Hub unit bearing

Abstract

We provide a hub unit bearing equipped with a cage that facilitates grease sealing. [Solution] The inner ring has a large flange portion that protrudes radially outward on the larger diameter side relative to the inner ring raceway. The large flange portion has a large flange surface facing the head of the conical roller, a large flange outer diameter surface facing radially outward, and a large flange chamfer surface formed between the large flange surface and the large flange outer diameter surface. The radially inner surface of the column portion has an inclined portion in a cross section perpendicular to the circumferential direction such that the angle of intersection with the central axis is smaller than the angle of intersection between the extension line from the large flange chamfer surface and the central axis.

Description

Technical Field

[0001] The present invention relates to a hub unit bearing.

Background Art

[0002] Conventionally, it is known that tapered rollers are used as rolling elements in hub unit bearings used in heavy automobiles. In this hub unit bearing, the tapered rollers are held in a freely rotatable state at equal intervals in the circumferential direction between an outer ring member and an inner ring member by a cage. Also, generally, a lubricant such as grease is used in hub unit bearings used in automobiles and the like.

[0003] In the hub unit bearing described in Patent Document 1, the cage has claw portions on the radially outer side of the column portion. By making the outer diameter side opening formed between the claw portions facing each other in the circumferential direction and the inner diameter side opening on the radially inner side of the column portion smaller than the diameter of the tapered roller, it is difficult for the tapered roller to fall off from the cage, facilitating assembly.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when the tapered roller is supported by the openings on the outer diameter side and the inner diameter side of the column portion of the cage as in the cage used in the hub unit bearing described in Patent Document 1, the column portion may be formed wide in the radial direction. In this case, when grease is enclosed in the space between the outer ring and the inner ring after assembling the hub unit bearing, the column portion of the cage obstructs the flow of the grease, increasing the flow path resistance, making it difficult to enclose the grease, and there is a problem that the grease cannot be completely filled in the space.

[0006] The present invention has been made in view of the above problems, and its objective is to provide a hub unit bearing equipped with a cage that facilitates the sealing of grease. [Means for solving the problem]

[0007] The above objective of the present invention is achieved by the following configuration. (1) An outer ring having an outer ring raceway on its inner circumference, An inner ring having an inner ring track on its outer surface, A plurality of tapered rollers are arranged between the outer ring raceway and the inner ring raceway, A retainer comprising a small-diameter annular portion, a large-diameter annular portion having a larger outer diameter than the small-diameter annular portion, and a plurality of columnar portions arranged at equal intervals in the circumferential direction and connecting the small-diameter annular portion and the large-diameter annular portion in the axial direction, wherein the portions between adjacent columnar portions in the circumferential direction are pockets for holding the tapered roller so that it can roll freely, A hub unit bearing equipped with, The inner ring has a large flange portion that protrudes radially outward on the larger diameter side relative to the inner ring raceway. The aforementioned large flange portion is The large flange surface facing the head of the aforementioned cone, The outer diameter surface of the large flange facing radially outward, A large flange chamfered surface formed between the large flange surface and the large flange outer diameter surface, It has, The radial inner surface of the column portion has an inclined portion such that, in a cross section perpendicular to the circumferential direction, the angle of intersection with the central axis is smaller than the angle of intersection between the extension line from the large flange chamfer surface and the central axis. A hub unit bearing characterized by the following features. [Effects of the Invention]

[0008] According to the present invention, a hub unit bearing can be provided that has a cage that does not block the grease flow path inside the hub unit bearing and facilitates the sealing of grease. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a partial cross-sectional view showing a hub unit bearing according to the first embodiment of the present invention. [Figure 2] Figure 2 is a perspective view of a portion of a cage, with a conical roller incorporated into a pocket, seen from the radially inward and obliquely upward. [Figure 3] Figure 3 is a cross-sectional view taken from the direction indicated by the arrow III-III in Figure 2. [Figure 4] Figure 4 is a schematic cross-sectional view showing the positional relationship between the cage, the tapered roller, and the inner ring. [Figure 5] Figure 5 is a perspective view of a part of the retainer according to the second embodiment, in which a tapered roller is incorporated into a pocket, viewed from the radially inward and obliquely upward. [Figure 6] Figure 6 is a schematic cross-sectional view showing the positional relationship between the retainer, tapered roller, and inner ring according to the second embodiment. [Modes for carrying out the invention]

[0010] (First Embodiment) Embodiments of the present invention will be described below with reference to the attached drawings. Figure 1 is a partial cross-sectional view showing a hub unit bearing according to the first embodiment of the present invention. The hub unit bearing 1 of this embodiment uses tapered rollers as rolling elements and is used to rotatably support the wheels of automobiles such as large SUVs and commercial vehicles.

[0011] As shown in Figure 1, the hub unit bearing 1 comprises an outer ring 2 that does not rotate in use, a hub 3 that rotates with the wheel and braking rotating body such as a disc or drum in use, double rows of tapered rollers 4a and 4b, two cages 30a and 30b, an outer sealing member 18, and an inner sealing member 19. With respect to the hub unit bearing, the axial outer side refers to the left side of Figure 1, which is the outer side in the width direction of the vehicle body when assembled to the vehicle, and the axial inner side refers to the right side of Figure 1, which is the center side in the width direction of the vehicle body when assembled to the vehicle.

[0012] The outer ring 2 is made of medium carbon steel such as S53C and has a substantially cylindrical shape. A stationary flange 5 that is coupled to the knuckle of the suspension device is provided at an axially intermediate portion of the outer peripheral surface of the outer ring 2. Double-row outer ring raceways 6a and 6b are provided on the inner peripheral surface of the outer ring 2. The double-row outer ring raceways 6a and 6b each have a conical surface shape, and their inclination directions are opposite to each other. The inner row outer ring raceway 6a located on the axially inner side has an increasing inner diameter toward the axially inner side, and the outer row outer ring raceway 6b located on the axially outer side has an increasing inner diameter toward the axially outer side.

[0013] The hub 3 is disposed coaxially with the outer ring 2 on the radially inner side of the outer ring 2, and is configured by combining a hub ring 7 made of medium carbon steel such as S53C and an inner ring 8 made of high carbon chromium steel such as SUJ2. Double-row inner ring raceways 10a and 10b are provided on the outer peripheral surface of the hub 3. The double-row inner ring raceways 10a and 10b each have a conical surface shape, and their inclination directions are opposite to each other. The inner row inner ring raceway 10a located on the axially inner side has an increasing outer diameter toward the axially inner side, and the outer row inner ring raceway 10b located on the axially outer side has an increasing outer diameter toward the axially outer side.

[0014] The hub ring 7 is a shaft member that externally fits and holds the inner ring 8, and has, in order from the axially outer side, a pilot portion 12, a rotating flange 9, a large flange portion 20b, an outer row inner ring raceway 10b, and a fitting shaft portion 11.

[0015] The pilot portion 12 is for externally fitting a wheel and a braking rotating body, and is provided so as to project axially outward from the radial intermediate portion of the axially outer portion of the hub ring 7, and has a substantially cylindrical shape. The rotating flange 9 is for attaching a wheel and a braking rotating body, and is provided on the axially outer portion of the hub ring 7 so as to project radially outward, and has a substantially circular ring shape. The large flange portion 20b is for regulating the axial position of the outer row of tapered rollers 4b and supporting the axial load acting on the outer row of tapered rollers 4b, and is provided adjacent to the axially outer side of the inner ring raceway 10b of the outer row. The axially inner surface of the large flange portion 20b is inclined in the direction of axially inward as it goes radially outward, and is in contact with and opposed to the head (large diameter side end portion) of the outer row of tapered rollers 4b. The inner ring raceway 10b of the outer row is formed in the axial intermediate portion of the outer peripheral surface of the hub ring 7. The fitting shaft portion 11 is provided in the axially inner portion of the hub ring 7, and the inner ring 8 is externally fitted by interference fit. A stepped surface 15 is provided between the outer peripheral surface of the fitting shaft portion 11 and the inner ring raceway 10b of the outer row. Further, a caulking portion 16 bent radially outward is formed at the axially inner end portion of the fitting shaft portion 11.

[0016] Instead of the structure of forming the caulking portion 16 at the axially inner end portion of the hub ring 7, a structure of screwing a nut to the axially inner end portion of the hub ring 7 can also be adopted. Further, since the hub unit bearing 1 of the present embodiment is for a driven wheel, the hub ring 7 is configured to be solid, but the present invention is also applicable to a hub unit bearing for a driving wheel. When applying to a hub unit bearing for a driving wheel, a spline hole for engaging a spline shaft, which is a driving shaft member, is formed so as to penetrate axially through the radial central portion of the hub ring 7.

[0017] The inner ring 8 has an annular shape and is fitted onto the fitting shaft portion 11 by interference fit. The outer axial end face of the inner ring 8 abuts against the stepped surface 15, and the inner axial end face of the inner ring 8 is pressed down by the crimping portion 16. The inner ring 8 has an inner ring raceway 10a of the inner row in the axial middle portion of its outer circumference. The inner ring 8 also has a large flange portion 20a that protrudes radially outward in the axial direction inward relative to the inner ring raceway 10a. The large flange surface 21, which is the outer axial surface of the large flange portion 20a, is inclined in the direction of axial outward as it extends radially outward, and is in contact with and opposite the head (large diameter side end) of the tapered roller 4a of the inner row. The large flange portion 20a prevents the tapered roller 4a of the inner row from falling out in the axial direction and supports the axial load acting on the tapered roller 4a of the inner row.

[0018] The tapered rollers 4a and 4b are made of high-carbon chromium steel such as SUJ2 and each has a conical shape. The tapered rollers 4a and 4b are arranged in double rows. The tapered roller 4a in the inner row, located axially inward, is rotatably positioned between the outer ring raceway 6a and the inner ring raceway 10a of the inner row via a cage 30a described later. The tapered roller 4b in the outer row, located axially outward, is rotatably positioned between the outer ring raceway 6b and the inner ring raceway 10b of the outer row via a cage 30b described later. The tapered rollers 4a in the inner row and the tapered rollers 4b in the outer row are subjected to a back-to-back contact angle and preload.

[0019] The outer sealing member 18 is fitted and fixed to the inner circumferential surface of the axially outer portion of the outer ring 2, preventing the grease sealed in the space 17 between the inner circumferential surface of the outer ring 2 and the outer circumferential surface of the hub 3 from leaking out through the axially outer opening of the space 17, and also preventing muddy water and dust from entering the space 17 from the outside.

[0020] The inner sealing member 19 is a so-called cover member and is fitted and fixed to the axially inner part of the outer ring 2. The inner sealing member 19 is made of a metal plate or resin and has a bottomed cylindrical shape as a whole. It is press-fitted into the inner circumferential surface of the axially inner part of the outer ring 2, thereby sealing the axially inner opening of the outer ring 2. This prevents the grease sealed in the space 17 from leaking out to the outside through the axially inner opening of the outer ring 2, and also prevents muddy water and dust from entering the space 17 from the outside. In addition, instead of a cover member as in this embodiment, a seal ring fitted between the outer ring 2 and the inner ring 8 can be used as the inner sealing member 19.

[0021] Here, the retainers 30a and 30b are called cage-type retainers, are made of synthetic resin, and are constructed in a partially conical shape. Examples of synthetic resins that can be used to make up the retainers 30a and 30b include polyamide resins such as polyamide 46 and polyamide 66, polybutylene terephthalate, polyphenylene sulfide (PPS), polyamide-imide (PAI), thermoplastic polyimide, polyether ether ketone (PEEK), and polyether nitrile (PEN). Furthermore, rigidity and dimensional accuracy can be improved by appropriately adding 10 to 50 wt% of fibrous filler (for example, glass fiber or carbon fiber) to these resins.

[0022] In this embodiment, both the inner row cage 30a and the outer row cage 30b are roller fall-prevention cages that have a structure to prevent the tapered rollers 4a and 4b from falling out of the pockets 34 of the cages 30a and 30b. The inner row cage 30a and the outer row cage 30b are identical parts, differing only in their assembly direction to the hub unit bearing 1. For this reason, only the inner row cage 30a will be described in detail below.

[0023] Figure 2 is a perspective view of a portion of a cage with tapered rollers incorporated into the pockets, viewed from the radially inward and obliquely upward. Figure 3 is a cross-sectional view taken from the direction of arrow III-III in Figure 2. Figure 4 is a cross-sectional view schematically showing the positional relationship between the cage, the tapered rollers, and the inner ring.

[0024] As shown in Figures 2 to 4, the retainer 30a comprises a small-diameter annular portion 31, a large-diameter annular portion 32 which is larger in diameter than the small-diameter annular portion 31, and a plurality of columnar portions 33 which are arranged at equal intervals in the circumferential direction and connect the small-diameter annular portion 31 and the large-diameter annular portion 32 in the axial direction. The portions between adjacent columnar portions 33 in the circumferential direction are formed as pockets 34. The radial width of the large-diameter annular portion 32 is smaller than the radial width of the columnar portions 33. The large-diameter annular portion 32 is also positioned radially outward from the rotation axis P of the conical roller 4a. In the inner row of retainers 30a, the small-diameter annular portion 31 is positioned axially outward, and the large-diameter annular portion 32 is positioned axially inward. In the outer row of retainers 30b, the small-diameter annular portion 31 is positioned axially inward, and the large-diameter annular portion 32 is positioned axially outward.

[0025] The columnar portion 33 is inclined radially outward as it moves away from the small-diameter annular portion 31. The radially outer surface of the columnar portion 33 is positioned approximately parallel to the outer ring raceway 6a of the inner row. The columnar portion 33 also has a circumferential side surface 36 that is formed to be approximately parallel to each other and flat, and a pair of claw portions 35 that gradually taper outward from the radially outer part of the circumferential side surface 36 of the columnar portion 33 and extend along the longitudinal direction of the conical roller 4a. The claw portions 35 are formed extending from the small-diameter end of the columnar portion 33 to the head side beyond the midpoint of the longitudinal direction of the conical roller 4a. Furthermore, the claw portions 35 are formed radially outward from the rotation axis P of the conical roller 4a.

[0026] Multiple columnar portions 33 are formed radially inward from the straight line L (see Figure 2) connecting the inner circumferential edge of the large-diameter side surface of the small-diameter annular portion 31 and the inner circumferential edge of the small-diameter side surface of the large-diameter annular portion 32, and each columnar portion 33 has a wing portion 37 having a radially inward surface 40. The radially inward surface 40 also has an inclined portion 42 (described later), a notch 44 provided between the inclined portion 42 and the inner circumferential edge of the large-diameter annular portion 32, and a parallel portion 43 formed on the smaller diameter side of the inclined portion 42 and substantially parallel to the rotation axis P of the conical roller 4a. The notch 44 has a curved shape in a cross section perpendicular to the circumferential direction.

[0027] As shown in Figures 2 to 4, the boundary between the parallel portion 43 or the inclined portion 42 and the circumferential side surface 36, that is, the radially inner end of the circumferential side surface 36, means that in this embodiment, the entire area of ​​the parallel portion 43 and the portion of the inclined portion 42 excluding a part on the large diameter side are located radially inward of the rotation axis P of the tapered roller 4a. Similarly, the opening 38 defined by the parallel portion 43, the inclined portion 42 and the circumferential side surface 36 is also located radially inward of the rotation axis P. The circumferential width W (see Figure 4) of the opening 38 located radially inward of the rotation axis P of the tapered roller 4a is smaller than the diameter of the tapered roller 4a at opposing axial positions. Furthermore, the circumferential width X (see Figure 4) of the radially outer opening 39 of the pocket 34, defined by the tips of the claw portions 35 of adjacent column portions 33 in the circumferential direction, is smaller than the diameter of the tapered roller 4a at opposing axial positions. In other words, the blade portion 37, which has a radially inner surface 40 including an inclined portion 42 and a parallel portion 43, supports the tapered roller 4a radially inward from the rotation axis P of the tapered roller 4a, and the claw portion 35 supports the tapered roller 4a radially outward from the rotation axis P of the tapered roller 4a, thereby preventing the tapered roller 4a from falling out of the pocket 34 on both radial sides.

[0028] Here, as mentioned above, the inner ring 8 is provided on the larger diameter side with respect to the inner ring raceway 10a and has a large flange portion 20a that protrudes radially outward. As shown in Figure 4, the large flange portion 20a has a large flange surface 21 facing the head of the tapered roller 4a, a large flange outer diameter surface 22 facing radially outward, and a large flange chamfer surface 23 formed between the large flange surface 21 and the large flange outer diameter surface 22. Note that the large flange chamfer surface 23 is omitted in Figure 1.

[0029] The inclined portion 42 is formed such that, in a cross section perpendicular to the circumferential direction, the angle α at the intersection of the straight line A extending the inclined portion 42 and the central axis O is smaller than the angle β at the intersection of the straight line B extending the large flange chamfer surface 23 and the central axis O. Straight line B is defined by the straight line connecting the boundary 25 between the large flange outer diameter surface 22 and the large flange chamfer surface 23, and the boundary 26 between the large flange surface 21 and the large flange chamfer surface 23 on the plane of Figure 3. For example, even if the large flange chamfer surface 23 is formed in a curved shape, straight line B is defined as the straight line connecting boundary 25 and boundary 26, as described above. Furthermore, the large diameter side end 41 of the inclined portion 42 is located radially outward from the boundary 26 between the large flange chamfer surface 23 and the large flange surface 21.

[0030] The following describes the method of sealing grease into the hub unit bearing 1 according to this embodiment, and the effects of the present invention. As shown in Figures 1 and 4, the grease is sealed in the direction of arrow IV from the axially inner opening formed between the outer ring 2 and the inner ring 8. The grease is pushed by itself between adjacent tapered rollers 4a in the circumferential direction, and spreads outward in the axial direction within the space 17. At this time, the grease passes through the space formed by the cage 30a and the outer ring raceway 6a and the inner ring raceway 10a.

[0031] As described above, the radial width of the large-diameter annular portion 32 is smaller than the radial width of the column portion 33, and the large-diameter annular portion 32 is positioned radially outward from the rotation axis P of the tapered roller 4a. This prevents the large-diameter annular portion 32 of the retainer 30a from obstructing the flow of grease.

[0032] Furthermore, with respect to the straight lines A and B, which are extensions of the inclined portion 42 and the large flange chamfered surface 23, the angles of intersection α between straight line A and the central axis and the angles of intersection β between straight line B and the central axis are formed such that α < β. This restricts the radial inward movement of the tapered roller 4a with the blade portion 37, while preventing the grease flow path from being blocked. This allows the grease to flow more easily along the inclined portion 42 in the axial outward direction of the hub unit bearing 1, making it easier to seal in the grease.

[0033] Furthermore, the large-diameter end 41 of the inclined portion 42 is located radially outward from the boundary 26 between the large flange chamfered surface 23 and the large flange surface 21. This ensures that there is space for grease to flow between the large flange portion 20a and the inclined portion 42, making it easier to seal the grease. In addition, although the grease is sealed in between adjacent tapered rollers 4a, 4a in the circumferential direction, the notch 44 formed on the large-diameter side of the inclined portion 42 widens the grease inlet, making it easier to seal the grease.

[0034] (Second embodiment) Next, a hub unit bearing according to the second embodiment of the present invention will be described with reference to Figures 5 and 6. Figure 5 is a perspective view of the cage according to the second embodiment, in which tapered rollers are incorporated into pockets, viewed from the radially inner side and obliquely upward. Figure 6 is a schematic cross-sectional view showing the positional relationship between the cage, tapered rollers, and inner ring according to the second embodiment. Note that some explanations regarding the hub unit bearing according to the second embodiment will be omitted if the configuration is the same as that of the first embodiment.

[0035] As shown in Figures 5 and 6, in this embodiment, the radial inner surface 40 of the column portion 33 has an inclined portion 42 and a notch 44 provided between the inclined portion 42 and the inner circumferential edge of the large-diameter annular portion 32, and the parallel portion 43 in the first embodiment is not formed. That is, the inclined portion 42 is formed continuously from the small-diameter end of the column portion 33. The angle α at the intersection of the straight line A, which is an extension of the inclined portion 42, and the central axis O is smaller than the angle β at the intersection of the straight line B, which is an extension of the large flange chamfer surface 23, and the central axis O. Furthermore, the inclined portion 42 is formed approximately parallel to the rotation axis P of the cone roller 4a. Moreover, the large-diameter end 41 of the inclined portion 42 is located radially outward from the boundary 26 between the large flange chamfer surface 23 and the large flange surface 21.

[0036] The opening 38 is defined by the boundary between the inclined portion 42 and the circumferential side surface 36, that is, by the radially inner end of the circumferential side surface 36. The opening 38 is located radially inward from the axis of rotation P of the tapered roller 4a. Furthermore, the circumferential width of the opening 38 is smaller than the diameter of the tapered roller 4a at opposing axial positions.

[0037] Furthermore, the small-diameter annular portion 31 has a chamfered surface 50 between its large-diameter side surface and its radially inner surface. This improves the fluidity of the grease on the radially inner side of the small-diameter annular portion 31 of the retainer 30a.

[0038] Even in the above configuration, the grease flow path is secured within the hub unit bearing 1 while the tapered roller 4a is held by the cage 30a, making it easy to fill with grease.

[0039] It should be noted that the present invention is not limited to the embodiments illustrated above, and can be modified as appropriate without departing from the spirit of the invention. In particular, the shape of the blade portion 37 should be such that it holds the conical rollers while not obstructing the flow of grease when grease is sealed inside.

[0040] As described above, the following matters are disclosed in this specification: (1) An outer ring having an outer ring raceway on its inner circumference, An inner ring having an inner ring track on its outer surface, A plurality of tapered rollers are arranged between the outer ring raceway and the inner ring raceway, A retainer comprising a small-diameter annular portion, a large-diameter annular portion having a larger outer diameter than the small-diameter annular portion, and a plurality of columnar portions arranged at equal intervals in the circumferential direction and connecting the small-diameter annular portion and the large-diameter annular portion in the axial direction, wherein the portions between adjacent columnar portions in the circumferential direction are pockets for holding the tapered roller so that it can roll freely, A hub unit bearing equipped with, The inner ring has a large flange portion that protrudes radially outward on the larger diameter side relative to the inner ring raceway. The aforementioned large flange portion is The large flange surface facing the head of the aforementioned cone, The outer diameter surface of the large flange facing radially outward, A large flange chamfered surface formed between the large flange surface and the large flange outer diameter surface, It has, The radial inner surface of the column portion has an inclined portion such that, in a cross section perpendicular to the circumferential direction, the angle of intersection with the central axis is smaller than the angle of intersection between the extension line from the large flange chamfer surface and the central axis. A hub unit bearing characterized by the following features. This configuration allows for the provision of a hub unit bearing equipped with a cage that allows for easy grease filling and prevents blockage of the grease flow path inside the hub unit bearing.

[0041] (2) The plurality of columnar portions are formed radially inward from the straight line connecting the inner circumferential edge on the large diameter side surface of the small diameter annular portion and the inner circumferential edge on the small diameter side surface of the large diameter annular portion, and each columnar portion has a wing portion having the radially inward surface. The radial inner surface is, The inclined portion and, A notch is provided between the inclined portion and the inner circumferential edge of the large-diameter annular portion, It has, The large-diameter end of the inclined portion is located radially outward from the boundary between the large flange chamfered surface and the large flange surface. The hub unit bearing according to (1), characterized in that This configuration allows for a larger flow path for grease between the retainer and the inner diameter raceway, making it easier for the grease to flow towards the smaller diameter side of the retainer. Additionally, the vanes provide support for the rollers from the radially inward side.

[0042] (3) The radial inner surface is It is formed on the smaller diameter side than the aforementioned inclined portion and further has a parallel portion that is substantially parallel to the axis of rotation of the tapered roller. A hub unit bearing as described in (1) or (2), characterized in that it is a hub unit bearing as described in (1) or (2). This configuration allows the tapered roller to be stably held in the parallel section.

[0043] (4) The inclined portion is substantially parallel to the axis of rotation of the cone roller. A hub unit bearing as described in (1) or (2), characterized in that it is a hub unit bearing as described in (1) or (2). This configuration allows for a larger flow path for grease between the retainer and the inner diameter raceway surface, making it easier for the grease to flow towards the smaller diameter side of the retainer.

[0044] (5) The plurality of columnar portions each have a pair of claw portions that protrude gradually in a tapered manner from the radially outer portion of the circumferential side surface of the columnar portion toward the circumferential direction and extend along the longitudinal direction of the cone roller, The circumferential width of the radially inner opening of the pocket, defined by the radially inner end of the circumferential side surface of the column, and the circumferential width of the radially outer opening of the pocket, defined by the tip of the claw portion of adjacent column portions in the circumferential direction, are formed to be smaller than the diameter of the tapered roller at opposing axial positions. A hub unit bearing according to any one of (1) to (4), characterized in that This configuration prevents the rollers from falling off radially inward and radially outward. [Explanation of Symbols]

[0045] 1 Hub unit bearing 2 Outer ring 3 Hubs 5. Static flange 6a, 6b Outer ring track 7 Hub Wheel 8 Inner Ring 9 Rotating flange 10a, 10b Inner ring track 11 Fitting shaft 12 Pilot Section 15 Step surface 16 Crimping part 17 Space 18 Outer sealing member 19. Inner sealing member 20a,20b Otsubabe 21 Large Tsubamen 22 Large tsuba outer diameter surface 23 Large tsuba chamfer surface 25,26 boundary 30a,30b retainer 31 Small diameter annular section 32 Large diameter annular section 33 Pillar section 34 pockets 35 Nail part 36 Circumferential side 37. Wing section 38,39 Opening 40 Radial inner surface 41 Large diameter side end 42 Slope 43 Parallel section 44 Notch 50 Chamfered surface

Claims

1. An outer ring having an outer ring raceway on its inner circumference, An inner ring having an inner ring track on its outer surface, A plurality of tapered rollers are arranged between the outer ring raceway and the inner ring raceway, A retainer comprising a small-diameter annular portion, a large-diameter annular portion having a larger outer diameter than the small-diameter annular portion, and a plurality of columnar portions arranged at equal intervals in the circumferential direction and connecting the small-diameter annular portion and the large-diameter annular portion in the axial direction, wherein the portions between adjacent columnar portions in the circumferential direction are pockets for holding the tapered roller so that it can roll freely, A hub unit bearing equipped with, The inner ring has a large flange portion that protrudes radially outward on the larger diameter side relative to the inner ring raceway. The aforementioned large flange portion is The large flange surface facing the head of the aforementioned cone, The outer diameter surface of the large flange facing radially outward, A large flange chamfered surface formed between the large flange surface and the large flange outer diameter surface, It has, The radial inner surface of the column portion has an inclined portion such that, in a cross section perpendicular to the circumferential direction, the angle of intersection with the central axis is smaller than the angle of intersection between the extension line from the large flange chamfer surface and the central axis. A hub unit bearing characterized by the following features.

2. The plurality of columnar portions are formed radially inward from the straight line connecting the inner circumferential edge of the large-diameter side surface of the small-diameter annular portion and the inner circumferential edge of the small-diameter side surface of the large-diameter annular portion, and each columnar portion has a wing portion having the radially inward surface. The radial inner surface is, The inclined portion and, A notch is provided between the inclined portion and the inner circumferential edge of the large-diameter annular portion, It has, The large-diameter end of the inclined portion is located radially outward from the boundary between the large flange chamfered surface and the large flange surface. A hub unit bearing according to claim 1, characterized in that...

3. The radial inner surface is, It is formed on the smaller diameter side than the aforementioned inclined portion and further has a parallel portion that is substantially parallel to the axis of rotation of the tapered roller. The hub unit bearing according to claim 2, characterized in that

4. The inclined portion is substantially parallel to the axis of rotation of the cone roller. The hub unit bearing according to claim 2, characterized in that

5. Each of the aforementioned columnar portions has a pair of claw portions that gradually taper outward from the radially outer portion of the circumferential side surface of the columnar portion and extend along the longitudinal direction of the tapered roller, The circumferential width of the radially inner opening of the pocket, defined by the radially inner end of the circumferential side surface of the column, and the circumferential width of the radially outer opening of the pocket, defined by the tip of the claw portion of adjacent column portions in the circumferential direction, are formed to be smaller than the diameter of the tapered roller at opposing axial positions. A hub unit bearing according to any one of claims 1 to 4, characterized in that

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