KR20240022519A - bearing with seal - Google Patents

Abstract

A bearing having a seal capable of maintaining a fluid lubricated state between the seal sliding surface (11) and the seal lip (10) of the seal member (2) by the plurality of protrusions (12) of the seal lip (10), wherein the seal lip In order to achieve both the molding of (10) and making the gap 13 between the projections 12 smaller, the projections 12 have a cross section perpendicular to the seal sliding surface 11 and along the circumferential direction. It is provided to have a convex arc-shaped surface with a radius of curvature (R) of 0.009 mm or more and less than 0.15 mm, and the circumferential pitch (P) between the protrusions 12 adjacent to each other in the circumferential direction is provided to be 0.010 mm or more and less than 0.3 mm. there is.

Description

bearing with seal

This invention relates to a rolling bearing and a bearing with a seal including a seal member.

To prevent premature failure of rolling bearings, seal members are used. For example, since foreign substances such as gear wear powder are mixed in transmissions mounted on vehicles such as automobiles and various construction machines, the seal member prevents wear powder etc. from entering the bearing interior.

Generally, a seal member has a seal lip formed in an annular shape from an elastic material such as a rubber-like material. A seal sliding surface that is in sliding contact with the seal lip is formed on a mating part, such as a raceway or a slinger, that rotates relative to the seal member in the circumferential direction as the bearing rotates.

In a general seal member, the seal lip and the seal sliding surface are in sliding contact around the entire circumference, and microscopically follow the boundary lubrication to mixed lubrication region. The drag resistance (seal torque) of the seal lip causes an increase in bearing torque. Additionally, the sliding contact becomes one of the causes of the temperature rise of the rolling bearing. In addition, since the inside of the bearing is blocked from the outside by a seal member, the pressure difference between the inside and outside of the bearing creates an adsorption effect in which the seal lip is pressed against the seal sliding surface, and the seal torque may increase. From these reasons, there is a limit to the high-speed operation of the bearing with general seal members.

By arranging the seal lip of the seal member in a non-contact manner with the mating part and forming a labyrinth seal, it is possible to eliminate the sealing torque, but it is not possible to prevent the intrusion of foreign matter of a given lip diameter relative to the size of the gap between the seal member and the mating part. It is difficult to manage various possible errors.

In contrast, the seal lip has a plurality of protrusions arranged in the circumferential direction, and these plural protrusions create a gap that communicates between the inside and the outside of the bearing through adjacent protrusions in the circumferential direction, and as the bearing rotates, the protrusion and the protrusion form the gap. A bearing having a seal that can maintain fluid lubrication between the seal lip and the seal sliding surface by an oil film of lubricating oil drawn between the seal sliding surfaces has been proposed (Patent Document 1).

The bearing with the seal of Patent Document 1 lubricates the lubricant on the seal sliding surface by allowing the lubricant to flow between the inner space and the outside of the rolling bearing through a gap that can prevent the intrusion of foreign matter of a predetermined particle size, The wedge effect when lubricating oil is drawn between the projections and the seal sliding surface as the bearing rotates creates a thick oil film, completely separating each projection and the seal sliding surface with an oil film, creating a fluid lubrication between the seal lip and the seal sliding surface. can do. For this reason, according to the bearing with the seal of Patent Document 1, it is possible to cope with high-speed operation of the bearing while preventing the intrusion of foreign matter of a predetermined particle size, and the seal torque can be significantly reduced.

In particular, in the bearing having the seal of Patent Document 1, the protrusion of the seal lip has a convex arc-shaped surface that is perpendicular to the seal sliding surface and has a radius of curvature of 0.15 mm or more and less than 2.0 mm in the cross section along the circumferential direction, and the protrusion of the protrusion The height is 0.07 mm or less, and the circumferential pitch between adjacent protrusions in the circumferential direction is 0.3 to 2.6 mm. By adopting the dimensions of these projections, it is possible to realize the above-mentioned fluid lubrication state, while manufacturing the mold for forming the seal lip is not difficult, that is, the transfer surface of the projection can be formed using general ball end mill processing during mold processing. It is possible to form

Patent Document 1: Japanese Patent Publication No. 2017-161069

In the bearing with the seal of Patent Document 1, while the processability of the mold for forming the seal lip is excellent, there is a limit to reducing the gap because the size of the protrusion is limited.

However, in the future, it is expected that the requirements for energy saving and environmental load reduction for rolling bearings will become more stringent, so there is a possibility that bearings with the seal of Patent Document 1 will be at a disadvantage in meeting these requirements. For example, when machine oil is supplied as lubricant from outside the bearing, there is a possibility that sufficient measures cannot be taken to reduce the stirring resistance by suppressing the inflow of excess lubricant from the gap. In addition, there is a possibility that sufficient measures cannot be taken to suppress the intrusion of foreign substances with smaller particle diameters and to extend the life of machine oil or grease encapsulated inside bearings.

In view of the above-mentioned background, the problem to be solved by this invention is a bearing having a seal capable of maintaining a fluid lubricated state between the seal sliding surface and the seal lip of the seal member by a plurality of protrusions of the seal lip, the seal The goal is to achieve both lip shaping and reducing the gap between the protrusions.

In order to achieve the above object, the present invention is provided with a seal member that seals the internal space of the rolling bearing against the outside, and a seal sliding surface that slides in the circumferential direction with respect to the seal member, wherein the seal member is made of an elastic material. It has a seal lip formed in an annular shape, wherein the seal lip has a plurality of protrusions arranged in a circumferential direction, and the plurality of protrusions create a gap between the protrusions adjacent to each other in the circumferential direction, and also as the bearing rotates. In a bearing having a seal formed in a manner that allows fluid lubrication between the seal lip and the seal sliding surface by an oil film of lubricating oil drawn between the protrusion and the seal sliding surface from the gap, the protrusion is: It is provided to have a convex arc-shaped surface orthogonal to the seal sliding surface and has a radius of curvature of 0.009 mm or more and less than 0.15 mm in a cross section along the circumferential direction, and the circumferential pitch between the protrusions adjacent in the circumferential direction is 0.010 mm or more. A configuration that provides a thickness of less than 0.3 mm was adopted.

As in the above configuration, if the radius of curvature of the convex arc shape of the projections is 0.009 mm or more and the circumferential pitch between the projections is 0.010 mm or more, it is possible to form a transfer surface of the projections on the mold using laser processing. , the seal lip can be formed. Additionally, if the radius of curvature of the convex arc shape of the protrusions is less than 0.15 mm and the circumferential pitch between the protrusions is less than 0.3 mm, it is possible to make the gap between the protrusions smaller.

Specifically, the protrusion may extend in a direction perpendicular to the circumferential direction. In this way, even if the curvature radius and circumferential pitch are small as described above, each projection can be prepared with the same precision.

Additionally, the height of the protrusion may be provided to be less than 0.05 mm. Within the range of the curvature radius and circumferential pitch of the protrusions described above, it is possible to set the height of the protrusions to less than 0.05 mm, and thereby the gap between the protrusions can be made small, especially in the height direction of the protrusions.

For example, the seal lip is formed of a rubber material.

Bearings with seals according to the present invention are used, for example, for vehicle motors, transmissions, differentials, constant velocity joints, propeller shafts, turbochargers, machine tools, wind power generators, wheel bearings, and for supporting rotating parts of any one of electric vertical takeoff and landing machines. It is suitable for use.

This invention relates to a bearing having a seal capable of maintaining a fluid lubricated state between the seal sliding surface and the seal lip of the seal member by employing the above-mentioned configuration by a plurality of protrusions of the seal lip, comprising forming the seal lip and forming the protrusion. Both can be achieved by making the gap between them smaller.

1 is a cross-sectional view showing a bearing with a seal according to an embodiment of the present invention.
FIG. 2 is an enlarged side view showing a part of the side surface on the inner space side of the seal lip in FIG. 1 in its natural state.
FIG. 3 is a cross-sectional view showing the protrusion of FIG. 1 sliding on the seal sliding surface.
4 is a graph showing the rotational torque of various specifications of bearings with seals according to embodiments.

As an example of this invention, a bearing with a seal according to an embodiment will be described based on FIGS. 1 to 4 of the accompanying drawings.

The bearing with this seal shown in FIG. 1 includes a rolling bearing 1 and two seal members 2 disposed on both sides of the rolling bearing 1.

The rolling bearing 1 holds an inner ring 3, an outer ring 4, a plurality of rolling elements 5 interposed between the inner ring 3 and the outer ring 4, and a plurality of rolling elements 5. It consists of a retainer (6) that does. The seal member 2 seals the internal space 7 of the rolling bearing 1 against the outside. The purpose of this sealing is to prevent premature damage to the rolling bearing (1) by suppressing foreign matter surrounding the bearing having this seal from entering the internal space (7) between the inner and outer rings (3, 4). , the internal space 7 is not sealed liquid-tightly.

The inner ring (3) and the outer ring (4) have a raceway surface corresponding to the rolling element (5). The inner ring 3 is attached to the rotating shaft S and rotates integrally with the rotating shaft S. The outer ring 4 is attached to a member that applies a load from the rotating shaft, such as a housing or gear. The rolling element (5) rotates while interposed between the inner ring (3) and the outer ring (4).

As the rolling element 5, a ball is adopted. The bearing with this seal is a deep groove ball bearing.

The internal space 7 is lubricated by lubricating oil (not shown; hereinafter the same applies) supplied from the outside. Examples of the lubrication method include a splash method in which lubricating oil is sprayed onto a bearing with a seal, or an oil bath method in which the lower part of a bearing with a seal is immersed in an oil bath. As an initial lubricant, an appropriate amount of grease may be sealed in the internal space 7. Additionally, a grease lubrication method may be used in which the base oil of the grease enclosed in the internal space 7 is used as a lubricant, and lubrication is performed only with this lubricant.

The rotation shaft S is, for example, a rotating part provided in any one of vehicle motors, transmissions, differentials, constant velocity joints, propeller shafts, turbochargers, machine tools, wind power generators, wheel bearings, and vertical electric takeoff and landing machines.

In addition, hereinafter, the direction along the bearing central axis (not shown, hereinafter the same applies) of a bearing with a seal is referred to as the “axial direction.” The direction perpendicular to the axial direction is called the “radial direction.” The direction along the circumference of the bearing's central axis is called the “circumferential direction.” In Fig. 1, the bearing central axis is the central axis of the inner ring 3, which serves as a rotating wheel. Figure 1 shows a cross-section of an imaginary plane containing the bearing central axis. The axial direction corresponds to the left-right direction in Figure 1, and the radial direction corresponds to the up-down direction in Figures 1 and 3.

A seal groove 8 for holding the seal member 2 is formed at the end of the inner circumference of the outer ring 4. The seal member 2 is attached to the outer ring 4 by pressing its outer peripheral edge into the seal groove 8.

Outside surrounding the bearing with this seal, foreign substances such as gear wear, clutch wear, fine crushed stone, etc. exist in the assembly area of the bearing with this seal. Such powder-like foreign matter may reach the vicinity of the seal member 2 depending on the flow of lubricating oil or atmosphere. The seal member 2 is for suppressing foreign matter from entering the internal space 7 from the outside.

The seal member 2 has a core 9 made of a metal plate and a seal lip 10 formed in an annular shape. The core metal 9 is a press-processed part formed into an annular shape continuous in the circumferential direction.

The seal lip 10 is formed of an elastic material. Examples of elastic materials include vulcanization molded rubber materials and elastic polymers equivalent to rubber materials. Examples of rubber materials include nitrile rubber (NBR), acrylic rubber (ACM), and fluorine rubber (FKM).

On the outer periphery of the inner ring 3, a seal sliding surface 11 is formed that slides in the circumferential direction with respect to the seal lip 10. The seal sliding surface 11 has a cylindrical surface shape that is continuous around the entire circumferential direction.

The seal lip 10 has a waist portion formed in an annular shape that is continuous in the radial direction with a constant width, and a head portion formed in a protruding piece shape that bends outward from the waist portion. The seal lip 10 in the example shown is a radial lip. Here, the radial lip is a seal lip that exerts a sealing action with a seal sliding surface along the axial direction or a seal sliding surface having an acute angle gradient of less than 45° with respect to the axial direction, and has a diameter between the seal sliding surface and the seal sliding surface. This refers to having a fastening margin in the direction.

Figure 2 shows the shape of the seal lip 10 when it is in its natural state (shape at the time of molding) as seen from the side, and Figure 3 shows the seal lip 10 of Figure 1 perpendicular to the seal sliding surface 11. It also represents a cross section cut along the circumferential direction.

The head of the seal lip 10 has a leading edge that defines the inner diameter of the seal lip 10 in the state shown in FIG. 2. When the seal member 2 is attached to the predetermined arrangement in FIG. 1, the seal lip 10 is pressed against the seal sliding surface 11 by the fastening allowance to the seal sliding surface 11, as shown in FIG. Likewise, deformation of the rubber-like elastic bent outward occurs, creating a tightening force of the seal lip 10. Errors in attachment and manufacturing of the seal member 2 are absorbed by changes in the bending state of the seal lip 10.

As shown in Figs. 2 and 3, the seal lip 10 has a plurality of protrusions 12 arranged in the circumferential direction. The protrusion 12 extends in a direction perpendicular to the circumferential direction over its entire length. The protrusions 12 are arranged at a constant pitch P in the circumferential direction. The entire length of the protrusion 12 extends over the entire range having a radial fastening allowance between it and the seal sliding surface 11. The overall shape of the seal lip 10 is rotationally symmetrical corresponding to the pitch of the projections 12.

In the state shown in FIG. 2, the protrusion 12 extends in a direction along the radial straight line Lr. Accordingly, the plurality of protrusions 12 extend radially with the radial center on the bearing central axis.

The protrusion 12 has a convex arc-shaped surface with a radius of curvature R of 0.009 mm or more and less than 0.15 mm in a cross section as shown in FIG. 3. Additionally, in reality, very slight elastic deformation of the projection 12 occurs due to the above-described tension force, but since it is negligible, Figure 3 shows the cross-sectional shape of the projection 12 during molding.

The circumferential pitch P between the protrusions 12 adjacent to each other in the circumferential direction is set to be 0.010 mm or more and less than 0.3 mm.

The height of the protrusion 12 is set to less than 0.05 mm. The height of the projection 12 is constant over its entire length. When the above-mentioned circumferential pitch (P) is in the range of 0.010 mm to less than 0.3 mm, and the radius of curvature (R) is in the range of 0.009 mm to less than 0.15 mm, the height of the protrusion 12 can be set to less than 0.05 mm. . It is believed that if large foreign matter exceeding 0.05 mm in particle size intrudes into the internal space 7, it will have a negative effect on the bearing life. If the height of the projection 12 is set to 0.07 mm or less, it is possible to create a gap 13 through which such large foreign matter cannot easily pass, but by setting the height of the projection 12 to less than 0.05 mm, Foreign matter with a smaller particle size can be prevented from easily passing through the gap 13, and it is also possible to further prevent external lubricating oil from flowing into the internal space 7 through the gap 13.

When attaching the seal member 2 to the rolling bearing 1 as shown in FIG. 1, the top portions of each of the plurality of projections 12 contact the seal sliding surface 11. As shown in FIG. 3, the protrusion 12 has a height in a direction perpendicular to the seal sliding surface 11, and therefore resists the tightening force of the seal lip 10. As a result, a gap 13 communicating with the internal space 7 and the outside is created between the protrusions 12 adjacent to each other in the circumferential direction and between the seal sliding surface 11 and the seal lip 10. The seal lip 10 slides with the seal sliding surface 11 only on the plurality of protrusions 12, and the lip portion connecting the protrusions 12 adjacent to each other in the circumferential direction is in non-contact with the seal sliding surface 11. It is meant to be maintained as is.

The protrusion 12 forms a wedge-shaped gap between the seal sliding surface 11 and the seal sliding surface 11, which is large on the gap 13 side and small on the protrusion 12 side. Additionally, the protrusion 12 has an area substantially along the seal sliding surface 11 on the virtual plane shown in FIG. 1 . This region exists with a width in the direction along the seal sliding surface 11 (corresponding to the axial direction in the illustrated example). For this reason, the sliding portion of the protrusion 12 and the seal sliding surface 11 due to the rotation of the bearing, that is, the protrusion 12 draws the lubricating oil in the gap 13 in the circumferential direction between the seal sliding surface 11 and the seal sliding surface 11. The formation of an oil film is promoted by the wedge effect when inserting, and the area where the oil film is interposed between the protrusion 12 and the seal sliding surface 11 is located in the direction along the seal sliding surface 11 on the above-mentioned virtual plane. It occurs with a finite length (La) of a certain length or more. Since the sliding portion of the protrusion 12 and the seal sliding surface 11 is considered to be formed in a contact elliptical shape based on Hertz's elastic contact theory, the major axis of the contact elliptical shape corresponds to the finite length La.

When the bearing rotation stops, the top of the protrusion 12 is pressed against the seal sliding surface 11 by the tightening force of the seal lip 10, as described above. For this reason, the solid contact area with the seal sliding surface 11 is distributed over the entire top of the projection 12.

When the bearing rotation starts from the stopped state, the protrusion 12 and the seal sliding surface 11 rotate relative to each other in the circumferential direction. Here, the circumferential direction in which the lubricant is drawn by rotating the seal sliding surface 11 relative to the protrusion 12 is assumed to be the direction indicated by the arrow line A in FIG. 3. In the sliding portion of the protrusion 12 and the seal sliding surface 11, the lubricating oil is drawn into the wedge-shaped gap between the protrusion 12 and the seal sliding surface 11 (the flow of lubricating oil is conceptually shown in FIG. (represented as ). At this time, the convex arc-shaped surface of the above-described protrusion 12 prevents the oil film from being confined by the protrusion 12, and oil film formation is effectively promoted by the wedge effect.

When the peripheral speed of relative rotation between the seal lip 10 and the seal sliding surface 11 is less than a certain level, a boundary lubrication state or a mixed lubrication state is reached microscopically. When the bearing rotation becomes faster and the peripheral speed of the relative rotation of the protrusion (12) and the seal sliding surface (11) becomes more than a certain level, the oil film thickness between the protrusion (12) and the seal sliding surface (11) is equal to that of the protrusion (12) and the seal sliding surface (11). The composite roughness σ between the sliding surfaces 11 is easily exceeded, and each protrusion 12 and the seal sliding surface 11 are in a state of fluid lubrication completely separated by an oil film. As a result, a fluid lubrication state can be established in which the space between the seal lip 10 and the seal sliding surface 11 is completely separated by an oil film. In such a fluid lubrication state, the seal torque due to the seal member 2 is reduced to the same level as that of the non-contact type seal, and further, the temperature rise of the bearing with the seal is suppressed, and the adsorption action of the seal lip 10 is prevented. You can.

Here, if the oil film parameter (Λ) ≥ 3, the lubrication mode of the sliding portion is considered to be a fluid lubrication state. The oil film parameter (Λ) is the ratio of the synthetic roughness (σ) to the minimum oil film thickness (h) in the sliding portion, and Λ=h/σ. The minimum oil film thickness (h) is obtained based on elastic fluid lubrication theory. Composite roughness (σ)=√((Rq ₁ ² +Rq ₂ ² )/2). Rq ₁ is the root mean square roughness of the seal sliding surface 11 forming the above-described sliding portion. If Rq ₂ is the root mean square roughness on the surface of the protrusion 12, the root mean square roughness is the value (μm) of the root mean square roughness (Rq) specified in JIS (B0601: 2013).

The oil film parameter (Λ) depends on the synthetic roughness (σ), and the smaller the synthetic roughness (σ), the thicker the oil film can be. In order to keep the sliding portion of the protrusion 12 and the seal sliding surface 11 in a fluid lubricated state from the above-described extremely low peripheral speed, it is desirable to make the resulting roughness σ in the sliding portion as small as possible.

For example, the composite roughness (σ) is 0.22 μm, the radius of curvature (R) of the convex arc shape of the protrusion 12 is 0.009 mm, and the peripheral speed of relative rotation between the seal sliding surface 11 and the protrusion 12 is 1.4 m/. s, under the calculation conditions assuming that the lubricant was transmission oil (100°C), the minimum oil film thickness was 1.359 ㎛, and the oil film parameter (Λ) was 3 or more. In addition, if the viscosity parameter (gv) and elastic parameter (ge), which are dimensionless numbers determined by Greenwood-Johnson, are calculated under these calculation conditions, the viscosity parameter (gv) is 1.59E-03 and the elastic parameter (ge) is 2.41. E-01, and when the oil lubrication mode was determined based on the lubrication region diagram (Johnson chart), it corresponded to the isoviscosity-rigid body region (R-I mode), so it is considered to be in a fluid lubrication state.

Additionally, the radius of curvature (R) of the protrusion 12 shown in FIG. 3 is changed in the range of 0.009 mm to less than 0.15 mm, and the number of the plurality of protrusions 12 is changed to change the circumference of the protrusion 12 shown in FIG. 2. In various specifications in which the direction pitch (P) was changed in the range of 0.010 mm or more and less than 0.3 mm, the rotational torque of the bearing with the seal was actually measured. The results are shown in Figure 4.

Here, among seal specifications A to C according to the embodiment, seal specification A has a relatively large radius of curvature (R) and a relatively small circumferential pitch (P) compared to seal specification B. In addition, seal specification B, compared to seal specification A, has a relatively small radius of curvature (R) and a relatively large circumferential pitch (P). In addition, seal specification C makes the radius of curvature (R) relatively small and the circumferential pitch (P) equal compared to seal specification A, and makes the circumferential pitch (P) relatively small compared to seal specification B. It was done. Additionally, in seal specifications A to C, the height of the protrusion 12 is set to less than 0.05 mm.

As shown in Fig. 4, the rotational torques of seal specifications A to C are all clearly smaller than those of conventional contact seals, and are almost the same as those of conventional non-contact seals. That is, the radius of curvature (R) of the above-described protrusion 12 is 0.009 mm or more and less than 0.15 mm, the above-described circumferential pitch (P) is 0.010 mm or more and less than 0.3 mm, and the height of the protrusion 12 is less than 0.05 mm. It has been suggested that a fluid lubrication state can be achieved even if the size of the radius of curvature (R) and the size of the circumferential pitch (P) are changed within this range.

If the circumferential pitch (P) of the projections 12 shown in FIG. 2 is less than 0.3 mm and the radius of curvature (R) shown in FIG. 3 is less than 0.15 mm, the transfer surface for forming the projections 12 is ball end milled. It cannot be formed with a mold. If the radius of curvature (R) is 0.009 mm or more and the circumferential pitch (P) is 0.010 mm or more, the transfer surface can be formed into a mold by laser processing. For example, when using a femtosecond laser processing machine, the pulse width is as short as femtoseconds, and the ablation effect of the workpiece (surface portion of the mold) in the meantime allows accurate removal processing of about 10 ㎛ without heat influence. For this reason, thermal damage is not inflicted on the transfer surface of the protrusion 12, and since no tool for removal processing is used, a fine pattern of about 10 μm is formed without burrs or droops. Therefore, the dimensional accuracy and surface roughness of each protrusion 12 can be adjusted to a level that does not interfere with the realization of a fluid lubrication state.

As described above, the bearing with this seal shown in FIGS. 1 to 3 has a seal member 2 that seals the internal space 7 of the rolling bearing 1 against the outside, and a seal member 2 with respect to the seal member 2. It has a seal sliding surface 11 that slides in the circumferential direction, and the seal member 2 has a seal lip 10 formed in an annular shape by an elastic material, and the seal lip 10 has a plurality of protrusions arranged in the circumferential direction ( 12), a plurality of protrusions 12 create a gap 13 between adjacent protrusions 12 in the circumferential direction, and as the bearing rotates, the protrusion 12 and the seal sliding surface are separated from the gap 13. 11) It is formed in a way that allows fluid lubrication between the seal lip 10 and the seal sliding surface 11 by an oil film of lubricating oil drawn between them, and the protrusion 12 is formed on the seal sliding surface 11. It is provided to have a convex arc-shaped surface with a radius of curvature of 0.009 mm or more and less than 0.15 mm in cross section along the circumferential direction, and the circumferential pitch (P) between the protrusions 12 adjacent in the circumferential direction is 0.010 mm or more. By being provided at less than 0.3 mm, it is possible to make the gap 13 smaller than that of Patent Document 1 while realizing molding of the seal lip 10 with a mold utilizing laser processing. For this reason, the bearing having this seal can achieve both the shaping of the seal lip 10 and making the gap 13 smaller, and further prevents the inflow of excess lubricating oil from the gap 13. By suppressing this, the stirring resistance within the internal space 7 can be reduced, and the intrusion of foreign matter with a smaller particle size can also be suppressed.

In addition, in a bearing with this seal, the projections 12 extend in a direction perpendicular to the circumferential direction, so that even if the radius of curvature R and the circumferential pitch P are small as described above, each projection 12 can be prepared with the same precision. That is, since the plurality of protrusions 12 are formed into a radial shape with a constant pitch, in laser processing, the transfer surface corresponding to each protrusion 12 is formed by the same linear removal process, so that precision can be uniformized. .

In addition, in the bearing with this seal, the height of the protrusion 12 is provided to be less than 0.05 mm, so that the gap 13 can be made small, especially in the height direction of the protrusion 12.

In the above-described embodiment, it is exemplified that the seal member is composed of a core metal and a vulcanized rubber material, but this invention can also be applied to a seal member containing an elastic material of a single material formed in a mold.

In addition, in the above-described embodiment, a radial lip is exemplified, but this invention can also be applied to a seal sliding surface having an inclination exceeding 45° with respect to the axial direction and a seal lip (axial lip) that exerts a sealing action. possible.

In addition, in the above-described embodiment, an inner ring rotating radial ball bearing is exemplified, but this invention can also be applied to appropriate types such as outer ring rotating bearings, thrust bearings, and roller bearings. In addition, although an example in which the seal sliding surface is formed on a rotating wheel is shown, this invention can also be applied when it is formed on a fixed wheel.

The embodiment disclosed this time should be considered in all respects as an example and not restrictive. Accordingly, the scope of the present invention is indicated by the claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the claims.

1: rolling bearing
2: Absence of seal
3: Inner ring
4: paddle
5: rolling element
7: Internal space
10: seal lip
11: Seal sliding surface
12: projection
13: gap

Claims (5)

It has a seal member that seals the internal space of the rolling bearing against the outside, and a seal sliding surface that slides in a circumferential direction with respect to the seal member,
The seal member has a seal lip formed annularly by an elastic material, the seal lip has a plurality of protrusions arranged in a circumferential direction, and the plurality of protrusions create a gap between the protrusions adjacent to each other in the circumferential direction. A bearing having a seal formed in a manner that allows fluid lubrication between the seal lip and the seal sliding surface by an oil film of lubricating oil drawn between the protrusion and the seal sliding surface from the gap as the bearing rotates. In
The protrusion is provided to have a convex arc-shaped surface that is perpendicular to the seal sliding surface and has a radius of curvature of 0.009 mm or more and less than 0.15 mm in a cross section along the circumferential direction,
A bearing with a seal, wherein the circumferential pitch between the protrusions adjacent to each other in the circumferential direction is provided at 0.010 mm or more and less than 0.3 mm. The bearing with a seal according to claim 1, wherein the protrusion extends in a direction perpendicular to the circumferential direction. The bearing with seal according to claim 1 or 2, wherein the height of the protrusion is provided to be less than 0.05 mm. The bearing according to any one of claims 1 to 3, wherein the seal lip is formed of a rubber material. The rotating part according to any one of claims 1 to 4, for use in vehicle motors, transmissions, differentials, constant velocity joints, propeller shafts, turbochargers, machine tools, wind power generators, wheel bearings, and electric vertical takeoff and landing machines. A bearing having a seal that supports.

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