JP2007205491A - Bearing device for fan motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance rotating performance and improve quietness while reducing the manufacturing cost in a fan motor. <P>SOLUTION: A region forming at least a radial bearing gap 16 of the inner peripheral face 12a of a bearing part 12 is formed on the inner peripheral face 15a of an electroformed part 15. A plurality of arc faces 15a1 as dynamic pressure generating parts are formed on the entire surface or one region of the inner peripheral face 15a of the electroformed part 15. Each arc face 15a1 is an eccentric arcuate face with each point offset at an equal distance from a rotating axis O. The arc faces 15a1 are formed at equal intervals in the circumferential direction. The radial bearing gap 16 is formed between the eccentric arcuate faces 15a1 and a separation groove 15a2 of the electroformed part 15, and a circular outer peripheral face 13a of a shaft member 13 by inserting the shaft member 13 in the inner peripheral face 15a of the electroformed part 15. A region in the radial bearing gap 16 formed by the eccentric arcuate faces 15a1 and the circular outer peripheral face 13a becomes a wedge shaped gap 15a3 made by gradually shrinking the gap width in the circumferential direction toward one side (rotational direction of the shaft member 13). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fan motor bearing device.

  Conventionally, information devices such as personal computers, personal digital assistants, mobile phones, and other electrical devices, such as office electrical devices such as copiers, facsimiles, printers, and telephones, and cooking appliances A fan motor is used as a cooling device for a heat generating component mounted on a device, an electric device for air conditioning, an electric device for cleaning, an electric device for lighting, and other electric devices that generate heat.

  This type of fan motor is roughly classified into an axial fan motor (also referred to as a propeller fan motor) and a centrifugal fan motor depending on the fan shape. Among these, the centrifugal fan motor is further classified into a sirocco fan motor and a cross flow fan motor (see, for example, Patent Document 1 or 2).

The fans of these fan motors are usually mounted on the rotor portion of the motor, and rotate together with the rotor portion as the motor is driven to rotate. At this time, the rotor portion that rotates together with the fan is often rotatably supported by a rolling bearing such as a ball bearing, and usable bearings include, for example, the above-described rolling bearing, a sliding bearing, a fluid dynamic pressure bearing, and the like. Have been proposed (see, for example, Patent Document 3). In the latter case, for example, a minute radial gap is formed between the outer peripheral surface of the shaft that constitutes the rotor portion and the inner peripheral surface of the bearing sleeve that constitutes the stator portion, and oil or gas is present in the minute gap. Each bearing is used in a state where is filled.
JP 2005-86967 A JP 2001-15997A JP 2004-332724 A

  Recently, with the miniaturization and portability of various information devices, there has been an increasing demand for downsizing the fan motor incorporated therein. Further, as described above, considering that this type of fan motor is used for information devices for general personal users such as personal computers, not only the rotation performance is improved, but also the quietness during operation (silence) ) Improvement is important. For example, when a rolling bearing such as a ball bearing is used as a bearing for a fan motor mounted on a portable device, an indentation is easily generated on the rolling surface due to a drop or the like during carrying. In this case, the contact state of the rolling elements is not stable, and there is a risk of increasing the vibrations and eventually deteriorating the quietness. In addition, since the number of parts is large, it is difficult to further reduce the price.

  For example, by adopting a slide bearing instead of the rolling bearing, the number of parts can be reduced, and the cost can be reduced. However, in this type of bearing, due to a problem in processing accuracy, the gap between the opposed surfaces of the rotor portion (rotation side member) and the stator portion (bearing side member) that must be supported must be relatively large. . With the miniaturization of the motor, the above tendency becomes particularly remarkable. This increases shaft runout and may not satisfy the characteristics required for fan motor bearings, particularly quietness and durability.

  An object of the present invention is to improve the quietness by improving the rotational performance while reducing the manufacturing cost in this type of fan motor.

  In order to solve the above-described problems, the present invention satisfies a fixing member, a rotating member for rotating a fan, a radial bearing gap formed between radial facing surfaces of the fixing member and the rotating member, and a radial bearing gap. Provided is a fan motor bearing device characterized in that at least a region for forming a radial bearing gap is formed by an electroformed portion of a radial facing surface of one of a fixed member and a rotating member in a fluid provided with a fluid. To do.

  As described above, the present invention is characterized in that at least a region where a radial bearing gap is formed on the radial facing surface of one of the fixed member and the rotating member is formed by the electroformed portion. Electroforming is a technique for forming a metal layer by electrodeposition (electrolytic deposition) of metal ions on the master surface. Due to the characteristics of electroforming, the surface on the master side of the electroformed part (surface on the deposition start side) ) The surface shape of the master is transferred to a very fine level with high accuracy. Therefore, if the surface accuracy of the master is increased and the surface on the deposition start side of the electroformed part is used as a surface for forming a radial bearing gap, a radial bearing surface having high surface accuracy can be obtained without any special post-processing. It can be obtained at low cost. As a result, the width of the radial bearing gap can be made relatively small, so that high rotational accuracy can be obtained between the rotating member to be supported, and the contact state between the rotating member and the fixed member can be improved. It is possible to improve the performance. In addition, the electroformed part in this invention contains what was formed by the electroless-plating process other than what was formed by the said electroforming process.

  In particular, in this type of fan motor, the size of the fan is limited as the size is reduced, so if you try to achieve both the reduction in size of the motor and high cooling performance, you must inevitably increase the rotational speed. In the present invention, since the bearing surface is formed by electroforming, the rotational accuracy during high-speed rotation can be ensured even when the motor is downsized. Therefore, it is possible to provide a small fan motor having both high silence and cooling performance.

  In the fan motor bearing device having the above-described configuration, a dynamic pressure generating portion for generating a dynamic pressure action of fluid is formed on either one of the region forming the radial bearing gap of the electroformed portion and the surface facing the region. You can also. In this type of dynamic pressure bearing, in order to effectively generate the fluid dynamic pressure action in the radial bearing gap, it is important to appropriately manage the width of the bearing gap. In the present invention, since at least one of the radial bearing gap forming regions is formed by the electroformed part, the width of the radial bearing gap can be freely and precisely set according to the size and shape of the dynamic pressure generating part. it can. Therefore, it is possible to further increase the radial bearing rigidity and support the rotating member in a non-contact manner with respect to the fixed member.

  In particular, when the dynamic pressure generating part is provided on the electroformed part side, the dynamic pressure groove can be easily and accurately formed by setting the outer surface shape of the master used for electroforming to a shape corresponding to the dynamic pressure groove. Can be formed. According to this, since only high-precision processing of the master is sufficient, for example, when the dynamic pressure groove is provided in a place other than the electroformed portion, the dynamic pressure generating portion is formed by, for example, resin injection molding or plastic processing of sintered metal. Compared to the case, the dynamic pressure generating portion can be formed with higher accuracy, and the processing cost can be greatly reduced.

  By the way, the required characteristics for the fan motor, in particular, the support form of the bearing, are often influenced by the shape of the fan provided in the fan motor. For example, in a centrifugal fan motor that blows air in the direction of centrifugal rotation of the fan, simultaneously with the fan blowing in the centrifugal direction (for example, the outer diameter direction), a drag according to the blow (in this case, a radial drag) is received. . Therefore, in a motor having this type of fan, the region where the radial bearing gap is formed may be formed by the electroformed part as described above. The bearing structure according to the form and the improvement of the bearing performance are required.

  That is, in an axial fan motor that blows air in the direction of the rotation axis of the fan, the fan receives a drag according to the blowing (in this case, a drag in the direction of the rotation axis) simultaneously with the blowing in the rotation axis direction. Therefore, in this type of fan motor, it is important to improve the supporting force against the load in the thrust direction as well as in the radial direction. In contrast, in the present invention, a thrust bearing gap is formed between the thrust facing surfaces of the fixed member and the rotating member, and at least a thrust bearing gap is formed on one of the thrust facing surfaces of the fixed member and the rotating member. A region to be formed was formed by an electroformed part. According to this configuration, even when a large load acts in the thrust direction, the thrust bearing gap between the surface of the electroformed part (surface on the deposition start side) excellent in surface accuracy and the surface facing this surface The rotating member can be supported in a state in which is controlled with high accuracy. Therefore, a high thrust support force can be obtained, and contact between the two members in the thrust bearing gap can be avoided as much as possible to improve quietness.

  Of course, similarly to the radial bearing gap, a dynamic pressure generating portion for generating a dynamic pressure action of the fluid may be formed in either one of the region where the thrust bearing gap of the electroformed portion is formed and the surface facing the same. it can. According to this configuration, it is possible to further increase the bearing rigidity in the thrust direction and further improve the silence and durability.

  The fan motor bearing device configured as described above can be suitably provided as a fan motor including, for example, the bearing device, a drive unit that rotationally drives the rotating member, and a fan that is provided on the rotating member and rotates together with the rotating member. is there.

  As described above, according to the present invention, in this type of fan motor, the rotational performance can be improved and the silence can be improved while reducing the manufacturing cost.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The “up and down” direction in the following description merely indicates the up and down direction in each drawing for the sake of convenience, and does not specify the installation direction, usage mode, or the like of the fan motor or the fluid bearing device.

  FIG. 1 is a longitudinal sectional view of a fan motor 1 according to the first embodiment of the present invention, and FIG. 2 is a plan view of the fan motor 1. The fan motor 1 is a so-called sirocco fan motor, which is a fan motor bearing device (fluid bearing device) 10 that rotatably supports a shaft member 13, a hub 2 that is attached to one end of the shaft member 13, for example, A drive unit 3 composed of a stator coil 3a and a rotor magnet 3b opposed to each other through a gap in the radial direction, and a housing 11 of a fan motor bearing device 10 are fixed to the inner periphery and parts to be cooled (in FIG. 1) And a base 4 attached to a component indicated by a one-dot chain line. A rotor magnet 3b is fixed to the inner diameter side of the hub 2, and a plurality of fans (blades) 5 are erected on the outer diameter side in the circumferential direction. In this embodiment, an opening 4 b is provided in a partial region in the circumferential direction of the outer wall 4 a of the base 4. The opening 4b acts as an exhaust port for an exhaust flow sent to the outer diameter side when the fan motor 1 is driven. Further, a partially annular upper wall 4c extending toward the inner diameter side is provided at the upper end of the outer wall 4a, and a hole 4d is formed in the inner periphery of the upper wall 4c.

  When the stator coil 3a is energized, the rotor magnet 3b is rotated by the exciting force between the stator coil 3a and the rotor magnet 3b, whereby the hub 2 and the plurality of fans 5 erected on the hub 2 are connected to the shaft member 13. And rotate together. By this rotation, each fan 5 generates an air flow in the outer diameter direction (the direction of arrow A in FIG. 1), and the intake air flows downward from the hole 4d in the axial direction (arrow B in FIG. 1). Direction). On the other hand, an exhaust flow is generated in the direction of the arrow C in FIG. 1 while being pushed out by an air flow in the outer diameter direction, and is discharged to the outside through the opening 4b provided in the outer wall portion 4a.

  In this embodiment, the fan motor bearing device 10 includes a housing 11 attached to the base 4, a bearing portion 12 disposed in the housing 11, and a shaft member 13 inserted into the inner periphery of the bearing portion 12. , And a seal portion 14. In this case, the shaft member 13 constitutes a rotating member. The housing 11, the bearing portion 12, and the seal portion 14 constitute a fixing member.

  In this embodiment, the shaft member 13 has a shaft shape with a constant diameter, and is formed of a metal material such as SUS. As shown in FIG. 4, the outer peripheral surface 13 a of the shaft member 13 has a perfect circular cross section, and as will be described later, a radial bearing gap 16 is formed between the inner peripheral surface 15 a of the electroformed portion 15 facing in the radial direction. . As shown in FIG. 3, the lower end surface 13b of the shaft member 13 has a substantially spherical shape. When the shaft member 13 is inserted into the inner periphery of the bearing portion 12, the lower end surface 13b of the shaft 11 contacts the upper end surface 11a1 of the bottom portion 11a of the housing 11. Touch. Note that the width dimension of the radial bearing gap 16 is slightly smaller than the width dimension of the shaft member 13 and the bearing portion 12, but in FIG. 4, it is drawn larger than the actual dimension for ease of understanding. Yes. The same applies to the radial bearing gap 36 and the thrust bearing gaps 38 and 53 described later.

  The bearing portion 12 includes an electroformed portion 15 and a mold forming portion 17 molded using the electroformed portion 15 as an insert part. A region of the inner peripheral surface 12 a of the bearing portion 12 where at least the radial bearing gap 16 is formed is formed by the inner peripheral surface 15 a of the electroformed portion 15.

  As shown in FIG. 4, a plurality of arcuate surfaces 15a1 (three surfaces in the figure) constituting the dynamic pressure generating portion are formed on the entire inner surface 15a of the electroformed portion 15 or a partial region thereof. Each arcuate surface 15a1 is an eccentric arcuate surface centered at a point offset from the rotation axis O by an equal distance, and is formed at equal intervals in the circumferential direction. Each eccentric circular arc surface 15a1 has a constant cross-sectional shape in the axial direction. An axial separation groove 15a2 is formed between each eccentric arc surface 15a1.

  By inserting the shaft member 13 into the inner peripheral surface 15a of the electroformed portion 15, a radial bearing is provided between the eccentric arc surface 15a1 and the separation groove 15a2 of the electroformed portion 15 and the perfect circular outer peripheral surface 13a of the shaft member 13. A gap 16 is formed. In the radial bearing gap 16, the area formed by the eccentric arc surface 15 a 1 and the perfect circular outer peripheral surface 13 a is a wedge in which the gap width is gradually reduced toward one in the circumferential direction (the rotation direction of the shaft member 13). The gap 15a3 is formed.

  The bearing portion 12 having the above-described configuration is manufactured through the following steps, for example.

  The bearing portion 12 includes a step of masking the outer surface of the master 18 used in electroforming with an insulating material, a step of electroforming the masked master 18 to form the electroformed portion 15, and an electroformed portion. 15 and the master 18 are manufactured through an insert part and a step of performing molding (insert molding) of the bearing portion 12 and a step of separating the electroformed portion 15 and the master 18 in this order.

  The master 18 serving as a molding base of the electroformed part 15 is made of, for example, stainless steel. Of the outer surface of the master 18, the formation area of the electroformed part 15 has a shape that follows the inner peripheral surface 15a of the electroformed part 15 to be deposited. In this embodiment, as shown in FIG. 5, an outer peripheral surface 18a having a shape corresponding to the eccentric arc surface 15a1 is provided so that a plurality of eccentric arc surfaces 15a1 are formed on the inner peripheral surface 15a of the electroformed portion 15. . In this case, since the surface accuracy of the outer peripheral surface 18a directly affects the surface accuracy of the inner peripheral surface 15a of the electroformed portion 15 to be a radial bearing surface, it is desirable that the surface accuracy be finished as high as possible. The same can be said for the master for forming the lower end surface 37a of the electroformed portion 37 and the upper end surface 52a of the electroformed portion 52, which will be described later.

  The material of the master 18 can be arbitrarily selected from metals and non-metals as long as it has masking properties, electrical conductivity, and chemical resistance other than stainless steel, such as a chromium-based alloy and a nickel-based alloy. is there. Further, the master 18 is not limited to a peeled shaft (solid shaft), but may be a solid shaft in which a hollow shaft or a hollow portion is filled with another material.

  As shown in FIG. 5, masking is performed on the outer surface of the master 18 except for a region where the electroformed portion 15 is to be formed. As the covering material for forming the masking portion 19, a material having insulating properties and corrosion resistance against the electrolyte solution is selectively used.

  In the electroforming process, the master 18 is immersed in an electrolyte solution containing metal ions such as Ni and Cu, and the electrolyte solution is energized to apply the target metal to a region of the outer surface of the master 18 excluding the masking portion 19. It is done by letting you analyze. The electrolyte solution may contain a sliding material such as PTFE or carbon, or a stress relaxation material such as saccharin, if necessary. In this embodiment, PTFE particles are used as a sliding material that is contained in an electrolyte solution. The kind of the deposited metal is appropriately selected according to required characteristics such as hardness required for the bearing surface of the bearing or resistance to lubricating oil (oil resistance).

  By passing through the above process, as shown in FIG. 6, the thin cylindrical electroformed part 15 is formed in the area | region which is not coat | covered with the masking part 19 of master 18 outer periphery. In this case, the above-mentioned PTFE particles are dispersed in the electroformed part 15 formed by precipitation, and a part thereof is present on the inner peripheral surface 15a serving as a radial bearing surface. In addition, if the thickness of the electroformed part 15 is too thin, it leads to a decrease in the durability of the bearing surface (inner peripheral surface 15a), and if it is too thick, the peelability from the master 18 may be reduced. The optimum thickness is set in accordance with the bearing performance, bearing size, application, etc., for example, in the range of 5 μm to 200 μm.

  The electroformed part 15 formed through the above steps is supplied and arranged as an insert part integrally with, for example, the master 18 in a mold for insert-molding the bearing part 12. In this case, the molding die to be used has a cavity that follows the bearing portion 12 shown in FIGS. 3 and 4, and insert molding is performed using the molding die having such a cavity. The bearing portion 12 integrally having the shape molding portion 17 and the electroformed portion 15 is molded.

  The material of the molding part 17, that is, the material filled in the cavity of the molding die may be any material having a lower melting point than the material of the electroformed part 15. For example, resin, metal, or the like can be used. Among these, examples of the resin material include crystalline resins such as liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyacetal (POM), polyamide (PA), or polyphenylsulfone. Amorphous resins such as (PPSU), polyethersulfone (PES), polyetherimide (PEI), and polyamideimide (PAI) can be used as the base resin. Moreover, you may add various fillers, such as a reinforcement (regardless of forms, such as a fiber form and a powder form), a lubrication agent, and a electrically conductive agent as needed.

  After molding, the molded product in which the master 18 and the bearing portion 12 (the electroformed portion 15 and the mold forming portion 17) are integrated is removed from the mold. This molded product is separated into the bearing portion 12 and the master 18 in a subsequent separation step.

  In the separation step, for example, an impact is applied to the master 18 or the electroformed part 15, thereby peeling the inner peripheral surface 15 a of the electroformed part 15 from the outer peripheral surface 18 a of the master 18. Thereby, the master 18 is pulled out from the bearing part 12 (electroformed part 15), and the bearing part 12 as a finished product is obtained.

  In addition to the above-described means, the electroformed part 15 may be separated by, for example, a method in which the electroformed part 15 and the master 18 are heated (or cooled) to cause a difference in thermal expansion between them, or both. Means using both means (impact and heating) can be used.

  The bearing portion 12 formed as described above is fixed to the housing 11 shown in FIG. 3, and the shaft member 13 separate from the extracted master 18 is inserted into the inner periphery of the fixed bearing portion 12. Then, lubricating oil is injected from the air release side (seal portion 14 side) of the radial bearing gap 16 between the bearing portion 12 and the shaft member 13. Thereby, the fan motor bearing device 10 in which the bearing internal space including the radial bearing gap 16 is filled with the lubricating oil is completed. In addition, a seal space S is formed between the inner peripheral surface 14a of the seal portion 14 and the outer peripheral surface 13a of the shaft member 13 facing the seal portion 14, but the bearing inner space is filled with the lubricating oil as described above. Then, the oil level of the lubricating oil is always maintained in the seal space S.

  In the fan motor bearing device 10 configured as described above, when the shaft member 13 rotates, the plurality of arcuate surfaces 15a1 formed on the inner peripheral surface 15a of the electroformed portion 15 serve as radial bearing surfaces and the outer peripheral surface 13a of the shaft member 13 and It faces through the radial bearing gap 16 to constitute a multi-arc bearing. As the shaft member 13 rotates, the lubricating oil in the radial bearing gap 16 is pushed in the gradually reducing direction of the wedge-shaped gap 15a3 formed in the gap 16, and the pressure rises. The shaft member 13 is supported in a non-contact manner in the radial direction by the dynamic pressure action of the circular arc surface 15a1 (wedge-shaped gap 15a3). At the same time, the lower end surface 13b of the shaft member 13 is contact-supported (pivot supported) by the upper end surface 11a1 of the bottom portion 11a opposite thereto, whereby the shaft member 13 is supported rotatably in the thrust direction.

  In this case, the electroformed portion 15 constituting the radial bearing surface is formed by electrodeposition (electrolytic deposition) of metal ions in the electrolyte solution on the outer peripheral surface 18a of the master 18, and the inner periphery of the electroformed portion 15 is also formed. The surface 15a is a surface onto which the shape of the outer peripheral surface 18a of the master 18 is transferred with high accuracy on the order of microns due to the characteristics of electroforming. Therefore, if the master 18 having improved surface accuracy of the outer peripheral surface 18a is used, the inner peripheral surface 15a having high surface accuracy can be obtained at low cost without performing post-processing particularly for increasing the surface accuracy.

  Therefore, if the inner peripheral surface 15 a of the electroformed portion 15 is used as a radial bearing surface of the bearing portion 12, high rotational accuracy can be obtained between the outer peripheral surface 13 a of the shaft member 13. In the case of the bearing portion 12 having high bearing surface accuracy, the radial dimension of the inner peripheral surface 15a or the outer peripheral surface 13a is set so that the width of the radial bearing gap 16 between the shaft member 13 and the shaft member 13 is as small as possible. Can do. Thereby, while reducing the shaft runout at the time of use, the contact state between the bearing part 12 and the shaft member 13 can be improved, and quietness can be improved.

  Moreover, in this embodiment, by molding the bearing portion 12 using the electroformed portion 15 as an insert part, the portion other than the electroformed portion 15 of the bearing portion 12 (molded portion 17) can be molded and assembled. Can be performed simultaneously in one process, leading to cost reduction. Further, by inserting the electroformed part 15 integrally with the master 18, even if the electroformed part 15 is thin, it can be easily integrally formed with the mold forming part 17. Further, there is no fear that the inner peripheral surface 15a serving as the bearing surface is deformed by the injection pressure at the time of molding.

  The first embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and is applicable to a fan motor bearing device according to another embodiment or a fan motor including this bearing device. Is possible. Hereinafter, the example is demonstrated based on FIGS.

  FIG. 7 shows a partial cross-sectional view of the fan motor 21 according to the second embodiment of the present invention. The fan motor 21 according to this embodiment is a so-called axial fan motor, and generates an air flow in the direction of the rotation axis of the fan motor 21 as the fan 25 rotates. In other words, the fan motor 21 rotates to rotate. The configuration of the fan motor 1 according to the first embodiment is different from that of the fan motor 1 in that an air flow is generated in the direction of the rotation axis.

  The fan motor bearing device 30 incorporated in the fan motor 21 closes the bearing portion 31 attached to the base 4, the shaft member 32 inserted into the inner periphery of the bearing portion 31, and one end side of the bearing portion 31. A lid member 34 and a seal portion 14 are provided. In this embodiment, a flange portion 33 as a retaining member is provided integrally or separately at an end portion of the shaft member 32 opposite to the attachment portion of the hub 2. A radial bearing gap 36 is formed between the outer peripheral surface 32a of the shaft member 32 and the inner peripheral surface of the bearing portion 31 facing the shaft member 32 (between the radial opposing surfaces), and the radial opposing surface (inner peripheral surface) of the bearing portion 31 is formed. The region where at least the radial bearing gap 36 is formed is formed by the electroformed portion 35. Further, a thrust bearing gap 38 is formed between the upper end surface 33a of the flange portion 33 and the lower end surface of the bearing portion 31 facing the flange portion 33 (between the thrust opposing surfaces), and the thrust opposing surface (lower end surface) of the bearing portion 31 is formed. The region where at least the thrust bearing gap 38 is formed is formed by the electroformed portion 37. In this case, the shaft member 32 and the flange portion 33 constitute a rotating member. The bearing portion 31, the lid member 34, and the seal portion 14 constitute a fixing member.

  As shown in FIG. 7, a plurality of inclined grooves 35a1 (also referred to as dynamic pressure grooves) are arranged in a herringbone shape as a dynamic pressure generating portion on the entire inner surface 35a or a partial region of the electroformed portion 35. Region is formed. In the illustrated example, the array regions of the inclined grooves 35a1 are formed at two locations separated in the axial direction. In addition, as shown in FIG. 8, a region where a plurality of radial grooves 37a1 are arranged in a spiral shape is formed as a dynamic pressure generating portion on the entire or partial region of the lower end surface 37a of the electroformed portion 37.

  The above-mentioned electroformed parts 35 and 37 and the bearing part 31 integrally including the mold forming part 39 molded with these as insert parts are electroformed into a masked master (not shown) in the same manner as described above. Forming the electroformed parts 35 and 37, forming the bearing 31 using the electroformed parts 35 and 37 and the master as insert parts (insert molding), and forming the electroformed parts 35 and 37 and the master. It forms through the process of isolate | separating in order. In this embodiment, the electroformed parts 35 and 37 are integrally formed, but at the time of electroforming, the electroformed part 35 and the electroformed part 37 are formed separately by devising masking or the like. Is also possible. Since the other configuration is the same as that of the first embodiment, the description thereof is omitted.

  In the fan motor 21 configured as described above, when the stator coil 3a is energized, the rotor magnet 3b is rotated by the exciting force between the stator coil 3a and the rotor magnet 3b, thereby being provided on the outer periphery of the hub 2 and the hub 2. The fan 25 rotates integrally with the shaft member 32. This rotation causes the fan 25 to generate an airflow in the direction of the motor rotation axis (in this embodiment, an airflow in the direction of arrow D in FIG. 7), and at the same time, a force opposite to the direction of the airflow (arrow E in the same figure). Force on the shaft member 32 that rotates integrally with the fan 25.

  In this case, of the inner peripheral surface 35a of the electroformed portion 35, the region excluding the plurality of inclined grooves 35a1 arranged in a herringbone shape is a radial bearing surface, and the outer peripheral surface 32a of the shaft member 32 and the radial bearing gap 36 are formed. Opposite through. As the shaft member 32 rotates, the lubricating oil in the radial bearing gap 36 is pushed into a specific location (in this embodiment, the bent portion of each inclined groove 35a1) by each inclined groove 35a1, and the pressure increases. To do. Due to the dynamic pressure action of the inclined groove 35a1, the shaft member 32 is supported in a non-contact manner so as to be rotatable in the radial direction.

  In addition, in FIG. 7, the shaft member 32 receives a force in a direction away from the lid member 34, so that the upper end surface 33 a of the flange portion 33 is formed on the lower end surface 37 a of the electroformed portion 37 facing the shaft member 32. Although pressed, the lower end surface 37a of the electroformed portion 37 is formed with a region in which a plurality of radial grooves 37a1 are arranged in a spiral shape as described above. Therefore, when the shaft member 32 rotates, a region of the lower end surface 37a excluding each radial groove 37a1 is opposed to the upper end surface 33a of the flange portion 33 via the thrust bearing gap 38 as a thrust bearing surface. As the shaft member 32 rotates, the lubricating oil in the thrust bearing gap 38 is pushed toward the inner diameter side of each radial groove 37a1, and the pressure rises. Due to the dynamic pressure action of the radial grooves 37a1, the flange portion 33 (the shaft member 32) is supported in a non-contact manner so as to be rotatable in the thrust direction.

  In this embodiment, the radial bearing surface is formed by the electroformed part 35 and the thrust bearing surface is also formed by the electroformed part 37. For this reason, a radial bearing surface having high surface accuracy (without performing post-processing to increase surface accuracy, in particular, by using a master with increased surface accuracy of the surfaces on which the electroformed portions 35 and 37 are formed by precipitation ( The inner peripheral surface 35a) and the thrust bearing surface (lower end surface 37a) can be formed at low cost. Thereby, high rotational accuracy can be obtained between the shaft members 32, and the width dimensions of the bearing gaps 36 and 38 can be minimized. Therefore, even when the fan motor 21 is used at high speed rotation, the contact state between the bearing portion 31 and the shaft member 32 can be improved and noise generation can be suppressed as much as possible. At the same time, it is possible to reduce the damage caused by the contact of each bearing surface, and to extend the life of the fan motor bearing device 30 and the fan motor 21 incorporating the same.

  Further, as in this embodiment, depending on the shape of the fan 25 (air blowing direction), support in the thrust direction as well as the radial direction may be important. However, as described above, at least one of the thrust bearing surfaces is By configuring the electroformed portion 37, the surface accuracy of the thrust bearing surface and the width dimension of the thrust bearing gap 38 can be managed with high accuracy. Therefore, a high thrust support force can be stably applied to the shaft member 32, and quietness can be improved. In particular, in this embodiment, since the radial groove 37a1 as the dynamic pressure generating portion is formed in the region where the thrust bearing gap 38 is formed on the lower end surface 37a of the electroformed portion 37, the bearing rigidity in the thrust direction is further increased. Further improvement in rotational accuracy and quietness can be achieved.

  In this embodiment, as the shaft member 32 rotates, the fan 25 is shaped so as to receive a force in a direction in which the shaft member 32 comes out of the fan motor bearing device 30 (a force indicated by an arrow E in FIG. 7). However, the present invention can also be applied to a fan motor provided with a fan whose air blowing direction is opposite to this.

  FIG. 9 shows a fan motor 41 according to the third embodiment of the present invention. The fan motor 41 shown in the figure is the same as the fan motor 21 according to the second embodiment in that an air flow in the rotation axis direction of the fan motor 41 is generated with the rotation of the fan 45, but the air blowing direction is different. ing. In other words, as the shaft member 32 rotates, the fan 45 generates an upward airflow (airflow in the direction of arrow F in FIG. 9), and thereby a force opposite to the direction of the airflow (arrow G in FIG. 9). The configuration of the fan motor 21 according to the second embodiment is different from that of the fan motor 21 according to the second embodiment.

  Specifically, in the fan motor bearing device 50 shown in the figure, a thrust bearing gap 53 is formed between the lower end surface 42a of the hub 42 and the upper end surface of the bearing portion 51 facing the hub 42 (between the thrust opposing surfaces). At the same time, at least a region where the thrust bearing gap 53 is formed on the thrust facing surface (upper end surface) of the bearing portion 51 is formed by the electroformed portion 52. A plurality of radial grooves having the same arrangement as in FIG. 8 are formed as a dynamic pressure generating part on the entire upper surface 52a of the electroformed part 52 or a partial region thereof. In this embodiment, a projecting portion 42b projecting downward from the lower end surface 42a of the hub 42 is provided, and between the inner peripheral surface 42b1 of the projecting portion 42b and the upper end outer peripheral surface 51a of the bearing portion 51 facing this. Is provided with a seal space S. The seal space S communicates with the thrust bearing gap 53 on the outer diameter side. In addition, as shown in FIG. 9, it is also possible to gradually reduce the radial dimension of the seal space S downward by forming the upper end outer peripheral surface 51a in a tapered shape. In this case, the rotating member includes the shaft member 32 and the hub 42. The fixing member includes the bearing portion 51 and the lid member 34. Since other configurations are the same as those in the above embodiment, the same reference numerals are given and the description thereof is omitted.

  Thus, even when the fan blowing direction is different, by adopting the above-described configuration, a high thrust support force can be stably applied to the shaft member 32 (rotating member), and quietness is improved. Can be achieved. Depending on the arrangement of the stator coil 3a and the rotor magnet 3b constituting the drive unit 3, an axial component may be generated in the exciting force between the two, thereby reversing the fan blowing direction and the thrust bearing surface direction. Therefore, it is preferable to determine the thrust bearing structure (direction of the bearing surface) of the bearing portions 31 and 51 in consideration of these. Of course, as in the second and third embodiments, when the rotating member is mainly supported by the thrust support force, only the regions where the thrust bearing gaps 38 and 53 are formed are formed by the electroformed portions 37 and 52. It doesn't matter.

  As another example, in the fan motor 21 (fan motor bearing device 30) according to the second embodiment, for example, although not shown, the other end surface (lower end surface 33b) of the flange portion 33 of the lid member 34 is shown. ) And the region facing in the thrust direction may be formed by an electroformed part. If it is this structure, the shaft member 32 can be supported by high thrust support force also about the fan motor which has the ventilation direction similar to 3rd Embodiment, for example. Similarly, in the fan motor 1 (fan motor bearing device 10) according to the first embodiment, the region of the upper end surface 11a1 of the bottom portion 11a of the housing 11 facing the lower end surface 13b of the shaft member 13 in the thrust direction is electroformed. The part can be formed.

  In the above embodiments (first to third embodiments), the case where the present invention is applied mainly to an axial fan motor and a sirocco fan motor has been described. However, the present invention has a radial bearing gap or a thrust bearing gap. As long as it is a fan motor bearing device and a fan motor provided with this bearing device, the present invention can be applied to other types of fan motors such as a crossflow fan motor.

  In the above embodiment, as the dynamic pressure generating portion, a region where a plurality of inclined grooves 35a1 are arranged in a so-called herringbone shape, a region where a plurality of eccentric arc surfaces 15a1 are arranged in the circumferential direction, or a plurality Although the region where the radial grooves 37a1 are arranged over the entire circumference is illustrated, it is of course possible to provide a dynamic pressure generating portion other than these. For example, in the fan motor bearing device 10 according to the first embodiment, a plurality of axial grooves are provided on the inner peripheral surface 15a of the electroformed portion 15 in the circumferential direction, and the outer peripheral surface 13a of the shaft member 13 facing these are provided. It is also possible to form so-called step bearings between them. Although not shown, a plurality of concentric circular arc surfaces are provided on the inner peripheral surface 15a of the electroformed portion 15, and the radial dimension is provided in both circumferential directions between the concentric circular arc surfaces and the outer peripheral surface 13a. It is also possible to constitute a multi-arc bearing that forms a wedge-shaped gap that gradually decreases. These dynamic pressure generating portions can be provided on the electroformed portion side, or can be formed on the surface facing the electroformed portion. Of course, without providing the dynamic pressure generating portion, for example, the inner peripheral surface 15a of the electroformed portion 15 and the outer peripheral surface 13a of the shaft member 13 are both made into a perfect circular cross section, and a so-called fluid true circular bearing is constituted by these both surfaces. Is also possible.

  Moreover, in the above embodiment, although the case where the bearing part 12 was formed by forming the mold forming part 17 by using the electroformed part 15 as an insert part was illustrated, it is not particularly limited to this. As long as it is an element other than the electroformed part and constitutes a fixing member, the electroformed part 15 is not limited to the bearing part 12 and can be integrally molded as an insert part. For example, in the case of the fan motor 1 (fan motor bearing device 10) according to the first embodiment, the housing 11 and the seal portion 14 are formed in the region excluding the electroformed portion 15 of the bearing portion 12 (in FIG. It can also be formed integrally with the same material as in 17). Further, the base 4 of the fan motor 1 can be further formed integrally with the housing 11 and the seal portion 14. In this case, the base 4 is a component of the fixing member of the fan motor bearing device 10, It is also a component of the fan motor 1. Of course, the electroformed portion 15 and the portion of the bearing portion 12 excluding the electroformed portion 15 may be formed separately and assembled later. A similar configuration can be adopted for the bearing portions 31 and 51 according to the second and third embodiments.

  Moreover, in the above embodiment, although the case where the electroformed part was provided in the fixing member side was illustrated, it can also be provided in the rotating member side. For example, in the fan motor bearing device 10 according to the first embodiment, although illustration is omitted, at least a region where the radial bearing gap 16 is formed on the outer peripheral surface 13a of the shaft member 13 may be formed by an electroformed part. Is possible. In the fan motor bearing device 30 according to the second embodiment, although not shown in the drawing, at least a region for forming the thrust bearing gap 38 on the upper end surface 33a of the flange portion 33 may be formed by an electroformed portion. Is possible. Or if it is the fan motor bearing apparatus 50 which concerns on 3rd Embodiment, although illustration is abbreviate | omitted similarly, the area | region which forms the thrust bearing clearance gap 53 of the lower end surface 42a of the hub 42 is formed in an electroformed part. Is also possible. Further, in the case of the elements constituting the rotating member, that is, the fan motor bearing device 50 according to the third embodiment, the shaft member 32 and the hub 42 can be integrally formed of the same material. Of course, each component may be formed separately and assembled later. Or you may shape | mold the remaining component integrally by making one or some component into an insert part.

  Moreover, in the above embodiment, although lubricating oil was illustrated as a fluid which fills the inside of the fan motor bearing apparatus 10, 30, 50 and produces a dynamic pressure action in each bearing gap, or a fluid which forms a lubricating film. In addition, a fluid that can cause a dynamic pressure action, for example, a gas such as air, a fluid lubricant such as a magnetic fluid, or a lubricating grease may be used.

It is sectional drawing of the fan motor which concerns on 1st Embodiment of this invention. It is a top view of a fan motor. It is sectional drawing of the bearing apparatus for fan motors. It is a cross-sectional view of the fan motor bearing device. It is a perspective view of the master of the state which performed masking. It is a perspective view of the master which formed the electroformed part in the outer periphery. It is sectional drawing of the fan motor which concerns on 2nd Embodiment of this invention. 4 is a bottom view of the bearing portion of the fan motor bearing device as viewed from the direction of arrow E. FIG. It is sectional drawing of the fan motor which concerns on 3rd Embodiment of this invention.

Explanation of symbols

1, 21, 41 Fan motor 2, 42 Hub 3a Stator coil 3b Rotor magnet 4 Base 5, 25, 45 Fan 10, 30, 50 Fan motor bearing device 13, 32 Shaft member 13a, 32a Outer peripheral surface 15, 35, 37 , 52 Electroformed part 15a1 Eccentric arc surface 15a3 Wedge-shaped gap 16, 36 Radial bearing gap 17, 39 Molding part 18 Master 19 Masking part 33 Flange part 35a1 Inclined groove 37a1 Radial groove 38, 53 Thrust bearing gap

Claims (6)

In a fan motor bearing device comprising: a fixing member; a rotating member for rotating the fan; a radial bearing gap formed between the radial facing surfaces of the fixing member and the rotating member; and a fluid satisfying the radial bearing gap. ,
A fan motor bearing device, wherein at least a region for forming a radial bearing gap is formed by an electroformed portion on a radial facing surface of one of a fixed member and a rotating member.   The fan motor bearing device according to claim 1, wherein a dynamic pressure generating portion for generating a dynamic pressure action of fluid is formed in either one of a region forming a radial bearing gap of the electroformed portion and a surface opposed to the region.   A thrust bearing gap is formed between the thrust facing surfaces of the fixed member and the rotating member, and at least a region of the thrust facing surface of either the fixed member or the rotating member is formed in the electroformed portion. The fan motor bearing device according to claim 1.   4. The fan motor bearing device according to claim 3, wherein a dynamic pressure generating part for generating a dynamic pressure action of fluid is formed in either one of a region forming a thrust bearing gap of the electroformed part and a surface facing the gap. In a fan motor bearing device comprising: a fixing member; a rotating member for rotating the fan; a thrust bearing gap formed between thrust opposing surfaces of the fixing member and the rotating member; and a fluid satisfying the thrust bearing gap.
A fan motor bearing device, wherein at least a region for forming a thrust bearing gap is formed by an electroformed portion on a thrust facing surface of one of a fixed member and a rotating member.   A fan motor comprising the fan motor bearing device according to claim 1, a drive unit that rotationally drives the rotating member, and a fan that is provided on the rotating member and rotates together with the rotating member.

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