WO2020017189A1 - Motor and method for manufacturing motor - Google Patents

Abstract

The rotor (3) of an embodiment is provided with a rotor body (31). The rotor body (31) is provided with a plurality of cores (312a) coupled through coupling portions (312b), wherein the plurality of cores (312a) are disposed in an annular shape.

Description

Motor and method of manufacturing motor

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

Conventionally, the rotor used in the permanent magnet embedded type synchronous motor has sometimes been formed by laminating a plurality of electromagnetic steel sheets punched into a circular outer shape. In some cases, a rotor core is used in which a plurality of core pieces formed by laminating steel pieces constituting a core piece are fixed to each other to form an annular rotor core (for example, see Patent Document 1).

JP 2012-257351 A

However, the rotor of the conventional permanent magnet embedded type synchronous motor has difficulty in fixing or magnetizing the magnet when the magnet is mounted on the rotor, or controlling d-axis inductance or q-axis inductance that determines reluctance torque. In some cases, it was difficult to fix the shaft to the rotor.

The present invention exemplifies the above-described problem as an example, and has an object to simply form a rotor.

ロ ー タ A rotor according to one embodiment of the present invention includes a rotor main body. The rotor body includes a plurality of cores connected via a connecting portion, and the plurality of cores are arranged in a ring.

According to one embodiment of the present invention, the rotor can be easily formed.

FIG. 1 is a perspective view illustrating a configuration example of the rotor according to the first embodiment. FIG. 2 is a plan view illustrating an example of a shape of a steel plate forming a connecting core according to the first embodiment. FIG. 3 is a perspective view illustrating an example of the shape of the connection core according to the first embodiment. FIG. 4 is a diagram illustrating an example of a measure against vibration. FIG. 5A is a diagram (1) illustrating an example in which the fixing between the rotor main body and the shaft is strengthened. FIG. 5B is a diagram (2) illustrating an example in which the fixing between the rotor main body and the shaft is strengthened. FIG. 6A is a diagram (1) illustrating another example in which the fixing between the rotor main body and the shaft is strengthened. FIG. 6B is a diagram (2) illustrating another example in which the fixing between the rotor main body and the shaft is strengthened. FIG. 7A is a perspective view (1) illustrating a configuration example of a motor. FIG. 7B is a perspective view (2) illustrating a configuration example of the motor. FIG. 8 is a perspective view illustrating a configuration example of a rotor according to the second embodiment. FIG. 9 is a plan view illustrating an example of a shape of a steel plate forming a connecting core according to the second embodiment. FIG. 10 is a perspective view showing an example of the shape of the connecting core according to the second embodiment. FIG. 11 is a diagram illustrating an example of a method of attaching a magnet to the connection core. FIG. 12 is a diagram illustrating an example of a grain-oriented electrical steel sheet. FIG. 13 is a diagram illustrating an example of a steel sheet formed by punching from a grain-oriented electrical steel sheet. FIG. 14 is an explanatory diagram of the d-axis inductance and the q-axis inductance. FIG. 15 is a plan view illustrating an example of a connection core according to the third embodiment. FIG. 16 is a plan view illustrating an example of a rotor main body according to the third embodiment.

Hereinafter, a motor and a method for manufacturing the motor according to the embodiment will be described with reference to the drawings. Note that the present invention is not limited by the embodiment. In addition, the dimensional relationship of each element, the ratio of each element, and the like in the drawings may be different from reality. Even in the drawings, there may be cases where portions having different dimensional relationships and ratios are included. In addition, the contents described in one embodiment or modification are similarly applied to other embodiments or modifications in principle.

(First embodiment)
FIG. 1 is a perspective view showing a configuration example of the rotor 3 according to the first embodiment. In FIG. 1, the rotor 3 includes a rotor main body 31 and a shaft 32. The rotor main body 31 is formed by bending a connecting core (312) described later, which is formed by laminating electromagnetic steel sheets as magnetic members. In the illustrated example, four substantially fan-shaped pieces 312a connected by the connecting portion 312b are bent so as to sandwich the rod-shaped shaft 32 and are formed in an annular shape. Piece 312a is an example of a core. The connecting portion 312c at the end of the connecting core where the connecting portion 312b does not exist is connected by laser welding or the like along the axial direction. The number of the pieces 312a is not limited to four, and may be an even number such as 6, 8, 10, or the like.

ピ ー ス Each piece 312a is provided with a substantially arc-shaped hole 312d penetrating in the axial direction, and a magnet 313 is arranged in the hole 312d as an example. By providing the magnet 313, torque (magnet torque) due to the magnet 313 is obtained as a motor, but even when the magnet 313 is not present, reluctance torque due to the hole 312d is obtained.

FIG. 2 is a plan view showing an example of the shape of the steel plate 311 forming the connection core according to the first embodiment. The steel plate 311 is formed by punching out a magnetic steel plate with a mold or the like. Also, a plurality of steel plates 311 are stacked to form a connection core (312).

に お い て In FIG. 2, in the example shown in FIG. 2, four piece steel plates 311a forming a substantially fan-shaped piece divided into four parts are connected via a connection part 311b. The connecting portion 311b is thinly formed by being sandwiched between an edge extending linearly on the outer peripheral side and an arc-shaped concave portion on the inner peripheral side, and can be easily bent in a direction in which the arc-shaped concave portion closes. . The left and right ends of the steel plate 311 are connection portions 311c, and a plurality of steel plates 311 are stacked to form a connection core. When the plurality of steel plates 311 are bent in an annular shape, the left and right connection portions 311c and the end surfaces of the piece steel plates 311a come into contact with each other. In the connection core, the position of the connection portion 311c in the radial direction is slightly closer to the center of the shaft (toward the shaft 32) than the outer peripheral surface of the piece steel plate 311a. This is because when the outer peripheral surface of the connecting portion 311c is connected by laser welding or the like, a part of the connecting portion formed by laser welding or the like (part of the connecting member) does not protrude from the outer peripheral surface of the rotor 3. In addition to this, it is to secure a margin for grinding and polishing the outer peripheral surface of the rotor 3 with a lathe or the like in order to improve accuracy. A shaft contact portion 311e that matches the curvature of the outer peripheral surface of the shaft 32 is formed on the inner side of the fan shape of each piece steel plate 311a. An arc-shaped hole 311d is provided in the center of the piece steel plate 311a. The shape of the hole 311d is not limited to the illustrated one, and may be any shape such as a V-shape or a straight shape in consideration of reluctance torque. The hole 311d is formed to be convex toward the inside of the connection core (toward the shaft 32), and the outer peripheral surface of the piece steel plate 311a is formed to be convex toward the outside of the connection core.

FIG. 3 is a perspective view showing an example of the shape of the connection core 312 according to the first embodiment. The connection core 312 is formed by laminating a plurality of steel plates 311 shown in FIG. Note that, in FIG. 3, streaks on an end surface indicating lamination of the electromagnetic steel sheets are omitted. In the illustrated example, four substantially fan-shaped pieces 312a that are divided into four pieces are connected via a connecting part 312b, and are arranged in one direction. The connecting portion 312b is formed thin by being sandwiched between a flat edge on the outer peripheral side and a curved concave portion on the inner peripheral side, and can be easily bent in a direction in which the curved concave portion closes. The left and right ends of the connection core 312 are formed as connection portions 312c, and the end surfaces of the left and right connection portions 312c and the piece 312a are in symmetrical contact with each other in an annularly bent state. A shaft contact portion 312e that matches the curvature of the outer peripheral surface of the shaft 32 is formed on the inner side of the fan shape of each piece 312a. An arc-shaped hole 312d is provided at the center of the piece 312a.

When the magnet 313 is arranged in the hole 312d of the connecting core 312, for example, the material forming the softened magnet is filled into the hole 312d by injection molding or the like, and the material is formed after the material forming the magnet is solidified. Magnetization is performed. The magnet (313) filled and formed by injection molding or the like is firmly fixed to the hole 312d. Further, in the state of the connecting core 312 in which the pieces 312a are arranged in a line (a state where the space between the pieces 312a is open), the magnets 313 of the pieces 312a can be magnetized for each magnet 313. , And the performance of the motor can be improved. For example, in a state where a plurality of magnets 313 are arranged close to each other as shown in FIG. 1, when applying a magnetic field for magnetizing from the outside, it is necessary to narrow down and apply the magnetic field to each magnet 313. It is difficult, and the strength of the applied magnetic field must be reduced in order to reduce adverse effects on magnets other than the magnet 313 to be magnetized, so that magnetization with sufficient strength may not be performed. However, when the magnets 313 are separated from each other, strong magnetization can be performed without affecting other magnets 313.

In addition, in FIG. 3, when a molded magnet 313 is disposed in the hole 312d of the connecting core 312, the magnetized magnet 313 may be inserted into the hole 312d, or may not be attached. The magnetization may be performed after the magnetic magnet 313 is inserted into the hole 312d. When the magnetizing is performed after the insertion of the magnet 313, the magnetizing can be performed strongly to the limit of the holding force as described above, and the performance of the motor can be improved. When the magnet 313 is inserted into the hole 312d, fixing means such as an adhesive may be applied to the magnet 313 and the hole 312d as necessary.

When the magnet 313 is not arranged in the hole 312d of the connecting core 312, the state of FIG. 3 is set. When the magnet 313 is arranged in the hole 312d of the connecting core 312, the arrangement (including magnetization) of the magnet 313 is changed. Later, the connection with the shaft 32 is performed. That is, the shaft contact portion 312e of the connection core 312 comes into contact with the outer peripheral surface of the shaft 32, the connection portion 312b is bent so as to sandwich the shaft 32, and the four pieces 312a are formed in an annular shape. The portion 312c is connected in the axial direction by laser welding or the like. This state corresponds to the rotor 3 shown in FIG. Press-fitting may be employed as a simple method of fixing the shaft 32 to the rotor body 31. In this regard, in the present embodiment, since the rotor main body 31 and the shaft 32 can be fixed only by bending the connecting core 312 and sandwiching the shaft 32, it is advantageous in that damage to the outer peripheral surface of the shaft 32 can be suppressed. .

FIG. 4 is a diagram showing an example of measures against vibration, and is a diagram of the rotor main body 31 viewed from the axial direction. In FIG. 4, an elastic member 314 such as rubber is disposed in an arc-shaped concave portion 312b-b of a connecting portion 312b formed between adjacent pieces 312a. That is, as shown in FIG. 3, in a state of the connecting core 312 in which the pieces 312a are arranged in a line (a state in which the space between the pieces 312a is open), an arc-shaped arc formed on the inner peripheral surface of the connecting portion 312b. A rod-shaped elastic member 314 having a diameter slightly larger than the diameter of the arc is sandwiched between the concave portions 312b-b, and the connecting portion 312b is bent to form the annular rotor body 31. Due to the elastic properties of the elastic member 314, excessive bending of the connecting portion 312b is suppressed, and the bending at the plurality of connecting portions 312b is performed evenly, so that the roundness of the rotor main body 31 is improved and the pieces 312a are biased. Contact can be avoided and vibration can be expected to be reduced. Note that a sheet-shaped elastic member may be arranged not only in the arc-shaped concave portion 312b-b of the connecting portion 312b but also in a portion where the adjacent pieces 312a face each other.

Next, a method of strengthening the fixing between the rotor body 31 and the shaft 32 to prevent the shaft 32 from rotating will be described. Until now, the cross-sectional shape of the shaft 32 has been circular, and the shaft 32 is fixed to the rotor main body 31 by tightening the connecting core 312 with the arc-shaped shaft contact portion 312e. Here, a method for further strengthening the fixing between the rotor main body 31 and the shaft 32 will be described.

5A and 5B are views showing an example in which the fixing between the rotor main body 31 and the shaft 32 is strengthened. FIG. 5A is a view of the rotor main body 31 viewed from the axial direction, and FIG. FIG. 4 is a cross-sectional view of a portion sandwiched between the components viewed from the axial direction. In FIG. 5A, the shaft contact portion 312e of the rotor main body 31 is linear in accordance with the cross-sectional shape of the shaft 32. Thereby, rotation of the shaft 32 is prevented in a state where the rotor main body 31 sandwiches the shaft 32, and strong fixing is performed.

6A and 6B are views showing another example in which the fixing between the rotor main body 31 and the shaft 32 is strengthened. FIG. 6A is a view of the rotor main body 31 viewed from the axial direction, and FIG. It is sectional drawing seen from the axial direction of the part pinched by the rotor main body 31. In FIG. 6A, three shaft contact portions 312 e of the rotor main body 31 have an arc shape and one has a straight line shape in accordance with the cross-sectional shape of the shaft 32. Thereby, rotation of the shaft 32 is prevented in a state where the rotor main body 31 sandwiches the shaft 32, and strong fixing is performed.

7A and 7B are perspective views showing a configuration example of the motor 1 to which the above-described rotor 3 is applied, FIG. 7A shows an external appearance, and FIG. 7B shows components. 7A, the motor 1 includes a tubular portion 11, lid portions 12 and 13, and a shaft 32. In FIG. 7B, a stator 2 is inserted (press-fitted) into a cylindrical tube portion 11, a rotor 3 is inserted into a central space of the stator 2, and upper and lower lid portions 12 and 13 provided with bearings are used to rotate the rotor 3. The shaft 32 is rotatably supported.

(Second embodiment)
In the above-described first embodiment, an example has been described in which the hole 312d is provided in the center of the piece 312a of the connection core 312, and the magnet 313 is disposed in the hole 312d as necessary. In the second embodiment, a hole is formed by the concave portion 312f of the adjacent piece 312a, and a magnet 313 is disposed in the hole as needed.

FIG. 8 is a perspective view showing a configuration example of the rotor 3 according to the second embodiment. 8, the rotor 3 includes a rotor body 31 and a shaft 32. The rotor main body 31 is formed by bending a connecting core (312) described later, which is formed by laminating electromagnetic steel sheets as magnetic members. In the illustrated example, four substantially fan-shaped pieces 312a connected by the connecting portion 312b are bent so as to sandwich the rod-shaped shaft 32 and are formed in an annular shape. The connecting portion 312c at the end of the connecting core where the connecting portion 312b does not exist is connected by laser welding or the like along the axial direction. The number of the pieces 312a is not limited to four, and may be an even number such as 6, 8, 10, or the like.

ピ ー ス Each piece 312a is provided with a substantially arc-shaped concave portion 312f penetrating in the axial direction, and a magnet 313 is disposed as an example in a hole formed by contact with the concave portion 312f of the adjacent piece 312a. By providing the magnet 313, a torque resulting from the magnet 313 is obtained as a motor. However, even when the magnet 313 is not present, a reluctance torque resulting from the hole 312d is obtained.

FIG. 9 is a plan view showing an example of the shape of the steel plate 311 forming the connecting core according to the second embodiment. The steel plate 311 is formed by punching out a magnetic steel plate with a mold or the like. Also, a plurality of steel plates 311 are stacked to form a connection core (312).

に お い て In FIG. 9, in the example shown in FIG. 9, four piece steel plates 311a forming a substantially fan-shaped piece divided into four parts are connected via a connection part 311b. The connecting portion 311b is thinly formed by being sandwiched between an edge extending linearly on the outer peripheral side and an arc-shaped concave portion on the inner peripheral side, and can be easily bent in a direction in which the arc-shaped concave portion closes. . The left and right ends of the steel plate 311 are connection portions 311c, and a plurality of steel plates 311 are stacked to form a connection core. When the plurality of steel plates 311 are bent in an annular shape, the left and right connection portions 311c and the end surfaces of the piece steel plates 311a come into contact with each other. In the connection core, the position of the connection portion 311c in the radial direction is slightly closer to the center of the shaft (toward the shaft 32) than the outer peripheral surface of the piece steel plate 311a. A shaft contact portion 311e that matches the curvature of the outer peripheral surface of the shaft 32 is formed on the inner side of the fan shape of each piece steel plate 311a. Further, an arc-shaped concave portion 311f extending from both chords of the piece steel plate 311a toward the outer peripheral portion is provided, and when the adjacent piece steel plate 311a comes into contact, the magnet 313 can (or may not) be housed. A hole is formed. The shape of the concave portion 311f is not limited to the one shown in the drawing, and the hole formed between the concave portion 311f and the adjacent concave portion 311f may be any shape in consideration of reluctance torque, such as a V shape or a straight line. it can.

FIG. 10 is a perspective view showing an example of the shape of the connection core 312 according to the second embodiment. The connection core 312 is formed by laminating a plurality of steel plates 311 shown in FIG. Note that, in FIG. 10, streaks on an end surface indicating lamination of the electromagnetic steel sheets are omitted. In the illustrated example, four substantially fan-shaped pieces 312a that are divided into four pieces are connected via a connecting part 312b, and are arranged in one direction. The connecting portion 312b is formed thin by being sandwiched between a flat edge on the outer peripheral side and a curved concave portion on the inner peripheral side, and can be easily bent in a direction in which the curved concave portion closes. The left and right ends of the connection core 312 are formed as connection portions 312c, and the end surfaces of the left and right connection portions 312c and the piece 312a are in symmetrical contact with each other in an annularly bent state. A shaft contact portion 312e that matches the curvature of the outer peripheral surface of the shaft 32 is formed on the inner side of the fan shape of each piece 312a. An arc-shaped recess 312f is provided from both chords of the piece 312a to the outer periphery.

FIG. 11 is a diagram illustrating an example of a method of attaching the magnet 313 to the connection core 312. When the magnets 313 are arranged in the holes formed by the recesses 312f of the adjacent pieces 312a, the adjacent pieces 312a are aligned in the state of the connection core 312 (the pieces 312a are opened). The end of the magnet 313 is inserted into the concave portion 311f of the 312a, and the connecting portion 312b is bent. At this time, the end of the slightly elastic magnet 313 is pushed into the concave portion 312f, and is fixed in the concave portion 312f in a state where the adjacent pieces 312a are in contact with each other. In this case, by setting the thickness of the magnet 313 to be slightly larger than the opening width of the concave portion 312f, the magnet 313 is firmly fixed when sandwiched.

The magnet 313 may be magnetized or non-magnetized. When the unmagnetized magnet 313 is mounted, the magnetizing is performed in a state where the bending of the connecting portion 312b has not progressed and a magnetic field can be applied to each magnet 313 independently. Thereby, it becomes possible to perform strong magnetization up to the limit of the holding force, and the performance of the motor can be improved.

The state shown in FIG. 10 when the magnet 313 is not disposed in the hole formed by the concave portion 312f of the connecting core 312, and the magnet shown in FIG. 10 when the magnet 313 is disposed in the hole formed by the concave portion 311f of the connecting core 312. After the arrangement (including the magnetization) of 313, the coupling with the shaft 32 is performed. That is, the shaft contact portion 312e of the connection core 312 comes into contact with the outer peripheral surface of the shaft 32, the connection portion 312b is bent so as to sandwich the shaft 32, and the four pieces 312a are formed in an annular shape, and the ends are connected. The part 312c is connected in the axial direction by laser welding or the like. This state corresponds to the rotor 3 shown in FIG. The insertion of the elastic member 314 as shown in FIG. 4 and the cross-sectional shape of the portion of the shaft 32 sandwiched between the rotor bodies 31 as shown in FIGS. 5A and 5B or FIGS. By doing so, a method of strengthening the fixation can be similarly applied.

Next, a method for easily controlling the d-axis inductance or the q-axis inductance for determining the reluctance torque will be described. Generally, in order to control the reluctance torque to a desired value, it is necessary to devise the shape of the air gap and the lamination arrangement of the magnetic steel sheets, but the reluctance torque can be easily increased by the following method.

FIG. 12 is a diagram illustrating an example of the grain-oriented electrical steel sheet 9. A grain-oriented electrical steel sheet is an electrical steel sheet whose magnetic properties are biased so that it is magnetized in a specific direction, such as by aligning the crystal axis direction when rolling the steel sheet. The difficulty is orthogonal to the difficulty. In FIG. 12, the vertical direction in the figure is the easy axis direction, and the horizontal direction in the figure is the hard magnetization direction.

FIG. 13 is a diagram illustrating an example of a steel plate 311 formed by punching from the grain-oriented electrical steel plate 9. That is, FIG. 13 shows a steel sheet 311 punched in the illustrated direction from the directional electromagnetic steel sheet 9 in the easy axis direction and the hard magnetization direction shown in FIG. In FIG. 13, the direction of easy axis of magnetization and the direction of hard magnetization of each piece steel plate 311 a of the steel plate 311 are the same as the direction of easy axis of magnetization and the direction of hard magnetization of the grain-oriented electrical steel sheet 9. That is, the vertical direction in the figure is the easy axis direction, and the horizontal direction in the figure is the hard magnetization direction. Also in the connection core 312 formed by laminating a plurality of steel plates 311, the easy axis direction and the hard direction are the same as those in FIG. 13.

Figure 14 is an explanatory view of a d-axis inductance L _d and q-axis inductance L _q, a view of the rotor body 31 from the axial direction. The d-axis direction is a radial direction passing through the center of the gap where the magnet is provided (including the case where the magnet is not provided and the gap is left), and is along the contact surface of the adjacent piece 312a. The q-axis direction is a direction that is magnetically orthogonal to the d-axis direction, and is a radial direction that passes through the center of the piece 312a.

As is clear from FIG. 14, the q-axis direction matches the easy axis direction, and the d-axis direction deviates from the easy axis direction. Also, the d-axis inductance L _d is determined by the magnetic path along the d-axis direction adjacent, since the q-axis inductance L _q by the magnetic path along the q-axis direction adjacent is determined, most of the magnetic path There easy axis q-axis inductance L _q in the direction is increased, most of the magnetic path is not along the hard magnetization direction, further d-axis inductance L _d along the air gap is reduced. Reluctance torque, since the magnitude corresponding to the difference between the q-axis inductance L _q and d-axis inductance L _d, it is possible to increase the reluctance torque by such a structure, it is possible to improve the performance of the motor.

In the case where the hole 312d (including the case where the magnet 313 is provided) is provided at the center of the piece 312a shown in FIGS. 1 to 3, the magnetization of the grain-oriented electrical steel sheet 9 is different from FIG. By reversing the easy axis direction and the hard magnetization direction, the reluctance torque can be increased to some extent. That is, in this case, the direction intersecting the radial direction of the central portion of the piece 312a is the q-axis direction, the radial direction of the central portion of the piece 312a is the d-axis direction, the d-axis direction is the hard magnetization direction, and the d-axis inductance L _{When d} becomes small, it works in a direction to increase the reluctance torque. The q-axis direction is affected by an increase in inductance due to the inclusion of a component in the direction of easy magnetization and a decrease in inductance due to air gaps.

(Third embodiment)
In the third embodiment, an improvement for facilitating a process of assembling the connecting core 312 in a circular shape will be described. For example, with respect to the two adjacent pieces 312a of the connecting core 312 in FIG. 3 described above, when bending the connecting portion 312b between the two pieces 312a, the side faces at both ends (the radius of the circle when assembled) over the two pieces 312a Consider a case where a surface forming a slit along the direction) is sandwiched between jigs such as pliers. In this case, since the side surface of the piece 312a is flat, there is no place to be hooked, the jig is slippery, and the process of assembling in a circular shape may not be easily performed. Therefore, in the third embodiment, a countermeasure will be presented.

FIG. 15 is a plan view showing an example of the connection core 312 according to the third embodiment, and shows a state in which the connection core 312 is formed in a straight line before being assembled in a circular shape. In FIG. 15, the connection core 312 has a plurality of (eight in the illustrated example) pieces 312a connected by a connection portion 312b. Each piece 312a is provided with a hole 312g in which a magnet is arranged. The end of the hole 312g in the left-right direction in the figure has a hole larger than the shape of the magnet in order to form a flux barrier. That is, the width between the side surface 312h and the contour of the hole 312g is set to a substantially uniform small value, and the outer peripheral surface is cut into an acute angle. The flux barrier is for preventing the magnetic flux flowing from the magnetic pole (magnetized in the radial direction) of the magnet of the rotor from flowing through the rotor, thereby preventing the magnetic flux flowing to the stator from decreasing. This is to narrow the magnetic path in the rotor.

溝 Furthermore, grooves 312i having a cross-sectional shape that is notched at an acute angle are provided along the axial direction on the side surfaces 312h at both ends of the piece 312a so that the jig can be easily caught. The groove 312i is also a concave portion and an engaging portion for hooking a jig. In the illustrated example, one groove 312i is provided on one side surface 312h, but a plurality of grooves may be provided. In the step of assembling the connection core 312 in a circular shape, for example, a jig such as pliers straddles the two pieces 312a adjacent to each other, sandwiches the side surfaces 312h at both ends, and applies a force to connect the two pieces 312a. The part 312b is bent. At this time, since the groove 312i on the side surface 312h engages with the jig, slippage is prevented, and the bending operation is performed smoothly.

FIG. 16 is a plan view showing an example of the rotor main body 31 according to the third embodiment. In FIG. 16, the rotor body 31 is formed by assembling a plurality of pieces 312 a (eight in the illustrated example) around the shaft 32. A rectangular parallelepiped magnet 313 is inserted into the hole 312g of each piece 312a. The holes 312g on both ends of the magnet 313 that are not filled with the magnet 313 form a flux barrier 312j. The groove 312i provided on the side surface 312h of the piece 312a forms a polygonal space with the groove 312i of the adjacent piece 312a. This space narrows the magnetic path for the magnet 313 and enhances its function as a flux barrier 312j.

The groove 312i can be applied to a piece 312a in which a hole 312d is formed as shown in FIG. 3, and concave portions 312f are formed at both ends as shown in FIG. The present invention can also be applied to the piece 312a.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

As described above, the motor according to the embodiment includes the rotor main body, the rotor main body includes a plurality of cores connected via a connecting portion, and the plurality of cores are arranged in a ring. Thus, the rotor can be easily formed.

The core has a hole. By providing these holes, reluctance torque can be generated. Thereby, reluctance torque that increases the torque of the motor can be generated.

The core has a concave portion, and the concave portions of two adjacent cores are in contact with each other to form a hole. The concave portions of the two adjacent cores form a hole, and the formation of the hole can generate a reluctance torque. Thereby, reluctance torque that increases the torque of the motor can be generated.

The rotor body further includes a magnet arranged in the hole. Thus, in addition to the reluctance torque, a torque (magnet torque) that increases the torque of the motor can be generated.

シ ャ フ ト The shaft is sandwiched between inner sides of the plurality of cores. Thus, the shaft can be firmly fixed to the plurality of cores with a simple configuration.

In addition, an elastic member is interposed between two adjacent cores among the plurality of cores. Thereby, the roundness of the rotor body can be increased. In addition, uneven contact between the cores can be avoided, and vibration can be reduced.

The core is formed of a plurality of grain-oriented electrical steel sheets, and a direction intersecting a radial direction of the core is a direction of an easy axis of magnetization of the grain-oriented electrical steel sheet. Thereby, the q-axis inductance can be increased, the reluctance torque can be increased, and the performance of the motor can be improved.

The core is formed of a plurality of grain-oriented electrical steel sheets, and the radial direction of the core is the direction of the axis of easy magnetization of the grain-oriented electrical steel sheet. Thereby, the q-axis inductance can be increased, the reluctance torque can be increased, and the performance of the motor can be improved.

Also, among the plurality of cores arranged in an annular shape, two adjacent cores are connected by a connecting member. Thus, the rotor body can be easily formed.

The method for manufacturing a motor according to the embodiment includes a first step of bending a connecting core in which a plurality of cores are arranged in one direction via a connecting portion to bend the connecting portion to make the plurality of cores annular. Thus, the rotor can be easily manufactured.

And a second step of sandwiching the shaft between the plurality of cores. Thus, the shaft can be easily fixed to the rotor body.

And a third step of disposing an elastic member in the concave portion of the connecting portion. As a result, the roundness of the rotor body can be increased, and uneven contact between the cores can be avoided, and vibration can be reduced.

The present invention is not limited by the above embodiments. The present invention also includes a configuration in which the above-described components are appropriately combined. Further, further effects and modified examples can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-described embodiments, and various modifications are possible.

This application enjoys the benefits of Japanese Patent Application No. 2018-134710, filed on July 18, 2018 in Japan.

1 motor, 2 stator, 3 rotor, 31 rotor body, 312 connection core, 312a piece, 312b connection, 312b-b recess, 312d hole, 312f recess, 313 magnet, 314 elastic member, 32 shaft, 9 directional electromagnetic steel sheet

Claims (12)

Equipped with a rotor body,
The rotor body includes a plurality of cores connected via a connection portion,
The plurality of cores are arranged in a ring,
motor. The core has a hole,
The motor according to claim 1. The core has a concave portion,
The recesses of two adjacent cores contact to form a hole,
The motor according to claim 1. The rotor body includes a magnet disposed in the hole.
The motor according to claim 2. A shaft sandwiched between inner sides of the plurality of cores;
The motor according to any one of claims 1 to 4. And an elastic member sandwiched between two adjacent cores among the plurality of cores,
The motor according to any one of claims 1 to 5. The core is formed of a plurality of grain-oriented electrical steel sheets,
The direction intersecting with the radial direction of the core is the direction of the easy axis of magnetization of the grain-oriented electrical steel sheet,
The motor according to any one of claims 1 to 6. The core is formed of a plurality of grain-oriented electrical steel sheets,
The radial direction of the core is the direction of the easy axis of magnetization of the grain-oriented electrical steel sheet,
The motor according to any one of claims 1 to 7. Among the plurality of cores arranged in an annular shape, two adjacent cores are connected by a connection member,
The motor according to any one of claims 1 to 8. A first step in which a plurality of cores are arranged in one direction via a connecting portion, and the connecting portion is bent to form the plurality of cores in an annular shape,
Motor manufacturing method. Having a second step of sandwiching a shaft between the plurality of cores;
A method for manufacturing a motor according to claim 10. A third step of disposing an elastic member in the concave portion of the connection portion,
A method for manufacturing a motor according to claim 10.

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