Ball bearing

Abstract

To provide a conical roller bearing in which even when being used under revolving environment, the inclination of an auto-rotation axis of a holder is suppressed to prevent abrasion of the holder.SOLUTION: A dimensionless number X determined by the following equation (1) is defined by a small diameter side clearance S1 that is a gap between a small diameter side annular part 6 of a holder 5 and a small flange part 2b of an inner ring 2, a large diameter side clearance S2 that is a gap between a large diameter side annular part 7 and a large flange part 2c of the inner ring 2, an average roller diameter d, a roller length l, and an outer member angle α. The dimensionless number X is within a range of 0.69<X<1.12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tapered roller bearing that can be used in a portion where centrifugal force acts, such as a planetary reduction gear unit of a construction machine or the like, particularly in the first-stage planetary portion where the centrifugal force is large.

Background Art

[0002] A general tapered roller bearing has a roller guiding type in which a cage 5 is guided by tapered rollers 4, as shown in FIG. 12, for example. However, a tapered roller bearing used in a revolving environment such as the planetary portion of a planetary reduction gear has low stability in the behavior of the cage due to the centrifugal force generated by revolution, and large wear of the column portion. Therefore, it is preferable that the bearing is of an inner ring guiding type.

[0003] To explain this, the upper part (Aa) to (Ad) of FIG. 14 shows the operation of a tapered roller bearing using a standard cage of the roller guiding type, and the lower part (Ba) to (Bd) shows a tapered roller bearing using a cage corresponding to high centrifugal force with inner ring guiding. As shown in FIGS. (Ab) and (Bb) of the same figure, when a tapered roller bearing is used for the planetary rotating body 105 of a planetary reduction gear, the centrifugal force G acts on the entire tapered roller bearing as the bearing revolves as indicated by the arrow c. The same applies to a tapered roller bearing using a cage corresponding to high centrifugal force with outer ring guiding. When the centrifugal force G due to revolution acts on the entire tapered roller bearing in this way, considering the action between the bearing component parts assuming that the inner ring 2, which is the fixed-side raceway ring of the tapered roller bearing, is in a stationary state, the centrifugal force G causes an action of pulling the cage 5 toward the inner diameter side, as shown in FIGS. (Ac) and (Bc) of the same figure, which show the bearing cross section. In this case, in the roller guiding type shown in the upper part, the gap d between the inner ring flange portion, particularly the small flange portion 2b and the cage 5 is large. When the cage 5 is pulled toward the inner diameter side by the centrifugal force G, the cage 5 moves greatly in the radial direction, and as shown in FIG. (Ad) of the same figure, the gap δ between the inner surface of the pocket of the cage 5 and the tapered roller 4 disappears, increasing the wear of the column portion 8. However, in the inner ring guiding types (Ba) to (Bd) in the lower row, the gaps d1 and d2 between the inner ring flange portions (the small flange portion 2b and the large flange portion 2c) and the cage 5 are small. Even if the cage 5 is pulled toward the inner diameter side by centrifugal force, the amount of radial movement of the cage 5 is small, and a state where there is a gap δ between the inner surface of the pocket and the tapered roller 4 is maintained, reducing the wear of the inner surface of the pocket of the column portion 8.

[0004] As a document of a tapered roller bearing with an inner ring guiding type, there is one in which flange portions are provided on both the small diameter side and the large diameter side of the cage, and the inner ring is used for guiding with these as sliding surfaces (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] A tapered roller bearing with a cage made of a metal plate such as an iron plate has the following problems. · When tightening the small diameter side of the cage column portion during assembly, the inner diameter dimension is likely to vary, and it may become single-flange guiding (hereinafter referred to as single-flange guiding). · When used in an environment where a high centrifugal force acts on the planetary part or the like, due to the wobbling and deformation of the cage, in design, the non-guiding side also rotates in a state where the outer diameter of the flange portion and the inner diameter of the cage are temporarily in contact, and the cage is operated with the rotation axis inclined. · When operated with the rotation axis inclined, a gyro moment is generated, and an axial force acts on the cage. Due to this axial force, the cage moves axially, and the roller end face and the axially facing surface portion of the inner surface of the pocket of the cage come into strong contact, resulting in wear and poor durability.

[0007] An object of the present invention is to provide a tapered roller bearing of an inner ring guiding type using a cage made of a metal plate such as an iron plate, in which the inclination of the rotation axis of the cage is suppressed and wear of the cage is unlikely to occur even when used in an environment where the bearing revolves.

Means for Solving the Problems

[0008] The tapered roller bearing of the present invention includes an inner ring with flanges, an outer member having an annular rolling surface facing the rolling surface of the inner ring, a plurality of tapered rollers interposed between the inner ring and the outer member, and a cage for holding the plurality of tapered rollers. The cage has a small-diameter side annular portion, a large-diameter side annular portion, and a plurality of column portions in the circumferential direction connecting the small-diameter side annular portion and the large-diameter side annular portion, and is a tapered roller bearing of an inner ring guiding type, a small-diameter side clearance S1 between the small-diameter side annular portion of the cage and the small flange portion of the inner ring, a large-diameter side clearance S2 between the large-diameter side annular portion of the cage and the large flange portion of the inner ring, an average roller diameter d, a roller length l, and a dimensionless number X determined by the following formula with the tapered opening angle α (where α is 20° to 40°) of the rolling surface of the outer member

[0009]

Equation

[0010] ​To appropriately maintain the inclination of the cage during operation, it is insufficient to simply adopt an inner ring guiding type for the cage. In addition to the clearances (the small-diameter side clearance S1 and the large-diameter side clearance S2) between the outer diameters of the respective flange portions of the inner ring at rest and the cage, it is necessary to appropriately manage the clearances (radial clearances and axial clearances) between the rollers and the cage during operation. The clearances between the rollers and the cage during operation are defined by the average roller diameter d and the roller length l. Considering this, the non-dimensional X determined by the average roller diameter d and the roller length l is considered for the small-diameter side clearance S1 and the large-diameter side clearance S2, and by managing the ratio of the small-diameter side clearance S1 and the large-diameter side clearance S2 so that this non-dimensional X falls within an appropriate range (the range of 0.69 < X < 1.12), it has been found that the inclination of the rotation axis of the cage can be suppressed. In this way, by reducing the difference between the clearances on the small-diameter side and the large-diameter side in the clearance between the outer diameter of the inner ring flange and the inner diameter of the cage, the bearing can be rotated in a state where the deviation between the rotation axis of the cage and the axis of the inner ring is small when a centrifugal force acts. Thereby, the wobbling of the cage can be reduced and the wear of the cage can be suppressed. By reducing the wobbling of the cage, the axial movement of the cage due to the gyro moment can be reduced, and the bearing can be operated in a stable state.

[0011] The reason for setting the outer member angle α to 20° to 40° is as follows. When the outer member angle α is 20° or less, the ability to bear an axial load is small. When the outer member angle α is 40° or more, the ability to bear an axial load is large, but the ability to bear a radial load becomes small. In a tapered roller bearing used in an environment where a centrifugal force acts, such as in a planetary reduction gear unit, since it mainly bears a radial load, there are few cases where a bearing product with a large outer member angle α is applied. Also, since the generation of an axial load may be considered due to the meshing of the gears of the planetary reducer, etc., when the outer ring member angle is 20° or less, there is a possibility that the ability to bear an axial load is insufficient.

[0012] In the present invention, the large-diameter side annular portion of the cage may have a flange-shaped portion that bends and extends inward in diameter with respect to the column portion, and the bending angle formed by this flange-shaped portion with respect to the column portion may be in the range of 90° ± 10° based on the cage angle, which is the angle at which the column portion inclines with respect to the bearing axis. When the bending angle of the flange-shaped portion is in the range of 90° ± 10°, it has an appropriate shape for making the cage an inner ring guiding type.

[0013] In the tapered roller bearing of the present invention, the large-diameter side annular portion of the cage has a flange-shaped portion that bends and extends inward in diameter with respect to the column portion via an arcuate bent portion, and the bending portion R dimension, which is the radius of curvature of the inner diameter side surface of the bent portion, may be in the range of 20 to 90% with respect to the axial length, which is the length in the direction in which the column portion of the large-diameter side annular portion extends. When the bending portion R dimension is 20 with respect to the axial length of the large-diameter side annular portion less than there is a concern that the stress concentration during bending increases and the cage may be damaged. Also, when it is 90% exceeding there is a concern that the arc shape of the inner diameter side surface of the bent portion becomes too gentle and the end face of the roller may hit the edge with respect to the opening edge of the pocket.

[0014] In the tapered roller bearing of the present invention, the small-diameter side annular portion and the large-diameter side annular portion of the cage may have a flange-shaped portion that bends and extends inward in diameter with respect to the column portion, and at a plurality of circumferential locations of this flange-shaped portion, there may be notch-shaped or window-shaped oil passageways that allow the passage of lubricating oil with respect to the inside and outside in the bearing axis direction of this flange-shaped portion. By forming the oil passageways as described above, it is easy for the lubricating oil to pass through the inside and outside of the flange-shaped portion of the cage, and good lubrication can be obtained between the rolling surfaces of the tapered rollers and the inner surface of the cage pocket.

[0015] In the tapered roller bearing of the present invention, the cross-sectional area ratio of the large-diameter side annular portion of the cage to the small-diameter side annular portion may be 1.0 to 1.2. When the cross-sectional area ratio of the large-diameter side annular portion to the small-diameter side annular portion is in the range of 1.0 to 1.2, the weight balance between the large-diameter side and the small-diameter side becomes appropriate, the rotation of the cage is suppressed, and good inner ring guidance can be achieved.

Advantages of the Invention

[0016] The tapered roller bearing of this invention includes an inner ring with double flanges, an outer member having an annular raceway surface facing the raceway surface of the inner ring, a plurality of tapered rollers interposed between the inner ring and the outer member, and a cage for holding the plurality of tapered rollers. The cage has a small-diameter side annular portion, a large-diameter side annular portion, and a plurality of column portions in the circumferential direction connecting the small-diameter side annular portion and the large-diameter side annular portion, and is a tapered roller bearing of an inner ring guidance type. Since the dimensionless number X determined by the above formula with the clearance S1 between the small-diameter side annular portion of the cage and the small flange portion of the inner ring, the clearance S2 between the large-diameter side annular portion of the cage and the large flange portion of the inner ring, the average roller diameter d, the roller length l, and the outer member angle α (where α is 20° to 40°) which is the tapered opening angle at which the raceway surface of the outer member is inclined is in the range of 0.69 < X < 1.12, even when used in an environment where a high centrifugal force acts, the inclination of the rotation axis of the cage is suppressed and wear of the cage is less likely to occur, resulting in excellent durability.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0018] The tapered roller bearing according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6. Note that this tapered roller bearing 1 is used for the planetary part in a planetary speed reducer or a planetary transmission that will be described later with reference to FIGS. 9 and 10. In FIG. 1, this tapered roller bearing 1 includes an inner ring 2, an outer member 3, a plurality of tapered rollers 4 interposed between the inner ring 2 and the outer member 3, and a cage 5 that holds these plurality of tapered rollers 4. The inner ring 2 has a rolling surface 2a that is a tapered surface whose diameter increases from near one axial end of the outer peripheral surface to near the other end, and has a small flange portion 2b at one end and a large flange portion 2c at the other end, and is provided with flanges at both ends. The outer member 3 is an annular component having a rolling surface 3a that is a tapered surface whose diameter increases from one end to the other end and faces the rolling surface 2a of the inner ring 2. The outer member 3 is a component corresponding to the "outer ring" in the case of a component having only the function of a bearing, but is a component of a concept including, for example, a component whose outer peripheral surface is a gear portion and whose inner peripheral surface has the rolling surface 3a, and is referred to as the "outer member" in this specification. In this specification, in test and analysis examples, etc., the "outer member" may be referred to as the "outer ring". The outer member 3 has no flange in the illustrated embodiment, but may have a flange portion (not shown) that protrudes inward in diameter at one end or the other end.

[0019] The cage 5 has a small-diameter-side annular portion 6, a large-diameter-side annular portion 7, and a plurality of column portions 8 in the circumferential direction connecting the small-diameter-side annular portion 6 and the large-diameter-side annular portion 7. Between adjacent column portions 8, there is a pocket 9 that holds the tapered roller 4. The inner diameter surfaces of the small-diameter-side annular portion 6 and the large-diameter-side annular portion 7 of the cage 5 are sized to be guided by the small flange portion 2b and the large flange portion 2c of the inner ring 2, respectively. Thereby, this tapered roller bearing 1 is a bearing of the inner ring guidance type. Note that the cage 5 only needs to be of the inner ring guidance type, and may be configured to be guided by only one of the small flange portion 2b and the large flange portion 2c of the inner ring 2. Basically, it is preferably configured to be guided by at least the small flange portion 2b of the inner ring 2. The cage 5 is a press cage made of a metal plate such as an iron plate in this embodiment, and the small-diameter-side annular portion 6 and the large-diameter-side annular portion 7 are formed by bending. The column 8 is formed by punching out the pocket 9 by pressing. The material of the cage 5 may be made of resin in addition to this.

[0020] The dimensional relationships of each part of this tapered roller bearing 1 will be described. A clearance S1 between the small-diameter side annular portion 6 of the cage 5 and the small flange portion 2b of the inner ring 2, a clearance S2 between the large-diameter side annular portion 7 and the large flange portion 2c of the inner ring 2, an average roller diameter d of the roller 4, a roller length l of the roller 4, and a conical opening angle (an angle formed by two straight lines indicating the running surfaces 3a on both sides when cross-sectioned in a plane including the bearing axis O of the outer ring 3) of the running surface 3a of the outer member 3, which is the outer member angle α (where α is 20° to 40°), are used to define a dimensionless number X determined by the following formula.

[0021]

Equation

[0022] The dimensionless number X thus defined is in the range of 0.69 < X < 1.12. More preferably, the dimensionless number X is 0.73 < X < 1.046. However, for the tapered roller bearing 1 of this embodiment, it is assumed that the outer member angle α is in the range of 20° to 40°.

[0023] The small-diameter side annular portion 6 and the large-diameter side annular portion 7 of the cage 5 have flange-shaped portions 6a and 7a that bend and extend inward with respect to the column portion 8. The bending angle β formed by the flange-shaped portion 7a of the large-diameter side annular portion 7 with respect to the column portion 8 is in the range of 90° ± 10° based on the cage angle (in other words, the direction in which the column portion 8 extends), which is the angle at which the column portion 8 inclines with respect to the bearing axis O. The inner diameter surfaces of the small-diameter side annular portion 6 and the large-diameter side annular portion 7 are preferably parallel to the outer peripheral surfaces of the small flange portion 2b and the large flange portion 2c of the inner ring 2, but they may be inclined.

[0024] As shown enlarged in FIG. 4, the large-diameter side annular portion 7 of the cage 5, more specifically, has the flange-shaped portion 7a bent inward with respect to the column portion 8 via an arcuate bending portion 7b (see FIG. 4). The bending portion R dimension b1, which is the radius of curvature of the inner diameter side surface of the bending portion 7b, is in the range of 20 to 90% with respect to the axial length a, which is the length in the direction in which the column portion 8 of the large-diameter side annular portion 7 extends. The bending portion R dimension b2 of the outer diameter side surface of the bending portion 7b is not particularly specified.

[0025] The flange-like portions 6a and 7a of the small-diameter side annular portion 6 and the large-diameter side annular portion 7 of the cage 5 have oil passages 10 and 11 that allow the passage of lubricating oil at a plurality of locations in the circumferential direction, both inside and outside in the axial direction of the bearing shaft of these flange-like portions 6a and 7a. In this embodiment, as shown in FIGS. 3(A) and 3(B), the oil passages 10 and 11 are formed as notches on the inner peripheral edges of the flange-like portions 6a and 7a. Specifically, they are formed as arc-shaped notches. As shown in FIGS. 7 and 8, the oil passages 10 and 11 may be in the shape of windows. In FIGS. 7 and 8, the oil passage 10 of the flange-like portion 6a of the small-diameter side annular portion 6 is circular, and the oil passage 11 of the flange-like portion 7a of the large-diameter side annular portion 7 is elliptical. Note that the oil passages 10 and 11 do not necessarily have to be provided.

[0026] In the embodiments shown in FIGS. 1 to 8, the cross-sectional area ratio of the large-diameter side annular portion 7 of the cage 5 to the small-diameter side annular portion 6 is in the range of 1.0 to 1.2. The cross-sectional ratio mentioned here is the cross-sectional ratio of the cross-section at the circumferential location where the oil passages 10 and 11 are not provided.

[0027] The operation of the above configuration will be described. As shown in FIG. 6, when the tapered roller bearing 1 is used in an environment with revolution (arrow c) such as in the planetary part of a planetary speed reducer, a centrifugal force G acts, and a force that tries to tilt the cage 5 with this centrifugal force acts. To appropriately maintain the tilt of the cage 5 during operation, it is not sufficient to simply use the inner ring guiding type for the cage 5. In addition to the clearances (the small-diameter side clearance S1 and the large-diameter side clearance S2) between the outer diameters of the respective flange portions 2b and 2c of the inner ring 2 at rest and the cage 5, it is necessary to appropriately manage the clearances (the radial clearance and the axial clearance) between the rollers 4 and the cage 5 during operation. The clearances between the rollers 4 and the cage 5 during operation are defined by the average roller diameter d and the roller length l. Taking this into consideration, considering the non-dimensional X determined by the average roller diameter d and the roller length l for the small-diameter side clearance S1 and the large-diameter side clearance S2, it has been found and confirmed by tests and analysis that if this non-dimensional X is within an appropriate range, the tilt of the rotation axis of the cage can be suppressed. As a result, it has been found that by controlling the ratios of the clearance S1 on the small-diameter side and the clearance S2 on the large-diameter side so that the dimensionless X falls within the range of 0.69 < X < 1.12, the inclination of the rotation axis of the cage 5 can be suppressed.

[0028] The test and analysis simulated the planetary part of the planetary speed reducer and were based on the condition of durability with a centrifugal force of 30 G or more. All the dimensions of the tapered roller bearing 1 used in the test and analysis were inner diameter φ76 × outer diameter φ136.5 × width 46.0 (unit: mm), and the outer ring angle (outer member angle α) was 35°. Also, for the dimensions of each part of the tapered roller bearing 1 used in the test and analysis (roller mean diameter, roller length, clearance S1 on the small-diameter side, clearance S2 on the large-diameter side), although the individual values are omitted, the dimensions were such that the dimensionless X became the values shown in Table 1.

[0029]

Table 1

[0030] As shown in Table 1 of the results of the test and analysis, within the range including samples (2) to (6), within the range of 0.69 < X < 1.12, good results (no wear or minor wear of the cage 5) were obtained. In particular, samples (3) and (4) had no wear, and it is more preferable that the range is 0.73 < X < 1.04. Thus, by reducing the difference between the clearances S1 and S2 on the small-diameter side and the large-diameter side in the clearance between the outer diameters of the inner ring flanges 2b and 2c and the inner diameter of the cage 5, the tapered bearing 1 can be rotated with a small deviation between the rotation axis of the cage 5 and the axis of the inner ring 2 when a centrifugal force acts, the wobbling of the cage 5 can be reduced, and the wear of the cage 5 can be suppressed. By reducing the wobbling of the cage 5, the axial movement of the cage 5 due to the gyro moment can be reduced, and the tapered roller bearing 1 can be operated in a stable state.

[0031] The outer member angle α was set to 20° to 40° for the following reasons. When the outer member angle α is 20° or less, the ability to bear the axial load is small. When the angle α of the outer member is 40° or more, the ability to bear axial load is large, but the ability to bear radial load becomes small. In a tapered roller bearing used in an environment where centrifugal force acts, such as in a planetary reduction gear unit, since it mainly bears radial load, there are few cases where a bearing product with a large outer member angle α is applied. Also, since axial load may be generated due to the meshing of gears in a planetary reducer, etc., when the outer ring member angle is 20° or less, there is a possibility that the ability to bear axial load is insufficient.

[0032] The cage 5 sets the bending angle β (the bending angle formed by the flange-like portion 7a with respect to the column portion 8) of the flange-like portion 7a of the large-diameter side annular portion 7 in the range of 90° ± 10° based on the cage angle. For this reason, it becomes an appropriate shape when the cage 5 is of an inner ring guiding type.

[0033] Since the bending portion R dimension b1 (FIG. 4) of the inner diameter side surface of the bending portion 7b in the large-diameter side annular portion 7 of the cage 5 is in the range of 20 to 90% with respect to the axial length a of the large-diameter side annular portion 7, the following problems do not occur. That is, when the bending portion R dimension b1 is 20 less than with respect to the axial length a of the large-diameter side annular portion 7, stress concentration during bending becomes large, and there is a concern that the cage 5 may be damaged. a certain . Also, when it is 90% exceeding as shown by the thin line in FIG. 5, the arc shape of the inner diameter side surface of the bending portion 7b becomes loose becomes too smooth, and there is a concern that the end face of the roller 4 may hit the edge with respect to the opening edge of the pocket 9. By setting it in the range of 20 to 90%, such problems are eliminated.

[0034] In this embodiment, notch-shaped or window-shaped oil passages 10 and 11 are provided at a plurality of circumferential locations in the flange-like portions 6a and 7a of the small-diameter side annular portion 6 and the large-diameter side annular portion 7 of the cage 5 as described above. Therefore, the following effects are obtained. That is, by forming the oil passages 10 and 11, lubricating oil easily passes inside and outside the flange-like portions 6a and 7a of the cage 5. Therefore, good lubrication is obtained between the rolling surface of the tapered roller 4 and the inner surface of the pocket of the cage 5.

[0035] In addition, since the cross-sectional area ratio of the large-diameter side annular portion 7 of the cage 5 to the small-diameter side annular portion 6 is set to 1.0 to 1.2, the following advantages can be obtained. That is, when the cross-sectional area ratio is in the range of 1.0 to 1.2, the weight balance between the large-diameter side and the small-diameter side becomes appropriate, the rotation of the cage 5 is suppressed, and good inner ring guidance can be achieved.

[0036] Figs. 9 and 10 show an example of a planetary speed reducer in which the tapered roller bearing 1 according to the above embodiment is used. In this planetary speed reducer, a plurality of planetary rotating bodies 105 as planetary gears meshing with both gears 102 and 104 are arranged between a sun gear 102 attached to an input shaft 101 and an internal gear 104 fixed to a housing 103. Each planetary rotating body 105 is rotatably supported with respect to a carrier 107 connected to an output shaft 106, and the revolution motion of the planetary rotating body 105 revolving while rotating between the sun gear 102 and the internal gear 104 is output to the output shaft 106 via the carrier 107. This planetary speed reducer performs the first-stage deceleration of a final reduction gear provided inside a wheel rim of a construction machine, for example.

[0037] The tapered roller bearings 1 are arranged in a pair between the planetary rotating body 105 and the carrier 107 of the planetary speed reducer. The outer member 3 (Fig. 1) of each tapered roller bearing 1 is attached to the planetary rotating body 105 and rotates integrally with the planetary rotating body 105. The inner ring 2 of each tapered roller bearing 1 is fixedly attached to a support shaft 108 provided on the carrier 107.

[0038] Note that the small-diameter side clearance S1 and the large-diameter side clearance S2 change due to insufficient caulking of the small-diameter side annular portion 6 of the cage 5 during assembly. Therefore, to measure the small-diameter side clearance S1, for example, as shown in Figs. 11(A) and 11(B), a reference clearance gauge 51 is inserted between the inner diameter of the cage and the outer diameter of the inner ring flange at a 180° phase, the small-diameter side clearances S1 at 0° and 180° phases are confirmed, and the averaged value is used as the reference clearance. After that, it is inserted into the small-diameter side clearance S1, and one side is set to the reference clearance (the aforementioned average value). While in this state, the small-diameter side clearance S1 is measured when the measurement clearance gauge 52 is inserted at a phase position of 180°, and it is confirmed whether it is within an appropriate range.

[0039] As described above, the embodiments for carrying out the present invention have been described based on the embodiments. However, the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0040] 1... Tapered roller bearing 2... Inner ring 2a... Rolling surface 2b... Small flange portion 2c... Large flange portion 3... Outer member 4... Tapered roller 5... Cage 3a... Rolling surface 6... Small-diameter side annular portion 6a... Flange-shaped portion 7... Large-diameter side annular portion 7a... Flange-shaped portion 7b... Bent portion 8... Column portion 9... Pocket 10, 11... Oil passage S1... Small-diameter side clearance S2... Large-diameter side clearance d... Average roller diameter l... Roller length α... Outer member angle X... Dimensionless number

Claims

1. An internal ring with double flanges, an outer member having an annular rolling surface facing the rolling surface of the internal ring, a plurality of tapered rollers interposed between the internal ring and the outer member, and a cage for holding the plurality of tapered rollers. The cage has a small-diameter-side annular portion, a large-diameter-side annular portion, and a plurality of column portions in the circumferential direction connecting the small-diameter-side annular portion and the large-diameter-side annular portion, and is a tapered roller bearing of an internal-ring guiding type, wherein the cage is a press cage made of a metal plate, a small-diameter-side clearance S1 between the small-diameter-side annular portion of the cage and the small flange portion of the internal ring, a large-diameter-side clearance S2 between the large-diameter-side annular portion of the cage and the large flange portion of the internal ring, an average roller diameter d, a roller length l, and an outer member angle α which is the tapered opening angle at which the rolling surface of the outer member is inclined (where α is 20° to 40°), and a dimensionless number X determined by the following formula, 【Number 1】 where 0.69 < X < 1.12 is in the range of, the large-diameter-side annular portion of the cage has a flange-shaped portion that bends and extends inward in diameter via an arcuate bent portion with respect to the column portion, and the bending portion R dimension which is the radius of curvature of the inner-diameter-side surface of the bent portion is in the range of 20 to 90% with respect to the axial length which is the length in the direction in which the column portion of the large-diameter-side annular portion extends, a tapered roller bearing used in a planetary part of a planetary reducer or a planetary transmission.

2. In the tapered roller bearing according to Claim 1, the large-diameter-side annular portion of the cage has a flange-shaped portion that bends and extends inward in diameter with respect to the column portion, and the bending angle formed by the flange-shaped portion with respect to the column portion is in the range of 90° ± 10° based on the cage angle which is the angle at which the column portion inclines with respect to the bearing axis. A tapered roller bearing.

3. In the tapered roller bearing according to Claim 1 or Claim 2, the small-diameter-side annular portion and the large-diameter-side annular portion of the cage have flange-shaped portions that bend and extend inward in diameter with respect to the column portion, and at a plurality of circumferential locations of the flange-shaped portion, there are notch-shaped or window-shaped oil passage paths that allow the passage of lubricating oil with respect to the inside and outside in the axial direction of the bearing of the flange-shaped portion. A tapered roller bearing.

4. In the tapered roller bearing according to any one of Claims 1 to 3, the cross-sectional area ratio of the large-diameter-side annular portion of the cage to the small-diameter-side annular portion is 1.0 to 1.

2. A tapered roller bearing.

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