rolling bearings

Abstract

In a rolling bearing (1), when an area enclosed by a line connecting the outer edge of a scatter diagram is defined as a retainer movable area (10), a ratio Ri / Re of a maximum inscribed circle diameter Ri of the retainer movable area (10) to a minimum circumscribed circle diameter Re of the retainer movable area (10) is less than 0.900, and the scatter diagram is obtained by plotting positions where a retainer (5) in a neutral position can exist without contacting a ball (4) several times on a two-dimensional coordinate system.

Description

Technical Field

[0001] The present invention relates to rolling bearings. Background Art

[0002] In rolling bearings featuring a pair of radially opposed raceways (inner and outer rings) that rotate relative to each other via multiple rolling elements, and an annular retainer that retains the rolling elements at circumferential intervals, the retainer is typically assembled between the inner and outer races so that it can move in both the radial and circumferential directions. Therefore, when the retainer is in its neutral position, radial clearances are formed between the raceways and the retainer, as well as radial and circumferential clearances between the retainer and the rolling elements housed in their receptacles (pockets). The radial clearances between the raceways and retainer are also referred to as "guide clearances," while the radial clearances and circumferential clearances between the pockets and the rolling elements are also referred to as "pocket radial clearances" and "pocket circumferential clearances," respectively. However, in rolling bearings employing retainers with radially uniform pocket shapes, for example, there is no "pocket radial clearance" (the pocket radial clearance is infinite).

[0003] Rolling bearings are broadly categorized as either rolling element-guided or raceway-guided. In rolling element-guided rolling bearings, the pocket radial clearance is smaller than the guide clearance, limiting radial movement of the retainer by contact between the inner surface (pocket surface) of the pocket and the rolling elements, preventing contact between the retainer and raceway. On the other hand, in raceway-guided rolling bearings, the guide clearance is smaller than the pocket radial clearance. In raceway-guided rolling bearings, when the guide clearance is smaller than the pocket circumferential clearance, the retainer first contacts the raceway when moving radially from a neutral position. When the guide clearance is larger than the pocket circumferential clearance, the retainer first contacts the rolling elements when moving radially if the rolling elements are evenly spaced. However, if the rolling elements are not evenly spaced, the retainer's range of motion changes, potentially leading to contact with the raceway. Whether a rolling element-guided or raceway-guided rolling bearing is appropriately selected (and the retainer guidance method is either rolling element-guided or raceway-guided) depends on the application and other factors of the rolling bearing.

[0004] During operation of a rolling bearing (when the inner and outer rings rotate relative to each other), frictional forces generated by the contact between the retainer and the rolling elements housed in the pockets sometimes cause the retainer to whirl at high speed (also known as the high-speed whirling phenomenon). This phenomenon is a major cause of problems such as abnormal noise, vibration, increased torque, heat generation, and even fatal problems such as retainer breakage.

[0005] Therefore, for example, in Patent Document 1 listed below, a predetermined unbalance is imparted to the retainer, allowing it to rotate eccentrically. This allows a portion of the rotating retainer to constantly contact the outer ring or rolling elements, thereby minimizing the occurrence of high-speed whirling and, consequently, preventing the occurrence of undesirable conditions such as abnormal noise and vibration.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-196513 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, the technical means (invention) for preventing the high-speed swirl phenomenon described in Patent Document 1 is not suitable for rolling bearings that use an inner ring guide as the retainer guide method (see paragraph 0036 of the document). Its practical application is limited to rolling bearings that use an outer ring guide or a rolling element guide as the retainer guide method. Furthermore, because the contact surface pressure at the contact portion tends to increase with increasing rotational speed, the technical means described in Patent Document 1 is not suitable for high-speed rotating rolling bearings where the dmn value, expressed as the product of the bearing's pitch circle diameter (mm) and the rotational speed (rpm), exceeds a specified value. However, high-speed swirl can also occur in rolling bearings that are difficult to apply the technical means described in Patent Document 1, namely, rolling bearings with inner ring guides and high-speed rotating bearings with raceway ring guides.

[0011] In view of the above circumstances, a first object of the present invention is to provide a means for preventing high-speed whirling that is widely applicable to all rolling bearings, regardless of the cage guiding method, bearing rotational speed (dmn value), etc.

[0012] In addition, a second object of the present invention is to provide a bearing ring-guided rolling bearing that can prevent the occurrence of high-speed whirling phenomenon as much as possible.

[0013] Means for solving problems

[0014] As described above, the retainer is usually assembled between the inner and outer rings in a state where it can move radially and circumferentially, and the range of movement of the retainer is limited to the smallest gap among the guide gap, the pocket radial gap, and the pocket circumferential gap. Therefore, if the position of the raceway ring and each rolling element is determined, the area where the center of the retainer can geometrically exist (the retainer can move without contacting the outer ring, inner ring, and rolling elements), that is, the "retainer movable area" can be estimated based on the configuration and shape of the pocket. Therefore, the inventors conducted dynamic analysis under various conditions, and found that under the analytical conditions that are believed to produce the high-speed gyration phenomenon, the shape of the retainer movable area becomes a circle or a regular polygon that is close to a circle. On the other hand, under the analytical conditions that are believed not to produce the high-speed gyration phenomenon, the shape of the retainer movable area becomes a circle or a "skewed shape" that deviates from the regular polygon that is close to a circle. Based on Figures 10A to 10D as well as Figures 11A to 11D The analysis results shown are used to illustrate this insight.

[0015] First, in Figure 10A 、 Figure 10C 、 Figure 11A and Figure 11C In the figure, the "cage movable area" and "cage center position" at the moment when the inner ring rotates 2.5 times are shown. Figure 10B 、 Figure 10D 、 Figure 11B and Figure 11D In the figure, the movable area becomes Figure 10A 、 Figure 10C 、 Figure 11A and Figure 11C The moving path of the center of the cage during 10 rotations of the inner ring of the rolling bearing shown. The shape of the cage's movable area is Figure 10A 、 Figure 10C In the case of a circle or a regular polygon close to a circle, a high-speed swirl phenomenon occurs, and as a result, Figure 10B and Figure 10D As shown in the figure, the lines representing the moving trajectory of the retainer center become extremely dense. In contrast, the shape of the retainer movable area is Figure 11A 、 Figure 11C In the case of the skewed shape shown, the high-speed swirl phenomenon does not occur, and as a result, Figure 11B and Figure 11D As shown, the line indicating the movement trajectory of the retainer center becomes extremely thick. The first invention of the present application was completed based on the above findings.

[0016] That is, the first invention of the present application, which has been completed to achieve the above-mentioned object, is characterized in that it comprises: an inner ring and an outer ring that rotate relative to each other via a plurality of rolling elements; and a retainer having a plurality of pockets provided at intervals in the circumferential direction to respectively accommodate the rolling elements, wherein, when a region enclosed by a line connecting outer edges of a scatter plot is defined as a retainer movable region, a ratio Ri / Re of a maximum inscribed circle diameter Ri of the retainer movable region to a minimum circumscribed circle diameter Re of the retainer movable region is not more than 0.900, and the scatter plot is obtained by repeatedly plotting on two-dimensional coordinates positions where the retainer can exist without contacting the inner ring, the outer ring, and the rolling elements.

[0017] The aforementioned ratio Ri / Re being 0.900 or less means that the shape of the retainer's movable region is circular or a skewed shape that deviates from a regular polygon that approximates a circle. Therefore, according to the present inventors' verification results, a rolling bearing having the aforementioned structure can effectively prevent the occurrence of high-speed gyration. It should be noted that although the specific reason why a skewed shape of the retainer's movable region is effective in preventing the occurrence of high-speed gyration cannot be determined, based on Figure 11A and Figure 11C The analytical results shown here are inferred to be due to the fact that when the retainer is displaced to a position where the movable area has a distorted shape, the frictional force between the pocket surface and the rolling elements, the driving force of the high-speed whirling phenomenon, acts in a direction that hinders motion. In other words, to generate the high-speed whirling phenomenon, it is believed that the direction of the force acting on the retainer must rotate like the hands of a clock, constantly acting as an acceleration of circular motion. It is speculated that distorting the shape of the movable area can hinder this effect.

[0018] Furthermore, the first invention does not always keep a specific portion of the cage in contact with the outer ring or rolling element as in the technical solution proposed in Patent Document 1. Therefore, the first invention of this application is applicable to various rolling bearings regardless of the cage guiding method.

[0019] In the above structure, to make the ratio Ri / Re 0.900 or less, for example, the plurality of pockets provided in the retainer may be constituted by large pockets or small pockets having different circumferential dimensions (circumferential opening dimensions).

[0020] Multiple large pockets can be provided. In this case, preferably, groups of at least one large pocket (two or more consecutively arranged) are arranged evenly spaced in the circumferential direction. For example, if there are 10 rolling elements, the arrangement should be large, large, small, small, small, large, large, small, small, small. This minimizes the occurrence of vibration and other problems caused by mass imbalance in the cage.

[0021] The circumferential dimension difference between the large and small pockets can be set to 0.1 mm or greater. In other words, simply by appropriately arranging large and small pockets with slightly different circumferential dimensions, high-speed whirling of the cage in the rolling bearing can be effectively prevented. It should be noted that the circumferential dimension difference between the large and small pockets can be appropriately varied based on various parameters, such as the total number of rolling elements (pockets) and bearing dimensions.

[0022] In addition, as described above, in a rolling bearing guided by a raceway ring, the radial movement of the retainer is limited by the contact between the raceway ring (the guiding surface) and the retainer (the guided surface). Therefore, based on the shapes of the guiding surface and the guided surface, it is possible to estimate the area where the center of the retainer can geometrically exist through simulation. In other words, it is possible to estimate the area where the retainer can move without contacting the raceway ring (guide wheel) (hereinafter referred to as the "retainer movable area"). In addition, the inventors have repeatedly conducted in-depth research and found that under analytical conditions that are believed to produce high-speed gyration phenomena, the closer the shape of the retainer movable area is to a perfect circle, the more likely it is to produce high-speed gyration phenomena. Conversely, the more the shape of the retainer movable area deviates from a circle (a perfect circle) into a "skewed shape", the less likely it is to produce high-speed gyration phenomena. The second invention of this application was completed based on the above insights.

[0023] Specifically, the second invention of the present application, which has been completed to achieve the second object, is a rolling bearing comprising: an inner ring and an outer ring that rotate relative to each other via a plurality of rolling elements; and a retainer having a plurality of pockets provided at intervals in the axial direction to accommodate the rolling elements, the retainer having an annular guided surface guided by an annular guide surface provided on the outer circumferential surface of the inner ring or the inner circumferential surface of the outer ring, the radial gap formed between the guide surface and the guided surface being smaller than the radial gap formed between the inner surface of the retainer pocket and the rolling elements. The invention is characterized in that, when a region enclosed by a line connecting outer edges of a scatter plot is defined as a movable region of the retainer, a ratio (Ri / Re) of a maximum inscribed circle diameter (Ri) of the movable region of the retainer to a minimum circumscribed circle diameter (Re) of the movable region of the retainer is less than 0.990. The scatter plot is obtained by plotting multiple positions on two-dimensional coordinates where the retainer, in a neutral position, can exist without contact with the inner ring, outer ring, and rolling elements.

[0024] The aforementioned ratio Ri / Re being less than 0.990 means that the shape of the retainer's movable area is skewed, deviating from a perfect circle. Therefore, according to the present inventors' verification results, a rolling bearing having the above-described structure can effectively prevent the occurrence of high-speed gyration. It should be noted that while the specific reason why a skewed shape of the retainer's movable area is effective in preventing the occurrence of high-speed gyration cannot be determined, it is speculated that this is because the skewed shape of the retainer's movable area deviates from the circular orbit, preventing the retainer's whirling motion from continuously accelerating. In other words, to produce high-speed gyration, the direction of the force acting on the retainer must rotate like the hands of a clock, constantly acting as circular acceleration. It is speculated that skewed shapes of the movable area can hinder this effect.

[0025] Furthermore, the technical approach employed in the second invention does not intentionally increase the unbalance of the retainer, as is the case with the technical approach proposed in Patent Document 1. Therefore, even when the present invention is applied to rolling bearings (particularly bearings of the raceway-guided type), there is no concern about increased centrifugal force or shaft NRRO due to unbalance. Therefore, the second invention is widely applicable to raceway-guided rolling bearings.

[0026] When a guiding surface is provided on the inner circumferential surface of the outer ring and a guided surface is provided on the outer circumferential surface of the retainer, for example, a straight line portion parallel to an axis-parallel plane extending along the axis of the rolling bearing is provided on the guided surface, thereby making the above-mentioned ratio Ri / Re less than 0.990.

[0027] When a guiding surface is provided on the outer circumferential surface of the inner ring and a guided surface is provided on the inner circumferential surface of the retainer, for example, a straight line portion parallel to an axis-parallel plane extending along the axis of the rolling bearing is provided on the guiding surface, thereby making the above-mentioned ratio Ri / Re less than 0.990.

[0028] Preferably, a plurality of the straight portions are provided at equal intervals in the circumferential direction. This can minimize the occurrence of problems such as vibration caused by mass imbalance of the cage and the inner ring.

[0029] Effects of the Invention

[0030] In summary, according to the first invention of the present application, the occurrence of the high-speed whirling phenomenon can be effectively prevented regardless of the guide method of the cage and the rotational speed (dmn value) of the bearing.

[0031] In addition, according to the second invention of this application, a raceway-guided rolling bearing can be realized that can prevent the occurrence of high-speed whirling phenomenon as much as possible regardless of whether it is inner ring guided or outer ring guided, and regardless of the bearing rotation speed (dmn value). BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A It is a front view of the rolling bearing according to the embodiment of the first invention.

[0033] Figure 1B It is composed Figure 1A Partial side view of the retainer of a rolling bearing.

[0034] Figure 1C yes Figure 1B The cross section is shown in the direction of the arrow on line A-A.

[0035] Figure 1D This is a partially enlarged side view of a retainer in which rolling elements are housed in pockets.

[0036] Figure 2 This is a conceptual diagram for explaining a method for determining the movable range of a retainer.

[0037] Figure 3 It means composition Figure 1A Diagram showing the movable range of the cage of a rolling bearing.

[0038] Figure 4A The shape of the movable area becomes Figure 3 FIG. 1 is a diagram showing the movement trajectory of the center of the cage during 10 rotations of the inner ring of the rolling bearing according to the embodiment of the shape shown.

[0039] Figure 4B Yes Figure 4A This graph shows the change in the cage velocity (translational velocity) during 10 rotations of the inner ring.

[0040] Figure 5 It is a diagram showing the movable range of the cage of a comparative rolling bearing that does not have the characteristic structure of the present invention.

[0041] Figure 6A The shape of the movable area becomes Figure 5 The diagram shows the movement trajectory of the center of the cage during 10 rotations of the inner ring of the rolling bearing of the shape shown.

[0042] Figure 6B Yes Figure 6A This graph shows the change in the cage velocity (translational velocity) during 10 rotations of the inner ring.

[0043] Figure 7A It is a diagram showing a movable range of a cage of a rolling bearing according to another embodiment of the first invention, etc.

[0044] Figure 7BIt is a diagram showing the movable range of the cage of a comparative rolling bearing that does not have the characteristic structure of the first invention.

[0045] Figure 8A It is a diagram showing a movable range of a cage of a rolling bearing according to another embodiment of the first invention, etc.

[0046] Figure 8B It is a diagram showing the movable range of the cage of a comparative rolling bearing that does not have the characteristic structure of the first invention.

[0047] Figure 9A It is a diagram showing a movable range of a cage of a rolling bearing according to another embodiment of the first invention, etc.

[0048] Figure 9B It is a diagram showing the movable range of the cage of a comparative rolling bearing that does not have the characteristic structure of the first invention.

[0049] Figure 10A This is a diagram showing the movable range of the retainer, etc., which was obtained during the development of the first invention.

[0050] Figure 10B It means that the movable area becomes Figure 10A The diagram shows the movement trajectory of the center of the cage during 10 rotations of the inner ring of the bearing in the shown area.

[0051] Figure 10C This is a diagram showing the movable range of the retainer, etc., which was obtained during the development of the first invention.

[0052] Figure 10D It means that the movable area becomes Figure 10C The diagram shows the movement trajectory of the center of the cage during 10 rotations of the inner ring of the bearing in the shown area.

[0053] Figure 11A This is a diagram showing the movable range of the retainer, etc., which was obtained during the development of the first invention.

[0054] Figure 11B It means that the movable area becomes Figure 11A The diagram shows the movement trajectory of the cage center during 10 rotations of the bearing inner ring.

[0055] Figure 11C This is a diagram showing the movable range of the retainer, etc., which was obtained during the development of the first invention.

[0056] Figure 11D It means that the movable area becomes Figure 11C The diagram shows the movement trajectory of the center of the cage during 10 rotations of the inner ring of the bearing in the shown area.

[0057] Figure 12 It is a top view of a rolling bearing according to an embodiment of the second invention.

[0058] Figure 13 yes Figure 12 Cross-sectional view in the direction of the arrow on line A-A.

[0059] Figure 14A yes Figure 12 Top view of the retainer of a rolling bearing.

[0060] Figure 14B yes Figure 14A Right side view.

[0061] Figure 15 This is a conceptual diagram for explaining a method for determining the movable range of a retainer.

[0062] Figure 16A Yes Figure 12 Diagram of the movable area of ​​the cage of a rolling bearing.

[0063] Figure 16B Yes Figure 12 A diagram showing the movement trajectory of the cage center during 10 rotations of the inner ring of a rolling bearing.

[0064] Figure 16C Yes Figure 12 This diagram shows the change in velocity (translational velocity) of the inner ring of a rolling bearing over 10 rotations.

[0065] Figure 17A This is a diagram showing the movable range of the cage of a comparative rolling bearing that does not have the characteristic structure of the second invention.

[0066] Figure 17B 1 is a diagram showing the movement trajectory of the center of the cage during 10 rotations of the inner ring of the bearing.

[0067] Figure 17C This is a diagram showing changes in the speed (translational speed) of the inner ring of the bearing during 10 rotations.

[0068] Figure 18A It is a top view of a cage according to a modified example.

[0069] Figure 18B yes Figure 18A Right side view.

[0070] Figure 19 It is a plan view of an inner ring of a rolling bearing constituting another embodiment of the second invention. DETAILED DESCRIPTION

[0071] The following describes an embodiment of the first invention of the present application based on the accompanying drawings. It should be noted that the terms "axial direction," "radial direction," and "circumferential direction" used below to indicate directionality refer to a direction parallel to the axis O of the rolling bearing 1 shown in FIG. 1 , a radial direction of a circle centered on the axis O, and a circumferential direction of a circle centered on the axis O, respectively.

[0072] Figure 1A This is a front view of a rolling bearing 1 according to an embodiment of the first invention. Figure 1B This is a partial side view of the retainer constituting the rolling bearing 1. Figure 1C yes Figure 1B A-A line schematic cross-sectional view, Figure 1D This is an enlarged side view of a portion of a retainer housing rolling elements within pockets. This rolling bearing 1 comprises a pair of radially opposed raceways (an inner race 2 and an outer race 3) formed from a highly rigid metal material such as bearing steel (high-carbon chromium bearing steel); a plurality of rolling elements (here, eight balls 4) rollably interposed between the inner raceway formed on the outer circumferential surface 2a of the inner race 2 and the outer raceway formed on the inner circumferential surface 3a of the outer race 3; and an annular retainer 5 that retains the plurality of balls 4 at intervals in the circumferential direction. This rolling bearing 1 is a so-called ball bearing.

[0073] The retainer 5 has a plurality of pockets 6 corresponding to the number of balls 4, with each pocket 6 housing a single ball 4. The inner surface (pocket surface) 6a of each pocket 6 is formed into a cylindrical surface with a constant diameter. The retainer 5 shown in the figure is a resin retainer formed by injection molding of a resin material. However, retainers other than resin retainers may also be used as retainers 5, depending on the required properties. For example, a cut retainer obtained by cutting a metal material into a predetermined shape, or a stamped retainer obtained by combining a pair of retainer materials stamped (punched) into a predetermined annular shape.

[0074] The cage 5 is assembled between the inner ring 2 and the outer ring 3 so as to form a radial gap between the inner ring 2 and the outer ring 3 and a circumferential gap between the cage 5 and the balls 4 accommodated in the pockets 6. Figure 1A As shown, when the retainer 5 is in the neutral position, radial gaps (first radial gap δ1 and second radial gap δ2), also called "guide gaps", are formed between the outer circumferential surface 2a of the inner ring 2 and the inner circumferential surface 5a of the retainer 5, and between the inner circumferential surface 3a of the outer ring 3 and the outer circumferential surface 5b of the retainer 5. In addition, a circumferential gap ε, also called "pocket circumferential gap", is formed between the ball 4 and the pocket surface 6a [see Figure 1D]. This allows rolling bearing 1 to operate smoothly. In the illustrated example of rolling bearing 1, second radial clearance δ2 is smaller than first radial clearance δ1. For example, second radial clearance δ2 has a diameter of 1.2 mm. That is, the diameter of inner circumferential surface 3a of outer ring 3 is 1.2 mm larger than the diameter of outer circumferential surface 5b of retainer 5.

[0075] Each pocket 6 is composed of two types of pockets that differ only in their circumferential dimensions (diameter dimensions) W, namely, a large pocket 6A with a relatively large diameter dimension W or a small pocket 6B with a relatively small diameter dimension W. Figure 1C The pocket 6 at the zero-hour position is designated as the large pocket 6A, and the remaining seven pockets 6 are designated as the small pockets 6B. For example, when using a ball 4 with a diameter of 9.525 mm, the diameter w of the large pocket 6A is set to 9.925 mm, and the diameter of the small pocket 6B is set to 9.725 mm. In this case, the circumferential gap ε formed between the pocket surface 6a of the large pocket 6A and the ball 4 (pocket circumferential gap) is 0.4 mm in diameter, and the circumferential gap ε formed between the pocket surface 6a of the small pocket 6B and the ball 4 is 0.2 mm in diameter.

[0076] For the rolling bearing 1 having the above structure, the "retainer movable area" is determined, that is, the area enclosed by a line connecting the outer edges of a scatter diagram obtained by plotting positions where the retainer 5 can exist without contacting the inner ring 2, outer ring 3, and balls 4 several times on a two-dimensional coordinate system. Figure 2 The conceptual diagram shown here explains a method for finding the position where the retainer 5 can exist without contacting the balls 4 , which is necessary for finding the “retainer movable range”.

[0077] Figure 2 This is a conceptual diagram showing a portion of retainer 5 and two balls 4 housed within its pockets. Reference numeral O in this figure represents the bearing center, reference numeral C represents the center C of retainer 5, reference numeral B represents the center of ball 4, and reference numeral P represents an arbitrary point on the pocket surface (inner surface of the pocket) of retainer 5. The subscripts (subscripts) of reference numeral B and the left-hand side of the subscripts of reference numeral P represent the ball 4 number, while the right-hand side of the subscripts of reference numeral P represents the j-th point when the pocket surface is discretized (meshed).

[0078] [First process]

[0079] First, the center B of ball 4 i Towards an arbitrary point P on the inner surface of the pocket 6 housing the ball 4 i,j The magnitude of the vector (absolute value d) is compared with the radius Dw / 2 of the ball 4.

[0080] When the absolute value d is greater than the radius Dw / 2, it is determined that the point P on the inner surface of the concave pocket 6 is i,j Does not interfere with ball 4,

[0081] When the absolute value d is less than or equal to the radius Dw / 2, it is determined that the point P on the inner surface of the concave pocket 6 is i,j Interferes with ball 4.

[0082] Hereinafter, the same determination operation is performed on other points P.

[0083] exist Figure 2 In the example shown, it can be said that the point P on the inner surface of the pocket 6 housing the ball 4 having the center indicated by the reference numeral B1 is 1,j , click P 1,j+1 Point P on the inner surface of the pocket 6 that houses the ball 4 having the center indicated by reference numeral B2 without interfering with the ball 4 2,j、 Click P 2,j+1 Interferes with ball 4.

[0084] Furthermore, if the relationship f(i, j) ≥ 0 holds for all i, j values ​​when f(i, j) = d - Dw / 2, the position of the retainer center C at that time is determined to be a point within the retainer's movable range where the retainer 5 can exist without contacting the balls 4.

[0085] [Second process]

[0086] The position of the retainer center C and the phase of the retainer are varied, and a determination process similar to that performed in the first step is performed. If a phase exists at the selected position of the retainer center C that is determined to be the "point within the retainer's movable range," the selected position of the retainer center C is determined to be the "point within the retainer's movable range."

[0087] like Figure 3 As shown, when using balls 4 having the aforementioned diameter dimensions and a retainer 5 having pockets 6, the shape of the movable region 10 is slightly deformed from a regular octagon, and the ratio of the maximum inscribed circle diameter Ri to the minimum circumscribed circle diameter Re (=Ri / Re) of this movable region 10 is 0.853. On the other hand, as a comparison object, the movable region of the retainer in a rolling bearing 1 was determined. This rolling bearing 1 was assembled with a rolling bearing in which the shape of the retainer 5 was only partially different. Specifically, it was assembled with a retainer 5 in which all of the eight pockets 6 provided were composed of the aforementioned small pockets 6B. In this case, the shape of the retainer movable region 10 is Figure 5In the substantially regular octagon shown in FIG. 1 , the ratio of the maximum inscribed circle diameter Ri to the minimum circumscribed circle diameter Re (=Ri / Re) of the movable region 10 is 0.921.

[0088] Furthermore, when the rolling bearing 1 of the present embodiment and a comparative rolling bearing were operated under the same conditions, dynamic analysis was performed to verify the movement trajectory of the center of each retainer and the change in the movement speed (translation speed) of each retainer. Figure 4A and Figure 4B The moving trajectory and velocity (translational velocity) of the center of the cage during 10 rotations of the inner ring 2 of the rolling bearing 1 according to this embodiment are shown. Figure 6A and Figure 6B The figure shows the movement trajectory and velocity (translational velocity) of the center of the cage during 10 rotations of the inner ring of the comparative rolling bearing.

[0089] When the general Figure 4A and Figure 6A When compared with the rolling bearing 1 of this embodiment, the rolling bearing of the comparative object shows that the lines of movement trajectory of the retainer are very dense. Figure 4B and Figure 6B , in the rolling bearing 1 of the present embodiment, the translational velocity of the retainer 5 gradually decreases as time passes after the start of operation, converging toward zero. In contrast, in the comparative rolling bearing, the translational velocity of the retainer rapidly increases after a predetermined time has elapsed after the start of operation, and this increased velocity persists. Based on these analysis results, it is believed that the high-speed whirling phenomenon of the retainer 5 does not occur in the rolling bearing 1 of the present embodiment, whereas it is believed that the high-speed whirling phenomenon of the retainer occurs in the comparative rolling bearing.

[0090] In addition, for rolling bearings using a retainer in which the total number of pockets 6 is set to 12, 20, or 31, the occurrence of the high-speed swirl phenomenon is also verified by the shape of the retainer movable region 10. Specifically, the retainer movable region 10 is determined for each of the rolling bearings (1) to (6) shown below, and the ratio Ri / Re of the maximum inscribed circle diameter Ri of the retainer movable region 10 to the minimum circumscribed circle diameter Re of the retainer movable region 10 is calculated. The retainer movable region 10 in the rolling bearings (1) to (6) shown below and the above ratio are shown in FIG. Figure 7A 、 Figure 7B 、 Figure 8A 、 Figure 8B 、 Figure 9A as well as Figure 9B .

[0091] (1) A rolling bearing wherein, in a resin cage having a total of 12 pockets, two pockets are large pockets and the remaining pockets are small pockets.

[0092] (2) A rolling bearing in which, in a resin cage having a total of 12 pockets, only one pocket is a large pocket and the remaining pockets are small pockets.

[0093] (3) A rolling bearing wherein, in a resin cage having a total number of pockets set to 20, four pockets are large pockets and the remaining pockets are small pockets.

[0094] (4) A rolling bearing, wherein, in a resin cage having a total number of pockets set to 20, three pockets are large pockets and the remaining pockets are small pockets.

[0095] (5) A rolling bearing, wherein, in a resin cage having a total number of pockets of 31, eight pockets are large pockets and the remaining pockets are small pockets.

[0096] (6) A rolling bearing, wherein, in a resin cage having a total number of pockets set to 31, five pockets are set as large pockets and the remaining pockets are set as small pockets.

[0097] Furthermore, the shape of the retainer movable region 10 becomes Figure 7A 、 Figure 7B 、 Figure 8A 、 Figure 8B 、 Figure 9A as well as Figure 9B The above rolling bearings with the shapes shown above were subjected to dynamic analysis. The moving trajectory of the retainer center in each rolling bearing is omitted, but the shape of the retainer movable area 10 is Figure 7A 、 Figure 8A as well as Figure 9A In the rolling bearing of the shape shown, it is considered that the high-speed rotation phenomenon of the retainer does not occur. In contrast, the shape of the retainer movable area 10 becomes Figure 7B 、 Figure 8B as well as Figure 9B In the rolling bearing shown, it is considered that a high-speed whirling phenomenon of the cage occurs.

[0098] In summary, by setting the ratio (Ri / Re) of the maximum inscribed circle diameter (Ri) of the movable retainer region 10 to the minimum circumscribed circle diameter (Re) of the movable retainer region 10 to 0.900 or less, that is, by setting the shape of the movable retainer region 10 to a "skewed shape" that deviates from a circle or a regular polygon approximating a circle, the occurrence of high-speed swirling of the retainer 5 can be effectively prevented. Furthermore, this effect can be achieved simply by configuring each of the multiple pockets 6 provided in the retainer 5 to have a relatively large circumferential dimension (large pocket 6A) or a relatively small circumferential dimension (small pocket 6B) (with some pockets having a larger circumferential dimension (W) than the remaining pockets). Therefore, the first invention is widely applicable to all rolling bearings, regardless of the retainer 5 guiding method, bearing rotational speed (dmn value), and other factors. Consequently, a quiet rolling bearing 1 can be achieved that prevents the occurrence of high-speed swirling and is less likely to generate abnormal noise and vibration.

[0099] It should be noted that in a rolling bearing 1 having a plurality of large pockets 6A in a retainer 5 (e.g., the rolling bearings of (1), (3), and (5) above), it is preferable to arrange the large pocket groups, each containing one or more large pockets 6A, at equal intervals in the circumferential direction. For example, if the total number of balls 4 (pockets 6) is ten, the pockets 6 are arranged in the order of large, large, small, small, small, large, large, small, small, small. This can minimize the occurrence of problems such as vibration caused by mass imbalance in the retainer 5.

[0100] As mentioned above, the rolling bearing 1 according to the embodiment of the first invention has been described. However, the embodiment of the first invention is not limited thereto, and various modifications can be made without departing from the spirit and scope of the invention.

[0101] For example, in the rolling elements constituting the rolling bearing 1, cylindrical rollers, needle rollers, etc. may be used instead of the balls 4. That is, the first invention can be applied not only to ball bearings but also to roller bearings such as cylindrical roller bearings and needle roller bearings. Figure 1B In addition to the circular shape in plan view as shown, for example, it may also be formed into an elliptical shape with a major axis arranged along the circumferential direction. In addition, it can be applied not only to single-row bearings but also to double-row bearings.

[0102] Hereinafter, an embodiment of the second invention of the present application will be described based on the accompanying drawings. It should be noted that, in order to indicate directionality, the "axial direction", "radial direction" and "circumferential direction" used below are respectively Figure 12 The directions parallel to the bearing center (axis) O of the rolling bearing 21 shown in FIG. 1 , the radial direction of a circle centered on the axis O, and the circumferential direction of a circle centered on the axis O are shown in FIG. 1 .

[0103] Figure 122 is a top view of a rolling bearing 21 according to an embodiment of the second invention. Figure 13 yes Figure 12 A-A line arrow direction schematic cross-sectional view, Figure 14A is a top view of the retainer 25 constituting the rolling bearing 21. Figure 4B This is a right side view of the retainer 25. The rolling bearing 21 is a so-called ball bearing and comprises a pair of radially opposed raceways (an inner race 22 and an outer race 23) formed of a highly rigid metal material such as bearing steel (high-carbon chromium bearing steel); a plurality of rolling elements (here, ten balls 24) routable between an inner raceway surface formed on the outer circumferential surface 22a of the inner race 22 and an outer raceway surface formed on the inner circumferential surface 23a of the outer race 23; and an annular retainer 25 that retains the balls 24 at intervals in the circumferential direction.

[0104] The retainer 25 has a plurality (10) of pockets 26 arranged at equal intervals in the circumferential direction, each pocket 26 housing a ball 24. The retainer 25 shown in the figure has an inner surface (pocket surface) 26a of each pocket 26 formed as a cylindrical surface with a constant diameter, that is, the shape of the pockets 26 is uniform in the radial direction. Furthermore, the retainer 25 is assembled between the inner ring 22 and the outer ring 23 so as to form a radial gap between them and a circumferential gap between the retainer 25 and the balls 24 housed in the pockets 26. In other words, as shown in FIG. Figure 12 As shown, when the retainer 25 is in the neutral position, radial gaps (first radial gap δ21 and second radial gap δ22) called "guide gaps" are formed between the outer circumferential surface 22a of the inner ring 22 and the inner circumferential surface 25a of the retainer 25, and between the inner circumferential surface 23a of the outer ring 23 and the outer circumferential surface 25b of the retainer 25. In addition, a circumferential gap ε also called "pocket circumferential gap" is formed between the ball 24 and the pocket surface 26a (see FIG. Figure 13 ). As a result, the rolling bearing 21 can operate smoothly.

[0105] In the illustrated example rolling bearing 21, the second radial clearance δ22 is smaller than the first radial clearance δ21. The second radial clearance δ22 is, for example, 0.8 mm in diameter. That is, the diameter of the inner circumferential surface 23a of the outer ring 23 is 0.8 mm larger than the diameter of the outer circumferential surface 25b of the retainer 25. Furthermore, the circumferential clearance ε is, for example, 1.2 mm in diameter. That is, the diameter W of the pocket 26 [see Figure 3(b)] is 1.2 mm larger than the diameter of ball 24. Therefore, in the rolling bearing 1 of this embodiment, the second radial clearance δ22 is the smallest of the first radial clearance δ21, the second radial clearance δ22, and the circumferential clearance ε. Therefore, in the rolling bearing 21 of this embodiment, radial movement of retainer 25 is restricted by contact between outer ring 23 (the raceway ring) and retainer 25.

[0106] Also like Figure 14A As shown, in the present embodiment, the inner circumferential surface 25a of the retainer 25 is formed into a true circular shape when viewed from above, while the outer circumferential surface 25b is formed into a non-circular shape. The non-circular shape of the outer circumferential surface 25b is achieved by forming a straight portion 27 at one point along the circumference of the outer circumferential surface 25b, which is parallel to an axis-parallel plane PP that includes the axis O of the rolling bearing 1 (the center Oc of the retainer 25). The inner diameter φa of the retainer 25 is, for example, 42.8 mm, and the outer diameter φb, assuming the outer circumferential surface 25b of the retainer 25 is a true circle, is, for example, 51.4 mm. The separation distance D1 between the axis-parallel plane PP (the center Oc of the retainer 25) and the straight portion 27 is, for example, 25.3 mm. In this case, the straight portion 27 is formed by removing a portion of the outer circumferential surface 25b of the retainer 25 by a maximum of 0.4 mm in the radial direction.

[0107] By forming the straight portion 27 on the outer peripheral surface 25b of the retainer 25, the second radial gap δ22 in the circumferential region where the straight portion 27 is formed is larger than the second radial gap δ22 in the circumferential region where the straight portion 27 is not formed (see Figure 12 ).

[0108] The retainer 25 of this embodiment, having the above structure, is a resin retainer formed from an injection-molded resin material. The pocket 26 is molded simultaneously with the injection molding of the retainer 25. Similar to the pocket 26, the straight portion 27 can be molded simultaneously with the injection molding of the retainer 25, or can be formed by machining after the molding process. Depending on the application and required characteristics, retainer 25 may also use a cut retainer obtained by cutting a retainer other than a resin retainer, such as a metal material, into a predetermined shape, or a stamped retainer obtained by combining a pair of retainer materials that have been stamped (punched) into a predetermined annular shape.

[0109] For the rolling bearing 21 having the above structure, the "retainer movable area" is calculated, that is, the area surrounded by the line connecting the outer edge of the scatter diagram obtained by plotting the position where the retainer 25 in the neutral position can exist without contacting the outer ring 23 (and the inner ring 22) several times on the two-dimensional coordinates. It should be noted that, as described above, in the rolling bearing 21 of the present embodiment, the second radial gap δ22 formed between the outer ring 23 and the retainer 25 is smaller than the first radial gap δ21 formed between the inner ring 22 and the retainer 25. Therefore, while the non-contact state of the retainer 25 and the outer ring 23 is maintained, the non-contact state of the retainer 25 and the inner ring 22 is also maintained. In short, when the retainer 25 is in a position where it can exist without contacting the outer ring 23, the retainer 25 is also not in contact with the inner ring 22 (and the balls 24). Based on Figure 15 A method of finding the position where the retainer 25 can exist without contacting the outer ring 23 , which is necessary for finding the “retainer movable region” in the rolling bearing 21 of the present embodiment, will be described.

[0110] Figure 15 This is a conceptual diagram showing a portion of the inner peripheral surface 23a of the outer ring 23 and the retainer 25 extracted. c As described above, the bearing center and the center of retainer 25 are represented, and reference symbol P represents an arbitrary point on outer peripheral surface 25b of retainer 25. Note that the subscript (subscript) of reference symbol P represents the jth point when outer peripheral surface 25b of retainer 25 is discretized (meshed).

[0111] First, a direction is drawn from the bearing center O toward an arbitrary point P on the outer peripheral surface 25b of the retainer 25. j The magnitude of the vector (absolute value d) is compared with the radius r of the inner circumferential surface 23a of the outer ring 23.

[0112] When the absolute value d is equal to or greater than the radius r, it is determined that any point P on the outer peripheral surface 25b of the retainer 25 is j Does not interfere with the outer ring 23,

[0113] When the absolute value d is smaller than the radius r, it is determined that any point P on the outer peripheral surface 25b of the retainer 25 is j It does not interfere with the outer ring 23.

[0114] Next, for any other point P on the outer peripheral surface 25b of the retainer 25, j+n The same judgment operation is performed.

[0115] exist Figure 15 In the example shown, it can be said that any point P on the outer peripheral surface 5b of the retainer 25 j、 Pj+1 It does not interfere with the outer ring 23.

[0116] Furthermore, when f(j)=d-r, if the relationship of f(j)<0 is satisfied for all j, it is determined that the cage center O at that time is c The position is a point on the movable range of the cage where the cage 25 can exist without contacting the outer ring 23 .

[0117] Next, make the holder center O c The same determination operation as the above determination operation is performed based on the position of the retainer 25 and the phase change of the retainer 25. c If there is a phase at the position determined to be the above-mentioned "point on the movable range of the retainer", it is determined to be the selected O c The position of , and the position of the retainer center Oc are “points on the retainer movable area”.

[0118] have Figure 12 The shape of the movable region 30 of the retainer of the rolling bearing 21 of the present embodiment shown in FIG. Figure 16A As shown, the shape is slightly deformed from the perfect circle, and the ratio of the maximum inscribed circle diameter Ri to the minimum circumscribed circle diameter Re (=Ri / Re) of the movable region 30 of the retainer is 0.986. On the other hand, as a comparison object with this, the movable region of the retainer in the rolling bearing 1 is obtained. The rolling bearing has a rolling bearing 21 in which the shape of the retainer 26 is partially different. Specifically, a straight portion 27 is provided at a circumferential position of the outer peripheral surface, and the separation distance D1 between the straight portion 27 and the center Oc is set to 25.5 mm. The shape of the movable region 30 of the retainer in this case is as follows Figure 17A As shown, the ratio of the maximum inscribed circle diameter Ri to the minimum circumscribed circle diameter Re (=Ri / Re) of the cage movable region 10 is 0.990.

[0119] Furthermore, when the rolling bearing 21 of the present embodiment and a comparative rolling bearing are operated under the same conditions, dynamic analysis is performed to verify the movement trajectory of the center of each retainer and how the movement speed (translation speed) of each retainer changes. Figure 16B and Figure 16C The moving trajectory and the change in speed (translational speed) of the center of the cage during 10 rotations of the inner ring 22 of the rolling bearing 21 according to the present embodiment are shown. Figure 17B and Figure 17C The figures show the movement trajectory of the center of the cage and the change in speed (translational speed) during 10 rotations of the inner ring of the comparative rolling bearing.

[0120] contrast Figure 16Band Figure 17B , compared with the rolling bearing 21 of this embodiment, the lines representing the moving trajectory of the retainer center of the comparative rolling bearing are very dense. Figure 16C and Figure 17C In the rolling bearing 21 of the present embodiment, the translational velocity of the retainer 25 gradually decreases and converges to zero over time after the start of operation. In contrast, in the comparative rolling bearing, the translational velocity of the retainer rapidly increases after a predetermined time has passed since the start of operation, and this increased velocity persists. Based on these analysis results, it is believed that the high-speed whirling phenomenon of the retainer 25 does not occur in the rolling bearing 21 of the present embodiment, while the high-speed whirling phenomenon of the retainer does occur in the comparative rolling bearing.

[0121] Therefore, setting the ratio (Ri / Re) of the maximum inscribed circle diameter (Ri) of the retainer movable region 30 to the minimum circumscribed circle diameter (Re) of the retainer movable region 30 to less than 0.990—that is, setting the shape of the retainer movable region 30 to a "skewed shape" that deviates from a true circle—is believed to effectively prevent the occurrence of high-speed whirling of the retainer 25. While the specific reasons why skewed shapes of the retainer movable region 30 are effective in preventing the occurrence of high-speed whirling are unclear, it is speculated that the skewed shape of the retainer movable region 30 deviates from the circular orbital direction of the frictional force generated during contact between the guiding surface (the inner circumferential surface 23a of the outer ring 23) and the guided surface (the outer circumferential surface 25b of the retainer 25), preventing the whirling motion of the retainer 25 from continuously accelerating. In other words, to generate high-speed whirling, the direction of the force acting on the retainer must rotate like the hands of a clock, constantly acting as circular acceleration. Skewed shapes of the retainer movable region are believed to hinder this effect.

[0122] To effectively prevent the occurrence of high-speed swirl of the retainer 25, as described above, the ratio Ri / Re of the maximum inscribed circle diameter Ri to the minimum circumscribed circle diameter Re of the retainer movable region 30 should be less than 0.990. However, if this ratio Ri / Re is too small, problems such as failure to ensure the required mechanical strength of the retainer 25 and disruption of the mass balance of the retainer 25 in the circumferential direction may arise, potentially adversely affecting the bearing performance of the rolling bearing 21. Therefore, the lower limit of the ratio Ri / Re is appropriately selected based on the required characteristics and dimensions.

[0123] Furthermore, the aforementioned technical means employed in the rolling bearing 21 of this embodiment do not intentionally increase the unbalance of the retainer, as is the case with the technical means proposed in Patent Document 1. Therefore, even when the present invention is applied to the rolling bearing 21, there is no concern about an increase in centrifugal force or shaft NRRO due to unbalance. Therefore, the present invention is widely applicable to raceway-guided rolling bearings.

[0124] In the embodiment described above, the straight portion 27 is provided at one location in the circumferential direction of the outer peripheral surface 25 b of the retainer 25 . However, the straight portion 27 may be provided at two or more locations in the circumferential direction. Figure 18A 、 18B 2 is a diagram illustrating a specific example of this, showing a retainer 25 having straight portions 27 provided at two locations on the outer peripheral surface 25b, opposite each other across the center Oc (retainer 25 having straight portions 27 evenly distributed at two locations on the outer peripheral surface 25b). Providing straight portions 27 in this manner prevents problems such as vibration caused by mass imbalance in retainer 25, thereby contributing to improved reliability of rolling bearing 21.

[0125] It should be noted that the straight portion 27, provided to achieve a ratio (Ri / Re) of the maximum inscribed circle diameter Ri of the retainer movable region 30 to the minimum circumscribed circle diameter Re of the retainer movable region 30 of less than 0.990, can also be provided on the inner circumferential surface 23a (the guiding surface) of the outer ring 23, which faces the outer ring 23 across the second radial gap δ2, instead of on the outer circumferential surface 25b (the guided surface) of the retainer 25. However, considering ease of machining, it is preferable to provide the straight portion 27 on the outer circumferential surface 25b of the retainer 25.

[0126] The rolling bearing 21 of the second embodiment of the invention described above is an outer ring guided type in which the inner circumferential surface 23a of the outer ring 23 serves as a guide surface for guiding the retainer 25. However, the present invention can also be applied to an inner ring guided type rolling bearing in which the outer circumferential surface 22a of the inner ring 22 serves as a guide surface and the inner circumferential surface 25a of the retainer 25 serves as a guided surface. Although illustration of the inner ring guided type rolling bearing is omitted, in this case, for example, Figure 19 As shown, by providing a straight portion 27 at a single circumferential location on the outer circumferential surface 22a of the inner ring 22, which serves as the guide surface, the ratio (Ri / Re) of the maximum inscribed circle diameter Ri of the movable retainer region 30 to the minimum circumscribed circle diameter Re of the movable retainer region 30 can be set to less than 0.990, achieving the same operational benefits as the aforementioned outer ring guide type rolling bearing 21. It should be noted that the straight portions 27 may be provided at two or more circumferential locations on the outer circumferential surface 22a of the inner ring 222. In this case, it is preferable to arrange the straight portions 27 at equal intervals along the circumference to prevent mass imbalance in the inner ring 22.

[0127] In an inner ring guided rolling bearing 21, the linear portion 27 can be provided on the inner circumferential surface 25a (guided surface) of the retainer 25, which faces the inner ring 22 across the first radial gap δ1, instead of on the outer circumferential surface 22a (guide surface) of the inner ring 22. However, considering ease of machining, it is preferable to provide the linear portion 27 on the outer circumferential surface 22a of the inner ring 22.

[0128] As mentioned above, the rolling bearing 21 according to the embodiment of the second invention has been described. However, the embodiment of the second invention is not limited thereto, and various modifications can be made without departing from the scope of the invention.

[0129] For example, rollers (cylindrical rollers, needle rollers, etc.) may be used in place of the balls 24 in the rolling elements of the rolling bearing 21. That is, the second invention is applicable not only to ball bearings but also to other well-known rolling bearings such as cylindrical roller bearings and needle roller bearings. Figure 13 In addition to the illustrated perfect circle in plan view, the shape may be an ellipse with a major axis arranged along the circumferential direction. In addition, the shape may be applied not only to single-row bearings but also to double-row bearings.

[0130] As described above, the first and second inventions of this application can effectively prevent the occurrence of high-speed whirling in the retainers 5 and 25 constituting the rolling bearings 1 and 21, and can therefore be particularly preferably applied to rolling bearings used in applications where high-speed whirling is likely to occur.

[0131] For example, rolling bearings (especially ball bearings) used to support the spindles of machine tools and reaction wheels of space equipment are subject to relatively large axial preloads during use. Specifically, the ratio of the radial load Fr to the axial load Fa (=Fr / Fa) during operation is often less than 3, and in such cases, high-speed gyration is particularly likely to occur. This is because the more constant the circumferential spacing of the rolling elements, the more likely high-speed gyration is to occur. Conversely, when the radial load acting on the ball bearing is significantly greater than the axial load (for example, when the aforementioned ratio Fr / Fa exceeds 3), each rolling element (ball) experiences a lead delay, and the spacing of the rolling elements becomes uneven, making it difficult to produce high-speed gyration. Therefore, the present invention can be particularly preferably applied to ball bearings used in applications such as spindles of machine tools and support bearings for reaction wheels of space equipment, where the following equation (1) holds true.

[0132] [Formula 1]

[0133]

[0134] Furthermore, when the theoretical rotational speed of the retainer is Nc (rpm), the pocket clearance is c (mm), the retainer mass is m (kg), and the average rolling element load within the bearing is Q (N), high-speed gyration is likely to occur when the following equation (2) holds true. Specifically, under operating conditions where the following equation (2) holds true, the centrifugal force of the retainer makes it difficult for the rolling elements to slide against the outer ring's raceway surface (outer raceway surface), and thus the spacing between the rolling elements is less likely to become uneven. Therefore, the first and second inventions of this application can be applied to rolling bearings operating under conditions where the following equation (2) holds true.

[0135] [Formula 2]

[0136]

[0137] It should be noted that the theoretical cage rotational speed Nc in the above-mentioned formula (2) can be calculated by the following formula (3) when the inner ring rotational speed is set to Ni (rpm), the outer ring rotational speed is set to Ne (rpm), the rolling element diameter is set to Dw (mm), the pitch circle diameter of the rolling element is set to dp (mm), and the contact angle of the rolling element with respect to the raceway surface is set to α (rad).

[0138] [Formula 3]

[0139]

[0140] As mentioned above, the rolling bearings 1 and 21 of the first and second inventions of the present application have been described. However, the first and second inventions are not limited to the above-described embodiments, and can be implemented in various other forms without departing from the gist of the invention.

[0141] Description of reference numerals:

[0142] 1.21 rolling bearings

[0143] 2.22 inner circle

[0144] 3.23 outer ring

[0145] 4. 24 balls (rolling elements)

[0146] 5.25 retainer

[0147] 6, 26 concave pockets

[0148] 6a, 26a concave pocket surface

[0149] 10, 30 retainer movable area

[0150] Re minimum circumscribed circle diameter

[0151] Ri is the maximum inscribed circle diameter.

Claims

1. A rolling bearing comprising: an inner ring and an outer ring which rotate relative to each other via a plurality of rolling elements; and an annular retainer having a plurality of pockets provided at intervals in the circumferential direction to accommodate the rolling elements, wherein: When the area enclosed by a line connecting the outer edges of the scatter plot is defined as the retainer movable area, the ratio Ri / Re of the maximum inscribed circle diameter Ri of the retainer movable area to the minimum circumscribed circle diameter Re of the retainer movable area is 0.900 or less. The scatter plot is obtained by plotting multiple times on two-dimensional coordinates positions where the retainer, in a neutral position, can exist without contact with the inner ring, outer ring, and rolling elements.

2. The rolling bearing according to claim 1, wherein: The plurality of pockets are constituted by large pockets or small pockets having different circumferential dimensions, whereby the ratio Ri / Re is set to 0.900 or less.

3. The rolling bearing according to claim 2, wherein: A plurality of large concave pockets are provided, and large concave pocket groups each including one or more large concave pockets are arranged at equal intervals in the circumferential direction.

4. The rolling bearing according to claim 2 or 3, wherein: The difference in circumferential dimension between the large concave pocket and the small concave pocket is set to be greater than 0.1 mm.

5. A rolling bearing comprising: an inner ring and an outer ring that rotate relative to each other via a plurality of rolling elements; and a retainer having a plurality of concave pockets spaced apart in the circumferential direction for accommodating the rolling elements, the retainer having an annular guided surface that is guided by an annular guide surface provided on the inner circumferential surface of the outer ring or the outer circumferential surface of the inner ring, wherein a radial gap formed between the guide surface and the guided surface is smaller than a radial gap formed between the inner surface of the concave pocket of the retainer and the rolling elements, characterized in that: When a region enclosed by a line connecting the outer edges of a scatter plot is defined as a movable retainer region, a ratio (Ri / Re) of a maximum inscribed circle diameter (Ri) of the movable retainer region to a minimum circumscribed circle diameter (Re) of the movable retainer region is less than 0.

990. The scatter plot is obtained by plotting multiple times on two-dimensional coordinates positions where the retainer, in a neutral position, can exist without contact with the inner ring, the outer ring, and the rolling elements.

6. The rolling bearing according to claim 5, wherein: The guiding surface is provided on the inner circumferential surface of the outer ring, and the guided surface is provided on the outer circumferential surface of the retainer. A straight portion parallel to an axis-parallel plane extending along the axis of the rolling bearing is provided on the guided surface, thereby making the ratio Ri / Re less than 0.

990.

7. The rolling bearing according to claim 5, wherein: The guiding surface is provided on the outer circumferential surface of the inner ring, and the guided surface is provided on the outer circumferential surface of the retainer. A straight portion parallel to an axis-parallel plane extending along the axis of the rolling bearing is provided on the guiding surface, thereby making the ratio Ri / Re less than 0.

990.

8. The rolling bearing according to claim 6 or 7, wherein: A plurality of the straight portions are provided at equal intervals in the circumferential direction.

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