JP2013076469A - Rolling slide member, rolling bearing, and method for manufacturing rolling slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling slide member having a contact surface where a uniform oil film is formed and a frictional coefficient is small and uniform even if lubricant supplied to the contact surface where rolling contact or slide contact occurs.SOLUTION: In a rolling bearing including an outer wheel 1, an inner wheel 2 and a rolling element 3 as rolling slide members, a plurality of fine recesses 5 are formed in at least one of an outer track surface 11, an inner track surface 21, and a rolling surface 31, each of which is rolling contact surfaces. An oil repellent agent 6 is attached to the inner surface of the recesses 5.

Description

  The present invention relates to a rolling sliding member, a rolling bearing, and a method for manufacturing the rolling sliding member.

  Among rolling sliding members that have a contact surface that causes relative rolling contact or sliding contact with the mating member, as a bearing sliding member that supports the load applied to the rotating shaft, the oil film thickness is relatively thin. Has proposed a bearing sliding member that can reduce sliding resistance and sliding loss (see, for example, Patent Document 1). As shown in FIG. 10, this bearing sliding member is provided with a fine dimple-shaped recess 22 on the sliding surface as the contact surface, and the area ratio of the recess 22 on this sliding surface is 5-60. %, And the amount of the bulge 23 formed around the recess 22 is smaller than the oil film thickness at the sliding portion.

JP 2003-184883 A

  However, when the amount of lubricating oil supplied to the bearing sliding member is reduced depending on usage conditions, the oil film formed on the flat portion 24 of the sliding surface becomes non-uniform and the sliding surface becomes uneven. There are a portion where an oil film is formed and a portion where no oil film is formed, and the portion where the oil film is not formed has a drawback that the friction coefficient increases and the friction loss increases.

  The present invention has been made in view of the above prior art, and even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface, and the value of the friction coefficient and its variation are changed. It is an object of the present invention to provide a rolling sliding member, a rolling bearing, and a method for manufacturing the rolling sliding member that can be reduced.

  The rolling sliding member of the present invention is a metal rolling sliding member having a contact surface that causes relative rolling contact or sliding contact with a mating member, and the contact surface has a large number of minute recesses. It is formed, and an oil repellent is adhered to the inner surface of the recess.

  In the rolling sliding member of the present invention, since the oil repellent is attached to the inner surfaces of a large number of fine recesses formed on the contact surface, the lubricating oil that has entered the recesses is exposed from the recesses to the outside by the oil repellent. Easily discharged and supplied to the contact surface. For this reason, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface. Therefore, the value of the coefficient of friction of the contact surface and its variation can be reduced.

  In the rolling sliding member of the present invention, it is preferable that the concave portion is formed by shot peening, and the oil repellent is projected together with the shot peening projection particles and attached to the concave portion.

  In this case, since the oil repellent agent can be reliably adhered to the inside of the recess, the lubricating oil that has entered the recess can be reliably discharged from the recess to the outside and supplied to the contact surface.

  In the rolling sliding member of the present invention, the oil repellent is preferably a fluororesin. Fluorocarbon resin easily adheres to the inner surface of the recess formed on the contact surface and has excellent oil repellency, so that lubricating oil that has entered the recess is efficiently discharged from the recess to the outside and supplied to the contact surface. can do.

  The method of manufacturing a rolling sliding member according to the present invention includes a step of polishing a metal intermediate material formed in a predetermined shape to form a contact surface that causes relative rolling contact or sliding contact with a counterpart member. And projecting the oil repellent along with the projecting particles by shot peening on the contact surface to form a large number of fine recesses on the contact surface, and simultaneously attaching the oil repellent to the inner surface of the recesses. Features.

  According to the method of manufacturing a rolling sliding member of the present invention, since a large number of fine recesses can be formed on the contact surface and at the same time, the oil repellent can be adhered to the inner surface of the recess, the oil repellent can be efficiently applied to the inner surface. An attached recess can be formed.

  In the manufacturing method of the rolling sliding member of this invention, it is preferable to project the projection particle | grains to which the oil repellent was made to adhere to a contact surface. In this case, the oil repellent agent can be attached only to the inner surface of the recess formed by shot peening, and the oil repellent agent can be prevented from attaching to the contact surface on which the projected particles are not projected.

  In the manufacturing method of the rolling sliding member of this invention, it is preferable to use a fluororesin as an oil repellent. Fluorocarbon resin easily adheres to the inner surface of the recess formed on the contact surface and has excellent oil repellency, so that lubricating oil that has entered the recess is efficiently discharged from the recess to the outside and supplied to the contact surface. can do.

  The rolling bearing of the present invention includes an outer ring having an outer raceway surface as a rolling contact surface on an inner periphery, an inner ring disposed coaxially with the outer ring and having an inner raceway surface as a rolling contact surface on the outer periphery, and the outer raceway surface. And a plurality of rolling elements having a rolling contact surface that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface on the outer periphery, the outer raceway surface, the inner raceway surface, and the rolling raceway. A large number of fine recesses are formed on at least one of the running surfaces, and an oil repellent is attached to the inner surface of the recesses.

  In this case, since the oil repellent is attached to the inner surfaces of a large number of fine recesses formed on at least one of the outer raceway surface, the inner raceway surface and the rolling contact surface which are rolling contact surfaces, The lubricating oil that has penetrated into the surface is easily discharged from the recess to the outside by the oil repellent and is supplied to the rolling contact surface. As a result, even if a small amount of lubricating oil is supplied to the rolling contact surface, a uniform oil film is formed on the rolling contact surface, so that the value of the friction coefficient of the rolling contact surface and its fluctuation are reduced. Can do.

  A radial ball bearing as another rolling bearing of the present invention has an outer ring having an outer raceway surface as a rolling contact surface on the inner periphery, and an inner raceway surface as a rolling contact surface arranged coaxially with the outer ring. An inner ring, and a rolling element comprising a plurality of balls that are interposed between the outer raceway surface and the inner raceway surface, and whose outer circumference constitutes a rolling contact surface that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface. A radial ball bearing comprising: a rolling ball housing, wherein the rolling element is housed in a pocket portion, and a peripheral surface includes a guide surface that is a sliding contact surface with respect to the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring; A plurality of fine recesses are formed in at least one of the inner raceway surface, the rolling surface, the cage pocket and the guide surface of the cage, and an oil repellent is attached to the inner surface of the recess. It is characterized by.

  In this radial ball bearing, on the inner surface of a number of fine recesses formed in at least one of the outer raceway surface, the inner raceway surface, the rolling surface, the cage pocket and the cage guide surface, Since the oil repellent is attached, the lubricating oil that has entered the recess is easily discharged from the recess by the oil repellent, and the outer raceway surface, the inner raceway surface, the rolling surface, and the pocket portion of the cage. And at least one contact surface of the guide surface of the cage. As a result, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface, so that the value of the friction coefficient of the contact surface and its variation can be reduced.

  A roller bearing as another rolling bearing of the present invention includes an outer ring having an outer raceway surface as a rolling contact surface on the inner periphery, and an inner ring having an inner raceway surface as a rolling contact surface disposed coaxially with the outer ring. A rolling element comprising a plurality of rollers interposed between the outer raceway surface and the inner raceway surface and having a rolling contact surface which is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface on the outer periphery, and A roller bearing in which at least one of the inner ring and the outer ring forms a flange surface that is a sliding contact surface with respect to an end surface of the rolling element, the outer raceway surface, A large number of fine recesses are formed in at least one of the inner raceway surface, the rolling surface, the end surface of the rolling element, the flange surface, and the pocket portion of the cage, and an oil repellent is attached to the inner surface of the recess. It is characterized by that.

  In this roller bearing, the inner surface of a number of minute recesses formed in at least one of the outer raceway surface, the inner raceway surface, the rolling surface, the end surface of the rolling element, the flange surface, and the pocket portion of the cage. Since the oil repellent is adhered, the lubricating oil that has entered the recess is easily discharged from the recess to the outside by the oil repellent and supplied to at least one of the contact surfaces. As a result, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface, so that the value of the friction coefficient of the contact surface and its variation can be reduced.

  A thrust roller bearing as still another rolling bearing according to the present invention has an outer ring having an outer raceway surface as a rolling contact surface on one side surface, and an inner raceway surface as a rolling contact surface on one side surface. Is interposed between the outer raceway surface and the inner raceway surface, and the outer raceway surface and the inner raceway are arranged on the outer periphery. A thrust roller bearing comprising a rolling element composed of a plurality of rollers having a rolling surface that is a rolling contact surface with respect to the surface, and a cage that accommodates the rolling element in a pocket portion, wherein the outer raceway surface and the inner raceway surface A plurality of fine recesses are formed in at least one of the rolling surface, the end face of the rolling element, and the pocket portion of the cage, and an oil repellent is attached to the inner surface of the recess.

  In this thrust roller bearing, the outer raceway surface, the inner raceway surface, the rolling surface, the end face of the rolling element, and the inner surface of a number of minute recesses formed in the pocket portion of the cage are repelled. Since the oil agent adheres, the lubricating oil that has entered the recess is easily discharged from the recess to the outside by the oil repellent and supplied to at least one of the contact surfaces. As a result, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface, so that the value of the friction coefficient of the contact surface and its variation can be reduced.

  A thrust ball bearing as still another rolling bearing of the present invention has an outer ring having an outer raceway surface as a rolling contact surface on one side surface, and an inner raceway surface as a rolling contact surface on one side surface. Is interposed between the outer raceway surface and the inner raceway surface, and the outer circumference is disposed between the outer raceway surface and the inner raceway. A thrust ball bearing comprising a rolling element composed of a plurality of balls constituting a rolling contact surface that is a rolling contact surface with respect to a surface, and a cage that accommodates the rolling element in a pocket portion, wherein the outer raceway surface and the inner raceway A large number of fine recesses are formed in at least one of the surface, the rolling surface, and the pocket of the cage, and an oil repellent is attached to the inner surface of the recess.

  In this thrust ball bearing, an oil repellent is attached to the inner surfaces of a number of fine recesses formed in at least one of the outer raceway surface, the inner raceway surface, the rolling surface, and the pocket portion of the cage. Therefore, the lubricating oil that has entered the recess is easily discharged from the recess by the oil repellent and supplied to at least one of the contact surfaces. As a result, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface, so that the value of the friction coefficient of the contact surface and its variation can be reduced.

  According to the rolling sliding member of the present invention, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface. Can be reduced.

  According to the method of manufacturing a rolling sliding member of the present invention, since a large number of fine recesses can be formed on the contact surface and at the same time, the oil repellent can be adhered to the inner surface of the recess, the oil repellent can be efficiently applied to the inner surface. An attached recess can be formed.

  According to the rolling bearing of the present invention, even if a small amount of lubricating oil is supplied to the contact surface, a uniform oil film is formed on the contact surface. can do.

It is sectional drawing which shows one Embodiment of the radial ball bearing as a rolling bearing of this invention. It is a cross-sectional schematic diagram which shows the state by which shot peening was given to the contact surface. It is process drawing which shows the manufacturing method of the inner ring | wheel of a radial ball bearing. It is sectional drawing which shows one Embodiment of a roller bearing. It is sectional drawing which shows other embodiment of a roller bearing. It is sectional drawing which shows one Embodiment of a thrust roller bearing. It is an atomic force microscope photograph of the test piece obtained in Example 1 of this invention. In Experimental example 2, it is a figure which shows the relationship between the friction speed / load of the test piece of Example 1 of this invention, the test piece of the comparative example 1, and the test piece of the comparative example 2, and friction coefficient resistance. It is a figure which shows the relationship between the friction distance of the test piece of Example 2 of this invention, the test piece of the comparative example 3, and the test piece of the comparative example 4, and a friction coefficient. It is a cross-sectional schematic diagram which shows the state by which shot peening was given to the surface of the conventional bearing sliding member.

  Hereinafter, embodiments of a rolling bearing according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a rolling bearing using a rolling sliding member of the present invention. This rolling bearing is a radial ball bearing, an outer ring 1 having an outer raceway surface 11 on the inner periphery, and an inner ring having an inner raceway surface 21 arranged coaxially with the outer ring 1 and facing the outer raceway surface 11 on the outer periphery. 2, a plurality of rolling elements 3 made of steel balls interposed between the outer raceway surface 11 and the inner raceway surface 21, and a cage 4 that holds the rolling bodies 3 at predetermined intervals along the circumferential direction. It has. The outer peripheral surface of the rolling element 3 is configured as a rolling surface 31 that rolls on the outer raceway surface 11 and the inner raceway surface 21.

  In this embodiment, the outer ring 1, the inner ring 2, the rolling element 3 and the cage 4 are respectively rolling sliding members, and the outer raceway surface 11, the inner raceway surface 21 and the rolling surface 31 of the rolling element 3 are provided. The rolling contact surface. The outer ring 1, the inner ring 2 and the rolling element 3 are made of bearing steel such as bearing steel or carburized steel, and are hardened to a predetermined hardness by heat treatment.

  The cage 4 is formed by forming a plurality of pocket portions 41 for housing the rolling elements 3 at predetermined intervals along the circumferential direction in a metal cylinder. The outer peripheral surface of the cage 4 is configured as a guide surface 42, and the rotation of the cage 4 is guided by bringing the guide surface 42 into sliding contact with the inner peripheral surface of the outer ring 1. The guide surface 42 of the cage 4 is a sliding contact surface with respect to the inner peripheral surface of the outer ring 1, and the pocket portion 41 is a sliding contact surface with respect to the rolling surface 31 of the rolling element 3.

  In the rolling bearing, at least one of the outer raceway surface 11, the inner raceway surface 21, and the rolling surface 31 of the rolling element 3, which is a rolling contact surface, is formed with a large number of minute recesses, and the inner surface of the recesses The oil repellent is attached to the surface. For example, taking the inner raceway surface 21 of the inner ring 2 as an example, as shown in FIG. 2, a large number of fine recesses 5 are formed in the inner raceway surface 21 of the inner ring 2, and the oil repellent 6 is applied to the inner surface of the recess 5. It is attached. FIG. 2 is a schematic cross-sectional view showing a state where shot peening is applied to the rolling contact surface of the inner ring 2.

  FIG. 3 is a process diagram showing a method for manufacturing the inner ring 2 of the rolling bearing. The recess 5 is formed on the inner raceway surface 21 of the inner ring 2 shown in FIG. 2, and the oil repellent 6 is attached to the inner surface of the recess 5. The case where it makes it show is shown.

In the process diagram showing this manufacturing method, first, a raceway portion is obtained by cutting an annular material A (see FIG. 3A) obtained by forging bearing steel such as bearing steel or carburized steel. Then, an intermediate material B in which the end surface, the inner peripheral surface and the outer peripheral surface are formed in a predetermined shape is obtained [see FIG. 3 (b)].
Next, the intermediate material B is subjected to a heat treatment to be cured so that the surface of the intermediate material B has a hardness in the range of, for example, HRC 60 to 64 (see FIG. 3C).
Further, the raceway portion, the end surface and the inner peripheral surface of the intermediate material B cured by the heat treatment are polished to have predetermined dimensions, and the raceway portion is superfinished to form the inner raceway surface 21. Finish to a predetermined surface roughness (see FIG. 3D).

  Thereafter, shot peening is performed on the inner raceway surface 21 to form the recess 5 on the surface of the inner raceway surface 21. At this time, by mixing the projected particles 7 and the oil repellent 6 in the pressure vessel 71 to which the compressed air for shot is supplied, the oil repellent 6 is adhered to the projected particles 7, The projection particles 7 are sprayed on the inner raceway surface 21. Thereby, the recessed part 5 can be formed in the said inner track surface 21, and the oil repellent agent 6 can be made to adhere to the inner surface of the said recessed part 5 (refer FIG.3 (e)).

  Thus, according to the manufacturing method of the rolling bearing, since a large number of fine recesses 5 can be formed on the rolling contact surface and the oil repellent 6 can be attached to the inner surface of the recess 5, the inner surface can be efficiently The recess 5 having the oil repellent 6 attached thereto can be formed.

  Examples of the projecting particles 7 used in the shot peening include metal spheres such as iron and stainless steel, ceramic spheres, and glass spheres. It is not limited. The particle diameter of the projected particles 7 is not particularly limited, but is preferably 10 μm or more, more preferably from the viewpoint of forming the recesses 5 that can sufficiently attach the oil repellent 6 to the rolling contact surface (inner raceway surface 21). From the viewpoint of allowing the lubricating oil that has entered the recess 5 to be easily discharged from the recess 5, it is preferably 200 μm or less, and more preferably 150 μm or less.

  The oil repellant 6 projected along with the projection particles 7 by shot peening may be any oil repellency with respect to the lubricating oil. Examples of the oil repellent 6 include a fluororesin and a silicone resin, and these can be used alone or in combination. Among the oil repellents 6, the oil repellent 6 is securely attached to the inner surface of the recess 5, and the viewpoint of efficiently supplying the lubricating oil that has entered the recess 5 from the recess 5 to the rolling contact surface and excellent solid lubricity From the viewpoint of having a fluorocarbon resin, a fluororesin is preferable. Further, since the fluororesin easily adheres to the surface of the projection particle 7, the fluororesin can be reliably adhered to the formed recess 5 at the same time as the recess 5 is formed in rolling contact by the projection particle 7. A typical example of the fluororesin is polytetrafluoroethylene.

  The oil repellent 6 may be either powder or liquid, but is preferably powder from the viewpoint of preventing mixing with the lubricating oil. When the powdered oil repellent 6 is used, the particle diameter is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less from the viewpoint of improving the adhesion of the oil repellent 6 to the inner surface of the recess 5. It is.

  When projecting the projected particles 7 and the oil repellent 6 onto the rolling contact surface by shot peening, the ratio of the projected particles 7 to the oil repellent 6 [projected particles / oil repellent (mass ratio)] increases the formation efficiency of the recess 5. From the viewpoint, it is preferably 1/1 or more, more preferably 3/1 or more, and from the viewpoint of increasing the adhesion efficiency of the oil repellent 6 to the inner surface of the recess 5, it is preferably 20/1 or less, more preferably 10 /. 1 or less.

  When projecting the projected particles 7 and the oil repellent 6 onto the rolling contact surface by shot peening, a mixture of the projection particles 7 and the powder of the oil repellent 6 may be projected onto the rolling contact surface, or You may roll and project the thing to which the oil-repellent agent 6 was beforehand attached to the surface of the projection particle | grains 7 on a contact surface. In the case where the surface of the projection particle 7 having the oil repellent 6 attached in advance is used, when the projection particle 7 is projected onto the rolling contact surface, the projection particle 7 is applied to a portion other than the portion in contact with the rolling contact surface. There is an advantage that the oil repellent 6 can be prevented from adhering.

  The total area of the recesses 5 on the rolling contact surface (the total area of the recesses 5 per unit area of the rolling contact surface) is determined by efficiently supplying lubricating oil that has entered the recess 5 to the rolling contact surface. From the viewpoint of forming a uniform oil film on the contact surface, it is preferably 5% or more, more preferably 10% or more, and the viewpoint of improving lubricity by relatively increasing the area where the lubricating oil exists on the rolling contact surface Therefore, it is preferably 30% or less, more preferably 25% or less. The total sum of the areas of the recesses 5 on the rolling contact surface can be easily adjusted by adjusting the number of projected particles 7 projected by shot peening per unit area of the rolling contact surface, for example.

  The diameter of the opening of the recess 5 formed on the rolling contact surface is preferably 1 μm or more, more preferably 2 μm from the viewpoint of firmly attaching the oil repellent 6 to the recess 5 in terms of an equivalent circular diameter. From the viewpoint of forming a uniform oil film on the rolling contact surface by efficiently discharging the lubricating oil from the recess 5 to the outside and supplying it to the rolling contact surface, it is preferably 25 μm or less, more preferably 20 μm. It is as follows. The diameter at the opening of the recess 5 can be easily adjusted, for example, by adjusting the diameter of the projected particle 7 projected by shot peening, the pressure when the projected particle 7 is projected onto the rolling contact surface, and the like. it can.

  When projecting particles 7 are projected onto the rolling contact surface by shot peening, a raised portion (not shown) is formed around the recess 5 formed on the rolling contact surface. The height of the raised portion is preferably 0.5 mm from the viewpoint of forming a uniform oil film on the rolling contact surface by efficiently discharging the lubricating oil from the recess 5 to the outside and supplying it to the rolling contact surface. Hereinafter, it is more preferably 0.1 mm or less, and further preferably 0.02 mm or less. In addition, the height of the bulging portion is adjusted, for example, by adjusting the pressure when the projected particles 7 roll and are projected onto the contact surface by shot peening, or after projecting the projected particles 7 by short peening, and performing barrel polishing. Can be easily adjusted.

  As described above, in the rolling bearing, since the oil repellent 6 is attached to the inner surfaces of a number of fine recesses 5 formed on the rolling contact surface, the lubricating oil that has entered the recesses 5 becomes oil repellent. 6 is easily discharged from the recess 5 to the outside and supplied to the rolling contact surface. Thereby, even if the amount of the oil repellent 6 supplied to the rolling contact surface is small, a uniform oil film is formed on the rolling contact surface, so that the value of the friction coefficient of the rolling contact surface and its fluctuation can be reduced. .

  In addition, from the viewpoint of forming a uniform oil film on the rolling contact surface and making the friction coefficient of the rolling contact surface small and uniform, the concave portion 5 is formed at least on both the outer raceway surface 11 and the inner raceway surface 21, It is preferable that the oil repellent 6 is attached to the inner surface of the recess 5.

  In the rolling bearing, at least one of the outer raceway surface 11, the inner raceway surface 21, the rolling surface 31 of the rolling element 3, the pocket portion 41 of the cage 4, and the guide surface 42 has a large number of minute recesses. 5 may be formed, and an oil repellent may adhere to the inner surface of the recess 5. Further, the guide surface 42 may be in sliding contact with the outer peripheral surface of the inner ring 2.

The rolling bearing may be a roller bearing such as a tapered roller bearing or a cylindrical roller bearing.
FIG. 4 is a cross-sectional view showing an embodiment of a roller bearing. This roller bearing is a tapered roller bearing, and has an outer ring 1 having a tapered outer raceway surface 11 on the inner periphery, and a tapered shape on the outer periphery that is arranged coaxially with the outer ring 1 and that faces the outer raceway surface 11. An inner ring 2 having an inner raceway surface 21, a plurality of rolling elements 3 made of tapered rollers interposed between the outer raceway surface 11 and the inner raceway surface 21, and the rolling elements 3 at predetermined intervals along the circumferential direction. And a retainer 4 to be held in the container. The outer peripheral surface of the rolling element 3 is configured as a rolling surface 31 that rolls on the outer raceway surface 11 and the inner raceway surface 21.

  In the tapered roller bearing, the outer ring 1, the inner ring 2, the rolling element 3 and the cage 4 are respectively rolling sliding members, and the outer raceway surface 11, the inner raceway surface 21, and the rolling surface 31 of the rolling element 3. The rolling contact surface.

At the end portion on the large diameter side of the inner ring 2, a flange surface 25 is formed which is in sliding contact with the end surface 32 on the large diameter side of the rolling element 3 and guides the rolling of the rolling element 3.
The cage 4 is formed by forming a plurality of pocket portions 41 for accommodating the rolling elements 3 at predetermined intervals along the circumferential direction in a metal cylinder. The pocket portion 41 of the cage 4 is configured as a sliding contact surface with respect to the rolling element 3. The flange surface 25 of the inner ring 2 is a sliding contact surface with respect to the end surface 32 of the rolling element 3, and the pocket portion 41 of the cage 4 is a sliding contact surface with respect to the rolling surface 31 of the rolling element 3.

  In the tapered roller bearing, the outer raceway surface 11, the inner raceway surface 21, the rolling surface 31 of the rolling element 3, the roller end surface (end surface of the rolling element 3) 32, the flange surface 25, and the pocket portion 41 of the cage 4. A large number of fine recesses 5 shown in FIG. 2 are formed in at least one of them, and an oil repellent 6 is attached to the inner surface of the recess 5.

  FIG. 5 is a sectional view showing still another embodiment of the roller bearing. This roller bearing is a cylindrical roller bearing, and has an outer ring 1 having an outer raceway surface 11 as a rolling contact surface on the inner circumference, and is arranged coaxially with the outer ring 1 and rolls on the outer circumference facing the outer raceway face 11. An inner ring 2 having an inner raceway surface 21 as a contact surface, a plurality of rolling elements 3 made of cylindrical rollers interposed between the outer raceway surface 11 and the inner raceway surface 21, and this rolling element 3 in a pocket portion 41. And a cage 4 to be accommodated. The outer peripheral surface of the rolling element 3 is configured as a rolling surface 31 that rolls on the outer raceway surface 11 and the inner raceway surface 21.

In the cylindrical roller bearing, the outer ring 1, the inner ring 2, the rolling element 3 and the cage 4 are rolling sliding members, respectively, and the outer raceway surface 11, the inner raceway surface 21, and the rolling surface 31 of the rolling element 3. The rolling contact surface.
At least one of the inner ring 2 and the outer ring is formed with a flange surface 25 that is in sliding contact with the end surface 32 of the rolling element 3 and guides the rolling of the rolling element 3. In the case of the figure, the flange surface 25 is formed at both end portions of the inner ring 2 and one end portion of the outer ring 1. Each of the flange surfaces 25 is a sliding contact surface with respect to the end surface 32 of the rolling element 3. Further, the pocket portion 41 of the cage 4 is configured as a sliding contact surface with respect to the rolling element 3.

  In the cylindrical roller bearing, the outer raceway surface 11, the inner raceway surface 21, the rolling surface 31 of the rolling element 3, the roller end surface (end surface of the rolling element 3) 32, the flange surface 25, and the pocket portion 41 of the cage 4. A large number of fine recesses 5 shown in FIG. 2 are formed in at least one of them, and an oil repellent 6 is attached to the inner surface of the recess 5.

In the tapered roller bearing and the cylindrical roller bearing, a uniform oil film is formed on the contact surface even if a small amount of the oil repellant 6 is supplied to the contact surface. can do.
In the roller bearing, when the cage 4 comes into contact with the outer peripheral surface of the raceway 25 of the bearing ring, for example, the inner race 2 and the rotation thereof is guided, the guide surface of the cage 4 or the cage surface 25 A large number of fine recesses 5 may be formed on the outer peripheral surface, and the oil repellent 6 may be attached to the inner surface of the recess 5.

  FIG. 6 is a sectional view showing still another embodiment of the rolling bearing of the present invention. This rolling bearing is a thrust roller bearing, and an outer ring 1 having an outer raceway surface 11 as a rolling contact surface on one side is concentric with an inner ring 2 having an inner raceway 21 as a contact surface on one side. Thus, they are opposed to each other with a predetermined gap in the axial direction. The outer raceway surface 11 and the inner raceway surface 21 are opposed to each other.

  Between the outer raceway surface 11 and the inner raceway surface 21, a rolling element 3 composed of a plurality of cylindrical rollers or needle rollers is interposed. The outer peripheral surface of the rolling element 3 is configured as a rolling surface 31 that is a rolling contact surface for the outer raceway surface 11 and the inner raceway surface 21. Further, between the outer ring 1 and the inner ring 2, a cage 4 for interposing each rolling element 3 in the pocket portion 41 is interposed.

  In this embodiment, the outer ring 1, the inner ring 2, the rolling element 3 and the cage 4 are respectively rolling sliding members, and the outer raceway surface 11, the inner raceway surface 21 and the rolling surface 31 of the rolling element 3 are provided. The rolling contact surface.

  In this thrust roller bearing, at least one of the outer raceway surface 11, the inner raceway surface 21, the rolling surface 31, the end face 32 of the rolling element 3, and the pocket portion 41 of the cage is provided with a large number of pieces shown in FIG. A fine recess 5 is formed, and an oil repellent is attached to the inner surface of the recess 5.

Even in this thrust roller bearing, even if a small amount of the oil repellent 6 is supplied to the contact surface, a uniform oil film is formed on the contact surface, so that the value of the friction coefficient of the contact surface and its variation can be reduced. it can.
The thrust roller bearing may be a thrust ball bearing in which a ball is used as the rolling element 3 and the outer raceway surface 11 and the inner raceway surface 21 have a circular arc shape in which the ball can roll. In this case, the outer peripheral surface of the rolling element 3 composed of the balls is configured as a rolling surface, and at least one of the outer raceway surface, the inner raceway surface, the rolling surface, and the pocket portion of the cage, A fine recess 5 is formed, and an oil repellent is attached to the inner surface of the recess 5.
Further, when the cage 4 comes into contact with the raceway, the outer raceway surface 11 or the inner raceway surface 21 and the rotation thereof is guided, the cage 4 is out of the guide surface, the outer raceway surface 11 and the inner raceway surface 21. In any of the above, a large number of fine recesses 5 may be formed, and the oil repellent 6 may be attached to the inner surface of the recess 5.

  The rolling sliding member of the present invention can be applied to various members having a contact surface that causes rolling contact and / or sliding contact with a counterpart member, such as various rolling bearings and sliding bearings. In any of the above cases, the rolling sliding member may be one that has not been heat-treated in addition to one that has been hardened by heat treatment.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Example 1
As atomized particles used for shot peening, iron-based atomized spherical particles (carbon steel containing carbon, silicon and manganese, average hardness: 860 Hv, particle size: about 40 μm) were used. Fluorine resin (polytetrafluoroethylene) particles having a particle size of about 10 μm were mixed with the projected particles so that the mass ratio of the spherical particles to the fluororesin particles was 7: 1. When the obtained mixed particles were observed with an optical microscope, the particles were aggregated. It was confirmed that the fluororesin particles were aggregated so as to cover the projected particles by mixing with the projected particles.

  Next, as a test piece, a test piece (φ56 mm × φ30 mm × height 9 mm) made of bearing steel (SUJ2 material) is precision-polished and a disk test piece having a mirror surface of Ra 5 nm is used. Is adjusted to 0.5 MPa, the mixed particles are projected with a direct pressure type peening apparatus at a projection distance of 200 mm, and the projection time is adjusted to obtain the total sum of the concave areas in the test piece (unit of the test piece). The total area of the recesses per area) was about 20%.

  In addition, when the projection amount of the particles was controlled by adjusting the nozzle shape, the overlap of the collision traces was reduced, and the concave portions could be provided in a discrete state.

  The projection mark formed on the test piece by the projected particles was photographed with an atomic force microscope. The micrograph is shown in FIG. FIG. 7 is an atomic force micrograph of the test piece. From the results shown in FIG. 7, the average diameter of the concave portion provided by the collision of the projecting particles with the test piece was 8 μm, and the depth thereof was about 0.3 μm. In addition, since the periphery of the recess is slightly raised, and there is a recess corresponding to the surface shape of the projected particle inside, the surface shape of the projected particle is reflected on the inner surface of the recess. I understand.

Comparative Example 1
In Example 1, shot peening was performed by projecting only projected particles onto a test piece with a peening apparatus in the same manner as in Example 1 except that the fluororesin particles were not used.

  Spindle oil was dropped on each test piece subjected to shot peening in Example 1 and Comparative Example 1. As a result, it was confirmed that in the test piece of Example 1, the spindle oil diffused so as to avoid dimples, whereas in the test piece of Comparative Example 1, the spindle oil entered the recess. From this, in the test piece of Example 1, it is thought that oil repellency is provided to the recessed part.

Comparative Example 2
A test piece of the same type as that used in Example 1 was used, and a test piece that was not subjected to shot peening was used as it was.

Experimental example 1
Spindle oil was dropped on each test piece of Example 1, Comparative Example 1 and Comparative Example 2, and after running-in test (friction speed 0.6 m / s, load 49 N, 600 seconds), new spindle oil was added. Was replaced.

  Next, a friction test was performed on each test piece. For the friction test, Satoshi Hoshino, Proceedings of the 2nd Annual Scientific Lecture of the Society of Materials Science 2008, No. 201 (2008) p35-36, a ring-on-disk friction tester was used. This ring-on-disk friction tester is a system in which a disk test piece is rotated by a motor and a contact load is applied by a weight to cause friction. The friction test was performed by supplying a sufficient amount of spindle oil as a lubricating oil to the friction surface of the disk test piece, contacting the ring test piece, applying a load, and rotating the disk test piece in the room temperature atmosphere.

  As the ring test piece, a cast iron (FC250) test piece (φ40 mm × φ32 mm × height 14 mm) was precision-polished to obtain a mirror surface of Ra 5 nm.

Experimental example 2
In Experimental Example 1, the test was performed in the same manner as in Experimental Example 1 except that the friction speed was changed stepwise under a constant load, and the friction speed / load value (hereinafter referred to as V / P value). The relationship between the friction coefficient and the friction coefficient was investigated. The result is shown in FIG. In FIG. 8, the black rectangle is the result when the test piece of Example 1 is used, the black rectangle is the result when the test piece of Comparative Example 1 is used, and the black circle is the test piece of Comparative Example 2. The result is shown.

  FIG. 8 shows a boundary lubrication state in which a V / P value is small and an oil film is hardly formed, and solid contact is likely to occur between two objects, a mixed lubrication state between boundary lubrication and fluid lubrication, and a V / P value is large. The transition state to the fluid lubrication state in which an oil film is easily formed is shown.

  From the results shown in FIG. 8, it can be seen that the friction coefficient in Example 1 tends to be lower than that in Comparative Examples 1 and 2 in any region of the V / P value. In particular, it can be seen that in the region where the V / P value is small (near 0.01), the friction coefficient in Example 1 is significantly small.

  Further, in the region where the V / P value is small, it is difficult to form an oil film due to the relative rotation between the two objects, and in Comparative Examples 1 and 2, the oil film breaks easily between the two objects. In Example 1, the concave portion has a function of storing lubricating oil as a storage (reservoir), and due to the oil repellency in the concave portion, the lubricating oil is supplied from the concave portion to the flat portion which is the contact surface, and a uniform oil film is formed. Since it is formed, it is considered that the friction coefficient is remarkably reduced.

Example 2
Glass beads (particle diameter: about 55 μm) were used as the projecting particles used for shot peening. The glass beads and fluororesin (polytetrafluoroethylene) particles having a particle size of 10 μm or less were mixed so that the mass ratio of the glass beads to the fluororesin particles was 7: 1. When the obtained mixed particles were observed with an optical microscope, it was confirmed that the fluororesin particles were adhered so as to cover the glass beads by being mixed with the glass beads.

  Using the glass beads to which the fluororesin is adhered, the gas pressure at the time of projection is adjusted to 0.5 MPa, and a direct pressure type peening apparatus with a projection distance of 200 mm, a disc specimen having a mirror surface of Ra 5 nm [aluminum alloy ( A6063), φ56 mm × φ30 mm × height 9 mm], and by adjusting the projection time, the total area of the recesses in the test piece (the total area of the recesses per unit area of the contact surface) is 17%. The degree.

  Next, after applying spindle oil to the friction surface of the disk test piece so as to have a thickness of about 20 μm, a ring test piece (made of cast iron (FC200), φ40 mm × φ32 mm × height 14 mm) is brought into contact. Using the same ring-on-disk friction tester as used in No. 1, a load of 45 N was applied, and the disk test piece was rotated at a speed of 0.1 m / s in the room temperature atmosphere. The relationship between distance and coefficient of friction was investigated. The result is shown in FIG.

Comparative Example 3
In Example 2, except that the fluororesin particles were not used, shot peening was performed in the same manner as in Example 2, and then a friction test of the disk test piece was performed to examine the relationship between the friction distance and the friction coefficient. It was. The result is shown in FIG.

Comparative Example 4
A disc test piece of the same type as that used in Example 2 was used, and the disc test piece was subjected to a friction test in the same manner as in Example 2 except that shot peening was not performed on this test piece. The relationship with the coefficient of friction was investigated. The result is shown in FIG.

From the results shown in FIG. 9, in the disk test piece not subjected to shot peening of Comparative Example 4, as shown in FIG. 9C, the friction coefficient is large and the friction in the range of the friction distance is 50 to 350 m. The coefficient is about 8 × 10 ^{−2 to} 19 × 10 ⁻² , and the variation range of the friction coefficient is about 4 × 10 ⁻¹ , so that the friction coefficient varies greatly depending on the surface portion of the disk specimen. I understand.

On the other hand, in the disk test piece subjected to shot peening without using the fluororesin particles of Comparative Example 3, the friction coefficient is small as shown in FIG. 9B, but the friction distance is 50 to 350 m. The friction coefficient in the range of about 1 × 10 ⁻² to 2 × 10 ⁻² and the variation range of the friction coefficient is about 1 × 10 ⁻² , so the variation of the friction coefficient on the surface of the disk test piece Is smaller than the disk test piece of Comparative Example 4, but is slightly larger.

On the other hand, in the disk test piece subjected to shot peening using the fluororesin particles of Example 2, as shown in FIG. 9A, the friction coefficient is small and the friction distance is 50 to 350 m. The friction coefficient in the range is about 1.2 × 10 ^{−2 to} 1.6 × 10 ⁻² , and the variation is about 0.4 × 10 ⁻² , so that the friction coefficient on the surface of the disk specimen is It can be seen that the variation in the difference is much smaller than that of the disk test pieces of Comparative Example 3 and Comparative Example 4.

  From the above, the rolling sliding member of the present invention has a small amount of lubricating oil supplied to the contact surface because the oil repellent is adhered to the inner surfaces of many fine recesses formed on the contact surface. However, since a uniform oil film is formed on the contact surface, it can be understood that the value of the friction coefficient of the contact surface and its variation can be reduced.

  In the rolling bearing of the present invention, the oil repellent is attached to the inner surfaces of a number of minute recesses formed on at least one of the outer raceway surface, the inner raceway surface and the rolling contact surface which are rolling contact surfaces. Therefore, even if a small amount of lubricating oil is supplied to the rolling contact surface, a uniform oil film is formed on the rolling contact surface. Therefore, the value of the friction coefficient of the rolling contact surface and its variation should be reduced. You can see that

1 Outer ring (rolling sliding member)
11 Outer raceway surface (rolling contact surface)
2 Inner ring (rolling sliding member)
21 Inner raceway surface (rolling contact surface)
25 ridge surface 3 rolling element (rolling contact surface)
4 Cage 41 Pocket portion 42 Guide surface 5 Recessed portion 6 Oil repellent 7 Projection particle B Intermediate material

Claims (7)

Polishing a metal intermediate material formed in a predetermined shape to form a contact surface that causes relative rolling contact or sliding contact with a mating member;
Projecting the oil repellent along with the projecting particles by shot peening on the contact surface to form a large number of fine recesses on the contact surface, and simultaneously attaching the oil repellent to the inner surface of the recess;
And a projecting particle having the oil repellent attached thereto is projected onto the contact surface.   The manufacturing method of the rolling sliding member of Claim 1 using a fluororesin as the said oil repellent. An outer ring having an outer raceway surface as a rolling contact surface on the inner circumference;
An inner ring disposed coaxially with the outer ring and having an inner raceway surface as a rolling contact surface on the outer periphery;
A plurality of rolling elements interposed between the outer raceway surface and the inner raceway surface, and having a rolling surface that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface on the outer periphery;
At least one of the outer raceway surface, the inner raceway surface, and the rolling surface is projected by shot peening with shot peening projection particles having an oil repellent attached thereto to form a large number of fine recesses. An oil repellent is attached to the inner surface of the rolling bearing. An outer ring having an outer raceway surface as a rolling contact surface on the inner circumference;
An inner ring disposed coaxially with the outer ring and having an inner raceway surface as a rolling contact surface on the outer periphery;
A rolling element comprising a plurality of balls that are interposed between the outer raceway surface and the inner raceway surface, and whose outer periphery constitutes a rolling contact surface that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface;
A radial ball bearing comprising: the rolling element housed in a pocket portion; and a cage having a guide surface which is a sliding contact surface with respect to an outer peripheral surface of an inner ring or an inner peripheral surface of an outer ring on a peripheral surface,
Projection particles for shot peening in which an oil repellent agent is adhered to at least one of the outer raceway surface, the inner raceway surface, the rolling surface, the pocket portion of the cage, and the guide surface of the cage are projected by shot peening. A radial ball bearing characterized in that a large number of fine recesses are formed, and an oil repellent is attached to the inner surface of the recesses. An outer ring having an outer raceway surface as a rolling contact surface on the inner circumference;
An inner ring disposed coaxially with the outer ring and having an inner raceway surface as a rolling contact surface on the outer periphery;
A rolling element comprising a plurality of rollers interposed between the outer raceway surface and the inner raceway surface and having a rolling contact surface on the outer periphery that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface;
A cage for storing the rolling elements in a pocket portion;
A roller bearing that forms a flange surface that is a sliding contact surface with respect to an end surface of the rolling element on at least one of the inner ring and the outer ring,
By shot peening, the shot particles for shot peening in which an oil repellent agent is attached to at least one of the outer raceway surface, the inner raceway surface, the rolling surface, the end surface of the rolling element, the flange surface and the pocket portion of the cage A roller bearing characterized in that a number of fine recesses are formed by projecting, and an oil repellent is attached to the inner surface of the recesses. An outer ring having an outer raceway surface as a rolling contact surface on one side surface;
An inner ring having an inner raceway surface as a rolling contact surface on one side surface, the inner raceway surface being disposed opposite to the outer raceway surface of the outer ring in a state of providing a gap in the axial direction;
A rolling element comprising a plurality of rollers interposed between the outer raceway surface and the inner raceway surface and having a rolling contact surface on the outer periphery that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface;
A thrust roller bearing comprising a cage for accommodating the rolling element in a pocket portion,
Projection particles for shot peening with an oil repellent adhered to at least one of the outer raceway surface, the inner raceway surface, the rolling surface, the end face of the rolling element, and the pocket portion of the cage are projected by shot peening. A thrust roller bearing, wherein a large number of fine recesses are formed, and an oil repellent is attached to the inner surface of the recesses. An outer ring having an outer raceway surface as a rolling contact surface on one side surface;
An inner race which has an inner raceway surface as a rolling contact surface on one side surface, and this inner raceway surface is disposed opposite to the outer raceway surface of the outer ring in a state of providing a gap in the axial direction;
A rolling element comprising a plurality of balls that are interposed between the outer raceway surface and the inner raceway surface and whose outer periphery constitutes a rolling contact surface that is a rolling contact surface with respect to the outer raceway surface and the inner raceway surface;
A thrust ball bearing comprising a cage for accommodating the rolling elements in a pocket portion,
A number of fine concave portions are formed by projecting shot peening projection particles with an oil repellent agent on at least one of the outer raceway surface, the inner raceway surface, the rolling surface and the pocket portion of the cage by shot peening. A thrust ball bearing characterized in that an oil repellent is adhered to the inner surface of the recess.