Wheel bearing device

Abstract

To provide a wheel bearing device capable of restraining a slinger from moving in an axial direction regardless of an appearance of axial length of a cylindrical part of the slinger.SOLUTION: An outer side seal member 10 of a wheel bearing device 1 comprises: a slinger 13 having a cylindrical part 13a provided at a base 3d of a hub flange 3b and fitted with an outer periphery 3j of a hub wheel 3 and a disc part 13b opposed to the hub flange 3b; and a seal member 12 having a seal lip. The outer periphery 3j of the hub wheel 3 has a fitting part 31 fitted with the cylindrical part 13a of the slinger 13. The fitting part 31 has a small-diameter part 311, and a large-diameter part 312 positioned further away from the hub flange 3b than the small-diameter part 311 in an axial direction, and formed to have a diameter larger than that of the small-diameter part 311.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a wheel bearing device. [Background technology]

[0002] A wheel bearing device that rotatably supports a wheel in a suspension system of an automobile, etc. is known. The wheel bearing device is provided with a sealing device that closes an open end of an annular space formed by an outer member and an inner member to prevent foreign matter such as muddy water from entering.

[0003] A known sealing device, for example, has a configuration including a core bar that is fitted onto the inner circumference of an outer ring, which is the outer member, a seal member that is integrally joined to the core bar and has multiple seal lips, and a slinger that is provided at the base of a hub flange formed on a hub wheel, which is the inner member, and has a cylindrical portion that fits onto the outer peripheral surface of the hub wheel, and a disc portion that is connected to the hub flange side end of the cylindrical portion and faces the hub flange.

[0004] In a sealing device having such a configuration, when the hub wheel is repeatedly subjected to a vehicle turning load or vibration from the wheel, the received load or vibration is transmitted to the slinger, which may cause the slinger to move in the axial direction.

[0005] If the slinger moves in the axial direction, the tightening margin of the seal lip in contact with the slinger may change, the slinger may interfere with the rolling elements housed between the raceway surface of the outer member and the raceway surface of the inner member, or a gap may appear between the slinger and the hub flange, allowing water to enter the interior.

[0006] Therefore, in the sealing device for a wheel bearing assembly disclosed in Patent Document 1, a ring-shaped protrusion is formed on the shoulder of the hub wheel, and the end face of the cylindrical portion of the slinger abuts against the protrusion of the hub wheel, thereby suppressing axial movement of the slinger. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6228756 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the sealing device of Patent Document 1, if the axial length of the cylindrical portion of the slinger is made shorter within the tolerance range, a gap will occur between the end face of the cylindrical portion of the slinger and the convex portion of the hub wheel.

[0009] If a gap occurs between the end face of the cylindrical portion and the convex portion of the hub wheel, the slinger will move axially within the range of the gap, changing the tightening margin of the seal lip, and it will be difficult to prevent a gap from occurring between the slinger and the hub flange, causing water to enter the interior.

[0010] The present invention has been made in consideration of the above-mentioned circumstances, and provides a wheel bearing device that can suppress axial movement of a slinger regardless of the quality of the axial length of the cylindrical portion of the slinger of the sealing device. [Means for solving the problem]

[0011] That is, the wheel bearing device comprises an inner member composed of an outer member having a double row outer raceway on its inner circumference, a hub wheel having an inner raceway on its outer circumference facing the outer raceway surface and a hub flange for mounting a wheel, and a raceway surface forming member connected to the hub wheel and having an inner raceway on its outer circumference facing the outer raceway surface, double row rolling elements accommodated in a rollable manner between the raceway surfaces of the outer member and the inner member, and an opening on one axial end side of an annular space formed by the outer member and the inner member. a sealing device that blocks an end of the hub flange, the sealing device comprising: a slinger provided at a base of the hub flange, the slinger having a cylindrical portion that fits into the outer peripheral surface of the hub wheel and a disc portion that faces the hub flange; and a seal member having a seal lip, the outer peripheral surface of the hub wheel having a fitting portion into which the cylindrical portion of the slinger fits, the fitting portion having a small diameter portion and a large diameter portion that is positioned axially farther from the hub flange than the small diameter portion and is formed with a larger diameter than the small diameter portion. Effect of the Invention

[0012] According to the present invention, axial movement of the slinger can be suppressed regardless of the quality of the axial length of the cylindrical portion of the slinger. [Brief description of the drawings]

[0013] [Figure 1] 1 is a side cross-sectional view showing a wheel bearing device. [Diagram 2] 4 is a side cross-sectional view showing an outer seal member and a fitting portion of a hub wheel into which a slinger of the outer seal member is fitted. FIG. [Diagram 3] FIG. 4 is an enlarged cross-sectional side view showing a fitting portion of the hub wheel. [Figure 4] 11 is a diagram showing the relationship between the fitting position of the slinger relative to the fitting portion and the pulling force of the slinger. FIG. [Diagram 5] 13 is an enlarged side cross-sectional view showing a fitting portion of a hub wheel according to a second embodiment. FIG. [Figure 6] 13 is an enlarged side cross-sectional view showing a fitting portion of a hub wheel according to a third embodiment. FIG. [Figure 7] 11 is an enlarged side cross-sectional view showing a cylindrical portion of a slinger according to a second embodiment. FIG. [Figure 8] FIG. 2 is a side cross-sectional view showing a wheel bearing device having a fourth-generation structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0015] [Wheel bearing device] A wheel bearing device 1 shown in FIG. 1 is one embodiment of a wheel bearing device according to the present invention, and supports a wheel rotatably in a suspension system of a vehicle such as an automobile.

[0016] In the following description, the axial direction refers to the direction along the rotation axis X of the wheel support bearing device 1. The outer side refers to one axial end side, which is the wheel side of the wheel support bearing device 1 when attached to the vehicle body, and the inner side refers to the other axial end side, which is the vehicle body side of the wheel support bearing device 1 when attached to the vehicle body.

[0017] The wheel bearing device 1 has a configuration called third generation, and includes an outer ring 2 as an outer member, a hub ring 3 and an inner ring 4 as inner members, two rolling rows of inner ball rows 5 and outer ball rows 6, an inner seal member 9 and an outer seal member 10. The inner ring 4 is an example of a raceway surface forming member connected to the hub ring.

[0018] An inner side opening 2a is formed at the inner side end of the outer ring 2, into which an inner side seal member 9 can be fitted. An outer side opening 2b is formed at the outer side end of the outer ring 2, into which an outer side seal member 10 can be fitted. The inner circumferential surface of the outer ring 2 is formed with an inner side outer raceway surface 2c and an outer side outer raceway surface 2d.

[0019] A vehicle body mounting flange 2e for mounting the outer ring 2 to a vehicle body member is integrally formed on the outer peripheral surface of the outer ring 2. The vehicle body mounting flange 2e is provided with bolt holes 2f into which fastening members (here, bolts) for fastening the outer ring 2 to the vehicle body member are inserted.

[0020] The inner end of the outer circumferential surface 3j of the hub wheel 3 is formed with a small diameter step 3a that is smaller in diameter than the outer end. A hub flange 3b for mounting a wheel is formed integrally with the outer end of the hub wheel 3. A plurality of bolt holes 3e are formed in the hub flange 3b. Hub bolts 3f for fastening the hub wheel 3 to a wheel or a brake component are press-fitted into the bolt holes 3e. The hub wheel 3 has a through hole 3i that passes through in the axial direction, and a constant velocity universal joint, which is an inner member, can be fitted into the through hole 3i so as to be rotatable integrally with the hub wheel 3.

[0021] An outer peripheral surface 3j of the hub ring 3 is provided with an outer-side inner raceway surface 3c so as to face the outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner raceway surface 3c is formed by the hub ring 3 on the outer side of the inner member. The inner raceway surface 3c is an example of one of the inner raceway surfaces that faces the outer raceway surface.

[0022] The inner seal member 9 is fitted into and closes the inner opening end of the annular space S formed by the outer ring 2 and the hub wheel 3. The outer seal member 10 is fitted into and closes the outer opening end of the annular space S formed by the outer ring 2 and the hub wheel 3. The outer seal member 10 is an example of a sealing device.

[0023] An inner ring 4 is provided on the small diameter step 3a of the hub ring 3. The inner ring 4 is fixed to the small diameter step 3a of the hub ring 3 by press fitting and crimping. The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6, which are the rolling rows. The inner ring 4 has an inner end face 4b at its inner end. At the inner end of the hub ring 3, a crimped portion 3h is formed that is crimped to the inner end face 4b of the inner ring 4.

[0024] An inner-side inner raceway surface 4a is provided on the outer peripheral surface of the inner ring 4 so as to face the inner-side outer raceway surface 2c of the outer ring 2. In other words, on the inner side of the inner member, the inner raceway surface 4a is formed by the inner ring 4. The inner raceway surface 4a is an example of the other inner raceway surface facing the outer raceway surface.

[0025] The inner ball row 5 and the outer ball row 6, which are rolling rows, are formed by a plurality of balls 7, which are rolling elements, being held by a cage 8. The inner ball row 5 is rollably sandwiched between the inner raceway surface 4a of the inner ring 4 and the inner-side outer raceway surface 2c of the outer ring 2. The outer ball row 6 is rollably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer raceway surface 2d of the outer ring 2. In other words, the inner ball row 5 and the outer ball row 6 are rollably housed between the raceway surfaces of the outer member and the inner member.

[0026] In the wheel bearing device 1, a double-row angular ball bearing is formed by the outer ring 2, hub ring 3, inner ring 4, inner ball row 5, and outer ball row 6. Note that the wheel bearing device 1 may be formed as a double-row tapered roller bearing instead of the double-row angular ball bearing.

[0027] [Outer seal material] 2, the outer seal member 10 has a core 11 that is fitted onto the inner circumference at the outer end of the outer ring 2, a seal member 12 that is integrally joined to the core 11, and a slinger 13 that is fitted onto a base 3d of a hub flange 3b of the hub wheel 3. The outer seal member 10 only needs to be fixed to the outer ring 2, which is the outer member, and may, for example, be fitted onto the outer periphery at the outer end of the outer ring 2.

[0028] The core bar 11 is made of, for example, a steel plate, and has a cylindrical fitting portion 11a that fits into the inner circumference of the outer side opening 2b of the outer ring 2, and an inner portion 11b that extends from the inner side end portion of the fitting portion 11a toward the inner diameter side.

[0029] The seal member 12 is formed of an elastic material such as synthetic rubber, and is joined to the core metal 11 by vulcanization adhesion. The seal member 12 has a base 12a, a first side lip 12b, a second side lip 12c, and a radial lip 12d. The base 12a is joined to the inner diameter side end of the inner side surface of the inner portion 11b of the core metal 11, the inner diameter side end face of the inner portion 11b, the outer side surface of the inner portion 11b, and the outer side end of the fitting portion 11a of the core metal 11.

[0030] The first side lip 12b extends from the core metal 11 toward the hub flange 3b, which is the outer side. Specifically, the first side lip 12b extends from the inner side portion 11b of the core metal 11 toward the hub flange 3b side and the outer diameter side. The first side lip 12b contacts the slinger 13. The first side lip 12b is an example of a seal lip that the seal member has.

[0031] The second side lip 12c extends from the core 11 toward the hub flange 3b on the outer side, on the inner diameter side of the first side lip 12b. Specifically, the second side lip 12c extends from the inner portion 11b of the core 11 toward the hub flange 3b side and the outer diameter side. The second side lip 12c is in sliding contact with the slinger 13. The second side lip 12c is an example of a seal lip that the seal member has.

[0032] The radial lip 12d extends from the core metal 11 toward the inner diameter side, radially inward of the second side lip 12c. Specifically, the radial lip 12d extends from the inner portion 11b of the core metal 11 toward the inner diameter side and the inner side. The radial lip 12d is in sliding contact with the slinger 13. The radial lip 12d is an example of a seal lip that the seal member has.

[0033] The slinger 13 is made of, for example, a steel plate, and has a cylindrical portion 13a, a disk portion 13b, a connecting portion 13c, and an extending portion 13d.

[0034] The cylindrical portion 13a is formed in a cylindrical shape, and is fitted onto the outer peripheral surface 3j of the hub wheel 3, on the inner side of the hub flange 3b. The inner peripheral surface of the cylindrical portion 13a is formed axially parallel to the rotation axis X. The cylindrical portion 13a faces the radial lip 12d in the radial direction, and the cylindrical portion 13a and the radial lip 12d are in contact with each other.

[0035] An outer peripheral surface 3j of the hub wheel 3 has a fitting portion 31 into which the cylindrical portion 13a of the slinger 13 fits. The fitting portion 31 is located on the outer peripheral surface 3j of the hub wheel 3 between the base portion 3d and the inner raceway surface 3c.

[0036] The disk portion 13b is located closer to the hub flange 3b than the cylindrical portion 13a. The disk portion 13b is formed in a disk shape and faces an inner side surface 3g of the base portion 3d of the hub flange 3b. A gap exists between the disk portion 13b and the inner side surface 3g of the hub flange 3b. The disk portion 13b faces the first side lip 12b in the axial direction, and the disk portion 13b and the first side lip 12b are in contact with each other.

[0037] The connecting portion 13c is formed in an arc shape when viewed in the circumferential direction, and connects the cylindrical portion 13a and the disk portion 13b. The connecting portion 13c faces the second side lip 12c in the axial direction, and the connecting portion 13c and the second side lip 12c are in contact with each other.

[0038] The extension 13d extends from the outer diameter end of the disk portion 13b toward the inner side and the outer diameter side. The outer peripheral surface at the outer end of the outer ring 2 is formed into a tapered surface 2g that narrows in diameter toward the outer side, and the extension 13d is formed to be parallel to the tapered surface 2g. The extension 13d and the tapered surface 2g overlap when viewed from the radial direction, and a labyrinth is formed by the extension 13d and the tapered surface 2g.

[0039] An elastic member 14 is integrally joined to the outer side surface at the boundary between the extension portion 13d and the disk portion 13b. The elastic member 14 is made of, for example, synthetic rubber. The elastic member 14 contacts the inner side surface 3g of the hub flange 3b and seals the gap between the inner side surface 3g of the hub flange 3b and the disk portion 13b of the slinger 13.

[0040] In the outer seal member 10 configured in this manner, when the hub wheel 3 is repeatedly subjected to the vehicle turning load and vibrations from the wheel, the received load and vibrations are transmitted to the slinger 13, which may cause the slinger 13 to move in the axial direction, such as to the inner side.

[0041] If the slinger 13 moves axially, the clamping margin of the first side lip 12b and the second side lip 12c that contact the slinger 13 may change, the cylindrical portion 13a of the slinger 13 may interfere with the ball 7 housed between the outer raceway surface 2d of the outer ring 2 and the inner raceway surface 3c of the hub wheel 3, or a gap may occur between the slinger 13 and the hub flange 3b, which may allow water to enter the inside of the wheel bearing device 1.

[0042] Therefore, in the wheel bearing device 1, the fitting portion 31 on the outer peripheral surface 3j of the hub wheel 3 into which the cylindrical portion 13a of the slinger 13 fits is configured as follows to prevent the slinger 13 from moving in the axial direction.

[0043] [Fitting part on outer circumferential surface of hub] As shown in FIG. 3, the fitting portion 31 of the hub wheel 3 has a small diameter portion 311 , a large diameter portion 312 , and a step portion 313 .

[0044] The small diameter portion 311 is formed on the inner side of the base portion 3d. The radial length from the rotation axis X to the small diameter portion 311 on the outer circumferential surface 3j of the hub wheel 3 is R1.

[0045] The large diameter portion 312 is located on the inner side of the small diameter portion 311. In other words, the large diameter portion 312 is located axially farther from the hub flange 3b than the small diameter portion 311. The large diameter portion 312 is formed to have a larger diameter than the small diameter portion 311, and a step portion 313 is formed between the small diameter portion 311 and the large diameter portion 312.

[0046] The radial length from the rotational axis X to the large diameter portion 312 on the outer peripheral surface 3j of the hub wheel 3 is R2. The step height h of the large diameter portion 312 relative to the small diameter portion 311 is the difference between the radial length R2 from the rotational axis X to the large diameter portion 312 and the radial length R1 from the rotational axis X to the small diameter portion 311 (h=R2-R1).

[0047] Axial length L1 of small diameter portion 311 and axial length L2 of large diameter portion 312 are both formed to be greater than the tolerance of the axial length of cylindrical portion 13a of slinger 13. Therefore, even if the axial length of cylindrical portion 13a varies within the tolerance range, when cylindrical portion 13a is fitted into fitting portion 31, slinger 13 can be fitted into both small diameter portion 311 and large diameter portion 312 across step portion 313.

[0048] Step portion 313 is located between small diameter portion 311 and large diameter portion 312 in the axial direction, and connects small diameter portion 311 and large diameter portion 312. Step portion 313 is formed by an inclined surface whose diameter increases from small diameter portion 311 to large diameter portion 312 in the axial direction.

[0049] The slinger 13 is pressed into the mating portion 31 on the outer peripheral surface 3j of the hub wheel 3 from the inner side, and the cylindrical portion 13a of the slinger 13 has a clamping margin between the mating portion 31 and the cylindrical portion 13a. However, since the large diameter portion 312 is formed to have a larger diameter than the small diameter portion 311, the clamping margin between the cylindrical portion 13a and the large diameter portion 312 is greater than the clamping margin between the cylindrical portion 13a and the small diameter portion 311.

[0050] In the wheel bearing device 1, when the hub wheel 3 is repeatedly subjected to the vehicle turning load and vibrations from the wheel, the received load and vibrations are transmitted to the slinger 13 of the outer seal member 10, and a force may act on the slinger 13 in a direction moving it toward the inner side.

[0051] On the other hand, when a force acts on the slinger 13 in a direction moving it toward the inner side, the greater the clamping margin of the slinger 13 relative to the outer peripheral surface 3j of the hub wheel 3, the greater the force required to move the slinger 13 toward the inner side.

[0052] Therefore, by having a small diameter portion 311 and a large diameter portion 312 located on the inner side of the small diameter portion 311, like the fitting portion 31 of the hub wheel 3, it is possible to increase the load-bearing capacity against forces in the direction of movement toward the inner side of the slinger 13.

[0053] In particular, even if the axial length of the cylindrical portion 13a of the slinger 13 changes within the tolerance range, the slinger 13 is engaged with both the small diameter portion 311 and the large diameter portion 312, so that axial movement of the slinger 13 can be suppressed regardless of the quality of the axial length of the cylindrical portion 13a of the slinger 13.

[0054] In addition, in the fitting portion 31, the small diameter portion 311 and the large diameter portion 312 are connected by a step portion 313, and the cylindrical portion 13a of the slinger 13 gets caught at the boundary between the step portion 313 and the large diameter portion 312. Therefore, it is possible to effectively increase the load-bearing capacity against forces moving the slinger 13 toward the inner side, compared to, for example, a case in which the fitting portion 31 is formed into a tapered shape in which the diameter gradually increases from the outer side to the inner side.

[0055] Furthermore, if the interference between the cylindrical portion 13a of the slinger 13 and the fitting portion 31 of the hub wheel 3 is too large, plastic deformation may occur in the slinger 13 when the slinger 13 is press-fitted into the fitting portion 31. Therefore, it is preferable that the step height h between the large diameter portion 312 and the small diameter portion 311 is equal to or less than half the radial thickness t of the cylindrical portion 13a of the slinger 13 (h≦(t / 2)).

[0056] Setting the step height h to half the thickness t or less can prevent the interference of the cylindrical portion 13a of the slinger 13 with the fitting portion 31 of the hub wheel 3 from becoming too large, thereby preventing plastic deformation of the slinger 13. From the viewpoint of preventing axial movement of the slinger 13, it is preferable that the step height h between the large diameter portion 312 and the small diameter portion 311 be 10 μm or more.

[0057] In hub wheel 3, inclination angle θ of the inclined surface of step portion 313 located between large diameter portion 312 and small diameter portion 311 with respect to the axial direction is set to be equal to or greater than 3° and equal to or less than 45°.

[0058] The larger the inclination angle θ, the greater the load resistance against movement of the slinger 13 toward the inner side, but if the inclination angle θ exceeds 45°, there is a risk that the amount of wear of the slinger 13 due to the step portion 313 when the slinger 13 is press-fitted into the fitting portion 31 may increase, so it is preferable that the inclination angle θ be 45° or less. From the viewpoint of suppressing axial movement of the slinger 13, the inclination angle θ is preferably 3° or more.

[0059] Although there is no particular limitation on the axial length L3 of the step portion 313, it can be set to 1 mm or less. By setting the axial length L3 of the step portion 313 to 1 mm or less, it becomes possible to set the inclination angle θ of the step portion 313 to a large value.

[0060] [Relationship between the fitting position of the slinger relative to the fitting part of the hub wheel and the pull-out force of the slinger] As shown in [A] of Figure 4, for example, when the cylindrical portion 13a of the slinger 13 is engaged only with the small diameter portion 311 of the engagement portion 31 and a gap is generated between the inner side end, which is the tip of the cylindrical portion 13a, and the step portion 313, the pulling force required to move the slinger 13 toward the inner side is F1.

[0061] When the slinger 13 moves from the state shown in [A] of Figure 4 to the inner side, and the inner end of the cylindrical portion 13a of the slinger 13 reaches the step portion 313 as shown in [B] of Figure 4, and the cylindrical portion 13a rides up the step portion 313 toward the large diameter portion 312, the pulling force of the slinger 13 becomes pulling force F2 which is greater than pulling force F1 (F2>F1).

[0062] 4[C], when slinger 13 moves further toward the inner side with cylindrical portion 13a of slinger 13 riding on large diameter portion 312 and engaged with both small diameter portion 311 and large diameter portion 312, the pulling force of slinger 13 increases as slinger 13 moves toward the inner side. The pulling force of slinger 13 becomes the largest pulling force F3 (F3>F2) just before the outer end of cylindrical portion 13a of slinger 13 moving toward the inner side reaches large diameter portion 312.

[0063] As shown in FIG. 4[D], when the outer end of the cylindrical portion 13a of the slinger 13 rides up onto the large diameter portion 312 and the entire cylindrical portion 13a is fitted into the large diameter portion 312, the pull-out force of the slinger 13 is slightly reduced from the pull-out force F3 to a pull-out force F4 (F4 <F3)。

[0064] In this way, the pulling force when the cylindrical portion 13a of the slinger 13 is engaged with both the small diameter portion 311 and the large diameter portion 312 is in the range of pulling force F2 to pulling force F3, and is greater than the pulling force F1 when the cylindrical portion 13a of the slinger 13 is engaged only with the small diameter portion 311 and a gap is generated between the inner side end of the cylindrical portion 13a and the step portion 313.

[0065] Therefore, it is possible to prevent the slinger 13 from moving in the axial direction when the cylindrical portion 13a is fitted into both the small diameter portion 311 and the large diameter portion 312. In particular, the pulling force of the slinger 13 becomes the largest pulling force F3 just before the outer end of the cylindrical portion 13a reaches the large diameter portion 312, so that it is possible to maintain the state in which the cylindrical portion 13a is fitted into both the small diameter portion 311 and the large diameter portion 312.

[0066] [Second embodiment of fitting portion in hub wheel] The fitting portion 31 of the hub wheel 3 can also be formed as fitting portion 32 shown in Fig. 5. Fitting portion 32 is located between base portion 3d and inner raceway surface 3c on the outer circumferential surface 3j of the hub wheel 3, and has a small diameter portion 321, a large diameter portion 322, and a stepped portion 323. The small diameter portion 321 and stepped portion 323 of fitting portion 32 are formed in the same manner as the small diameter portion 311 and stepped portion 313 of fitting portion 31.

[0067] The large diameter portion 322 is located on the inner side of the small diameter portion 321. In other words, the large diameter portion 322 is located axially farther from the hub flange 3b than the small diameter portion 321. The large diameter portion 322 is formed to have a larger diameter than the small diameter portion 321, and a step portion 323 is formed between the large diameter portion 322 and the small diameter portion 321.

[0068] The large diameter portion 322 has a first large diameter portion 322a, a second large diameter portion 322b, and a step portion 322c. The first large diameter portion 322a is formed continuous with the step portion 323 on the inner side.

[0069] The second large diameter portion 322b is located on the inner side of the first large diameter portion 322a. In other words, the second large diameter portion 322b is located farther away from the hub flange 3b in the axial direction than the first large diameter portion 322a.

[0070] The first large diameter portion 322a and the second large diameter portion 322b are formed to have a larger diameter than the small diameter portion 321. The second large diameter portion 322b is formed to have a larger diameter than the first large diameter portion 322a, and a step portion 322c is formed between the first large diameter portion 322a and the second large diameter portion 322b.

[0071] The step portion 322c connects the first large diameter portion 322a and the second large diameter portion 322b. The step portion 322c is formed by an inclined surface whose diameter increases from the first large diameter portion 322a to the second large diameter portion 322b in the axial direction. The step portion 322c can be formed in the same manner as the step portion 313.

[0072] Cylindrical portion 13a of slinger 13 is fitted over small diameter portion 321, first large diameter portion 322a, and second large diameter portion 322b of fitting portion 32. In fitting portion 32, small diameter portion 321, first large diameter portion 322a, and second large diameter portion 322b are arranged in this order from the outer side to the inner side.

[0073] The interference of the cylindrical portion 13a with respect to the first large diameter portion 322a is greater than the interference of the cylindrical portion 13a with respect to the small diameter portion 321, and the interference of the cylindrical portion 13a with respect to the second large diameter portion 322b is greater than the interference of the cylindrical portion 13a with respect to the first large diameter portion 322a. In other words, the interference of the cylindrical portion 13a with respect to the fitting portion 32 increases from the outer side to the inner side. This makes it possible to increase the load resistance against a force in a direction moving the slinger 13 toward the inner side.

[0074] In this way, the large diameter portion 322 can have a plurality of portions with different outer diameters, such as the first large diameter portion 322a and the second large diameter portion 322b. In this embodiment, the large diameter portion 322 has two portions with different outer diameters, but it is also possible to configure the large diameter portion 322 with three or more portions with different outer diameters. In addition, the plurality of portions with different outer diameters can be arranged so that the diameter increases from the outer side toward the inner side.

[0075] [Third embodiment of fitting portion in hub wheel] The fitting portion 31 of the hub wheel 3 can also be formed as fitting portion 33 shown in Fig. 6. The fitting portion 33 is located between the base portion 3d and the inner raceway surface 3c on the outer circumferential surface 3j of the hub wheel 3, and has a small diameter portion 331, a large diameter portion 332, and a stepped portion 333. The small diameter portion 331 and the stepped portion 333 of the fitting portion 33 are formed in the same manner as the small diameter portion 311 and the stepped portion 313 of the fitting portion 31.

[0076] The large diameter portion 332 is located on the inner side of the small diameter portion 331. In other words, the large diameter portion 332 is located axially farther from the hub flange 3b than the small diameter portion 331. The large diameter portion 332 has a portion formed to have a larger diameter than the small diameter portion 331, and a step portion 333 is formed between the large diameter portion 332 and the small diameter portion 331.

[0077] The large diameter portion 332 has a first large diameter portion 332a, a second large diameter portion 332b, a recess 332c, a first step portion 332d, and a second step portion 332e. The first large diameter portion 332a is formed continuously with the inner side of the step portion 333.

[0078] The second large diameter portion 332b is located on the inner side of the first large diameter portion 332a. In other words, the second large diameter portion 332b is located farther from the hub flange 3b in the axial direction than the first large diameter portion 332a.

[0079] The first large diameter portion 332a and the second large diameter portion 332b are formed to have a larger diameter than the small diameter portion 331. The first large diameter portion 332a and the second large diameter portion 332b are formed to have the same diameter. However, the first large diameter portion 332a and the second large diameter portion 332b can be formed to have different outer diameters. In this case, the second large diameter portion 332b can be formed to have a larger diameter than the first large diameter portion 332a, and the first large diameter portion 332a can also be formed to have a larger diameter than the second large diameter portion 332b.

[0080] A recess 332c is located between the first large diameter portion 332a and the second large diameter portion 332b. The recess 332c is formed to have a smaller diameter than the first large diameter portion 332a and the second large diameter portion 332b. In other words, the first large diameter portion 332a and the second large diameter portion 332b are located apart in the axial direction with the recess 332c sandwiched therebetween.

[0081] A first step 332d is formed between the first large diameter portion 332a and the recess 332c. The first step 332d connects the first large diameter portion 332a and the recess 332c. The first step 332d is formed by an inclined surface that decreases in diameter from the first large diameter portion 332a to the recess 332c in the axial direction. The first step 332d can be formed in the same manner as the step 313, except for the inclination direction.

[0082] A second step 332e is formed between the recess 332c and the second large diameter portion 332b. The second step 332e connects the recess 332c and the second large diameter portion 332b. The second step 332e is formed by an inclined surface that increases in diameter from the recess 332c toward the second large diameter portion 332b in the axial direction. The second step 332e can be formed in the same manner as the step 313.

[0083] The cylindrical portion 13a of the slinger 13 is fitted over the small diameter portion 331, the first large diameter portion 332a, the recess 332c, and the second large diameter portion 332b of the fitting portion 33. In the fitting portion 33, the small diameter portion 331, the first large diameter portion 332a, the recess 332c, and the second large diameter portion 332b are arranged in this order from the outer side to the inner side.

[0084] The clamping margin of the cylindrical portion 13a relative to the first large diameter portion 332a and the second large diameter portion 332b is greater than the clamping margin of the cylindrical portion 13a relative to the small diameter portion 331, and the clamping margin of the cylindrical portion 13a relative to the recess 332c is smaller than the clamping margin of the cylindrical portion 13a relative to the first large diameter portion 332a and the second large diameter portion 332b.

[0085] In other words, between the first large diameter portion 332a and the second large diameter portion 332b, where the clamping margin of the cylindrical portion 13a is larger than that of the small diameter portion 331, there is located the recess 332c, where the clamping margin of the cylindrical portion 13a is smaller than that of the first large diameter portion 332a and the second large diameter portion 332b.

[0086] As a result, when the cylindrical portion 13a of the slinger 13 is fitted into the fitting portion 33, Since the recess 332c, where the clamping margin of the cylindrical portion 13a is small, is present between the first large diameter portion 332a and the second large diameter portion 332b, where the clamping margin of the cylindrical portion 13a is large, it is possible to prevent the clamping margin of the cylindrical portion 13a from becoming too large and causing plastic deformation of the cylindrical portion 13a.

[0087] On the other hand, in the cylindrical portion 13a of the slinger 13, the clamping margin of the portion engaged with the first large diameter portion 332a and the second large diameter portion 332b is greater than the clamping margin of the portion engaged with the small diameter portion 331, so it is possible to increase the load-bearing capacity against forces moving the slinger 13 toward the inner side.

[0088] In this way, the large diameter portion 332 has a configuration in which a small diameter portion is located between large diameter portions, such as a configuration in which the recess 332c is formed between the first large diameter portion 332a and the second large diameter portion 332b. Also, the large diameter portion 332 may have a configuration in which a small diameter portion is formed between large diameter portions, which configuration is repeated multiple times in the axial direction. Furthermore, the large diameter portion 332 according to the third embodiment and the large diameter portion 322 according to the second embodiment may be configured to be arranged side by side in the axial direction.

[0089] [Second embodiment of the cylindrical portion of the slinger] The cylindrical portion 13a of the slinger 13 that is fitted into the fitting portion 31 of the hub wheel 3 can also be formed like the cylindrical portion 113a of the slinger 113 shown in FIG.

[0090] The cylindrical portion 113a is formed continuously with the inner side of the connection portion 113c of the slinger 113. The inner peripheral surface of the cylindrical portion 113a is formed into a tapered surface whose diameter increases from the outer side to the inner side, and is inclined with respect to the rotation axis X.

[0091] The cylindrical portion 113a of the slinger 113 is fitted over the small diameter portion 311 and the large diameter portion 312, and the interference of the portion of the cylindrical portion 113a that fits into the large diameter portion 312 is greater than the interference of the portion of the cylindrical portion 113a that fits into the small diameter portion 311.

[0092] However, cylindrical portion 113a expands in diameter toward the inner side, and the inner portion of cylindrical portion 113a that fits into large diameter portion 312 is formed with a larger diameter than the outer portion of cylindrical portion 113a that fits into small diameter portion 311, so the tightening margin of the portion of cylindrical portion 113a that fits into large diameter portion 312 does not become excessively large.

[0093] This makes it possible to increase the load resistance against a force in a direction moving the slinger 13 toward the inner side while suppressing plastic deformation of the slinger 13. Also, because the tightening margin of the portion that fits into the large diameter portion 312 of the cylindrical portion 113a does not become excessively large, the pressing force when the slinger 113 is press-fitted into the fitting portion 31 of the hub wheel 3 can be reduced, improving the operability of the press-fitting operation.

[0094] The wheel bearing device 1 in this embodiment is configured as a wheel bearing device 1 of a third generation structure in which the inner raceway surface 3c is formed directly on the outer periphery of the hub wheel 3, but is not limited to this, and the wheel bearing device 1 can also have a fourth generation structure in which, instead of forming an inner raceway surface opposing the outer raceway surface 2c of the outer ring 2 on the inner ring 4, it is formed on a constant velocity universal joint that fits into the through hole 3i of the hub wheel 3, and is configured without the inner ring 4. In this case, the constant velocity universal joint becomes a raceway surface forming member connected to the hub wheel.

[0095] A wheel bearing device of the fourth generation structure not including an inner ring 4 can be configured, for example, as a wheel bearing device 1A shown in Fig. 8. The wheel bearing device 1A includes a constant velocity universal joint 50 connected to a hub wheel 3A, and does not include an inner ring 4. The constant velocity universal joint 50 is an example of a raceway surface forming member connected to a hub wheel.

[0096] Constant velocity universal joint 50 includes a mouth portion 52 that supports a shaft to which driving force is input from a drive source, and a stem portion 53 that extends toward the outer side from mouth portion 52. Hub wheel 3A has a through hole 3i that passes through in the axial direction, and through hole 3i and stem portion 53 are spline-fitted.

[0097] An inner raceway surface 58 that faces the inner outer raceway surface 2c of the outer ring 2 is formed on the outer peripheral surface of the outer end of the mouth portion 52. The inner raceway surface 58 is an example of the other inner raceway surface that faces the outer raceway surface. The inner ball row 5 is rollably sandwiched between the inner outer raceway surface 2c of the outer ring 2 and the inner raceway surface 58 of the mouth portion 52 of the constant velocity universal joint 50.

[0098] That is, in the wheel bearing device 1A, the constant velocity universal joint 50 having the inner raceway surface 58 opposing the outer raceway surface 2c of the outer ring 2 also serves as the inner ring.

[0099] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, which are merely illustrative, and it goes without saying that the present invention can be embodied in various other forms without departing from the gist of the present invention. The scope of the present invention is indicated by the claims, and further includes the equivalent meanings set forth in the claims, and all modifications within the scope of the claims. [Explanation of symbols]

[0100] 1 Wheel bearing device 2 Outer ring 2b Outer side opening 2c (inner side) outer raceway 2d (Outer side) outer raceway 3 Hub wheel 3b Hub flange 3c Inner raceway surface 3d base 3j Outer surface 4. Inner Circle 4a Inner raceway surface 5 Inner ball row 6 Outer ball row 10 Outer seal member 11 Core wire 12 Sealing material 12b First Side Lip 12c 2nd Side Lip 12d radial lip 13, 113 Slinger 13a, 113a Cylindrical part 13b Disc section 31 Fitting part 311, 321, 331 Small diameter section 312, 322, 332 Large diameter section 313, 323, 333 Steps 322a, 332a First large diameter section 322b, 332b Second large diameter section 332c Recess h Step height t Thickness S Annular space

Claims

1. an outer member having a double row outer raceway surface on an inner periphery thereof; an inner member including a hub wheel having, on its outer periphery, one inner raceway surface opposing the outer raceway surface and a hub flange for mounting a wheel; and a raceway surface forming member connected to the hub wheel and having, on its outer periphery, the other inner raceway surface opposing the outer raceway surface; a double row of rolling elements rollably accommodated between the raceway surfaces of the outer member and the inner member; a sealing device that closes an open end on one axial end side of an annular space formed by the outer member and the inner member, The sealing device is a slinger provided at a base of the hub flange and having a cylindrical portion that fits into an outer peripheral surface of the hub wheel and a disk portion that faces the hub flange; a seal member having a seal lip; an outer circumferential surface of the hub wheel has a fitting portion into which the cylindrical portion of the slinger fits; The fitting portion has a small diameter portion and a large diameter portion that is located axially farther from the hub flange than the small diameter portion and has a larger diameter than the small diameter portion.

2. 2. The wheel bearing device according to claim 1, wherein a radial step height of the large diameter portion relative to the small diameter portion is equal to or less than half a radial thickness of the cylindrical portion of the slinger.

3. the fitting portion has a step portion connecting the small diameter portion and the large diameter portion, the step portion is formed by an inclined surface whose diameter increases from the small diameter portion to the large diameter portion in the axial direction, 3. The wheel bearing device according to claim 1, wherein an inclination angle of the inclined surface with respect to the axial direction is equal to or greater than 3 degrees and equal to or less than 45 degrees.

4. the large diameter portion has a first large diameter portion formed to have a larger diameter than the small diameter portion and a second large diameter portion formed to have a larger diameter than the first large diameter portion, 3. The wheel bearing device according to claim 1, wherein the second large diameter portion is positioned farther away from the hub flange than the first large diameter portion.

5. the large diameter portion has a first large diameter portion and a second large diameter portion formed to have a larger diameter than the small diameter portion, 3. The wheel bearing device according to claim 1, wherein a recess having a smaller diameter than the first large diameter portion and the second large diameter portion is formed between the first large diameter portion and the second large diameter portion in the axial direction.

6. 3. The wheel bearing device according to claim 1, wherein the cylindrical portion of the slinger is formed in a tapered shape such that a diameter of the cylindrical portion increases as the cylindrical portion moves away from the disk portion in the axial direction.

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