JP2016102514A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing excellent in holding force of lubricant and having long service life.SOLUTION: A rolling bearing includes an inner ring 1, an outer ring 2, a plurality of rolling bodies 3, and a holder 4. At least a part of the surface of the holder 4 is a rough surface having a minute micro recess part 11 forming surface rough and a plurality of macro recess parts 12 larger than the micro recess part 11. The macro recess part 12 is a groove having a width of beyond 0 μm and 5000 μm or less. The grooves are aligned with intervals in parallel. A ratio of a width to an interval is over 0% and 71.4% or less.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rolling bearing.

Patent Documents 1 and 2 disclose rolling bearings in which the retaining force of the lubricant in the pocket is improved by roughening the inner surface of the pocket of the cage.
However, in the minute recesses that form the surface roughness, the amount of the lubricant that can be held in the inside is small, and the improvement degree of the retention force of the lubricant cannot be said to be sufficient.

Japanese Patent Laid-Open No. 11-108064 JP 2007-198469 A

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a rolling bearing having excellent lubricant retention and a long life.

  In order to solve the above-described problems, a rolling bearing according to an aspect of the present invention includes an inner ring, an outer ring, a plurality of rolling elements that are freely rollable between the inner ring and the outer ring, and an inner ring and an outer ring. A retainer for holding a plurality of rolling elements, and at least a part of the surface of the retainer has a micro-recess having a surface roughness and a plurality of macro-recesses larger than the micro-recess. The surface is a rough surface, and the macro concave portion is a groove having a width of more than 0 μm and not more than 5000 μm, and these grooves are arranged in parallel at intervals, and the ratio of the width to the interval is more than 0% and not more than 71.4% Is the gist.

  In the rolling bearing according to the above aspect, at least a part of the surface of the pocket of the cage may be a rough surface. In the rolling bearing according to the above aspect, the cage is a raceway guide type cage guided by the inner ring or the outer ring, and has a guided surface guided by the inner ring or the outer ring. At least a part of the surface may be a rough surface.

  The rolling bearing of the present invention has an excellent lubricant retention and a long life.

It is a fragmentary longitudinal cross-section which shows the structure of the angular ball bearing which concerns on one Embodiment of the rolling bearing of this invention. It is a figure explaining the structure and angle (alpha) of a holder | retainer. It is a figure explaining the structure and axial position (beta) of a holder | retainer. It is explanatory drawing which showed the structure of the rough surface typically. It is a graph which shows the relationship between the width | variety of a groove | channel, and the seizure lifetime of an angular contact ball bearing. It is a graph which shows the relationship between the ratio of the width | variety with respect to the space | interval of a groove | channel, and the seizure lifetime of an angular contact ball bearing. It is a graph which shows the relationship between a formula value and the seizure life of an angular contact ball bearing. It is a graph which shows the relationship between the angle (alpha) and the seizure lifetime of an angular contact ball bearing.

An angular ball bearing according to an embodiment of the rolling bearing of the present invention will be described in detail with reference to the drawings.
The angular ball bearing shown in FIG. 1 includes an inner ring 1 having a raceway surface 1a on the outer peripheral surface, an outer ring 2 having an inner raceway with a raceway surface 2a facing the raceway surface 1a of the inner ring 1, and a raceway surface 1a and an outer ring of the inner ring 1. A plurality of rolling elements (balls) 3 that are arranged so as to be freely rollable between the two raceway surfaces 2 a, a cage 4 that holds the plurality of rolling elements 3 between the inner ring 1 and the outer ring 2, Contact type seals 5 and 5 that cover the opening of the gap between the outer ring 2 and the outer ring 2. Note that the seal 5 may not be provided.

  Although the kind of this holder | retainer 4 is not specifically limited, For example, the holder | retainer 4 as shown to FIG.2, 3 is mention | raise | lifted. That is, the cage 4 is formed by forming a plurality of pockets 4b in a cylindrical main body 4a. The pocket 4b is formed of a circular through hole that penetrates the inner peripheral surface and the outer peripheral surface of the main body 4a. The plurality of pockets 4b are arranged in a row with a space in the circumferential direction of the main body 4a.

  At least a part of the surface of the cage 4 is a rough surface. The rough surface has minute micro concave portions 11 that form surface roughness and a plurality of macro concave portions 12 that are larger than the micro concave portions 11 (see FIG. 4). The macro concave portion 12 is a groove, and a plurality of grooves extending substantially linearly are arranged in parallel at intervals. The cross-sectional shape of the groove is not particularly limited, and may be, for example, a rectangular shape, a triangular shape, or an arc shape.

  The rough surface will be described in more detail with reference to FIG. A plurality of macro concave portions 12 are formed on the rough surface, and the entire rough surface including the inner surface of the macro concave portion 12, that is, a portion of the rough surface where the macro concave portions 12 are not formed (hereinafter referred to as “convex portions”). ) And a micro-recess 11 that forms surface roughness is formed on the inner surface of the macro-recess 12. The surface roughness Ra of the convex portion is not particularly limited, but may be, for example, more than 0 μm Ra, and is preferably 1 μm Ra or more and 10 μm Ra or less. The micro concave portion 11 formed on the inner surface of the macro concave portion 12 is the same as the micro concave portion 11 formed on the convex portion.

The width of the groove formed as the macro concave portion 12 on the rough surface is 0 μm to 5000 μm or less. And the ratio of the width of the groove with respect to the interval between these grooves is set to 0% and 71.4% or less. In addition, although the width | variety of the some groove | channel formed in a rough surface and the space | interval of these grooves are all the same, it is not necessary to make all the same.
Furthermore, the macro recessed part 12 is not formed in the part which is not made into the rough surface among the surfaces of the holder | retainer 4, and only the micro recessed part 11 is formed. The surface roughness Ra of the portion of the surface of the cage 4 that is not roughened is not particularly limited, but may be the same as the surface roughness Ra of the convex portion. That is, you may form the same micro recessed part 11 in the part which is not made into the rough surface among the surfaces of the holder | retainer 4, and a convex part.

  If at least a part of the surface of the cage 4 is rough as described above, the lubricant such as lubricating oil and grease is held on the rough surface, so that the angular ball bearing has an excellent holding power of the lubricant. Long service life. More specifically, since the lubricant held in the micro-recess 11 is supplied to the contact interface between the mating member (for example, the inner ring 1, the outer ring 2, the rolling element 3) and the cage 4 in contact with the cage 4. The lubricity between the cage 4 and the mating member and the lubricity between the inner ring 1 and the outer ring 2 and the rolling element 3 are improved.

  The lubricant held in the macro recess 12 moves into the micro recess 11 due to the capillary phenomenon of the micro recess 11 and is supplied to the contact interface between the cage 4 and the mating member. Moreover, it is possible to supply almost all of the lubricant retained in the macro recess 12 to the contact interface by capillary action. Since the macro concave portion 12 can hold a larger amount of lubricant than the micro concave portion 11, the angular ball bearing of this embodiment has a better lubricant retention and a longer life. That is, the rolling bearing of the present embodiment is superior in the retention of lubricant and has a long life compared to conventional rolling bearings having only minute micro concave portions that form surface roughness.

Furthermore, when at least a part of the surface of the cage 4 is rough as described above, the action of discharging abrasion powder from the contact interface between the cage 4 and the mating member, and suppression of the revolving slip of the rolling element 3 are suppressed. The action and the action of suppressing heat generation due to friction are also obtained.
The width of the groove formed as the macro concave portion 12 on the rough surface is more than 0 μm and not more than 5000 μm. If the width of the groove exceeds 5000 μm, the rolling element 3 may fall into the groove. Then, since the corner | angular part of the edge of a groove | channel will contact the rolling element 3, a contact surface pressure becomes large and there exists a possibility that the lifetime of a rolling bearing may fall. In addition, vibration may occur when the rolling element 3 moves between the convex portion and the groove.

  Further, the ratio of the groove width to the groove interval is more than 0% and not more than 71.4%. The macro concave portion 12 does not contact the mating member, and the convex portion contacts the mating member to support the load. However, if the ratio of the groove width to the groove interval exceeds 71.4%, the convex portion is narrow. A large contact surface pressure is applied to this portion. As a result, there is a possibility that the wear of the micro concave portion 11 formed in the convex portion is promoted.

  In order to further improve the lubricity of the angular ball bearing, it is preferable that a portion of the surface of the cage 4 that faces the mating member be a rough surface. Since the portion facing the mating member may come into contact with the mating member, it is preferable to improve the lubricity by using a rough surface. For example, the surface of the pocket 4b among the surfaces of the cage 4 may be a rough surface. Further, the cage 4 provided in the angular ball bearing of FIG. 1 is an outer ring guide type cage guided by the outer ring 2 (may be an inner ring guide type cage guided by the inner ring 1). Although the guided surface 4c is guided by the cage guide surface 2b formed on the inner peripheral surface, the guided surface 4c of the surface of the cage 4 may be a rough surface. Of course, both the surface of the pocket 4b and the guided surface 4c may be roughened.

  The macro recess 12 formed on the surface of the pocket 4b or the guided surface 4c is preferably a groove extending along the sliding direction with the mating member. That is, a groove may be formed on the surface of the pocket 4b so as to extend along the sliding direction between the rolling element 3 and the surface of the pocket 4b. Further, a groove may be formed in the guided surface 4c so as to extend along the sliding direction of the cage guide surface 2b of the outer ring 2 and the guided surface 4c of the cage 4.

  However, if all of the surface of the cage 4 that faces the mating member is rough, the convex portion that supports the load when contacting the mating member becomes narrow, so that the convex portion is formed as described above. There is a possibility that the wear of the formed micro-recess 11 is promoted. Further, only a part of the cage 4 that faces the mating member is in contact with the mating member, and many portions are in contact only with the lubricant.

  In view of these circumstances, if a part of the part facing the mating member in the cage 4 is roughened, both the suppression of wear of the micro-concave part 11 formed in the convex part and the retention of the lubricant can be achieved. Thus, the rolling bearing can have a longer life. For example, if only the portion of the surface of the pocket 4b that does not come into contact with the rolling element 3 is roughened, the wear of the micro concave portion 11 formed on the convex portion is suppressed, and the rolling bearing can have a longer life. Further, if only the portion of the outer peripheral surface of the cage 4 that does not contact the cage guide surface 2b of the outer ring 2 is roughened (in the case of an inner ring guide type cage, the inner ring If only the portion that does not contact the cage guide surface is a rough surface), the wear of the micro concave portion 11 formed in the convex portion is suppressed, and the rolling bearing can have a longer life.

  In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, the rolling bearing of the present embodiment includes the cage having the shape as described above, but the type of the cage is not particularly limited, and a crown-shaped cage, a corrugated cage, and a cage-shaped cage. One shape holder may be used. The material of the cage is not particularly limited, and metal, resin, etc. can be used, but if a resin is used, a cage having a rough surface can be produced by injection molding, so that the production can be performed. Easy.

  Further, in the present embodiment, the angular ball bearing has been described as an example of the rolling bearing, but the rolling bearing of the present invention can be applied to various types of rolling bearings. For example, radial rolling bearings such as deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, and self-aligning roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.

  Further, when the rolling bearing is provided with the contact type seal 5, even if the present invention is applied to a portion of the lip of the seal 5 that contacts the raceway ring (inner ring 1 in the case of the angular ball bearing in FIG. 1). Good. That is, at least a part of the portion of the lip of the seal 5 that comes into contact with the raceway may be a rough surface having minute micro concave portions forming surface roughness and a plurality of macro concave portions larger than the micro concave portions. . Also in the case of the seal 5, the macro concave portion is a groove having a width exceeding 0 μm and not more than 5000 μm, and these grooves are arranged in parallel at intervals, and the ratio of the width to the interval is more than 0% and not more than 71.4%. With such a configuration, the lubricity between the seal 5 and the race is improved, so that the seal 5 is hardly damaged and the rolling bearing has a long life.

〔Example〕
The present invention will be described more specifically with reference to the following examples. In the outer ring guide type angular contact ball bearings as shown in Fig. 1 (nominal number: 70BNR10HTV1V), we prepared various changes in the properties of the rough surface provided in the cage, and performed rotation tests on these angular ball bearings. The property (seizure life) was evaluated. As the properties of the rough surface, the width and interval of the grooves as the macro concave portions were changed as shown in Table 1. The depth of the groove was 100 μm in any angular ball bearing. In Comparative Example 3, only micro concave portions are formed, and no macro concave portion is formed.

  The site | part which forms a rough surface is the whole surface of the pocket of a holder | retainer, and the whole outer peripheral surface of a holder | retainer. Moreover, the groove | channel as a macro recessed part was formed in parallel with the sliding direction. That is, the groove formed in the pocket of the cage is parallel to the sliding direction of the pocket and the rolling element, and the groove formed on the outer circumferential surface of the cage is formed between the outer circumferential surface of the cage and the inner circumferential surface of the outer ring. Parallel to the direction of sliding. Furthermore, the surface roughness formed by the micro-recesses has no directionality in any angular ball bearing and is 2.5 μmRa.

These cages were produced by injection molding of a polyphenylene sulfide resin composition (a composition in which 70% by mass of polyphenylene sulfide resin and 30% by mass of carbon fiber were mixed). Protrusions were formed on the surface of the mold used for injection molding, and these were transferred to form micro-recesses and macro-recesses.
The conditions of the rotation test are as follows.

Lubricant: Lubricated with 2.6 g of grease per bearing Rotational speed: 16000 min ^-1 (dmn: 1.24 million)
Cooling method: Outer cylinder cooling

  The angular ball bearing was rotated under the above conditions, and the time until the outer ring temperature exceeded a predetermined temperature was defined as the seizure life. The results are shown in Table 1 and the graphs of FIGS. The seizure life shown in Table 1 and FIGS. 5 and 6 are shown as relative values when the seizure life of Comparative Example 3 in which no macro concave portion is formed is 1. Moreover, the circular plot in the graph of FIG.5, 6 shows Examples 1-10, and the triangular plot shows Comparative Examples 1-3.

As can be seen from the results of Table 1 and the graphs of FIGS. 5 and 6, the angular ball bearings of Examples 1 to 10 have a better seizure life than the angular ball bearing of Comparative Example 3 and form micro and macro recesses. The seizure prevention effect by having the roughened surface was confirmed.
Further, in the angular ball bearings of Examples 1 to 10, the micro concave portions and the macro concave portions remained on the outer peripheral surface of the cage even after the end of the rotation test. From this, it is understood that the grease is easily held on the rough surface, and the lubricity between the outer peripheral surface of the cage and the inner peripheral surface of the outer ring is improved.

Furthermore, it can be seen from Examples 1 to 10 and Comparative Examples 1 and 2 that the groove width needs to be 5000 μm or less, and that the smaller the groove width, the better the seizure life. Further, it can be seen that the interval between the grooves is preferably 20000 μm or less. Furthermore, when the ratio of the width to the groove interval is 5% or more and 71.4% or less, it is understood that the seizure prevention effect is excellent.
Furthermore, from the results of Examples 1 to 10 and Comparative Examples 1 to 3, a value calculated by substituting the width of the groove, the interval, and the ratio of the width to the interval of the groove into the following formula (hereinafter referred to as “formula value”). However, it was found that there is a correlation with the seizure life of the angular ball bearing. In addition, the unit of the width | variety and space | interval of a groove | channel in a type | formula is micrometer, and the unit of the ratio of the width | variety with respect to the space | interval of a groove | channel is%.

Formula: ([width] × 3 + [interval]) / 500+ [ratio]
The results are shown in Table 1 and the graph of FIG. From the graphs in Table 1 and FIG. 7, it can be seen that if the formula value is 32 or more and 93 or less, the seizure life is excellent, and if the formula value is 32 or more and 80 or less, the seizure life is further excellent. In addition, the circular plot in the graph of FIG. 7 shows Examples 1-10, and the triangular plot shows Comparative Examples 1-3.

  Next, in the outer ring guide type angular contact ball bearing as shown in FIG. 1 (nominal number: 70BNR10HTV1V), the surface of the rough surface formed on the cage is variously changed as shown in Table 2, These angular ball bearings were subjected to a rotation test to evaluate durability (seizure life). Except for various changes in the width of the rough surface formed on the cage, the structure and test conditions of the angular ball bearings are the same as those in the above-mentioned tests performed by changing the properties of the rough surface. Only the description will be given, and description of similar parts will be omitted.

  The site | part which forms a rough surface is the surface of the pocket of a holder | retainer, and the outer peripheral surface of a holder | retainer. First, the rough surface formed on the surface of the pocket will be described. The angle α in Table 2 and FIG. 2 is a value that defines a region where a rough surface (macro concave portion) is formed in the surface of the pocket.

  A line passing through the center of the pocket and extending in the circumferential direction of the cage intersects the surface of the pocket at two points. One of these two points has an angle α = 0 ° and the other has an angle α = 180 °. Then, which phase region of the surface of the pocket has the rough surface is displayed in the range of the angle α. For example, in the case of Example 11, 0 to 360 ° is shown in Table 2, but the surface of the pocket has a rough surface in the region from the phase of angle α = 0 ° to the phase of angle α = 360 °. Means. That is, it means that the entire surface of the pocket has a rough surface.

  In the case of Example 13, for example, 30 to 150 and 210 to 330 are shown in Table 2, but the region from the phase of angle α = 30 ° to the phase of angle α = 150 ° on the surface of the pocket, In addition, it means that the surface has a rough surface in the region from the phase at the angle α = 210 ° to the phase at the angle α = 330 ° (the angle indicated by the broken line in FIG. 2). Rough surfaces (macro concave portions) are not formed in regions other than these regions, and only minute micro concave portions that form surface roughness are formed.

  Next, the rough surface formed on the outer peripheral surface of the cage will be described. The axial position β in Table 2 and FIG. 3 is a value that defines a region where a rough surface (macro concave portion) is formed in the outer peripheral surface of the cage. Of the outer peripheral surface of the cage, one axial end (right end in FIG. 3) is the axial position β = 1, and the other axial end (left end in FIG. 3) is the axial position β = 0. Then, which region in the axial direction of the outer peripheral surface of the cage has the rough surface is displayed in the range of the axial position β.

  The angular ball bearing used in this test is an outer ring guide type bearing, and as can be seen from FIG. 1, the inner peripheral surface of the outer ring is held by one end in the axial direction from the rolling element (right side in FIG. 1). It becomes a container guide surface, and only this portion is in contact with the guided surface of the cage. In this way, when only one axial end side (the right side in FIG. 1) of the outer peripheral surface of the cage is a guided surface, the side of the outer peripheral surface of the cage where the cage guide surface is located. The axial end (right end in FIG. 3) is the axial position β = 1.

  For example, in the case of Example 11, 0 to 1 are shown in Table 2, but a rough surface is formed on the outer peripheral surface of the cage from the position of the axial position β = 0 to the position of the axial position β = 1. It means having. That is, it means that the entire outer peripheral surface of the cage has a rough surface. For example, in the case of Example 18, 0 to 0.25 is shown in Table 2, but the position of the axial position β = 0.25 from the position of the axial position β = 0 on the outer peripheral surface of the cage. It means having a rough surface in the region up to (the axial position indicated by the broken line in FIG. 3). Rough surfaces (macro concave portions) are not formed in regions other than these regions, and only minute micro concave portions that form surface roughness are formed. In Comparative Example 4, no macro concave portion is formed on either the surface of the pocket of the cage or the outer peripheral surface of the cage, and only the micro concave portion is formed.

In any angular ball bearing, the width of the groove as the macro concave portion was 1000 μm, the interval was 2000 μm, and the depth was 100 μm. Further, the surface roughness formed by the micro-recesses has no directionality in any angular ball bearing and is 3.5 μmRa.
Each angular ball bearing shown in Table 2 was rotated under the same conditions as above, and the time until the outer ring temperature exceeded a predetermined temperature was defined as the seizure life. The results are shown in Table 2 and the graph of FIG. The seizure life shown in the graphs of Table 2 and FIG. 8 is 1 for the seizure life of Comparative Example 4 in which no macro recess is formed on either the surface of the pocket of the cage or the outer peripheral surface of the cage. The relative value is shown. Further, the graph of FIG. 8 is obtained by plotting the smallest numerical value in the range of the angle α shown in Table 2. For example, in Example 12, since the angle α is 15 to 165 and 195 to 345, the minimum 15 is plotted. In the case of Example 17 and Comparative Example 4, 90 was plotted as the angle α. Furthermore, the circular plot in the graph of FIG. 8 shows Examples 11 to 22, and the triangular plot shows Comparative Example 4.

As can be seen from the results of the graphs in Table 2 and FIG. 8, the angular ball bearings of Examples 11 to 22 have better seizure life than the angular ball bearing of Comparative Example 4, and the micro concave portion and the macro concave portion are formed. The anti-seizure effect by having a rough surface was confirmed.
Further, the entire surface of the pocket is not in contact with the rolling elements, but in terms of the angle α, the vicinity of the phase 0 ° and the vicinity of the phase 180 ° mainly contact each other, and the vicinity of the phase 90 ° and the phase The vicinity of 270 ° is difficult to contact. In addition, the outer peripheral surface of the cage is in contact with the inner peripheral surface of the outer ring at the right end portion in the axial direction from the rolling element 3 serving as the guided surface, but the left end portion in the axial direction from the rolling element 3 is the inner periphery of the outer ring. Do not touch the surface.

  In Example 11, a rough surface (macro concave portion) is also formed in a portion of the pocket surface that contacts the rolling element, but Examples 12 to 16 have a portion in contact with the rolling element in the pocket surface. No rough surface (macro concave portion) is formed, or even if it is formed, the region is small. Therefore, it is considered that the lubricity is further improved and the life is extended. Further, in Example 11, a rough surface (macro concave portion) is also formed in a portion of the outer peripheral surface of the cage that contacts the outer ring, but in Examples 18 to 20, the outer ring is included in the outer peripheral surface of the cage. It is considered that a rough surface (macro concave portion) is not formed in the contact portion, or even if it is formed, the region is small, so that the lubricity is further improved and the life is extended.

  Further, in the angular ball bearings of Examples 11 to 22, the micro concave portion and the macro concave portion remained on the outer peripheral surface of the cage even after the end of the rotation test. From this, it is understood that the grease is easily held on the rough surface, and the lubricity between the outer peripheral surface of the cage and the inner peripheral surface of the outer ring is improved.

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Rolling element 4 Cage 4b Pocket 4c Guided surface 11 Micro recessed part 12 Macro recessed part

Claims (2)

An inner ring, an outer ring, a plurality of rolling elements arranged to roll between the inner ring and the outer ring, and a cage for holding the plurality of rolling elements between the inner ring and the outer ring, Prepared,
At least a part of the surface of the cage is a rough surface having fine micro concave portions that form a surface roughness and a plurality of macro concave portions larger than the micro concave portions,
The macro concave portion is a groove having a width of more than 0 μm and less than or equal to 5000 μm, and the grooves are arranged in parallel at intervals, and a ratio of the width to the interval is more than 0% and not more than 71.4%.   The cage is a raceway guide type cage guided by the inner ring or the outer ring, and has a guided surface guided by the inner ring or the outer ring, and at least a part of the guided surface is the The rolling bearing according to claim 1, wherein the rolling bearing is a rough surface.

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