WO2019082870A1

WO2019082870A1 - Grease-sealed bearing

Info

Publication number: WO2019082870A1
Application number: PCT/JP2018/039272
Authority: WO
Inventors: 涼太近藤; 川村　隆之
Original assignee: Ntn株式会社
Priority date: 2017-10-23
Filing date: 2018-10-23
Publication date: 2019-05-02

Abstract

Provided is a grease-sealed roller bearing having exceptional bearing life when used in high-temperature conditions and light-load conditions. A tapered roller bearing 11 comprises: an inner ring 12 and outer ring 13, which are bearing rings; a plurality of tapered rollers 14, which roll between the inner ring 12 and the outer ring 13; and grease 16 sealed in the peripheries of the tapered rollers 14. The inner ring 12 has a large flange 12b and comes into sliding contact with the tapered rollers 14 in the large flange 12b, the tapered roller bearing 11 is used in high-temperature conditions of 80°C or greater and in light-load conditions, the contact state between the large flange 12b and the tapered rollers 14 in these conditions falls under an equal viscosity-rigid body area in a Greenwood-Johnson diagram, the base oil of the grease 16 has mineral oil as a primary component, and a thickener of the grease 16 is an aliphatic diurea compound.

Description

Grease-filled roller bearings

The present invention relates to a grease-sealed roller bearing used under high temperature conditions and light load conditions, and more particularly to a tapered roller bearing.

Roller bearings are widely used as bearings for high loads such as power transmission systems for automobiles and industries. Grease is enclosed in such a roller bearing in order to provide lubricity. In recent years, with the miniaturization and high performance of equipment in which grease filled roller bearings are used, the use environment of the roller bearings is becoming more and more severe, and greases exhibiting excellent lubricating characteristics even under high load conditions. Examinations are being conducted. For example, Patent Document 1 describes that incorporation of a melamine (iso) cyanuric acid adduct into a grease exhibits excellent lubricating properties even under severe conditions and is also excellent in bearing life.

JP 2005-15556 A

Grease-sealed roller bearings are used not only under heavy load conditions but also under light load conditions. It is desirable that the roller bearings used under such light load conditions also have excellent bearing life. However, there is still room for improvement in the grease of the roller bearing.

Further, in the grease-sealed roller bearing, since the roller which is the rolling element and the flange portion of the bearing ring come into sliding contact, the lubricity at this contact portion greatly affects the durability of the bearing. Heretofore, no attention has been paid to the grease composition in a predetermined contact state, focusing on the contact state of the rollers and the buttocks.

The present invention has been made in view of the above circumstances, and has excellent bearing life in use under high temperature conditions and light load conditions (conditions in which rollers and ridges are in a predetermined contact state). An object of the present invention is to provide a sealed roller bearing.

The grease-sealed roller bearing according to the present invention comprises an inner ring and an outer ring which is a bearing ring, a plurality of rollers rolling between the inner ring and the outer ring, and a grease sealed around the roller. A grease-sealed roller bearing having a ridge and in sliding contact with the roller at the ridge, the roller bearing being used under high temperature conditions of 80 ° C. or higher and light load conditions under these conditions The contact state between the buttocks and the rollers belongs to the isoviscous-rigid region in the Greenwood-Johnson diagram, the base oil of the grease is mainly composed of mineral oil, and the thickener of the grease is aliphatic. It is characterized by being a diurea compound.

The light load condition is characterized in that the maximum contact surface pressure of the bearing ring is 0.3 GPa or less and the surface pressure of the heel portion is 0.1 GPa or less. The bearing member of at least one of the inner ring, the outer ring, and the roller is made of carburized steel.

The grease-sealed roller bearing is a tapered roller bearing, and the roller is a tapered roller, and the inner ring has a small bowl and a large bowl as the collar portion, and is in sliding contact with the tapered roller at the large bowl. It is characterized by

The selection method of the present invention comprises an inner ring and an outer ring which are races, a plurality of rollers rolling between the inner ring and the outer ring, and a grease sealed around the rollers, and the inner ring has a ridge portion A grease-sealed roller bearing having a sliding contact with the roller at the buttock portion, the selection method of selecting a thickener for the grease, wherein the base oil of the grease contains a mineral oil as a main component; The method includes a calculation step of calculating a lubrication area in a Greenwood-Johnson diagram from use conditions of the roller bearing, and a selection step of selecting the thickener according to the calculated lubrication area, and the selection step includes In the calculation step, it is determined that the use condition of the roller bearing is used under the high temperature condition of 80 ° C. or more and the light load condition and belongs to the equal viscosity-rigid region. In case a step of selecting the thickener of the grease aliphatic diurea compound, characterized by.

The grease-sealed roller bearing according to the present invention is a bearing in which a ridge is formed on the inner ring and is in sliding contact with the roller at the ridge, and the roller bearing is used under high temperature conditions of 80 ° C. or higher and light load conditions The contact with the buttocks under these conditions belongs to the isoviscous-rigid region in the Greenwood-Johnson diagram. In this case, the surfaces of the tapered roller and the buttocks that are in sliding contact with each other are completely separated by the grease (fluid lubrication state). In this condition of use, the base oil of grease is mineral oil as the main component and the thickener of grease is an aliphatic diurea compound, so bearing life when used under high temperature conditions of 80 ° C or more and light load conditions Can be extended.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the grease-sealed roller bearing of this invention. It is a figure which shows a lubrication area | region.

In the present invention, in the grease-sealed roller bearing, attention is paid to the contact state between the roller and the collar portion. The contact between the roller and the ridge in the presence of grease can be considered using the elastic fluid lubrication (EHL) theory. That is, the contact state in use may be considered as any of four lubricating regions considering the presence or absence of elastic deformation of the friction surface of two objects and the presence or absence of viscosity change of grease (lubricating oil) it can. Among these, in grease filled roller bearings, in order to improve the bearing life in use in the lubricating region (IR region described later) under high temperature conditions and light load conditions, the results of intensive studies on the grease to be used for lubrication By blending a mineral oil and an aliphatic diurea compound as a predetermined thickener, it has been found that the bearing life under the above conditions is improved.

A tapered roller bearing which is an example of the grease-sealed roller bearing of the present invention will be described based on FIG. As shown in FIG. 1, the tapered roller bearing 11 has an inner ring 12 having a tapered raceway surface 12a on the outer peripheral surface, an outer ring 13 having a tapered raceway surface 13a on the inner peripheral surface, and a raceway surface 12a of the inner ring 12 And a raceway surface 13a of the outer ring 13, and a cage 15 for holding each tapered roller 14 in a pocket portion so as to roll freely. The cage 15 has a large diameter ring portion and a small diameter ring portion connected by a plurality of column portions, and the tapered roller 14 is housed in a pocket portion between the column portions. A large weir 12b is integrally formed on the large diameter end of the inner ring 12, and a small weir 12c is integrally formed on the small diameter end. The inner ring in a tapered roller bearing has a tapered raceway surface and therefore has a small diameter side and a large diameter side as viewed in the axial direction, and "small ridge" is a weir provided at the small diameter side end, "large diameter" "鍔" is a bowl provided at the large diameter end. When a load is applied, the tapered roller 14 is pressed to the large diameter side, and the large diameter 12b receives this load. In addition, the small roller 12c prevents the tapered roller 14 from falling off to the small diameter side until the bearing is incorporated into various devices.

In the above configuration, the tapered roller 14 receives rolling friction between the raceway surface 12 a of the inner ring 12 and the raceway surface 13 a of the outer ring 13, and receives sliding friction between the raceway 12 b of the inner ring 12. Grease 16 is enclosed at least around tapered roller 14 to reduce these frictions. When the tapered roller bearing 11 is used, the load on the portion where the large diameter 12 b and the tapered roller 14 make sliding contact is particularly large, and this portion is easily damaged, which affects the bearing life. The large bowl 12b and the tapered roller 14 are in point contact with each other.

In the present invention, tapered roller bearings are characterized in that they are used under high temperature conditions of 80 ° C. or higher and under light load conditions. The light load condition is a condition in which the surface pressure at the buttocks (including the large ridges) is smaller than the surface pressure of a general tapered roller bearing. In the present invention, the contact state with the heel under high temperature conditions of 80 ° C. or higher and light load conditions belongs to the isoviscous-rigid region in the Greenwood-Johnson diagram.

Tapered roller bearings are subject to rolling friction and sliding friction in the presence of grease. Here, the state of friction at the sliding portion in the presence of the lubricant (including grease) is (1) equal viscosity from the point of presence or absence of elastic deformation of the sliding member and presence or absence of viscosity increase of the lubricant due to pressure. -Rigid body area (IR area), (2) high pressure viscosity-rigid body area (PR area), (3) isometric viscosity-elastic body area (IE area), (4) high pressure viscosity-elastic body area (PE area) 4 It is roughly divided into two areas. The “high temperature condition of 80 ° C. or more and the light load condition” in the present invention is a condition in which the state of friction in the buttocks belongs to the IR region among the four regions. In the IR region, the deformation on the friction surface between the tapered roller and the buttock can be ignored, and the viscosity increase due to the pressure of the grease can be ignored. That is, in the state where the contact state at the buttocks belongs to the IR region, the surfaces of the tapered rollers and the buttocks that are in sliding contact with each other are completely separated by the grease (fluid lubrication state).

Whether the contact state (point contact state) at the flange of the grease-sealed roller bearing belongs to the IR region is specified using the lubrication area diagram shown in FIG. The lubrication region diagram is also referred to as a Greenwood-Johnson diagram, and is a diagram in which the horizontal axis is dimensionless number g _E which is an elastic parameter and the vertical axis is dimensionless number g _V which is a viscosity parameter. The dimensionless number g _E and the dimensionless number g _V are respectively represented by the following equations (1) and (2).

g _E = (ω / ER _X ² ) ^8/3 / (η ₀ u / ER _X ) ² (1)
g _V = (αE) (ω / ER _X ² ) ³ / (η ₀ u / ER _X ) ² (2)
In the above equation, R _X represents the equivalent radius in the plane including the x axis, u = (u ₁ + u ₂ ) / 2, η ₀ is the viscosity under atmospheric pressure, and α is the pressure of viscosity Indicate a coefficient, ω indicates a load, and E indicates an equivalent elastic modulus.

The lubricating region diagram of FIG. 2 is divided into the above-mentioned regions (1) to (4) according to the dimensionless numbers g _E and g _V. The dimensionless numbers g _E and g _V calculated by the above equation are applied to FIG. 2 to identify to which region the contact state under the use conditions belongs. As described above, the grease-sealed roller bearing of the present invention is used under the condition that the contact state between the flange and the tapered roller belongs to the IR region.

More specifically, as the light load condition, the surface pressure of the buttock portion is 0.1 GPa or less, preferably 0.05 GPa or less, more preferably 0.01 GPa or less. At this time, it is particularly preferable that the maximum contact surface pressure at the bearing ring is 0.3 GPa or less.

In the grease-sealed roller bearing of the present invention, the bearing members of the inner ring, the outer ring, and the roller are made of an iron-based metal material. As the iron-based metal material, bearing steel, carburized steel, carbon steel for machine structure, cold-rolled steel, or hot-rolled steel can be used. Among these, it is preferable to use a carburized steel having high heat resistance. As carburized steel, SCM415 grade | etc., Can be mentioned, for example. The iron-based metal materials used for the bearing members may be different from each other.

The grease sealed in the grease-sealed roller bearing of the present invention is composed of a base oil containing mineral oil and a thickener. As mineral oil, spindle oil, refrigeration oil, turbine oil, machine oil, dynamo oil, highly refined mineral oil and the like can be mentioned. Highly refined mineral oil is obtained, for example, by catalytically hydrocracking and synthesizing a slug wax obtained from the residue of vacuum distillation. The highly refined mineral oil preferably has a sulfur content of less than 0.1% by weight, more preferably less than 0.01% by weight. Other examples include GTL oils synthesized by the Fischer-Tropsch method.

The above-mentioned base oil consists only of mineral oil or is a mixture of mineral oil and other base oils. As an oil to be mixed with a mineral oil, for example, ether oil, ester oil, synthetic hydrocarbon oil (PAO oil), silicone oil, fluorine oil and a mixture of these oils can be used. Since the base oil of the present invention contains a mineral oil as a main component, the content of the mineral oil is 50% by mass or more, preferably 80% by mass or more based on the whole base oil (mixed oil). In particular, it is preferable to use a base oil consisting only of mineral oil (100% ether oil).

The kinematic viscosity of the base oil (in the case of the mixed oil, the kinematic viscosity of the mixed oil) is preferably 10 to 200 mm ² / s at 40 ° C. More preferably, it is 10 to 100 mm ² / s, further preferably 30 to 100 mm ² / s.

The base oil is preferably contained in an amount of 60 to 90% by mass with respect to the entire grease. If the content of the base oil is less than 60% by mass, the life may be reduced, and if it exceeds 90% by mass, the amount of the thickening agent may be relatively reduced to make it difficult to form a grease.

Aliphatic diurea compounds are used as thickening agents. Aliphatic diurea compounds are obtained by reacting a diisocyanate component with a monoamine component. Examples of the diisocyanate component include phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate (MDI), octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, and the like. Among these, aromatic diisocyanates are more preferred. In addition, aliphatic monoamines are used as the monoamine component, and examples thereof include hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, stearylamine, oleylamine and the like.

An aliphatic diurea compound is blended with a base oil as a thickener to obtain a base grease. The base grease having an aliphatic diurea compound as a thickener is prepared by reacting a diisocyanate component and a monoamine component in a base oil. The proportion of the thickener contained in the base grease is 10% by mass or more and less than 30% by mass, preferably 10% by mass or more and less than 20% by mass.

The combined penetration (JIS K 2220) of the grease is preferably in the range of 200 to 350. If the consistency is less than 200, oil separation may be small, resulting in poor lubrication. On the other hand, when the consistency is more than 350, the grease is soft and tends to flow out of the bearing, which is not preferable.

Further, known additives can be added to the grease as required. Additives include, for example, extreme pressure agents such as organic zinc compounds and organic molybdenum compounds, antioxidants such as amines, phenols and sulfur compounds, antiwear agents such as sulfur and phosphorus compounds, polyhydric alcohols Antirust agents such as esters, friction reducing agents such as molybdenum disulfide and graphite, and oil agents such as esters and alcohols.

Although the tapered roller bearing is shown in FIG. 1, the grease-sealed roller bearing according to the present invention is the end portion of the roller and the flange portion of the bearing ring (the large diameter of the tapered roller bearing and both axial ends of the inner ring in the cylindrical roller bearing In addition to tapered roller bearings, cylindrical roller bearings, self-aligning roller bearings, needle roller bearings, thrust cylindrical roller bearings, thrust tapered roller bearings, thrust needles may be used as long as they have a sliding contact with the wedge). Roller bearings, thrust spherical roller bearings, etc. can be used.

Moreover, since the grease-sealed roller bearing of the present invention is excellent in durability under high temperature, it is used at high temperature of 80 ° C. or more. Preferably, it is used at a high temperature of 100 ° C. or more. In consideration of the above, the grease-sealed roller bearing according to the present invention is a high temperature of 100 ° C. or more, and a maximum contact surface pressure at the bearing ring is 0.3 GPa or less, and a surface pressure at the heel portion is 0.1 GPa or less It is particularly preferable to be used under the following conditions, or at a high temperature of 100 ° C. or more, and a condition in which the contact state with the buttocks belongs to the IR region. As an apparatus used as such a use condition, a transmission etc. are mentioned, for example.

Example 1, Comparative Example 1, and Comparative Example 2
<Seized life test>
The greases having the compositions shown in Table 1 were each enclosed in 1.8 g of tapered roller bearings 30204 (bearing dimensions: inner diameter 20 mm, outer diameter 47 mm, width 15.25 mm) to produce test bearings. The obtained test bearing was rotated at a rotational speed of 5000 min ⁻¹ under the conditions of a bearing outer ring outer temperature of 120 ° C., a radial load of 67 N and an axial load of 67 N, and the time until the seizure was measured. Under this test condition, the maximum contact surface pressure at the bearing ring is 0.21 GPa, and the surface pressure at the gutter is 0.05 Pa. Moreover, in Oiso, the dimensionless number g _E calculated from the above equation (1) is 2, and the dimensionless number g _V calculated from the above equation (2) is 5, so Belongs. In addition, in this seizing life test, 1500 hours or more was taken as pass.

A test was also conducted using a ball bearing as reference data. A seizure life test was conducted under the same conditions for ball bearings obtained by sealing the same grease as above in deep groove ball bearings 6204 (bearing size: inner diameter 20 mm, outer diameter: 47 mm, width 14 mm). In addition, in the test, all the bearings were implemented in the open state without the seal cover. The results are shown in Table 1.

The result was a pass only when the grease of Example 1 was used. From Table 1, when aliphatic diurea compounds are used as thickeners, the life is longer than when aromatic diurea compounds are used (Comparative Example 1) or when lithium soap is used (Comparative Example 2). It could be extended significantly. The bearing life due to the difference between these thickeners was greater for aromatic diurea compounds than for lithium soaps, and was further greater for aliphatic diurea compounds than for aromatic diurea compounds. On the other hand, when deep groove ball bearings were used as reference data, the magnitude of the bearing life was surprisingly reversed. That is, the bearing life of the aromatic diurea compound was larger than that of the aliphatic diurea compound, and further, the lithium soap was larger than that of the aromatic diurea compound. The tapered roller bearing, unlike the ball bearing, has a portion (ridge portion) in sliding contact with the rolling element, and it is considered that the difference in the type of contact is different between the roller bearing and the ball bearing.

As described above, according to the present invention, in the roller bearing, when the contact state between the roller and the collar portion is in the IR region, it has been found that the thickening agent suitable for extending the bearing life is different from the ball bearing. That is, when the above contact state is in a state of belonging to the IR region, an aliphatic diurea compound can be selected as a thickener. In other words, the present invention can also be said to be a selection method of selecting a thickener for grease according to the contact state between the roller and the heel portion. This selection method includes a calculation step of calculating the lubrication region in the Greenwood-Johnson diagram from the use conditions of the roller bearings, and a selection step of selecting a thickener when the calculated lubrication region is in the IR region.

Next, in the grease-sealed roller bearing, in order to improve the bearing life in use under high load conditions, of the above contact states, regarding the selection of grease under the state of belonging to the PE area (high pressure viscosity-elastic body area) I examined it. As a result, it has been found that the bearing life under the above conditions is improved by blending a mineral oil and an aromatic diurea compound as a predetermined thickener. In the PE region, the friction surface between the tapered roller and the ridge elastically deforms, and the viscosity of the grease increases with an increase in pressure. The PE area is also referred to as a hard EHL area. Whether the contact state (point contact state) at the flange portion of the grease-sealed roller bearing belongs to the PE region is specified using the lubrication region diagram shown in FIG.

As a high load condition, in terms of specific numerical values, the contact pressure of the buttocks (large diameter in the case of tapered roller bearings) is 0.08 GPa or more, and the maximum contact surface pressure at the bearing ring is 0.4 GPa or more is there. Furthermore, it is more preferable that the contact pressure of the buttocks be 0.09 GPa or more and the maximum contact surface pressure at the bearing ring be 0.5 GPa or more.

In the grease used in the PE region, the same mineral oil as in the case of the IR region can be used as the base oil. An aromatic diurea compound is used as a thickener. The aromatic diurea compound is obtained by reacting a diisocyanate component with a monoamine component. Examples of the diisocyanate component include phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate (MDI), octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, and the like. Among these, aromatic diisocyanates are more preferred. Also, as the monoamine component, aromatic monoamine is used, and examples thereof include aniline and p-toluidine.

Grease used in the PE area is the same as in the IR area with respect to the conditions other than the thickener, such as the blending amount of base oil and thickener, consistency of grease, types of additives, applicable bearing types, etc. is there.

Since the grease-sealed roller bearing in which the grease is sealed is excellent in the durability under a high load, it is suitable, for example, as a roller bearing used in a transmission device or differential device such as an automobile, an industrial machine, and a railway vehicle.

Test Example 1 to Test Example 3
<Seized life test>
The greases having the compositions shown in Table 2 were each enclosed in 1.8 g of tapered roller bearings 30204 (bearing size: inner diameter 20 mm, outer diameter 47 mm, width 15.25 mm) to prepare test bearings. The obtained test bearing was rotated at a rotational speed of 5000 min ⁻¹ under the conditions of a bearing outer ring outer temperature of 120 ° C., a radial load of 67 N, and an axial load of 640 N, and the time until the seizure was measured. Under this test condition, the maximum contact surface pressure at the bearing ring is 0.56 GPa, and the surface pressure at the gutter is 0.09 GPa. Moreover, in Oiso, the dimensionless number g _E calculated from the above equation (1) is 220, and the dimensionless number g _V calculated from the above equation (2) is 1300, so Belongs. In addition, in this seizing life test, 500 hours or more was taken as passing.

A test under the condition of becoming an IR region was also conducted as reference data. In this test, the test bearing obtained above is rotated at a rotational speed of 5000 min ^-1 under the conditions of the bearing outer ring outer temperature 120 ° C., radial load 67 N and axial load 67 N to reach seizure Time was measured. Under this test condition, the maximum contact surface pressure at the bearing ring is 0.21 GPa, and the surface pressure at the gutter is 0.05 GPa. In addition, all the above-mentioned bearings were implemented in the open state without a seal cover. The results are shown in Table 2.

The result was passed only when the grease of Test Example 1 was used. From Table 2, when an aromatic diurea compound is used as a thickener, the life is longer than when an aliphatic diurea compound is used (Test Example 2) or when a lithium soap is used (Test Example 3). It could be extended significantly. Under the condition that the contact state belongs to the PE region, the aromatic diurea compound was superior to the aliphatic diurea compound. On the other hand, in the test in the IR region which is the reference data, the result shows that the magnitude of the bearing life between the aromatic diurea compound and the aliphatic diurea compound is reversed. That is, in this test, the bearing life of the aliphatic diurea compound was longer than that of the aromatic diurea compound. It is considered that the characteristics of the grease required for oil film formation differ depending on the contact state between the roller and the heel, and the results are different between the aromatic diurea compound and the aliphatic diurea compound depending on the difference in the characteristics.

As described above, when the contact state between the roller and the ridge portion belongs to the PE region, the aromatic diurea compound can be selected as the thickener, and the contact state belongs to the IR region. Can select an aliphatic diurea compound as a thickener.

In detail, in consideration of both of the above-described IR region and PE region, the selection method of the present invention includes a calculation step of calculating the lubrication region in the Greenwood-Johnson diagram from the use condition of the roller bearing, and the calculated lubrication And a selection step of selecting the thickener according to the region, and the calculation step includes (1) the high temperature condition of 80.degree. C. or more and the light load condition of the roller bearing from the use condition of the roller bearing When it is used and the contact state between the flange and the roller belongs to the isoviscous-rigid region in the Greenwood-Johnson diagram, or (2) the roller bearing is the maximum contact surface pressure of the bearing ring Is 0.5 GPa or more, and the contact pressure of the buttocks is 0.09 GPa or more, and the contact state between the buttocks and the rollers is Greenwood-Johnso It is a process of determining that it is in the state of belonging to the high pressure viscosity-elastic region in the diagram, and the selection step is the thickener thickening agent of the grease in the case of belonging to the equal viscosity-rigid region of (1) above. Is selected as an aliphatic diurea compound, and when it belongs to the high pressure viscosity-elastic region of (2), it is a step of selecting a thickener of the grease as an aromatic diurea compound.

The grease-sealed roller bearing according to the present invention has excellent bearing life in use under high temperature conditions and light load conditions, and thus can be widely used as grease-sealed roller bearings used under such conditions. For example, it is used for a transmission.

11 tapered roller bearing 12 inner ring 13 outer ring 14 tapered roller 15 cage 16 grease

Claims

An inner ring and an outer ring which is a bearing ring, a plurality of rollers rolling between the inner ring and the outer ring, and a grease sealed around the rollers, the inner ring having a ridge portion, the ridge portion A grease-sealed roller bearing in sliding contact with the roller at
The roller bearing is used under high temperature conditions of 80 ° C. or higher and under light load conditions, and the contact state between the flange and the roller under these conditions is in the isoviscous-rigid region in the Greenwood-Johnson diagram. It belongs to the state,
A grease-sealed roller bearing characterized in that a base oil of the grease contains a mineral oil as a main component, and a thickener of the grease is an aliphatic diurea compound.
The grease-sealed roller according to claim 1, wherein the light load condition is that the maximum contact surface pressure of the bearing ring is 0.3 GPa or less and the surface pressure of the flange portion is 0.1 GPa or less. bearing.
The grease-sealed roller bearing according to claim 1, wherein at least one bearing member of the inner ring, the outer ring, and the roller is made of carburized steel.
The grease-sealed roller bearing is a tapered roller bearing,
The grease-sealed roller bearing according to claim 1, wherein the roller is a tapered roller, and the inner ring has a small bowl and a large bowl as the ridge, and is in sliding contact with the tapered roller at the large bowl.
An inner ring and an outer ring which is a bearing ring, a plurality of rollers rolling between the inner ring and the outer ring, and a grease sealed around the rollers, the inner ring having a ridge portion, the ridge portion In the grease-sealed roller bearing in sliding contact with the roller, the selection method for selecting a thickener for the grease,
The grease base oil is mainly composed of mineral oil,
The selection method includes a calculation step of calculating a lubrication region in a Greenwood-Johnson diagram from use conditions of the roller bearing, and a selection step of selecting the thickener according to the calculated lubrication region.
In the selection step, it is determined in the calculation step that the use conditions of the roller bearing are used under high temperature conditions of 80 ° C. or higher and light load conditions, and that they are in a state belonging to the isoviscous-rigid region. A selection method characterized in that it is a step of selecting a thickener of the grease as an aliphatic diurea compound.