JP7147578B2 - Combined seal ring and hub unit bearing - Google Patents

Description

The present invention relates to a combination seal ring formed by combining a slinger and a seal ring, and a hub unit bearing including the combination seal ring.

A hub unit bearing for rotatably supporting a wheel of an automobile with respect to a suspension system is used in an environment where muddy water splashes directly. For this reason, such a hub unit bearing incorporates a sealing device to prevent foreign matter such as rainwater and mud from entering the rolling element installation space where the rolling elements are installed, and to prevent leakage of the enclosed grease to the outside. prevent this from happening. Specifically, the opening at the end in the axial direction of the rolling element installation space is closed with a combined seal ring composed of a slinger and a seal ring.

FIG. 9 shows a combined seal ring described in JP-A-2018-59594. Combination seal ring 100 comprises slinger 101 and seal ring 102 .

The slinger 101 includes a fitting cylinder portion 104 externally fitted to the axial end portion of the inner ring 103 and a circle bent radially outward from one axial end (right side in FIG. 9) of the fitting cylinder portion 104 . A wheel plate portion 105 is provided.

The seal ring 102 includes a metal core 106 and an elastic sealing material 107 .

The core bar 106 has a cylindrical portion 109 fitted inside the axial end portion of the outer ring 108 and a bent portion 110 bent radially inward from the end portion on the other axial side (left side in FIG. 9) of the cylindrical portion 109. and

The sealing material 107 includes a base portion 111 , a plurality of (three in the illustrated example) seal lips 112 a , 112 b , 112 c and a labyrinth lip 113 . The base portion 111 is fixed to the core bar 106 so as to cover the inner peripheral surface and one axial end portion of the cylindrical portion 109 of the core bar 106 and the one axial side surface and radial inner end portion of the bent portion 110 . It is Each of the seal lips 112a, 112b, and 112c extends from the base portion 111 toward the outer peripheral surface of the fitting cylinder portion 104 of the slinger 101 or the other axial side surface of the circular ring plate portion 105, and the tip portion thereof extends toward the fitting cylinder portion. 104 or the other side surface of the circular disk portion 105 in the axial direction. The labyrinth lip 113 is an extending base part located radially outside of the connecting part 117 to which the base end of the radially outermost seal lip 112a of the seal lips 112a, 112b, and 112c is connected. 118 to one side in the axial direction and radially inward. By making the tip end surface of the labyrinth lip 113 closely face the other axial side surface of the circular disk portion 105 of the slinger 101, the tip surface of the labyrinth lip 113 and the other axial side surface of the circular disk portion 105 are arranged. A labyrinth seal 114 is formed between.

According to the hub unit bearing provided with such a combined seal ring 100, it is possible to prevent foreign matter such as rainwater and mud from entering through the openings at the ends of the rolling element installation spaces in the axial direction. It is possible to prevent the enclosed grease from leaking to the outside.

JP 2018-59594 A

In the structure described in Japanese Patent Application Laid-Open No. 2018-59594, the labyrinth lip 113 extends from the base portion 111 to one side in the axial direction and radially inward. For this reason, a recessed groove 115 that is recessed radially outward is formed over the entire circumference of the portion of the seal ring 102 located on the other axial side of the labyrinth lip 113 . Therefore, from the portion between the tip end surface of the labyrinth lip 113 and the other side surface in the axial direction of the circular disk portion 105 of the slinger 101, foreign matter such as rainwater and mud may enter inside the labyrinth seal 114 (toward the rolling element installation space). Once the foreign matter 116 has entered, there is a possibility that the foreign matter 116 will accumulate in the portion of the groove 115 that is positioned below the hub unit bearing with the combined seal ring 100 assembled to the vehicle. The foreign matter 116 accumulated in the groove 115 is difficult to be discharged to the outside space, and may wear the tip portions of the seal lips 112a, 112b, 112c to reduce durability.

SUMMARY OF THE INVENTION In view of the circumstances described above, the present invention has been made to realize a structure of a combination seal ring and a hub unit bearing including the combination seal ring, which can sufficiently ensure sealing performance for a long period of time. be.

The combination seal ring of the present invention comprises a slinger and a seal ring.
The slinger has a fitting tubular portion and a circular disk portion bent radially outward from an axial end portion of the fitting tubular portion.
The seal ring has a core metal and a sealing material fixed to the core metal.
The sealing material has a base, one or more sealing lips, and a labyrinth lip.
The base is fixed to the core bar.
The seal lip extends from the base portion toward the surface of the slinger, and the tip portion is in sliding contact with the surface of the slinger over the entire circumference.
The labyrinth lip extends axially from an extending base portion radially outward of a connecting portion to which a base end portion of a seal lip radially outermost among the seal lips is connected. It includes a portion extending radially outward toward the disc portion.
The labyrinth lip includes a base half portion extending axially toward the circular disk portion from the extended base portion and extending radially outward, and a tip end portion of the base half portion bent to extend radially outward. and the fixed facing surface provided on the side surface of the front half portion that is closer to the circular disk portion in the axial direction.
The slinger or another member fixed to the slinger has the rotation facing surface on a side surface perpendicular to the central axis of the slinger and axially facing the fixed facing surface, and extends radially inward. It has a facing stepped surface over the entire circumference.
Further, in the combination seal ring of the present invention, the rotationally facing surface and the fixedly facing surface are closely opposed to form a radial labyrinth seal between the rotationally facing surface and the fixedly facing surface. In addition, an axial labyrinth seal is formed between the tip surface of the front half portion and the stepped surface by making the tip surface of the front half portion and the stepped surface face each other closely .
Further, the labyrinth lip is elastically deformed so as to reduce the distance between the fixed facing surface and the rotating facing surface as the slinger and the seal ring rotate relative to each other.
Further, in a state in which the seal ring and the slinger are not relatively rotated, the side surface of the front half portion on the opposite side of the fixed facing surface in the axial direction is the axially rotated portion of the stepped surface. It is located on the side farther from the rotation facing surface in the axial direction than the end on the side farther from the facing surface. Then, the facing area between the front end surface of the front half portion of the labyrinth lip and the stepped surface is larger than that in the state where the seal ring and the slinger do not rotate relative to each other. Make it bigger while you are doing it.

Although it is out of the technical scope of the present invention, the labyrinth lip has the fixed facing surface on its outer peripheral surface or inner peripheral surface, and the slinger or other member fixed to the slinger. Alternatively, the rotation facing surface may be provided on a peripheral surface radially facing the fixed facing surface.

Additionally, the thickness of the labyrinth lip can be less than the thickness of the radially outermost sealing lip.
Additionally or alternatively, the thickness of the leading half of the labyrinth lip may be less than the thickness of the base half.

A hub unit bearing of the present invention comprises an outer ring member, an inner ring member, a plurality of rolling elements, and a combined seal ring.
The outer ring member has an outer ring raceway on its inner peripheral surface.
The inner ring member has an inner ring raceway on its outer peripheral surface.
The rolling elements are arranged between the outer ring raceway and the inner ring raceway.
The combination seal ring closes the opening at the axial end of the rolling element installation space that exists between the inner peripheral surface of the outer ring member and the outer peripheral surface of the inner ring member.
In particular, in the hub unit bearing of the present invention, the combined seal ring is the combined seal ring of the present invention, and the fitting cylindrical portion of the slinger is externally fitted and fixed to the axial end portion of the inner ring member, and the seal The core bar of the ring is internally fitted and fixed to the axial end of the outer ring member.

According to the combined seal ring and hub unit bearing of the present invention, sufficient sealing performance can be ensured for a long period of time.

FIG. 1 is a cross-sectional view of a hub unit bearing according to a first example of a reference example . FIG. 2 is an enlarged view of part X in FIG. FIG. 3 is a diagram corresponding to FIG. 2, showing a second example of the reference example . FIG. 4 is a diagram corresponding to FIG. 2, showing the first example of the embodiment. 5 is an enlarged view of the Y portion of FIG. 4. FIG. FIG. 6 is a diagram corresponding to FIG. 2, showing a second example of the embodiment. FIG. 7 is a diagram corresponding to FIG. 2, showing a third example of the reference example . FIG. 8 is a diagram corresponding to FIG. 2, showing a fourth example of the reference example . FIG. 9 is an enlarged cross-sectional view of an upper portion and a lower portion of an example of a combined seal ring structure in an attached state.

[First example of reference example ]
1 and 2 show a first reference example related to the present invention. The hub unit bearing 1 of this reference example includes an outer ring 2 which is an outer ring member which does not rotate when in use, a hub 3 which is an inner ring member which rotates together with a braking rotating body such as a wheel, a disk, and a drum when in use, It comprises a plurality of rolling elements 4 , an outer sealing member 5 and a combined sealing ring 6 .

The outer ring 2 is made of a hard metal such as medium carbon steel and comprises double row outer ring raceways 7a, 7b and a stationary flange 8 for fixing the outer ring 2 to the suspension. The double-row outer ring raceways 7a and 7b are formed in axially intermediate portions of the inner peripheral surface of the outer ring 2, respectively. The stationary flange 8 is formed in the axially intermediate portion of the outer ring 2 so as to protrude radially outward, and has support holes 9 at a plurality of locations in the circumferential direction. The outer ring 2 is supported and fixed to the knuckle of the suspension system by a connecting member such as a bolt screwed into or passed through the support hole 9 .

The hub 3 is arranged radially inwardly of and coaxially with the outer ring 2, and includes double-row inner ring raceways 10a and 10b and a rotary flange 11 for supporting and fixing the wheels and the braking rotor. . The double-row inner ring raceways 10a and 10b are formed in portions of the outer peripheral surface of the hub 3 that face the double-row outer ring raceways 7a and 7b. The rotary flange 11 is formed in a portion of the hub 3 that is axially outside the axially outer end of the outer ring 2 so as to protrude radially outward. has a mounting hole 12 in the . The wheel and the braking rotor are supported on the rotary flange 11 by a stud 13 press-fitted into the mounting hole 12 or a hub bolt screwed into the mounting hole 12 which is a threaded hole.

In this reference example , the axially outer side refers to the left side in FIGS. It refers to the right side of FIGS. 1 and 2, which is the center side in the width direction of the vehicle in the state.

In this reference example , the hub 3 is formed by coupling and fixing a hub body 14 and an inner ring 15 .

Of the double-row inner ring raceways 10a and 10b, the hub body 14 has the axially outer inner ring raceway 10a on the outer peripheral surface of the axially intermediate portion, and is located axially outside the axially outer inner ring raceway 10a. The part has a rotary flange 11 projecting radially outward. Further, the hub body 14 has a small-diameter tubular portion 16 at its axially inner portion, the outer diameter of which is smaller than that of the portion adjacent to the axially outer side. It has an inward facing stepped portion 17 .

The inner ring 15 has the axially inner inner ring raceway 10b among the double-row inner ring raceways 10a and 10b on the outer peripheral surface of the axially intermediate portion.

In this reference example , in a state where the inner ring 15 is fitted onto the small-diameter cylindrical portion 16, the portion of the small-diameter cylindrical portion 16 protruding axially inward from the axially inner end face of the inner ring 15 is directed radially outward. A crimped portion 18 formed by plastic deformation holds down the axially inner end surface of the inner ring 15 . As a result, the inner ring 15 is axially sandwiched between the crimped portion 18 and the stepped portion 17, and the hub body 14 and the inner ring 15 are coupled and fixed to form the hub 3. As shown in FIG.

The hub 3 is formed on the outer peripheral surface of a portion of the hub body that protrudes axially inward from the axially inner end surface of the inner ring in a state where the inner ring is fitted onto the small-diameter tubular portion of the hub body. Alternatively, a nut may be screwed onto the externally threaded portion to fix it.

A plurality of rolling elements 4 for each row are held between the double-row outer ring raceways 7a, 7b and the double-row inner ring raceways 10a, 10b, respectively, in the pockets 20 of the retainer 19, and roll. placed freely. Although balls are used as the rolling elements 4 in this reference example , tapered rollers can also be used.

The outer sealing member 5 is a seal ring made of a metal plate having sufficient strength and rigidity, such as a steel plate. An outer seal member 23 made of an elastic material such as an elastomer is fixed to the outer core metal 21 and has a plurality of (three in the illustrated example) seal lips 22a, 22b, and 22c.

In this reference example , the tip of the radially innermost seal lip 22c among the seal lips 22a, 22b, and 22c slides on the outer peripheral surface of the shoulder portion 24a adjacent to the axially outer side of the outer ring raceway 7a on the axially outer side. While contacting, the tip portions of the remaining seal lips 22a and 22b are slidably contacted with the axial inner surface of the rotary flange 11 or the connecting portion between the axial inner surface of the rotary flange 11 and the outer peripheral surface of the shoulder portion 24a. I am letting As a result, the grease that exists between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 and that is enclosed in the cylindrical rolling element installation space 25 in which the rolling elements 4 are arranged is transferred to the rolling element installation space 25. In addition to preventing leakage from the axially outer opening, foreign matter such as mud and rainwater is prevented from entering from the axially outer opening of the rolling element installation space 25 .

A combination seal ring 6 comprises a slinger 26 and a seal ring 27 .

The slinger 26 is made by bending a metal plate such as a stainless steel plate having sufficient strength and rigidity as well as being rust-proof and having an L-shaped cross section and an annular shape as a whole. It has a cylindrical portion 28 and a circular plate portion 29 that is bent radially outward at right angles from an axially inner end portion of the fitting cylindrical portion 28 . The fitting cylinder portion 28 is formed on the outer peripheral surface of the axially inner end portion of the hub 3, specifically, on the outer peripheral surface of the shoulder portion 24b of the inner ring 15, which is adjacent to the axially inner side of the inner ring raceway 10b on the axially inner side. , are externally fixed by an interference fit.

The seal ring 27 includes a cored bar 30 and a sealing member 31 fixed to the cored bar 30 .

The core metal 30 is made by bending a metal plate such as a steel plate having sufficient strength and rigidity to form an annular shape with a substantially L-shaped cross section. and a bent portion 33 bent radially inward from the axially outer end. The cylindrical portion 32 is internally fitted and fixed to the inner peripheral surface of the axially inner end portion of the outer ring 2 by interference fit.

The sealing material 31 is made of an elastic material such as an elastomer such as rubber, and is fixed to the surface of the core metal 30 over the entire circumference by vulcanization adhesion. The seal member 31 includes a base portion 34 , a plurality of (three in the illustrated example) seal lips 35 a , 35 b , 35 c and one labyrinth lip 36 .

The base portion 34 is vulcanized to cover the outer peripheral surface and the axially inner end of the cylindrical portion 32 of the core bar 30 and the axially inner surface and the radially inner end of the bent portion 33 . is fixed by

The seal lips 35a, 35b, and 35c extend from the base portion 34 toward the surface of the slinger 26, and the tip portions are in sliding contact with the surface of the slinger 26 over the entire circumference. Specifically, of the seal lips 35a, 35b, and 35c, the radially outermost seal lip 35a extends axially inward and radially outward from the base portion 34 toward the circular ring plate portion 29 of the slinger 26. , the tip portion is in sliding contact with the axial outer surface of the circular ring plate portion 29 over the entire circumference. The two radially inner seal lips 35 b and 35 c extend radially inward from the base portion 34 toward the tubular fitting portion 28 of the slinger 26 , and their distal end portions extend toward the outer peripheral surface of the tubular fitting portion 28 . is in sliding contact with the entire circumference.

The labyrinth lip 36 has a base half 37 and a front half 38 .

The base half portion 37 extends axially inward and radially from an extending base portion 50 that is located radially outside a connecting portion 49 to which the base end portion of the radially outermost seal lip 35a is connected. It extends outward. Therefore, the inner peripheral surface of the base half portion 37 is a conical surface inclined in a direction in which the inner diameter increases toward the inner side in the axial direction. In this reference example , the portion of the surface of the base portion 34 adjacent to the axially outer side of the inner peripheral surface of the base half portion 37 is positioned on the same conical surface as the inner peripheral surface of the base half portion 37. A flat surface orthogonal to the central axis of the outer ring 2 connects this portion and a connecting portion 49 to which the base end portion of the radially outermost seal lip 35a is connected. In short, in the combination seal ring 6 of this reference example , the combination seal ring 100 described in JP-A-2018-59594 is provided in the space 48 existing between the labyrinth lip 36 and the radially outermost seal lip 35a. There is no recessed groove 115 that is recessed radially outward (see FIG. 9).

The front half portion 38 has a ring shape, is bent from the front end portion (the axially inner end portion) of the base half portion 37, and extends radially outward. The front half portion 38 has a fixed facing surface 39 on its axial inner surface which is a flat surface perpendicular to the central axis of the outer ring 2 . In this reference example , the fixed opposing surface 39 is axially closely opposed to the rotationally opposing surface 40 provided on the radially outer portion of the axially outer surface of the circular disk portion 29 of the slinger 26, so that the fixed opposing surface A radially extending labyrinth seal 41 is formed between 39 and the rotation-opposing surface 40 .

In addition, in this reference example , the thickness of the labyrinth lip 36 is appropriately regulated so that the rigidity of the labyrinth lip 36 is set to an appropriate level. That is, the labyrinth lip 36 reduces the gap between the fixed facing surface 39 and the rotating facing surface 40 due to the action of the airflow generated between the fixed facing surface 39 and the rotating facing surface 40 as the hub 3 rotates. The rigidity of the labyrinth lip 36 is regulated to the extent that it can be elastically deformed in the direction.

By closing the axial inner opening of the rolling element installation space 25 with such a combination seal ring 6, the grease enclosed in the rolling element installation space 25 is prevented from leaking from the axial inner opening of the rolling element installation space 25. In addition, foreign substances such as mud and rainwater are prevented from entering through the axially inner opening of the rolling element installation space 25 .

According to the hub unit bearing 1 of this reference example , it is possible to sufficiently ensure the sealing performance of the axial inner opening of the rolling element installation space 25 in which the combined seal ring 6 is installed for a long period of time.

That is, in this reference example , the base half portion 37 of the labyrinth lip 36 that constitutes the seal ring 27 is extended axially inward and radially outward from the base portion 34 so that the inner peripheral surface of the base half portion 37 is is a conical surface inclined in a direction in which the inner diameter increases toward the inner side in the axial direction. Therefore, in this reference example , the space 48 existing between the labyrinth lip 36 and the radially outermost seal lip 35a has a diameter similar to that provided in the combination seal ring 100 described in Japanese Patent Application Laid-Open No. 2018-59594. There is no recessed groove 115 that is recessed outward in the direction. Therefore, if a foreign object such as rainwater or muddy water falls between the axial inner surface (fixed facing surface 39) of the front half 38 and the axial outer surface (rotational facing surface 40) of the circular disk portion 29 of the slinger 26, Even if foreign matter enters the space 48 inside (on the rolling element installation space 25 side) of the labyrinth seal 41 through the intermediate portion (labyrinth seal 41 ), the foreign matter can be prevented from accumulating in the space 48 . For this reason, the foreign matter that has entered the space 48 is guided along the inner peripheral surface of the base half 37 by the action of gravity, moves axially inward, and is then moved inward in the axial direction by the centrifugal force accompanying the rotation of the hub 3 (slinger 26). As a result, it is discharged to the external space through the labyrinth seal 41 .

Furthermore, in this reference example , since the rigidity of the labyrinth lip 36 is set at an appropriate level, when the hub 3 rotates as the vehicle travels, the action of the airflow generated between the fixed facing surface 39 and the rotating facing surface 40 As a result, the labyrinth lip 36 is elastically deformed in a direction in which the distance between the fixed facing surface 39 and the rotating facing surface 40 becomes smaller. As a result, the axial width of the labyrinth seal 41 can be reduced, and the sealing effect of the labyrinth lip 36 can be improved. On the other hand, when the hub 3 stops as the vehicle stops, the front half portion 38 is elastically restored, and the distance between the fixed facing surface 39 and the rotating facing surface 40 widens. Therefore, foreign matter that has entered the space 48 existing between the labyrinth lip 36 and the radially outermost seal lip 35a can be easily discharged to the external space through the labyrinth seal 41 by the action of gravity.

For the reasons described above, even if foreign matter enters the space 48 inside the labyrinth seal 41, the foreign matter accumulates in the space existing between the labyrinth lip 36 and the radially outermost seal lip 35a. can be prevented. Therefore, it is possible to prevent the tip portions of the seal lips 35a, 35b, and 35c from being worn by foreign matter, and the sealing performance of the axially inner opening of the rolling element installation space 25 can be ensured for a long period of time.

[Second example of reference example ]
FIG. 3 shows a second example of a reference example related to the present invention. The slinger 26a that constitutes the combination seal ring 6a of this reference example has a substantially U-shaped (substantially U-shaped) cross-sectional shape. That is, the slinger 26a includes a fitting cylinder portion 28 fitted on the outer peripheral surface of the axially inner end portion of the hub 3 (see FIG. 1), and a radially extending portion extending from the axially inner end portion of the fitting cylinder portion 28. It has a circular disk portion 29 bent outward at a right angle, and a canopy portion 42 bent axially outward at a right angle from the radially outer end of the circular disk portion 29 . The eaves portion 42 has a rotation-facing surface 40 a on its inner peripheral surface, which is a cylindrical surface centered on the central axis of the hub 3 .

The labyrinth lip 36a of the seal material 31a that constitutes the seal ring 27a includes a base half portion 37a that extends axially inward and radially outward from the base portion 34, and a tip portion of the base half portion 37a that is bent to , and a cylindrical front half 38a extending axially inward. The inner peripheral surface of the base half portion 37a is a conical surface inclined in a direction in which the inner diameter increases toward the inner side in the axial direction. The front half portion 38a has a fixed facing surface 39a on its outer peripheral surface, which is a cylindrical surface centered on the central axis of the outer ring 2 (see FIG. 1). In this reference example , the fixed facing surface 39a of the labyrinth lip 36a and the rotationally facing surface 40a of the slinger 26a are arranged in close proximity to each other in the radial direction. It constitutes an elongated labyrinth seal 41a.

In addition, in this reference example , the thickness of the labyrinth lip 36a is moderately regulated so that the rigidity of the labyrinth lip 36a is moderate. Specifically, the labyrinth slip 36a moves between the fixed facing surface 39a and the rotating facing surface 40a due to the action of the airflow generated between the fixed facing surface 39a and the rotating facing surface 40a as the hub 3 rotates. The rigidity of the labyrinth lip 36a is regulated to the extent that it can be elastically deformed in the direction in which the gap becomes smaller.

In the case of this reference example as well, since the base half portion 37a of the labyrinth lip 36a extends axially inwardly and radially outwardly from the base portion 34, there is no gap between the labyrinth lip 36a and the radially outermost seal lip 35a. In the space 48a existing in the space 48a, there is no recessed groove 115 recessed radially outward, which is provided in the combination seal ring 100 described in Japanese Patent Laid-Open No. 2018-59594. Therefore, even if foreign matter such as rainwater or muddy water enters the space 48a inside the labyrinth seal 41a (on the side of the rolling element installation space 25), the foreign matter can be prevented from accumulating in the space 48a. can.

In addition, since the rigidity of the labyrinth slip 36a is set at an appropriate level, when the hub 3 rotates as the vehicle travels, the action of the airflow generated between the fixed facing surface 39a and the rotation facing surface 40a causes the labyrinth slip. 36a elastically deforms in a direction in which the distance between the fixed facing surface 39a and the rotating facing surface 40a becomes smaller. As a result, the radial width of the labyrinth seal 41a can be reduced, and the sealing effect of the labyrinth lip 36a can be improved. On the other hand, when the hub 3 stops as the vehicle stops, the front half portion 38a is elastically restored, the distance between the fixed facing surface 39a and the rotating facing surface 40a widens, and the labyrinth lip 36a and the outermost radially outermost surface 38a widen. Foreign matter that has entered the space 48a existing between the seal lip 35a can be easily discharged to the external space. The configuration and effects of other parts are the same as those of the first example of the reference example .

[ First example of embodiment]
4 and 5 show a first example of an embodiment of the invention. The combined seal ring 6 b of this example comprises the encoder 43 in addition to the slinger 26 and seal ring 27 . The encoder 43 is made of a permanent magnet such as a rubber magnet or a plastic magnet, and has a ring shape as a whole. is attached and fixed to the The encoder 43 has, at its radially outer end, a ridge portion 44 that protrudes axially outward from the axial outer surface (rotationally opposed surface 40) of the circular disk portion 29 over the entire circumference. The inner peripheral surface of 44 has a stepped surface 45 facing radially inward. In this example, the stepped surface 45 is a conical surface inclined in a direction in which the inner diameter increases toward the axially outer side.

In this example, the fixed facing surface 39 provided on the leading half portion 38 of the labyrinth lip 36 is axially closely opposed to the rotating facing surface 40 provided on the circular disk portion 29 of the slinger 26, and the leading half portion The tip surface (peripheral surface) of 38 is made to closely face the stepped surface 45 in the radial direction. As a result, a radially extending labyrinth seal 41 is formed between the fixed facing surface 39 and the rotating facing surface 40 , and the labyrinth seal 41 is formed between the tip surface of the front half portion 38 and the stepped surface 45 . It forms an axial labyrinth seal 46 bent axially outward from the radially outer end. In this example, when the hub 3 is not rotating, the axial inner portion of the front end surface of the front half portion 38 is closely opposed to the axial outer portion of the step surface 45 . In other words, when the hub 3 is not rotating, the axial outer surface of the front half portion 38 is located axially outside the axial outer surface of the ridge portion 44 .

In this example, when the labyrinth lip 36 is elastically deformed in the direction in which the gap between the fixed facing surface 39 and the rotation facing surface 40 becomes smaller as the hub 3 rotates, the axial width dimension of the labyrinth seal 41 becomes smaller. Along with this, the facing area between the tip surface of the front half portion 38 and the stepped surface 45 increases. In other words, the axial length of the portion where the tip surface of the front half portion 38 and the stepped surface 45 overlap in the radial direction, that is, the axial length of the labyrinth seal 46 in the axial direction is increased.

In this example, when the labyrinth lip 36 is elastically deformed as the hub 3 rotates, the width dimension of the labyrinth seal 41 in the axial direction becomes smaller, and the radially outer end of the labyrinth seal 41 is bent axially outward. As a result, the axial length of the axial labyrinth seal 46 increases. Therefore, the sealing effect of the labyrinth lip 36 can be further improved as compared with the combination seal ring 6 of the first example of the reference example .

On the other hand, when the labyrinth lip 36 is elastically restored as the hub 3 stops, the axial width of the labyrinth seal 41 increases and the axial length of the labyrinth seal 46 decreases. Therefore, the foreign matter that has entered the space 48 existing between the labyrinth lip 36 and the radially outermost seal lip 35a is discharged to the external space through the labyrinth seal 41 and the axial labyrinth seal 46 by the action of gravity. can be made easier. Particularly in this example, since the stepped surface 45 is formed as a conical surface inclined in a direction in which the inner diameter increases toward the outer side in the axial direction, the foreign matter that has moved to the tip of the front half portion 38 is guided toward the outer space. can do. The configuration and effects of other parts are the same as those of the first example of the reference example .

[ Second example of embodiment]
FIG. 6 shows a second example of an embodiment of the invention. In addition to the slinger 26 and the seal ring 27, the combination seal ring 6c of this example includes an encoder 43a attached and fixed to the axially inner surface and the radially outer end of the circular disk portion 29 of the slinger 26. As shown in FIG. The encoder 43a has a convex portion 47 protruding axially outward from the axial outer side surface of the slinger 26 at the radially outer end of the encoder 43a over the entire circumference. A radially inner portion has a rotation-facing surface 40b that is a flat surface perpendicular to the central axis of the hub 3 (see FIG. 1). Further, the encoder 43a has, on the radially outer portion of the tip surface of the projection 47, a ridge portion 44a that protrudes axially outward from the radially inner portion (the rotation-facing surface 40b). The inner peripheral surface has a stepped surface 45a facing radially inward. The stepped surface 45a is a conical surface inclined in a direction in which the inner diameter increases toward the axially outer side.

In this example, the fixed facing surface 39 provided on the front half portion 38 of the labyrinth lip 36 is axially closely opposed to the rotation facing surface 40b provided on the encoder 43a, and the tip surface (outer peripheral surface) of the front half portion 38 surface) is radially opposed to the stepped surface 45a. As a result, a radially extending labyrinth seal 41b is formed between the fixed facing surface 39 and the rotation facing surface 40b, and the labyrinth seal 41b is formed between the tip surface of the front half portion 38 and the stepped surface 45a. It forms an axial labyrinth seal 46a bent axially outward from the radially outer end. In this example, when the hub 3 is not rotating, the axially inner portion of the front end surface of the front half portion 38 is closely opposed to the axially outer portion of the stepped surface 45a. Other configurations and effects are the same as those of the first example of the reference example and the first example of the embodiment .

[ Third example of reference example ]
FIG. 7 shows a third example of a reference example related to the present invention. The slinger 26b that constitutes the combined seal ring 6d of this reference example extends axially outward and radially inward from the radially outer end of the annular disk portion 29 in addition to the fitting cylinder portion 28 and the annular disk portion 29. It has a canopy portion 42a bent at an acute angle. Therefore, the outer peripheral surface of the eaves portion 42a is a conical surface inclined in a direction in which the outer diameter increases toward the inner side in the axial direction.

Further, in this reference example , the entire labyrinth lip 36b of the sealing material 31b that constitutes the seal ring 27b extends axially inward and radially outward from the base portion 34 . The inner peripheral surface of the labyrinth lip 36b is a conical surface inclined in a direction in which the inner diameter increases toward the inner side in the axial direction. In this reference example , a fixed facing surface 39b provided on the axially inner portion of the inner peripheral surface of the labyrinth lip 36b and a rotationally facing surface 40c provided on the axially outer portion of the outer peripheral surface of the eaves portion 42a are closely opposed to each other. Thus, a labyrinth seal 41c extending radially outward toward the axially inner side is formed between the fixed opposing surface 39b and the rotationally opposing surface 40c.

In this reference example , when the hub 3 rotates, the airflow generated between the fixed facing surface 39b and the rotating facing surface 40c causes the labyrinth slip 36b to reduce the gap between the fixed facing surface 39b and the rotating facing surface 40c. elastic deformation in any direction. As a result, the width dimension of the labyrinth seal 41c is reduced, and the sealing effect of the labyrinth lip 36b can be improved. On the other hand, when the hub 3 stops, the labyrinth lip 36b is elastically restored and the width dimension of the labyrinth seal 41c increases. Foreign matter that has entered the space 48b can be easily discharged. In particular, in this reference example , the conical inner peripheral surface of the labyrinth lip 36b can guide the foreign matter radially outward, so that the foreign matter can be discharged more satisfactorily. The configuration and effects of other parts are the same as those of the first and second reference examples .

[ Fourth example of reference example ]
FIG. 8 shows a fourth reference example related to the present invention. The slinger 26c that constitutes the combination seal ring 6e of this reference example has an eaves portion 42b that is bent axially outward at right angles from the radially outer end portion of the circular ring plate portion 29. As shown in FIG. Further, the encoder 43b has a protruding portion 47a with a substantially trapezoidal cross-section formed over the entire circumference at the radially outer end portion so as to cover the eaves portion 42b. The convex portion 47a has an outer peripheral surface that is a conical surface inclined in a direction in which the outer diameter increases toward the axially outer side, while an inner peripheral surface that is centered on the central axis of the hub 3 (see FIG. 1). It is assumed to be a cylindrical surface.

In this reference example , a fixed facing surface 39b provided on the axially inner portion of the inner peripheral surface of the labyrinth lip 36b and a rotationally facing surface 40d provided on the axially outer portion of the outer peripheral surface of the convex portion 47a are closely opposed to each other. Thus, a labyrinth seal 41d extending radially outward toward the axially inner side is formed between the fixed opposing surface 39b and the rotationally opposing surface 40d.

In this reference example , by forming the inner peripheral surface of the convex portion 47a into a cylindrical surface, a concave portion recessed radially outward is provided in the space 48b existing between the labyrinth lip 36b and the radially outermost seal lip 35a. prevents the formation of This prevents the foreign matter that has entered the space 48b from accumulating in the space 48b. Other configurations and effects are the same as those of the first and third reference examples .

In each example of the reference example and each example of the embodiment described above, the case where the combination seal ring is installed in the opening portion inside the rolling element installation space in the axial direction has been explained, but the hub unit bearing of the present invention is implemented. In some cases, the combination seal ring of the present invention can also be installed in the axially outer opening of the rolling element installation space.

1 hub unit bearing 2 outer ring 3 hub 4 rolling element 5 outer sealing member 6, 6a, 6b, 6c, 6d, 6e combination seal ring 7a, 7b outer ring raceway 8 stationary flange 9 support hole 10a, 10b inner ring raceway 11 rotating flange 12 mounting Hole 13 Stud 14 Hub body 15 Inner ring 16 Small diameter cylindrical portion 17 Step portion 18 Crimped portion 19 Cage 20 Pocket 21 Outer core metal 22a, 22b, 22c Seal lip 23 Outer seal material 24a, 24b Shoulder 25 Rolling element installation space 26, 26a, 26b, 26c slingers 27, 27a, 27b seal ring 28 fitting cylinder portion 29 circular disk portion 30 core metal 31, 31a, 31b seal material 32 cylindrical portion 33 bent portion 34 base portion 35a, 35b, 35c seal lip 36, 36a, 36b Labyrinth lip 37, 37a Base half 38, 38a Front half 39, 39a, 39b Fixed facing surface 40, 40a, 40b, 40c, 40d Rotating facing surface 41, 41a, 41b, 41c, 41d Labyrinth seal 42, 42a, 42b Eaves 43, 43a, 43b Encoder 44, 44a Ridge 45, 45a Step surface 46, 46a Axial labyrinth seal 47, 47a Convex 48, 48a, 48b Space 49 Coupling 50 Extension base 100 Combination Seal ring 101 Slinger 102 Seal ring 103 Inner ring 104 Fitting cylindrical portion 105 Circular disc portion 106 Core metal 107 Seal material 108 Outer ring 109 Cylindrical portion 110 Bent portion 111 Base portion 112a, 112b, 112c Seal lip 113 Labyrinth lip 114 Labyrinth seal 115 Concave Groove 116 Foreign matter 117 Joining portion 118 Extension base

Claims (4)

a slinger having a tubular fitting portion and a circular disk portion bent radially outward from an axial end portion of the tubular fitting portion;
a seal ring having a core metal and a sealing material fixed to the core metal;
with
The sealing material includes a base portion fixed to the core metal, and one or more seals extending from the base portion toward the surface of the slinger and having tip portions in sliding contact with the surface of the slinger over the entire circumference. The annular ring extends axially from an extending base portion located radially outwardly of a connecting portion to which the lip and the base portion of the radially outermost seal lip of the base portion are connected. a labyrinth lip including a portion facing the plate portion and extending radially outward,
The labyrinth lip has a base half portion extending from the extended base portion toward the circular ring plate portion in the axial direction and radially outward, and a tip portion of the base half portion that is bent to extend radially. It has a circular ring-shaped front half portion extending outward, and a fixed facing surface provided on a side surface of the front half portion that is closer to the circular ring plate portion in the axial direction,
The slinger or another member fixed to the slinger has a rotation facing surface on a side surface perpendicular to the central axis of the slinger and axially facing the fixed facing surface, and facing radially inward. It has a stepped surface along the entire circumference,
A radial labyrinth seal is formed between the rotationally opposed surface and the fixedly opposed surface by causing the rotationally opposed surface and the fixedly opposed surface to face each other closely , and An axial labyrinth seal is formed between the front end surface of the front half portion and the stepped surface by making the surface and the stepped surface face each other closely ,
The labyrinth lip is elastically deformed in a direction in which the gap between the fixed facing surface and the rotating facing surface becomes smaller as the slinger and the seal ring rotate relative to each other,
In a state in which the seal ring and the slinger are not relatively rotated, the side surface of the front half portion on the opposite side of the fixed facing surface in the axial direction is the rotation facing surface in the axial direction of the stepped surface. is located on the side farther from the rotation facing surface in the axial direction than the end on the side farther from the
The facing area between the front end surface of the front half portion of the labyrinth lip and the stepped surface is larger than the area where the seal ring and the slinger rotate relative to each other than when the seal ring and the slinger do not rotate relative to each other. grow in the presence of
Combination seal ring. the thickness of the labyrinth lip is less than the thickness of the radially outermost seal lip;
The combination seal ring according to claim 1. the thickness of the front half of the labyrinth lip is smaller than the thickness of the base half;
The combination seal ring according to claim 1 or 2. an outer ring member having an outer ring raceway on its inner peripheral surface;
an inner ring member having an inner ring raceway on its outer peripheral surface;
a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway;
a combination seal ring that closes an opening at an axial end of a space for installing the rolling elements existing between the inner peripheral surface of the outer ring member and the outer peripheral surface of the inner ring member;
with
The combination seal ring is the combination seal ring according to any one of claims 1 to 3 , and the fitting cylinder portion of the slinger is externally fitted and fixed to the axial end portion of the inner ring member. In addition, the core metal of the seal ring is internally fitted and fixed to the axial end of the outer ring member,
hub unit bearings.

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