WO2022113404A1 - Motor manufacturing method - Google Patents

Abstract

This motor manufacturing method comprises a step of preparing parts of an axial gap motor and a step of assembling the parts. The parts include: a rotor; a stator; a shaft that is the rotational axis of the rotor; a bearing for rotatably supporting the shaft; a case having a first plane on which the stator and the bearing are placed; and a shim disposed between the first plane and the bearing or between the first plane and the stator. The step of preparing the parts has: a step of obtaining a predicted length of the gap between the rotor and the stator in consideration of the actual dimension of the stator; and a step of determining the thickness of the shim on the basis of the difference between the design length of the gap and the predicted length thereof.

Description

Motor manufacturing method

The present disclosure relates to a method of manufacturing a motor.
This application claims priority based on Japanese Patent Application No. 2020-195500 of the Japanese application dated November 25, 2020, and incorporates all the contents described in the Japanese application.

As shown in FIG. 10 of Patent Document 1, the axial gap type rotary electric machine of Patent Document 1 includes a case, a stator, a rotor, a shaft, and a bearing. The case includes a cylindrical peripheral wall portion and a pair of disk-shaped plates. A pair of plates are attached to both ends of the peripheral wall portion. A through hole is formed in the center of the pair of plates. A shaft is provided in the through hole. The stator and rotor are arranged in the case so as to face the axial direction of the shaft. The stator is located on the plate. The rotor is provided with a gap from the stator. The shaft is the axis of rotation of the rotor. The bearing rotatably supports the shaft.

Japanese Unexamined Patent Publication No. 2020-108323

The method for manufacturing the motor of the present disclosure is as follows.
The process of preparing parts for axial gap type motors and
With the process of assembling the parts
The parts are
With the rotor
With the stator,
The shaft, which is the rotation axis of the rotor, and
A bearing that rotatably supports the shaft and
A case having a first plane on which the stator and the bearing are placed, and
Includes shims located between the first plane and the bearing, or between the first plane and the stator.
The process of preparing the parts is
The step of obtaining the predicted length of the gap between the rotor and the stator in consideration of the actual size of the stator, and
It comprises a step of determining the thickness of the shim based on the difference between the design length of the gap and the predicted length.

FIG. 1 is a schematic cross-sectional view showing an outline of a motor manufactured by the method for manufacturing a motor according to the first embodiment. FIG. 2 is a schematic cross-sectional view showing the region A of FIG. 1 in an enlarged manner. FIG. 3 is a schematic cross-sectional view showing another example of region A in FIG. 1 in an enlarged manner. FIG. 4 is a cross-sectional view showing an outline of a virtual motor. FIG. 5 is a schematic cross-sectional view showing the region A of FIG. 4 in an enlarged manner. FIG. 6 is a schematic cross-sectional view showing another example of the region A in FIG. 4 in an enlarged manner. FIG. 7 is a diagram showing a graph showing the relationship between the load on the inner race of the first bearing and the deviation amount of the inner race with respect to the outer race of the first bearing. FIG. 8 is a schematic cross-sectional view showing an outline of a motor manufactured by the method for manufacturing a motor according to the second embodiment. FIG. 9 is a schematic cross-sectional view showing the region A of FIG. 8 in an enlarged manner. FIG. 10 is a schematic cross-sectional view showing another example of region A in FIG. 8 in an enlarged manner. FIG. 11 is a plan view of a shim provided in the motor manufactured by the method for manufacturing the motor according to the second embodiment as viewed from the first plate portion side. FIG. 12 is a cross-sectional view showing an outline of a virtual motor. FIG. 13 is a schematic cross-sectional view showing the region A of FIG. 12 in an enlarged manner. FIG. 14 is a schematic cross-sectional view showing another example of the region A in FIG. 12 in an enlarged manner. FIG. 15 is a diagram illustrating a method for manufacturing a motor according to the third embodiment. FIG. 16 is a plan view of a shim provided in the motor manufactured by the method for manufacturing the motor according to the fourth embodiment as viewed from the first plate portion side. FIG. 17 is a diagram illustrating a method for manufacturing a motor according to the fifth embodiment. FIG. 18 is a diagram illustrating a method for manufacturing a motor according to the sixth embodiment.

[Problems to be solved by this disclosure]
It is desired to improve the manufacturability of the axial gap type motor.

One of the purposes of the present disclosure is to provide a method for manufacturing a motor having excellent manufacturability of the motor.

[Effect of this disclosure]
The motor manufacturing method of the present disclosure is excellent in motor manufacturability.

<< Explanation of Embodiments of the present disclosure >>
The axial gap type motor is manufactured, for example, through two assembly steps of a temporary assembly of motor parts and a main assembly. The reason for temporarily assembling the parts is that it is difficult to set the length of the gap between the stator and the rotor as the design length when the parts are assembled once. The design length of the gap is a target value of the design gap length determined based on the specifications of the motor. Therefore, the length of the gap of the temporarily assembled motor is measured. Find the difference between the measured length of the gap obtained by the measurement and the design length of the gap. After determining the measured length of the gap, disassemble the motor.

The parts are assembled using a shim that has the same thickness as the above difference. The shim is placed between the bearing and the plate. By placing the shim, the bearing position is separated from the plate by the thickness of the shim. When the bearings are separated from each other, the shaft supported by the bearings is displaced in the axial direction of the shaft. The displacement of the shaft causes the rotor to move away from the stator. As the rotors move apart, the length of the gap becomes longer than the measured length. That is, the length of the gap becomes longer than the measured length by the thickness of the shim. Since the thickness of the shim is the same as the above difference, the length of the gap can be used as the design length.

In the manufacturing method described above, the manufacturing work becomes complicated because the number of times of assembling the parts is twice.

The present inventors have diligently studied a method for manufacturing a motor. As a result, the present inventors have developed a manufacturing method capable of making the length of the gap between the stator and the rotor substantially the same as the design length by assembling the parts only once. First, embodiments of the present disclosure will be listed and described.

(1) The method for manufacturing a motor according to one aspect of the present disclosure is as follows.
The process of preparing parts for axial gap type motors and
With the process of assembling the parts
The parts are
With the rotor
With the stator,
The shaft, which is the rotation axis of the rotor, and
A bearing that rotatably supports the shaft and
A case having a first plane on which the stator and the bearing are placed, and
Includes shims located between the first plane and the bearing, or between the first plane and the stator.
The process of preparing the parts is
The step of obtaining the predicted length of the gap between the rotor and the stator in consideration of the actual size of the stator, and
It comprises a step of determining the thickness of the shim based on the difference between the design length of the gap and the predicted length.

The above motor manufacturing method is excellent in motor manufacturability with excellent assembly accuracy. In the above manufacturing method, the predicted length of the gap can be obtained in consideration of the above actual dimensions before assembling the parts. That is, in the above manufacturing method, the difference between the predicted gap length and the design length can be obtained before assembling the parts.

The predicted gap length obtained in consideration of the above actual dimensions is the gap length calculated using the actual dimensions of the stator, which will be described in detail later. The predicted length of the gap obtained in consideration of the above actual dimensions may be referred to as the first predicted length. On the other hand, the predicted length of the gap can also be obtained from the design dimensions and dimensional tolerances of the parts. The predicted gap length obtained from the design dimensions and dimensional tolerances of the parts is the gap length calculated using the design dimensions and dimensional tolerances of each part excluding shims. The predicted length of the gap obtained from the design dimensions and dimensional tolerances of the part is sometimes called the second predicted length. The first predicted length is more accurate than the second predicted length. That is, the difference between the first predicted length and the design length is more accurate than the difference between the second predicted length and the design length.

The above manufacturing method can assemble parts containing shims having the same thickness as the exact above difference. Therefore, in the above manufacturing method, the length of the gap can be set as the design length by assembling the parts only once.

(2) As one form of the above motor manufacturing method,
If the predicted length exceeds the design length
In the step of assembling the parts, the shim may be arranged between the first plane and the stator.

The above-mentioned motor manufacturing method is excellent in the manufacturability of a motor having excellent assembly accuracy when the predicted length exceeds the design length.

(3) As one form of the above motor manufacturing method,
If the predicted length is less than the designed length
In the step of assembling the parts, the shims may be arranged between the first plane and the bearings.

The above-mentioned motor manufacturing method is excellent in the manufacturability of a motor having excellent assembly accuracy when the predicted length is less than the design length.

(4) As one form of the above motor manufacturing method,
In the step of obtaining the predicted length, it is preferable to further obtain the predicted length in consideration of the actual dimensions of each of the rotor, the shaft, and the bearing.

Since the above manufacturing method can obtain an accurate predicted length, it is possible to manufacture a motor having excellent assembly accuracy.

(5) As one form of the above motor manufacturing method,
The rotor is
Annulus plate-shaped rotor body and
With at least one magnet fixed to the rotor body,
The bearing is a radial bearing or an angular bearing having an inner race and an outer race.
Each of the inner race and the outer race has a first end surface facing the rotor body.
In the step of obtaining the predicted length, the predicted length is further obtained in consideration of the amount of deviation between the first end surface of the outer race and the first end surface of the inner race.
The amount of deviation may be determined in consideration of the load acting on the inner race due to the weight of the shaft and the rotor, and the load acting on the inner race due to the attractive force of the magnet to the stator.

Depending on the weight of the shaft and rotor and the magnitude of the attractive force of the magnet, the first end surface of the inner race may shift from the first end surface of the outer race. The difference between the predicted gap length and the design length increases by the amount of deviation. Therefore, even if a part including a shim having the same thickness as the difference between the predicted length and the design length obtained by considering only the above actual dimensions is assembled, it may be difficult to set the gap length as the design length.

In the above manufacturing method, even if the first end surface of the inner race deviates from the first end surface of the outer race, the predicted length can be obtained in consideration of the amount of deviation. Therefore, the exact difference between the predicted length and the design length can be obtained. Therefore, in the above manufacturing method, the length of the gap can be set as the design length by assembling the parts only once. Therefore, the above manufacturing method is excellent in the manufacturability of the motor having excellent assembly accuracy.

(6) As one form of the above motor manufacturing method,
The stator is
Annulus plate-shaped yoke and
With a plurality of columnar teeth arranged at intervals in the circumferential direction of the yoke,
The yoke has a first surface in contact with the first plane.
The teeth have end faces facing the rotor and
In the step of obtaining the predicted length, the predicted length may be obtained in consideration of the actual size between the first surface of the yoke and the end surface of the teeth.

Since the above manufacturing method can obtain an accurate predicted length, it is possible to manufacture a motor having excellent assembly accuracy.

(7) As one form of the above motor manufacturing method,
The stator may include a stator core made of a dust compact.

The above manufacturing method can manufacture a motor having excellent assembly accuracy even when the stator core is provided with a dust compact having a lower dimensional accuracy than the stator core of an electromagnetic steel sheet.

(8) As one form of the above motor manufacturing method,
The part may include a fastening member that secures the first plane and the stator.

In the above manufacturing method, since the displacement between the stator and the first plane can be suppressed by the fastening member, it is possible to manufacture a motor having excellent assembly accuracy.

(9) As one form of the above motor manufacturing method,
The rotor is
Annulus plate-shaped rotor body and
With at least one magnet fixed to the rotor body,
The rotor body has a front surface facing the magnet and has a front surface.
The magnet has a first end surface facing the stator and has a first end surface.
In the step of obtaining the predicted length, in the rotor in which the rotor body and the magnet are fixed, the actual dimension of the length between the first surface of the rotor body and the first end surface of the magnet is obtained. It is advisable to obtain the predicted length in consideration of this.

Since the above manufacturing method can obtain an accurate predicted length, it is possible to manufacture a motor having excellent assembly accuracy.

(10) As one form of the motor manufacturing method of the above (9),
The number of the magnets is one.
The shape of the magnet may be annular.

In the above manufacturing method, the number of magnets is one, so that the number of parts is smaller than that in the case where the number of magnets is multiple. Therefore, the above manufacturing method is excellent in the manufacturability of the motor. Moreover, the above manufacturing method can manufacture a motor having excellent assembly accuracy.

(11) As one form of the above motor manufacturing method,
In the step of assembling the parts, the shaft may be press-fitted into the rotor.

In the above manufacturing method, the rotor can be positioned with respect to the shaft by press-fitting the shaft into the rotor. Therefore, the above manufacturing method can manufacture a motor having a small rotor runout. Moreover, the above manufacturing method can manufacture a motor having excellent assembly accuracy.

(12) As one form of the above motor manufacturing method,
Repeat the process of assembling the parts,
In the step of obtaining the predicted length, the predicted length is obtained in consideration of the average value of the actual dimensions of each of the stator, the rotor, the shaft, and the bearing, which is smaller than the number of manufactured motors. good.

The above manufacturing method is excellent in the manufacturability of a plurality of motors having excellent assembly accuracy. Therefore, the above manufacturing method can manufacture a plurality of motors having a small variation in performance. In particular, in the manufacturing method, the predicted length is obtained in consideration of the average value of the actual dimensions, which is smaller than the number of manufactured pieces, and thus the predicted length is obtained in consideration of the same number of the actual dimensions as the number of manufactured pieces. Compared with the case, it is easy to improve the manufacturability.

(13) As one form of the above motor manufacturing method,
It is preferable that the number of the stators and the number of the rotors are one each.

The above manufacturing method is excellent in the manufacturability of a single stator / single rotor type motor having excellent assembly accuracy.

(14) As one form of the above motor manufacturing method,
It is preferable that the number of the stators is two and the number of the rotors is one.

The above manufacturing method is excellent in the manufacturability of a double stator / single rotor type motor having excellent assembly accuracy.

<< Details of Embodiments of the present disclosure >>
Details of the embodiments of the present disclosure will be described below. The same reference numerals in the figure indicate the same names.

<< Embodiment 1 >>
[Motor manufacturing method]
The method for manufacturing the motor according to the first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 is a cross-sectional view of a motor 1A manufactured by the method for manufacturing a motor of the present embodiment, cut along a plane parallel to the axial direction of the shaft 4. The motor 1A of FIG. 1 is assembled using all the parts. The parts include a stator 2, a rotor 3, a shaft 4, a first bearing 51, a shim 6 and a case 7. FIG. 1 illustrates a single stator / single rotor type axial gap motor as the manufactured motor 1A. The single stator / single rotor type refers to a motor in which the number of stators 2 and the number of rotors 3 are one each. The axial gap motor is a motor in which the stator 2 and the rotor 3 face each other with a gap in the axial direction of the shaft 4. FIG. 4 shows a cross-sectional view of a virtual motor 1Z cut along a plane parallel to the axial direction of the shaft 4.

The method for manufacturing a motor of this embodiment includes a step of assembling the above-mentioned parts of the motor 1A shown in FIG. The motor 1A manufactured by assembling the parts has a gap between the stator 2 and the rotor 3. In the method for manufacturing the motor of this embodiment, steps A and B are performed in order.
In step A, the above parts are prepared.
In step B, the above parts are assembled.

One of the features of the method for manufacturing the motor of this embodiment is that the following requirements (a) and (b) are satisfied.
(A) Step A includes steps A1 and A2.
In step A1, the predicted length G0 shown in FIGS. 4 to 6 is obtained. The predicted length G0 is obtained in consideration of the actual dimensions of specific parts other than the shim 6 among the above parts.
Step A2 determines the thickness Ts of the shim 6. The thickness Ts is determined based on the difference between the design length G1 of the gap shown in FIGS. 1 to 3 and the predicted length G0 of the gap shown in FIGS. 4 to 6. The design length G1 is a target value of the design gap length determined based on the specifications of the motor 1A. The design length G1 has a certain allowable width.
(B) In step B, shims 6 having a thickness Ts determined before assembling the parts are placed at predetermined positions.

The motor 1A manufactured earlier will be described. After that, a method of manufacturing a motor for manufacturing the motor 1A will be described. As shown in FIGS. 2 and 5 or 3 and 6, the method for manufacturing the motor of the present embodiment exemplifies the case where the predicted length G0 is less than the design length G1.

(motor)
<Stator>
As shown in FIG. 1, the stator 2 is arranged on the first plane 71f of the case 7. As shown in FIG. 1, the stator 2 includes a stator core 21 and a plurality of coils 25.

Stator core The stator core 21 includes an annular plate-shaped yoke 22 and a plurality of columnar teeth 23.

The yoke yoke 22 magnetically couples adjacent teeth 23 among the teeth 23 arranged in the circumferential direction of the yoke 22. As shown in FIG. 2, the yoke 22 has a planar first surface 22f, a planar second surface 22s, an outer peripheral surface, and an inner peripheral surface. The first surface 22f and the second surface 22s are surfaces connecting the outer peripheral surface and the inner peripheral surface. The first surface 22f is in contact with the first plane 71f. The second surface 22s is a surface connected to the side surface of the teeth 23.

The teeth 23 is provided with a coil 25 as shown in FIG. The number of teeth 23 is plural. The teeth 23 are arranged at predetermined intervals in the circumferential direction of the yoke 22. Each tooth 23 projects so as to be orthogonal to the second surface 22s of the yoke 22 shown in FIG. Each of the teeth 23 and the yoke 22 of this embodiment is composed of an integral dust compact. The shape and size of each tooth 23 are the same. The shape of each tooth 23 is prismatic or columnar. Each tooth 23 has a side surface and an end surface 23a. The side surface is a surface connected to the second surface 22s of the yoke 22. The side surface protrudes from the second surface 22s of the yoke 22. The end face 23a is located at the tip in the protruding direction. The end surface 23a is a surface connected to the side surface. The end face 23a faces the magnet 35 of the rotor 3, which will be described later.

-Hole portion The stator core 21 has a hole portion as shown in FIG. A fastening member 91 is provided in this hole. The fastening member 91 fixes the stator core 21 to the first plane 71f. The fastening member 91 suppresses the positional deviation between the stator 2 and the first plane 71f. An example of the fastening member 91 is a screw, a bolt, or the like. The hole portion is formed from the first surface 22f to the middle of the teeth 23. The number of holes may be less than the number of teeth 23, or may be the same as the number of teeth 23.

Coil Each coil 25 has a tubular portion. The tubular portion is configured by winding a winding spirally. The coil 25 of this embodiment is an edgewise winding coil. A covered flat wire is used for the winding of the coil 25. Each coil 25 is arranged outside the teeth 23. The cross-sectional shape of the tubular portion of each coil 25 may be, for example, a shape corresponding to the cross-sectional shape of the teeth 23. The axial length of the tubular portion is slightly shorter than the length of the teeth 23. In FIG. 1, only the tubular portion is shown, and both ends of the winding are not shown.

<Rotor>
The rotor 3 is provided with a gap from the stator 2. The rotor 3 includes a rotor main body 31 and at least one magnet 35.

-Rotor body The rotor body 31 is rotatably supported by the shaft 4 with respect to the case 7. The rotor body 31 is an annular member. The rotor main body 31 is provided with a through hole in the center. A third shaft portion 43 of the shaft 4, which will be described later, is provided in this through hole. In this embodiment, the rotor main body 31 and the shaft 4 are combined by press-fitting the third shaft portion 43 into the through hole. By being press-fitted, the rotor 3 can be positioned with respect to the shaft 4. Therefore, the runout of the rotor 3 tends to be small. The position of the rotor main body 31 along the axial direction of the shaft 4 is positioned by the rotor main body 31 being stopped by the second end surface 42s of the second shaft portion 42, which will be described later.

As shown in FIG. 2, the rotor main body 31 has a first surface 31f, a second surface 31s, an inner peripheral surface, and an outer peripheral surface. The first surface 31f and the second surface 31s connect the inner peripheral surface and the outer peripheral surface. The first surface 31f is a surface on the stator 2 side. The second surface 31s is the surface on the second bearing 55 side shown in FIG. The second bearing 55 will be described later. The first surface 31f of this embodiment is in contact with the second end surface 42s. A recess 32 is provided on the first surface 31f of this embodiment. The recess 32 is open to the stator 2 side. A magnet 35 is fixed to the bottom surface 32a of the recess 32. The inner peripheral surface of the rotor body 31 is in contact with the third shaft portion 43 of the shaft 4. As shown in FIG. 1, the outer peripheral surface of the rotor main body 31 is not in contact with the inner peripheral surface of the peripheral wall portion 73 of the case 7. A gap is provided between the outer peripheral surface of the rotor main body 31 and the inner peripheral surface of the peripheral wall portion 73 of the case 7.

-Magnet The magnet 35 is fixed to the rotor main body 31. As shown in FIG. 2, an adhesive 38 is used to fix the magnet 35. The number of magnets 35 may be one or a plurality. When the number of magnets 35 is one, the number of parts is small and the rotor 3 can be easily manufactured as compared with the case where the number of magnets 35 is a plurality. Therefore, it is easy to improve the manufacturability of the motor 1A. Moreover, it is easy to manufacture the motor 1A having excellent assembly accuracy.

When the number of magnets 35 is one, the shape of the magnets 35 is annular. In one magnet 35, S poles and N poles are alternately arranged in the circumferential direction. When the number of magnets 35 is plural, the specific number of magnets 35 is the same as the number of teeth 23. The plurality of magnets 35 are arranged at equal intervals in the circumferential direction of the rotor main body 31. The shape of each magnet 35 is, for example, a flat plate. The planar shape of each magnet 35 is, for example, the same as the planar shape of the end surface 23a of the teeth 23. Each magnet 35 is magnetized in the axial direction of the rotation axis of the rotor 3. The magnetization directions of the magnets 35 adjacent to each other in the circumferential direction of the rotor main body 31 are opposite to each other. The rotating magnetic field generated by the stator 2 causes the magnet 35 to repeatedly attract and repel each tooth 23 to rotate the rotor 3.

The magnet 35 is a permanent magnet. Specific examples of permanent magnets are ferrite magnets, neodymium magnets, samarium-cobalt magnets, or bond magnets. In particular, neodymium magnets and samarium-cobalt magnets have strong magnetic forces.

<shaft>
The shaft 4 is a rotation shaft of the rotor 3. The shaft 4 is composed of a solid round bar. As shown in FIG. 1, the shaft 4 has a plurality of shaft portions having different diameters. The plurality of shaft portions are integrally configured. The shaft 4 of the present embodiment has the first shaft portion 41, the second shaft portion 42, the third shaft portion 43, and the fourth shaft portion in order from the first plate portion 71 side to the second plate portion 72 side of the case 7. It has 44 and a fifth shaft portion 45.

As shown in FIG. 1, the first shaft portion 41 is provided in the first bearing 51. As shown in FIG. 2, the outer peripheral surface of the first shaft portion 41 is in contact with the inner peripheral surface of the inner race 52 of the first bearing 51.

As shown in FIG. 1, the second shaft portion 42 has a diameter larger than the diameter of the first shaft portion 41. As shown in FIG. 2, the second shaft portion 42 has a first end surface 42f and a second end surface 42s. The first end surface 42f is in contact with the first end surface 52f of the inner race 52. The first end surface 42f is not in contact with the outer race 53 of the first bearing 51. The second end surface 42s is in contact with the first surface 31f of the rotor main body 31.

As shown in FIG. 1, the third shaft portion 43 is provided in the through hole of the rotor main body 31. As shown in FIG. 2, the outer peripheral surface of the third shaft portion 43 is in contact with the inner peripheral surface of the rotor main body 31. As shown in FIG. 1, the third shaft portion 43 has a diameter smaller than the diameter of the second shaft portion 42. As shown in FIG. 2, the third shaft portion 43 has an end face 43a. The end surface 43a is in contact with the first end surface of the inner race 56 of the second bearing 55.

As shown in FIG. 1, the fourth shaft portion 44 is provided in the second bearing 55. The outer peripheral surface of the fourth shaft portion 44 is in contact with the inner peripheral surface of the inner race 56. The fourth shaft portion 44 has a diameter smaller than the diameter of the third shaft portion 43.

The fifth shaft portion 45 is provided in the through hole 72h. The through hole 72h is provided in the second plate portion 72, which will be described later. The outer peripheral surface of the fifth shaft portion 45 is not in contact with the inner peripheral surface of the second plate portion 72. The fifth shaft portion 45 has a diameter smaller than the diameter of the fourth shaft portion 44.

<First bearing / Second bearing>
The first bearing 51 and the second bearing 55 rotatably support the shaft 4. The first bearing 51 is mounted on the first shaft portion 41. The second bearing 55 is mounted on the fourth shaft portion 44. The configurations of the first bearing 51 and the second bearing 55 may be the same or different from each other.

The first bearing 51 is a radial bearing or an angular bearing. The first bearing 51 has an inner race 52 and an outer race 53, as shown in FIGS. 2 and 3. The first bearing 51 of the present embodiment is a ball bearing in which a ball 54 is arranged between the inner race 52 and the outer race 53. The inner peripheral surface of the inner race 52 is in contact with the outer peripheral surface of the first shaft portion 41 of the shaft 4. The outer peripheral surface of the outer race 53 is in contact with the protrusion 71a, which will be described later.

The inner race 52 has a first end surface 52f and a second end surface 52s. The outer race 53 has a first end surface 53f and a second end surface 53s. The first end surface 52f and the first end surface 53f face the rotor main body 31. The first end surface 52f is in contact with the first end surface 42f. The first end surface 53f is not in contact with the shaft 4. The second end surface 52s and the second end surface 53s face the shim 6. The second end surface 52s is not in contact with the shim 6 and the case 7. In this embodiment, the second end surface 52s is in contact with a fixing member (not shown). This fixing member mechanically fixes the first bearing 51 and the first shaft portion 41. An example of this fixing member is a retaining ring, a nut for a shaft, or the like. When a shaft nut is used as the fixing member, it is preferable to form a threaded portion on the outer peripheral surface of the first shaft portion 41. This fixing member may not be used. In that case, the inner race 52 and the first shaft portion 41 are fixed by fitting them together. The second end surface 53s is in contact with the shim 6. FIG. 2 shows an example in which the first end surface 52f and the first end surface 53f are not displaced along the axial direction of the first bearing 51. FIG. 3 shows an example in which the first end surface 52f and the first end surface 53f are displaced along the axial direction of the first bearing 51. As will be described in detail later, the first end surface 52f and the first end surface 53f may be displaced along the axial direction of the first bearing 51.

The second bearing 55 is a radial bearing or an angular bearing. The configuration of the second bearing 55 is the same as that of the first bearing 51. That is, the second bearing 55 has an inner race 56 and an outer race 57, as shown in FIGS. 2 and 3. The inner peripheral surface of the inner race 56 is in contact with the outer peripheral surface of the fourth shaft portion 44. The outer peripheral surface of the outer race 57 is in contact with the inner peripheral surface of the recess 72a. The recess 72a is provided in the second plate portion 72 of the case 7. Each of the inner race 56 and the outer race 57 has a first end surface and a second end surface. Each first end surface faces the rotor body 31. The first end surface of the inner race 56 is not in contact with the rotor main body 31, but is in contact with the end surface 43a. The second end surface of the inner race 56 is not in contact with the elastic member 8 and the case 7. The second end surface of the inner race 56 may or may not be in contact with the same fixing member as the first bearing 51. This is because the outer race 57 is pressed toward the rotor 3 by the elastic member 8. The first end surface of the outer race 57 is not in contact with the rotor 3 and the shaft 4. The second end surface of the outer race 57 faces the elastic member 8. The second end surface of the outer race 57 is in contact with the elastic member 8.

<Elastic member 8>
The elastic member 8 presses the second bearing 55 toward the rotor 3. The elastic member 8 is arranged between the outer race 57 and the bottom of the recess 72a. An example of the elastic member 8 is a spring washer, a disc spring washer, a corrugated washer, an O-ring made of rubber, or the like.

<Case>
The case 7 houses the stator 2, the rotor 3, a part of the shaft 4, the first bearing 51, the second bearing 55, the shim 6, and the like inside. The case 7 includes a peripheral wall portion 73, a first plate portion 71, and a second plate portion 72.

The peripheral wall portion 73 and the second plate portion 72 of this embodiment are integrally configured. The peripheral wall portion 73 and the first plate portion 71 of this embodiment are configured as separate bodies. Unlike this embodiment, the peripheral wall portion 73 and the first plate portion 71 may be integrally configured, and the peripheral wall portion 73 and the second plate portion 72 may be configured separately. Further, unlike the present embodiment, the peripheral wall portion 73, the first plate portion 71, and the second plate portion 72 may be configured separately. The peripheral wall portion 73 and the first plate portion 71 of this embodiment are fixed to each other by a fastening member 92. An example of the fastening member 92 is a screw, a bolt, or the like, like the fastening member 91.

The peripheral wall portion 73 surrounds the outer periphery of the stator 2 and the rotor 3. A hole is provided in the end surface of the peripheral wall portion 73. A fastening member 92 is provided in this hole.

The first plate portion 71 has a first flat surface 71f, a protruding portion 71a, a first through hole, a second through hole, and a third through hole. The first plane 71f is provided inside the case 7. A stator 2 and a shim 6 described later are arranged on the first plane 71f. The protrusion 71a is provided between the stator 2 and the first bearing 51. The protrusion 71a is connected to the first plane 71f. The protruding portion 71a protrudes from the first plane 71f. The shape of the protrusion 71a is, for example, a cylinder. The inner peripheral surface of the protruding portion 71a is in contact with the outer peripheral surface of the outer race 53. The protrusion 71a can be used for positioning the first bearing 51. The outer peripheral surface of the protrusion 71a may or may not be in contact with the inner peripheral surface of the yoke 22. A part of the first shaft portion 41 is provided in the first through hole. A fastening member 91 is provided in the second through hole. The second through hole is provided at a position corresponding to the hole portion of the stator core 21. A fastening member 92 is provided in the third through hole. The second through hole is provided at a position corresponding to the hole portion of the peripheral wall portion 73.

The second plate portion 72 has a recess 72a in the center. A through hole 72h is provided at the bottom of the recess 72a. A fifth shaft portion 45 is provided in the through hole 72h. The inner diameter of the through hole 72h is larger than the outer diameter of the fifth shaft portion 45. Therefore, the shaft 4 rotates without contacting the inner peripheral surface of the through hole 72h with the fifth shaft portion 45. A second bearing 55 is arranged between the inner peripheral surface of the recess 72a and the fifth shaft portion 45.

<Sim>
The shim 6 adjusts the length of the gap between the stator 2 and the rotor 3. In this embodiment, the shim 6 is arranged between the first plane 71f and the outer race 53, as shown in FIGS. 2 and 3. The shim 6 has a first surface and a second surface. The first surface is in contact with the first plane 71f. The second surface is in contact with the second end surface 53s without being in contact with the second end surface 52s. The shape of the shim 6 is an annular plate shape. The shim 6 may be formed of a single plate or may be formed by stacking a plurality of shim pieces.

The length of the gap can be changed by changing the thickness Ts of the shim 6. When the shim 6 is arranged between the first plane 71f and the second end surface 53s, the first is compared with the case where the shim 6 is not arranged between the first plane 71f and the second end surface 53s. The positions of both first end surfaces 52f and 53f of the bearing 51 are separated from the first plane 71f. When the first end surface 52f and the first end surface 42f are in contact with each other, the shaft 4 is separated from the first plane 71f. The rotor 3 is separated from the first plane 71f by the contact between the second end surface 42s and the first surface 31f. Therefore, the length of the gap when the shim 6 is arranged between the first plane 71f and the second end surface 53s is not such that the shim 6 is arranged between the first plane 71f and the second end surface 53s. It will be longer than the length of the gap in the case. The thickness Ts of the shim 6 is a thickness at which the length of the gap becomes the design length G1.

[Step A]
The parts prepared in step A are the parts of the motor 1 described above with reference to FIG. In this embodiment, the parts include a stator 2, a rotor 3, a shaft 4, a first bearing 51, a second bearing 55, a shim 6, a case 7, an elastic member 8, a fastening member 91, and a fastening member 92.

(Step A1)
The predicted gap length G0 obtained in step A1 means the length of the gap in the virtual motor 1Z shown in FIG. The virtual motor 1Z is a virtual assembly using the above parts excluding the shim 6, and is not an actual assembly. The virtual motor 1Z includes the case 7, the stator 2, the rotor 3, the shaft 4, the first bearing 51, and the second bearing 55, but does not include the shim 6 shown in FIG. 1, which is the point of the motor of the present embodiment. It is different from the motor 1A manufactured by the manufacturing method. In the virtual motor 1Z, the first bearing 51 is arranged on the first plane 71f of the case 7 where the shim 6 is arranged in the manufactured motor 1A. In the virtual motor 1Z, the positions of the first bearing 51, the shaft 4, and the rotor 3 are located on the first plane 71f side with respect to the manufactured motor 1A by the thickness Ts of the shim 6. There is. FIG. 5 shows an example in which the first end surface 52f and the first end surface 53f are not displaced along the axial direction of the first bearing 51. FIG. 6 shows an example in which the first end surface 52f and the first end surface 53f are displaced along the axial direction of the first bearing 51. As will be described in detail later, the first end surface 52f and the first end surface 53f may be displaced along the axial direction of the first bearing 51.

The predicted length G0 is obtained in consideration of the actual size of the stator 2. The actual size of the stator 2 is the actual size of the stator 2 before assembly. The consideration of the actual size includes the case of considering the actual size itself and the case of considering the calculated value obtained from the actual size. The calculated value obtained from the actual dimensions is, for example, the average value of the actual dimensions of each stator 2 obtained from the plurality of stators 2.

The number of measurements to obtain the average value is less than the number of motors 1A manufactured. For example, assume the case of manufacturing 1000 motors 1A. If one stator 2 is used for one motor 1A, the number of measurements for obtaining the average value of the actual dimensions of the parts may be less than 1000. Even when two stators 2 are used, the number of measurements for obtaining the average value of the actual dimensions of the parts may be less than 1000. More specifically, it is possible to obtain an average value from the actual dimensions of 50 or less stators 2. The average value is preferably obtained for each lot of the stator 2.

The actual size of the stator 2 is the actual size of the length L1 of the stator core 21 shown in FIG. The actual dimension of the length L1 is determined by the actual dimension of the length between the first surface 22f of the yoke 22 and the end surface 23a of the teeth 23. The actual dimension of the length between the first surface 22f and the end surface 23a can be measured using a height gauge equipped with a class 0 surface plate.

Place the stator core 21 on the surface plate so that the end face 23a faces upward. A plurality of measurement points are selected on the end face 23a. The measurement point is set, for example, on a straight line drawn so that the center of gravity of the end surface 23a and the center of the yoke 22 pass through the stator core 21 in a plan view. It is preferable to select three or more measurement points on the straight line. In particular, the measurement points are the center of gravity of the end face 23a, the edge portion of the end face 23a located on the center side of the yoke 22, and the edge portion of the end face 23a located on the side far from the center of the yoke 22 on the straight line. It is preferable to include it. The length between the first surface 22f and the end surface 23a is the average value of the lengths of the straight lines connecting the surface plate and each measurement point among the straight lines orthogonal to the surface plate.

The actual size of the stator 2 may be obtained from the actual size of the length between the contact point between the first plane 71f and the first surface 22f and the end surface 23a. The actual size of the stator 2 may be determined by the actual size of the length between the first plane 71f and the end surface 23a. The actual dimension of the length between the first plane 71f and the end surface 23a is obtained in the same manner as the actual dimension of the length between the first surface 22f and the end surface 23a. That is, the first plate portion 71 is placed on the surface plate, and the stator core 21 is placed on the first plate portion 71. The measurement point is the same as the measurement point when measuring the actual dimension of the length between the first surface 22f and the end surface 23a.

The predicted length G0 is obtained by the "actual dimensions of length L2 + length L3 + length L4-length L5-length L1" shown in FIG.

The length L2 is the length between the first contact point and the second contact point. The first contact point is a contact point between the first plane 71f and the first bearing 51. The second contact point is a contact point between the first bearing 51 and the first end surface 42f. The length L2 is the height of the first bearing 51.
The length L3 is the length between the second contact point and the third contact point. The third contact point is a contact point between the second end surface 42s and the first surface 31f. The length L3 is the length of the second shaft portion 42. That is, the length L3 is the length between the first end surface 42f and the second end surface 42s.
The length L4 is the length between the third contact point and the bottom surface 32a. The length L4 is the depth of the recess 32. That is, the length L4 is the length between the first surface 31f and the bottom surface 32a.
The length L5 is the length between the bottom surface 32a and the first end surface 35f. The length L5 is the thickness Tm of the magnet 35. When the magnet 35 and the rotor main body 31 are fixed by the adhesive 38, the length L5 is the sum of the thickness Tm of the magnet 35 and the thickness Ta of the adhesive 38.

All of these lengths are along the axial direction of the shaft 4. The lengths L2 to L5 are all design dimensions and are known. The difference between the actual dimension and the design dimension of the length L2 to L5 tends to be smaller than the difference between the actual dimension and the design dimension of the length L1. The difference between the actual size and the design size of the length L1 tends to be large especially when the stator core 21 is made of a dust compact. Therefore, it is necessary to consider the actual size of the length L1 for the predicted length G0. Of course, it is preferable that the predicted length G0 considers at least one actual dimension of length L2 to length L5. The concept of the actual dimensions of each of the length L2 to the length L5 is the same as the concept of the actual dimensions of the stator 2. Further, the concept of each calculated value obtained from the actual dimensions of the length L2 to the length L5 is the same as the concept of the calculated value obtained from the actual dimensions of the stator 2.

The actual size of the length L2 may be either the actual height of the inner race 52 or the actual height of the outer race 53. The actual height of the outer race 53 is preferable because it is easier to measure than the actual height of the inner race 52. The actual height of the inner race 52 or the actual height of the outer race 53 shall be the average value of the heights at a plurality of measurement points. The measurement points are set at equal intervals in the circumferential direction of the inner race 52 or the outer race 53. The number of measurement points shall be 3 or more.

The actual size of the length L3 is the average value of the lengths at a plurality of measurement points. The measurement points are evenly spaced in the circumferential direction of the second shaft portion 42. The number of measurement points shall be 3 or more.

The actual size of the length L4 is the average value of the depths at multiple measurement points. The measurement points are evenly spaced on the circumferences of the three concentric circles. The three circumferences are, in a plan view of the recess 32, on the circumference of the inner peripheral edge of the recess 32, on the circumference of the outer peripheral edge of the recess 32, and at the intermediate point between the inner peripheral edge and the outer peripheral edge of the recess 32. It is on the circumference. The number of measurement points on each circumference shall be 3 or more. A measurement point on the circumference of the inner peripheral edge, a measurement point on the circumference of the outer peripheral edge, and a measurement point on the circumference of the intermediate point are located on a straight line along the radial direction of the rotor 3. .. The depth of each measurement point is the length along the axial direction of the rotor 3 between each measurement point and the first surface 31f of the rotor main body 31.

When the number of magnets 35 is plural, the actual dimension of the length L5 is the average value of the thickness Tm of the plurality of magnets 35. Each thickness Tm may be the thickness of one measurement point, or may be the average value of the thickness Tm of a plurality of measurement points. One measurement point is the center of gravity of the first end surface 35f in a plan view of the magnet 35. The plurality of measurement points are set on a straight line drawn so as to pass through the center of gravity of the first end surface 35f and the center of the rotor 3 in a plan view of the magnet 35. It is preferable to take three or more measurement points on the straight line. In particular, the plurality of measurement points are the center of gravity of the first end surface 35f, the edge of the first end surface 35f located on the center side of the rotor 3, and the first located on the side far from the center of the rotor 3 on the straight line. It is preferable to include an edge portion of the end face 35f. The thickness Tm of each magnet 35 is an average value of the lengths of the rotor 3 along the axial direction at each measurement point.

The actual size of the length L5 is the average value of the thickness Tm of a plurality of measurement points when the number of magnets 35 is one and the shape of the magnets 35 is annular. The measurement points are evenly spaced on the circumferences of the three concentric circles. The three circumferences are a plan view of the magnet 35, on the circumference of the inner peripheral edge of the first end surface 35f, on the circumference of the outer peripheral edge of the first end surface 35f, and the inner peripheral edge and the outer edge of the first end surface 35f. It shall be on the circumference of the midpoint with the periphery. The number of measurement points on each circumference shall be 3 or more. A measurement point on the circumference of the inner peripheral edge, a measurement point on the circumference of the outer peripheral edge, and a measurement point on the circumference of the intermediate point are located on a straight line along the radial direction of the rotor 3. .. The thickness of each measurement point is the length along the axial direction of the rotor 3 at each measurement point.

The actual size of the length L5 is the actual size in which the rotor body 31 and the magnet 35 are fixed when the adhesive 38 is provided. That is, the actual dimension of the length L5 is the average of the lengths along the axial direction of the rotor 3 between the measurement point of the thickness Tm of the magnet 35 and the bottom surface 32a of the recess 32 described above.

The predicted length G0 is preferably obtained in consideration of the deviation amount g of the first bearing 51 shown in FIG. That is, it is preferable to obtain the length L2 in consideration of the deviation amount g. The deviation amount g is the length along the axial direction of the first bearing 51 between the first end surface 53f and the first end surface 52f.

The deviation amount g is obtained in consideration of the load acting on the inner race 52 due to the weight of the shaft 4 and the rotor 3 and the load acting on the inner race 52 due to the attractive force of the magnet 35 to the stator 2. The deviation amount g is a load acting on the inner race 52 due to the weight of the second bearing 55, and a load acting on the inner race 52 due to a pressing force for pressing the second bearing 55 toward the first bearing 51 by the elastic member 8. , Is required in consideration of at least one of them.

The load due to the weight of the shaft 4 and the rotor 3 and the load due to the attractive force of the magnet 35 to the stator 2 mainly act on the inner race 52. Further, at least one of a load due to the weight of the second bearing 55 and a load due to the pressing force of the elastic member 8 pressing the second bearing 55 toward the first bearing 51 acts on the inner race 52. Depending on the magnitude of the load, the first end surface 52f deviates from the first end surface 53f. In particular, the deviation of the first end surface 52f is greatly affected by the attractive force of the magnet 35. That is, the stronger the magnetic force of the magnet 35, the more the first end surface 52f shifts. The difference between the predicted gap length G0 shown in FIG. 6 and the design length G1 shown in FIG. 3 increases by the amount of the deviation amount g. Therefore, it is preferable to consider the deviation amount g.

The deviation amount g may be obtained from a graph as shown in FIG. 7. The load (N) on the vertical axis of FIG. 7 indicates the load on the inner race 52 of the first bearing 51. The deviation amount (mm) on the horizontal axis in FIG. 7 indicates the deviation amount g of the first end surface 52f of the inner race 52 with respect to the first end surface 53f of the outer race 53 of the first bearing 51. The graph of FIG. 7 may be prepared in advance. Specifically, the graph of FIG. 7 can be obtained by applying the axial load of the first bearing 51 to the inner race 52 while displacing it.

The predicted length G0 is obtained by "(length L2-shift amount g) + length L3 + length L4-length L5-actual size of length L1". Even when the deviation amount g is taken into consideration, it is preferable that at least one of the length L2 to the length L5 is the actual size.

(Step A2)
In step A2, the thickness Ts of the shim 6 is the design length G1 of the gap shown in FIG. 2 and the predicted length of the gap shown in FIG. 5 before the process of assembling the parts, that is, before manufacturing the motor 1A described above. It is determined from the difference from G0. Alternatively, the thickness Ts of the shim 6 is determined from the difference between the design length G1 of the gap shown in FIG. 3 and the predicted length G0 of the gap shown in FIG.

[Step B]
In step B of assembling the parts, the stator 2, the rotor 3, the shaft 4, the first bearing 51, and the shim 6 are arranged at predetermined positions in the case 7. As long as the motor 1A as shown in FIG. 1 can be manufactured by this step B, the order of assembling the parts is not particularly limited. As an example of the step B, the following steps B1 to B5 may be performed in order.

(An example of the order in which parts are assembled)
In step B1, the shim 6 and the stator 2 are arranged on the first plane 71f of the first plate portion 71. The thickness Ts of the shim 6 is the same as the difference between the design length G1 and the predicted length G0 of the gap, as described above. When the predicted length G0 is shorter than the design length G1 as in the present embodiment, in the step B1, the shim 6 is arranged on the first plane 71f corresponding to the lower part of the first bearing 51.
In step B2, the first bearing 51 is arranged on the shim 6.
In step B3, the first shaft portion 41 of the shaft 4 is arranged in the first bearing 51. A rotor assembly that combines the rotor 3 and the shaft 4 is prepared in advance. In step B3, the first shaft portion 41 of the rotor assembly is arranged in the first bearing 51. In that case, the process B4 is performed without going through the process B31. When the rotor 3 and the shaft 4 which are not combined are prepared without preparing the rotor assembly, the process B31 is performed before the step B4. In step B31, the rotor 3 is fitted to the shaft 4 in a state where the first shaft portion 41 is arranged in the first bearing 51.
In step B4, the second bearing 55 is fitted to the fourth shaft portion 44 of the shaft 4.
In step B5, the through hole 72h of the second plate portion 72 is fitted into the fifth shaft portion 45 of the shaft 4, and the end face of the peripheral wall portion 73 and the first plate portion 71 are abutted against each other. Then, the first plate portion 71 and the peripheral wall portion 73 are fixed by the fastening member 92. The fastening member 92 is provided in the third through hole of the first plate portion 71 and the hole portion of the peripheral wall portion 73.

By assembling the parts in this order, the motor 1A shown in FIG. 1 is manufactured. The gap length of the manufactured motor 1A is the design length G1 as shown in FIG. 2 or FIG. The design length G1 shown in FIG. 2 or FIG. 3 is longer than the predicted length G0 of the virtual motor 1Z shown in FIG. 5 or FIG. 6 by the thickness Ts of the shim 6 shown in FIG. 2 or FIG. ..

[Action effect]
In the method of manufacturing the motor of this embodiment, before assembling the parts, the estimated gap length G0 is taken into consideration in consideration of the actual dimensions of the specific parts, and by extension, the difference between the predicted gap length G0 and the design length G1. Can be asked. The estimated gap length G0 obtained in consideration of the above actual dimensions is more accurate than the predicted gap length obtained from the design dimensions and dimensional tolerances of the parts. That is, the difference between the predicted gap length G0 and the design length G1 obtained in consideration of the above actual dimensions is compared with the difference between the predicted gap length and the design length of the gap obtained from the design dimensions and dimensional tolerances. Is accurate.

The load acting on the first end surface 52f of the inner race 52 of the first bearing 51 may cause the first end surface 52f of the inner race 52 to deviate from the first end surface 53f of the outer race 53. Even in this case, in the method of manufacturing the motor of this embodiment, the predicted length G0 is obtained in consideration of the deviation amount g, so that the accurate predicted length G0, and by extension, the predicted length G0 and the design length The exact difference from G1 can be obtained.

The method of manufacturing the motor of this embodiment can assemble a part including a shim 6 having the same thickness as the exact above difference. Therefore, in the method of manufacturing the motor of this embodiment, the length of the gap can be set to the design length G1 by assembling the parts only once. Therefore, the method for manufacturing the motor of this embodiment is excellent in the manufacturability of the motor 1A, which is excellent in assembly accuracy.

The method for manufacturing a motor of this embodiment is excellent in the manufacturability of a plurality of motors 1A having excellent assembly accuracy even when the step B of assembling parts is repeated. Therefore, the motor manufacturing method of the present embodiment can manufacture a plurality of motors 1A having small variations in performance. In particular, since the predicted length is obtained in consideration of the average value of the actual dimensions smaller than the number of manufactured products, compared with the case where the predicted length is obtained in consideration of the same number of actual dimensions as the number of manufactured products. , It is easy to improve the manufacturability of the motor 1A.

<< Embodiment 2 >>
[Motor manufacturing method]
The method of manufacturing the motor of the second embodiment will be described with reference to FIGS. 8 to 14. FIG. 8 is a cross-sectional view of the motor 1A manufactured by the method of manufacturing the motor of the present embodiment cut along a plane parallel to the axial direction of the shaft 4. The motor 1A of FIG. 8 is assembled using all the parts. FIG. 8 illustrates a single stator / single rotor type axial gap motor as the manufactured motor 1A. FIG. 12 shows a cross-sectional view of the virtual motor 1Z cut along a plane parallel to the axial direction of the shaft 4.

The motor manufacturing method of the present embodiment differs from the motor manufacturing method of the first embodiment in that the shim 6 is arranged in the process B. The following description will focus on the differences from the first embodiment. The description of the same configuration as that of the first embodiment may be omitted.

The motor 1A manufactured earlier will be described. After that, a method of manufacturing a motor for manufacturing the motor 1A will be described. As shown in FIGS. 9 and 13 or FIGS. 10 and 14, the method for manufacturing the motor of the present embodiment exemplifies the case where the predicted length G0 exceeds the design length G1.

<Sim>
In this embodiment, the shim 6 is arranged between the first plane 71f and the first plane 22f, as shown in FIGS. 8 to 10. The first surface of the shim 6 is in contact with the first plane 71f. The second surface of the shim 6 is in contact with the first surface 22f. As shown in FIG. 11, the shape of the shim 6 is an annulus plate. The shim 6 of this embodiment is composed of a single plate.

When the shim 6 is arranged between the first plane 71f and the first surface 22f as shown in FIGS. 8 to 10, the shim 6 is not arranged between the first plane 71f and the first surface 22f. Compared with the case, the position of the end surface 23a approaches the first end surface 35f. Therefore, the length of the gap when the shim 6 is arranged between the first plane 71f and the first surface 22f is such that the shim 6 is not arranged between the first plane 71f and the first surface 22f. It will be shorter than the length of the gap in the case. The thickness Ts of the shim 6 is a thickness at which the length of the gap becomes the design length G1.

As shown in FIG. 11, the shim 6 has a plurality of through holes 61. The through hole 61 is a hole into which the fastening member 91 is fitted. The through hole 61 is provided at a position corresponding to the hole portion of the stator core 21.

The area of the first surface and the second surface of the shim 6 is preferably 95% or more and 100% or less with respect to the area of the first surface 22f of the yoke 22. This is because the shim 6 easily dissipates heat from the stator 2. The area of the first surface and the second surface of the shim 6 is preferably more than 95% and less than 100% with respect to the area of the first surface 22f, and particularly 96% or more and 99% with respect to the area of the first surface 22f. The following is preferable.

(Process A1 and Process A2)
The method of obtaining the predicted length G0 in the step A1 and the method of determining the thickness Ts of the shim 6 in the step A2 are the same as those in the first embodiment.

[Step B]
In step B1, the shim 6 and the first bearing 51 are arranged on the first plane 71f of the first plate portion 71. The thickness Ts of the shim 6 is the same as the difference between the design length G1 and the predicted length G0 of the gap, as described above. When the predicted length G0 is longer than the design length G1 as in the present embodiment, in the step B1, the shim 6 is arranged on the first plane 71f corresponding to the lower side of the stator 2.
In step B2, the stator 2 is arranged on the shim 6.
The steps B3 and subsequent steps are the same as those in the first embodiment.

[Action effect]
The method for manufacturing the motor of this embodiment is excellent in the manufacturability of the motor 1A, which is excellent in assembly accuracy, as in the first embodiment.

<< Embodiment 3 >>
[Motor manufacturing method]
A method of manufacturing the motor of the third embodiment will be described with reference to FIG. FIG. 15 is a cross-sectional view of the motor 1A manufactured by the method for manufacturing the motor of the present embodiment, cut along a plane parallel to the axial direction of the shaft 4.

The motor manufacturing method of the present embodiment is different from the motor manufacturing method of the second embodiment in that at least one of the prepared stator core 21 and the first plate portion 71 has a positioning portion of the shim 6. The following description will focus on the differences from the second embodiment. The description of the configuration similar to that of the second embodiment may be omitted. These points are the same in the fourth and sixth embodiments described later.

In this embodiment, both the stator core 21 and the first plate portion 71 have a shim 6 positioning portion. The first surface 22f of the stator core 21 is provided with a recess 221 as a positioning portion. The first plane 71f of the first plate portion 71 is provided with a recess 711 as a positioning portion. The shape of the recess 221 and the shape of the recess 711 are the same as each other. The shape of the recess 221 and the shape of the recess 711 are annular shapes corresponding to the shape of the shim 6. The total depth of the recess 221 and the recess 711 is greater than the thickness of the shim 6. The depth of the recess 221 and the depth of the recess 711 may be the same or different from each other.

The area of the first surface of the shim 6 is less than 100% of the area of the first surface 22f of the yoke 22. The lower limit of the area of the first surface of the shim 6 is the same as that of the second embodiment.

(Process A1 and Process A2)
The method of obtaining the predicted length G0 in the step A1 is the same as that of the first embodiment. In step A2, the thickness of the shim 6 is determined by "predicted length G0-design length G1 + actual dimension of depth of recess 221 + depth of recess 711".

The actual dimension of the depth of the recess 221 is the actual dimension of the length between the first surface 22f and the bottom surface of the recess 221. The depth of the recess 221 is the length along the axial direction of the shaft 4. The actual dimension of the depth of the recess 221 is the average value of the depths at a plurality of measurement points. The method of taking the measurement point is the same as the method of taking the measurement point in the above-mentioned method of obtaining the actual size of the length L4.

The depth of the recess 711 is the length between the first plane 71f and the bottom surface of the recess 711. The depth of the recess 711 is a design dimension and is known. The depth of the recess 711 is preferably the actual size. The actual dimension of the depth of the recess 711 is the average value of the depths at a plurality of measurement points. The method of taking the measurement point is the same as the method of taking the measurement point in the method of obtaining the actual size with the length L4.

[Step B]
In step B1, the shim 6 is arranged in the recess 711. In step B1, the location of the first bearing 51 is the same as that of the second embodiment.
In step B2, the stator 2 is arranged so that the recess 221 fits into the shim 6. A gap is formed between the first surface 22f and the first plane 71f. The size of this gap is the difference between the predicted length G0 and the design length G1.
The steps B3 and subsequent steps are the same as those in the second embodiment.

[Action effect]
In the method of manufacturing the motor of this embodiment, the shim 6 can be easily positioned with respect to the first plate portion 71. Moreover, the method of manufacturing the motor of this embodiment makes it easy to position the stator 2 with respect to the shim 6. Therefore, the method of manufacturing the motor of this embodiment makes it easy to assemble the parts.

<< Embodiment 4 >>
[Motor manufacturing method]
A method of manufacturing the motor of the fourth embodiment will be described with reference to FIG. The motor manufacturing method of the present embodiment differs from the motor manufacturing method of the second embodiment in the following requirements (a) and (b).
(A) The stator core 21 to be prepared has a plurality of stator core pieces 210.
(B) The shim 6 to be prepared has a plurality of shim pieces 60.

Stator core piece The stator core piece 210 is composed of one yoke piece 220 and at least one tooth. The number of stator core pieces 210 can be appropriately selected. The number of the stator core pieces 210 of this embodiment is six. That is, the number of yoke pieces 220 in this embodiment is six. The shape of the yoke piece 220 is a fan plate shape. The number of teeth connected to each yoke piece 220 may be one or plural. In this embodiment, the number of teeth connected to each yoke piece 220 is two. In this embodiment, the actual dimensions of the length of each stator core piece 210 are substantially the same. The actual length of each stator core piece 210 is the actual length between the first surface 22f of the yoke piece 220 and the end surface of the tooth. The method of obtaining the actual size of the length of each stator core piece 210 is the same as the method of obtaining the actual size of the length L1 described in the first embodiment.

<Sim>
The shim 6 is composed of shim pieces 60 divided into a plurality of parts in the circumferential direction. The number of shim pieces 60 is the same as the number of stator core pieces 210. The shape of the shim piece 60 is the same as the shape of the yoke piece 220. The shape of the shim piece 60 of this embodiment is a fan plate shape.

(Step A1)
In step A1, when the actual dimensions of the lengths of the stator core pieces 210 are substantially the same as in the present embodiment, the predicted length G0 corresponding to one stator core piece 210 may be obtained. Alternatively, in step A1, even when the actual dimensions of the lengths of the stator core pieces 210 are substantially the same as in the present embodiment, the predicted length G0 corresponding to each stator core piece 210 may be obtained. good. That is, the predicted length G0, which is the same as the number of the stator core pieces 210, is obtained. The method of obtaining the predicted length G0 is the same as the method of obtaining the predicted length G0 described in the first embodiment.

(Step A2)
In step A2, the thickness of all shim pieces 60 is determined from the difference between one predicted length G0 and the design length G1. Alternatively, the thickness of each shim piece 60 may be determined from the difference between each predicted length G0 and the design length G1. The method of obtaining the thickness of each shim piece 60 is the same as the method of obtaining the thickness of the shim 6 described in the first embodiment.

[Action effect]
The method for manufacturing a motor of this embodiment is excellent in the manufacturability of a motor having excellent assembly accuracy even when the stator core 21 includes a plurality of stator core pieces 210.

<< Embodiment 5 >>
A method of manufacturing the motor of the fifth embodiment will be described with reference to FIG. FIG. 17 is a cross-sectional view of the motor 1A manufactured by the method of manufacturing the motor of the present embodiment cut along a plane parallel to the axial direction of the shaft 4.

The motor manufacturing method of the present embodiment differs from the motor manufacturing method of the fourth embodiment in the following requirements (a) and (b).
(A) Of the plurality of stator core pieces 210 to be prepared, the actual size of the length L1 of at least one stator core piece 210 is different from the actual size of the length L1 of the other stator core pieces 210.
(B) Of the plurality of shim pieces 60 to be prepared, the thickness of at least one shim piece 60 is different from the thickness of the other shim pieces 60.
The following description will focus on the differences from the fourth embodiment. The description of the configuration similar to that of the fourth embodiment may be omitted.

(Step A1)
In step A1, when the actual size of the length L1 of at least one stator core piece 210 is different from the actual size of the length L1 of the other stator core piece 210 as in the present embodiment, the stator core pieces 210 having different lengths are dealt with. Find the predicted length G0. For example, of the six stator core pieces 210, three stator core pieces 210 having a length L1 of A (mm), two stator core pieces 210 having a length L1 of B (mm), and C (mm) length L1. ), One stator core piece 210, and A ≠ B ≠ C. In this case, three predicted lengths G0 are obtained. The first predicted length G0 is a predicted length corresponding to the stator core piece 210 having a length L1 of A (mm). The second predicted length G0 is a predicted length corresponding to the stator core piece 210 having a length L1 of B (mm). The third predicted length G0 is a predicted length corresponding to the stator core piece 210 having a length L1 of C (mm). Of course, in step A1, the predicted length G0 corresponding to each stator core piece 210 may be obtained. That is, the predicted length G0, which is the same as the number of the stator core pieces 210, is obtained. The method of obtaining each predicted length G0 is the same as the method of obtaining the predicted length G0 described in the first embodiment.

(Step A2)
In step A2, the thickness of each shim piece 60 is determined from the difference between the three predicted lengths G0 and the design length G1. The method of obtaining the thickness of each shim piece 60 is the same as the method of obtaining the thickness of the shim 6 described in the first embodiment.

[Action effect]
The method for manufacturing the motor of this embodiment is excellent in the manufacturability of the motor 1A, which is excellent in assembly accuracy, even when the length L1 of the stator core pieces 210 is different.

<< Embodiment 6 >>
[Motor manufacturing method]
A method of manufacturing the motor of the sixth embodiment will be described with reference to FIG. FIG. 18 is a cross-sectional view of the motor 1A manufactured by the method for manufacturing the motor of the present embodiment, cut along a plane parallel to the axial direction of the shaft 4.

The method for manufacturing the motor of this embodiment is different from the method for manufacturing the motor of the second embodiment in that a double stator / single rotor type axial gap motor is manufactured. The double stator / single rotor type is a motor in which the number of stators 2 is two and the number of rotors 3 is one. In the double stator / single rotor type, one rotor 3 is assembled so as to be sandwiched between the two stators 2 from the axial direction of the shaft 4.

<Rotor>
The rotor body 31 is an annular flat plate member. The rotor body 31 has one first through hole and at least one second through hole. The first through hole is provided in the center. A third shaft portion 43 of the shaft 4 is provided in the first through hole. The second through hole is provided on the outer peripheral side of the first through hole. A magnet 35 is provided in the second through hole. The number of second through holes is the same as the number of magnets 35.

As shown in FIG. 18, the thickness of the rotor main body 31 and the thickness of the magnet 35 in this embodiment are the same. That is, the first surface of the rotor body 31 and the first end surface of the magnet 35 are flush with each other. Further, the second surface of the rotor main body 31 and the second end surface of the magnet 35 are flush with each other. The first surface of the rotor body 31 and the first end surface of the magnet 35 are surfaces provided on one of the stator 2 sides. The second surface of the rotor body 31 and the second end surface of the magnet 35 are surfaces provided on the other stator 2 side. Here, the stator 2 shown on the lower side of the paper in FIG. 18 is one of the stators 2. Further, the stator 2 shown on the upper side of the paper in FIG. 18 is the other stator 2. Although not shown, the thickness of the rotor body 31 and the magnet 35 may not be the same.

<Case>
The case 7 of this embodiment includes a pair of first plate portions 71 and a peripheral wall portion 73. The pair of first plate portions 71 and the peripheral wall portion 73 are configured as separate bodies. One of the first plate portion 71 and the peripheral wall portion 73 is fixed by a fastening member 92. The other first plate portion 71 and the peripheral wall portion 73 are fixed by a fastening member 92.

(Process A1 and Process A2)
On the other hand, the method of obtaining the predicted length is the same as that of the first embodiment. The other predicted length is obtained by "the height of the other first bearing 51 + the length of the third shaft portion 43-the thickness of the magnet 35-the actual dimension of the length of the stator core 21". On the lower side of the paper in FIG. 18, the length of the gap in the state where the shim 6 is not arranged is defined as one of the predicted lengths. Further, on the upper side of the paper surface of FIG. 18, the length of the gap in the state where the shim 6 is not arranged is defined as the other predicted length. The method of obtaining the thickness of one shim 6 and the method of obtaining the thickness of the other shim 6 are the same as those in the first embodiment.

The length of the third shaft portion 43 is the length between the end surface 43a and the second end surface 42s. The length of the third shaft portion 43 is the length along the axial direction of the third shaft portion 43. The length of the third shaft portion 43 is a design dimension and is known. The length of the third shaft portion 43 is preferably the actual size. The actual size of the length of the third shaft portion 43 is the average value of the lengths at a plurality of measurement points. The measurement points are evenly spaced in the circumferential direction of the third shaft portion 43. The number of measurement points shall be 3 or more. The length of each measurement point is the length along the axial direction of the third shaft portion 43 at each measurement point.

[Action effect]
The method for manufacturing the motor of this embodiment is excellent in the manufacturability of the motor 1A, which is excellent in assembly accuracy, as in the first embodiment.

The present invention is not limited to these examples, but is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1A motor, 1Z virtual motor 2 stator 21 stator core, 210 stator core piece 22 yoke, 220 yoke piece,
22f 1st surface, 221 recesses, 22s 2nd surface 23 teeth, 23a end surface 25 coil 3 rotor 31 rotor body 31f 1st surface, 31s 2nd surface, 32 recesses, 32a bottom surface 35 magnets, 35f 1st end surface, 38 adhesive 4 Shaft 41 1st shaft part 42 2nd shaft part, 42f 1st end surface, 42s 2nd end face 43 3rd shaft part, 43a End face 44 4th shaft part, 45 5th shaft part 51 1st bearing 52 Inner race, 52f 1st end face, 52s 2nd end face 53 outer race, 53f 1st end face, 53s 2nd end face 54 ball 55 2nd bearing 56 inner race, 57 outer race 6 shims, 60 shim pieces, 61 through holes 7 cases 71 1st plate Part 71f First plane, 711 Recessed part, 71a Protruding part 72 Second plate part 72a Recessed part, 72h Through hole, 73 Peripheral wall part 8 Elastic member 91, 92 Fastening member L1, L2, L3, L4, L5 Length G0 Predicted length , G1 Design length g Deviation amount Ts, Tm, Ta Thickness

Claims (14)

The process of preparing parts for axial gap type motors and
With the process of assembling the parts
The parts are
With the rotor
With the stator,
The shaft, which is the rotation axis of the rotor, and
A bearing that rotatably supports the shaft and
A case having a first plane on which the stator and the bearing are placed, and
Includes shims located between the first plane and the bearing, or between the first plane and the stator.
The process of preparing the parts is
The step of obtaining the predicted length of the gap between the rotor and the stator in consideration of the actual size of the stator, and
It comprises a step of determining the thickness of the shim based on the difference between the design length of the gap and the predicted length.
How to make a motor. If the predicted length exceeds the design length
The method for manufacturing a motor according to claim 1, wherein in the step of assembling the parts, the shim is arranged between the first plane and the stator. If the predicted length is less than the designed length
The method for manufacturing a motor according to claim 1, wherein in the step of assembling the parts, the shim is arranged between the first plane and the bearing. The step of obtaining the predicted length is further described in any one of claims 1 to 3, wherein the predicted length is obtained in consideration of the actual dimensions of each of the rotor, the shaft, and the bearing. How to make a motor. The rotor is
Annulus plate-shaped rotor body and
With at least one magnet fixed to the rotor body,
The bearing is a radial bearing or an angular bearing having an inner race and an outer race.
Each of the inner race and the outer race has a first end surface facing the rotor body.
In the step of obtaining the predicted length, the predicted length is further obtained in consideration of the amount of deviation between the first end surface of the outer race and the first end surface of the inner race.
The deviation amount is obtained from claim 1 in consideration of the load acting on the inner race due to the weight of the shaft and the rotor and the load acting on the inner race due to the attractive force of the magnet to the stator. The method for manufacturing a motor according to any one of claims 4. The stator is
Annulus plate-shaped yoke and
With a plurality of columnar teeth arranged at intervals in the circumferential direction of the yoke,
The yoke has a first surface in contact with the first plane.
The teeth have end faces facing the rotor and
The step of obtaining the predicted length is any one of claims 1 to 5, wherein the predicted length is obtained in consideration of the actual size between the first surface of the yoke and the end surface of the teeth. The method for manufacturing a motor according to the section. The method for manufacturing a motor according to any one of claims 1 to 6, wherein the stator includes a stator core made of a dust compact. The method for manufacturing a motor according to any one of claims 1 to 7, wherein the part includes a fastening member for fixing the first plane and the stator. The rotor is
Annulus plate-shaped rotor body and
With at least one magnet fixed to the rotor body,
The rotor body has a front surface facing the magnet and has a front surface.
The magnet has a first end surface facing the stator and has a first end surface.
In the step of obtaining the predicted length, in the rotor in which the rotor body and the magnet are fixed, the actual dimension of the length between the first surface of the rotor body and the first end surface of the magnet is obtained. The method for manufacturing a motor according to any one of claims 1 to 8, wherein the predicted length is obtained in consideration of the above. The number of the magnets is one.
The method for manufacturing a motor according to claim 9, wherein the shape of the magnet is annular. The method for manufacturing a motor according to any one of claims 1 to 10, wherein in the step of assembling the parts, the shaft is press-fitted into the rotor. Repeat the process of assembling the parts,
In the step of obtaining the predicted length, the predicted length is obtained in consideration of the average value of the actual dimensions of each of the stator, the rotor, the shaft, and the bearing, which is smaller than the number of manufactured motors. The method for manufacturing a motor according to any one of claims 1 to 11. The method for manufacturing a motor according to any one of claims 1 to 12, wherein the number of the stators and the number of the rotors are one each. The method for manufacturing a motor according to any one of claims 1 to 12, wherein the number of the stators is two and the number of the rotors is one.

Images