Rolling bearings
The rolling bearing design with an annular slinger and adhesive member effectively prevents foreign matter intrusion and reduces rotational torque by extending the labyrinth gap and avoiding contact, addressing dimensional and operational challenges.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- JTEKT CORP
- Filing Date
- 2024-10-30
- Publication Date
- 2026-05-15
AI Technical Summary
Existing rolling bearings face limitations in extending the intrusion path length for foreign matter prevention due to dimensional constraints and potential contact issues with shield plates, leading to increased rotational torque.
A rolling bearing design incorporating an annular slinger with an adhesive member in its structure, which captures foreign matter and prevents it from entering the bearing, while maintaining smooth rotation by avoiding contact with other components.
Enhances foreign matter intrusion prevention and reduces rotational resistance by extending the labyrinth gap length and ensuring the adhesive member does not interfere with the bearing's operation.
Smart Images
Figure 2026079251000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a rolling bearing.
Background Art
[0002] In a rolling bearing, it is necessary to prevent foreign matter from entering the bearing. To prevent the intrusion of foreign matter, a rolling bearing is known in which a shield plate is provided at an axial end of an annular space formed between an inner ring and an outer ring (see, for example, FIG. 1 of Patent Document 1).
[0003] The rolling bearing shown in Patent Document 1 has an annular first shield plate attached to the outer ring and non-contact with the inner ring, and an annular second shield plate attached to the inner ring and non-contact with the outer ring. A labyrinth gap is formed between the first shield plate and the second shield plate, and the labyrinth gap prevents foreign matter from entering the bearing.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In the case of the rolling bearing as described above, the effect increases as the length of the intrusion path of foreign matter in the radial direction in the labyrinth gap becomes longer. However, in order to increase the intrusion path length, it is necessary to increase the first shield plate and the second shield plate in the radial direction, but there are limitations to the dimensions between the inner and outer rings of the rolling bearing, and there is a limit to increasing the intrusion path length. In addition, such a shield plate is likely to tilt when assembled to the outer ring or the inner ring, and may contact other parts. When the shield plate contacts other parts, the rotational torque of the rolling bearing increases.
[0006] The purpose of this disclosure is to provide a rolling bearing that can enhance the effect of suppressing the intrusion of foreign matter into the bearing. [Means for solving the problem]
[0007] The rolling bearing comprises an inner ring, an outer ring, a plurality of rolling elements disposed between the inner ring and the outer ring, an annular shield plate fixed to the inner circumferential surface of the outer ring and facing the outer circumferential surface of the inner ring with a first gap between them, and an annular slinger located axially adjacent to the shield plate and fixed to the outer circumferential surface of the inner ring. The slinger has an inner cylindrical portion pressed into the outer circumferential surface of the inner ring, an inner annular portion extending radially outward from the axial end of the inner cylindrical portion, an outer cylindrical portion extending axially from the radially outer end of the inner annular portion, and an outer annular portion extending radially outward from the axial end of the outer cylindrical portion and having a side surface that faces the side surface of the outer ring with a second gap between them, and an adhesive member is provided in the space surrounded by the inner cylindrical portion, the inner annular portion, and the outer cylindrical portion. [Effects of the Invention]
[0008] According to the rolling bearing of the present invention, it is possible to enhance the effect of suppressing the intrusion of foreign matter into the bearing. [Brief explanation of the drawing]
[0009] [Figure 1] Figure 1 is a cross-sectional view showing one embodiment of a rolling bearing. [Figure 2] Figure 2 is a cross-sectional view showing how the adhesive member is provided in the space of the bent portion. [Modes for carrying out the invention]
[0010] <Overview of Embodiments> (1) A rolling bearing comprises an inner ring, an outer ring, a plurality of rolling elements disposed between the inner ring and the outer ring, an annular shield plate fixed to the inner circumferential surface of the outer ring and facing the outer circumferential surface of the inner ring with a first gap between them, and an annular slinger located axially adjacent to the shield plate and fixed to the outer circumferential surface of the inner ring, The slinger has an inner cylindrical portion pressed into the outer circumferential surface of the inner ring, an inner annular portion extending radially outward from the axial end of the inner cylindrical portion, an outer cylindrical portion extending axially from the radially outer end of the inner annular portion, and an outer annular portion extending radially outward from the axial end of the outer cylindrical portion and having a side surface that faces the side surface of the outer ring with a second gap between them, and an adhesive member is provided in the space surrounded by the inner cylindrical portion, the inner annular portion, and the outer cylindrical portion.
[0011] Foreign matter may float around the rolling bearing (outside the bearing), and even if this foreign matter enters the labyrinth gap, it may be captured by the adhesive member provided on the slinger. Therefore, the effect of suppressing the entry of foreign matter is enhanced.
[0012] (2) In the rolling bearing described in (1) above, the adhesive member is grease. The grease may be one used as a lubricant for rolling bearings, or it may have different properties than the grease used as a lubricant for rolling bearings. If the adhesive material is grease, even if it is scattered around, there is no risk of it interfering with the rotation of the rolling bearing.
[0013] (3) Or, in the rolling bearing of (1) above, the adhesive member is a silicone-based adhesive. A configuration is obtained in which the adhesive material is less likely to flow even when the rolling bearing rotates.
[0014] (4) In any one of the rolling bearings described in (1) to (3) above, an adhesive member is provided on the side surface of the outer ring portion. This enhances the effect of preventing foreign matter from the outside of the bearing from entering the inside of the bearing.
[0015] (5) In any one of the rolling bearings (1) to (4) above, the adhesive member is provided within a range that passes through the side surface of the outer annular portion and does not cross a virtual plane perpendicular to the bearing center line. With this configuration, it becomes possible to prevent the adhesive member from touching the shield plate. An increase in the rotational resistance of the rolling bearing is prevented.
[0016] <Details of the Embodiment> Hereinafter, preferred embodiments will be described with reference to the drawings. 〔Overall Configuration of the Rolling Bearing〕 FIG. 1 is a cross-sectional view showing an embodiment of a rolling bearing. The rolling bearing 10 shown in FIG. 1 has an outer ring 11, an inner ring 12, a plurality of balls (rolling elements) 13, and a cage 14. In the case of this embodiment, the inner ring 12 rotates about the center line C of the rolling bearing 10.
[0017] The definitions of each direction of the rolling bearing 10 will be described. The direction along the center line C of the rolling bearing 10 and the direction parallel to the center line C are the axial directions of the rolling bearing 10, simply referred to as the "axial direction". The direction perpendicular to the center line C is the radial direction of the rolling bearing 10, simply referred to as the "radial direction". The direction along a circle centered on the center line C is the circumferential direction of the rolling bearing 10, simply referred to as the "circumferential direction". The circumferential direction is the rotational direction of the inner ring 12.
[0018] The region between the outer ring 11 and the inner ring 12 where the balls 13, which are rolling elements, exist is the inside of the rolling bearing 10 (hereinafter, also referred to as the "bearing inside"). The side (direction) from the inside (the lower side in FIG. 1) to the outside (the upper side in FIG. 1) of the rolling bearing 10 is the axially outer side (axially outward). The side (direction) from the outside (the upper side in FIG. 1) to the inside (the lower side in FIG. 1) of the rolling bearing 10 is the axially inner side (axially inward).
[0019] The outer ring 11 is cylindrical. The outer ring 11 has a raceway surface 11a and shoulders 11b on its inner circumference. The raceway surface 11a is the surface on which the balls 13 rollingly contact. The raceway surface 11a is a surface with a cross-sectional arc shape that is recessed outward in the radial direction. The shoulders 11b are located on both axial sides of the raceway surface 11a. The inner circumferential surface of the shoulder 11b is a cylindrical surface centered on the center line C.
[0020] The inner ring 12 is located radially inward of the outer ring 11. The inner ring 12 is cylindrical. The outer circumferential surface of the inner ring 12 has a raceway surface 12a and shoulders 12b. The raceway surface 12a is the surface on which the balls 13 rollingly contact. The raceway surface 12a is a surface with a cross-sectional arc shape that is recessed inward in the radial direction. The shoulders 12b are located on both axial sides of the raceway surface 12a. The shoulders 12b of the inner ring 12 are located opposite to the shoulders 11b of the outer ring 11. The outer circumferential surface of the shoulder 12b is a cylindrical surface centered on the center line C. The outer circumferential surface of the shoulder 12b on the outer axial side of the inner ring 12 extends axially outward beyond the side surface 11c on the outer axial side of the outer ring 11.
[0021] A plurality of balls 13 are arranged between the outer ring 11 and the inner ring 12. The balls 13 are arranged in a plurality along the circumferential direction in an annular space 15 formed between the outer ring 11 and the inner ring 12. The rolling bearing 10 disclosed in FIG. 1 has a configuration of a deep groove ball bearing. The cage 14 holds the plurality of balls 13 at intervals in the circumferential direction.
[0022] [[ID=X]] The rolling bearing 10 has an annular shield plate 20 and an annular slinger 30. The shield plate 20 and the slinger 30 are members for suppressing the intrusion of foreign matter into the bearing interior (annular space 15). The shield plate 20 is fixed to the inner circumferential surface of the outer ring 11 and is located at the outer axial end of the annular space 15. The slinger 30 is fixed to the outer circumferential surface of the inner ring 12. The slinger 30 is located adjacent to the outer axial side of the shield plate 20 and the side surface 11c of the outer ring 11.
[0023] 〔Configuration of the shield plate 20〕 The shield plate 20 faces the outer surface of the shoulder 12b of the inner ring 12 with a gap (the first gap S1 described later) between them. The specific configuration of the shield plate 20 will now be explained. The shield plate 20 has a first cylindrical portion 21, a first annular portion 22, and a second cylindrical portion 23. The first cylindrical portion 21, the first annular portion 22, and the second cylindrical portion 23 are connected and form a single unit. The first cylindrical portion 21 is cylindrical in shape. The first cylindrical portion 21 is press-fitted and fixed onto the axially outer shoulder 11b of the outer ring 11. The first annular portion 22 is annular in shape. The first annular portion 22 extends radially inward from the axially outer end 211 of the first cylindrical portion 21. The axially outer side surface 22a of the first annular portion 22 is positioned substantially flush with the side surface 11c of the outer ring 11.
[0024] The second cylindrical portion 23 is cylindrical in shape. The second cylindrical portion 23 extends axially inward from the radially inner end 221 of the first annular portion 22 along the shoulder 12b of the inner ring 12. In this embodiment, the axial length of the second cylindrical portion 23 is shorter than the axial length of the first cylindrical portion 21. However, the axial length of the second cylindrical portion 23 may be greater than or equal to the axial length of the first cylindrical portion 21. The inner circumferential surface 23a of the second cylindrical portion 23 faces the shoulder 12b of the inner ring 12 with a small gap between them.
[0025] [Slinger 30 configuration] The slinger 30 has an inner cylindrical portion 31, an inner annular portion 32, an outer cylindrical portion 33, and an outer annular portion 34. The inner cylindrical portion 31, the inner annular portion 32, the outer cylindrical portion 33, and the outer annular portion 34 are connected and form a single unit.
[0026] The inner cylindrical portion 31 is cylindrical in shape. The inner cylindrical portion 31 is press-fitted and fixed to the outer circumferential surface of the axially outer shoulder 12b of the inner ring 12. The inner annular portion 32 is circular. The inner annular portion 32 extends radially outward from the axial outer end 311 of the inner cylindrical portion 31. The radial length of the inner annular portion 32 is shorter than the axial length of the inner cylindrical portion 31.
[0027] The outer cylindrical portion 33 is substantially cylindrical. The outer cylindrical portion 33 extends axially inward from the radially outer end 321 of the inner annular portion 32. The outer cylindrical portion 33 is inclined radially outward as it extends axially inward from the radially outer end 321 of the inner annular portion 32. The outer cylindrical portion 33 extends from the radially outer end 321 of the inner annular portion 32 toward the radially inner end 111 of the side surface 11c of the outer ring 11.
[0028] The outer annular portion 34 is circular. The outer annular portion 34 extends straight radially outward from the axial inner end 331 of the outer cylindrical portion 33 in a direction perpendicular to the center line C. The outer annular portion 34 extends from the axial inner end 331 of the outer cylindrical portion 33 along the side surface 11c of the outer ring 11 to the vicinity of the radial outer end 112 of the side surface 11c. The radial outer end 341 of the outer annular portion 34 is located radially outward from the inner circumferential surface of the shoulder 11b of the outer ring 11. The side surface 34a of the outer annular portion 34 is provided in the same plane as a virtual plane Q perpendicular to the center line C, and substantially over its entirety, it faces the side surface 11c of the outer ring 11 in the axial direction with a gap (the second gap S2 described later) between them. The axially inner side surface 34a of the outer annular portion 34 is flush with the axially inner side surface 31a of the inner cylindrical portion 31.
[0029] [Labyrinth gap] The inner diameter D23 of the second cylindrical portion 23 of the shield plate 20 is slightly larger than the outer diameter D12 of the inner ring 12. The inner circumferential surface 23a of the second cylindrical portion 23 faces the shoulder 12b of the inner ring 12 with a small gap between them. This small gap is the first gap S1. The side surface 34a of the outer ring portion 34 of the slinger 30 faces the side surface 11c of the outer ring 11 with a small gap between them. This small gap is the second gap S2. The first gap S1 and the second gap S2 are connected. The first gap S1 and the second gap S2 form a labyrinth gap S. The labyrinth gap S prevents foreign matter from outside the bearing from entering the bearing.
[0030] The second gap S2, which forms part of the labyrinth gap S, extends to the vicinity of the radially outer end 112 of the side surface 11c of the outer ring 11. This increases the radial distance L from the radially outer opening of the second gap S2 to the first gap S1, i.e., the radial length L of the foreign matter intrusion path of the labyrinth gap S. As a result, the effect of suppressing the intrusion of foreign matter into the bearing interior is enhanced.
[0031] As the aforementioned entry path length L increases, the slinger 30 becomes longer in the radial direction. The slinger 30 has a bent portion 35 with a substantially U-shaped cross-section, formed by an inner cylindrical portion 31, an inner annular portion 32, and an outer cylindrical portion 33. This bent portion 35 increases the rigidity of the slinger 30 compared to the case where the slinger 30 has an annular shape that extends straight in the radial direction. When assembling the slinger 30 to the inner ring 12, it is possible to suppress the tilting of the slinger 30 with respect to the radial direction. As a result, the slinger 30 is less likely to come into contact with other surrounding parts, preventing an increase in the rotational torque of the rolling bearing 10.
[0032] As described above, the outer cylindrical portion 33 of the slinger 30 is inclined radially outward as it extends axially inward. Therefore, compared to the case where the outer cylindrical portion 33 extends straight in the axial direction, when the slinger 30 is press-fitted onto the outer circumferential surface of the inner ring 12, deformation of the slinger 30 can be suppressed so that the radially outer end portion 341 of the outer annular portion 34 bends axially outward. This prevents the second gap S2 from widening in the axial direction, and the effect of suppressing the intrusion of foreign matter through the labyrinth gap S is not reduced.
[0033] [Regarding the adhesive material 50] An adhesive member 50 is provided on the bent portion 35 of the slinger 30. In other words, the adhesive member 50 is provided in the space K surrounded by the inner cylindrical portion 31, the inner annular portion 32, and the outer cylindrical portion 33. Foreign matter may float around the rolling bearing 10 (outside the bearing), and even if this foreign matter enters the labyrinth gap S, some or all of it may be captured by the adhesive member 50 provided on the slinger 30. The amount of foreign matter passing through the labyrinth S is reduced by the amount captured by the adhesive member 50, thereby increasing the effect of suppressing the entry of foreign matter into the bearing.
[0034] The adhesive member 50 is provided within a range that does not extend axially inward from the virtual surface Q shown in Figure 1. The virtual surface Q is a virtual surface that passes through the side surface 34a which is the axially inward end of the outer annular portion 34 and is perpendicular to the center line C. The adhesive member 50 may be provided such that its axially inner surface 501 coincides with the virtual surface Q (see Figure 1), but as shown in Figure 2, the axially inner surface 501 of the adhesive member 50 may be located axially outward from the virtual surface Q.
[0035] If the adhesive member 50 is positioned such that its axially inner surface 501 coincides with the virtual surface Q, the axial distance between the adhesive member 50 and the labyrinth gap S (second gap S2) is small, making it easier to capture foreign matter passing through the labyrinth gap S. Furthermore, since the adhesive member 50 is separated from the shield plate 20 by the axial width of the labyrinth gap S (second gap S2), the adhesive member 50 is prevented from adhering to the shield plate 20. This prevents the adhesive member 50 from contacting both the slinger 30 and the shield plate 20, which would hinder the smooth transfer of the inner ring 12 relative to the outer ring 11 and thus prevent an increase in the rotational resistance (rotational torque) of the rolling bearing 10.
[0036] Figure 2 shows a modified example of Figure 1, and is a cross-sectional view showing how the adhesive member 50 is provided in the space K of the bent portion 35. The configuration, in which the surface 501 of the adhesive member 50 does not extend beyond the virtual surface Q, makes it possible to more reliably prevent the adhesive member 50 from touching the shield plate 20. As described above, the adhesive member 50 prevents an increase in the rotational resistance of the rolling bearing 10.
[0037] If we define "100% filling rate" as the case where the surface 501 of the adhesive member 50 coincides with the virtual surface Q, then Figure 2(A) shows the case of "80% filling rate". Figure 2(B) shows the case of "60% filling rate". It is preferable that the filling rate of the adhesive member 50 in space K is 50% or more.
[0038] To enhance the effect of preventing foreign matter from outside the bearing from entering the bearing, the adhesive member 50 may be further provided on at least a portion of the surface of the inner cylindrical portion 31 of the slinger 30, excluding the inner circumferential surface. For example, the adhesive member 50 may be provided on the side surface 34a of the outer annular portion 34. However, the adhesive member 50 located on the side surface 34a is not in contact with the outer ring 11 (side surface 11c). This is to prevent the rotational resistance (rotational torque) of the rolling bearing 10 from increasing due to the adhesive member 50 contacting both the side surface 34a and the outer ring 11, which would create resistance that hinders relative rotation between the inner and outer rings.
[0039] The adhesive member 50 may be a petrochemical substance such as grease or oil, or it may be a silicone-based adhesive.
[0040] If the adhesive member 50 is grease, that grease may be the same type used as a lubricant for the rolling bearing 10, or it may have different properties than the grease used as a lubricant for the rolling bearing 10. The grease used as the adhesive member 50 is preferably relatively hard, with a consistency of No. 2 or higher, and may also be No. 3. The kinematic viscosity of the base oil contained in the grease is preferably 80 mm² / s (40°C) or higher. The upper limit is 180 mm² / s (40°C) or lower. The kinematic viscosity is determined based on JIS K2283:2000. This type of grease provides the adhesive properties of the adhesive member 50 against foreign matter, and also prevents the adhesive member 50 from scattering radially outward due to centrifugal force even when the rolling bearing 10 rotates.
[0041] If the adhesive member 50 is oil, its viscosity index is preferably 100 or higher. Its upper limit is 200 or lower. The viscosity index is determined based on JIS K2283:2000. This type of oil provides the adhesive properties of the adhesive member 50 against foreign matter, and also prevents the adhesive member 50 from scattering radially outward due to centrifugal force even when the rolling bearing 10 rotates.
[0042] When the adhesive member 50 is a silicone-based adhesive, a configuration is obtained in which the adhesive member 50 is less likely to flow even when the rolling bearing 10 rotates. For this reason, the silicone-based adhesive used as the adhesive member 50 is preferably highly adhesive, and its adhesive strength is preferably 1 N / mm or more. Furthermore, its upper limit is 5 N / mm or less. This adhesive provides the adhesive properties of the adhesive member 50 against foreign matter, and also prevents the adhesive member 50 from scattering radially outward due to centrifugal force even when the rolling bearing 10 rotates.
[0043] If the adhesive member 50 is grease or oil, it is preferable that its flash point be 280°C or higher. The operating temperature range for the rolling bearing 10 is from 0°C to 70°C. Therefore, when the adhesive member 50 is grease, oil, or a silicone-based adhesive, it is preferable that its pour point or dropping point is 80°C or higher. With this configuration, the grease, oil, or silicone-based adhesive is less likely to soften, and even when the rolling bearing 10 rotates, the adhesive member 50 is less likely to be scattered radially outward by centrifugal force.
[0044] 〔others〕 The embodiments disclosed are illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments described above and includes all modifications within the scope equivalent to the configurations described in the claims. [Explanation of Symbols]
[0045] 10 Rolling bearings 11 Outer ring 11c side 12 Inner Ring 13 Balls (rolling elements) 20 Shielding plate 30 Slinger 31 Inner cylindrical part 32 Inner annular section 33 Outer cylindrical part 34 Outer annular portion 34a side 50 Adhesive material K space C Bearing centerline Q Virtual surface S1 First gap S2 Second gap
Claims
1. Insider, Outer ring and, A plurality of rolling elements are arranged between the inner ring and the outer ring, An annular shield plate fixed to the inner circumferential surface of the outer ring and facing the outer circumferential surface of the inner ring with a first gap between them, It has an annular slinger located adjacent to the shield plate in the axial direction and fixed to the outer circumferential surface of the inner ring, The aforementioned slinger is The inner cylindrical portion is press-fitted onto the outer circumferential surface of the inner ring, An inner annular portion extending radially outward from the axial end of the inner cylindrical portion, An outer cylindrical portion extending axially from the radially outer end of the inner annular portion, It has an outer annular portion that extends radially outward from the axial end of the outer cylindrical portion and has a side surface that faces the side surface of the outer ring with a second gap between them, An adhesive member is provided in the space enclosed by the inner cylindrical portion, the inner annular portion, and the outer cylindrical portion. Rolling bearings.
2. The rolling bearing according to claim 1, wherein the adhesive member is grease.
3. The rolling bearing according to claim 1, wherein the adhesive member is a silicone-based adhesive.
4. The adhesive member is provided in a range that passes through the side surface of the outer annular portion and does not exceed a virtual plane perpendicular to the bearing centerline. A rolling bearing according to claim 1.
5. The rolling bearing according to claim 1, wherein an adhesive member is provided on the side surface of the outer ring portion.