Sleeve, sleeve with bearing and rotating equipment

Abstract

The present invention provides a sleeve capable of suppressing the formation of indentations on a raceway ring of a rolling bearing when a rotating device is assembled and suppressing the generation of abnormal sound when the rotating device rotates. A sleeve (140) is a cylindrical sleeve having a first bearing (1A) mounted on the inside thereof, and is provided with: an outer ring support section (143) that is in contact with the end surface of an outer ring (20) of the first bearing (1A) from below; and a protruding section (144) that is formed below the outer ring support section (143) and that protrudes further toward the inside in the radial direction than the outer ring support section (143).

Description

Technical Field

[0001] This invention relates to a sleeve, a sleeve with a bearing, and a rotating device. Background Technology

[0002] Generally, a rolling bearing comprises: a pair of raceway rings (outer ring and inner ring) arranged coaxially; and multiple rolling elements disposed between the pair of raceway rings. Various types of rolling bearings are known and used in various rotating equipment, depending on the type of load they support (radial load, axial load, etc.) or their application. In particular, ball bearings, which utilize spheres as rolling elements, are suitable for use in rotating equipment with shafts containing high-speed rotating parts.

[0003] Sometimes, rotating equipment includes a cylindrical sleeve that is inserted into the shaft and holds a rolling bearing inside (see, for example, Patent Documents 1 and 2). There are two possible sequences for installing the sleeve, rolling bearing, and shaft together. One sequence involves pre-assembling the rolling bearing inside the sleeve and then inserting the shaft into the inner ring of the rolling bearing. The other sequence involves pre-inserting the shaft into the inner ring of the rolling bearing and then inserting the shaft and rolling bearing integrally into the inner sleeve.

[0004] Prior art literature Patent documents Patent Document 1: Japanese Patent Application Publication No. 2000-34999; Patent document 2: Japanese Patent Application Publication No. 8-186956. Summary of the Invention

[0005] The problem that the invention aims to solve Furthermore, in rotating equipment, when mounting the sleeve, rolling bearing, and shaft together, a force may be applied to the sleeve and shaft in an direction that causes them to tilt relative to each other. Generally, rolling bearings are provided with angular clearance. Angular clearance is the angle at which one of the outer and inner rings can tilt. If the sleeve and shaft tilt relative to each other while the rolling bearing is positioned between the sleeve and shaft, the outer and inner rings of the rolling bearing will also tilt relative to each other within a range below the angular clearance. However, if the relative tilt of the outer and inner rings exceeds the permissible angular clearance determined by the rolling bearing product, indentations may sometimes form on at least one of the outer and inner rings due to the rolling elements. If indentations form on either the outer or inner ring, abnormal noise may occur when the rotating equipment rotates. Therefore, in existing rotating equipment, there is a problem of suppressing the formation of indentations on the raceways of the rolling bearings during assembly.

[0006] Therefore, the present invention provides a sleeve, a bearing sleeve having the sleeve, and a rotating device, wherein the sleeve suppresses the formation of indentations on the raceway ring of the rolling bearing during the assembly of the rotating device, thereby suppressing abnormal noise generated when the rotating device rotates.

[0007] Solution for solving the problem The first aspect of the present invention relates to a sleeve that is a cylindrical sleeve in which a rolling bearing is mounted on the inner side. The sleeve includes: an outer ring support portion that contacts the end face of the outer ring of the rolling bearing from one side in the axial direction; and a protrusion portion that is formed to be closer to the aforementioned side in the axial direction than the aforementioned outer ring support portion and protrudes further in the radial direction than the aforementioned outer ring support portion.

[0008] According to the first embodiment, when the shaft portion inserted into the inner ring of the rolling bearing is inclined relative to the central axis of the sleeve, the shaft portion contacts the protrusion, thereby limiting further inclination of the shaft portion. Here, without the protrusion on the sleeve, the portion on the inner circumferential surface of the sleeve that can contact the inclined shaft portion is located radially outward than the inner circumferential edge of the outer ring support, thus insufficiently limiting the inclination of the shaft portion. According to the first embodiment, the protrusion protrudes radially inward more than the outer ring support, thus effectively limiting the inclination of the shaft portion. Therefore, it is possible to suppress the large inclination of the inner ring of the rolling bearing relative to the outer ring, preventing the formation of indentations of rolling elements in at least one of the inner and outer rings. Therefore, when assembling a rotating device with a sleeve, suppressing the formation of indentations on the raceway rings of the rolling bearing can suppress abnormal noise during the rotation of the rotating device.

[0009] The sleeve in the second aspect of the present invention may also be: in the sleeve in the first aspect described above, the protrusion has a limiting portion, which can contact the shaft portion inserted through the inner ring when the inclination between the outer ring and the inner ring of the rolling bearing is less than the angular clearance.

[0010] According to the second embodiment, the tilting of the shaft above the angular clearance of the rolling bearing can be limited by the limiting part. Therefore, when assembling a rotating device with a sleeve, the formation of indentations on the raceway ring of the rolling bearing can be more reliably suppressed.

[0011] The sleeve involved in the third aspect of the present invention may also be: in the sleeve involved in the first or second aspect described above, the aforementioned outer ring support portion has an inner diameter that is larger than the outer diameter of the inner ring of the aforementioned rolling bearing.

[0012] According to the third scheme, 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.

[0013] The sleeve involved in the fourth aspect of the present invention may also be: in the sleeve involved in the third aspect above, the inner diameter of the aforementioned protrusion is less than or equal to the outer diameter of the aforementioned inner ring.

[0014] According to the fourth scheme, 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 restricted.

[0015] 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, which integrally has the aforementioned outer ring support portion and the aforementioned protrusion portion.

[0016] According to Option 5, the sleeve can be formed from a single component. Therefore, it is possible to reduce the manufacturing cost of the sleeve.

[0017] The sleeve according to the sixth aspect of the present invention may also be the sleeve according to any one of the first to fourth aspects described above, comprising: a sleeve body having the aforementioned protrusion; and a support member disposed inside the aforementioned sleeve body and overlapping the aforementioned protrusion from the other side of the aforementioned axial direction, forming the aforementioned outer ring support portion.

[0018] According to the sixth embodiment, the sleeve body can be made into a simple shape with fewer height differences, 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 to achieve the above-mentioned effects.

[0019] The sleeve involved in the seventh aspect of the present invention may also be: the sleeve involved in the second aspect and the various aspects of the second aspect mentioned above, having a bearing retaining portion that retains another rolling bearing on the side further in the axial direction than the protrusion, the end portion of the shaft portion on the side in the axial direction having a tapered surface that tapers towards the side in the axial direction, and the protrusion being able to contact the shaft portion when the tapered surface is in contact with the opening edge of the inner ring of the other rolling bearing.

[0020] According to the seventh embodiment, when the shaft is inserted into another rolling bearing from the other side in the axial direction, even if the shaft is deviated from the central axis of the sleeve due to tilting or other reasons, the tapered surface can still contact the opening edge of the inner ring of the other rolling bearing. This prevents the end face of the shaft from touching the inner ring of the other rolling bearing and applying excessive force to it. Therefore, it suppresses the formation of indentations on the raceway of the other rolling bearing, thus suppressing abnormal noise during the rotation of the rotating equipment.

[0021] The sleeve involved in the eighth aspect of the present invention may also be: the sleeve involved in any of the above-mentioned first to seventh aspects, which is formed of an insulating synthetic resin.

[0022] According to scheme 8, it is possible to suppress the current flowing inside the rolling bearing and thus prevent electrolytic corrosion.

[0023] The sleeve involved in the ninth aspect of the present invention may also be: in the sleeve involved in the eighth aspect above, the aforementioned synthetic resin includes potassium titanate whiskers.

[0024] According to the ninth embodiment, the sleeve can be made into a component with excellent wear resistance and surface smoothness. Furthermore, the synthetic resin including potassium titanate whiskers has good machinability and is less prone to clogging during grinding, resulting in excellent machinability. Therefore, compared to cases where the sleeve uses glass fiber or carbon fiber as reinforcing material, the machinability is improved when forming the sleeve through machining such as cutting or grinding, and also when finishing the injection-molded sleeve through two machining processes such as cutting or grinding.

[0025] The bearing sleeve according to the tenth aspect of the present invention comprises: a sleeve according to any one of the first to ninth aspects described above; and the aforementioned rolling bearing, which is assembled inside the aforementioned sleeve.

[0026] According to the 10th scheme, when assembling a rotating device with a bearing sleeve, it is possible to suppress the formation of indentations on the raceway ring of the rolling bearing, thereby suppressing abnormal noise generated when the rotating device rotates.

[0027] The rotating device according to the 11th aspect of the present invention comprises: a bearing sleeve according to the 10th aspect described above; and a shaft portion inserted through the inner ring of the aforementioned rolling bearing.

[0028] According to scheme 11, abnormal noises during rotation can be suppressed.

[0029] The rotating device according to the 12th aspect of the present invention may also be: in the rotating device according to the 11th aspect above, the aforementioned shaft is the rotating shaft of a motor, and the aforementioned sleeve is integrally formed from synthetic resin and the base of the aforementioned motor.

[0030] According to the 12th scheme, the rolling bearing is electrically insulated, which can suppress electrolytic corrosion in the rolling bearing. In addition, the sleeve and the base are integrally formed, thereby reducing the number of parts and improving the productivity of the motor.

[0031] Invention Effects According to the present invention, indentations are suppressed on the raceway rings of rolling bearings during the assembly of rotating equipment, thereby suppressing abnormal noises generated when the rotating equipment rotates. Attached Figure Description

[0032] Figure 1 This is a longitudinal cross-sectional view illustrating an embodiment of the fan motor.

[0033] Figure 2 This is a top view of the rolling bearing according to the first embodiment.

[0034] Figure 3 This is a longitudinal sectional view of the rolling bearing according to the first embodiment, showing... Figure 2 The cross section along line III-III.

[0035] Figure 4 It shows that Figure 3 The diagram shows the state in which the inner ring of the rolling bearing is tilted relative to the outer ring.

[0036] Figure 5 This is a longitudinal sectional view of the fan motor according to the first embodiment, and an enlarged view showing the periphery of the sleeve.

[0037] Figure 6 It shows that Figure 5 The diagram shows the state in which the shaft is tilted and in contact with the limiting part of the sleeve.

[0038] Figure 7 It is shown Figure 5 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.

[0039] Figure 8 This is a longitudinal sectional view of the fan motor according to the second embodiment, and an enlarged view showing the periphery of the sleeve.

[0040] Figure 9 This is a longitudinal sectional view of the fan motor according to the third embodiment, and an enlarged view showing the periphery of the sleeve.

[0041] Figure 10 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.

[0042] Figure 11 This is a longitudinal sectional view of a fan motor according to a modified example of the implementation method, and an enlarged view showing the periphery of the sleeve. Detailed Implementation

[0043] 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.

[0044] Figure 1 This is a longitudinal cross-sectional view illustrating an embodiment of the fan motor.

[0045] 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 fitted to 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 extending radially from the central axis O orthogonal to 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 as downward.

[0046] The sleeve 140 is inserted into the shaft portion 111 of the rotating body 110. The sleeve 140 supports the shaft portion 111 in a rotatable manner via a pair of bearings 1. The specific shape of the sleeve 140 will be described later.

[0047] 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 high precision, and exhibit excellent chemical resistance. Potassium titanate whiskers are also suitable as a reinforcing material added to the synthetic resin. The potassium titanate whiskers are preferably added in an amount of 5% to 50%, more preferably 10% to 30%. Furthermore, it is ideal not to add glass fibers or carbon fibers as reinforcing materials to the synthetic resin. This is because if hard glass fibers or carbon fibers are added to the synthetic resin, it is difficult to perform finishing work on the injection-molded sleeve 140 using centerless machining or other mechanical processing methods, and it can easily damage grinding stones or cutting tools. Furthermore, 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, compared to glass fiber or carbon fiber, potassium titanate whiskers are softer, and their smaller size and length make them easier to machine. Synthetic resins with added potassium titanate whiskers are easier to machine than synthetic resin monomers. Even if potassium titanate whiskers detach from the synthetic resin and enter the bearing's interior, their small size makes them less likely to cause improper bearing rotation. Furthermore, the absence of carbon fiber as a reinforcing material ensures the electrical insulation of the sleeve 140.

[0048] Alternatively, the sleeve 140 can also be formed from a metallic material. Examples of metals that can be used to form the sleeve 140 include brass. The metallic sleeve 140 can be formed, for example, by machining.

[0049] The base 120 is engaged with 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 and the sleeve 140 are integrally formed. That is, the base 120 and the sleeve 140 are integrally formed from the same material. The base 120 is, for example, the base of the fan motor 100. Alternatively, the base 120 may be provided as a component different from the sleeve 140.

[0050] A rotating body 110 is positioned above the base 120. The rotating body 110 includes a shaft portion 111 and a fan 112, which is 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 a vertical direction. The lower end of the shaft portion 111 has a downwardly tapered annular surface 111a. The entire tapered surface 111a is located further 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 tapered surface 111a.

[0051] 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 radially outer side of the peripheral wall 114. The peripheral wall 114 surrounds the sleeve 140 throughout its entire circumference in a state of being radially spaced relative to the sleeve 140.

[0052] The drive unit 130 is the drive source for the fan motor 100. The drive unit 130 includes: a stator 131 having coils; and a rotor 132 having 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.

[0053] 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 arranged coaxially with each other. The pair of bearings 1 are arranged side by side with a gap in the axial direction.

[0054] 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, thus restricting its 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 relative to the rotating body 110 in the axial direction inward (downward).

[0055] 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, thus restricting its displacement outward (upward) in the axial direction. Alternatively, the outer ring 20 of the second bearing 1B can be fixed to the sleeve 140, thus restricting its displacement to both sides in the axial direction. The inner ring 10 of the second bearing 1B contacts a C-ring 103 fitted to 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 by the C-ring 103 to its displacement outward (downward) relative to the shaft portion 111 in the axial direction.

[0056] The construction of bearing 1 will be described.

[0057] Figure 2 This is a top view of the bearing according to the first embodiment. Figure 3 This is a longitudinal sectional view of the bearing according to the first embodiment, showing... Figure 2 The cross section along line III-III.

[0058] 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 where they are inclined to each other (described later). The outer ring 20 and the sleeve 140 share a common axis about the central axis O.

[0059] 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 radially outer 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 axially outer side.

[0060] 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. 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 on the inner circumferential surface 22. The outer ring raceway surface 23 is recessed radially outward. The outer ring raceway surface 23 is hemispherically shaped in cross-section as if viewed along the outer surface of the rolling element 30, and is formed in a ring shape extending circumferentially throughout the entire 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. In the longitudinal section of the bearing 1, the outer ring raceway surface 23 has a radius of curvature larger than the radius of the rolling element 30.

[0061] 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 inner peripheral surface 22.

[0062] 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 throughout 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. In the longitudinal section of the bearing 1, the inner ring raceway surface 11 has a radius of curvature larger than the radius of the rolling element 30.

[0063] 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.

[0064] 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.

[0065] 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 arranged coaxially with the central axis O. The sealing member 50 is fitted onto 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 periphery of the cover portion 53 is arranged 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.

[0066] Figure 4 It shows that Figure 3 The diagram shows the bearing with its inner ring tilted relative to its outer ring.

[0067] like Figure 4 As shown, the inner ring 10 and outer ring 20 have radii of curvature greater than the radius of the rolling element 30 via the outer ring raceway surface 23 and the inner ring raceway surface 11, allowing them to tilt relative to each other. Figure 4 In this configuration, axis P is the central axis of the inner ring 10, which is inclined 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 according to the bearing 1.

[0068] [First Implementation] The sleeve 140 of the first embodiment will be described in detail.

[0069] Figure 5 This is a longitudinal sectional view of the fan motor according to the first embodiment, and an enlarged view showing the periphery of the sleeve.

[0070] 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, an outer ring support portion 143, and a protrusion 144. Sleeve 140 is formed entirely of the aforementioned synthetic resin.

[0071] The first retaining portion 141 holds the first bearing 1A in a manner that prevents it from displacing in the radial direction. The first retaining portion 141 surrounds the first bearing 1A from the outer side in the radial direction. The first retaining portion 141 has a first retaining surface 141a that slides in contact with the outer peripheral surface of the outer ring 20 of the first bearing 1A. The first retaining surface 141a is part of the inner peripheral surface of the sleeve 140, and is a cylindrical surface that faces inward in the radial direction and extends in the axial direction. The first retaining surface 141a extends downward from the upper end opening edge of the sleeve 140.

[0072] The second retaining portion 142 holds the second bearing 1B in a manner that prevents it from displacing radially. The second retaining portion 142 surrounds the second bearing 1B from the outer side in the radial direction. The second retaining portion 142 has a second retaining surface 142a that slides in contact with the outer peripheral surface of the outer ring 20 of the second bearing 1B. The second retaining surface 142a is part of the inner peripheral surface of the sleeve 140, and is a cylindrical surface extending radially inward and axially. The second retaining surface 142a extends upward from the lower end opening edge of the sleeve 140.

[0073] The outer ring support portion 143 contacts the inner end face of the outer ring 20 of the first bearing 1A from below. The outer ring support portion 143 is part of the inner circumferential surface of the sleeve 140. The outer ring support portion 143 is located inside (below) in the axial direction and inside in the radial direction relative to the first retaining portion 141. The outer ring support portion 143 extends from the inner end edge (lower end edge) of the first retaining surface 141a in the axial direction to the inner side in the radial direction. The outer ring support portion 143 extends outward (above) in the axial direction and in the circumferential direction. The outer ring support portion 143 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The outer ring support portion 143 is a flat surface orthogonal to the axial direction. The inner diameter of the 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 outer ring support portion 143 may be smaller than the inner diameter of the outer ring 20.

[0074] A protrusion 144 is provided on the inner circumferential surface of the sleeve 140. The protrusion 144 is located between the first retaining portion 141 and the second retaining portion 142. That is, the protrusion 144 is formed to be lower than the outer ring support portion 143. The axial direction of the protrusion 144 includes the center position of the first bearing 1A and the second bearing 1B. The protrusion 144 protrudes further radially inward than the outer ring support portion 143. The protrusion 144 extends continuously throughout the circumferential direction. The protrusion 144 includes: an inner circumferential surface 145, which extends axially at a position further radially inward than the inner circumferential edge of the outer ring support portion 143; an upper end surface 146, which extends radially outward from the upper end edge of the inner circumferential surface 145; and a lower end surface 147, which extends radially outward from the lower end edge of the inner circumferential surface 145.

[0075] The inner circumferential surface 145 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 145 is axially spaced apart from the outer ring support portion 143. The inner diameter of the protrusion 144 is below the outer diameter of the inner ring 10 of the first bearing 1A. Furthermore, the inner diameter of the protrusion 144 is the inner diameter of the inner circumferential surface 145. The protrusion 144 has an inner diameter larger than the inner diameter of the inner ring 10 of the first bearing 1A, forming a radial gap with the outer circumferential surface of the shaft portion 111. The upper edge of the inner circumferential surface 145 is located lower than the inner ring 10 of the first bearing 1A. The lower edge of the inner circumferential surface 145 is located higher than the second bearing 1B.

[0076] The inner peripheral surface 145 of the protrusion 144 has a limiting portion 145a. The limiting portion 145a is at least a part of the protrusion 144. The range of the limiting portion 145a is defined by its function as described later.

[0077] The upper end face 146 faces upward and extends circumferentially. The upper end face 146 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The upper end face 146 is a flat surface orthogonal to the axial direction. The upper end face 146 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 147 faces downward and extends circumferentially. The lower end face 147 has a constant width in the radial direction and extends continuously throughout the circumferential direction. The lower end face 147 is a flat surface orthogonal to the axial direction.

[0078] When the shaft portion 111 is installed on the sleeve 140, the shaft portion 111 is inserted into the inner side of the sleeve 140 from above. As a method for installing the shaft portion 111 on the sleeve 140, there are the following methods: a method of inserting the shaft portion 111 into the sleeve 140 with the first bearing 1A and the second bearing 1B held in the retaining portions 141 and 142 (hereinafter referred to as the first method); and a method of inserting the shaft portion 111 with the first bearing 1A inserted into it into the sleeve 140 with the second bearing 1B held in the second retaining portion 142 (hereinafter referred to as the second method).

[0079] The first method will be described. After penetrating the first bearing 1A, the shaft portion 111 passes inside the protrusion 144 of the sleeve 140. During the insertion and penetration process into the first bearing 1A, the shaft portion 111 can contact the inner circumferential surface 145 of the protrusion 144. Furthermore, when the shaft portion 111 is not tilted relative to the central axis O, the shaft portion 111 does not contact the protrusion 144.

[0080] like Figure 6 As shown, if the shaft portion 111 tilts relative to the central axis O along with the tilt of the inner ring 10 of the first bearing 1A relative to the outer ring 20, the shaft portion 111 can contact the inner peripheral surface 145 of the protrusion 144. With the shaft portion 111 in contact with the limiting portion 145a in the inner peripheral surface 145 of the protrusion 144, the tilt between the outer ring 20 and the inner ring 10 of the first bearing 1A is less than or equal to the angular clearance. That is, the limiting portion 145a of the protrusion 144 contacts the shaft portion 111 during the insertion and penetration process into the first bearing 1A, thereby limiting the tilt of the inner ring 10 of the first bearing 1A relative to the outer ring 20 to be greater than the angular clearance. In this embodiment, the limiting portion 145a extends continuously upward from the lower end of the inner peripheral surface 145 of the protrusion 144. Furthermore, when the inclination between the outer ring 20 and the inner ring 10 is less than the angular clearance, the shaft portion 111 may not contact the upper end of the inner circumferential surface 145 of the protrusion 144. In this case, the upper end of the inner circumferential surface 145 of the protrusion 144 is not included in the limiting portion 145a. However, the limiting portion 145a may include the upper end of the inner circumferential surface 145 of the protrusion 144.

[0081] The lower end of the shaft portion 111 moves downward inside the protrusion 144 and inserts into the second bearing 1B. For example... Figure 7As shown, if the shaft portion 111 approaches the second bearing 1B with an inclination relative to the central axis O, the tapered surface 111a at the lower end of the shaft portion 111 slides into contact with the upper opening edge of the inner ring 10 of the second bearing 1B. The shaft portion 111 moves downward, causing the tapered surface 111a to slide against the upper opening edge of the inner ring 10 of the second bearing 1B, thereby eliminating the inclination 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 downward. 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 144. This suppresses the inclination of the shaft portion 111 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 end opening edge of the inner ring 10 of the second bearing 1B, the limiting portion 145a of the inner peripheral surface 145 of the protrusion 144 contacts the shaft portion 111.

[0082] Alternatively, in the first method, the second bearing 1B can be assembled into the sleeve 140 after the shaft portion 111 is inserted through it. In this case, the upper opening edge of the inner ring 10 of the second bearing 1B, which moves upward, also slides on the tapered surface 111a of the shaft portion 111, thereby eliminating the inclination of the shaft portion 111 relative to the central axis O and simultaneously penetrating the second bearing 1B. This prevents the inner ring 10 of the second bearing 1B from being excessively pressed downward by the shaft portion 111.

[0083] The second method will be described. When the shaft portion 111 is inserted into the sleeve 140, it passes inside the protrusion 144. The lower end of the shaft portion 111 moves downward toward the second bearing 1B inside the protrusion 144. When the first bearing 1A is assembled in the sleeve 140 before the shaft portion 111 is inserted into the second bearing 1B, the protrusion 144, 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 assembled in the sleeve 140, the limiting portion 145a of the protrusion 144 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, when the shaft portion 111 moves downward toward the second bearing 1B after the first bearing 1A is assembled into the sleeve 140, the limiting portion 145a of the protrusion 144 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.

[0084] On the other hand, when the shaft portion 111 is inserted into the second bearing 1B before the first bearing 1A is assembled into the sleeve 140, there is a possibility that the lower end of the shaft portion 111 approaches the second bearing 1B with its axis deviating from the central axis O. Even if the axis of the shaft portion 111 deviates from the central axis O, the shaft portion 1111 eliminates the deviation from the central axis O and simultaneously penetrates the second bearing 1B by sliding its tapered surface 111a at the lower end of the upper opening edge of the inner ring 10 of 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 144. This prevents the end face of the shaft portion 111 from contacting the inner ring 10 of the second bearing 1B and pressing downwards.

[0085] As described above, the sleeve 140 includes: an 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 144 formed to be located further below the outer ring support portion 143 and protruding further in the radial direction than the 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 inclined relative to the central axis O of the sleeve 140, the shaft portion 111 contacts the protrusion 144, thereby limiting further inclination of the shaft portion 111. Here, without the protrusion 144, the portion of the inner circumferential surface of the sleeve 140 that can contact the inclined shaft portion 111 is located further outward in the radial direction than the inner circumferential edge of the outer ring support portion 143, so the inclination of the shaft portion 111 cannot be sufficiently limited. According to this embodiment, the protrusion 144 protrudes further in the radial direction than the 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, when assembling the fan motor 100 with the sleeve 140, suppressing the formation of indentations on the raceway ring of the first bearing 1A can suppress abnormal noise during the rotation of the fan motor 100.

[0086] The protrusion 144 has a limiting portion 145a, which, when the inclination 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 145a can limit the shaft portion 111 from tilting above the angular clearance of the first bearing 1A. Therefore, when assembling the fan motor 100 with the sleeve 140, 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.

[0087] The 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 outer ring support portion 143 from contacting the inner ring 10 of the first bearing 1A. Therefore, it prevents the sleeve 140 from interfering with the rotation of the shaft portion 111.

[0088] The inner diameter of the protrusion 144 is less than or equal to the outer diameter of the inner ring 10. This configuration prevents the sleeve 140 from contacting the inner ring 10 of the first bearing 1A, while simultaneously bringing the protrusion 144 close to the central axis O of the sleeve 140. Therefore, tilting of the shaft portion 111 can be more effectively restricted.

[0089] The sleeve 140 integrally has an outer ring support portion 143 and a protrusion 144. With this configuration, the sleeve 140 can be formed from a single component. Therefore, it is possible to reduce the manufacturing cost of the sleeve 140.

[0090] The lower end of the shaft portion 111 has a tapered surface 111a that tapers downwards. The protrusion 144 can contact the shaft portion 111 when the tapered surface 111a is in contact with the opening edge of the inner ring 10 of the second bearing 1B. According to this configuration, when the shaft portion 111 is inserted into the second bearing 1B from above, even if the shaft portion 111 is deviated from the central axis O of the sleeve 140 due to tilting or other reasons, the tapered surface 111a can still contact the opening edge of the inner ring 10 of the second bearing 1B. This prevents the end face of the shaft portion 111 from contacting the inner ring 10 of the second bearing 1B and applying excessive force to the inner ring 10. Therefore, preventing indentation from forming on at least one of the inner ring 10 and outer ring 20 of the second bearing 1B can suppress abnormal noise when the fan motor 100 rotates.

[0091] The sleeve 140 is formed of an insulating synthetic resin. According to this configuration, bearings 1A and 1B are electrically insulated, thereby suppressing electrolytic corrosion in bearings 1A and 1B.

[0092] The synthetic resin forming the sleeve 140 includes potassium titanate whiskers. Based on this configuration, the sleeve 140 can be a component with excellent wear resistance and surface smoothness. Furthermore, the synthetic resin including potassium titanate whiskers has good machinability and is less prone to clogging during grinding, resulting in excellent processability. Therefore, compared to the case where the sleeve 140 includes glass fiber or carbon fiber as a reinforcing material, the processability when forming the sleeve through machining such as cutting or grinding is improved, as is the processability when finishing the sleeve 140 after injection molding through two processes such as cutting or grinding.

[0093] The fan motor 100 includes: the aforementioned sleeve 140; and a shaft 111 inserted into the inner ring 10 of the first bearing 1A. This configuration can suppress abnormal noise during rotation.

[0094] The shaft 111 is the rotating shaft of the fan motor 100. The sleeve 140 is integrally formed of synthetic resin and the base 120, which serves as the base of the fan motor 100. With this configuration, it is possible to suppress electrolytic corrosion in the bearings 1A and 1B caused by current flowing through them. In addition, the sleeve 140 and the base are integrally formed, thereby reducing the number of parts and improving the productivity of the fan motor 100.

[0095] [Second Implementation] Next, refer to Figure 8 The second embodiment will now be described. The second embodiment differs from the first embodiment in that the outer ring support portion 143 and the protrusion 144 are formed from different components. Furthermore, the configuration is the same as the first embodiment except for the configuration described below.

[0096] Figure 8 This is a longitudinal sectional view of the fan motor according to the second embodiment, and an enlarged view showing the periphery of the sleeve.

[0097] like Figure 8 As shown, the sleeve 140A 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 presents the same shape as the sleeve 140 of the first embodiment. The sleeve body 140a forms at least an outer peripheral surface, two end surfaces, and a protrusion 144 in the sleeve 140A. 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. For example, the support member 140b is a washer or a C-ring. The support member 140b is inserted from above into the inner side of the first retaining portion 141 of the sleeve body 140a and overlaps from above with the upper end surface 146 of the protrusion 144, thereby forming an outer ring support portion 143 of the sleeve 140A. The sleeve body 140a is formed of the aforementioned synthetic resin or metal material. The support component 140b is formed of a hard material such as the aforementioned synthetic resin or metal.

[0098] In this embodiment, the same effects as in the first embodiment are achieved. In addition, the following effects are achieved in this embodiment: The sleeve 140A includes: a sleeve body 140a having a protrusion 144; and a support member 140b disposed inside the sleeve body 140a and overlapping the protrusion 144 from above, forming an outer ring support portion 143. With this configuration, the sleeve body 140a can be a simple shape with fewer height differences, resulting in a sleeve 140A with excellent manufacturability. Especially when the sleeve body 140a is made of metal, complex processing can be avoided during the formation of the sleeve body 140a, thus making it a suitable configuration for achieving the aforementioned effects.

[0099] [Third Implementation] Next, refer to Figure 9 The third embodiment will now be described. In the third embodiment, the position of the lower edge of the inner peripheral surface 145B of the protrusion 144B differs from that in the first embodiment. Furthermore, the configuration, except for the configuration described below, is the same as that in the first embodiment.

[0100] Figure 9 This is a longitudinal sectional view of the fan motor according to the third embodiment, and an enlarged view showing the periphery of the sleeve.

[0101] like Figure 9 As shown, the lower edge of the inner peripheral surface 145B of the protrusion 144B is located above that in the first embodiment. For example, the axial direction of the protrusion 144B does not include the center positions of the first bearing 1A and the second bearing 1B. In this embodiment, 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 lower edge of the inner peripheral surface 145B of the protrusion 144B moves away from the second bearing 1B in a manner where the protrusion 144B and the shaft portion 111 do not contact each other. Even with this configuration, the same effect as in the first embodiment is achieved by including the limiting portion 145a in the inner peripheral surface 145B of the protrusion 144B.

[0102] [Fourth Implementation] Next, refer to Figure 10 The fourth embodiment will now be described. In the fourth embodiment, the upper end face 146C of the protrusion 144C differs from that in the first embodiment. However, the configuration is the same as in the first embodiment except for the configuration described below.

[0103] Figure 10 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.

[0104] like Figure 10As shown, the upper end face 146C of the protrusion 144C connects the upper edge of the inner circumferential surface 145 of the protrusion 144C and the inner circumferential edge of the outer ring support 143. The upper end face 146C extends continuously in the longitudinal section of the sleeve 140C between the upper edge of the inner circumferential surface 145 of the protrusion 144C and the inner circumferential edge of the outer ring support 143. In the illustrated example, the upper end face 146C is a conical surface extending linearly in the longitudinal section of the sleeve 140C between the upper edge of the inner circumferential surface 145 of the protrusion 144C and the inner circumferential edge of the outer ring support 143. However, the upper end face 146C may also be curved in the longitudinal section of the sleeve 140C. The upper end face 146C may or may not 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 below. Even with this configuration, the protrusion 144C of the sleeve 140C, which includes a limiting portion 145a, achieves the same effect as in the first embodiment.

[0105] Furthermore, the present invention is not limited to the embodiments described above with reference to the accompanying drawings, and various variations can be considered within its technical scope.

[0106] For example, in the above embodiment, a sleeve provided for a fan motor that is a rotating device is illustrated, but the present invention can be applied to sleeves provided for all rotating devices.

[0107] In the above embodiments, the outer ring 20 of the second bearing 1B is not pressurized, but as Figure 11 As shown, a force-applying component 150, such as a helical spring, may also be disposed on the inner side of the second retaining part 142, which is located between the outer ring 20 and the protrusion 144 and presses the outer ring 20 downward.

[0108] In the above embodiment, the outer ring support portion 143 extends continuously throughout the circumferential direction, but it is not limited to this configuration. That is, the outer ring support portion may also be provided intermittently along the circumferential direction.

[0109] In the above embodiment, the protrusion 144 extends continuously throughout the circumferential direction, but is not limited to this configuration. For example, the limiting portion of the protrusion may be provided intermittently along the circumferential direction.

[0110] In the above embodiment, the limiting portion 145a of the protrusion 144 is provided on the cylindrical inner circumferential surface 145, 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 shape that tapers radially inward on 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 along the axial direction.

[0111] In the above embodiments, there are no particular limitations on the dimensions of the various parts of the bearing assembled in the sleeve, and the bearing assembled in the sleeve may not be limited to radial bearings as described 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. Alternatively, the angular clearance of the bearing can be derived from the dimensions of the various parts of the bearing, for example, by referring to "Introduction to Ball Bearing Design Calculation" (Nikkan Kogyo Shimbun, September 2011, pp. 22-32).

[0112] Furthermore, without departing from the spirit of the present invention, the constituent elements in the above embodiments can be appropriately replaced with known constituent elements. In addition, the above embodiments and variations can be appropriately combined.

[0113] Explanation of reference numerals in the attached figures 1A…First bearing (rolling bearing) 1B…Second bearing (another rolling bearing) 10…Inner ring 20…Outer ring 100…Fan motor (rotating equipment) 111…Shaft 111a…Tapered surface 140, 140A, 140B, 140C, 140D…Sleeve 140a…Sleeve body 140b…Support component 142…Second retaining part (bearing retaining part) 143…Outer ring support part 144, 144B, 144C…Protrusion 145a…Restriction part.

Claims

1. A sleeve, which is a cylindrical sleeve with a rolling bearing mounted on its inner side. The sleeve comprises: The outer ring support portion contacts the end face of the outer ring of the rolling bearing from one side in the axial direction; and The protrusion is formed to be located further along the axial direction than the outer ring support portion and to protrude further in the radial direction than the outer ring support portion.

2. The sleeve according to claim 1, wherein, The protrusion has a limiting portion that, when the inclination between the outer and inner rings of the rolling bearing is less than the angular clearance, can contact the shaft portion inserted through the inner ring.

3. The sleeve according to claim 1, 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.

4. The sleeve according to claim 3, wherein, The inner diameter of the protrusion is less than or equal to the outer diameter of the inner ring.

5. The sleeve according to claim 1, wherein, It integrally comprises the outer ring support portion and the protrusion portion.

6. The sleeve according to claim 1, wherein, have: Sleeve body having the aforementioned protrusion; and A support member is disposed inside the sleeve body and overlaps with the protrusion from the other side in the axial direction, forming the outer ring support portion.

7. The sleeve according to claim 2, wherein, It has a bearing retainer that holds another rolling bearing on the side further in the axial direction than the protrusion. The end portion of the shaft portion on one side in the axial direction has a tapered surface that tapers towards that side in the axial direction. 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.

8. The sleeve according to claim 1, wherein, It is formed from a synthetic resin that has insulating properties.

9. The sleeve according to claim 8, wherein, The synthetic resin includes potassium titanate whiskers.

10. A bearing sleeve, comprising: The sleeve according to any one of claims 1 to 9; and The rolling bearing is fitted inside the sleeve.

11. A rotating device comprising: The bearing sleeve according to claim 10; and The shaft portion is inserted through the inner ring of the rolling bearing.

12. The rotating device according to claim 11, wherein, The shaft is the rotating shaft of the motor. The sleeve is integrally formed from synthetic resin and the base of the motor.

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