JP2021055570A

JP2021055570A - Blower

Info

Publication number: JP2021055570A
Application number: JP2019177235A
Authority: JP
Inventors: 福島　和彦; Kazuhiko Fukushima; 和彦福島; 健人玉岡; Taketo Tamaoka
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-04-08
Anticipated expiration: 2039-09-27
Also published as: JP7423958B2

Abstract

To provide a blower improving a dust-proof function of a motor.SOLUTION: A blower 1 includes a motor that has a stationary element having a stator, and a rotator 3 that rotates about a center axis vertically extending and opposing to the stator in a diametrical direction. The stationary element has a base 211 extending in a diametrical direction, and the rotator has an impeller 31 and rotates while keeping a space from the base axially above the base. The space has a first space S1 and a second space S2, and the rotator and the base are formed oppositely in the axial direction in the first space and the second space. The second space continues to the first space on the outside in the diametrical direction of the first space. The second space positions on the outermost position in the diametrical direction, and the axial length of the first space is narrower than the axial length of the second space.SELECTED DRAWING: Figure 3

Description

本発明は、送風装置に関する。 The present invention relates to a blower.

従来、送風装置は、回転子と固定子とを有するモータを備える。回転子は、インペラを有する。固定子は、ステータとベースとを有する。このような送風装置として、インペラはベースとの間に隙間を空けて回転可能であり、当該隙間によっていわゆるラビリンス構造を形成する送風装置が知られている。これにより、気流により外部からラビリンス構造へ入り込んだ塵が、回転子とベースとの間に挟まれた空間における内部側に入り込むことを抑制する（例えば、特許文献１参照）。 Conventionally, a blower device includes a motor having a rotor and a stator. The rotor has an impeller. The stator has a stator and a base. As such a blower, the impeller can rotate with a gap between it and the base, and a blower that forms a so-called labyrinth structure by the gap is known. As a result, dust that has entered the labyrinth structure from the outside due to the air flow is suppressed from entering the inner side in the space sandwiched between the rotor and the base (see, for example, Patent Document 1).

特開２０１１−４７３８７号公報Japanese Unexamined Patent Publication No. 2011-47387

現状、上記ラビリンス構造を用いた防塵機能のさらなる改善が望まれている。 At present, further improvement of the dustproof function using the above labyrinth structure is desired.

上記状況に鑑み、本発明は、防塵機能を向上させた送風装置を提供することを目的とする。 In view of the above situation, it is an object of the present invention to provide a blower device having an improved dustproof function.

本発明の例示的な送風装置は、ステータを有する固定子と、上下に延びる中心軸を中心として回転し、前記ステータと径方向に対向する回転子と、を有するモータを備える。前記固定子は、径方向に延びるベースを有する。前記回転子は、インペラを有する。前記回転子は、前記ベースよりも軸方向上方で前記ベースと隙間を空けて回転する。前記隙間は、第１の隙間と、第２の隙間と、を有する。前記第１の隙間および前記第２の隙間は、前記回転子と前記ベースとが軸方向に対向して形成される。前記第２の隙間は、前記第１の隙間の径方向外側に前記第１の隙間と連続する。前記第２の隙間は、径方向の最も外側に位置する。前記第１の隙間の軸方向長さは、前記第２の隙間の軸方向長さよりも狭い。 An exemplary blower of the present invention includes a stator having a stator and a motor having a rotor that rotates about a central axis extending vertically and faces the stator in the radial direction. The stator has a base that extends radially. The rotor has an impeller. The rotor rotates axially above the base with a gap from the base. The gap has a first gap and a second gap. The first gap and the second gap are formed so that the rotor and the base face each other in the axial direction. The second gap is continuous with the first gap on the radial outer side of the first gap. The second gap is located on the outermost side in the radial direction. The axial length of the first gap is narrower than the axial length of the second gap.

本発明の例示的な送風装置によれば、防塵機能を向上させることができる。 According to the exemplary blower of the present invention, the dustproof function can be improved.

図１は、本発明の例示的な実施形態に係る送風装置の斜視図である。FIG. 1 is a perspective view of a blower device according to an exemplary embodiment of the present invention. 図２は、本発明の例示的な実施形態に係る送風装置の断面斜視図である。FIG. 2 is a cross-sectional perspective view of a blower device according to an exemplary embodiment of the present invention. 図３は、送風装置に設けられるラビリンス構造の第１実施形態を示す一部を拡大した拡大断面図である。FIG. 3 is an enlarged cross-sectional view of a part showing the first embodiment of the labyrinth structure provided in the blower. 図４は、ラビリンス構造の第２実施形態を示す一部を拡大した拡大断面図である。FIG. 4 is an enlarged cross-sectional view of a part showing the second embodiment of the labyrinth structure. 図５は、ラビリンス構造の第３実施形態を示す一部を拡大した拡大断面図である。FIG. 5 is an enlarged cross-sectional view of a part showing the third embodiment of the labyrinth structure. 図６は、ラビリンス構造の第４実施形態を示す一部を拡大した拡大断面図である。FIG. 6 is an enlarged cross-sectional view of a part showing the fourth embodiment of the labyrinth structure. 図７は、ラビリンス構造の第５実施形態を示す一部を拡大した拡大断面図である。FIG. 7 is an enlarged cross-sectional view of a part showing the fifth embodiment of the labyrinth structure. 図８は、ラビリンス構造の第６実施形態を示す一部を拡大した拡大断面図である。FIG. 8 is an enlarged cross-sectional view of a part showing the sixth embodiment of the labyrinth structure.

以下に本発明の例示的な実施形態について図面を参照して説明する。なお、本明細書では、後述する中心軸Ｃ１の延びる方向を「上下方向」とする。但し、この「上下方向」は、実際の機器に組み込まれたときの上下方向を示すものではない。また、中心軸Ｃ１を中心とする径方向を単に「径方向」と呼び、中心軸Ｃ１を中心とする周方向を単に「周方向」と呼ぶ。 An exemplary embodiment of the present invention will be described below with reference to the drawings. In this specification, the extending direction of the central axis C1 described later is referred to as the "vertical direction". However, this "vertical direction" does not indicate the vertical direction when it is incorporated in an actual device. Further, the radial direction centered on the central axis C1 is simply referred to as "diametrical direction", and the circumferential direction centered on the central axis C1 is simply referred to as "circumferential direction".

＜１．送風装置の全体構成＞
図１は、本発明の例示的な実施形態に係る送風装置１の斜視図である。また、図２は、本発明の例示的な実施形態に係る送風装置１の断面斜視図である。なお、図２は、図１において、中心軸Ｃ１を含む切断面により上下方向に切断した状態を示す。 <1. Overall configuration of the blower>
FIG. 1 is a perspective view of a blower 1 according to an exemplary embodiment of the present invention. Further, FIG. 2 is a cross-sectional perspective view of the blower 1 according to the exemplary embodiment of the present invention. Note that FIG. 2 shows a state in which the cutting surface including the central axis C1 cuts in the vertical direction in FIG.

送風装置１は、遠心ファンである。送風装置１は、例えば、ＰＣ（パーソナルコンピュータ）に搭載され、ＰＣの筐体内部の機器の冷却に利用される。 The blower 1 is a centrifugal fan. The blower 1 is mounted on a PC (personal computer), for example, and is used for cooling the equipment inside the housing of the PC.

送風装置１は、モータＭを有する。モータＭは、固定子２と、回転子３と、を有する。固定子２は、下ハウジング部２１と、ステータ２２と、軸部材２３と、キャップ２４と、を有する。回転子３は、インペラ３１と、ハブ３２と、マグネット３３と、を有する。回転子３は、中心軸Ｃ１を中心として回転可能である。 The blower 1 has a motor M. The motor M has a stator 2 and a rotor 3. The stator 2 has a lower housing portion 21, a stator 22, a shaft member 23, and a cap 24. The rotor 3 has an impeller 31, a hub 32, and a magnet 33. The rotor 3 is rotatable about the central axis C1.

下ハウジング部２１は、ベース２１１と、軸受保持部２１２と、第１周壁部２１３と、第２周壁部２１４と、を有する。ベース２１１と、軸受保持部２１２と、第１周壁部２１３と、第２周壁部２１４と、は、樹脂等により単一の部材で形成される。 The lower housing portion 21 has a base 211, a bearing holding portion 212, a first peripheral wall portion 213, and a second peripheral wall portion 214. The base 211, the bearing holding portion 212, the first peripheral wall portion 213, and the second peripheral wall portion 214 are formed of a single member by resin or the like.

ベース２１１は、径方向に拡がる板状部材である。すなわち、固定子２は、径方向に延びるベース２１１を有する。ベース２１１は、インペラ３の下方を覆う。第１周壁部２１３および第２周壁部２１４は、ベース２１１の周縁から上方に延び、周方向に間隔を空けて配置される。 The base 211 is a plate-shaped member that expands in the radial direction. That is, the stator 2 has a base 211 extending in the radial direction. The base 211 covers the lower part of the impeller 3. The first peripheral wall portion 213 and the second peripheral wall portion 214 extend upward from the peripheral edge of the base 211 and are arranged at intervals in the circumferential direction.

送風装置１は、不図示の上ハウジング部を有する。上ハウジング部は、下ハウジング部２１の上方に配置される。上ハウジング部は、インペラ３１の上方を覆う。上ハウジング部と下ハウジング部２１とで囲まれる空間にインペラ３１は収容される。 The blower 1 has an upper housing portion (not shown). The upper housing portion is arranged above the lower housing portion 21. The upper housing portion covers the upper part of the impeller 31. The impeller 31 is housed in a space surrounded by the upper housing portion and the lower housing portion 21.

軸受保持部２１２は、ベース２１１の径方向中央位置に配置される。軸受保持部２１２は、第１筒状部２１２Ａと、第２筒状部２１２Ｂと、第３筒状部２１２Ｃと、を有する。第１筒状部２１２Ａ、第２筒状部２１２Ｂ、および第３筒状部２１２Ｃは、いずれも中心軸Ｃ１を中心とした筒状に形成される。 The bearing holding portion 212 is arranged at the radial center position of the base 211. The bearing holding portion 212 has a first tubular portion 212A, a second tubular portion 212B, and a third tubular portion 212C. The first tubular portion 212A, the second tubular portion 212B, and the third tubular portion 212C are all formed in a tubular shape centered on the central axis C1.

第２筒状部２１２Ｂは、第１筒状部２１２Ａの上方に配置される。第２筒状部２１２Ｂの内径は、第１筒状部２１２Ａの内径よりも長い。第１段差面ＤＳ１は、第１筒状部２１２Ａの軸方向に延びる内周面の上端から径方向外側に拡がって円環状に形成される。 The second tubular portion 212B is arranged above the first tubular portion 212A. The inner diameter of the second tubular portion 212B is longer than the inner diameter of the first tubular portion 212A. The first stepped surface DS1 extends radially outward from the upper end of the inner peripheral surface extending in the axial direction of the first tubular portion 212A and is formed in an annular shape.

第２筒状部２１２Ｂの外径は、第１筒状部２１２Ａの外径よりも短い。第２段差面ＤＳ２は、第１筒状部２１２Ａの軸方向に延びる外周面の上端から径方向内側に拡がって円環状に形成される。第２段差面ＤＳ２は、第１段差面ＤＳ１より径方向外側に配置される。 The outer diameter of the second tubular portion 212B is shorter than the outer diameter of the first tubular portion 212A. The second stepped surface DS2 extends radially inward from the upper end of the outer peripheral surface extending in the axial direction of the first tubular portion 212A and is formed in an annular shape. The second step surface DS2 is arranged radially outside the first step surface DS1.

第３筒状部２１２Ｃは、第２筒状部２１２Ｂの上方に配置される。第３筒状部２１２Ｃの内径は、第２筒状部２１２Ｂの内径よりも長い。第３段差面ＤＳ３は、第２筒状部２１２Ｂの軸方向に延びる内周面の上端から径方向外側に拡がって円環状に形成される。第３筒状部２１２Ｃの外径は、第２筒状部２１２Ｂの外径と等しい。 The third tubular portion 212C is arranged above the second tubular portion 212B. The inner diameter of the third tubular portion 212C is longer than the inner diameter of the second tubular portion 212B. The third stepped surface DS3 extends radially outward from the upper end of the inner peripheral surface extending in the axial direction of the second tubular portion 212B and is formed in an annular shape. The outer diameter of the third tubular portion 212C is equal to the outer diameter of the second tubular portion 212B.

軸受としてのスリーブ４は、中心軸Ｃ１を中心とする円筒状である。スリーブ４は、第２筒状部２１２Ｂ内に挿入される。スリーブ４の外周面は、第２筒状部２１２Ｂの内周面と接触する。スリーブ４の下面が第１段差面Ｄ１に接触することにより、スリーブ４は軸受保持部２１２に保持される。 The sleeve 4 as a bearing has a cylindrical shape centered on the central axis C1. The sleeve 4 is inserted into the second tubular portion 212B. The outer peripheral surface of the sleeve 4 comes into contact with the inner peripheral surface of the second tubular portion 212B. When the lower surface of the sleeve 4 comes into contact with the first stepped surface D1, the sleeve 4 is held by the bearing holding portion 212.

軸部材２３は、円板部２３Ａと、軸部２３Ｂと、を有する。軸部２３Ｂは、円板部２３Ａの径方向中央位置から上方へ突出する。円板部２３Ａは、スリーブ４の下面に設けられ、軸方向上方に凹む凹部４Ａに収容される。軸部２３Ｂは、スリーブ４の内周面の径方向内側に配置される。 The shaft member 23 has a disk portion 23A and a shaft portion 23B. The shaft portion 23B projects upward from the radial center position of the disc portion 23A. The disk portion 23A is provided on the lower surface of the sleeve 4 and is housed in a recess 4A recessed upward in the axial direction. The shaft portion 23B is arranged inside the inner peripheral surface of the sleeve 4 in the radial direction.

円板状のキャップ２４は、スリーブ４の凹部４Ａに固定され、円板部２３Ａの下方を覆う。 The disc-shaped cap 24 is fixed to the recess 4A of the sleeve 4 and covers the lower part of the disc portion 23A.

ハブ３２は、蓋部３２Ａと、外側壁部３２Ｂと、内側壁部３２Ｃと、軸受部３２Ｄと、を有する。蓋部３２Ａは、円板状である。外側壁部３２Ｂは、蓋部３２Ａの周縁から下方へ突出して円筒状に形成される。内側壁部３２Ｃは、蓋部３２Ａの周縁より径方向内側から下方へ突出して円筒状に形成される。軸受部３２Ｄは、蓋部３２Ａの径方向中央位置から下方へ突出して円柱状に形成される。 The hub 32 has a lid portion 32A, an outer wall portion 32B, an inner side wall portion 32C, and a bearing portion 32D. The lid portion 32A has a disk shape. The outer side wall portion 32B projects downward from the peripheral edge of the lid portion 32A and is formed in a cylindrical shape. The inner side wall portion 32C is formed in a cylindrical shape so as to project downward from the inside in the radial direction from the peripheral edge of the lid portion 32A. The bearing portion 32D projects downward from the radial center position of the lid portion 32A and is formed in a columnar shape.

軸受部３２Ｄは、下端から上方へ向けて柱状に凹む柱状凹部３２Ｄ１を有する。軸部材２３の軸部２３Ｂは、柱状凹部３２Ｄ１に挿入される。内側壁部３２Ｃは、第３筒状部２１２Ｃとスリーブ４とで挟まれる円筒状の空間に挿入される。 The bearing portion 32D has a columnar recess 32D1 that is recessed in a columnar shape from the lower end to the upper side. The shaft portion 23B of the shaft member 23 is inserted into the columnar recess 32D1. The inner side wall portion 32C is inserted into a cylindrical space sandwiched between the third tubular portion 212C and the sleeve 4.

ステータ２２は、中心軸Ｃ１を中心とする環状を有し、軸受保持部２１２の外周面に固定される。ステータ２２は、ステータコア２２１と、不図示のインシュレータと、コイル２２２と、を有する。ステータコア２２１は、薄板状の電磁鋼板が軸方向に積層されて構成される。インシュレータは、ステータコア２２１の表面を被覆する絶縁体である。コイル２２２は、インシュレータに対して導線が巻き付けられて形成される。 The stator 22 has an annular shape centered on the central axis C1 and is fixed to the outer peripheral surface of the bearing holding portion 212. The stator 22 includes a stator core 221, an insulator (not shown), and a coil 222. The stator core 221 is formed by laminating thin sheet-shaped electromagnetic steel plates in the axial direction. The insulator is an insulator that covers the surface of the stator core 221. The coil 222 is formed by winding a lead wire around an insulator.

マグネット３３は、円筒状であり、ハブ３２の外側壁部３２Ｂの内周面に固定される。マグネット３３は、ステータ２２の径方向外側に配置され、ステータ２２と径方向に対向する。 The magnet 33 has a cylindrical shape and is fixed to the inner peripheral surface of the outer wall portion 32B of the hub 32. The magnet 33 is arranged on the outer side in the radial direction of the stator 22, and faces the stator 22 in the radial direction.

すなわち、送風装置１は、ステータ２２を有する固定子２と、上下に延びる中心軸Ｃ１を中心として回転し、ステータ２２と径方向に対向する回転子３と、を有するモータＭを備える。 That is, the blower 1 includes a stator 2 having a stator 22 and a motor M having a rotor 3 that rotates about a central axis C1 extending vertically and faces the stator 22 in the radial direction.

インペラ３１は、インペラカップ３１１と、複数の羽根３１２と、を有する。インペラカップ３１１は、軸方向に貫通する貫通穴３１１Ａを有する。外側壁部３２Ｂは、貫通穴３１１Ａに嵌る。インペラカップ３１１は、外側壁部３２Ｂに対して圧入または接着などにより固定される。すなわち、回転子３は、インペラ３１が径方向外側に固定されるハブ３２を有する。インペラカップ３１１の外周面は、下方へ向かうにしたがって径が大きくなる。 The impeller 31 has an impeller cup 311 and a plurality of blades 312. The impeller cup 311 has a through hole 311A penetrating in the axial direction. The outer side wall portion 32B fits into the through hole 311A. The impeller cup 311 is fixed to the outer wall portion 32B by press fitting or adhesion. That is, the rotor 3 has a hub 32 to which the impeller 31 is fixed radially outward. The outer peripheral surface of the impeller cup 311 has a larger diameter toward the lower side.

インペラ３１は、モータＭの駆動により、軸方向上方から視て中心軸Ｃ１を中心として時計回りに回転する。複数の羽根３１２は、インペラカップ３１１の外周端部に固定され、周方向に並んで配置される。羽根３１２の外周端は、羽根３１２の内周端よりも回転方向後方に配置される。これにより、羽根３１２は、径方向に対して傾斜している。 The impeller 31 is driven by the motor M and rotates clockwise around the central axis C1 when viewed from above in the axial direction. The plurality of blades 312 are fixed to the outer peripheral end portion of the impeller cup 311 and are arranged side by side in the circumferential direction. The outer peripheral end of the blade 312 is arranged behind the inner peripheral end of the blade 312 in the rotational direction. As a result, the blade 312 is inclined with respect to the radial direction.

モータＭの駆動によりインペラ３１が回転すると、不図示の上記上ハウジング部に設けられる吸気口から隣り合う羽根３１２の間の内周側端部に空気が取り込まれる。取り込まれた空気は、隣り合う羽根３１２の間を通って径方向外側に向かって加速され、インペラ３１の径方向外側に吹き出される。 When the impeller 31 is rotated by the drive of the motor M, air is taken into the inner peripheral side end portion between the adjacent blades 312 from the intake port provided in the upper housing portion (not shown). The taken-in air is accelerated outward in the radial direction through the space between the adjacent blades 312 and blown out in the radial direction of the impeller 31.

ここで、ベース２１１は、径方向に対して垂直な方向に直線状に延びる直線部２１１１Ａを含む縁部２１１１を有する。縁部２１１１の一方側端部は、第１周壁部２１３の端部と接続される。縁部２１１１の他方側端部は、第２周壁部２１４の端部と接続される。上ハウジング部と下ハウジング部２１とで、空気の通路が形成される。上ハウジング部と下ハウジング部２１により、直線部２１１１Ａの位置に吹出し口が形成される。インペラ３１から上記のように吹き出された空気は、上ハウジング部と下ハウジング部２１とにより囲まれた空気通路を通り、上記吹出し口から外部へ排出される。 Here, the base 211 has an edge portion 2111 including a straight portion 2111A extending linearly in a direction perpendicular to the radial direction. One end of the edge 2111 is connected to the end of the first peripheral wall 213. The other end of the edge 2111 is connected to the end of the second peripheral wall 214. An air passage is formed between the upper housing portion and the lower housing portion 21. The upper housing portion and the lower housing portion 21 form an outlet at the position of the straight portion 2111A. The air blown out from the impeller 31 as described above passes through an air passage surrounded by the upper housing portion and the lower housing portion 21, and is discharged to the outside from the blowout port.

＜２．ラビリンス構造の第１実施形態＞
回転子３は、ベース２１１よりも軸方向上方でベース２１１と隙間ＳＰ(図２)を空けて回転する。インペラ３１の回転により発生する気流によって塵が隙間ＳＰにおける径方向内側へ入り込むことを抑制するために、送風装置１にはラビリンス構造が設けられている。特に、送風装置１が屋外で使用可能なＰＣに備えられる場合、砂または砂利の多い環境で送風装置１が使用されることが想定され、送風装置１における防塵機能が重要となる。 <2. First Embodiment of Labyrinth Structure>
The rotor 3 rotates above the base 211 in the axial direction with a gap SP (FIG. 2) between the base 211 and the rotor 3. The blower 1 is provided with a labyrinth structure in order to prevent dust from entering the inside of the gap SP in the radial direction due to the air flow generated by the rotation of the impeller 31. In particular, when the blower 1 is provided in a PC that can be used outdoors, it is assumed that the blower 1 is used in an environment with a lot of sand or gravel, and the dustproof function of the blower 1 is important.

図３は、送風装置１に設けられるラビリンス構造を示す一部拡大断面図である。図３は、図２に示す領域Ａ付近を拡大した図である。 FIG. 3 is a partially enlarged cross-sectional view showing a labyrinth structure provided in the blower 1. FIG. 3 is an enlarged view of the vicinity of the region A shown in FIG.

図３に示すラビリンス構造は、第１隙間Ｓ１と、第２隙間Ｓ２と、第３隙間Ｓ３と、を有する。隙間ＳＰは、第１隙間Ｓ１と、第２隙間Ｓ２と、第３隙間Ｓ３と、を有する。第２隙間Ｓ２は、インペラ３１のインペラ下面３１Ａと、ベース２１１のベース上面２１１Ａとが軸方向に対向して形成される。インペラ３１は、インペラ下面３１Ａから軸方向下方へ立ち下がるインペラ壁部３１Ｂを有する。ベース２１１は、ベース上面２１１Ａから軸方向上方へ立ち上がるベース壁部２１１Ｂを有する。第１隙間Ｓ１は、インペラ壁部３１Ｂの下面とベース壁部２１１Ｂの上面とが軸方向に対向して形成される。 The labyrinth structure shown in FIG. 3 has a first gap S1, a second gap S2, and a third gap S3. The gap SP has a first gap S1, a second gap S2, and a third gap S3. The second gap S2 is formed so that the lower surface 31A of the impeller of the impeller 31 and the upper surface 211A of the base of the base 211 face each other in the axial direction. The impeller 31 has an impeller wall portion 31B that descends axially downward from the lower surface 31A of the impeller. The base 211 has a base wall portion 211B that rises upward in the axial direction from the base upper surface 211A. The first gap S1 is formed so that the lower surface of the impeller wall portion 31B and the upper surface of the base wall portion 211B face each other in the axial direction.

すなわち、第１の隙間Ｓ１および第２の隙間Ｓ２は、回転子３とベース２１１とが軸方向に対向して形成される。また、第２の隙間Ｓ２は、第１の隙間Ｓ１の径方向外側に第１の隙間Ｓ１と連続する。第２の隙間Ｓ２は、径方向の最も外側に位置する。第１の隙間Ｓ１の軸方向長さは、第２の隙間Ｓ２の軸方向長さよりも狭い。 That is, the first gap S1 and the second gap S2 are formed so that the rotor 3 and the base 211 face each other in the axial direction. Further, the second gap S2 is continuous with the first gap S1 on the radial outer side of the first gap S1. The second gap S2 is located on the outermost side in the radial direction. The axial length of the first gap S1 is narrower than the axial length of the second gap S2.

第３の隙間Ｓ３は、第１の隙間Ｓ１よりも径方向内側に配置されて第１の隙間Ｓ１と連通する。なお、連通とは、間接的に接続されることも含む。ここで、ハブ３２は、外側壁部３２Ｂの外周面から径方向外側に突出する突出部３２Ｔを有する。第３の隙間Ｓ３は、突出部３２Ｔとベース２１１により挟まれて形成される。第３の隙間Ｓ３の延びる方向は、径方向外側に向かうにつれて軸方向から径方向へ変化する。すなわち、第３の隙間Ｓ３は、湾曲する。 The third gap S3 is arranged radially inside the first gap S1 and communicates with the first gap S1. Note that communication includes indirect connection. Here, the hub 32 has a protruding portion 32T protruding outward in the radial direction from the outer peripheral surface of the outer wall portion 32B. The third gap S3 is formed by being sandwiched between the protrusion 32T and the base 211. The extending direction of the third gap S3 changes from the axial direction to the radial direction as it goes outward in the radial direction. That is, the third gap S3 is curved.

径方向の最も外側に位置する第２の隙間Ｓ２は、外部空間ＯＳとつながる。インペラ３１の回転に位置するより発生した気流が外部空間ＯＳから第２の隙間Ｓ２に入っても、第１の隙間Ｓ１の軸方向長さは第２の隙間Ｓ２の軸方向長さよりも狭いので、気流は第１の隙間Ｓ１には入らずに第２の隙間Ｓ２より再び外部空間ＯＳへ戻りやすい。従って、気流に含まれた塵が隙間ＳＰにおける径方向内側へ入り込むことを抑制できる。 The second outermost gap S2 located in the radial direction is connected to the external space OS. Even if the airflow generated by the rotation of the impeller 31 enters the second gap S2 from the external space OS, the axial length of the first gap S1 is narrower than the axial length of the second gap S2. , The airflow does not enter the first gap S1 and is more likely to return to the external space OS than the second gap S2. Therefore, it is possible to prevent dust contained in the airflow from entering the inside of the gap SP in the radial direction.

また、インペラ下面３１Ａは、回転子３の回転子下面３Ａに相当する。すなわち、第２の隙間Ｓ２は、回転子３の軸方向下方の面である回転子下面３Ａと、ベース２１１の軸方向上方の面であるベース上面２１１Ａと、が対向して形成される。回転子下面３Ａおよびベース上面２１１Ａは、径方向に延びる。これにより、外部空間ＯＳより第２の隙間Ｓ２に入り、回転子下面３Ａとベース上面２１１Ａの一方に沿って流れる空気は、他方に沿って流れて外部空間ＯＳに戻りやすい。従って、気流に含まれた塵が隙間ＳＰにおける径方向内側へ入り込むことを抑制できる。 Further, the lower surface 31A of the impeller corresponds to the lower surface 3A of the rotor of the rotor 3. That is, the second gap S2 is formed so that the lower surface of the rotor 3A, which is the lower surface of the rotor 3 in the axial direction, and the upper surface of the base 211A, which is the upper surface of the base 211 in the axial direction, face each other. The rotor lower surface 3A and the base upper surface 211A extend in the radial direction. As a result, the air that enters the second gap S2 from the external space OS and flows along one of the rotor lower surface 3A and the base upper surface 211A easily flows along the other and returns to the external space OS. Therefore, it is possible to prevent dust contained in the airflow from entering the inside of the gap SP in the radial direction.

また、回転子下面３Ａとベース上面２１１Ａとは、平行である。これにより、第２の隙間Ｓ２の外部空間ＯＳとつながる箇所の隙間を狭くし、第２の隙間Ｓ２に気流が入り込むのを抑制できる。 Further, the lower surface 3A of the rotor and the upper surface 211A of the base are parallel to each other. As a result, the gap of the second gap S2 connected to the external space OS can be narrowed, and airflow can be suppressed from entering the second gap S2.

また、ベース２１１は、ベース２１１の上面から軸方向上方に延びるベース壁部２１１Ｂを有し、第１の隙間Ｓ１は、回転子３とベース壁部２１１Ｂの上面とが対向して形成される。これにより、図３において実線矢印で示す気流ＦＬ１のように、外部空間ＯＳより第２の隙間Ｓ２に入りこんでベース２１１に沿って流れる空気は、ベース壁部２１１Ｂの壁面に沿って流れ、第１の隙間Ｓ１に入らずに回転子３側を流れて外部空間ＯＳへ戻りやすい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, the base 211 has a base wall portion 211B extending upward in the axial direction from the upper surface of the base 211, and the first gap S1 is formed so that the rotor 3 and the upper surface of the base wall portion 211B face each other. As a result, the air that enters the second gap S2 from the external space OS and flows along the base 211 flows along the wall surface of the base wall portion 211B as shown by the solid line arrow FL1 in FIG. It is easy to return to the external space OS by flowing on the rotor 3 side without entering the gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

また、インペラ壁部３１Ｂは、回転子３の回転子壁部３Ｂに相当する。すなわち、回転子３は、回転子３の下面から軸方向下方に延びる回転子壁部３Ｂを有し、第１の隙間Ｓ１は、回転子壁部３Ｂの下面とベース２１１とが対向して形成される。これにより、図３において破線矢印で示す気流ＦＬ２のように、外部空間ＯＳより第２の隙間Ｓ２に入り込んで回転子３に沿って流れる空気は、回転子壁部３Ｂの壁面に沿って流れ、第１の隙間Ｓ１に入らずにベース２１１側を流れて外部空間ＯＳへ戻りやすい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, the impeller wall portion 31B corresponds to the rotor wall portion 3B of the rotor 3. That is, the rotor 3 has a rotor wall portion 3B extending downward in the axial direction from the lower surface of the rotor 3, and the first gap S1 is formed so that the lower surface of the rotor wall portion 3B and the base 211 face each other. Will be done. As a result, as in the airflow FL2 indicated by the broken line arrow in FIG. 3, the air that enters the second gap S2 from the external space OS and flows along the rotor 3 flows along the wall surface of the rotor wall portion 3B. It easily flows to the base 211 side and returns to the external space OS without entering the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

特に、図３に示す実施形態では、ベース２１１は、ベース２１１の上面から軸方向上方に延びるベース壁部２１１Ｂを有し、回転子３は、回転子３の下面から軸方向下方へ延びる回転子壁部３Ｂを有する。第１の隙間Ｓ１は、ベース壁部２１１Ｂの上面と回転子壁部３Ｂの下面とが対向して形成される。これにより、図３において気流ＦＬ１，ＦＬ２で示すように、ベース２１１および回転子３のいずれに沿って流れる空気も第１の隙間Ｓ１に入り込むことを抑制できる。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 In particular, in the embodiment shown in FIG. 3, the base 211 has a base wall portion 211B extending axially upward from the upper surface of the base 211, and the rotor 3 is a rotor extending axially downward from the lower surface of the rotor 3. It has a wall portion 3B. The first gap S1 is formed so that the upper surface of the base wall portion 211B and the lower surface of the rotor wall portion 3B face each other. As a result, as shown by the airflows FL1 and FL2 in FIG. 3, it is possible to prevent the air flowing along any of the base 211 and the rotor 3 from entering the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

また、ベース壁部２１１Ｂは、径方向外側にベース２１１の上面から軸方向上方に延びるベース外壁面２１１Ｂ１を有し、回転子壁部３Ｂは、径方向外側に回転子３の下面から軸方向下方に延びる回転子外壁面３Ｂ１を有する。そして、ベース外壁面２１１Ｂ１の軸方向上端と回転子外壁面３Ｂ１の軸方向下端との径方向位置は同じである。これにより、気流ＦＬ１のように、ベース外壁面２１１Ｂ１に沿って流れる空気は、回転子外壁面３Ｂ１に沿って流れやすくなり、気流ＦＬ２のように、回転子外壁面３Ｂ１に沿って流れる空気は、ベース外壁面２１１Ｂ１に沿って流れやすくなる。すなわち、気流が第１の隙間Ｓ１に入り込むのをより抑制できる。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, the base wall portion 211B has a base outer wall surface 211B1 extending axially upward from the upper surface of the base 211 on the radial outer side, and the rotor wall portion 3B is axially downward from the lower surface of the rotor 3 on the radial outer side. It has a rotor outer wall surface 3B1 extending to. The radial upper end of the base outer wall surface 211B1 and the axial lower end of the rotor outer wall surface 3B1 are the same. As a result, the air flowing along the base outer wall surface 211B1 like the air flow FL1 becomes easy to flow along the rotor outer wall surface 3B1, and the air flowing along the rotor outer wall surface 3B1 like the air flow FL2 becomes easy to flow. It becomes easy to flow along the base outer wall surface 211B1. That is, it is possible to further suppress the air flow from entering the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

なお、図３に示すように、ベース外壁面２１１Ｂ１とベース上面２１１Ａとのなす角度を９０度とする以外にも、９０度より大きくし、ベース外壁面２１１Ｂ１を傾斜させてもよい。同様に、図３に示すように、回転子外壁面３Ｂ１と回転子上面３Ａとのなす角度を９０度とする以外にも、９０度より大きくし、回転子外壁面３Ｂ１を傾斜させてもよい。このようにしても、ベース外壁面２１１Ｂの上端と回転子外壁面３Ｂ１の上端の径方向位置が一致していれば、上記効果を享受できる。さらに、このような傾斜した外壁面は、直線状に限らず、曲線状でもよい。 As shown in FIG. 3, in addition to setting the angle formed by the base outer wall surface 211B1 and the base upper surface 211A to 90 degrees, the base outer wall surface 211B1 may be tilted by making it larger than 90 degrees. Similarly, as shown in FIG. 3, the angle formed by the rotor outer wall surface 3B1 and the rotor upper surface 3A may be larger than 90 degrees and the rotor outer wall surface 3B1 may be tilted. .. Even in this way, the above effect can be enjoyed as long as the upper end of the base outer wall surface 211B and the upper end of the rotor outer wall surface 3B1 are in the same radial position. Further, such an inclined outer wall surface is not limited to a straight line, but may be a curved line.

また、図３に示すように、第１の隙間Ｓ１の軸方向中心位置Ｐ１は、第２の隙間Ｓ２の軸方向中心位置Ｐ２と一致する。これにより、ベース壁部２１１Ｂの壁面と回転子壁部３Ｂの壁面のそれぞれの長さを十分に確保し、それぞれの壁面に沿って流れる空気が第１の隙間Ｓ１に入り込むことをより抑制できる。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, as shown in FIG. 3, the axial center position P1 of the first gap S1 coincides with the axial center position P2 of the second gap S2. As a result, the lengths of the wall surface of the base wall portion 211B and the wall surface of the rotor wall portion 3B can be sufficiently secured, and the air flowing along the respective wall surfaces can be further suppressed from entering the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

また、図３に示すように、ベース外壁面２１１Ｂ１と回転子外壁面３Ｂ１の両方の延びる方向は、軸方向に平行である。なお、ベース外壁面２１１Ｂ１と回転子外壁面３Ｂ１のいずれかの延びる方向が軸方向と非平行でもよい。すなわち、ベース外壁面２１１Ｂ１と回転子外壁面３Ｂ１との少なくとも一方の延びる方向は、軸方向に平行である。これにより、ベース外壁面２１１Ｂまたは回転子外壁面３Ｂ１に沿って流れる空気は、軸方向に平行に流れるので、第１の隙間Ｓ１に入り込みにくい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, as shown in FIG. 3, the extending directions of both the base outer wall surface 211B1 and the rotor outer wall surface 3B1 are parallel to the axial direction. The extending direction of either the base outer wall surface 211B1 or the rotor outer wall surface 3B1 may be non-parallel to the axial direction. That is, at least one extending direction of the base outer wall surface 211B1 and the rotor outer wall surface 3B1 is parallel to the axial direction. As a result, the air flowing along the base outer wall surface 211B or the rotor outer wall surface 3B1 flows parallel to the axial direction, so that it is difficult for the air to enter the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

ただし、図３に示すように、ベース外壁面２１１Ｂ１の一部は、アール部Ｒ１であり、軸方向に平行でなくてもよい。同様に、回転子外壁面３Ｂ１の一部は、アール部Ｒ２であり、軸方向に平行でなくてもよい。アール部Ｒ１，Ｒ２を設けることにより、径方向に流れる気流を軸方向の流れへ滑らかに変化させることができる。 However, as shown in FIG. 3, a part of the base outer wall surface 211B1 is a rounded portion R1 and does not have to be parallel to the axial direction. Similarly, a part of the rotor outer wall surface 3B1 is a rounded portion R2 and does not have to be parallel to the axial direction. By providing the rounded portions R1 and R2, the airflow flowing in the radial direction can be smoothly changed to the flow in the axial direction.

また、図３に示すように、ベース外壁面２１１Ｂ１とベース２１１の上面とがなす角度は９０度であり、回転子外壁面３Ｂ１と回転子３の上面とがなす角度は９０度である。これにより、ベース外壁面２１１Ｂ１に沿って流れる空気、および回転子外壁面３Ｂ１に沿って流れる空気は、第１の隙間Ｓ１側へ向かうことを抑制される。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, as shown in FIG. 3, the angle formed by the base outer wall surface 211B1 and the upper surface of the base 211 is 90 degrees, and the angle formed by the rotor outer wall surface 3B1 and the upper surface of the rotor 3 is 90 degrees. As a result, the air flowing along the base outer wall surface 211B1 and the air flowing along the rotor outer wall surface 3B1 are suppressed from going toward the first gap S1 side. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

＜ラビリンス構造の第２実施形態＞
以下、上述した図３に示すラビリンス構造の各種変形例について述べる。図４は、ラビリンス構造の第２実施形態を示す一部拡大断面図である。 <Second Embodiment of Labyrinth Structure>
Hereinafter, various modifications of the labyrinth structure shown in FIG. 3 described above will be described. FIG. 4 is a partially enlarged cross-sectional view showing a second embodiment of the labyrinth structure.

図４に示す構成では、インペラ下面３１Ａ、すなわち回転子下面３Ａがベース壁部２１１Ｂの上方まで延びる。従って、第１の隙間Ｓ１は、回転子下面３Ａとベース壁部２１１Ｂの上面とが軸方向に対向して形成される。すなわち、第１の隙間Ｓ１は、回転子３とベース壁部２１１Ｂの上面とが対向して形成される。これにより、図４に示す気流ＦＬ１１のように、ベース２１１に沿って流れる空気は、ベース壁部２１１Ｂのベース外壁面２１１Ｂ１に沿って流れ、第１の隙間Ｓ１に入らずに回転子３に沿って流れて外部空間ＯＳへ戻りやすい。 In the configuration shown in FIG. 4, the lower surface 31A of the impeller, that is, the lower surface 3A of the rotor extends above the base wall portion 211B. Therefore, the first gap S1 is formed so that the lower surface of the rotor 3A and the upper surface of the base wall portion 211B face each other in the axial direction. That is, the first gap S1 is formed so that the rotor 3 and the upper surface of the base wall portion 211B face each other. As a result, as in the air flow FL11 shown in FIG. 4, the air flowing along the base 211 flows along the base outer wall surface 211B1 of the base wall portion 211B, and flows along the rotor 3 without entering the first gap S1. It is easy to flow and return to the external space OS.

＜ラビリンス構造の第３実施形態＞
図５は、ラビリンス構造の第３実施形態を示す一部拡大断面図である。 <Third embodiment of labyrinth structure>
FIG. 5 is a partially enlarged cross-sectional view showing a third embodiment of the labyrinth structure.

図５に示す構成では、ベース上面２１１Ａがインペラ壁部３１Ｂ、すなわち回転子壁部３Ｂの下方まで延びる。従って、第１の隙間Ｓ１は、回転子壁部３Ｂの下面とベース上面２１１Ａとが軸方向に対向して形成される。すなわち、第１の隙間Ｓ１は、回転子壁部３Ｂの下面とベース２１１とが対向して形成される。これにより、図５に示す気流ＦＬ１２のように、回転子３に沿って流れる空気は、回転子壁部３Ｂの回転子外壁面３Ｂ１に沿って流れ、第１の隙間Ｓ１に入らずにベース２１１に沿って流れて外部空間ＯＳへ戻りやすい。 In the configuration shown in FIG. 5, the upper surface 211A of the base extends below the impeller wall portion 31B, that is, the rotor wall portion 3B. Therefore, the first gap S1 is formed so that the lower surface of the rotor wall portion 3B and the upper surface 211A of the base face each other in the axial direction. That is, the first gap S1 is formed so that the lower surface of the rotor wall portion 3B and the base 211 face each other. As a result, as in the airflow FL12 shown in FIG. 5, the air flowing along the rotor 3 flows along the rotor outer wall surface 3B1 of the rotor wall portion 3B, and does not enter the first gap S1 but enters the base 211. It is easy to flow along and return to the external space OS.

＜ラビリンス構造の第４実施形態＞
図６は、ラビリンス構造の第４実施形態を示す一部拡大断面図である。 <Fourth Embodiment of Labyrinth Structure>
FIG. 6 is a partially enlarged cross-sectional view showing a fourth embodiment of the labyrinth structure.

図６に示す構成では、インペラ３１は、インペラ３１の下面から下方へ立ち下がるインペラ壁部３１Ｂを有する。ハブ３２は、外側壁部３２Ｂの外周面から径方向外側へ突出する突出部３２Ｔを有する。突出部３２Ｔは、インペラ壁部３１Ｂの径方向外側の壁面の下方まで突出する。これにより、インペラ壁部３１Ｂと突出部３２Ｔとから回転子壁部３Ｂが構成される。第１の隙間Ｓ１は、突出部３２Ｔの下面とベース壁部２１１Ｂの上面とが軸方向に対向して形成される。すなわち、第１の隙間Ｓ１は、ベース壁部２１１Ｂの上面と回転子壁部３Ｂの下面とが対向して形成される。 In the configuration shown in FIG. 6, the impeller 31 has an impeller wall portion 31B that descends downward from the lower surface of the impeller 31. The hub 32 has a protruding portion 32T protruding outward in the radial direction from the outer peripheral surface of the outer wall portion 32B. The protruding portion 32T protrudes below the wall surface on the outer side in the radial direction of the impeller wall portion 31B. As a result, the rotor wall portion 3B is formed from the impeller wall portion 31B and the projecting portion 32T. The first gap S1 is formed so that the lower surface of the protruding portion 32T and the upper surface of the base wall portion 211B face each other in the axial direction. That is, the first gap S1 is formed so that the upper surface of the base wall portion 211B and the lower surface of the rotor wall portion 3B face each other.

これにより、図６に示す気流ＦＬ２１のように、ベース２１１に沿って流れる空気は、ベース壁部２１１Ｂの壁面に沿って流れ、第１の隙間Ｓ１に入らずに回転子壁部３Ｂに沿って流れやすい。また、図６に示す気流ＦＬ２２のように、第２の隙間Ｓ２内部から回転子３の下面に沿って流れる空気は、回転子壁部３Ｂに沿って流れ、第１の隙間Ｓ１に入らずにベース壁部２１１Ｂの壁面に沿って流れやすい。 As a result, as in the air flow FL21 shown in FIG. 6, the air flowing along the base 211 flows along the wall surface of the base wall portion 211B, does not enter the first gap S1, and flows along the rotor wall portion 3B. Easy to flow. Further, as in the air flow FL22 shown in FIG. 6, the air flowing from the inside of the second gap S2 along the lower surface of the rotor 3 flows along the rotor wall portion 3B and does not enter the first gap S1. It is easy to flow along the wall surface of the base wall portion 211B.

また、図６に示す構成では、回転子３は、インペラ壁部３１Ｃを有する。インペラ壁部３１Ｃは、インペラ壁部３１Ｂの径方向外側に位置する壁面に接続されてインペラ壁部３１Ｂの上方且つ径方向外側に位置する。インペラ壁部３１Ｃは、上方壁部３Ｃに相当する。すなわち、回転子３は、回転子壁部３Ｂの壁面に接続されて回転子壁部３Ｂの軸方向上方且つ径方向外側に位置し、回転子３の上面から軸方向下方へ延びる上方壁部３Ｃを有する。これにより、図６に示す気流ＦＬ２３のように、回転子３に沿って流れる空気は、より径方向外側に位置する上方壁部３Ｃの壁面に沿って流れるので、空気が第１の隙間Ｓ１に入り込みにくい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 Further, in the configuration shown in FIG. 6, the rotor 3 has an impeller wall portion 31C. The impeller wall portion 31C is connected to a wall surface located on the radial outer side of the impeller wall portion 31B and is located above and radially outer side of the impeller wall portion 31B. The impeller wall portion 31C corresponds to the upper wall portion 3C. That is, the rotor 3 is connected to the wall surface of the rotor wall portion 3B, is located above the rotor wall portion 3B in the axial direction and radially outside, and extends downward in the axial direction from the upper surface of the rotor 3 3C. Has. As a result, as in the air flow FL23 shown in FIG. 6, the air flowing along the rotor 3 flows along the wall surface of the upper wall portion 3C located on the outer side in the radial direction, so that the air flows into the first gap S1. Difficult to get in. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

なお、ベース２１１に下方壁部を設けてもよい。すなわち、ベース２１１は、ベース壁部２１１Ｂの壁面に接続されてベース壁部２１１Ｂの軸方向下方且つ径方向外側に位置し、ベース２１１の下面から軸方向下方へ延びる下方壁部を有する。これにより、ベース２１１に沿って流れる空気は、より径方向外側に位置する下方壁部の壁面に沿って流れるので、空気が第１の隙間Ｓ１に入り込みにくい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 The base 211 may be provided with a lower wall portion. That is, the base 211 is connected to the wall surface of the base wall portion 211B, is located axially downward and radially outward of the base wall portion 211B, and has a lower wall portion extending axially downward from the lower surface of the base 211. As a result, the air flowing along the base 211 flows along the wall surface of the lower wall portion located on the outer side in the radial direction, so that it is difficult for the air to enter the first gap S1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

＜ラビリンス構造の第５実施形態＞
図７は、ラビリンス構造の第５実施形態を示す一部拡大断面図である。 <Fifth Embodiment of Labyrinth Structure>
FIG. 7 is a partially enlarged cross-sectional view showing a fifth embodiment of the labyrinth structure.

図７に示す構成では、インペラ３１は、インペラ３１の下面から軸方向下方に延びるインペラ壁部３１Ｂを有する。インペラ壁部３１Ｂは、径方向外側にインペラ３１の下面から軸方向下方へ延びるインペラ壁面３１Ｂ１を有する。ハブ３２は、外側壁部３２Ｂ、すなわち筒状部と、突出部３２Ｔと、を有する。上記筒状部は、インペラ３１の内周面と径方向に対向する外周面３２Ｂ１を有する。突出部３２Ｔは、インペラ壁部３１Ｂの軸方向下方においてインペラ壁面３１Ｂ１よりも径方向外側に外周面３２Ｂ１から突出する。第１の隙間Ｓ１は、突出部３２Ｔの下面とベース壁部２１１Ｂの上面とが軸方向に対向して形成される。 In the configuration shown in FIG. 7, the impeller 31 has an impeller wall portion 31B extending axially downward from the lower surface of the impeller 31. The impeller wall portion 31B has an impeller wall surface 31B1 extending radially downward from the lower surface of the impeller 31 on the outer side in the radial direction. The hub 32 has an outer wall portion 32B, that is, a tubular portion and a protruding portion 32T. The tubular portion has an outer peripheral surface 32B1 that faces the inner peripheral surface of the impeller 31 in the radial direction. The protruding portion 32T protrudes from the outer peripheral surface 32B1 radially outward of the impeller wall surface 31B1 below the impeller wall portion 31B in the axial direction. The first gap S1 is formed so that the lower surface of the protruding portion 32T and the upper surface of the base wall portion 211B face each other in the axial direction.

これにより、図７に示す気流ＦＬ３１のように、ベース２１１に沿って流れる空気は、ベース壁部２１１Ｂの壁面から突出部３２Ｔの下面に沿って流れ、第２の隙間Ｓ２より外部空間へ戻りやすい。また、図７に示す気流ＦＬ３２のように、インペラ３１に沿って流れる空気は、インペラ壁部３１Ｂの壁面から突出部３２Ｔの上面に沿って流れ、第２の隙間Ｓ２より外部空間へ戻りやすい。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 As a result, like the airflow FL31 shown in FIG. 7, the air flowing along the base 211 flows from the wall surface of the base wall portion 211B along the lower surface of the protruding portion 32T, and is more likely to return to the external space than the second gap S2. .. Further, like the air flow FL32 shown in FIG. 7, the air flowing along the impeller 31 flows from the wall surface of the impeller wall portion 31B along the upper surface of the protruding portion 32T, and is more likely to return to the external space than the second gap S2. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

＜ラビリンス構造の第６実施形態＞
図８は、ラビリンス構造の第６実施形態を示す一部拡大断面図である。 <Sixth Embodiment of Labyrinth Structure>
FIG. 8 is a partially enlarged cross-sectional view showing a sixth embodiment of the labyrinth structure.

図８に示す構成では、第１の隙間Ｓ１は、ベース壁部２１１Ｂの上面と、インペラ壁部３１Ｂ、すなわち回転子壁部３Ｂの下面とが軸方向に対向して形成される。そして、ベース壁部２１１Ｂのベース外壁面２１１Ｂ１が軸方向に平行であり、ベース外壁面２１１Ｂ１とベース２１１の上面とがなす角度θ１は、９０度より小さい。また、回転子壁部３Ｂの回転子外壁面３Ｂ１が軸方向に平行であり、回転子外壁面３Ｂ１と回転子３の下面とがなす角度θ２は、９０度より小さい。 In the configuration shown in FIG. 8, the first gap S1 is formed so that the upper surface of the base wall portion 211B and the lower surface of the impeller wall portion 31B, that is, the rotor wall portion 3B face each other in the axial direction. The base outer wall surface 211B1 of the base wall portion 211B is parallel to the axial direction, and the angle θ1 formed by the base outer wall surface 211B1 and the upper surface of the base 211 is smaller than 90 degrees. Further, the rotor outer wall surface 3B1 of the rotor wall portion 3B is parallel in the axial direction, and the angle θ2 formed by the rotor outer wall surface 3B1 and the lower surface of the rotor 3 is smaller than 90 degrees.

すなわち、図３に示した第１実施形態と同様に、ベース外壁面２１１Ｂ１の延びる方向が軸方向に平行であり、ベース外壁面２１１Ｂ１とベース２１１の上面とがなす角度は、９０度以下であり、回転子外壁面３Ｂ１の延びる方向が軸方向に平行であり、回転子外壁面３Ｂ１と回転子３の上面とがなす角度は、９０度以下である。これにより、ベース２１１に沿って流れる空気がベース外壁面２１１Ｂ１に沿って第１の隙間Ｓ１側へ向かうことを抑制できる。または、回転子３に沿って流れる空気が回転子外壁面３Ｂ１に沿って第１の隙間Ｓ１側へ向かうことを抑制できる。従って、気流に含まれた塵が第１の隙間Ｓ１に入り込むことを抑制できる。 That is, as in the first embodiment shown in FIG. 3, the extending direction of the base outer wall surface 211B1 is parallel to the axial direction, and the angle formed by the base outer wall surface 211B1 and the upper surface of the base 211 is 90 degrees or less. The extending direction of the rotor outer wall surface 3B1 is parallel to the axial direction, and the angle formed by the rotor outer wall surface 3B1 and the upper surface of the rotor 3 is 90 degrees or less. As a result, it is possible to prevent the air flowing along the base 211 from heading toward the first gap S1 along the base outer wall surface 211B1. Alternatively, it is possible to prevent the air flowing along the rotor 3 from heading toward the first gap S1 along the rotor outer wall surface 3B1. Therefore, it is possible to prevent dust contained in the air flow from entering the first gap S1.

＜その他＞
以上、本発明の実施形態について説明したが、本発明の趣旨の範囲内であれば、実施形態は種々の変更が可能である。 <Others>
Although the embodiments of the present invention have been described above, the embodiments can be changed in various ways within the scope of the gist of the present invention.

例えば、本発明は、遠心ファンに限らず、その他の送風装置、例えば軸流ファン等に適用することも可能である。 For example, the present invention can be applied not only to a centrifugal fan but also to other blowers such as an axial fan.

本発明は、例えば、各種の送風装置に利用することができる。 The present invention can be used, for example, in various blowers.

１・・・送風装置、２・・・固定子、２１・・・下ハウジング部、２１１・・・ベース、２１１Ａ・・・ベース上面、２１１Ｂ・・・ベース壁部、２１１Ｂ１・・・ベース外壁面、２１２・・・軸受保持部、２１３・・・第１周壁部、２１４・・・第２周壁部、２２・・・ステータ、２２１・・・ステータコア、２２２・・・コイル、２３・・・軸部材、２４・・・キャップ、３・・・回転子、３Ａ・・・回転子下面、３Ｂ・・・回転子壁部、
３Ｂ１・・・回転子外壁面、３Ｃ・・・上方壁部、３１・・・インペラ、３１Ａ・・・インペラ下面、３１Ｂ・・・インペラ壁部、３１Ｃ・・・インペラ壁部、３１１・・・インペラカップ、３１２・・・羽根、３２・・・ハブ、３２Ａ・・・蓋部、３２Ｂ・・・外側壁部、３２Ｃ・・・内側壁部、３２Ｄ・・・軸受部、３２Ｔ・・・突出部、３３・・・マグネット、Ｍ・・・モータ、Ｓ１・・・第１の隙間、Ｓ２・・・第２の隙間、Ｓ３・・・第３の隙間、ＳＰ・・・隙間、ＯＳ・・・外部空間、Ｃ１・・・中心軸 1 ... Blower, 2 ... Stator, 21 ... Lower housing, 211 ... Base, 211A ... Base top surface, 211B ... Base wall, 211B1 ... Base outer wall , 212 ... bearing holding part, 213 ... first peripheral wall part, 214 ... second peripheral wall part, 22 ... stator, 221 ... stator core, 222 ... coil, 23 ... shaft Member, 24 ... cap, 3 ... rotor, 3A ... rotor lower surface, 3B ... rotor wall,
3B1 ... Rotor outer wall surface, 3C ... Upper wall part, 31 ... Impeller, 31A ... Impeller lower surface, 31B ... Impeller wall part, 31C ... Impeller wall part, 311 ... Impeller cup, 312 ... blades, 32 ... hub, 32A ... lid, 32B ... outer wall, 32C ... inner side wall, 32D ... bearing, 32T ... protruding Part, 33 ... Magnet, M ... Motor, S1 ... 1st gap, S2 ... 2nd gap, S3 ... 3rd gap, SP ... Gap, OS ...・ External space, C1 ・・・ Central axis

Claims

A stator with a stator and
A rotor that rotates around a central axis that extends vertically and faces the stator in the radial direction.
Equipped with a motor with
The stator has a radially extending base and
The rotor has an impeller and
The rotor rotates axially above the base with a gap from the base.
The gap has a first gap and a second gap.
The first gap and the second gap are formed so that the rotor and the base face each other in the axial direction.
The second gap is continuous with the first gap on the radial outer side of the first gap.
The second gap is located on the outermost side in the radial direction.
A blower having an axial length of the first gap narrower than the axial length of the second gap.

The second gap is formed so that the lower surface of the rotor, which is the lower surface of the rotor in the axial direction, and the upper surface of the base, which is the upper surface of the base in the axial direction, face each other.
The blower according to claim 1, wherein the lower surface of the rotor and the upper surface of the base extend in the radial direction.

The blower according to claim 2, wherein the lower surface of the rotor and the upper surface of the base are parallel to each other.

The base has a base wall portion extending axially upward from the upper surface of the base.
The blower according to any one of claims 1 to 3, wherein the first gap is formed so that the rotor and the upper surface of the base wall portion face each other.

The rotor has a rotor wall portion extending axially downward from the lower surface of the rotor.
The blower according to any one of claims 1 to 4, wherein the first gap is formed so that the lower surface of the rotor wall portion and the base face each other.

The base has a base wall portion extending axially upward from the upper surface of the base.
The rotor has a rotor wall portion extending axially downward from the lower surface of the rotor.
The blower according to any one of claims 1 to 3, wherein the first gap is formed so that the upper surface of the base wall portion and the lower surface of the rotor wall portion face each other.

The base wall portion has a base outer wall surface extending radially upward from the upper surface of the base on the outer side in the radial direction.
The rotor wall portion has a rotor outer wall surface extending axially downward from the lower surface of the rotor on the outer side in the radial direction.
The blower according to claim 6, wherein the axial upper end of the base outer wall surface and the axial lower end of the rotor outer wall surface have the same radial position.

The base wall portion has a base outer wall surface extending radially upward from the upper surface of the base on the outer side in the radial direction.
The rotor wall portion has a rotor outer wall surface extending axially downward from the lower surface of the rotor on the outer side in the radial direction.
The blower according to claim 6 or 7, wherein at least one extending direction of the base outer wall surface and the rotor outer wall surface is parallel to the axial direction.

The blower according to claim 8, wherein the extending direction of the outer wall surface of the base is parallel to the axial direction, and the angle formed by the outer wall surface of the base and the upper surface of the base is 90 degrees or less.

The blower according to claim 8 or 9, wherein the extending direction of the rotor outer wall surface is parallel to the axial direction, and the angle formed by the rotor outer wall surface and the upper surface of the rotor is 90 degrees or less. apparatus.

According to claim 6, the base is connected to the wall surface of the base wall portion, is located axially downward and radially outward of the base wall portion, and has a lower wall portion extending axially upward from the lower surface of the base. The blower according to any one of claims 10.

The rotor is connected to the wall surface of the rotor wall portion, is located axially upward and radially outward of the rotor wall portion, and has an upper wall portion extending axially downward from the upper surface of the rotor. The blower according to any one of claims 6 to 11.

The blower according to any one of claims 1 to 12, wherein the axial center position of the first gap coincides with the axial center position of the second gap.

The rotor has a hub to which the impeller is radially outwardly fixed.
The impeller has an impeller wall portion extending axially downward from the lower surface of the impeller.
The impeller wall portion has an impeller wall surface extending radially downward from the lower surface of the impeller on the outer side in the radial direction.
The hub
A tubular portion having an outer peripheral surface that faces the inner peripheral surface of the impeller in the radial direction,
A protruding portion that protrudes from the outer peripheral surface in the radial direction outward from the impeller wall surface below the impeller wall portion in the axial direction.
Have,
The blower according to claim 4, wherein the first gap is formed so that the lower surface of the protruding portion and the upper surface of the base wall portion face each other in the axial direction.