Sleeve, sleeve with bearing and rotating device

Abstract

Provided is a sleeve capable of suppressing the occurrence of electrocorrosion in a rolling bearing. The sleeve (140) is a cylindrical sleeve having a bearing (1) attached to the inside thereof, and is provided with: holding parts (141, 142) that hold the outer peripheral surface of the bearing (1); and outer ring support sections (143, 144) that are in contact with the end surface of the outer ring (20) of the bearing (1) from the inside in the axial direction. The holding portions (141, 142) have recessed portions (141a, 142a) that open inward in the radial direction toward the outer peripheral surface of the bearing (1). At least a portion of the sleeve (140) is formed of an electrically insulating synthetic resin.

Description

Technical Field

[0001] This invention relates to sleeves, sleeves with bearings, and rotating devices. Background Technology

[0002] In rotating equipment, a cylindrical sleeve is sometimes provided to support the shaft in a rotatable manner on the inner side. The sleeve holds the rolling bearing on the inner side. As rolling bearings, rolling bearings with structures for preventing electro-corrosion are known (for example, see Patent Documents 1 and 2). Specifically, there are techniques such as electrically insulating the outer ring from the inner ring by making the rolling elements ceramic as insulators, or electrically insulating the sleeve from the outer ring by covering the outer circumferential surface of the outer ring with an insulating film.

[0003] Prior art literature Patent documents Patent Document 1: Japanese Patent Application Publication No. 2019-206980; Patent document 2: Japanese Patent Application Publication No. 2001-99176. Summary of the Invention

[0004] The problem that the invention aims to solve However, the cost of ceramic rolling elements is high, leading to increased manufacturing costs. Furthermore, the use of an insulating film to cover the outer circumference of the outer ring inevitably increases manufacturing costs due to the added manufacturing steps. Moreover, in rolling bearings with an insulating film on the outer circumference of the outer ring, given standard dimensions, the metal body of the raceway ring needs to be formed thinner radially to match the thickness of the insulating film. Therefore, concerns arise regarding a decrease in the roundness or rigidity of the rolling bearing.

[0005] Furthermore, with the increasing speed of rotation in rotating equipment in recent years, slippage between the sleeve and the outer circumferential surface of the outer ring due to the accompanying rotation of the outer ring has become a problem. If slippage occurs in the outer ring, it can sometimes generate noise, wear particles, or overheating of the sliding parts. In such cases, damage to the conveying surface of the raceway and rolling elements may occur due to the intrusion of wear particles, or deterioration of the internal grease of the rolling bearing and a decrease in bearing life may occur due to overheating of the sliding parts. The same problems may also occur in the case of creep or fretting wear. In particular, structures with an insulating film on the outer circumferential surface of the outer ring are more prone to the aforementioned problems caused by slippage.

[0006] Thus, in the existing rolling bearings described above, various problems may arise in the construction methods for suppressing the generation of electro-corrosion. Therefore, it is desirable to develop a construction method that suppresses the generation of electro-corrosion on the sleeve side of the rolling bearing.

[0007] Therefore, the present invention provides a sleeve capable of suppressing electro-corrosion in rolling bearings, as well as a sleeve with bearings and a rotating device having the sleeve.

[0008] Solution for solving the problem The first aspect of the present invention relates to a sleeve that is a cylindrical sleeve on which a rolling bearing is mounted on the inner side, comprising: a retaining portion that retains the outer peripheral surface of the aforementioned rolling bearing; and an outer ring support portion that contacts the end face of the outer ring of the aforementioned rolling bearing from the inner side in the axial direction, wherein the aforementioned retaining portion has a recess that opens inward toward the aforementioned outer peripheral surface in the radial direction, and at least a portion is formed of a synthetic resin having electrical insulating properties.

[0009] According to the first scheme, current flow through the sleeve into the rolling bearing can be suppressed. This, in turn, suppresses electro-corrosion in the rolling bearing.

[0010] In order to suppress slippage of the outer ring of the rolling bearing relative to the sleeve, it is necessary to fix the outer ring to the sleeve. Either press-fitting or bonding can be used as methods for fixing the outer ring to the sleeve.

[0011] In a configuration where the outer ring is fixed to the sleeve by pressing, there is a possibility that deformation of the synthetic resin sleeve may affect the outer ring. If the sleeve deformation affects the outer ring, there is a possibility that the contact point between the raceway surface of the outer ring and the rolling elements may change, leading to malfunction of the rolling bearing. According to the first embodiment, a recessed portion opening towards the outer circumferential surface of the rolling bearing is provided in the retaining portion that holds the outer circumferential surface of the rolling bearing. This prevents the sleeve deformation from affecting the outer ring via the contact point between the sleeve and the outer ring. Therefore, it is possible to suppress malfunction of the rolling bearing caused by changes in the contact point between the raceway surface and the rolling elements.

[0012] When the outer ring is fixed to the sleeve by adhesive bonding, the recess can function as an adhesive accumulation area. This prevents adhesive from leaking between the sleeve and the outer ring into the interior of the rolling bearing, and also prevents adhesive from adhering to unintended locations and causing malfunctions in the rolling bearing.

[0013] Through the above, a synthetic resin sleeve can be formed that suppresses the occurrence of various adverse conditions while simultaneously mounting rolling bearings.

[0014] The sleeve according to the second aspect of the present invention may also be, in the sleeve according to the first aspect, having a parting line formed during the molding of the sleeve at the position opposite to the outer ring support portion on the inner circumferential surface of the aforementioned retaining portion.

[0015] According to the second scheme, the parting line can be avoided at the contact portion between the sleeve and the rolling bearing. Therefore, the assembly accuracy of the rolling bearing can be suppressed due to the parting line, and there is no need for machining such as cutting off the parting line to install the rolling bearing into the sleeve, thus reducing the increase in manufacturing costs.

[0016] The sleeve involved in the third aspect of the present invention may also be the sleeve involved in the first or second aspect, in which potassium titanate whiskers are added to the aforementioned synthetic resin.

[0017] According to the third embodiment, the sleeve can be made into a component with excellent wear resistance and surface smoothness. Furthermore, the synthetic resin containing potassium titanate whiskers has good machinability and is less prone to clogging during grinding, thus exhibiting excellent processability. Therefore, compared to the case where the sleeve contains glass fiber or carbon fiber as a reinforcing material, the processability when forming the sleeve through machining such as cutting or grinding, as well as the processability when finishing the injection-molded sleeve through two processes such as cutting or grinding, can be improved.

[0018] The sleeve involved in the fourth aspect of the present invention may also be the sleeve involved in any of the first to third aspects described above, wherein the aforementioned recess extends continuously throughout the circumferential direction.

[0019] According to the fourth scheme, the deformation of the sleeve affecting the outer ring can be suppressed more reliably. In addition, the recess can function more reliably as an adhesive accumulation area.

[0020] The sleeve involved in the fifth aspect of the present invention may also be the sleeve involved in any of the first to fourth aspects described above, wherein the aforementioned recess has an inclined portion whose inner diameter decreases as it moves outward toward the aforementioned axial direction.

[0021] According to Option 5, when the sleeve is injection molded, the portion of the metal mold that forms the recess can be easily pulled out. Therefore, the sleeve can be easily formed by injection molding.

[0022] The sleeve involved in the sixth aspect of the present invention may also be the sleeve involved in any of the first to fifth aspects described above, wherein the aforementioned retaining portion has a press-in portion with an inner diameter smaller than the outer diameter of the aforementioned rolling bearing.

[0023] According to the sixth embodiment, the outer ring is fixed to the retaining part of the sleeve by pressing, thus achieving a suitable configuration that can suppress the deformation of the sleeve and the outer ring.

[0024] The sleeve involved in the seventh aspect of the present invention may also be the sleeve involved in any of the first to sixth aspects described above, wherein the aforementioned recess is positioned at intervals relative to the aforementioned outer ring support portion along the aforementioned axial direction.

[0025] According to the seventh embodiment, compared to a configuration where the recess is positioned axially without any interval between it and the outer ring support, the distance of the path between the sleeve and the outer ring, from the recess through the end face of the outer ring and the outer ring support to the interior of the rolling bearing, can be extended. Therefore, in a configuration where the outer ring is fixed to the sleeve by adhesive bonding, leakage of adhesive disposed in the recess through the end face of the outer ring and the outer ring support into the interior of the rolling bearing can be prevented. Thus, it is more reliable to prevent adhesive from adhering to unexpected locations and causing malfunctions in the rolling bearing.

[0026] The sleeve involved in the eighth aspect of the present invention may also be the sleeve involved in any of the first to seventh aspects described above, which is entirely formed of the aforementioned synthetic resin.

[0027] According to the eighth embodiment, current flow through the sleeve into the rolling bearing can be more reliably suppressed. Furthermore, compared to a structure where only a portion of the sleeve is formed of synthetic resin, the sleeve can be easily formed, thereby reducing the manufacturing cost of the sleeve.

[0028] The sleeve according to the ninth aspect of the present invention may also be the sleeve according to any of the first to eighth aspects described above, further comprising a protrusion formed on the inner side of the outer ring support portion in the axial direction and protruding on the inner side of the outer ring support portion in the radial direction.

[0029] According to the ninth embodiment, when the shaft portion inserted into the inner ring of the rolling bearing is tilted relative to the central axis of the sleeve, further tilting of the shaft portion can be limited by contact between the shaft portion and the protrusion. Here, without the protrusion on the sleeve, the point on the inner circumferential surface of the sleeve that can contact the tilted shaft portion is located radially outward than the inner circumferential edge of the outer ring support, thus failing to sufficiently limit the tilting of the shaft portion. According to the ninth embodiment, the protrusion protrudes radially inward more than the outer ring support, thus effectively limiting the tilting of the shaft portion. Therefore, it is possible to suppress the formation of rolling element indentations in at least one of the inner and outer rings due to significant tilting of the inner ring relative to the outer ring. Thus, during the assembly of a rotating device with a sleeve, it is possible to suppress the formation of indentations on the raceway rings of the rolling bearing and suppress abnormal noise during the rotation of the rotating device.

[0030] The sleeve according to the 10th aspect of the present invention may also be the sleeve according to the 9th aspect described above, wherein the protrusion has a limiting portion that can contact the shaft portion inserted through the inner ring when the tilt angle between the outer ring and the inner ring of the rolling bearing is less than the angular clearance.

[0031] According to the 10th solution, the tilting of the shaft portion can be limited by the limiting part to exceed the angular clearance of the rolling bearing. Therefore, during the assembly of a rotating device with a sleeve, the formation of indentations on the raceway ring of the rolling bearing can be more reliably suppressed.

[0032] The sleeve involved in the 11th aspect of the present invention may also be the sleeve involved in the 9th or 10th aspects described above, wherein the outer ring support portion has an inner diameter that is larger than the outer diameter of the inner ring of the rolling bearing.

[0033] According to solution 11, contact between the outer ring support and the inner ring of the rolling bearing can be avoided. Therefore, interference of the sleeve with the rotation of the shaft can be prevented.

[0034] The sleeve according to the 12th aspect of the present invention may also be, in the sleeve according to the 11th aspect above, wherein the inner diameter of the aforementioned protrusion is less than or equal to the outer diameter of the aforementioned inner ring.

[0035] According to the 12th solution, contact between the sleeve and the inner ring of the rolling bearing can be avoided, while simultaneously bringing the protrusion closer to the central axis of the sleeve. Therefore, shaft tilting can be more effectively limited.

[0036] The sleeve involved in the 13th aspect of the present invention may also be the sleeve involved in any of the 9th to 12th aspects described above, which integrally has the aforementioned outer ring support portion and the aforementioned protrusion portion.

[0037] According to Option 13, the sleeve can be formed from a single component. Therefore, it is possible to reduce the manufacturing cost of the sleeve.

[0038] The sleeve according to the 14th aspect of the present invention may also be the sleeve according to any one of the 9th to 13th aspects described above, comprising: a sleeve body having the aforementioned protrusion; and a support member disposed inside the aforementioned sleeve body, overlapping the aforementioned protrusion from the other side in the aforementioned axial direction to form the aforementioned outer ring support portion.

[0039] According to the 14th embodiment, the sleeve body can be made into a simple shape with fewer steps, resulting in a sleeve with excellent manufacturability. In particular, when the sleeve body is made of metal, complex processing can be avoided during the formation of the sleeve body, thus making it a suitable configuration that achieves the aforementioned effects.

[0040] The sleeve according to the 15th aspect of the present invention may also be the sleeve according to the 10th aspect and the above-mentioned aspects, in which another rolling bearing is held at the position opposite to the aforementioned protrusion of the aforementioned rolling bearing, the end portion of the aforementioned shaft portion has a tapered surface with a tapered end shape, and the aforementioned protrusion portion can contact the aforementioned shaft portion when the aforementioned tapered surface is in contact with the opening edge of the inner ring of the aforementioned other rolling bearing.

[0041] According to the 15th embodiment, when the shaft is inserted from the rolling bearing side into another rolling bearing, even if the shaft is offset due to tilting relative to the central axis of the sleeve, the tapered surface can still contact the opening edge of the inner ring of the other rolling bearing. This prevents excessive force from being applied to the inner ring due to contact between the end face of the shaft and the inner ring of the other rolling bearing. Therefore, it suppresses the formation of indentations on the raceway of the other rolling bearing and suppresses abnormal noise during the rotation of the rotating equipment.

[0042] The bearing sleeve according to the 16th aspect of the present invention comprises: the sleeve according to any one of the first to 15 aspects described above; and the aforementioned rolling bearing, which is installed on the inner side of the aforementioned sleeve.

[0043] According to the 16th embodiment, a bearing sleeve can be provided to suppress electro-corrosion in rolling bearings.

[0044] The bearing sleeve involved in the 17th aspect of the present invention may also be the bearing sleeve involved in the 16th aspect described above, wherein the aforementioned rolling bearing is bonded to the aforementioned sleeve, and an adhesive is disposed in the aforementioned recess.

[0045] According to the 17th embodiment, the recess functions as an adhesive accumulation area. This prevents adhesive from leaking between the sleeve and the outer ring into the interior of the rolling bearing, and also prevents adhesive from adhering to unintended locations and causing malfunctions in the rolling bearing.

[0046] The rotating device according to the 18th aspect of the present invention includes: a sleeve with a bearing as described in the 16th or 17th aspect above; and a shaft portion inserted through the inner ring of the aforementioned rolling bearing.

[0047] According to Solution 18, the increase in rotational resistance of rolling bearings caused by electro-corrosion can be suppressed. Therefore, the service life of rotating equipment can be extended.

[0048] The rotating device according to the 19th aspect of the present invention includes: a sleeve according to the 6th aspect and the above-mentioned aspects; the aforementioned rolling bearing, which is installed inside the aforementioned sleeve; a shaft portion inserted through the inner ring of the aforementioned rolling bearing; and a force-applying member that applies force to the aforementioned inner ring in the aforementioned axial direction, wherein the aforementioned pressing portion is located further outward in the aforementioned axial direction than the aforementioned recess.

[0049] According to embodiment 19, the rolling element is subjected to a force applied by the force-applying component and contacts the raceway surface of the outer ring at a point further inward in the axial direction than its axial center. A recess is provided at this point, further inward in the axial direction than the press-in portion, to prevent contact between the sleeve and the outer ring, thereby suppressing deformation waves of the sleeve and the vicinity of the contact point with the rolling element in the outer ring. Therefore, changes in the contact point between the raceway surface of the outer ring and the rolling element can be prevented, thus suppressing malfunctions of the rolling bearing.

[0050] The rotating device according to the 20th aspect of the present invention may also be the rotating device according to the 18th or 19th aspect described above, wherein the aforementioned shaft is the rotating shaft of a motor, and the aforementioned sleeve and the chassis of the aforementioned motor are integrally formed of synthetic resin.

[0051] According to Option 20, by forming the sleeve and chassis as a single unit, the number of parts can be reduced, thereby improving the productivity of the motor.

[0052] The effects of the invention According to the present invention, a sleeve capable of suppressing electro-corrosion in rolling bearings, and a sleeve with bearings having the sleeve and a rotating device thereof can be provided. Attached Figure Description

[0053] Figure 1 This is a longitudinal cross-sectional view illustrating an embodiment of the fan motor.

[0054] Figure 2 This is a top view of the rolling bearing according to the embodiment.

[0055] Figure 3 This is a longitudinal cross-sectional view of the rolling bearing according to the embodiment, showing... Figure 2 The cross section on line III-III.

[0056] Figure 4 It shows that Figure 3 The diagram shows the state of the bearing's inner ring tilted relative to the outer ring.

[0057] Figure 5 This is a longitudinal cross-sectional view of the fan motor according to the first embodiment, and an enlarged view showing the periphery of the sleeve.

[0058] Figure 6 This is a longitudinal cross-sectional view of the fan motor according to the second embodiment, and an enlarged view showing the periphery of the sleeve.

[0059] Figure 7 This is a longitudinal cross-sectional view of the fan motor according to the third embodiment, and an enlarged view showing the periphery of the sleeve.

[0060] Figure 8 This is a longitudinal cross-sectional view of the fan motor according to the fourth embodiment, and an enlarged view showing the periphery of the sleeve.

[0061] Figure 9 This is a longitudinal cross-sectional view of the fan motor according to the fifth embodiment, and an enlarged view showing the periphery of the sleeve.

[0062] Figure 10 It shows that Figure 9 The diagram shows the state in which the shaft is tilted and in contact with the limiting part of the sleeve.

[0063] Figure 11 It is shown Figure 9 The diagram shows the state in which the tapered surface of the shaft contacts the upper opening edge of the inner ring of the second bearing.

[0064] Figure 12 This is a longitudinal cross-sectional view of the fan motor according to the sixth embodiment, and an enlarged view showing the periphery of the sleeve.

[0065] Figure 13 This is a longitudinal cross-sectional view of the fan motor according to the seventh embodiment, and an enlarged view showing the periphery of the sleeve.

[0066] Figure 14 This is a longitudinal cross-sectional view of the fan motor according to the eighth embodiment, and an enlarged view showing the periphery of the sleeve.

[0067] Figure 15 This is a longitudinal cross-sectional view of a fan motor in a modified embodiment of the implementation, and an enlarged view showing the periphery of the sleeve. Detailed Implementation

[0068] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. Furthermore, in the following description, components having the same or similar functions will be labeled with the same reference numerals. Also, repeated descriptions of these components will sometimes be omitted.

[0069] Figure 1 This is a longitudinal cross-sectional view illustrating an embodiment of the fan motor.

[0070] Figure 1The fan motor 100 shown is an example of a rotating device. The fan motor 100 includes: a rotating body 110 having a shaft 111; a cylindrical sleeve 140 supporting the shaft 111 of the rotating body 110 in a rotatable manner; a base 120 supporting the sleeve 140 in a non-rotatable manner; a drive unit 130 that rotates the rotating body 110 relative to the base 120; and a pair of rolling bearings 1 mounted on the sleeve 140 and supporting the shaft 111 in a rotatable manner. In the following description, the rolling bearings are sometimes referred to simply as bearings. Furthermore, in this embodiment, the direction in which the central axis O of the sleeve 140 extends is called the axial direction, the direction orthogonal to the central axis O and extending radially from the central axis O is called the radial direction, and the direction surrounding the central axis O is called the circumferential direction. Additionally, one of the directions parallel to the axial direction and pointing in opposite directions is defined as upward, and the other is defined as downward.

[0071] The sleeve 140 is inserted into the shaft 111 of the rotating body 110. The sleeve 140 supports the shaft 111 in a rotatable manner via a pair of bearings 1. The specific shape of the sleeve 140 will be described later.

[0072] The sleeve 140 is formed from a synthetic resin material with electrical insulation properties. Preferably, the synthetic resin used to form the sleeve 140 is one or more of polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polyetheretherketone (PEEK), which have low moisture absorption, are easy to mold with precision, and exhibit excellent chemical resistance. Potassium titanate whiskers can also be added to the synthetic resin as a reinforcing material. Potassium titanate whiskers are preferably added at 5% to 50%, more preferably at 10% to 30%. Furthermore, it is ideal that glass fibers or carbon fibers are not added to the synthetic resin as reinforcing materials. This is because if hard glass fibers or carbon fibers are added to the synthetic resin, it becomes difficult to process the injection-molded sleeve 140 using centerless machining or other mechanical processing methods, and it can easily damage grinding stones or cutting tools. Furthermore, there is a risk that hard glass fibers or carbon fibers may detach from the synthetic resin and enter the interior of the bearing, causing poor rotation. On the other hand, potassium titanate whiskers are softer than glass fibers or carbon fibers, and their small size and length make them easy to machine. Synthetic resins with added potassium titanate whiskers are easier to machine than synthetic resin monomers. Even if potassium titanate whiskers were to detach from the synthetic resin and enter the bearing's interior, their small size makes it unlikely to cause improper bearing rotation. Furthermore, by not including carbon fibers as reinforcement, the electrical insulation of the sleeve 140 can be ensured.

[0073] The base 120 is joined to the lower end of the sleeve 140 in a manner that prevents relative rotation. The base 120 extends radially outward from the lower end of the sleeve 140. The base 120 is integrally formed with the sleeve 140. That is, the base 120 is integrally formed from the same material as the sleeve 140. The base 120 is, for example, the chassis of the fan motor 100. Alternatively, the base 120 may be configured as a separate component from the sleeve 140. In this case, the base may also be formed of a metallic material.

[0074] A rotating body 110 is positioned above the base 120. The rotating body 110 includes a shaft portion 111 and a fan 112 connected to the shaft portion 111 on the outside of the sleeve 140. The shaft portion 111 is coaxially arranged with the sleeve 140. The shaft portion 111 extends through the sleeve 140 in the vertical direction. The lower end of the shaft portion 111 has an annular tapering surface 111a that tapers downwards. The tapering surface 111a is located entirely below the pair of bearings 1. Furthermore, in the illustrated example, the shaft portion 111 has an end face orthogonal to the axial direction, surrounded by the tapering surface 111a.

[0075] The fan 112 is fixed to the upper end of the shaft portion 111. The fan 112 includes: a flange 113 that extends radially outward from the upper end of the shaft portion 111 and extends integrally throughout the circumferential direction; a peripheral wall 114 that extends integrally downward from the outer periphery of the flange 113; and a plurality of blades 115 that are arranged at intervals in the circumferential direction on the outer side of the peripheral wall 114 in the radial direction. The peripheral wall 114 surrounds the sleeve 140 throughout its entire circumference in a state that is spaced apart from the sleeve 140 in the radial direction.

[0076] The drive unit 130 is the drive source for the fan motor 100. The drive unit 130 includes a stator 131 with coils and a rotor 132 with magnets. The stator 131 is fixed to the base 120 outside the sleeve 140. The rotor 132 is fixed to the peripheral wall 114 of the fan 112 radially outside the stator 131.

[0077] A pair of bearings 1 are respectively located between the inner circumferential surface of the sleeve 140 and the outer circumferential surface of the shaft portion 111. Each bearing 1 is a ball bearing. The pair of bearings 1 are coaxially arranged. The pair of bearings 1 are arranged side by side with a gap in the axial direction.

[0078] A pair of bearings 1 are a first bearing 1A and a second bearing 1B. The first bearing 1A is inserted into the sleeve 140 from the side of the rotating body 110. The outer ring 20 of the first bearing 1A cannot rotate relative to the sleeve 140. The outer ring 20 of the first bearing 1A engages with the inner circumferential surface of the sleeve 140 and is restricted from displacement in the axial direction inward (downward). The inner ring 10 of the first bearing 1A contacts a force-applying member 101. The force-applying member 101 is a helical spring. The force-applying member 101 is located on the outer side (above) of the first bearing 1A in the axial direction. The force-applying member 101 is inserted into the shaft portion 111 of the rotating body 110 and is coaxially arranged with the central axis O. The force-applying member 101 is located between the inner ring 10 of the first bearing 1A and the flange 113 of the fan 112. The force-applying member 101 applies force to the inner ring 10 of the first bearing 1A in the axial direction inward (downward) relative to the rotating body 110.

[0079] The second bearing 1B is inserted into the sleeve 140 from the opposite side of the rotating body 110. The outer ring 20 of the second bearing 1B cannot rotate relative to the sleeve 140. The outer ring 20 of the second bearing 1B engages with the inner circumferential surface of the sleeve 140 and is restricted from displacement in the axial direction inward (upward). The inner ring 10 of the second bearing 1B contacts a C-ring 103 mounted on the shaft portion 111. The C-ring 103 is positioned between the second bearing 1B and the tapered surface 111a of the shaft portion 111. The inner ring 10 of the second bearing 1B is restricted from displacement in the axial direction outward (downward) relative to the shaft portion 111 by the C-ring 103.

[0080] The structure of bearing 1 will be described.

[0081] Figure 2 This is a top view of the bearing in the embodiment. Figure 3 This is a longitudinal cross-sectional view of the bearing according to the embodiment, showing... Figure 2 The cross section on line III-III.

[0082] like Figure 2 and Figure 3 As shown, each bearing 1 includes an inner ring 10 and an outer ring 20 as raceways, a plurality of rolling elements 30, a retainer 40, and a pair of sealing elements 50. The inner ring 10 and the outer ring 20 are coaxially arranged except when they are tilted relative to each other (described later). The outer ring 20 and the sleeve 140 share a common axis about the central axis O.

[0083] The inner ring 10 is configured as a rotating ring. The inner ring 10 is inserted into the shaft portion 111. The outer ring 20 is configured as a fixed ring. The outer ring 20 surrounds the inner ring 10 from the radial side, with an annular space between it and the inner ring 10. A plurality of rolling elements 30 are disposed between the inner ring 10 and the outer ring 20, and are held in a rolling manner by a retainer 40. The retainer 40 holds each rolling element 30 in a rotatable manner, with the plurality of rolling elements 30 evenly arranged in the circumferential direction. A sealing member 50 covers the annular space between the inner ring 10 and the outer ring 20 from the axial side.

[0084] The outer ring 20 is formed in a ring shape from a metal material such as stainless steel or bearing steel. The outer ring 20 has an inner circumferential surface 22 facing the inner ring 10 and an inner end face facing the axial direction. On the inner circumferential surface 22, an outer ring raceway surface 23 for the rolling element 30 to roll and a fitting groove 24 for retaining the sealing member 50 are formed. The outer ring raceway surface 23 is recessed radially outward. The outer ring raceway surface 23 is formed in a hemispherical shape in cross-section, along the outer surface of the rolling element 30, and is formed in a ring shape extending circumferentially throughout the entire circumference of the inner circumferential surface 22. The outer ring raceway surface 23 is formed in the central portion of the inner circumferential surface 22 in the axial direction. The outer ring raceway surface 23 has a radius of curvature in the longitudinal section of the bearing 1 that is larger than the radius of the rolling element 30.

[0085] A pair of fitting grooves 24 are formed at the axial end of the inner peripheral surface 22. The fitting grooves 24 are recessed outward in the radial direction. The fitting grooves 24 open across the inner peripheral surface 22 and the axial end face. The fitting grooves 24 are formed in a ring shape extending circumferentially around the entire circumference of the inner peripheral surface 22.

[0086] The inner ring 10 is formed in a circular shape from a metal material such as stainless steel or bearing steel. An inner ring raceway surface 11, recessed radially inward, is formed on the outer circumferential surface of the inner ring 10. The inner ring raceway surface 11 is hemispherical in cross-sectional view, extending along the outer surface of the rolling element 30, and is formed in a ring shape extending circumferentially across the entire outer circumference. The inner ring raceway surface 11 is formed in the central portion of the outer circumferential surface of the inner ring 10 in the axial direction, and is arranged radially opposite to the outer ring raceway surface 23. The inner ring raceway surface 11 has a radius of curvature larger than the radius of the rolling element 30 in the longitudinal section of the bearing 1.

[0087] Multiple rolling elements 30 are formed in a spherical shape from a metal material such as stainless steel or bearing steel. The multiple rolling elements 30 are disposed between the outer ring raceway surface 23 and the inner ring raceway surface 11, and are supported by the outer ring raceway surface 23 and the inner ring raceway surface 11 in a rolling manner. The circumferential spacing of the multiple rolling elements 30 is maintained by a retainer 40.

[0088] like Figure 3As shown, the retainer 40 is integrally formed in a ring shape from synthetic resin or metal. The retainer 40 is coaxially arranged with respect to the central axis O. The retainer 40 includes: an annular portion 41, which is formed in a ring shape and disposed below a plurality of rolling elements 30; and a plurality of column portions 42, which protrude upward from the annular portion 41 and are spaced apart in the circumferential direction. The column portions 42 are evenly arranged in the circumferential direction. A pair of adjacent column portions 42 in the circumferential direction form a ball cavity between them. The ball cavity penetrates the retainer 40 in the radial direction and opens upward on the upper end face of the retainer 40. The number of ball cavities corresponds to the number of rolling elements 30, holding each rolling element 30 in a rollable manner. Thus, the retainer 40 arranges the rolling elements 30 evenly spaced apart in the circumferential direction.

[0089] like Figure 2 and Figure 3 As shown, the sealing member 50 is formed in the shape of an annular plate. The sealing member 50 is coaxially arranged with the central axis O. The sealing member 50 is mounted on the outer ring 20. One sealing member 50 is arranged on each side in the axial direction relative to the plurality of rolling elements 30. The sealing member 50 includes: a sealing fitting portion 51 that fits into the fitting groove 24 of the outer ring 20; and a cover portion 53 that extends radially inward from the sealing fitting portion 51. The sealing member 50 extends radially in a manner that at least crosses the center of the rolling element 30 when viewed from above. The inner peripheral edge of the cover portion 53 is disposed with a gap between it and the outer peripheral surface of the inner ring 10. The sealing fitting portion 51 engages with the wall surface of the fitting groove 24, thereby fixing the sealing member 50 to the outer ring 20.

[0090] Figure 4 It shows that Figure 3 The diagram shows the state of the bearing's inner ring tilted relative to the outer ring.

[0091] like Figure 4 As shown, the radii of curvature of the outer raceway surface 23 and the inner raceway surface 11 are larger than the radius of the rolling element 30, thus allowing the inner ring 10 and the outer ring 20 to tilt relative to each other. Figure 4 In this configuration, axis O' is the central axis of the inner ring 10, which is tilted relative to the outer ring 20. An angular clearance is provided in the bearing 1. The angular clearance is the angle at which the inner ring 10 can tilt relative to the outer ring 20. The angular clearance is determined for each bearing 1.

[0092] [First Implementation] The sleeve 140 of the first embodiment will be described in detail.

[0093] Figure 5 This is a longitudinal cross-sectional view of the fan motor according to the first embodiment, and an enlarged view showing the periphery of the sleeve.

[0094] like Figure 5As shown, sleeve 140 is a single component that is entirely continuous. Sleeve 140 integrally includes a first retaining portion 141, a second retaining portion 142, a first outer ring support portion 143, and a second outer ring support portion 144. Sleeve 140 is formed entirely of the aforementioned electrically insulating synthetic resin.

[0095] The first retaining portion 141 retains the outer peripheral surface of the first bearing 1A. The first retaining portion 141 surrounds the first bearing 1A from the outer side in the radial direction. The first retaining portion 141 retains the outer ring 20 of the first bearing 1A in a manner that prevents displacement in the radial direction by contacting or approaching the outer peripheral surface of the outer ring 20 in the radial direction. The first retaining portion 141 has: a first recess 141a that opens radially inward toward the outer peripheral surface of the outer ring 20 of the first bearing 1A; and a first retaining surface 141b (press-in portion) that abuts the first recess 141a and extends along the outer peripheral surface of the outer ring 20 of the first bearing 1A.

[0096] The first recess 141a is formed at the inner end of the inner circumferential surface of the first retaining portion 141 in the axial direction. The first recess 141a extends continuously throughout the circumferential direction. The opening of the first recess 141a faces the inner end of the outer circumferential surface of the outer ring 20 of the first bearing 1A in the axial direction. The first recess 141a faces the outer end of the outer circumferential surface of the outer ring 20 from a position further outward in the axial direction than the center position of the outer ring raceway surface 23 in the axial direction to the inner end in the axial direction. Thus, the sleeve 140 does not contact the portion of the outer circumferential surface of the outer ring 20 of the first bearing 1A from the center position of the outer ring raceway surface 23 in the axial direction to the inner end in the axial direction. Furthermore, the center position of the outer ring raceway surface 23 in the axial direction is a position where the normal direction of the outer ring raceway surface 23 is parallel to the radial direction. The first recess 141a includes: an outer surface 141c (inclined portion) extending radially outward from the axially outer side of the opening edge of the first recess 141a; an inner surface extending radially outward from the axially inner side of the opening edge of the first recess 141a; and a bottom surface connecting the outer surface 141c and the inner surface, and facing radially inward. The bottom surface is a cylindrical surface extending in the axial direction. The outer surface 141c is a conical surface facing radially inward and axially inward, with its inner diameter decreasing as it faces outward in the axial direction. The inner surface is a flat surface extending in a direction orthogonal to the axial direction. The first recess 141a is not provided with an adhesive, but is filled with a gas such as air.

[0097] The first retaining surface 141b is located further outward in the axial direction than the first recess 141a. The first retaining surface 141b extends axially outward from the portion axially outward of the opening edge of the first recess 141a. The first retaining surface 141b extends downward from the upper opening edge of the sleeve 140. The first retaining surface 141b is a cylindrical surface extending axially. The first retaining surface 141b faces only the portion axially outward of the outer peripheral surface of the outer ring 20 that is further outward than the axial center position of the outer ring raceway surface 23. The first retaining surface 141b faces the axially outward end of the outer peripheral surface of the outer ring 20. Alternatively, the first retaining surface 141b may not face the axially outward end of the outer peripheral surface of the outer ring 20. In this case, the first bearing 1A protrudes axially outward from the inside of the first retaining surface 141b. When the first bearing 1A is not inserted into the first retaining part 141, the inner diameter of the first retaining surface 141b is smaller than the outer diameter of the outer ring 20 of the first bearing 1A. As a result, the first bearing 1A is pressed into the inner side of the first retaining surface 141b.

[0098] The second retaining portion 142 is positioned axially spaced from the first retaining portion 141. The second retaining portion 142 retains the outer peripheral surface of the second bearing 1B. The second retaining portion 142 surrounds the second bearing 1B from the outer side in the radial direction. The second retaining portion 142 retains the outer ring 20 of the second bearing 1B in a manner that prevents displacement in the radial direction by contacting or approaching the outer peripheral surface of the outer ring 20 in the radial direction. The second retaining portion 142 has: a second recess 142a that opens radially inward toward the outer peripheral surface of the outer ring 20 of the second bearing 1B; and a second retaining surface 142b that abuts the second recess 142a and extends along the outer peripheral surface of the outer ring 20 of the second bearing 1B.

[0099] The second recess 142a is formed at the inner end of the inner circumferential surface of the second retaining portion 142 in the axial direction. The second recess 142a extends continuously throughout the circumferential direction. The opening of the second recess 142a faces the inner end of the outer circumferential surface of the outer ring 20 in the axial direction. The second recess 142a faces the outer circumferential surface of the outer ring 20 of the second bearing 1B from a position further outward in the axial direction than the center position of the outer ring raceway surface 23 to the inner end in the axial direction. Thus, the sleeve 140 does not contact the portion of the outer circumferential surface of the outer ring 20 of the second bearing 1B from the center position of the outer ring raceway surface 23 in the axial direction to the inner end in the axial direction. The second recess 142a includes: an outer surface 142c (inclined portion) extending radially outward from the axially outer side of the opening edge of the second recess 142a; an inner surface extending radially outward from the axially inner side of the opening edge of the second recess 142a; and a bottom surface connecting the outer surface 142c and the inner surface, and facing radially inward. The bottom surface is a cylindrical surface extending in the axial direction. The outer surface 142c is a conical surface facing radially inward. The inner surface is a flat surface extending in a direction orthogonal to the axial direction. The second recess 142a is not provided with an adhesive, but is filled with a gas such as air.

[0100] The second retaining surface 142b is located further outward in the axial direction than the second recess 142a. The second retaining surface 142b extends axially outward from the portion axially outward of the opening edge of the second recess 142a. The second retaining surface 142b is a cylindrical surface extending axially. The second retaining surface 142b faces only the portion of the outer peripheral surface of the outer ring 20 that is further outward in the axial direction than the center position of the outer ring raceway surface 23. The end of the second retaining surface 142b facing the outer peripheral surface of the outer ring 20 is axially outward. Alternatively, the second retaining surface 142b may not face the end of the outer peripheral surface of the outer ring 20. In this case, the second bearing 1B protrudes axially outward from the inside of the second retaining surface 142b. When the second bearing 1B is not inserted into the second retaining portion 142, the inner diameter of the second retaining surface 142b is smaller than the outer diameter of the outer ring 20 of the second bearing 1B. This results in the second bearing 1B being pressed into the inside of the second retaining surface 142b.

[0101] The first outer ring support portion 143 contacts the inner end face of the outer ring 20 of the first bearing 1A from the inner side (below) in the axial direction. The first outer ring support portion 143 is part of the inner circumferential surface of the sleeve 140. The first outer ring support portion 143 is provided at a position that is both axially and radially inner relative to the first retaining portion 141. The first outer ring support portion 143 is provided without spacing from the first recess 141a in the axial direction. The first outer ring support portion 143 extends radially inward from the axially inner portion of the opening edge of the first recess 141a. The first outer ring support portion 143 extends circumferentially outward (above) in the axial direction. The first outer ring support portion 143 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The first outer ring support portion 143 is a flat surface that extends in a direction orthogonal to the axial direction. That is, the first outer ring support portion 143 extends continuously from the inner side of the first recess 141a. The inner diameter of the first outer ring support portion 143 is larger than the outer diameter of the inner ring 10 and larger than the inner diameter of the outer ring 20. However, the inner diameter of the first outer ring support portion 143 may also be smaller than the inner diameter of the outer ring 20. In this case, the inner diameter of the first outer ring support portion 143 is larger than the outer diameter of the inner ring 10 of the first bearing 1A.

[0102] The second outer ring support portion 144 contacts the inner end face of the outer ring 20 of the second bearing 1B from the inner side (above) in the axial direction. The second outer ring support portion 144 is part of the inner circumferential surface of the sleeve 140. The second outer ring support portion 144 is located in the inner side in the axial direction and in the inner side in the radial direction relative to the second retaining portion 142. The second outer ring support portion 144 is provided without spacing from the second recess 142a in the axial direction. The second outer ring support portion 144 extends from the inner side in the axial direction of the opening edge of the second recess 142a to the inner side in the radial direction. The second outer ring support portion 144 faces the outer side (below) in the axial direction and extends in the circumferential direction. The second outer ring support portion 144 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The second outer ring support portion 144 is a flat surface that extends in a direction orthogonal to the axial direction. That is, the second outer ring support portion 144 extends continuously from the inner side of the second recess 142a. The inner diameter of the second outer ring support portion 144 is larger than the outer diameter of the inner ring 10 and larger than the inner diameter of the outer ring 20. However, the inner diameter of the second outer ring support portion 144 may also be smaller than the inner diameter of the outer ring 20. In this case, the inner diameter of the second outer ring support portion 144 is larger than the outer diameter of the inner ring 10 of the second bearing 1B.

[0103] A parting line P, formed during the injection molding of the sleeve 140, is formed on the inner circumferential surface of the sleeve 140. The parting line P extends continuously throughout the circumferential direction. The parting line P is located on the opposite side of the first retaining portion 141 relative to the first outer ring support portion 143 and on the opposite side of the second retaining portion 142 relative to the second outer ring support portion 144. Thus, the parting line P is located further inward in the axial direction than both the first bearing 1A and the second bearing 1B, and does not contact the first bearing 1A and the second bearing 1B.

[0104] The effects of this embodiment will now be explained. Furthermore, unless otherwise specified below, while the effects of the mounting structure for the first bearing 1A will be explained, the effects of the mounting structure for the second bearing 1B will also be the same.

[0105] The sleeve 140 is a cylindrical sleeve on which the first bearing 1A is mounted internally. It includes: a first retaining portion 141 that retains the outer peripheral surface of the first bearing 1A; and a first outer ring support portion 143 that contacts the end face of the outer ring 20 of the first bearing 1A from the inner side in the axial direction. The first retaining portion 141 has a first recess 141a that opens radially inward toward the outer peripheral surface of the outer ring 20. The sleeve 140 is formed of an electrically insulating synthetic resin. With this configuration, current flow through the sleeve 140 into the first bearing 1A can be suppressed. Therefore, electro-corrosion in the first bearing 1A can be suppressed.

[0106] Here, in order to suppress slippage of the outer ring 20 of the first bearing 1A relative to the sleeve 140, it is necessary to fix the outer ring 20 to the sleeve 140. In a configuration where the outer ring 20 is fixed to the sleeve 140 by pressing, there is a possibility that deformation of the synthetic resin sleeve 140 may affect the outer ring 20. If deformation of the sleeve 140 affects the outer ring 20, there is a possibility that the contact point between the outer ring raceway surface 23 of the outer ring 20 and the rolling element 30 may change, leading to malfunction of the first bearing 1A. According to this embodiment, a first recess 141a opening toward the outer peripheral surface of the first bearing 1A is provided in the first holding portion 141 that holds the outer peripheral surface of the first bearing 1A, thereby suppressing the impact of deformation of the sleeve 140 on the outer ring 20 via the contact point between the sleeve 140 and the outer ring 20. Therefore, it is possible to suppress malfunction of the first bearing 1A due to changes in the contact point between the outer ring raceway surface 23 and the rolling element 30. Through the above, a synthetic resin sleeve 140 can be formed to suppress the occurrence of various adverse conditions and simultaneously install the first bearing 1A.

[0107] The sleeve 140 has a parting line P formed during the molding of its inner circumferential surface at a position opposite to the first outer ring support portion 143 on its first retaining portion 141. This configuration prevents the parting line P from forming at the contact portion between the sleeve 140 and the first bearing 1A. Therefore, the assembly accuracy of the first bearing 1A can be suppressed from decreasing due to the parting line P, and machining such as removing the parting line P to install the first bearing 1A into the sleeve 140 is unnecessary, thus reducing manufacturing costs.

[0108] Potassium titanate whiskers are added to the synthetic resin forming the sleeve 140. Based on this configuration, the sleeve 140 can be a component with excellent wear resistance and surface smoothness. Furthermore, the synthetic resin containing potassium titanate whiskers has good machinability and is less prone to clogging during grinding, thus exhibiting excellent processability. Therefore, compared to the case where the sleeve 140 contains glass fiber or carbon fiber as a reinforcing material, the processability when forming the sleeve through machining such as cutting or grinding, as well as the processability when finishing the injection-molded sleeve 140 through two machining processes such as cutting or grinding, can be improved.

[0109] The first recess 141a extends continuously throughout the circumferential direction. Based on this configuration, deformation waves of the sleeve 140 and the outer ring 20 can be suppressed more reliably.

[0110] The first recess 141a has an outer surface 141c whose inner diameter decreases as it moves outward in the axial direction. With this configuration, when the sleeve 140 is injection molded, the portion of the metal mold where the first recess 141a is formed can be easily pulled outward in the axial direction. Therefore, the sleeve 140 can be easily formed by injection molding.

[0111] The first retaining portion 141 has a first retaining surface 141b with an inner diameter smaller than the outer diameter of the first bearing 1A, located further outward in the axial direction than the first recess 141a. With this configuration, the outer ring 20 is fixed to the sleeve 140 by pressing in the first retaining portion 141, thus achieving a suitable configuration that can suppress the deformation waves of the sleeve 140 and the outer ring 20.

[0112] The sleeve 140 is entirely made of synthetic resin. This configuration allows for more reliable suppression of current flow through the sleeve 140 into the first bearing 1A. Furthermore, compared to a configuration where only a portion of the sleeve is made of synthetic resin, the sleeve 140 can be easily formed, thus reducing the manufacturing cost of the sleeve 140.

[0113] The fan motor 100 includes: a sleeve 140; a first bearing 1A mounted inside the sleeve 140; and a shaft portion 111 inserted into the inner ring 10 of the first bearing 1A. With this configuration, the increase in rotational resistance of the first bearing 1A due to electro-corrosion can be suppressed. Therefore, a longer lifespan for the fan motor 100 can be achieved.

[0114] The fan motor 100 also includes a force-applying member 101 that applies force to the inner ring 10 in the axial direction. According to this configuration, the rolling element 30, under the force applied by the force-applying member 101, contacts the outer ring raceway surface 23 at a location further inward in the axial direction than its axial center. A first recess 141a is provided at a location further inward in the axial direction than the first retaining surface 141b to prevent contact between the sleeve 140 and the outer ring 20, thereby suppressing deformation waves of the sleeve 140 and the vicinity of the contact point between the sleeve 140 and the rolling element 30 in the outer ring 20. Therefore, it is possible to suppress changes in the contact point between the outer ring raceway surface 23 and the rolling element 30, thus preventing malfunction of the first bearing 1A.

[0115] Specifically, in this embodiment, the sleeve 140 does not contact the outer peripheral surface of the outer ring 20 at a position further in the axial direction than the center position of the outer ring raceway surface 23. Therefore, even if deformation occurs in the sleeve 140 near the contact point between the outer ring 20 and the rolling element 30, this deformation can be prevented from affecting the outer ring 20. Thus, it is possible to suppress malfunctions of the first bearing 1A due to changes in the contact point between the outer ring raceway surface 23 and the rolling element 30.

[0116] The shaft 111 is the rotating shaft of the fan motor 100. The sleeve 140 and the base 120, which serves as the chassis of the fan motor 100, are integrally formed of synthetic resin. This configuration suppresses current flow inside the first bearing 1A, preventing electro-corrosion in the first bearing 1A. Furthermore, by integrally forming the sleeve 140 and the chassis, the number of parts can be reduced, thereby improving the productivity of the fan motor 100.

[0117] Furthermore, in this embodiment, the recesses 141a and 142a of each retaining portion 141 and 142 face the portion of the outer peripheral surface of the outer ring 20 that corresponds to the center position in the axial direction of the outer ring raceway surface 23, but this configuration is not limited to this. That is, the recess may also face only the portion of the outer peripheral surface of the outer ring that is further inward in the axial direction than the center position in the axial direction of the outer ring raceway surface 23.

[0118] [Second Implementation] The sleeve 240 of the second embodiment will be described in detail. In the second embodiment, the shapes of the first recess and the second recess of the sleeve are different from those of the first embodiment. Furthermore, the configuration is the same as that of the first embodiment, except for the configuration described below.

[0119] Figure 6 This is a longitudinal cross-sectional view of the fan motor according to the second embodiment, and an enlarged view showing the periphery of the sleeve.

[0120] like Figure 6 As shown, the sleeve 240 has a first retaining portion 241 and a second retaining portion 242 instead of the first retaining portion 141 and the second retaining portion 142 of the first embodiment.

[0121] The first retaining portion 241 has a first recess 241a instead of the first recess 141a in the first embodiment. The first recess 241a is a curved surface that is recessed radially outward in the longitudinal section of the sleeve 240. The first half 241c (inclined portion) of the first recess 241a, which is axially outward, extends radially outward from the axially outward portion of the opening edge of the first recess 241a, and its inner diameter decreases as it moves towards the axially outward. The second half of the first recess 241a, which is axially inward, extends radially outward from the axially inward portion of the opening edge of the first recess 241a, and its inner diameter decreases as it moves towards the axially inward.

[0122] The second retaining portion 242 has a second recess 242a instead of the second recess 142a in the first embodiment. The second recess 242a is a curved surface that is recessed radially outward in the longitudinal section of the sleeve 240. The first half 242c of the second recess 242a, which is axially outward, extends radially outward from the axially outward portion of the opening edge of the second recess 242a, and its inner diameter decreases as it moves axially outward. The second half of the second recess 242a, which is axially inward, extends radially outward from the axially inward portion of the opening edge of the second recess 242a, and its inner diameter decreases as it moves axially inward.

[0123] In this embodiment, the sleeve 240 is formed of an electrically insulating synthetic resin, and the retaining portions 241 and 242 have recesses 241a and 242a that open inward in the radial direction, thus achieving the same effect as in the first embodiment.

[0124] [Third Implementation] The sleeve 340 of the third embodiment will be described in detail. In the first embodiment, bearings 1A and 1B are fixed to the sleeve 140 by pressing. In contrast, the third embodiment differs from the first embodiment in that bearings 1A and 1B are fixed to the sleeve 340 by bonding. Furthermore, the configuration is the same as that of the first embodiment except for the configuration described below.

[0125] Figure 7 This is a longitudinal cross-sectional view of the fan motor according to the third embodiment, and an enlarged view showing the periphery of the sleeve.

[0126] like Figure 7 As shown, the sleeve 340 has a first retaining portion 341 and a second retaining portion 342 instead of the first retaining portion 141 and the second retaining portion 142 of the first embodiment.

[0127] The first retaining portion 341 has a first recess 341a and a first retaining surface 341b instead of the first recess 141a and the first retaining surface 141b of the first embodiment.

[0128] The first recess 341a is formed at intervals in the axial direction relative to the first outer ring support portion 143. The first recess 341a extends continuously throughout the circumferential direction. The portion of the opening of the first recess 341a that faces the outer circumferential surface of the outer ring 20 of the first bearing 1A further outward in the axial direction than the end portion that is inward in the axial direction. Furthermore, in this embodiment, the portion of the opening of the first recess 341a that faces the outer circumferential surface of the outer ring 20 that is inward in the axial direction than the end portion that is inward in the axial direction.

[0129] The first recess 341a includes: an outer surface 341c (inclined portion) extending radially outward from a portion axially outward of the opening edge of the first recess 341a; and an inner surface extending radially outward from a portion axially inward of the opening edge of the first recess 341a. The outer surface 341c is a conical surface facing axially inward and radially inward, with its inner diameter decreasing as it faces axially outward. The inner surface, connected to the radially inward end edge of the outer surface 341c, is a flat surface extending in a direction orthogonal to the axial direction.

[0130] An adhesive (not shown) is disposed in the first recess 341a, which functions as an adhesive reservoir. The adhesive secures the sleeve 340 to the outer ring 20.

[0131] The first retaining surface 341b is located further axially inward than the first recess 341a. The first retaining surface 341b extends axially inward from the portion axially inward of the opening edge of the first recess 341a. The axially inward end edge of the first retaining surface 341b connects to the first outer ring support portion 143. The first retaining surface 341b is a cylindrical surface extending axially. The axially inward end of the first retaining surface 341b faces the outer peripheral surface of the outer ring 20.

[0132] Furthermore, in this embodiment, the first retaining surface 341b is also located further outward in the axial direction than the first recess 341a. The first retaining surface 341b extends axially outward from the portion axially outward of the opening edge of the first recess 341a. The first retaining surface 341b extends downward from the upper opening edge of the sleeve 340. The end of the first retaining surface 341b facing the axially outward end of the outer peripheral surface of the outer ring 20. Alternatively, the first retaining surface 341b may not face the axially outward end of the outer peripheral surface of the outer ring 20. In this case, the first bearing 1A protrudes axially outward from the inside of the first retaining surface 341b.

[0133] When the first bearing 1A is not inserted into the first retaining portion 341, the inner diameter of the first retaining surface 341b is greater than or equal to the outer diameter of the outer ring 20 of the first bearing 1A. Therefore, even when the first bearing 1A is inserted into the first retaining portion 341, the inner diameter of the first retaining surface 341b is still greater than or equal to the outer diameter of the outer ring 20 of the first bearing 1A. When the inner diameter of the first retaining surface 341b is larger than the outer diameter of the outer ring 20, the adhesive can be placed between the first retaining surface 341b and the outer peripheral surface of the outer ring 20.

[0134] The second retaining portion 342 has a second recess 342a and a second retaining surface 342b instead of the second recess 142a and the second retaining surface 142b of the first embodiment.

[0135] The second recess 342a is formed at intervals in the axial direction relative to the second outer ring support portion 144. The second recess 342a extends continuously throughout the circumferential direction. The portion of the opening of the second recess 342a that faces the outer circumferential surface of the outer ring 20 of the second bearing 1B further outward in the axial direction than the end portion that is inward in the axial direction. Furthermore, in this embodiment, the portion of the opening of the second recess 342a that faces the outer circumferential surface of the outer ring 20 that is inward in the axial direction than the end portion that is inward in the axial direction.

[0136] The second recess 342a includes: an outer surface 342c (inclined portion) extending radially outward from a portion axially outward of the opening edge of the second recess 342a; and an inner surface extending radially outward from a portion axially inward of the opening edge of the second recess 342a. The outer surface 342c is a conical surface facing axially inward and radially inward, with its inner diameter decreasing as it faces axially outward. The inner surface, connected to the radially inward end edge of the outer surface 342c, is a flat surface extending in a direction orthogonal to the axial direction.

[0137] An adhesive (not shown) is disposed in the second recess 342a, which functions as an adhesive reservoir. The adhesive secures the sleeve 340 to the outer ring 20.

[0138] The second retaining surface 342b is located further axially inward than the second recess 342a. The second retaining surface 342b extends axially inward from the portion axially inward of the opening edge of the second recess 342a. The axially inward end edge of the second retaining surface 342b connects to the second outer ring support portion 144. The second retaining surface 342b is a cylindrical surface extending axially. The axially inward end of the second retaining surface 342b faces the outer peripheral surface of the outer ring 20.

[0139] Furthermore, in this embodiment, the second retaining surface 342b is also located further outward in the axial direction than the second recess 342a. The second retaining surface 342b extends outward in the axial direction from the portion of the opening edge of the second recess 342a. The end of the second retaining surface 342b facing the outer peripheral surface of the outer ring 20 in the axial direction is also outward. Alternatively, the second retaining surface 342b may not face the outer peripheral surface of the outer ring 20 in the axial direction. In this case, the second bearing 1B protrudes outward in the axial direction from the inside of the second retaining surface 342b.

[0140] When the second bearing 1B is not inserted into the second retaining portion 342, the inner diameter of the second retaining surface 342b is greater than or equal to the outer diameter of the outer ring 20 of the second bearing 1B. Therefore, even when the second bearing 1B is inserted into the second retaining portion 342, the inner diameter of the second retaining surface 342b is still greater than or equal to the outer diameter of the outer ring 20 of the second bearing 1B. When the inner diameter of the second retaining surface 342b is larger than the outer diameter of the outer ring 20, the adhesive can be placed between the second retaining surface 342b and the outer peripheral surface of the outer ring 20.

[0141] In this embodiment, the same effects as in the first embodiment are achieved. In addition, in this embodiment, the following effects are achieved. Furthermore, unless otherwise specified below, although the effects of the mounting structure for the first bearing 1A are described, the effects of the mounting structure for the second bearing 1B are also the same.

[0142] In this embodiment, the sleeve 340 fixes the outer ring 20 by adhesive bonding. When the outer ring 20 is fixed to the sleeve 340 by adhesive bonding, the first recess 341a can function as an adhesive accumulation area. This prevents adhesive from leaking between the sleeve 340 and the outer ring 20 into the interior of the first bearing 1A, and prevents adhesive from adhering to unexpected locations and causing malfunction of the first bearing 1A. Through the above, a synthetic resin sleeve 340 that suppresses various malfunctions while simultaneously mounting the first bearing 1A can be formed.

[0143] The first recess 341a extends continuously throughout the circumferential direction. Based on this configuration, the first recess 341a can function more reliably as an adhesive storage portion.

[0144] The first recess 341a is positioned axially spaced from the first outer ring support 143. According to this configuration, compared to a configuration where the first recess is not spaced axially from the first outer ring support, the distance between the sleeve 340 and the outer ring 20, from the first recess 341a through the end face of the outer ring 20 and the first outer ring support 143 to the interior of the first bearing 1A, can be extended. Therefore, in a configuration where the outer ring 20 is fixed to the sleeve 340 by adhesive, leakage of adhesive disposed in the first recess 341a through the end face of the outer ring 20 and the first outer ring support 143 into the interior of the first bearing 1A can be suppressed more reliably. Thus, malfunction of the first bearing 1A due to adhesive adhering to unexpected locations can be more reliably prevented.

[0145] [Fourth Implementation] The sleeve 440 of the fourth embodiment will be described. In the third embodiment, in each retaining portion of the sleeve, the retaining surface is located further outward in the axial direction than the recess. In contrast, the fourth embodiment differs from the third embodiment in that the retaining surface is not located further outward in the axial direction than the recess. Furthermore, the configuration is the same as that of the third embodiment, except for the configuration described below.

[0146] Figure 8 This is a longitudinal cross-sectional view of the fan motor according to the fourth embodiment, and an enlarged view showing the periphery of the sleeve.

[0147] like Figure 8 As shown, the sleeve 440 has a first retaining portion 441 and a second retaining portion 442 instead of the first retaining portion 341 and the second retaining portion 342 of the third embodiment.

[0148] The first retaining portion 441 has a first recess 441a and a first retaining surface 441b instead of the first recess 341a and the first retaining surface 341b of the third embodiment.

[0149] The first recess 441a is formed at an axial interval relative to the first outer ring support portion 143. The first recess 441a extends continuously throughout the circumferential direction. The opening of the first recess 441a faces the axially outer end of the outer circumferential surface of the outer ring 20. Thus, the sleeve 440 does not contact the axially outer end of the outer circumferential surface of the outer ring 20 of the first bearing 1A. The first recess 441a opens axially outward at the axial end of the sleeve 440.

[0150] The first recess 441a includes: an inner surface extending radially outward from the axially inner portion of the opening edge of the first recess 441a; and a bottom surface extending axially outward from the radially outer end edge of the inner surface. The inner surface is a flat surface extending in a direction orthogonal to the axial direction. The bottom surface is a cylindrical surface extending in the axial direction. Thus, the entire wall surface of the first recess 441a is inclined radially inward or axially outward relative to the radially inner component, such that its normal vector does not include the axially inner component.

[0151] An adhesive (not shown) is disposed in the first recess 441a, which functions as an adhesive reservoir. The adhesive secures the sleeve 440 to the outer ring 20.

[0152] The first retaining surface 441b is located further axially inward than the first recess 441a. The first retaining surface 441b extends axially inward from the portion axially inward of the opening edge of the first recess 441a. The axially inward end edge of the first retaining surface 441b connects to the first outer ring support portion 143. The first retaining surface 441b is a cylindrical surface extending axially. The axially inward end of the first retaining surface 441b faces the outer peripheral surface of the outer ring 20.

[0153] When the first bearing 1A is not inserted into the first retaining portion 441, the inner diameter of the first retaining surface 441b is greater than or equal to the outer diameter of the outer ring 20 of the first bearing 1A. Therefore, even when the first bearing 1A is inserted into the first retaining portion 441, the inner diameter of the first retaining surface 441b is still greater than or equal to the outer diameter of the outer ring 20 of the first bearing 1A. When the inner diameter of the first retaining surface 441b is larger than the outer diameter of the outer ring 20, the adhesive can be placed between the first retaining surface 441b and the outer peripheral surface of the outer ring 20.

[0154] The second retaining portion 442 has a second recess 442a and a second retaining surface 442b instead of the second recess 342a and the second retaining surface 342b of the first embodiment.

[0155] The second recess 442a is formed axially spaced relative to the second outer ring support portion 144. The second recess 442a extends continuously throughout the circumferential direction. The opening of the second recess 442a faces the axially outer end of the outer circumferential surface of the outer ring 20. Therefore, the sleeve 440 does not contact the axially outer end of the outer circumferential surface of the outer ring 20 of the second bearing 1B. The second recess 442a opens axially outward at the axial end face of the sleeve 440.

[0156] The second recess 442a includes: an inner surface extending radially outward from the axially inner portion of the opening edge of the second recess 442a; and a bottom surface extending axially outward from the radially outer end edge of the inner surface. The inner surface is a flat surface extending in a direction orthogonal to the axial direction. The bottom surface is a cylindrical surface extending in the axial direction. Thus, the entire wall surface of the second recess 442a is inclined radially inward or axially outward relative to the radially inner component, such that its normal vector does not include the axially inner component.

[0157] An adhesive (not shown) is disposed in the second recess 442a, which functions as an adhesive reservoir. The adhesive secures the sleeve 440 to the outer ring 20.

[0158] The second retaining surface 442b is located further axially inward than the second recess 442a. The second retaining surface 442b extends axially inward from the portion axially inward of the opening edge of the second recess 442a. The axially inward end edge of the second retaining surface 442b connects to the second outer ring support portion 144. The second retaining surface 442b is a cylindrical surface extending axially. The axially inward end of the second retaining surface 442b faces the outer peripheral surface of the outer ring 20.

[0159] When the second bearing 1B is not inserted into the second retaining portion 442, the inner diameter of the second retaining surface 442b is greater than or equal to the outer diameter of the outer ring 20 of the second bearing 1B. Therefore, even when the second bearing 1B is inserted into the second retaining portion 442, the inner diameter of the second retaining surface 442b is still greater than or equal to the outer diameter of the outer ring 20 of the second bearing 1B. When the inner diameter of the second retaining surface 442b is larger than the outer diameter of the outer ring 20, the adhesive can be placed between the second retaining surface 442b and the outer peripheral surface of the outer ring 20.

[0160] In this embodiment, the same effect as in the third embodiment is achieved. In addition, in this embodiment, the following effects are achieved. Furthermore, unless otherwise specified below, although the effects of the mounting structure for the first bearing 1A are described, the effects of the mounting structure for the second bearing 1B are also the same.

[0161] The first recess 441a opens outward in the axial direction at its axial end face of the sleeve 440. With this configuration, when the sleeve 440 is injection molded, the portion of the metal mold in which the first recess 441a is formed can be easily pulled outward in the axial direction. Therefore, the sleeve 440 can be easily formed by injection molding.

[0162] [Fifth Implementation] The sleeve 140A of the fifth embodiment will be described. The fifth embodiment differs from the first embodiment in that a protrusion is provided on the inner circumferential surface of the sleeve. Otherwise, the configuration is the same as that of the first embodiment, except for the configuration described below.

[0163] Figure 9 This is a longitudinal cross-sectional view of the fan motor according to the fifth embodiment, and an enlarged view showing the periphery of the sleeve.

[0164] like Figure 9 As shown, sleeve 140A is a single component that is continuous throughout. In addition to the first retaining portion 141, the second retaining portion 142, the first outer ring support portion 143, and the second outer ring support portion 144, sleeve 140A also has a protrusion 145.

[0165] A protrusion 145 is provided on the inner circumferential surface of the sleeve 140A. The protrusion 145 is provided between the first retaining portion 141 and the second retaining portion 142. That is, the protrusion 145 is formed further below the first outer ring support portion 143. The axial direction of the protrusion 145 includes the center position of the first bearing 1A and the second bearing 1B. The protrusion 145 protrudes further radially inward than the first outer ring support portion 143. The protrusion 145 extends continuously throughout the circumferential direction. The protrusion 145 includes: an inner circumferential surface 146, which extends axially at a position further radially inward than the inner circumferential edge of the first outer ring support portion 143; an upper end surface 147, which extends radially outward from the upper end edge of the inner circumferential surface 146; and a lower end surface 148, which extends radially outward from the lower end edge of the inner circumferential surface 146.

[0166] The inner circumferential surface 146 is a cylindrical surface centered on the central axis O, extending axially with a constant inner diameter. The upper edge of the inner circumferential surface 146 is spaced apart axially from the first outer ring support portion 143. The inner diameter of the protrusion 145 is below the outer diameter of the inner ring 10 of the first bearing 1A. Furthermore, the inner diameter of the protrusion 145 is the inner diameter of the inner circumferential surface 146. The protrusion 145 has an inner diameter larger than the inner diameter of the inner ring 10 of the first bearing 1A, forming a radial gap between it and the outer circumferential surface of the shaft portion 111. The upper edge of the inner circumferential surface 146 is located lower than the inner ring 10 of the first bearing 1A. The lower edge of the inner circumferential surface 146 is located higher than the second bearing 1B.

[0167] The inner peripheral surface 146 of the protrusion 145 has a limiting portion 146a. The limiting portion 146a is at least a part of the protrusion 145. The extent of the limiting portion 146a is defined by its function as described later.

[0168] The upper end face 147 faces upward and extends circumferentially. The upper end face 147 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The upper end face 147 is a flat surface orthogonal to the axial direction. The upper end face 147 may or may not contact the inner ring 10 of the first bearing 1A, which is inclined relative to the outer ring 20 at an angle less than the angular clearance, from below. The lower end face 148 faces downward and extends circumferentially. The lower end face 148 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The lower end face 148 is a flat surface orthogonal to the axial direction.

[0169] When assembling the shaft portion 111 into the sleeve 140A, the shaft portion 111 is inserted into the inner side of the sleeve 140A from above. As a method for assembling the shaft portion 111 into the sleeve 140A, there are two methods: one is to insert the shaft portion 111 into the sleeve 140A while the first bearing 1A and the second bearing 1B are held by the holding portions 141 and 142 (hereinafter referred to as the first method); and the other is to insert the shaft portion 111 with the first bearing 1A inserted into it into the sleeve 140A while the second bearing 1B is held by the second holding portion 142 (hereinafter referred to as the second method).

[0170] The first method will be described. After passing through the first bearing 1A, the shaft portion 111 passes inside the protrusion 145 of the sleeve 140A. The shaft portion 111, during the insertion process through the first bearing 1A, can contact the inner circumferential surface 146 of the protrusion 145. Furthermore, if the shaft portion 111 is not tilted relative to the central axis O, the shaft portion 111 does not contact the protrusion 145.

[0171] like Figure 10As shown, if the shaft portion 111 tilts relative to the central axis O along with the tilting movement of the inner ring 10 of the first bearing 1A relative to the outer ring 20, the shaft portion 111 can contact the inner circumferential surface 146 of the protrusion 145. When the shaft portion 111 is in contact with the limiting portion 146a in the inner circumferential surface 146 of the protrusion 145, the tilting degree between the outer ring 20 and the inner ring 10 of the first bearing 1A is less than the angular clearance. That is, the limiting portion 146a of the protrusion 145, by contacting the shaft portion 111 during the insertion process through the first bearing 1A, limits the tilting of the inner ring 10 of the first bearing 1A relative to the outer ring 20 to a greater extent than the angular clearance. In this embodiment, the limiting portion 146a extends continuously upward from the lower end of the inner circumferential surface 146 of the protrusion 145. Alternatively, when the tilt between the outer ring 20 and the inner ring 10 is less than an angular clearance, the shaft portion 111 cannot contact the upper end of the inner circumferential surface 146 of the protrusion 145. In this case, the upper end of the inner circumferential surface 146 of the protrusion 145 is not included in the limiting portion 146a. However, the limiting portion 146a may include the upper end of the inner circumferential surface 146 of the protrusion 145.

[0172] The lower end of the shaft portion 111 moves downward inside the protrusion 145 and is inserted into the second bearing 1B. For example... Figure 11 As shown, if the tapered surface 111a of the lower end of the shaft portion 111 approaches the second bearing 1B while the shaft portion 111 is tilted relative to the central axis O, it will slide into contact with the upper opening edge of the inner ring 10 of the second bearing 1B. By moving downwards, the shaft portion 111 causes the tapered surface 111a to slide against the upper opening edge of the inner ring 10 of the second bearing 1B, eliminating the tilt relative to the central axis O and simultaneously penetrating the second bearing 1B. This prevents the shaft portion 111 from excessively pressing the inner ring 10 of the second bearing 1B downwards. Furthermore, when the tapered surface 111a of the shaft portion 111 contacts the upper opening edge of the inner ring 10 of the second bearing 1B, the shaft portion 111 can contact the protrusion 145. This prevents the shaft portion 111 from tilting relative to the central axis O to an angle where the tapered surface 111a of the shaft portion 111 does not contact the upper opening edge of the inner ring 10 of the second bearing 1B. Furthermore, ideally, when the tapered surface 111a of the shaft portion 111 contacts the upper opening edge of the inner ring 10 of the second bearing 1B, the limiting portion 146a of the inner circumferential surface 146 of the protrusion 145 contacts the shaft portion 111.

[0173] Furthermore, in the first method, the second bearing 1B can be installed in the sleeve 140A after the shaft portion 111 is inserted through the sleeve 140A. Even in this case, by sliding the upper end opening edge of the inner ring 10 of the second bearing 1B, which moves upward, on the tapered surface 111a of the shaft portion 111, the shaft portion 111 eliminates its tilt relative to the central axis O and simultaneously penetrates the second bearing 1B. As a result, it is possible to prevent the inner ring 10 of the second bearing 1B from being excessively pressed downward by the shaft portion 111.

[0174] The second method will be described. If the shaft portion 111 is inserted into the sleeve 140A, it moves downward toward the second bearing 1B through the inner side of the protrusion 145. When the first bearing 1A is installed in the sleeve 140A before the shaft portion 111 is inserted into the second bearing 1B, the protrusion 145, shaft portion 111, and first bearing 1A function in the same way as in the first method. That is, when the first bearing 1A is installed in the sleeve 140A, the limiting portion 146a of the protrusion 145 contacts the shaft portion 111, thereby limiting the inner ring 10 of the first bearing 1A from tilting more than the angular clearance relative to the outer ring 20. Furthermore, after the first bearing 1A is installed in the sleeve 140A and the shaft portion 111 moves downward toward the second bearing 1B, the limiting portion 146a of the protrusion 145 contacts the shaft portion 111, thereby limiting the inner ring 10 of the first bearing 1A from tilting more than the angular clearance relative to the outer ring 20.

[0175] On the other hand, if the shaft portion 111 is inserted into the second bearing 1B before the first bearing 1A is installed into the sleeve 140A, there is a possibility that the lower end of the shaft portion 111 may approach the second bearing 1B if the axis of the shaft portion 111 is offset relative to the central axis O. Even if the axis of the shaft portion 111 is offset relative to the central axis O, the shaft portion 111 eliminates the offset relative to the central axis O and simultaneously passes through the second bearing 1B by sliding its tapered surface 111a at the lower end of the inner ring 10 of the second bearing 1B at the upper end opening edge. As a result, it is possible to prevent the shaft portion 111 from pressing the inner ring 10 of the second bearing 1B excessively downward. Furthermore, when the tapered surface 111a of the shaft portion 111 contacts the upper end opening edge of the inner ring 10 of the second bearing 1B, the shaft portion 111 can contact the protrusion 145. As a result, it is possible to prevent the end face of the shaft portion 111 from contacting the inner ring 10 of the second bearing 1B and pressing downward.

[0176] As explained above, the sleeve 140A includes: a first outer ring support portion 143 that contacts the end face of the outer ring 20 of the first bearing 1A from below; and a protrusion 145 formed below the first outer ring support portion 143 and protruding radially inward from the first outer ring support portion 143. According to this configuration, when the shaft portion 111 inserted into the inner ring 10 of the first bearing 1A is tilted relative to the central axis O of the sleeve 140A, the contact between the shaft portion 111 and the protrusion 145 can limit further tilting of the shaft portion 111. Here, without the protrusion 145 on the sleeve 140A, the location on the inner circumferential surface of the sleeve 140A that can contact the tilted shaft portion 111 is located radially outward from the inner circumferential edge of the first outer ring support portion 143, thus insufficiently limiting the tilting of the shaft portion 111. According to this embodiment, the protrusion 145 protrudes further in the radial direction than the first outer ring support 143, thus effectively limiting the tilting of the shaft portion 111. This prevents the inner ring 10 of the first bearing 1A from tilting significantly relative to the outer ring 20, thus suppressing the formation of indentations on at least one of the inner ring 10 and the outer ring 20 of the rolling element 30. Therefore, during the assembly of the fan motor 100 with the sleeve 140A, the formation of indentations on the raceway ring of the first bearing 1A can be suppressed, thereby suppressing abnormal noise during the rotation of the fan motor 100.

[0177] The protrusion 145 has a limiting portion 146a, which, when the tilt angle between the outer ring 20 and the inner ring 10 of the first bearing 1A is less than the angular clearance, can contact the shaft portion 111 inserted through the inner ring 10. According to this configuration, the limiting portion 146a can limit the tilt of the shaft portion 111 to above the angular clearance of the first bearing 1A. Therefore, during the assembly of the fan motor 100 with the sleeve 140A, the formation of indentations in at least one of the inner ring 10 and the outer ring 20 of the first bearing 1A can be more reliably suppressed.

[0178] The first outer ring support portion 143 has an inner diameter larger than the outer diameter of the inner ring 10 of the first bearing 1A. This configuration prevents the first outer ring support portion 143 from contacting the inner ring 10 of the first bearing 1A. Therefore, it prevents the sleeve 140A from interfering with the rotation of the shaft portion 111.

[0179] The inner diameter of the protrusion 145 is less than or equal to the outer diameter of the inner ring 10. This configuration prevents the sleeve 140A from contacting the inner ring 10 of the first bearing 1A, while simultaneously bringing the protrusion 145 close to the central axis O of the sleeve 140A. Therefore, tilting of the shaft portion 111 can be more effectively limited.

[0180] The sleeve 140A integrally has a first outer ring support portion 143 and a protrusion 145. With this configuration, the sleeve 140A can be formed from a single component. Therefore, it is possible to reduce the manufacturing cost of the sleeve 140A.

[0181] The lower end of the shaft portion 111 has a tapered surface 111a that tapers downwards. The protrusion 145 can contact the shaft portion 111 while the tapered surface 111a is in contact with the opening edge of the inner ring 10 of the second bearing 1B. With this configuration, when the shaft portion 111 is inserted into the second bearing 1B from above from the first bearing 1A side, even if the shaft portion 111 is offset due to tilting relative to the central axis O of the sleeve 140A, the tapered surface 111a can still contact the opening edge of the inner ring 10 of the second bearing 1B. This prevents excessive force from being applied to the inner ring 10 due to contact between the end face of the shaft portion 111 and the inner ring 10 of the second bearing 1B. Therefore, it is possible to suppress the formation of indentations on at least one of the inner ring 10 and outer ring 20 of the second bearing 1B, thereby suppressing abnormal noise during the rotation of the fan motor 100.

[0182] The fan motor 100 includes the aforementioned sleeve 140A and a shaft portion 111 that is inserted into and passes through the inner ring 10 of the first bearing 1A. With this configuration, abnormal noise generated during rotation can be suppressed.

[0183] [Sixth Implementation] Next, refer to Figure 12 The sixth embodiment will now be described. The sixth embodiment differs from the fifth embodiment in that the first outer ring support portion 143 and the protrusion 145 are formed from different components. Furthermore, the configuration is the same as the first embodiment, except for the configuration described below.

[0184] Figure 12 This is a longitudinal cross-sectional view of the fan motor according to the sixth embodiment, and an enlarged view showing the periphery of the sleeve.

[0185] like Figure 12As shown, the sleeve 140B includes a cylindrical sleeve body 140a and a support member 140b disposed inside the sleeve body 140a. By combining the sleeve body 140a and the support member 140b, it forms the same shape as the sleeve 140 of the fifth embodiment. The sleeve body 140a forms at least an outer peripheral surface, two end surfaces, and a protrusion 145 in the sleeve 140B. The sleeve body 140a has a first retaining portion 141. The support member 140b extends in an annular or arcuate shape coaxial with the sleeve body 140a. The support member 140b is provided in an upper and lower pair. For example, the support member 140b is a washer or a C-ring. The upper support member 140b is inserted into the inner side of the first retaining portion 141 of the sleeve body 140a from above, and overlaps with the upper end face 147 of the protrusion 145 from above, thereby forming the first outer ring support portion 143 of the sleeve 140B. Furthermore, the lower support member 140b is inserted from below into the inner side of the second retaining portion 142 of the sleeve body 140a, and overlaps with the lower end face 148 of the protrusion 145 from below, thereby forming the second outer ring support portion 144 of the sleeve 140B. The sleeve body 140a is formed of the aforementioned synthetic resin or metal material. The support member 140b is formed of a hard material such as the aforementioned synthetic resin or metal material.

[0186] In this embodiment, the same effects as in the fifth embodiment are achieved. In addition, this embodiment provides the following additional effects: The sleeve 140B includes: a sleeve body 140a having a protrusion 145; and a support member 140b disposed inside the sleeve body 140a, overlapping the protrusion 145 from above to form a first outer ring support portion 143. With this configuration, the sleeve body 140a can be made into a simple shape with fewer steps, resulting in a sleeve 140B with excellent manufacturability. In particular, when the sleeve body 140a is made of metal, complex processing can be avoided during its formation, thus making it a suitable configuration that achieves the aforementioned effects.

[0187] [Seventh Implementation] Next, refer to Figure 13 The seventh embodiment will now be described. In the seventh embodiment, the position of the lower edge of the inner peripheral surface 146C of the protrusion 145C differs from that in the fifth embodiment. Furthermore, the configuration, except for the configuration described below, is the same as that in the fifth embodiment.

[0188] Figure 13 This is a longitudinal cross-sectional view of the fan motor according to the seventh embodiment, and an enlarged view showing the periphery of the sleeve.

[0189] like Figure 13As shown, the lower edge of the inner peripheral surface 146C of the protrusion 145C is located above that in the fifth embodiment. For example, the axial direction of the protrusion 145C does not include the center positions of the first bearing 1A and the second bearing 1B. In this embodiment, the lower edge of the inner peripheral surface 146C of the protrusion 145C separates from the second bearing 1B, such that when the tapered surface 111a of the shaft portion 111 contacts the upper opening edge of the inner ring 10 of the second bearing 1B, the protrusion 145C and the shaft portion 111 do not contact each other. Even with this configuration, the inclusion of the limiting portion 146a in the inner peripheral surface 146C of the protrusion 145C achieves the same effect as in the fifth embodiment.

[0190] [Eighth Implementation] Next, refer to Figure 14 The eighth embodiment will now be described. In the eighth embodiment, the upper end face 147D of the protrusion 145D is configured differently from that in the fifth embodiment. However, the configuration is the same as that in the fifth embodiment, except for the configuration described below.

[0191] Figure 14 This is a longitudinal cross-sectional view of the fan motor according to the eighth embodiment, and an enlarged view showing the periphery of the sleeve.

[0192] like Figure 14 As shown, the upper end face 147D of the protrusion 145D connects the upper edge of the inner peripheral surface 146 of the protrusion 145D to the inner peripheral edge of the first outer ring support 143. The upper end face 147D extends continuously in the longitudinal section of the sleeve 140D between the upper edge of the inner peripheral surface 146 of the protrusion 145D and the inner peripheral edge of the first outer ring support 143. In the illustrated example, the upper end face 147D is a conical surface extending linearly in the longitudinal section of the sleeve 140D between the upper edge of the inner peripheral surface 146 of the protrusion 145D and the inner peripheral edge of the first outer ring support 143. However, the upper end face 147D may also be curved in the longitudinal section of the sleeve 140D. The upper end face 147D may be able to contact the inner ring 10 of the first bearing 1A, which is inclined relative to the outer ring 20 at an angle less than the angular clearance, from the lower side, or it may not be able to contact the inner ring 10 of the first bearing 1A, which is inclined relative to the outer ring 20. Even with this configuration, the protrusion 145D of the sleeve 140D includes a limiting portion 146a, which achieves the same effect as in the fifth embodiment.

[0193] Furthermore, the present invention is not limited to the embodiments described above with reference to the accompanying drawings, and various modifications can be considered within its technical scope.

[0194] For example, in the above embodiment, a sleeve provided in a fan motor that is a rotating device is illustrated, but the present invention can be applied to sleeves that are generally provided in rotating devices.

[0195] In the above embodiments, the entire sleeve is formed of an electrically insulating synthetic resin, but this configuration is not limited to this. As long as the components supporting the sleeve in the rotating device can be electrically insulated from the bearing, for example, only the contact portion of the sleeve with the bearing may be formed of synthetic resin, or only a portion of the sleeve may be made of synthetic resin.

[0196] In the above embodiments, the recesses extend continuously throughout the circumferential direction in each retaining portion of the sleeve, but this configuration is not limited to this. That is, the recesses may also be provided only in a portion of the circumferential direction.

[0197] In the above embodiments, the method of fixing a pair of bearings relative to the sleeve is either press-fitting or bonding, but is not limited to this. Alternatively, one bearing can be fixed relative to the sleeve by press-fitting, and the other bearing can be fixed by bonding.

[0198] In the above embodiments, the outer ring 20 of the second bearing 1B is not pressurized, but as Figure 15 As shown, a force-applying member 150, such as a coil spring, which presses the outer ring 20 downwards, can also be disposed inside the second retaining portion 142, between the outer ring 20 and the protrusion 145. In this case, the lower end face of the force-applying member 150 can also be used as the second outer ring support portion 144.

[0199] In the above embodiment, the protrusion 145 extends continuously throughout the circumferential direction, but is not limited to this configuration. For example, the limiting portion of the protrusion may also be provided intermittently along the circumferential direction.

[0200] In the above embodiment, the limiting portion 146a of the protrusion 145 is provided on the cylindrical inner circumferential surface 146, but it is not limited to this configuration. For example, the limiting portion may also be formed in a conical shape. Alternatively, the protrusion may have a tapered end shape on the radially inner side of the longitudinal section of the sleeve, and the limiting portion may be provided at the radially inner end of the protrusion, and substantially have no size in the axial direction.

[0201] In the above embodiments, the dimensions of each part of the bearing mounted on the sleeve are not specifically limited, and the bearing mounted on the sleeve may be limited to radial bearings as specified in ISO or JIS standards. In this case, the main dimensions of the radial bearing are specified by ISO 15 or JIS B 1512-1. Furthermore, the angular clearance of the bearing can be derived from the dimensions of each part of the bearing, for example, by referring to "Introduction to Ball Bearing Design Calculation" (Nikkan Kogyo Shimbun, September 2011, pp. 22-32).

[0202] Furthermore, without departing from the spirit of the invention, the constituent elements in the above embodiments can be appropriately replaced with well-known constituent elements, and the various embodiments described above can also be appropriately combined. For example, the embodiment in which the sleeve is fixed to the bearing by pressing can be changed to a configuration in which the bearing is fixed by bonding. Additionally, the embodiment in which the sleeve is fixed to the bearing by bonding can be changed to a configuration in which the bearing is fixed by pressing. Furthermore, the shape and position of the recess of the retaining portion in each of the above embodiments can be appropriately combined with other embodiments. Furthermore, in the embodiment in which the sleeve has a protrusion, the shape and position of the recess of the retaining portion can be appropriately modified.

[0203] Explanation of reference numerals in the attached figures 1... Rolling bearings 1A... First bearing (rolling bearing) 1B... Second bearing (rolling bearing, another rolling bearing) 10...Inner Circle 20……Outer ring 100……Fan motor (rotating equipment) 101……Force-applying components 111……shaft 111a……Gradient surface 140, 140A, 140B, 140C, 140D, 140E, 240, 340, 440... Sleeves 140a……Sleeve body 140b... Support component 141, 241, 341, 441... First Maintenance Section (Maintenance Section) 141a, 241a, 341a, 441a... first concave portion (concave portion) 141c, 341c... outer surface (sloping part) 142, 242, 342, 442... Second Holding Section (Holding Section) 142a, 242a, 342a, 442a... second concave portion (concave portion) 143……First Outer Ring Support (Outer Ring Support) 144……Second outer ring support (outer ring support) 145, 145C, 145D... protrusions 146a...Restriction Section 241c, 242c... Part 1 (sloping section) P... fractal line.

Claims

1. A sleeve, which is a cylindrical sleeve on the inner side for mounting a rolling bearing, comprising: A retaining part that holds the outer peripheral surface of the rolling bearing; and The outer ring support portion contacts the end face of the outer ring of the rolling bearing from its inner side in the axial direction. The retaining portion has a recessed portion that opens radially inward toward the outer peripheral surface. At least a portion of it is formed from a synthetic resin that has electrical insulation properties.

2. The sleeve according to claim 1, wherein, The retaining portion on the inner circumferential surface, on the opposite side of the outer ring support portion, has a parting line formed during the molding of the sleeve.

3. The sleeve according to claim 1, wherein, Potassium titanate whiskers are added to the synthetic resin.

4. The sleeve according to claim 1, wherein, The recess extends continuously throughout the circumferential direction.

5. The sleeve according to claim 1, wherein, The recess has an inclined portion whose inner diameter decreases as it moves outward toward the axial direction.

6. The sleeve according to claim 1, wherein, The retaining portion has a press-in portion with an inner diameter smaller than the outer diameter of the rolling bearing.

7. The sleeve according to claim 1, wherein, The recess is positioned at intervals relative to the outer ring support portion along the axial direction.

8. The sleeve according to claim 1, wherein, The entire assembly is formed from the synthetic resin.

9. The sleeve according to claim 1, wherein, It also has a protrusion formed on the inner side of the outer ring support portion in the axial direction and protruding on the inner side of the outer ring support portion in the radial direction.

10. The sleeve according to claim 9, wherein, The protrusion has a limiting portion that allows it to contact a shaft portion inserted through the inner ring when the tilt angle between the outer and inner rings of the rolling bearing is less than an angular clearance.

11. The sleeve according to claim 9, wherein, The outer ring support portion has an inner diameter that is larger than the outer diameter of the inner ring of the rolling bearing.

12. The sleeve according to claim 11, wherein, The inner diameter of the protrusion is less than or equal to the outer diameter of the inner ring.

13. The sleeve according to claim 9, wherein, It integrally comprises the outer ring support portion and the protrusion portion.

14. The sleeve according to claim 9, wherein, have: Sleeve body having the aforementioned protrusion; and A support member is disposed on the inner side of the sleeve body and overlaps with the protrusion from the other side in the axial direction to form the outer ring support portion.

15. The sleeve according to claim 10, wherein, Another rolling bearing is held at a position opposite to the protrusion of the rolling bearing. The end portion of the shaft has a tapered surface that tapers towards the end. The protrusion can contact the shaft portion when the tapered surface is in contact with the opening edge of the inner ring of the other rolling bearing.

16. A sleeve with a bearing, comprising: The sleeve according to claim 1; and The rolling bearing is installed inside the sleeve.

17. The sleeve with bearing according to claim 16, wherein, The rolling bearing is bonded to the sleeve. An adhesive is provided in the recess.

18. A rotating device comprising: The sleeve with bearing according to claim 16; and The shaft portion is inserted through the inner ring of the rolling bearing.

19. A rotating device comprising: The sleeve according to claim 6; The rolling bearing is installed inside the sleeve; A shaft portion, which is inserted through the inner ring of the rolling bearing; and The force-applying component applies force to the inner ring in the axial direction. The pressed portion is located further outward in the axial direction than the recessed portion.

20. The rotating device according to claim 18 or claim 19, wherein, The shaft is the rotating shaft of the motor. The sleeve and the chassis of the motor are integrally formed from synthetic resin.

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