Motor and fan motor

Abstract

To provide a technique of safely adjusting the posture of a rotor even after assembled.SOLUTION: In a motor 101, a rotor 1 is supported by a bearing 32 in a rotatable manner about a center axis extending in an axis direction. The rotor includes a rotor lid portion 11 and a first projection portion 14. The rotor lid portion radially expands. The first projection portion projects from the rotor lid portion to one side in the axis direction, extends along the center axis, and is supported by the bearing in a rotatable manner. The bearing has a cylindrical shape extending in the axis direction and surrounds the first projection portion. A hole portion 141 extending to the other side in the axis direction is disposed on one side end in the axis direction of the first projection portion. The axis direction length of the hole portion is shorter than a half of the axis direction length of the first projection portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, there is known a fan motor in which rotor blades can rotate in a circumferential direction together with a rotor. For example, a fan motor has a bearing device, a plurality of fans such as rotor blades, and a drive unit for rotating the fans together with a rotating member. The bearing device has a rotating member such as a rotor, and a bearing. The plurality of fans are provided on the rotating member. The rotating member has a hub portion and a shaft portion. The shaft portion is formed integrally with the hub portion and is inserted into the inner circumference of the bearing. The drive unit has a fixed-side coil and a magnet fixed to the rotating-side hub portion. The rotating member rotates relative to the bearing as the magnet rotates due to the excitation force between the coil and the rotating member (see JP 2015-064019 A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-064019 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in JP 2015-064019 A, the shaft of the rotating member is cylindrical and extends in the axial direction. Therefore, when an external force is applied to adjust the attitude of the rotating member to adjust the rotation balance after assembling the fan motor, the shaft may be deformed due to insufficient strength and rigidity. In other words, it may be difficult to adjust the attitude of the rotating member after assembly.

[0005] An object of the present invention is to provide a technique for safely adjusting the attitude of a rotor even after assembly. [Means for solving the problem]

[0006] In an exemplary motor of the present invention, a rotor is supported by bearings so as to be rotatable around a central axis extending in the axial direction. The rotor has a rotor lid and a first protrusion. The rotor lid extends in a radial direction. The first protrusion protrudes from the rotor lid in one axial direction and extends along the central axis, and is rotatably supported by the bearing. The bearing is cylindrical and extends in the axial direction, surrounding the first protrusion. A hole extending in the other axial direction is disposed at one axial end of the first protrusion. The axial length of the hole is less than half the axial length of the first protrusion.

[0007] An exemplary fan motor of the present invention includes the above-described motor. Effect of the Invention

[0008] According to the exemplary motor and fan motor of the present invention, it is possible to provide a technique for safely adjusting the attitude of the rotor even after assembly. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a fan motor. [Diagram 2] FIG. 2 is a perspective view showing the appearance of the fan motor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Exemplary embodiments are described below with reference to the drawings.

[0011] In this specification, in the fan motor 100 and the motor 101, the direction parallel to the central axis CA is referred to as the "axial direction." Within the axial direction, the direction from the base portion 33 to the rotor lid portion 11, which will be described later, is referred to as the "one axial direction Da," and the direction from the rotor lid portion 11 to the base portion 33 is referred to as the "other axial direction Db." Additionally, the direction perpendicular to the central axis CA is referred to as the "radial direction." Within the radial direction, the direction approaching the central axis CA is referred to as the "radial inward," and the direction away from the central axis CA is referred to as the "radial outward." Additionally, the direction of rotation about the central axis CA is referred to as the "circumferential direction."

[0012] In this specification, "annular" refers not only to a shape that is continuous and uninterrupted throughout the entire circumferential area centered on the central axis CA, but also to a shape that has one or more interruptions in a portion of the entire area centered on the central axis CA. It also refers to a shape that describes a closed curve on a curved surface that intersects with the central axis CA.

[0013] In addition, in the positional relationship between any one of a direction, a line, and a plane and any other, "parallel" includes not only a state in which the two do not intersect at all no matter how far they are extended, but also a state in which they are substantially parallel. Furthermore, "perpendicular" and "orthogonal" each include not only a state in which the two intersect at 90 degrees, but also a state in which they are substantially perpendicular and a state in which they are substantially orthogonal, respectively. In other words, "parallel," "perpendicular," and "orthogonal" each include a state in which there is an angle deviation in the positional relationship between the two to an extent that does not deviate from the gist of the present invention.

[0014] Note that these are names used merely for the purpose of explanation, and are not intended to limit the actual positional relationships, directions, names, and the like.

[0015] <1. Embodiment> Fig. 1 is a cross-sectional view showing an example of the configuration of a fan motor 100. Fig. 2 is a perspective view showing the external appearance of the fan motor 100. Fig. 1 shows a cross-sectional structure in a case where the fan motor 100 is virtually cut along a plane including a two-dot chain line II and a central axis CA in Fig. 2.

[0016] <1-1. Fan motor 100> The fan motor 100 of this embodiment is an axial fan that blows air in the axial direction. However, this example does not exclude a configuration in which the fan motor 100 is a fan other than an axial fan. For example, the fan motor 100 may be a blower fan or a centrifugal fan.

[0017] 1 and 2, the fan motor 100 includes a motor 101 and an impeller 102. The impeller 102 is rotatable about a central axis CA together with a rotor 1 (described later) of the motor 101, and is fixed to at least a rotor lid portion 11 of the rotor 1. The motor 101 drives and rotates the impeller 102. In the fan motor 100 of this embodiment, as will be described later, the attitude of the rotor 1 (and the impeller 102) can be safely adjusted even after assembly.

[0018] The impeller 102 has an impeller cover portion 1021, an impeller cap 1022, an impeller cylinder portion 1023, and a plurality of rotor blades 1024. The impeller cover portion 1021 has an annular shape surrounding a second protruding portion 16 of the rotor 1, which will be described later, and is disposed on the other axial end surface of the rotor cover portion 11. As described above, the impeller 102 has the impeller cover portion 1021. The impeller cap 1022 is disposed on the radial inner end portion of the impeller cover portion 1021, and covers an opening (reference numeral omitted) of the impeller cover portion 1021 and one axial end portion of the second protruding portion 16 of the rotor 1. The opening is disposed on the radial inner side of the radial inner end portion of the impeller cover portion 1021. The impeller cap 1022 can be omitted. The impeller cylinder portion 1023 is cylindrical and extends from the radial outer end of the impeller lid portion 1021 in one axial direction Da. The impeller lid portion 1021 and the impeller cylinder portion 1023 form a covered cylindrical impeller base (reference numeral omitted) that extends in the axial direction and is attached to the rotor 1. A plurality of rotor blades 1024 are disposed on the radial outer surface of the impeller cylinder portion 1023 and are aligned in the circumferential direction. When the motor 101 rotates the impeller 102, the rotor blades 1024 rotate in the circumferential direction. This causes the airflow to flow in the axial direction.

[0019] Preferably, the material of the impeller 102 is polycarbonate resin. Polycarbonate resin is a material with high toughness and mechanical strength. Therefore, by employing polycarbonate resin, the rigidity of the impeller 102 can be improved. However, this example does not exclude a configuration in which the material of the impeller 102 is not polycarbonate resin. For example, the material of the impeller 102 may be a resin material other than polycarbonate resin, or may be a metal material such as Al or an Al alloy.

[0020] It should be noted that the present invention is not limited to the above-mentioned example, and the rotor blades 1024 may be integral with the rotor 1, or may be arranged in a row on the radially outer surface of the rotor 1. In this case, the impeller lid portion 1021, the impeller cap 1022, and the impeller cylinder portion 1023 are omitted.

[0021] The fan motor 100 further includes a cylindrical housing 103 and a rib 104. The cylindrical housing 103 extends in the axial direction and surrounds the motor 101 and the impeller 102. The cylindrical housing 103 faces the motor 101 and the impeller in the radial direction with a gap therebetween, and forms an air tunnel (reference numeral omitted) in which air flows in the space between them. The ribs 104 extend at least in the radial direction, and are arranged in a row in the circumferential direction on one axial direction Da side of the air tunnel. The ribs 104 function as stator blades that straighten the air flow through the air tunnel. The ribs 104 also connect the base portion 33 of the motor 101 to one axial end portion of the cylindrical housing 103. That is, the radial inner end portion of the rib 104 is connected to the base portion 33. The radial outer end portion of the rib 104 is connected to the radial inner side surface of the cylindrical housing 103.

[0022] <1-2.Motor 101> Next, a configuration example of a motor 101 will be described with reference to Figures 1 and 2. The motor 101 includes a rotor 1, a stator 2, a housing 3, a circuit board 4, a stopper 5, a first dynamic pressure groove 61, a second dynamic pressure groove 62, and a third dynamic pressure groove 63. Note that hereinafter, the first dynamic pressure groove 61, the second dynamic pressure groove 62, and the third dynamic pressure groove 63 may be collectively referred to as "dynamic pressure groove 6".

[0023] <1-2-1.Rotor 1> In the motor 101 of this embodiment, the rotor 1 is supported by bearings 32 so as to be rotatable about a central axis CA extending in the axial direction. In this embodiment, the rotor 1 is made of a metal such as stainless steel, Al, or an Al alloy.

[0024] The rotor 1 has a rotor lid portion 11, a rotor cylinder portion 12, a magnet 13, a first protruding portion 14, a wall portion 15, and a second protruding portion 16.

[0025] The rotor lid portion 11 extends in the radial direction. As described above, the rotor 1 has the rotor lid portion 11. The rotor lid portion 11 is disposed on the other axial direction Db than the stator 2.

[0026] Moreover, the rotor cylindrical portion 12 extends in one axial direction Da from the radial outer end portion of the rotor lid portion 11. As described above, the rotor 1 has the rotor cylindrical portion 12. The rotor cylindrical portion 12 is cylindrical and surrounds the stator 2.

[0027] The impeller 102 (more specifically, the impeller base) is fixed to the rotor lid portion 11 and the rotor cylinder portion 12. In this manner, the impeller 102 can be fixed to the rotor 1 afterwards. Therefore, corrections such as wobble correction can be easily performed after fixing. Furthermore, even if such corrections are performed or an external force acts on the impeller 102, the support structure of the rotor 1 is unlikely to be affected. Therefore, the risk of damage to the bearings 32 supporting the rotor 1 can be reduced or prevented. Therefore, the posture of the impeller 102 can be safely adjusted even after the fan motor 100 has been assembled.

[0028] In this embodiment, the rotor cylinder portion 12 is press-fitted into the inside of the impeller cylinder portion 1023, and thereby fixed to the inner circumferential surface (radially inner surface) of the impeller cylinder portion 1023. When press-fitting, the rotor lid portion 11 is arranged not to abut against the impeller 102 in the axial direction. In other words, in the axial direction, the upper surface of the rotor lid portion 11 faces the impeller 102 (e.g., the lower surface of the impeller lid portion 1021) with a ring-shaped gap surrounding the central axis CA. In other words, the upper surface of the rotor lid portion 11 and the lower surface of the impeller lid portion 1021 do not come into contact with each other in the axial direction over the entire circumference in the circumferential direction.

[0029] In this way, when the impeller 102 is attached to the rotor 1 by press-fitting, for example, a press-fitting jig with high parallelism accuracy is used, thereby preventing the impeller 102 from vibrating during rotation. In detail, when the rotor cylinder 12 is press-fitted into the inner peripheral surface of the impeller cylinder 1023, a press-fitting jig with high parallelism accuracy is disposed between the upper surface of the rotor lid 11 and the lower surface of the impeller lid 1021 in the axial direction. This allows a gap to be provided between the rotor lid 11 and the impeller lid 1021 while keeping them parallel with high accuracy, thereby preventing the two from butting against each other during press-fitting. In other words, the rotor lid 11 can be prevented from abutting against the impeller lid 1021 in the axial direction. Therefore, even if one of the upper surface of the rotor lid 11 and the lower surface of the impeller lid 1021 is inclined from a plane perpendicular to the rotation axis (center axis CA) of the rotor 1, the other can be prevented from being inclined from the plane due to the abutment. In other words, if they do not butt against each other, the rotor cylinder part 12 is press-fitted into the inner peripheral surface of the impeller cylinder part 1023 following the press-fitting jig, so that the two can be made parallel with high accuracy. Therefore, it is possible to suppress or prevent the central axis of the impeller 102 from being displaced from the rotation axis of the rotor 1 (i.e., the central axis CA) due to the abutment between the two. Furthermore, even if the impeller 102 rotates and vibrates after installation, a gap is provided between the upper surface of the rotor cover part 11 and the lower surface of the impeller cover part 1021, so that the part of the impeller 102 that vibrates more can be adjusted in position by applying pressure to one side in the axial direction (i.e., the rotor 1 side). In other words, even after installation, the relative positional relationship of the central axis of the impeller 102 with respect to the rotation axis of the rotor 1 (i.e., the central axis CA) can be easily adjusted, and the vibrating of the impeller 102 can be effectively suppressed or prevented.

[0030] The magnet 13 is disposed on the radially inner surface of the rotor tube portion 12 and faces the stator 2 (particularly, the stator core 21 described later) in the radial direction. For example, the magnet 13 is disposed radially outward of the stator 2 (particularly, the stator core 21) and surrounds the stator 2 (particularly, the stator core 21). On the radially inner surface of the magnet 13, different magnetic poles (S poles, N poles) are alternately arranged in the circumferential direction. The magnet 13 may be directly disposed on the radially inner surface of the rotor tube portion 12, or may be disposed with a magnetic body (not shown) sandwiched therebetween. For example, in the latter case, a magnetic body (a cylindrical body or a plurality of magnetic pieces arranged in the circumferential direction) may be disposed on the radially inner surface of the rotor tube portion 12, and the magnet 13 may be disposed on the radially inner surface of the magnetic body.

[0031] The first protruding portion 14 is the shaft (rotating shaft) of the rotor 1. The first protruding portion 14 protrudes from the rotor lid portion 11 in one axial direction Da and extends along the central axis CA. As described above, the rotor 1 has the first protruding portion 14. The first protruding portion 14 is rotatably supported by the bearing 32. Furthermore, a hole portion 141 extending in the other axial direction Db is disposed at one axial end portion of the first protruding portion 14. The hole portion 141 is a recess recessed into the other axial direction Db, and extends along the central axis CA.

[0032] The axial length L1 of the hole 141 is less than half the axial length L2 of the first protrusion 14. In this way, the axial length L1 of the cylindrical portion having the hole 141 on one axial side Da of the first protrusion 14 rotatably supported by the bearing 32 is smaller than the axial length L2 of the solid portion on the other axial side Db of the cylindrical portion. That is, more than half of the first protrusion 14 is a solid columnar body. Therefore, the strength and rigidity of the first protrusion 14 can be improved. In addition, the solid portion is connected to the rotor cover 11. Therefore, even if the attitude of the rotor 1 (and the impeller 102) is adjusted to adjust the rotation balance after the fan motor 100 is assembled (especially after the first protrusion 14 is supported by the bearing 32), distortion due to an external force is unlikely to occur in the first protrusion 14 and the bearing 32. Therefore, the strength and rigidity of the support structure of the first protrusion 14 by the bearing 32 can be improved. Therefore, even after the fan motor 100 and the motor 101 are assembled, the attitude of the rotor 1 (and the impeller 102) can be safely adjusted.

[0033] The wall portion 15 protrudes from the rotor lid portion 11 in one axial direction Da and surrounds the other axial end of the bearing 32. As described above, the rotor 1 has a cylindrical wall portion 15. Furthermore, the wall portion 15 surrounds the other axial end of the first protrusion portion 14. That is, the wall portion 15 is a cylindrical body disposed on one axial end face of the rotor lid portion 11 and extending in the axial direction. The wall portion 15 is disposed radially outward from the first protrusion portion 14 and the bearing 32, and faces the other axial end of the bearing 32 with a gap in the radial direction. The cylindrical wall portion 15 forms a cylindrical first space (reference numeral omitted) extending in the axial direction between the other axial end of the bearing 32 and the cylindrical wall portion 15. The first space functions as a first labyrinth, and can suppress, for example, leakage of a fluid F described later between the first protrusion portion 14 and the bearing 32, intrusion of water and dust from the outside into the space between the first protrusion portion 14 and the bearing 32, and the like.

[0034] Note that, without being limited to the example of this embodiment, the wall portion 15 may rotatably support the other axial end portion of the bearing 32. In other words, the radially inner surface of the wall portion 15 may be in direct contact with the other axial end portion of the bearing 32 so as to be slidable thereon, or may be in indirect contact with the other axial end portion of the bearing 32 via the fluid F or the like. In this way, the rotor 1 can rotate in a more balanced manner.

[0035] The second protruding portion 16 protrudes from the rotor lid portion 11 in the other axial direction Db and extends along the central axis CA. As described above, the rotor 1 has the second protruding portion 16. That is, the second protruding portion 16 is a columnar body extending in the axial direction, and is disposed in the center of the other axial end face of the rotor lid portion 11.

[0036] 1, the outer diameter φ2 of the second protruding portion 16 is preferably larger than the outer diameter φ1 of the first protruding portion 14 when viewed in the axial direction. This makes it possible to increase the thickness of the rotor 1 (for example, the sum of the axial width of the rotor lid portion 11 and the axial width W2 of the second protruding portion 16, which will be described later) in the vicinity of the connection portion between the first protruding portion 14 and the rotor lid portion 11. This makes it possible to improve the strength and rigidity of the connection portion between the two.

[0037] More preferably, as shown in Fig. 1, the outer diameter φ2 of the second protruding portion 16 is larger than the outer diameter φ3 of the bearing 32 when viewed from the axial direction. This makes it possible to increase the thickness of the rotor 1 (for example, the sum of the axial width of the rotor lid portion 11 and the axial width W2 of the second protruding portion 16) in a wide range centered on the connection portion between the first protruding portion 14 and the rotor lid portion 11 when viewed from the axial direction. This makes it possible to further improve the strength and rigidity of the connection portion between them.

[0038] However, the above examples do not exclude a configuration where φ1≧φ2 and a configuration where (φ1≦)φ2≦φ3, and do not exclude a configuration where the second protruding portion 16 is tubular and extends in the axial direction.

[0039] Also, preferably, the other axial end of the second protruding portion 16 of the motor 101 is disposed on the other axial direction Db than the radial inner end of the impeller lid portion 1021. In other words, the axial width W2 of the second protruding portion 16 is larger than the axial width W1 of the radial inner end of the impeller lid portion 1021. In this way, the axial width W2 of the second protruding portion 16 can be made larger, so that the thickness of the rotor 1 near the connection portion between the first protruding portion 14 and the rotor lid portion 11 (for example, the sum of the axial width of the rotor lid portion 11 and the axial width W2 of the second protruding portion 16) can be made larger. Therefore, the strength and rigidity of the connection portion between the two can be further improved. However, this example does not exclude a configuration where W1≧W2.

[0040] In this embodiment, the second protrusion 16 has a gap between it and the impeller 102 (for example, the radial inner end of the impeller lid portion 1021, the impeller cap 1022). However, this is not limited to the example, and the second protrusion 16 may be in contact with the impeller 102. For example, the radial outer end of the second protrusion 16 may be in contact with the impeller 102. In addition, the second protrusion 16 (particularly the other axial end) may be in contact with the impeller 102 (particularly the impeller cap 1022). In this way, the second protrusion 16 can be fitted into the opening of the impeller lid portion 1021, the recess (reference numeral omitted) on one axial side Da of the impeller cap 1022, or the like. Therefore, the impeller 102 can be fixed to the rotor 1 more firmly.

[0041] In this embodiment, the rotor lid 11, the rotor cylinder 12, the first protrusion 14, the wall 15, and the second protrusion 16 are integral with each other and form a single member. However, this example does not exclude a configuration in which at least some of these do not form a single member with the other parts. For example, the first protrusion 14 may be integral with at least the rotor lid 11 by insert molding or the like, but may not be a single member.

[0042] <1-2-2. Stator 2> The stator 2 rotates the rotor 1 by magnetic flux generated by energization. As shown in FIG.

[0043] The stator core 21 is an annular magnetic body surrounding the central axis CA, and in this embodiment is a laminated body in which plate-shaped electromagnetic steel sheets extending in the radial direction are stacked in the axial direction. The stator core 21 is fixed to the radial outer surface of the bearing holder 31. The stator core 21 also has slots (not shown). The slots penetrate the stator core 21 in the axial direction and are arranged in multiple slots in the circumferential direction. The stator core 21 has coil portions 23 arranged in multiple slots in the circumferential direction.

[0044] The insulators 22 have electrical insulation properties and are arranged on the surfaces of the stator core 21 (particularly, both axial end faces and inner surfaces of the slots, etc.).

[0045] The coil portion 23 is a member in which a conductor wire (reference number omitted) is arranged in a coil shape on the stator core 21 via the insulator 22. The conductor wire is, for example, an enamel-coated copper wire, a metal wire coated with an electrical insulating material, or the like, and the coil portion 23 is formed by being wound around teeth (not shown) between circumferentially adjacent slots of the stator core 21. When a driving current is supplied to each coil portion 23, the stator 2 is excited to drive the rotor 1.

[0046] <1-2-3. Housing 3> The housing 3 has a bearing holder 31 , a bearing 32 , and a base portion 33 .

[0047] The bearing holder 31 has a cylindrical shape extending in the axial direction, and surrounds and holds the bearing 32. The motor 101 further includes a bearing holder 31. In addition, the bearing holder 31 surrounds the central axis CA and the first protrusion 14, and holds the stator core 21 on its radially outer surface.

[0048] Moreover, the bearing holder 31 further surrounds at least one axial direction Da side of the wall portion 15. In this way, a cylindrical second space (reference number omitted) extending in the axial direction can be further formed between the wall portion 15 and the cylindrical bearing holder 31 (for example, the holder peripheral wall portion 312). The second space functions as a second labyrinth, and can further suppress, for example, leakage of the fluid F between the first protrusion portion 14 and the bearing 32, intrusion of water and dust from the outside into the space between the first protrusion portion 14 and the bearing 32, and the like.

[0049] For example, the bearing holder 31 has a holder tubular portion 311 and a holder peripheral wall portion 312. The holder tubular portion 311 is cylindrical and extends in the axial direction, and surrounds the central axis CA, the first protruding portion 14, and the bearing 32. The holder peripheral wall portion 312 is cylindrical and extends from the other axial end portion of the holder tubular portion 311 in the other axial direction Db, and surrounds at least one axial direction Da side of the wall portion 15 of the rotor 1. That is, the holder peripheral wall portion 312 is disposed radially outward from the wall portion 15, and faces the wall portion 15 in the radial direction with a gap therebetween. In addition, the other axial end portion of the holder peripheral wall portion 312 faces the one axial end face of the rotor lid portion 11 in the axial direction with a gap therebetween.

[0050] Preferably, the holder peripheral wall portion 312 is disposed at the radially outer end at the other axial end of the holder tubular portion 311. In this way, the one axial end of the wall portion 15 can be opposed to the other axial end of the holder tubular portion 311 with a gap in the axial direction. Therefore, a third space (reference numeral omitted) having an annular shape can be further formed between the wall portion 15 and the other axial end of the holder tubular portion 311. The third space can function as a third labyrinth. However, this example does not exclude a configuration in which the holder peripheral wall portion 312 is disposed at the radially inner side (particularly the radially inner end) at the other axial end of the holder tubular portion 311.

[0051] Moreover, the bearing holder 31 further has an inner flange 313. The holder peripheral wall portion 312 and the inner flange 313 spread radially inward from one axial end of the holder cylindrical portion 311 and extend in the circumferential direction. For example, the inner flange 313 may be in a circular ring shape surrounding the central axis CA. However, this example does not exclude a configuration in which the inner flange 313 is not in a circular ring shape as described above.

[0052] The bearing 32 is disposed on the inner peripheral surface (i.e., the radially inner surface) of the bearing holder 31. The bearing 32 is cylindrical and extends in the axial direction, and surrounds the first protruding portion 14. In other words, the first protruding portion 14 is inserted into the inside of the bearing holder 31 and the bearing 32. The bearing holder 31 rotatably supports the first protruding portion 14 via the bearing 32. In addition, one axial end face of the bearing 32 faces the other axial end face of a flange portion 52 of the stopper portion 5, which will be described later, in the axial direction, via the fluid F. The other axial end face of the bearing 32 faces the one axial end face of the rotor lid portion 11 in the axial direction, via the fluid F. The radially inner surface of the bearing 32 faces the radially outer surface of the first protruding portion 14 in the radial direction, via the fluid F.

[0053] In this embodiment, the bearing 32 is a sleeve that functions as a fluid dynamic bearing. A fluid F is disposed between the first protruding portion 14 and the bearing 32. In this embodiment, the fluid F is a lubricating oil. However, the present invention is not limited to this example, and the fluid F may be a liquid other than the lubricating oil, or may be a gas such as air. A third dynamic pressure groove 63, which will be described later, is disposed on at least one of the radial outer surface of the first protruding portion 14 and the radial inner surface of the bearing 32 in order to generate dynamic pressure in the fluid F interposed therebetween. When the shaft 10 rotates, the third dynamic pressure groove 63 generates dynamic pressure in the fluid F between the two. This dynamic pressure separates the bearing 32 and the first protruding portion 14. As a result, the rotating first protruding portion 14 is rotatably supported in a non-contact state with the bearing 32.

[0054] Moreover, in this embodiment, the bearing 32 has a protruding wall portion 321. The protruding wall portion 321 protrudes in one axial direction Da at a radially outer end portion of one axial end portion of the bearing 32. The protruding wall portion 321 is cylindrical and surrounds the center axis CA and the stop portion 5 (a flange portion 52 described later). The protruding wall portion 321 faces the flange portion 52 in the radial direction, and faces an inner flange portion 313 of the bearing holder 31 in the axial direction.

[0055] The base portion 33 is disposed on one axial direction Da from the stator 2 and spreads outward in the radial direction from one axial end of the bearing holder 31. The base portion 33 has a plate portion 331, an inner peripheral wall portion 332, and an outer peripheral wall portion 333. The plate portion 331 spreads outward in the radial direction from one axial end of the bearing holder 31 (holder cylinder portion 311) and extends in the circumferential direction. In this embodiment, the plate portion 331 has an annular shape surrounding one axial end of the bearing holder 31. The inner peripheral wall portion 332 is disposed on one axial end of the bearing holder 31 and spreads in the circumferential direction from the radial inner end of the plate portion 331 in the other axial direction Db. The outer peripheral wall portion 333 extends in the circumferential direction from the radial outer end of the plate portion 331 in the other axial direction Db. The radial inner end of the rib 104 is connected to the radial outer surface of the outer peripheral wall portion 333. In this embodiment, the inner peripheral wall portion 332 and the outer peripheral wall portion 333 are cylindrical and extend in the axial direction.

[0056] <1-2-4. Circuit board 4> The circuit board 4 is disposed on the other axial end surface of the plate portion 331 of the base portion 33. The circuit board 4 is electrically connected to a lead wire (reference numeral omitted) drawn from the coil portion 23. The circuit board 4 is mounted with a drive circuit for the stator 2 and the like, and is electrically connected to external wiring (not shown). The external wiring is drawn out to the outside of the motor 101, and electrically connects the circuit board 4 to an external device, power source, and the like.

[0057] <1-2-5. Stopper 5> The stopper portion 5 is attached to one axial end of the first protruding portion 14. As described above, the motor 101 includes the stopper portion 5. As described above, the stopper portion 5 is attached to one axial end of the first protruding portion 14, and is rotatable together with the rotor 1 (particularly the first protruding portion 14) about the central axis CA.

[0058] The stopper 5 has a column portion 51. The column portion 51 is a columnar body extending in the axial direction, and fits into the hole portion 141 of the first protruding portion 14. That is, the column portion 51 is accommodated in the hole portion 141. In the hole portion 141, a fourth space (reference numeral omitted) is arranged on the other axial direction Db from the column portion 51. That is, the other axial end portion of the column portion 51 faces the inner surface (i.e., the other axial end face) facing the one axial direction Da of the hole portion 141 with a gap (i.e., the fourth space) therebetween. In this way, the column portion 51 can be inserted into the hole portion 141 more reliably and stably. Therefore, the stopper 5 can be attached to the one axial end portion of the first protruding portion 14 with higher accuracy.

[0059] The stopper portion 5 further has a flange portion 52. The flange portion 52 is disposed on one axial side Da from the first protruding portion 14 and extends in the radial direction. For example, the flange portion 52 is disk-shaped and extends radially outward from one axial end of the column portion 51.

[0060] The fastening portion 5 can be attached to the first protrusion 14 by bonding with an adhesive, welding, brazing with silver solder or the like, screwing, press-fitting the column portion 51, or the like.

[0061] <1-2-6. Dynamic pressure groove 6> The dynamic pressure grooves 6 are a wedge-shaped pattern arranged in the circumferential direction and are composed of a plurality of grooves. The dynamic pressure grooves 6 are disposed on at least one of the pair of opposing surfaces and generate dynamic pressure in the fluid F interposed between the opposing surfaces.

[0062] The first dynamic pressure groove 61 as the dynamic pressure groove 6 is disposed on either one axial end face (at least a part of it) of the bearing 32 or the other axial end face (at least a part of it) of the flange portion 52. In this embodiment, the first dynamic pressure groove 61 is disposed on one axial end face of the bearing 32. As a result, the first dynamic pressure groove 61 can generate dynamic pressure in the thrust direction (i.e., axial direction) between one axial end face of the bearing 32 and the other axial end face of the flange portion 52, which face each other in the axial direction via the fluid F. This dynamic pressure allows the bearing 32 to function as a fluid dynamic pressure bearing with respect to the flange portion 52 of the stopper portion 5. Here, the first dynamic pressure groove 61 is connected to one axial end of the third dynamic pressure groove 63 on one axial direction Da side in this embodiment, but is not limited to this example and may not be connected.

[0063] The second dynamic pressure groove 62 as the dynamic pressure groove 6 is disposed on either the other axial end face of the bearing 32 (at least a part of it) or the other axial end face of the rotor lid 11. In this embodiment, the second dynamic pressure groove 62 is disposed on the other axial end face of the bearing 32. As a result, the second dynamic pressure groove 62 can generate dynamic pressure in the thrust direction between the other axial end face of the bearing 32 and the one axial end face of the rotor lid 11, which face each other in the axial direction via the fluid F. This dynamic pressure allows the bearing 32 to function as a fluid dynamic pressure bearing with respect to the rotor lid 11. Here, the second dynamic pressure groove 62 is connected to the other axial end of the third dynamic pressure groove 63 on the other axial direction Db side in this embodiment, but is not limited to this example and may not be connected.

[0064] For example, the first dynamic pressure groove 61 and the second dynamic pressure groove 62 of the dynamic pressure groove 6 include a first groove and a second groove. The first groove extends radially inward as it moves toward one circumferential direction. The second groove extends radially outward as it moves toward one circumferential direction. For example, the second groove extends from one circumferential end of the first groove. As a result, the first groove and the second groove form a wedge shape. The first dynamic pressure groove 61 and the second dynamic pressure groove 62 are formed of a plurality of wedge-shaped grooves arranged in the circumferential direction. Note that the shape (in other words, the pattern) formed by the first groove and the second groove is not limited to this example, and various shapes can be formed as long as the first groove and the second groove are included. For example, the shape of at least one of the first dynamic pressure groove 61 and the second dynamic pressure groove 62 may be a herringbone shape or a zigzag shape.

[0065] In this embodiment, the motor 101 includes both the first dynamic pressure groove 61 and the second dynamic pressure groove 62. However, this is not limiting, and either of the two may be omitted. In other words, the motor 101 needs to include at least one of the dynamic pressure grooves 6, the first dynamic pressure groove 61 and the second dynamic pressure groove 62. In this way, at least one of the first dynamic pressure groove 61 and the second dynamic pressure groove 62 can suppress wobble in the axial direction of the rotor 1 (particularly the first protruding portion 14).

[0066] As the dynamic pressure groove 6, the third dynamic pressure groove 63 is disposed on either (at least a part of) the radial inner surface of the bearing 32 or (at least a part of) the radial outer surface of the first protruding portion 14. In this embodiment, the third dynamic pressure groove 63 is disposed on a part of the radial inner surface of the bearing 32. As a result, the third dynamic pressure groove 63 can generate dynamic pressure in the radial direction (i.e., in the radial direction) between the radial inner surface of the bearing 32 and the radial outer surface of the first protruding portion 14, which face each other in the radial direction via the fluid F. This dynamic pressure allows the bearing 32 to function as a fluid dynamic pressure bearing with respect to the first protruding portion 14. Therefore, the third dynamic pressure groove 63 can suppress the vibration of the rotor 1 (particularly the first protruding portion 14) in the radial direction.

[0067] For example, the third dynamic pressure groove 63 of the dynamic pressure grooves 6 includes a third groove and a fourth groove. The first groove extends in one axial direction Da as it moves in one circumferential direction. The fourth groove extends in the other axial direction Db as it moves in one circumferential direction. For example, the fourth groove extends from one circumferential end of the third groove. As a result, the third groove and the fourth groove form a wedge shape. The third dynamic pressure groove 63 is formed of a plurality of wedge-shaped grooves arranged in the circumferential direction. Note that the shape (in other words, the pattern) formed by the third groove and the fourth groove is not limited to this example, and various shapes can be formed as long as it includes the third groove and the fourth groove. For example, the shape of the third dynamic pressure groove 63 may be a herringbone shape or a zigzag shape.

[0068] In addition, in a configuration in which the wall portion 15 of the rotor 1 rotatably holds the other axial end portion of the bearing 32, the motor 101 may include a fourth dynamic pressure groove (not shown) as the dynamic pressure groove 6. The fourth dynamic pressure groove is disposed on either the inner circumferential surface (i.e., the radially inner surface) of the wall portion 15 or the radially outer surface at the other axial end portion of the bearing 32. The fourth dynamic pressure groove may or may not be connected to the radially outer end portion of the second dynamic pressure groove 62. The fourth dynamic pressure groove may be formed of a plurality of wedge-shaped grooves arranged in the circumferential direction, similar to the third dynamic pressure groove 63. Alternatively, the shape of the fourth dynamic pressure groove may be a herringbone shape or a zigzag shape.

[0069] In this way, the fourth dynamic pressure groove can generate dynamic pressure in the radial direction (i.e., in the radial direction) between the radially outer surface of the bearing 32 and the inner circumferential surface of the wall portion 15, which face each other in the radial direction via the fluid F. This dynamic pressure allows the bearing 32 to function as a fluid dynamic pressure bearing with respect to the wall portion 15. However, this example does not exclude a configuration in which the motor 101 does not include the fourth dynamic pressure groove, even if the wall portion 15 is configured to rotatably hold the other axial end portion of the bearing 32.

[0070] <2.Other> The embodiments of the present invention have been described above. Note that the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented by adding various modifications to the above-described embodiments without departing from the spirit of the invention. Furthermore, the matters described in the above-described embodiments can be appropriately combined in any manner as long as no contradiction occurs.

[0071] For example, in this embodiment, the bearing 32 functions as a fluid dynamic bearing. However, this example does not exclude a configuration in which the bearing 32 does not function as a fluid dynamic bearing. For example, the example of this embodiment does not exclude a configuration in which the bearing 32 is a sliding bearing and the dynamic pressure grooves 6 (and the fluid F) are omitted.

[0072] <3. Summary> The embodiments described thus far will be summarized below.

[0073] For example, the motors disclosed herein may include: A motor in which a rotor is supported by a bearing so as to be rotatable about a central axis extending in an axial direction, The rotor is A rotor lid portion extending in a radial direction; a first protruding portion that protrudes from the rotor lid portion in one axial direction, extends along the central axis, and is rotatably supported by the bearing; having The bearing has a cylindrical shape extending in the axial direction and surrounds the first protrusion, A hole portion extending in the other axial direction is disposed at one end of the first protrusion, The axial length of the hole is less than half the axial length of the first protrusion (first configuration).

[0074] The motor of the first configuration is as follows: a stopper portion attached to one axial end portion of the first protrusion; At least one of a first dynamic pressure groove and a second dynamic pressure groove; Further equipped with The stopper portion has a flange portion that is disposed on one side of the first protruding portion in the axial direction and extends in a radial direction, The dynamic pressure groove is A first groove extending radially inward toward one side in the circumferential direction; A second groove extending radially outward toward one side in the circumferential direction; Including, an axial end surface of the bearing faces an axial end surface of the flange portion via a fluid; the first dynamic pressure groove is disposed in one of an axial end surface of the bearing and an axial end surface of the flange portion, the other axial end surface of the bearing faces the one axial end surface of the rotor lid portion via the fluid, The second dynamic pressure groove may be arranged on either the other axial end surface of the bearing or one axial end surface of the rotor lid (second configuration).

[0075] In addition, the motor of the first or second configuration has The rotor may further include a cylindrical wall portion that protrudes from the rotor lid portion in one axial direction and surrounds the other axial end of the bearing (third configuration).

[0076] The motor of the third configuration is as follows: The bearing holder further includes a cylindrical bearing holder that extends in the axial direction and surrounds and holds the bearing. The bearing holder may further surround at least one axial side of the wall portion (fourth configuration).

[0077] In addition, the motor having any one of the first to fourth configurations is The rotor further has a second protruding portion protruding from the rotor lid portion in the other axial direction and extending along the central axis, The second protruding portion may have an outer diameter larger than an outer diameter of the first protruding portion when viewed in the axial direction (fifth configuration).

[0078] The motor of the fifth configuration is as follows: The second protruding portion may have an outer diameter larger than an outer diameter of the bearing when viewed in the axial direction (sixth configuration).

[0079] In addition, the fan motor disclosed in this specification is The motor has a configuration (seventh configuration) including a motor having any one of the first to sixth configurations.

[0080] In addition, the fan motor of the seventh configuration is as follows: an impeller rotatable about the central axis together with the rotor of the motor; the rotor further includes a rotor cylinder portion extending in one axial direction from a radially outer end portion of the rotor lid portion, The impeller may be fixed to the rotor lid portion and the rotor cylinder portion (eighth configuration).

[0081] Alternatively, the fan motor disclosed herein may include A motor according to the fifth or sixth configuration; an impeller rotatable about the central axis together with the rotor of the motor and fixed to at least the rotor lid portion of the rotor; Equipped with the impeller has an impeller lid portion that is annular and surrounds the second protrusion and is disposed on the other axial end surface of the rotor lid portion, The other axial end of the second protruding portion of the motor is configured to be disposed on the other axial side of the radially inner end of the impeller lid portion (ninth configuration).

[0082] Moreover, the fan motor of the eighth or ninth configuration is In the axial direction, an upper surface of the rotor lid portion may be configured to face the impeller with a ring-shaped gap surrounding the central axis (tenth configuration).

[0083] In addition, the fan motor having any one of the eighth to tenth configurations is The material of the impeller may be polycarbonate resin (eleventh configuration). [Industrial Applicability]

[0084] The present invention is useful for a motor whose shaft is rotatably supported by a cylindrical bearing, and for an apparatus including such a motor. [Explanation of symbols]

[0085] 100 fan motor, 101 motor, 102 impeller, 1021 impeller cover portion, 1022 impeller cap, 1023 impeller cylinder portion, 1024 rotor blade, 103 cylindrical housing, 104 rib, 1 rotor, 11 rotor cover portion, 12 rotor cylinder portion, 13 magnet, 14 first protrusion portion, 141 hole portion, 15 wall portion, 16 second protrusion portion, 2 stator, 21 stator core, 22 insulator, 23 coil portion, 3 housing, 31 bearing holder Da, 311...holder cylindrical portion, 312...holder peripheral wall portion, 313...inner flange portion, 32...bearing, 321...projecting wall portion, 33...base portion, 331...plate portion, 332...inner peripheral wall portion, 333...outer peripheral wall portion, 4...circuit board, 5...stopping portion, 51...column portion, 52...flange portion, 6...dynamic pressure groove, 61...first dynamic pressure groove, 62...second dynamic pressure groove, 63...third dynamic pressure groove, F...fluid, CA...central axis, Da...one axial direction, Db...other axial direction, L1, L2...axial length, W1, W2...axial width, φ1, φ2, φ3...outer diameter

Claims

1. A motor in which a rotor is supported by a bearing so as to be rotatable about a central axis extending in an axial direction, The rotor is A rotor lid portion extending in a radial direction; a first protruding portion that protrudes from the rotor lid portion in one axial direction, extends along the central axis, and is rotatably supported by the bearing; having The bearing has a cylindrical shape extending in an axial direction and surrounds the first protrusion, a hole portion extending in the other axial direction is disposed at one end of the first protrusion, A motor, wherein the axial length of the hole is less than half the axial length of the first protrusion.

2. a stopper portion attached to one axial end portion of the first protrusion; At least one of a first dynamic pressure groove and a second dynamic pressure groove; Further equipped with The stop portion has a flange portion that is disposed on one side of the first protruding portion in the axial direction and extends in a radial direction, The dynamic pressure groove is A first groove extending radially inward toward one side in the circumferential direction; A second groove extending radially outward toward one side in the circumferential direction; Including, an axial end surface of the bearing faces an axial end surface of the flange portion via a fluid; the first dynamic pressure groove is disposed on one of an axial end surface of the bearing and an axial end surface of the flange portion, the other axial end surface of the bearing faces the one axial end surface of the rotor lid portion via the fluid, 2 . The motor according to claim 1 , wherein the second dynamic pressure grooves are arranged on either the other axial end surface of the bearing or one axial end surface of the rotor lid.

3. 2. The motor according to claim 1, wherein the rotor further includes a cylindrical wall portion that protrudes from the rotor lid portion in one axial direction and surrounds the other axial end of the bearing.

4. The bearing holder further includes a cylindrical bearing holder that extends in the axial direction and surrounds and holds the bearing. The motor according to claim 3 , wherein the bearing holder further surrounds at least one axial side of the wall portion.

5. The rotor further includes a second protruding portion protruding from the rotor lid portion in the other axial direction and extending along the central axis, The motor according to claim 1 , wherein an outer diameter of the second protrusion is larger than an outer diameter of the first protrusion when viewed in the axial direction.

6. The motor according to claim 5 , wherein an outer diameter of the second protrusion is larger than an outer diameter of the bearing when viewed in the axial direction.

7. A fan motor comprising the motor according to claim 1.

8. an impeller rotatable about the central axis together with the rotor of the motor; the rotor further includes a rotor cylinder portion extending in one axial direction from a radially outer end portion of the rotor lid portion, The fan motor according to claim 7 , wherein the impeller is fixed to the rotor lid portion and the rotor cylinder portion.

9. A motor according to claim 5; an impeller rotatable about the central axis together with the rotor of the motor and fixed to at least the rotor lid portion of the rotor; Equipped with the impeller has an impeller lid portion that is annular and surrounds the second protruding portion and is disposed on the other axial end surface of the rotor lid portion, A fan motor, wherein the other axial end of the second protrusion of the motor is positioned on the other axial side of the radial inner end of the impeller lid portion.

10. 10. The fan motor according to claim 8, wherein an upper surface of the rotor lid portion faces the impeller in the axial direction with a ring-shaped gap surrounding the central axis.

11. 10. The fan motor according to claim 8, wherein the impeller is made of polycarbonate resin.

Images