JP2022147349A - Sealing device and rolling bearing device - Google Patents

Abstract

To provide a sealing device which can stably maintain a lip adsorption prevention effect for a long period of time.SOLUTION: A sealing device 50 has a seal member 54 for sealing an internal space S of a bearing 1. The seal member 54 comprises a core grid 541, and a lip part 542 fixed to the core grid 541, and formed of an elastic material. A bearing-side lip 542b slide-contacting with a slide mating member 62 and an anti-bearing side lip 542c slide-contacting with the slide mating member 62 are arranged at the lip part 542. An inter-lip space T is formed between the bearing-side lip 542b and the anti-bearing side lip 542c. A bearing-side space U communicating with the internal space S of the bearing 1 is formed at a side opposite to the inter-lip space T with the lip part 542 sandwiched therebetween. A ventilation structure 70 for performing ventilation between the inter-lip space T and the bearing-side space U is arranged at the seal member 54.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sealing device having a sealing member and a rolling bearing device having the sealing device.

Some rolling bearing devices are used to support the axles of railway vehicles. This type of railroad vehicle axle bearing device has a bearing and a sealing device with a sealing member. The sealing device has a seal case fixed to the outer ring of the bearing and a seal member fixed to the inner circumference of the seal case. The bearing inner space between the bearing outer ring and the bearing inner ring is sealed on both sides in the axial direction by the sealing member slidingly contacting the outer peripheral surface of the oil drainer or the rear cover attached to the axle.

The sealing member has a core metal and a lip portion made of an elastic material such as rubber fixed to the core metal. Two lips (main lip and dust lip) are provided on the lip portion, and these two lips are in sliding contact with the rear cover (or oil drainer) at two locations separated in the axial direction, thereby removing grease, etc. from the space inside the bearing. leakage of the lubricant and entry of foreign substances such as dust and water into the inner space of the bearing are prevented.

Since the main lip and the dust lip are in sliding contact with other members such as the rear cover, the space between the two lips forms an inter-lip space isolated from the bearing inner space and the bearing outer space. Depending on the conditions of use, negative pressure may be generated in the space between the lips, and both lips may be pressed against and attracted to the outer peripheral surface of another member due to the air pressure difference between the space inside the bearing and the space outside the bearing. . Continuous or frequent adsorption of the lip promotes heat generation in the sealing member and causes abnormal wear of the tip of the lip, resulting in deterioration of sealing performance and shortening of bearing life.

In order to solve such a problem, Patent Document 1 discloses providing a rib at the lip tip portion (Means 1), and Patent Document 2 discloses rubber, a metal core, and a seal case that constitute a sealing member. Provide a vent hole or a recess that communicates the space between the lips with the space outside the bearing (means 2), and provide a vent hole that communicates the space between the lips with the inside or outside of the bearing in the oil drainer or the rear lid. (Means 3) is disclosed.

Japanese Patent Application Laid-Open No. 2020-12478 JP 2017-227239 A

In the means 1 described in Patent Document 1, the projection (rib) provided at the tip of the lip wears due to contact with the oil drainer and the rear lid, which are the contact partner members, so the function of preventing adsorption may be lost depending on the situation. There is a risk. Means 2 described in Patent Document 2 requires additional processing for forming holes and recesses in various members, which leads to an increase in cost. Moreover, in the means 3, additional work is required for the oil drainer and the rear lid, which similarly leads to an increase in cost.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a sealing device that can stably maintain a lip adsorption prevention effect for a long period of time, and a rolling bearing device using this sealing device.

A sealing device according to the present invention has a sealing member for sealing an inner space of a bearing, the sealing member includes a core metal and a lip portion made of an elastic material fixed to the core metal, and the lip portion is a bearing-side lip in sliding contact with a mating sliding member and a non-bearing-side lip in sliding contact with the sliding mating member, and a space between the lips is defined between the bearing-side lip and the non-bearing-side lip. is formed, and a bearing-side space communicating with the internal space of the bearing is formed on the opposite side of the inter-lip space sandwiching the lip portion, wherein the gap between the inter-lip space and the bearing-side space is It is characterized by having a ventilation structure for ventilation between them.

Since the ventilation structure is provided between the space between the lips and the space on the bearing side in this way, the air pressure difference between the space between the lips and the space on the bearing side can be eliminated. Therefore, generation of negative pressure in the space between the lips can be prevented. This prevents the lip on the bearing side and the lip on the anti-bearing side from being attracted to the mating sliding member due to negative pressure, reduces the amount of heat generated by the seal member, and avoids deterioration in sealing performance due to abnormal wear at the tip of the lip. It becomes possible to

In such a configuration, the lip portion may be provided with a ventilation hole opening to the bearing-side space and the space between the lips, and the ventilation hole may form a ventilation path as the ventilation structure.

In this case, the effect of preventing adsorption of the lip can be obtained simply by forming a vent hole in the lip portion. Since it is sufficient to form this vent hole only in the lip portion, additional machining is not required for each part constituting the sealing device, and an increase in cost due to additional machining can be avoided.

If the vent holes are formed in a tapered shape, lubricant such as grease sealed inside the bearing can be retained in the vent holes. Therefore, it is possible to prevent the lubricant from entering the space between the lips.

In this sealing device, a first sealing member and a second sealing member are provided as the sealing members, and a first lip made of an elastic material and fixed to the first core metal and the first core metal is attached to the first sealing member. the second seal member is provided with a second core and a second lip portion made of an elastic material fixed to the second core bar; and the first lip portion is provided with a lip on the bearing side. , the second lip portion may be provided with a lip on the side opposite to the bearing.

In this case, by arranging the first sealing member and the second sealing member in contact with each other and interposing a groove in the contact portion between the two, a ventilation path as the ventilation structure can be formed (FIG. 8). reference).

Further, an axial gap is provided between the first seal member and the second seal member, a vent hole is provided in the first seal member for communicating the bearing-side space and the axial gap, and The axial gap and the ventilation hole may form a ventilation path as the ventilation structure (see FIGS. 9, 10, and 12 to 15).

When an axial gap is provided between the first seal member and the second seal member in this manner, the circumference of the lip portion of either one of the first seal member and the second seal member The directional partial area is brought into contact with the other sealing member (see FIGS. 9 and 10). This makes it possible to position the sealing member in the axial direction.

The first cored bar of the first sealing member and the second cored bar of the second sealing member are brought into contact with each other in the axial direction on the outer diameter side of the gap in the axial direction (see FIG. 13), or are first supported. and a second support member fixed to the inner periphery of the first support member, the first metal core of the first seal member is fixed to the inner periphery of the second support member, and the first support member and the second support member are provided. The second core bar of the second seal member may be constrained from both sides in the axial direction with the support member (see FIGS. 14 and 15). In this case also, it is possible to position the sealing member in the axial direction.

It is preferable that the seal member is configured so as not to include an air passage that communicates the space outside the bearing and the space between the lips. As a result, it is possible to more reliably prevent the lubricant from leaking out of the bearing.

It is preferable to dispose a vent member with a slit in the air passage, or arrange a vent member made of a porous material in the air passage. Thereby, it is possible to prevent the lubricant from flowing into the inter-lip space.

A rolling bearing device comprising an inner ring having an inner raceway surface, an outer ring having an outer raceway surface, rolling elements arranged between the inner raceway surface and the outer raceway surface, and the sealing device described above. , a highly durable rolling bearing device can be obtained at low cost.

As described above, according to the present invention, the lip adsorption prevention effect in the sealing device can be stably maintained for a long period of time.

1 is a cross-sectional view showing a bearing device for a railway vehicle axle; FIG. 2 is a cross-sectional view showing an enlarged region A in FIG. 1; FIG. FIG. 4 is a plan view of a slitted vent member; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a plan view of a vent member made of a porous material; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a perspective view of a first lip portion; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device; FIG. 4 is a cross-sectional view showing another embodiment of a sealing device;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing.

FIG. 1 shows a bearing device according to an embodiment of the invention. This bearing device is used for supporting an axle of a railway vehicle, and includes a bearing 1 and a sealing device 50. As shown in FIG. A bearing 1 is a double-row tapered roller bearing, which is a type of rolling bearing, and includes an outer ring 10 , two inner rings 20 , a plurality of tapered rollers 30 as rolling elements, and a retainer 40 .

The outer ring 10 has conical raceway surfaces 12 arranged in double rows on the inner circumference, and the inner ring 20 has conical raceway surfaces 22 on the outer circumference. A double-row raceway surface 22 is formed by arranging the small-diameter side ends of the two inner rings 20 against each other. A spacer 23 is arranged between the small diameter side ends of the inner ring 20 . The spacer 23 may be omitted, and the small-diameter side ends of the inner ring 20 may be directly butted against each other. Tapered rollers 30 arranged in double rows are interposed between the raceway surface 12 of the outer ring 10 and the raceway surface 22 of the inner ring 20 . The retainer 40 retains the tapered rollers 30 in each row at regular intervals in the circumferential direction. A space S formed between the inner peripheral surface of the outer ring 10 and the outer peripheral surface of the inner ring 20 (hereinafter referred to as "bearing internal space") is filled with a lubricant such as grease. A sealing device 50 seals on both sides.

The outer ring 10 is fixed to the axle box (not shown) of the railway vehicle by fitting the outer peripheral surface to the inner peripheral surface of the axle box and fixing the axial end face in the axial direction. An oil slinger 61 and a rear cover 62 as sliding members are arranged on the outer sides of the bearings of the two inner rings 20, respectively. A lid member 64 is fixed to the shaft end of the axle 2 with a bolt 66. Between the lid member 64 and the shoulder portion 2a of the axle 2, an oil drainer 61, an inner ring 20 and a rear lid are fitted to the outer periphery of the axle 2. 62 is clamped and fixed.

A radial through hole 67 is formed between the pair of raceway surfaces 12 of the outer ring 10, and a vent 68 (differential pressure valve) is mounted in this through hole 67. As shown in FIG. The vent 68 maintains the pressure inside the bearing S at the same pressure as the atmosphere. In addition, it is sufficient to mount the vent 68 in a hole of the bearing component formed between the bearing inner space S and the atmosphere. Therefore, the mounting position of the vent 68 is not limited to the outer ring 10, and the vent can be mounted on the oil drainer 61 or the rear lid 62, for example.

Next, the configuration of the sealing device 50 will be described. In the following description, the direction of the sealing device 50 approaching the bearing 1 (the left side in FIG. 2) is called the "bearing side", and the direction away from the bearing 1 (the right side of FIG. 2) is called the "anti-bearing side". called.

As shown in an enlarged view in FIG. 2, the sealing device 50 includes a seal case 52 as a stepped cylindrical first support member, a seal member 54, and a partition as a second support member having an L-shaped cross section. It is composed of a member (partition plate) 55 . Each of the two seal cases 52 has one axial end (bearing-side end) press-fitted and fixed to the inner periphery of openings at both axial ends of the outer ring 10 . The ends of the two seal cases 52 are inserted into a recess 61a (see FIG. 1) formed in the end surface of the oil drainer 61 and a recess 62a formed in the end surface of the rear lid 62, respectively, to form non-contact seals. there is In the following description, the sealing device 50 on the center side (right side in FIG. 1) of the axle 2 is taken as an example. A similar configuration can be applied to the sealing device 50 on the left side of the . However, in the sealing device 50 on the shaft end side, the rear lid 62 is replaced with the oil drainer 61 as the mating sliding member.

As shown enlarged in FIG. 2 , a partition member 55 is press-fitted and fixed to the inner periphery of the cylindrical portion of the seal case 52 , and a seal member 54 is press-fit and fixed to the inner periphery of the cylindrical portion of the partition member 55 . Therefore, the seal member 54 is in a state of being supported by the seal case 52 as the first support member and the partition member 55 as the second support member. The partition member 55 has a portion radially extending from the bearing-side end of the cylindrical portion, and its inner diameter end is adjacent to the outer peripheral surface of the rear lid 62 to form a non-contact seal. The partition member 55 prevents the lubricant such as grease filled in the inner space of the bearing 1 from rushing directly to the seal member 54 .

As shown in FIG. 2 , the seal member 54 is a so-called oil seal, and includes a metal core 541 , a lip portion 542 fixed to the core 541 and made of an elastic material, and a garter spring 543 . The core metal 541, the lip portion 542, and the garter spring 543 are all annularly formed.

The core bar 541 integrally has a cylindrical press-fitting portion 541a press-fitted into and fixed to the inner periphery of the partition member 55, and a radial portion 541b extending radially inward from the end of the press-fitting portion 541a on the side opposite to the bearing. A lip portion 542 is provided at the inner diameter end of the radial portion 541b.

The lip portion 542 is made of an elastic material such as nitrile rubber, acrylic rubber, fluororubber, or the like. The lip portion 542 is fixed to the metal core 541 by means of vulcanization adhesion, for example.

The lip portion 542 has a fixing portion 542a fixed to the core metal 541, a main lip 542b extending from the fixing portion 542a toward the bearing side, and a dust lip 542c extending from the fixing portion 542a toward the bearing side. . The main lip 542b serves as a lip on the bearing 1 side, and the dust lip 542c serves as a lip on the side opposite to the bearing.

The tips of both lips 542b and 542c are in contact with the outer peripheral surface (sliding surface) of the rear lid 62 with interference. An inter-lip space T surrounded by the lip portion 542 and the outer peripheral surface of the rear lid 62 is formed between the main lip 542b and the dust lip 542c. On the bearing side of the core metal 541 , the space T between the lips and the lip portion 542 is interposed therebetween. A communicating bearing-side space U is formed. On the opposite side of the core bar 54 to the bearing, a bearing external space V open to the atmosphere is formed on the side opposite to the inter-lip space T with the lip portion 542 therebetween.

The garter spring 543 is attached to the outer periphery of the tip of the main lip 542b. The elastic force of the garter spring 543 in the diameter contracting direction cooperates with the tightening margin to apply a predetermined tightening force to the tip portion of the main lip 542b.

The sealing device 50 according to the present embodiment is provided with a ventilation structure 70 for performing ventilation between the space T between the lips and the space U on the bearing side. In the embodiment shown in FIG. 2, as an example of the ventilation structure 70, the lip portion 542 is provided with a ventilation hole 71 opening to the space T between the lips and the space U on the bearing side. The air hole 71 functions as an air passage that communicates the space T between the lips and the space U on the side of the bearing. The vent hole 71 may be provided at one position in the circumferential direction of the lip portion 542, or may be provided at a plurality of positions in the circumferential direction.

Since the ventilation path is provided between the space T between the lips and the space U on the bearing side in this manner, the air pressure difference between the space T between the lips and the space U on the bearing side can be eliminated. Therefore, generation of negative pressure in the inter-lip space T can be prevented. This prevents the main lip 542b and the dust lip 542c from sticking to the rear lid 62 due to the negative pressure, reduces the amount of heat generated by the seal member 54, and avoids deterioration in sealing performance due to abnormal wear of the tip of the lip. It becomes possible. Since the bearing inner space S communicating with the bearing side space U communicates with the atmosphere through the vent 68 provided in the outer ring 10, the bearing side space U communicating with the bearing inner space S and further the bearing side space U The communicating inter-lip space T can be maintained at atmospheric pressure.

Also, this effect can be obtained simply by forming the vent hole 71 in the lip portion 542 . Since the vent hole 71 can be formed at the same time as the lip portion 542 is formed, for example, additional machining is not required for multiple parts that constitute the sealing device 50, and cost increases due to additional machining can be avoided. Furthermore, since the vent hole 71 does not come into sliding contact with the rear lid 62, the sealing function of the sealing member 54 can be stably maintained over a long period of time. As a result, the service life of the bearing 1 can be extended.

A vent member 72 is preferably attached to the ventilation hole 71 described above. This vent member 72 can be formed of, for example, a rubber film having a slit 72a, as shown in FIG. By attaching the vent member 72 to the ventilation hole 71 in this way, it is possible to prevent the grease from entering the space T between the lips while permitting ventilation. In addition, as shown in FIGS. 4 and 5, as the vent member 72, a porous body having air permeability, for example, a porous body made of PTFE resin material can be used. If a porous material having air permeability is used, slits in the vent member 72 are not required.

As shown in FIG. 2, if the angle of inclination of the vent hole 71 with respect to the axis is large, it may be difficult to separate the lip portion 542 from the mold. If mold releasability is a problem, as shown in FIG. 6, the inclination angle α of the vent hole 71 with respect to the axis is reduced (for example, 45° or less). As a result, the releasability of the lip portion 542 during molding can be enhanced.

In the embodiment shown in FIG. 7, a vent hole 71 is formed in a tapered shape in which the inner diameter dimension is reduced toward the inter-lip space T side. As an example of the tapered shape, there is a case of forming a conical surface shape. By forming the vent hole 71 in a tapered shape with a smaller diameter toward the space T between the lips, the grease can be retained in the vent hole 71, thereby preventing the grease from entering the space between the lips. can. In this case, the vent member 72 with the slit 72a (see FIGS. 2 and 3) and the vent member 72 made of porous material (see FIGS. 4 and 5) can be omitted. The taper angle β of the vent hole 71 is preferably in the range of 10° to 30°.

Next, the embodiment shown in FIGS. 8 to 15 uses a first sealing member 54-1 and a second sealing member 54-2 as the sealing member 54. FIG. The first sealing member 54-1 is provided with a first cored bar 541-1 and a first lip portion 542-1 made of an elastic material and fixed to the tip of the first cored bar 541-1. The second sealing member 54-2 is provided with a second core 541-2 and a second lip portion 542-2 made of an elastic material and fixed to the tip of the second core 541-2. A main lip 542b, which is a lip on the bearing side, is formed on the lip portion 542-1 of the first sealing member 54-1, and a lip on the anti-bearing side is formed on the lip portion 542-2 of the second sealing member 54-2. A dust lip 542c is formed.

In the embodiment shown in FIG. 8, the first sealing member 54-1 and the second sealing member 54-2 are arranged in contact. In this embodiment, the cylindrical press-fit portion 541a of the second cored bar 541-2 is press-fitted and fixed to the inner periphery of the cylindrical portion of the partition member 55, and the inner periphery of the press-fitted portion 541a of the second cored bar 541-2 is fixed. A cylindrical press-fitting portion 541a of the first cored bar 541-1 is press-fitted and fixed. The radial portion 541b of the first cored bar 541-1 and the radial portion 541b of the second cored bar 541-2 are in contact with each other in the axial direction.

In this embodiment, the ventilation path as the ventilation structure 70 is formed by interposing the groove 73 in the contact portion between the first cored bar 541-1 and the second cored bar 541-2. The groove 73 is formed, for example, continuously at the contact portions of the press-fit portion 541a and the radial portion 541b of the first cored bar 541-1 and the second cored bar 541-2. With this configuration, the groove 73 forms an air passage between the space T between the lips and the space U on the bearing side. It becomes possible to prevent negative pressure from being generated at T.

Note that the groove 73 can be formed at the same time when the first cored bar 541-1 is formed by press working or the like, so the cost increase associated with the formation of the groove 73 can be minimized. The groove 73 may be provided in the first cored bar 541-1, the second cored bar 541-2, or may be provided in both the first cored bar 541-1 and the second cored bar 541-2. .

In the embodiment shown in FIGS. 9 and 10, an axial gap 74 is provided between the first seal member 54-1 and the second seal member 54-2, and the first cored bar 541-1 is provided with the A vent hole 75 is provided through the core metal 541-1 to communicate with the space U on the bearing side and the gap 74 in the axial direction. 9 and 10 show cross-sectional views at different positions in the circumferential direction.

By using the axial gap 74 and the air hole 75 in this manner, a ventilation path is formed as the ventilation structure 70 for performing ventilation between the space T between the lips and the space U on the bearing side. It is possible to prevent the generation of negative pressure at Further, when obtaining this ventilation structure 70, additional work on the first sealing member 54-1 and the second sealing member 54-2 is not required. Therefore, cost reduction of the sealing device 50 can be achieved. The press-fit portion 541a of the first cored bar 541-1 and the press-fitted portion 541a of the second cored bar 541-2 are both press-fitted and fixed to the inner circumference of the cylindrical portion of the partition member 55. As shown in FIG.

In this embodiment, the tip of the press-fit portion 541a of the first cored bar 541-1 is brought into contact with the partition member 55 in the axial direction, and the tip of the press-fitted portion 541b of the second cored bar 541-2 is brought into contact with the seal case 52 in the axial direction. make contact. In addition, as shown in FIG. 10, a protruding portion 76 protruding in the axial direction is formed in a part of the circumferential direction of the region facing the second lip portion 542-2 of the first lip portion 542-1. The projecting portion 76 is in axial contact with the second seal member 54-2 (in this embodiment, the second metal core 541-2). As shown in FIG. 11, the protrusions 76 can be provided at a plurality of locations in the circumferential direction of the first lip portion 542-1, but the number of the protrusions 76 is arbitrary, and one or more can be provided. can.

With the above configuration, the sealing members 54-1 and 54-2 can be positioned in the axial direction, and the axial gap 76 can be maintained at an appropriate width. In addition to being provided on the first lip portion 542-1, the projecting portion 76 may be provided on the second lip portion 542-2, or may be provided on both the first lip portion 542-1 and the second lip portion 542-2. good.

In the embodiment shown in FIG. 12, in the embodiment shown in FIGS. 9 to 11, the position of the vent hole 75 is changed to the corner between the press-fit portion 541a and the radial portion 541b of the first cored bar 541-1. is. Since the first lip portion 542-1 covers most of the radial portion 541b of the first cored bar 541-1, this embodiment is effective when the space for the vent hole 75 cannot be secured.

The embodiment shown in FIGS. 13 to 15 is different from the embodiment shown in FIGS. 9 to 11 in the axial positioning structure of the first seal member 54-1 and the second seal member 54-2.

In the embodiment shown in FIG. 13, the axial bearing side of the second cored bar 541-2 is positioned by the first cored bar, and the axial opposite bearing side of the second cored bar 541-2 is positioned by the seal case 52. It is something to do. Specifically, the tip of the press-fit portion 541a of the first cored bar 541-1 is brought into contact with the partition member 55 in the axial direction, and the tip of the second cored bar 541-2 is brought into contact with the seal case 52 in the axial direction. are in contact. Also, the first cored bar 541-1 and the second cored bar 541-2 are brought into contact with each other in the axial direction on the outer diameter side of the gap 74 in the axial direction. Further, the press-fitting portions 541a of the first cored bar 541-1 and the second cored bar 541-2 are press-fitted into the inner circumference of the cylindrical portion of the partition member 55. As shown in FIG. In this embodiment, a region 541d between the press-fitting portion 541a and the radial portion 541b of the first cored bar 541-1 is formed in an arc shape, and the arced portion 541d is axially aligned with the second cored bar 541-2. are in contact with each other. With such a configuration, the axial positioning of the first sealing member 54-1 and the second sealing member 54-2 is performed with high precision, so that the width of the axial gap 74 between the two sealing members can be controlled with high precision. It becomes possible.

In the embodiment shown in FIG. 14, the partition member 55 positions the second cored bar 541-2 on the bearing side in the axial direction, and the seal case 52 positions the second cored bar 541-2 on the opposite side to the bearing in the axial direction. It is. That is, the seal case 52 and the partition member 55 constrain the second cored bar 541-2 from both sides in the axial direction. Specifically, the press-fit portion 541a of the first cored bar 541-1 is press-fitted and fixed to the inner periphery of the cylindrical portion of the partition member 55, and the tip of the press-fitted portion 541a of the first cored bar 541-1 is axially moved. It is brought into contact with the partition member 55 . Further, the tip portion of the second cored bar 541-2 is brought into contact with the seal case 52 in the axial direction, and a claw portion 541e projecting in the radial direction is formed at the tip of the press-fitting portion 541a of the second cored bar 541-2. The claw portion 541e is engaged with the tip of the cylindrical portion of the partition member 55 in the axial direction. With such a configuration, the axial positioning of the first sealing member 54-1 and the second sealing member 54-2 is performed with high precision, so that the width of the axial gap 74 between the two sealing members can be controlled with high precision. It becomes possible.

In the embodiment shown in FIG. 15, similarly to the embodiment shown in FIG. 14, the axial bearing side of the second cored bar 541-2 is positioned by a partition member 55, and the second cored bar 541-2 is axially displaced. The bearing side is positioned by the seal case 52 . Therefore, in this case as well, the seal case 52 and the partition member 55 constrain the second cored bar 541-2 from both sides in the axial direction. The press-fitting portion 541-2 of the second cored bar 541-2 is press-fitted and fixed to the inner periphery of the seal case 52 instead of the partition member 55, and the tip of the cylindrical portion of the partition member 55 is the second It is different from the embodiment shown in FIG. 14 in that the corner portion between the press-fit portion 541a and the radial portion 541b of the cored bar 541-2 is axially abutted. With such a configuration, the axial positioning of the first sealing member 54-1 and the second sealing member 54-2 is performed with high precision, so that the width of the axial gap 74 between the two sealing members can be controlled with high precision. It becomes possible.

With the configuration of the embodiment shown in FIGS. 13 to 15, the protrusion 76 of the lip portion required in the embodiment shown in FIGS. 9 to 11 is not required. Therefore, it is possible to further reduce the manufacturing cost. 9 to 15, the vent member 72 with slits shown in FIGS. is preferred.

In each embodiment described above, it is sufficient to form the ventilation holes 71 and 75 or the groove 73 in one member constituting the sealing device 50, so that the processing cost can be reduced. Further, in each of the embodiments described above, the sealing members 54, 54-1, 54-2 are not provided with air passages for communicating the bearing external space V and the space T between the lips. Therefore, it is possible to prevent the lubricant from leaking to the outside of the bearing.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments in any way, but is merely an example. It can be implemented in a different form.

Reference Signs List 1 Bearing 2 Axle 10 Outer ring 20 Inner ring 30 Rolling element 40 Cage 50 Sealing device 52 Seal case (first support member)
54 seal member 54-1 first seal member 54-2 second seal member 55 partition member (second support member)
541 Metal core 541-1 First metal core 541-2 Second metal core 542 Lip part 542-1 First lip part 542-2 Second lip part 542b Main lip (bearing side lip)
542c dust lip (lip on opposite side of bearing)
61 Oil slinger (sliding mating member)
62 Rear lid (sliding mating member)
70 ventilation structure 71 ventilation holes (vent holes formed in the lip)
72 Vent 73 Groove 75 Ventilation hole (vent hole formed in the metal core)
S Internal space of the bearing T Space between lips U Space on the bearing side V Space outside the bearing

Claims (13)

A seal member for sealing the inner space of the bearing is provided, the seal member includes a core metal and a lip portion made of an elastic material fixed to the core metal, and the lip portion is in sliding contact with a mating sliding member. It comprises a bearing-side lip and a non-bearing-side lip that is in sliding contact with the mating sliding member, a space between the lips is formed between the bearing-side lip and the non-bearing-side lip, and the lip portion A sealing device in which a bearing-side space communicating with the internal space of the bearing is formed on the opposite side of the space between the sandwiched lips,
A sealing device, comprising: a ventilation structure for performing ventilation between the inter-lip space and the bearing-side space. 2. A sealing device according to claim 1, wherein said lip portion is formed with a vent hole opening to said bearing-side space and a space between lips, and said vent hole forms a vent path as said ventilation structure. 3. A sealing device according to claim 2, wherein said vent is tapered. A first sealing member and a second sealing member are provided as the sealing members, the first sealing member is provided with a first cored bar and a first lip part fixed to the first cored bar and made of an elastic material, 2. The sealing member is provided with a second core metal and a second lip portion made of an elastic material fixed to the second core metal, the first lip portion is provided with a lip on the bearing side, and the second lip portion is provided. 2. The sealing device according to claim 1, wherein the lip on the side opposite to the bearing is provided on the . 5. The sealing device according to claim 4, wherein the first sealing member and the second sealing member are arranged in contact with each other, and a groove is interposed in the contact portion between the two to form a ventilation path as the ventilation structure. An axial gap is provided between the first seal member and the second seal member, a vent hole communicating between the bearing-side space and the axial gap is provided in the first seal member, and the axial gap is provided in the axial direction. 5. The sealing device according to claim 4, wherein the gap and the vent hole form a vent path as the vent structure. 7. The sealing device according to claim 6, wherein a circumferential partial region of the lip portion of one of the first seal member and the second seal member is brought into contact with the other seal member. 7. The sealing device according to claim 6, wherein the first cored bar of the first seal member and the second cored bar of the second seal member are axially contacted on the outer diameter side of the axial gap. A first supporting member and a second supporting member fixed to the inner circumference of the first supporting member, the first core metal of the first sealing member being fixed to the inner circumference of the second supporting member, and the first supporting member 7. The sealing device according to claim 6, wherein the second core metal of the second seal member is constrained from both sides in the axial direction by the second support member and the second support member. The sealing device according to any one of claims 1 to 4 and 6 to 9, wherein a vent member with a slit is arranged in the air passage. A sealing device according to any one of claims 1 to 4 and 6 to 9, wherein a vent member made of a porous material is arranged in the air passage. The sealing device according to any one of claims 1 to 11, wherein the seal member does not have an air passage that communicates the space outside the bearing and the space between the lips. An inner ring having an inner raceway surface, an outer ring having an outer raceway surface, rolling elements arranged between the inner raceway surface and the outer raceway surface, and the sealing device according to any one of claims 1 to 12. rolling bearing device.

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