Motor

Abstract

To provide a motor with improved dust resistance.SOLUTION: A motor (1) according to the present invention includes a rotating shaft (172), a bearing (19), a bearing holder (111) that houses the bearing (19), a holder (17) arranged on one end (111a) side of the bearing holder (111) in the direction of the rotating shaft, and a lid (113) arranged on the side of the other end (111b) of the bearing holder (111) in the direction of the rotating shaft, and one end (111a) of the bearing holder (111) and an inner peripheral portion (171) of the holder (17) form a labyrinth structure, and / or the rotating shaft (172) and the lid (113) form a labyrinth structure.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor. [Background technology]

[0002] 2. Description of the Related Art Conventionally, motors have been used as drive sources for various devices. For example, Patent Document 1 discloses an outer rotor type motor in which a preloadable bearing is disposed inside a bearing holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-157407 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a motor is used outdoors, for example, dust may get inside the motor and affect the drive components. This may hinder the motor's long lifespan. An example of an object of the present invention is to provide a motor with improved dust resistance. [Means for solving the problem]

[0005] The motor of the present invention comprises a rotating shaft, a bearing, a bearing holder that houses the bearing, a holder arranged on one end side of the bearing holder in the direction of the rotational axis, and a lid arranged on the other end side of the bearing holder in the direction of the rotational axis, wherein a labyrinth structure is formed by one end of the bearing holder and an inner circumference of the holder, and / or a labyrinth structure is formed by the rotating shaft and the lid.

[0006] In a motor according to one embodiment of the present invention, the labyrinth structure is formed by one end of the bearing holder and the inner circumference of the holder, the inner circumference of the holder is fixed to the rotating shaft, the holder has a wall portion protruding in the direction of the rotating shaft, one end of the bearing holder has a wall portion protruding in the direction of the rotating shaft, and the wall portion of the holder and the wall portion of the bearing holder inside the wall portion of the holder face each other in the radial direction.

[0007] In a motor according to one embodiment of the present invention, the labyrinth structure is formed by the rotating shaft and the lid, the lid has a wall portion protruding in the direction of the rotating shaft, and the outer peripheral surface of the rotating shaft and the wall portion of the lid face each other in the radial direction.

[0008] In the motor according to one embodiment of the present invention, the wall portion of the lid biases the bearing in the direction of the rotation axis. In the motor according to one embodiment of the present invention, the inner circumferential surface of the other end of the bearing holder and the outer circumferential surface of the cover are screwed together. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an overall configuration of an outer rotor type motor according to an embodiment of the present invention; [Diagram 2] 1 is a cross-sectional perspective view of a motor according to an embodiment of the present invention; [Diagram 3] 1 is a perspective view showing an overall configuration of a stator core of a motor according to an embodiment of the present invention; [Figure 4] 1 is a partial cross-sectional view showing a labyrinth structure of a motor according to an embodiment of the present invention; [Diagram 5] FIG. 11 is a partial cross-sectional view showing a labyrinth structure of a motor according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Overview of the embodiment First, a typical embodiment of the invention disclosed in this application will be outlined. In the following description, as an example, reference numerals in the drawings corresponding to components of the invention are given in parentheses.

[0011] [1] A motor (1) according to a representative embodiment of the present invention includes a rotating shaft (172), a bearing (19), a bearing holder (111) that houses the bearing (19), a holder (17) arranged on one end (111a) side of the bearing holder (111) in the direction of the rotation axis, and a lid (113) arranged on the other end (111b) side of the bearing holder (111) in the direction of the rotation axis, and a labyrinth structure is formed by the one end (111a) of the bearing holder (111) and an inner periphery (171) of the holder (17) and / or a labyrinth structure is formed by the rotating shaft (172) and the lid (113).

[0012] [2] The labyrinth structure is formed by one end (111a) of the bearing holder (111) and the inner peripheral portion (171) of the holder (17), the inner peripheral portion (171) of the holder (17) is fixed to the rotating shaft (172), the holder (17) has a wall portion (17w) protruding in the direction of the rotating shaft, and one end (111a) of the bearing holder (111) has a wall portion (111w) protruding in the direction of the rotating shaft, and the wall portion (17w) of the holder (17) and the wall portion (111w) of the bearing holder (111) located inside the wall portion (17w) of the holder (17) face each other in the radial direction.

[0013] [3] The labyrinth structure is formed by a rotating shaft (172) and a lid (113), and the lid (113) has a wall portion (113w) protruding in the direction of the rotating shaft. An outer circumferential surface (172o) of the rotating shaft (172) and a wall portion (113w) of the lid (113) face each other in the radial direction.

[0014] [4] The wall portion (113w) of the cover (113) biases the bearing (19) in the direction of the rotation axis. [5] The inner peripheral surface (111bi) of the other end (111b) of the bearing holder (111) and the outer peripheral surface (113o) of the cover (113) are screwed together.

[0015] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the overall configuration of an outer rotor type motor according to an embodiment of the present invention. Fig. 2 is a cross-sectional perspective view of the motor according to an embodiment of the present invention. Fig. 3 is a perspective view showing the overall configuration of a stator core of the motor according to an embodiment of the present invention. Fig. 4 is a partial cross-sectional view showing a labyrinth structure of the motor according to an embodiment of the present invention.

[0016] In the following description of this embodiment, for convenience, the direction in which axis X extends when motor 1 rotates is defined as the rotation axis direction. In the following description, for convenience, the direction of arrow a in the rotation axis direction is defined as the upper side, and the direction of arrow b is defined as the lower side. In the radial direction perpendicular to axis X, the direction of arrow c moving away from axis X is defined as the outer circumferential side, and the direction of arrow d moving closer to axis X is defined as the inner circumferential side. In the circumferential direction of motor 1, the direction of arrow e is defined as the clockwise direction, and the direction of arrow f is defined as the counterclockwise direction. In the following description, the upper side (the direction of arrow a) and the lower side (the direction of arrow b) refer to the up-down relationship of motor 1 on the drawing, and do not necessarily coincide with the up-down relationship in the direction of gravity.

[0017] As shown in FIGS. 1 to 4, the motor 1 is an outer rotor type brushless motor mounted on a floating mobile body such as a drone (not shown).

[0018] A drone's propeller (not shown) is attached to holder 17 (FIG. 1) on the upper side (arrow a direction) of motor 1, and the drone's body is attached to stator holder 11 (FIG. 2) on the lower side (arrow b direction). As shown in FIG. 2, motor 1 mainly has stator holder 11, stator 13, rotor 15, holder 17, and bearing 19.

[0019] The stator holder 11 has a bearing holder 111 which is a cylindrical inner peripheral portion, a cylindrical outer peripheral portion 112, a cover 113, and a connecting portion 115. The bearing holder 111 is formed in a substantially cylindrical shape extending in the direction of the rotation axis. The bearing holder 111 accommodates a bearing 19 on its surface (hereinafter referred to as the "inner peripheral surface") on the inner peripheral side (direction of the arrow d).

[0020] Specifically, the bearing holder 111 holds the bearing 19a at one end 111a side (arrow a direction) in the rotation axis direction, and holds the bearing 19b at the other end 111b side (arrow b direction). In this case, an outer ring 19ao of the bearing 19a and an outer ring 19bo of the bearing 19b are press-fitted into an inner circumferential surface 111i of the bearing holder 111. The bearings 19a and 19b are, for example, ball bearings, but are not limited to this and may be various other bearings such as sleeve bearings.

[0021] As shown in Fig. 4, the bearing holder 111 includes a flange portion 111f and a wall portion 111w at one end portion 111a. The flange portion 111f is formed in an annular or substantially annular shape that protrudes radially inward (in the direction of arrow d). The flange portion 111f biases the outer ring 19ao of the bearing 19a downward (in the direction of arrow b) in the direction of the rotation axis. In the radial direction, a gap is formed between the flange portion 111f and a rotation shaft 172 described later.

[0022] A wall portion 111w of the bearing holder 111 is formed in a cylindrical or approximately cylindrical shape protruding toward an inner periphery 171 of a holder 17 described later in the rotation axis direction. The wall portion 111w is formed coaxially and with the same diameter as the bearing holder 111. The wall portion 111w is located inside a wall portion 17w of the holder 17 described later in the radial direction, and faces the wall portion 17w. A gap is formed between the wall portion 111w and the holder 17 described later in the rotation axis direction and the radial direction.

[0023] The other end 111b of the bearing holder 111 has an inner peripheral surface 111bi on the radially inner side (the direction of the arrow d). A spiral groove (hereinafter referred to as a female thread groove) is formed on the inner peripheral surface 111bi, which is screwed into a spiral groove (hereinafter referred to as a male thread groove) formed on an outer peripheral surface 113o of the lid 113 described later.

[0024] The outer peripheral portion 112 of the stator holder 11 is formed in a cylindrical or substantially cylindrical shape extending in the direction of the rotation axis. The bearing holder 111 and the outer peripheral portion 112 both have central axes along the axis X. The length of the outer peripheral portion 112 in the direction of the rotation axis is shorter than the length of the bearing holder 111 in the direction of the rotation axis.

[0025] Between the bearing holder 111 and the outer circumferential portion 112 of the stator holder 11, a connecting portion 115 is formed integrally with the bearing holder 111 and the outer circumferential portion 112. The connecting portion 115 connects the bearing holder 111 and the outer circumferential portion 112 to each other. The connecting portion 115 extends from the outer circumferential end of the bearing holder 111 toward the outer circumferential side (in the direction of arrow c) and is connected to the inner circumferential end of the outer circumferential portion 112.

[0026] 2 and 4, the lid 113 is disposed on the other end 111b side of the bearing holder 111 in the rotation shaft direction. The lid 113 is made of an aluminum alloy and has an overall disk shape. However, this is not limited to this, and the lid 113 may be made of other materials such as resin or plastic.

[0027] The lid 113 has a bottom 113a and a wall 113w. The bottom 113a is formed in a disk shape or a substantially disk shape. The lid 113 has an outer peripheral surface 113o on the outer peripheral side of the bottom 113a in the radial direction (the direction of the arrow c). A male screw groove is formed on the outer peripheral surface 113o, and the male screw groove is screwed into a female screw groove formed on an inner peripheral surface 111bi of the other end 111b of the bearing holder 111.

[0028] The wall 113w of the lid 113 protrudes from the bottom 113a toward the bearing 19 (upward (in the direction of arrow a)) in the rotation axis direction and is formed in a substantially cylindrical shape. The wall 113w of the lid 113 has an outer periphery 113wh and a step 113ws that forms a flat surface higher than a portion of the wall 113w. The outer periphery 113wh and the step 113ws are formed in a cylindrical or substantially cylindrical shape that protrudes from the bottom 113a toward the bearing 19 (upward (in the direction of arrow a)) in the rotation axis direction.

[0029] The step 113ws is connected to the surface of the inner circumference side (arrow d direction) of the outer circumference 113wh in the radial direction, and the length of the step 113ws that protrudes in the rotation axis direction is shorter than that of the outer circumference 113wh. In the rotation axis direction, the surface of the step 113ws that faces the bearing 19b is closer to the bottom 113a side (arrow b direction) than the surface of the rotating shaft 172 that faces the bottom 113a, which will be described later. In addition, in the radial direction, the inner surface of the step 113ws is outside (arrow c direction) the inner ring 19ai of the bearing 19a and the inner ring 19bi of the bearing 19b.

[0030] The wall 113w of the lid 113 is formed radially outward (in the direction of arrow c) of a rotating shaft 172, which will be described later. The wall 113w of the lid 113 faces an outer circumferential surface 172o of the rotating shaft 172, which will be described later, in the radial direction. A gap is formed between the lid 113 and the rotating shaft 172, which will be described later. The wall 113w of the lid 113 (specifically, the outer circumferential surface 113wh) urges the bearing 19b upward (in the direction of arrow a) in the rotating shaft direction.

[0031] A stator core 131 of the stator 13 is fixed to a surface on the outer periphery side of the outer periphery portion 112 (hereinafter referred to as the “outer periphery surface”). The stator 13 includes the stator core 131, an insulator 135, and a coil 139.

[0032] Stator core 131 (FIG. 3) is a laminate of silicon steel plates or the like as a magnetic body, and includes an annular portion 132, a plurality of teeth portions 133 extending from annular portion 132 toward the outer periphery (the side in the direction of arrow d), and magnetic pole portions 134 as the outer periphery ends of each of the teeth portions. In other words, between annular portion 132 and magnetic pole portions 134, there is a part of the stator core (connecting portion) extending in the radial direction.

[0033] An inner peripheral surface of annular portion 132 of stator core 131 is fixed to an outer peripheral surface of outer peripheral portion 112 of stator holder 11. Magnetic pole portions 134 of stator core 131 protrude in the clockwise direction (direction of arrow e) and counterclockwise direction (direction of arrow f) in the circumferential direction, and the gap between adjacent magnetic pole portions 134 is narrower than the gap (slot) between adjacent teeth portions 133.

[0034] An insulator 135 made of an insulating material is attached to the teeth 133 of the stator core 131. A coil 139 is wound around the teeth 133 via the insulator 135. The teeth 133 of the stator core 131 and the coil 139 are electrically insulated from each other via the insulator 135.

[0035] The rotor 15 (FIG. 2) has a yoke 151 and a magnet 153. The yoke 151 is an annular, cylindrical iron core extending in the direction of the rotation axis. The yoke 151 surrounds the magnet 153 and holds the magnet 153 together. The yoke 151 prevents leakage of the magnetic field of the magnet 153, and is made of a magnetic material such as an iron core.

[0036] The holder 17 is disposed on one end 111a side of the bearing holder 111 in the rotation shaft direction. The holder 17 is formed of an aluminum alloy, which is a metal, and has an overall disk shape. However, this is not limited to this, and the holder 17 may be formed of other materials such as resin or plastic. The holder 17 is formed with high precision by cutting. However, this is not limited to this, and the holder 17 may be formed by press molding or the like.

[0037] As shown in Figures 1 and 2, holder 17 has an inner peripheral portion 171 provided on the inner peripheral side (direction of arrow d), an outer peripheral portion 173 provided at the end on the outer peripheral side (direction of arrow c), spokes 175, and a wall portion 17w.

[0038] The inner circumferential portion 171 of the holder 17 has a cylindrical protrusion 171d provided with a circular recess 171h centered on the axis X, and a flange portion 171f extending radially from the outer circumferential end of the protrusion 171d. The flange portion 171f has a size capable of covering the bearing holder 111 from above (the direction of the arrow a).

[0039] The convex portion 171d of the inner peripheral portion 171 has a substantially cylindrical rotating shaft 172 extending in the up-down direction (the direction of the arrow ab) centered on the axis X. The space between the inside of the rotating shaft 172 and the concave portion 171h is closed. An inner ring 19ai of the bearing 19a and an inner ring 19bi of the bearing 19b are held on the outer peripheral surface of the rotating shaft 172. In this embodiment, the rotating shaft 172 is integrally formed as a part of the holder 17, so that the inner peripheral portion 171 of the holder 17 is fixed to the rotating shaft 172.

[0040] The rotating shaft 172 protrudes in the rotation axis direction toward the lid 113 (downward (in the direction of arrow b)) beyond the end face of the bearing 19b that faces the lid 113. An outer circumferential surface 172o of the rotating shaft 172 faces a wall portion 113w of the lid 113 in the radial direction.

[0041] A plurality of (for example, six) spokes 175 are connected to the end portion on the outer circumferential side (direction of arrow c) of flange portion 171f, and annular outer circumferential portion 173 is connected to the tip portion on the outer circumferential side in the radial direction (direction of arrow c) of spokes 175. That is, spokes 175 connect flange portion 171f of inner circumferential portion 171 and outer circumferential portion 173.

[0042] An outer peripheral portion 173 of the holder 17 is fixed to the yoke 151 of the rotor 15. The holder 17 and the rotor 15 rotate together around the axis X. In this embodiment, the outer surface of the outer peripheral portion 173 of the holder 17 fits into the inner surface of the yoke 151 of the rotor 15, and an end of the yoke 151 of the rotor 15 on the holder 17 side engages with the outer surface of the outer peripheral portion 173 of the holder 17, whereby the outer peripheral portion 173 of the holder 17 is fixed to the yoke 151 of the rotor 15. However, this is not limited thereto, and the outer peripheral portion 173 of the holder 17 may be fixed to the yoke 151 of the rotor 15 by press-fitting, adhesion, or both.

[0043] As shown in Fig. 4, the wall 17w of the holder 17 is formed in a cylindrical shape that protrudes from the inner periphery 171 of the holder 17 toward the bearing holder 111 (in the direction of arrow b) in the rotation axis direction. The wall 17w of the holder 17 is formed outside the wall 111w of the bearing holder 111 in the radial direction (in the direction of arrow c). The wall 17w of the holder 17 is formed inside a portion of the spoke 175 in the radial direction (in the direction of arrow d). The wall 17w of the holder 17 faces the wall 111w of the bearing holder 111 in the radial direction. A gap is formed between the wall 17w of the holder 17 and the wall 111w of the bearing holder 111 in the radial direction.

[0044] As shown in Fig. 4, bearings 19a and 19b are fixed by bearing holder 111, cover 113, and rotating shaft 172. In the vicinity of bearing 19a, a labyrinth structure is formed by one end 111a of bearing holder 111 and inner peripheral portion 171 of holder 17. Specifically, a gap formed between flange portion 111f of bearing holder 111 and rotating shaft 172 in the radial direction and a gap formed between wall portion 111w of bearing holder 111 and holder 17 in the rotating shaft direction and radial direction are connected to form a passage that bends multiple times and leads to bearing 19a.

[0045] In addition, in the vicinity of bearing 19b, a labyrinth structure is formed by rotating shaft 172 and lid 113. Specifically, a gap formed between bottom portion 113a of lid 113 and rotating shaft 172 in the rotating shaft direction and a gap formed between wall portion 113w of lid 113 and rotating shaft 172 in the radial direction are connected to form a passage that bends multiple times and leads to bearing 19b.

[0046] In the above configuration, the motor 1 can prevent dust from getting into the bearing 19a due to the labyrinth structure formed by one end 111a of the bearing holder 111 and the inner periphery 171 of the holder 17. Specifically, in order for dust to reach the bearing 19a, it must pass through a passage formed by the flange portion 111f and wall portion 111w of the bearing holder 111, the inner periphery 171 and wall portion 17w of the holder 17, and the rotating shaft 172, which bends multiple times, and therefore the dust has difficulty finally reaching the bearing 19a.

[0047] Furthermore, the motor 1 can prevent dust from getting into the bearing 19b due to the labyrinth structure formed by the rotating shaft 172 and the lid 113. Specifically, in order for dust to reach the bearing 19b, the dust must pass through a passage formed by the rotating shaft 172 and the bottom 113a and wall 113w of the lid 113, which bends multiple times, and therefore the dust is unlikely to ultimately reach the bearing 19b.

[0048] In addition, the motor 1 does not require a separate dust cover or the like because dust is difficult to invade due to the labyrinth structure formed by the bearing holder 111, the holder 17, the rotating shaft 172, and the lid 113. Therefore, it is possible to improve the dust resistance of the motor while suppressing the increase in cost and weight that would otherwise accompany an increase in the number of parts.

[0049] Although the motor 1 of this embodiment is configured as an outer rotor type brushless motor, the present invention is also applicable to motors other than brushless motors. The present invention is also applicable to inner rotor type motors.

[0050] Although the motor of the present invention has been described above with reference to preferred embodiments, the motor of the present invention is not limited to the configuration of the above embodiments. For example, in the present embodiment, a labyrinth structure is formed by one end 111a of the bearing holder 111 and the inner periphery 171 of the holder 17, and a labyrinth structure is also formed by the rotating shaft 172 and the lid 113. However, the present invention is not limited to this, and the labyrinth structure may be formed only by one end 111a of the bearing holder 111 and the inner periphery 171 of the holder 17. Also, the labyrinth structure may be formed only by the rotating shaft 172 and the lid 113.

[0051] In this embodiment, a case has been described in which the space between the inside of the rotating shaft 172 and the recess 171h is blocked, but the present invention is not limited to this, and the inside of the rotating shaft and the recess may be connected to form a through hole. In this embodiment, the case where the bottom 113a of the lid 113 is formed in a disk shape or an approximately disk shape has been described, but the present invention is not limited to this, and the bottom of the lid may be formed with a convex portion that protrudes toward the inside of the rotation shaft.

[0052] In this embodiment, a case has been described in which one wall portion 111w of the bearing holder 111 and one wall portion 17w of the holder 17 are formed, but the present invention is not limited to this, and either one or both of the wall portion of the bearing holder and the wall portion of the holder may be formed in multiples.

[0053] In this embodiment, the case has been described in which the inner circumferential portion 171 of the holder 17 has a cylindrical protrusion 171d, but the present invention is not limited to this, and as in another embodiment (variant) shown in Figure 5, the inner circumferential portion 271 of the holder 27 may have a flat shape without having a cylindrical protrusion.

[0054] In this embodiment, the rotating shaft 172 is integrally formed as a part of the holder 17. However, the present invention is not limited to this. As in another embodiment (variant) shown in FIG. 5, the rotating shaft 272 and the holder 27 may be formed as separate members and fixed to each other by press-fitting, adhesive bonding, or both.

[0055] In this embodiment, the wall portion 111w of the bearing holder 111 is formed coaxially and with the same diameter as the bearing holder 111, but the present invention is not limited to this, and the wall portion of the bearing holder does not have to be formed with the same diameter as the bearing holder. For example, as in another embodiment (modification) shown in Fig. 5, the wall portion 211w of the bearing holder 211 may be formed at the end portion on the inner periphery side (direction of arrow d) of the flange portion 211f. In this case, as shown in Fig. 5, the wall portion 27w of the holder 27 may be formed to face the flange portion 211f in the rotation axis direction.

[0056] In this embodiment, a case has been described in which, in the rotation axis direction, the surface of step portion 113ws of wall portion 113w of lid 113 that faces bearing 19b is located closer to bottom 113a (in the direction of arrow b) than the surface of rotating shaft 172 that faces bottom 113a. However, the present invention is not limited to this, and as in another embodiment (variant example) shown in Figure 5, in the rotation axis direction, the surface of step portion 213ws of wall portion 213w of lid 213 that faces bearing 19b may be closer to holder 27 (in the direction of arrow a) than the surface of rotating shaft 272 that faces bottom 213a.

[0057] In this embodiment, a case has been described in which the inner surface of step portion 113ws of wall portion 113w of lid 113 is radially outboard (in the direction of arrow c) of inner ring 19ai of bearing 19a and inner ring 19bi of bearing 19b. However, the present invention is not limited to this, and as in another embodiment (variant example) shown in Figure 5, on a rotating shaft, the surface of step portion 113ws of wall portion 113w of lid 113 that faces bearing 19b may face inner ring 19bi of bearing 19b.

[0058] In another embodiment (modification) shown in FIG. 5, the bearings 19a and 19b are fixed by the bearing holder 211, the cover 213, and the rotating shaft 272. In the vicinity of the bearing 19a, a labyrinth structure is formed by one end 211a of the bearing holder 211 and the inner peripheral portion 271 of the holder 27. This labyrinth structure can prevent dust from entering the bearing 19a. Specifically, a gap formed between the wall portion 211w of the bearing holder 211 and the inner peripheral portion 271 of the holder 27 in the rotation axis direction and the radial direction, a gap formed between the wall portion 211w of the bearing holder 211 and the wall portion 27w of the holder 27 in the radial direction, and a gap formed between the flange portion 211f of the bearing holder 211 and the wall portion 27w of the holder 27 in the rotation axis direction are connected to form a passage that is bent multiple times and leads to the bearing 19a. In order for dust to reach the bearing 19a, it must pass through the passage, and therefore the dust is unlikely to ultimately reach the bearing 19a.

[0059] Further, in the vicinity of the bearing 19b, a labyrinth structure is formed by the rotating shaft 272 and the lid 213. This labyrinth structure can prevent dust from entering the bearing 19b. Specifically, a gap formed between the bottom 213a of the lid 213 and the rotating shaft 272 in the rotating shaft direction and a gap formed between the wall portion 213w of the lid 213 and the rotating shaft 272 in the radial direction are connected to form a passage that bends multiple times and leads to the bearing 19b. Since dust must pass through this passage to reach the bearing 19b, it is difficult for the dust to finally reach the bearing 19b.

[0060] In addition, those skilled in the art can appropriately modify the motor of the present invention in accordance with conventionally known knowledge. As long as the motor of the present invention is still provided after such modification, it is of course included in the scope of the present invention. [Explanation of symbols]

[0061] 1...motor, 11...stator holder, 13...stator, 15...rotor, 17...holder, 17w...wall portion, 19 (19a, 19b)...bearing, 111...bearing holder, 111a...one end, 111b...other end, 111bi...inner peripheral surface, 111f...flange portion, 111w...wall portion, 112...outer peripheral portion, 113...lid, 113a...bottom portion, 113o...outer peripheral surface, 113w...wall portion, 113ws...step portion, 113wh...outer peripheral portion, 115...connecting portion, 131...stator core, 132...annular portion, 133...tooth portion, 135...insulator, 139...coil, 151...yoke, 153...magnet, 171...inner circumference, 171d...convex portion, 171f...flange portion, 171h...concave portion, 172...rotating shaft, 173...outer circumference, 175...spokes, 27...holder, 27w...wall portion, 211...bearing holder, 211f...flange portion, 211w...wall portion, 213...lid, 213a...bottom portion, 213w...wall portion, 213ws...step portion, 213wh...outer circumference, 271...inner circumference, 272...rotating shaft.

Claims

1. A rotation axis; A bearing, a bearing holder that houses the bearing; a holder disposed on one end side of the bearing holder in a rotation axis direction; a cover disposed on the other end side of the bearing holder in the rotation axis direction, the holder includes an inner circumferential portion fixed to the rotating shaft, a wall portion protruding in a direction of the rotating shaft, an outer circumferential portion, and a plurality of spokes connecting the inner circumferential portion and the outer circumferential portion, the inner periphery of the holder includes a radially extending portion; the radially extending portion covers the bearing holder and the bearing, A magnet is fixed to the outer periphery of the holder, one end of the bearing holder includes a wall portion protruding in a rotation axis direction and a flange portion extending radially toward the rotation axis, A wall portion of the holder and a wall portion of the bearing holder face each other in a radial direction, a labyrinth structure is formed by a wall portion and a flange portion of the bearing holder and an inner circumferential portion and a wall portion of the holder, The labyrinth structure includes a multi-turn passageway leading to the bearing.

2. The motor according to claim 1 , wherein a wall portion of the holder and a wall portion of the bearing holder located inside the wall portion of the holder face each other in a radial direction.

3. another labyrinth structure formed by the rotating shaft and the lid; The cover includes a wall portion protruding in a rotation shaft direction, The motor according to claim 1 or 2, wherein an outer circumferential surface of the rotary shaft and a wall portion of the lid face each other in a radial direction.

4. The motor according to claim 3 , wherein the wall portion of the lid biases the bearing in the direction of the rotation axis.

5. 5. The motor according to claim 3, wherein an inner peripheral surface of the other end of the bearing holder and an outer peripheral surface of the lid are screwed together.

6. The motor according to claim 1 , wherein a gap is formed between the flange portion and the rotating shaft in a radial direction.

7. The motor according to claim 1 , wherein a gap is formed between the flange portion and the wall portion of the holder in the rotation axis direction.

Images