JP2020159454A - Axle bearing device - Google Patents

Abstract

To maintain axial accuracy of a bearing for a long period to extend a service life of a bearing device, while reliably preventing fretting abrasion and preventing abrasion powder from entering the inside of the bearing due to the fretting abrasion.SOLUTION: An axle bearing device 1 comprises a rolling bearing 2, and a first spacer 15 arranged between a mating surface 17 of an inner ring 5 of the rolling bearing 2 and a mating surface 18 of a spacer 8. The mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 comprise a direct contact part 19 for contacting each other on the inner diameter side. The first spacer 15 comprises a core metal 20 that contacts the mating surface 18 of the spacer 8 on the outer diameter side of the direct contact part 19 and has an axial gap G1 with the inner ring 5, and an elastic sealing material 21 that seals a gap between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 on the outer diameter side of the axial gap G1.SELECTED DRAWING: Figure 2

Description

The present invention relates to an axle bearing device used for an axle of a railway vehicle.

Conventionally, as a bearing device used for an axle of a railway vehicle, there is a bearing device including a tapered roller bearing as a rolling bearing and a positioning member for positioning the tapered roller bearing with respect to the axle.

Tapered roller bearings are held so as to be rollable between a pair of inner rings having a raceway surface on the outer peripheral surface, an outer ring having a double row of raceway surfaces on the inner peripheral surface, and a raceway surface of the inner ring and a raceway surface of the outer ring. It is equipped with tapered rollers.

The positioning member is mounted on the outer peripheral surface of the axle and positions the inner ring of the tapered roller bearing in the axial direction with respect to the axle. The positioning member includes, for example, a rear lid arranged on the axial rear end side of the inner ring, an oil drain (or front lid) arranged on the axial front end side of the inner ring, and arranged between a pair of inner rings. For example, a seat. By bringing these positioning members and the inner ring into contact with each other, the tapered roller bearings are positioned at predetermined positions on the axle.

In the above axle bearing device, when a radial load peculiar to a railroad vehicle is applied to the axle, a bending moment acts on the axle, causing the axle to bend. As a result of the axle rotating in a bent state in this way, repeated stress is generated in the contact portion between the inner ring and the rear lid, and fretting wear may occur in the contact portion.

Fretting wear is unavoidable for railroad vehicles in which a radial load is applied to the axles, and as this wear progresses, the axial accuracy of the tapered roller bearings deteriorates. In addition, the generated wear debris invades the inside of the bearing, deteriorates the lubricant sealed in the internal space, and shortens the life of the bearing device. Therefore, for example, in the bearing device of Patent Document 1, a resin spacer is arranged between the inner ring and the rear lid in order to suppress fretting wear.

Further, in recent years, in order to further extend the life of the bearing device, it may be desired to suppress fretting wear at the contact portion between the inner ring and the spacer. Therefore, for example, in the bearing device of Patent Document 1, in order to suppress fretting wear between the inner ring and the spacer (interval ring), a resin spacer is also arranged between them.

Special Table 2004-500518

In the bearing device of Patent Document 1, the thickness of the resin spacer arranged between the inner ring and the positioning member directly affects the positioning accuracy of the inner ring. However, the resin spacer is more easily deformed than the inner ring and the positioning member, and its thickness can be changed by the pressing force acting between the inner ring and the positioning member. As a result, at the time of assembly, the axial accuracy of the bearing is lowered, and it becomes difficult to manage the gap inside the bearing.

In addition, the resin spacer may be creep-deformed depending on the period of use, and a gap may be formed between the inner ring and the positioning member, which may cause a displacement of the inner ring. In a configuration in which such a gap can be formed, the axial accuracy of the bearing tends to decrease during use as well as during assembly. Therefore, it is difficult to maintain the axial accuracy of the bearing for a long period of time, and the life of the bearing device cannot be sufficiently extended.

The present invention extends the life of a bearing device by maintaining the axial accuracy of the bearing for a long period of time while reliably suppressing fretting wear and the accompanying wear debris from entering the bearing. Make it an issue.

The present invention, which was devised to solve the above problems, includes a rolling bearing having an inner ring and an outer ring, a positioning member mounted on the outer peripheral surface of the axle, and a positioning member for axially positioning the inner ring with respect to the axle, and an inner ring. Axle bearing device provided with a spacer arranged between the mating surface of the inner ring and the mating surface of the positioning member. The mating surface of the inner ring and the mating surface of the positioning member are in direct contact with each other on the inner diameter side. A core metal having a contact portion, the spacer is in contact with either the mating surface of the inner ring or the mating surface of the positioning member on the outer diameter side of the direct contact portion, and has an axial gap between the other and the other. It is characterized by including an elastic sealing material that seals between the mating surface of the inner ring and the mating surface of the positioning member on the outer diameter side of the axial gap.

In this way, the elastic sealing material seals the outer diameter side between the mating surface of the inner ring and the mating surface of the positioning member, so that fretting wear is performed between the mating surface of the inner ring and the mating surface of the positioning member. Even if the wear debris is generated, it is possible to prevent the wear debris from entering the inside of the bearing.

At the time of assembly, the inner ring can be accurately positioned with respect to the axle by the direct contact portion between the mating surface of the inner ring and the mating surface of the positioning member. At this time, since there is an axial gap between the core metal and the mating surface of the inner ring or the mating surface of the positioning member, the core metal does not positively press the inner ring. That is, the core metal does not adversely affect the positioning of the inner ring by the direct contact portion.

Due to the deflection of the axle during use, for example, in the lower region of the axle, a pressure region on which a force acting to narrow the distance between the mating surface of the inner ring and the mating surface of the positioning member acts is formed, and the upper part of the axle is formed. A decompression region is formed in the region on which a force for increasing the distance between the mating surfaces of the inner ring and the mating surfaces of the positioning members acts. In the pressurized region, at least a part of the axial gap disappears with compression deformation of the elastic sealing material. As a result, at least a part of the core metal comes into contact with both the mating surface of the inner ring and the mating surface of the positioning member. By the contact of the core metal, the pressing force acting on the direct contact portion can be dispersed to the core metal, and the pressing force acting on the direct contact portion in the pressurized region can be relatively small. Therefore, at the time of use, the difference between the pressing force acting on the direct contact portion in the depressurized region and the pressing force acting on the direct contact portion in the pressurized region can be reduced. Therefore, the repetitive stress acting with the rotation of the axle is reduced, and the fretting wear at the direct contact portion can be suppressed. In addition, since the fretting wear tends to be smaller on the inner diameter side than on the outer diameter side, the fretting wear on the direct contact portion can be more reliably suppressed by providing the direct contact portion on the inner diameter side. That is, if the inner ring is accurately positioned with respect to the axle by the direct contact portion at the time of assembly, the axial accuracy of the bearing can be maintained for a long period of time by the direct contact portion even during the subsequent use.

In the above configuration, either one of the mating surface of the inner ring and the mating surface of the positioning member is provided with an axial recess at a position on the outer diameter side of the direct contact portion, and the core metal is a shaft that engages with the axial recess. It is preferable to provide a directional protrusion.

In this way, the radial movement of the spacer is restricted by engaging the axial concave portion and the axial convex portion with each other, so that the spacer assembly work and the bearing device assembly work can be efficiently performed. it can.

In the above configuration, the inner rings are arranged in pairs at intervals in the axial direction, and the positioning members are arranged between the pair of inner rings via spacers, and have mating surfaces with respect to the inner rings on both ends in the axial direction. It is preferable to provide a spacer.

In this way, fretting wear between the mating surface of the inner ring and the mating surface of the spacer can be suppressed.

When the inner ring is separated into two and the positioning member is provided with a spacer, the core metal is provided between the mating surface of one inner ring and the mating surface provided on one end side in the axial direction of the spacer, and the other. A pair of first metal portions arranged between the mating surface of the inner ring and the mating surface provided on the other end side in the axial direction of the spacer, and a pair of the said ones arranged on the outer peripheral surface of the spacer. It is preferable to include a second metal portion that connects the first metal portions.

In this way, the axial distance between the pair of first metal portions can be maintained constant by the second metal portions, so that the core metal is applied to the mating surfaces provided at both ends in the axial direction of the spacer. It becomes easy to arrange the provided spacer.

When the core metal includes the first metal portion and the second metal portion, it is preferable that the first metal portion abuts on the mating surface of the spacer and has an axial gap between the mating surface of the inner ring.

When the core metal includes the first metal portion and the second metal portion, an axial gap is formed between the mating surface of the spacer and the first metal portion at the time of assembly, and the first metal portion is formed on both mating surfaces of the pair of inner rings. When a single metal portion (core metal) is brought into contact with the metal portion, there is a possibility that the mating surfaces of the inner rings and the mating surfaces of the spacers are prevented from directly contacting each other. This is because the second metal portion (axial portion of the core metal) hits and stretches the mating surfaces of the inner ring before the mating surfaces of the spacer. On the other hand, if the first metal portion is brought into contact with the mating surface of the spacer and an axial gap is formed between the mating surface of the inner ring as in the above configuration, such a problem may occur. There is no need to ensure that the mating surfaces of the inner ring and the mating surfaces of the spacers are in direct contact with each other. That is, it becomes easy to form the direct contact portion.

In the above configuration, it is preferable that the positioning member is arranged on the rear end side in the axial direction of the inner ring via a spacer, and has a rear lid having a mating surface with respect to the inner ring on the front end side in the axial direction.

In this way, fretting wear between the mating surface of the inner ring and the mating surface of the rear lid can be suppressed.

In the above configuration, the hardness of the core metal is preferably lower than the hardness of the inner ring.

In this way, the fretting wear of the inner ring can be suppressed more reliably.

In this case, the core metal is preferably made of a cold-rolled rigid plate, a hot-rolled soft rigid plate, a high-strength rigid plate, a stainless steel plate, a high-dip galvanized rigid plate, or a brass plate.

By doing so, it is possible to impart an appropriate hardness to the core metal.

In the above configuration, the elastic sealing material is preferably made of nitrile rubber, acrylic rubber or fluororubber.

In this way, the heat resistance, oil resistance and abrasion resistance of the elastic sealing material can be improved.

According to the present invention, the life of the bearing device for axles is extended because the axial accuracy of the bearing can be maintained for a long period of time while reliably suppressing the fretting wear and the accompanying wear debris from entering the bearing. it can.

It is sectional drawing which shows the whole structure of the bearing device for an axle which concerns on embodiment of this invention. It is sectional drawing which shows the periphery of the spacer of FIG. 1 enlarged. It is sectional drawing for demonstrating the procedure of incorporating a 1st spacer into a spacer. It is sectional drawing which shows the state which incorporated the 1st spacer into a spacer. FIG. 5 is an enlarged cross-sectional view showing the periphery of the rear lid of FIG. It is sectional drawing which enlarges and shows the periphery of the spacer of FIG. 1 in the pressure region at the time of use. It is sectional drawing which enlarges and shows the periphery of the spacer of FIG. 1 in the decompression region at the time of use. It is sectional drawing which enlarges and shows the periphery of the spacer in the bearing device for an axle which concerns on another Embodiment of this invention. It is sectional drawing which enlarges and shows the periphery of the spacer in the bearing device for an axle which concerns on another Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification, the "axial direction" means the axial direction (longitudinal direction) of the axle. The position closer to the axial end of the axle is called "front", and the position closer to the center of the axle in the axial direction is called "rear". The "radial direction" basically refers to the radial direction of the axle, but refers to the radial direction of members (for example, the front lid, the rear lid, the inner ring, the outer ring, etc. of the rolling bearing) arranged concentrically with the axle. In some cases, when describing the relative positional relationship, the position on the inner side in the radial direction (the position closer to the axle) is called the "inner diameter side", and the position on the outer side in the radial direction (the position closer to the axle) than the inner diameter side. The position away from the axle) is called the "outer diameter side".

FIG. 1 shows an example in which an axle bearing device (hereinafter, simply referred to as a bearing device) 1 according to an embodiment of the present invention is assembled to an axle S of a railway vehicle. The bearing device 1 includes a rolling bearing 2 that rotatably supports the axle S, and a pair of sealing devices 3.

The rolling bearing 2 is a so-called double-row tapered roller bearing, and includes an outer ring 4, a pair of inner rings 5, a plurality of tapered rollers 6 as rolling elements, and a cage 7.

The outer ring 4 has conical raceway surfaces 4a arranged in a plurality of rows on the inner peripheral surface.

Each of the pair of inner rings 5 has a conical raceway surface 5a on the outer peripheral surface. A spacer 8 is provided between the pair of inner rings 5. The pair of inner rings 5 are arranged so that their small-diameter side ends face each other in the axial direction via the spacer 8.

The plurality of tapered rollers 6 are arranged in a double row corresponding to the raceway surface 4a of the double row of the outer ring 4 and the raceway surface 5a of the pair of inner rings 5.

The cage 7 holds the tapered rollers 6 in each row at equal intervals in the circumferential direction.

The outer ring 4 is fitted to the inner peripheral surface of the axle box (not shown) of the railway vehicle. On the other hand, the inner ring 5 is fitted to the outer peripheral surface of the axle S. An oil drain 9 and a rear lid 10 are provided on the front end side and the rear end side of the pair of inner rings 5 outside the bearing, respectively. A front lid 11 is fixed to the front end (shaft end) of the axle S with a bolt 12, and an oil drain mounted on the outer peripheral surface of the axle S together with the inner ring 5 between the front lid 11 and the shoulder portion Sa of the axle S. 9. The spacer 8 and the rear lid 10 are sandwiched and fixed. That is, in the present embodiment, the oil drain 9, the spacer 8 and the rear lid 10 are positioning members for positioning the inner ring 5 in the axial direction. These positioning members have a tubular shape for mounting on the outer peripheral surface of the axle S.

A lubricant such as grease is sealed in the bearing internal space formed between the outer ring 4 and the inner ring 5.

The pair of sealing devices 3 seal the front and rear ends of the bearing internal space in which the lubricant is sealed. In each sealing device 3, the sealing member 13 and the stepped cylindrical seal cover 14 whose outer diameter side end is fixed to the outer ring 4 and whose inner diameter side end is arranged close to the oil drain 9 or the rear lid 10. And. The seal member 13 is attached to the inner peripheral surface of the seal cover 14. The seal member 13 may be either a so-called contact type or a non-contact type.

A first spacer 15 is arranged between the inner ring 5 and the spacer 8, and a second spacer 16 is arranged between the rear lid 10 and the inner ring 5.

As shown in FIG. 2, the mating surfaces 17 of the pair of inner rings 5 adjacent to the first spacer 15 are provided on the rear end side of the inner ring 5 on the front side and the front end side of the inner ring 5 on the rear side, respectively. The mating surface 17 of each inner ring 5 is an end surface extending in the radial direction. The mating surfaces 18 of the spacer 8 adjacent to the first spacer 15 are provided on both front and rear ends of the spacer 8. Each mating surface 18 of the spacer 8 extends radially (rearly or forwardly) from the mating surface 17 of the inner ring 5 with respect to the inner diameter side end surface 18a extending in the radial direction. It is provided with a radial end surface 18b. The inner diameter side portion of the mating surface 17 of the inner ring 5 and the inner diameter side end surface 18a of the spacer 8 form a direct contact portion 19 that directly contacts each other.

The first spacer 15 includes a core metal 20 and an elastic sealing material 21 integrally formed with the core metal 20. The core metal 20 and the elastic sealing material 21 may be separate bodies that can be separated from each other.

The core metal 20 comes into contact with the outer diameter side end surface 18b of the mating surface 18 of the spacer 8, and has a pair of first metal portions 22 having an axial gap G1 with the mating surface 17 of the inner ring 5, and a pair of first metal portions 22. A second metal portion 23 that connects between the outer diameter side ends of the one metal portion 22 and abuts on the outer peripheral surface 8a extending in the axial direction of the spacer 8 is provided. The first metal portion 22 and the second metal portion 23 may be in direct contact with the spacer 8 as shown in the illustrated example, or may be in contact with the spacer 8 via an elastic sealing material (not shown). Good.

The first metal portion 22 has an annular plate shape, and the second metal portion 23 has a cylindrical shape. The axial separation distance of the pair of first metal portions 22 is maintained constant by the second metal portions 23.

The first metal portion 22 is provided on the inner diameter side of the thick portion 22a and the outer diameter side of the thick portion 22a, and is provided in the axial direction (rear or front) from the mating surface 17 of the inner ring 5 with respect to the thick portion 22a. ) Is provided with a thin-walled portion 22b. That is, on the mating surface 17 side of the inner ring 5 of the first metal portion 22, an axial step portion 22x is formed between the thick portion 22a and the thin wall portion 22b, and the seat of the first metal portion 22. On the mating surface 18 side of 8, the thick portion 22a and the thin portion 22b are smoothly continuous. The thickness of the first metal portion 22 may be constant.

The axial gap G1 is formed at a position on the outer diameter side of the direct contact portion 19 and corresponding to the vicinity of the inner diameter side end portion of the thick portion 22a and the thin wall portion 22b. In the present embodiment, the elastic sealing material 21 is not in contact with the mating surface 17 of the inner ring 5 due to the axial gap G1 at the position corresponding to the vicinity of the inner diameter side end portion of the thin wall portion 22b.

The axial clearance G1 is formed in a state where the axle S is not bent at the time of assembly or the like, and its size changes according to the bending of the axle S. The size of the axial gap G1 is such that when the elastic sealing material 28 is compressed and deformed due to the bending of the axle S, at least a part of the first metal portion 22 of the core metal 20 is the mating surface 17 of the inner ring 5 and the spacer 8. The range is set so that both of the mating surfaces 18 can be contacted (see FIG. 6).

The elastic sealing material 21 can be expanded or deformed or compressed and deformed according to the bending of the axle S, and the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 are formed on the outer diameter side of the axial gap G1. Seal between. Specifically, the elastic sealing material 21 has an outer surface (outer peripheral surface) of the second metal portion 23 and an outer surface (surface on the inner ring 5 side) of the thin-walled portion 22b of the first metal portion 22 continuous thereto. Covering. As a result, when viewed from the outer diameter side, the space between the mating surfaces 17 of the pair of inner rings 5 is covered with the elastic sealing material 21. The elastic sealing material 21 is sandwiched from both sides by a pair of wall surfaces (in the illustrated example, the mating surfaces 17 of the inner rings 5) extending in the radial direction and facing each other in the axial direction in order to improve the sealing property. Is preferable.

The first spacer 15 is divided into a plurality of parts (for example, two) in the circumferential direction, and as shown in FIG. 3, each part of the divided first spacer 15 is attached to the spacer 8 from the outer diameter side. It is possible.

The spacer 8 has an axial recess 18c between the inner diameter side end surface 18a and the outer diameter side end surface 18b, and the first metal portion 22 of the core metal 20 engages with the axial recess 18c at the inner diameter side end surface. It has an axially convex portion 22c to be formed. By engaging the axial convex portion 22c with the axial concave portion 18c, even if the first spacer 15 is divided in the circumferential direction, the axial convex portion 22c is caught by the axial concave portion 18c and is the first with respect to the spacer 8. The radial movement of the spacer 15 is restricted. The axial concave portion 18c and the axial convex portion 22c may be provided intermittently in the circumferential direction, but are provided on the entire circumference in the present embodiment. The axial concave portion 18c and the axial convex portion 22c may be omitted.

As shown in FIG. 4, in the state where the first spacer 15 is attached to the spacer 8 (the state before positioning the inner ring 5), the maximum width in the axial direction of the elastic sealing material 21 is A, and the axial direction of the core metal 20 is set. When the maximum width of is B and the maximum width of the inner diameter side end surface 18a of the spacer 8 in the axial direction is C, the relationship A> C> B is established. As a result, as shown in FIG. 2, in a state where the spacer 8 is pressed against the inner ring 5 and the inner ring 5 is positioned with respect to the axle S, the first spacer arranged between the spacer 8 and the inner ring 5 is provided. The elastic sealing material 21 of 15 is compressed by a predetermined crushing allowance α ((AC) / 2) to improve the sealing property. Further, in a state where the elastic sealing material 21 and the inner diameter side end surface 18a of the spacer 8 are in contact with the mating surface 17 of the inner ring 5, an axial gap G1 is automatically formed between the core metal 20 and the inner ring 5. To. The crushing allowance α of the elastic sealing material 21 is set within a range in which the elastic sealing material 21 can be compressed and deformed. Specifically, the crushing allowance α is, for example, 0.1 to 0.5 mm.

As shown in FIG. 5, the mating surface 24 of the inner ring 5 adjacent to the second spacer 16 is provided on the rear end side of the inner ring 5 on the rear side. The mating surface 24 of the inner ring 5 is an end surface extending in the radial direction. The mating surface 25 of the rear lid 10 adjacent to the second spacer 16 is provided on the front end side of the rear lid 10. The mating surface 25 of the rear lid 10 includes an inner diameter side end surface 25a extending in the radial direction and an outer diameter side end surface 25b extending in the radial direction at a position shifted rearward from the inner diameter side end surface 25a. The inner diameter side portion of the mating surface 24 of the inner ring 5 and the inner diameter side end surface 25a of the rear lid 10 form a direct contact portion 26 that directly contacts each other.

The second spacer 16 includes a core metal 27 and an elastic sealing material 28 integrally formed with the core metal 27. The core metal 27 and the elastic sealing material 28 may be separate bodies that can be separated from each other.

The core metal 27 is in contact with the outer diameter side end surface 25b of the mating surface 25 of the rear lid 10, and has an axial gap G2 between the core metal 27 and the mating surface 24 of the inner ring 5 and the first metal portion 29. A second metal portion 30 which is connected to the outer diameter side end portion of the rear lid 10 and abuts on the outer peripheral surface 10a extending in the axial direction of the rear lid 10 is provided. The first metal portion 29 and the second metal portion 30 may be in direct contact with the rear lid 10 as shown in the illustrated example, or may be in contact with the rear lid 10 via an elastic sealing material (not shown). Good.

The first metal portion 29 has an annular plate shape, and the second metal portion 30 has a cylindrical shape. The second spacer 16 may be divided in the circumferential direction, but in the present embodiment, it is a single member that is not divided in the circumferential direction. The radial movement of the second spacer 16 with respect to the rear lid 10 is regulated by the second metal portion 30. In this case, the second spacer 16 can be attached to the rear lid 10 from the axial direction. The core metal 27 may be a plate-like body composed of only the first metal portion 29, omitting the second metal portion 30.

The first metal portion 29 is a thin portion 29a provided on the inner diameter side and a thin portion 29a provided on the outer diameter side of the thick portion 29a and separated from the mating surface 24 of the inner ring 5 rearward from the thick portion 29a. 29b and. That is, on the mating surface 24 side of the inner ring 5 of the first metal portion 29, an axial step portion 29x is formed between the thick portion 29a and the thin wall portion 29b, and the rear lid of the first metal portion 29. On the mating surface 25 side of 10, the thick portion 29a and the thin portion 29b are smoothly continuous. The thickness of the first metal portion 29 may be constant.

The axial gap G2 is formed at a position on the outer diameter side of the direct contact portion 26 and corresponding to the vicinity of the inner diameter side end portion of the thick portion 29a and the thin wall portion 29b. In the present embodiment, the elastic sealing material 28 is not in contact with the mating surface 24 of the inner ring 5 due to the axial gap G2 at the position corresponding to the vicinity of the inner diameter side end portion of the thin wall portion 29b.

The axial clearance G2 is formed in a state where the axle S is not bent at the time of assembly or the like, and its size changes according to the bending of the axle S. The size of the axial gap G2 is such that when the elastic sealing material 28 is compressed and deformed due to the bending of the axle S, at least a part of the first metal portion 29 of the core metal 27 is the mating surface 24 of the inner ring 5 and the rear lid 10. The range is set so that both of the mating surfaces 25 can be contacted.

The elastic sealing material 28 can be expanded or deformed or compressively deformed according to the bending of the axle S, and the mating surface 24 of the inner ring 5 and the mating surface 25 of the rear lid 10 are on the outer diameter side of the axial gap G2. Seal between. Specifically, the elastic sealing material 28 includes an outer surface (outer peripheral surface) of the second metal portion 30 and an outer surface (surface on the inner ring 5 side) of the thin-walled portion 29b of the first metal portion 29 continuous thereto. Covering. As a result, when viewed from the outer diameter side, the space between the mating surface 24 of the inner ring 5 and the mating surface 25 of the rear lid 10 is covered with the elastic sealing material 28. The elastic sealing material 28 extends in the radial direction and faces each other in the axial direction in order to improve the sealing property (in the case of the illustrated example, the mating surface 24 of the inner ring 5 and the rear lid 10 in the radial direction). It is preferable that the outer peripheral surface 10b) extends from both sides.

The core metal 20 of the first spacer 15 and the core metal 27 of the second spacer 16 preferably have a hardness lower than that of the inner ring 5. The cores 20 and 27 are preferably made of, for example, a cold-rolled rigid plate, a hot-rolled soft rigid plate, a high-strength rigid plate, a stainless steel plate, a high-dip galvanized rigid plate, or a brass plate. The thickness of the cores 20 and 27 is preferably 0.8 to 2.0 mm, for example.

The elastic sealing material 21 of the first spacer 15 and the elastic sealing material 28 of the second spacer 16 are preferably made of nitrile rubber, acrylic rubber or fluororubber.

According to the bearing device 1 having the above configuration, the following effects can be obtained. The action and effect of the first spacer 15 and the direct contact portion 19 between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 is such that the second spacer 16 and the direct contact portion 26 have the inner ring 5. It is substantially the same as the action and effect exerted between the mating surface 24 and the mating surface 25 of the rear lid 10. In the following, the action and effect obtained by the first spacer 15 and the direct contact portion 19 will be described as an example, and the description of the action and effect obtained by the second spacer 16 and the direct contact portion 26 will be omitted.

The elastic sealing material 21 of the first spacer 15 seals the outer diameter side of the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8. As shown in FIG. 6, a pressure region (for example, the axle S) on which a force F1 acting to narrow the distance between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 acts due to the deflection of the axle S during use. In the lower region) D, the elastic sealing material 21 is compressed and deformed. On the other hand, as shown in FIG. 7, a decompression region (for example, the axle S) on which a force F2 acting to increase the distance between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 acts due to the deflection of the axle S during use. In the upper region) U, the elastic sealing material 21 expands and deforms. Due to such compression deformation and expansion deformation of the elastic sealing material 21, the outer diameter side of the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 is always sealed. As a result, even if wear debris due to fretting wear is generated between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8, it is possible to prevent the wear debris from invading the inside of the bearing.

Since the direct contact portion 19 is provided on the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8, the inner ring 5 can be accurately positioned in the axial direction with respect to the axle S by the spacer 8 at the time of assembly. At this time, since the core metal 20 of the first spacer 15 is not in contact with the mating surface 17 of the inner ring 5 due to the axial gap G1, the positioning accuracy of the inner ring 5 by the direct contact portion 19 is not adversely affected. .. Here, in the pressurizing region D, the distance between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 is narrowed, so that the amount of pressurization in the pressurizing region D is from the inner diameter side to the outer diameter side. growing. On the other hand, in the decompression region U, the distance between the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8 is increased, so that the amount of decompression in the decompression region U increases from the inner diameter side to the outer diameter side. That is, the fretting wear tends to be large on the outer diameter side and smaller on the inner diameter side. Therefore, by providing the direct contact portion 19 on the inner diameter side, fretting wear in the direct contact portion 19 can be reduced.

As shown in FIG. 6, in the pressure region D in which the force F1 acts due to the bending of the axle S during use, at least a part of the axial gap G1 disappears with compression deformation of the elastic sealing material 21. As a result, at least a part of the core metal 20 comes into contact with both the mating surface 17 of the inner ring 5 and the mating surface 18 of the spacer 8. By the contact of the core metal 20, the pressing force acting on the direct contact portion 19 can be dispersed to the core metal 20, and the pressing force acting on the direct contact portion 19 in the pressurizing region D can be made relatively small. Therefore, at the time of use, the difference between the pressing force acting on the direct contact portion 19 in the decompression region U and the pressing force acting on the direct contact portion 19 in the pressurizing region D can be reduced. Therefore, the repetitive stress acting with the rotation of the axle S is reduced, and the fretting wear at the direct contact portion 19 can be suppressed more reliably. That is, if the inner ring 5 is accurately positioned in the axial direction with respect to the axle S by the direct contact portion 19 at the time of assembly, fretting wear and the accompanying wear debris will be transferred to the inside of the bearing even during the subsequent use. Since the axial accuracy of the rolling bearing 2 can be maintained for a long period of time while reliably suppressing intrusion, the life of the bearing device 1 can be sufficiently extended.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea.

In the above embodiment, the core metal 20 of the first spacer 15 comes into contact with the mating surfaces 18 provided on both front and rear ends of the spacer 8 and has an axial gap G1 with the mating surfaces 17 of the inner ring 5. An example is illustrated in which a pair of first metal portions 22 and a second metal portion 23 that connects between the outer diameter side ends of the pair of first metal portions 22 and abuts on the outer peripheral surface 8a of the spacer 8 are provided. However, as shown in FIG. 8, the second metal portion 23 may be divided into two in the axial direction. Alternatively, as shown in FIG. 9, the core metal 20 of the first spacer 15 may be a plate-like body (for example, an annular plate shape) composed of only the first metal portion 22 by omitting the second metal portion 23. In the case of the embodiment illustrated in FIGS. 8 and 9, separate first spacers 15 are attached to both front and rear ends of the spacer 8.

In the above embodiment, the cores 20 and 27 of the first spacer 15 and the second spacer 16 come into contact with positioning members such as the spacer 8 and the rear lid 10, and the axial gaps G1 and G2 are brought into contact with the inner ring 5. However, the present invention is not limited to this. The cores 20 and 27 may come into contact with the inner ring 5 and have an axial gap between them and the positioning member.

In the above embodiment, the case where the spacer 8 is provided with the axial recess 18c and the core metal 20 of the first spacer 15 is provided with the axial convex portion 22c that engages with the axial recess 18c has been illustrated. May be provided on the inner ring 5, and an axially convex portion that engages with the axial concave portion may be provided on the core metal 20 of the first spacer 15. Further, the core metal 27 of the second spacer 16 may be provided with an axial convex portion, and the rear lid 10 may be provided with an axial concave portion that engages with the axial convex portion. Alternatively, an axial recess may be provided in the inner ring 5, and an axial convex portion that engages with the axial recess may be provided in the core metal 27 of the second spacer 16.

In the above embodiment, the case where the first spacer 15 is arranged between the inner ring 5 and the spacer 8 and the second spacer 16 is arranged between the inner ring 5 and the rear lid 10 has been illustrated. A spacer according to the present invention may also be arranged between the 9 and the inner ring 5. That is, between the inner ring 5 and the spacer 8, between the inner ring 5 and the rear lid 10, and between the inner ring 5 and the oil drain 9 (the oil drain 9 is omitted, and the front lid 11 directly contacts the inner ring 5). In this case, the spacer according to the present invention may be arranged in at least one of (between the inner ring 5 and the front lid 11). However, since the fretting wear tends to decrease toward the front end of the axle S, from the viewpoint of suppressing the fretting wear, only between the inner ring 5 and the rear lid 10, or the inner ring 5 and the rear lid 10 It is preferable to apply the spacer according to the present invention between the inner ring 5 and the spacer 8.

In the above embodiment, as the inner ring, a spacer 8 is provided between the pair of inner rings 5 divided into two, but the inner ring is a pair of inner rings 5 with the spacer 8 omitted. The small diameter side ends may be directly butted, or a single member in which a pair of inner rings 5 are integrated may be used.

In the above embodiment, the tapered roller bearing is exemplified as the rolling bearing 2, but the present invention is not limited to this, and the present invention can be applied to a cylindrical roller bearing and other bearings.

1 Bearing device 2 Rolling bearing 3 Sealing device 4 Outer ring 5 Inner ring 6 Conical rollers 7 Cage 8 Spacer 10 Rear lid 15 First spacer 16 Second spacer 19 Direct contact part 20 Core metal 21 Elastic sealant 26 Direct contact part 27 Core metal 28 Elastic sealant G1 Axial gap G2 Axial gap S Axle

Claims (9)

A rolling bearing having an inner ring and an outer ring, a positioning member mounted on the outer peripheral surface of the axle and positioning the inner ring in the axial direction with respect to the axle, and a mating surface of the inner ring and a mating surface of the positioning member. Axle bearing device with spacers arranged between them.
The mating surface of the inner ring and the mating surface of the positioning member are provided with direct contact portions that come into contact with each other on the inner diameter side.
The spacer is in contact with either one of the mating surface of the inner ring and the mating surface of the positioning member on the outer diameter side of the direct contact portion, and has an axial gap between the spacer and the other. An axle bearing device comprising an elastic sealing material that seals between the mating surface of the inner ring and the mating surface of the positioning member on the outer diameter side of the axial gap. One of the mating surface of the inner ring and the mating surface of the positioning member is provided with an axial recess at a position on the outer diameter side of the direct contact portion, and the core metal is a shaft that engages with the axial recess. The axle bearing device according to claim 1, further comprising a directional protrusion. The inner rings are arranged in pairs at intervals in the axial direction.
The first or second aspect of the present invention, wherein the positioning member is arranged between the pair of inner rings via the spacer, and has spacers having mating surfaces with respect to the inner rings on both end sides in the axial direction. Axle bearing device. The core metal is provided between the mating surface of one inner ring and the mating surface provided on one end side in the axial direction of the spacer, and the mating surface of the other inner ring and the axial direction of the spacer. A pair of first metal portions arranged between the mating surfaces provided on the end side and a second metal arranged on the outer peripheral surface of the spacer and connecting between the pair of first metal portions. The axle bearing device according to claim 3, further comprising a portion. The axle bearing device according to claim 4, wherein the first metal portion is in contact with the mating surface of the spacer and has the axial gap between the mating surface of the inner ring. Claims 1 to 5 are characterized in that the positioning member is arranged on the rear end side of the inner ring in the axial direction via the spacer, and has a rear lid having a mating surface with respect to the inner ring on the front end side in the axial direction. The axle bearing device according to any one of the above. The axle bearing device according to any one of claims 1 to 6, wherein the hardness of the core metal is lower than the hardness of the inner ring. The axle bearing according to claim 7, wherein the core metal is made of a cold-rolled rigid plate, a hot-rolled soft rigid plate, a high-tensile rigid plate, a stainless steel plate, a high-dip galvanized rigid plate, or a brass plate. apparatus. The axle bearing device according to any one of claims 1 to 8, wherein the elastic sealing material is made of nitrile rubber, acrylic rubber or fluororubber.

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