JP2020159456A - Sealing device and rolling bearing - Google Patents

Abstract

To provide a sealing device capable of discharging foreign matter such as muddy water entering and adhering from the outside of a bearing, to return, to the inside of the bearing, grease sealed inside the bearing or lubricant separated from the grease, and provide a rolling bearing.SOLUTION: A sealing device comprises a seal member having a sealing part brought into sliding contact with a seal surface of a raceway ring or facing the seal surface at a predetermined interval, and seals a bearing space between a pair of raceway rings. On the seal surface, a water-repellent surface is provided on the inside of a bearing with respect to the seal part of the seal member. A surface-treated surface is formed in which the water-repellent surface is continuously reduced from the inside of the bearing toward the outside of the bearing.SELECTED DRAWING: Figure 1

Description

The present invention relates to sealing devices and rolling bearings.

Rolling bearings used in the rotary support of various machines and devices are used between a pair of raceway wheels in order to prevent leakage of grease to be sealed and foreign matter such as dust and water from the outside entering the bearing. A sealing device that seals the bearing space is attached.

Conventionally, a slinger or the like, which is a component of a sealing device, is provided with a water-repellent film (Patent Documents 1 and 2), and a surface treatment that imparts water repellency and oil repellency to the surface of the component of the sealing device is applied. There are those that have been applied (Patent Document 3) and the like.

That is, in Patent Document 1, the slinger is provided with an inclined portion that inclines toward the outer side of the bearing, and a water-repellent treatment film is also formed in this inclined portion. Therefore, even if water or the like tries to enter the inside of the bearing through this sealing device, it is swung off to the outside of the bearing along the inclined portion by centrifugal force, and the intrusion of water or the like into the inside of the bearing can be prevented.

In Patent Document 2, one or both of the fitting surface of the annular portion of the slinger with respect to the outer peripheral surface of the inner ring and the outer peripheral surface of the inner ring, and the fitting surface and the outer ring corresponding to the inner peripheral surface of the outer ring of the annular portion of the core metal. An uneven water-repellent coating is formed on either or both of the inner peripheral surfaces and at least one of them. This enhances the performance of preventing water from entering the bearing.

In Patent Document 3, the inner end portion of the sealing device, the facing surface of the inner ring facing the inner end portion, the inner surface of the groove of the outer ring to which the sealing device is attached, the outer end portion of the sealing device fitted in the groove, and the like are described. A surface treatment that imparts water repellency and oil repellency is applied. This makes it difficult for the lubricant to leak out and for foreign matter to enter.

Further, although not limited to the sealing device for rolling bearings, the contact area between the biofluid droplets and the substrate surface is reduced by forming a highly hydrophobic hydrophobic surface on the upper surface of the substrate, and two types of hydrophobic surfaces are combined. There is one that provides a microdroplet transport device that constructs a surface tension gradient in a hydrophobic region, thereby enabling biofluid transport (Patent Document 4).

JP-A-2002-408147 JP-A-2010-236622 Japanese Unexamined Patent Publication No. 2012-167765 Japanese Unexamined Patent Publication No. 2005-331410

In Patent Document 1, an inclined portion is provided that is swung off to the outside of the bearing by the centrifugal force generated during rotation. However, since the centrifugal force is not generated (acted) when the rotation is stopped, water or the like is provided to the outside of the bearing. Does not have a guide (do not shake) function. Therefore, if water or the like is splashed on the sealing device when the rotation is stopped, there is a risk that water or the like may enter the inside of the sealing device. Since it has an inclined portion, it has a function of returning the lubricating oil to the inside of the bearing when the rotation is stopped.

Further, Patent Document 2 and Patent Document 3 are not provided with an inclined portion having a function of guiding (not shaking) water or the like to the outside of the bearing like the sealing device described in Patent Document 1. Therefore, Patent Documents 2 and 3 do not have a function of returning the lubricating oil to the inside of the bearing and a function of blowing off water or the like.

The one described in Patent Document 4 makes it possible to transport a biological fluid containing a protein or the like in one direction, and does not have a function of returning lubricating oil to the inside of the bearing or a function of blowing off water or the like. ..

Therefore, in view of the above problems, the present invention discharges foreign matter such as muddy water that has entered or adhered from the outside of the bearing to the outside of the bearing, and returns the grease sealed inside the bearing or the lubricating oil degreased from the grease to the inside of the bearing. It is intended to provide a sealing device and a rolling bearing capable of capable.

The sealing device of the present invention includes a sealing member having a sealing portion that is in sliding contact with or facing the sealing surface of the raceway ring at a predetermined interval, and seals the bearing space between the pair of raceway wheels. A water-repellent surface is provided on the inner side of the bearing with respect to the seal portion of the seal member, and a surface-treated surface is formed in which the water-repellent surface continuously decreases from the inner side of the bearing to the outer side of the bearing.

According to the sealing device of the present invention, the water-repellent surface is provided on the inner side of the bearing, and the area of the water-repellent surface is reduced from the inner side of the bearing to the outer side of the bearing. The function is high, and the water-repellent function decreases from the inside of the bearing to the outside of the bearing. Therefore, water or the like easily flows from the inner side of the bearing to the outer side of the bearing. Further, the water-repellent surface on the inner side of the bearing of this surface-treated surface can be a water-repellent oil-repellent surface or a water-repellent oil-repellent surface. If it is water-repellent and oil-repellent, the lubricating oil can be repelled inside the bearing to prevent the lubricating oil from flowing out to the outside of the bearing. If the water-repellent surface is water-repellent oil-repellent oil, the lubricating oil that tries to flow out from the inside of the bearing collects on the water-repellent oil-repellent surface and goes to the outside of the bearing. The outflow can be prevented.

Further, the surface-treated surface includes a water-repellent oil-repellent treated surface on the inner side of the bearing, a hydrophilic oil-repellent treated surface on the outer side of the bearing, and a water-repellent oil-repellent treated surface and a hydrophilic oil-repellent treated surface at an intermediate portion thereof. It is preferable to form the surface with a mixed surface and reduce the area of the water-repellent oil-repellent oil-treated surface from the inside of the bearing to the outside of the bearing. Here, the water-repellent parent oil has the property of repelling water and adapting to oil, and the hydrophilic oil-repellent has the property of adapting to water and repelling oil.

With this configuration, the inner side of the bearing repels water and becomes compatible with oil, and the outer side of the bearing repels water and repels oil. Therefore, water or the like flows from the inside of the bearing toward the outside of the bearing, and oil flows from the outside of the bearing toward the inside of the bearing.

The water-repellent treated surface of the surface-treated surface can be a water-repellent oil-repellent treated surface or a water-repellent oil-repellent treated surface. Here, the water-repellent base oil has the property of repelling water and adapting to oil, and the water-repellent oil-repellent has the property of repelling both water and oil.

The surface-treated surface includes a first water-repellent surface on the inner side of the bearing, a second water-repellent surface on the outer side of the bearing, which has a smaller contact angle than the first water-repellent surface, and intermediate portions thereof. It is composed of a mixed surface of a first water-repellent treated surface and a second water-repellent treated surface, and reduces the area of the first water-repellent treated surface from the inner side of the bearing to the outer side of the bearing. May be good. When the solid surface is in contact with liquid and gas, the angle at which the liquid surface forms with the solid surface at the boundary line where the three phases are in contact is called the contact angle, and the state where the contact angle is 90 ° or less is called wet. The property of having a small contact angle is called hydrophilicity (adapting to water), and the property of having a large contact angle is called water repellency (adapting to oil). Particularly strong water repellency and hydrophilicity are called superhydrophobicity and superhydrophilicity.

Therefore, with such a configuration, the repelling of the water-repellent surface on the outer side of the bearing is worse than that on the inner side of the bearing. Therefore, water or the like easily flows from the inner side of the bearing to the outer side of the bearing.

The sealing member has a plurality of sealing portions, and the surface-treated surface is provided in a range from the innermost side of the bearing to the outermost side of the bearing than the outermost sealing portion of the bearing. It may be the one that exists. With such a configuration, water or the like can more easily flow from the inside of the bearing to the outside of the bearing.

Further, the sealing surface has a first surface parallel to the rotation surface, a second surface orthogonal to the rotation axis of the rotation axis, or a third surface inclined at a predetermined angle with a surface orthogonal to the rotation axis of the rotation axis. It is preferable that the third surface is arranged on the outer side of the bearing, the first surface is the surface-treated surface, and the second or third surface is the water-repellent surface.

With such a configuration, the water-repellent function is high on the inner side of the bearing on the first surface, and the water-repellent function is lowered from the inner side of the bearing on the first surface toward the outer side of the bearing. Therefore, on the first surface, water or the like easily flows from the inside of the bearing to the outside of the bearing. Further, since the second surface or the third surface is a water-repellent treated surface, these surfaces exhibit the property of repelling water. Therefore, it is possible to prevent water or the like from entering the bearing.

The rolling bearing of the present invention is a rolling bearing including an inner ring, an outer ring, a rolling element interposed between the inner ring and the outer ring, and a cage for holding the rolling element, and is a sealing device. To be equipped with.

In the present invention, even if water tries to enter the inside of the bearing from the outside of the bearing, the infiltration of the water into the bearing can be effectively prevented on the surface treatment surface. Further, regardless of whether the water-repellent surface on the inner side of the bearing of the surface-treated surface is a water-repellent oil-repellent surface or a water-repellent oil-repellent surface, it is possible to prevent the lubricating oil from flowing out to the outside of the bearing. Therefore, the sealing property of the sealing device can be improved and the leakage of the lubricating oil can be reduced, so that the life of the bearing can be effectively prevented from being shortened. That is, it is possible to provide a long-life, high-quality product (bearing).

It is sectional drawing of the main part of the rolling bearing using the sealing device which concerns on this invention. It is an enlarged view of the main part of a sealing device. It is a simplified development view of the surface treatment surface. It is a figure which shows the relationship between hydrophilic oil-repellent, hydrophilic parent oil, water-repellent oil-repellent, and water-repellent parent oil. It is a simplified development view of another surface-treated surface. It is a simplified development view of another surface-treated surface. It is a simplified development view of still another surface treatment surface. It is explanatory drawing of the contact angle. It is a figure which shows super hydrophilicity, hydrophilicity, water repellency, and the relationship between super hydrophilicity, super water repellency and a contact angle. It is an enlarged sectional view of another sealing device. It is sectional drawing of the bearing device for a wheel. It is an enlarged view of the main part of the outer side seal (sealing device) of the wheel bearing device of FIG. It is an enlarged view of the main part of the inner side seal (sealing device) of the wheel bearing device of FIG. It is sectional drawing of the main part of the rolling bearing using the non-contact type sealing device. It is sectional drawing of the main part of the bearing using the sealing device which the seal lip part is sliding contact with the outer ring side.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 12. 1 and 2 show a rolling bearing using the sealing device according to the present invention. In this rolling bearing, an inner ring 2 having a raceway surface 1 formed on an outer peripheral surface and a raceway surface 3 formed on an inner peripheral surface thereof. A cage (a cage) that accommodates and holds a plurality of rolling elements 5 incorporated between the outer ring 4 and the raceway surfaces 1 and 3 of the inner ring 2 and the outer ring 4, and the plurality of rolling elements 5 at intervals in the circumferential direction. (Not shown). In this case, a steel ball is used as the rolling element 5.

Then, the bearing space between the pair of raceway rings (inner and outer rings 2 and 4) is sealed by the sealing device S. The sealing device S is composed of a sealing member 10 made of rubber or synthetic resin, and a core metal 11 embedded in the sealing member 10. In this embodiment, the seal member 10 is fixed to the outer ring 4 side, and the main lip 12 and the dust strip 13, which will be described later, are in sliding contact with the seal member 10 on the inner ring side.

That is, a fitting circumferential groove 15 is formed on the axially outer side of the inner peripheral surface of the outer ring 4, and a bulging portion 10a provided on the outer peripheral edge of the seal member 10 is press-fitted into the circumferential groove 15. Is fixed. A circumferential notch 16 that opens outward in the axial direction is formed on the outer side of the fitting circumferential groove 15.

Further, a circumferential groove 17 is provided on the outer side of the outer peripheral surface of the inner ring 2 in the axial direction, and a circumferential notch 18 that opens outward in the axial direction is provided on the outer side of the circumferential groove. There is. Then, as shown in FIG. 2, the main lip 12 as the sealing portion of the sealing member 10 is in sliding contact with the rising wall surface 17a on the inner side of the bearing of the circumferential groove 17, and the dust strip 13 as the sealing portion of the sealing member 10 is rotated. It is in sliding contact with the directional notch 18. Therefore, in this embodiment, the range of cross-hatching in FIG. 2 constitutes the seal surface 20.

A surface-treated surface P is formed on the sealing surface 20. That is, the water-repellent surface 21 is provided on the inner side of the bearing from the sliding contact portion of the main lip 12, which is the seal portion of the seal member 10, and the water-repellent surface 21 is continuous from the inner side of the bearing to the outer side of the bearing. It is configured to decrease in terms of weight. In this embodiment, as shown in FIG. 3, the water-repellent treated surface 21 is a water-repellent oil-repellent oil-treated surface 21A, and the area of the water-repellent oil-treated surface 21A decreases from the inside of the bearing to the outside of the bearing. A wedge-shaped water-repellent oil-repellent surface 21Aa is provided. That is, a plurality of wedge-shaped water-repellent oil-repellent oil-treated surfaces 21Aa whose areas gradually decrease from the inside of the bearing to the outside of the bearing are arranged along the circumferential direction.

Further, on the outer side of the bearing, a hydrophilic treatment surface 22 is provided on the outer side in the axial direction of the sliding contact portion of the dust strip 13 of the seal member 10. The hydrophilic treated surface 22 is a hydrophilic oil repellent treated surface 22A, and the hydrophilic oil repellent treated surface 22A is provided with a wedge-shaped hydrophilic oil repellent treated surface 22Aa whose area decreases from the outer side of the bearing toward the inner side of the bearing. That is, a plurality of wedge-shaped hydrophilic oil-repellent treated surfaces 22Aa whose areas gradually decrease from the outer side of the bearing to the inner side of the bearing are arranged along the circumferential direction.

Therefore, a mixed surface in which the wedge-shaped water-repellent oil-repellent surface 21Aa and the wedge-shaped hydrophilic oil-repellent surface 22Aa are alternately formed is formed between the water-repellent surface 21 and the hydrophilic surface 22. The wedge shape of each wedge-shaped water-repellent oil-repellent treated surface 21Aa and each wedge-shaped hydrophilic oil-repellent treated surface 22Aa has, for example, a base of about 10 μm to 1 mm and a length of about 1 mm to 30 mm.

By the way, the water-repellent parent oil has a property of repelling water and adapting to oil, and the hydrophilic oil-repellent property has a property of repelling oil by repelling water. In addition, there are water-repellent oil-repellent oil and hydrophilic lipophilic oil. Water and oil repellency has the property of repelling both water and oil, and hydrophilic lipophilic oil has the property of being compatible with both water and oil. The relationship between hydrophilic oil repellency, water repellency oil repellency, hydrophilic lipophilic oil, and water repellent oil repellency is shown in FIG.

The water-repellent lipophilic surface can be formed by applying, for example, the water-repellent lipophilic resin described in JP-A-2017-008180, and the hydrophilic oil-repellent surface can be described in, for example, JP-A-2017-193683. It can be formed by applying the above-mentioned hydrophilic oil repellent. The water- and oil-repellent treated surface can be formed by applying a water- and oil-repellent oil-repellent compound such as a fluorine-based compound or a silicone-based compound, and the hydrophilic lipophilic surface can be a hydrophilic lipophilic agent such as a polyester alkylene glycol copolymer resin. Can be formed by applying.

The water-repellent surface and the oil-repellent surface can also be formed by providing a minute uneven structure on the surface. The uneven structure can be formed by irradiating the surface with a laser, and as the laser, a pulse laser such as a femtosecond laser, a picosecond laser, or a nanosecond laser can be used.

As described above, the surface-treated surface P shown in FIG. 3 is the water-repellent oil-repellent surface 21A on the inner side of the bearing, the hydrophilic oil-repellent surface 22A on the outer side of the bearing, and the water-repellent oil-repellent surface in the intermediate portion between them. It is composed of a mixed surface of 21Aa and a hydrophilic oil-repellent treated surface 22Aa, and the area of the water-repellent oil-repellent treated surface 21A is reduced from the inside of the bearing to the outside of the bearing.

In this sealing device, the water-repellent surface 21 is provided on the inner side of the bearing, and the area of the water-repellent surface 21 is reduced from the inner side of the bearing to the outer side of the bearing. Therefore, the inner side of the bearing has a water-repellent function. It is high, and the water-repellent function decreases from the inside of the bearing to the outside of the bearing. Therefore, water or the like easily flows from the inner side of the bearing to the outer side of the bearing. Further, the water-repellent surface on the inner side of the bearing of the surface-treated surface 21 can be a water-repellent oil-repellent surface or a water-repellent oil-repellent surface. If it is water-repellent and oil-repellent, the lubricating oil can be repelled inside the bearing to prevent the lubricating oil from flowing out to the outside of the bearing. If the water-repellent surface is water-repellent oil-repellent oil, the lubricating oil that tries to flow out from the inside of the bearing collects on the water-repellent oil-repellent surface and goes to the outside of the bearing. The outflow can be prevented.

As described above, in this sealing device, even if water tries to enter the inside of the bearing from the outside of the bearing, the infiltration of the water into the bearing can be effectively prevented by the surface treatment surface P. Further, regardless of whether the water-repellent surface on the inner side of the bearing of the surface-treated surface P is a water-repellent oil-repellent surface or a water-repellent oil-repellent surface, it is possible to prevent the lubricating oil from flowing out to the outside of the bearing. Therefore, the sealing property of the sealing device can be improved and the leakage of the lubricating oil can be reduced, so that the life of the bearing can be effectively prevented from being shortened. That is, it is possible to provide a long-life, high-quality product (bearing).

FIG. 5 shows another surface-treated surface P, and in this case, the hydrophilic oil-repellent treated surface on the outer side of the bearing is omitted. When water droplets are dropped on the surface-treated surface P, they flow in the direction of the arrow, that is, from the bearing inner side to the bearing outer side.

Further, FIG. 6 shows another surface-treated surface P, and in this case, a water-repellent treated surface 23 is provided on the inner side of the bearing. The water-repellent and oil-repellent treated surface 23 is a water- and oil-repellent treated surface 23A, and the water- and oil-repellent treated surface 23A has a wedge shape in which the area decreases from the inside of the bearing to the outside of the bearing. A water- and oil-repellent treated surface 23Aa is provided. That is, a plurality of wedge-shaped water-repellent and oil-repellent treated surfaces 23Aa whose areas gradually decrease from the inside of the bearing to the outside of the bearing are arranged along the circumferential direction. The hydrophilic oil repellent surface on the outer side of the bearing is omitted.

When water droplets are dropped on the surface treated surface P, they flow in the arrow direction, that is, from the bearing inner side to the bearing outer side, and when oil droplets are dropped, they flow in the arrow direction, that is, from the bearing inner side to the bearing outer side.

FIG. 7 shows yet another surface-treated surface P. In this case, the first water-repellent treated surface 21A on the inner side of the bearing and the second water-repellent surface 21A on the outer side of the bearing have a smaller contact angle than the first water-repellent surface 21A. It is composed of the water-repellent surface 21B of the above, and a mixed surface of the first water-repellent surface 21A and the second water-repellent surface 21B of the intermediate portion thereof. A plurality of wedge-shaped water-repellent treated surfaces 21Aa whose area is sequentially reduced from the outside of the bearing to the inside of the bearing are arranged along the circumferential direction, and the area is gradually reduced from the inside of the bearing to the outside of the bearing. A plurality of wedge-shaped water-repellent treated surfaces 21Ba are arranged along the circumferential direction.

When the solid surface is in contact with liquid and gas, the angle at which the liquid surface forms with the solid surface at the contact boundary line of these three phases is called the contact angle, and as shown in FIG. 8, the contact angle θ is 90 ° or less. The state of is called wet. Further, as shown in FIG. 9, the property of having a small contact angle θ is called hydrophilicity (adapting to water), and the property of having a large contact angle θ is called water repellency (repelling water). Particularly strong water repellency and hydrophilicity are called superhydrophobicity and superhydrophilicity.

Therefore, on the surface-treated surface P shown in FIG. 7, the inner side of the bearing has poor wettability and the outer side of the bearing has good wettability. Therefore, on the surface-treated surface P shown in FIG. 7, when water droplets are dropped on the surface-treated surface P, they flow in the arrow direction, that is, from the bearing inner side to the bearing outer side.

As described above, even on the surface-treated surface P shown in FIGS. 5 to 7, water flows from the inside of the bearing to the outside of the bearing. In addition, the following Table 1 is a classification of the surface-treated surface P, A in Table 1 shows the surface-treated surface P in FIG. 3, B shows the surface-treated surface P in FIG. 5, and C shows the surface-treated surface P in FIG. The surface-treated surface P of FIG. 7 is shown, and D shows the surface-treated surface P of FIG. 7.

Next, FIG. 10 shows another embodiment of the sealing device, which is press-fitted into the inner peripheral surface of the outer ring, the slinger 31 pressed into the outer peripheral surface of the inner ring, and the core metal 30. A seal member 32 to be joined is provided.

The core metal 30 is composed of a short cylindrical first portion 30a and a ring-shaped second portion 30b extending from the end of the first portion 30a on the inner side of the bearing to the inner diameter side, and the first portion 30a is an outer ring. It is press-fitted to the inner peripheral surface. Further, the slinger 31 is composed of a short cylindrical first portion 31a and a ring-shaped second portion 31b extending in the outer diameter direction from the end of the first portion 31a on the outer side of the bearing, and the first portion 31a is an inner ring. It is press-fitted to the outer peripheral surface.

The seal member 32 is made of rubber or synthetic resin, and extends radially inwardly toward the inner diameter side of a pair of side lips 32a and 32b extending outwardly in the radial direction. It has a grease lip 32c. In this case, the side lips 32b and 32b are in sliding contact with the inner surface of the second portion 31b of the slinger 31, and the grease lip 32c is in sliding contact with the outer surface of the slinger 31. Therefore, each of the sealing portions including the pair of side lips 32a and 32b and the grease lip 32c has the sealing surface 20 on the inner side of the sealing device of the slinger 31.

Therefore, the seal surface 20 has a first surface 35 parallel to the rotation surface and a second surface 36 orthogonal to the rotation axis of the rotation axis, and the second surface 36 is arranged on the outer side of the bearing. The first surface 35 is the surface treated surface P, and the second surface 36 is the water repellent surface 21. A magnetic encoder 33 is attached to the slinger 31.

With such a configuration, the water-repellent function is high on the inner side of the bearing of the first surface 35, and the water-repellent function is lowered from the inner side of the bearing on the first surface 35 toward the outer side of the bearing. Therefore, on the first surface 35, water or the like easily flows from the inner side of the bearing to the outer side of the bearing. Further, since the second surface 36 is a water-repellent treated surface, it exhibits the property of repelling water on these surfaces. Therefore, it is possible to prevent water or the like from entering the bearing. The water-repellent surface 21 may be a water-repellent oil-repellent surface 21A or a water-repellent oil-repellent surface 23A.

FIG. 11 shows a wheel bearing device, which has a vehicle body mounting flange 42 integrally attached to a vehicle body (not shown) on the outer circumference, and a double row of outer rolling surfaces 48a and 48b formed on the inner circumference. It includes a square member 41 and a hub ring 44 integrally having a wheel mounting flange 47 to which a wheel (not shown) is mounted at one end. The hub wheel 44 has a cylindrical main body 44a in which serrations 46 for torque transmission are formed on the inner circumference and the wheel mounting flange 47, and the main body 44a has a shaft on the opposite side of the wheel mounting flange 47. A cylindrical small-diameter step portion 54 extending in the direction is provided, and an inner ring 45 is press-fitted into the small-diameter step portion 54. Then, an inner rolling surface 49a facing one outer rolling surface 48a is formed on the outer diameter surface of the main body portion 44a of the hub ring 44, and the outer diameter surface of the inner ring 45 is formed on the other outer rolling surface 48b. Opposing inner rolling surfaces 49b are formed.

A double-row rolling element (ball) 50 is rotatably accommodated between the double-row outer rolling surfaces 48a and 48b and the inner rolling surfaces 49a and 49b facing them by a cage 51. Further, the sealing devices S and S are respectively mounted in the annular space formed between the inner member 43 composed of the hub ring 44 and the inner ring 45 and the outer member 41, and the lubricating grease sealed inside the bearing. It prevents the leakage of grease and the intrusion of rainwater and dust into the bearing from the outside.

As shown in FIG. 12, one sealing device (outer side seal) S has a core metal 60 attached to the axial end portion of the outer member 41 and a seal member 61 attached to the core metal 60. Be prepared. The seal member 61 is made of rubber or resin and has three seal lips 61a, 61b, 61c. The seal lips 61a, 61b, and 61c are in sliding contact with the joint portion having an arc-shaped cross section between the cylindrical main body portion 44a of the hub ring 44 and the flange 47. Therefore, this connecting portion becomes the sealing surface 20, and any of the surface-treated surfaces P described above is formed on the sealing surface 20.

Further, as shown in FIG. 13, the other sealing device (inner side seal) S has the core metal 70 press-fitted into the inner peripheral surface of the outer member 41 and the inner ring, similarly to the sealing device shown in 10. A slinger 71 that is press-fitted into the outer peripheral surface and a seal member 72 that is joined to the core metal 70 are provided.

In this case as well, the core metal 70 is composed of a short cylindrical first portion 70a and a ring-shaped second portion 70b extending from the end portion of the first portion 70a on the inner side of the bearing to the inner diameter side. 70a is press-fitted into the inner peripheral surface of the outer member. Further, the slinger 71 is composed of a short cylindrical first part 71a and a ring-shaped second part 71b extending in the outer diameter direction from the end of the first part 71a on the outer side of the bearing, and the first part 71a is an inner ring. It is press-fitted to the outer peripheral surface.

The seal member 72 is made of rubber or synthetic resin, and extends radially inwardly toward the inner diameter side of a pair of side lips 72a, 72b extending outward in the radial direction. It has a grease lip 72c. In this case, the side lips 72a and 72b are in sliding contact with the inner surface of the second portion 71b of the slinger 71, and the grease lip 72c is in sliding contact with the outer surface of the slinger 71. Therefore, the inner surface of the sealing device of the slinger 71 becomes the sealing surface 20.

Therefore, the seal surface 20 has a first surface 35 parallel to the rotation surface and a second surface 36 orthogonal to the rotation axis of the rotation axis, and the second surface 36 is arranged on the outer side of the bearing. One surface 35 is a surface-treated surface P, and the second surface is a water-repellent surface. A magnetic encoder 73 is attached to the slinger 71.

Next, in the sealing device shown in FIG. 14, the lip 81a of the sealing member 81 is not in contact with the inner ring 4. That is, this sealing device includes a seal ring 82 including a core metal 80 and a seal member 81 attached to the core metal 80. Then, the outer diameter portion of the seal ring 82 is fitted into the fitting groove 83 provided at the axial end portion on the inner peripheral surface of the outer ring.

Further, a concave groove 84 is formed at the axial end portion of the outer diameter surface of the inner ring 2. Then, the lip 81a of the seal member 81 is loosely fitted into the concave groove 84. Therefore, the inner surface of the concave groove 84 becomes the sealing surface 20. Therefore, any of the surface-treated surfaces P is formed on the seal surface 20. In FIG. 14, 88 is a cage that holds the ball 5 which is a rolling element. A bulging portion 85 that bulges toward the inner diameter side is provided on the outer side of the fitting groove 83, and a circumferential notch 86 that opens outward in the axial direction is provided on the outer side of the concave groove 84. There is.

Next, in the sealing device of FIG. 15, the sealing surface 20 is formed on the outer ring side, and the sealing member 10 is fixed on the inner ring 2 side. Also in this case, the seal member 10 made of rubber or synthetic resin and the core metal 11 embedded in the seal member 10 are composed of the seal member 10. In this embodiment, the seal member 10 is fixed to the outer ring 4 side, and the main lip 12 and the dust strip 13 slide into contact with the seal member 10 on the inner ring side.

That is, a fitting circumferential groove 95 is formed on the axially outer side of the inner peripheral surface of the inner ring, and a bulging portion 10a provided on the inner peripheral edge of the seal member 10 is press-fitted and fixed to the circumferential groove 95. ing. A circumferential notch 96 that opens outward in the axial direction is formed on the outer side of the fitting circumferential groove 95.

Further, a circumferential groove 97 is provided on the outer side of the outer peripheral surface of the outer ring 4 in the axial direction, and a circumferential notch 98 that opens outward in the axial direction is provided on the outer side of the circumferential groove 97. ing. Then, the main lip 12 of the seal member 10 is in sliding contact with the rising wall surface 97a on the inner side of the bearing of the circumferential groove 97, and the dust strip 13 of the seal member 10 is in sliding contact with the notch 98 in the circumferential direction. Therefore, in this embodiment, the range from the inner surface of the circumferential groove 97 to the circumferential notch 98 constitutes the seal surface 20. Therefore, any of the surface-treated surfaces P is formed on the seal surface 20.

By forming the surface-treated surface P in this way, the sealing device (sealing device shown in FIGS. 10, 12, 13, 14, and 15) of each embodiment also has water from the outside of the bearing to the inside of the bearing. Even if water is about to infiltrate, the surface treated surface P can effectively prevent the water from invading the inside of the bearing. In addition, it is possible to prevent the lubricating oil from flowing out to the outside of the bearing.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be deformed in various ways, even if a cylindrical roller, a tapered roller, or the like is used as the bearing. Good. Further, in the case of radial ball bearings, angular contact ball bearings or deep groove ball bearings may be used.

By the way, in the sealing device shown in FIG. 10 and the like, the first surface 36 has a second surface orthogonal to the rotating surface of the rotating shaft, but is inclined at a predetermined angle with the surface orthogonal to the rotating surface of the rotating shaft. It may have a third surface (not shown). This predetermined angle can also be set arbitrarily. That is, it may be inclined toward the inside of the bearing and may be inclined toward the outside of the bearing with respect to the orthogonal surfaces.

1,3 Track surface 2 Inner ring 4 Outer ring 5 Rolling element 10 Sealing member 12 Sealing part (main lip)
13 Seal part (dust strip)
20 Sealing surface 21,21A, 21B Water-repellent treated surface 21Aa Water-repellent oil-repellent treated surface 22Aa Hydrophilic oil-repellent treated surface 23Aa Water-repellent oil-repellent treated surface 30 Core metal 32 Sealing member 32a, 32b Sealing part (side lip)
32c Seal (grease lip)
35 1st surface 36 2nd surface 61 Seal member 61a Seal part (seal lip)
72 Seal members 72a, 72b Seal part (side lip)
72c Seal (grease lip)
81 Seal member 81a Seal part (lip)
P Surface treated surface S Sealing device θ Contact angle

Claims (8)

In a sealing device provided with a sealing member having a sealing portion that is in sliding contact with or facing the sealing surface of the raceway ring at a predetermined interval and seals the bearing space between the pair of raceway wheels.
A water-repellent surface is provided on the inner side of the bearing with respect to the seal portion of the seal member on the seal surface, and a surface-treated surface is formed in which the water-repellent surface continuously decreases from the inner side of the bearing to the outer side of the bearing. A sealing device characterized by being bearing. The surface-treated surface is a mixed surface of a water-repellent oil-repellent treated surface on the inner side of the bearing, a hydrophilic oil-repellent treated surface on the outer side of the bearing, and a water-repellent oil-repellent treated surface and a hydrophilic oil-repellent treated surface at an intermediate portion between them. The sealing device according to claim 1, wherein the area of the water-repellent oil-repellent oil-treated surface is reduced from the inner side of the bearing to the outer side of the bearing. The sealing device according to claim 1, wherein the water-repellent surface of the surface-treated surface is a water-repellent oil-repellent surface. The sealing device according to claim 1, wherein the water-repellent treated surface of the surface-treated surface is a water-repellent and oil-repellent treated surface. The surface-treated surface includes a first water-repellent surface on the inner side of the bearing, a second water-repellent surface on the outer side of the bearing, which has a smaller contact angle than the first water-repellent surface, and intermediate portions thereof. It is composed of a mixed surface of a first water-repellent treated surface and a second water-repellent treated surface, and is characterized in that the area of the first water-repellent treated surface is reduced from the inside of the bearing to the outside of the bearing. The sealing device according to claim 1. The sealing member has a plurality of sealing portions, and the surface-treated surface is provided in a range from the innermost side of the bearing to the outermost side of the bearing than the outermost sealing portion of the bearing. The sealing device according to claim 1, wherein the sealing device is provided. The sealing surface has a first surface parallel to the rotation surface, a second surface orthogonal to the rotation surface of the rotation axis, or a third surface inclined at a predetermined angle with a surface orthogonal to the rotation surface of the rotation axis. Claim 1 is characterized in that two or third surfaces are arranged on the outer side of the bearing, the first surface is the surface treated surface, and the second or third surface is a water repellent surface. The sealing device described in. A rolling bearing including an inner ring, an outer ring, a rolling element interposed between the inner ring and the outer ring, and a cage for holding the rolling element.
A rolling bearing provided with the sealing device according to any one of claims 1 to 7.

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