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CN119677961A - Blower fan - Google Patents

Blower fan Download PDF

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Publication number
CN119677961A
CN119677961A CN202480003661.1A CN202480003661A CN119677961A CN 119677961 A CN119677961 A CN 119677961A CN 202480003661 A CN202480003661 A CN 202480003661A CN 119677961 A CN119677961 A CN 119677961A
Authority
CN
China
Prior art keywords
ball bearing
shaft
impeller
inner ring
axial direction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202480003661.1A
Other languages
Chinese (zh)
Inventor
池田仁子
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MinebeaMitsumi Inc
Original Assignee
MinebeaMitsumi Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2023212865A external-priority patent/JP2024114608A/en
Application filed by MinebeaMitsumi Inc filed Critical MinebeaMitsumi Inc
Publication of CN119677961A publication Critical patent/CN119677961A/en
Pending legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/051—Axial thrust balancing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/056—Bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/14—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load
    • F16C19/16—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with a single row of balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C25/00—Bearings for exclusively rotary movement adjustable for wear or play
    • F16C25/06—Ball or roller bearings
    • F16C25/08—Ball or roller bearings self-adjusting

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

本发明提供一种能提高叶轮的转速的送风机。送风机(1)具备：轴(10)；套筒(81)；叶轮(56)，可旋转地支承于轴(10)的轴向上的一侧，通过旋转生成从轴向上的一侧朝向另一侧的空气流；第一球轴承(20)，其包括：内圈(21)，支承于轴(10)上的靠近叶轮(56)的部分；和外圈(22)，固定于套筒(81)的内周面(81i)；第二球轴承(30)，其内圈(31)支承于轴(10)上的比内圈(21)远离叶轮(56)的部分；第一凸缘部(28)，支承于轴(10)上的内圈(21)与内圈(31)之间的部分，并从轴(10)向径向的外侧伸出；和第一弹簧(40)，配置于第一凸缘部(28)与内圈(31)之间。第一凸缘部(28)在叶轮(56)旋转时，将内圈(21)从另一侧朝向一侧推压。

The present invention provides a blower capable of increasing the rotation speed of an impeller. The blower (1) comprises: a shaft (10); a sleeve (81); an impeller (56) rotatably supported on one side of the shaft (10) in the axial direction, and generating an air flow from one side to the other side in the axial direction by rotation; a first ball bearing (20) comprising: an inner ring (21) supported on a portion of the shaft (10) close to the impeller (56); and an outer ring (22) fixed to an inner peripheral surface (81i) of the sleeve (81); a second ball bearing (30) whose inner ring (31) is supported on a portion of the shaft (10) farther from the impeller (56) than the inner ring (21); a first flange portion (28) supported on a portion between the inner ring (21) and the inner ring (31) on the shaft (10) and extending radially outward from the shaft (10); and a first spring (40) disposed between the first flange portion (28) and the inner ring (31). When the impeller (56) rotates, the first flange portion (28) presses the inner ring (21) from the other side toward one side.

Description

Blower fan
Technical Field
The present invention relates to a blower.
Background
A device is known which includes a rotary shaft rotatably supported by two ball bearings and an impeller mounted on the rotary shaft and rotating together with the rotary shaft (for example, refer to patent document 1 below). In the device described in patent document 1, an air flow is generated from the impeller side toward the opposite side of the impeller in the axial direction by rotation of the impeller. In contrast, a thrust force (thrust) is generated from the opposite side of the impeller toward the impeller side with respect to the rotation shaft or the like.
In the device described in patent document 1, a preload spring is disposed closer to the impeller than the ball bearing on the impeller side. In the device described in patent document 1, when the impeller rotates, the ball bearing on the impeller side receives a force in a direction opposite to the direction of the pushing force (a direction from the impeller side toward the opposite side of the impeller) by the preload spring, and thus preload is applied.
Prior art literature
Patent literature
Patent document 1 Japanese patent application laid-open No. 2017-210878
Disclosure of Invention
Problems to be solved by the invention
In general, the thrust force becomes large according to the rotation speed of the impeller. In the device described in patent document 1, a force is applied to the ball bearing on the impeller side in a direction opposite to the direction in which the thrust force acts by the preload spring. Therefore, in the device described in patent document 1, in order to always apply preload to the ball bearing when the impeller rotates, it is necessary to increase the urging force of the preload spring as the rotation speed of the impeller increases. However, in general, a maximum value (predetermined value) is defined for the surface pressure applied to the ball bearing. That is, there is an upper limit to the preload that can be applied to the ball bearing. Therefore, conventionally, it has been difficult to increase the rotation speed of the impeller due to such restrictions of the ball bearing.
Thus, the first and second substrates are bonded together, the present invention provides a blower capable of increasing the rotation speed of an impeller as one of the problems.
Solution for solving the problem
The blower of the present invention includes a shaft, a sleeve that accommodates a portion of the shaft therein, an impeller rotatably supported on one side in an axial direction of the shaft and that generates an air flow from the one side in the axial direction toward the other side in the axial direction by rotation, a first ball bearing that includes an inner ring supported on the shaft at a portion near the impeller, and an outer ring fixed to an inner peripheral surface of the sleeve, a second ball bearing whose inner ring is supported on the shaft at a portion farther from the impeller than the inner ring of the first ball bearing, a first flange portion supported on a portion between the inner ring of the first ball bearing and the inner ring of the second ball bearing on the shaft and that protrudes radially outward from the axial direction perpendicular to the axial direction, and a first spring disposed between the first flange portion and the inner ring of the second ball bearing. In this blower, the first flange portion presses the inner ring of the first ball bearing from the other side toward the one side when the impeller rotates.
The other blower of the present invention includes a shaft, a sleeve that accommodates a part of the shaft therein, an impeller rotatably supported on one side in an axial direction of the shaft and configured to generate an air flow from the one side in the axial direction toward the other side in the axial direction by rotation, a first ball bearing including an inner ring supported on the shaft in a portion adjacent to the impeller, and an outer ring disposed on an inner periphery of the sleeve, a second ball bearing having an inner ring supported on a portion of the shaft farther from the impeller than the inner ring of the first ball bearing, a first flange portion supported on a portion between the inner ring of the first ball bearing and the inner ring of the second ball bearing in a radial direction perpendicular to the axial direction and configured to extend radially outward from the inner ring of the first ball bearing, and a first spring disposed between the first flange portion and the inner ring of the second ball bearing, the first ball bearing having an extending portion that extends radially inward, and a first flange portion that urges the first ball bearing toward the other side when the first ball bearing is abutted against the first ball bearing.
These blowers may further have at least one of the following configurations.
The impeller may form a part of a rotor that rotates with respect to the sleeve in accordance with the rotation of the shaft, and the maximum value of the load applied by the first spring may be smaller than the load applied by the rotor.
The movement of the outer race of the second ball bearing in the axial direction may be restricted.
The blower may further include a fixing portion fixed to an inner peripheral surface of the sleeve and extending inward in the radial direction, the sleeve may include a stepped portion protruding inward in the radial direction at a portion closer to the one side than the fixing portion, and the outer ring of the second ball bearing may be held between the stepped portion and the fixing portion to be restricted from moving in the axial direction.
The blower may further include a second flange portion supported by the shaft at a portion closer to the other side than the inner ring of the second ball bearing and extending outward in the radial direction from the axial direction, and a second spring disposed between the second flange portion and the inner ring of the second ball bearing. In this case, the impeller may form a part of a rotor that rotates with respect to the sleeve in accordance with the rotation of the shaft, and the amount of change in the load ((applied force)) applied by the first spring and the second spring may be larger than the weight of the inner ring of the second ball bearing when the amounts of deflection of the first spring and the second spring change by the amounts of axial play of the first ball bearing and/or the second ball bearing.
The blower may further include a second flange portion supported by the shaft at a portion closer to the other side than the inner ring of the second ball bearing and extending outward in the radial direction from the axial direction, wherein the inner peripheral surface of the sleeve may include a stepped portion protruding inward in the radial direction at a portion between the outer ring of the first ball bearing and the outer ring of the second ball bearing in the axial direction, and a third spring may be disposed between the stepped portion in the axial direction and the outer ring of the second ball bearing, and the second flange portion may push the inner ring of the second ball bearing from the other side toward the one side when the impeller rotates. In this case, the impeller may form a part of a rotor that rotates with respect to the sleeve in accordance with the rotation of the shaft, and the maximum value of the load applied by the first spring and the maximum value of the load applied by the third spring may be smaller than the load applied by the rotor.
In the blower, a washer may be supported on the other surface of the impeller, and the shaft may pass through the washer.
Effects of the invention
According to the present invention, a blower capable of increasing the rotation speed of an impeller is provided.
Drawings
Fig. 1 is a cross-sectional view in the axial direction of a blower according to a first embodiment of the present invention.
Fig. 2 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 1 when the impeller is stationary.
Fig. 3 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 1 when the impeller rotates.
Fig. 4 is a cross-sectional view in the axial direction of a blower according to a second embodiment of the present invention.
Fig. 5 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 4 when the impeller is stationary.
Fig. 6 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 4 when the impeller rotates.
Fig. 7 is a cross-sectional view in the axial direction of a blower according to a third embodiment of the present invention.
Fig. 8 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 7 when the impeller is stationary.
Fig. 9 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 7 when the impeller rotates.
Fig. 10 is a cross-sectional view in the axial direction of a blower according to a fourth embodiment of the present invention.
Fig. 11 is an enlarged and schematic cross-sectional view of the bearing device shown in fig. 10 when the impeller is stationary.
Detailed Description
Hereinafter, a mode for implementing the blower of the present invention is shown by way of example together with the drawings. The embodiments illustrated below are intended to facilitate the understanding of the present invention and are not intended to limit the present invention. The present invention can be modified and improved according to the following embodiments without departing from the gist thereof. In the drawings, the dimensions of the respective members may be exaggerated or reduced or hatched for the convenience of understanding.
(First embodiment)
Fig. 1 is a cross-sectional view in the axial direction of the blower according to the present embodiment. As shown in fig. 1, the blower 1 includes a casing 11, a bearing device 80, a stator 70, and a rotor 50 as main components.
The bearing device 80 includes a cylindrical (in this embodiment, cylindrical) sleeve 81, a shaft 10, a first ball bearing 20, a second ball bearing 30, a washer 29, a first flange portion 28, a first spring 40, and a fixing portion 60.
The sleeve 81 is made of, for example, metal, and accommodates therein the first ball bearing 20, the second ball bearing 30, the first flange 28, the first spring 40, the fixing portion 60, a part of the shaft 10, and the like.
The shaft 10 passes through the center of the sleeve 81 in the radial direction. A part of the shaft 10 is a protruding portion 10a protruding outward from the inside of the sleeve 81. In the present embodiment, the blower 1 is configured to be concentric with the shaft 10 at the center in the radial direction. However, the positional relationship of the shaft 10 and the like in the blower 1 is not limited to concentric circles. The longitudinal direction of the shaft 10 is the axial direction of the blower 1, and the axial direction is perpendicular to the radial direction. Hereinafter, a side facing the protruding portion 10a side in the axial direction may be referred to as "upper", "upper" or "one side", and a side facing the protruding portion 10a side opposite thereto may be referred to as "lower", "lower" or "other side". In addition, the side radially closer to the shaft 10 is sometimes referred to as "inner" or "inner", and the side further from the shaft 10 is sometimes referred to as "outer" or "outer".
The first ball bearing 20 is fitted near the protruding portion 10a in the shaft 10 (i.e., one side of the shaft 10). In the axial direction, the protruding portion 10a is located above the first ball bearing 20. The second ball bearing 30 is fitted near the end of the lower side of the shaft 10 (i.e., the other side of the shaft 10). The second ball bearing 30 is located below the first ball bearing 20. The first ball bearing 20 and the second ball bearing 30 rotatably support the shaft 10.
The washer 29 is located above the first ball bearing 20, and the shaft 10 penetrates a hole formed in the center of the washer 29 in the radial direction. The first flange 28 is supported by the shaft 10 below the first ball bearing 20. The first spring 40 is disposed between the first flange 28 and the second ball bearing 30 in the axial direction. The fixing portion 60 is disposed below the second ball bearing 30.
The bearing device 80 will be described in more detail later.
The housing 11 has a cylindrical shape, and may be, for example, substantially square, substantially rectangular, circular, or the like when viewed from the axial direction. The inner space of the housing 11 is formed as a wind tunnel through which the air flow flows from the upper side toward the lower side in the axial direction. That is, an air inlet 11i for sucking air into the interior space of the housing 11 is formed at the upper end 11u of the housing 11, and an air outlet 11o for discharging air is formed at the lower end 11d of the housing 11. The bearing device 80, the stator 70, the rotor 50, and the like are accommodated in the inner space of the housing 11. The housing 11 includes a side wall 12, a base portion 13, and a fixed vane 14.
The side wall 12 is located radially outward of the rotor 50 and surrounds the periphery of the rotor 50. The side wall 12 is connected to an upper end 11u of the housing 11. The side wall 12 has a cylindrical shape centered on the shaft 10, and is disposed with a gap from the rotor 50. The side wall 12 also has a function of protecting the rotor 50, the bearing device 80, and the like disposed therein.
The stationary blade 14 is constituted by a plurality of stationary vanes. By this fixed vane 14, the side wall 12 and the base portion 13 are connected in the radial direction.
The base portion 13 includes a disk-shaped bottom portion 13a perpendicular to the axial direction, a cylindrical outer peripheral wall 13b extending a predetermined length upward in the axial direction from an outer end portion of the bottom portion 13a, and a cylindrical boss portion 13c protruding a predetermined length upward in the axial direction from an inner end portion of the bottom portion 13 a. The outer peripheral wall 13b and the boss portion 13c are concentric with respect to the shaft 10.
The fixed blades 14 are integrally formed on the outer peripheral surface of the outer peripheral wall 13 b. That is, the outer peripheral wall 13b is supported by the side wall 12 via the fixed vane 14. The sleeve 81 of the bearing device 80 is press-fitted to the inner peripheral surface of the boss portion 13c, for example.
The side wall 12 of the housing 11, the base portion 13, and the fixed blades 14 may be integrally formed by injection molding of a synthetic resin (e.g., polybutylene terephthalate resin). Instead of the fixed blade 14 connecting the side wall 12 and the base portion 13, a plurality of spokes formed from a rod-like portion may be used.
Next, the stator 70 will be described.
The stator 70 includes a stator core 71, an insulator 72, and a plurality of coils 73 as main components.
In the present embodiment, the stator core 71 is formed of a laminate in which a plurality of cores of electromagnetic steel plates made of a soft magnetic material are laminated. The stator core 71 is located outside with respect to the sleeve 81 of the bearing device 80. In the present embodiment, a circular opening 71h is formed in the inner peripheral surface of the stator core 71. The sleeve 81 penetrates the opening 71h of the stator core 71 in the axial direction. The sleeve 81 is attached to the stator core 71 by, for example, being press-fitted into the opening 71h of the stator core 71. The stator core 71 may be fixed to the sleeve 81 with an adhesive.
The insulator 72 is made of an insulating material, is attached to the stator core 71, and covers a portion of the stator core 71. An outer peripheral surface 71o of the stator core 71 is exposed from the insulator 72. The plurality of coils 73 are wound around the stator core 71 with an insulator 72 interposed therebetween at predetermined intervals in the circumferential direction of the stator core 71. Therefore, the stator core 71 and the plurality of coils 73 are insulated via the insulator 72.
Next, the rotor 50 will be described.
The rotor 50 includes an impeller 56, a rotor yoke 52, a magnet 51, and a bushing 53 as main components.
The impeller 56 includes a hub 54 and a plurality of blades 55 provided on the outer peripheral surface of the hub 54 in the circumferential direction. The hub 54 and the plurality of blades 55 may be integrally formed by injection molding a synthetic resin (e.g., polybutylene terephthalate resin including glass fibers), for example.
The hub 54 has a cup-like shape having a bottom cross section in a substantially inverted U shape, and includes a plate-like base 54a perpendicular to the axial direction and a cylindrical (cylindrical) side wall 54b extending substantially in the axial direction from an outer end portion of the base 54 a. The boss 54 is disposed with the base 54a facing upward. The hub 54 covers the rotor yoke 52, the magnet 51, the bushing 53, the stator 70, the bearing device 80, and the like from the upper side. In this way, the hub 54 suppresses foreign matter from entering the inside of the hub 54.
The plurality of blades 55 have substantially the same shape and extend outward from the side wall 54b of the hub 54. The plurality of blades 55 are arranged at substantially equal intervals in the circumferential direction of the side wall 54b of the hub 54. The plurality of blades 55 are each formed so as to generate an air flow that flows in the axial direction from the upper side toward the lower side in the internal space of the casing 11 when the impeller 56 rotates.
The bushing 53 is made of, for example, a soft magnetic material. A through hole 53h penetrating the bush 53 in the axial direction is formed in the center of the bush 53 in the radial direction. The shaft 10 is fitted to the bush 53 by, for example, pressing the protruding portion 10a of the shaft 10 into the through hole 53h. Further, a concave portion 53c recessed inward is formed in an upper portion of the bush 53.
The rotor yoke 52 has a cup-like shape having a bottom section with a substantially inverted U-shape, and is made of, for example, a soft magnetic material. The rotor yoke 52 includes a plate-shaped base 52a perpendicular to the axial direction and a cylindrical (cylindrical) side wall 52b extending substantially in the axial direction from an end portion outside the base 52 a. The rotor yoke 52 is disposed with the base 52a facing upward. The rotor yoke 52 covers the magnet 51, the stator 70, the bearing device 80, and the like from above. In this way, the rotor yoke 52 suppresses the entry of foreign matter inside the rotor yoke 52.
A circular hole is formed in the center of the base 52a of the rotor yoke 52 in the radial direction when viewed from the axial direction. The hole is defined by an inner peripheral surface 52ai of the base 52 a. The inner peripheral surface 52ai of the pedestal 52a and its vicinity are caulked and fixed to the upper side portion of the bush 53. As a result, the recess 53c is formed in the upper portion of the bush 53. Further, an upper portion of the outer peripheral surface of the side wall 52b of the rotor yoke 52 is fixed to the inner peripheral surface of the side wall 54b of the hub 54 of the impeller 56 using, for example, an adhesive. In this way, the rotor yoke 52 is fixed to the inner peripheral surface of the impeller 56.
The magnet 51 is formed in a ring shape when viewed from the axial direction, and in the present embodiment, is formed in a cylindrical shape. The outer peripheral surface of the magnet 51 is fixed to the inner peripheral surface of the side wall 52b of the rotor yoke 52 via an adhesive, for example. The magnets 51 are alternately magnetized in the circumferential direction into N-poles and S-poles. The inner peripheral surface 51i of the magnet 51 is located outside the stator 70 in the radial direction, and faces the outer peripheral surface 71o of the stator core 71 with an air gap therebetween.
In the blower 1, when current is supplied to the plurality of coils 73, magnetic interaction occurs between the outer peripheral surface 71o of the stator core 71 and the inner peripheral surface 51i of the magnet 51, and a magnetic circuit is formed in the blower 1. The shaft 10 rotates through the magnetic circuit, and as the shaft 10 rotates, the rotor 50 including the impeller 56 rotates around the shaft 10. That is, the rotor 50 including the impeller 56 rotates relatively with respect to the bearing device 80 including the stator 70 and the sleeve 81. In this way, the blower 1 is configured as an outer rotor type. Then, by the rotation of the impeller 56, an air flow flowing in the axial direction from the upper side (one side) toward the lower side (the other side) in the inner space of the housing 11 is generated.
Next, the bearing device 80 will be described in more detail.
As shown in fig. 1, in the bearing device 80, the first ball bearing 20 is disposed in the vicinity of the protruding portion 10a of the shaft 10. As shown in fig. 1, a base 54a of the hub 54 is provided on the upper side of the protruding portion 10 a. Accordingly, the first ball bearing 20 is located closer to the base portion 54a of the hub 54 than the second ball bearing 30. That is, the first ball bearing 20 is located closer to the impeller 56 than the second ball bearing 30.
Fig. 2 is an enlarged and schematic cross-sectional view of the bearing device 80 when the impeller 56 is stationary. Further, fig. 2 shows a case of the bearing device 80 when the impeller 56 is stationary in a case where the blower 1 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction.
As shown in fig. 2, the first ball bearing 20 has an inner race 21, an outer race 22, and a plurality of rolling bodies (balls) 23. The shaft 10 is inserted into a through hole defined by the inner peripheral surface of the inner ring 21. The inner race 21 is supported by the shaft 10 penetrating the through hole of the inner race 21. The inner race 21 is supported in the shaft 10 at a portion near the impeller 56. A concave portion 21c that is recessed in an arc shape toward the inside when viewed in the radial direction is formed in the center in the axial direction in the outer peripheral surface 21o of the inner ring 21. The outer peripheral surface of the outer ring 22 is fixed to the inner peripheral surface 81i of the sleeve 81, for example, using an adhesive. An arc-shaped concave portion 22c recessed outward when viewed in the radial direction is formed in the center in the axial direction of the inner peripheral surface 22i of the outer ring 22. The plurality of rotors 23 are sandwiched and supported by the concave portion 21c of the inner ring 21 and the concave portion 22c of the outer ring 22. In this way, by sandwiching the plurality of rotors 23 between the inner ring 21 and the outer ring 22, the inner ring 21 is rotated together with the shaft 10 with respect to the outer ring 22 fixed to the sleeve 81.
The second ball bearing 30 has the same configuration as the first ball bearing 20. The shaft 10 is inserted into a through hole defined by the inner peripheral surface of the inner ring 31 of the second ball bearing 30. The inner race 31 is supported by the shaft 10 penetrating the through hole of the inner race 31. The inner ring 31 is supported in a portion of the shaft 10 farther from the impeller 56 than the inner ring 21. The outer peripheral surface of the outer ring 32 is substantially in surface contact with the inner peripheral surface 81i of the sleeve 81. The plurality of rotating bodies 33 are sandwiched and supported by the concave portion 31c of the inner ring 31 and the concave portion 32c of the outer ring 32. In this way, the plurality of rotors 33 are interposed between the inner race 31 and the outer race 32, so that the inner race 31 rotates together with the shaft 10 relative to the outer race 32.
In the present embodiment, the outer ring 22 of the first ball bearing 20 is fixed to the sleeve 81 by adhesion, but the inner ring 21 of the first ball bearing 20 and the inner ring 31 and the outer ring 32 of the second ball bearing 30 are respectively in clearance fit. Specifically, the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 are respectively in clearance fit with the shaft 10, and the outer ring 32 of the second ball bearing 30 is in clearance fit with the sleeve 81.
The sleeve 81 includes a stepped portion 81P protruding inward in the radial direction. The stepped portion 81P is axially located between the outer race 22 of the first ball bearing 20 and the outer race 32 of the second ball bearing 30. The end surface 81Pe of the stepped portion 81P is located at the same position as the inner peripheral surface 22i of the outer ring 22 of the first ball bearing 20 or at a position outside the inner peripheral surface 22i, and is located at the same position as the inner peripheral surface 32i of the outer ring 32 of the second ball bearing 30 or at a position outside the inner peripheral surface 32i in the radial direction. The upper surface 81Pu of the stepped portion 81P is in contact with the lower surface 22d of the outer race 22 of the first ball bearing 20. The lower surface 81Pd of the stepped portion 81P contacts the upper surface 32u of the outer race 32 of the second ball bearing 30. In the present embodiment, the stepped portion 81P is integrated with the sleeve 81, but may be formed of a substantially cylindrical other member fixed to the inner peripheral surface 81i of the sleeve 81 by adhesion or the like.
The fixing portion 60 is located below (on the other side of) the stepped portion 81P. In other words, the stepped portion 81P is located above (on one side of) the fixed portion 60. The fixing portion 60 is fixed to the inner peripheral surface 81i of the sleeve 81 and protrudes inward. In the present embodiment, the fixing portion 60 includes a washer 62 fixed to an inner peripheral surface 81i of the sleeve 81 and protruding inward, and a spacer 61 disposed on an upper surface of the washer 62. The lower surface 32d of the outer race 32 of the second ball bearing 30 is in contact with the upper surface of the spacer 61. The spacer 61 and the washer 62 are annular, and the shaft 10 is inserted inside the inner peripheral surface of the spacer 61 and inside the inner peripheral surface of the washer 62. The fixing portion 60 is not limited to this, and may be constituted by, for example, only the washer 62 or only the spacer 61 fixed to the inner peripheral surface 81 i.
In the present embodiment, the outer race 32 of the second ball bearing 30 is held between the stepped portion 81P and the fixed portion 60 and is restrained from moving in the axial direction. The movement of the outer ring 32 in the axial direction may be restricted by adhering the outer ring 32 of the second ball bearing 30 to the inner peripheral surface 81i of the sleeve 81 with an adhesive or the like.
The first flange portion 28 is fixed to a portion between the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 in the shaft 10, and protrudes radially outward from the shaft 10. In the present embodiment, the first flange portion 28 is a washer, and is fitted into a groove formed in the outer peripheral surface 10o of the shaft 10, thereby being supported by the shaft 10. The configuration of the first flange 28 is not limited to this, and may be, for example, a flange-shaped portion integrally formed with the shaft 10. In the present embodiment, the first flange 28 is located directly below the inner ring 21 of the first ball bearing 20, and is in contact with the lower surface 21d of the inner ring 21 of the first ball bearing 20 when the impeller 56 is stationary, but may not be in contact.
The first spring 40 is disposed between the lower surface of the first flange 28 and the upper surface 31u of the inner race 31 of the second ball bearing 30. The shaft 10 penetrates the inside of the first spring 40. That is, the first spring 40 surrounds a portion of the outer circumferential surface 10o of the shaft 10.
In the present embodiment, the washer 29 is supported by the shaft 10. For example, the washer 29 is supported by the shaft 10 by being fitted into a groove formed in the outer peripheral surface 10o of the shaft 10. The shaft 10 is inserted into the through hole 53h of the bush 53.
When the blower 1 is disposed such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction, a load F1 applied by the rotor 50 acts on the shaft 10 from the upper side toward the lower side when the impeller 56 is stationary, as indicated by an arrow in fig. 2. Then, the shaft 10 and the inner ring 21 of the first ball bearing 20 supported by the shaft 10 move downward. As described above, the outer race 22 of the first ball bearing 20 is fixed to the sleeve 81. Accordingly, the inner race 21 of the first ball bearing 20 is located on the lower side opposite to the outer race 22. Therefore, when the impeller 56 is stationary, the rotor 23 of the first ball bearing 20 contacts the upper region of the recess 21c of the inner race 21 and the lower region of the recess 22c of the outer race 22. That is, when the impeller 56 is stationary, as shown by a chain line in fig. 2, the first ball bearing 20 is preloaded in a state in which a straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined with respect to the radial direction so as to be directed radially outward as going downward.
Since the first spring 40 is disposed on the upper surface 31u of the inner ring 31 of the second ball bearing 30, the inner ring 31 supported by the shaft 10 also moves downward as the shaft 10 receives the load F1 applied by the rotor 50. As described above, the movement of the outer race 32 of the second ball bearing 30 in the axial direction is restricted. Accordingly, the inner race 31 of the second ball bearing 30 is located on the lower side opposite to the outer race 32. Therefore, when the impeller 56 is stationary, the rotor 33 of the second ball bearing 30 contacts the upper region of the concave portion 31c of the inner race 31 and the lower region of the concave portion 32c of the outer race 32. That is, when the impeller 56 is stationary, as shown by a chain line in fig. 2, the second ball bearing 30 is preloaded in a state in which a straight line connecting the contact points of the inner ring 31 and the outer ring 32 with the rotor 33 is inclined with respect to the radial direction so as to be directed radially outward as going downward.
In this way, in the bearing device 80, when the impeller 56 is stationary, the preload applied to the first ball bearing 20 and the second ball bearing 30 is combined in parallel in such a manner that the straight line connecting the contact points of the respective inner ring and outer ring with the rotor is inclined with respect to the radial direction so as to be directed radially outward.
Further, the first spring 40 is in contact with the first flange portion 28 supported by the shaft 10, but is not in contact with the first ball bearing 20. Accordingly, the urging force of the first spring 40 is prevented from being transmitted to the first ball bearing 20 by the first flange portion 28 supported by the shaft 10. That is, when the impeller 56 is stationary, substantially only the preload generated by the load F1 applied by the rotor 50 is applied to the first ball bearing 20.
Next, the bearing device 80 in the case where the impeller 56 rotates will be described.
Fig. 3 is an enlarged and schematic cross-sectional view of the bearing device 80 when the impeller 56 rotates. Further, fig. 3 shows a case of the bearing device 80 when the impeller 56 rotates in the case where the blower 1 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction.
As shown by an arrow in fig. 3, when the blower 1 is disposed such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction, when the impeller 56 rotates, a thrust force F2 acts on the shaft 10 in addition to a load F1 applied from the upper side to the lower side by the rotor 50. The thrust F2 acts from the lower side (the other side) toward the upper side (the one side) by the air flow from the upper side toward the lower side generated by the rotation of the impeller 56.
Specifically, when the rotation speed of the impeller 56 increases (when the impeller 56 rotates at a high speed), the thrust force F2 is greater than the load F1 applied by the rotor 50, and as a result, the shaft 10 and the first flange portion 28 supported by the shaft 10 move upward by the thrust force F2. As a result of the first flange 28 moving upward, the inner ring 21 of the first ball bearing 20 is pushed from the lower side (the other side) toward the upper side (the one side) by the first flange 28 in contact with the lower surface 21d of the inner ring 21, and moves upward. The outer race 22 of the first ball bearing 20 is fixed to the sleeve 81. Therefore, the inner race 21 is located on the upper side with respect to the outer race 22. Therefore, when the impeller 56 rotates at a high speed, the rotor 23 of the first ball bearing 20 contacts the lower region of the concave portion 21c of the inner ring 21 and the upper region of the concave portion 22c of the outer ring 22. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 3, the first ball bearing 20 is preloaded in a state in which a straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
The rotation speed of the impeller 56 is not particularly limited, and may be 8000rpm or more, 10000rpm or more, 15000rpm or more, or 30000rpm or more, for example.
When the impeller 56 rotates at a high speed, the inner ring 31 of the second ball bearing 30 supported by the shaft 10 moves upward together with the shaft 10 due to the thrust force F2. However, as the force of the inner ring 31 pressing the first spring 40 increases, the first spring 40 rebounds to press the inner ring 31 downward. As a result, the inner ring 31 is held in the lower position. The movement of the outer race 32 of the second ball bearing 30 in the axial direction is restricted, and therefore, the inner race 31 is located on the lower side relative to the outer race 32. Therefore, when the impeller 56 rotates at a high speed, the rotor 33 of the second ball bearing 30 contacts the upper region of the concave portion 31c of the inner ring 31 and the lower region of the concave portion 32c of the outer ring 32. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 3, the second ball bearing 30 is preloaded in a state in which a straight line connecting the contact points of the inner ring 31 and the outer ring 32 with the rotor 33 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
In this way, in the bearing device 80, when the impeller 56 rotates at a high speed, the preload applied to the first ball bearing 20 and the second ball bearing 30 becomes a so-called front combination.
Although not particularly limited, in the bearing device 80 of the present embodiment, the maximum value of the load (urging force) applied by the first spring 40 is smaller than the load F1 applied by the rotor 50 when the blower 1 is disposed such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction. Here, as described above, the thrust force F2 at the time of high-speed rotation of the impeller 56 is larger than the load F1 applied by the rotor 50. That is, in the present embodiment, the load applied by the first spring 40 is smaller than the thrust force F2 at the time of high-speed rotation. Therefore, in the bearing device 80, particularly at the time of high-speed rotation, the urging force exerted by the first spring 40 is suppressed from acting in such a manner as to overcome the urging force F2.
As described above, the blower 1 according to the present embodiment includes the shaft 10, the sleeve 81 that accommodates a part of the shaft 10 (a part substantially excluding the protruding portion 10 a) therein, the impeller 56 rotatably supported on one side in the axial direction of the shaft 10 and generates an air flow from one side in the axial direction toward the other side in the axial direction by rotation, the first ball bearing 20 that includes the inner ring 21 supported on the shaft 10 and that is close to the impeller 56, and the outer ring 22 that is fixed to the inner circumferential surface 81i of the sleeve 81, the second ball bearing 30 that has the inner ring 31 supported on the shaft 10 and that is further from the impeller 56 than the inner ring 21 of the first ball bearing 20, the first flange 28 that is supported on a part between the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 and that protrudes radially outward from the shaft 10, and the first spring 40 that is disposed between the first flange 28 and the inner ring 31 of the second ball bearing 30. In the blower 1, the first flange 28 presses the inner ring 21 of the first ball bearing 20 from the other side to the one side when the impeller 56 rotates.
The first ball bearing 20 is located close to the impeller 56 and is located far from the base portion 13 of the housing 11 supporting the bearing device 80, and therefore, particularly when the impeller 56 rotates at a high speed, a large moment generated by the rotation of the impeller 56 acts on the first ball bearing 20. However, according to such a blower 1, as described above, when the impeller 56 rotates, the preload can be applied to the first ball bearing 20 only by the thrust force from the lower side to the upper side. That is, in the blower 1, even when the impeller 56 is rotated at a high speed, the urging force of the spring does not need to be applied so as to overcome the urging force, and therefore, excessive surface pressure exceeding a predetermined value is suppressed from being applied to the first ball bearing 20. Therefore, according to the blower 1, even when a relatively large moment acts on the first ball bearing 20 due to the high-speed rotation of the impeller 56, it is possible to suppress the application of an excessive load to the first ball bearing 20 and to apply a preload to the first ball bearing 20.
On the other hand, when the blower 1 is disposed such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction, the second ball bearing 30 located on the lower side is located at a position away from the impeller 56 and at a position close to the base portion 13 of the housing 11 supporting the bearing device 80. Therefore, even when the impeller 56 rotates at a high speed, a relatively small moment acts on the second ball bearing 30. Therefore, even when the preload is applied to the second ball bearing 30 by the urging force of the first spring 40 at the time of high-speed rotation of the impeller 56, the load on the second ball bearing 30 is relatively small.
As described above, according to the blower 1, even when the impeller 56 rotates at a high speed, the first ball bearing 20 and the second ball bearing 30 can be preloaded without applying excessive load, and therefore the rotation speed of the impeller 56 can be increased.
Further, in the blower 1, as described above, when the impeller 56 is stationary, since the load F1 applied by the rotor 50 is applied only to the first ball bearing 20 (i.e., since the force applied by the spring is not applied to the first ball bearing 20), the preload applied to the first ball bearing 20 is reduced. In this way, in the blower 1, since the resistance when the stationary impeller 56 is to be rotated is reduced, the impeller 56 can be started to rotate more smoothly.
In the blower 1, as described above, the upper surface 21u of the inner ring 21 of the first ball bearing 20 is in contact with the washer 29. Therefore, the upper surface 21u of the inner ring 21 and the lower surface 53d of the bush 53 do not relatively move (e.g., rotate) in a state of direct contact, and generation of noise or abrasion of the inner ring 21 is suppressed.
(Second embodiment)
Next, a blower according to a second embodiment will be described. Fig. 4 is a cross-sectional view in the axial direction of the blower 2 according to the present embodiment. As shown in fig. 4, the blower 2 has the same configuration as the blower 1 except that a part of the configuration of the bearing device 280 is different from the configuration of the bearing device 80 of the blower 1. Therefore, only points different from the blower 1 will be described below for the blower 2, and the same reference numerals as those in the first embodiment will be given to other components, and the description thereof will be omitted.
Fig. 5 is an enlarged and schematic cross-sectional view of the bearing device 280 when the impeller 56 is stationary. Further, fig. 5 shows a case of the bearing device 80 when the impeller 56 is stationary in a case where the blower 2 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction. As shown in fig. 5, the bearing device 280 includes the second flange portion 228 and the second spring 240.
The second flange portion 228 is supported on a portion of the shaft 10 on the lower side (the other side) than the inner ring 31 of the second ball bearing 30, and extends radially outward from the shaft 10. In the present embodiment, the second flange portion 228 is a washer, and is fitted into a groove formed in the outer peripheral surface 10o of the shaft 10. The configuration of the second flange portion 228 is not limited to this, and may be, for example, a portion integrally formed with the shaft 10 in a flange shape.
The second spring 240 is disposed directly under the inner ring 31 of the second ball bearing 30 and between the upper surface of the second flange 228 and the lower surface 31d of the inner ring 31 of the second ball bearing 30. The shaft 10 penetrates the inside of the second spring 240. That is, the second spring 240 surrounds a portion of the outer circumferential surface 10o of the shaft 10.
When the impeller 56 is stationary with the blower 2 disposed so that the protruding portion 10a of the shaft 10 faces upward in the vertical direction, as in the bearing device 80, as shown by the chain line in fig. 5, a load F1 applied by the rotor 50 applies preload to the first ball bearing 20 while the straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined in the radial direction so as to face inward in the radial direction as it goes upward. When the impeller 56 is stationary, the load F1 applied by the rotor 50 acts only on the first ball bearing 20, as in the bearing device 80.
When the impeller 56 is stationary, the inner ring 31 of the second ball bearing 30 moves downward together with the shaft 10 by the load F1 applied by the rotor 50. However, at a certain point in time when the inner ring 31 moves downward, the force applied to the inner ring 31 by the first spring 40 balances the force applied to the inner ring 31 by the second spring 240 disposed between the inner ring 31 and the second flange portion 228, and the inner ring 31 is held at the position at that point in time. As in the case of the bearing device 80, the movement of the outer race 32 of the second ball bearing 30 in the axial direction is restricted. Accordingly, the inner race 31 of the second ball bearing 30 is located on the lower side opposite to the outer race 32. Therefore, when the impeller 56 is stationary, the rotor 33 of the second ball bearing 30 contacts the upper region of the concave portion 31c of the inner race 31 and the lower region of the concave portion 32c of the outer race 32. That is, when the impeller 56 is stationary, as shown by a chain line in fig. 5, the second ball bearing 30 is preloaded in a state in which a straight line connecting the contact points of the inner ring 31 and the outer ring 32 with the rotor 33 is inclined with respect to the radial direction so as to be directed radially outward as going downward.
In this way, in the bearing device 280, when the impeller 56 is stationary, the preload applied to the first ball bearing 20 and the second ball bearing 30 is combined in parallel so that the linear lines connecting the respective contact points of the inner ring and the outer ring with the rotor are inclined with respect to the radial direction so as to be directed radially outward.
Next, the bearing device 280 when the impeller 56 rotates will be described.
Fig. 6 is an enlarged and schematic cross-sectional view of the bearing device 280 when the impeller rotates. Further, fig. 6 shows a case of the bearing device 280 when the impeller 56 rotates in the case where the blower 1 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction.
As shown by the arrow in fig. 6, when the impeller 56 rotates at a high speed, the thrust F2 is larger than the load F1 applied by the rotor 50, and as a result, the shaft 10 and the first flange portion 28 supported by the shaft 10 move upward by the thrust F2. As a result of the first flange 28 moving upward, the inner ring 21 of the first ball bearing 20 is pushed from the lower side (the other side) toward the upper side (the one side) by the first flange 28 in contact with the lower surface 21d of the inner ring 21, and moves upward. As in the first embodiment, the outer race 22 of the first ball bearing 20 is fixed (bonded by an adhesive) to the sleeve 81. Therefore, the inner race 21 is located on the upper side with respect to the outer race 22. Therefore, when the impeller 56 rotates at a high speed, the rotor 23 of the first ball bearing 20 contacts the lower region of the concave portion 21c of the inner ring 21 and the upper region of the concave portion 22c of the outer ring 22. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 6, the first ball bearing 20 is preloaded in a state in which a straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
When the impeller 56 rotates at a high speed, the inner ring 31 of the second ball bearing 30 supported by the shaft 10 moves upward together with the shaft 10 due to the thrust force F2. When the rotation speed of the impeller 56 increases and the thrust force F2 increases, the inner ring 31 moves further upward. Then, at a point of time when the inner ring 31 moves to a certain extent upward, the force applied to the inner ring 31 by the first spring 40 balances with the force applied to the inner ring 31 by the second spring 240 fitted to the second flange portion 228 and the inner ring 31, and the inner ring 31 is held at the position at this point of time. The movement of the outer race 32 of the second ball bearing 30 in the axial direction is restricted. Accordingly, the inner race 31 of the second ball bearing 30 is located on the upper side opposite to the outer race 32. Therefore, when the impeller 56 rotates at a high speed, the rotor 33 of the second ball bearing 30 contacts the lower region of the concave portion 31c of the inner ring 31 and the upper region of the concave portion 32c of the outer ring 32. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 6, the second ball bearing 30 is preloaded in a state in which a straight line connecting the contact points of the inner ring 31 and the outer ring 32 with the rotor 33 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
In this way, in the bearing device 280, when the impeller 56 rotates at a high speed, the preload applied to the first ball bearing 20 and the second ball bearing 30 is combined in parallel (that is, in parallel with the stationary phase), and the preload is applied in a state where the straight line connecting the contact points of the inner ring and the outer ring with the rotor is inclined with respect to the radial direction so as to be directed outward in the radial direction.
Although not particularly limited, in the present embodiment, it is preferable that the amount of change in the load ((applied force)) applied by the first spring 40 and the second spring 240 is larger than the weight of the inner race 31 of the second ball bearing 30 when the amount of deflection of the first spring 40 and the second spring 240 is changed by the amount of axial play of the first ball bearing 20 and/or the second ball bearing 30.
As described above, the blower 2 according to the present embodiment includes the shaft 10, the sleeve 81 that accommodates a part of the shaft 10 (a part substantially excluding the protruding portion 10 a) therein, the impeller 56 rotatably supported on one side in the axial direction of the shaft 10 and generates an air flow from one side in the axial direction toward the other side in the axial direction by rotation, the first ball bearing 20 that includes the inner ring 21 supported on the shaft 10 and that is close to the impeller 56, and the outer ring 22 that is fixed to the inner circumferential surface 81i of the sleeve 81, the second ball bearing 30 that has the inner ring 31 supported on the shaft 10 and that is further from the impeller 56 than the inner ring 21 of the first ball bearing 20, the first flange 28 that is supported on a part between the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 and that protrudes radially outward from the shaft 10, and the first spring 40 that is disposed between the first flange 28 and the inner ring 31 of the second ball bearing 30. In the blower 2, the first flange 28 presses the inner ring 21 of the first ball bearing 20 from the other side to the one side when the impeller 56 rotates.
Therefore, according to the blower 2, the rotation speed of the impeller 56 can be increased for the same reason as the blower 1, and the impeller 56 can be smoothly started to rotate. Further, since the blower 2 includes the gasket 29 as in the first embodiment, noise generated when the impeller 56 rotates or abrasion of the inner ring 21 is suppressed.
In the blower 2, the inner ring 31 of the second ball bearing 30 is supported in a state sandwiched between the first spring 40 and the second spring 240 from above and below, and therefore, in particular, the impact absorption performance to the inner ring 31 of the second ball bearing 30 is excellent.
(Third embodiment)
Next, a blower according to a third embodiment will be described. Fig. 7 is a cross-sectional view in the axial direction of the blower 2 according to the present embodiment. As shown in fig. 7, the blower 3 has the same configuration as the blower 1 except that a part of the configuration of the bearing device 380 is different from the configuration of the bearing device 80 of the blower 1. Therefore, only points different from the blower 1 will be described below for the blower 3, and the same reference numerals as those in the first embodiment will be given to other components, and the description thereof will be omitted.
Fig. 8 is an enlarged and schematic cross-sectional view of the bearing device 380 when the impeller 56 is stationary. Further, fig. 8 shows a case of the bearing device 380 when the impeller 56 is stationary in a case where the blower 3 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction. As shown in fig. 8, the bearing device 380 includes a second flange portion 328 and a third spring 340.
The second flange 328 is supported on a portion of the shaft 10 below (on the other side of) the inner ring 31 of the second ball bearing 30, and extends radially outward from the shaft 10. In the present embodiment, the second flange 328 is a washer, and is fitted into a groove formed in the outer peripheral surface 10o of the shaft 10. In the present embodiment, the second flange 328 is in contact with the lower surface 31d of the inner ring 31 of the second ball bearing 30 when the impeller 56 is stationary, but may not be in contact. The configuration of the second flange 328 is not limited to this, and may be, for example, a flange-shaped portion integrally formed with the shaft 10.
The third spring 340 is disposed between the stepped portion 81P of the sleeve 81 and the outer race 32 of the second ball bearing 30 in the axial direction. That is, the third spring 340 is disposed between the lower surface 81Pd of the stepped portion 81P of the sleeve 81 and the upper surface 32u of the outer race 32 of the second ball bearing 30. In the present embodiment, the third spring 340 is constituted by one spring, but may be constituted by two or more spring pieces arranged at equal intervals in the circumferential direction.
The bearing device 380 does not have the fixing portion 60 unlike the bearing devices 80 and 280.
When the impeller 56 is stationary with the blower 3 disposed so that the protruding portion 10a of the shaft 10 faces upward in the vertical direction, as in the bearing device 80, as shown by the chain line in fig. 8, a load F1 applied by the rotor 50 applies preload to the first ball bearing 20 while the straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined in the radial direction so as to face outward in the radial direction as going downward. When the impeller 56 is stationary, the load F1 applied by the rotor 50 acts only on the first ball bearing 20, as in the bearing device 80.
When the impeller 56 is stationary, the inner ring 31 of the second ball bearing 30 supported by the shaft 10 moves downward together with the shaft 10 by the load F1 applied by the rotor 50. On the other hand, the outer race 32 of the second ball bearing 30 is moved downward by the urging force of the third spring 340. Accordingly, the inner race 31 and the outer race 32 of the second ball bearing 30 are disposed at substantially the same position in the axial direction. Therefore, substantially no preload is applied to the second ball bearing 30 when the impeller 56 is stationary.
In this way, the bearing device 380 is a combination in which, when the impeller 56 is stationary, the first ball bearing 20 is preloaded and the second ball bearing 30 is not preloaded in a state in which the straight line connecting the contact points between the inner ring and the outer ring and the rotor is inclined in the radial direction so as to be directed inward in the radial direction with the upward direction.
Next, the bearing device 380 in the case where the impeller 56 rotates will be described.
Fig. 9 is an enlarged and schematic cross-sectional view of the bearing device 380 when the impeller rotates. Further, fig. 9 shows a case of a bearing device 380 when the impeller 56 rotates in a case where the blower 3 is arranged such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction.
As shown by the arrow in fig. 9, when the impeller 56 rotates at a high speed, the thrust F2 is larger than the load F1 applied by the rotor 50, and as a result, the shaft 10 and the first flange portion 28 supported by the shaft 10 move upward by the thrust F2. As a result of the first flange 28 moving upward, the inner ring 21 of the first ball bearing 20 is pushed from the lower side (the other side) toward the upper side (the one side) by the first flange 28 in contact with the lower surface 21d of the inner ring 21, and moves upward. As in the first embodiment, the outer race 22 of the first ball bearing 20 is fixed (bonded by an adhesive) to the sleeve 81. Therefore, the inner race 21 is located on the upper side with respect to the outer race 22. Therefore, when the impeller 56 rotates at a high speed, the rotor 23 of the first ball bearing 20 contacts the lower region of the concave portion 21c of the inner ring 21 and the upper region of the concave portion 22c of the outer ring 22. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 9, the first ball bearing 20 is preloaded in a state in which a straight line connecting the contact points of the inner ring 21 and the outer ring 22 with the rotor 23 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
When the impeller 56 rotates at a high speed, the second flange 328 moves upward integrally with the shaft 10 by the thrust F2. As a result, the second flange 328 contacts the lower surface 31d of the inner ring 31 of the second ball bearing 30, and moves (presses) the inner ring 31 from the lower side (the other side) to the upper side (the one side). When the rotation speed of the impeller 56 increases and the thrust force F2 increases, the inner ring 31 moves further upward by the second flange 328. At this time, the inner ring 31 is held at a position in contact with the second flange portion 328 by the urging force applied to the inner ring 31 by the first spring 40. On the other hand, the outer race 32 of the second ball bearing 30 is pushed upward via the rotor 33 as the inner race 31 moves upward, but the upward movement is restricted by the urging force of the third spring 340. Accordingly, the inner race 31 of the second ball bearing 30 is located on the upper side opposite to the outer race 32. Therefore, when the impeller 56 rotates at a high speed, the rotor 33 of the second ball bearing 30 contacts the lower region of the concave portion 31c of the inner ring 31 and the upper region of the concave portion 32c of the outer ring 32. That is, when the impeller 56 rotates at a high speed, as shown by a chain line in fig. 9, the second ball bearing 30 is preloaded in a state in which a straight line connecting the contact points of the inner ring 31 and the outer ring 32 with the rotor 33 is inclined to the radial direction so as to be directed outward in the radial direction with the upward direction.
In this way, in the bearing device 380, when the impeller 56 rotates at a high speed, the preload applied to the first ball bearing 20 and the second ball bearing 30 is combined in parallel in such a manner that the straight line connecting the contact points of the respective inner ring and outer ring with the rotor is inclined with respect to the radial direction so as to be directed radially outward.
Although not particularly limited, in the bearing device 380 of the present embodiment, the maximum value of the load (urging force) by the first spring 40 and the maximum value of the load (urging force) by the third spring 340 are smaller than the load F1 applied by the rotor 50 when the blower 2 is disposed such that the protruding portion 10a of the shaft 10 faces upward in the vertical direction. Here, as described above, the thrust force F2 at the time of high-speed rotation of the impeller 56 is larger than the load F1 applied by the rotor 50. That is, in the present embodiment, the load applied by the first spring 40 and the load applied by the third spring 340 are smaller than the thrust force F2 at the time of high-speed rotation, respectively. Accordingly, in the bearing device 380, particularly at the time of high-speed rotation, the respective urging forces of the first spring 40 and the third spring 340 are suppressed from acting in such a manner as to overcome the urging force F2.
As described above, the blower 3 according to the present embodiment includes the shaft 10, the sleeve 81 that accommodates a part of the shaft 10 (a part substantially excluding the protruding portion 10 a) therein, the impeller 56 rotatably supported on one side in the axial direction of the shaft 10 and generates an air flow from one side in the axial direction toward the other side in the axial direction by rotation, the first ball bearing 20 that includes the inner ring 21 supported on the shaft 10 and that is close to the impeller 56, and the outer ring 22 that is fixed to the inner circumferential surface 81i of the sleeve 81, the second ball bearing 30 that has the inner ring 31 supported on the shaft 10 and that is further from the impeller 56 than the inner ring 21 of the first ball bearing 20, the first flange 28 that is supported on a part between the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 and that protrudes radially outward from the shaft 10, and the first spring 40 that is disposed between the first flange 28 and the inner ring 31 of the second ball bearing 30. In the blower 3, the first flange 28 presses the inner ring 21 of the first ball bearing 20 from the other side to the one side when the impeller 56 rotates.
Therefore, according to the blower 3, the rotation speed of the impeller 56 can be increased and the impeller 56 can be smoothly started to rotate for the same reason as the blower 1. Further, since the blower 2 includes the gasket 29 as in the first embodiment, noise generated when the impeller 56 rotates or abrasion of the inner ring 21 is suppressed.
In the blower 3, since the outer ring 32 of the second ball bearing 30 is supported via the third spring 340, the impact absorbing property of the outer ring 32 of the second ball bearing 30 is excellent in particular.
(Fourth embodiment)
Next, a blower according to a fourth embodiment will be described. Fig. 10 is a cross-sectional view in the axial direction of the blower 4 according to the present embodiment. Fig. 11 is an enlarged and schematic cross-sectional view of the bearing device 480 shown in fig. 10 when the impeller is stationary. As shown in fig. 10 and 11, the blower 4 has the same configuration as the blower 1 except for a point that a part of the configuration of the bearing device 480 is different from the configuration of the bearing device 80 of the blower 1, and the like. Therefore, only points different from the blower 1 will be described below for the blower 4, and the same reference numerals as those in the first embodiment will be given to other components, and the description thereof will be omitted.
As shown in fig. 10 and 11, the bearing device 480 of the blower 4 has substantially the same configuration as the bearing device 80 of the blower 1, but is different from the bearing device 80 of the blower 1 mainly in that the sleeve 481 has the protruding portion 482, and the sleeve 81 of the bearing device 80 includes the stepped portion 81P, whereas in the bearing device 480, the sleeve 481 does not include the stepped portion as the stepped portion 81P, but includes the spacer 483 separate from the sleeve 481. These differences will be described below.
As shown in fig. 10 and 11, a projection 482 protruding inward in the radial direction is formed on the inner periphery of the sleeve 481. The protruding portion 482 is formed at or near the upper end of the sleeve 481 in the axial direction, and is formed integrally with other portions of the sleeve 481. The inner peripheral surface 482i of the protruding portion 482 is located inside with respect to the other portion of the sleeve 481 in the radial direction. The inner peripheral surface 482i of the protruding portion 482 may be located at the same position as the inner peripheral surface 22i of the outer ring 22 of the first ball bearing 20, or may be located inside or outside the inner peripheral surface 22i in the radial direction. In the radial direction, a gap is formed between the inner peripheral surface 482i of the protruding portion 482 and the surface 53i of the bush 53 facing the inner peripheral surface 482 i. The protruding portion 482 may be formed in a ring shape (over the entire circumference of the sleeve 481) or may be formed as a part of the sleeve 481 in the circumferential direction. An upper surface 22u (an end portion on one side in the axial direction of the first ball bearing 20) of the outer ring 22 of the first ball bearing 20 is in contact with a lower surface (lower surface) of the protruding portion 482. Therefore, the protruding portion 482 restricts the outer race 22 of the first ball bearing 20 from moving upward.
In the present embodiment, the inner peripheral surface 481i of the sleeve 481 is formed on the same surface except for the inner peripheral surface 482i of the extension 482.
The bearing device 480 is provided with a spacer 483. The spacer 483 is a member different from the sleeve 481. The spacer 483 is supported so as not to move in the axial direction with respect to the sleeve 481. The spacer 483 may be pressed against the inner peripheral surface 482i of the sleeve 481, or may be bonded to the inner peripheral surface 482i. As described above, since the spacer 483 is a member different from the sleeve 481, the first ball bearing 20 can be inserted into the sleeve 481 from the opening 481bo at the lower side of the sleeve 481, the first ball bearing 20 can be moved toward the upper end portion of the sleeve 481, and the spacer 483 can be inserted into the sleeve 481 from the opening 481bo, thereafter, the spacer 483 can be moved toward the first ball bearing 20. In the axial direction, the spacer 483 is between the first ball bearing 20 and the second ball bearing 30.
In the axial direction, the outer ring 22 of the first ball bearing 20 is held by being sandwiched by the protruding portion 482 and the spacer 483, whereby the movement of the outer ring 22 of the first ball bearing 20 in the axial direction is restricted. In the present embodiment, unlike the first, second, and third embodiments, the outer ring 22 of the first ball bearing 20 is not fixed (for example, bonded using an adhesive) to the inner peripheral surface 482i of the sleeve 481, but is held by, for example, a clearance fit, an intermediate fit, an interference fit, or the like, and is disposed on the inner periphery of the sleeve 481. However, the outer ring 22 of the first ball bearing 20 may be fixed to the inner peripheral surface 482i of the sleeve 481 in the same manner as in the first, second and third embodiments.
As described above, in the blower 4 of the present embodiment, the protruding portion 482 protruding radially inward is provided on the inner periphery of the sleeve 481, and one end portion of the first ball bearing 20 (the upper surface 22u of the outer ring 22 of the first ball bearing 20) is abutted against the protruding portion 482, and the outer ring 22 of the first ball bearing 20 is disposed on the inner periphery of the sleeve 481. According to such a configuration, the outer ring 22 of the first ball bearing 20 can be restrained from moving upward without fixing (e.g., adhering) the outer ring 22 of the first ball bearing 20 to the sleeve 481. In the present embodiment, since the spacer 483 is further provided, the movement of the outer race 22 of the first ball bearing 20 in the axial direction can be restricted without fixing (e.g., bonding) the outer race 22 of the first ball bearing 20 to the sleeve 481. The blower 4 has the same configuration as the blower 1 of the first embodiment except for these points. Therefore, even when the impeller 56 rotates at a high speed, the rotation speed of the impeller 56 can be increased by applying a preload to both the first ball bearing 20 and the second ball bearing 30 without applying an excessive load.
The protruding portion 482 and the spacer 483 can be applied to the first, second, and third embodiments. In this case, the outer race 22 of the first ball bearing 20 is not fixed to the sleeve, and the axial movement of the outer race 22 of the first ball bearing 20 can be restricted (the position of the outer race 22 in the axial direction is maintained). In particular, in the case where the protruding portion 482 and the spacer 483 are applied to the first embodiment and the second embodiment, the outer race 22 of the first ball bearing 20 and the outer race 32 of the second ball bearing 30 can be sandwiched in the axial direction by the protruding portion 482 and the fixing portion 60, whereby the axial movement of the outer races 22, 32 can be restricted. In addition, in the case where the protruding portion 482 and the spacer 483 are applied to the first embodiment and the second embodiment, the spacer 483 may not be supported (e.g., fixed) so as not to move in the axial direction with respect to the sleeve 481. When the protruding portion 482 and the spacer 483 are applied to the first and second embodiments, the outer race 22 of the first ball bearing 20, the outer race 32 of the second ball bearing 30, and the spacer 483 can be sandwiched between the protruding portion 482 and the fixed portion 60, and therefore the axial movement of the two outer races 22, 32 and the spacer 483 can be restricted. In this way, when the inner ring 21 of the first ball bearing 20 and the inner ring 31 of the second ball bearing 30 are not fixed to the shaft 10, and the outer ring 22 of the first ball bearing 20, the outer ring 32 of the second ball bearing 30, and the spacer 483 are not fixed to the sleeve 481, the assembly of the blower 4 is facilitated by omitting the fixing step such as bonding. Further, the blower 4 is more easily disassembled and repaired.
The present invention has been described above by taking the above embodiments as an example, but the present invention is not limited to this.
For example, in the above embodiment, the example provided with the gasket 29 has been described, but the gasket 29 may not be provided.
In the above embodiment, the example in which the stepped portion 81P is formed in the sleeve 81 has been described, but the stepped portion 81P may not be formed. In this case, the outer peripheral surface of the outer ring 32 of the second ball bearing 30 may be bonded to the inner peripheral surface 81i of the sleeve 81.
In addition, the blower of the present invention can be appropriately modified by those skilled in the art based on conventional known knowledge. The present invention is, of course, within the scope of the present invention as long as the constitution of the present invention is still provided by the modification.
Description of the reference numerals
1. 2, 3, 4, Blower 10, shaft 20, first ball bearing 21, inner race 22, outer race 28, first flange portion 29, washer 30, second ball bearing 31, inner race 32, outer race 40, first spring 50, rotor 56, impeller 60, fixing portion 81, 481, 81P, step portion 228, 328, second flange portion 240, second spring 340, third spring 482, extension portion.

Claims (8)

1. An air blower, the air blower comprising:
A shaft;
a sleeve housing a portion of the shaft therein;
an impeller rotatably supported on one side in an axial direction of the shaft, the impeller generating an air flow from the one side in the axial direction toward the other side in the axial direction by rotation;
The first ball bearing comprises an inner ring, an outer ring and a first ball bearing, wherein the inner ring is supported on the part, close to the impeller, of the shaft;
A second ball bearing having an inner ring supported on the shaft at a portion farther from the impeller than the inner ring of the first ball bearing;
A first flange portion supported by a portion between an inner ring of the first ball bearing and an inner ring of the second ball bearing on the shaft and extending from an outer side in a radial direction perpendicular to the axial direction, and
A first spring disposed between the first flange portion and an inner race of the second ball bearing,
The first flange portion presses the inner ring of the first ball bearing from the other side toward the one side when the impeller rotates.
2. An air blower, the air blower comprising:
A shaft;
a sleeve housing a portion of the shaft therein;
an impeller rotatably supported on one side in an axial direction of the shaft, the impeller generating an air flow from the one side in the axial direction toward the other side in the axial direction by rotation;
the first ball bearing comprises an inner ring, an outer ring and a first ball bearing, wherein the inner ring is supported on the part, close to the impeller, of the shaft;
A second ball bearing having an inner ring supported on the shaft at a portion farther from the impeller than the inner ring of the first ball bearing;
A first flange portion supported by a portion between an inner ring of the first ball bearing and an inner ring of the second ball bearing on the shaft and extending from an outer side in a radial direction perpendicular to the axial direction, and
A first spring disposed between the first flange portion and an inner race of the second ball bearing,
An extension part protruding to the inner side in the radial direction is arranged on the inner circumference of the sleeve,
The end of the one side of the first ball bearing abuts against the protruding portion,
The first flange portion presses the inner ring of the first ball bearing from the other side toward the one side when the impeller rotates.
3. The blower according to claim 1 or 2, wherein,
The impeller forms part of a rotor that rotates with respect to the sleeve as the shaft rotates,
The maximum value of the load applied by the first spring is smaller than the load applied by the rotor.
4. The blower according to claim 1 or 2, wherein,
Movement of the outer race of the second ball bearing in the axial direction is restricted.
5. The blower according to claim 4, wherein,
The blower further includes a fixing portion fixed to an inner peripheral surface of the sleeve and extending inward in the radial direction,
The sleeve includes a stepped portion protruding inward in the radial direction at a portion closer to the one side than the fixing portion,
The outer race of the second ball bearing is held between the stepped portion and the fixed portion so as to be restrained from moving in the axial direction.
6. The blower according to claim 5, wherein,
The blower further includes:
A second flange portion supported by the shaft at a portion closer to the other side than the inner ring of the second ball bearing and extending outward in the radial direction from the shaft direction, and
And a second spring disposed between the second flange portion and the inner ring of the second ball bearing.
7. The blower according to claim 6, wherein,
The impeller forms part of a rotor that rotates with respect to the sleeve as the shaft rotates,
The amount of change in the load applied by the first spring and the second spring is greater than the weight of the inner race of the second ball bearing in the case where the amount of deflection of the first spring and the second spring is changed by the amount of axial play of the first ball bearing and/or the second ball bearing.
8. The blower according to claim 1 or 2, wherein,
The blower further includes a second flange portion supported by the shaft at a portion closer to the other side than the inner ring of the second ball bearing and extending outward in the radial direction from the axial direction,
The portion of the sleeve between the outer race of the first ball bearing and the outer race of the second ball bearing in the axial direction includes a stepped portion protruding inward in the radial direction,
A third spring is arranged between the step portion and the outer race of the second ball bearing in the axial direction,
The second flange portion presses the inner ring of the second ball bearing from the other side toward the one side when the impeller rotates.
CN202480003661.1A 2023-02-10 2024-01-24 Blower fan Pending CN119677961A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2023-019097 2023-02-10
JP2023019097 2023-02-10
JP2023212865A JP2024114608A (en) 2023-02-10 2023-12-18 Blower
JP2023-212865 2023-12-18
PCT/JP2024/001958 WO2024166681A1 (en) 2023-02-10 2024-01-24 Blower

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CN202480003661.1A Pending CN119677961A (en) 2023-02-10 2024-01-24 Blower fan

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CN (1) CN119677961A (en)
TW (1) TW202432946A (en)
WO (1) WO2024166681A1 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0629518Y2 (en) * 1988-11-07 1994-08-10 ソニー株式会社 Axial fan motor
JP2002247798A (en) * 2001-02-20 2002-08-30 Sanyo Denki Co Ltd Fan motor
WO2008119404A1 (en) * 2007-03-31 2008-10-09 Ebm-Papst St. Georgen Gmbh & Co. Kg Arrangement for delivering fluids
JP7409934B2 (en) * 2020-03-30 2024-01-09 ミネベアミツミ株式会社 fan motor

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