WO2020137292A1 - Motor manufacturing method, motor assembly apparatus, and motor - Google Patents

Abstract

This motor manufacturing method, for manufacturing a motor comprising a rotor, which comprises a shaft extending along the central axis and a rotor main body fixed on the outer peripheral surface of the shaft, and a stator which is positioned radially outside of the rotor, involves a step for using a motor assembly apparatus to arrange the rotor radially inside of the stator. The shaft has a female screw hole disposed on the end surface on one side in the axial direction and recessed towards the other side in the axial direction. The motor assembly apparatus is provided with a stator attachment part, and a rotor attachment part to which the rotor is attached. The rotor attachment part has a screw member which extends in the axial direction. The step for arranging the rotor involves a step for attaching the stator to the stator attachment part, a step for tightening the screw member in the female screw hole to attach the rotor to the rotor attachment part, a step for moving the rotor attachment part nearer the stator attachment part and inserting the rotor radially inside of the stator, and a step for removing the screw member from the female screw hole.

Description

Motor manufacturing method, motor assembly apparatus, and motor

The present invention relates to a motor manufacturing method, a motor assembly device, and a motor.

A motor including a rotor and a stator located radially outside the rotor is known. For example, Patent Document 1 describes a motor mounted in a multicopter as such a motor.

Japanese Patent Laid-Open Publication No. 2018-988662

When manufacturing the above motor, it is necessary to insert and arrange the rotor inside the stator in the radial direction. In this case, for example, it is conceivable to sandwich the rotor shaft in the radial direction and insert the rotor inside the stator in the radial direction. However, depending on the shape of the shaft, it may be difficult to stably grip the shaft. Therefore, it may be difficult to arrange the rotor radially inside the stator.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a motor manufacturing method and a motor assembling apparatus in which the rotor can be easily arranged radially inside the stator regardless of the shape of the shaft. Another object of the present invention is to provide a motor having a structure in which the rotor can be easily arranged radially inside the stator regardless of the shape of the shaft.

One aspect of a motor manufacturing method of the present invention is a rotor having a shaft extending along a central axis and a rotor body fixed to an outer peripheral surface of the shaft, and a stator positioned radially outside the rotor. And a step of disposing the rotor inside a radial direction of the stator by using a motor assembling apparatus. The shaft has a female screw hole that is recessed toward the other side in the axial direction on the end surface on the one side in the axial direction. The motor assembly device includes a stator mounting portion to which the stator is mounted, and a rotor mounting portion that is axially movable on one axial side of the stator mounting portion and to which the rotor is mounted. The rotor mounting portion has a screw member extending in the axial direction. The step of disposing the rotor includes the step of attaching the stator to the stator attachment portion, the step of tightening the screw member into the female screw hole to attach the rotor to the rotor attachment portion, and the step of attaching the rotor attachment portion to the rotor attachment portion. The method includes the steps of bringing the rotor closer to the stator mounting portion and inserting the rotor radially inside the stator, and the step of removing the screw member from the female screw hole.

One aspect of a motor assembly device of the present invention includes a rotor having a shaft extending along a central axis, a rotor body fixed to an outer peripheral surface of the shaft, and a stator positioned radially outside the rotor. It is a motor assembly device which assembles the motor provided. The motor assembly device includes a stator mounting portion to which the stator is mounted, and a rotor mounting portion that is axially movable on one axial side of the stator mounting portion and to which the rotor is mounted. The shaft has a female screw hole that is recessed toward the other side in the axial direction on the end surface on the one side in the axial direction. The rotor mounting portion has a screw member extending in the axial direction. The screw member is fastened to the female screw hole, and the rotor can be attached to the rotor attachment portion.

One aspect of a motor of the present invention is a rotor having a shaft extending along a central axis and a rotor main body fixed to an outer peripheral surface of the shaft, a stator positioned radially outside the rotor, the rotor, and A housing that accommodates the stator. The shaft has a female screw hole that is recessed toward the other side in the axial direction on the end surface on the one side in the axial direction. The housing includes a tubular portion that opens to one side in the axial direction, and a lid member that closes the opening of the tubular portion on the one side in the axial direction. The lid member covers the female screw hole from one side in the axial direction.

According to one aspect of the present invention, when manufacturing a motor, the rotor can be easily arranged radially inside the stator regardless of the shape of the shaft.

FIG. 1 is a cross-sectional view showing the motor of this embodiment. FIG. 2 is a flowchart showing the procedure of the motor manufacturing method of this embodiment. FIG. 3 is a cross-sectional view showing the motor assembly device of this embodiment. FIG. 4 is a cross-sectional view showing a state of the motor assembly device in the stator mounting process and the rotor mounting process of this embodiment. FIG. 5 is a cross-sectional view showing a state of the motor assembly device in the rotor inserting step of this embodiment. FIG. 6 is a cross-sectional view showing a state of the motor assembling apparatus in the mounting/dismounting step of this embodiment. FIG. 7 is a cross-sectional view showing a state of the motor assembling apparatus after the attaching/detaching step of this embodiment.

The Z-axis direction that is shown in each drawing as appropriate indicates the axial direction of the central axis J that is a virtual line that is shown as appropriate in each drawing. In the following description, the axial direction of the central axis J is simply referred to as “axial direction”, the radial direction around the central axis J is simply referred to as “radial direction”, and the circumferential direction around the central axis J is simply referred to. This is called "circumferential direction".

<Motor> In the following description of the configuration of the motor 10 described with reference to FIG. 1, the positive side in the Z-axis direction is referred to as “one side in the axial direction”, and the negative side in the Z-axis direction is referred to as the “axial direction”. The other side". One side in the axial direction is the lower side of FIG. The other side in the axial direction is the upper side in FIG.

As shown in FIG. 1, the motor 10 of the present embodiment is mounted on the rotary wing device 1. The rotary wing device 1 is mounted on, for example, an unmanned aerial vehicle. The rotary wing device 1 includes a motor 10 and a propeller 2. The motor 10 includes a rotor 20 rotatable about a central axis J, a stator 30, a housing 40, a sensor assembly 50, a bus bar assembly 60, a first bearing 71, a second bearing 72, and a propeller mounting portion. And 80.

The housing 40 accommodates the rotor 20, the stator 30, the sensor assembly 50, the bus bar assembly 60, the first bearing 71, and the second bearing 72 therein. The housing 40 has a tubular portion 41 and a lid member 42. The tubular portion 41 has a lid-like tubular shape that opens to one side in the axial direction. In the present embodiment, the tubular portion 41 has a cylindrical shape centered on the central axis J. In the present embodiment, the tubular portion 41 is a single member. The tubular portion 41 has a top wall portion 41b, a tubular portion main body 41a, and a holding portion 41c.

The top wall portion 41b is located on the other axial side of the stator 30 and covers the other axial side of the stator 30. The top wall portion 41b has an annular plate shape centered on the central axis J. The tubular portion main body 41a extends from the radially outer peripheral edge portion of the top wall portion 41b to one side in the axial direction. The tubular portion main body 41a has a cylindrical shape centering on the central axis J and opening to one side in the axial direction. A stator core 31, which will be described later, is fixed to the inner peripheral surface of the tubular portion main body 41a. A plurality of fins 45 are provided along the circumferential direction on the outer peripheral surface of the tubular portion main body 41a. The holding portion 41c projects from the radially inner peripheral edge portion of the top wall portion 41b to the other side in the axial direction. The second bearing 72 is held inside the holding portion 41c in the radial direction.

The lid member 42 closes the opening on the one axial side of the tubular portion 41. In the present embodiment, the lid member 42 has a bottom wall portion 43 and a bearing holder 44. The bottom wall portion 43 has an annular plate shape centered on the central axis J. The radial outer peripheral edge portion of the bottom wall portion 43 is fixed to the axially one end portion of the tubular portion 41 by, for example, a screw. The radially inner peripheral edge portion of the bottom wall portion 43 is located radially inward of the stator 30.

The bearing holder 44 holds the first bearing 71. The bearing holder 44 is fitted and fixed inside the bottom wall portion 43 in the radial direction. The bearing holder 44 closes the radially inner opening of the bottom wall 43. The bearing holder 44 covers the rotor 20 from one side in the axial direction. As a result, the lid member 42 covers a female screw hole 21c, which will be described later, provided on the shaft 21 from one axial side. A preload member 90 is provided between the bearing holder 44 and the first bearing 71. The preload member 90 applies a preload to the outer ring of the first bearing 71 in the other axial direction. The preload member 90 is, for example, a wave washer.

The rotor 20 has a shaft 21 and a rotor body 24 fixed to the outer peripheral surface of the shaft 21. The shaft 21 extends along the central axis J. The shaft 21 has a cylindrical shape that extends in the axial direction around the central axis J. The end of the shaft 21 on the other side in the axial direction protrudes to the other side in the axial direction than the housing 40. The propeller mounting portion 80 is fixed to the end portion of the shaft 21 on the other axial side. That is, in the present embodiment, the end of the shaft 21 on the other side in the axial direction is the end on the output side that outputs the rotation of the motor 10. The one end in the axial direction of the shaft 21 is positioned on the other side in the axial direction than the end of the tubular portion 41 on the one side in the axial direction. In the present embodiment, the end of the shaft 21 on one side in the axial direction is the end opposite to the output side.

The shaft 21 is supported by the first bearing 71 and the second bearing 72 so as to be rotatable about the central axis J. The first bearing 71 and the second bearing 72 are, for example, ball bearings. The inner ring of the first bearing 71 and the inner ring of the second bearing 72 are press-fitted and fixed to the outer peripheral surface of the shaft 21.

The first bearing 71 supports a portion of the shaft 21 located on one axial side of the rotor body 24. The first bearing 71 is held by the bearing holder 44. The first bearing 71 is located on the other side in the axial direction than the end portion on the one side in the axial direction of the tubular portion 41. The axially one end of the first bearing 71 is arranged at substantially the same position as the axially one end of the shaft 21 in the axial direction. The second bearing 72 supports a portion of the shaft 21 located on the other axial side of the rotor body 24. The second bearing 72 is held by the holding portion 41c.

The shaft 21 has a shaft flange portion 21d at a portion on the other axial side of the portion of the shaft 21 to which the rotor body 24 is fixed. The shaft flange portion 21d projects outward in the radial direction. The shaft flange portion 21d has, for example, an annular shape around the central axis J. The shaft flange portion 21d contacts the inner ring of the second bearing 72 from one side in the axial direction.

A portion of the shaft 21 located between the rotor body 24 and the first bearing 71 in the axial direction has an outer diameter changing portion 21 a whose outer diameter changes along the axial direction. In the present embodiment, the outer diameter changing portion 21a is a portion whose outer diameter increases from one axial side toward the other axial side. The outer peripheral surface of the outer diameter changing portion 21a is a concave curved surface that is recessed radially inward. The end of the outer diameter changing portion 21a on the one side in the axial direction has a larger outer diameter than the portion of the shaft 21 located on the one side in the axial direction of the outer diameter changing portion 21a. An end portion on the one axial side of the outer diameter changing portion 21a contacts the inner ring of the first bearing 71 from the other axial side.

In the present embodiment, the portion of the shaft 21 located between the rotor main body 24 and the first bearing 71 in the axial direction refers to the end of the portion of the shaft 21 to which a rotor core 22 described later is fixed, on one axial side. It is a portion from the portion to the end portion on the other axial side of the portion to which the first bearing 71 is fixed. The axial dimension H1 of the portion of the shaft 21 located between the rotor body 24 and the first bearing 71 in the axial direction is half or less than the axial dimension H2 of the rotor body 24. In the present embodiment, the axial dimension H2 of the rotor body 24 is the axial dimension of the rotor magnet 23 described later. The dimension H1 is smaller than half the dimension H2, for example.

The shaft 21 has a shaft hole portion 21b that is recessed toward the other side in the axial direction on the end surface on the one side in the axial direction. The shaft hole portion 21b is a hole that extends in the axial direction and has a bottom portion on the other side in the axial direction. By providing the shaft hole portion 21b, the shaft 21 can be thinned and the motor 10 can be reduced in weight. The shaft hole portion 21b extends from the end surface on one axial side of the shaft 21 to a portion of the shaft 21 supported by the second bearing 72. The cross-sectional shape of the shaft hole portion 21b orthogonal to the axial direction is, for example, a circular shape centered on the central axis J.

A female screw portion is provided on a portion of the inner peripheral surface of the shaft hole portion 21b including the end portion on one axial side. As a result, the portion of the shaft hole portion 21b including the end portion on the one side in the axial direction becomes the female screw hole 21c. That is, the shaft 21 has a female screw hole 21c that is recessed toward the other side in the axial direction on the end face on the one side in the axial direction. The female screw hole 21c extends in the axial direction around the central axis J. The female screw hole 21c extends, for example, from an end surface on one axial side of the shaft 21 to an end on one axial side of a portion of the shaft 21 to which the rotor body 24 is fixed.

The rotor body 24 has a rotor core 22 and a rotor magnet 23. The rotor core 22 is fixed to the outer peripheral surface of the shaft 21. The rotor core 22 has an annular shape. In the present embodiment, the rotor core 22 has an annular shape centered on the central axis J. The rotor core 22 has an inner core portion 22a, an outer core portion 22b, and a plurality of connecting portions 22c.

The inner core portion 22a has an annular shape along the circumferential direction. In the present embodiment, the inner core portion 22a has an annular shape centered on the central axis J. The inner core portion 22a is fixed to the outer peripheral surface of the shaft 21. The outer core portion 22b is located radially outside the inner core portion 22a. In this embodiment, the outer core portion 22b has an annular shape along the circumferential direction. More specifically, the outer core portion 22b has an annular shape centered on the central axis J. The outer core portion 22b projects more axially than the inner core portion 22a.

The plurality of connecting portions 22c are located between the inner core portion 22a and the outer core portion 22b in the radial direction. The plurality of connecting portions 22c connect the inner core portion 22a and the outer core portion 22b. The plurality of connecting portions 22c are arranged along the circumferential direction. The axial dimension of the connecting portion 22c is the same as the axial dimension of the inner core portion 22a. The other axial end of the connecting portion 22c is arranged at the same axial position as the other axial end of the inner core portion 22a. The end of the connecting portion 22c on the one side in the axial direction is arranged at the same position in the axial direction as the end of the inner core portion 22a on the one side in the axial direction.

The rotor magnet 23 is fixed to the radially outer surface of the rotor core 22. In this embodiment, the rotor magnet 23 is fixed to the radially outer surface of the rotor core 22 with an adhesive. The radially outer surface of the rotor core 22 is the radially outer surface of the outer core portion 22b. Although not shown, in the present embodiment, a plurality of rotor magnets 23 are provided at intervals along the circumferential direction. The plurality of rotor magnets 23 are arranged at equal intervals over the entire circumference in the circumferential direction. For example, 20 rotor magnets 23 are provided.

Each of the plurality of rotor magnets 23 has an N pole and an S pole as magnetic poles along the radial direction. In the magnetic poles of the rotor magnets 23 that are adjacent to each other in the circumferential direction, the radial positions of the N pole and the S pole are reversed from each other. That is, in the rotor magnets 23 adjacent to each other in the circumferential direction, when one rotor magnet 23 has an N pole on the outer side in the radial direction, the other rotor magnet 23 has an S pole on the outer side in the radial direction.

The end of the rotor magnet 23 on the other axial side is arranged at the same position as the end of the outer core portion 22b on the other axial side in the axial direction. The one end in the axial direction of the rotor magnet 23 is positioned on the one side in the axial direction with respect to the one end in the axial direction of the outer core portion 22b. A portion of the rotor magnet 23 that is located on one axial side of the outer core portion 22b is a protruding portion 23a that projects on one axial side of the rotor core 22. That is, each of the plurality of rotor magnets 23 has a protrusion 23 a that protrudes toward the one side in the axial direction with respect to the rotor core 22.

The stator 30 is located radially outside the rotor 20. The stator 30 has a stator core 31, an insulator 32, and a plurality of coils 33. The plurality of coils 33 are attached to the stator core 31 via the insulator 32.

The sensor assembly 50 is located on one axial side of the rotor 20. In this embodiment, the sensor assembly 50 is fixed to the bearing holder 44. The sensor assembly 50 includes a sensor holder 51, a rotation sensor 52, and a circuit board 53. The sensor holder 51 is fixed to the bearing holder 44.

The rotation sensor 52 is held by the sensor holder 51. The rotation sensor 52 is a magnetic sensor that detects the magnetic field of the rotor magnet 23. The rotation sensor 52 is, for example, a Hall element such as a Hall IC. The rotation sensor 52 detects the rotation of the rotor 20 by detecting the magnetic field of the rotor magnet 23. Although illustration is omitted, a plurality of rotation sensors 52 are provided along the circumferential direction. The rotation sensor 52 may be a magnetoresistive element. The circuit board 53 is fixed to the sensor holder 51. The terminals of the rotation sensor 52 are electrically connected to the circuit board 53.

The rotation sensor 52 is located inside the protrusion 23a in the radial direction. Therefore, the rotation sensor 52 can easily suitably detect the magnetic field of the rotor magnet 23 having the N pole and the S pole as magnetic poles along the radial direction. Thereby, the rotation detection accuracy of the rotor 20 by the rotation sensor 52 can be improved. Further, it is not necessary to separately provide a magnet for detecting with the rotation sensor 52 in addition to the rotor magnet 23, and the number of parts of the motor 10 can be reduced. The rotation sensor 52 faces the end portion on the one axial side on the radially inner side surface of the protruding portion 23a in the radial direction with a gap therebetween.

The bus bar assembly 60 is located on one axial side of the stator 30. The bus bar assembly 60 is located radially outside the sensor assembly 50. The busbar assembly 60 has a busbar holder 61 and a busbar 62. The busbar holder 61 holds the busbar 62. The bus bar 62 is electrically connected to the coil 33. The propeller attaching portion 80 is a portion to which the propeller 2 is attached. The propeller attaching portion 80 is fixed to the end portion on the other axial side of the rotor 20. The propeller mounting portion 80 is located outside the housing 40.

<Motor Manufacturing Method and Motor Assembly Device> As shown in FIG. 2, the above-described motor 10 manufacturing method includes a rotor placement step S1 and a lid member fixing step S2. The rotor placement step S1 is a step of placing the rotor 20 inside the stator 30 in the radial direction using the motor assembly apparatus 100 shown in FIG.

In addition, in the following description of the method of manufacturing the motor 10 and the motor assembly device 100 described with reference to FIGS. 2 to 7, one side in the axial direction in the description of the motor 10 described above, that is, the positive side in the Z-axis direction. Is called the "upper side". Further, the other side in the axial direction in the description of the motor 10 described above, that is, the negative side in the Z-axis direction is referred to as “lower side”. Further, in FIGS. 3 to 7, the central axis J is shown at a position passing through the center of the shaft 21 in the rotor 20 attached to the motor assembly apparatus 100, similarly to FIG.

Note that the upper side and the lower side are simply names for explaining the positional relationship between the respective parts, and the actual positional relationship may be a positional relationship other than the positional relationship indicated by these names. ..

As shown in FIG. 3, the motor assembly device 100 includes a stator mounting portion 110, a pair of column portions 131a and 131b, a rotor mounting portion 120, and a pair of elastic members 141a and 141b.

The stator attachment portion 110 is a portion to which the stator 30 is attached in the rotor placement step S1. The stator mounting portion 110 has a base portion 111, a stator support portion 112, and a holding portion 113. The base 111 extends in a direction orthogonal to the axial direction.

The stator support 112 is fixed to the center of the upper surface of the base 111 with screws. The stator support portion 112 has a recess 112a that is recessed downward from the upper surface. A convex portion 112b protruding upward is provided on the bottom surface of the concave portion 112a. The convex 112b has an annular shape centered on the central axis J. In the present embodiment, the bottom surface of the recess 112a is the surface located on the lower side and facing the upper side of the inner surface of the recess 112a.

The pressing portion 113 extends upward from a portion of the base portion 111 radially outside the stator support portion 112. The upper end portion of the pressing portion 113 is located above the stator support portion 112. The upper end of the pressing portion 113 projects radially inward. Although illustration is omitted, a plurality of pressing portions 113 are provided along the circumferential direction. The plurality of pressing portions 113 are, for example, arranged at equal intervals over the entire circumference in the circumferential direction.

The stator mounting portion 110 has a through hole 110a that penetrates the stator mounting portion 110 in the axial direction. The through hole 110a axially penetrates the base portion 111 and the stator support portion 112. The upper end of the through hole 110a opens to the bottom surface of the recess 112a. The above-described convex portion 112b projects upward from the peripheral portion of the through hole 110a on the bottom surface of the concave portion 112a.

The pair of pillar portions 131a and 131b extend upward from a portion of the base portion 111 that is radially outside the holding portion 113. The pair of pillar portions 131a and 131b are, for example, cylindrical shapes extending in the axial direction. The lower ends of the pair of pillars 131a and 131b are fixed to the base 111 by screws, for example. The upper ends of the pair of pillars 131a and 131b are positioned higher than the upper ends of the pressing portions 113. The pair of pillar portions 131a and 131b are arranged so as to sandwich the stator support portion 112 in one direction orthogonal to the axial direction. In the present embodiment, one direction in which the pair of pillar portions 131a and 131b sandwich the stator support portion 112 is the left-right direction in FIG.

In the following description, one direction in which the pair of pillar portions 131a and 131b sandwich the stator support portion 112 is referred to as a “left-right direction”. Note that the left-right direction is simply a name for explaining the positional relationship between the respective parts, and the actual positional relationship may be a positional relationship other than the positional relationship indicated by these names.

Bushings 133 are attached to the lower ends of the pair of pillars 131a and 131b, respectively. The bush 133 has a cylindrical shape that is open on both sides in the axial direction and surrounds the pillar portions 131a and 131b. The bush 133 is fitted in the pillar portions 131a and 131b from the outside in the radial direction. The lower end of the bush 133 contacts the upper surface of the base 111. The bush 133 has a flange 133a at the lower end. The flange portion 133a projects outward in the radial direction of the bush 133.

The rotor attachment portion 120 is a portion to which the rotor 20 is attached in the rotor placement step S1. The rotor mounting portion 120 is arranged above the stator mounting portion 110 so as to be movable in the axial direction. The rotor mounting portion 120 has a main body portion 121, a guide bush 125, a spacer 126, a bearing holding portion 122, and a screw member 123.

The main body 121 extends in the left-right direction. A pair of through holes 121a and 121b penetrating the main body 121 in the axial direction is provided at both left and right ends of the main body 121. Each of the pair of through- holes 121a and 121b passes through each of the pair of column portions 131a and 131b in the axial direction. Guide bushes 125 are arranged between the pair of through holes 121a and 121b and the pair of pillar portions 131a and 131b, respectively.

The guide bush 125 has a cylindrical shape that opens on both sides in the axial direction and surrounds each of the column portions 131a and 131b. The guide bush 125 is fitted inside the through holes 121a and 121b in the radial direction. The guide bush 125 is fitted to the pillar portions 131a and 131b from the outside in the radial direction. The upper end of the guide bush 125 is located above the main body 121. The lower end of the guide bush 125 is located below the main body 121. The guide bush 125 has a flange portion 125a at the upper end portion. The flange portion 125a projects outward in the radial direction of the guide bush 125. The flange portion 125a contacts the upper surface of the main body portion 121.

The spacer 126 is attached to each of the guide bushes 125. The spacer 126 has an annular shape that surrounds a portion of the guide bush 125 located below the main body 121. The spacer 126 is fitted to the guide bush 125 from the outside in the radial direction. The upper end of the spacer 126 contacts the lower surface of the main body 121.

The bearing holding portion 122 is fixed to the central portion of the lower surface of the main body portion 121 with, for example, a screw. The bearing holder 122 has a recess 122a that is recessed upward from the lower surface. The bottom surface of the recess 122a is provided with a protrusion 122b protruding downward. The convex portion 122b has an annular shape centered on the central axis J. In the present embodiment, the bottom surface of the recess 122a is a surface located on the upper side and facing the lower side of the inner surface of the recess 122a.

The rotor mounting portion 120 has a screw through hole 124 that penetrates the rotor mounting portion 120 in the axial direction. The screw through hole 124 penetrates the body 121 and the bearing holder 122 in the axial direction. The lower end of the screw through hole 124 opens to the bottom surface of the recess 122a. The above-mentioned convex portion 122b projects downward from the peripheral portion of the screw through hole 124 on the bottom surface of the concave portion 122a.

The screw through hole 124 is a circular hole centered on the central axis J when viewed along the axial direction. The screw through hole 124 has a counterbore. That is, the screw through hole 124 has a large diameter hole portion 124a and a small diameter hole portion 124b. The large diameter hole portion 124a is recessed downward from the upper surface of the main body portion 121. The large diameter hole portion 124a is exposed on the upper side of the motor assembly device 100.

The small diameter hole portion 124b is connected to the lower end of the large diameter hole portion 124a. The inner diameter of the small diameter hole portion 124b is smaller than the inner diameter of the large diameter hole portion 124a. Accordingly, a step surface facing upward is provided between the large diameter hole portion 124a and the small diameter hole portion 124b in the axial direction. The lower end of the small-diameter hole portion 124b is the lower end of the screw through hole 124 and opens on the bottom surface of the recess 122a. The small diameter hole portion 124b is provided so as to straddle the main body portion 121 and the bearing holding portion 122.

The pair of elastic members 141a and 141b are located between the stator mounting portion 110 and the rotor mounting portion 120 in the axial direction. In this embodiment, the elastic members 141a and 141b are coil springs that extend in the axial direction. The elastic member 141a is arranged so as to surround the column portion 131a. The elastic member 141b is arranged so as to surround the column portion 131b.

The lower ends of the elastic members 141a and 141b contact the flange 133a of the bush 133 from above. The upper ends of the elastic members 141a and 141b contact the spacer 126 from below. The elastic members 141a and 141b apply upward elastic force to the spacer 126. As a result, the elastic members 141a and 141b apply an elastic force to the rotor mounting portion 120 in a direction away from the stator mounting portion 110. In a state where no external force is applied, the rotor mounting portion 120 is supported by the pair of elastic members 141a and 141b from the lower side, and is arranged apart from the upper side of the stator mounting portion 110.

The screw member 123 extends in the axial direction. The screw member 123 has a screw head 123a with an increased outer diameter at the upper end. As shown in FIG. 4, the screw member 123 is inserted into the screw through hole 124 from above and is tightened in the female screw hole 21 c of the shaft 21. As a result, the screw member 123 is tightened in the female screw hole 21c, and the rotor 20 can be attached to the rotor attachment portion 120.

As shown in FIG. 2, the rotor placement step S1 includes a stator attachment step S1a, a rotor attachment step S1b, a rotor insertion step S1c, and an attachment release step S1d. The stator mounting step S1a is a step of mounting the stator 30 on the stator mounting portion 110. As shown in FIG. 4, in the stator mounting step S1a, an operator or the like mounts the stator 30 on the stator mounting portion 110 in a state where the stator 30 is axially inverted with respect to the posture shown in FIG.

In addition, in the present specification, the “worker or the like” includes a worker who performs each work, an assembly device, and the like. Each work may be performed only by the operator, may be performed only by the assembling apparatus, or may be performed by the operator and the assembling apparatus. Further, the assembly device may be a part of the motor assembly device 100.

In the stator mounting step S1a of this embodiment, the stator 30 is in a state of being fixed inside the tubular portion 41. Further, in the stator mounting step S1a, the second bearing 72 and the bus bar assembly 60 are arranged inside the tubular portion 41. That is, an operator or the like arranges the second bearing 72, the stator 30, and the bus bar assembly 60 inside the tubular portion 41, and then attaches the stator 30 together with the tubular portion 41 to the stator attachment portion 110. The lid member 42 is not fixed to the tubular portion 41 in the stator mounting step S1a. Therefore, the tubular portion 41 is attached to the stator attachment portion 110 in a state of being opened upward.

The assembly in which the stator 30, the bus bar assembly 60, the tubular portion 41, and the second bearing 72 are combined is supported from below by the stator support portion 112 and is pressed from above by the plurality of pressing portions 113, It is attached to the stator attachment portion 110. In this embodiment, the inner ring of the second bearing 72 is supported from below by the protrusion 112b of the stator support 112. Further, in the present embodiment, the upper ends of the plurality of pressing portions 113 press the upper ends of the tubular portion 41 from the upper side. In the state where the tubular portion 41 is attached to the stator attachment portion 110, the lower end portion of the holding portion 41c is inserted into the recess 112a.

The rotor mounting step S1b is a step of tightening the screw member 123 into the female screw hole 21c and mounting the rotor 20 on the rotor mounting portion 120. As shown in FIG. 4, in the rotor mounting step S1b, an operator or the like mounts the rotor 20 on the rotor mounting portion 120 in a state in which the rotor 20 is axially inverted with respect to the posture shown in FIG. In the rotor mounting step S1b of this embodiment, the first bearing 71 is fixed to the shaft 21. That is, the worker or the like attaches the rotor 20 to the rotor attachment portion 120 after fixing the first bearing 71 to the shaft 21.

When the rotor 20 is attached to the rotor attachment portion 120, the screw head portion 123a of the screw member 123 is housed in the large diameter hole portion 124a. The screw head 123a comes into contact with a step surface facing upward, which is provided between the large diameter hole portion 124a and the small diameter hole portion 124b. As a result, the screw head 123a is caught on the step surface and the screw member 123 is tightened in the female screw hole 21c, so that the rotor 20 can be attached to the rotor attachment portion 120 by the screw member 123. The screw head 123a is exposed to the upper side of the motor assembly device 100.

When the rotor 20 is attached to the rotor attachment portion 120, the first bearing 71 fixed to the shaft 21 is fitted inside the recess 122a in the radial direction. The inner ring of the first bearing 71 contacts the convex portion 122b from below. The upper end of the shaft 21 may contact the convex portion 122b from the lower side.

The rotor insertion step S1c is a step of bringing the rotor mounting portion 120 closer to the stator mounting portion 110 and inserting the rotor 20 inside the stator 30 in the radial direction. As shown in FIG. 5, in the rotor insertion step S1c, an operator or the like applies a downward force to the rotor mounting portion 120 against the elastic force of the elastic members 141a and 141b to move the rotor mounting portion 120 downward. Move to the side. The operator or the like moves the rotor mounting portion 120 downward until the rotor 20 is positioned inside the stator 30 in the radial direction. More specifically, the operator or the like moves the rotor mounting portion 120 downward until the shaft flange portion 21d contacts the inner ring of the second bearing 72.

In the rotor insertion step S1c of the present embodiment, an operator or the like inserts the rotor 20 inside the stator 30 in the radial direction through the upper opening of the tubular portion 41. In addition, in the rotor insertion step S1c of the present embodiment, an operator or the like inserts the first bearing 71 below the upper end of the tubular portion 41. As a result, the entire first bearing 71 is inserted inside the tubular portion 41.

When the rotor 20 is inserted inside the stator 30 in the radial direction, the lower end of the shaft 21 is press-fitted inside the inner ring of the second bearing 72 in the radial direction. That is, in the rotor insertion step S1c, an operator or the like press fits the shaft 21 into the second bearing 72. At this time, the downward force applied to the rotor mounting portion 120 is transmitted from the convex portion 122b to the inner ring of the first bearing 71, and is transmitted to the shaft 21 via the inner ring of the first bearing 71. As a result, the shaft 21 is pushed downward and pressed into the second bearing 72. As described above, when the convex portion 122b contacts the upper end of the shaft 21, the shaft 21 receives a downward force directly from the convex portion 122b of the rotor mounting portion 120, and It is press-fitted into the two bearings 72.

The mounting release step S1d is a step of removing the screw member 123 from the female screw hole 21c. As shown in FIG. 6, in the mounting/dismounting step S1d, the worker or the like rotates the screw member 123 from the upper side through the screw head 123a in the direction opposite to the tightening direction, and then from the female screw hole 21c and the screw through hole 124. Pull out. As a result, the attachment of the rotor 20 to the rotor attachment portion 120 is released.

In the mounting removal step S1d of the present embodiment, the worker or the like continues to apply the downward force applied to the rotor mounting section 120 in the rotor insertion step S1c to the rotor mounting section 120. That is, in the present embodiment, the mounting release step S1d is performed while the downward force is still being applied to the rotor mounting portion 120. After removing the screw member 123 to remove the rotor 20 from the rotor mounting portion 120, an operator or the like stops applying downward force to the rotor mounting portion 120. As a result, as shown in FIG. 7, the rotor attachment portion 120 moves upward by the elastic force of the elastic members 141a and 141b and returns to the original position while leaving the rotor 20 inside the stator 30 in the radial direction. As described above, according to the present embodiment, since the elastic members 141a and 141b are provided, the rotor mounting portion 120 can be returned to the original position by the elastic force, which is easy.

The lid member fixing step S2 is provided after the rotor placement step S1. The lid member fixing step S2 is a step of fixing the lid member 42 closing the opening of the tubular portion 41 to the tubular portion 41. Although illustration is omitted, after the operator or the like removes the assembly including the rotor 20, the stator 30, the bus bar assembly 60, the tubular portion 41, the first bearing 71, and the second bearing 72 from the stator mounting portion 110, The lid member 42 is fixed to the tubular portion 41. More specifically, an operator or the like fixes the bottom wall portion 43 to the tubular portion 41, and then fits and fixes the bearing holder 44 on the radially inner side of the bottom wall portion 43. As a result, the female screw hole 21c is covered from above by the lid member 42. When the bearing holder 44 is fixed, the preload member 90 is arranged between the bearing holder 44 and the first bearing 71. In the present embodiment, since the sensor assembly 50 is fixed to the bearing holder 44 of the lid member 42, the sensor assembly 50 is arranged inside the tubular portion 41 in the lid member fixing step S2. The motor 10 is manufactured through the above steps.

According to this embodiment, the rotor 20 can be attached to the rotor attachment portion 120 by tightening the screw member 123 extending in the axial direction into the female screw hole 21c provided in the upper end surface of the shaft 21. Therefore, the rotor 20 can be easily attached to the rotor attachment portion 120 regardless of the shape of the shaft 21. As a result, even if the shaft 21 has a shape that is difficult to grip by being sandwiched in the radial direction, the rotor 20 can be stably inserted inside the stator 30 in the radial direction. Therefore, according to the method of manufacturing the motor 10 using the motor assembly apparatus 100 of the present embodiment, in manufacturing the motor 10, the rotor 20 can be easily arranged inside the stator 30 in the radial direction regardless of the shape of the shaft 21.

In particular, in the present embodiment, a portion of the shaft 21 located between the rotor body 24 and the first bearing 71 in the axial direction has an outer diameter changing portion 21a whose outer diameter changes along the axial direction. Such an outer diameter changing portion 21a is difficult to be sandwiched in the radial direction by a jig or the like, and even when sandwiched, it is difficult to stably grasp. That is, when the shaft 21 has the outer diameter changing portion 21a, it becomes more difficult to arrange the rotor 20 inside the stator 30 in the radial direction while gripping the shaft 21 in the radial direction. Therefore, the effect of easily disposing the rotor 20 inside the stator 30 in the radial direction regardless of the shape of the shaft 21 is particularly useful when the shaft 21 has the outer diameter changing portion 21a.

Further, in the present embodiment, the axial dimension H1 of the portion of the shaft 21 located between the rotor body 24 and the first bearing 71 is half or less than the axial dimension H2 of the rotor body 24. .. Therefore, a portion of the shaft 21 located between the rotor body 24 and the first bearing 71 in the axial direction is relatively short in the axial direction, and is difficult to be sandwiched in the radial direction by using a jig or the like. That is, when the dimension H1 is half or less of the dimension H2, it becomes more difficult to dispose the rotor 20 inside the stator 30 in the radial direction while gripping the shaft 21 in the radial direction. Therefore, the effect of easily disposing the rotor 20 on the inner side in the radial direction of the stator 30 regardless of the shape of the shaft 21 is that when the dimension H1 of the shaft 21 is half or less of the dimension H2 of the rotor body 24, Especially useful.

Further, according to the present embodiment, the screw head 123a of the screw member 123 is exposed on the upper side of the motor assembly device 100, so that the screw member 123 can be easily tightened and removed from the upper side of the motor assembly device 100. Can be done. Therefore, it is possible to easily attach the rotor 20 to the rotor attachment portion 120 and remove the rotor 20 from the rotor attachment portion 120.

Further, according to the present embodiment, the mounting release step S1d is performed while the downward force is still being applied to the rotor mounting portion 120. Therefore, the screw member 123 can be removed while the elastic force of the elastic members 141a and 141b is canceled by the downward force applied to the rotor mounting portion 120. As a result, the screw member 123 can be rotated in the removal direction in a state in which the upward elastic force of the elastic members 141a and 141b is suppressed from being applied to the screw member 123. Therefore, the screw member 123 can be easily rotated, and the screw member 123 can be easily removed from the female screw hole 21c.

Further, when a downward force is applied to the rotor mounting portion 120, the inner ring of the second bearing 72 is pressed from above by the shaft flange portion 21 d of the shaft 21 against the convex portion 112 b of the stator support portion 112. .. Further, the inner ring of the first bearing 71 is pressed against the convex portion 122b of the bearing holding portion 122 from below by the outer diameter changing portion 21a of the shaft 21. Therefore, when a downward force is applied to the rotor mounting portion 120, the inner ring of the first bearing 71 and the inner ring of the second bearing 72 are hard to rotate, and the shaft 21 is hard to rotate. This can prevent the shaft 21 from rotating together with the screw member 123 when the screw member 123 is relatively rotated with respect to the shaft 21 and is removed from the female screw hole 21c. Therefore, the screw member 123 can be more easily removed from the female screw hole 21c.

Further, according to the present embodiment, the first bearing 71 is fixed to the shaft 21 in the rotor mounting step S1b. Therefore, the first bearing 71 is an obstacle, and it is difficult to grip the shaft 21 in the radial direction with a jig or the like. On the other hand, according to the present embodiment, as described above, the rotor 20 can be attached to the rotor attachment portion 120 without gripping the shaft 21 by sandwiching it in the radial direction. Therefore, when the rotor 20 with the first bearing 71 fixed is mounted on the rotor mounting portion 120, the rotor 20 can be arranged radially inside the stator 30 without gripping the shaft 21 in the radial direction. The effect can be obtained more usefully.

Further, according to the present embodiment, in the stator mounting step S1a, the stator 30 is in a state of being fixed inside the tubular portion 41, and in the rotor insertion step S1c, through the opening on the upper side of the tubular portion 41. The rotor 20 is inserted inside the stator 30 in the radial direction. Therefore, for example, when gripping the shaft 21 while sandwiching it in the radial direction, a jig or the like that grips the shaft 21 interferes with the upper end of the tubular portion 41, and the rotor 20 is disposed inside the stator 30 in the radial direction. It can be difficult. Even if the rotor 20 can be arranged inside the stator 30 in the radial direction, the tubular portion 41 may obstruct the removal of the jig or the like from the shaft 21.

On the other hand, in the present embodiment, the rotor 20 is attached to the rotor attachment portion 120 by the screw member 123 tightened in the axial direction. Therefore, when the rotor 20 is arranged inside the stator 30 in the radial direction, the rotor mounting portion 120 can be prevented from interfering with the tubular portion 41. Further, since the screw member 123 can be pulled out and removed from the upper side, the rotor 20 can be removed from the rotor mounting portion 120 without interfering with the tubular portion 41. Therefore, when the rotor 20 is arranged radially inside the stator 30 fixed inside the tubular portion 41, the above-described effect that the rotor 20 can be easily arranged radially inside the stator 30 is more useful. can get.

Further, according to the present embodiment, in the rotor insertion step S1c, the operator or the like inserts the first bearing 71 below the upper end of the tubular portion 41. In such a case, in the method of gripping the shaft 21 by sandwiching it in the radial direction, a jig or the like that grips the shaft 21 is more likely to interfere with the tubular portion 41. Therefore, when the first bearing 71 is inserted below the upper end of the tubular portion 41, the above-described effect of easily arranging the rotor 20 inside the stator 30 in the radial direction can be obtained more effectively.

According to the present embodiment, the lid member fixing step S2 is provided after the rotor arranging step S1, and the female screw hole 21c is covered from the upper side by the lid member 42. Therefore, after the motor 10 is assembled, for example, a male screw member such as the screw member 123 cannot be screwed into the female screw hole 21c. That is, in this embodiment, the female screw hole 21c is a hole used only when assembling the motor 10. Therefore, the configuration such as the inner diameter of the female screw hole 21c may be appropriately selected within a range in which the female screw hole 21c can be mounted on the rotor mounting portion 120, and the degree of freedom for making the female screw hole 21c can be improved.

Further, since the upper end surface of the shaft 21 provided with the female screw hole 21c is also covered with the lid member 42, the upper end portion of the shaft 21 is the end portion on the opposite side to the output side that does not project from the housing 40. In this way, by providing the female screw hole 21c at the end opposite to the output side, for example, when the female screw hole 21c is formed, it is possible to prevent a problem such as the distortion of the shape of the output end of the shaft 21. it can. Therefore, a device or the like that outputs the rotation of the motor 10 can be stably connected to the shaft 21. In this embodiment, the propeller attaching portion 80 can be stably attached to the lower end portion of the shaft 21.

Further, the lid member 42 can protect the upper end of the shaft 21 and the first bearing 71, and can prevent water, dust, and the like from entering the inside of the motor 10. Such an effect is particularly useful when the motor 10 is used outdoors.

Further, for example, a method in which the lid member 42 is attached to the rotor 20 before the rotor arranging step S1 and the rotor 20 and the lid member 42 are collectively arranged in the rotor arranging step S1 is also conceivable. In this case, in the configuration in which the shaft 21 is press-fitted into the second bearing 72 as in the present embodiment, it is necessary to apply a force to the lid member 42 to press-fit the shaft 21 into the second bearing 72. However, in this case, a relatively large axial force is applied to the outer ring of the first bearing 71 from the bearing holder 44 of the lid member 42. Therefore, there is a risk that the outer ring may come off the inner ring and the first bearing 71 may be damaged.

On the other hand, according to the present embodiment, the lid member fixing step S2 is provided after the rotor arranging step S1. Therefore, in the rotor arranging step S1, the shaft 21 can be pressed into the second bearing 72 by applying an axial force to the inner ring of the first bearing 71 or the shaft 21. As a result, it is possible to suppress the occurrence of problems such as damage to the first bearing 71.

Further, according to the present embodiment, the worker or the like press fits the shaft 21 into the second bearing 72 in the rotor insertion step S1c. Therefore, when the rotor 20 is arranged inside the stator 30 in the radial direction, it is necessary to apply a relatively large force to the rotor mounting portion 120 and the rotor 20. In such a case, if the attachment of the rotor 20 to the rotor attachment portion 120 is unstable, the rotor 20 may tilt and the rotor 20 may be difficult to arrange. On the other hand, according to the present embodiment, the rotor 20 is mounted on the rotor mounting portion 120 by screwing the screw member 123 into the female screw hole 21c, so that the rotor 20 is stably mounted on the rotor mounting portion 120. Therefore, even when the shaft 21 is press-fitted into the second bearing 72 as in the present embodiment, the rotor 20 can be stably arranged inside the stator 30 in the radial direction.

The present invention is not limited to the above-mentioned embodiments, and other methods and configurations can be adopted. Although the rotor attachment step S1b is described as being performed after the stator attachment step S1a in the above-described embodiment, the present invention is not limited to this. If the stator attaching step S1a and the rotor attaching step S1b are performed before the rotor inserting step S1c, the timing of performing each step is not limited. For example, the rotor mounting step S1b may be performed before the stator mounting step S1a, or the stator mounting step S1a and the rotor mounting step S1b may be performed at the same time. The demounting step S1d may be performed without applying downward force to the rotor mounting portion.

In the motor assembly device, the elastic member is not particularly limited as long as it applies an elastic force to the rotor mounting portion in a direction away from the stator mounting portion. Only one elastic member may be provided, or three or more elastic members may be provided. The elastic member may not be provided.

In the motor, the shape of the shaft is not particularly limited. The shaft may not have the outer diameter changing portion. The axial dimension H1 of the portion of the shaft located between the rotor body and the first bearing may be larger than half the axial dimension H2 of the rotor body. The female screw hole provided in the shaft may be a through hole that penetrates the shaft in the axial direction. The first bearing may be located axially on one side of the axial end on the axial one side.

The use of the motor of the above-mentioned embodiment is not particularly limited. The motor of the above-described embodiment may be mounted on, for example, a vehicle. It should be noted that the configurations described in this specification can be appropriately combined as long as they do not conflict with each other.

DESCRIPTION OF SYMBOLS 10... Motor, 20... Rotor, 21... Shaft, 21a... Outer diameter change part, 21c... Female screw hole, 24... Rotor body, 30... Stator, 40... Housing, 41... Cylindrical part, 42... Lid member, 71... 1st bearing, 72... 2nd bearing, 100... Motor assembly device, 110... Stator mounting part, 120... Rotor mounting part, 123... Screw member, 141a, 141b... Elastic member, J... Central axis, S1... Rotor arranging process (Step of arranging rotor), S1a... Stator mounting step (stator mounting step), S1b... Rotor mounting step (rotor mounting step), S1c... Rotor insertion step (step of inserting rotor to inner side of radial direction of stator) , S1d... Unmounting step (step of removing the screw member from the female screw hole), S2... Lid member fixing step (step of fixing the lid member to the tubular portion)

Claims (13)

1. 
   A method of manufacturing a motor, comprising: a rotor having a shaft extending along a central axis; and a rotor main body fixed to an outer peripheral surface of the shaft; and a stator positioned radially outside the rotor,
   
   Arranging the rotor radially inside the stator using a motor assembly device,
   
   The shaft has an internal threaded hole that is recessed toward the other side in the axial direction on the end face on the one side in the axial direction,
   
   The motor assembly device is
   
   A stator mounting portion to which the stator is mounted,
   
   A rotor mounting portion arranged axially movably on one axial side of the stator mounting portion, to which the rotor is mounted;
   
   Equipped with
   
   The rotor mounting portion has a screw member extending in the axial direction,
   
   The step of disposing the rotor includes
   
   Attaching the stator to the stator attachment portion,
   
   Tightening the screw member into the female screw hole, and attaching the rotor to the rotor attachment portion,
   
   A step of bringing the rotor mounting portion close to the stator mounting portion, and inserting the rotor radially inside the stator;
   
   Removing the screw member from the female screw hole,
   
   A method of manufacturing a motor, including:
   
2. 
   The motor assembly device further includes an elastic member that applies an elastic force to the rotor mounting portion in a direction away from the stator mounting portion,
   
   In the step of inserting the rotor radially inward of the stator, a force is applied to the rotor mounting portion in the other axial direction against the elastic force of the elastic member,
   
   The method for manufacturing a motor according to claim 1, wherein the step of removing the screw member from the female screw hole is performed in a state where a force in the other axial direction is applied to the rotor attachment portion.
   
3. 
   In the step of attaching the rotor to the rotor attachment portion, a first bearing that supports a portion of the shaft located on one axial side of the rotor body is fixed to the shaft. The method for manufacturing the motor according to 1.
   
4. 
   The motor includes a housing that houses the rotor and the stator,
   
   The housing has a tubular portion that opens to one side in the axial direction,
   
   In the step of attaching the stator to the stator attachment portion, the stator is in a state of being fixed inside the tubular portion,
   
   The motor according to claim 3, wherein in the step of inserting the rotor radially inside the stator, the rotor is inserted radially inside the stator through an opening on one axial side of the tubular portion. Production method.
   
5. 
   The motor according to claim 4, wherein, in the step of inserting the rotor inside the stator in the radial direction, the first bearing is inserted on the other side in the axial direction than the end portion on the one side in the axial direction of the tubular portion. Production method.
   
6. 
   After the step of disposing the rotor, the method further includes the step of fixing a lid member that closes the opening of the tubular portion to the tubular portion.
   
   The method of manufacturing a motor according to claim 4, wherein the lid member covers the female screw hole from one side in the axial direction.
   
7. 
   In the step of attaching the stator to the stator attachment portion, a second bearing that supports a portion of the shaft located on the other axial side of the rotor body is disposed inside the tubular portion,
   
   The motor manufacturing method according to claim 4, wherein the shaft is press-fitted into the second bearing in the step of inserting the rotor radially inside the stator.
   
8. 
   A motor assembling apparatus for assembling a motor, comprising: a shaft having a shaft extending along a central axis; and a rotor having a rotor body fixed to an outer peripheral surface of the shaft; and a stator located radially outside the rotor.
   
   A stator mounting portion to which the stator is mounted,
   
   A rotor mounting portion arranged axially movably on one axial side of the stator mounting portion, to which the rotor is mounted;
   
   Equipped with
   
   The shaft has an internal threaded hole that is recessed toward the other side in the axial direction on the end face on the one side in the axial direction,
   
   The rotor mounting portion has a screw member extending in the axial direction,
   
   The motor assembly device, wherein the screw member is tightened in the female screw hole so that the rotor can be attached to the rotor attachment portion.
   
9. 
   The motor assembly device according to claim 8, further comprising an elastic member that applies an elastic force to the rotor mounting portion in a direction away from the stator mounting portion.
   
10. 
    A shaft having a shaft extending along a central axis, and a rotor body fixed to an outer peripheral surface of the shaft;
    
    A stator located radially outside the rotor,
    
    A housing that houses the rotor and the stator;
    
    Equipped with
    
    The shaft has an internal threaded hole that is recessed toward the other side in the axial direction on the end face on the one side in the axial direction,
    
    The housing is
    
    A tubular portion that opens to one side in the axial direction,
    
    A lid member that closes the opening of the tubular portion on one side in the axial direction,
    
    Have
    
    The lid member is a motor that covers the female screw hole from one axial side.
    
11. 
    A first bearing that supports a portion of the shaft that is located on one axial side of the rotor body,
    
    The motor according to claim 10, wherein the first bearing is located on the other side in the axial direction than the end portion on the one side in the axial direction of the tubular portion.
    
12. 
    The motor according to claim 11, wherein a portion of the shaft located between the rotor body and the first bearing in the axial direction has an outer diameter changing portion whose outer diameter changes in the axial direction.
    
13. 
    The axial dimension of a portion of the shaft located between the rotor body and the first bearing in the axial direction is not more than half the axial dimension of the rotor body. Motor.

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