Rolling bearing, abnormality diagnosis device for rolling bearing, and abnormality diagnosis method for rolling bearing

Abstract

This rolling bearing (1) comprises an outer ring (4), an inner ring (7) that is provided inside the outer ring (4), a plurality of rolling bodies (8) that roll between the outer ring (4) and the inner ring (7), and a retainer (9) that holds the rolling bodies (8) while maintaining an interval between adjacent rolling bodies (8). The retainer (9) of the rolling bearing (1) has an indication part (14) on a surface that can be in contact with the outer ring (4), the inner ring (7), or the rolling bodies (8), the indication part (14) being colored in different colors according to the depth from the outer surface portion of said surface toward the inside.

Description

Rolling bearing, rolling bearing abnormality diagnosis device, and rolling bearing abnormality diagnosis method

[0001] The present disclosure relates to a rolling bearing and an abnormality diagnosis device for the rolling bearing.

[0002] Conventionally, rolling bearings used in rotating machinery can suffer damage and wear at the contact points between the cage and rolling elements after long-term continuous use. When damage or wear occurs, the cage can begin to whirl, causing problems. If the damage progresses further, it can lead to major bearing failure. For this reason, rotating machinery is regularly inspected for abnormalities in bearings and other rotating parts after a certain period of use. Inspecting such rotating parts for abnormalities takes a considerable amount of time and effort.

[0003] One example of an inspection for abnormalities is disclosed in which a coating made of a material different from that of the bearing components is formed on the surface of the cage. In this example, when cage damage occurs due to contact between the cage and the rolling elements, the coating material mixed into the lubricating oil as wear debris is detected by a detection device, making it possible to detect the presence or absence of cage damage and the extent of its progression (for example, Patent Document 1).

[0004] JP 2014-66310 A

[0005] In conventional technology, detecting wear debris requires special detection equipment that matches the coating material formed on the surface of the cage, and there is also the problem of requiring a process for operating and maintaining the special equipment.

[0006] The present disclosure has been made to solve the above-mentioned problems, and provides a rolling bearing, a rolling bearing abnormality diagnosis device, and a rolling bearing abnormality diagnosis method that can easily inspect the state of damage and wear of the cage of the rolling bearing without using special equipment.

[0007] One claim of the present disclosure relates to a rolling bearing comprising an outer ring, an inner ring provided inside the outer ring, a plurality of rolling elements that roll between the outer ring and the inner ring, and a retainer that maintains the spacing between adjacent rolling elements and holds the rolling elements, wherein the retainer has indicator portions on its surfaces that may come into contact with the outer ring, the inner ring, or the rolling elements that are colored in different colors depending on the depth from the surface of said surfaces toward the interior.

[0008] According to the present disclosure, the state of damage and wear of the cage can be quantitatively determined by observing the cage, and therefore diagnosis can be easily performed without using special equipment.

[0009] 1 is an example of a cross-sectional view taken along a plane perpendicular to the rotation axis of a rolling bearing illustrating the first embodiment. FIG. 2 is an example of a cross-sectional view taken along a plane including the rotation axis of a rolling bearing illustrating the first embodiment. FIG. 3 is an example of a perspective view of a normal cage illustrating the first embodiment. FIG. 4 is an example of a perspective view of a worn cage illustrating the first embodiment. FIG. 5 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a periphery including an index portion provided on a bar portion of the cage illustrating the first embodiment. FIG. 6 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a periphery including an index portion provided on the outer peripheral surface of the cage of the cage illustrating the first embodiment. FIG. 7 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a periphery including an index portion provided on the inner peripheral surface of the cage of the cage illustrating the first embodiment. FIG. 8 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a bar portion of the cage illustrating the first embodiment. FIG. 9 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a bar portion of the cage illustrating the first embodiment. FIG. 10 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a bar portion having an index portion according to the first embodiment. FIG. 11 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a bar portion having a conical index portion according to the first embodiment. FIG. 1 is an example of a partial cross-sectional view of a column portion having indicator portions whose diameters change stepwise, showing the first embodiment, cut along a plane perpendicular to the rotation axis. FIG. 2 is an example of a partial cross-sectional view of a column portion having indicator portions of different depths, showing the first embodiment, cut along a cylindrical plane. FIG. 3 is an example of a partial cross-sectional view of a column portion having indicator portions of holes of different depths, showing the first embodiment, cut along a cylindrical plane. FIG. 4 is an example of a partial cross-sectional view of a ring portion having indicator portions of different depths on the outer peripheral surface of the cage, cut along a plane perpendicular to the rotation axis. FIG. 5 is an example of a partial cross-sectional view of a ring portion having indicator portions of different depths on the inner peripheral surface of the cage, cut along a plane perpendicular to the rotation axis. FIG. 6 is an example of a partial cross-sectional view of a ring portion having indicator portions of holes of different depths on the outer peripheral surface of the cage, cut along a plane perpendicular to the rotation axis. FIG. 7 is an example of a partial cross-sectional view of a ring portion having indicator portions of holes of different depths on the inner peripheral surface of the cage, cut along a plane perpendicular to the rotation axis. Fig. 1 is an example of a configuration diagram of a rolling bearing abnormality diagnosis device showing Embodiment 3. Fig. 2 is another example of a configuration diagram of a rolling bearing abnormality diagnosis device showing Embodiment 3. Fig. 3 is an example of a configuration diagram of hardware of a rolling bearing abnormality diagnosis device showing Embodiment 3.

[0010] Embodiment 1. A rolling bearing according to this embodiment comprises an outer ring, an inner ring provided inside the outer ring, a plurality of rolling elements that roll between the outer ring and the inner ring, and a cage that holds the rolling elements and maintains the spacing between adjacent rolling elements.

[0011] Here, a rolling bearing has the function of holding an outer ring and an object connected to the outer ring, and an inner ring and an object connected to the inner ring, so that they can rotate relative to each other around a rotation axis. In this disclosure, the axis of rotation about which the outer ring and inner ring rotate relative to each other is referred to as the rotation axis, the direction of the rotation axis is referred to as the axial direction, and the direction perpendicular to the axis is referred to as the radial direction. Furthermore, in this disclosure, the outer side (there are two sides) as viewed from the axial center of the rolling bearing is referred to as the axial outer side, the outer side as viewed from the radial rotation axis of the rolling bearing is referred to as the radial outer side, and the opposite side is referred to as the radial inner side. Furthermore, the direction in which a point at a certain radial distance from the rotation axis rotates around the rotation axis is referred to as the circumferential direction. When viewed locally, the circumferential direction is perpendicular to the radial direction. Furthermore, the radial outer side may also be referred to as the outer circumferential side, and the radial inner side as the inner circumferential side.

[0012] The rolling elements basically roll against the outer periphery of the inner ring and the inner periphery of the outer ring. The cage holds the rolling elements so as to maintain a gap between them, so they basically rotate around the rotation axis as the rolling elements move in the circumferential direction. However, misalignment can occur depending on the clearance between the parts, the load conditions, and the state of wear.

[0013] In the past, there have been cases where a specific coating was formed on the surface of the cage, and the presence or absence of cage wear and the degree of wear were determined by detecting the coating material that turns into wear debris in the lubricating oil that lubricates the inside of the bearing. However, such cases required special detection equipment to detect the wear debris, which is the specific coating material, and it was also necessary to drain the lubricating oil inside the bearing and run it through the detection equipment, operate the equipment, and then maintain the detection equipment. Not only did this require the preparation of a special detector, but the detection process also required a considerable amount of time and effort.

[0014] Furthermore, cage wear is characterized by the order of cage bar, cage outer peripheral surface (or cage inner peripheral surface), and cage inner peripheral surface (or cage outer peripheral surface). It is difficult to quantitatively evaluate the amount of wear at each potential wear location. In other words, simply detecting the overall wear debris content makes it difficult to detect events where a specific area is significantly worn. Diagnosing the condition based solely on the overall wear debris content may result in an incorrect assessment of the cage's remaining lifespan.

[0015] The present disclosure solves the above-mentioned problems and provides a rolling bearing, a rolling bearing abnormality diagnosis device, or a rolling bearing abnormality diagnosis method that can diagnose abnormalities with improved speed, simplicity, and accuracy.

[0016] Fig. 1 is an example of a cross-sectional view taken along a plane perpendicular to the rotation axis of a rolling bearing showing this embodiment. Fig. 2 is an example of a cross-sectional view taken along a plane including the rotation axis of a rolling bearing showing this embodiment. In the figure, the rolling bearing 1 comprises an outer ring 4, an inner ring 7 provided inside the outer ring 4, a plurality of rolling elements 8 that roll between the outer ring 4 and the inner ring 7, and a cage 9 that holds the rolling elements 8 and maintains the spacing between adjacent rolling elements 8. The cage 9 has indicator portions 14 on its surfaces that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8, which are colored in different colors depending on the depth from the surface of the surface toward the interior.

[0017] Here, the outer ring 4 and the inner ring 7 rotate relatively around the same rotation axis. The rolling elements 8 are provided between the outer ring 4 and the inner ring 7 and basically perform a rolling motion relative to the outer ring 4 and the inner ring 7. The rolling elements 8 roll between the outer ring 4 and the inner ring 7, rotating and revolving around the rotation axis. The surfaces of the outer ring 4 and the inner ring 7 on which the rolling elements 8 roll are called raceway surfaces. That is, the raceway surfaces include the outer ring raceway surface 3, which is the raceway surface of the outer ring 4, and the inner ring raceway surface 6, which is the raceway surface of the inner ring 7. The load applied to the bearing is supported by contact between the raceway surfaces (outer ring raceway surface 3, inner ring raceway surface 6) and the rolling elements 8.

[0018] The outer ring 4 has an outer ring inner protruding surface 2 that protrudes radially inward from the axially outer side of the outer ring raceway surface 3 of the outer ring 4 to prevent the rolling elements 8 from deviating from the outer ring raceway surface 3. The inner ring 7 has an inner ring outer peripheral surface 5 that is axially outward of the inner ring raceway surface 6.

[0019] Furthermore, since the outer ring 4 and the inner ring 7 move (rotate) relative to each other, if one is fixed and considered as a fixed ring, the other is a rotating ring. Normally, in a rolling bearing 1, the outer ring 4 is connected to one component, and the inner ring 7 is connected to the other component. With the above structure, the outer ring 4 and the inner ring 7 of the rolling bearing 1 rotate relatively around the rotation axis, and the one component and the other component function as a bearing that can rotate relatively. The rolling elements 8 may be "cylindrical rollers," "tapered rollers," or "balls."

[0020] The cage 9 holds the rolling elements 8 so as to maintain the spacing between them, and therefore basically rotates around the rotation axis in accordance with the circumferential movement of the rolling elements 8. However, strictly speaking, misalignment may occur depending on the clearance between the parts, the load condition, and the wear condition.

[0021] FIG. 3 is an example of a perspective view of a normal cage 9 according to this embodiment. A normal cage 9 refers to a cage 9 before it is damaged or worn. In the figure, the cage 9 fits between the outer ring 4 and the inner ring 7 and has a rough shape of an annular ring with holes equal to the number of rolling elements 8 so as to maintain the spacing between adjacent rolling elements 8. For example, the cage 9 may be configured using a pair of annular portions 10 and column portions 11 connecting the two annular portions 10 in the axial direction. In this case, the two annular portions 10 are annular rings with the same central axis on the same rotation axis and the same outermost diameter and innermost diameter. The cage 9 has annular portions 10 on both axial sides of the rotation axis. The column portions 11 include the same number of column portions 11 as the number of rolling elements 8 (16 in the example of FIG. 3 ), and each column portion 11 connects two annular portions 10.

[0022] With the above configuration, the cage 9 has a hole formed by a pair of annular portions 10 and two adjacent column portions 11. The hole formed by a pair of annular portions 10 and two adjacent column portions 11 is called a pocket portion 12. The cage 9 has pocket portions 12 equal to the number of rolling elements 8, and holds the rolling elements 8 in the pocket portions 12. Note that Fig. 3 shows an example in which the cage 9 has 16 pocket portions 12 and holds the same number of cylindrical rollers.

[0023] In Figure 3, the hole (space) formed by a pair of annular portions 10 and two adjacent columnar portions 11 is a pocket portion 12. The rolling elements 8 are housed in the pocket portion 12, which is a hole (space). The movement of the rolling elements 8 is restricted by the configuration in which the cage 9 and the rolling elements 8 housed in the pocket portion 12 are provided between the outer ring 4 and the inner ring 7. Specifically, the radial movement of the rolling elements 8 is restricted by the outer ring raceway surface 3 and the inner ring raceway surface 6, and the rolling elements 8 rotate while revolving circumferentially around the bearing center. The cage 9 maintains a distance between each rolling element 8 adjacent to it in the circumferential direction, thereby preventing contact between the rolling elements 8.

[0024] The cage 9 rotates in the same direction as the circumferential rotation of the rolling elements 8. At this time, the cage 9 is not always in contact with the outer ring raceway surface 3 and the inner ring raceway surface 6 in the radial direction, and the cage 9 is sometimes in contact with the rolling elements 8 in the circumferential direction, but is sometimes spaced apart. The cage 9 wears at the above-mentioned contact points as the rolling bearing 1 rotates repeatedly.

[0025] Here, the portions of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8 will be defined in detail. In Fig. 2 , the portion of the cage 9 that may come into contact with the outer ring 4 is the outer ring inner protruding surface 2 (shaded portion in Fig. 2 ) that protrudes radially inward from the axial outside of the outer ring raceway surface 3 of the outer ring 4. In this case, the portion of the cage 9 that may come into contact with the outer ring inner protruding surface 2 is the cage outer peripheral surface 9a of the annular portion 10 of the cage 9 (shaded portion in Fig. 2 ). The cage outer peripheral surface 9a can also be said to be the surface that faces the outer ring 4 on the radially outer side of the rotation axis of the annular portion 10. In addition, the portion of the cage 9 that may come into contact with the inner ring 7 is the inner ring outer peripheral surface 5 (shaded portion in Fig. 2 ), which is located axially outside the inner ring raceway surface 6. In this case, the portion of the cage 9 that may come into contact with the inner ring outer peripheral surface 5 is the cage inner peripheral surface 9b (shaded portion in Fig. 2 ) of the annular portion 10 of the cage 9. The cage inner peripheral surface 9b can be said to be a surface that faces the inner ring 7 on the radially inner side of the rotation axis of the annular portion 10.

[0026] Furthermore, the portion of the cage 9 where the cage 9 and the rolling elements 8 can come into contact is the pocket side surface 12a of the column portion 11 in FIG.

[0027] Next, we will explain wear on the cage 9 due to use of the rolling bearing 1. The rolling elements 8 mainly receive loads from the inner ring 7 or the outer ring 4. Of the multiple rolling elements 8, the rolling elements 8 that mainly receive the load are those that, when viewed from the central axis of rotation, lie within a certain angular range in the circumferential direction from the direction of the load. Here, when viewed from the central axis of rotation, the range within a certain angular range from the direction of the load refers to the load bearing zone where the load is applied.

[0028] As the inner ring 7 and the outer ring 4 rotate relative to each other, the rolling elements 8 move by revolving around the rotation axis while rotating on their own axes. Focusing on one rolling element 8, the rolling element 8 moves from outside the load zone to enter the load zone, passes through the load zone, and then leaves the load zone.

[0029] When the rolling elements 8 pass through the loaded zone and escape, they are locally accelerated due to the fact that slippage has been suppressed by the load that had been applied up until then, and due to the force in the release direction (revolution direction) that is generated by the change from compression to unloading. As the rolling elements 8 accelerate, they come into contact with the cage 9 at the position where the rolling elements 8 escape from the loaded zone. Then, at the position where the rolling elements 8 escape from the loaded zone, the cage 9 is subjected to a force in the tangential direction of the circumference passing through the center of the radial width of the cage 9. While rotating together with the rolling elements 8, the cage 9 is intermittently subjected to the force in the tangential direction of the circumference at the position where the rolling elements 8 escape from the loaded zone.

[0030] Contact between the cage 9 and the rolling elements 8 causes wear at the pocket side surfaces 12a of the column portions 11 of the cage 9, which are surfaces that come into contact with the rolling elements 8 in the pocket portions 12. When the pocket side surfaces 12a of the column portions 11 wear, the column portions 11 become thinner, and the circumferential width of the pocket portions 12, which are holes (spaces), increases. The cage 9, whose circumferential width of the pocket portions 12 has increased due to wear, moves more when it receives a force tangential to the circumference at a position away from the above-mentioned rolling elements 8 that has escaped the load zone, and therefore the amount of eccentricity of the eccentric revolution (whirl) increases.

[0031] As the wear on the pocket side surface 12 a of the column portion 11 increases, the eccentric revolution (whirl) phenomenon described above also increases, resulting in contact between the inner protruding surface 2 of the outer ring 4 and the outer peripheral surface 9 a of the cage 9, or between the inner peripheral surface 5 of the inner ring 7 and the inner peripheral surface 9 b of the cage 9.

[0032] Here, whether the cage outer peripheral surface 9a of the cage 9 comes into contact first with the outer ring inner protruding surface 2 of the outer ring 4, or the cage inner peripheral surface 9b of the cage 9 comes into contact first with the inner ring outer peripheral surface 5 of the inner ring 7, differs depending on the type of bearing. Contact between the cage 9 and the rolling elements 8 causes wear of the pocket side surface 12a of the cage 9. When the cage outer peripheral surface 9a of the cage 9 comes into contact with the outer ring inner protruding surface 2 of the outer ring 4, the cage outer peripheral surface 9a of the cage 9 is worn. Furthermore, when the cage inner peripheral surface 9b of the cage 9 comes into contact with the inner ring outer peripheral surface 5 of the inner ring 7, the cage inner peripheral surface 9b of the cage 9 is worn.

[0033] FIG. 4 shows an example of a worn cage 9 when these types of wear occur. The state of wear can be seen by comparing it with FIG. 3. In the figure, the pocket portion side surface 12a of the cage 9 is worn away, causing the column portions 11 of the cage 9 to narrow in the circumferential direction, with holes opening in the central portion of the radial width. Furthermore, the outer peripheral surface 9a and the inner peripheral surface 9b of the cage 9 are worn away, causing the radial width of the annular portion 10 of the cage 9 to narrow. As a result, the radial portions of the column portions 11 of the cage 9 remain, and FIG. 4 shows an example in which they protrude radially outward from the annular portion 10.

[0034] Wear of the cage 9 caused by use of the rolling bearing 1 varies greatly depending on the conditions of use, etc., and it is difficult to predict the extent to which wear will progress in any given location. In some cases, wear may progress significantly in some areas. This makes it difficult to quantitatively evaluate the amount of wear in each area that may be subject to wear. For example, it is difficult to evaluate such a situation using the content of coating material in the lubricating oil of the prior art.

[0035] Next, the configuration, manufacturing method, and effects of the present invention will be described. FIG. 5 is an example of a partial cross-sectional view of an indicator portion 14 of a cage 9 according to this embodiment, taken along a plane perpendicular to the rotation axis. In the figure, the cage 9 has an indicator portion 14 on the pocket side surface 12a of the cage 9, which is a surface that may come into contact with the rolling elements 8 during operation. The indicator portion 14 is colored differently depending on the depth from the surface of the surface that may come into contact with the rolling elements 8 toward the interior. Such indicator portion 14 makes it possible to quantitatively determine the wear of the pocket side surface 12a of the cage 9, which is a surface that may come into contact with the rolling elements 8. Here, the shaded area around the indicator portion 14 conveniently represents the pocket side surface hole 13 into which the indicator portion 14 is inserted.

[0036] Specifically, the retainer 9 may have an indicator portion 14 on a surface perpendicular to the circumferential direction of the column portion 11, which is the surface facing the rolling element 8 of the retainer 9, and whose color changes gradually from the surface toward the inside in a direction perpendicular to the surface.

[0037] Furthermore, the indicator portions 14 provided on the surfaces of the cage 9 that may come into contact with the rolling elements 8 may be embedded in pocket side surface holes 13 formed in the surfaces (pocket side surfaces 12 a) on which the indicator portions 14 are provided. Furthermore, the depth of the pocket side surface holes 13 (the depth-wise length of the indicator portions 14) is preferably equal to or less than half the circumferential thickness of the column portions 11. This is because if the pocket side surface holes 13 are too deep, the strength of the cage 9 decreases. Furthermore, the radial width of the pocket side surface holes 13 (the radial width of the indicator portions 14) is preferably equal to or less than half the radial thickness of the column portions 11.

[0038] Furthermore, the shape of the indicator portion 14 that appears on the surface on which the indicator portion 14 is provided (the pocket portion side surface 12a) may be circular as shown in the figure, or may be substantially quadrilateral.

[0039] The indicator portion 14 may be made of a material whose hardness is equal to or less than that of the rolling elements 8, outer ring 4, and inner ring 7. By configuring it in this manner, it is possible to prevent the indicator portion 14 itself from being scratched or eroded (attacked) by friction when it comes into contact with the rolling elements 8 (cylindrical rollers 8), outer ring 4, and inner ring 7. For the above-mentioned purpose, the indicator portion 14 may be made of a thermosetting resin or a thermoplastic resin. Furthermore, it is preferable that the Vickers hardness of the indicator portion 14 is 50 or less.

[0040] The indicator 14 may be made of a material containing a phosphorescent or fluorescent material to improve visibility.

[0041] The indicator portion 14 is colored in different colors depending on the depth from the surface on which it is provided in a direction perpendicular to the surface. For example, the color of the indicator portion 14 may change stepwise depending on the depth. When the cage 9 comes into contact with the rolling elements 8 and the cage 9 wears, the shallower portions of the indicator portion 14 are worn away first. An observer can recognize the wear (abrasion) of that portion of the cage 9 (pocket portion side surface 12 a) from the color of the remaining shallower portions of the indicator portion 14.

[0042] A plurality of indicator portions 14 may be provided on the same surface.

[0043] The indicator portion 14 may be colored in one or more colors. For example, the indicator portion 14 may be colored in a combination of red, green, and blue, which are known as the three primary colors, or a combination of blue, yellow, and red, as seen in traffic lights. The indicator portion 14 may also be colored in one of the seven colors of the rainbow, which are red, orange, yellow, green, blue, indigo, and purple. Furthermore, the color may be a gradation in which the colors change continuously. However, when the indicator portion 14 is colored in multiple colors, the person assessing abnormalities or wear prepares a document indicating the relationship between the depth position of the indicator portion 14 and the color. Furthermore, the relationship between the depth position and color of the indicator portion 14 may be indicated on a surface of the rolling bearing 1 that is not subject to wear.

[0044] The indicator portion 14 may be a colored bottom surface of the pocket side hole 13. The color can be identified by observing the bottom surface of the hole (pocket side hole 13). Even if it is a single color, if the cage 9 wears and the color of the indicator portion 14 appears on the surface, or if the indicator portion 14 is completely worn away, it can be determined that an abnormality has occurred, and thus an abnormality can be detected. In other words, the depth of the indicator portion 14 may be set to a depth that serves as a threshold for determining an abnormality.

[0045] There is also another example in which the indicator 14 is colored on the bottom surface of the pocket side hole 13. For example, a plurality of holes (pocket side hole 13) of different depths may be provided as indicator 14, and the bottom surface of the holes (pocket side hole 13) may be colored a different color depending on their depth. The bottoms of holes (pocket side hole 13) of the same depth are colored the same color. This is because the wear state can be determined by determining which colored holes have worn away and which colored holes remain.

[0046] Furthermore, although the indicator portion 14 is colored in the above description, the rolling bearing 1 may not be colored, and the state of the hole may be used to determine the indicator portion 14. In this case, the color of the indicator portion 14 can be considered to be the color of the component on which the indicator portion 14 is provided. This is because even if the indicator portion 14 is not colored, the hole serving as the indicator portion 14 remains, and an abnormality can be determined based on whether the hole is open or whether the indicator portion 14 has worn away and disappeared. When the indicator portion 14 is not colored, the indicator portion 14 may be set to a single depth, or multiple indicator portions 14 may be provided as holes of different depths. In particular, when multiple holes for the indicator portion 14 of different depths are provided, holes serving as the indicator portion 14 of different depths may be provided on the same surface of the cage 9.

[0047] The coloring of the indicator portion 14 may be such that the wall surface of the pocket side hole 13 is colored in different colors depending on the depth. This is because even if the wall surface of the pocket side hole 13 is colored, it can still be observed from the outside.

[0048] Furthermore, a plurality of indicator portions 14 having different lengths in the depth direction may be provided on the cage 9. In this case, a plurality of indicator portions 14 having different lengths in the depth direction may be provided on a surface of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8.

[0049] Furthermore, the cage 9 may be provided with indicator portions 14 on any one, any two, or all of the surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8. In this case, the indicator portions 14 may be colored the same color on all surfaces as long as the color is the same depth. This configuration makes it easier to grasp the amount of wear. Furthermore, if the abnormality determination based on the amount of wear differs on the surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8, the indicator portions 14 may be colored the same depth or different colors on all surfaces. The indicator portions 14 provided on surfaces where even a small amount of wear should be determined to be abnormal may be colored in a color that indicates an abnormality from a shallower depth. For example, the color of the indicator portion 14 provided on the surface of the retainer 9 that has the thinnest thickness in the direction perpendicular to the surface that may come into contact with the outer ring 4, the inner ring 7, or the rolling element 8 may be a color that indicates an abnormality from a portion that is shallower in the depth direction than the indicator portions 14 on the other surfaces.

[0050] FIG. 6 is an example of a partial cross-sectional view of the cage 9 according to this embodiment, taken along a plane perpendicular to the rotation axis and including an indicator portion 14 provided on the cage outer peripheral surface 9 a of the cage 9. In the figure, the cage 9 has an indicator portion 14 on the cage outer peripheral surface 9 a of the cage 9, which is a surface that may come into contact with the outer ring 4 during operation. In the figure, the position of the indicator portion 14 is indicated by a cage outer peripheral surface hole 15 into which the indicator portion 14 is inserted. The cage outer peripheral surface 9 a on which the indicator portion 14 is provided faces the outer ring inner protruding surface 2 of the outer ring 4 and may come into contact with the outer ring inner protruding surface 2 when the outer ring 4 and the inner ring 7 of the rolling bearing 1 rotate relative to each other. The indicator portion 14 is colored differently depending on the depth from the surface of the surface toward the inside of the surface that may come into contact with the outer ring 4. Such indicator portion 14 makes it possible to quantitatively determine the wear of the cage outer peripheral surface 9 a of the cage 9, which is a surface that may come into contact with the outer ring 4.

[0051] Specifically, the retainer 9 may have an indicator portion 14 on a surface perpendicular to the radial direction of the retainer outer surface 9a, which is the surface facing the outer ring 4 of the retainer 9, and whose color changes gradually from the surface toward the inside in a direction perpendicular to the surface.

[0052] Furthermore, the indicator portions 14 provided on the surface of the cage 9 that may come into contact with the outer ring 4 may be embedded in cage outer peripheral surface holes 15 drilled in the surface (cage outer peripheral surface 9 a) on which the indicator portions 14 are provided. Furthermore, the depth of the cage outer peripheral surface holes 15 (the depth-wise length of the indicator portions 14) is preferably equal to or less than half the radial thickness of the annular portion 10. This is because if the cage outer peripheral surface holes 15 are too deep, the strength of the cage 9 will decrease. Furthermore, the radial width of the cage outer peripheral surface holes 15 (the axial width of the indicator portions 14) is preferably equal to or less than half the axial thickness of the annular portion 10.

[0053] The indicator portion 14 provided on the outer peripheral surface 9a of the retainer 9 may have the same hardness, color, fluorescence / luminescence, and colored location as the indicator portion 14 provided on the pocket side surface 12a, or may have an uncolored pattern.

[0054] FIG. 7 is an example of a partial cross-sectional view taken along a plane perpendicular to the rotation axis of a cage including an indicator portion 14 provided on the cage inner peripheral surface 9b of the cage according to this embodiment. In the figure, the cage 9 has an indicator portion 14 on the cage inner peripheral surface 9b of the cage 9, which is a surface that may come into contact with the inner ring 7 during operation. In the figure, the position of the indicator portion 14 is indicated by a cage inner peripheral hole 16 into which the indicator portion 14 is inserted. The cage inner peripheral surface 9b on which the indicator portion 14 is provided faces the inner ring outer peripheral surface 5 of the outer ring 4 and may come into contact with the inner ring outer peripheral surface 5 when the outer ring 4 and inner ring 7 of the rolling bearing 1 rotate relative to each other. The indicator portion 14 is colored differently depending on the depth from the surface of the surface that may come into contact with the inner ring 7 in the direction inward. Such indicator portion 14 makes it possible to quantitatively determine the wear of the cage inner peripheral surface 9b of the cage 9, which is a surface that may come into contact with the inner ring 7. FIG. 7 shows the indicators 14 provided on the pocket side surface 12a and the outer peripheral surface 9a of the cage.

[0055] Specifically, the retainer 9 may have an indicator portion 14 on a surface perpendicular to the radial direction of the retainer inner surface 9b, which is the surface facing the inner ring 7 of the retainer 9, and whose color changes gradually from the surface toward the inside in a direction perpendicular to the surface.

[0056] Furthermore, the indicator portions 14 provided on the surface of the cage 9 that may come into contact with the inner ring 7 may be embedded in cage inner peripheral surface holes 16 drilled in the surface (cage inner peripheral surface 9b) on which the indicator portions 14 are provided. Furthermore, the depth of the cage inner peripheral surface holes 16 (the depth-wise length of the indicator portions 14) is preferably equal to or less than half the radial thickness of the annular portion 10. This is because if the cage inner peripheral surface holes 16 are too deep, the strength of the cage 9 will decrease. Furthermore, the radial width of the cage inner peripheral surface holes 16 (the axial width of the indicator portions 14) is preferably equal to or less than half the axial thickness of the annular portion 10.

[0057] The indicator portion 14 provided on the retainer inner surface 9b of the retainer 9 may have the same hardness, color, fluorescence / luminescence, and colored location as the indicator portion 14 provided on the pocket portion side surface 12a, or may have an uncolored pattern.

[0058] FIG. 8 is an example of a cross-sectional view of the bar portion 11 of the cage 9 of this embodiment, cut along a plane perpendicular to the rotation axis. FIG. 9 is an example of a cross-sectional view of the bar portion 11, on which the indicator portion 14 of the cage 9 of this embodiment is located, cut along a plane perpendicular to the rotation axis. In FIG. 8 , pocket side surfaces 12 a, which are surfaces of the cage 9 that can come into contact with the rolling elements 8, are present on both circumferential sides. In this example, the pocket side surfaces 12 a are configured as concave grooves to come into contact with the rolling elements 8. In FIG. 9 , indicator portions 14 are disposed on the pocket side surfaces 12 a, which are surfaces that can come into contact with the rolling elements 8, of the bar portion 11 of the cage 9. Here, the indicator portions 14 are colored in different colors depending on the depth from the surface of the surface that can come into contact with the rolling elements 8 toward the inside. In the figure, the different colors of the indicator portions 14 are represented by different diagonal lines. In this case, the depth direction is approximately the circumferential direction.

[0059] Figure 9 shows an index portion 14 as an example of a pocket side surface 12a, which is a surface that can come into contact with the rolling elements 8 of the cage 9. As in Figure 9, the same form applies when the index portion 14 is provided on the cage outer peripheral surface 9a, which is a surface that can come into contact with the outer ring 4 of the cage 9, or on the cage inner peripheral surface 9b, which is a surface that can come into contact with the inner ring 7 of the cage 9. In either case, the depth direction (orientation) of the index portion 14 is perpendicular to the surface on which it is provided, and is a direction (orientation) from the surface toward the inside. However, when viewed as a rolling bearing 1, the depth direction of the index portion 14 provided on the pocket side surface 12a is the circumferential direction, and the depth direction of the index portion 14 provided on the cage outer peripheral surface 9a or the cage inner peripheral surface 9b is the radial direction.

[0060] Next, a manufacturing method for the rolling bearing 1 of this embodiment will be described. Basically, the components other than the indicator portion 14 are the same as in conventional bearings. One example of manufacturing the indicator portion 14 involves drilling a hole in the surface where the rolling element 8, outer ring 4, or inner ring 7 may come into contact with the cage 9, and inserting the indicator portion 14 into the hole. The hole is the pocket portion side hole 13, the cage outer peripheral surface hole 15, or the cage inner peripheral surface hole 16. In this case, the component to be inserted as the indicator portion 14 is prepared as a component with the same diameter or interference fit tolerance as the hole drilled in the surface, and is inserted (or press-fitted) into the hole drilled in the surface. Alternatively, the manufacturing process may involve applying an adhesive to the component to be the indicator portion 14, or to one or both of the pocket portion side hole 13, the cage outer peripheral surface hole 15, and the cage inner peripheral surface hole 16, before insertion. This is expected to prevent the indicator portion 14 from falling off.

[0061] Furthermore, the parts to be inserted as the indicator portion 14 may be prepared as separate members for each different color, and each member of a different color may be inserted separately.

[0062] Furthermore, in the manufacturing process, holes may be formed in the surfaces where the rolling elements 8, the outer ring 4, or the inner ring 7 may come into contact with the cage 9, and colored paint may be applied to the holes. In this case, the paint may be applied to the bottom surface of the hole or to the wall surface of the hole. If the wall surface of the hole is colored differently depending on the depth, the cross-section will be similar to that shown in FIG. 9 (the same applies to the cage outer peripheral surface hole 15 and the cage inner peripheral surface hole 16). In this case, however, the indicator portion 14 will be visible not as a cross-section but as a wall surface. If the hole is drilled with a sharp tool such as a drill, the bottom surface of the hole will be conical. In this case, the bottom surface of the hole may be configured as the bottom of the hole (a concave conical surface) and colored (FIGS. 6 and 7).

[0063] Furthermore, when the indicator 14 is provided without being colored, a hole of a predetermined depth is drilled to form the indicator 14. Holes of different depths may be drilled perpendicular to the surface on the surface where the rolling elements 8, outer ring 4 or inner ring 7 and the cage 9 may come into contact. When holes of different depths are provided in the pocket side holes 13, the holes may be provided in a straight line in the axial direction. Furthermore, when holes of different depths are provided in the cage outer peripheral surface holes 15 or the cage inner peripheral surface holes 16, the holes may be provided in a line in the circumferential direction. This is because it is believed that the wear condition will be uniform in these directions.

[0064] Furthermore, the area of ​​the plane parallel to the surface on which indicator portion 14 is provided (the cross-sectional area of ​​the cross section perpendicular to the direction from the surface toward the inside) may increase or decrease as the depth of indicator portion 14 increases. If the area of ​​the plane parallel to the surface on which indicator portion 14 is provided increases as the depth of indicator portion 14 increases, the indicator visible from the surface becomes larger as wear progresses, making it easier to notice.

[0065] Furthermore, the area or dimensions (length and width) of the indicator portion 14 that appears on the surface correlates with the degree of wear of the cage 9. In other words, if an operator or a device measures the area or dimensions (length and width) that appear on the surface of the indicator portion 14, the degree of wear of the cage 9 can be quantitatively determined.

[0066] In addition, in the above description, a configuration has been shown in which the area of ​​the surface parallel to the surface on which the indicator portion 14 is provided increases as the depth of the indicator portion 14 increases. With such a configuration, the degree of wear of the cage 9 can be quantitatively determined by measuring the area or dimensions (length and width) that appear on the surface of the indicator portion 14, without having to color the indicator portion 14. In this case, the holes, specifically the pocket portion side surface holes 13, the cage outer peripheral surface holes 15, or the cage inner peripheral surface holes 16, serve as the indicator portion 14.

[0067] The structure of the cage 9 can be utilized to configure the area of ​​the plane parallel to the plane on which the indicator portion 14 is provided to increase in the depth direction of the indicator portion 14. Specifically, the cage 9 utilizes the fact that it is configured by connecting the annular portion 10 and the column portion 11. The cage outer peripheral surface hole 15 or the cage inner peripheral surface hole 16 can be machined in the axial direction from the axial end face of the annular portion 10 to form a hole that has a trapezoidal (or triangular) shape that continues axially when viewed from the axial direction.

[0068] The pocket portion side surface holes 13 can be formed by machining a similar hole in the axial direction from the surface of the column portion 11 that connects to the annular portion 10. If the indicator portion 14 is not to be colored, the machined hole serves as the indicator portion 14. If a colored indicator portion 14 is to be used, a colored indicator portion 14 shaped to fit into the hole can be inserted axially into the hole (pocket portion side surface holes 13, cage outer peripheral surface holes 15, or cage inner peripheral surface holes 16).

[0069] Furthermore, the area of ​​the surface parallel to the surface on which the indicator portion 14 is provided may be configured to decrease as the indicator portion 14 increases in the depth direction. Such a configuration is effective when the indicator portion 14 is provided on the wall or bottom surface of a hole drilled in the surface of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8. This makes it easier for an operator or device to observe the bottom or wall surface of the hole (pocket portion side surface hole 13, cage outer peripheral surface hole 15, or cage inner peripheral surface hole 16) from the surface. Specific examples are shown below.

[0070] The pocket side hole 13, the cage outer peripheral surface hole 15, or the cage inner peripheral surface hole 16, which are holes in which the indicator portion 14 is provided, may have a conical shape that tapers in the depth direction. Fig. 10 shows an example in which the indicator portion 14 is provided in the pocket side hole 13, but the other indicator portions 14 may be similar.

[0071] 10 is an example of a partial cross-sectional view of a column 11 having a conical indicator 14, cut along a plane perpendicular to the rotation axis. In the figure, the pocket side surface 12a of the column 11 has a conical hole, which becomes the pocket side surface hole 13. The pocket side surface hole 13 is provided with a conical indicator 14. In the example shown, the color of the conical indicator 14 changes stepwise in the depth direction.

[0072] Next, the manufacturing method will be described. For example, in the manufacturing process, conical holes for the pocket side surface hole 13, the cage outer peripheral surface hole 15, and the cage inner peripheral surface hole 16, a conical index portion 14 to be inserted into the deepest portion of the hole, and a truncated conical index portion 14 to be inserted next are prepared in advance. The deepest portion of the hole uses a conical index portion 14 with a larger apex angle than the conical holes for the pocket side surface hole 13, the cage outer peripheral surface hole 15, and the cage inner peripheral surface hole 16, thereby achieving an interference fit. Next, in the manufacturing process, the truncated cones are inserted in order. The index portion 14 of the truncated cone is made to have the same apex angle as the index portion 14 of the previously inserted cone, thereby achieving an interference fit.

[0073] The conical index portions 14 and truncated conical index portions 14 are separated by different colors and inserted into the holes sequentially. In the manufacturing process, an adhesive may be applied to the index portions 14, or the holes in the pocket side surface holes 13, the cage outer peripheral surface holes 15, or the cage inner peripheral surface holes 16, or both, before insertion. This more firmly fixes the index portions 14 to the holes in the pocket side surface holes 13, the cage outer peripheral surface holes 15, and the cage inner peripheral surface holes 16, preventing them from falling off. Note that the conical shapes of the cage outer peripheral surface holes 15 and the cage inner peripheral surface holes 16 are omitted from the drawings.

[0074] By forming the pocket side surface holes 13, the cage outer peripheral surface holes 15, and the cage inner peripheral surface holes 16 into conical holes, the bottom diameter of the cone and truncated cone indicator portion 14 (on the surface, the diameter at the surface of the indicator portion 14) also changes as wear progresses. Therefore, with the above configuration, by observing the bottom diameter at the same time as the color change, it is possible to evaluate the progress of wear in more detail.

[0075] Another example will be shown in which the area of ​​the surface parallel to the surface on which the indicator portion 14 is provided becomes smaller as the indicator portion 14 becomes deeper in the depth direction.

[0076] 11 is an example of a partial cross-sectional view of a post 11 having an index portion 14 whose diameter changes stepwise, cut along a plane perpendicular to the rotation axis. This figure shows an example of a pocket side hole 13. As shown in the figure, the pocket side hole 13, the cage outer peripheral surface hole 15, and the cage inner peripheral surface hole 16 may be cylindrical in shape with a diameter that changes stepwise.

[0077] Next, a method for forming a cylindrical hole having a stepped diameter for the index portion 14 will be described. In the manufacturing process, the pocket side surface hole 13, the cage outer peripheral surface hole 15, or the cage inner peripheral surface hole 16 is first formed. In this process, a stepped cylindrical hole is formed in the pocket side surface 12a, the cage outer peripheral surface 9a, or the cage inner peripheral surface 9b so that the hole diameter is small at its deepest point and increases toward the surface. Separately, cylindrical index portion 14 portions with interference fit tolerances corresponding to the hole diameter are prepared. The cylindrical index portion 14 portions are prepared in different colors. In the next manufacturing process, the cylindrical index portion 14 portions are inserted into the stepped cylindrical hole in order of decreasing diameter. Here, the insertion process may involve applying an adhesive to the index portion 14, the pocket side surface hole 13, the cage outer peripheral surface hole 15, or the cage inner peripheral surface hole 16, or both. This makes it possible to more firmly fix the indicator portion 14 to the pocket side surface hole 13, the cage outer peripheral surface hole 15, or the cage inner peripheral surface hole 16, preventing it from falling off. Note that the conical shapes of the cage outer peripheral surface hole 15 and the cage inner peripheral surface hole 16 are not shown in the drawings.

[0078] As a result of the above, the pocket portion side surface holes 13, the cage outer peripheral surface holes 15, and the cage inner peripheral surface holes 16 can be formed into cylindrical holes whose diameter changes stepwise, such that the diameter is small at the deepest point and increases toward the surface. By configuring the holes in this way, if the hole diameter is small at its deepest point, the risk of breakage due to the effect of reduced strength caused by wear can be reduced when wear progresses.

[0079] Next, a specific example will be described in which multiple indicator portions 14 with different depth lengths are provided on the surface of the retainer 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling element 8.

[0080] FIG. 12 is an example of a partial cross-sectional view of a column portion 11 having indicator portions 14 of different depths, cut by a cylindrical surface. Here, the cylindrical surface used for cutting is a cylindrical surface centered on the rotation axis, and is the cylindrical surface that cuts the indicator portions 14. As shown in the figure, the pocket portion side surface holes 13 may be multiple holes of different depths. The multiple holes of different depths are positioned in a row in the axial direction on the pocket portion side surface 12a, at equal intervals, in order of hole depth. In FIG. 12, six indicator portions 14 are lined up in a row.

[0081] Next, a method for forming holes in the pocket side surface 12a with varying depths aligned in a row at equal intervals in the axial direction will be described. In the manufacturing process, cylindrical holes are first formed in the pocket side surface holes 13 of the column portions 11 of the cage 9, aligned in a row at equal intervals in the axial direction in the order of depth. In addition, in the preparation process, cylindrical indicator portions 14 are prepared corresponding to the holes, with the hole diameter set to the cylindrical diameter and the hole depth set to the length, and with an interference fit tolerance. In the manufacturing process, the prepared cylindrical indicator portions 14 are inserted into the corresponding holes, one for each color. This insertion process may involve applying adhesive to either the indicator portions 14 or the pocket side surface holes 13, or both. This securely fixes the pocket side surface holes 13 and the indicator portions 14 together, preventing them from falling off.

[0082] If indicators 14 are provided in holes of different depths that are aligned in a row in the axial direction at equal intervals in order of depth on the pocket side surface 12a, the holes will wear away and disappear in order from shallowest to shallowest due to wear, which is expected to improve the visibility of the wear progression state.

[0083] Even when there are multiple pocket side holes 13, the diameter of the holes can be any diameter, and they may be conical or cylindrical in shape with a diameter that changes stepwise in the depth direction. The effects of using a conical shape or a cylindrical shape with a diameter that changes stepwise in the depth direction are the same as those described above, so a description thereof will be omitted.

[0084] Furthermore, a plurality of holes (pocket side surface holes 13) of different depths aligned in a row in the axial direction at equal intervals in order of depth can be provided on the pocket side surface 12a, and these holes can be used as indicator portions 14 without being colored (FIG. 13). In this case, the degree of wear of the cage can be determined by determining the depth of the holes at which indicator portions 14 remain, even without coloring the indicator portions 14.

[0085] Furthermore, the cage 9 may be provided with marks indicating the presence of the indicator portions 14 on surfaces of the cage 9 other than the surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, and the rolling elements 8. Specifically, the marks indicating the presence of the indicator portions 14 may be on the outer or inner peripheral surfaces of the column portions 11, or on a surface perpendicular to the axial direction of the annular portion 10 (either one or both of the end faces). The marks may be stamped with a punch or the like. When all of the indicator portions 14 are worn away, it can be determined that all have been worn away.

[0086] FIG. 14 is an example of a partial cross-sectional view of the annular portion 10 cut along a plane perpendicular to the rotation axis, in which indicator portions 14 of different depths are located on the cage outer peripheral surface 9a. FIG. 15 is an example of a partial cross-sectional view of the annular portion 10 cut along a plane perpendicular to the rotation axis, in which indicator portions 14 of different depths are located on the cage inner peripheral surface 9b. As shown in the figure, the cage outer peripheral surface holes 15 and the cage inner peripheral surface holes 16 may be multiple holes of different depths. The multiple holes of different depths are aligned in a circumferential row on the cage outer peripheral surface 9a and the cage inner peripheral surface 9b at equal intervals in order of hole depth. Different colored indicator portions 14 may be embedded in the holes of different depths. In the figure, six indicator portions 14 are lined up.

[0087] Next, a method for creating holes with different depths aligned in a circumferential row at equal intervals in order of depth on the cage outer peripheral surface 9 a and the cage inner peripheral surface 9 b will be described. In the manufacturing process, cage outer peripheral surface holes 15 are drilled in advance on the cage outer peripheral surface 9 a, and cage inner peripheral surface holes 16 are drilled in advance on the cage inner peripheral surface 9 b. The cage outer peripheral surface holes 15 are cylindrical holes drilled in order of depth so as to be aligned in a circumferential row on the cage outer peripheral surface 9 a. Similarly, the cage inner peripheral surface holes 16 are cylindrical holes drilled in order of depth so as to be aligned in a circumferential row on the cage inner peripheral surface 9 b. Separately, cylindrical indicator portions 14 are prepared for the cage outer peripheral surface holes 15 and the cage inner peripheral surface holes 16. These indicator portions have the same nominal diameter as the hole diameter, the same length as the hole depth, and an interference fit tolerance. In the manufacturing process, indicator portions 14 of different colors and corresponding depths are inserted into the cage outer peripheral surface holes 15 or the cage inner peripheral surface holes 16. Here, in the insertion step, adhesive may be applied to the indicator portion 14, or one or both of the retainer outer peripheral surface hole 15 and the retainer inner peripheral surface hole 16. By doing so, the indicator portion 14 can be more firmly fixed to the retainer outer peripheral surface hole 15 and the retainer inner peripheral surface hole 16, preventing them from falling off.

[0088] Even when the cage outer peripheral surface hole 15 and the cage inner peripheral surface hole 16 are multiple holes, the diameter of the holes may be any diameter, and they may be conical or cylindrical in shape with a diameter that changes stepwise in the depth direction. The effects of using a conical shape or a cylindrical shape with a diameter that changes stepwise in the depth direction are the same as those described above, so a description thereof will be omitted.

[0089] Furthermore, holes (retainer outer peripheral surface holes 15 and / or retainer inner peripheral surface holes 16) of varying depths that are aligned in a circumferential row at equal intervals in descending order of depth on the retainer outer peripheral surface 9a and / or retainer inner peripheral surface 9b can be formed, and these holes can be used as indicators 14 without being colored (FIGS. 16 and 17). In this case, the degree of wear of the retainer can be determined by determining the depth of the holes at which indicators 14 remain, even without coloring the indicators 14.

[0090] The above example shows the provision of a mark at the location of the indicator portion 14 provided on the pocket side surface 12 a. Similarly to this example, for the indicator portion 14 provided on the cage outer peripheral surface 9 a and / or the cage inner peripheral surface 9 b, a mark indicating the presence of the indicator portion 14 may be provided on a surface of the cage 9 other than the surface of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, and the rolling elements 8.

[0091] Next, a description will be given of a method for using the rolling bearing 1 of this embodiment. The wear state of the cage 9 of a rolling bearing 1 that has been used can be checked, for example, by the following procedure.

[0092] (1) Make the cage 9 of the rolling bearing 1 in a state where it can be observed from the outside. If the cage 9 can be observed as is, continue as is. If the cage 9 can be observed by removing a cover or the like from the rolling bearing 1, remove the cover. If necessary, disassemble the rolling bearing 1 so that the cage 9 can be observed.

[0093] (2) The worker observes the portion of the cage 9 where the indicator portion 14 is provided. If visual observation is possible, the worker performs visual observation. A microscope is inserted between the outer ring 4 and the cage 9 or between the inner ring 7 and the cage 9, and the pocket side surface 12a, the cage outer peripheral surface 9a, and the cage inner peripheral surface 9b, where the indicator portion 14 is provided, are observed using the microscope. Here, the observation may be performed by photographing the pocket side surface 12a, the cage outer peripheral surface 9a, and the cage inner peripheral surface 9b with a photographing device. The images photographed by the photographing device are stored in a storage device. Note that the objects to be observed may be one, two, or all of the pocket side surface 12a, the cage outer peripheral surface 9a, and the cage inner peripheral surface 9b.

[0094] (3) The worker determines the color of the indicator portion 14. If there are multiple indicator portions 14 with different depths, the worker counts the number of indicator portions 14. Alternatively, if the dimensions of the indicator portions 14 vary depending on their depth, the worker measures the dimensions that appear on the surface. Here, if the image is captured by the imaging device as described above and stored in a storage device, the image information stored in the storage device may be read out and displayed to determine the color of the indicator portions 14, count the number of indicator portions 14, or measure the dimensions of the indicator portions 14.

[0095] (4) In the next step, the degree of wear of the target portion of the observed indicator portion 14 is determined from the information obtained in (3) and pre-prepared information describing the relationship between the depth and color of the indicator portion 14. If there are multiple indicator portions 14 with different depths, the degree of wear of the target portion of the observed indicator portion 14 is determined from the information on the number obtained in (3) and pre-prepared information relating the number of remaining indicator portions 14 and the amount of wear. If the dimensions change depending on the depth of the indicator portion 14, the degree of wear of the target portion of the observed indicator portion 14 is determined from the dimensions obtained in (3) and pre-prepared information relating the depth and dimensions of the indicator portion 14.

[0096] The method for diagnosing an abnormality in a rolling bearing according to this embodiment can also be understood as follows: This method for diagnosing an abnormality in a rolling bearing 1 includes an outer ring 4, an inner ring 7 located inside the outer ring 4, a plurality of rolling elements 8 that roll between the outer ring 4 and the inner ring 7, and a cage 9 that holds the rolling elements 8 and maintains a spacing between adjacent rolling elements 8, and comprises an imaging step of imaging indicator portions 14 that are provided on surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8 and that are colored differently depending on the depth from the surface of the surface toward the interior, an image recording step of recording image information of the indicator portions 14 imaged in the imaging step, and a diagnosis step of diagnosing an abnormality in the rolling bearing 1 based on the color of the indicator portions 14 in the recorded image information.

[0097] Furthermore, the video recording step may be performed by a photographing device such as a digital camera, and the diagnosis step may be performed on a computer.

[0098] According to this embodiment, the cage 9 has indicator portions 14 that are colored in different colors depending on the depth from the surface toward the inside of the cage on the surfaces that may come into contact with the outer ring 4, inner ring 7, or rolling elements 8, so that the wear state of each portion of the cage can be directly observed by color. As a result, this embodiment makes it possible to easily inspect the cage of the rolling bearing 1 for damage and wear without using any special equipment.

[0099] Furthermore, there is no need to install detection equipment for detecting wear debris or to add a detection process, as was done in the past. Conventionally, a considerable amount of time and effort was spent to determine whether or not the cage was worn and how far the wear had progressed by detecting wear debris from the coating material that coated the cage. According to this embodiment, the indicator portion 14 appears in a different color as it wears, and the progress of wear can be easily evaluated by directly observing the indicator portion 14.

[0100] According to this embodiment, there is no need to quantitatively determine cage wear through analysis or analytical work, thereby saving time. Also, according to this embodiment, there is no influence from grease or oil, which has the effect of improving the accuracy of abnormality diagnosis. Furthermore, with conventional techniques that sample bearing lubricants such as grease or oil to detect wear particles, differences depending on the location of sampling can be significant and can become a major source of error, but with this embodiment, each part of the cage 9 can be directly observed, so the above-mentioned source of error is eliminated.

[0101] Furthermore, the wear of the cage 9 is characterized by the order of wear: column portions 11 of the cage 9, cage outer peripheral surface 9a (or cage inner peripheral surface 9b), and cage inner peripheral surface 9b (or cage outer peripheral surface 9a). The rolling bearing 1 of this embodiment is capable of quantitatively evaluating the amount of wear at each wear location. Therefore, even if the wear state differs greatly between different parts of the cage 9, the rolling bearing 1 can accurately grasp the wear state. For this reason, this embodiment makes it possible to accurately determine the remaining life of the cage.

[0102] Embodiment 2. In embodiment 1, an example was described in which an indicator portion 14 was provided on the cage 9 of the rolling bearing 1. In this embodiment, an example is described in which an observation hole for observing the indicator portion 14 is provided on the rolling bearing 1 of embodiment 1. By providing the observation hole, the worker can easily observe the indicator portion 14. In this embodiment, the observation hole, which is a difference from embodiment 1, will be mainly described. In addition, in this embodiment, terms and symbols that are the same as those in the previous embodiment refer to the same things as in the previous embodiment, unless otherwise specified.

[0103] The rolling bearing 1 of this embodiment comprises an outer ring 4, an inner ring 7 provided inside the outer ring 4, a plurality of rolling elements 8 that roll between the outer ring 4 and the inner ring 7, and a cage 9 that holds the rolling elements 8 and maintains the spacing between adjacent rolling elements 8. As in the first embodiment above, the cage 9 has indicator portions 14 on surfaces that may come into contact with the outer ring 4, the inner ring 7 or the rolling elements 8 that are colored in different colors depending on the depth from the surface of said surfaces toward the interior.

[0104] The outer ring 4 or inner ring 7 of the rolling bearing 1 is provided with an observation hole 17 for observing an indicator portion 14 provided on the surface of the cage 9 that may come into contact with the outer ring 4, inner ring 7 or rolling element 8.

[0105] 18 is an example of a partial cross-sectional view of a rolling bearing 1 including an observation hole 17 according to the present embodiment. In the figure, the outer ring 4 has an observation hole 17 penetrating radially through its axial center, more specifically, an outer ring-side pocket observation hole 18a. The inner ring 7 also has an observation hole 17 penetrating radially through its axial center, more specifically, an inner ring-side pocket observation hole 18b.

[0106] 19 is an example of a partial cross-sectional view of a rolling bearing 1 according to this embodiment that includes an observation hole 17 different from the above. In the figure, the outer ring 4 has a radially penetrating observation hole 17, more specifically an outer peripheral observation hole 19, at a position that is shifted (offset) in one axial direction from the axial center. Furthermore, the inner ring 7 has a radially penetrating observation hole 17, more specifically an inner peripheral observation hole 20, at a position that is shifted (offset) in one axial direction from the axial center.

[0107] The rolling bearing 1 may be provided with all, one, or more of the outer ring side pocket observation hole 18a, inner ring side pocket observation hole 18b, outer circumference observation hole 19, and inner circumference observation hole 20. The observation holes 17 may be (1) provided in the outer ring 4 with the outer ring side pocket observation hole 18a and outer circumference observation hole 19, (2) provided in the inner ring 7 with the inner ring side pocket observation hole 18b and inner circumference observation hole 20, or (3) provided with all of the outer ring side pocket observation hole 18a, outer circumference observation hole 19, inner ring hole 18 for observing the pocket side surface, and inner circumference observation hole 20. Any of the above may be selected depending on the usage environment of the bearing.

[0108] The outer ring side pocket observation hole 18a or the inner ring side pocket observation hole 18b is provided in the axial center of the inner ring 7, and is therefore suitable for observing the axial center of the column portion 11 of the cage 9. In this case, an operator can look through the outer ring side pocket observation hole 18a or the inner ring side pocket observation hole 18b and directly observe the indicator portions 14 provided on the pocket side surfaces 12a. Depending on the dimensional relationship, an operator can also look through the outer ring side pocket observation hole 18a and directly observe the indicator portions 14 provided on the cage outer peripheral surface 9a. Also, an operator can look through the inner ring side pocket observation hole 18b and directly observe the indicator portions 14 provided on the cage inner peripheral surface 9b.

[0109] Furthermore, the outer peripheral observation hole 19 and the inner peripheral observation hole 20 are provided at positions offset in the axial direction from the axial center of the inner rings 7, 7. Therefore, they are suitable for observing the same side of the cage outer peripheral surface 9 a and cage inner peripheral surface 9 b of the cage 9 as the observation hole 17 is provided on, offset in the axial direction. In this case, an operator can look through the outer peripheral observation hole 19 and directly visually observe the indicator portion 14 provided on one of the cage outer peripheral surfaces 9 a. Similarly, an operator can look through the inner peripheral observation hole 20 and directly visually observe the indicator portion 14 provided on one of the cage inner peripheral surfaces 9 b.

[0110] Depending on the dimensional relationship, an operator may be able to directly visually observe the indicator portions 14 provided on the pocket side surfaces 12a by looking through the outer peripheral observation hole 19. In particular, if the outer peripheral observation hole 19 is provided in an intermediate position between the axial center of the outer ring 4 and the axial position where the indicator portions 14 are provided on the cage outer peripheral surface 9a, it becomes possible to observe the indicator portions 14 provided on both the pocket side surfaces 12a and the cage outer peripheral surface 9a.

[0111] In addition, when an outer peripheral observation hole 19 is provided, it is provided at a position axially shifted (offset) from the axial center, so an indicator portion 14 is provided on the retainer outer peripheral surface 9a on the same side as the axially shifted side on which the outer peripheral observation hole 19 is provided, and it is not necessary to provide an indicator portion 14 on the opposite side.

[0112] Similarly, depending on the dimensional relationship, an operator may be able to directly visually observe the indicator portion 14 provided on the pocket side surface 12a by looking through the inner peripheral observation hole 20. In particular, if the inner peripheral observation hole 20 is provided in the middle between the axial center of the inner ring 7 and the axial position where the indicator portion 14 is provided on the cage inner peripheral surface 9b, it becomes possible to observe the indicator portion 14 provided on both the pocket side surface 12a and the cage inner peripheral surface 9b.

[0113] Furthermore, similar to the outer peripheral observation hole 19, when an inner peripheral observation hole 20 is provided, an indicator portion 14 is provided on the inner peripheral surface 9b of the retainer on the same axially offset side as the inner peripheral observation hole 20, and it is not necessary to provide an indicator portion 14 on the opposite side.

[0114] Furthermore, the rolling bearing 1 may be provided with an observation hole 17, which is a hole for the above-mentioned observation, so that a photographing device such as a microscope can be inserted into the observation hole 17 to observe the indicator portion 14. This has the effect of enabling the degree of wear to be grasped and evaluated more accurately. Note that the size of these holes is arbitrary, but it is preferable that the diameter of the hole be such that a microscope or the like can be inserted.

[0115] Furthermore, when observation hole 17 is not being used for observation, it may be covered with a lid (not shown). For example, a screw may be provided on the inside of observation hole 17, and a screw may be provided on the lid to fasten to this screw, making the lid removable. By covering with the lid when rolling bearing 1 is in operation, lubricating oil etc. inside rolling bearing 1 is prevented from leaking, and when diagnosing an abnormality, the lid of observation hole 17 can be removed to observe the interior.

[0116] The rolling bearing abnormality diagnostic method described in Embodiment 1 can be explained as follows when applied to the rolling bearing 1 of this embodiment. The rolling bearing abnormality diagnostic method of this embodiment is a method for diagnosing abnormalities in a rolling bearing 1 that includes an outer ring 4, an inner ring 7 located inside the outer ring 4, a plurality of rolling elements 8 that roll between the outer ring 4 and the inner ring 7, and a cage 9 that holds the rolling elements 8 and maintains spaces between adjacent rolling elements 8, and comprises an imaging step of imaging, through an observation hole 17 made in the outer ring 4 or the inner ring 7, indicator portions 14 that are provided on surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8 and that are colored differently depending on the depth from the surface of the surface toward the interior,

[0117] According to this embodiment, the outer ring 4 or the inner ring 7 is provided with an observation hole 17 that passes through in the radial direction, allowing an operator to observe the indicator portion 14 visually or with a photographing device such as a microscope. Therefore, the rolling bearing 1 of this embodiment makes it even easier to inspect the cage of the rolling bearing 1 for damage and wear.

[0118] Embodiment 3. In embodiment 2, an example of a rolling bearing 1 was described in which an indicator portion 14 was provided on the cage 9 of the rolling bearing 1, and an observation hole 17 was provided in the outer ring 4 or the inner ring 7. In this embodiment, a rolling bearing abnormality diagnosis device that performs abnormality diagnosis on the rolling bearing 1 of embodiment 1 or embodiment 2 will be described. Note that in this embodiment, terms and symbols that are the same as those in the previous embodiment refer to the same things as in the previous embodiment, unless otherwise specified.

[0119] The rolling bearing 1 of this embodiment comprises an outer ring 4, an inner ring 7 provided inside the outer ring 4, a plurality of rolling elements 8 that roll between the outer ring 4 and the inner ring 7, and a cage 9 that holds the rolling elements 8 and maintains the spacing between adjacent rolling elements 8. As in the first embodiment above, the cage 9 has indicator portions 14 on surfaces that may come into contact with the outer ring 4, the inner ring 7 or the rolling elements 8 that are colored in different colors depending on the depth from the surface of said surfaces toward the interior.

[0120] Furthermore, in addition to the configuration of the above-described first embodiment, the outer ring 4 or inner ring 7 of the rolling bearing 1 of this embodiment may be provided with an observation hole 17 for observing an indicator portion 14 provided on the surface of the cage 9 that may come into contact with the outer ring 4, inner ring 7 or rolling elements 8. This is the same as the rolling bearing 1 of the second embodiment.

[0121] The rolling bearing abnormality diagnosis device 100 of this embodiment comprises an imaging unit 110 that photographs indicator portions 14 that are provided on the surfaces of the cage 9 that may come into contact with the outer ring 4, the inner ring 7 or the rolling elements 8 and that are colored differently depending on the depth from the surface of the surface toward the interior, a recording unit 120 that records the video information of the indicator portions 14 photographed by the imaging unit 110, and a diagnosis unit 130 that diagnoses abnormalities in the rolling bearing 1 based on the color of the indicator portions 14 in the video information recorded in the recording unit 120.

[0122] The photographing unit 110 may take photographs using a microscope 30 passed through an observation hole 17 provided in the outer ring 4 or inner ring 7 to be observed.

[0123] 20 is an example of a configuration diagram of a rolling bearing abnormality diagnosis device 100 of this embodiment. The rolling bearing abnormality diagnosis device 100 is made up of a photographing unit 110 that photographs the indicator portion 14 of the cage 9, a recording unit 120 that records the image photographed by the photographing unit 110 as image information, and a diagnosis unit 130 that determines the wear state of the cage 9 based on the color of the indicator portion 14 in the image information. The output of the diagnosis unit 130 is displayed on a display unit 140.

[0124] The photographing unit 110 photographs the indicator portion 14 of the rolling bearing 1 of embodiment 1 or embodiment 2. In the rolling bearing 1 of embodiment 1, it may be possible to photograph the indicator portion 14, which is colored in different colors depending on the depth from the surface of the outer ring 4 or inner ring 7 of the cage 9, on the surface that may come into contact with the outer ring 4, inner ring 7, or rolling elements 8, without disassembly or the like. In this case, the photographing unit 110 of the rolling bearing abnormality diagnosis device 100 photographs the indicator portion 14 directly. In this case, a microscope may be used to photograph the area between the cage 9 and the outer ring 4, or the cage 9 and the inner ring 7. Also, it may be necessary to partially disassemble the rolling bearing 1 in order to photograph the indicator portion 14. In this case, the rolling bearing 1 is partially disassembled and then photographed. The photographing unit 110 may also be referred to as a photographing device, or a microscope and photographing device. The photographing device is a digital camera, and the photographed image becomes video information and is converted into digital data.

[0125] 21 is an example of a configuration diagram of a rolling bearing abnormality diagnosis device 100 for diagnosing abnormalities in a rolling bearing 1 according to embodiment 2. In the figure, the rolling bearing 1 has observation holes 17 for observing indicator portions 14 provided on the surface of the cage 9 that may come into contact with the outer ring 4, the inner ring 7, or the rolling elements 8. The photographing unit 110 inserts a microscope through the observation holes 17 (outer ring side pocket observation hole 18a, inner ring side pocket observation hole 18b, outer circumference observation hole 19, inner circumference observation hole 20) to photograph the indicator portions 14. In this case, the photographing unit 110 can also be said to be both a microscope and a photographing device.

[0126] The recording unit 120 records the video information captured by the imaging unit 110 in a storage device.

[0127] The diagnosing unit 130 diagnoses an abnormality in the rolling bearing 1 based on the color of the indicator portion 14 in the video information recorded in the recording unit 120. The diagnosing unit 130 stores in advance the types of colors that the indicator portion 14 has, information about each color, and information about the depth to which each color is colored (color information of the indicator portion). The diagnosing unit 130 references the color information of the indicator portion and searches for the indicator portion 14 in the video information using the color as a clue. The diagnosing unit 130 compares the color information of the pixel in the video information of the indicator portion 14 with the color information of the indicator portion, and obtains the depth range of the indicator portion 14 colored with that color from the color information of the indicator portion that matches the color information of the pixel in the video information. The diagnosing unit 130 outputs a representative value of the obtained depth range of the indicator portion 14. This output value represents the amount of wear of the corresponding portion of the cage 9.

[0128] The display unit 140 displays the representative value of the depth range of the indicator portion 14 output by the diagnosing unit 130. The recording unit 120 and the diagnosing unit 130 may be realized by a computer 200.

[0129] 22 is a hardware configuration diagram of a computer 200 that implements the recording unit 120 and diagnosis unit 130 of the rolling bearing abnormality diagnosis device 100. In the figure, the computer 200 has a memory unit 230 that stores digital information, a central processing unit 210 that processes information based on the information stored in the memory unit 230, a bus 220 that connects the central processing unit 210 and the memory unit 230, and an external interface 240 that is connected to the bus 220 and interfaces with an external device. The external interface 240 is connected to an imaging device 250 or a display device 260. The memory unit 230 may be implemented using a semiconductor memory or a magnetic storage medium such as a hard disk.

[0130] The photographing unit 110 is executed by an imaging device 250 such as a digital camera, and the photographed image information is input to the computer 200 via the external interface 240. The recording unit 120 is executed by storing the image information input from the external interface 240 in the memory unit 230. The diagnosis unit 130 performs information processing by the central processing unit 210 to determine the amount of wear of the cage 9 from the image information and color information of the indicator portion stored in the memory unit 230. The output of the diagnosis unit 130 is output to the display device 260 via the external interface 240 and displayed.

[0131] According to this embodiment, the diagnostic unit 130 photographs the indicator portions 14 provided on the surfaces of the retainer 9 that may come into contact with the outer ring 4, inner ring 7, or rolling elements 8 and colored in different colors depending on the depth from the surface of the surface toward the interior, and determines the degree of wear of the retainer 9 from the color of the indicator portions 14 in the photographed image, so that the worker can determine the degree of wear of the retainer 9 even if he or she does not remember the color information of the indicator portions 14.

[0132] Furthermore, even if the indicator portion 14 of the cage 9 is difficult to see, the indicator portion 14 can be easily photographed using a microscope, and the wear of the cage 9 can be checked.

[0133] In particular, in the example where observation holes 17 are provided in the outer ring 4 and the inner ring 7, the wear conditions of the pocket side surface 12a, the cage outer peripheral surface 9a, and the cage inner peripheral surface 9b can be easily checked, so that even if any part is extremely worn, an abnormality in the rolling bearing can be detected at an early stage.

[0134] REFERENCE SIGNS LIST 1 Rolling bearing 2 Outer ring inner protruding surface 3 Outer ring raceway surface 4 Outer ring 5 Inner ring outer peripheral surface 6 Inner ring raceway surface 7 Inner ring 8 Rolling element 9 Cage 9a Cage outer peripheral surface 9b Cage inner peripheral surface 10 Ring portion 11 Column portion 12 Pocket portion 12a Pocket portion side surface 13 Pocket portion side surface hole 14 Index portion 15 Cage outer peripheral surface hole 16 Cage inner peripheral surface hole 17 Observation hole 18a Outer ring side pocket portion observation hole 18b Inner ring side pocket portion observation hole 19 Outer peripheral observation hole 20 Inner peripheral observation hole 30 Microscope 100 Rolling bearing abnormality diagnosis device 110 Photography unit 120 Recording unit 130 Diagnosis unit 140 Display unit.

Claims

1. A rolling bearing comprising an outer ring, an inner ring disposed inside the outer ring, a plurality of rolling elements which roll between the outer ring and the inner ring, and a retainer which maintains the spacing between adjacent rolling elements and holds the rolling elements, wherein the retainer has indicator portions on its surfaces which may come into contact with the outer ring, the inner ring or the rolling elements which are colored in different colors depending on the depth from the surface of said surfaces toward the inside.

2. A rolling bearing as claimed in claim 1, wherein the retainer has a column section parallel to the axis of rotation about which the bearing rotates, between adjacent rolling elements, and the indicator section is provided on the surface of the column section facing the rolling elements.

3. A rolling bearing as described in claim 1, wherein the retainer has continuous annular portions on both axial sides of the rotating shaft about which the bearing rotates, the annular portions being a central axis, the rotating shaft on which the bearing rotates between the outer ring and the inner ring, and the indicator portion is provided on a surface of the annular portion facing the outer ring on the radially outer periphery of the rotating shaft, or on a surface of the annular portion facing the inner ring on the radially inner periphery of the rotating shaft.

4. A rolling bearing as described in claim 1, wherein the indicator portions are provided at a plurality of locations on the retainer on a surface that may come into contact with the outer ring, the inner ring or the rolling element, and have different lengths in the depth direction from the surface of the surface toward the inside.

5. A rolling bearing as claimed in claim 1, wherein the indicator portion is coloured in a stepwise manner in the depth direction from the surface of the surface that may come into contact with the outer ring, the inner ring or the rolling element, and the colour changes stepwise.

6. A rolling bearing as claimed in claim 1, wherein the indicator portion is a color that changes stepwise in the depth direction from the surface of the surface to the inside of the surface of a hole provided in the wall of the surface that may come into contact with the outer ring, the inner ring or the rolling element.

7. A rolling bearing as claimed in claim 1, wherein said indicator portion is a coloured bottom surface of a hole provided in a surface which may come into contact with said outer ring, said inner ring or said rolling element.

8. A rolling bearing as claimed in claim 4, wherein the index portions have different lengths in the depth direction and are provided in a plurality of parallel rows on a surface facing the rolling elements of a column portion parallel to the rotational axis about which the bearing rotates, between adjacent rolling elements of the cage, or in a plurality of circumferential directions centered on the rotational axis on a surface facing the outer ring on the radially outer side of the rotational axis of a continuous annular portion, the rotational axis being the central axis, or on a surface facing the inner ring on the radially inner side of the rotational axis of the annular portion.

9. A rolling bearing according to any one of claims 1 to 8, wherein the index portion is cylindrical.

10. A rolling bearing as claimed in any one of claims 1 to 8, wherein the cross-sectional area of ​​a surface of said indicator portion that may come into contact with said outer ring, said inner ring or said rolling element, taken perpendicular to a direction from the surface of said surface toward the inside, decreases from the surface of said surface toward the inside.

11. A rolling bearing according to any one of claims 1 to 8, characterized in that the indicator portion is made of a material that is softer than the hardness of the retainer and has a Vickers hardness of 50 or less.

12. A rolling bearing according to any one of claims 1 to 8, wherein the indicator portion is made of a thermosetting resin or a thermoplastic resin.

13. A rolling bearing according to any one of claims 1 to 8, wherein the indicator portion contains a phosphorescent material or a fluorescent material.

14. A rolling bearing as claimed in any one of claims 1 to 8, wherein the outer ring or the inner ring has an observation hole for observing the indicator portion provided on a surface that may come into contact with the outer ring, the inner ring or the rolling element.

15. A rolling bearing comprising an outer ring, an inner ring provided inside the outer ring, a plurality of rolling elements which roll between the outer ring and the inner ring, and a retainer which maintains the spacing between adjacent rolling elements and holds the rolling elements, characterized in that the retainer has a plurality of index portions which have different depths from the surface of the surface which may come into contact with the outer ring, the inner ring or the rolling elements, toward the inside of the surface.

16. A rolling bearing abnormality diagnosis device for diagnosing abnormalities in a rolling bearing having an outer ring, an inner ring disposed inside the outer ring, a plurality of rolling elements which roll between the outer ring and the inner ring, and a cage which maintains the spacing between adjacent rolling elements and holds the rolling elements, comprising: a photographing unit which photographs indicator parts which are provided on a surface of the cage which may come into contact with the outer ring, the inner ring or the rolling elements and which are colored differently depending on the depth from the surface of said surface toward the inside; a recording unit which records video information of the indicator parts photographed by the photographing unit; and a diagnosis unit which diagnoses abnormalities based on the color of the indicator parts in the video information recorded in the recording unit.

17. A method for diagnosing abnormalities in a rolling bearing comprising an outer ring, an inner ring disposed inside the outer ring, a plurality of rolling elements which roll between the outer ring and the inner ring, and a cage which maintains the spacing between adjacent rolling elements and holds the rolling elements, the method comprising: an imaging step of imaging an indicator portion which is provided on a surface of the cage which may come into contact with the outer ring, the inner ring or the rolling elements and which is colored in a different color depending on the depth from the surface of the surface toward the inside; an image recording step of recording image information of the indicator portion imaged in the imaging step; and a diagnosis step of diagnosing abnormalities in the rolling bearing based on the color of the indicator portion in the recorded image information.

Images