Abstract:
A wheel bearing includes a hub provided with a flange; and an outer ring having an end close to the flange and the other end opposite to the end and relatively rotatable to the hub. A sealing structure for sealing the space between the flange and the end of the outer ring is further included.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0015451 filed in the Korean Intellectual Property Office on Jan. 30, 2015, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to a sealing structure of a wheel bearing for a vehicle. More particularly, the present invention relates to a sealing structure of a wheel bearing for a vehicle which is mounted between an outer ring and a flange of the wheel bearing for the vehicle and can prevent inflow of foreign materials, and the wheel bearing provided with the same. 
     (b) Description of the Related Art 
     Generally, a bearing is disposed between a rotating element and a non-rotating element so as to smooth rotation of the rotating element. Various types of bearings such as a ball bearing, a taper roller bearing, needle bearing, and so on are currently used. 
     A wheel bearing is one type of such bearings, and rotatably connects a wheel that is the rotating element to a vehicle body that is non-rotating element. The wheel bearing includes an inner ring (and/or a hub) connected to one of a wheel or a vehicle body, an outer ring connected to the other of the wheel or the vehicle body, and rolling elements disposed between the outer ring and the inner ring. 
     Since such the wheel bearing is mounted at the wheel of the vehicle, the wheel bearing is always exposed to foreign materials such as dust and moisture. If the foreign materials enter an inside of the wheel bearing, particularly a portion on which the rolling elements are mounted, raceways that are grinded may be damaged. The damaged raceways may generate noise and vibration when the wheel bearing operates and may shorten a lifetime of the wheel bearing. Therefore, sealing apparatus for preventing inflow of the foreign materials may be mounted at one end or both ends of the wheel bearing. Particularly, the sealing apparatus for sealing a space between the outer ring and the hub may be provided to the wheel bearing. 
     A conventional sealing apparatus includes an inner supporter, a sealing member, and a lip portion. In addition, the sealing apparatus may further include an outer supporter. The inner supporter is mounted on an exterior circumference of one end portion of the outer ring, the outer supporter is mounted on a flange and faces the inner supporter, and sealant is applied to a contacting surface of the outer supporter and the flange so as to seal a gap between the outer supporter and the flange. The lip portion includes a plurality of lips. Some lips contact with the outer supporter and seal a space between the inner supporter and the outer supporter. That is, the plurality of lips prevent inflow of the foreign materials into the sealing apparatus. The sealing member is integrally formed with the lip portion and mounted on the inner supporter. 
     The conventional sealing apparatus can prevent inflow of the foreign materials to some degree, but the foreign materials (dust or moisture) falling down on the flange may flow into the sealing apparatus. 
     In addition, a plurality of lips are configured to contact with the outer supporter in order to further prevent inflow of the foreign materials into the sealing apparatus, thereby increasing drag torque of the bearing. 
     Furthermore, the inflow foreign materials cannot flow out from the conventional sealing apparatus. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in an effort to provide a sealing structure of a wheel bearing having advantages of blocking foreign materials falling down on a surface of a flange and easily dropping the foreign materials down to a ground by forming a staying recess at a radially outmost end of the outer supporter. 
     Another embodiment of the present invention provides a sealing structure of a wheel bearing having advantages of tapping the foreign materials by forming a pocket lip at an inside of the sealing apparatus and of sending the trapped foreign materials out from the sealing apparatus. 
     Yet another embodiment of the present invention provides a sealing structure of a wheel bearing having advantages of preventing inflow of foreign materials in an axial direction by mounting a blocking wall extending to a radial outer direction from an exterior circumference of an inner supporter. 
     A sealing structure of a wheel bearing which includes a hub provided with a flange and an outer ring having an end close to the flange and the other end opposite to the end and relatively rotatable to the hub is configured to seal a space between the flange and the end of the outer ring. The sealing structure may include: an inner supporter mounted at an end portion of the outer ring; an outer supporter having a flange contact portion mounted at a side surface of the flange; and a sealing member mounted on the inner supporter and having at least one seal lip contacting with the outer supporter, wherein at least a portion of the outer supporter at a radial exterior of the flange contact portion is spaced from the flange and forms a staying recess together with the flange. 
     The outer supporter spaced from the flange may be extended axially far away from the flange. 
     The sealing member may include a blocking wall spaced from an end of the outer supporter that is extended axially and extended radially further than the end of the outer supporter. 
     A surface of the blocking wall opposite to the end of the outer supporter may be formed of a slanted surface. 
     At least a portion of the outer supporter at a radial interior of the flange contact portion may be spaced from the flange and may be extended in an axially inboard direction and a radially inner direction. 
     In one aspect, the sealing structure may further include a pocket lip extended from the sealing member and having a pocket shape opening toward a radially outer direction. 
     An end of the pocket lip may be spaced from the outer supporter. 
     In another aspect, the sealing structure may further include a pocket lip extended slantly from the sealing member in a radially outer direction and contacting with the outer supporter. 
     The inner supporter may include: an axially extending portion press-fitted onto an exterior circumference of an end portion of the outer ring and extending axially; a radially extending portion bent from an end of the axially extending portion, extending in a radially inner direction, and contacting with the end of the outer ring, wherein the other end of the axially extending portion is spaced from an exterior circumference of the outer ring and is formed of a thin end portion. 
     The sealing structure may further include a slanted lip mounted at a radially inner end of the inner supporter and extending in a radially inner direction and an axially inboard direction. 
     The sealing structure may further include an extended portion enclosing a radially inner end of the inner supporter. 
     A wheel bearing according to another exemplary embodiment of the present invention may include: a hub provided with a flange; an outer ring having an end close to the flange and the other end opposite to the end and relatively rotatable to the hub; and a sealing apparatus configured to seal a space between the flange and the end of the outer ring. 
     The flange may include a flange base, a flange extended portion extended in a radially outer direction from the flange base, and a flange curved portion concave toward an axially outboard direction at a radial exterior of the flange base. 
     The sealing apparatus may include an inner supporter mounted at an end portion of the outer ring, an outer supporter having a flange contact portion, and a sealing member mounted on the inner supporter and having at least one seal lip contacting with the outer supporter, wherein at least a portion of the outer supporter contacts with the flange extended portion. 
     At least a portion of the outer supporter at a radial exterior of the flange contact portion may be spaced from the flange curved portion and may form a staying recess together with the flange curved portion. 
     Above-described sealing structure according to the exemplary embodiment of the present invention may be used in the wheel bearing according to another exemplary embodiment of the present invention with or without a suitable modification being applied. 
     As described above, since a staying recess is formed between a radially outmost end of an outer supporter and a flange and a blocking wall is mounted on an exterior circumference of an inner supporter, inflow of foreign materials may be effectively prevented according to an exemplary embodiment of the present invention. If the foreign materials flow into a sealing apparatus, the foreign materials are trapped in a pocket lip and flow out from the sealing apparatus again. Further, the sealing apparatus according to an exemplary embodiment of the present invention may improve sealing performance, and thereby achieving sufficient sealing purpose even though one seal lip contacts with the outer supporter. Therefore, drag torque of the bearing may be reduced and fuel economy may be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a wheel bearing according to an exemplary embodiment of the present invention. 
         FIG. 2  is an enlarged view of “A” portion in  FIG. 1  and a cross-sectional view of a sealing structure of a wheel bearing according to an exemplary embodiment of the present invention. 
         FIG. 3  is a cross-sectional view of a sealing structure of a wheel bearing according to another exemplary embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
         FIG. 5  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
         FIG. 6  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
     In the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
     For better comprehension and ease of description, a portion close to a wheel in an axial direction (the left in the drawings) will be called ‘one side’, ‘one end’, ‘one end portion’ or similar designations thereto, and a portion far from the wheel in the axial direction (the right in the drawings) will be called ‘the other side’, ‘the other end’, ‘the other end portion’ or similar designations thereto. 
     In the specification, the same or similar reference numerals refer to the same or similar constituent elements. 
       FIG. 1  is a cross-sectional view of a wheel bearing according to an exemplary embodiment of the present invention. 
     A wheel bearing illustrated in  FIG. 1 , for better comprehension and ease of description, exemplifies any one wheel bearing among various wheel bearings. Therefore, it is to be understood that spirit of the present invention is not limited to be applied to the wheel bearing exemplified in this specification but is applied to various wheel bearings. 
     As shown in  FIG. 1 , a wheel bearing  1  according to an exemplary embodiment of the present invention includes a hub  10 , an inner ring  11  engaged on an exterior circumference of the hub  10 , an outer ring  12  spaced radially apart from the hub  10  and the inner ring  11 , first rolling elements  13  disposed between the hub  10  and the outer ring  12 , second rolling elements  14  disposed between the outer ring  12  and the inner ring  11 , and a sealing apparatus  100  and an inboard seal  20  disposed between the hub  10  (or the inner ring  11 ) and the outer ring  12 . 
     The hub  10  includes a flange  15  of disk shape extending in a radially outer direction at a side portion thereof, a middle portion  25  of cylindrical shape extending toward the other side from the flange  15 , and an inner ring receiving portion  35  formed at an exterior circumference of the other side portion of the hub  10  and stepped in a radially inner direction. A bolt hole  17  is formed at the flange  15  and a hub bolt  19  is fixedly mounted in the bolt hole  17 . A vehicle wheel (not shown) is mounted at the hub bolt  19 . In addition, a pilot  52  is protruded from a side surface of the hub  10  in an axial direction. The pilot  52  guides the wheel when the wheel is mounted at the flange  15 . The hub  10  further includes a hub raceway  31  formed at an exterior circumference thereof between the flange  15  and the middle portion  25 . In addition, a bending portion  50  is formed at the other end of the hub  10  so as to hold the inner ring  11  mounted on the hub  10  and apply preload to the rolling elements. 
     The inner ring  11  has a cylindrical shape and is press-fitted onto the inner ring receiving portion  35  of the hub  10 . An inner ring raceway  32  is formed on an exterior circumference of the inner ring  11 . 
     The outer ring  12  has a hollow cylindrical shape and encloses the exterior circumference of the hub  10 . That is, a hollow space is formed in a radially inner portion of the outer ring  12  along a center axis, and the hub  10  and the inner ring  11  are insert in the hollow space. An outer ring flange  39  is extended from an exterior circumference of the outer ring  12  in the radially outer direction, and an outer ring bolt hole  37  for mounting the wheel bearing  1  to a vehicle body (particularly, a knuckle) is formed at the outer ring flange  39 . In addition, first and second outer ring raceways  41  and  42  are formed respectively on interior circumferences of both end portions of the outer ring  12 . The first outer ring raceway  41  formed on the interior circumference of the end portion of the outer ring  12  faces the hub raceway  31 . In addition, the second outer ring raceway  42  formed on the interior circumference of the other end portion of the outer ring  12  faces the inner ring raceway  32 . 
     The first rolling elements  13  are mounted between the hub raceway  31  and the first outer ring raceway  41  and the second rolling elements  14  are mounted between the inner ring raceway  32  and the second outer ring raceway  42 . The first rolling elements  13  and the second rolling elements  14  have various shapes such as a ball shape or a cylinder shape. A predetermined distance is maintained between one rolling element included in the first rolling elements  13  or the second rolling elements  14  and another neighboring rolling element by a retainer  18 . 
     The inboard seal  20  is mounted at the other end portion of the outer ring  12 . The inboard seal  20  closes a radial space formed between the outer ring  12  and the inner ring  11  so as to prevent inflow of foreign materials (dust or moisture) into the radial space between the outer ring  12  and the ring  11 . 
     The sealing apparatus  100  is mounted at the end portion of the outer ring  12  so as to prevent inflow of foreign materials into a space between the outer ring  12  and the hub  10 . The sealing apparatus  100  will be described in further detail with reference to  FIG. 2 . 
       FIG. 2  is an enlarged view of “A” portion in  FIG. 1 . 
     As shown in  FIG. 2 , a wheel bearing sealing apparatus  100  according to an exemplary embodiment of the present invention is mounted between the end portion of the outer ring  12  and the flange  15 . The flange  15  includes a flange base  151  connected to the hub raceway  31  and concavely curved, a flange extended portion  152  connected to the flange base  151  and extending substantially in the radially outer direction, and a flange curved portion  153  stepped from a radial outer end of the flange extended portion  152  in the axial direction. 
     The sealing apparatus  100  includes an outer supporter  60 , an inner supporter  70  and a sealing member  80 . 
     The outer supporter  60  includes a first cylindrical portion  61 , a first sealing portion  62 , a second sealing portion  63 , a flange contact portion  64 , a connecting portion  65  and a second cylindrical portion  66 . 
     The first cylindrical portion  61  is spaced apart from the other surface of the flange  15  and extends in an axially inboard direction. 
     The first sealing portion  62  extends from the end of the first cylindrical portion  61  in the radially inner direction, and the second sealing portion  63  extends from a radially inner end of the first sealing portion  62  in an axially outboard direction and contacts with the other surface of the flange  15 . When being projected in the axial direction, the first sealing portion  62  and the second sealing portion  63  are overlapped with the flange curved portion  153 . Therefore, a volume of a staying recess  110  formed by the first sealing portion  62 , the second sealing portion  63 , the flange curved portion  153  and the flange extended portion  152  increases, and foreign materials falling down on the other surface of the flange  15  are temporarily stored in the staying recess  110 . The foreign materials temporarily stored in the staying recess  110  fall down along an exterior circumference of the outer supporter  60  by gravity or are dropped due to rotation of the hub  10 , and is removed from the wheel bearing  1 . 
     The flange contact portion  64  is bent and extends in the radially inner direction from an end of the second sealing portion  63 , and contacts with the other surface of the flange  15 . Adhesive may be sprayed on the flange contact portion  64  and the other surface of the flange  15  such that the foreign materials falling down on the other surface of the flange  15  are prevented from flowing into a gap between the flange contact portion  64  and the other space of the flange  15 . 
     The connecting portion  65  is slanted in the radially inner direction and the axially inboard direction from a radial inner end of the flange contact portion  64 . Since the connecting portion  65  is slanted and spaced apart from the hub  10 , a space between the outer supporter  60  and the inner supporter  70  is narrow and inflow of the foreign materials into the sealing apparatus  100  may be effectively prevented. In addition, a curving process of the connecting portion  65  so as to contact the connecting portion  65  with the hub  10  may be omitted, and deformation of the flange contact portion  64  and the second cylindrical portion  66  contacting respectively with the flange  15  and the hub  10  when mounting the outer supporter  60  may be absorbed to some degree. Furthermore, a space between the connecting portion  65  and the flange base  151  may be filled with sealant or adhesive. In this case, the sealant or the adhesive completely prevent inflow of the foreign materials into a gap between the outer supporter  60  and the flange  15 . 
     The second cylindrical portion  66  extends in the axially inboard direction from the other end of the connecting portion  65  and contacts with the exterior circumference of the hub  10 . The second cylindrical portion  66  may be press-fitted onto the exterior circumference of the hub  10 . 
     The inner supporter  70  includes an axially extending portion  71 , a first radially extending portion  72 , a slanted portion  73  and a second radially extending portion  74 . In addition, the outer ring  12  includes a small diameter portion  121 , a transient portion  122 , and a large diameter portion  123 . The small diameter portion  121  is formed on an exterior circumference of the end portion of the outer ring  12 , the transient portion  122  is connected to the small diameter portion  121  and has an increasing diameter toward the axially inboard direction, and the large diameter portion  123  is connected to the transient portion  122 . 
     The axially extending portion  71  is press-fitted onto the exterior circumference of the end portion of the outer ring  12  and extends in the axial direction. The axially extending portion  71  may be press-fitted onto the small diameter portion  121  of the outer ring  12 . The other end of the axially extending portion  71  includes a thin end portion  71   a  having a decreasing thickness. The thin end portion  71   a  is slanted in the radially inner direction and the axially outboard direction, and a part of the thin end portion  71   a  is spaced apart from the exterior circumference of the outer ring  12 . Since at least a part of the thin end portion  71   a  is enclosed by the sealing member  80  when molding the sealing member  80 , the sealing member  80  is prevented from being detached from the inner supporter  70 . In addition, when the inner supporter  70  is press-fitted onto the exterior circumference of the outer ring  12 , a part of the sealing member  80  gets between the thin end portion  71   a  and the exterior circumference of the outer ring  12 . Therefore, the inner supporter  70  may be prevented from leaving the outer ring. 
     The first radially extending portion  72  is bent toward the radially inner direction from the end of the axially extending portion  71  and contacts with the end portion of the outer ring  12 . A radial inner end of the first radially extending portion  72  may be positioned at a region radially more inner than an interior circumference of the end portion of the outer ring  12 . Therefore, a space for positioning the slanted portion  73  without interference with the interior circumference of the outer ring  12  is secured. 
     The slanted portion  73  extends from a radially inner end of the first radially extending portion  72  in the radially inner direction and the axial inboard direction, and the second radially extending portion  74  extends from a radially inner end of the slanted portion  73  in the radially inner direction. 
     The sealing member  80  encloses at least a part of an exterior circumference of the axially extending portion  71 , the first radially extending portion  72 , the slanted portion  73 , and the second radially extending portion  74 . The sealing member  80  may be made of a rubber or a similar material thereto. The transient portion  122  defines an inboard boundary of the sealing member  80  in the axial direction. 
     The sealing member  80  includes a blocking wall  81  and an extended portion  82 . The blocking wall  81  is spaced apart from the first cylindrical portion  61  toward the axially inboard direction, and has a shape enclosing the axially extending portion  71  and thin end portion  71   a . The side portion of the blocking wall  81  extends in the radially outer direction more than the first cylindrical portion  61 . Since the blocking wall  81  extends in the radially outer direction, inflow of foreign materials from an axial inboard side may be effectively prevented. In addition, the other side portion of the blocking wall  81  is formed of a slanted surface  85  that is slanted in the radially inner direction and the axial inboard direction. Since the blocking wall  81  extends in the radially outer direction and thus is easily deformed, as shown in  FIG. 2 , the blocking wall  81  is formed to be thick in the axial direction. Since the slanted surface  85  is formed at the other side portion of the blocking wall  81 , however, a volume of the blocking wall  81  may be reduced and manufacturing cost may be curtailed. In addition, the foreign materials coming from the axially inboard side are bumped and bounced against the blocking wall  81 , or climb over the blocking wall  81  and drop on the exterior circumference of the first cylindrical portion  61 . Therefore, the foreign materials moving in the axial direction may be prevented from flowing into the sealing member  80  through a space between the blocking wall  81  and the first cylindrical portion  61 . Therefore, the blocking wall  81  may have a suitable radial height. 
     It is exemplified in this specification and the drawings but is not limited that the slanted surface  85  is formed at the other side portion of the blocking wall  81 . It is to be understood that the present invention is intended to cover a perpendicular surface or a curved surface formed at the other side portion of the blocking wall  81 . 
     The extended portion  82  encloses the second radially extending portion  74  at a radially inner end of the sealing member  80  and prevents the sealing member  80  from being detached from the inner supporter  70 . 
     The sealing member  80  includes a lip portion  90  including at least one seal lip  92 . Since the seal lip  92  contacts with the other side surface of the outer supporter  60 , inflow of foreign materials into the space between the hub  10  and the outer ring  12  may be prevented. At least one seal lip  92  may be prevented, and the number of the seal lips  92  may be selected by a designer depending on target sealing performance. It is exemplified in an exemplary embodiment of the present invention but is not limited that the sealing apparatus  100  includes one seal lip  92 . As shown in  FIG. 2 , if one seal lip  92  contacts with the outer supporter  60 , drag torque may be reduced. 
     The lip portion  90  further includes a pocket lip  91  and a slanted lip  93 . The pocket lip  91  has a pocket shape that can trap the foreign materials flowing into the space between the outer supporter  60  and the blocking wall  81 . The pocket lip  91  has the pocket shape opening toward the radially outer direction such that the foreign materials flowing into the space between the outer supporter  60  and the inner supporter  70  can be temporarily stored in the pocket lip  91 . In addition, an end of the pocket lip  91  is positioned at an axially outboard region more than the first sealing portion  62 , and thereby completely trapping the foreign materials flowing into the space between the outer supporter  60  and the inner supporter  70 . However, a shape of the pocket lip  91  is not limited to the shape illustrated in  FIG. 2 . 
     The foreign materials flowing into the sealing apparatus  100  are trapped by the pocket lip  91 , and a part of the trapped foreign materials falls down on an exterior circumference of the pocket lip  91  and flows out from the sealing apparatus  100 . In addition, since the end of the pocket lip  91  is positioned close but does not contact with the second sealing portion  63  and the flange contact portion  64 , a labyrinth seal is formed therebetween and inflow of the foreign materials into the sealing apparatus  100  can be effectively prevented. If the foreign materials are not trapped by the pocket lip  91  and flows into the sealing apparatus  100  more than the pocket lip  91 , the foreign materials are further blocked by the seal lip  92 , fall down on an exterior circumference of the seal lip  92 , and flow out from the sealing apparatus  100 . 
     The slanted lip  93  extends from the radially inner end of the inner supporter in the radially inner direction and the axially inboard direction. Therefore, if the lubricant in a space between the outer ring  12  and the hub  10  passes the slanted lip  93  and flows out from the sealing apparatus  100 , the slanted lip  93  is straightened in a radial direction by pressure of the lubricant and contacts with the second cylindrical portion  66 . Therefore, leakage of the lubricant may be prevented. 
     Since the pocket lip  91  and the slanted lip  93  are configured not to contact with the outer supporter  60 , drag torque may be reduced. 
     Hereinafter, operation of the sealing structure according to an exemplary embodiment of the present invention will be described in detail. 
     The foreign materials falling down on the other surface of the flange  15  are trapped in the staying recess  110  formed by the flange  15  and the first and second sealing portions  62  and  63 . The trapped foreign materials fall down on the exterior circumference of the second sealing portion  63  or are dropped down to the ground due to rotation of the hub  10 . 
     In addition, the foreign materials coming from the axially inboard side are bumped and bounced against the blocking wall  81 , or climb over the blocking wall  81  and drop on the exterior circumference of the first cylindrical portion  61 . The foreign materials dropping on the exterior circumference of the first cylindrical portion  61  fall down on the exterior circumference of the first cylindrical portion  61  or are trapped in the staying recess  110  and are removed. 
     In addition, since the outer supporter  60 , the inner supporter  70  and the sealing member  80  form the labyrinth seal, inflow of the foreign materials into the sealing apparatus  100  may be further prevented. 
     In addition, the foreign materials flowing into the sealing apparatus  100  through the space between the outer supporter  60  and the inner supporter  70  are trapped by the pocket lip  91  and are removed from the sealing apparatus  100 . Furthermore, the foreign materials that are not removed by the pocket lip  91  are blocked by the seal lip  92  and cannot flow into the sealing apparatus  100 . 
     Hereinafter, referring to  FIG. 3  to  FIG. 6 , sealing structures of a wheel bearing according to exemplary embodiments of the present invention will be described in detail. Since the sealing structures of a wheel bearing according to exemplary embodiments of the present invention are similar to that the sealing structure according to the exemplary embodiment of the present invention, differences therebetween will be mainly described. 
       FIG. 3  is a cross-sectional view of a sealing structure of a wheel bearing according to another exemplary embodiment of the present invention. 
     As shown in  FIG. 3 , a sealing apparatus  200  of a wheel bearing according to another exemplary embodiment of the present invention includes an outer supporter  260 , an inner supporter  270  and a sealing member  280 . 
     The outer supporter  260  includes a first cylindrical portion  261 , a first sealing portion  262 , a flange contact portion  264 , a connecting portion  265  and a second cylindrical portion  266 . 
     The first cylindrical portion  261  is spaced apart from the other surface of the flange  15  and extends in an axially inboard direction. 
     The first sealing portion  262  extends from the end of the first cylindrical portion  261  in the radially inner direction and the axial outboard direction. A radially inner end of the first sealing portion  262  is positioned at a region radially more outer than the flange curved portion  153 . 
     The flange contact portion  264  is bent and extends in the radially inner direction from an end of the first sealing portion  262 , and contacts with the other surface of the flange  15 . At least a part of the flange contact portion  264  is spaced apart from the other surface of the flange  15 . Therefore, the staying recess  110  is formed by the first sealing portion  262 , the flange contact portion  264  and the flange curved portion  153 . 
     The connecting portion  265  is slanted in the radially inner direction and the axially inboard direction from a radial inner end of the flange contact portion  264 . 
     The second cylindrical portion  266  extends in the axially inboard direction from the other end of the connecting portion  265  and contacts with the exterior circumference of the hub  10 . 
     The inner supporter  270  includes an axially extending portion  271 , a first radially extending portion  272 , a slanted portion  273  and a second radially extending portion  274 . 
     The sealing member  280  encloses at least a part of an exterior circumference of the axially extending portion  271 , the first radially extending portion  272 , the slanted portion  273 , and the second radially extending portion  274 . 
     The sealing member  280  includes a blocking wall  281  and an extended portion  282 . The blocking wall  281  is spaced apart from the first cylindrical portion  261  toward the axially inboard direction, and the side portion of the blocking wall  281  extends in the radially outer direction more than the first cylindrical portion  261 . The other side portion of the blocking wall  281  is formed of a slanted surface  285  that is slanted in the radially inner direction and the axial inboard direction. 
     The sealing member  280  includes a lip portion  290  including at least one seal lip  292 . Since the seal lip  292  contacts with the other side surface of the outer supporter  260 , inflow of foreign materials into the space between the hub  10  and the outer ring  12  may be prevented. 
     The lip portion  290  further includes a pocket lip  291  and a slanted lip  293 . The pocket lip  291  has a pocket shape that can trap the foreign materials flowing into the space between the outer supporter  260  and the blocking wall  281 . Since an end of the pocket lip  291  is positioned close to the flange contact portion  264 , a labyrinth seal is formed. Therefore, inflow of the foreign materials into the sealing apparatus  200  may be effectively prevented. 
     The slanted lip  293  extends from the radially inner end of the inner supporter in the radially inner direction and the axially inboard direction. 
     Since the pocket lip  291  and the slanted lip  293  are configured not to contact with the outer supporter  260 , drag torque may be reduced. 
       FIG. 4  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
     As shown in  FIG. 4 , a sealing apparatus  300  of a wheel bearing according to other exemplary embodiment of the present invention includes an outer supporter  360 , an inner supporter  370  and a sealing member  380 . 
     The outer supporter  360  includes a first cylindrical portion  361 , a first sealing portion  362 , a flange contact portion  364 , a connecting portion  365  and a second cylindrical portion  366 . 
     The first cylindrical portion  361  is spaced apart from the other surface of the flange  15  and extends in an axially inboard direction. 
     The first sealing portion  362  extends from the end of the first cylindrical portion  361  in the radially inner direction and the axial outboard direction. When being projected in the axial direction, the first sealing portion  362  is overlapped with the flange curved portion  153 . Therefore, the first sealing portion  362  and the flange curved portion  153  form a staying recess  110 . 
     The flange contact portion  364  is bent and extends in the radially inner direction from an end of the first sealing portion  362 , and contacts with the other surface of the flange  15 . 
     The connecting portion  365  is slanted in the radially inner direction and the axially inboard direction from a radial inner end of the flange contact portion  364 . 
     The second cylindrical portion  366  extends in the axially inboard direction from the other end of the connecting portion  365  and contacts with the exterior circumference of the hub  10 . 
     The inner supporter  370  includes an axially extending portion  371 , a first radially extending portion  372 , a slanted portion  373  and a second radially extending portion  374 . 
     The sealing member  380  encloses at least a part of an exterior circumference of the axially extending portion  371 , the first radially extending portion  372 , the slanted portion  373 , and the second radially extending portion  374 . 
     The sealing member  380  includes a blocking wall  381  and an extended portion  382 . The blocking wall  381  is spaced apart from the first cylindrical portion  361  toward the axially inboard direction, and the side portion of the blocking wall  381  extends in the radially outer direction more than the first cylindrical portion  361 . The other side portion of the blocking wall  381  is formed of a slanted surface  385  that is slanted in the radially inner direction and the axial inboard direction. 
     The sealing member  380  includes a lip portion  390  including at least one seal lip  392 . Since the seal lip  392  contacts with the other side surface of the outer supporter  360 , inflow of foreign materials into the space between the hub  10  and the outer ring  12  may be prevented. 
     The lip portion  390  further includes a pocket lip  391  and a slanted lip  393 . The pocket lip  391  is configured to trap the foreign materials flowing into the space between the outer supporter  360  and the blocking wall  381 . In  FIG. 4 , the pocket lip  391  is slanted in the radially outer direction and the axially outboard direction. An end of the pocket lip  391  is positioned close to the flange contact portion  364  so as to form a labyrinth seal therebetween. Therefore, inflow of the foreign materials into the sealing apparatus  300  may be effectively prevented. 
     Since the pocket lip  391  and the slanted lip  393  are configured not to contact with the outer supporter  360 , drag torque may be reduced. 
       FIG. 5  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
     As shown in  FIG. 5 , a sealing apparatus  400  of a wheel bearing according to other exemplary embodiment of the present invention includes an outer supporter  460 , an inner supporter  470  and a sealing member  480 . 
     The outer supporter  460  includes a first cylindrical portion  461 , a first sealing portion  462 , a flange contact portion  464 , a connecting portion  465  and a second cylindrical portion  466 . 
     The first cylindrical portion  461  is spaced apart from the other surface of the flange  15  and extends in an axially inboard direction. 
     The first sealing portion  462  is curved from the end of the first cylindrical portion  461  in the radially inner direction and the axial outboard direction. When being projected in the axial direction, the first sealing portion  462  is overlapped with the flange curved portion  153 . Therefore, the first sealing portion  462  and the flange curved portion  153  form a staying recess  110 . 
     The flange contact portion  464  is bent and extends in the radially inner direction from an end of the first sealing portion  462 , and contacts with the other surface of the flange  15 . 
     The connecting portion  465  is slanted in the radially inner direction and the axially inboard direction from a radial inner end of the flange contact portion  464 . 
     The second cylindrical portion  466  extends in the axially inboard direction from the other end of the connecting portion  465  and contacts with the exterior circumference of the hub  10 . 
     The inner supporter  470  includes an axially extending portion  471 , a first radially extending portion  472 , a slanted portion  473  and a second radially extending portion  474 . 
     The sealing member  480  encloses at least a part of an exterior circumference of the axially extending portion  471 , the first radially extending portion  472 , the slanted portion  473 , and the second radially extending portion  474 . 
     The sealing member  480  includes a blocking wall  481  and an extended portion  482 . The blocking wall  481  is spaced apart from the first cylindrical portion  461  toward the axially inboard direction, and the side portion of the blocking wall  481  extends in the radially outer direction more than the first cylindrical portion  461 . The other side portion of the blocking wall  481  is formed of a slanted surface  485  that is slanted in the radially inner direction and the axial inboard direction. 
     The sealing member  480  includes a lip portion  490  including at least one seal lip  492 . Since the seal lip  492  contacts with the other side surface of the outer supporter  460 , inflow of foreign materials into the space between the hub  10  and the outer ring  12  may be prevented. 
     The lip portion  490  further includes a pocket lip  491  and a slanted lip  493 . The pocket lip  491  is configured to trap the foreign materials flowing into the space between the outer supporter  460  and the blocking wall  481 . In  FIG. 5 , the pocket lip  491  is slanted in the radially outer direction and the axially outboard direction and contacts with the flange contact portion  464 . Therefore, inflow of the foreign materials may be further prevented while increasing drag torque. 
     Since the slanted lip  493  is configured not to contact with the outer supporter  460 , drag torque may be reduced. 
       FIG. 6  is a cross-sectional view of a sealing structure of a wheel bearing according to other exemplary embodiment of the present invention. 
     As shown in  FIG. 6 , a sealing apparatus  500  of a wheel bearing according to other exemplary embodiment of the present invention includes an outer supporter  560 , an inner supporter  570  and a sealing member  580 . 
     The outer supporter  560  includes a first cylindrical portion  561 , a first sealing portion  562 , a flange contact portion  564 , a connecting portion  565  and a second cylindrical portion  566 . 
     The first cylindrical portion  561  is spaced apart from the other surface of the flange  15  and extends in an axially inboard direction. 
     The first sealing portion  562  is slanted from the end of the first cylindrical portion  561  in the radially inner direction and the axial outboard direction. When being projected in the axial direction, the first sealing portion  562  is overlapped with the flange curved portion  153 . Therefore, the first sealing portion  562  and the flange curved portion  153  form a staying recess  110 . 
     The flange contact portion  564  is bent and extends in the radially inner direction from an end of the first sealing portion  562 , and contacts with the other surface of the flange  15 . 
     The connecting portion  565  is slanted in the radially inner direction and the axially inboard direction from a radial inner end of the flange contact portion  564 . The connecting portion  565  may contact with the flange base  151  or may be spaced from the flange base  151 . 
     The second cylindrical portion  566  extends in the axially inboard direction from the other end of the connecting portion  565  and contacts with the exterior circumference of the hub  10 . 
     The inner supporter  570  includes an axially extending portion  571 , a first radially extending portion  572 , a slanted portion  573  and a second radially extending portion  574 . 
     The sealing member  580  encloses at least a part of an exterior circumference of the axially extending portion  571 , the first radially extending portion  572 , the slanted portion  573 , and the second radially extending portion  574 . 
     The sealing member  580  includes a blocking wall  581  and an extended portion  582 . The blocking wall  581  is spaced apart from the first cylindrical portion  561  toward the axially inboard direction, and the side portion of the blocking wall  581  extends in the radially outer direction more than the first cylindrical portion  561 . The other side portion of the blocking wall  581  is formed of a slanted surface  585  that is slanted in the radially inner direction and the axial inboard direction. 
     The sealing member  580  includes a lip portion  590  including at least one seal lip  592 . Since the seal lip  592  contacts with the other side surface of the outer supporter  560 , inflow of foreign materials into the space between the hub  10  and the outer ring  12  may be prevented. 
     The lip portion  590  further includes a pocket lip  591  and a slanted lip  593 . The pocket lip  591  is configured to trap the foreign materials flowing into the space between the outer supporter  560  and the blocking wall  581 . In  FIG. 6 , the pocket lip  591  is slanted in the radially outer direction and the axially outboard direction and contacts with the flange contact portion  564 . Therefore, inflow of the foreign materials may be further prevented while increasing drag torque. 
     Since the slanted lip  593  is configured to contact with the outer supporter  560 , grease in the wheel bearing may not be leaked. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.