Motor and electric wheel

Abstract

A motor and an electric wheel are provided. One embodiment of the motor is an external rotor type motor, comprising: a rotor that rotates about a central axis; a stator that is radially opposed to the rotor with a gap; an outer wall portion located axially closer to the stator, having a first through hole extending axially; a lead wire electrically connected to the stator and led out to the outside of the motor via the first through hole; an elastic member having a second through hole extending axially for the lead wire to pass through, the elastic member being housed inside the first through hole; and a fixing member fixed to the outer wall portion and contacting the elastic member from one axial side. The outer wall portion has a support portion supporting the elastic member from the other axial side. The elastic member is elastically deformed by being clamped axially by the fixing member and the support portion.

Description

[0001] This application is a divisional application of the invention patent application with application number 201911173029.9, application date November 26, 2019, and invention title "Motor and Electric Wheel". Technical Field

[0002] This invention relates to motors and electric wheels. Background Technology

[0003] It is known that there are external rotor type motors in which the leads electrically connected to the stator are led out to the outside through through holes. For example, Patent Document 1 describes a structure in which the leads of the windings are led out from lead holes provided on a fixed shaft.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2000-60095

[0005] In the aforementioned motor, water and dust may enter the motor interior through the gap between the first wall and the outer wall.

[0006] In motors like the one described above, water and dust can potentially enter the motor's interior through the through-hole. Therefore, for example, it has been considered to place an elastic member, such as one made of rubber, inside the through-hole to seal the gap between the through-hole and the lead wire. However, simply placing an elastic member may sometimes be insufficient to adequately seal the gap between the through-hole and the lead wire. Summary of the Invention

[0007] One of the objectives of this invention is to provide a motor and an electric wheel that can improve the sealing performance of the gap between the first wall portion and the outer wall portion.

[0008] One of the objectives of this invention is to provide a motor and an electric wheel that can improve the sealing performance of the gap between the lead wire and the first through hole through which the lead wire passes.

[0009] One embodiment of the motor of the present invention is an external rotor type motor, wherein the motor comprises: a rotor that rotates about a central axis; a stator that is radially opposed to the rotor by a gap; an outer wall portion located on an axial side relative to the stator, having a first through hole extending axially; a lead wire electrically connected to the stator and led out to the outside of the motor via the first through hole; an elastic member having a second through hole extending axially for the lead wire to pass through, the elastic member being housed inside the first through hole; and a fixing member fixed to the outer wall portion and contacting the elastic member from an axial side. The outer wall portion has a support portion that supports the elastic member from the other axial side. The elastic member is elastically deformed by being clamped axially by the fixing member and the support portion.

[0010] One aspect of the motor of the present invention is an external rotor type motor, wherein the motor comprises: a rotor that rotates about a central axis; a stator that is radially opposed to the rotor by a gap; an outer wall portion located axially closer to the stator, having a first through hole opening on one side of an intersecting direction intersecting the axial direction; a lead wire electrically connected to the stator and led out to the outside of the motor via the first through hole; an elastic member having a second through hole extending along the intersecting direction for the lead wire to pass through, the elastic member being housed inside the first through hole; and a fixing member fixed to the outer wall portion and contacting the elastic member from one side of the intersecting direction. The outer wall portion has a support portion supporting the elastic member from the other side of the intersecting direction. The elastic member is elastically deformed by being clamped by the fixing member and the support portion in the intersecting direction.

[0011] One embodiment of the present invention provides an electric wheel having the aforementioned motor.

[0012] According to one aspect of the invention, in motors and electric wheels, the sealing performance of the gap between the lead wire and the first through hole through which the lead wire passes can be improved. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the electric wheel of the first embodiment.

[0014] Figure 2 This is a cross-sectional view showing the electric wheel of the first embodiment, along... Figure 1 A sectional view along line II-II in the diagram.

[0015] Figure 3 This is a cross-sectional view showing a portion of the motor according to the first embodiment.

[0016] Figure 4 This is a perspective view showing a portion of the elastic member in the motor of the first embodiment in a state where the fixing member is not fixed.

[0017] Figure 5 This is a perspective view showing the fixing component of the first embodiment.

[0018] Figure 6 This is a cross-sectional view showing a portion of the motor of a first variant of the first embodiment.

[0019] Figure 7 This is a cross-sectional view showing a portion of the motor in a second variation of the first embodiment.

[0020] Figure 8 This is a cross-sectional view showing a portion of the motor in a third variation of the first embodiment.

[0021] Figure 9 This is a cross-sectional view showing a portion of the motor according to the second embodiment.

[0022] Label Explanation

[0023] 1: Electric wheel; 10, 110, 210, 310, 410: Motor; 20: Fixed shaft; 30: Rotor; 35, 36: Bearings; 40: Stator; 50, 450: Outer wall portion; 54, 154, 254, 354, 454: First through hole; 54a, 154a, 454c: Large diameter hole portion; 54b, 154b, 254b, 454d: Small diameter hole portion; 55, 255, 45 5: Stepped surface (support part); 60, 460: Fixing parts; 62, 462: Protrusions; 70, 470: Lead wires; 80, 180, 280, 380, 480: Elastic parts; 80a, 480a: Second through hole; 81, 181: Large diameter part; 81a: Recess; 82, 182: Small diameter part; 90: Deformation promoting part; 354a: Inner circumferential surface (support part); J: Central axis. Detailed Implementation

[0024] In the figures, the X-axis direction is shown as a left-right direction with the positive side as "left" and the negative side as "right". The central axis J shown in the figures is an imaginary line parallel to the X-axis direction and extending in the left-right direction. In the following description, the axial direction of the central axis J, i.e., the direction parallel to the left-right direction, will be simply referred to as "axial direction". The radial direction centered on the central axis J will be simply referred to as "radial direction". The circumferential direction centered on the central axis J will be simply referred to as "circumferential direction".

[0025] In addition, "left and right directions", "left side" and "right side" are just names used to describe the configuration relationships of each part. The actual configuration relationships may be other than those indicated by these names.

[0026] <First Implementation Method>

[0027] In this embodiment, the left side corresponds to one side of the axial direction, and the right side corresponds to the other side of the axial direction.

[0028] Figure 1 The electric wheel 1 shown in this embodiment is mounted on a vehicle such as an electric motorcycle. Figure 1 As shown, the electric wheel 1 has a motor 10 and a rim 2. The rim 2 is annular about the central axis J.

[0029] like Figure 1 and Figure 2As shown, motor 10 is an external rotor type motor. Motor 10 has a fixed shaft 20, a stator 40, an outer wall portion 50, a rotor 30, leads 70, a flexible member 80, a fixed member 60, and bearings 35 and 36. Bearings 35 and 36 are rolling bearings such as ball bearings. Bearings 35 and 36 support the rotor 30 so that it can rotate.

[0030] The fixed shaft 20 extends along the central axis J. The fixed shaft 20 is, for example, cylindrical with the central axis J as its center. The axial ends of the fixed shaft 20 protrude beyond the electric wheel 1. The axial ends of the fixed shaft 20 are fixed to the frame of the vehicle carrying the electric wheel 1.

[0031] like Figure 2 As shown, the stator 40 and rotor 30 are radially opposed with a gap between them. The stator 40 is located radially inside the rotor magnet 34, which will be described later. The stator 40 is fixed to the fixed shaft 20 via a spacer 45 and a connecting member 44. The spacer 45 is cylindrical with its central axis J as its center. The spacer 45 is fixed to the outer circumferential surface of the fixed shaft 20. The connecting member 44 is annular with its central axis J as its center. The connecting member 44 is fixed to the outer circumferential surface of the spacer 45.

[0032] The stator 40 has a stator core 41, an insulator 42, and a plurality of coils 43. The stator core 41 is fixed to the outer peripheral surface of the connecting member 44. The stator core 41 has a core back 41a and a plurality of teeth 41b extending radially outward from the core back 41a. The plurality of coils 43 are mounted on each of the plurality of teeth 41b through the insulator 42.

[0033] The outer wall portion 50 forms part of the housing of the motor 10. The outer wall portion 50 is located to the left of the stator 40. The outer wall portion 50 is located to the left of the connecting member 44. The outer wall portion 50 is, for example, an annular shape centered on the central axis J. The fixed shaft 20 passes radially inward through the outer wall portion 50. The outer wall portion 50 is fixed to the outer peripheral surface of the fixed shaft 20. For example, the outer wall portion 50 is fixed to the outer peripheral surface of the portion of the outer peripheral surface of the fixed shaft 20 that is to the left of the portion of the stator 40 fixed via the spacer 45 and the connecting member 44. The outer wall portion 50 has a main body portion 51, a positioning portion 52, and a flange portion 53.

[0034] Furthermore, in this specification, the phrase "the outer wall portion is located on the axial side of the stator" is sufficient as long as at least a portion of the outer wall portion is located on the axial side of the stator. In the outer wall portion 50, for example, the main body portion 51 and the flange portion 53 are located on the left side of the stator 40.

[0035] The main body 51 is an annular portion centered on the central axis J and fixed to the outer circumferential surface of the fixed shaft 20. For example... Figure 3As shown, a groove 51a, recessed radially outward, is provided on the inner circumferential surface of the main body 51. The groove 51a is annular about the central axis J. An O-ring 85 is embedded in the groove 51a. The O-ring 85 seals the outer circumferential surface of the fixed shaft 20 and the inner circumferential surface of the outer wall 50 throughout the entire circumference. The inner ring of the bearing 35 is fitted and fixed to the right portion of the outer circumferential surface of the main body 51. Thus, the outer wall 50 holds the bearing 35.

[0036] like Figure 2 As shown, the positioning part 52 protrudes to the right from the radially inner periphery of the main body part 51. The positioning part 52 is cylindrical with the central axis J as its center. The right end of the positioning part 52 contacts the left end of the spacer 45. The flange part 53 protrudes radially outward from the right end of the main body part 51. The flange part 53 is annular with the central axis J as its center. The flange part 53 supports the inner ring of the bearing 35 from the right side.

[0037] like Figure 3 As shown, the outer wall portion 50 has a first through hole 54 extending axially through the outer wall portion 50. The first through hole 54 opens on both axial sides. The first through hole 54, for example, extends axially through the main body portion 51. The first through hole 54 is located radially outward of the fixed shaft 20. Figure 4 As shown, when viewed along the axial direction, the first through hole 54 is, for example, circular in shape.

[0038] Furthermore, in the following description, the radial direction centered on the axis AX, which passes through the center of the first through hole 54 and extends axially, will be referred to as the "diameter direction". The axis AX is an imaginary line parallel to the central axis J and located radially outside the central axis J.

[0039] like Figure 3 As shown, the first through hole 54 has a large-diameter hole portion 54a and a small-diameter hole portion 54b. The left end of the large-diameter hole portion 54a is the left end of the first through hole 54. The small-diameter hole portion 54b is located to the right of the large-diameter hole portion 54a. The left end of the small-diameter hole portion 54b is connected to the right end of the large-diameter hole portion 54a. The right end of the small-diameter hole portion 54b is the right end of the first through hole 54. The inner diameter of the small-diameter hole portion 54b is smaller than the inner diameter of the large-diameter hole portion 54a. Therefore, a stepped surface 55 facing to the left is provided between the large-diameter hole portion 54a and the small-diameter hole portion 54b in the axial direction. In this embodiment, the stepped surface 55 corresponds to a support portion. That is, the outer wall portion 50 has the stepped surface 55 as a support portion. The axial dimension of the small-diameter hole portion 54b is, for example, smaller than the axial dimension of the large-diameter hole portion 54a.

[0040] Rotor 30 rotates around its central axis J. For example... Figure 2As shown, the rotor 30 is supported by bearings 35 and 36 fixed to the fixed shaft 20 to enable rotation. The bearing 35 is fixed to the left side of the portion of the stator 40 in the fixed shaft 20 via the outer wall portion 50 and the portion fixed via the spacer 45 and the connecting member 44. The bearing 36 is directly fixed to the right side of the portion of the stator 40 in the fixed shaft 20, which is fixed via the spacer 45 and the connecting member 44.

[0041] The rotor 30 has a first wall portion 31, a second wall portion 32, a peripheral wall portion 33, and a rotor magnet 34. The first wall portion 31, the second wall portion 32, the peripheral wall portion 33, and the rotor magnet 34 are, for example, separate components. The first wall portion 31, the second wall portion 32, and the peripheral wall portion 33 constitute part of the housing of the motor 10. The housing of the motor 10 is, for example, composed of an outer wall portion 50, the first wall portion 31, the second wall portion 32, and the peripheral wall portion 33.

[0042] The first wall portion 31 is, for example, in a generally annular shape centered on the central axis J. The first wall portion 31 is connected to the outer wall portion 50 via a bearing 35. The first wall portion 31 is located on the left side of the stator 40. The first wall portion 31 covers the left side of the stator 40.

[0043] The first wall portion 31 has a first connecting portion 31b and a first wall portion body 31a. The first connecting portion 31b is the portion connected to the outer wall portion 50 via a bearing 35. The first connecting portion 31b is cylindrical with openings on both sides of the central axis J. The radially inner side of the right side portion 31c of the first connecting portion 31b fits into the outer ring of the bearing 35. The inner and outer diameters of the left side portion 31d of the first connecting portion 31b are smaller than the inner and outer diameters of the right side portion 31c. An oil seal 83 is disposed between the inner circumferential surface of the left side portion 31d of the first connecting portion 31b and the outer circumferential surface of the outer wall portion 50. The oil seal 83 is annular with the central axis J as its center. The oil seal 83 seals the first wall portion 31 and the outer wall portion 50 radially throughout their entire circumference.

[0044] The first wall body 31a extends radially outward from the central portion axially of the first connecting portion 31b. The first wall body 31a covers the left side of the stator 40. The first wall body 31a is annular about the central axis J. The radially outer periphery of the first wall body 31a is fixed to the left end of the peripheral wall portion 33 by means of screws.

[0045] The second wall portion 32 is, for example, in a generally annular shape centered on the central axis J. The second wall portion 32 is connected to the fixed shaft 20 via a bearing 36. The second wall portion 32 is located on the right side of the stator 40. The second wall portion 32 covers the right side of the stator 40.

[0046] The second wall portion 32 has a second connecting portion 32b and a second wall portion body 32a. The second connecting portion 32b is the part connected to the fixed shaft 20 via a bearing 36. The second connecting portion 32b is cylindrical with openings on both sides of the central axis J. The radially inner side of the left portion 32c of the second connecting portion 32b fits into the outer ring of the bearing 36. The inner and outer diameters of the right portion 32d of the second connecting portion 32b are smaller than those of the left portion 32c. An oil seal 84 is disposed between the inner circumferential surface of the right portion 32d of the second connecting portion 32b and the outer circumferential surface of the fixed shaft 20. The oil seal 84 is annular with the central axis J as its center. The oil seal 84 seals the second wall portion 32 and the fixed shaft 20 radially throughout their entire circumference.

[0047] The second wall body 32a extends radially outward from the left side portion 32c of the second connecting portion 32b. The second wall body 32a covers the right side of the stator 40. The second wall body 32a is annular about the central axis J. The radially outer periphery of the second wall body 32a is fixed to the right end of the peripheral wall portion 33 by means of screws.

[0048] The peripheral wall portion 33 is cylindrical, extending axially around the central axis J. The peripheral wall portion 33 has openings on both axial sides. The radially outer peripheral edges of the first wall portion 31 and the second wall portion 32 are fixed to the ends of the peripheral wall portion 33 on both axial sides, respectively. Thus, the peripheral wall portion 33 connects the first wall portion 31 and the second wall portion 32. The peripheral wall portion 33 surrounds the stator 40 radially outward. The inner circumferential surface of the rim 2 is fixed to the outer circumferential surface of the peripheral wall portion 33. Thus, the rim 2 is fixed to the rotor 30. The rotor magnet 34 is fixed to the inner circumferential surface of the peripheral wall portion 33. The rotor magnet 34 is positioned opposite the radially outer side of the stator core 41 with a gap between them.

[0049] Lead 70 is electrically connected to stator 40. More specifically, lead 70 is electrically connected to coil 43. Lead 70 extends from stator 40, for example. Lead 70 is led out from stator 40 through first through hole 54 to the outside of motor 10. Lead 70 is led out, for example, on the left side of motor 10. Lead 70 is connected to an external power source (not shown). Thus, power is supplied from an external power source to stator 40 via lead 70.

[0050] like Figure 3 As shown, the elastic member 80 is housed inside the first through hole 54. The material of the elastic member 80 is, for example, an elastomer such as rubber. The elastic member 80 extends axially. Figure 4As shown, when viewed axially, the elastic member 80 has a circular shape centered on the axis AX. The elastic member 80 has a second through hole 80a extending axially through the elastic member 80. When viewed axially, the second through hole 80a is circular in shape centered on the axis AX. By providing the second through hole 80a, the elastic member 80 becomes a cylindrical shape extending axially around the axis AX and opening on both sides of the axial direction. Figure 3 As shown, the lead wire 70 passes through the second through hole 80a along the axial direction.

[0051] The elastic member 80, for example, has a large-diameter portion 81 and a small-diameter portion 82. The left end of the large-diameter portion 81 is the left end of the elastic member 80. The left end of the large-diameter portion 81 is axially positioned at the same location as the left end of the main body portion 51. The large-diameter portion 81 is housed inside the large-diameter hole portion 54a. The large-diameter portion 81 contacts the inner peripheral surface 54c of the large-diameter hole portion 54a and the outer peripheral surface 70a of the lead wire 70. More specifically, the outer peripheral surface of the large-diameter portion 81 contacts the inner peripheral surface 54c of the large-diameter hole portion 54a. The inner peripheral surface of the portion of the large-diameter portion 81 in the second through hole 80a contacts the outer peripheral surface 70a of the lead wire 70. The right end of the large-diameter portion 81 contacts the stepped surface 55. Specifically, the right end of the large-diameter portion 81 is a right-facing end face that contacts the left-facing stepped surface 55. Thus, the stepped surface 55 supports the elastic member 80 from the right side.

[0052] The outer diameter of the minor diameter portion 82 is smaller than the outer diameter of the major diameter portion 81. The minor diameter portion 82 is located to the right of the major diameter portion 81. The left end of the minor diameter portion 82 is connected to the right end of the major diameter portion 81. The right end of the minor diameter portion 82 is the right end of the elastic member 80. The right end of the minor diameter portion 82 is, for example, positioned axially at the same location as the right end of the main body portion 51. The axial dimension of the minor diameter portion 82 is, for example, larger than the axial dimension of the major diameter portion 81.

[0053] The small-diameter portion 82 is housed inside the small-diameter hole portion 54b. The small-diameter portion 82 contacts the inner peripheral surface 54d of the small-diameter hole portion 54b and the outer peripheral surface 70a of the lead wire 70. More specifically, the outer peripheral surface of the small-diameter portion 82 contacts the inner peripheral surface 54d of the small-diameter hole portion 54b. The inner peripheral surface of the portion of the second through hole 80a provided in the small-diameter portion 82 contacts the outer peripheral surface 70a of the lead wire 70.

[0054] The elastic member 80 has a recess 81a that is recessed to the right. The recess 81a is recessed to the right from the left side of the large-diameter portion 81. Figure 4 As shown, when viewed axially, the recess 81a is annular in shape with the axis AX as its center. The recess 81a surrounds the second through hole 80a. Figure 3As shown, the recess 81a is pressed and expanded in the aperture direction by the protrusion 62, which will be described later, and undergoes elastic deformation. In the pressed and expanded state, the inner surface of the recess 81a extends, for example, along the outer surface of the protrusion 62. Figure 3 The double-dotted line shown represents, for example, the recess 81a before elastic deformation.

[0055] like Figure 2 As shown, the fixing member 60 is fixed to the outer wall portion 50. More specifically, the fixing member 60 is fixed to the left side of the outer wall portion 50 by means of screws 63. Figure 5 As shown, the fixing component 60 is, for example, in the shape of an annular plate centered on the central axis J. Figure 2 As shown, the inner diameter of the fixing member 60 is larger than the outer diameter of the fixing shaft 20. The fixing shaft 20 passes through the radially inner side of the fixing member 60. The outer diameter of the fixing member 60 is smaller than the outer diameter of the main body 51.

[0056] like Figure 5 As shown, the fixing member 60 has a fixing member body 61 and a protrusion 62. The fixing member body 61 is an annular plate-shaped portion centered on the central axis J. The fixing member body 61 has a third through hole 61a and a plurality of mounting holes 61b. The third through hole 61a extends axially through the fixing member body 61. The third through hole 61a is, for example, located at the radial center of the radially inner periphery and the radially outer periphery of the fixing member body 61. The third through hole 61a is, for example, circular in shape centered on the axis AX. Figure 3 As shown, the inner diameter of the third through hole 61a is larger than the outer diameter of the lead wire 70. The lead wire 70, which extends from the second through hole 80a to the left, passes through the third through hole 61a.

[0057] like Figure 5 As shown, multiple mounting holes 61b extend axially through the main body 61 of the fixing component. The mounting holes 61b are, for example, circular in shape. The mounting holes 61b are arranged at equal intervals along the circumference. For example, three mounting holes 61b are provided. Figure 2 As shown, a screw 63, which is screwed into an internally threaded hole provided on the outer wall portion 50 from the left, passes through a mounting hole 61b.

[0058] like Figure 5 As shown, the protrusion 62 protrudes to the right from the fixing member body 61. The protrusion 62 protrudes in a ring shape, for example, from the periphery of the third through hole 61a in the fixing member body 61. The protrusion 62 is, for example, in a ring shape centered on the axis AX. Figure 3As shown, the protrusion 62 surrounds the lead wire 70. The dimension of the protrusion 62 decreases towards the right in at least one direction perpendicular to the axial direction. For example, the dimension of the protrusion 62 decreases towards the right in the aperture direction. In other words, the protrusion 62 tapers towards the right. The protrusion 62 is pressed into the recess 81a, for example. The protrusion 62 is formed, for example, by plastically deforming a portion of the fixing member body 61 to the right.

[0059] The fixing member 60 contacts the elastic member 80 from the left. More specifically, the periphery of the third through hole 61a in the right side surface of the fixing member 60 contacts the left side surface of the large-diameter portion 81. The outer surface of the protrusion 62 contacts the inner surface of the recess 81a. The fixing member 60 presses the large-diameter portion 81 against the stepped surface 55 from the left. As a result, the large-diameter portion 81 undergoes compressive elastic deformation in the axial direction. That is, the elastic member 80 is elastically deformed by being clamped in the axial direction by the fixing member 60 and the stepped surface 55, which serves as a support.

[0060] The elastic member 80 undergoes elastic deformation in a direction perpendicular to the axial direction through compressive elastic deformation in the axial direction. Therefore, as... Figure 3 As indicated by the hollow arrow, the elastic member 80, which is annular due to the second through hole 80a, can elastically deform both inward and outward in the aperture direction. This allows the elastic member 80 to make close contact with the outer peripheral surface 70a of the lead wire 70 and the inner peripheral surface of the first through hole 54. In this embodiment, the large-diameter portion 81 undergoes compressive elastic deformation using the fixing member 60 and the stepped surface 55, thus enabling close contact between the large-diameter portion 81 and the outer peripheral surface 70a of the lead wire 70 and the inner peripheral surface 54c of the large-diameter hole portion 54a. Therefore, according to this embodiment, the gap between the lead wire 70 and the first through hole 54 can be appropriately sealed using the elastic member 80.

[0061] Furthermore, since the fixing member 60 contacts the elastic member 80 from the left, at least a portion of the elastic member 80 is covered by the fixing member 60 from the left. Therefore, contact between the elastic member 80 and external gas can be suppressed. Consequently, the elastic member 80 is less prone to deterioration, thereby suppressing any decrease in sealing performance based on the elastic member 80. Moreover, even if the elastic member 80 deteriorates, the elastic deformation of the elastic member 80 due to pressing the fixing member 60 easily maintains the surface contact state between the large-diameter portion 81 and the stepped surface 55, further suppressing any decrease in sealing performance based on the elastic member 80.

[0062] In summary, according to this embodiment, the sealing performance of the gap between the lead wire 70 and the first through hole 54 through which the lead wire 70 passes can be improved in the motor 10 and the electric wheel 1, and the sealing performance can be appropriately maintained. Therefore, water and dust can be appropriately prevented from entering the interior of the motor 10 through the first through hole 54. Here, the electric wheel 1 is mounted on a vehicle such as an electric motorcycle, and is therefore mostly used outdoors. Therefore, when the motor 10 is mounted on the electric wheel 1, the effect of preventing water and dust from entering the interior of the motor 10 can be more usefully obtained.

[0063] Furthermore, by fixing the fixing member 60, the elastic member 80 can undergo elastic deformation in the aperture direction. Therefore, even if the inner diameter of the first through hole 54 is larger than the outer diameter of the elastic member 80 when the fixing member 60 is not fixed, the outer peripheral surface of the elastic member 80 can still contact the inner peripheral surface of the first through hole 54. Similarly, even if the inner diameter of the second through hole 80a is larger than the outer diameter of the lead wire 70 when the fixing member 60 is not fixed, the inner peripheral surface of the second through hole 80a can still contact the outer peripheral surface 70a of the lead wire 70.

[0064] Therefore, by making the inner diameter of the first through hole 54, when the fixing member 60 is not fixed, larger than the outer diameter of the elastic member 80, the elastic member 80 can be easily positioned inside the first through hole 54 during motor 10 assembly, and the gap between the first through hole 54 and the elastic member 80 can be properly sealed after the fixing member 60 is fixed. Furthermore, by making the inner diameter of the second through hole 80a, when the fixing member 60 is not fixed, larger than the outer diameter of the lead wire 70, the lead wire 70 can easily pass through the second through hole 80a during motor 10 assembly, and the gap between the second through hole 80a and the elastic member 80 can be properly sealed.

[0065] Furthermore, according to this embodiment, the first through hole 54 has a large-diameter hole portion 54a and a small-diameter hole portion 54b. Therefore, a stepped surface 55 serving as a support portion can be easily provided between the large-diameter hole portion 54a and the small-diameter hole portion 54b in the axial direction. Additionally, the elastic member 80 has: a large-diameter portion 81 that contacts the inner peripheral surface 54c of the large-diameter hole portion 54a and the outer peripheral surface 70a of the lead wire 70; and a small-diameter portion 82 that contacts the inner peripheral surface 54d of the small-diameter hole portion 54b and the outer peripheral surface 70a of the lead wire 70. Therefore, in addition to the large-diameter portion 81, which undergoes elastic deformation due to being sandwiched between the fixing member 60 and the stepped surface 55 serving as a support portion, the gap between the lead wire 70 and the first through hole 54 can also be sealed using the small-diameter portion 82. Thus, the gap between the lead wire 70 and the first through hole 54 can be sealed more appropriately.

[0066] like Figure 3As shown, at least one of the fixing member 60 and the elastic member 80 has a deformation promoting portion 90 that promotes elastic deformation of the elastic member 80 in a direction perpendicular to the axial direction. The deformation promoting portion 90, for example, promotes elastic deformation of the elastic member 80 in the aperture direction. Therefore, it is easy to use the fixing member 60 to make the elastic member 80, which has undergone compressive elastic deformation in the axial direction, elastically deform in the aperture direction. This allows for closer contact between the elastic member 80 and the outer peripheral surface 70a of the lead wire 70 and the inner peripheral surface of the first through hole 54. Therefore, the elastic member 80 can more appropriately seal the gap between the lead wire 70 and the first through hole 54. The deformation promoting portion 90 is provided, for example, on both the fixing member 60 and the elastic member 80.

[0067] The fixing member 60 has a protrusion 62 that protrudes to the right and contacts the elastic member 80 as a deformation-promoting part 90. Therefore, the protrusion 62 can be used to locally and forcefully press the elastic member 80. Thus, as... Figure 3 As indicated by the hollow arrow, the portions of the elastic member 80 located on either side of the aperture direction in contact with the protrusion 62 can easily undergo further elastic deformation in the aperture direction. Therefore, the gap between the lead wire 70 and the first through hole 54 can be sealed more appropriately. Furthermore, even if, for example, the elastic member 80 does not protrude to the left of the first through hole 54 when the fixing member 60 is not fixed, the protrusion 62 can be inserted into the first through hole 54 to cause elastic deformation of the elastic member 80.

[0068] Furthermore, according to this embodiment, the protrusion 62 protrudes in an annular shape, surrounding the lead wire 70. Therefore, it is easy for the elastic member 80 to elastically deform in both directions in the aperture direction throughout the entire circumference of the lead wire 70. This allows for a more appropriate sealing of the gap between the lead wire 70 and the first through hole 54 throughout the entire circumference.

[0069] Furthermore, according to this embodiment, the dimension of the protrusion 62 decreases towards the right in at least one direction perpendicular to the axial direction. Therefore, the front end of the protrusion 62 can be made thinner, increasing the force applied from the protrusion 62 to the elastic member 80. This facilitates further elastic deformation of the elastic member 80 in the aperture direction. Consequently, the gap between the lead wire 70 and the first through hole 54 can be sealed more appropriately.

[0070] The elastic member 80 has a recessed portion 81a on the right side as a deformation promoting portion 90. Therefore, when the elastic member 80 undergoes compressive elastic deformation in the axial direction, the portions of the elastic member 80 located on both sides of the recessed portion 81a in the aperture direction are easily elastically deformed further to both sides of the aperture direction. As a result, the gap between the lead wire 70 and the first through hole 54 can be sealed more properly.

[0071] Furthermore, according to this embodiment, the protrusion 62 is pressed into the recess 81a. Therefore, as Figure 3 As indicated by the hollow arrow, the protrusion 62 allows the recess 81a to expand laterally in the aperture direction. This facilitates further elastic deformation of the portions of the elastic member 80 located on either side of the recess 81a in the aperture direction. Consequently, the gap between the lead wire 70 and the first through hole 54 can be sealed more appropriately. Furthermore, as described above, the front end of the protrusion 62 is tapered, making it easier for the front end of the protrusion 62 to enter the interior of the recess 81a and for the protrusion 62 to be pressed into the recess 81a.

[0072] When the fixing member 60 is removed from the outer wall portion 50, the elastic member 80 deforms axially and returns to its original shape. For example... Figure 4 As shown, the elastic member 80 protrudes to a position further to the left of the first through hole 54, for example, when the fixing member 60 is not fixed to the outer wall portion 50. Therefore, by fixing the fixing member 60 to the outer wall portion 50 and pressing the portion of the elastic member 80 that protrudes to the left of the first through hole 54 to the right, the elastic member 80 can undergo more appropriate compressive elastic deformation in the axial direction. As a result, the elastic member 80 can undergo more appropriate elastic deformation in the bore diameter direction. Therefore, the gap between the lead wire 70 and the first through hole 54 can be more properly sealed using the elastic member 80.

[0073] Furthermore, according to this embodiment, the outer wall portion 50 is fixed to the outer peripheral surface of the fixed shaft 20 to hold the bearing 35. By providing the outer wall portion 50 in this way and providing the first through hole 54 on the outer wall portion 50, even when most of the housing of the motor 10 rotates as the rotor 30 as in this embodiment, the lead wire 70 can be easily led out to the outside of the motor 10.

[0074] (First variation of the first embodiment)

[0075] Hereinafter, a first variation of the first embodiment will be described. In addition, in this variation, for structures that are equivalent to the structure of the first embodiment, the hundreds place of the reference numeral is marked with "1" and their description is omitted. On the other hand, the modified parts will be described in particular.

[0076] like Figure 6As shown, in the first through hole 154 of the motor 110 in this modified example, the axial dimension of the large-diameter hole portion 154a is larger than the axial dimension of the small-diameter hole portion 154b. In the elastic member 180, the axial dimension of the large-diameter portion 181 is larger than the axial dimension of the small-diameter portion 182. Therefore, the large-diameter portion 181, which undergoes elastic deformation while being sandwiched between the fixing member 60 and the stepped surface 55 serving as a support portion, can be increased axially. As a result, the portion that undergoes elastic deformation in the bore diameter direction and comes into close contact with the outer peripheral surface 70a of the lead wire 70 and the inner peripheral surface of the first through hole 154 can be increased. Therefore, the gap between the lead wire 70 and the first through hole 154 can be sealed more appropriately using the elastic member 180.

[0077] (Second variation of the first embodiment)

[0078] Hereinafter, a first variation of the first embodiment will be described. In addition, in this variation, for structures that are equivalent to the structure of the first embodiment, the hundreds place of the reference numeral is marked with "2" and the description is omitted. On the other hand, the changes will be described in particular.

[0079] like Figure 7 As shown, in this modified example, the elastic member 280 of the motor 210 is housed inside the large-diameter bore 154a. More specifically, the elastic member 280 is entirely housed inside the large-diameter bore 154a. Unlike the elastic members 80 and 180 described above, the elastic member 280 does not have small-diameter portions 82 and 182. The elastic member 280 is cylindrical with the same outer diameter throughout its axial direction. Thus, by adopting a structure in which the elastic member 280 is housed inside the large-diameter bore 154a, the shape of the elastic member 280 can be made simple, lacking the small-diameter portions 82 and 182. Therefore, the elastic member 280 can be easily manufactured.

[0080] In the first through hole 254, the inner diameter of the small-diameter hole portion 254b is smaller than the inner diameters of the aforementioned small-diameter hole portions 54b and 154b. Therefore, the area of ​​the stepped surface 255 can be increased. Consequently, in the elastic member 280, the portion that elastically deforms when the fixed member 60 and the stepped surface 255 serving as a support are clamped in the axial direction can be increased. Therefore, the elastic member 280 can further elastically deform in the bore diameter direction, and the gap between the lead wire 70 and the first through hole 254 can be sealed more appropriately.

[0081] The inner circumferential surface 254d of the small-diameter hole 254b and the outer circumferential surface 70a of the lead wire 70 are positioned opposite each other in the bore diameter direction with a gap between them. As described above, since the inner diameter of the small-diameter hole 254b is relatively small, the gap between the inner circumferential surface 254d of the small-diameter hole 254b and the outer circumferential surface 70a of the lead wire 70 can be reduced. Therefore, the gap between the lead wire 70 and the first through hole 254 can be sealed more appropriately.

[0082] Alternatively, by pressing the elastic member 280 to the right using the fixing member 60, a portion of the elastic member 280 that has undergone elastic deformation can enter the interior of the small-diameter hole 254b.

[0083] (Third variation of the first embodiment)

[0084] The third variation of the first embodiment will now be described. Furthermore, in this variation, structures equivalent to those in the first embodiment are marked with "3" in the hundreds place of the reference numeral and their descriptions are omitted. On the other hand, the changes will be described in particular.

[0085] like Figure 8 As shown, in this modified example, the first through hole 354 of the motor 310 is a tapered hole whose inner diameter decreases as it faces to the right. Unlike the structures described above, the first through hole 354 does not have a stepped surface that serves as a support. In this modified example, the support is the inner circumferential surface 354a of the first through hole 354.

[0086] The elastic member 380 is a frustum-shaped cone extending axially around the axis AX. The outer diameter of the elastic member 380 decreases as it faces to the right. The elastic member 380 is elastically deformed by being clamped axially by the fixing member 60 and the inner circumferential surface 354a of the first through hole 354, which serves as a support.

[0087] According to this modified example, since the first through hole 354 is a tapered hole, even if the outer diameter of the elastic member 380 has a dimensional error, by pressing the elastic member 380 to the right, the outer peripheral surface of the elastic member 380 can still contact the inner peripheral surface 354a of the first through hole 354. This allows the elastic member 380 to further tighten its contact with the inner peripheral surface 354a of the first through hole 354. Therefore, the gap between the lead wire 70 and the first through hole 354 can be sealed more appropriately.

[0088] <Second Implementation>

[0089] The second embodiment will now be described. Furthermore, in the second embodiment, structures equivalent to those in the first embodiment are marked with "4" in the hundreds place of the reference numeral and their descriptions are omitted. On the other hand, the modified parts will be described in particular.

[0090] Figure 9 The Z-axis direction shown is a vertical direction with the positive side as the "top" and the negative side as the "bottom". In this embodiment, the vertical direction corresponds to the direction that intersects the axial direction. The bottom corresponds to one side of the intersecting direction. The top corresponds to the other side of the intersecting direction.

[0091] like Figure 9 As shown, in the motor 410 of this embodiment, the outer wall portion 450 has a lead-out portion 456. The lead-out portion 456 is provided on the left side of the main body portion 51. The lead-out portion 456 has a first lead-out portion 456a and a second lead-out portion 456b. The first lead-out portion 456a protrudes to the left from the main body portion 51. For example, the first lead-out portion 456a protrudes to the left from a portion of the main body portion 51 that is vertically downward relative to the fixed shaft 20. The second lead-out portion 456b protrudes downward from the left end of the first lead-out portion 456a.

[0092] The first through hole 454, for example, penetrates the main body portion 51 and the outlet portion 456. The first through hole 454 has a first portion 454a and a second portion 454b. The first portion 454a penetrates the main body portion 51 axially and extends to the first outlet portion 456a. The second portion 454b extends downward from the left end of the first portion 454a and penetrates the second outlet portion 456b vertically. The second portion 454b is open at the bottom. That is, the first through hole 454 is open at the bottom.

[0093] The second part 454b has a large-diameter hole 454c and a small-diameter hole 454d. The small-diameter hole 454d is connected to the upper side of the large-diameter hole 454c. The inner diameter of the small-diameter hole 454d is smaller than the inner diameter of the large-diameter hole 454c. A step surface 455 facing downward is provided between the large-diameter hole 454c and the small-diameter hole 454d in the vertical direction. In this embodiment, the step surface 455 corresponds to a support portion.

[0094] The lead wire 470 passes through the first through hole 454 and emerges from the opening on the lower side of the second part 454b to the outside of the motor 410. More specifically, the lead wire 470 extends to the left from the stator 40, passes through the first part 454a, bends downward at the boundary between the first part 454a and the second part 454b, and then passes through the second part 454b to emerge to the outside of the motor 410.

[0095] The elastic member 480 is housed within the second portion 454b of the first through hole 454. The shape of the elastic member 480 is, for example, the same as that of the elastic member 80 in the first embodiment. The elastic member 480 has a second through hole 480a that extends vertically through the elastic member 480 for the lead wire 470 to pass through.

[0096] The fixing member 460 is fixed to the lower end face of the second lead-out portion 456b by means of screws 463. The fixing member body 461 of the fixing member 460 is an annular plate with the plate surface facing axially. The hole in the center of the fixing member body 461 is a third through hole 461a for the lead wire 470 to pass through. The protrusion 462 protrudes annularly from the fixing member body 461 toward the upper side. The shape of the protrusion 462 is the same as the shape of the protrusion 62 in the first embodiment.

[0097] According to this embodiment, the elastic member 480 is clamped in the vertical direction by the fixing member 460 and the stepped surface 455 serving as a support, and thus undergoes elastic deformation. Therefore, similar to the first embodiment, the sealing performance of the gap between the lead wire 470 and the first through hole 454 can be improved, and the sealing performance can be appropriately maintained. In addition, according to this embodiment, the opening direction of the first through hole 454 is downward, so water and dust can be prevented from reaching the area around the lead wire 470. Furthermore, even if water and dust reach the area around the lead wire 470, they easily fall off. As a result, water and dust can be further prevented from reaching the interior of the motor 410 from the first through hole 454.

[0098] This invention is not limited to the embodiments described above, and other structures may also be used. The motor is not particularly limited as long as it is an external rotor type motor. For example, the motor may also have a structure with a bracket fixed to the device on which it is mounted. The rotor may also have a rotating shaft.

[0099] The outer wall portion is not particularly limited as long as it is located on the axial side of the stator and has a first through hole. For example, in the case where the motor has a bracket as described above, the bracket may also have an outer wall portion.

[0100] There are no particular limitations as long as the lead wire is electrically connected to the stator and extends to the outside of the motor through the first through hole. For example, the lead wire can also extend from a circuit board electrically connected to the stator. In this case, the lead wire is electrically connected to the stator via the circuit board.

[0101] The material of the elastic member is not particularly limited as long as it can undergo elastic deformation. The direction in which the elastic member undergoes elastic deformation when clamped is not particularly limited. In the second embodiment, the direction in which the elastic member undergoes elastic deformation when clamped is a vertical direction intersecting the axial direction, but it is not limited to this. The direction in which the elastic member undergoes elastic deformation when clamped can also be a direction intersecting both the axial and vertical directions, for example, a horizontal direction. In this case, for example, the first through hole opens on the horizontal side. The elastic member may also lack a deformation-promoting part. Alternatively, the elastic member can be entirely housed inside the first through hole when the fixing member is not fixed.

[0102] The fixing member only needs to have an elastic member sandwiched between it and the support part; there are no particular limitations. The fixing member may also lack a deformation-promoting part. There are no particular limitations on the method of fixing the fixing member to the outer wall part. For example, the fixing member may also be fixed to the outer wall part by means of an adhesive.

[0103] The protrusion serving as a deformation facilitator may not be pressed into the recess serving as a deformation facilitator. The protrusion and recess may also be staggered. The shape of the protrusion is not particularly limited. The shape of the recess is not particularly limited. Either or both of the protrusion and recess may be omitted.

[0104] The application of the motor described in the above embodiments is not particularly limited. The motor described in the above embodiments can also be mounted on devices other than electric wheels. Furthermore, the various structures described in this specification can be appropriately combined without contradiction.

Claims

1. A motor, which is an external rotor type motor, wherein, The motor has: The rotor rotates around its central axis; The stator is positioned radially opposite the rotor, separated by a gap. The outer wall portion, located on the axial side of the stator, holds the bearing that supports the rotor so that it can rotate; A fixed shaft extending along the central axis, on which the stator and the outer wall portion are fixed; and Leads, which are electrically connected to the stator, are led out to the outside of the motor. The outer wall portion has a first through hole that extends axially between the bearing and the fixed shaft and allows the lead wire to pass through. The rotor has a first wall portion connected to the outer wall portion via the bearing. An oil seal is disposed between the inner circumferential surface of the first wall portion and the outer circumferential surface of the outer wall portion, and at a position axially closer to the bearing.

2. The motor according to claim 1, characterized in that, The motor also includes a sealing component that is sandwiched between the first through hole and the lead wire.

3. The motor according to claim 2, characterized in that, The sealing component is an elastic component. The elastic component has a second through hole that extends axially and through which the lead wire passes. The elastic component is housed inside the first through hole.

4. The motor according to claim 3, characterized in that, The outer wall portion has a support portion that supports the elastic member from the other side of the axial direction.

5. The motor according to claim 4, characterized in that, The motor has a fixing component that is fixed to the outer wall portion and contacts the elastic component from one axial side. The elastic component is held axially by the fixing component and the support portion and thus deforms elastically.

6. The motor according to claim 5, characterized in that, The fixing member has a protrusion that extends axially to the other side and contacts the elastic member.

7. The motor according to claim 6, characterized in that, The elastic member has a recess that is recessed to the other side in the axial direction. The protrusion is pressed into the recess.

8. The motor according to claim 4, characterized in that, The first through hole has: Large diameter bore; and The smaller diameter bore is located on the opposite side of the larger diameter bore along its axial direction, and its inner diameter is smaller than that of the larger diameter bore. The support portion is a stepped surface disposed between the large-diameter hole and the small-diameter hole in the axial direction and facing one side of the axial direction. The elastic component has: The large-diameter portion is housed within the large-diameter hole and contacts the inner circumferential surface of the large-diameter hole and the outer circumferential surface of the lead wire; and The small diameter portion is housed inside the small diameter hole and contacts the inner circumferential surface of the small diameter hole and the outer circumferential surface of the lead wire.

9. The motor according to claim 4, characterized in that, The first through hole is a tapered hole whose inner diameter decreases as it faces the opposite side of the axial direction. The support portion is the inner circumferential surface of the first through hole.

10. A motor, which is an external rotor type motor, characterized in that, The motor has: The rotor rotates around its central axis; The stator is positioned radially opposite the rotor, separated by a gap. The outer wall portion, located on the axial side of the stator, holds the bearing that supports the rotor so that it can rotate; A fixed shaft extending along the central axis, on which the stator and the outer wall portion are fixed; and Leads, which are electrically connected to the stator, are led out to the outside of the motor. The outer wall portion has a first through hole through which the lead wire passes. The first through hole has: The first part extends axially between the bearing and the fixed shaft; and The second part extends radially from one end of the axial direction of the first part. The rotor has a first wall portion connected to the outer wall portion via the bearing. An oil seal is disposed between the inner circumferential surface of the first wall portion and the outer circumferential surface of the outer wall portion, and at a position axially closer to the bearing.

11. The motor according to claim 10, characterized in that, The motor also includes a sealing component that is sandwiched between the first through hole and the lead wire.

12. The motor according to claim 11, characterized in that, The sealing component is an elastic component. The elastic component has a second through hole that extends radially through the lead wire. The elastic component is housed inside the first through hole.

13. The motor according to claim 12, characterized in that, The outer wall portion has a support portion that supports the elastic member from the other radial side.

14. The motor according to claim 13, characterized in that, The motor has a fixing component that is fixed to the outer wall portion and contacts the elastic component from one radial side. The elastic member is held radially by the fixing member and the support and thus deforms elastically.

15. The motor according to claim 14, characterized in that, The fixing member has a protrusion that extends radially to the other side and contacts the elastic member.

16. The motor according to claim 15, characterized in that, The elastic member has a recess that is recessed to the other side radially. The protrusion is pressed into the recess.

17. The motor according to claim 13, characterized in that, The second part has: Large diameter bore; and The smaller diameter orifice is located on the radial side opposite to the larger diameter orifice, and its inner diameter is smaller than that of the larger diameter orifice. The support portion is a stepped surface disposed radially between the large-diameter hole and the small-diameter hole and facing to one radial side. The elastic component has: The large-diameter portion is housed within the large-diameter hole and contacts the inner circumferential surface of the large-diameter hole and the outer circumferential surface of the lead wire; and The small diameter portion is housed inside the small diameter hole and contacts the inner circumferential surface of the small diameter hole and the outer circumferential surface of the lead wire.

18. The motor according to claim 13, characterized in that, The first through hole is a tapered hole whose inner diameter decreases as it faces the opposite radial direction. The support portion is the inner circumferential surface of the first through hole.

19. An electric wheel, wherein, The electric wheel has a motor as described in any one of claims 1 to 18.

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