CN117588487A - Rolling bearings and axle bearings for railway vehicles - Google Patents

Abstract

A rolling bearing including an inner ring, an outer ring, rolling elements sandwiched between the inner and outer rings, a retainer disposed between the inner and outer rings to hold the rolling elements, and an opening between the inner and outer rings. Sealed sealing device. Let the volume of the static space in the sealing device be A and A', and the volume of the static space between a pair of inner rings and the inner surface of the outer ring facing them be B. From the cage and the roller, When the volume of the moving space, excluding the volume of the cage and the roller itself, is set to A1 and A1', and the total space volume of the bearing is set to V, let it be V=(A‑+‑A'+B +A1+A1'), and set to 15V%≤(A1+A1')≤45V%.

Description

Rolling bearings and axle bearings for railway vehicles

Technical field

The present invention relates to rolling bearings and axle bearings for railway vehicles.

Background technique

As shown in FIG. 4 , the bearing for railway vehicles includes an outer ring 1 , a pair of inner rings 2 , 2 , and tapered rollers 3 as rolling elements forming two rows. The tapered rollers 3 in each row are held at a predetermined position in the circumferential direction. The main components are retainers 4 at intervals and sealing devices S installed at both ends of the outer ring 1 .

The outer ring 1 is assembled to an axle box (not shown), and the pair of inner rings 2 and 2 are fitted to the shaft ends of the axle 5 . A pair of inner rings 2, 2 are sandwiched, a slinger 6 is provided on one end side of the axle shaft 5, and a back cover 7 is provided on the opposite side (the other end side).

The sealing device S is composed of a sealing case 10 and a sealing member 11 including an oil seal housed in the sealing case 10 . The sealing case 10 is made of metal, and in this illustration, has a three-stage cylindrical shape including a large diameter portion 10a, a medium diameter portion 10b, and a small diameter portion 10c. Among them, the large-diameter portion 10 a is fitted and fixed to the inner circumference of the outer ring 1 by, for example, press-fitting, whereby the sealing device S is fixed to the outer ring 1 .

However, in recent axle bearings for railway vehicles, acceleration and deceleration are repeated over a wide range of rotational speeds during use, the applied load always fluctuates, and they are used under various weather conditions. Therefore, regular maintenance is required, and maintenance-saving is sought. Reduced maintenance costs.

Therefore, the extension of the maintenance cycle of vehicles has attracted attention, and bearings are required to have a longer life. The life of sealed double-row tapered roller bearings used in axle bearings for railway vehicles has a greater impact on the lubrication life due to deterioration of the lubricant than the rolling fatigue life of the bearing. Therefore, by increasing the By increasing the amount of lubricants such as grease, a longer life is expected. On the other hand, if there is too much grease, there is a problem of stirring resistance of the grease and heat generation due to the entanglement of the grease, thereby accelerating the deterioration of the grease.

Conventionally, a device equipped with a mechanism for replenishing new grease into the inside of the bearing from the outside has been proposed for a bearing device that is assembled in a railway vehicle and is in use (Patent Document 1). In this case, there is an intermediate grease supply mechanism that supplies an auxiliary lubricating material to the existing lubricant sealed inside the bearing. In addition, the intermediate fat supply mechanism has a structure in which the liquid is filled into the bag body, and the liquid leaks out of the bag body due to the deterioration of the bag body over time. The volume of the expansion body is increased by contact with the liquid, and through the expansion The volume of the body increases and the auxiliary lubricant is squeezed out into the inside of the bearing.

Therefore, after a predetermined period of time has elapsed after the bearing device is assembled on the axle, the new auxiliary lubricant automatically supplied from the intermediate grease supply mechanism contributes to the lubrication based on the existing lubricant inside the bearing. Therefore, this auxiliary Lubricants maintain the lubricity of bearings. In this way, the lubrication life of the bearing device can be extended by using a simple automatic greasing means such as an intermediate grease supply mechanism installed in the bearing device. As a result, maintenance man-hours and equipment costs for intermediate grease supply can be easily reduced.

Prior technical documents

patent documents

Patent Document 1: Japanese Patent Application Publication No. 2020-148321

As described in the above-mentioned Patent Document 1, in a device provided with an intermediate grease supply mechanism, it is considered that by supplying auxiliary grease midway, the bearing lubrication life can be extended, thereby extending the maintenance cycle of the vehicle. However, the timing of supplying auxiliary grease depends on the deterioration of the bag due to heat generated by the bearing. Therefore, the material, thickness, etc. of the bag need to be carefully checked for each use condition, making control complicated. In addition, since the deteriorated grease inside the bearing is not discharged to the outside of the bearing, the grease sealing capacity inside the bearing is increased. Therefore, in consideration of the fear of an increased chance of temperature rise due to the entanglement of grease, by just adding the oil to the bearing Stirring of the internally replenished auxiliary grease takes into account the possibility of temporary heating of the bearing.

Contents of the invention

Invent the problem to be solved

Therefore, the present invention provides a rolling bearing and a railway vehicle axle bearing that can ensure a grease sealing amount that satisfies a required lubrication life by optimizing the space volume inside the bearing without changing the conventional bearing component structure. .

Solutions for solving problems

The rolling bearing of the present invention includes an inner ring, an outer ring, rolling elements sandwiched between the inner and outer rings, a retainer disposed between the inner and outer rings to hold the rolling elements, and sealing the opening between the inner and outer rings. For a sealing device, let the volumes of the static spaces in the sealing device be A and A', and let the volumes of the static spaces between a pair of inner rings and the inner surfaces of the outer rings facing them be B, When the volume of the moving space minus the volume of the retainer and rolling elements themselves is represented by the space through which the cage and rolling elements pass, let A1 and A1' be represented, and the total space volume of the bearing is represented by V, let V=(A+ A'+B+A1+A1'), and set to 15V%≤(A1+A1')≤45V%.

In the rolling bearing of the present invention, by setting 15V% ≤ (A1 + A1') ≤ 45V%, a certain degree of capacity of the static space (the static space of the sealing device) is ensured with respect to the amount of grease ejected from the moving space. , thus suppressing the heating of the bearing to a certain extent and obtaining some effects of extending the lubrication life. When the ratio of the volume of the moving space (A1+A1') to the total space volume V is greater than 45%, the capacity of the static space (the static space of the sealing device) is insufficient relative to the amount of grease ejected from the moving space. , the grease is frequently re-rolled due to the grease returning to the moving space side during use. When the initial grease filling amount is limited in order to suppress heat generation, the lubrication life is reduced due to insufficient grease amount. When the ratio of the volume of the moving space (A1+A1') to the total space volume V is less than 15% (less than 15%), the grease present in the moving space is affected by the pushing of the rolling elements and the centrifugal force. , grease accumulates in the static space (the static space of the sealing device), but at this ratio, the amount of grease that pops out is small, and the influence of heat caused by the re-rolling of grease, etc. is small. However, the proportion of rolling elements relative to the overall space volume of the bearing becomes smaller, and the rated load becomes too low relative to the bearing size.

When the ratio of the volume of the moving space (A1+A1') to the total space volume V is 15% or more and less than 30%, a sufficient static space (the sealing device) is required for the amount of grease ejected from the moving space. The capacity of the static space is ensured, thereby suppressing the heat generation of the bearing and achieving the effect of extending the lubrication life. In addition, when the ratio of the volume of the moving space (A1 + A1') to the total space volume V is 30% or more and 45% or less, the static space ( The capacity of the static space of the sealing device is ensured, so the heating of the bearing is suppressed to a certain extent, and a certain effect of extending the lubrication life is obtained.

Let the total space volume of the bearing be V, let the volume of the static space in the sealing device be A, A', and let the static space between a pair of inner rings and the inner surface of the outer ring facing it be When the volume of is B, it is 30V%≤(A+A')≤60V%, and B is preferably 15% or more of V.

When the ratio of the volume of the static space (A+A') in the sealing device to the total space volume V is less than 30%, due to the influence of centrifugal force during use and the influence of the rolling elements pushing away the grease, the grease accumulates in The static space within the sealing device is small, and the splashed grease returns to the moving space, causing frequent heat generation due to grease entanglement. In order to suppress heat generation, when the amount of grease sealed is reduced, the lubrication life is reduced. When the ratio of the volume (A+A') of the static space in the sealing device to the total space volume V is greater than 60%, a sufficient retention space for grease splashed by centrifugal force or the like can be ensured, and the heat generation of the bearing can be suppressed. . However, the proportion of rolling elements relative to the overall space volume of the bearing becomes smaller, and the rated load becomes too low relative to the bearing size.

When the ratio of the volume of the static space (A+A') in the sealing device to the total space volume V is 30% or more and less than 40%, a retention space for grease splashed by centrifugal force or the like is ensured to a certain extent. , suppressing the heating of the bearing to a certain extent and obtaining some effects of extending the lubrication life. In addition, when the ratio of the volume (A+A') of the static space in the sealing device to the total space volume V is 40% or more and 60% or less, retention of grease splashed by centrifugal force or the like can be sufficiently ensured. Space can suppress the heat generation of the bearing, thereby achieving the effect of extending the lubrication life.

When the ratio of the volume B of the static space (the static space between the inner rings) to the total space capacity V is less than 15%, the amount of grease filled becomes small. Therefore, it is preferable to set the ratio of the static space (the static space between the inner rings) B to the total space capacity V to be 15% or more.

It should be noted that it may also be the volume of the moving space (A1+A1’): the volume of the static space (A+A’): the volume of the static space B = 0.15: 0.30: 0.55. Even with this setting, there will be no problems with bearing function.

When the volumes of the static spaces in the sealing device are A and A', and the volumes of the static spaces between a pair of inner rings and the inner surfaces of the outer rings facing them are B, When the amount of grease sealed inside is G, it is 30(A+A'+B)%≤G≤80(A+A'+B)%.

When the ratio of the grease filling amount to the volume of the static space (A+A'+B) is less than 30%, the grease existing in the moving space is pushed away by the rotation of the bearing, and sufficient centrifugal force can be ensured. Although the space after the movement of splashed grease suppresses heat generation caused by the entanglement of grease, etc., it is not recommended because the grease is insufficient and the lubrication life is shortened.

When the ratio of the grease sealing amount to the volume of the static space (A+A'+B) is 30% or more and 70% or less, the capacity of the static space is sufficient relative to the amount of grease ejected from the moving space. It is ensured that heat generation is suppressed. In addition, when the ratio of the grease sealing amount to the volume of the static space (A+A'+B) is greater than 70% and 80% or less, a certain amount of grease is ejected from the moving space. The capacity of the static space is ensured, thus suppressing heat generation to a certain extent. When the ratio of the grease sealing amount to the volume of the static space (A+A'+B) is greater than 80%, the capacity of the static space is insufficient for the amount of grease ejected from the moving space, and the grease is used. Frequent fever occurs due to re-involvement.

An axle bearing for a railway vehicle of the present invention includes the rolling bearing. The axle bearing for railway vehicles of the present invention can ensure a grease sealing amount that satisfies the required lubrication life by optimizing the space volume inside the bearing without changing the conventional bearing component structure.

The axle bearing for a railway vehicle preferably includes an outer ring having a double-row track on its inner circumference, a pair of inner rings having a track on its outer circumference, and a double-row double-row bearing sandwiched between the inner ring and the outer ring. Tapered rollers, and retainers that maintain the tapered rollers in each row at predetermined intervals in the circumferential direction.

Invention effect

In the present invention, the grease sealing amount that satisfies the required lubrication life can be ensured by optimizing the space volume inside the bearing without changing the conventional bearing component structure.

Description of drawings

FIG. 1 is a cross-sectional view showing a railway vehicle axle bearing using the rolling bearing of the present invention.

FIG. 2 is an enlarged cross-sectional view of one sealing device.

Fig. 3 is an enlarged cross-sectional view of the other sealing device.

FIG. 4 is a cross-sectional view showing a conventional axle bearing for railway vehicles.

Explanation of reference symbols:

S, Sa, Sb sealing device

S1, 2 static space

S3, 4 mobile space

S5 still space

21 outer ring

21a track

22 inner ring

22a track

23 rolling elements

23 outer ring

24 retainer

27 Washers.

Detailed ways

Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 3 . FIG. 1 is an enlarged cross-sectional view showing a main part of a railway vehicle axle bearing according to the present invention. The bearing for a railway vehicle axle is mounted on the small diameter end portion 20a of the axle 20, and has an outer ring 21, a pair of inner rings 22, 22, and a plurality of rolling elements 23 as main components. The outer ring 21 is a double-row outer ring with two rows of rails 21a and 21a formed on the inner periphery. Rails 22a, 22a are formed on the outer periphery of each inner ring 22, 22. Two rows of rolling elements 23 are sandwiched between the track 21a of the outer ring 21 and the track 22a of the inner ring 22 so as to be rotatable. It should be noted that the rolling elements 23 are composed of tapered rollers 23a, and the tapered rollers 23a in each row are held at predetermined intervals in the circumferential direction by the retainer 24.

The outer ring 21 is fixed to an axle box (not shown), and the axle box is fixed to a trolley frame or the like via an axle spring. A front cover 25 is provided on one shaft end side of the pair of inner rings 22 , 22 , and a rear cover 26 is provided on the other shaft end side of the pair of inner rings 22 , 22 . In addition, the inner ring 22 has a large flange 22b on the large diameter side of its track 22a, and has a small flange 22c on the small diameter side of its track 22a.

As shown in FIGS. 1 and 2 , the front cover 25 includes a ring-shaped main body 25 a and a short cylindrical protrusion 25 b protruding from the outer diameter side of the inner surface of the main body 25 a toward the inside of the bearing. In this case, the protruding portion 25b is in a state of being fitted onto the end portion of the axle 20. In addition, a slinger 29 is interposed between the main body portion 25a of the front cover 25 and the inner ring 22 on the front cover 25 side. This slinger 29 has a short cylindrical main body part 29a and an inner flange part 29b that comes into contact with the inner ring of the main body part 29a. In addition, the inner diameter surface of the inner flange part 29b is in contact with the outer diameter surface of the end part of the axle 20.

As shown in FIGS. 1 and 3 , the rear cover 26 is composed of a cylinder having a tapered portion 26 a and a notch 26 b on the inner side of the counter bearing, and a small diameter portion 26 c and a large diameter portion 26 d formed on the outer diameter surface.

In addition, as shown in FIG. 1 , a sealing device S (Sa, Sb) for sealing the opening in the axial direction of the rolling bearing is disposed. It should be noted that the sealing devices Sa and Sb have substantially the same structure, so the sealing device Sa on the front cover 25 side will be described first.

As shown in FIG. 2 , the sealing device Sa includes a sealing case 40 attached to the axial end on the inner diameter side of the outer ring 21 , and a sealing member 43 disposed in the sealing case 40 .

The sealing case 40 is composed of a stepped cylindrical body having a large diameter portion 40a, a medium diameter portion 40b, and a small diameter portion 40c. A step portion 40d is provided between the large diameter portion 40a and the medium diameter portion 40b. A step portion 40e is provided between the small diameter portion 40c and the small diameter portion 40c. The large diameter portion 40a is fitted into the circumferential notch portion 21b provided at the end of the outer ring 21. In addition, the small diameter portion 40 c of the seal case 40 is fitted into the groove 25 a 1 provided on the outer diameter side of the end surface inside the bearing of the front cover 25 in a clearance fitting manner.

A frame 41 having an inverted L-shaped cross section is accommodated in the sealed case 40 . The frame 41 is composed of a first portion 41 a formed of a short cylinder embedded in the middle diameter portion 40 b of the sealing case 40 and a flat ring-shaped second portion 41 b. The portion 41b extends from the inner side of the bearing to the inner diameter side of the first portion 41a. The sealing member 43 includes a core metal 44 and a sealing lip 45 attached to the core metal 44 . The core member 44 is composed of a short cylindrical first portion 44a embedded in the first portion 41a of the frame 41 and a second portion 44b extending radially inward from the bearing outer end of the first portion 44a. The portion 44b is equipped with a sealing lip 45.

As shown in FIG. 3 , the other sealing device also includes a sealing case 40 having a large diameter portion 40a, a medium diameter portion 40b, a small diameter portion 40c, and step portions 40d and 40e, and a sealing case 40 disposed in the sealing case 40. Sealing member 43. In addition, the large diameter portion 40a is fitted into the circumferential notch portion 21c provided at the end portion of the outer ring 21. A circumferential groove 26e1 is provided on the stepped surface 26e of the outer surface of the rear cover 26, and the small diameter portion 40c of the sealing case 40 is fitted into the groove 26e1 in a clearance fitting manner.

Furthermore, a frame 41 having an inverted L-shaped cross section is accommodated in the sealing case 40 , and the sealing member 43 also includes a core member 44 and a sealing lip 45 attached to the core member 44 . It should be noted that the frame 41 is also composed of a first part 41a and a second part 41b, and the core member 44 is composed of a short cylindrical first part 44a embedded in the first part 41a of the frame 41 and a second part 44a formed from the first part 41a of the frame 41. A second portion 44b is formed from a bearing outer end of the first portion 44a extending radially inward, and a sealing lip 45 is mounted on the second portion 44b.

Grease is sealed inside the bearing of this rolling bearing. Here, grease refers to a semi-solid lubricant prepared by adjusting the viscosity of lubricating oil. The components of grease are basically composed of three types: base oil (raw oil), thickener, and additives. Base oil is an oil that serves as the base material of grease, and base oils are roughly divided into mineral oils and synthetic oils. Synthetic oil has excellent high-temperature stability and temperature-viscosity characteristics. Synthetic oil is used under conditions that cannot be handled by mineral oil. The base oil greatly affects the lubricity, heat resistance, oxidation stability, low-temperature properties, etc. of the grease. Main component of rubber resistance and resin resistance. Thickeners maintain grease in a semi-solid or solid state, so metal (Li, Ca) soaps are the mainstream, but non-soap organic compounds (urea) are also commonly used. In addition to maintaining the structure, they are also effective in maintaining the grease. Heat resistance, water resistance, and mechanical stability are affected.

The inside of the bearing filled with grease is the static spaces S1 and S2 in the sealing devices Sa and Sb, and the moving spaces S3 and S4, which are the spaces through which the retainer 24 and the roller 23a pass, excluding the volume of the retainer 24 and the roller 23a itself. The static space S5 is between the pair of inner rings 22 and 22 and between the inner surface of the outer ring 21 opposite thereto.

In this case, the static space S1 of the one sealing device Sa is formed from the large diameter portion 40 a to the middle diameter portion 40 b of the seal housing 40 , the frame 41 , the outer diameter surface of the slinger 29 , and the large protrusion of the inner ring 22 A space surrounded by a part of the edge 22b and the axial direction outer side of the roller/cage assembly 42 composed of the roller 23a and the retainer 24.

In addition, the static space S2 of the other sealing device Sb is formed from the large diameter portion 40a to the middle diameter portion 40b of the sealing case 40, the frame 41, the small diameter portion 26c of the outer diameter surface of the back cover 26, and the inner ring 22 The space S2 is surrounded by a part of the large flange 22b and the axial direction outer side of the roller/cage assembly 42 composed of the roller 23a and the retainer 24.

In addition, the static space S5 is composed of the outer surface of the pair of inner rings 22 and 22, the outer surface of the gasket 27 between the pair of inner rings 22 and 22, the inner surface of the outer ring 21 opposite thereto, and the rollers 23a and 23a and the cage. The space S5 enclosed by the inner sides of the roller/cage assemblies 42 and 42 in the axial direction constituted by 24 and 24 . It should be noted that when there is no washer 27, the static space S5 is composed of the outer surfaces of a pair of inner rings 22 and 22, the inner surface of the outer ring 21 facing them, the rollers 23a, 23a and the retainer 24, The space S5 enclosed by the inner side of the roller/cage assembly 42 and 42 in the axial direction.

The still space S5 is indicated by thick crosshatching, and the still spaces S1 and S2 are indicated by thin crosshatching. In addition, the entire space of the bearing is the space obtained by adding the static spaces S1 and S1, the movement spaces S3 and S4, and the static space S5.

Let the volumes of the static spaces S1 and S2 in the sealing devices Sa and Sb be A and A', and the static spaces S5 between the pair of inner rings 22 and 22 and between the inner surfaces of the outer rings 21 facing them. When the volume is B, the volumes of the moving spaces S3 and S4, which are the spaces through which the cage and rollers pass, minus the volume of the cage and the rollers themselves, are A1 and A1', and the total space volume of the bearing is V. , let V=(A+A'+B+A1+A1'), let it be 15V%≤(A1+A1')≤45V%, preferably 15V%≤(A1+A1')≤30V%.

By setting 15V% ≤ (A1 + A1') ≤ 45V%, a certain degree of capacity of the static space (static space of the sealing device) is ensured relative to the amount of grease ejected from the moving space, so the bearing is suppressed to a certain extent. The heat is generated and some effects of extending the lubrication life are obtained. When the ratio of the volume of the moving space (A1 + A1') to the total space volume V is greater than 45%, the capacity of the static space (the static space of the sealing device) is not equal to the amount of grease ejected from the moving space. Because the grease returns to the moving space side during use, the grease is frequently re-rolled. When the initial grease filling amount is limited in order to suppress heat generation, the lubrication life is reduced due to insufficient grease amount. When the ratio of the volume of the moving space (A1+A1') to the total space volume V is less than 15% (less than 15%), the grease present in the moving space is affected by the pushing of the rollers and the centrifugal force. , the grease accumulates in the static space (the static space of the sealing device), but in this ratio, the amount of grease that is ejected is small, and the influence of heat caused by the re-rolling of grease, etc. is small. However, the proportion of the rollers relative to the overall space volume of the bearing becomes smaller, and the rated load becomes too low relative to the bearing size.

When the ratio of the volume of the moving space (A1+A1') to the total space volume V is 15% or more and less than 30%, a sufficient static space (the sealing device) is required for the amount of grease ejected from the moving space. The capacity of the static space is ensured, thereby suppressing the heat generation of the bearing and achieving the effect of extending the lubrication life. In addition, when the ratio of the volume of the moving space (A1 + A1') to the total space volume V is 30% or more and 45% or less, the static space ( The capacity of the static space of the sealing device is ensured, so the heat generation of the bearing is suppressed to a certain extent, and a certain effect of extending the lubrication life is obtained.

Let the total space volume of the bearing be V, let the volume of the static space in the sealing device be A, A', and let the volume of the static space between a pair of inner rings and the inner surface of the outer ring facing it be When B is used, 30V%≤(A+A')≤60V% is set, and B is preferably 15% or more of V.

With this structure, when the ratio of the volume of the static space (A+A') in the sealing device to the total space volume V is less than 30%, the influence of the centrifugal force and the influence of the roller pushing away the grease during use , grease accumulates in the static space within the sealing device, but this space is small, and the splashed grease returns to the range of the moving space, and heat caused by the grease entanglement is frequently generated. When the filling amount of grease is reduced in order to suppress heat generation, the lubrication life is reduced. When the ratio of the volume of the static space (A+A') in the sealing device to the total space volume V is greater than 60%, a sufficient space for the grease to stay due to centrifugal force or the like can be ensured, and the heat generation of the bearing can be suppressed. . However, the proportion of the rollers relative to the overall space volume of the bearing becomes smaller, and the rated load becomes too low relative to the bearing size.

When the ratio of the volume of the static space (A+A') in the sealing device to the total space volume V is 30% or more and less than 40%, a retention space for grease splashed by centrifugal force or the like is ensured to a certain extent. , thus suppressing the heating of the bearing to a certain extent and obtaining some effects of extending the lubrication life. In addition, when the ratio of the volume (A+A') of the static space in the sealing device to the total space volume V is 40% or more and 60% or less, retention of grease splashed by centrifugal force or the like can be sufficiently ensured. Space can suppress the heat generation of the bearing, thereby achieving the effect of extending the lubrication life.

When the ratio of the volume of the static space (the static space between the inner rings) B to the total space capacity V is less than 15%, the sealed amount of grease becomes small. Therefore, the ratio of the static space (the static space between the inner rings) B to the total space capacity V is preferably 15% or more.

It should be noted that it can also be moving space (A1+A1’): stationary space (A+A’): stationary space B=0.15:0.30:0.55. Even with this setting, there will be no problems with bearing function.

When the volumes of the static spaces in the sealing device S are denoted by A and A', and the volumes of the static spaces between the pair of inner rings 22 and 22 and between the inner surfaces of the outer rings facing them are denoted by B. , when the amount of grease sealed into the inside of the bearing is set to G, it can be set to 30(A+A'+B)%≤G≤80(A+A'+B)%.

When the ratio of the grease filling amount to the volume of the static space (A+A'+B) is less than 30%, the grease existing in the moving space is pushed away by the rotation of the bearing, and sufficient centrifugal force can be ensured. Although the space after the movement of splashed grease suppresses heat generation caused by the entanglement of grease, etc., it is not recommended because the grease is insufficient and the lubrication life is shortened.

When the ratio of the grease sealing amount to the volume of the static space (A+A'+B) is 30% or more and 70% or less, the capacity of the static space is sufficient relative to the amount of grease ejected from the moving space. It is ensured that heat generation is suppressed. In addition, when the ratio of the grease sealing amount to the volume of the static space (A+A'+B) is greater than 70% and 80% or less, there is a certain degree of static motion relative to the amount of grease ejected from the moving space. The capacity of the space is ensured, thus suppressing heat generation to a certain extent. When the ratio of the amount of grease enclosed to the volume of the static space (A+A'+B) is greater than 80%, the capacity of the static space is insufficient relative to the amount of grease ejected from the moving space, and the amount of grease is Fever caused by re-entry etc. occurs frequently.

In the present invention, by optimizing the space volume inside the bearing without changing the conventional bearing component structure, it is possible to ensure a grease sealing amount that satisfies the required lubrication life.

An axle bearing for a railway vehicle of the present invention includes the rolling bearing. Therefore, the railway vehicle axle bearing of the present invention can ensure a grease filling amount that satisfies the required lubrication life by optimizing the space volume inside the bearing without changing the conventional bearing component structure.

As an axle bearing for a railway vehicle, it is preferable to include an outer ring 21 having double-row rails 21a, 21a on its inner periphery, and a pair of inner rings 22 having rails 22a, 22a on its outer periphery. The inner ring 22 and the outer ring are sandwiched between the inner ring 22 and the outer ring. 21 between the double rows of tapered rollers 23a, and a retainer that maintains the tapered rollers 23a of each row at a predetermined interval in the circumferential direction.

The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments and can be modified in various ways. The rolling bearing in the embodiments has the washer 27 sandwiched between the pair of inner rings 22 and 22 . , but it may also be a type in which the gasket 27 is not interposed. The embodiments of the present invention have been described using an embodiment applied to a bearing for a railway vehicle axle as an example. However, the present invention is not limited to the embodiments shown in the drawings and described above, and can be applied without departing from the scope of the claims. Various changes are implemented.

As an example, the case where a double-row tapered roller bearing is used is taken as an example here, but the same application can be made when a double-row cylindrical roller bearing is used. In this case, of course, appropriate replacement should be made, such as replacing the tapered roller with the cylindrical roller, replacing the large flange with the flange, etc. In addition, the use is not limited to railway vehicle use.

The sealing device S is not limited to the structure shown and described here. In particular, the shape and structure of the lip may be any shape or structure. For example, you can select and use oil seals specified in JIS B2402-1:2013.

[Example 1]

In the railway vehicle axle bearing having the structure shown in Fig. 1, the ratio of the volumes (A1+A1') of the moving spaces S3 and S4 to the total volume V was investigated. In this case, the volumes A1 and A1' of the movement spaces S3 and S4 are less than 15% of the total volume, the volumes A1 and A1' of the movement spaces S3 and S4 are 15% or more and less than 30% of the total volume, and the volumes of the movement space S3 The cases where the volumes A1 and A1' of S4 are 30% to 45% of the total volume and the volumes A1 and A1 of the moving spaces S3 and S4 are larger than 45V% were investigated, and the results are shown in Table 1 below.

[Table 1]

The ratio of moving space (A1+A1’) to the total space volume determination ~Less than 15% ▲ More than 15% and less than 30% ○ More than 30% and less than 45% △ Greater than 45%~ ×

determination

○: Has lubrication life extension effect

ΔII has a slight lubrication life extension effect

▲: There is a lubrication life extension effect but the bearing rated load becomes too small.

×: No lubrication life extension effect

A judgment of ○ indicates that the lubrication life extension effect is present. In this case, the lubrication life extension effect is extended by more than 20% compared with a bearing without the lubrication life extension effect in which the lubrication life is not set to such a ratio. The Δ in the judgment indicates that there is a slight lubrication life extension effect, which is about 10 to 20% longer than a bearing that is not set to such a ratio and has no lubrication life extension effect. ▲There is a lubrication life extension effect, but the bearing rated load becomes too small. The so-called bearing rated load becomes too small and is 95% or less compared to bearings judged as other than ▲. × shows the life extension effect without lubrication.

From this result, it can be seen that it is preferable that 30% × total space volume ≤ (volume A1, A1' of the movement space S3, S4) ≤ 45%. In particular, it is found that 15% or more and less than 30% is preferred.

[Example 2]

In the railway vehicle axle bearing having the structure shown in Fig. 1, the ratio of the volumes (A+A') of the static spaces S1 and S2 was investigated. In this case, the volume (A+A') of the still spaces S1 and S2 is less than 30% of the total space volume, the volume (A+A') of the still spaces S1 and S2 is 30% or more of the total space volume V, and Less than 40%, the volume (A+A') of the static spaces S1 and S2 is more than 40% and less than 60% of the total space volume V, and the volume (A+A') of the static spaces S1 and S2 is greater than the total space volume V 60% of cases were investigated, and the results are shown in Table 2 below.

[Table 2]

The ratio of static space (A+A’) to the total space volume determination ~Below 30% × Above 30% and below 40% Δ More than 40% and less than 60% ○ More than 60%~ ▲

determination

○: Has lubrication life extension effect

△: Slight lubrication life extension effect

▲: There is a lubrication life extension effect but the bearing rated load becomes too small.

×: No lubrication life extension effect

○, Δ, ▲, and × in the determination in this case are the same as ○, Δ, ▲, and × in the determination shown in Table 1 above. In this way, it can be seen that 30% × total space volume ≤ (volume A, A' of the static space S1, S2) ≤ 60% is preferable, and it is particularly preferred that 40% or more and 60% or less are preferred.

[Example 3]

The ratio of the grease sealing amount to the volumes (A+A’+B) of the static spaces S1, S2, and S was investigated. In this case, the grease filling amount is less than 30% relative to the volume (A+A'+B) of the static spaces S1, S2, S, and the grease filling amount is relative to the volumes of the static spaces S1, S2, S. (A+A'+B) is 30% or more and 70% or less, and the grease filling amount is more than 70% and 80% or less relative to the volume (A+A'+B) of the static spaces S1, S2, S. , the case where the grease sealing amount was more than 80% relative to the volume (A+A'+B) of the static spaces S1, S2, S was investigated, and the results are shown in Table 3 below.

[table 3]

Ratio of grease filling amount to static space (A+A’) determination ~Below 30% ▲ Above 30% and below 70% ○ Greater than 70% and less than 80% △ greater than 80% ×

determination

○: No heat generated by grease

Δ: Slight heat generation caused by grease

▲: No heat generated by grease but shortened bearing life

×: There is heat generation caused by grease

Each judgment is the result of the time operation corresponding to the maintenance period of the bearing. ○ indicates no heat generation caused by grease, △ indicates slight heat generation caused by grease, and "slightly" indicates a temperature rise of 0 to 5°C. ▲ indicates There is no heat generated by the grease, but the bearing life is shortened. The so-called shortened life is equal to or less shortened than a bearing that is not set to such a grease ratio. × shows heat generation caused by grease.

From this result, it can be seen that it is preferable that 30%×quiescent space (A+A'+B)≤(grease sealing amount)≤30%×quiescent space (A+A'+B)≤80%. In particular, it can be seen that 30% Above and below 70% is preferred.

Industrial availability

The rolling bearing of the present invention can ensure a grease sealing amount that satisfies the required lubrication life by optimizing the space volume inside the bearing, and is most suitable for bearings for railway vehicles.

Claims (9)

1. A rolling bearing comprising an inner ring, an outer ring, rolling elements interposed between the inner ring and the outer ring, a retainer disposed between the inner ring and the outer ring and holding the rolling elements, and a sealing device for sealing an opening between the inner ring and the outer ring,

when the volume of the stationary space in the seal device is A, A ', the volume of the stationary space between the pair of inner rings and the inner surface of the outer ring facing the pair of inner rings is B, the volumes of the moving spaces excluding the volumes of the cage and the rolling elements themselves from the space where the cage and the rolling elements pass through are A1 and A1', and the volume of the entire space of the bearing is V, V= (A+A ' +B- + -A1+A1 '), and 15V% -45 V% (A1+A 1 ').

2. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

when the total space volume of the bearing is set to V and the volumes of the moving space excluding the volumes of the cage and the rolling elements themselves from the space through which the cage and the rolling elements pass are set to A1 and A1', the volume is set to 15V% -30 V% (A1+A1').

3. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

when the total volume of the space of the bearing is V, the volume of the stationary space in the sealing device is A, A ', and the volume of the stationary space between the pair of inner rings and the inner surface of the outer ring facing the pair of inner rings is B, the volume of the stationary space is 30V% -60 V% (A+A') -, and B is 15% or more of V.

4. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

when the total volume of the space of the bearing is V, the volume of the stationary space in the sealing device is A, A ', and the volume of the stationary space between the pair of inner rings and the inner surface of the outer ring facing the pair of inner rings is B, the volume of the stationary space is 40V% -60 V% (A+A') -, and B is 15% or more of V.

5. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

when the volume of the stationary space in the sealing device is A, A ', the volume of the moving space between the pair of inner rings and the inner surface of the outer ring facing the pair of inner rings is B, and the grease sealing amount to be sealed into the bearing is G, the sealing device is 30 (A+A ' +B)% -G-80 (A+A ' +B)%.

6. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

when the volume of the stationary space in the sealing device is A, A ', the volume of the moving space between the pair of inner rings and the inner surface of the outer ring facing the pair of inner rings is B, and the grease sealing amount to be sealed into the bearing is G, the sealing device is 30 (A+A ' +B)% -G-70 (A+A ' +B)%.

7. A rolling bearing according to claim 1, wherein the rolling bearing is a rolling bearing,

a gasket is disposed between the pair of inner rings.

8. A railway vehicle axle bearing is characterized in that,

the railway vehicle axle bearing uses the rolling bearing of any one of claims 1 to 7.

9. A railway vehicle axle bearing comprising an outer ring having a double row track on an inner periphery thereof, a pair of inner rings having tracks on respective outer peripheries thereof, double row tapered rollers interposed between the inner rings and the outer ring, and retainers for retaining the tapered rollers of each row at predetermined intervals in a circumferential direction,

the rolling bearing according to any one of claims 1 to 8 is used for the axle bearing for railway vehicles.