Wheel bearing device

Abstract

To provide a wheel bearing device which can easily discharge muddy water intruding into a labyrinth seal of a sealing device.SOLUTION: An inner-side seal member 10 of a wheel bearing device 1 comprises: a seal member 13 having a core grid 11 composed of an inner fitting part 11a fit to an outer ring 2, and a side plate part 11b extending to an inside-diameter side from an outer-side end part of the inner first part 11a, and an elastic member 12 integrally joined to the core grid 11; and a slinger 14 having an outer fitting part 14a fit to an inner ring 4, a circular ring part 14b extending to an outside-diameter side from the inner-side end part of the outer fitting part 14a, and opposing the side plate part 11b in an axial direction, and a protrusion 14c protruding toward the side plate part 11b side from the outside-diameter end part of the circular ring part 14b, and opposing the side plate part 11b with a clearance between the side plate part and itself. The inner fitting part 11a and the protrusion 14c are overlapped on each other when viewed from a radial direction, and the seal member 13 has a drain part 13A in which the inner fitting part 11a is notched in the axial direction in a prescribed region at a road face side in a peripheral direction.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] For example, the sealing device disclosed in Patent Document 1 includes a core bar consisting of an inner fitting portion that is fitted onto the inner circumference of an outer ring, which is an outer member, and a side plate portion extending from the inner fitting portion toward the inner diameter side, and a seal member having an elastic member that is integrally joined to the core bar and has multiple seal lips formed thereon, and a slinger having an outer fitting portion that is fitted onto the outer circumference of an inner ring, which is an inner member, a circular plate portion extending from the outer fitting portion toward the outer diameter side, and a protrusion that protrudes from the circular plate portion toward the side plate portion and faces the side plate portion with a gap.

[0004] A labyrinth seal is formed by the inner fitting portion of the core bar, the protruding portion of the slinger, and the seal lip located on the outermost diameter side of the elastic member, thereby improving resistance to muddy water and preventing muddy water from entering the sealing device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5170366 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a configuration in which a labyrinth seal is formed using a protrusion that protrudes from the disc portion of the slinger toward the side plate portion, such as the sealing device described in Patent Document 1, once muddy water has entered the labyrinth seal, it is difficult for it to be discharged to the outside, which ultimately hinders improvement in muddy water resistance.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and provides a wheel bearing device which is capable of easily discharging muddy water that has entered the inside of a labyrinth seal, even when a labyrinth seal is formed in the sealing device. [Means for solving the problem]

[0008] That is, the bearing device for a wheel includes an outer member having a double-row outer raceway surface on its inner periphery, a hub wheel having an axially extending small diameter step portion on its outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub wheel, an inner member having a double-row inner raceway surface facing the double-row outer raceway surface, double-row rolling elements accommodated in a rollable manner between both raceway surfaces of the outer member and the inner member, and a sealing device that closes an opening end on one axial end side of an annular space formed by the outer member and the inner member, the sealing device comprising an inner fitting portion that is fitted into the inner periphery of the outer member, the seal member having an elastic member integrally joined to the core metal, an outer fitting portion fitted to an outer periphery of the inner member, a ring portion extending from one axial end of the outer fitting portion to the outer diameter side and facing the side plate portion in the axial direction, and a slinger having a protrusion protruding from the outer diameter side end of the ring portion towards the side plate portion and facing the side plate portion with a gap therebetween, the inner fitting portion of the seal member and the protrusion of the slinger overlap when viewed in a radial direction, and the seal member has a predetermined area on the road surface side in the circumferential direction. only The inner fitting portion has a drain portion cut out in the axial direction. Effect of the Invention

[0009] According to the present invention, muddy water that has infiltrated into the inside of the sealing device can be easily discharged to the outside of the sealing device through the drain portion, and the muddy water resistance performance of the sealing device can be effectively improved. [Brief description of the drawings]

[0010] [Figure 1] 1 is a side cross-sectional view showing a wheel bearing device. [Diagram 2] FIG. 4 is a side cross-sectional view showing an inner seal member. [Diagram 3] 4 is a view of the road surface side portion of the inner seal member as viewed from the inner side in the axial direction. FIG. [Figure 4] 10 is a side cross-sectional view showing a state in which the inner circumferential surface of the inner opening of the outer ring significantly protrudes below the drain portion of the inner seal member. FIG. [Diagram 5] FIG. 11 is a side cross-sectional view showing another embodiment of an inner seal member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] [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.

[0013] The wheel bearing device 1 has a configuration referred to as the 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 consisting of an inner ball row 5 and an outer ball row 6, an inner seal member 10, and an outer seal member 20.

[0014] Here, the inner side refers to the vehicle body side of the wheel bearing device 1 when it is attached to the vehicle body, and the outer side refers to the wheel side of the wheel bearing device 1 when it is attached to the vehicle body. Also, the lower side of the wheel bearing device 1 when it is attached to the vehicle body is referred to as the road surface side, and the upper side is referred to as the opposite road surface side. Furthermore, the axial direction refers to the direction along the rotation axis of the wheel bearing device 1. In this embodiment, the inner side is one axial end side, and the outer side is the other axial end side.

[0015] An inner side opening 2a is formed at the inner side end of the outer ring 2, into which the inner side seal member 10 can be fitted. An outer side opening 2b is formed at the outer side end of the outer ring 2, into which the outer side seal member 20 can be fitted.

[0016] The inner seal member 10 is fitted into the inner opening 2a to close the inner opening end of the annular space S formed by the outer ring 2 as the outer member and the hub ring 3 and inner ring 4 as the inner members. The outer seal member 20 is fitted into the outer opening 2b to close the outer opening end of the annular space S.

[0017] The inner seal member 10 and the outer seal member 20 are sealing devices that close the open ends of the annular space S. In this manner, by closing the open ends on the inner side and the outer side of the annular space S with the inner seal member 10 and the outer seal member 20, foreign matter such as muddy water is prevented from entering the inside of the wheel bearing device 1.

[0018] An inner-side outer raceway surface 2c and an outer-side outer raceway surface 2d are formed on the inner peripheral surface of the outer ring 2. 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.

[0019] The inner end of the outer circumferential surface of the hub wheel 3 is formed with a small diameter step 3a that is smaller in diameter than the outer end. A wheel mounting flange 3b for mounting a wheel is formed integrally with the outer end of the hub wheel 3. A plurality of bolt holes 3f are formed in the wheel mounting flange 3b. Hub bolts for fastening the hub wheel 3 to a wheel or a brake component can be press-fitted into the bolt holes 3f.

[0020] In the hub wheel 3, a sliding surface 3d with which the outer seal member 20 slides is formed on the base side of the wheel mounting flange 3b. An outer inner raceway surface 3c is provided on the outer peripheral surface of the hub wheel 3 so as to face the outer outer raceway surface 2d on the outer side of the outer ring 2. In other words, the hub wheel 3 forms the inner raceway surface 3c on the outer side of the inner member.

[0021] 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 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.

[0022] An inner-side inner raceway surface 4a is provided on an outer peripheral surface 4c of the inner ring 4 so as to face an 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.

[0023] 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.

[0024] 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.

[0025] [Outer seal material] The outer seal member 20 has a core metal 21 and an elastic member 22. The core metal 21 is formed into a cylindrical shape from, for example, a steel plate, and is fitted into the outer opening 2b of the outer ring 2 at its inner diameter.

[0026] The elastic member 22 is made of, for example, synthetic rubber, and is bonded by vulcanization adhesion to the core metal 21. The elastic member 22 has a base 22a that is vulcanization bonded to the core metal 21, and a first side lip 22b, a second side lip 22c, and a grease lip 22d that extend from the base 22a and are each formed in an annular shape.

[0027] The first side lip 22b is located on the outermost side of the seal lips of the elastic member 22, and extends from the base 22a toward the outer diameter side and the outer side. The second side lip 22c is located on the inner diameter side of the first side lip 22b, and extends from the base 22a toward the outer diameter side and the outer side. The grease lip 22b is located on the inner diameter side of the second side lip 22c, and extends from the base 22a toward the inner diameter side and the inner side.

[0028] The first side lip 22b, the second side lip 22c and the grease lip 22d of the elastic member 22 are in slidable contact with the lip sliding contact surface 3d of the hub wheel 3.

[0029] [Inner seal material] As shown in Fig. 2(a), the inner seal member 10 includes a seal member 13 having a core metal 11 and an elastic member 12, and a slinger 14. The core metal 11 is made of, for example, a steel plate, and includes a cylindrical inner fitting portion 11a that fits into the inner circumference of the inner opening portion 2a of the outer ring 2, and an annular side plate portion 11b that extends from the outer end portion of the inner fitting portion 11a toward the inner diameter side. The inner opening portion 2a of the outer ring 2 is an example of a fitted portion into which the inner fitting portion 11a of the core metal 11 fits.

[0030] The elastic member 12 is made of, for example, synthetic rubber, and is integrally joined to the core metal 11 by vulcanization adhesion. The elastic member 12 has a base 121 that is vulcanization-adhered to the core metal 11, and a first side lip 122, a second side lip 123, and a grease lip 124 that extend from the base 121 and are each formed in an annular shape. The first side lip 122, the second side lip 123, and the grease lip 124 are seal lips that the elastic member 12 has.

[0031] The base portion 121 is joined to the inner peripheral surface, inner end face, and inner portion of the outer peripheral surface of the inner fitting portion 11a, as well as to the inner side surface, inner diameter end face, and inner diameter portion of the outer side surface of the side plate portion 11b.

[0032] The first side lip 122 is located on the outermost side of the seal lips of the elastic member 12, and extends from the base 121 toward the outer diameter side and the inner side. The first side lip 122 is an example of an outermost seal lip. The second side lip 123 is located on the inner diameter side of the first side lip 122, and extends from the base 121 toward the outer diameter side and the inner side. The grease lip 124 is located on the inner diameter side of the second side lip 123, and extends from the base 121 toward the inner diameter side and the outer side.

[0033] The slinger 14 is made of, for example, a steel plate, and has a cylindrical outer fitting portion 14a that fits onto the outer peripheral surface 4c at the inner end portion of the inner ring 4, an annular portion 14b that extends from the inner end portion of the outer fitting portion 14a toward the outer diameter side, and a protrusion portion 14c that protrudes from the outer diameter side end portion of the annular portion 14b toward the outer side, which is the side plate portion 11b side.

[0034] The protruding portion 14c is located radially between the inner fitting portion 11a of the core metal 11 and the first side lip 122 of the elastic member 12. The annular portion 14b of the slinger 14 is located axially inner than the side plate portion 11b of the core metal 11, and the annular portion 14b and the side plate portion 11b face each other in the axial direction. The tip of the protruding portion 14c faces the side plate portion 11b of the core metal 11 with a gap in the axial direction.

[0035] The first side lip 122 of the elastic member 12 faces the annular portion 14b of the slinger 14 in the axial direction with a gap d1 therebetween. In other words, the first side lip 122 is a non-contact lip that is provided in a non-contact state with the annular portion 14b. The tip surface 122a of the first side lip 122 faces the outer diameter side in the radial direction and is located on the inner side (the annular portion 14b side) by a distance d2 from the outer end portion (the end portion on the side plate portion 11b side) of the protruding portion 14c of the slinger 14.

[0036] The second side lip 123 of the elastic member 12 faces the annular portion 14b of the slinger 14 in the axial direction. The tip of the second side lip 123 is in slidable contact with the annular portion 14b, and the second side lip 123 is a contact lip. The first side lip 122 and the second side lip 123 are seal lips that extend toward the annular portion 14b of the slinger 14 in the axial direction.

[0037] The grease lip 124 of the elastic member 12 faces the outer fitting portion 14a of the slinger 14 in the radial direction. The tip end of the grease lip 124 is in slidable contact with the outer fitting portion 14a, and the grease lip 124 is a contact lip.

[0038] In the inner side seal member 10 configured in this manner, the inner fitting portion 11a of the core metal 11 of the seal member 13, the protruding portion 14c of the slinger 14, and the first side lip 122 of the elastic member 12 of the seal member 13 overlap when viewed from the radial direction, and the inner fitting portion 11a, the protruding portion 14c, and the first side lip 122 form a labyrinth seal.

[0039] In the inner side seal member 10, the inner fitting portion 11a, the protrusion 14c, and the first side lip 122 are located on the outer periphery of the inner side seal member 10, and by forming a labyrinth seal with the inner fitting portion 11a, the protrusion 14c, and the first side lip 122, it is possible to prevent muddy water from penetrating into the inside of the inner side seal member 10, thereby improving the muddy water resistance.

[0040] In particular, in the inner side seal member 10, the first side lip 122 is provided in a non-contact state with the annular portion 14b of the slinger 4, and a labyrinth seal is formed between the first side lip 122 and the annular portion 14b, as well as between the inner fitting portion 11a and the protruding portion 14c, so that it is possible to improve the muddy water resistance while suppressing an increase in the sealing torque in the inner side seal member 10.

[0041] In this way, when a labyrinth seal is formed in the inner seal member 10 to prevent muddy water from entering the inside, once muddy water has entered the labyrinth seal, it tends to be difficult to drain it to the outside. Therefore, in the inner seal member 10, a drain portion 13A is formed in the seal member 13 so that muddy water can be easily drained even if it has entered the labyrinth seal.

[0042] [Drain section] 3, the drain portion 13A is formed in a predetermined circumferential region on the road surface side of the seal member 13. In the present embodiment, the drain portion 13A is located at the lowermost part of the seal member 13, and is formed in a region of angle θ in the circumferential direction of the seal member 13. In other words, the drain portion 13A is formed in a range of angle θ in the circumferential direction with the lower end PL1 of the seal member 13 as the center. The angle θ can be set in a range of 45° or less.

[0043] 2(b) and 3, in the region where the drain portion 13A of the seal member 13 is formed, the inner fitting portion 11a of the core metal 11 is cut out toward the outer side in the axial direction to form a notch 111. The notch 111 is formed so that its axial length is shorter than other portions of the inner fitting portion 11a, and the inner side end of the notch 111 is located on the outer side of the inner side ends of the other portions of the inner fitting portion 11a.

[0044] In drain portion 13A, cutout portion 111 of inner fitting portion 11a does not overlap protruding portion 14c of slinger 14 when viewed from the radial direction. That is, in drain portion 13A, inner fitting portion 11a is cut out in the axial direction to a position where it does not overlap protruding portion 14c of slinger 14 when viewed from the radial direction, and a gap d3 exists between cutout portion 111 and protruding portion 14c in the axial direction.

[0045] In this way, by forming the drain portion 13A in the seal member 13, even if muddy water infiltrates into the inside of the inner seal member 10, the infiltrated muddy water flows downward by gravity and is easily discharged to the outside of the inner seal member 10 from between the protruding portion 14c and the cutout portion 111 in the drain portion 13A. In particular, since the cutout portion 111 is cut out in the axial direction to a position where it does not overlap with the protruding portion 14c, the muddy water that has infiltrated into the inside of the inner seal member 10 is more easily discharged to the outside.

[0046] This makes it possible to effectively improve muddy water resistance even when a labyrinth seal is formed in the inner seal member 10 using the protruding portion 14c of the slinger 14. Also, in the inner seal member 10, a labyrinth seal is formed in areas other than where the drain portion 13A is formed, so that sealing performance can be ensured.

[0047] Also, the wheel bearing device 1 supporting the left wheel and the wheel bearing device 1 supporting the right wheel may be mounted on the vehicle with their circumferential phases shifted to opposite sides. However, in the inner seal member 10, the drain portion 13A is formed in the circumferential direction within a range of angle θ centered on the lower end PL of the seal member 13, and the angle θ is set to a maximum of 45°, so that the drain portion 13A can be positioned at the lower end of the inner seal member 10 in both the wheel bearing device 1 supporting the left wheel and the wheel bearing device 1 supporting the right wheel, thereby improving the versatility of the muddy water resistance.

[0048] [Discharge section] In the wheel bearing device 1, by forming a drain portion 13A in the seal member 13 of the inner seal member 10, it is possible to easily discharge muddy water that has infiltrated into the inner seal member 10 to the outside. However, as shown in Fig. 4, if the inner peripheral surface of the inner opening 2a of the outer ring 2 protrudes significantly below the drain portion 13A, the muddy water W discharged to the outside of the inner seal member 10 may accumulate on the inner peripheral surface of the inner opening 2a, preventing further discharge of the muddy water. Therefore, in the wheel bearing device 1, in addition to the drain portion 13A of the seal member 13, a discharge portion 2A is formed in the inner opening 2a of the outer ring 2.

[0049] 3, the discharge portion 2A is formed in a predetermined region in the circumferential direction on the road surface side of the inner side opening 2a of the outer ring 2. In the case of this embodiment, the discharge portion 2A is located at the bottom of the inner side opening 2a and is formed in a region of angle θ in the circumferential direction of the inner side opening 2a.

[0050] The discharge portion 2A is formed in the same region as the drain portion 13A in the circumferential direction. That is, the discharge portion 2A is formed in a range of an angle θ centered on the lower end PL2 of the inner side opening 2a in the circumferential direction. The angle θ can be set in a range of 45° or less.

[0051] As shown in Figures 2(b) and 3, in the region where the discharge portion 2A of the inner-side opening 2a is formed, the inner-side opening 2a is cut out toward the outer side in the axial direction to form a notch 21. The axial length of the notch 21 is shorter than other parts of the inner-side opening 2a, and the inner-side end of the notch 21 is located on the outer side relative to the inner-side ends of the other parts of the inner-side opening 2a. The notch 21 is also formed across the entire inner-side opening 2a in the radial direction.

[0052] In this way, by forming the discharge portion 2A at the inner opening 2a of the outer ring 2, muddy water discharged from the drain portion 13A to the outside of the inner seal member 10 flows downward through the discharge portion 2A by gravity, making it easier to be discharged to the outside of the wheel bearing device 1. As a result, even when a labyrinth seal is formed in the inner seal member 10 using the protruding portion 14c of the slinger 14, it is possible to more effectively improve the muddy water resistance.

[0053] Furthermore, because the discharge portion 2A formed on the outer ring 2, which is the fixed ring, is formed in the same region in the circumferential direction as the drain portion 13A is formed in, when the seal member 13 is assembled to the inner side opening 2a of the outer ring 2, the phase of the drain portion 13A of the seal member 13 can be aligned with the phase of the discharge portion 2A of the inner side opening 2a. In this way, by using the discharge portion 2A of the outer ring 2 as a position reference for assembly when assembling the seal member 13 to the outer ring 2, it is possible to prevent incorrect assembly of the seal member 13.

[0054] In addition, in the discharge portion 2A, the inner side end of the cutout portion 21 is located a distance d4 on the inner side from the inner side end of the cutout portion 111 in the drain portion 13A. In other words, the cutout portion 21 of the inner side opening 2a is cut out in the axial direction further toward the annular portion 14b of the slinger 14 than the cutout portion 111 of the inner fitting portion 11a.

[0055] In this way, the inner side end of the cutout portion 21 in the discharge portion 2A protrudes further inward than the inner side end of the cutout portion 111 in the drain portion 13A, so that the elastic member 12 joined to the inner and outer surfaces of the inner fitting portion 11a is not exposed to the outside, and damage to the elastic member 12 due to external forces can be prevented.

[0056] Furthermore, like the drain section 3A, the discharge section 2A is formed in the circumferential direction within a range of angle θ centered on the lower end PL of the sealing member 13, and the angle θ is set to a maximum of 45°.Therefore, it is possible to position the discharge section 2A at the lower end of the wheel bearing device 1 in both the wheel bearing device 1 supporting the left wheel and the wheel bearing device 1 supporting the right wheel, thereby increasing the versatility of the muddy water resistance performance.

[0057] [Another embodiment of the inner seal member] In the above-described inner seal member 10, the first side lip 122 of the elastic member 12 is a non-contact lip that faces the annular portion 14b of the slinger 14 with a gap d1 therebetween, but it may also be formed as a contact lip.

[0058] 5 has an elastic member 32 instead of the elastic member 12, and other configurations are similar to those of the inner seal member 10. The inner seal member 30 includes a seal member 33 and a slinger 14, and the seal member 33 has a core metal 11 and an elastic member 32.

[0059] The seal member 33 has a base 321, a first side lip 322, a second side lip 323, and a grease lip 324. The base 321, the second side lip 323, and the grease lip 324 are configured similarly to the base 121, the second side lip 123, and the grease lip 124, respectively.

[0060] The first side lip 322 extends from the base 321 and is formed in an annular shape. The first side lip 322 is a seal lip of the elastic member 32. The first side lip 322 is located on the outermost side of the seal lips of the elastic member 32, and extends from the base 321 toward the outer diameter side and the inner side. In the radial direction, the protruding portion 14c is located between the inner fitting portion 11a of the core metal 11 and the first side lip 322 of the elastic member 32.

[0061] The first side lip 322 of the elastic member 32 faces the annular portion 14b of the slinger 14 in the axial direction. The tip of the first side lip 322 is in slidable contact with the annular portion 14b, and the first side lip 322 is a contact lip.

[0062] Thus, even in the inner seal member 30 in which the first side lip 322 of the elastic member 32 is a sliding lip, the inner fitting portion 11a of the core metal 11 of the seal member 33 and the protruding portion 14c of the slinger 14 overlap when viewed from the radial direction, and the inner fitting portion 11a and the protruding portion 14c form a labyrinth seal. This makes it possible to prevent muddy water from entering the inside of the inner seal member 30, improving the muddy water resistance.

[0063] Furthermore, in the inner side seal member 30, a drain portion 33A having a configuration similar to that of the drain portion 13A can be configured. By configuring the drain portion 33A, it becomes easier to discharge muddy water that has infiltrated into the inner side seal member 30 to the outside, thereby effectively improving the muddy water resistance.

[0064] The configuration of the drain portion 13A in the inner seal member 30 can also be applied to an outer seal member provided at the outer end of the wheel bearing device. The configuration of the discharge portion 2A in the outer ring 2 can also be applied to the outer opening of the outer ring into which the outer seal member is fitted. When the configuration of the drain portion 13A and discharge portion 2A is applied to the outer side, the outer side becomes one axial end side, and the inner side becomes the other axial end side.

[0065] In addition, 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 this is not limited to this and may be a second generation structure in which a pair of inner rings 4 are press-fitted into the hub wheel 3.

[0066] 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]

[0067] 1 Wheel bearing device 2 Outer ring 2A discharge section 2a Inner side opening 2b Outer side opening 2c (inner side) outer raceway 2d (Outer side) outer raceway 3 Hub wheel 3b Wheel mounting flange 3c Inner raceway surface 4. Inner Circle 4a Inner raceway surface 5 Inner ball row 6 Outer ball row 10 Inner seal member 11 Core wire 11a Inner fitting part 11b Side plate part 12 Elastic member 13 Sealing material 13A Drain section 14 Slinger 14b Circular section 14c Protrusion 21 Notch 111 Notch 122 First side lip 123 2nd side lip PL1 (Lower end of sealing material) PL2 (Bottom end of inner opening) θ angle

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 an axially extending small diameter step on an outer periphery thereof and at least one inner ring press-fitted into the small diameter step of the hub wheel, the inner member having a double row inner raceway surface facing the double row outer raceway surfaces; 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 core bar including an inner fitting portion that is fitted to an inner periphery of the outer member and a side plate portion that extends from the other axial end of the inner fitting portion toward an inner diameter side, and a seal member having an elastic member that is integrally joined to the core bar; a slinger including: an outer fitting portion that is fitted onto an outer periphery of the inner member; an annular portion that extends from one axial end of the outer fitting portion toward the outer diameter side and faces the side plate portion in the axial direction; and a protruding portion that protrudes from the outer diameter side end of the annular portion toward the side plate portion and faces the side plate portion with a gap therebetween; The inner fitting portion of the seal member and the protruding portion of the slinger overlap when viewed from a radial direction, The seal member has a drain portion formed by cutting out the inner fitting portion in the axial direction only in a predetermined region on the road surface side in the circumferential direction of the wheel bearing device.

2. 2. The wheel bearing device according to claim 1, wherein the drain portion is cut out in the axial direction to a position where the internal fitting portion does not overlap with the protruding portion.

3. 3. The wheel bearing device according to claim 1, wherein the drain portion is formed in a range of 45° or less around the lower end of the seal member in the circumferential direction.

4. The outer member includes: a fitted portion into which the inner fitting portion is fitted; The wheel bearing device according to any one of claims 1 to 3, further comprising a discharge portion in which the fitted portion is cut out in the axial direction in the same circumferential region as the drain portion is formed.

5. The wheel bearing device according to claim 4 , wherein the fitted portion of the discharge portion is cut out in the axial direction further toward the annular portion than the inner fitting portion of the drain portion.

6. 6. The wheel bearing device according to claim 4, wherein the discharge portion is formed in a range of 45° or less around a lower end of the seal member in the circumferential direction.

7. The elastic member has a plurality of seal lips extending toward the annular portion of the slinger, Among the plurality of seal lips, an outermost seal lip located on the outermost diameter side is provided in a state of not contacting the slinger, 7. The wheel bearing device according to claim 1, wherein a tip end surface of the outermost seal lip is located closer to the annular portion than a side end of the side plate portion of the protruding portion.

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