JP2013108470A - Fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of a lubricant by reducing a difference in pressure between an upper space formed between an upper seal part and a rotor holder, and a lower part space where a lower seal part is located.SOLUTION: A fan 1 includes a plurality of blades 122 and a motor 11 which rotates the plurality of blades. The motor includes: a substantially cylindrical covered rotor holder 121 with the blades arranged on the outer circumferential surface thereof; a shaft 41; a sleeve 44 into which the shaft is inserted; a holder which retains the sleeve; and a thrust plate 42 arranged on the lower side of the shaft. A radial bearing part 66a, which supports the shaft in the radial direction, is formed in a radial gap between the shaft and the sleeve. A lower seal part 62a, on which an interface on the lower side of the lubricant is positioned, is formed between the thrust plate and the holder. An upper seal part 61a, on which an interface on the upper side of the lubricant is positioned, is formed between the holder and the sleeve.

Description

  The present invention relates to a fan that generates a flow of air.

Conventionally, a cooling fan for cooling electronic components is provided inside a housing of various electronic devices. The fan motor disclosed in Japanese Utility Model Publication No. 6-31199 includes a case, a stator, a sleeve, a shaft, an annular member, a rotor, and a plurality of blades. The stator is provided on the outer periphery of the inner cylinder of the case. The sleeve is fitted and fixed in the inner cylinder. The shaft is inserted into the sleeve. A groove for generating dynamic pressure is provided on the outer peripheral surface of the shaft. The annular member is fitted and fixed to the lower end portion of the shaft. The annular member faces the lower surface of the sleeve in the axial direction. Lubricating fluid is sealed between the sleeve and the shaft and between the sleeve and the annular member. A rotor is fixed to the upper end of the shaft. A magnet is fixed to the inner periphery of the cylindrical mounting member of the rotor, and the magnet faces the stator in the radial direction. A plurality of blades are fixed to the outer periphery of the mounting member. In the fan motor, a radial dynamic pressure bearing is constituted by a shaft and a sleeve. A thrust dynamic pressure bearing is constituted by the sleeve and the annular member.
Japanese Utility Model Publication No. 6-31199

  By the way, when driving the fan disclosed in Japanese Utility Model Publication No. 6-31199, the upper interface of the lubricating fluid formed between the sleeve and the shaft, and between or near the lower surface of the sleeve and the upper surface of the annular member. There is a risk that a pressure difference will occur with the lower interface of the lubricating fluid. As a result, the lubricating fluid may leak out.

  An object of the present invention is to prevent leakage of lubricating oil by reducing a pressure difference between an upper space between the upper seal portion and the rotor holder and a lower space where the lower seal portion is located.

  An exemplary fan according to the first aspect of the present invention includes a plurality of blades and a motor that rotates the plurality of blades around a central axis, the motor including a stationary portion having a stator, A rotating part having a rotor magnet disposed radially outside the stator, and a bearing mechanism that rotatably supports the rotating part with respect to the stationary part, wherein the rotating part has the plurality of the outer peripheral surfaces A closed-cylindrical rotor holder with a wing disposed therein, wherein the bearing mechanism includes a shaft, a sleeve into which the shaft is inserted, a holder for holding the sleeve, and a thrust disposed under the shaft. A radial bearing portion configured to support the shaft in a radial direction by a radial gap between the shaft and the sleeve, and the thrust plate and the ho A lower seal portion in which a lower interface of the lubricating oil is located between the upper part and the upper seal portion in which an upper interface of the lubricating oil is located between the holder and the sleeve, The holder includes a communication path forming portion that forms a communication path that connects an upper space between the interior of the rotor holder and the upper seal portion and a lower space in which the lower seal portion is located.

  An exemplary fan according to the second aspect of the present invention includes a plurality of blades and a motor that rotates the plurality of blades around a central axis, the motor including a stationary portion having a stator, A rotating part having a rotor magnet disposed radially outside the stator, and a bearing mechanism that rotatably supports the rotating part with respect to the stationary part, wherein the rotating part has the plurality of the outer peripheral surfaces A closed-cylindrical rotor holder with a wing disposed therein, wherein the bearing mechanism includes a shaft, a sleeve into which the shaft is inserted, a holder for holding the sleeve, and a thrust disposed under the shaft. A first cylindrical holder that covers the outer peripheral surface of the sleeve and the outer peripheral surface of the thrust plate, and the inner peripheral surface to which the outer peripheral surface of the first holder is fixed. A second holder on the outside of the stator, and a radial bearing portion configured to support the shaft in a radial direction is formed in a radial gap between the shaft and the sleeve, and the thrust plate and the first A lower seal portion in which a lower interface of the lubricating oil is located between the holder and the shaft is formed between the shaft and an annular upper portion protruding radially inward above the sleeve of the first holder. An upper seal portion in which the upper interface of the lubricating oil is located is formed, the second holder is located in the upper space between the interior of the rotor holder and the upper seal portion, and the lower seal portion is located And a communication path forming unit that forms a communication path that communicates with the lower space.

  A fan according to an exemplary third aspect of the present invention includes a plurality of blades and a motor that rotates the plurality of blades around a central axis, and the motor includes a stationary portion having a stator; A rotating part having a rotor magnet disposed radially outside the stator, and a bearing mechanism that rotatably supports the rotating part with respect to the stationary part, wherein the stationary part radially supports the stator And the rotating part includes a substantially cylindrical covered rotor holder in which the plurality of blades are disposed on the outer peripheral surface, and the bearing mechanism includes a shaft and a bearing into which the shaft is inserted. And a thrust plate disposed on the lower side of the shaft, and a radial bearing portion configured to support the shaft in a radial direction at a radial gap between the shaft and the bearing portion is configured. And a lower seal portion in which a lower interface of the lubricating oil is located between the thrust plate and the bearing portion, and the rotor extends axially downward from the thrust portion that extends radially outward from the upper portion of the shaft. An upper seal portion where an upper interface of the lubricating oil is located is formed between the cylindrical portion and the bearing portion, and the bush includes an upper space between the interior of the rotor holder and the upper seal portion, A communication path forming portion that forms a communication path that communicates with the lower space in which the lower seal portion is located.

  According to the present invention, it is possible to prevent leakage of the lubricating oil by reducing the pressure difference between the upper space and the lower space.

FIG. 1 is a cross-sectional view of the fan according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the bearing mechanism. FIG. 3 is an enlarged sectional view of the bearing mechanism. FIG. 4 is a cross-sectional view of the bearing mechanism. FIG. 5 is a plan view of the thrust plate. FIG. 6 is a cross-sectional view of a holder according to another example. FIG. 7 is a cross-sectional view of a bearing mechanism according to another example. FIG. 8 is a cross-sectional view of a bearing mechanism according to still another example. FIG. 9 is a cross-sectional view of a bearing mechanism according to still another example. FIG. 10 is a cross-sectional view of the holder. FIG. 11 is a cross-sectional view of a fan according to the second embodiment. FIG. 12 is a cross-sectional view of a fan according to the third embodiment. FIG. 13 is an enlarged cross-sectional view of the bearing mechanism. FIG. 14 is a cross-sectional view of a bearing mechanism according to another example. FIG. 15 is a cross-sectional view of a fan according to the fourth embodiment. FIG. 16 is a cross-sectional view of a fan according to another example. FIG. 17 is a cross-sectional view of a fan according to still another example.

  In the present specification, the upper side of FIG. 1 in the direction of the central axis of the motor is simply referred to as “upper side”, and the lower side is simply referred to as “lower side”. Note that the vertical direction does not indicate the positional relationship or direction when incorporated in an actual device. A direction parallel to the central axis is referred to as an “axial direction”, a radial direction centered on the central axis is simply referred to as “radial direction”, and a circumferential direction centered on the central axis is simply referred to as “circumferential direction”.

(First embodiment)
FIG. 1 is a cross-sectional view of an axial fan 1 according to the first embodiment of the present invention. Hereinafter, the axial fan 1 is simply referred to as “fan 1”. The fan 1 includes a motor 11, an impeller 12, a housing 13, and a plurality of support ribs 14. The housing 13 surrounds the outer periphery of the impeller 12. The plurality of support ribs 14 are arranged in the circumferential direction. The housing 13 and the motor 11 are connected via the support rib 14.

  The impeller 12 is made of resin and includes a substantially cylindrical covered rotor holder 121 and a plurality of blades 122. The rotor holder 121 covers the outside of the motor 11. The rotor holder 121 also serves as a part of the rotating part 2 of the motor 11 described later. The rotor holder 121 includes a top surface portion 123, a side wall portion 124, and a cylindrical bushing 125. The top surface portion 123 extends perpendicular to the central axis J1. The side wall portion 124 extends downward from the outer edge portion of the top surface portion 123. The bushing 125 is made of metal and is fixed in the central hole of the top surface portion 123. The plurality of blades 122 extend radially outward from the outer peripheral surface of the side wall portion 124 around the central axis J1. The rotor holder 121 and the plurality of blades 122 are configured as a continuous member by resin injection molding.

  In the fan 1, the impeller 12 is rotated about the central axis J <b> 1 by the motor 11, whereby an air flow is generated from the upper side to the lower side.

  The motor 11 is an outer rotor type single-phase or three-phase motor. The motor 11 includes a rotating unit 2, a stationary unit 3, and a bearing mechanism 401. The rotating part 2 is supported by the bearing mechanism 401 so as to be rotatable with respect to the stationary part 3. The rotating unit 2 includes a covered substantially cylindrical rotor holder 121, a substantially cylindrical metal yoke 21, and a rotor magnet 22. The yoke 21 is fixed inside the side wall portion 124 of the rotor holder 121. The rotor magnet 22 is fixed to the inner peripheral surface of the yoke 21.

  The stationary part 3 includes a base part 31, a stator 32, and a circuit board 33. The stator 32 is disposed on the outer periphery of the bearing mechanism 401. The stator 32 includes a stator core 321 and a plurality of coils 322 formed on the stator core 321. Stator core 321 is formed of a magnetic steel plate. A circuit board 33 is fixed to the lower part of the stator 32. By attaching a lead wire from the coil 322 to a pin (not shown) inserted into the circuit board 33, the stator 32 and the circuit board 33 are electrically connected. The lead wire of the coil 322 may be directly connected to the circuit board 33. When the motor 11 is driven, a rotational force is generated between the rotor magnet 22 and the stator 32 positioned on the radially inner side of the rotor magnet 22.

  A Hall element 331 and a drive circuit (not shown) are provided on the upper surface of the circuit board 33. The hall element 331 is located below the rotor magnet 22 and detects a change in magnetic flux accompanying the rotation of the rotor magnet 22.

  A magnetic attractive force that attracts the rotor magnet 22 downward is generated between the rotor magnet 22 and the stator 32. As a result, the force with which the impeller 12 floats with respect to the stationary part 3 can be reduced.

  The bearing mechanism 401 includes a shaft 41, an annular thrust plate 42, a sleeve 44, a thrust cap 45 that is a cap member, a holder 46, and a lubricating oil 47. The shaft 41 is inserted into the sleeve 44. The upper portion of the shaft 41 is indirectly fixed to the top surface portion 123 via the bushing 125. The upper portion of the shaft 41 may be directly fixed to the top surface portion 123 without using the bushing 125. The thrust plate 42 is fixed to the lower end portion of the shaft 41 below the sleeve 44. The thrust plate 42 extends radially outward from the outer peripheral surface of the shaft 41. The thrust plate 42 has an inclined surface 421 that is inclined radially inward downward between the outer peripheral surface and the lower surface.

  The sleeve 44 is a sintered metal body impregnated with a lubricating oil 47, and is held in a substantially cylindrical holder 46. The holder 46 is a member connected to the base portion 31 and the support rib 14 and extends upward from the center of the base portion 31. The holder 46, the base portion 31, and the support rib 14 are molded from resin. Note that these members may be made of metal. The upper portion of the holder 46 includes an upper annular portion 461 and an upper cylindrical portion 462. The upper annular portion 461 has an annular shape centered on the central axis J <b> 1 and is located on the upper side of the sleeve 44. The upper cylindrical portion 462 extends upward from the outer edge portion of the upper annular portion 461. The holder 46 further includes a communication path forming unit 5. The communication path forming unit 5 forms a communication path 51 in the holder 46. A radially inner portion of the stator core 321 is fixed to the outer peripheral surface of the holder 46. The shaft 41 and the thrust plate 42 also serve as a part of the rotating unit 2. The sleeve 44, the thrust cap 45 and the holder 46 also serve as a part of the stationary part 3.

  FIG. 2 is an enlarged sectional view showing a part of the bearing mechanism 401. The upper part and the lower part of the sleeve 44 are respectively fixed to the inner peripheral part of the holder 46. Hereinafter, a portion of the inner peripheral portion of the holder 46 that is in contact with the upper portion of the sleeve 44 in the radial direction is referred to as an “upper contact portion 463”. A portion that contacts the lower portion of the sleeve 44 in the radial direction is referred to as a “lower contact portion 464”. The outer peripheral surface of the sleeve 44 has an inclined surface 441 that is inclined inward in the radial direction upward between the upper contact portion 463 and the lower contact portion 464.

  Between the inclined surface 441 of the sleeve 44 and the inner peripheral surface 46a of the holder 46, an upper seal gap 611 is formed in which the radial width gradually increases upward. The upper seal gap 611 includes an upper seal portion 61a that holds the lubricating oil 47 by capillary action. An upper interface of the lubricating oil 47 exists in the upper seal portion 61a.

  FIG. 3 is an enlarged view showing the upper part of the fan 1. FIG. 4 is a cross-sectional view of the bearing mechanism 401 taken at the position indicated by the arrow A in FIG. The upper contact portion 463 of the holder 46 is provided with a notch portion 463a extending in the vertical direction. The notch 463 a becomes a ventilation path 651 extending in the vertical direction between the upper contact portion 463 and the outer peripheral surface of the sleeve 44.

  As shown in FIG. 3, the bushing 125 is located above the holder 46. A lateral gap 652 is formed between the lower surface of the bushing 125 and the upper surface of the upper annular portion 461 so as to extend in a direction perpendicular to the central axis J1. A vertical gap 653 extending in the axial direction is formed between the outer peripheral surface of the bushing 125 and the inner peripheral surface of the upper cylindrical portion 462. The vertical gap 653 has an annular shape centered on the central axis J1. The upper seal gap 611 includes a ventilation path 651, a space 656 between the upper surface of the sleeve 44 and the lower surface of the upper annular portion 461, a gap between the inner end of the upper annular portion 461 and the shaft 41, a lateral gap 652 and a vertical gap. It connects with the space above the stator 32 of FIG. In the following description, the upper seal gap 611, the air passage 651, the space 656, the lateral gap 652 and the vertical gap 653, that is, the space surrounded by the sleeve 44, the holder 46, the shaft 41, and the bushing 125 are collectively referred to as “upper space 61. " However, the upper space 61 may include a space between the inner peripheral portion of the stator 32 in FIG.

  As shown in FIG. 2, the thrust cap 45 has a disk shape and is fixed to the lower portion of the holder 46 below the thrust plate 42. The lower portion of the holder 46 is closed by the thrust cap 45. In the bearing mechanism 401, a space 62 surrounded by the thrust cap 45, the thrust plate 42, the holder 46 and the shaft 41 is configured. Hereinafter, the space 62 existing above the thrust cap 45 is referred to as a “lower space 62”. A portion of the lower space 62 between the inclined surface 421 of the thrust plate 42 and the inner peripheral surface 46a of the holder 46 is referred to as a “lower seal gap 621”. The width of the lower seal gap 621 in the radial direction gradually increases downward. The lower seal gap 621 includes a lower seal portion 62a that holds the lubricating oil 47 by capillary action. The lower seal portion 62a has a lower interface of the lubricating oil 47.

  The communication path 51 configured by the communication path forming unit 5 includes a vertical hole 511, an upper horizontal hole 512, and a lower horizontal hole 513. The vertical hole 511 extends in the vertical direction inside the holder 46. The upper horizontal hole 512 extends radially inward from the upper part of the vertical hole 511. The opening of the upper horizontal hole 512, that is, the opening on the upper side of the communication path 51 is located at the center of the inner peripheral surface 46 a of the holder 46. The upper horizontal hole 512 communicates with the upper seal gap 611 on the upper side of the upper seal portion 61a. The lower horizontal hole 513 extends radially inward from the lower portion of the vertical hole 511. The opening of the lower horizontal hole 513, that is, the opening on the lower side of the communication path 51 is located at the lower part of the inner peripheral surface 46 a of the holder 46. The lower horizontal hole 513 is connected to the lower space 62 on the lower side of the lower seal portion 62a. In the bearing mechanism 401, the upper space 61 and the lower space 62 communicate with each other through the communication path 51.

  Under the thrust cap 45, a seal member 311 that is a name plate is attached to the lower surface of the base portion 31. In the fan 1, a space 622 is formed between the seal member 311, the lower surface of the thrust cap 45, and the inner peripheral surface of the base portion 31. Hereinafter, the space 622 existing below the thrust cap 45 is referred to as a “cap lower space 622”.

  Between the upper surface of the thrust plate 42 and the lower surface of the sleeve 44, a thrust gap 64 that extends in the radial direction is formed. FIG. 5 is a plan view of the thrust plate 42. A herringbone-shaped thrust dynamic pressure groove array 641 is formed on the upper surface of the thrust plate 42. When the motor 11 is driven, a thrust bearing 64 a that generates a thrust dynamic pressure with respect to the lubricating oil 47 is formed in the thrust gap 64 by the thrust dynamic pressure groove array 641.

  A radial gap 66 extending in the axial direction is formed between the inner peripheral surface of the sleeve 44 and the outer peripheral surface of the shaft 41. In the radial gap 66, a radial bearing portion 66 a is constituted by the lubricating oil 47. As shown in FIG. 3, the upper portion of the sleeve 44 has an upper groove portion 442 extending in the radial direction. An annular upper plate 48 is disposed on the upper surface of the sleeve 44. A communication passage 654 extending in the radial direction is formed between the upper groove portion 442 and the upper plate 48.

  By providing the communication path 654, the lubricating oil 47 that oozes out from the upper portion of the sleeve 44 can be guided to the radial gap 66, and leakage of the lubricating oil 47 from the upper portion of the sleeve 44 can be prevented. Note that the lubricating oil 47 in the communication path 654 may flow toward the upper seal gap 611. Further, in the bearing mechanism 401, the provision of the horizontal gap 652 and the vertical gap 653 suppresses the movement of the air containing the lubricating oil vaporized from the upper part of the radial gap 66 to the outside of the bearing mechanism 401. As a result, evaporation of the lubricating oil 47 in the bearing mechanism 401 can be suppressed.

  When the fan 1 shown in FIG. 1 is driven, the thrust plate 42 is stably supported in the axial direction with respect to the stationary portion 3 by the thrust bearing portion 64a. The shaft 41 is stably supported in the radial direction by the radial bearing portion 66a. In the fan 1, since the bearing mechanism using a fluid dynamic pressure is used, manufacturing cost can be suppressed compared with the fan which has a ball bearing. Further, noise during driving of the fan can be reduced.

  Although the fan 1 according to the first embodiment has been described above, in the fan 1, the upper space 61 existing between the interior of the rotor holder 121 and the upper seal portion 61 a is connected to the lower space 62 via the communication path 51. It leads to. Thereby, the pressure difference produced between the upper space 61 and the lower space 62 can be reduced or prevented. As a result, leakage of the lubricating oil 47 from the upper seal portion 61a and the lower seal portion 62a is prevented. By providing the thrust cap 45 between the space on the downstream side of the fan 1 and the lower space 62, the pressure difference between the lower space 62 and the upper space 61 can be further suppressed.

  FIG. 6 is a cross-sectional view showing another example of the holder 46. The holder 46 is provided with a plurality of communication path forming portions 5. The plurality of communication paths 51 formed by the plurality of communication path forming portions 5 are arranged at equal intervals in the circumferential direction. By providing the plurality of communication paths 51, it is possible to more reliably suppress the occurrence of a pressure difference between the upper space 61 and the lower space 62 shown in FIG.

  FIG. 7 is a cross-sectional view of a bearing mechanism 401 according to another example. The holder 46 includes a communication path forming portion 5a that forms a communication path 51a. The communication path 51 a has a vertical groove 514, an upper horizontal hole 512, and a lower horizontal hole 513. The vertical groove 514 extends in the vertical direction on the outer peripheral surface of the holder 46 inside the stator 32. Precisely, the vertical groove 514 and the stator 32 constitute a vertical hole 514a that is a part of the communication path 51a. The vertical groove 514 connects the upper horizontal hole 512 and the lower horizontal hole 513 in the vertical direction.

  The upper horizontal hole 512 penetrates the holder 46 in the radial direction above the vertical groove 514. The opening on the inner side in the radial direction of the upper horizontal hole 512 is located at the center of the inner peripheral surface 46 a of the holder 46 and is connected to the upper seal gap 611. The lower horizontal hole 513 passes through the holder 46 in the radial direction below the vertical groove 514. The radially inner opening of the lower horizontal hole 513 is positioned below the inner peripheral surface 46 a of the holder 46 and is connected to the lower seal gap 621.

  Also in the bearing mechanism 401, by providing the communication path 51a, it is possible to suppress the occurrence of a pressure difference between the upper space 61 and the lower space 62. In the bearing mechanism 401, when the holder 46 is molded by resin injection molding, a part of the mold is pulled out radially outward to easily form the vertical groove 514, the upper horizontal hole 512, and the lower horizontal hole 513. can do.

  FIG. 8 is a cross-sectional view of a bearing mechanism 401 according to still another example. In FIG. 8, the shape of the back side of the bearing mechanism 401 is also shown. The same applies to FIG. 9 described later. The holder 46 includes a communication path forming portion 5b that forms the communication path 51b. The communication path 51 b includes a holder groove 515 and a holder through hole 516. The holder groove 515 extends in the vertical direction on the outer peripheral surface of the holder 46 inside the inner peripheral surface of the stator 32. The holder through-hole 516 penetrates in the vertical direction from the lower end of the holder groove 515 to the lower end of the outer peripheral portion of the holder 46. Precisely, a part of the communication path 51b is configured by the holder groove 515 and the inner peripheral surface of the stator 32.

  The holder through-hole 516 is located outside the thrust cap 45 so as to circumscribe the thrust cap 45. A groove portion 516 a that extends continuously in the axial direction from the holder through-hole 516 is provided on the radially outer side of the thrust cap 45 of the holder 46. Between the holder 46 and the thrust cap 45, the groove 516a forms a part of the communication path 51b. Precisely, a part of the communication path 51b is formed between the groove 516a and the outer peripheral surface of the thrust cap 45.

  The thrust cap 45 has a cap through-hole 451 penetrating the thrust cap 45 in the vertical direction. When the bearing mechanism 401 is manufactured, the lubricating oil 47 is filled into the bearing mechanism 401 through the cap through hole 451.

  The stator core 321 has a notch 321a extending in the vertical direction on the inner periphery. The notch 321a is used for positioning of each magnetic steel plate in the circumferential direction when a plurality of magnetic steel plates constituting the stator core 321 are stacked. In the bearing mechanism 401, the notch 321a and the holder groove 515 overlap in the radial direction. Note that the holder groove 515 does not necessarily overlap the notch 321a of the stator core 321 in the radial direction, and the inner peripheral portion other than the notch 321a of the stator core 321 and the holder groove 515 may overlap in the radial direction.

  In the bearing mechanism 401, the upper space 61 including the space above the interface of the upper seal gap 611 is connected to the lower space 62 through the communication path 51 b, the cap lower space 622, and the cap through hole 451, thereby lower space 62. And the pressure difference between the upper space 61 can be suppressed.

  FIG. 9 is a cross-sectional view of a bearing mechanism 401 according to still another example. FIG. 10 is a cross-sectional view of the holder 46 taken at the position of the arrow B shown in FIG. The holder 46 has a communication path forming portion 5 c that constitutes the communication path 52. The communication path 52 is a vertical hole extending in the vertical direction. The radially inner portion of the communication path 52 has a slit-like portion (hereinafter referred to as “slit portion 521”) extending in the vertical direction.

  As shown in FIG. 10, the circumferential width of the slit portion 521 is sufficiently smaller than the width in the same direction of the radially outer portion of the connecting path 52 than the slit portion 521. As shown in FIG. 9, the communication path 52 connects a portion above the upper seal portion 61 a of the upper seal gap 611 and a portion below the lower seal portion 62 a of the lower seal gap 621. Thereby, generation | occurrence | production of the pressure difference between the upper space 61 and the lower space 62 can be suppressed. In the bearing mechanism 401, the lubricating oil 47 is prevented from entering the communication path 52 by sufficiently reducing the circumferential width of the slit portion 521.

(Second Embodiment)
FIG. 11 is a diagram illustrating the fan 1 according to the second embodiment. The thrust cap 45 of the fan 1 has a cap through hole 451 that penetrates the thrust cap 45 in the vertical direction. The base part 31 has a base through-hole 312 that penetrates the base part 31 in the vertical direction. The circuit board 33 has a substrate through hole 332 that penetrates the circuit board 33 in the vertical direction. The base through hole 312 and the substrate through hole 332 overlap in the axial direction. However, these through holes 312 and 332 do not need to overlap exactly in the axial direction.

  The upper part of the holder 46 has a lateral hole 517 that penetrates in the radial direction. The opening on the radially inner side of the horizontal hole 517 is located on the inner peripheral surface of the upper contact portion 463. The lateral hole 517 is connected to the upper seal gap 611 through the ventilation path 651. In the fan 1, one end portion of the resin tube 16 is inserted into the lateral hole 517 through gaps in the circumferential direction of the plurality of coils 322 of the stator 32. The tube 16 is inserted into the substrate through hole 332 and the base through hole 312, and the other end is inserted into the cap through hole 451. Other structures of the fan 1 are the same as those of the fan 1 according to the first embodiment.

  In the second embodiment, the upper space 61 and the lower space 62 communicate with each other by providing the tube 16 that is a communication path forming portion, and the occurrence of a pressure difference between the upper space 61 and the lower space 62 is suppressed. Can do. As a result, leakage of the lubricating oil 47 is prevented. The same applies to other embodiments below.

(Third embodiment)
FIG. 12 is a diagram illustrating a fan 1a according to the third embodiment. The bearing mechanism 402 of the fan 1 a includes a shaft 41, a sleeve 44, a holder 7, a thrust plate 42, a thrust cap 45, and a lubricating oil 47. The shaft 41 is inserted into the sleeve 44. The sleeve 44 is a sintered body impregnated with a lubricating oil 47. The thrust plate 42 is fixed to the lower end portion of the shaft 41.

  The holder 7 includes a first holder 71 and a second holder 72. The first holder 71 has a substantially cylindrical shape centered on the central axis J <b> 1 and holds the sleeve 44. The outer peripheral surface of the sleeve 44 and the outer peripheral surface of the thrust plate 42 are covered with a first holder 71. The first holder 71 has an annular portion 711 protruding radially inward on the upper side of the sleeve 44. Hereinafter, the portion 711 is referred to as “annular upper portion 711”.

  The second holder 72 has a substantially cylindrical shape centered on the central axis J1. The outer peripheral surface of the first holder 71 is fixed to the inner peripheral surface of the second holder 72. The stator 32 is fixed to the outer peripheral surface of the second holder 72. The second holder 72 has a communication path forming part 73 that forms a communication path 730. The structure of the fan 1a other than the bearing mechanism 402 is the same as that of the fan 1 according to the first embodiment. Hereinafter, the same reference numerals are given to the same components.

  A radial bearing 66 a is formed in the radial gap 66 between the inner peripheral surface of the sleeve 44 and the outer peripheral surface of the shaft 41. On the upper side of the radial gap 66, an upper seal gap 611 is formed between the inner peripheral surface of the annular upper portion 711 and the outer peripheral surface of the shaft 41 so that the radial width gradually increases upward. An upper seal portion 61 a that holds the lubricating oil 47 is configured in the upper seal gap 611, and an upper interface of the lubricating oil 47 is located in the upper seal portion 61 a. A lower seal gap 621 is formed between the outer peripheral surface of the thrust plate 42 and the lower portion of the inner peripheral surface of the first holder 71 so that the radial width gradually increases downward. The lower seal gap 621 includes a lower seal portion 62a that holds the lubricating oil 47, and a lower interface of the lubricating oil 47 is located in the lower seal portion 62a.

  As shown in FIG. 13, a minute gap 74 extending in the axial direction is formed between the upper portion of the outer peripheral surface of the first holder 71 and the upper portion of the inner peripheral surface of the second holder 72. The minute gap 74 is connected to the upper seal portion 61 a via a lateral gap 652 formed between the lower surface of the bushing 125 and the upper surface of the annular upper portion 711. Hereinafter, the upper seal gap 611, the minute gap 74, the lateral gap 652, and the vertical gap 653 configured between the outer peripheral surface of the bushing 125 and the upper portion of the inner peripheral surface of the second holder 72, that is, the shaft 41, the holder 7 and the space surrounded by the rotor holder 121 are collectively referred to as “upper space 61”. However, the upper space 61 may include a space between the inner peripheral portion of the stator 32 and the rotor holder 121.

  The communication path 730 includes a vertical hole 731, an upper horizontal hole 732, and a lower horizontal hole 733. The vertical hole 731 extends in the vertical direction inside the second holder 72. The upper horizontal hole 732 extends radially inward from the upper part of the vertical hole 731. The opening of the upper horizontal hole 732, that is, the opening on the upper side of the communication path 730 is located at the upper part of the inner peripheral surface of the second holder 72 and is connected to the minute gap 74.

  The thrust cap 45 is fixed to the lower part of the second holder 72. The inner peripheral portion of the second holder 72 has a groove portion extending in the radial direction above the thrust cap 45, and the groove portion is a lower horizontal hole between the thrust cap 45 and the inner peripheral portion of the second holder 72. 733. The lower horizontal hole 733 extends radially inward from the lower part of the vertical hole 731. The opening of the lower horizontal hole 733, that is, the opening on the lower side of the communication path 730 is located at the lower part of the inner peripheral surface of the second holder 72. The thrust cap 45, the thrust plate 42, the holder 7 and the shaft 41 constitute a lower space 62.

  Also in the third embodiment, the upper space 61 existing between the inside of the rotor holder 121 and the upper seal portion 61a communicates with the lower space 62 via the communication path 730, whereby the lower space 62 and the upper space 61 are obtained. Occurrence of a pressure difference between the two is suppressed.

  FIG. 14 is a cross-sectional view of a bearing mechanism 402 according to another example. The 2nd holder 72 has the connection path formation part 73a which forms the connection path 730a. The communication path 730 a has a vertical groove 734 and a vertical hole 735. The vertical groove 734 is located on the outer peripheral surface of the second holder 72. Precisely, the vertical groove 734 and the inner peripheral surface of the stator 32 constitute a vertical hole continuous above the vertical hole 735. The vertical hole 735 penetrates the outer periphery of the second holder 72 in the vertical direction below the vertical groove 734. The thrust cap 45 has a cap through-hole 451 penetrating the thrust cap 45 in the vertical direction. By sticking the seal member 311 to the lower surface of the base portion 31, a cap lower space 622 is formed below the thrust cap 45. Similarly to FIG. 8, the lower space 62 is connected to the upper space 61 via the cap through-hole 451, the cap lower space 622, and the communication path 730a.

(Fourth embodiment)
FIG. 15 is a diagram illustrating a fan 1b according to the fourth embodiment. The fan 1b includes a rotating part 2a, a stationary part 3a, and a bearing mechanism 403. The bearing mechanism 403 includes a shaft 41, a bearing portion 49, a thrust plate 42, and a thrust cap 45. The bearing portion 49 includes a sleeve 491 that is a cylindrical member and a holder 492. The holder 492 covers the outer peripheral surface of the sleeve 491. The shaft 41 is inserted into the sleeve 491. A thrust plate 42 is fixed to the lower end portion of the shaft 41. The upper surface of the thrust plate 42 faces the lower surface of the sleeve 491 in the axial direction. In the bearing mechanism 403, a lower seal portion 62 a in which the lower interface of the lubricating oil 47 is located between the outer edge portion of the thrust plate 42 and the lower end portion of the holder 492 is configured. The thrust plate 42, the bearing portion 49, and the thrust cap 45 constitute a lower space 62.

  The rotor holder 121a of the rotating unit 2a includes a first rotor member 126 and a second rotor member 127. The first rotor member 126 has a substantially annular shape centered on the central axis J1 and extends from the upper portion of the shaft 41 outward in the radial direction. The second rotor member 127 is attached to the outer peripheral surface of the first rotor member 126. The second rotor member 127 has a cylindrical portion 127a, the rotor magnet 22 is fixed to the inner peripheral surface of the cylindrical portion 127a, and the blades 122 are disposed on the outer peripheral surface.

  The first rotor member 126 has a cylindrical rotor cylindrical portion 126 a that extends downward in the axial direction outside the holder 492 in the radial direction. An upper seal gap 611 is formed between the inner peripheral surface of the rotor cylindrical portion 126a and the upper portion of the outer peripheral surface of the holder 492 so that the radial width gradually increases downward. In the upper seal gap 611, an upper seal portion 61a where the interface of the lubricating oil 47 is located is formed.

  The stationary part 3a has a substantially cylindrical bush 31a. The bush 31 a extends upward from the central portion of the base portion 31. The bush 31a and the base portion 31 are a continuous member. A thrust cap 45 is fixed to the lower part of the bush 31a below the thrust plate 42, and the opening on the lower side of the bush 31a is closed by the thrust cap 45. The stator 32 is fixed to the outer peripheral surface of the bush 31a, and the holder 492 is fixed to the inner peripheral surface. The bush 31 a includes a communication path forming part 34 that constitutes the communication path 340 and a protrusion 313. The protruding portion 313 extends upward on the outer side of the rotor cylindrical portion 126a. A longitudinal gap 655 extending in the axial direction is formed between the rotor cylindrical portion 126a and the protruding portion 313, and evaporation of the lubricating oil 47 from the upper seal portion 61a is suppressed. The vertical gap 655 passes through a space 623 surrounded by a recess recessed radially inward at the center of the outer peripheral surface of the holder 492, a lower portion of the rotor cylindrical portion 126a, and a portion inside the protrusion 313 of the bush 31a. To the upper seal gap 611. Hereinafter, the vertical gap 65, the space 623, and the upper seal gap 611 (more precisely, the space below the interface of the upper seal gap 611) are collectively referred to as “upper space 61”.

  The communication path 340 has a vertical hole 341 and a lower horizontal hole 342. The vertical hole 341 extends in the axial direction inside the protrusion 313. The upper opening of the vertical hole 341 is connected to the upper space 61. The thrust cap 45 is fixed to the lower part of the bush 31a. The inner peripheral portion of the bush 31 a has a notch-shaped groove portion extending in the radial direction above the thrust cap 45, and the groove portion is a lower horizontal hole between the thrust cap 45 and the inner peripheral portion of the second holder 72. 342. The lower horizontal hole 342 extends radially inward from the lower end of the vertical hole 341. The opening of the lower horizontal hole 342, that is, the opening on the lower side of the communication path 340 is located on the inner peripheral surface of the bush 31a. The lower space 62 is connected to the lower horizontal hole 342.

  In the bearing mechanism 403, an upper thrust bearing portion 661a that supports the first rotor member 126 in the axial direction is formed in an upper thrust gap 661 between the lower surface of the first rotor member 126 and the upper surface of the sleeve 491. Thus, the first rotor member 126 serves as a thrust portion that forms the upper thrust bearing portion 661a. A lower thrust bearing portion 662 a that supports the thrust plate 42 in the axial direction is formed in the lower thrust gap 662 between the lower surface of the sleeve 491 and the upper surface of the thrust plate 42. A radial bearing 66 a that supports the shaft 41 in the radial direction is formed in a radial gap 66 between the outer peripheral surface of the shaft 41 and the inner peripheral surface of the sleeve 491.

  Also in the fourth embodiment, as in the first embodiment, the upper space 61 existing between the inside of the rotor holder 121a and the upper seal portion 61a is formed in the lower portion above the thrust cap 45 via the communication path 340. The space 62 can be communicated, and the occurrence of a pressure difference between the upper space 61 and the lower space 62 can be suppressed. In the bearing mechanism 403, an upper thrust bearing portion may be configured between the first rotor member 126 and the upper surface of the holder 492. The same applies to FIG. 16 below.

  FIG. 16 is a cross-sectional view of a bearing mechanism 403 according to another example. The connecting path 340a configured by the connecting path forming portion 34a of the bush 31a has a bush groove 343 and a bush through hole 344. The bush groove 343 extends in the vertical direction on the outer peripheral surface of the bush 31 a inside the inner peripheral surface of the stator 32. The bush through hole 344 penetrates in the vertical direction from the lower end of the bush groove 343 to the lower end of the outer peripheral portion of the bush 31a. Precisely, the bush groove 343 and the inner peripheral surface of the stator 32 constitute a vertical hole continuous above the bush through hole 344. The thrust cap 45 has a cap through hole 451. A cap lower space 622 is formed between the thrust cap 45 and the seal member 311 attached to the lower surface of the base portion 31 below the thrust cap 45.

  In the bearing mechanism 403, the lower space 62 communicates with the upper space 61 via the cap through hole 451, the cap lower space 622, and the communication path 340a.

  FIG. 17 is a view showing a bearing mechanism 403 according to still another example. The bearing mechanism 403 includes a bearing portion 493 that is a sleeve formed of one metal. The outer peripheral surface of the bearing portion 493 is fixed to the bush 31a. A radial bearing portion 66 a is formed in a radial gap 66 between the inner peripheral surface of the bearing portion 493 and the outer peripheral surface of the shaft 41 inserted into the bearing portion 493. An upper thrust bearing portion 661 a is formed in the upper thrust gap 661 between the upper surface of the bearing portion 493 and the lower surface of the first rotor member 126. In the bearing mechanism 403, the lower thrust bearing portion is not configured. Other structures of the bearing mechanism 403 are the same as the bearing mechanism 403 of the fan 1b shown in FIG. Also in the case shown in FIG. 17, by providing the communication path 340, the upper space 61 and the lower space 62 communicate with each other, and the occurrence of a pressure difference between the gaps 61 and 62 is suppressed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible. For example, the bearing mechanism 401 shown in FIG. 2 has a part above the upper horizontal hole 512 of the holder 46, a part below the lower horizontal hole 513, and the communication path forming part 5 between the two parts. A site | part may be comprised with another member. Thereby, the communication path formation part 5 can be shape | molded easily.

  In the third embodiment, the upper space 61 and the lower space 62 may be connected via the tube 16. The same applies to the fourth embodiment. In the fan 1 a shown in FIG. 12, the communication path may be configured by a groove portion extending in the vertical direction on the inner peripheral surface of the second holder 72. The same applies to the bush 31a shown in FIGS.

  The configurations in the above embodiment and each modification may be combined as appropriate as long as they do not contradict each other.

  The present invention can be used for a fan that generates an air flow.

DESCRIPTION OF SYMBOLS 1,1a, 1b Fan 2 Rotating part 3 Static part 5, 5a-5c, 34, 34a, 73, 73a Connection path formation part 7, 46, 492 Holder 11 Motor 22 Rotor magnet 31a Bush 32 Stator 41 Shaft 42 Thrust plate 44 , 491 Sleeve 45 Thrust cap 49 Bearing part 51, 51a, 51b, 52, 340, 340a, 730, 730a Connecting path 61 Upper space 61a Upper seal part 62 Lower space 62a Lower seal part 64, 662 Lower thrust gap 64a, 662a Below Thrust bearing portion 66 Radial gap 66a Radial bearing portion 71 First holder 72 Second holder 121 Rotor holder 122 Wings 126 First holder member 126a Rotor cylindrical portion 311 Seal member 343 Bush groove 344 Bushing through holes 401-4 03 Bearing mechanism 451 Cap through hole 515 Holder groove 516 Holder through hole 622 Cap lower space 661a Upper thrust bearing portion 661 Upper seal gap 711 Annular upper part J1 Central axis

Claims (18)

With multiple wings,
A motor that rotates the plurality of blades around a central axis;
With
The motor is
A stationary part having a stator;
A rotating part having a rotor magnet disposed on the radially outer side of the stator;
A bearing mechanism that rotatably supports the rotating part with respect to the stationary part;
With
The rotating part includes a substantially cylindrical lid holder with a lid on which the plurality of blades are disposed on an outer peripheral surface,
The bearing mechanism is
A shaft,
A sleeve into which the shaft is inserted;
A holder for holding the sleeve;
A thrust plate disposed under the shaft;
With
A radial bearing portion configured to support the shaft in a radial direction by a radial gap between the shaft and the sleeve;
A lower seal portion in which a lower interface of the lubricating oil is located between the thrust plate and the holder, and an upper seal in which an upper interface of the lubricant is located between the holder and the sleeve Part is composed,
A fan, wherein the holder includes a communication path forming portion that forms a communication path that connects an upper space between the interior of the rotor holder and the upper seal portion and a lower space in which the lower seal portion is located. With multiple wings,
A motor that rotates the plurality of blades around a central axis;
With
The motor is
A stationary part having a stator;
A rotating part having a rotor magnet disposed on the radially outer side of the stator;
A bearing mechanism that rotatably supports the rotating part with respect to the stationary part;
With
The rotating part includes a substantially cylindrical lid holder with a lid on which the plurality of blades are disposed on an outer peripheral surface,
The bearing mechanism is
A shaft,
A sleeve into which the shaft is inserted;
A holder for holding the sleeve;
A thrust plate disposed under the shaft;
With
The holder is
A substantially cylindrical first holder that covers the outer peripheral surface of the sleeve and the outer peripheral surface of the thrust plate;
A second holder having an inner peripheral surface to which an outer peripheral surface of the first holder is fixed, and wherein the stator is disposed outside;
With
A radial bearing portion configured to support the shaft in a radial direction by a radial gap between the shaft and the sleeve;
A lower seal portion is formed between the thrust plate and the first holder, where a lower interface of the lubricating oil is located, and is radially inward above the shaft and the sleeve of the first holder. An upper seal portion where the upper interface of the lubricating oil is located is formed between the protruding annular upper portion,
The second holder includes a communication path forming part that forms a communication path that connects an upper space between the interior of the rotor holder and the upper seal part and a lower space in which the lower seal part is located, fan. With multiple wings,
A motor that rotates the plurality of blades around a central axis;
With
The motor is
A stationary part having a stator;
A rotating part having a rotor magnet disposed on the radially outer side of the stator;
A bearing mechanism that rotatably supports the rotating part with respect to the stationary part;
With
The stationary part comprises a bush for holding the stator radially outward;
The rotating part includes a substantially cylindrical lid holder with a lid on which the plurality of blades are disposed on an outer peripheral surface,
The bearing mechanism is
A shaft,
A bearing portion into which the shaft is inserted;
A thrust plate disposed under the shaft;
With
A radial bearing portion that supports the shaft in a radial direction is configured in a radial gap between the shaft and the bearing portion,
A lower seal portion in which a lower interface of the lubricating oil is located between the thrust plate and the bearing portion, and the rotor cylinder extends axially downward from the thrust portion that extends radially outward from the upper portion of the shaft. And an upper seal portion in which the upper interface of the lubricating oil is located between the portion and the bearing portion,
The fan includes a communication path forming portion that forms a communication path that connects an upper space between the interior of the rotor holder and the upper seal portion and a lower space in which the lower seal portion is located.   The fan according to claim 1 or 2, wherein a lower thrust bearing portion that supports the thrust plate in an axial direction is configured in a lower thrust gap between a lower surface of the sleeve and an upper surface of the thrust plate.   The fan according to claim 3, wherein a lower thrust bearing portion that supports the thrust plate in an axial direction is configured in a lower thrust gap between a lower surface of the bearing portion and an upper surface of the thrust plate. The bearing portion is
A sleeve which is a cylindrical member;
A holder covering the outer peripheral surface of the sleeve;
With
The fan according to claim 3 or 5, wherein an upper thrust bearing portion that supports the thrust portion in an axial direction is formed between an upper surface of the sleeve and a lower surface of the thrust portion. Between the outer peripheral surface of the sleeve and the inner peripheral surface of the holder, an upper seal gap is formed in which the radial width gradually increases upward, and the upper seal portion is formed in the upper seal gap,
The fan according to claim 1, wherein the upper space is a space surrounded by the sleeve, the holder, the shaft, and the rotor holder. Between the inner peripheral surface of the annular upper portion and the outer peripheral surface of the shaft, an upper seal gap is formed in which the radial width gradually increases upward, and the upper seal portion is formed in the upper seal gap. ,
The fan according to claim 2, wherein the upper space is a space surrounded by the shaft, the holder, and the rotor holder.   The fan according to any one of claims 1, 2, 4, 7, and 8, wherein an opening on an upper side of the communication path forming portion is located on an inner peripheral surface of the holder.   The fan according to any one of claims 1, 2, 4, and 7 to 9, wherein an opening on a lower side of the communication path forming portion is located on an inner peripheral surface of the holder. The bearing mechanism further includes a cap member that closes an opening at a lower portion of the holder,
The fan according to claim 1, wherein the lower space exists above the cap member. The cap member includes a cap through-hole penetrating the cap member in a vertical direction;
The fan according to claim 11, wherein the lower space communicates with the upper space via the cap through-hole and the communication path. The connecting path is
A holder groove extending in the vertical direction on the outer peripheral surface of the holder inside the inner peripheral surface of the stator;
A holder through-hole penetrating from the holder groove to the lower end of the holder;
Including
A seal member that forms a space between the cap member and the cap member;
The lower space communicates with the upper space via the cap through-hole, the space between the cap member and the seal member, the holder through-hole, and the holder groove. fan.   The fan in any one of Claim 3, 5 and 6 with which the opening below the said communication path formation part is located in the internal peripheral surface of the said bush. The bearing mechanism further comprises a cap member that closes an opening at a lower portion of the bush;
The fan according to any one of claims 3, 5, 6, and 14, wherein the lower space exists above the cap member. The cap member includes a cap through-hole penetrating the cap member in a vertical direction;
The fan according to claim 15, wherein the lower space communicates with the upper space via the cap through-hole and the communication path. The connecting path is
A bush groove extending in the vertical direction on the outer peripheral surface of the bush inside the inner peripheral surface of the stator,
A bush through hole penetrating from the bush groove to the lower end of the bush;
Including
A seal member that forms a space between the cap member and the cap member;
The lower space communicates with the upper space via the cap through hole, the space between the cap member and the seal member, the bush through hole, and the bush groove. fan.   The fan according to any one of claims 1 to 17, wherein the communication path forming unit forms a plurality of communication paths including the communication path, and the plurality of communication paths are arranged at equal intervals in the circumferential direction.

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