Patent Publication Number: US-2009226125-A1

Title: Bearing seal

Description:
This application is a continuation of U.S. application Ser. No. 12/076,345, filed Mar. 17, 2008, which is a continuation of U.S. application Ser. No. 11/655,994, filed Feb. Jan. 22, 2007, now abandoned, which is a continuation of U.S. application Ser. No. 11/059,690, filed Feb. 17, 2005. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a bearing seal that is designed so that it can be mounted between one element and the other element of a bearing that rotate relative to each other, thereby sealing the bearing both internally and externally. More particularly, the present invention relates to such bearing seal that is suitable for use with a water pump that is used in conjunction with the water-cooled engine on an automotive vehicle. 
     2. Prior Art 
     In the bearing that includes two elements rotating relative to each other, such as an inner race and an outer race, there is a bearing seal that may be mounted between those two elements, e.g., the inner race and outer race of the bearing, thereby sealing the bearing both internally and externally, wherein it is well known that such bearing seal includes a metallic reinforcing ring and an elastic element, such as rubber, that is reinforced by the reinforcing ring. 
     In the water pump that is used with a water-cooled engine and the like on an automotive vehicle, such bearing seal as the one that includes the metallic reinforcing ring and the elastic element reinforced by the reinforcing ring may also be used. 
     One example of the water pump is shown in  FIG. 10 , in which it is known that such water pump includes a pump shaft  53  having an impeller  51  connected to one end thereof and a pulley  52  connected to the other end thereof, and may be operated so that it can circulate cooling water by rotating the pulley  52  that causes the impeller  51  to rotate. In the example shown in  FIG. 10 , the water pump generally has a water pump bearing that may be inserted under the applied pressure into a pump housing  50  that is being mounted on the automotive vehicle engine. In the water pump bearing, the pump shaft  53  having the impeller  51  connected to one end thereof and the pulley  52  connected to the other end may be mounted rollingly to the outer race of the bearing by way of the rolling element  55 . 
     Between the outer race  54  and pump shaft  53 , there is a mechanical seal  57  that is designed to seal the area between the space  58  existing between the pump housing  50  and pump shaft  53  and the impeller  51 . 
     On each of the opposite ends of the outer race  54  is a bearing seal that is designed to seal the interior of the bearing. One of those bearing seals, that is, the bearing seal  56  on one end of the outer race  54  on which the impeller  51  is provided generally includes a metallic reinforcing ring and an elastic element reinforced by the reinforcing ring. 
     The bearing seal that includes the metallic reinforcing ring and the elastic element reinforced by the reinforcing ring and may be mounted between the two elements of the bearing rotating relative to each other, thereby sealing the bearing both internally and externally is required to provide the sealing capabilities with the high reliability even when it is used under the hardest operating environment for an extended period of the time. The reason is that if the bearing seal should fail and its sealing capability should thus be affected, this would lead to the failure of the bearing on which the bearing seal is mounted, resulting in the failure of the device on which such bearing is mounted. Finally, the lifetime of the device would become shorter. 
     For example, the sealing capability may be affected when the bearing seal  56  mounted on the side of the impeller is heated or cooled each time the engine is stopped or restarted, causing the air inside the bearing to expand or contract. 
     For the water pump described earlier, on the other hand, if the sealing capability of the mechanical seal  57  degrades over the time, the cooling water may flow from the side of the impeller  51  into the space  58  between the pump housing  50  and pump shaft  53 . 
     The cooling water that has flowed into the space  58  between the pump housing  50  and pump shaft  53  or the steam that has been produced as the cooling water has been heated may go through the location of the bearing seal  56  into the bearing. If this actually occurs, it may cause the grease filled in the bearing to degrade, producing rust that may cause the water pump to fail. Thus, the lifetime of the water pump may become shorter. 
     It may also be appreciated from the preceding description that the grease that is filled inside the bearing might pass through the location of the bearing seal if its sealing capability should accidentally be lost, flowing out from inside the bearing. If this actually occurs, the friction between the rolling element  55  and pump shaft  53  will become greater, causing the water pump bearing to be damaged. This will result in the lifetime of the water pump becoming shorter. 
     In connection with the bearing seal that is designed to be mounted between one element and the other element of the bearing rotating relative to each other for sealing the bearing, more specifically, the bearing seal that is designed for use with the water pump employed in the water-cooled engine on the automotive vehicle, the inventor of the present invention has addressed the problems associated with the prior art described above, and has proposed various bearing seals as disclosed in Japanese patent application now published under No. 2003-155998. 
     SUMMARY OF THE INVENTION 
     Following the various water pump bearing seals proposed as disclosed in the above Japanese patent application No. 2003-155998, the inventor of the present application has made further studies, and has successfully developed a bearing seal designed to be mounted between the two elements of the bearing rotating relative to each other for sealing the bearing, wherein the bearing seal can provide the sealing capabilities with the high reliability even when it is used under the hardest operating environment for an extended period of the time, and can effectively accommodate any misalignment that may occur when the bearing is mounted, or any misalignment in the axial direction that may be caused by any errors in mounting the bearing. 
     In order to solve the aforementioned problems, the present invention proposes to provide a bearing seal that includes a seal ring and a seal body that may be fitted on and secured to one element and the other element of the bearing rotating relative to each other, respectively, wherein the bearing seal has the structural features and forms that may be characterized as described below by referring to the accompanying drawings. 
     The seal body  4  includes a reinforcing ring  2  having one end extending radially and adapted to be fitted on and secured to the peripheral wall of the other element of the bearing rotating relative to the one element, and an elastic element  3  reinforced by the reinforcing ring  2 . 
     The seal ring  8  includes a first cylindrical portion  5  extending in the axial direction of the bearing perpendicular to the radial direction of the seal body  4  and adapted to be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element, a flange portion  6  extending from the first cylindrical portion  5  toward the radial direction, and a second cylindrical portion  7  extending from the forward end of the flange portion  6  toward the axial direction of the bearing. 
     The embodiment in which the first cylindrical portion  5  of the seal ring  8  is adapted to be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element may have two different forms, one being the form in which the first cylindrical portion  5  may be fitted on and secured to the peripheral wall in the direct manner as shown in  FIGS. 1 to 6 , and the other being the form in which the first cylindrical portion  5  may be fitted on and secured to the peripheral wall indirectly, that is, by way of a slinger  23  including a cylindrical portion  21  extending in the axial direction of the bearing and a flange portion  20  extending from the end of the cylindrical portion  21  located on the axial outer side thereof toward the radial direction as shown in  FIGS. 7 to 9 . 
     In the form in which the first cylindrical portion  5  may be fitted on and secured to the peripheral wall indirectly, that is, by way of the slinger  23 , one peripheral surface of the cylindrical portion  21  of the slinger  23  may be fitted on and secured to the first cylindrical portion  5  of the seal ring  8 , with the other peripheral surface being fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element. 
     The elastic element  3  that forms part of the seal body  4  has the structural features that will be described below. 
     The elastic element  3  includes a first lip portion  9 , a second lip portion  10  and a third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) or  11   b  ( FIGS. 4 to 6 ), each of which has the respective structural features and forms that will be described below. Because of the structural features and forms, those lip portions may provide the respective functions that will also be described below, when the seal ring  8  and seal body  4  are mounted on the bearing. 
     Specifically, the first lip portion  9  is provided so that it extends from the reinforcing ring  2  of the seal body  4  toward the other end opposite the radial one end, and may be made to make sliding contact with the peripheral wall  53   a  of one element of the bearing rotating relative to the other element or the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 . For example, the first lip portion  9  extends from the reinforcing ring  2  of the seal body  4  toward the other end opposite the radial one end, that is, toward the axial outer side (the right side in  FIGS. 1 to 6 ) and then extends obliquely toward the radial inner side (the lower side in  FIGS. 1 to 6 ), and is adapted to make sliding contact with the peripheral wall  53   a  of one element of the bearing rotating relative to the other element as shown in  FIGS. 2 ,  3 ,  5  and  6 , or the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  as shown in  FIGS. 1 and 4 . 
     In the form as shown in  FIGS. 7 to 9  in which the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element indirectly, that is, by way of the slinger  23 , the first lip portion  9  may be brought into sliding contact with the one peripheral surface of the cylindrical portion  21  of the slinger  23  as shown in  FIGS. 8 and 9 , or may be brought into sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  as shown in  FIG. 7 . 
     The second lip portion  10  is located on the axial inner side of the bearing from the first lip portion  9  as shown in  FIGS. 1 to 9 , extends from the reinforcing ring  2  of the seal body  4  toward the other end opposite the radial one end, and is adapted to make sliding contact with the peripheral wall  53   a  of one element of the bearing rotating relative to the other element or the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 . For example, the second lip portion  10  extends from the reinforcing ring  2  of the seal body  4  toward the other end opposite the radial one end, that is, extends toward the axial outer side (the right side in  FIGS. 1 to 9 ) and then extends obliquely toward the radial inner side (the lower side in  FIGS. 1 to 9 ), and is adapted to make sliding contact with the peripheral wall  53   a  of one element of the beating rotating relative to the other element as shown in  FIGS. 3 and 6 , or the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  as shown in  FIGS. 1 ,  2 ,  4  and  5 . 
     In the form as shown in  FIGS. 7 to 9  in which the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element indirectly, that is, by way of the slinger  23 , the second lip portion  10  may be brought into sliding contact with the one peripheral surface of the cylindrical portion  21  of the slinger  23  as shown in  FIG. 9 , or may be brought into sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  as shown in  FIGS. 7 and 8 . 
     The third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) or  11   b  ( FIGS. 4 to 6 ) is located on the axial inner side of the bearing from the second lip portion  10 , extends from the reinforcing ring  2  of the seal body  4  toward the radial direction, and is adapted to make sliding contact with the peripheral wall  7   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) or  7   b  ( FIGS. 4 to 6 ) of the second cylindrical portion  7  of the seal ring  8 . For example, the third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) extends from the reinforcing ring  2  toward the radial direction, that is, extends toward the axial inner side (the left side in  FIGS. 1 to 3  and  FIGS. 7 to 9 ) and then extends obliquely toward the radial outer side (the upper side in  FIGS. 1 to 3  and  FIGS. 7 to 9 ), and is adapted to make sliding contact with the inner peripheral wall  7   a  of the second cylindrical portion of the seal ring  8 . Alternatively, the third lip portion  11   b  ( FIGS. 4 to 6 ) extends from the reinforcing ring  2  toward the radial direction, that is, extends toward the axial inner side (the left side in  FIGS. 4 to 6 ) and then extends obliquely toward the radial inner side (the lower side in FIG.  FIGS. 4 to 6 ), and is adapted to make sliding contact with the outer peripheral wall  7   b  of the second cylindrical portion  7  of the seal ring  8 . 
     According to the bearing seal  1  of the present invention that has the structural features described above, one end of the seal body  4  may be fitted on and secured to the peripheral wall of the other element of the bearing rotating relative to the one element, and the first lip portion  9  and second lip portion  10  that correspond to the other end of the seal body  4  and are reinforced by the reinforcing ring  2  of the seal body  4 , extending toward the seal ring  8  may be made to make sliding contact with the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element or the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  that is fitted on and secured to the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element. When the bearing seal  1  of the present invention is thus mounted on the bearing that includes the one element and the other element rotating relative to each other, it can seal the bearing both internally and externally with the high reliability. 
     In the form as shown in  FIGS. 7 to 9  in which the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element indirectly, that is, by way of the slinger  23 , the first lip portion  9  and the second lip portion  10  may be brought into sliding contact with the one peripheral surface of the cylindrical portion  21  of the slinger  23 , or may be brought into sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 . The first cylindrical portion  5  of the seal ring  8  is fitted on and secured to the one peripheral surface of the cylindrical portion  21  of the slinger  23 . Even in such case as shown in  FIGS. 7 to 9 , when the bearing seal  1  is mounted on the bearing including the one and other elements rotating relative to each other the bearing can be sealed both internally and externally with the high reliability. 
     The third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) or  11   b  ( FIGS. 4 to 6 ) that is provided on the elastic element  3  reinforced by the reinforcing ring  2  of the seal body  4  and is located on the axial inner side from the first lip portion  9  and second lip portion  10  are provided to extend toward the second cylindrical portion  7  extending in the axial direction from the forward end of the flange portion  6  of the seal ring  8  extending in the radial direction from the first cylindrical portion  5 , and may be made to make sliding contact with the peripheral wall  7   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) or peripheral wall  7   b ( FIGS. 4 to 6 ) of the second cylindrical portion  7 . Any misalignment that may occur when the bearing is mounted or any misalignment in the axial direction that may be caused by any errors in mounting the bearing can be accommodated effectively in this way. 
     As a first alternative form of the bearing seal that has been described so far, the first lip portion  9  and second lip portion  10  provided on the elastic element  3  reinforced by the reinforcing ring  2  may be provided to extend from the reinforcing ring  2  of the seal body  4  toward the seal ring  8 , and may be made to make sliding contact with the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element, as shown in  FIGS. 2 ,  3 ,  5  and  6 . As a second alternative form, the first lip portion  9  and second lip portion  10  may be provided to extend from the reinforcing ring  2  of the seal body  4  toward the seal ring  8  so that both may be made to make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  as shown in  FIGS. 1 and 4 . As a third alternative form, the first lip portion  9  may be provided to make sliding contact with the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element, while the second lip portion  10  may be provided to make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 , as shown in  FIGS. 2 and 5 . 
     Similarly, as one variation of the form as shown in  FIGS. 7 to 9  in which the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element indirectly, that is, by way of the slinger  23 , the first lip portion  9  having the elastic element  3  reinforced by the reinforcing ring  2  and the second lip portion  10  may be provided to extend from the reinforcing ring  2  of the seal body  4  toward the cylindrical portion  21  of the slinger  23  so that both can make sliding contact with the one peripheral surface of the cylindrical portion  21  of the slinger  23 , with the other peripheral surface being fitted on and secured to the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element, as shown in  FIG. 9 . As another variation, the first lip portion  9  and the second lip portion  10  may be provided to extend from the reinforcing ring  2  of the seal body  4  toward the cylindrical portion  21  of the slinger  23  so that both can make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 , as shown in  FIG. 7 . As a further variation, as shown in  FIG. 8 , the first lip portion  9  may be provided so that it can make sliding contact with the one peripheral surface of the cylindrical portion  21  of the slinger  23 , with the other peripheral surface being fitted on and secured to the peripheral wall  53   a  of the one element of the bearing rotating relative to the other element, and the second lip portion  10  may be provided so that it can make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 . 
     In any of the alternative forms described above, the bearing that includes the two elements rotating relative to each other can be sealed both internally and externally with the high reliability when the bearing seal  1  of the present invention is mounted on such bearing. 
     As a further alternative form of the bearing seal  1  of the present invention described so far, the second cylindrical portion  7  of the seal ring  8  may be provided to extend toward the axial outer side of the bearing, and the third lip portion  11   a  may be provided to extend toward the radial outer side and then extend obliquely toward the axial inner side and may be made to make sliding contact with the peripheral wall  7   a  on the radial inner side of the second cylindrical portion  7  of the seal ring  8 . 
     As a still further alternative form, the second cylindrical portion  7  of the seal ring  8  may be provided to extend toward the axial outer side of the bearing, and the third lip portion  11   b  may be provided to extend toward the radial inner side and then extend obliquely toward the axial inner side of the bearing and may be made to make sliding contact with the peripheral wall  7   b  on the radial outer side of the second cylindrical portion  7  of the seal ring  8 . 
     In any of the further alternative forms just described above, any misalignment that may occur when the bearing is mounted, or any misalignment in the axial direction that may be caused by any errors in mounting the bearing can be accommodated effectively. 
     In any of the embodiments of the bearing seal  1  shown in  FIGS. 1 to 9  and in any of the alternative forms thereof, the reinforcing ring  2 , seal ring  8  and slinger  23  may be shaped from any of the metals that are known in the relevant field. It should be noted, however, that when the bearing seal of the present invention is utilized in the water pump used with the water-cooled engine on the automotive vehicle, the reinforcing ring  2  and seal ring  8  may desirably be shaped from any metals that resist the corrosion, such as stainless steel, in order to avoid that any rust gathers on those elements. In this case, any type of metal can be used for shaping those elements without any limitation if such metal can resist the corrosion. For example, steel may be used as the base metal, which may be plated with any anticorrosive metal. 
     The elastic element  3  may be shaped using rubber, synthetic resin and the like that are known in the relevant field. 
     According to the present invention, the bearing seal may be mounted between the two elements of the bearing rotating relative to each other, such as the outer race and inner race, and can provide the sealing capabilities with the high reliability even when it is used under the hardest operating environment for an extended period of the time. Also, it can effectively accommodate any misalignment that may occur when the bearing is mounted or any misalignment in the axial direction that may be caused by any errors in mounting the bearing. 
     It may be appreciated from the foregoing description that the bearing seal of the present invention may be mounted between the two elements of the bearing rotating relative to each other, such as the outer race and inner race, and can provide the sealing capabilities with the high reliability even when it is used under the hardest operating environment for an extended period of the time. Accordingly, it can effectively accommodate any misalignment that may occur when the bearing is mounted or may be caused by any errors in mounting the bearing. 
     In the example shown in  FIG. 10 , a water pump bearing is provided, in which a pump shaft having an impeller connected to one end thereof and a pulley connected to the other end is rotatably mounted to the outer race of the bearing by way of a rolling element and a bearing seal is mounted on each of the opposite ends of the pump shaft mounted on the outer race for sealing the interior of the bearing, wherein, in particular, the bearing seal of the present invention is employed on the one end of the pump shaft on which the impeller is provided. 
     In the water pump bearing in which the bearing seal of the present invention is particularly employed on the side of the pump shaft on which the impeller is mounted, any entry of water into the bearing from the outside can be prevented effectively, and any leak of grease from the bearing can also be prevented effectively. Any misalignment that may occur when the bearing is mounted or may be caused by any errors in mounting the bearing can be accommodated by the seal portions that are created between the respective third lip portion  11   a ,  11   b  and the inner peripheral wall  7   a  or outer peripheral wall  7   b  of the second cylindrical portion  7  of the seal ring  8 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional view that represents a bearing seal according to one preferred embodiment of the present invention, with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 2  is a cross sectional view that represents a bearing seal according to a variation of the embodiment shown in  FIG. 1 , with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 3  is a cross sectional view that represents a bearing seal according to another variation of the embodiment shown in  FIG. 1 , with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 4  is a cross sectional view that represents a bearing seal according to another preferred embodiment of the present invention, with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 5  is a cross sectional view that represents a bearing seal according to a variation of the embodiment shown in  FIG. 4 , with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 6  is a cross sectional view that represents a bearing seal according to another variation of the embodiment shown in  FIG. 4 , with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 7  is a cross sectional view that represents a bearing seal according to further preferred embodiment of the present invention, with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 8  is a cross sectional view that represents a bearing seal according to a variation of the embodiment shown in  FIG. 7 , with some non-essential parts or elements being not shown for clarity of the illustration; 
         FIG. 9  is a cross sectional view that represents a bearing seal according to another variation of the embodiment shown in  FIG. 7 , with some non-essential parts or elements being not shown for clarity of the illustration; and 
         FIG. 10  is a cross sectional view that illustrates the water pump bearing section in a water pump, with some non-essential parts or elements being not shown for clarity of the illustration. 
     
    
    
     BEST MODES OF EMBODYING THE INVENTION 
     Several preferred embodiments of the present invention are now described in further detail by referring to the accompanying drawings. 
       FIGS. 1 to 9  represent three different forms of a bearing seal  1  according to the present invention that are shown in cross section, although some non-essential parts or elements are not shown. It may be seen from  FIGS. 1 to 9  that the bearing on which the bearing seal  1  may be mounted for sealing it is constructed to permit a pump shaft  53  rotatably to be mounted to an outer race  54  by way of a rolling element  55  and to permit the peripheral surface of the pump shaft  53  and the peripheral surface of the outer race  54  to rotate relative to each other. 
     As shown in  FIGS. 1 to 9 , the bearing seal  1  includes a seal ring  8  and a seal body  4 , both of which may be fitted on and secured to one element (pump shaft  53 ) and the other element (outer race  54 ) rotating relative to each other, respectively. 
     The seal ring  8 , which may be made of stainless steel, for example, includes a first cylindrical portion  5  extending in the axial direction of the bearing (in the horizontal direction in  FIGS. 1 to 9 ) and adapted to be fitted on and secured to the peripheral wall  53   a  of the pump shaft  53  as shown in  FIGS. 1 to 6 , a flange portion  6  extending from the first cylindrical portion  5  toward the radial direction (in the vertical direction in  FIGS. 1 to 9 ), and a second cylindrical portion  7  extending from the forward end of the flange portion  6  toward the axial direction of the bearing. 
     The seal body  4  includes a metallic reinforcing ring  2  and an elastic element  3  made of rubber and reinforced by the reinforcing ring  2 . 
     On one end of the seal body  4  that extends in the radial, there is an end  13  of the elastic element  3  that is formed like a bump. The outer side in the radial direction located on the upper end in the examples shown in  FIGS. 1 to 9  is the one end of the seal body  4 . As shown in  FIGS. 1 to 9 , the seal ring  8  may be inserted under the applied pressure in the direction of the axial inner side (the left side in  FIGS. 1 to 9 ), thereby permitting the first cylindrical portion  5  of the seal ring  8  to be fitted on and secured to the peripheral wall  53   a  of the pump shaft  53 , and the seal body  4  may then be inserted under the applied pressure in the direction of the axial inner side (the left side in  FIGS. 1 to 9 ). In this way, the end  13  of the elastic element  3  formed like the bump on the radial outer side may be made to engage a fitting groove  12  formed in the peripheral wall of the outer race  54 , and the radial outer side of the seal body  14  may be fitted on and secured to the peripheral wall of the outer race  54 . 
     The elastic element  3  includes a first lip portion  9 , a second lip portion  10  and a third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ),  11   b  ( FIGS. 4 to 6 ). 
     The first lip portion  9  is provided so that it extends from the reinforcing ring  2  of the seal body  4  toward the radial inner side (toward the lower side in  FIGS. 1 to 9 ). Specifically, in each of the embodiments shown in  FIGS. 1 to 9 , the first lip portion  9  extends from the reinforcing ring  2  of the seal body toward the axial outer side (toward the right side in  FIGS. 1 to 9 ), and then extends obliquely toward the radial inner side (toward the lower side in  FIGS. 1 to 9 ). 
     The second lip portion  10  is located on the inner side (the left side in  FIGS. 1 to 9 ) in the axial direction (the horizontal direction in  FIGS. 1 to 9 ) from the first lip portion  9 , and extends from the reinforcing ring  2  of the seal body  4  toward the radial inner side (the lower side in  FIGS. 1 to 9 ). Specifically, in each of the embodiments shown in  FIGS. 1 to 9 , the second lip portion  10  that is located on the axial inner side (on the left side in  FIGS. 1 to 9 ) from the first lip portion  9  extends toward the axial outer side (toward the right side in  FIGS. 1 to 9 ), and then extends from the reinforcing ring  2  of the seal body  4  obliquely toward the radial inner side (toward the lower side in  FIGS. 1 to 9 ). 
     The third lip portion  11   a  ( FIGS. 1 to 3  and  FIGS. 7 to 9 ) is located on the inner side (on the left side in  FIGS. 1 to 3  and  FIGS. 7 to 9 ) in the axial direction (in the horizontal direction in  FIGS. 1 to 3  and  FIGS. 7 to 9 ) from the second lip portion  10  and extends from the reinforcing ring  2  of the seal body  4  toward the radial outer side (the upper side in  FIGS. 1 to 3  and  FIGS. 7 to 9 ), while the third lip portion  11   b  ( FIGS. 4 to 6 ) is located on the inner side (on the left side in  FIGS. 4 to 6 ) in the axial direction (in the horizontal direction in  FIGS. 4 to 6 ) from the second lip portion  10  and extends from the reinforcing ring  2  of the seal body  4  toward the radial outer side (the lower side in  FIGS. 4 to 6 ). 
     More specifically, in the embodiment shown in  FIGS. 1 to 3  and  FIGS. 7 to 9 , the third lip portion  11   a  that is located on the inner side (on the left side in  FIG. 1 , etc) in the axial direction (in the horizontal direction in  FIG. 1 , etc) from the second lip portion  10  extends toward the axial inner side (the left side in  FIG. 1 , etc), and then extends from the reinforcing ring  2  of the seal body  4  obliquely toward the radial inner side (the lower side in  FIG. 1 , etc). 
     Similarly, in the embodiment shown in  FIGS. 4 to 6 , the third lip portion  11   b  ( FIG. 4 , etc) that is located on the inner side (on the left side in  FIG. 4 , etc) in the axial direction (in the horizontal direction in  FIG. 4 , etc) from the second lip portion  10  extends toward the axial inner side (the left side in  FIG. 4 , etc), and then extends from the reinforcing ring  2  of the seal body  4  obliquely toward the radial inner side (the upper side in  FIG. 4 , etc). With the seal ring  8  and seal body  4  being mounted on the bearing as shown in  FIGS. 1 to 6 , the radial outer side of the seal body  4  may be fitted on and secured to the peripheral wall of the outer race  54 , and at the same time, in the embodiment shown in  FIGS. 1 and 4 , the first lip portion  9  that extends toward the axial outer side (the right side in  FIGS. 1 and 4 ) and then extends obliquely toward the radial inner side (the lower side in  FIGS. 1 and 4 ) may be made to make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8 , while the second lip portion  10  that extends toward the axial outer side (the right side in  FIGS. 1 and 4 ) and then extends obliquely toward the radial inner side (the lower side in  FIGS. 1 and 4 ) may be made to make sliding contact with the peripheral wall  5   a  of the first cylindrical portion  5  of the seal ring  8  on the axial inner side from the first lip portion  9 . Further, the third lip portion  11   a  that extends toward the axial inner side (the left side in  FIG. 1 ) and then extends obliquely toward the radial outer side (the upper side in  FIG. 1 ) may be made to make sliding contact with the peripheral wall  7   a  of the second cylindrical portion  7  of the seal ring  8  on the axial inner side from the second lip portion  10 . Similarly, in the embodiment shown in  FIG. 4 , the third lip portion  11   b  that extends toward the axial inner side (the left side in  FIG. 4 ) and then extends obliquely toward the radial outer side (the lower side in  FIG. 4 ) may be made to make sliding contact with the peripheral wall  7   b  of the second cylindrical portion  7  of the seal ring  8  on the axial inner side from the second lip portion  10 . 
     With the bearing seal  1  of the present invention being mounted on the bearing that includes the two elements (one being the pump shaft  53  and the other being the outer race  54 ) rotating relative to each other as described above, the pump shaft  54  made of metal and the first cylindrical portion  5  made of stainless steel may be secured by engaging each other through the respective outer peripheral surface  53   a  and inner peripheral surface, both of which are made of metals, and two seal portions may also be created such that they can be spaced axially away from each other, one seal portion being created between the outer peripheral surface of the stainless steel first cylindrical portion  5  and the first lip portion  9  extending toward the axial outer side (the right side in  FIGS. 1 and 4 ) and then extending obliquely toward the radical inner side (the lower side in  FIGS. 1 and 4 ) and the other seal portion being created between the outer peripheral surface of the first cylindrical portion  5  and the second lip portion  10  extending toward the axial outer side (the right side in  FIGS. 1 and 4 ) and then extending obliquely toward the radial inner side (the lower side in  FIGS. 1 and 4 ). 
     In the embodiment shown in  FIG. 1 , a further seal portion may also be created between the inner peripheral surface  7   a  of the second cylindrical portion  7  made of stainless steel and the third lip portion  11   a  extending toward the axial inner side (the left side in  FIG. 1 ) and then extending obliquely toward the radial outer side (the upper side in  FIG. 1 ) so that the seal portion can be located on the axial inner side (the left side in  FIG. 1 ) from the two seal portions mentioned above. In the embodiment shown in  FIG. 4 , a further seal portion may also be created between the outer peripheral surface  7   b  of the stainless steel second cylindrical portion  7  and the third lip portion  11   b  extending toward the axial inner side (the left side in  FIG. 4 ) and then extending obliquely toward the radial inner side (the lower side in  FIG. 4 ) so that the seal portion can be located on the axial inner side (the left side in  FIG. 4 ) from the two seal portions mentioned above. 
     In either of the embodiments shown in  FIGS. 1 and 4 , a first sealed space  14  may thus be created among the first lip portion  9 , the second lip portion  10  and the outer peripheral surface of the first cylindrical portion  5 . Furthermore, in the embodiment shown in  FIG. 1 , a second sealed space  15  may be created among the second lip portion  10 , the third lip portion  11   a  and the inner peripheral surface  7   a  of the second cylindrical portion  7  while in the embodiment shown in  FIG. 4 , a second seal portion IS may be created among the second lip portion  10 , the third lip portion  11   a  and the outer peripheral surface  7   b  of the second cylindrical portion  7 . 
     Thereby, when the bearing seal  1  is installed on the bearing by mounting the seal ring  8  and seal body  14  on the two elements rotating relative to each other, according to the before described construction, any entry of water from the outside into the bearing is prevented effectively, also any leak of grease from the bearing to the outside is prevented effectively. 
     More specifically, any entry of water from the outside into the bearing (in the direction of the left side in  FIGS. 1 and 4 ) that might otherwise occur can be prevented by the two seal portions that are created among the outer peripheral surface of the stainless steel first cylindrical portion  5 , the first lip portion  9 , and the second lip portion  10  extending toward the axial outer side (the right side in  FIGS. 1 and 4 ) and then extending obliquely toward radial inner side (the lower side in  FIGS. 1 and 4 ) so that the seal portions can be spaced axially away from each other, and further by the first sealed space  14  that is created by those two seal portions. 
     Furthermore, any leak of grease from the bearing to the outside (in the direction of the right side in  FIGS. 1 and 4  that might otherwise occur can also be prevented effectively by the seal portion that is created between the inner peripheral surface  7   a  of the stainless steel second cylindrical portion  7  and the third lip portion  11   a  extending toward the axial inner side (the left side in  FIG. 1 ) and then extending obliquely toward the radial outer side (the upper side in  FIG. 1 ), the seal portion that is created between the outer peripheral surface  7   b  of the stainless steel second cylindrical portion  7  and the third lip portion  11   a  extending toward the axial inner side (the left side in  FIG. 1 ) and then extending obliquely toward the radial inner side (the lower side in  FIG. 1 ), and the second sealed space  15  that is thus created among those two seal portions, the outer peripheral surface of the stainless steel first cylindrical portion  5  and the second lip portion  10 . 
     When the bearing seal  1  is installed on the bearing by mounting the seal ring  8  and seal body  14  on the two elements rotating relative to each other (pump shaft  53  and outer race  54 ) of the bearing, respectively, as shown in  FIGS. 1 and 4 , in the first embodiment of the present invention, the seal portion may be formed by causing the third lip portion  11   a  extending toward the axial inner side (the left side in  FIG. 1 ) and then extending obliquely toward the radial outer side (the upper side in  FIG. 1 ) to make sliding contact with the inner peripheral wall  7   a  of the second cylindrical portion  7  of the seal ring  8 . In the second embodiment, the seal portion may be formed by causing the third lip portion  11   b  extending toward the axial inner side (the left side in  FIG. 4 ) and then extending obliquely toward the radial inner side (the lower side in  FIG. 4 ) to make sliding contact with the outer peripheral wall  7   b  of the second cylindrical portion  7  of the seal ring  8 . 
     Even if there is any misalignment that may occur when the bearing is mounted or any axial misalignment that may be caused by any errors in mounting the bearing, such misalignment can effectively be accommodated by the seal portions that are created between the respective third lip portion  11   a  or  11   b  and the inner peripheral wall  7   a  or outer peripheral wall  7   b  of the second cylindrical portion  7  of the seal ring  8 . 
     In the form shown in  FIGS. 1 to 6 , the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element in the direct manner, while in the form shown in  FIGS. 7 to 9 , the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element indirectly, that is, by way of the slinger  23  including the cylindrical portion  21  extending in the axial direction of the bearing and the flange portion  20  extending from the end of the cylindrical portion  21  located on the axial outer side toward the radial direction. 
     Except for the above, the form shown in  FIGS. 7 to 9  is substantially the same as the form shown in  FIGS. 1 to 3 . In  FIGS. 7 to 9 , therefore, the parts or elements that are common to those in  FIGS. 1 to 3  are given the same reference numerals, and the explanation of those parts or elements will be omitted to avoid the duplication. 
     The form shown in  FIGS. 7 to 9  may provide the functions and effects that are explained below, in addition to those that are provided by the form shown in  FIGS. 1 to 3 . 
     If cooling water should enter the space  58  ( FIG. 10 ) between the pump housing  50  and pump shaft  53  where the cooling water should be heated for producing water vapor (steam), the cooling water and/or water vapor would be prevented from hitting the second lip portion  9  made of rubber or elastic element  3  directly, because of the presence of the flange  20 . Furthermore, the slinger  23 , which is rotating in the peripheral direction of the pump shaft  53  can expel the cooling water and/or water vapor toward the radial outer side (in the direction of an arrow  24 ) in the case shown in  FIGS. 7 to 9 , preventing the cooling water and/or water vapor from hitting the second lip portion  9  of rubber or elastic element  3 . Thus, the second lip portion or elastic element  3  can have the extended lifetime. 
     In the form shown in  FIGS. 7 to 9 , the first cylindrical portion  5  of the seal ring  8  may be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element by way of the slinger  23  including the cylindrical portion  21  extending in the axial direction of the bearing and the flange portion  20  extending from the end of the cylindrical portion  21  located on the radial outer side. Once the bearing seal  1  is completed by assembling its component parts, such as the seal body  4 , seal ring  8  and slinger  23 , it is impossible to disassemble the bearing seal into those component parts easily. 
     Furthermore, once the bearing seal  1  is completed by assembling its component parts, such as the seal body  4 , seal ring  8  and slinger  23  as shown in  FIG. 3 , and is then fitted in the bearing by using any pressure tool, the contact area between the pressure tool and the bearing seal  1  can be enlarged by the presence of the slinger  23 . This ensures that the bearing seal  1  is fitted in the bearing more smoothly. 
     Although this is not shown, the form shown in  FIGS. 4 to 6  may also provide the functions and effects similar to those in the form shown in  FIGS. 7 to 9 , by permitting the first cylindrical portion  5  of the seal ring  8  to be fitted on and secured to the peripheral wall of the one element of the bearing rotating relative to the other element by way of the slinger including the cylindrical portion  21  extending in the axial direction of the bearing and the flange portion extending from the end of the cylindrical portion  21  located on the axial outer side toward the radial direction. 
     Although some preferred embodiments have been illustrated and described specifically so far, it may be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and without departing from the spirit and intended scope of the invention.