Rolling bearings

Abstract

To provide a rolling bearing capable of preventing occurrence of a high-speed whirl phenomenon as much as possible at low cost.SOLUTION: In a rolling bearing 1 in which a retainer 5 has an annular guided surface Sb (outer peripheral surface 5b) guided by an annular guide surface Sa (inner peripheral surface 3a) provided on an outer ring 3, the following expression (1) is satisfied when a size of a radial gap Ga2 formed between the guide surface Sa and the guided surface Sb is δ, a size of a circumferential gap Gb formed between a rolling element 4 and a pocket 5 is ε, circularity of the guide surface Sa is R1, and circularity of the guided surface Sb is R2.SELECTED DRAWING: Figure 3

Description

[Technical Field] 【0001】 This invention relates to rolling bearings. [Background technology] 【0002】 Figure 6(a) shows a schematic cross-sectional view of a typical rolling bearing 100. The rolling bearing 100 shown in the figure comprises a pair of raceway rings (inner ring 101 and outer ring 102) that rotate relative to each other via a plurality of rolling elements 103 while being arranged radially opposite to each other, and an annular cage 104 that holds the plurality of rolling elements (e.g., balls) 103 at intervals in the circumferential direction. The cage 104 is incorporated between the outer circumferential surface 101a of the inner ring 101 and the inner circumferential surface 102a of the outer ring 102 in a manner that allows it to move in the radial and circumferential directions. In other words, the retainer 104 is incorporated between a pair of raceway rings such that, in the neutral position, it forms radial gaps 111 and 112 between the outer circumferential surface 101a of the inner ring 101 and the inner circumferential surface 102a of the outer ring 102, respectively, and a circumferential gap 113 between the retainer 104 and the rolling elements 103 housed and held in a rolling element housing (pocket 105) whose circumferential opening dimension Y is constant along the radial direction. 【0003】 Rolling bearings are broadly classified into "rolling element guided type" and "raceway ring guided type" according to the guide type of the cage 104. The "raceway ring guided type" is further classified into the "outer ring guided type" as exemplified in Figure 6(a) and the "inner ring guided type" as exemplified in Figure 6(b). In a broad sense, the "outer ring guided type" is a type in which the radial clearance 112 is smaller than the radial clearance 111, 112 formed between the cage 104, which is located in the neutral position, and the inner ring 101 and outer ring 102, respectively. In a broad sense, the "inner ring guided type" is a type in which the radial clearance 111 is smaller than the radial clearance 111 of the two radial clearances 111, 112. 【0004】 Incidentally, during the operation of the rolling bearings 100, 100' (when the inner ring 101 and outer ring 102 rotate relative to each other), the frictional force F generated when the cage 104 and the rolling elements 103 housed in its pockets 105 come into contact can cause the cage 104 to vibrate at an abnormal speed, sometimes called the "high-speed whirl phenomenon" (self-excited vibration that vibrates at several times or more the cage's rotation frequency). When the high-speed whirl phenomenon occurs, it can cause problems such as abnormal noise, vibration, increased torque, torque fluctuations, and heat generation, and in some cases, it can even cause fatal problems such as cage fracture. 【0005】 Therefore, as described in Patent Document 1 below, for example, a predetermined amount of unbalance is intentionally applied to the retainer to make it eccentric (a state in which a part of the retainer is constantly in contact with the raceway), thereby enabling it to rotate in this state, and thereby preventing the occurrence of high-speed whirl phenomena and the resulting malfunctions such as abnormal noise and vibration as much as possible. 【0006】 The reason why the technical means described in Patent Document 1 can prevent the occurrence of the high-speed whirl phenomenon as much as possible will be briefly explained below. For example, in the outer ring guide type rolling bearing 100 illustrated in Figure 6(a), suppose the cage 104 is eccentric to the 12 o'clock (0 o'clock) direction with respect to the bearing center O, as shown in the figure. In this case, when the rolling elements 103 (in the illustrated example, the rolling elements 103 located at the 3 o'clock and 9 o'clock positions out of a total of four rolling elements 103) that rotate in the opposite direction (counterclockwise) to the inner ring 101, which is affected by the rotational force of the inner ring 101 which rotates clockwise, come into contact with the inner surface of the pocket 105, a frictional force F is generated between these rolling elements 103 and the cage 104, directed to the right in the plane of the paper. On the other hand, when the eccentric cage 104 in the above configuration comes into contact with the outer ring 102, a frictional force F' is generated between the outer ring 102 and the cage 104, with the direction of force opposite to the frictional force F generated between the rolling elements 103 and the cage 104. 【0007】 As mentioned above, the high-speed whirl phenomenon is caused by the frictional force F generated between the rolling element 103 and the cage 104. Therefore, if a frictional force F' is generated between the raceway ring (outer ring 102 or inner ring 101) and the cage 104 during the operation of the rolling bearing, the frictional force F generated between the rolling element 103 and the cage 104 will be reduced (canceled), and as a result, it will be possible to prevent the occurrence of the high-speed whirl phenomenon as much as possible. [Prior art documents] [Patent Documents] 【0008】 [Patent Document 1] Japanese Patent Publication No. 2011-196513 [Overview of the project] [Problems that the invention aims to solve] 【0009】 However, the above-described technical means in Patent Document 1 has the problem of high processing and manufacturing costs because, in order to suppress wear at the contact area between the raceway and the retainer, it is necessary to perform finishing processes such as precision polishing on the two opposing surfaces of the raceway and the retainer that come into contact with each other, and to finish these two surfaces with extremely high precision. 【0010】 In view of these circumstances, the present invention aims to realize a rolling bearing at low cost that can prevent as much as possible the occurrence of high-speed whirl phenomena and the resulting malfunctions such as abnormal noise and vibration. [Means for solving the problem] 【0011】 The present invention, devised to achieve the above objective, is a rolling bearing comprising a pair of raceway rings that rotate relative to each other via a plurality of rolling elements while being arranged radially opposite to each other, and a cage having a plurality of pockets that individually house the rolling elements, spaced apart in the circumferential direction, wherein the cage has an annular guided surface that is guided by an annular guide surface provided on the raceway ring, and is characterized in that when the size of the radial clearance formed between the guide surface and the guided surface is δ, the size of the circumferential clearance formed between the rolling element and the pocket is ε, the roundness of the guide surface is R1, and the roundness of the guided surface is R2, the present invention satisfies the following equation (1). Furthermore, the "radial clearance" mentioned above is strictly speaking the average value of the radial clearance at each phase within a single bearing, while the "circumferential clearance" is the value obtained by subtracting the "diameter of the rolling element" from the "circumferential opening dimension of the pocket." Also, "roundness" refers to the roundness specified in JIS B 0621. 【0012】 【number】 【0013】 First, if the cage moves radially in the phase where the relationship δ / 2 + (R1 + R2) / 2 > ε / 2 in equation (1) above holds, the position (movement) of the cage in the radial direction is limited by the contact between the cage and the rolling elements (rolling elements housed in pockets) in the circumferential direction before the cage contacts the raceway rings. Also, if the cage moves radially in the phase where the relationship ε / 2 > δ / 2 - (R1 + R2) / 2 in equation (1) holds, the position (movement) of the cage in the radial direction is limited by the contact between the cage and the raceway rings before the cage contacts the rolling elements. 【0014】 In short, in the rolling bearing according to the present invention, when the pair of raceway rings rotate relative to each other and the cage moves radially, the movable range is restricted by the rolling elements and the raceway rings (guide surfaces), so the cage can contact both the rolling elements and the raceway rings (guide surfaces). And as described above, among the frictional forces generated at the contact portions between the cage and the rolling elements and between the cage and the raceway rings, the directions of the forces are opposite to each other. Therefore, the frictional force generated at the contact portion between the cage and the rolling elements, which is the cause of the high-speed whirl phenomenon, is reduced by the frictional force generated at the contact portion between the cage and the raceway rings. Thereby, the occurrence of the high-speed whirl phenomenon can be prevented as much as possible. 【0015】 Due to the structure of the present invention, the guided surface of the cage does not always contact the guide surface of the raceway ring, and the contact frequency between the guide surface and the guided surface can be suppressed. Therefore, even if the guide surface of the raceway ring (and the guided surface of the cage) is not finished to an extremely high-precision surface with additional finishing such as precision polishing, wear of the guide surface and the guided surface can be suppressed. Therefore, it is sufficient not to perform the finishing process on the guide surface (and the guided surface), and an increase in manufacturing cost can be prevented. 【0016】 As described above, in the rolling bearing according to the present invention, it is not necessary to perform a finishing process for precisely finishing the guide surface of the raceway ring. Therefore, the guide surface can be a surface (unfinished surface without finishing) having an arithmetic mean roughness Ra of 0.1 μm or more (specified in JIS B 0601-2001). 【0017】 When the cage is an injection-molded resin product, the roundness (value of R2) of the guided surface is likely to be larger than when the cage is a machined metal product or a press-formed metal product. Therefore, the above formula (1) is likely to hold. Therefore, the present invention can be suitably adopted for a rolling bearing using a cage made of an injection-molded resin product. 【0018】 When a radial clearance is formed between the cage pocket and the rolling element, this radial clearance is made larger than the radial clearance formed between the guide surface and the guided surface. In short, the rolling bearing according to the present invention is fundamentally a so-called raceway-guided type. 【0019】 In the above configuration, the guide surface may be the inner circumferential surface of the outer ring of the pair of raceway rings, which is located radially outward of the cage, or the outer circumferential surface of the inner ring of the pair of raceway rings, which is located radially inward of the cage. In other words, the present invention can be applied to both outer ring guided rolling bearings and inner ring guided rolling bearings. [Effects of the Invention] 【0020】 Based on the above, the present invention makes it possible to realize a rolling bearing at low cost that can prevent the occurrence of high-speed whirl phenomena and the resulting malfunctions such as abnormal noise and vibration as much as possible. [Brief explanation of the drawing] 【0021】 [Figure 1] (a) is a partial front view of a rolling bearing according to the first embodiment of the present invention, and (b) is a cross-sectional view taken along the line AA in (a). [Figure 2] This is a schematic cross-sectional view illustrating the characteristic configuration of a rolling bearing according to the first embodiment of the present invention. [Figure 3] Figure 1-2 is a diagram illustrating the characteristic configuration of the rolling bearing. [Figure 4] This is a schematic cross-sectional view illustrating the characteristic configuration of a rolling bearing according to a second embodiment of the present invention. [Figure 5] This diagram illustrates the characteristic configuration of the rolling bearing shown in Figure 4. [Figure 6] (a) is a schematic cross-sectional view of a typical outer ring guide type rolling bearing, and (b) is a schematic cross-sectional view of a typical inner ring guide type rolling bearing. [Modes for carrying out the invention] 【0022】 Embodiments of the present invention will be described below with reference to the drawings. The terms "axial direction," "radial direction," and "circumferential direction" used below to indicate directionality refer to the direction parallel to the axis O of the rolling bearing 1 shown in Figure 1(a), the radial direction of the circle centered on the axis O, and the circumferential direction of the circle centered on the axis O, respectively. 【0023】 Figure 1(a) is a partial front view of a rolling bearing 1 according to the first embodiment of the present invention, Figure 1(b) is a cross-sectional view taken along the line AA in Figure 1(a), and Figure 2 is a schematic cross-sectional view of the rolling bearing 1 in a simplified form to explain the characteristic configuration of the rolling bearing 1. Accordingly, in Figure 2, the number of balls 4, which will be described later, has been reduced. This rolling bearing 1 is a so-called angular contact ball bearing, comprising a pair of raceway rings (inner ring 2 and outer ring 3) made of a highly rigid metal material such as bearing steel (high-carbon chromium bearing steel), a plurality of rolling elements (here, balls 4) interposed between the inner ring 2 and the outer ring 3 so as to be able to roll, and an annular cage 5 that holds the plurality of balls 4, wherein the balls 4 contact the arc-shaped inner raceway surface 2b formed on the outer circumferential surface 2a of the inner ring 2 and the arc-shaped outer raceway surface 3b formed on the inner circumferential surface 3a of the outer ring 3 with a contact angle α. 【0024】 The cage 5 has a plurality of pockets 6 spaced apart in the circumferential direction, and each pocket 6 houses one ball 4. As shown in Figure 2, each pocket 6 is formed such that the circumferential opening dimension X is constant along the radial direction. Figure 1(a) illustrates a rolling bearing 1 in which the cage 5, having a total of 18 pockets 6 spaced at 20° intervals, is a component. 【0025】 The retainer 5 uses a resin retainer made from an injection-molded resin material. However, in addition to the resin retainer, the retainer 5 can also be a so-called machined retainer obtained by machining a metal material into a predetermined shape, or a pressed retainer obtained by joining a pair of retainer materials that have been press-formed (punched) into a predetermined annular shape. 【0026】 The cage 5 is incorporated between the inner ring 2 and the outer ring 3 such that, in an unloaded state where gravity, rotational force, etc., does not act on the rolling bearing 1, it forms a radial clearance between itself and the inner ring 2 and the outer ring 3, and a circumferential clearance between itself and the balls 4 housed in the pockets 6. That is, when the cage 5 is in the neutral position, a first radial clearance Ga1 is formed between the outer circumferential surface 2a of the inner ring 2 and the inner circumferential surface 5a of the cage 5, a second radial clearance Ga2 is formed between the inner circumferential surface 3a of the outer ring 3 and the outer circumferential surface 5b of the cage 5, and a circumferential clearance Gb is formed between the balls 4 and the inner surface (pocket surface) 6a of the pockets 6 of the cage 5 that house them. As a result, the rolling bearing 1 can operate smoothly. 【0027】 In the rolling bearing 1 of this embodiment, the second radial clearance Ga2 is smaller than the first radial clearance Ga1, and therefore the radial range of motion of the cage 5 is limited by the inner circumferential surface 3a of the outer ring 3. For this reason, the rolling bearing 1 of this embodiment is an outer ring guided angular contact ball bearing in which the guide surface (Sa) and guided surface (Sb) as referred to in the present invention are the inner circumferential surface 3a of the outer ring 3 and the outer circumferential surface 5b of the cage 5, respectively. 【0028】 Figure 3 shows a schematic diagram illustrating the characteristic configuration of the rolling bearing 1 of this embodiment, i.e., an outer ring guide type angular contact ball bearing, having the above configuration. As shown in the figure, in this rolling bearing 1, the size of the second radial clearance Ga2 (= the difference in diameter between the two opposing surfaces that form the clearance) is not constant in the circumferential direction, but gradually changes along the circumferential direction. Here, the radial clearance Ga2 is shown such that the maximum clearance portion 7, where the size of the radial clearance Ga2 is largest, is located on a straight line passing through 3 o'clock and 9 o'clock, and the minimum clearance portion 8, where the size of the radial clearance Ga2 is smallest, is located on a straight line passing through 12 o'clock and 6 o'clock. 【0029】 Note that Figure 3 exaggerates the contour shapes of the inner circumferential surface 3a (guide surface Sa) of the outer ring 3 and the outer circumferential surface 5b (guided surface Sb) of the retainer 5, as well as the dimensional difference between the maximum clearance 7 and the minimum clearance 8, for the sake of easier understanding. In reality, the dimensional difference between the maximum clearance 7 and the minimum clearance 8 is at most only a few hundred micrometers. 【0030】 The size (diameter value) of the radial gap Ga2 at the widest part of the gap 7 is δ MAX Assuming that the average value of the radial clearance Ga2 is δ, the roundness of the inner circumferential surface 3a of the outer ring 3 as the guide surface Sa is R1, and the roundness of the outer circumferential surface 5b of the retainer 5 as the guided surface Sb is R2, then as shown in Figure 3 δ MAX / 2 = δ / 2 + (R1 + R2) / 2 That is the case. Furthermore, the size (diameter value) of the radial gap Ga2 at the smallest gap 8 is δ MIN Therefore, as shown in Figure 3, δ MIN / 2 = δ / 2 - (R1 + R2) / 2 That is the case. Then, if we let ε be the size of the circumferential gap Gb formed between the ball 4 and the inner surface 6a of the pocket 6 of the retainer 5 (here, "opening dimension X of pocket 6" - "diameter dimension of ball 4"), then the size of ε is the same as δ above. MAX and δ MIN It is set between these two points. δ MAX >ε>δ MIN Therefore, when this is converted, the above equation (1) relating to the rolling bearing according to the present invention is obtained. 【0031】 In the rolling bearing 1 of this embodiment having the above configuration, as the inner ring 2 and the outer ring 3 rotate relative to each other, when the cage 5 moves radially at a phase (3 o'clock and 9 o'clock in Figure 3) where the relationship δ / 2 + (R1 + R2) / 2 > ε / 2 in equation (1) above holds true, the position (movement) of the cage 5 in the radial direction is restricted because the balls 4 and the pocket surface 6a of the cage 5 housing the balls 4 come into contact in the circumferential direction before the outer circumferential surface 5a (guided surface Sb) of the cage 5 comes into contact with the inner circumferential surface 3a (guiding surface Sa) of the outer ring 3. Furthermore, as the inner ring 2 and outer ring 3 rotate relative to each other, when the cage 5 moves radially at a phase (12 o'clock and 6 o'clock positions in Figure 3) where the relationship ε / 2 > δ / 2 - (R1 + R2) / 2 in equation (1) above holds, the position (movement) of the cage 5 is restricted in the radial direction because the guided surface Sb of the cage 5 and the guide surface Sa of the outer ring 3 come into contact before the ball 4 contacts the pocket surface 6a of the cage 5. 【0032】 In short, the rolling bearing 1 (outer ring guided ball bearing) of this embodiment has a range of motion in which the cage 5 moves radially as the inner ring 2 and outer ring 3 rotate relative to each other. This range of motion is limited by both the balls 4 housed in the pockets 6 and the outer ring 3 (guide surface Sa), which is the guide ring. Therefore, the cage 5 can contact both the balls 4 and the outer ring 3. As explained with reference to Figure 6(a), the frictional force F generated at the contact point with the balls 4 (pocket surface 6a) and the frictional force F' generated at the contact point with the outer ring 3 (guided surface Sb) are in opposite directions. Thus, the frictional force F generated at the pocket surface 6a, which is the cause of the high-speed whirl phenomenon, can be reduced by the frictional force F' generated at the guided surface Sb. This makes it possible to prevent the occurrence of the high-speed whirl phenomenon as much as possible. 【0033】 However, due to the configuration of the present invention, the guided surface Sb of the cage 5 does not always contact the guiding surface Sa of the outer ring 3, and the contact frequency with the guiding surface Sa can be suppressed. Therefore, the guiding surface Sa of the outer ring 3 made of steel material is not an extremely high-precision (smooth) surface with additional finishing such as precision polishing, but for example, a surface roughness (arithmetic mean roughness) Ra is 0.1 μm or more and no finishing is performed (non-finished surface). Even in this case, wear of the guiding surface Sa and the guided surface Sb can be suppressed. Also, even when using a metal cage 5, it is not necessary to finish the guided surface Sb of the cage 5 with particularly high precision. Therefore, it is sufficient not to perform finishing on the guiding surface Sa (and the guided surface Sb), and an increase in manufacturing cost can be prevented. 【0034】 From the above, according to the present invention, it is possible to realize a quiet and reliable rolling bearing 1 at low cost that can prevent, as much as possible, the occurrence of the high-speed whirl phenomenon in which the cage 5 swings at high speed during the relative rotation of the inner ring 2 and the outer ring 3, and further prevent the occurrence of problems such as abnormal noise and vibration caused by this high-speed whirl phenomenon. 【0035】 In addition, in this embodiment, since a resin cage is used for the cage 5, the roundness (value of R2) of the guided surface Rb is likely to be larger than when using a metal punching cage or a press cage for the cage 5. When the value of R2 becomes larger, the size of the radial clearance Ga2 at the maximum clearance portion 7 (= δ MAX ) becomes larger, and the size of the radial clearance Ga2 at the minimum clearance portion 8 (= δ MIN ) becomes smaller, so the above formula (1) is likely to hold. Therefore, the rolling bearing 1 of this embodiment using a resin cage for the cage 5 has the advantage that the present invention can be easily applied. 【0036】 The rolling bearing 1 according to the first embodiment of the present invention has been described above. However, the present invention can be applied not only to the outer ring guided type described above, but also to the inner ring guided type rolling bearing. Hereinafter, the inner ring guided type rolling bearing according to the second embodiment of the present invention will be described based on Figures 4 and 5. In this description, members and parts that have substantially the same roles and functions as those of the rolling bearing 1 of the first embodiment will be given common reference numbers, and redundant explanations will be omitted or the explanations will be simplified. 【0037】 Figure 4 shows a schematic cross-sectional view illustrating the characteristic configuration of a rolling bearing 1' according to a second embodiment of the present invention. The rolling bearing 1' shown in the figure is a ball bearing (angular contact ball bearing) that, like the rolling bearing 1 shown in Figures 1 and 2, comprises a pair of raceway rings (inner ring 2 and outer ring 3), a plurality of rolling elements (balls 4), and a cage 5. The cage 5 is incorporated between the inner ring 2 and the outer ring 3 such that, when in the neutral position, it forms radial clearances Ga1 and Ga2 between itself and the inner ring 2 and the outer ring 3, and a circumferential clearance Gb between itself and the balls 4 housed in the pockets 6. However, the size of the first radial clearance Ga1 formed between the outer circumferential surface 2a of the inner ring 2 and the inner circumferential surface 5a of the cage 5 is set to be smaller than the size of the second radial clearance Ga2 formed between the inner circumferential surface 3a of the outer ring 3 and the outer circumferential surface 5b of the cage 5, and the radial range of motion of the cage 5 is limited by the outer circumferential surface 2a of the inner ring 2. Therefore, the rolling bearing 1' of this embodiment is an inner ring guide type rolling bearing (angular contact ball bearing) in which the guide surface Sa and the guided surface Sb are composed of the outer circumferential surface 2a of the inner ring 2 and the inner circumferential surface 5a of the cage 5, respectively. 【0038】 Figure 5 shows a schematic diagram illustrating the characteristic configuration of the rolling bearing 1' of the second embodiment having the above configuration. As shown in the figure, in this rolling bearing 1', the size of the first radial clearance Ga1 is not constant, but gradually changes along the circumferential direction. Here, the maximum clearance portion 7, where the size of the radial clearance Ga1 is maximum, is located on a straight line passing through the 3 o'clock and 9 o'clock positions of a clock, while the minimum clearance portion 8, where the size of the radial clearance Ga1 is minimum, is located on a straight line passing through the 12 o'clock (12 o'clock) and 6 o'clock positions of a clock. 【0039】 In Figure 5, for the sake of ease of understanding, the contour shapes of the outer circumferential surface 2a (guide surface Sa) of the inner ring 2 and the inner circumferential surface 5b (guided surface Sb) of the retainer 5, as well as the dimensional difference between the maximum clearance 7 and the minimum clearance 8, are exaggerated. However, in reality, the dimensional difference between the maximum clearance 7 and the minimum clearance 8 is at most only a few hundred micrometers. 【0040】 The size (diameter value) of the radial gap Ga1 at the widest part of the gap 7 is δ MAX Assuming that the average value of the radial clearance Ga1 is δ, the roundness of the outer circumferential surface 2a of the inner ring 2 as the guide surface Sa is R1, and the roundness of the inner circumferential surface 5a of the retainer 5 as the guided surface Sb is R2, then as shown in Figure 5, δ MAX / 2 = δ / 2 + (R1 + R2) / 2 That is the case. Furthermore, the size (diameter value) of the radial gap Ga2 at the smallest gap 8 is δ MIN Therefore, as shown in Figure 5, δ MIN / 2 = δ / 2 - (R1 + R2) / 2 That is the case. Then, if we let ε be the size of the circumferential gap Gb formed between the ball 4 and the inner surface 6a of the pocket 6 of the retainer 5 (here, "opening dimension X of pocket 6" - "diameter dimension of ball 4"), then the size of ε is the same as δ above. MAX and δ MIN It is set between these two points. δ MAX >ε>δ MIN Therefore, when this is converted, equation (1) of the rolling bearing according to the present invention is obtained. 【0041】 With this configuration, the rolling bearing 1' according to the second embodiment can achieve the same effects and advantages as the rolling bearing 1 according to the first embodiment, which was described with reference to Figures 1 to 3. 【0042】 Although the rolling bearings 1 and 1' according to the first and second embodiments of the present invention have been described above, the embodiments of the present invention are not limited thereto, and various modifications can be made without departing from the spirit of the present invention. 【0043】 For example, the rolling elements 4 that make up the rolling bearings 1,1' can use rollers (cylindrical rollers, needle rollers, etc.) instead of balls. In other words, the present invention is applicable not only to ball bearings but also to roller bearings such as cylindrical roller bearings and needle roller bearings. Furthermore, the cage 5 that makes up the rolling bearings 1,1' can use a double-row cage with two rows of pockets 6 (groups of pockets) instead of a single-row cage with a single row of pockets 6 (groups of pockets) arranged in one row. In other words, the present invention is applicable not only to single-row rolling bearings but also to double-row rolling bearings. 【0044】 Furthermore, although not shown in the illustration, a cage 5 having a pocket 6 that forms a radial clearance between it and the rolling element 4 may be used. In this case, this radial clearance is made larger than the radial clearance (guide clearance) formed between the guide surface Sa and the guided surface Sb. In this way, the present invention can be applied even to rolling bearings that employ the cage 5 described above. 【0045】 As described above, the present invention can effectively prevent the occurrence of high-speed whirring in the cage 5 that constitutes the rolling bearing 1, and is therefore particularly suitable for use in rolling bearings used in applications where high-speed whirring is likely to occur. 【0046】 For example, when ball bearings are used as rolling bearings to support the spindles of machine tools or the reaction wheels of aerospace equipment, these ball bearings are subjected to a relatively large axial preload during use. Specifically, the ratio of the radial load Fr to the axial load Fa (=Fr / Fa) received during operation is often 3 or less, and in such cases, the high-speed whirl phenomenon is particularly likely to occur. This is because the higher the spacing between the rolling elements (balls), the more likely the high-speed whirl phenomenon is to occur. Conversely, when the radial load acting on the ball bearing is significantly larger than the axial load (for example, when the above ratio Fr / Fa exceeds 3), a delay occurs in the advance of each ball, resulting in uneven spacing between the balls, making the high-speed whirl phenomenon less likely to occur. Therefore, the present invention can be particularly suitably applied to ball bearings used in applications where the following equation (2) holds true, such as the spindles of machine tools and the support bearings for the reaction wheels of aerospace equipment. 【0047】 【number】 【0048】 Furthermore, when the theoretical rotational speed of the cage is Nc (rpm), the pocket clearance is c (mm), the cage mass is m (kg), and the average rolling element load in the bearing is Q (N), the high-speed whirl phenomenon is likely to occur when the following equation (3) holds. That is, in operating conditions where the following equation (3) holds, the rolling elements are less likely to slip against the raceway surface of the outer ring (outer raceway surface) due to the centrifugal force of the cage, so the spacing between the rolling elements is less likely to become uneven. Therefore, the present invention can be suitably applied to rolling bearings operated under conditions where the following equation (3) holds. 【0049】 【number】 【0050】 In equation (3) above, the theoretical rotational speed Nc of the cage is equal to the rotational speed of the inner ring n. i (rpm), the rotational speed of the outer wheel is n e (rpm), rolling element diameter D w(mm), the pitch circle diameter of the rolling element is d p When the contact angle of the rolling element with respect to the raceway surface is α (rad), it can be calculated using the following equation (4). 【0051】 【number】 【0052】 Although the rolling bearing 1 according to the present invention has been described above, the present invention is not limited in any way to the embodiments described above, and it goes without saying that it can be implemented in various other forms without departing from the spirit of the invention. The scope of the present invention is indicated by the claims, and further includes all modifications within the meaning and scope of equivalents set forth in the claims. [Explanation of Symbols] 【0053】 1 Rolling bearing 1' Rolling bearing 2 Inner ring 2a Outer surface 3 Outer ring 3a Inner surface 4 Rolling elements 5 Cage 6 pockets 6a Pocket side 7. Widest gap 8. Smallest gap F,F' Frictional force Ga1 First radial clearance Ga2 Second radial clearance Gb circumferential clearance δ Radial clearance size ε is the size of the circumferential clearance. R1 Roundness of the guide surface R2 Roundness of the guided surface Sa Guide Sb guided surface

Claims

[Claim 1] A rolling bearing comprising a pair of raceway rings that rotate relative to each other via a plurality of rolling elements, and an annular cage having a plurality of pockets that individually house the rolling elements, spaced apart in the circumferential direction, wherein the cage has an annular guided surface that is guided by an annular guide surface provided on the raceway ring, A rolling bearing characterized in that, when the size of the radial clearance formed between the guide surface and the guided surface is δ, the size of the circumferential clearance formed between the rolling element and the pocket is ε, the roundness of the guide surface is R1, and the roundness of the guided surface is R2, it satisfies the following formula (1). [Math 1] [Claim 2] The rolling bearing according to claim 1, wherein the surface roughness Ra of the guide surface is 0.1 μm or more. [Claim 3] The rolling bearing according to claim 1, wherein the retainer is an injection-molded resin product. [Claim 4] The rolling bearing according to claim 1, wherein the guide surface is the inner circumferential surface of the outer ring of the pair of raceway rings, which is located radially outward of the retainer. [Claim 5] The rolling bearing according to claim 1, wherein the guide surface is the outer circumferential surface of the inner ring of the pair of raceway rings, which is positioned radially inward of the retainer.