Tapered roller bearings

Abstract

The present invention relates to a tapered roller bearing, wherein a large diameter side annular portion (12) has a large diameter side pocket surface (16) opposed to a large end surface (11) of each tapered roller (4), and an oil retaining recess (20) opening between an inner peripheral surface of the large diameter side annular portion (12) and the large diameter side pocket surface (16), wherein the surface of the inner surface of the oil retaining recess (20) facing radially inward is an inclined surface approaching radially inward as it approaches the tapered roller (4).

Description

Technical Field

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

[0002] For the transmission or differential mechanism of the automobile, bearings that can support both radial load and axial load, namely tapered roller bearings, are often used.

[0003] This tapered roller bearing has an outer ring, an inner ring coaxially arranged inside the outer ring, a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction, and an annular retainer that maintains the circumferential intervals between the plurality of tapered rollers. The inner ring has a large flange that contacts the large end faces of each tapered roller. When the bearing rotates, the large end faces of the tapered rollers and the large flange of the inner ring support a portion of the axial load through contact with sliding.

[0004] The tapered roller bearing is lubricated by the splash of lubricating oil that jumps up due to the rotation of the gear or the lubricating oil that is pumped from the oil pump. Here, when the bearing rotates, the lubricating oil is continuously supplied to the tapered roller bearing from the outside, but when the bearing stops, the supply of lubricating oil to the tapered roller bearing from the outside stops. Therefore, if the tapered roller bearing stops for a long time, most of the lubricating oil attached to the tapered roller bearing will flow away, and then, when the tapered roller bearing is started, insufficient lubrication is likely to occur.

[0005] In particular, in recent years, there has been a trend to use low-viscosity lubricants or reduce the amount of lubricants in automobile transmissions or differential mechanisms in order to suppress energy loss caused by the stirring resistance of lubricants. Therefore, when the tapered roller bearing is stopped for a long time, the amount of lubricants remaining in the tapered roller bearing tends to become too small, and there is a concern that the temperature between the large end face of the tapered roller and the large flange of the inner ring will rise rapidly when the tapered roller bearing is started.

[0006] Therefore, as a tapered roller bearing that can lubricate the large end surface of the tapered roller and the large flange of the inner ring even when the supply of lubricating oil from the outside to the tapered roller bearing is stopped in order to prevent such rapid temperature rise, there is known a tapered roller bearing as shown in FIG. Fig.14 The bearing described in Patent Document 1. Fig.14 The retainer of the tapered roller bearing has a large diameter side annular portion extending in the circumferential direction along the large end face of the tapered roller, a small diameter side annular portion extending in the circumferential direction along the small end face of the tapered roller, and a plurality of columnar portions connecting the large diameter side annular portion and the small diameter side annular portion, and a plurality of oil retaining recesses are formed at intervals in the circumferential direction on the large diameter side annular portion. The oil retaining recess opens between the inner circumferential surface of the large diameter side annular portion and the large diameter side pocket surface. The oil retaining recess is formed into an arch shape with a single concave arc surface as the inner surface when viewed in the axial direction. The large diameter side pocket surface is a surface facing the large end face of the tapered roller.

[0007] The tapered roller bearing of Patent Document 1 stores a portion of the lubricating oil in the oil retaining recess on the inner circumference of the large diameter side annular portion of the retainer when lubricating oil is continuously supplied to the tapered roller bearing from the outside. Thereafter, when the supply of lubricating oil to the tapered roller bearing from the outside is stopped for some reason, the lubricating oil flowing out of the oil retaining recess on the inner circumference of the large diameter side annular portion of the retainer lubricates the large end face of the tapered roller and the large flange of the inner ring.

[0008] Patent Document 1: Japanese Patent No. 5668420

[0009] However, in the tapered roller bearing of Patent Document 1, the bottom surface of the oil retaining recess formed in the large diameter side annular portion of the retainer (i.e., the surface of the inner surface of the oil retaining recess facing the radial inside) is inclined so as to approach the radial outside as it approaches the tapered roller. That is, the bottom surface of the oil retaining recess is inclined in a direction approaching the radial outside as it approaches the tapered roller, so that when the lubricating oil in the oil retaining recess is subjected to centrifugal force as the bearing rotates, a component force in the direction toward the large end surface of the tapered roller is generated on the lubricating oil in the oil retaining recess.

[0010] However, if the tapered roller bearing is stopped for a long time, the lubricating oil in the oil retaining recess moves toward the tapered roller due to the inclination of the bottom surface of the oil retaining recess, and gradually flows out through the gap between the large end face of the tapered roller and the large diameter side annular portion of the retainer. Afterwards, when the tapered roller bearing is started, there is a possibility that the large end face of the tapered roller and the large flange of the inner ring cannot be fully lubricated. As a result, there is a concern that the temperature between the large end face of the tapered roller and the large flange of the inner ring will rise rapidly. Summary of the invention

[0011] Therefore, an object of the present invention is to provide a tapered roller bearing capable of preventing a rapid temperature rise between the large end surface of the tapered roller and the large flange of the inner ring when the tapered roller bearing is started after being stopped for a long time.

[0012] In order to solve the above-mentioned problems, in the first invention, a tapered roller bearing having the following structure is provided.

[0013] A tapered roller bearing, comprising an outer ring; an inner ring coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential intervals between the plurality of tapered rollers, the inner ring having a large flange in contact with the large end faces of the tapered rollers, the retainer having a large diameter side annular portion extending in the circumferential direction along the large end faces of the plurality of tapered rollers, a small diameter side annular portion extending in the circumferential direction along the small end faces of the plurality of tapered rollers, and a retainer that holds the large diameter side annular portion in the circumferential direction. The tapered roller bearing comprises a plurality of columnar portions connected to the small-diameter side annular portion, the large-diameter side annular portion, the small-diameter side annular portion and the plurality of columnar portions dividing a plurality of pockets for respectively accommodating the plurality of tapered rollers, the large-diameter side annular portion having a large-diameter side pocket surface opposite to the large end surfaces of the tapered rollers, and an oil-retaining recessed portion opening between the inner circumferential surface of the large-diameter side annular portion and the large-diameter side pocket surface, the tapered roller bearing being characterized in that the surface facing radially inward in the inner surface of the oil-retaining recessed portion is an inclined surface which approaches radially inward as it approaches the tapered rollers.

[0014] In this way, the bottom surface of the oil retaining recess located below the axis (i.e., the surface facing radially inward in the inner surface of the oil retaining recess) is inclined upward as it approaches the tapered roller. Therefore, when the tapered roller bearing stops operating, the lubricating oil in the oil retaining recess located below the axis of the rotating shaft of the tapered roller bearing is not easy to flow out of the oil retaining recess. In addition, if the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves toward the tapered roller side along the inclination due to centrifugal force, thereby being able to lubricate the large end surface of the tapered roller. Therefore, after the tapered roller bearing has been stopped for a long time, when the tapered roller bearing is started, it is possible to effectively prevent the large end surface of the tapered roller and the large flange of the inner ring from rapidly heating up.

[0015] It is preferable that the inclination angle of the inclined surface with respect to a direction parallel to the axis of the retainer is 10 degrees or less.

[0016] In this way, the lubricating oil in the oil retaining recess can properly lubricate the large end surface during the rotation of the tapered roller bearing, and is properly retained in the oil retaining recess when the tapered roller bearing stops. In addition, it becomes a range that can cope with unreasonable demolding during resin molding.

[0017] The oil retaining recessed portion preferably has a square cross-sectional shape perpendicular to the axis of the cage.

[0018] In this way, the lubricating oil is retained at the corners of the square cross-section of the oil retaining recess due to the surface tension of the lubricating oil, so that the lubricating oil is easily retained in the oil retaining recess.

[0019] In addition, in order to solve the above-mentioned problems, in the second invention, a tapered roller bearing of the following structure is provided. A tapered roller bearing, comprising: an outer ring; an inner ring coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential intervals between the plurality of tapered rollers, the inner ring having a large flange in contact with the large end faces of the tapered rollers, the retainer having a large diameter side annular portion extending in the circumferential direction along the large end faces of the plurality of tapered rollers, a small diameter side annular portion extending in the circumferential direction along the small end faces of the plurality of tapered rollers, and a retainer that holds the large diameter side annular portion in the circumferential direction. The tapered roller bearing comprises a plurality of column portions connected to the small diameter side annular portion, the large diameter side annular portion, the small diameter side annular portion and the plurality of column portions divide the plurality of pockets for respectively accommodating the plurality of tapered rollers, the large diameter side annular portion having a large diameter side pocket surface opposite to the large end surfaces of the tapered rollers, and an oil retaining recess opening between the inner circumferential surface of the large diameter side annular portion and the large diameter side pocket surface, the tapered roller bearing being characterized in that the oil retaining recess is formed into a polygonal shape having two or more corner portions where adjacent inner surfaces of the oil retaining recess intersect each other when viewed in the axial direction.

[0020] In this way, in the corner portion of the oil retaining recess, the lubricating oil and the adjacent inner surfaces of the oil retaining recess are in contact with each other, so the lubricating oil is easily retained in the oil retaining recess by the surface tension of the lubricating oil. Therefore, during the stop of the bearing, the lubricating oil in the oil retaining recess is suppressed from flowing out due to its own weight, so that the lubricating oil can be retained in the oil retaining recess even when the bearing is stopped for a long time. Thereafter, if the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves toward the tapered roller side due to centrifugal force, thereby being able to lubricate the large end face of the roller. Therefore, after the tapered roller bearing has been stopped for a long time, when the tapered roller bearing is started, it is possible to effectively prevent the large end face of the tapered roller and the large flange of the inner ring from rapidly heating up.

[0021] Preferably, the oil retaining recess has an inner wall surface extending from the inner peripheral surface of the large diameter side annular portion toward the inside of the large diameter side annular portion in a cross section perpendicular to the circumferential direction, and an oil retaining groove recessed in the axial direction is formed on the inner wall surface.

[0022] In this way, compared with the case where the entire surface of the inner wall surface is formed into a flat surface, the inner surface of the oil retaining recess has an increased unevenness due to the presence of the oil retaining groove on the inner wall surface. Therefore, the lubricating oil is easily retained in the oil retaining recess by the surface tension of the lubricating oil. Therefore, the lubricating oil in the oil retaining recess can properly lubricate the roller large end surface during the rotation of the tapered roller bearing, and can be properly retained in the oil retaining recess when the tapered roller bearing stops.

[0023] It is preferable that the oil retaining groove is formed in a region separated radially outward from the inner peripheral surface of the large-diameter-side annular portion so as to have no portion opening to the inner peripheral surface of the large-diameter-side annular portion.

[0024] In this way, in the oil retaining recess located on the upper side of the axis of the rotating shaft of the tapered roller bearing, the lubricating oil inside is properly retained by the oil retaining groove. That is, in the oil retaining recess located on the upper side of the axis, the lubricating oil inside is acted on by gravity in the downward direction (towards the inner peripheral surface side of the large diameter side annular portion), but the oil retaining groove in the oil retaining recess does not have a portion that opens to the inner peripheral surface of the large diameter side annular portion. Therefore, the lubricating oil in the oil retaining groove is not easy to flow out of the oil retaining groove due to its own weight. Therefore, the lubricating oil in the oil retaining recess can be properly retained in the oil retaining recess by the oil retaining groove.

[0025] Preferably, the oil retaining groove includes a transverse groove portion extending from one side to the other side in the circumferential direction, and a longitudinal groove portion branching off from the middle of the transverse groove portion and extending radially outward.

[0026] As a result, the surface area of ​​the inner surface of the oil retaining groove increases, and the contact area between the lubricating oil in the oil retaining recess and the inner surface of the oil retaining groove increases. Therefore, the surface tension generated in the oil retaining groove and between the inner surface and the lubricating oil becomes larger. Therefore, the lubricating oil in the oil retaining recess can be more appropriately retained in the oil retaining recess.

[0027] It is preferable that the corner portion include two or more corner portions having acute angles in which the adjacent inner surfaces intersect each other at an angle of 90° or less when viewed in the axial direction.

[0028] In this way, at the corner portion where the inner surfaces of the oil retaining recess intersect each other at an angle of 90° or less, the lubricating oil easily contacts each of the adjacent surfaces. Therefore, at such a corner portion, the contact area between the lubricating oil in the oil retaining recess and the inner surface of the oil retaining recess becomes larger. Furthermore, the surface tension generated between the lubricating oil and the inner surface of the oil retaining recess becomes larger, so that the lubricating oil in the oil retaining recess can be more appropriately retained in the oil retaining recess.

[0029] Preferably, in the corner portion, the adjacent inner surfaces intersect each other via an R surface having a curvature radius of preferably 1.0 mm or less, and at least 2.0 mm or less.

[0030] In this way, the intersection of the adjacent inner surfaces of the corner portion passes through the R surface, so it is possible to suppress the stress concentration on the corner portion when the bearing rotates, and the formability of the oil retaining recess is improved. In addition, the curvature radius of the R surface is 1.0 mm or less, at least 2.0 mm or less, so it is possible to suppress the stress concentration on the corner portion when the bearing rotates.

[0031] In the first and second inventions, it is preferable that a plurality of the oil retaining recesses are arranged in the circumferential direction between the column portions adjacent to each other in the circumferential direction.

[0032] In this way, the area of ​​the inner surface of the oil retaining recess can be increased compared to the case where one oil retaining recess is provided between the circumferentially adjacent columnar portions. Therefore, the contact area between the lubricating oil in the oil retaining recess and the inner surface of the oil retaining recess increases, and the surface tension acting between the inner surface and the lubricating oil increases. As a result, it becomes easier to retain the lubricating oil in the oil retaining recess.

[0033] In the first invention and the second invention, when the tapered roller has a recessed portion at the center of the large end surface, it is preferable that the oil retaining recessed portions are arranged on both sides sandwiching the recessed portion.

[0034] This prevents the lubricating oil retained in the oil retaining recess from flowing out to the recess on the large end face of the tapered roller when the tapered roller bearing stops, thereby reducing the friction between the tapered roller and the large flange of the inner ring while lubricating the large end face of the tapered roller.

[0035] In the first and second inventions, it is preferred that an opening area of ​​a portion of the opening on the large diameter pocket surface side of the oil retaining recess facing the large end surface of each tapered roller is 50% or more of an opening area on the large diameter pocket surface side of the oil retaining recess.

[0036] In this way, more than 50% of the openings on the large-diameter pocket surface side of the oil retaining recess are opposite to the large end surface of the tapered roller. Therefore, most of the lubricating oil that flows out of the oil retaining recess through the openings on the large-diameter pocket surface side of the oil retaining recess can be efficiently attached to the large end surface of the tapered roller, thereby effectively lubricating the large end surface of the tapered roller.

[0037] In the first and second inventions, the oil retaining recess is preferably located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller.

[0038] By forming the oil retaining recess in the above manner, the lubricating oil retained in the oil retaining recess can be efficiently supplied to the large roller end surface, thereby achieving an effect of facilitating lubrication between the large roller end surface and the large flange surface of the inner ring.

[0039] In the first and second inventions, it is preferred that the inner ring has a small flange facing the small end faces of the tapered rollers, and when the retainer is integrally formed from a resin composition, a resin material having an elastomer added thereto is used as the resin composition.

[0040] That is, the tapered roller bearing can be assembled as follows. First, the tapered roller is inserted into each pocket of the retainer. Next, the inner ring is inserted into the retainer in a state where the tapered roller is stored in each pocket. At this time, the tapered roller needs to pass over the small flange of the inner ring, but the tapered roller is restricted by the retainer to move radially outward, so it cannot pass over the small flange while maintaining the original dimensional relationship. Therefore, in order to make the small flange pass over the tapered roller, when the retainer is formed integrally with the resin composition, when the tapered roller rides on the small flange, the retainer is elastically deformed by the force in the diameter expansion direction received by the tapered roller from the small flange. Here, if a substance with an elastomer added to the resin material is used as the resin composition forming the retainer, the elasticity of the retainer is improved, so the operation of inserting the inner ring into the retainer in a state where the tapered roller is stored in each pocket becomes easy, thereby improving the assembly performance of the tapered roller bearing.

[0041] It is preferable that a fiber reinforcement material is further added to the above-mentioned resin material.

[0042] In this way, the fiber-reinforced material can compensate for the decrease in toughness and strength of the cage caused by adding the elastomer to the resin material. Therefore, the toughness and strength of the cage and the assembly performance of the tapered roller bearing can be achieved at the same time.

[0043] If the tapered roller bearing of the first invention is used, the bottom surface of the oil retaining recess located below the axis (i.e., the surface facing radially inward in the inner surface of the oil retaining recess) is inclined upward as it approaches the tapered roller. Therefore, when the tapered roller bearing stops running, the lubricating oil in the oil retaining recess located below the axis of the rotating shaft of the tapered roller bearing is not easy to flow out of the oil retaining recess. In addition, if the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves toward the tapered roller side along its inclination due to centrifugal force, thereby being able to lubricate the large end surface. Therefore, after the tapered roller bearing has been stopped for a long time, when the tapered roller bearing is started, it is possible to effectively prevent the large end surface of the tapered roller and the large flange of the inner ring from rapidly heating up.

[0044] In addition, in the tapered roller bearing of the second invention, the lubricating oil and the adjacent inner surfaces of the oil retaining recess are in contact with each other in the corner portion of the oil retaining recess, so that the lubricating oil is easily retained in the oil retaining recess by the surface tension of the lubricating oil. Therefore, during the stop of the bearing, the lubricating oil in the oil retaining recess is suppressed from flowing out due to its own weight, so that the lubricating oil can be retained in the oil retaining recess even when the bearing is stopped for a long time. Thereafter, if the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves toward the tapered roller side due to centrifugal force, thereby being able to lubricate the large end face of the roller. Therefore, after the tapered roller bearing has been stopped for a long time, when the tapered roller bearing is started, it is possible to effectively prevent the large end face of the tapered roller and the large flange of the inner ring from rapidly heating up. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a cross-sectional view along an axial plane of the tapered roller bearing according to the embodiment of the first invention.

[0046] Figure 2 yes Figure 1 A perspective view of the retainer shown.

[0047] Figure 3 yes Figure 1 A partial enlarged view of the vicinity of the oil retaining recess.

[0048] Figure 4 Yes Figure 1 The cage shown is a partial cross-sectional view of the tapered roller as viewed from the large end surface side.

[0049] Figure 5 Yes means Figure 1 A partially enlarged view of the details near the oil retaining recess.

[0050] Figure 6 It is a cross-sectional view along an axial plane of a tapered roller bearing according to an embodiment of the second invention.

[0051] Figure 7 yes Figure 6 A partial enlarged view of the vicinity of the oil retaining recess.

[0052] Figure 8 Yes Figure 6 The holder shown is a perspective view as viewed from its inner diameter side.

[0053] Fig. 9 Yes Figure 6 The illustrated partial cross-sectional view of the large diameter side annular portion of the cage is viewed from the large end surface side of the tapered roller.

[0054] Fig. 10A yes Figure 6 The shown figure is an enlarged view of the vicinity of the oil retaining recess of the tapered roller bearing after it has been stopped for a long time.

[0055] Fig. 10B It means that Fig. 10A The oil retaining recess shown is a cross-sectional view of a state in which it is broken along a plane orthogonal to the circumferential direction of the cage.

[0056] Fig.11A This is an enlarged view of the vicinity of the oil retaining recess of the tapered roller bearing of the comparative example after being stopped for a long period of time.

[0057] Fig. 11B It means that Fig.11A The oil retaining recess shown is a cross-sectional view of a state in which it is broken along a plane orthogonal to the circumferential direction of the cage.

[0058] Fig.12 Yes means Fig. 9 FIG. 2 is a diagram showing a modified example of the oil retaining recess.

[0059] Fig.13 Yes means Fig. 9 FIG. 2 is a diagram showing other modified examples of the oil retaining recess.

[0060] Fig.14 Yes means Fig. 9 FIG. 4 is a diagram showing yet another modified example of the oil retaining recess.

[0061] Fig.15 is along Fig.14 A cross-sectional view of line XV-XV.

[0062] Fig.16 It means using Figure 1 or Figure 6 A diagram showing an example of a tapered roller bearing transmission.

[0063] Fig.17 It means using Figure 1 or Figure 6 A diagram showing an example of a tapered roller bearing differential mechanism. DETAILED DESCRIPTION

[0064] exist Figure 1 , a tapered roller bearing 1 according to an embodiment of the first invention is shown. The tapered roller bearing 1 comprises an outer ring 2, an inner ring 3 coaxially arranged inside the outer ring 2, a plurality of tapered rollers 4 assembled at intervals in the circumferential direction between the outer ring 2 and the inner ring 3, and an annular retainer 5 for maintaining the intervals in the circumferential direction of the plurality of tapered rollers 4. The tapered roller bearing 1 is a bearing of a size used in automobiles, and as a specific example, is a bearing of a size in which the inner diameter of the inner ring 3 is 50 mm or less (or may be 35 mm or less).

[0065] A tapered outer ring raceway surface 6 is formed on the inner circumference of the outer ring 2. A tapered inner ring raceway surface 7 radially opposite to the outer ring raceway surface 6, a small flange 8 located on the small diameter side of the inner ring raceway surface 7, and a large flange 9 located on the large diameter side of the inner ring raceway surface 7 are formed on the outer circumference of the inner ring 3. The tapered rollers 4 are in rolling contact with the outer ring raceway surface 6 and the inner ring raceway surface 7.

[0066] The small flange 8 is formed to protrude from the inner ring raceway surface 7 to the outer diameter side in a manner opposite to the small end face 10 of the tapered roller 4. The small flange 8 restricts the tapered roller 4 from moving to the small diameter side of the inner ring raceway surface 7, and prevents the tapered roller 4 from falling off the inner ring raceway surface 7. The large flange 9 is formed to protrude from the inner ring raceway surface 7 to the outer diameter side in a manner opposite to the large end face 11 of the tapered roller 4. When the bearing rotates, the large end face 11 of the tapered roller 4 and the large flange 9 of the inner ring 3 support a part of the axial load by sliding contact.

[0067] like Figure 1 , Figure 2 As shown, the retainer 5 has a large diameter side annular portion 12 extending in the circumferential direction along the large end surface 11 of each tapered roller 4, a small diameter side annular portion 13 extending in the circumferential direction along the small end surface 10 of each tapered roller 4, and a plurality of columnar portions 14 passing through between the tapered rollers 4 adjacent in the circumferential direction and connecting the large diameter side annular portion 12 and the small diameter side annular portion 13.

[0068] The large diameter side annular portion 12, the small diameter side annular portion 13 and the plurality of columnar portions 14 define a plurality of pockets 15 for accommodating the plurality of tapered rollers 4. Here, the large diameter side annular portion 12 and the small diameter side annular portion 13 define the two ends of the pocket 15 in the axial direction of the retainer, and the columnar portion 14 defines the two ends of the pocket 15 in the circumferential direction of the retainer. The large diameter side annular portion 12 is formed with a large diameter side pocket surface 16 that faces the large end surface 11 of the tapered roller 4, and the small diameter side pocket surface 17 that faces the small end surface 10 of the tapered roller 4 is formed with the small diameter side annular portion 13. The large diameter side pocket surface 16 is formed to be inclined relative to the axial perpendicular direction (the vertical direction in the figure) of the retainer 5 in a manner that allows surface contact with the large end surface 11 of the tapered roller 4. The columnar portion 14 has a roller guide surface that contacts the outer periphery of the tapered roller 4 at a position that faces the outer periphery of the tapered roller 4.

[0069] A plurality of oil retaining recesses 20 are formed at intervals in the circumferential direction of the retainer on the inner periphery of the large-diameter-side annular portion 12. The oil retaining recesses 20 are formed between the inner periphery of the large-diameter-side annular portion 12 and the large-diameter-side pocket surface 16. That is, the oil retaining recesses 20 are formed to open to the inner periphery of the large-diameter-side annular portion 12 and to open to the large-diameter-side pocket surface 16. The opening portion of the oil retaining recess 20 that opens to the inner periphery of the large-diameter-side annular portion 12 is formed in a rectangular shape when viewed from the radially inner side of the retainer. The opening portion of the oil retaining recess 20 that opens to the large-diameter-side pocket surface 16 is formed in a rectangular shape when viewed in the axial direction.

[0070] like Figure 3 As shown in FIG. 1 , the inner surface of the oil retaining recess 20 is composed of a bottom surface 21 facing radially inward, and an inner wall surface 22 rising radially inward from the periphery of the bottom surface 21 and extending to the opening edge of the oil retaining recess 20. The bottom surface 21 is an inclined surface that approaches radially inward as it approaches the tapered roller. That is, the radial depth of the oil retaining recess 20 gradually increases as it moves away from the opening of the large-diameter pocket surface 16 in the axial direction. The inclination angle θ of the bottom surface 21 with respect to the direction parallel to the axis of the retainer 5 is greater than 0 degrees and less than 10 degrees (preferably greater than 5 degrees and less than 10 degrees).

[0071] like Figure 5As shown, the inner wall surface 22 is composed of a pair of opposing surfaces 24 opposed in the circumferential direction of the retainer, and a connecting surface 25 connecting one end of the opposing surfaces 24 to each other. The connecting surface 25 is an upright surface facing the large end surface 11 of the tapered roller 4 in the axial direction. The opposing surface 24 and the connecting surface 25 directly intersect each other, or intersect each other via a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The opposing surface 24 and the bottom surface 21 also directly intersect each other, or intersect each other via a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The connecting surface 25 and the bottom surface 21 also directly intersect each other, or intersect each other via a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The cross-sectional shape of the oil retaining recess 20 perpendicular to the axis of the retainer 5 is formed in a square shape, and the cross-sectional shape of the oil retaining recess 20 perpendicular to the radial direction is also formed in a square shape. Therefore, a concave corner 26 is formed between the bottom surface 21 and the facing surface 24, a concave corner 27 is formed between the bottom surface 21 and the connecting surface 25, and a concave corner 28 is formed between the facing surface 24 and the connecting surface 25.

[0072] Here, the depth of the oil retaining recess 20 (i.e., the distance from the deepest part of the oil retaining recess 20 to the inner diameter surface of the large diameter side annular portion 12) is 0.2 mm to 2.0 mm (preferably 0.3 mm to 1.0 mm), or Figure 3 The relationship between H and h shown is in the range of 0.2<h / H<0.7. There is a concern that the oil retention effect will be too small at the lower limit of h / H, and the strength will be insufficient at the upper limit.

[0073] The tapered roller 4 has a recess 11a at the center of the large end surface 11. The large end surface 11 is composed of the recess 11a and an annular surface 11b surrounding the recess 11a. The annular surface 11b is a surface pressed by the large flange 9. The annular surface 11b is a spherical surface with a sufficiently large radius of curvature (at least a radius of curvature larger than the radius of the inner ring 3). The oil-retaining recess 20 is arranged on both sides of the recess 11a. The recess 11a is formed to open in a circular shape on the large end surface 11, and enters from the opening to the small end surface side of the tapered roller in the axial direction.

[0074] A plurality of oil retaining recesses 20 are arranged in the circumferential direction between the circumferentially adjacent columnar portions 14. That is, a plurality of oil retaining recesses 20 are provided on each of the large diameter side pocket surfaces 16. As an example of such an oil retaining recess 20, Figure 4 , Figure 5, an oil retaining recess 20 is provided at two locations on each large diameter side pocket surface 16. The oil retaining recess 20 at the two locations is separated and arranged on both sides of the circumferential direction of the retainer 5 with respect to the center of the large diameter side pocket surface 16. That is, the oil retaining recess 20 is provided at each location in the left-right direction of the recess 11a of the roller large end surface 11 in the figure. The oil retaining recess 20 is arranged outside the recess 11a of the roller large end surface 11 so as not to face the recess 11a of the large end surface 11 but only to face a part of the annular surface 11b.

[0075] The oil retaining recess 20 is located inside the periphery of the large end surface 11 so as not to protrude outside the region facing the large end surface 11 of the tapered roller 4. Figure 4 As shown in FIG. 1 , when viewed from above from the side of the large end face 11, the entire area inside the opening edge of the oil retaining recess 20 is located inside the peripheral edge of the large end face 11. In addition, the oil retaining recess 20 is provided so as not to protrude inside the opening edge of the recess 11a of the large end face 11 of the roller. That is, when viewed from above from the side of the large end face 11, the entire area inside the opening edge of the oil retaining recess 20 is located outside the opening edge of the recess 11a of the large end face 11 of the roller.

[0076] Here, the large-diameter-side annular portion 12 has a weld line L (a portion where resins merge when the retainer 5 is resin-molded). Specifically, the weld line L is provided between adjacent oil-retaining recesses 20, thereby ensuring a sufficient wall thickness of the large-diameter-side annular portion 12 compared to a structure in which the weld line L is provided at a position overlapping with the oil-retaining recess 20, and the oil-retaining recess 20 can be provided without causing a significant decrease in strength.

[0077] The retainer 5 is seamlessly integrally formed of a synthetic resin. That is, the large-diameter annular portion 12, the small-diameter annular portion 13, and the plurality of pillar portions 14 constituting the retainer 5 are seamlessly integrally formed of a resin composition. The resin composition constituting the retainer 5 may be a resin material, but here, a resin material to which an elastomer and a fiber reinforcement material are added is used.

[0078] As the resin material that becomes the matrix of the resin composition, polyamide (PA) can be used. As polyamide, polyamide 66 (PA66), polyamide 46 (PA46), polynonamethylene terephthalamide (PA9T), etc. can be used. If polyamide is used, since polyamide has a relatively high lipophilicity, the lubricating oil is easily affinity with the inner surface of the oil retaining recess 20, so that the lubricating oil can be effectively retained in the oil retaining recess 20 by the surface tension of the lubricating oil. Instead of polyamide, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), etc. can also be used. The elastomer added to the resin material is, for example, a thermoplastic elastomer.

[0079] As the fiber reinforcement material added to the resin material, glass fiber, carbon fiber, aramid fiber, etc. can be used. In the case of using glass fiber as the fiber reinforcement material, the content of glass fiber in the fiber reinforcement material can be 10 to 50 weight % (preferably 20 to 40 weight %, more preferably 25 to 35 weight %). In addition, as long as it is a combination of the types of resin material, elastomer, and fiber reinforcement material, it can be freely selected as appropriate.

[0080] exist Fig.16 2 is a partial structural diagram showing a case where the tapered roller bearing 1 is arranged in a transmission 30 of an automobile.

[0081] In particular, in recent years, there has been a trend to use low-viscosity lubricating oil or reduce the amount of lubricating oil in the transmission or differential mechanism of automobiles in order to suppress energy loss caused by the stirring resistance of the lubricating oil. Therefore, when the tapered roller bearing 1 is stopped for a long time, the amount of lubricating oil remaining in the tapered roller bearing 1 tends to become too small, and then, when the tapered roller bearing 1 is started, there is a possibility that a rapid temperature rise will occur between the large end face 11 of the tapered roller 4 and the large flange 9 of the inner ring 3.

[0082] In view of this problem, in the tapered roller bearing 1 of the present embodiment, lubricating oil is introduced into the oil retaining recess 20 when the tapered roller bearing 1 rotates. Here, as described above, the bottom surface 21 of the oil retaining recess 20 is inclined radially inward as it approaches the tapered roller 4. Therefore, when the tapered roller bearing 1 stops, a force acts on the lubricating oil in the oil retaining recess 20 in a direction in which the lubricating oil flows into the inner part of the oil retaining recess 20 along the inclination of the bottom surface 21 due to gravity. Therefore, even when the tapered roller bearing 1 stops for a long time, the lubricating oil is accumulated in the oil retaining recess 20 and is not easy to flow out of the oil retaining recess 20. Thereafter, when the tapered roller bearing 1 starts, centrifugal force acts on the lubricating oil in the oil retaining recess 20. In this way, the lubricating oil moves toward the tapered roller 4 side along the inclination of the bottom surface 21, flows out of the oil retaining recess 20, and is supplied to the large end surface 11 of the tapered roller 4. Therefore, when the tapered roller bearing 1 is started after being stopped for a long time, a rapid temperature rise between the large end surface 11 of the tapered roller 4 and the large flange 9 of the inner ring 3 can be effectively prevented.

[0083] In addition, since the tapered roller bearing 1 has the oil retaining recesses 20 disposed on both sides of the recesses 11a of the large end faces 11 of the tapered roller 4, when the tapered roller bearing 1 stops, the lubricating oil retained in the oil retaining recesses 20 can be prevented from flowing out of the recesses 11a of the large end faces 11 of the tapered roller 4, thereby reducing the friction between the tapered roller 4 and the large flange 9 of the inner ring 3 while lubricating the large end faces 11 (particularly the annular surface 11b) of the tapered roller 4.

[0084] In addition, in the tapered roller bearing 1, since the opening area of ​​the portion of the opening on the large-diameter side pocket surface 16 side of the oil retaining recess 20 that faces the large end surface 11 of the tapered roller 4 is 50% or more (preferably 70% or more, and more preferably 90% or more) of the opening area on the large-diameter side pocket surface 16 side of the oil retaining recess 20, most of the lubricating oil that flows out of the oil retaining recess 20 through the opening on the large-diameter side pocket surface 16 side of the oil retaining recess 20 can be efficiently attached to the large end surface 11 (particularly the annular surface 11b) of the tapered roller 4, thereby effectively lubricating the large end surface 11 of the tapered roller 4.

[0085] In addition, since the tapered roller bearing 1 sets the inclination angle θ of the bottom surface 21 of the oil retaining recess 20 to 10 degrees or less, the lubricating oil in the oil retaining recess 20 flows smoothly toward the large end surface 11 of the tapered roller 4 during the rotation of the tapered roller bearing 1, thereby effectively lubricating the large end surface 11 of the tapered roller 4. In addition, since the inclination angle θ of the bottom surface 21 of the oil retaining recess 20 is set to be greater than 0 degrees, preferably set to be greater than 5 degrees, the lubricating oil can be reliably retained in the oil retaining recess 20 when the tapered roller bearing 1 stops.

[0086] In addition, as described above, the cross-sectional shape of the oil retaining recess 20 perpendicular to the axis of the retainer 5 is formed in a square shape, and the cross-sectional shape of the oil retaining recess 20 perpendicular to the radial direction is also formed in a square shape, and a plurality of corners 26, 27, and 28 are formed inside the oil retaining recess 20. Therefore, the surface tension acting between the inner surface of the oil retaining recess 20 and the lubricating oil is larger than that of an oil retaining recess having a circular cross-sectional shape and no corners 26, 27, and 28. Therefore, the surface tension effectively acts on the lubricating oil retained in the oil retaining recess 20, and the lubricating oil is easily retained in the oil retaining recess 20.

[0087] In addition, the tapered roller bearing 1 is provided with an oil retaining recess 20 on the inner side than the periphery of the large end face 11 so that the oil retaining recess 20 does not protrude to the outside of the region facing the large end face 11 of each tapered roller 4. Therefore, when the tapered roller bearing 1 stops, the lubricating oil retained in the oil retaining recess 20 can be effectively prevented from passing through the outside of the large end face 11 and flowing out of the oil retaining recess 20.

[0088] The above-mentioned tapered roller bearing 1 can be assembled as follows. First, the tapered roller 4 is inserted into each pocket 15 of the retainer 5. Next, the inner ring 3 is inserted into the retainer 5 in a state where the tapered roller 4 is accommodated in each pocket 15. At this time, the tapered roller 4 needs to pass over the small flange 8 of the inner ring 3, but the tapered roller 4 is restricted from moving radially outward by the retainer 5, and therefore cannot pass over the small flange 8 with the original dimensional relationship. Therefore, in order to allow the small flange 8 to pass over the tapered roller 4, the retainer 5 is elastically deformed by the force in the diameter expansion direction received by the tapered roller 4 from the small flange 8 when the tapered roller 4 rides on the small flange 8. Here, in the above-mentioned embodiment, as the resin composition forming the retainer 5, a material in which an elastomer is added to the resin material is used, so the retainer 5 has high elasticity, and the work of inserting the inner ring 3 into the retainer 5 in a state where the tapered roller 4 is accommodated in each pocket 15 is easy, so that the excellent assembly performance of the tapered roller bearing 1 can be obtained.

[0089] In addition, the tapered roller bearing 1 adopts a material obtained by adding an elastomer to a resin material and further adding a fiber reinforcement material as a resin composition for forming the retainer 5, so that the fiber reinforcement material can compensate for the decrease in toughness and strength of the retainer 5 caused by the addition of the elastomer. Therefore, the toughness and strength of the retainer 5 and the assembly performance of the tapered roller bearing 1 can be achieved at the same time.

[0090] exist Figure 6 to Figure 10B , a tapered roller bearing 1 according to an embodiment of the second invention is shown. The embodiment of the second invention differs from the embodiment of the first invention in that only the structure of the oil retaining recess 20 is different, and the other structures are the same. Therefore, the same reference numerals are attached to the parts corresponding to the embodiment of the first invention, and the description thereof is omitted.

[0091] like Fig. 9 As shown, the oil retaining recess 20 is formed in a square shape having two corner portions 31 where adjacent inner surfaces of the oil retaining recess 20 intersect each other when viewed in the axial direction from the roller large end surface 11 side.

[0092] like Figure 6 to Figure 9 As shown, the inner surface of the oil retaining recess 20 has a bottom surface 32 facing the radial inner side of the retainer, a pair of opposing surfaces 33 that are rising surfaces rising from both ends of the bottom surface 32 in the circumferential direction toward the radial inner side, and a cross section of the tapered roller bearing 1 along the axial plane (i.e., Figure 6 , Figure 7The inner wall surface 34 is formed from the inner circumference of the large-diameter side annular portion 12 to the inside of the large-diameter side annular portion in the cross section shown in FIG. The inner wall surface 34 is adjacent to the opposing surface 33 and the bottom surface 32, respectively. A corner portion 31 is formed between the bottom surface 32 and the inner wall surface 34, between the bottom surface 32 and the opposing surface 33, and between the opposing surface 33 and the inner wall surface 34. The corner portion 31 is formed into an R-surface shape having a curvature radius of 2.0 mm or less (preferably 1.0 mm or less, more preferably 0.3 mm or less, and further preferably 0.2 mm or less).

[0093] The depth of the oil retaining recess 20 (ie, the width from the bottom surface 32 of the oil retaining recess 20 to the inner diameter surface of the large-diameter side annular portion 12) is 1.4 mm or less.

[0094] A force (hereinafter referred to as a retaining force F1) acts on the lubricating oil in the oil retaining recess 20 due to the surface tension of the lubricating oil, and the lubricating oil is retained in the oil retaining recess 20. When the retaining force F1 is greater than the gravity F2 acting on the lubricating oil, the lubricating oil is retained in the oil retaining recess 20. The retaining force F1 and the gravity F2 can be calculated by the following calculation formula.

[0095] Holding force F1 = surface tension γ of lubricating oil × wet edge length L (the total length of the inner surface of the oil retaining recess in contact with the lubricating oil) × cosθ (θ is the contact angle of the lubricating oil)

[0096] Gravity F2 acting on the lubricant = gravitational acceleration g × density of lubricant ρ × volume of lubricant V

[0097] Here, the wet edge length L is the total value of the axial length of the region in contact with the lubricating oil on the facing surface 33 and the circumferential length of the region in contact with the lubricating oil on the inner wall surface 34 .

[0098] For example, when the surface tension of the lubricating oil is γ = 30 (mN / m), the contact angle θ = 18.5 (°), the wet edge length L = 2.8 (mm), and the density of the lubricating oil is ρ = 0.85 (g / mm 3 ), lubricating oil volume V = 0.49 (mm 3 ), F1=8.0×10 －5 N. At this time, the gravity F2 acting on the lubricating oil is F2 = 4.0 × 10 －9 N. Therefore, F1 ≥ F2, and the lubricating oil in the oil retaining recess is retained in the oil retaining recess by surface tension.

[0099] exist Fig.16 2 is a partial structural diagram showing a case where the tapered roller bearing 1 is arranged in a transmission 30 of an automobile.

[0100] In particular, in recent years, there has been a trend to use low-viscosity lubricating oil or reduce the amount of lubricating oil in the transmission or differential mechanism of an automobile in order to suppress energy loss caused by the stirring resistance of the lubricating oil. Fig.11A The oil retaining recess 51 of the retainer 50 shown as a comparative example in FIG. 1 is formed in an arc shape with a single concave arc surface as the inner surface when viewed in the axial direction. Since it has no corner portion, it is difficult to retain lubricating oil in the oil retaining recess 51. Therefore, when the tapered roller bearing 1 stops for a long time, Fig. 11B As shown, the lubricating oil flows out of the oil retaining recess 51, so that the amount of lubricating oil remaining in the tapered roller bearing 1 tends to become too small. Then, when the tapered roller bearing 1 is started, a rapid temperature rise may occur between the large end face 11 of the tapered roller 4 and the large flange 9 of the inner ring 3.

[0101] To solve this problem, in the tapered roller bearing 1 of the present embodiment, lubricating oil is introduced into the oil retaining recess 20 when the tapered roller bearing 1 rotates. Fig. 10A As shown, the oil retaining recess 20 is formed into a square having two corner portions 31 where adjacent inner surfaces of the oil retaining recess 20 intersect each other when viewed in the axial direction. In the corner portions 31 of the oil retaining recess 20, the lubricating oil is in contact with the adjacent inner surfaces of the oil retaining recess 20, respectively, so that the lubricating oil is easily retained in the oil retaining recess 20 by the surface tension of the lubricating oil. Therefore, during the stoppage of the bearing, the lubricating oil in the oil retaining recess 20 is suppressed from flowing out due to its own weight, so that the lubricating oil can be retained in the oil retaining recess 20 even when the tapered roller bearing 1 is stopped for a long time. Thereafter, if the tapered roller bearing 1 rotates, the lubricating oil in the oil retaining recess 20 is as follows. Fig. 10B As shown, the large end face 11 can be lubricated by the centrifugal force and moved toward the tapered roller 4. Therefore, after the tapered roller bearing 1 has been stopped for a long time, when the tapered roller bearing 1 is started, the rapid temperature rise between the large end face 11 of the tapered roller 4 and the large flange 9 of the inner ring 3 can be effectively prevented.

[0102] In addition, the corner portion 31 includes two or more corner portions 31 at acute angles in which adjacent inner surfaces intersect each other at an angle of 90° or less when viewed in the axial direction. At the corner portion 31 in which the inner surfaces of the oil retaining recess intersect each other at an angle of 90° or less, the lubricating oil easily contacts each of the adjacent surfaces. Therefore, in such a corner portion 31, the contact area between the lubricating oil in the oil retaining recess and the inner surface of the oil retaining recess becomes larger. Furthermore, the surface tension generated between the lubricating oil and the inner surface of the oil retaining recess 20 becomes larger, so that the lubricating oil in the oil retaining recess 20 can be more appropriately retained in the oil retaining recess 20.

[0103] In addition, since the intersection of the adjacent inner surfaces of the corner portion 31 passes through the R surface, it is possible to suppress the stress concentration on the corner portion 31 when the bearing rotates, and the moldability of the oil retaining recess 20 is improved. In addition, the curvature radius of the R surface is preferably 1.0 mm or less, at least 2.0 mm or less, so it is possible to suppress the stress concentration on the corner portion 31 when the bearing rotates.

[0104] In addition, since a plurality of oil retaining recesses 20 are arranged in the circumferential direction between the columnar portions 14 adjacent in the circumferential direction, the area of ​​the inner surface of the oil retaining recess 20 can be increased compared to the case where one oil retaining recess 20 is provided between the columnar portions 14 adjacent in the circumferential direction. Therefore, the contact area between the lubricating oil in the oil retaining recess 20 and the inner surface of the oil retaining recess 20 increases, and the surface tension acting between the inner surface and the lubricating oil increases. As a result, it becomes easy to retain the lubricating oil in the oil retaining recess 20.

[0105] In addition, since the tapered roller bearing 1 has the oil retaining recesses 20 disposed on both sides of the recesses 11a of the large end faces 11 of the tapered roller 4, when the tapered roller bearing 1 stops, the lubricating oil retained in the oil retaining recesses 20 can be prevented from flowing out of the recesses 11a of the large end faces 11 of the tapered roller 4, thereby reducing the friction between the tapered roller 4 and the large flange 9 of the inner ring 3 while lubricating the large end faces 11 (particularly the annular surface 11b) of the tapered roller 4.

[0106] In addition, in the tapered roller bearing 1, since the opening area of ​​the portion of the opening on the large-diameter side pocket surface 16 side of the oil retaining recess 20 that faces the large end surface 11 of the tapered roller 4 is 50% or more (preferably 70% or more, and more preferably 90% or more) of the opening area on the large-diameter side pocket surface 16 side of the oil retaining recess 20, most of the lubricating oil that flows out of the oil retaining recess 20 through the opening on the large-diameter side pocket surface 16 side of the oil retaining recess 20 can be efficiently attached to the large end surface 11 (particularly the annular surface 11b) of the tapered roller 4, thereby effectively lubricating the large end surface 11 of the tapered roller 4.

[0107] In addition, if the tapered roller bearing 1 is preferably provided with an oil retaining recess 20 on the inner side than the periphery of the large end face 11 of the roller so that the oil retaining recess 20 does not protrude to the outside of the area opposite to the large end face 11 of each tapered roller 4, then when the tapered roller bearing 1 stops, the lubricating oil retained in the oil retaining recess 20 can be efficiently supplied to the large end face 11 of the roller, thereby achieving an effect of facilitating lubrication between the large end face of the roller and the large flange surface of the inner ring.

[0108] In the above embodiment, as the polygonal oil retaining recess 20 having two or more corner portions 31 where the adjacent inner surfaces of the oil retaining recess 20 intersect each other when viewed in the axial direction, a square structure having two corner portions 31 is described as an example, but it may also be as follows. Fig.12 As shown, when viewed in the axial direction, the oil retaining recess 20 is formed into a hexagonal shape having four corner portions 31 where adjacent inner surfaces of the oil retaining recess 20 intersect each other.

[0109] exist Fig.12 In the embodiment, the oil retaining recess 20 is formed in a hexagonal shape when viewed from the roller large end surface 11 side. Corner portions 31 are formed at four locations where adjacent inner surfaces in the oil retaining recess 20 intersect each other. The hexagonal oil retaining recess 20 has a bottom surface 32 facing the inner side of the retainer in the radial direction, a first surface 36 intersecting both ends of the bottom surface 32 in the retainer circumferential direction, and a second surface 37 intersecting the end of the first surface and opening to the large diameter side pocket surface 16 side of the oil retaining recess 20. The inner angle of the corner portion 31 between the bottom surface 32 and the first surface 36 is formed to be 90° or more. The inner angle of the corner portion 31 between the first surface 36 and the second surface 37 is a right angle or an acute angle less than 90°. In this way, the hexagonal oil retaining recess 20 when viewed in the axial direction increases the number of corner portions 31 in the oil retaining recess 20 compared to the case where the square oil retaining recess 20 when viewed in the axial direction is used. Therefore, the lubricating oil can be more effectively retained in the oil retaining recess 20 .

[0110] In addition, if Fig.13 As shown, the hexagonal oil retaining recess 20 can be formed into a hexagonal shape in which the inner angle of the corner between the bottom surface 32 and the first surface 36 is an acute angle less than 90°, and the outer angle of the corner between the first surface 36 and the second surface 37 is an obtuse angle exceeding 180°.

[0111] like Fig.14 , Fig.15 As shown, it is possible to form an axial direction ( Fig.15 The oil retaining groove 35 is formed in a region separated from the inner circumference of the large-diameter side annular portion 12 in the radial direction outward so as not to have a portion open to the inner circumference of the large-diameter side annular portion 12. The axial direction ( Fig.15 The depth in the left-right direction (in the image) is less than 1.0 mm (preferably less than 0.5 mm).

[0112] The oil retaining groove 35 has a Fig.14 The transverse groove portion 35a extends from one side to the other side (in the left-right direction) and the longitudinal groove portion 35b branches from the middle of the transverse groove portion 35a and extends radially outward. Fig.14The width of the longitudinal groove portion 35b in the vertical direction (in the vertical direction) is 0.1 mm to 1.0 mm (preferably 0.2 mm to 0.8 mm, more preferably 0.4 mm to 0.6 mm). The width of the longitudinal groove portion 35b in the circumferential direction is 0.1 mm to 1.0 mm (preferably 0.2 mm to 0.8 mm, more preferably 0.4 mm to 0.6 mm).

[0113] like Fig.14 , Fig.15 As shown, if the oil retaining groove 35 recessed in the axial direction is formed on the inner wall surface 34, the lubricating oil in the oil retaining recess 20 enters the oil retaining groove 35 formed on the inner wall surface 34 of the oil retaining recess 20, and is easily retained in the oil retaining recess 20. Therefore, the lubricating oil in the oil retaining recess 20 can properly lubricate the roller large end surface 11 during the rotation of the tapered roller bearing 1, and can be properly retained in the oil retaining recess 20 when the tapered roller bearing 1 stops.

[0114] In addition, the oil retaining groove 35 is formed in a region separated from the inner peripheral surface of the large-diameter side annular portion 12 toward the radially outer side so as not to have a portion opening to the inner peripheral surface of the large-diameter side annular portion 12. Therefore, in the oil retaining recess 20 located above the axis of the rotating shaft of the tapered roller bearing 1, the lubricating oil inside is appropriately retained by the oil retaining groove 35. That is, in the oil retaining recess 20 located above the axis, the lubricating oil inside is acted on downward (toward the inner peripheral surface side of the large-diameter side annular portion 12) by gravity, but the oil retaining groove 35 in the oil retaining recess 20 does not have a portion opening to the inner peripheral surface of the large-diameter side annular portion 12. Therefore, the lubricating oil in the oil retaining groove 35 is not likely to flow out of the oil retaining groove 35 due to its own weight. Therefore, the lubricating oil in the oil retaining recess 20 can be appropriately retained in the oil retaining recess 20 by the oil retaining groove 35.

[0115] In addition, the oil retaining groove 35 includes a transverse groove portion 35a extending from one side to the other side in the circumferential direction and a longitudinal groove portion 35b branching from the middle of the transverse groove portion 35a and extending radially outward, and the surface area of ​​the inner surface of the oil retaining groove 35 is increased, and the contact area between the lubricating oil in the oil retaining recess 20 and the inner surface of the oil retaining groove 35 is increased. Therefore, the surface tension generated in the oil retaining groove 35 and between the inner surface and the lubricating oil becomes larger. Therefore, the lubricating oil in the oil retaining recess 20 can be more appropriately retained in the oil retaining recess 20.

[0116] The tapered roller bearing 1 can also be used as Fig.17 The input shaft of the differential mechanism 40 shown is supported by a rotatable rolling bearing.

[0117] Furthermore, although the embodiment of the present invention has been described, the scope of the present invention is not limited to the above-described embodiment, and various modifications can be applied.

[0118] In the above embodiments, Figure 2 , Figure 4 , Figure 5 , Figure 8 As shown, oil retaining recesses 20 are provided at two locations on each large-diameter side pocket surface 16, but oil retaining recesses 20 may be provided at three or more locations on each of the large-diameter side pocket surfaces 16, or oil retaining recesses 20 may be provided at one location, and different numbers of oil retaining recesses 20 may be provided on each of the large-diameter side pocket surfaces 16.

[0119] The embodiments disclosed this time should be considered in all respects as illustrative and non-restrictive descriptions. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0120] Description of reference numerals:

[0121] 1…tapered roller bearing; 2…outer ring; 3…inner ring; 4…tapered roller; 5…cage; 8…small flange; 9…large flange; 10…small end face; 11…large end face; 11a…recess; 12…large diameter side annular portion; 13…small diameter side annular portion; 14…column; 15…pocket; 16…large diameter side pocket surface; 20…oil retaining recess; 21…bottom surface (the surface facing radially inward on the inner surface of the oil retaining recess); 31…corner; 34…inner wall surface; 35…oil retaining groove; 35a…lateral groove portion; 35b…longitudinal groove portion.

Claims

1. A tapered roller bearing comprising: Outer ring; An inner ring, which is coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential spacing of the plurality of tapered rollers, The inner ring has a large flange that contacts the large end faces of the tapered rollers. The retainer comprises a large-diameter annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end surfaces of the plurality of tapered rollers, and a plurality of columnar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of columnar portions define a plurality of pockets for accommodating the plurality of tapered rollers, respectively. The large diameter side annular portion has a large diameter side pocket surface facing the large end surface of each tapered roller, and an oil retaining recessed portion opening between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The tapered roller bearing is characterized in that: The surface of the inner surface of the oil retaining recess facing the radial inner side is an inclined surface which approaches the radial inner side as it approaches the tapered roller. The tapered roller has a recessed portion at the center of the large end surface. The oil retaining recess is arranged on both sides sandwiching the recess.

2. A tapered roller bearing comprising: Outer ring; An inner ring, which is coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential spacing of the plurality of tapered rollers, The inner ring has a large flange that contacts the large end faces of the tapered rollers. The retainer comprises a large-diameter annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end surfaces of the plurality of tapered rollers, and a plurality of columnar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of columnar portions define a plurality of pockets for accommodating the plurality of tapered rollers, respectively. The large diameter side annular portion has a large diameter side pocket surface facing the large end surface of each tapered roller, and an oil retaining recessed portion opening between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The tapered roller bearing is characterized in that: The oil retaining recess is formed in a polygonal shape having two or more corner portions where adjacent inner surfaces of the oil retaining recess intersect each other when viewed in the axial direction. The tapered roller has a recessed portion at the center of the large end surface. The oil retaining recess is arranged on both sides sandwiching the recess.

3. The tapered roller bearing according to claim 2, wherein: The oil retaining recess has an inner wall surface extending from the inner peripheral surface of the large-diameter side annular portion toward the inside of the large-diameter side annular portion in a cross section perpendicular to the circumferential direction, and an oil retaining groove recessed in the axial direction is formed on the inner wall surface.

4. The tapered roller bearing according to claim 3, wherein: The oil retaining groove is formed in a region separated from the inner peripheral surface of the large-diameter side annular portion toward the radially outer side so as not to have a portion open to the inner peripheral surface of the large-diameter side annular portion.

5. The tapered roller bearing according to claim 3 or 4, wherein: The oil retaining groove includes a transverse groove portion extending from one side to the other side in the circumferential direction, and a longitudinal groove portion branching from the middle of the transverse groove portion and extending radially outward.

6. The tapered roller bearing according to any one of claims 1 to 4, wherein: The oil retaining recess is located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller.

7. The tapered roller bearing according to any one of claims 1 to 4, wherein: The inner ring has a small flange facing the small end surface of each tapered roller. The retainer is integrally formed of a resin composition in which an elastomer is added to a resin material.

8. A tapered roller bearing comprising: Outer ring; An inner ring, which is coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential spacing of the plurality of tapered rollers, The inner ring has a large flange that contacts the large end faces of the tapered rollers. The retainer comprises a large-diameter annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end surfaces of the plurality of tapered rollers, and a plurality of columnar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of columnar portions define a plurality of pockets for accommodating the plurality of tapered rollers, respectively. The large diameter side annular portion has a large diameter side pocket surface facing the large end surface of each tapered roller, and an oil retaining recessed portion opening between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The tapered roller bearing is characterized in that: The surface of the inner surface of the oil retaining recess facing the radial inner side is an inclined surface which approaches the radial inner side as it approaches the tapered roller. The oil retaining recess is located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller.

9. A tapered roller bearing comprising: Outer ring; An inner ring, which is coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential spacing of the plurality of tapered rollers, The inner ring has a large flange that contacts the large end faces of the tapered rollers. The retainer comprises a large-diameter annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end surfaces of the plurality of tapered rollers, and a plurality of columnar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of columnar portions define a plurality of pockets for accommodating the plurality of tapered rollers, respectively. The large diameter side annular portion has a large diameter side pocket surface facing the large end surface of each tapered roller, and an oil retaining recessed portion opening between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The tapered roller bearing is characterized in that: The oil retaining recess is formed in a polygonal shape having two or more corner portions where adjacent inner surfaces of the oil retaining recess intersect each other when viewed in the axial direction. The oil retaining recess is located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller.

10. The tapered roller bearing according to claim 9, wherein: The oil retaining recess has an inner wall surface extending from the inner peripheral surface of the large-diameter side annular portion toward the inside of the large-diameter side annular portion in a cross section perpendicular to the circumferential direction, and an oil retaining groove recessed in the axial direction is formed on the inner wall surface.

11. The tapered roller bearing according to claim 10, wherein: The oil retaining groove is formed in a region separated from the inner peripheral surface of the large-diameter side annular portion toward the radially outer side so as not to have a portion open to the inner peripheral surface of the large-diameter side annular portion.

12. The tapered roller bearing according to claim 10 or 11, wherein: The oil retaining groove includes a transverse groove portion extending from one side to the other side in the circumferential direction, and a longitudinal groove portion branching from the middle of the transverse groove portion and extending radially outward.

13. The tapered roller bearing according to any one of claims 8 to 11, wherein: The inner ring has a small flange facing the small end surface of each tapered roller. The retainer is integrally formed of a resin composition in which an elastomer is added to a resin material.

14. A tapered roller bearing comprising: Outer ring; An inner ring, which is coaxially arranged on the inner side of the outer ring; a plurality of tapered rollers assembled between the outer ring and the inner ring at intervals in the circumferential direction; and an annular retainer that maintains the circumferential spacing of the plurality of tapered rollers, The inner ring has a large flange that contacts the large end faces of the tapered rollers. The retainer comprises a large-diameter annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end surfaces of the plurality of tapered rollers, and a plurality of columnar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of columnar portions define a plurality of pockets for accommodating the plurality of tapered rollers, respectively. The large diameter side annular portion has a large diameter side pocket surface facing the large end surface of each tapered roller, and an oil retaining recessed portion opening between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The tapered roller bearing is characterized in that: The oil retaining recess is formed in a polygonal shape having two or more corner portions where adjacent inner surfaces of the oil retaining recess intersect each other when viewed in the axial direction. The oil retaining recess has an inner wall surface extending from the inner circumferential surface of the large-diameter side annular portion toward the inside of the large-diameter side annular portion in a cross section at right angles to the circumferential direction, and an oil retaining groove recessed in the axial direction is formed on the inner wall surface. The oil retaining groove is formed in a region separated from the inner peripheral surface of the large-diameter side annular portion toward the radially outer side so as not to have a portion open to the inner peripheral surface of the large-diameter side annular portion.

15. The tapered roller bearing according to claim 14, wherein: The oil retaining groove includes a transverse groove portion extending from one side to the other side in the circumferential direction, and a longitudinal groove portion branching from the middle of the transverse groove portion and extending radially outward.

16. The tapered roller bearing according to claim 14 or 15, wherein: The inner ring has a small flange facing the small end surface of each tapered roller. The retainer is integrally formed of a resin composition in which an elastomer is added to a resin material.

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