewed in the axial direction.

Both ends in the circumferential direction of each magnet 40 are arranged, for example, apart from the surfaces of the inner surface of each accommodating hole 33 located on both sides in the circumferential direction. For example, gaps are provided on both sides of each magnet 40 in the circumferential direction. In the present embodiment, each magnet 40 is arranged at a position offset outward in the radial direction in each accommodation hole 33. As shown in FIG. 3, the radial outer surface of the magnet 40 is in contact with, for example, a surface of the inner surface of the accommodating hole 33 located on the radial outer side. The radial inner surface of the magnet 40 is arranged, for example, radially outward from the surface of the inner surface of the accommodating hole 33 located on the inner side in the radial direction.

The magnet 40 is provided over substantially the entire axial direction of the accommodating hole 33 except for the upper end portion where the retaining portion 35 is provided. The lower surface of the magnet 40 is located at substantially the same position in the axial direction as, for example, the lower surface 30a of the rotor core 30. The upper surface of the magnet 40 is located, for example, below the upper surface 30b of the rotor core 30. The axial dimension of the magnet 40 is smaller than the axial distance between the retaining portion 35 and the base 51 described later. A gap is provided at least one of the axial direction between the lower surface of the magnet 40 and the base 51 and the axial direction between the upper surface of the magnet 40 and the retaining portion 35. The type of magnet 40 is not particularly limited.

The fixing member 50 is a member that fixes the magnet 40 to the rotor core 30. The fixing member 50 has a base portion 51 and an extension portion 52. As shown in FIG. 5, in the present embodiment, the base 51 extends in the circumferential direction around the central axis J. The base portion 51 extends in an arc shape centered on the central axis J, for example. Both ends in the circumferential direction of the base 51 are arranged so as to face each other with a slight gap, for example. The base 51 has, for example, a shape in which a part of the annular shape is divided in the circumferential direction by a slit when viewed in the axial direction. The base 51 has, for example, a plate shape in which the plate surface faces the axial direction. The plate surface of the base 51 is, for example, orthogonal to the axial direction.

As shown in FIGS. 2 and 3, in the present embodiment, the base 51 is located below the plurality of accommodating holes 33. The base 51, for example, closes the lower opening of each accommodation hole 33 almost entirely. In the present embodiment, the base 51 is arranged so as to face the lower side of the magnet 40. The upper surface of the base 51 may be in contact with the lower surface of the magnet 40, or may be opposed to the lower surface of the magnet 40 via a gap.

As shown in FIG. 3, the base 51 is in contact with the lower surface 30a of the rotor core 30. The radial outer edge of the base 51 is located, for example, radially outside the accommodating hole 33. The radial outer edge portion of the base portion 51 is in contact with a portion of the lower surface 30a located on the radial outer side of the accommodating hole 33. The radial position of the radial inner edge portion of the base 51 is, for example, the same as the radial position of the radial inner edge portion of the accommodating hole 33.

The stretched portion 52 extends upward from the base portion 51 and is passed through the accommodating hole 33. The extending portion 52 is inserted into the accommodating hole 33 from below, and protrudes above the accommodating hole 33, for example. As shown in FIG. 2, in the present embodiment, the stretched portion 52 is provided for each accommodating hole 33. That is, in the present embodiment, a plurality of stretched portions 52 are provided along the circumferential direction. The plurality of stretched portions 52 are arranged at equal intervals, for example, along the circumferential direction. Eight stretched portions 52 are provided, for example. As shown in FIG. 5, in the present embodiment, the plurality of stretched portions 52 extend upward from the radial inner edge portion of the base portion 51. That is, in the present embodiment, the base 51 connects a plurality of stretched portions 52.

As shown in FIG. 3, the stretched portion 52 has a magnet support portion 53 and a rotor core support portion 54. The magnet support portion 53 is located in the accommodating hole 33. In the present embodiment, the magnet support portion 53 is located radially inside the magnet 40. The magnet support portion 53 is located in a radial gap between the radial inner surface of the magnet 40 and the inner surface of the accommodating hole 33 that is located radially inside. The radial gap between the radial inner surface of the magnet 40 and the inner surface of the accommodating hole 33 located on the inner side in the radial direction is larger than the plate thickness of the plate-shaped stretched portion 52.

The magnet support portion 53 extends in the axial direction. More specifically, the magnet support 53 extends upward from the radial inner edge of the base 51. The magnet support portion 53 has a plate shape whose plate surface faces in the radial direction. In the present embodiment, the magnet support portion 53 faces the first straight line portion 53a, the first connecting portion 53b, the contact portion 53c, the second connecting portion 53d, and the second straight line portion 53e from the lower side to the upper side. Have in the order of the lever.

The first straight line portion 53a extends straight upward from the radial inner edge portion of the base portion 51. The lower end of the first straight line portion 53a is the lower end of the magnet support portion 53. The radial inner surface of the first straight line portion 53a is in contact with the inner surface of the accommodating hole 33 located on the inner side in the radial direction. The radial outer surface of the first straight line portion 53a is arranged radially inward from the radial inner surface of the magnet 40. The first connecting portion 53b extends outward in the upper diagonal radial direction from the upper end portion of the first straight line portion 53a. The first connecting portion 53b connects the first straight line portion 53a and the contact portion 53c in the axial direction.

The contact portion 53c extends straight upward from the upper end portion of the first connecting portion 53b. The radial outer surface of the contact portion 53c is in contact with the radial inner surface of the magnet 40. The radial inner surface of the contact portion 53c is arranged radially outward from the surface of the inner surface of the accommodating hole 33 located on the inner side in the radial direction. The axial dimension of the contact portion 53c is, for example, larger than the axial dimension of the other portion of the magnet support portion 53. That is, the axial dimensions of the contact portion 53c are, for example, the axial dimension of the first straight line portion 53a, the axial dimension of the first connecting portion 53b, the axial dimension of the second connecting portion 53d, and the second. It is larger than the axial dimension of the straight portion 53e. The second connecting portion 53d extends inward in the upper diagonal radial direction from the upper end portion of the contact portion 53c. The second connecting portion 53d connects the contact portion 53c and the second straight line portion 53e in the axial direction.

The second straight line portion 53e extends straight upward from the upper end portion of the second connecting portion 53d. The upper end of the second straight line portion 53e is the upper end of the magnet support portion 53. The radial inner surface of the second straight line portion 53e is in contact with the inner surface of the accommodating hole 33 located on the inner side in the radial direction. The radial outer surface of the second straight line portion 53e is arranged radially inward from the radial inner surface of the magnet 40. The axial dimension of the second straight line portion 53e is smaller than, for example, the axial dimension of the first straight line portion 53a.

The magnet support portion 53 has a shape in which the contact portion 53c protrudes outward in the radial direction by providing the first connecting portion 53b and the second connecting portion 53d at an angle with respect to the axial direction. The contact portion 53c can be elastically displaced in the radial direction because the first connecting portion 53b and the second connecting portion 53d function as leaf springs. As a result, the magnet support portion 53 functions as an elastic body that can be elastically deformed in the radial direction.

The magnet support portion 53 is sandwiched between a surface of the inner surface of the accommodation hole 33 located on the inner side in the radial direction and the radial inner side surface of the magnet 40 in a state of being accommodated in the accommodation hole 33, and the contact portion 53c is the first. It is in a state of being elastically displaced inward in the radial direction with respect to the first straight line portion 53a and the second straight line portion 53e. That is, the magnet support portion 53 is in a state in which an elastic force can be applied in the radial direction to the member with which the magnet support portion 53 comes into contact in the accommodating hole 33. As a result, the magnet support portion 53 applies a radial outward force to the magnet 40 via the contact portion 53c. The magnet 40 is pressed against the inner surface of the accommodating hole 33, which is located on the outer side in the radial direction, by receiving a force in the radial outward direction from the magnet support portion 53. In this way, the magnet support portion 53 presses the magnet 40 against the inner surface of the accommodating hole 33.

In the present embodiment, the rotor core support portion 54 projects radially inward from the upper end portion of the magnet support portion 53. The rotor core support portion 54 has, for example, a plate shape in which the plate surface faces the axial direction. The plate surface of the rotor core support portion 54 is, for example, orthogonal to the axial direction. The rotor core support portion 54 is located above the rotor core 30. The radially inner end of the rotor core support 54 is located radially outward of the through hole 34.

The rotor core support portion 54 is in contact with the upper surface 30b of the rotor core 30. The lower surface of the rotor core support portion 54 is in contact with, for example, a portion of the upper surface 30b located on the radial inside of the accommodating hole 33 and on the radial outside of the through hole 34. The lower surface of the rotor core support portion 54 is in contact with, for example, the radial inner portion of the peripheral edge portion of the accommodating hole 33 on the upper surface 30b.

In the present embodiment, the rotor core support portion 54 is a caulked portion in which the upper end portion of the stretched portion 52 is crimped. In the present specification, the caulked portion means a portion formed by plastically deforming a part of a member by, for example, pressing. That is, the rotor core support portion 54 is a portion formed by plastically deforming the upper end portion of the stretched portion 52. In the present embodiment, the rotor core support portion 54 is made by bending the upper end portion of the stretched portion 52 inward in the radial direction and plastically deforming it. The rotor core support portion 54 is caulked inward in the radial direction with respect to the upper end portion of the magnet support portion 53. The fixing member 50 shown in FIG. 5 shows a state before the upper end portion of the stretched portion 52 is crimped, that is, a state before the rotor core support portion 54 is formed.

In this embodiment, the fixing member 50 is a single member. The fixing member 50 is made of sheet metal, for example. That is, the fixing member 50 is made by, for example, machining a sheet metal. A worker or the like who makes the fixing member 50 bends the metal member 150 shown in FIG. 6 punched out from the sheet metal by press working or the like by pressing or the like, so that the fixing member 50 in the state shown in FIG. 5, that is, the rotor core support portion 54 is formed. The fixing member 50 in the state before being made is made.

In addition, in this specification, "worker etc." includes a worker who performs each work, equipment and the like. Each work may be performed only by the worker, may be performed only by the equipment or the like, or may be performed by the worker and the equipment or the like.

As shown in FIG. 6, the metal member 150 has a first portion 151 and a plurality of second portions 152. The first portion 151 is a rectangular plate-shaped portion extending linearly. The plurality of second portions 152 are rectangular plate-shaped portions extending linearly from the first portion 151 in a direction orthogonal to the direction in which the first portion 151 extends. The direction in which the second portion 152 extends is a direction parallel to the plate surface of the first portion 151. The plurality of second portions 152 are arranged side by side at intervals along the direction in which the first portion 151 extends. The plate surface of the first portion 151 and the plate surface of the second portion 152 are parallel to each other.

The first portion 151 is a portion that is bent in an arc shape in a plane parallel to the plate surface of the first portion 151 to become a base portion 51. The second portion 152 is a portion that is bent in a direction orthogonal to the plate surface to form a stretched portion 52. The second portion 152 is, for example, bent along the alternate long and short dash line shown in FIG. 6 to become the stretched portion 52 before the rotor core support portion 54 is formed, that is, the stretched portion 52 shown in FIG. The direction in which the second portion 152 is bent along the alternate long and short dash line is opposite to the direction in which the second portion 152 is bent along the alternate long and short dash line. For example, the operator or the like bends the second portion 152 along the alternate long and short dash line and then bends the first portion 151 in an arc shape. When bending the second portion 152, the operator or the like, for example, bends the plurality of second portions 152 together.

After inserting the magnet 40 into each of the accommodating holes 33 of the rotor core 30 from below, the operator or the like inserts each extended portion 52 of the fixing member 50 in the state shown in FIG. 5 into each accommodating hole 33 from below. Insert. An operator or the like inserts the stretched portion 52 into the accommodating hole 33 until the upper surface of the base portion 51 contacts the lower surface 30a of the rotor core 30. An operator or the like crimps the upper end portion of the extending portion 52 protruding upward from the upper opening of the accommodating hole 33 inward in the radial direction to bring it into contact with the upper surface 30b of the rotor core 30. As a result, the rotor core support portion 54 that contacts the upper surface 30b of the rotor core 30 is formed, and the magnet 40 and the fixing member 50 are assembled to the rotor core 30. When assembling the magnet 40 and the fixing member 50 to the rotor core 30, the operator or the like may, for example, invert the posture of the rotor core 30 up and down to perform each operation.

According to the present embodiment, the fixing member 50 for fixing the magnet 40 to the rotor core 30 has a base portion 51 that contacts the lower surface 30a of the rotor core 30 and an extension portion 52 that extends upward from the base portion 51 and is passed through the accommodating hole 33. And have. The stretched portion 52 has a magnet support portion 53 that presses the magnet 40 against the inner surface of the accommodating hole 33, and a rotor core support portion 54 that contacts the upper surface 30b of the rotor core 30. By pressing the magnet 40 against the inner surface of the accommodating hole 33 by the magnet support portion 53, the magnet 40 can be fixed to the rotor core 30. Further, when the base portion 51 contacts the lower surface 30a of the rotor core 30 and the rotor core support portion 54 contacts the upper surface 30b of the rotor core 30, it is possible to prevent the fixing member 50 from being axially disengaged from the rotor core 30. Further, since the rotor core 30 can be pressed from both sides in the axial direction by the base portion 51 and the rotor core support portion 54, it is possible to prevent a part of the plate member 31 constituting the rotor core 30 from being turned over.

As described above, the fixing member 50 for fixing the magnet 40 to the rotor core 30 is provided with the base 51 and the rotor core support portion 54, and the fixing member 50 can be used as a member for holding the plurality of laminated plate members 31. It is possible to prevent the plate member 31 from being turned over without separately providing the member. Therefore, it is possible to suppress an increase in the number of parts of the rotor 20 while suppressing the plate member 31 from turning over. As a result, it is possible to suppress an increase in the assembly man-hours of the rotor 20, and it is possible to suppress an increase in the assembly man-hours of the motor 10. Therefore, the manufacturing cost of the rotor 20 and the manufacturing cost of the motor 10 can be reduced.

Further, by attaching the fixing member 50 to the rotor core 30, it is possible to easily perform the work of fixing the magnet 40 to the rotor core 30 and the work of pressing the plurality of stacked plate members 31. Therefore, as compared with the case where, for example, a resin member for pressing the magnet 40 and the plate member 31 is manufactured by insert molding using the rotor core 30 and the magnet 40 as the insert member, the work of fixing the magnet 40 to the rotor core 30 and a plurality of laminated plates are performed. The time and man-hours required to perform the work of pressing the member 31 can be reduced. Therefore, the manufacturing cost of the rotor 20 and the manufacturing cost of the motor 10 can be further reduced.

Further, according to the present embodiment, a plurality of accommodating holes 33 are provided along the circumferential direction around the central axis J. The magnet 40 and the extending portion 52 are provided for each accommodating hole 33, respectively. The base portion 51 extends in the circumferential direction around the central axis J and connects a plurality of extending portions 52. Therefore, each magnet 40 can be fixed to the rotor core 30 by the magnet support portion 53 of each extension portion 52. Further, the plate member 31 can be pressed by the rotor core support portions 54 of the plurality of stretched portions 52. Therefore, it is possible to more preferably suppress the plate member 31 from turning over.

Further, since the plurality of stretched portions 52 are connected by one base portion 51, by attaching one fixing member 50 to the rotor core 30, the plurality of stretched portions 52 can be collectively attached to the rotor core 30. Therefore, as compared with the case where a plurality of fixing members having one base portion 51 and one extension portion 52 are provided, workability when attaching the fixing member 50 to the rotor core 30 can be improved, and the fixing member 50 can be attached to the rotor core 30. It is possible to shorten the work time required for the work of attaching to. Further, the man-hours for manufacturing the fixing member 50 can be reduced as compared with the case where a plurality of fixing members having one base portion 51 and one extending portion 52 are made. As a result, the manufacturing cost of the fixing member 50 can be reduced, and the manufacturing cost of the rotor 20 and the manufacturing cost of the motor 10 can be further reduced.

Further, according to the present embodiment, the rotor core support portion 54 is a caulked portion in which the upper end portion of the stretched portion 52 is crimped. Therefore, as described above, the rotor core support portion 54 can be easily and suitably formed by passing the stretched portion 52 through the accommodating hole 33 and then caulking the upper end portion of the stretched portion 52. Further, it is easy to accurately bring the rotor core support portion 54 into contact with the upper surface 30b of the rotor core 30. Therefore, it is possible to more preferably press the plurality of plate members 31.

Further, according to the present embodiment, the fixing member 50 is a single member. Therefore, it is possible to further suppress an increase in the number of parts of the rotor 20 and the number of parts of the motor 10. Further, the man-hours for manufacturing the fixing member 50 can be reduced as compared with the case where a plurality of members are connected to form the fixing member 50. As a result, the manufacturing cost of the rotor 20 and the manufacturing cost of the motor 10 can be further reduced.

Further, according to the present embodiment, the fixing member 50 is made of sheet metal. Therefore, the manufacturing cost of the fixing member 50 can be reduced as compared with the case where the fixing member 50 is made by die casting or the like, for example. As a result, the manufacturing cost of the rotor 20 and the manufacturing cost of the motor 10 can be further reduced. Further, since the stretched portion 52 has a plate shape, it is easy to crimp the upper end portion of the stretched portion 52 to form the rotor core support portion 54.

Further, according to the present embodiment, the base 51 is arranged so as to face the lower side of the magnet 40. The rotor core 30 has a retaining portion 35 arranged to face the upper side of the magnet 40. Therefore, the magnet 40 can be sandwiched in the axial direction by the base portion 51 and the retaining portion 35. As a result, it is possible to prevent the magnet 40 from coming out of the accommodating hole 33 in the axial direction and the magnet 40 from being displaced in the axial direction. Further, since it is possible to prevent the magnets 40 from being displaced in the axial direction, it is easy to preferably align the axial positions of the plurality of magnets 40, and it is possible to suppress the range of the magnetic field generated by each magnet 40 from being displaced in the axial direction. Therefore, by using the fixing member 50, the rotor 20 having excellent magnetic characteristics can be manufactured at low cost. Further, by suppressing the variation in the axial position of the magnet 40, for example, when a magnetic sensor capable of detecting the magnetic field of the magnet 40 is provided, it is possible to suppress the variation in the axial distance between the magnet 40 and the magnetic sensor. can. Therefore, the magnetic field of the magnet 40 can be suitably detected by the magnetic sensor.

Further, for example, when the magnet support portion 53 is located radially inside the magnet 40 and the rotor core support portion 54 projects radially outward from the upper end portion of the magnet support portion 53, the rotor core support portion 54 is used as the rotor core. In order to bring the rotor core support portion 54 into contact with the upper surface 30b of 30, it is necessary to extend the rotor core support portion 54 radially outside the accommodating hole 33. Therefore, in order to suitably secure an area where the plate member 31 can be pressed by the rotor core support portion 54, it is necessary to relatively increase the radial dimension of the rotor core support portion 54.

On the other hand, according to the present embodiment, the magnet support portion 53 is located radially inward with respect to the magnet 40, and the rotor core support portion 54 projects radially inward from the upper end portion of the magnet support portion 53. There is. Therefore, even if the radial dimension of the rotor core support portion 54 is small, the rotor core support portion 54 can be easily brought into contact with the upper surface 30b of the rotor core 30. As a result, the area where the plate member 31 can be pressed by the rotor core support portion 54 is preferably set while reducing the radial dimension of the rotor core support portion 54 as compared with the case where the rotor core support portion 54 projects outward in the radial direction. Easy to secure. Therefore, it is easy to suitably hold the plate member 31 by the rotor core support portion 54 while reducing the radial dimension of the rotor core support portion 54 to reduce the manufacturing cost of the fixing member 50.

Further, according to the present embodiment, the axial dimensions of the contact portion 53c are the axial dimension of the first straight line portion 53a, the axial dimension of the first connecting portion 53b, and the axial dimension of the second connecting portion 53d. It is larger than the dimension and the axial dimension of the second straight portion 53e. Therefore, the axial dimension of the contact portion 53c can be made relatively large. As a result, the area in which the magnet support portion 53 contacts the magnet 40 in the accommodating hole 33 can be increased. Therefore, a radial outward force can be suitably applied to the magnet 40 via the contact portion 53c, and the magnet 40 can be suitably fixed in the accommodating hole 33 by the magnet support portion 53.

Further, according to the present embodiment, the contact portion 53c is a portion of the magnet support portion 53 provided at a position closer to the base portion 51 than the second connecting portion 53d and the second straight line portion 53e. That is, the contact portion 53c is provided closer to the base portion 51 than the upper end portion of the magnet support portion 53. Therefore, for example, as compared with the case where the contact portion 53c is provided at the upper end portion of the magnet support portion 53, when the stretched portion 52 starts to be inserted into the accommodating hole 33 from the lower side, the upper side of the stretched portion 52 The end is hard to come into contact with the magnet 40. This makes it easier for the stretched portion 52 to pass through the accommodating hole 33. Therefore, the fixing member 50 can be more easily attached to the rotor core 30. In particular, in the present embodiment, a second straight line portion 53e extending linearly in the axial direction is provided at the upper end portion of the magnet support portion 53, and the second straight line portion 53e and the contact portion 53c are in the axial direction. A second connecting portion 53d extending diagonally with respect to the axial direction is provided between them. Therefore, when the extended portion 52 is inserted into the accommodating hole 33 from the lower side, the second straight line portion 53e can be easily inserted from the lower opening of the accommodating hole 33. Further, the second connecting portion 53d extending diagonally makes it easy to insert the contact portion 53c between the radial inner surface of the accommodating hole 33 and the radial inner surface of the magnet 40 while elastically displacement the contact portion 53c in the radial direction. ..

Further, according to the present embodiment, each magnet 40 is pressed against the radial outer surface in each accommodation hole 33 by each magnet support portion 53. Therefore, each magnet 40 can be positioned in the radial direction by the radial outer surface in each accommodation hole 33. As a result, the radial positions of the magnets 40 can be suitably aligned regardless of the accuracy of the work performed by the operator or the like. That is, it is possible to prevent the radial positions of the magnets 40 from fluctuating. Therefore, the magnetic characteristics of the rotor 20 can be improved, and the quality of the motor 10 such as the output torque can be improved. In addition, vibration and eccentric load caused by centrifugal force generated when the rotor 20 rotates can be reduced. Therefore, the load on the bearings 14 and 15 that support the rotor 20 can also be reduced. Thereby, the life of the motor 10 can be improved. Further, by using the fixing member 50, it is possible to suppress the variation in the magnetic characteristics of the rotor 20 because the radial position of the magnet 40 is unlikely to vary when the rotor 20 is assembled. As a result, it is possible to suppress variations in the quality of the motor 10 such as the output torque.

(Variation example of the first embodiment)
In the rotor 220 of the motor 210 shown in FIG. 7, the base portion 251 of the fixing member 250 has a base portion main body 251a and a folded-back portion 255. The base body 251a has the same shape as the base 51 described above. The folded-back portion 255 projects downward from the radial inner edge portion of the base main body 251a, is folded back radially inward and upward, and is connected to the lower end portion of the magnet support portion 53. The folded-back portion 255, for example, bends the second portion 152 of the metal member 150 shown in FIG. 6 from the root in a direction orthogonal to the plate surface with respect to the first portion 151, and then further folds the second portion 152 in the opposite direction. Made by Other configurations of the motor 210 can be the same as the other configurations of the motor 10 described above.

According to this modification, the rigidity of the connecting portion between the base portion 251 and the extending portion 52 can be increased by providing the folded-back portion 255. Therefore, the stretched portion 52 is less likely to be displaced with respect to the base portion 251, and it is possible to easily maintain a state in which the magnet 40 and the plate member 31 are suitably pressed by the magnet support portion 53 and the rotor core support portion 54 of the stretched portion 52. Further, when the fixing member 250 is made of sheet metal, it is easy to secure the rigidity at the connecting portion between the base portion 251 and the extended portion 52 even if the thickness of the sheet metal is reduced. Therefore, the thickness of the sheet metal for making the fixing member 250 can be reduced. As a result, the manufacturing cost of the fixing member 250 can be further reduced. Therefore, the manufacturing cost of the rotor 220 and the manufacturing cost of the motor 210 can be further reduced. Further, since the fixing member 250 can be reduced in weight by reducing the thickness of the sheet metal, the rotor 220 and the motor 210 can be reduced in weight.

Further, for example, in a configuration in which the magnet 40 can be inserted from the opening on the upper side of the accommodating hole 33, when the fixing member 250 is attached to the rotor core 30 and then the magnet 40 is inserted into the accommodating hole 33 from above, the magnet 40 is subjected to magnetic force. Even if the base portion 251 is sucked into the accommodating hole 33 and collides with the base portion 251 from above, the base portion 251 can be prevented from being deformed with respect to the stretched portion 52. As a result, it is possible to prevent the magnet 40 from being displaced.

<Second Embodiment>
As shown in FIG. 8, in the rotor 320 of the motor 310 of the present embodiment, the rotor core 330 has a different shape of the first plate member 331a from the rotor core 30 of the first embodiment. The retaining portion 335 of the first plate member 331a projects radially inward from the radial outer inner surface at the upper end portion of the accommodating hole 33. The retaining portion 335 covers the entire opening of the upper side of the accommodating hole 33 except for the radial inner end. In the present embodiment, the shape of the portion of the accommodating hole 33 exposed above the first plate member 331a is a slit shape having a width wider than the plate thickness of the sheet metal constituting the fixing member 350. In the present embodiment, the retaining portion 335 covers, for example, the entire upper side of the magnet 40.

In the fixing member 350 of the present embodiment, the rotor core support portion 354 of the stretched portion 352 projects radially outward from the upper end portion of the magnet support portion 353. At least a part of the rotor core support portion 354 is in contact with the upper surface of the retaining portion 335. As a result, the first plate member 331a can be pressed from above by the rotor core support portion 354. Therefore, it is possible to prevent the plurality of plate members 31 constituting the rotor core 330 from being turned over. In the present embodiment, the rotor core support portion 354 is almost entirely in contact with the upper surface of the retaining portion 335. Other configurations of the motor 310 can be the same as the other configurations of the motor 10 of the first embodiment. The rotor core support portion 354 may be in contact with the upper surface of the retaining portion 335 in any way. The rotor core support portion 354 and the retaining portion 335 may be in point contact with each other, for example.

According to the present embodiment, the rotor core support portion 354 projects radially outward from the upper end portion of the stretched portion 352. Therefore, when the through hole 34 is provided inside the accommodating hole 33 in the radial direction, the rotor core support portion 354 does not block the through hole 34 even if the radial dimension of the rotor core support portion 354 is increased. As a result, the air flowing in the through hole 34 is not obstructed by the rotor core support portion 354. Therefore, air can be suitably flowed through the through hole 34, and the rotor 320 can be suitably cooled.

<Third Embodiment>
As shown in FIG. 9, in the rotor 420 of the motor 410 of the present embodiment, the rotor core 430 does not have the first plate member 31a unlike the first embodiment. The plurality of plate members 31 constituting the rotor core 430 include, for example, only the second plate member 31b. Unlike the first embodiment, the rotor core 430 does not have a retaining portion 35.

The upper end portion of the stretched portion 452 in the fixing member 450 of the present embodiment is bifurcated at intervals in the circumferential direction. One of the upper end portions of the bifurcated extension portion 452 is a rotor core support portion 454. The rotor core support portion 454 projects radially inward from the upper end portion of the magnet support portion 53. The rotor core support portion 454 is, for example, a caulked portion in which the upper end portion of the stretched portion 452 is caulked inward in the radial direction. The rotor core support portion 454 is in contact with the upper surface of the rotor core 430. In the present embodiment, the upper surface of the rotor core 430 is the upper surface of the second plate member 31b located on the uppermost side of the plurality of plate members 31.

The other end of the bifurcated extension 452 is a protrusion 456 that projects radially outward from the upper end of the magnet support 53. That is, in the present embodiment, the stretched portion 452 has a protruding portion 456. The protruding portion 456 is, for example, a caulked portion in which the upper end portion of the stretched portion 452 is caulked outward in the radial direction.

The protrusion 456 covers at least a part of the accommodating hole 33 from above. In the present embodiment, the protrusion 456 covers a part of the accommodating hole 33 from above. The protrusion 456 is arranged so as to face the upper side of the magnet 40. The lower surface of the protrusion 456 may be in contact with the upper surface of the magnet 40, or may be opposed to the upper surface of the magnet 40 via a gap. In the present embodiment, the upper surface of the magnet 40 is arranged at the same position in the axial direction as the upper surface of the rotor core 430. Other configurations of the motor 410 can be the same as the other configurations of the motor of each embodiment described above. In the present embodiment, the inner side in the radial direction corresponds to "one side in the radial direction", and the outer side in the radial direction corresponds to "the other side in the radial direction".

According to the present embodiment, the stretched portion 452 has a protruding portion 456 that covers at least a part of the accommodating hole 33 from above. Therefore, even if the rotor core 430 is not provided with the retaining portion 35, the protruding portion 456 can prevent the magnet 40 from coming out of the accommodating hole 33 upward. Further, when the protruding portion 456 is used as a caulking portion, the protruding portion 456 can be suitably brought into contact with the upper surface of the magnet 40. Therefore, the magnet 40 can be more preferably held in the axial direction.

Further, when the protruding portion 456 is used as a caulking portion, the opening on the upper side of the accommodating hole 33 can be made in a state in which the magnet 40 can be inserted before the protruding portion 456 is caulked. Therefore, for example, an assembly method in which one of the upper ends of the bifurcated extension portion 452 is caulked to form a rotor core support portion 454, a fixing member 450 is attached to the rotor core 430, and then a magnet 40 is inserted from above the accommodating hole 33. Can be adopted. As a result, the degree of freedom in the assembly method of the rotor 420 can be improved.

The present invention is not limited to the above-described embodiment, and other configurations may be adopted within the scope of the technical idea of the present invention. The fixing member may be configured by connecting a plurality of members. The material constituting the fixing member is not particularly limited. The fixing member may be made of resin. The fixing member may be manufactured by a method such as die casting in which a material is poured into a mold and molded. A plurality of fixing members may be provided. In this case, each fixing member may have one base and at least one stretched portion. The number of stretched portions included in one fixing member is not particularly limited. One fixing member may have only one stretched portion. The shape of the base is not particularly limited. The base may be an annular shape connected over the entire circumference.

The magnet support portion may be arranged at any position with respect to the magnet in the accommodating hole. The magnet support portion may be located radially outside the magnet in the accommodating hole, or may be located in the accommodating hole at a position adjacent to the magnet in the circumferential direction. When the magnet support portion is located radially outside the magnet, the magnet support portion presses, for example, the magnet against the inner surface of the accommodating hole, which is located radially inside. When the magnet support portion is located on one side in the circumferential direction of the magnet, the magnet support portion presses the magnet, for example, against the inner surface of the accommodating hole, which is located on the other side in the circumferential direction. For example, in the first embodiment described above, the magnet support portion 53 may be arranged in any of the gap portions provided on both sides of the magnet 40 in the circumferential direction. The shape of the magnet support portion is not particularly limited as long as the magnet can be pressed against the inner surface of the accommodating hole.

When the magnet support is located radially outside the magnet, the rotor core support projects radially outward from the axially other end of the magnet support, and the stretched portion is axially the other side of the magnet support. It may have a protruding portion that protrudes radially inward from the end portion of the magnet. Also in this configuration, the protrusion covers at least a part of the accommodation hole from the other side in the axial direction, so that the protrusion can prevent the magnet from coming out of the accommodation hole, as in the third embodiment. In this case, the outer side in the radial direction corresponds to "one side in the radial direction", and the inner side in the radial direction corresponds to "the other side in the radial direction".

The protruding portion provided on the stretched portion may come into contact with the other surface of the rotor core in the axial direction. For example, in the third embodiment described above, the protruding portion 456 may further protrude outward in the radial direction and come into contact with a portion of the upper surface of the rotor core 430 located outside the accommodating hole 33 in the radial direction. In this case, the plate member 31 can be pressed while suppressing the magnet 40 from coming out upward by the protrusion 456. Therefore, the plate member 31 can be pressed more preferably.

The rotor core support portion may have any shape as long as it contacts the other surface of the rotor core in the axial direction. The rotor core support portion may be at least partially in contact with the other surface of the rotor core in the axial direction. The rotor core support portion does not have to be a caulking portion. In this case, the rotor core support may be, for example, a portion formed by die casting. Two or more rotor core support portions may be provided in one extension portion. The fixing member may have an extension portion that does not have a rotor core support portion. For example, in the first embodiment described above, some of the stretched portions 52 among the plurality of stretched portions 52 may not have the rotor core support portion 54.

The shape of the magnet is not particularly limited. The number of magnets is not particularly limited. Only one magnet may be provided. In this case, the magnet may be an annular shape surrounding the central axis. The material of the plurality of plate members constituting the rotor core is not particularly limited. The plurality of plate members may include three or more types of plate members having different shapes. The number of plate members is not particularly limited as long as it is two or more. In the fourth embodiment described above, the rotor core 430 may have a retaining portion.

The shape of the accommodating hole provided in the rotor core as viewed in the axial direction is not particularly limited. The rotor core may be provided with a pair of accommodating holes extending in a direction away from each other in the circumferential direction toward the outer side in the radial direction when viewed in the axial direction. In this case, a plurality of pairs of accommodating holes may be provided along the circumferential direction. Further, in this case, the pair of accommodating holes may have a substantially rectangular shape extending diagonally with respect to the radial direction when viewed in the axial direction. Further, in this case, the pair of accommodating holes may be arranged along a V-shape that opens radially outward when viewed in the axial direction. It should be noted that the pair of accommodating holes may extend in a direction closer to each other in the circumferential direction toward the outer side in the radial direction when viewed in the axial direction. In this case, the pair of accommodating holes may be arranged along a V-shape that opens inward in the radial direction when viewed in the axial direction.

The application of the motor to which the present invention is applied is not particularly limited. The motor may be mounted on a vehicle, for example, or may be mounted on a device other than the vehicle. As described above, the configurations described in the present specification can be appropriately combined within a range that does not contradict each other.

10,210,310,410 ... motor, 12 ... stator, 20,220,320,420 ... rotor, 21 ... shaft, 30,330,430 ... rotor core, 31 ... plate member, 31a, 331a ... first plate member ( Plate member), 31b ... Second plate member (plate member), 33 ... Accommodating hole, 35,335 ... Retaining part, 40 ... Magnet, 50, 250, 350, 450 ... Fixing member, 51,251 ... Base, 52 , 352,452 ... Stretched part, 53,353 ... Magnet support part, 54,354,454 ... Rotor core support part, 456 ... Protruding part, J ... Central axis

Claims (10)

A shaft that can rotate around a central axis that extends in the axial direction,
A rotor core fixed to the shaft and configured by laminating a plurality of plate members in the axial direction,
The magnet fixed to the rotor core and
A fixing member that fixes the magnet to the rotor core,
Equipped with
The rotor core has an accommodation hole that penetrates in the axial direction.
The magnet is accommodated in the accommodating hole and is accommodated in the accommodating hole.
The fixing member is
A base that contacts one surface of the rotor core in the axial direction and
An elongated portion extending axially from the base portion to the other side and passing through the accommodating hole,
Have,
The stretched portion
A magnet support portion located in the accommodation hole and pressing the magnet against the inner surface of the accommodation hole,
A rotor core support portion that contacts the other side surface of the rotor core in the axial direction,
Has a rotor. A plurality of the accommodating holes are provided along the circumferential direction around the central axis.
The magnet and the stretched portion are provided for each of the accommodating holes, respectively.
The rotor according to claim 1, wherein the base portion extends in the circumferential direction around the central axis and connects a plurality of the stretched portions. The rotor according to claim 1 or 2, wherein the rotor core support portion is a caulked portion in which an end portion on the other side in the axial direction of the stretched portion is caulked. The rotor according to any one of claims 1 to 3, wherein the fixing member is a single member. The rotor according to claim 4, wherein the fixing member is made of sheet metal. The base is arranged so as to face one side of the magnet in the axial direction.
The rotor according to any one of claims 1 to 5, wherein the rotor core has a retaining portion arranged so as to face the other side in the axial direction of the magnet. The magnet support portion is located radially inside the magnet and extends axially.
The rotor core support portion protrudes radially outward from the end portion on the other side in the axial direction of the magnet support portion, and at least a part of the rotor core support portion is in contact with the surface on the other side in the axial direction of the retaining portion. 6. The rotor according to 6. The magnet support portion is located radially inside the magnet and extends axially.
The rotor according to any one of claims 1 to 6, wherein the rotor core support portion projects radially inward from an end portion on the other side in the axial direction of the magnet support portion. The magnet support portion is located on one side in the radial direction with respect to the magnet and extends in the axial direction.
The rotor core support portion protrudes from the end portion on the other side in the axial direction of the magnet support portion to one side in the radial direction.
The stretched portion has a protruding portion that protrudes from the end portion on the other side in the axial direction of the magnet support portion to the other side in the radial direction.
The rotor according to any one of claims 1 to 6, wherein the protrusion covers at least a part of the accommodating hole from the other side in the axial direction. The rotor according to any one of claims 1 to 9,
With the stator facing the rotor through a gap,
Equipped with a motor.

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