US20130266463A1 - Fan motor - Google Patents
Fan motor Download PDFInfo
- Publication number
- US20130266463A1 US20130266463A1 US13/439,440 US201213439440A US2013266463A1 US 20130266463 A1 US20130266463 A1 US 20130266463A1 US 201213439440 A US201213439440 A US 201213439440A US 2013266463 A1 US2013266463 A1 US 2013266463A1
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- US
- United States
- Prior art keywords
- flange
- shaft
- static
- fan motor
- rotating
- 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.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
- F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
- F04D25/0613—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump the electric motor being of the inside-out type, i.e. the rotor is arranged radially outside a central stator
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- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/325—Rotors specially for elastic fluids for axial flow pumps for axial flow fans
- F04D29/329—Details of the hub
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- 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
- F04D29/60—Mounting; Assembling; Disassembling
- F04D29/64—Mounting; Assembling; Disassembling of axial pumps
- F04D29/644—Mounting; Assembling; Disassembling of axial pumps especially adapted for elastic fluid pumps
- F04D29/646—Mounting or removal of fans
Definitions
- the present invention relates to a fan motor including a rotating fan blade.
- Fan motors that rotate a fan blade are built in electronic devices like a personal computer.
- Such fan motors promote heat dissipation inside the electronic device, thereby contributing the downsizing and speedup of such a device.
- Fan motors are nowadays often built in especially portable electronic devices like a laptop computer.
- the fan motors built in the portable electronic devices like a laptop computer In comparison with the fan motors built in stationary electronic devices like a desktop computer, it is necessary for the fan motors built in the portable electronic devices like a laptop computer to have a shock resistance and a vibration resistance in order to withstand a shock like falling and a vibration at the time of carrying and to have the extended lifetime.
- JP 2007-205491 A discloses a fan motor including a blade fixed to a rotating body and a bearing supporting the rotating body.
- Conventional fan motors like one disclosed in JP 2007-205491 A have a rotating body with a blade and a static body.
- the rotating body with the blade may contact the static body in the axial direction.
- the fan motor breaks down within a relatively short duration of use, and thus the lifetime thereof becomes short.
- the rotating body with the blade travels in the axial direction, and thus the rotating body and the static body may contact with each other.
- the present invention has been made in view of the above-explained circumstance, and it is an object of the present invention to provide a technology of preventing a rotating body with a blade from contacting a static body or suppressing a reduction of the lifetime of a fan motor.
- a first aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a first static flange which is disposed in an area at a side of the first end of the shaft in an axial direction and which faces the rotating flange in the axial direction; a second static flange which is disposed in an area at a side of the second end of the shaft in the axial direction and which faces the rotating flange in the axial direction; a first dynamic pressure generating groove that is provided in either one of surfaces of the rotating
- a second aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange and which is joined with the static body so as to overlap with the rotating flange in the radial direction; a dynamic pressure generating groove which is disposed outwardly of a portion of the sleeve retaining the shaft in the radial direction and which is provided in either one of surfaces of the
- a third aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange, and which is joined with the static body so as to overlap the rotating flange in a radial direction; a dynamic pressure generating groove provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction; and a lubricant present between the static body and the
- FIG. 1A is a diagram showing a fan motor according to an embodiment of the present invention.
- FIG. 1B is a diagram showing the fan motor according to the embodiment of the present invention.
- FIG. 2 is a cross-sectional view taken along a line A-A in FIG. 1A ;
- FIG. 3 is an enlarged cross-sectional view showing a periphery of a joined portion between a hub and an annular portion in FIG. 2 in an enlarged manner;
- FIG. 4 is an enlarged bottom view showing a periphery of a base hole in FIG. 2 in an enlarged manner
- FIG. 5 is an enlarged cross-sectional view showing a periphery of a rotating flange and a sleeve in FIG. 2 in an enlarged manner.
- a fan motor of an embodiment is appropriate as a fan motor built in an electronic device like a personal computer.
- FIG. 1A is a top view showing a fan motor 100 according to an embodiment.
- FIG. 1B is a side view showing the fan motor 100 of the embodiment.
- the fan motor 100 includes a static body 2 and a rotating body 4 .
- the static body 2 includes a base 6 and an outer periphery wall 16 .
- the rotating body 4 includes a shaft 8 , a hub 10 , and a blade unit 12 .
- the shaft 8 has a first end 8 A that is shown in FIG. 1A at a side toward a reader and a second end 8 B opposite to the first end 8 A.
- posture of the fan motor of the present invention when in use is not limited to this definition.
- the fan motor of the present invention can be used in any arbitrary posture.
- the blade unit 12 includes a blade base 18 and, for example, 10 blades 14 .
- the number of blades can be changed as needed depending on the application, the rotating speed, etc., of the fan motor 100 .
- the blade base 18 includes a cylinder part 18 A, a disc part 18 B, and a through hole 18 C.
- the cylinder part 18 A is a hollow cylinder.
- the disc part 18 B protrudes inwardly of the radial direction from the upper end of the cylinder part 18 A.
- the through hole 18 C is disposed at the center of the disc part 18 B.
- the 10 blades 14 protrude outwardly of the radial direction from the outer periphery of the cylinder part 18 A and are fixed thereto.
- the blades 14 are disposed at a substantially equal interval in the circumferential direction.
- the blade unit 12 is formed of a resin material like polycarbonate by molding.
- the blade unit 12 may contain glass fibers at a predetermined ratio.
- the blade unit 12 has an outer diameter of, for example, 30 mm and a height of, for example, 5 mm.
- the blade unit 12 has the blade base 18 fixed to the hub 10 by bonding.
- the blade unit 12 may be fixed to the hub 10 by other techniques.
- the outer periphery wall 16 has a substantially rectangular external shape and an opening 16 B located at the center thereof, and encircles the blade unit 12 .
- the outer periphery wall 16 is formed of a resin material like polycarbonate by molding.
- the outer periphery wall 16 may contain glass fibers at a predetermined ratio.
- the outer periphery wall 16 has a recess 16 A in an end face in the axial direction.
- the base 6 is fitted in the recess 16 A of the outer periphery wall 16 and fixed to the outer periphery wall 16 by bonding.
- FIG. 2 is a cross-sectional view taken along a line A-A in FIG. 1A .
- FIG. 2 is symmetrical relative to a rotation axis R.
- the static body 2 further includes a sleeve 20 , a first static flange 24 , a second static flange 26 , a housing 28 , a stator core 58 , a core holder 62 , coils 60 , and a magnetic ring 44 .
- the rotating body 4 further includes a rotating flange 22 .
- the rotating flange 22 encircles the sleeve 20 , and is fixed to the hub 10 .
- the sleeve 20 encircles the shaft 8 .
- the sleeve 20 is surrounded by the housing 28 and is fixed thereto.
- the housing 28 is fixed to the base 6 .
- the first static flange 24 is fixed to the sleeve 20 , and is located above the rotating flange 22 in the axial direction via a clearance.
- the second static flange 26 is fixed to the housing 28 , and is located below the rotating flange 22 in the axial direction via a clearance.
- the rotating flange 22 is rotatable in a space defined by the clearances with the first static flange 24 and with the second static flange 26 in the axial direction.
- the hub 10 includes an external wall 10 A, a disc part 10 B, a through hole 10 C, and a first cylinder part 36 .
- the external wall 10 A is in a hollow cylindrical shape.
- the disc part 10 B protrudes inwardly of the radial direction from the upper end of the external wall 10 A.
- the through hole 10 C is provided at the center of the disc part 10 B.
- the hub 10 is formed of a soft magnetic material like SUS430F.
- the hub 10 is formed in a predetermined shape by, for example, cutting.
- the hub 10 may be shaped by pressing instead of cutting.
- the hub 10 has the external wall 10 A fitted inwardly of the cylinder part 18 A of the blade base 18 .
- the hub 10 has the disc part 10 B abutting the lower face of the disc part 10 B of the blade base 18 .
- the hub 10 has the through hole 10 C where the first end 8 A of the shaft 8 is inserted.
- the first cylinder part 36 protrudes downwardly from the disc part 10 B in the axial direction.
- the first cylinder part 36 has the inner periphery coaxial with the through hole 10 C.
- the first cylinder part 36 encircles and fastens a second cylinder part 38 to be discussed later.
- FIG. 3 is an enlarged cross-sectional view showing a periphery of a joined portion between the hub 10 and the blade base 18 .
- the hub 10 has, for example, six boss holes 10 D
- the blade base 18 has, for example, six bosses 18 D.
- the six boss holes 10 D pass all the way through the disc part 10 B in the axial direction.
- the six boss holes 10 D are disposed in the circumferential direction at a substantially equal interval.
- bosses 18 D are provided at positions corresponding to respective boss holes 10 D.
- the bosses 18 D protrude downwardly from the disc part 18 B in the axial direction.
- the bosses 18 D each include a boss protrusion 18 E and a boss thicker part 18 F.
- the boss protrusion 18 E passes all the way through the boss hole 10 D and protrudes from the lower face of the disc part 10 B.
- the boss thicker part 18 F is fixed to the tip of the boss protrusion 18 E, and has a larger diameter than that of the boss hole 10 D.
- the boss thicker part 18 F can be formed by heating the tip of the boss protrusion 18 E to let the tip deformed.
- the boss 18 D, the boss protrusion 18 E, and the boss thicker part 18 F are continuous in a seamless manner.
- Such a configuration restricts the traveling of the blade base 18 in the axial direction relative to the hub 10 .
- the rotating flange 22 is in, for example, a flat annular shape.
- the rotating flange 22 encircles the sleeve 20 , and rotates together with the rotating body 4 .
- the rotating flange 22 includes a second cylinder part 38 protruding downwardly from the outer periphery of the rotating flange 22 .
- the rotating flange 22 and the second cylinder part 38 are joined together in a seamless manner.
- the rotating flange 22 and the second cylinder part 38 are an annular member having a cross section of a reversed L shape.
- the rotating flange 22 is formed of an iron-and-steel material like SUS430F by, for example, cutting.
- the rotating flange 22 may be formed of a metal by pressing. Alternatively, the rotating flange 22 may be formed of a resin material by molding. The rotating flange 22 rotates in a space defined by the first static flange 24 and the second static flange 26 in the axial direction.
- the second cylinder part 38 has the outer periphery fixed to the inner periphery of the first cylinder part 36 by bonding.
- a magnet 40 in a ring shape is fixed inwardly of the external wall 10 A of the hub 10 by bonding.
- the magnet 40 contains materials, such as neodymium, iron, and born.
- the magnet 40 has a surface on which an anti-corrosive process is applied like electrodeposition coating or spray coating.
- the magnet 40 has driving magnetic poles of, for example, 16 poles disposed in the circumferential direction on the inner periphery of the magnet 40 .
- the magnet 40 has the inner periphery facing twelve tips 58 C of a stator core 58 to be discussed later in the radial direction.
- the shaft 8 is formed of an iron-and-steel material like stainless steel in an elongated cylindrical shape.
- the shaft 8 has the first end 8 A fitted in the through hole 10 C of the hub 10 and fixed thereto by bonding.
- the shaft 8 has the second end 8 B retained in the sleeve 20 and supported in a freely rotatable manner.
- the sleeve 20 includes a cylinder part 20 A.
- the cylinder part 20 A is a hollow cylinder.
- the first static flange 24 extends outwardly of the radial direction from the upper part of the cylinder part 20 A.
- the cylinder part 20 A and the first static flange 24 are formed together with each other.
- the first static flange 24 is joined with the cylinder part 20 A in a seamless manner.
- the first static flange 24 and the cylinder part 20 A are formed of a metal like brass by, for example, cutting.
- the first static flange 24 and the cylinder part 20 A have, for example, an electroless nickel plating layer on the surface thereof.
- the first static flange 24 and the cylinder part 20 A may be formed of a resin material by molding.
- the cylinder part 20 A retains the second end 8 B of the shaft 8 and supports the second end 8 B in a freely rotatable manner.
- the housing 28 includes a cylinder part 28 A and a bottom 28 C.
- the cylinder part 28 A is a hollow cylinder.
- the second static flange 26 is fixed to an upper end of the cylinder part 28 A.
- the bottom 28 C is fixed to the lower end face of the cylinder part 28 A, and covers the lower end face thereof.
- the second static flange 26 , the cylinder part 28 A, and the bottom 28 C are formed together.
- the second static flange 26 , the cylinder part 28 A, and the bottom 28 C are joined together in a seamless manner.
- the second static flange 26 , the cylinder part 28 A, and the bottom 28 C are formed of a metal like brass by, for example, cutting.
- the second static flange 26 , the cylinder part 28 A, and the bottom 28 C have, for example, electroless nickel plating layer on the surface thereof.
- the second static flange 26 , the cylinder part 28 A, and the bottom 28 C may be formed of a resin material by molding.
- the outer periphery of the cylinder part 20 A of the sleeve 20 is fitted in and bonded with the inner periphery of the cylinder part 28 A and thus the housing 28 fixes the sleeve 20 .
- the housing 28 has the cylinder part 28 A encircling the cylinder part 20 A of the sleeve 20 .
- the second static flange 26 is located below the first static flange 24 in the axial direction with a space.
- the housing 28 is fitted in a base hole 6 A and fixed therewith by bonding.
- the base 6 has a substantially rectangular external shape, and has the base hole 6 A passing all the way through in the axial direction at the center of the base 6 .
- the base 6 has ventilation slots in an area facing the blades 14 in the axial direction.
- the base 6 has a core layer mainly composed of, for example, iron, and a surface layer mainly composed of, for example, zinc adhered to the surface of the core layer.
- the base 6 is formed of a cold-rolled steel plate with a zinc plating in a predetermined shape by, for example, pressing.
- the base 6 may be formed of the other materials like a stainless steel.
- FIG. 4 is a bottom view showing the periphery of the base hole 6 A and the bottom 28 C of the housing 28 in an enlarged manner.
- the edge of the base hole 6 A and the housing 28 have, for example, a welded part 42 joined by welding.
- the welded part 42 is in a ring shape along the edge of the base hole 6 A.
- FIG. 5 is an enlarged cross-sectional view showing the periphery of the sleeve 20 in an enlarged manner, and shows the left-half of such a periphery relative to the rotation axis R.
- a pair of radial dynamic pressure generating grooves 50 and 52 are disposed in the inner periphery of the cylinder part 20 A of the sleeve 20 .
- the radial dynamic pressure generating grooves 50 and 52 may be disposed in an outer periphery 8 BA of the shaft 8 .
- the radial dynamic pressure generating grooves 50 and 52 are in, for example, a herringbone shape.
- those grooves may be in the other shapes like a spiral shape.
- a lubricant 34 is present between the sleeve 20 and the shaft 8 .
- a first dynamic pressure generating groove 54 is disposed in a surface of the rotating flange 22 facing with the first static flange 24 in the axial direction.
- the first dynamic pressure generating groove 54 may be disposed in a surface of the first static flange 24 facing with the rotating flange 22 in the axial direction.
- a second dynamic pressure generating groove 56 is disposed in a surface of the rotating flange 22 facing with the second static flange 26 in the axial direction.
- the second dynamic pressure generating groove 56 may be disposed in a surface of the second static flange 26 facing with the rotating flange 22 in the axial direction.
- the first and second dynamic pressure generating grooves 54 and 56 are formed in, for example, a herringbone shape.
- the first and second dynamic pressure generating grooves 54 and 56 may be in the other shapes like a spiral shape.
- the lubricant 34 is also present between the first static flange 24 and the rotating flange 22 and between the second static flange 26 and the rotating flange 22 .
- the radial dynamic pressure generating grooves 50 , 52 , the first dynamic pressure generating groove 54 , and the second dynamic pressure generating groove 56 respectively generate dynamic pressures applied to the lubricant 34 .
- a capillary seal 46 is located at a space between the inner periphery of the second cylinder part 38 and the outer periphery of the housing 28 in the radial direction.
- the lubricant 34 is continuously present in spaces between the upper face of the bottom 28 C of the housing 28 and the sleeve 20 and the shaft 8 , a space between the first static flange 24 and the rotating flange 22 , a space between the second static flange 26 and the rotating flange 22 , and a space between the second cylinder part 38 and the housing 28 .
- An air-liquid interface 34 A of the lubricant 34 contacts both of the inner periphery of the second cylinder part 38 and the outer periphery of the housing 28 in the capillary seal 46 .
- the capillary seal 46 has a wide space in the axial direction which is close to the second end 8 B of the shaft 8 .
- the capillary seal 46 can suppress a leak-out of the lubricant 34 by capillary force.
- the static body 2 further has a communicated passage BP of the lubricant 34 .
- the communicated passage BP communicates the capillary seal 46 with a space above the bottom 28 C of the housing 28 .
- the communicated passage BP suppresses a pressure difference in the lubricant 34 between the capillary seal 46 and the space above the bottom 28 C of the housing 28 .
- the sleeve 20 has a recess 20 B formed in the outer periphery of the sleeve 20 and continuous in the direction along the rotation axis R.
- the recess 20 B is filled with the lubricant 34 , and is a part of the communicated passage BP.
- the communicated passage BP of the lubricant 34 includes the recess 20 B.
- the housing 28 may have a passage that is a part of the communicated passage BP instead of the sleeve 20 .
- the magnetic ring 44 is, for example, a flat ring having a through hole provided in the center thereof.
- the magnetic ring 44 is formed of, for example, a magnetic steel plate by pressing.
- the magnetic ring 44 is located at an area outwardly of the stator core 58 in the radial direction.
- the magnetic ring 44 faces a lower end face 40 A of the magnet 40 in the axial direction, and is fixed to the base 6 by bonding.
- the magnetic ring 44 may be fixed to the base 6 by caulking.
- the magnetic ring 44 causes the magnet 40 to have magnetic suction force in the direction toward the base 6 .
- the blades 14 are pushed down in the direction toward the base 6 , and it becomes possible to prevent the blades 14 from floating because of reactive force of airflows produced by the blades 14 .
- the magnetic ring 44 may be joined together with the base 6 in a seamless manner.
- the stator core 58 includes a core annular part 58 A, for example, twelve core teeth 58 B and a core tip 58 C.
- the core annular part 58 A is in a ring shape surrounding the center hole.
- the twelve core teeth 58 B protrude outwardly of the radial direction from the outer periphery of the core annular part 58 A.
- the twelve core teeth 58 B are arranged at, for example, substantially equal interval in the circumferential direction.
- the core tip 58 C extends outwardly of the radial direction at respective outer peripheries of the core teeth 58 B.
- the stator core 58 is fixed to an upper face of the base 6 by means of a core holder 62 to be discussed later.
- the stator core 58 is formed by stacking and caulking, for example, six thin electromagnetic steel plates together.
- the core teeth 58 B are surrounded by a cover 62 C to be discussed later.
- the stator core 58 may have an insulative layer formed on the surface thereof.
- Such an insulative layer is formed by, for example, electrodeposition coating, or powder coating.
- the coil 60 is provided at each of the core teeth 58 B of the stator core 58 .
- the coil 60 is formed by winding, for example, an electrical wire covered with an insulative material like poly urethane around each of the core teeth 58 B.
- the coil 60 is coupled to a predetermined drive circuit.
- the core holder 62 includes a mount 62 A, a cover 62 C, and for example, six spacers 62 D.
- the mount 62 A joins the cover 62 C and the six spacers 62 D in a seamless manner.
- the mount 62 A, the cover 62 C, and the six spacers 62 D may be formed separately and joined together later.
- the core holder 62 is formed of a resin material like poly-carbonate by molding.
- the core holder 62 may contain glass fibers, etc., at a predetermined ratio.
- the mount 62 A is formed in, for example, a substantially annular shape.
- the mount 62 A may be in other shapes.
- the mount 62 A surrounds the housing 28 .
- the mount 62 A is present between the core annular part 58 A and the base 6 in the axial direction.
- the spacer 62 D is present between the core tip 58 C and the base 6 in the axial direction.
- the six spacers 62 D are each in a substantially cylindrical shape, and disposed in the circumferential direction at a substantially equal interval.
- the spacer 62 D has a protrusion 62 E and a stopper 62 F.
- the core teeth 58 B is fastened to the cover 62 C, thereby fastening the stator core 58 to the core holder 62 .
- the base 6 has a holder hole 6 B at a location corresponding to each of the spacers 62 D.
- the holder hole 6 B passes all the way through the base 6 in the axial direction, and includes a smaller diameter part and a larger diameter part successive from the lower portion of the smaller diameter part.
- the spacer 62 D has the protrusion 62 E passing all the way through the holder hole 6 B.
- the stopper 62 F is retained in the larger diameter part of the holder hole 6 B, and has a larger diameter than the minimum diameter of the holder hole 6 B.
- the stopper 62 F can be formed by heating the protrusion 62 E to be deformed.
- stator core 58 and the core holder 62 are fixed to the base 6 .
- a drive current of a three-phase substantially sinusoidal wave is supplied from the predetermined drive circuit to the coils 60 .
- Such magnetic fluxes give a torque to the magnet 40 , and the blades 14 and the hub 10 fastened to the magnet 40 start rotating by that torque.
- the blades 14 generate airflows downwardly of the axial direction by their own rotation.
- the blades 14 may generate airflows upwardly of the axial direction by their own rotation.
- the joined portion between the hub 10 and the blade base 18 receives force in the direction of rotation.
- the force in the direction of rotation may mutually displace the hub 10 and the blade base 18 , and such a joined portion may be damaged.
- the hub 10 has the six boss holes 10 D and the blade base 18 has the six bosses 18 D.
- each boss 18 D passes all the way through each boss hole 10 D, the mutual displacement of the blade base 18 to the hub 10 in the direction of rotation can be restricted.
- the hub 10 and the blade base 18 are fastened together and are capable of withstanding such a force. Hence, the possibility that the joined portion is damaged can be reduced.
- the radial dynamic pressure generating grooves 50 , 52 , and the first and second dynamic pressure generating grooves 54 , 56 respectively generate dynamic pressures applied to the lubricant 34 , and such dynamic pressures support the rotating body 4 with the blades 14 in the radial direction and in the axial direction.
- the rotating flange 22 is located outwardly of the radial direction from the cylinder part 20 A of the sleeve 20 .
- first and second dynamic pressure generating grooves 54 and 56 are located outwardly of the shaft 8 or the cylinder part 20 A of the sleeve 20 in the radial direction.
- respective diameters of the first and second dynamic pressure generating grooves 54 , 56 can be increased.
- the dynamic pressure to be generated is increased to support the rotating body 4 with the blades 14 in the radial direction and in the axial direction in a non-contact manner with the static body 2 , and to increase the rigidity of the bearing.
- the non-contact condition results in a suppression of the generation of slide noises.
- the blades 14 may receive an acceleration in a direction departing from the base 6 in the axial direction.
- the rotating body 4 with the blades 14 may move in the direction departing from the base 6 in the axial direction, and respective faces of the static body 2 and the rotating body 4 facing with each other in the axial direction may contact with each other.
- the fan motor 100 breaks down if such a contact repeats.
- the first and second dynamic pressure generating grooves 54 and 56 are provided in both faces of the rotating flange 22 in the axial direction.
- the first and second dynamic pressure generating grooves 54 and 56 support the rotating body 4 with the blades 14 in a non-contact manner with the static body 2 in the axial direction at the time of the rotating operation, and thus the possibility that the rotating body 4 contacts the static body 2 can be reduced.
- an end of the shaft 8 where the rotating body 4 with the blades 14 is joined is an output end of the shaft 8 .
- the first end 8 A is the output end.
- the shaft According to a design of disposing a dynamic pressure generating groove at an area distant from the output end of the shaft in the axial direction, the shaft has a high possibility of precessing when rotating.
- the wear of the shaft or the sleeve may increase, resulting in the reduction of the lifetime of the fan motor.
- the rotating flange 22 is disposed at an area close to the first end 8 A of the shaft 8 rather than the second end 8 B thereof in the axial direction.
- first and second dynamic pressure generating grooves 54 and 56 are located at respective areas close to the first end 8 A of the shaft 8 rather than the second end 8 B thereof in the axial direction.
- the rotating flange 22 is located at an area close to the first end 8 A of the shaft 8 rather than the weighted center G of the rotating body 4 in the axial direction.
- the rotating flange 22 Since the rotating flange 22 is distant from the second end 8 B of the shaft 8 , the principle of leverage acts, and the rotating flange 22 together with the first and second static flanges 24 and 26 can suppress the precession movement of the shaft 8 , i.e., the wobbling of the rotating body 4 in the rotational direction.
- the rotating flange 22 can support, together with the first and second static flanges 24 and 26 , an off-centered load by contacting one another when the fan motor 100 is not rotating and when the off-centered load is applied to the blades 14 .
- the dimension of the radial dynamic pressure generating groove in the axial direction decreases by what corresponds to such a configuration, resulting in the reduction of the bearing rigidity in some cases.
- the rotating flange 22 is fixed to the hub 10 , and thus it does not bring about the reduction of the bearing rigidity.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
Abstract
A fan motor includes a static body, a rotating body that has a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, a sleeve that retains thereinside a portion of the shaft at a second end side, a rotating flange which encircles the sleeve and which rotates together with the hub, a static flange which is disposed in an area at a side of the first end of the shaft, and which is joined with the static body so as to overlap the rotating flange in a radial direction, a dynamic pressure generating groove provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction, and a lubricant present between the static body and the rotating body.
Description
- 1. Field of the Invention
- The present invention relates to a fan motor including a rotating fan blade.
- 2. Description of the Related Art
- Fan motors that rotate a fan blade are built in electronic devices like a personal computer.
- Such fan motors promote heat dissipation inside the electronic device, thereby contributing the downsizing and speedup of such a device.
- Fan motors are nowadays often built in especially portable electronic devices like a laptop computer.
- In comparison with the fan motors built in stationary electronic devices like a desktop computer, it is necessary for the fan motors built in the portable electronic devices like a laptop computer to have a shock resistance and a vibration resistance in order to withstand a shock like falling and a vibration at the time of carrying and to have the extended lifetime.
- For example, JP 2007-205491 A discloses a fan motor including a blade fixed to a rotating body and a bearing supporting the rotating body.
- Conventional fan motors like one disclosed in JP 2007-205491 A have a rotating body with a blade and a static body.
- When an acceleration is applied to the blade due to falling, etc., of the electronic device, the rotating body with the blade may contact the static body in the axial direction.
- In general, when the rotating body and the static body contact with each other, those parts may be damaged in the worst case.
- Alternatively, when the rotating body repeats contacting the static body, in general, the fan motor breaks down within a relatively short duration of use, and thus the lifetime thereof becomes short.
- Moreover, according to such conventional fan motors, when the blade rotates, the blade receives force in the opposite direction to the direction of blowing.
- When the blade receives such force, the rotating body with the blade travels in the axial direction, and thus the rotating body and the static body may contact with each other.
- When the rotating body contacts the static body while the blade is rotating, the contacting portions are worn out, and may be damaged in the worst case, resulting in the reduction of the lifetime of the fan motor.
- Moreover, when the rotating body contacts the static body while the blade is rotating, slide noises are generated from the fan motor. Such slide noises are unpleasant to the user of the electronic device.
- Such a technical issue arises in the case of fan motors built in other various electronic devices in addition to the fan motors built in portable electronic devices.
- The present invention has been made in view of the above-explained circumstance, and it is an object of the present invention to provide a technology of preventing a rotating body with a blade from contacting a static body or suppressing a reduction of the lifetime of a fan motor.
- A first aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a first static flange which is disposed in an area at a side of the first end of the shaft in an axial direction and which faces the rotating flange in the axial direction; a second static flange which is disposed in an area at a side of the second end of the shaft in the axial direction and which faces the rotating flange in the axial direction; a first dynamic pressure generating groove that is provided in either one of surfaces of the rotating flange and the first static flange facing with each other in the axial direction; a second dynamic pressure generating groove that is provided in either one of surfaces of the rotating flange and the second static flange facing with each other in the axial direction; and a lubricant present between the static body and the rotating body.
- A second aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange and which is joined with the static body so as to overlap with the rotating flange in the radial direction; a dynamic pressure generating groove which is disposed outwardly of a portion of the sleeve retaining the shaft in the radial direction and which is provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction; and a lubricant present between the static body and the rotating body.
- A third aspect of the present invention provides a fan motor that includes: a static body including a base; a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body; a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base; a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub; a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange, and which is joined with the static body so as to overlap the rotating flange in a radial direction; a dynamic pressure generating groove provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction; and a lubricant present between the static body and the rotating body.
- Any combination of the above-explained structural elements and mutual replacement of the structural elements and expressions of the present invention among a method, a device, and a system, etc., are also effective as an embodiment of the present invention.
-
FIG. 1A is a diagram showing a fan motor according to an embodiment of the present invention; -
FIG. 1B is a diagram showing the fan motor according to the embodiment of the present invention; -
FIG. 2 is a cross-sectional view taken along a line A-A inFIG. 1A ; -
FIG. 3 is an enlarged cross-sectional view showing a periphery of a joined portion between a hub and an annular portion inFIG. 2 in an enlarged manner; -
FIG. 4 is an enlarged bottom view showing a periphery of a base hole inFIG. 2 in an enlarged manner; and -
FIG. 5 is an enlarged cross-sectional view showing a periphery of a rotating flange and a sleeve inFIG. 2 in an enlarged manner. - A preferred embodiment of the present invention will be explained below with reference to the accompanying drawings.
- The same or equivalent structural element or member shown in respective figures will be denoted by the same reference numeral and the duplicated explanation thereof will be omitted accordingly.
- The dimension of a member in each figure is enlarged or reduced as needed in order to facilitate understanding.
- A part of a member not important to explain the embodiment will be also omitted in each figure.
- A fan motor of an embodiment is appropriate as a fan motor built in an electronic device like a personal computer.
-
FIG. 1A is a top view showing afan motor 100 according to an embodiment. -
FIG. 1B is a side view showing thefan motor 100 of the embodiment. - The
fan motor 100 includes astatic body 2 and a rotatingbody 4. - The
static body 2 includes abase 6 and anouter periphery wall 16. - The rotating
body 4 includes ashaft 8, ahub 10, and ablade unit 12. - The
shaft 8 has afirst end 8A that is shown inFIG. 1A at a side toward a reader and asecond end 8B opposite to thefirst end 8A. - The explanation below will be given based on a definition that the
first end 8A of theshaft 8 is an upper side with respect to thesecond end 8B thereof. - However, the posture of the fan motor of the present invention when in use is not limited to this definition.
- The fan motor of the present invention can be used in any arbitrary posture.
- The
blade unit 12 includes ablade base 18 and, for example, 10blades 14. The number of blades can be changed as needed depending on the application, the rotating speed, etc., of thefan motor 100. - The
blade base 18 includes acylinder part 18A, adisc part 18B, and a throughhole 18C. - The
cylinder part 18A is a hollow cylinder. - The
disc part 18B protrudes inwardly of the radial direction from the upper end of thecylinder part 18A. - The through
hole 18C is disposed at the center of thedisc part 18B. - The 10
blades 14 protrude outwardly of the radial direction from the outer periphery of thecylinder part 18A and are fixed thereto. - The
blades 14 are disposed at a substantially equal interval in the circumferential direction. - The
blade unit 12 is formed of a resin material like polycarbonate by molding. - The
blade unit 12 may contain glass fibers at a predetermined ratio. - The
blade unit 12 has an outer diameter of, for example, 30 mm and a height of, for example, 5 mm. - The
blade unit 12 has theblade base 18 fixed to thehub 10 by bonding. - The
blade unit 12 may be fixed to thehub 10 by other techniques. - The
outer periphery wall 16 has a substantially rectangular external shape and anopening 16B located at the center thereof, and encircles theblade unit 12. - The
outer periphery wall 16 is formed of a resin material like polycarbonate by molding. - The
outer periphery wall 16 may contain glass fibers at a predetermined ratio. - The
outer periphery wall 16 has arecess 16A in an end face in the axial direction. - The
base 6 is fitted in therecess 16A of theouter periphery wall 16 and fixed to theouter periphery wall 16 by bonding. -
FIG. 2 is a cross-sectional view taken along a line A-A inFIG. 1A . -
FIG. 2 is symmetrical relative to a rotation axis R. - Hence, indication of a reference numeral to a portion of the same element at one side in the horizontal direction will be omitted in
FIG. 2 . - The
static body 2 further includes asleeve 20, a firststatic flange 24, a secondstatic flange 26, ahousing 28, astator core 58, acore holder 62, coils 60, and amagnetic ring 44. - The
rotating body 4 further includes arotating flange 22. - The rotating
flange 22 encircles thesleeve 20, and is fixed to thehub 10. - The
sleeve 20 encircles theshaft 8. - The
sleeve 20 is surrounded by thehousing 28 and is fixed thereto. - The
housing 28 is fixed to thebase 6. - The first
static flange 24 is fixed to thesleeve 20, and is located above the rotatingflange 22 in the axial direction via a clearance. - The second
static flange 26 is fixed to thehousing 28, and is located below the rotatingflange 22 in the axial direction via a clearance. - Hence, the rotating
flange 22 is rotatable in a space defined by the clearances with the firststatic flange 24 and with the secondstatic flange 26 in the axial direction. - The
hub 10 includes anexternal wall 10A, adisc part 10B, a throughhole 10C, and afirst cylinder part 36. - The
external wall 10A is in a hollow cylindrical shape. - The
disc part 10B protrudes inwardly of the radial direction from the upper end of theexternal wall 10A. - The through
hole 10C is provided at the center of thedisc part 10B. - The
hub 10 is formed of a soft magnetic material like SUS430F. - The
hub 10 is formed in a predetermined shape by, for example, cutting. - The
hub 10 may be shaped by pressing instead of cutting. - The
hub 10 has theexternal wall 10A fitted inwardly of thecylinder part 18A of theblade base 18. - The
hub 10 has thedisc part 10B abutting the lower face of thedisc part 10B of theblade base 18. - The
hub 10 has the throughhole 10C where thefirst end 8A of theshaft 8 is inserted. - The
first cylinder part 36 protrudes downwardly from thedisc part 10B in the axial direction. - The
first cylinder part 36 has the inner periphery coaxial with the throughhole 10C. - The
first cylinder part 36 encircles and fastens asecond cylinder part 38 to be discussed later. -
FIG. 3 is an enlarged cross-sectional view showing a periphery of a joined portion between thehub 10 and theblade base 18. - According to the
fan motor 100 of this embodiment, thehub 10 has, for example, sixboss holes 10D, and theblade base 18 has, for example, sixbosses 18D. - The six
boss holes 10D pass all the way through thedisc part 10B in the axial direction. - The six
boss holes 10D are disposed in the circumferential direction at a substantially equal interval. - Conversely, the
bosses 18D are provided at positions corresponding to respective boss holes 10D. - The
bosses 18D protrude downwardly from thedisc part 18B in the axial direction. - The
bosses 18D each include aboss protrusion 18E and a bossthicker part 18F. - The
boss protrusion 18E passes all the way through theboss hole 10D and protrudes from the lower face of thedisc part 10B. - The boss
thicker part 18F is fixed to the tip of theboss protrusion 18E, and has a larger diameter than that of theboss hole 10D. - The boss
thicker part 18F can be formed by heating the tip of theboss protrusion 18E to let the tip deformed. - That is, the
boss 18D, theboss protrusion 18E, and the bossthicker part 18F are continuous in a seamless manner. - Such a configuration restricts the traveling of the
blade base 18 in the axial direction relative to thehub 10. - Returning to
FIG. 2 , the rotatingflange 22 is in, for example, a flat annular shape. - The rotating
flange 22 encircles thesleeve 20, and rotates together with therotating body 4. - The rotating
flange 22 includes asecond cylinder part 38 protruding downwardly from the outer periphery of therotating flange 22. - The rotating
flange 22 and thesecond cylinder part 38 are joined together in a seamless manner. - That is, the rotating
flange 22 and thesecond cylinder part 38 are an annular member having a cross section of a reversed L shape. - The rotating
flange 22 is formed of an iron-and-steel material like SUS430F by, for example, cutting. - The rotating
flange 22 may be formed of a metal by pressing. Alternatively, the rotatingflange 22 may be formed of a resin material by molding. The rotatingflange 22 rotates in a space defined by the firststatic flange 24 and the secondstatic flange 26 in the axial direction. - The
second cylinder part 38 has the outer periphery fixed to the inner periphery of thefirst cylinder part 36 by bonding. - A
magnet 40 in a ring shape is fixed inwardly of theexternal wall 10A of thehub 10 by bonding. - The
magnet 40 contains materials, such as neodymium, iron, and born. - The
magnet 40 has a surface on which an anti-corrosive process is applied like electrodeposition coating or spray coating. - The
magnet 40 has driving magnetic poles of, for example, 16 poles disposed in the circumferential direction on the inner periphery of themagnet 40. - The
magnet 40 has the inner periphery facing twelvetips 58C of astator core 58 to be discussed later in the radial direction. - The
shaft 8 is formed of an iron-and-steel material like stainless steel in an elongated cylindrical shape. - The
shaft 8 has thefirst end 8A fitted in the throughhole 10C of thehub 10 and fixed thereto by bonding. - The
shaft 8 has thesecond end 8B retained in thesleeve 20 and supported in a freely rotatable manner. - The
sleeve 20 includes acylinder part 20A. - The
cylinder part 20A is a hollow cylinder. - The first
static flange 24 extends outwardly of the radial direction from the upper part of thecylinder part 20A. - The
cylinder part 20A and the firststatic flange 24 are formed together with each other. - That is, the first
static flange 24 is joined with thecylinder part 20A in a seamless manner. - The first
static flange 24 and thecylinder part 20A are formed of a metal like brass by, for example, cutting. - The first
static flange 24 and thecylinder part 20A have, for example, an electroless nickel plating layer on the surface thereof. - The first
static flange 24 and thecylinder part 20A may be formed of a resin material by molding. - The
cylinder part 20A retains thesecond end 8B of theshaft 8 and supports thesecond end 8B in a freely rotatable manner. - The
housing 28 includes acylinder part 28A and a bottom 28C. - The
cylinder part 28A is a hollow cylinder. - The second
static flange 26 is fixed to an upper end of thecylinder part 28A. - The bottom 28C is fixed to the lower end face of the
cylinder part 28A, and covers the lower end face thereof. - The second
static flange 26, thecylinder part 28A, and the bottom 28C are formed together. - That is, the second
static flange 26, thecylinder part 28A, and the bottom 28C are joined together in a seamless manner. - The second
static flange 26, thecylinder part 28A, and the bottom 28C are formed of a metal like brass by, for example, cutting. - The second
static flange 26, thecylinder part 28A, and the bottom 28C have, for example, electroless nickel plating layer on the surface thereof. The secondstatic flange 26, thecylinder part 28A, and the bottom 28C may be formed of a resin material by molding. - The outer periphery of the
cylinder part 20A of thesleeve 20 is fitted in and bonded with the inner periphery of thecylinder part 28A and thus thehousing 28 fixes thesleeve 20. - That is, the
housing 28 has thecylinder part 28A encircling thecylinder part 20A of thesleeve 20. - The second
static flange 26 is located below the firststatic flange 24 in the axial direction with a space. - The
housing 28 is fitted in abase hole 6A and fixed therewith by bonding. - The
base 6 has a substantially rectangular external shape, and has thebase hole 6A passing all the way through in the axial direction at the center of thebase 6. - The
base 6 has ventilation slots in an area facing theblades 14 in the axial direction. - The
base 6 has a core layer mainly composed of, for example, iron, and a surface layer mainly composed of, for example, zinc adhered to the surface of the core layer. - The
base 6 is formed of a cold-rolled steel plate with a zinc plating in a predetermined shape by, for example, pressing. - The
base 6 may be formed of the other materials like a stainless steel. -
FIG. 4 is a bottom view showing the periphery of thebase hole 6A and the bottom 28C of thehousing 28 in an enlarged manner. - The edge of the
base hole 6A and thehousing 28 have, for example, a weldedpart 42 joined by welding. - The welded
part 42 is in a ring shape along the edge of thebase hole 6A. -
FIG. 5 is an enlarged cross-sectional view showing the periphery of thesleeve 20 in an enlarged manner, and shows the left-half of such a periphery relative to the rotation axis R. - A pair of radial dynamic
pressure generating grooves cylinder part 20A of thesleeve 20. - The radial dynamic
pressure generating grooves shaft 8. - The radial dynamic
pressure generating grooves - However, those grooves may be in the other shapes like a spiral shape.
- A
lubricant 34 is present between thesleeve 20 and theshaft 8. - A first dynamic
pressure generating groove 54 is disposed in a surface of therotating flange 22 facing with the firststatic flange 24 in the axial direction. - The first dynamic
pressure generating groove 54 may be disposed in a surface of the firststatic flange 24 facing with the rotatingflange 22 in the axial direction. - A second dynamic
pressure generating groove 56 is disposed in a surface of therotating flange 22 facing with the secondstatic flange 26 in the axial direction. - The second dynamic
pressure generating groove 56 may be disposed in a surface of the secondstatic flange 26 facing with the rotatingflange 22 in the axial direction. - The first and second dynamic
pressure generating grooves - The first and second dynamic
pressure generating grooves - The
lubricant 34 is also present between the firststatic flange 24 and therotating flange 22 and between the secondstatic flange 26 and therotating flange 22. - When the
shaft 8 and therotating flange 22 rotate, the radial dynamicpressure generating grooves pressure generating groove 54, and the second dynamicpressure generating groove 56 respectively generate dynamic pressures applied to thelubricant 34. - A
capillary seal 46 is located at a space between the inner periphery of thesecond cylinder part 38 and the outer periphery of thehousing 28 in the radial direction. - The
lubricant 34 is continuously present in spaces between the upper face of the bottom 28C of thehousing 28 and thesleeve 20 and theshaft 8, a space between the firststatic flange 24 and therotating flange 22, a space between the secondstatic flange 26 and therotating flange 22, and a space between thesecond cylinder part 38 and thehousing 28. - An air-
liquid interface 34A of thelubricant 34 contacts both of the inner periphery of thesecond cylinder part 38 and the outer periphery of thehousing 28 in thecapillary seal 46. - The
capillary seal 46 has a wide space in the axial direction which is close to thesecond end 8B of theshaft 8. - Hence, the
capillary seal 46 can suppress a leak-out of thelubricant 34 by capillary force. - The
static body 2 further has a communicated passage BP of thelubricant 34. - The communicated passage BP communicates the
capillary seal 46 with a space above the bottom 28C of thehousing 28. - By employing such a structure, the communicated passage BP suppresses a pressure difference in the
lubricant 34 between thecapillary seal 46 and the space above the bottom 28C of thehousing 28. - The
sleeve 20 has arecess 20B formed in the outer periphery of thesleeve 20 and continuous in the direction along the rotation axis R. - The
recess 20B is filled with thelubricant 34, and is a part of the communicated passage BP. - That is, the communicated passage BP of the
lubricant 34 includes therecess 20B. - The
housing 28 may have a passage that is a part of the communicated passage BP instead of thesleeve 20. - Returning to
FIG. 2 , themagnetic ring 44 is, for example, a flat ring having a through hole provided in the center thereof. - The
magnetic ring 44 is formed of, for example, a magnetic steel plate by pressing. - The
magnetic ring 44 is located at an area outwardly of thestator core 58 in the radial direction. - The
magnetic ring 44 faces a lower end face 40A of themagnet 40 in the axial direction, and is fixed to thebase 6 by bonding. - The
magnetic ring 44 may be fixed to thebase 6 by caulking. - The
magnetic ring 44 causes themagnet 40 to have magnetic suction force in the direction toward thebase 6. - As a result, the
blades 14 are pushed down in the direction toward thebase 6, and it becomes possible to prevent theblades 14 from floating because of reactive force of airflows produced by theblades 14. - The
magnetic ring 44 may be joined together with thebase 6 in a seamless manner. - The
stator core 58 includes a coreannular part 58A, for example, twelvecore teeth 58B and acore tip 58C. - The core
annular part 58A is in a ring shape surrounding the center hole. - The twelve
core teeth 58B protrude outwardly of the radial direction from the outer periphery of the coreannular part 58A. - The twelve
core teeth 58B are arranged at, for example, substantially equal interval in the circumferential direction. - The
core tip 58C extends outwardly of the radial direction at respective outer peripheries of thecore teeth 58B. - The
stator core 58 is fixed to an upper face of thebase 6 by means of acore holder 62 to be discussed later. - The
stator core 58 is formed by stacking and caulking, for example, six thin electromagnetic steel plates together. - The
core teeth 58B are surrounded by acover 62C to be discussed later. - The
stator core 58 may have an insulative layer formed on the surface thereof. - Such an insulative layer is formed by, for example, electrodeposition coating, or powder coating.
- The
coil 60 is provided at each of thecore teeth 58B of thestator core 58. - The
coil 60 is formed by winding, for example, an electrical wire covered with an insulative material like poly urethane around each of thecore teeth 58B. - The
coil 60 is coupled to a predetermined drive circuit. - When a drive current of a three-phase substantially sinusoidal wave is caused to flow through the
coil 60, drive magnetic fluxes are generated along thecore tip 58C. - The
core holder 62 includes amount 62A, acover 62C, and for example, sixspacers 62D. - The
mount 62A joins thecover 62C and the sixspacers 62D in a seamless manner. - The
mount 62A, thecover 62C, and the sixspacers 62D may be formed separately and joined together later. - The
core holder 62 is formed of a resin material like poly-carbonate by molding. - The
core holder 62 may contain glass fibers, etc., at a predetermined ratio. - The
mount 62A is formed in, for example, a substantially annular shape. - The
mount 62A may be in other shapes. - The
mount 62A surrounds thehousing 28. - The
mount 62A is present between the coreannular part 58A and thebase 6 in the axial direction. - The
spacer 62D is present between thecore tip 58C and thebase 6 in the axial direction. - The six
spacers 62D are each in a substantially cylindrical shape, and disposed in the circumferential direction at a substantially equal interval. - The
spacer 62D has aprotrusion 62E and astopper 62F. - The
core teeth 58B is fastened to thecover 62C, thereby fastening thestator core 58 to thecore holder 62. - The
base 6 has aholder hole 6B at a location corresponding to each of thespacers 62D. - The
holder hole 6B passes all the way through thebase 6 in the axial direction, and includes a smaller diameter part and a larger diameter part successive from the lower portion of the smaller diameter part. - The
spacer 62D has theprotrusion 62E passing all the way through theholder hole 6B. - The
stopper 62F is retained in the larger diameter part of theholder hole 6B, and has a larger diameter than the minimum diameter of theholder hole 6B. - The
stopper 62F can be formed by heating theprotrusion 62E to be deformed. - According to such a structure, the
stator core 58 and thecore holder 62 are fixed to thebase 6. - Next, an explanation will be given of an operation of the
fan motor 100 employing the above-explained structure together with an advantage thereof. - In order to rotate the
blades 14, a drive current of a three-phase substantially sinusoidal wave is supplied from the predetermined drive circuit to thecoils 60. - As a result, the drive magnetic fluxes are generated along the
core tip 58C. - Such magnetic fluxes give a torque to the
magnet 40, and theblades 14 and thehub 10 fastened to themagnet 40 start rotating by that torque. - For example, the
blades 14 generate airflows downwardly of the axial direction by their own rotation. - The
blades 14 may generate airflows upwardly of the axial direction by their own rotation. - When the
hub 10 starts rotating, the joined portion between thehub 10 and theblade base 18 receives force in the direction of rotation. Hence, when thehub 10 repeats rotating and stopping inherent to the use of thefan motor 100, the force in the direction of rotation may mutually displace thehub 10 and theblade base 18, and such a joined portion may be damaged. - However, according to the
fan motor 100 of this embodiment, thehub 10 has the sixboss holes 10D and theblade base 18 has the sixbosses 18D. - Since each
boss 18D passes all the way through eachboss hole 10D, the mutual displacement of theblade base 18 to thehub 10 in the direction of rotation can be restricted. - Accordingly, even if the force in the direction of rotation is applied to the joined portion between the
hub 10 and theblade base 18, thehub 10 and theblade base 18 are fastened together and are capable of withstanding such a force. Hence, the possibility that the joined portion is damaged can be reduced. - When the
shaft 8 and therotating flange 22 rotate, the radial dynamicpressure generating grooves pressure generating grooves lubricant 34, and such dynamic pressures support therotating body 4 with theblades 14 in the radial direction and in the axial direction. - In general, when the diameter of a dynamic pressure generating groove is reduced, the dynamic pressure to be generated becomes small. This brings about the reduction of the rigidity of a bearing, and the possibility that the rotating body and the static body contact increases.
- According to the
fan motor 100 of this embodiment, the rotatingflange 22 is located outwardly of the radial direction from thecylinder part 20A of thesleeve 20. - Hence, the first and second dynamic
pressure generating grooves shaft 8 or thecylinder part 20A of thesleeve 20 in the radial direction. - Accordingly, respective diameters of the first and second dynamic
pressure generating grooves rotating body 4 with theblades 14 in the radial direction and in the axial direction in a non-contact manner with thestatic body 2, and to increase the rigidity of the bearing. Moreover, the non-contact condition results in a suppression of the generation of slide noises. - Moreover, in the rotating operation, the
blades 14 may receive an acceleration in a direction departing from thebase 6 in the axial direction. In this case, therotating body 4 with theblades 14 may move in the direction departing from thebase 6 in the axial direction, and respective faces of thestatic body 2 and therotating body 4 facing with each other in the axial direction may contact with each other. In the worst case, thefan motor 100 breaks down if such a contact repeats. - According to the
fan motor 100 of this embodiment, however, the first and second dynamicpressure generating grooves rotating flange 22 in the axial direction. - As explained above, the first and second dynamic
pressure generating grooves rotating body 4 with theblades 14 in a non-contact manner with thestatic body 2 in the axial direction at the time of the rotating operation, and thus the possibility that therotating body 4 contacts thestatic body 2 can be reduced. - It is presumed that an end of the
shaft 8 where therotating body 4 with theblades 14 is joined is an output end of theshaft 8. In this case, according to thefan motor 100 of this embodiment, thefirst end 8A is the output end. - According to a design of disposing a dynamic pressure generating groove at an area distant from the output end of the shaft in the axial direction, the shaft has a high possibility of precessing when rotating.
- When the shaft precesses, the wear of the shaft or the sleeve may increase, resulting in the reduction of the lifetime of the fan motor.
- However, according to the
fan motor 100 of this embodiment, the rotatingflange 22 is disposed at an area close to thefirst end 8A of theshaft 8 rather than thesecond end 8B thereof in the axial direction. - Hence, the first and second dynamic
pressure generating grooves first end 8A of theshaft 8 rather than thesecond end 8B thereof in the axial direction. - As a result, the possibility that the
shaft 8 precesses can be reduced, thereby suppressing the reduction of the lifetime of thefan motor 100. - In addition, according to the
fan motor 100 of this embodiment, the rotatingflange 22 is located at an area close to thefirst end 8A of theshaft 8 rather than the weighted center G of therotating body 4 in the axial direction. - Since the rotating
flange 22 is distant from thesecond end 8B of theshaft 8, the principle of leverage acts, and therotating flange 22 together with the first and secondstatic flanges shaft 8, i.e., the wobbling of therotating body 4 in the rotational direction. - According to such a configuration, the rotating
flange 22 can support, together with the first and secondstatic flanges fan motor 100 is not rotating and when the off-centered load is applied to theblades 14. - When the fan motor has a dimension in the axial direction constant and the rotating flange is fixed to the shaft, the dimension of the radial dynamic pressure generating groove in the axial direction decreases by what corresponds to such a configuration, resulting in the reduction of the bearing rigidity in some cases.
- However, according to the
fan motor 100 of this embodiment, the rotatingflange 22 is fixed to thehub 10, and thus it does not bring about the reduction of the bearing rigidity. - The embodiment of the present invention was explained above, but the present invention is not limited to the above-explained embodiment. Various changes and modifications can be made without departing from the scope and spirit of the present invention.
Claims (20)
1. A fan motor comprising:
a static body including a base;
a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body;
a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base;
a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub;
a first static flange which is disposed in an area at a side of the first end of the shaft in an axial direction and which faces the rotating flange in the axial direction;
a second static flange which is disposed in an area at a side of the second end of the shaft in the axial direction and which faces the rotating flange in the axial direction;
a first dynamic pressure generating groove that is provided in either one of surfaces of the rotating flange and the first static flange facing with each other in the axial direction;
a second dynamic pressure generating groove that is provided in either one of surfaces of the rotating flange and the second static flange facing with each other in the axial direction; and
a lubricant present between the static body and the rotating body.
2. The fan motor according to claim 1 , wherein the rotating flange is located outwardly of a portion of the sleeve retaining the shaft in a radial direction.
3. The fan motor according to claim 1 , wherein the rotating flange is located at an area close to the first end of the shaft rather than the second end thereof in the axial direction.
4. The fan motor according to claim 1 , wherein the rotating flange is located in an area at the side of the first end of the shaft beyond a weighted center of the rotating body in the axial direction.
5. The fan motor according to claim 1 , wherein the rotating flange is joined with the hub.
6. The fan motor according to claim 1 , wherein the first static flange is joined with the sleeve.
7. The fan motor according to claim 1 , further comprising a radial dynamic pressure groove provided in either one of an outer periphery of the shaft and an inner periphery of the sleeve.
8. The fan motor according to claim 1 , further comprising a housing which is joined with the second static flange and which encircles the sleeve.
9. The fan motor according to claim 8 , wherein
the base is provided with a base hole where the housing is inserted to fasten the housing, and
the fan motor further comprising a welded part that joins an edge of the base hole with the housing.
10. The fan motor according to claim 1 , further comprising:
a magnet joined with the hub; and
a magnetic member which is joined with the static body and which suctions the magnet toward the base.
11. The fan motor according to claim 1 , further comprising:
a first cylinder part joined with the hub; and
a second cylinder part encircled by and joined with the first cylinder part and having an inner periphery holding an air-liquid interface of the lubricant.
12. The fan motor according to claim 11 , wherein the second cylinder part and the rotating flange are joined together in a seamless manner.
13. The fan motor according to claim 1 , further comprising:
a stator core including a core encircling part, core teeth running outwardly of the radial direction from the core encircling part and each having a coil, and a core tip running outwardly of the radial direction from the core teeth;
a core holder that joins the stator core and the base; and
a ring magnet which encircles the stator core, is joined with the hub, and has a magnetic polarity at a surface facing the core tip in the radial direction.
14. The fan motor according to claim 13 , further comprising a spacer present between the core tip and the base in the axial direction.
15. A fan motor comprising:
a static body including a base;
a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body;
a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base;
a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub;
a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange and which is joined with the static body so as to overlap with the rotating flange in the radial direction;
a dynamic pressure generating groove which is disposed outwardly of a portion of the sleeve retaining the shaft in the radial direction and which is provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction; and
a lubricant present between the static body and the rotating body.
16. The fan motor according to claim 15 , wherein the rotating flange is located outwardly of a portion of the sleeve retaining the shaft in a radial direction.
17. The fan motor according to claim 15 , wherein the rotating flange is located at an area close to the first end of the shaft rather than the second end thereof in the axial direction.
18. The fan motor according to claim 15 , wherein the rotating flange is located in an area at the side of the first end of the shaft beyond a weighted center of the rotating body in the axial direction.
19. The fan motor according to claim 15 , wherein the static flange is joined with the sleeve.
20. A fan motor comprising:
a static body including a base;
a rotating body which includes a shaft, a hub encircling a first end of the shaft and joined with the first end, and a blade joined around an outer periphery of the hub, and which rotates relative to the static body;
a sleeve which retains thereinside a portion of the shaft at a second end side and which is joined with the base;
a rotating flange which encircles at least a portion of the sleeve and which rotates together with the hub;
a static flange which is disposed in an area at a side of the first end of the shaft in an axial direction with reference to the rotating flange, and which is joined with the static body so as to overlap the rotating flange in a radial direction;
a dynamic pressure generating groove provided in either one of surfaces of the static body and the rotating body facing with each other in the axial direction; and
a lubricant present between the static body and the rotating body.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/439,440 US20130266463A1 (en) | 2012-04-04 | 2012-04-04 | Fan motor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/439,440 US20130266463A1 (en) | 2012-04-04 | 2012-04-04 | Fan motor |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130266463A1 true US20130266463A1 (en) | 2013-10-10 |
Family
ID=49292447
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/439,440 Abandoned US20130266463A1 (en) | 2012-04-04 | 2012-04-04 | Fan motor |
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Country | Link |
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US (1) | US20130266463A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150176587A1 (en) * | 2013-12-20 | 2015-06-25 | Nidec Corporation | Fan |
US20190186495A1 (en) * | 2016-06-24 | 2019-06-20 | Nidec Servo Corporation | Blower |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030164653A1 (en) * | 2001-01-30 | 2003-09-04 | Hisafumi Yasuda | Fluid dynamic pressure bearing for small flat motor, small flat motor, fan motor, and forced air feed type air cell |
US7431506B2 (en) * | 2004-12-14 | 2008-10-07 | Foxconn Technology Co., Ltd. | Motor with fluid dynamic bearing and fan employing the motor |
US7489059B2 (en) * | 2006-01-30 | 2009-02-10 | Victor Company Of Japan, Limited | Motor mounted with improved dynamic pressure fluid bearing mechanism |
US20090230593A1 (en) * | 2005-09-05 | 2009-09-17 | Ntn Corporation | Method for forming dynamic pressure generating grooves |
US8734018B2 (en) * | 2006-03-27 | 2014-05-27 | Ntn Corporation | Fluid dynamic bearing device and method of manufacturing the same |
-
2012
- 2012-04-04 US US13/439,440 patent/US20130266463A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030164653A1 (en) * | 2001-01-30 | 2003-09-04 | Hisafumi Yasuda | Fluid dynamic pressure bearing for small flat motor, small flat motor, fan motor, and forced air feed type air cell |
US7431506B2 (en) * | 2004-12-14 | 2008-10-07 | Foxconn Technology Co., Ltd. | Motor with fluid dynamic bearing and fan employing the motor |
US20090230593A1 (en) * | 2005-09-05 | 2009-09-17 | Ntn Corporation | Method for forming dynamic pressure generating grooves |
US7489059B2 (en) * | 2006-01-30 | 2009-02-10 | Victor Company Of Japan, Limited | Motor mounted with improved dynamic pressure fluid bearing mechanism |
US8734018B2 (en) * | 2006-03-27 | 2014-05-27 | Ntn Corporation | Fluid dynamic bearing device and method of manufacturing the same |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150176587A1 (en) * | 2013-12-20 | 2015-06-25 | Nidec Corporation | Fan |
US10047755B2 (en) * | 2013-12-20 | 2018-08-14 | Nidec Corporation | Fan |
US20190186495A1 (en) * | 2016-06-24 | 2019-06-20 | Nidec Servo Corporation | Blower |
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