Patent Document

[0001]     This application is a continuation of U.S. Ser. No. 10/690,550, filed Oct. 23, 2003. 
     
    
     BACKGROUND  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an improvement to and/or in an encoder-equipped sealing device or sealing device that has a magnet-based encoder incorporated therein. More particularly, the present invention relates to such encoder-equipped sealing device that provides capabilities for preventing physical cohesion by magnetic attraction from occurring between two or more units of encoder-based sealing devices that are adjacent to each other, when these units are placed one over another so that they are oriented in one particular direction.  
         [0004]     2. Description of the Prior Art  
         [0005]     An encoder (pulse coder) that is incorporated in the encoder-equipped sealing device that has been described above takes the form of a pulse generator ring that may be mounted on an automotive vehicle in order to flexibly control a device that ensures that the vehicle can be running with safety and stability, such as an anti-lock braking system (ABS), traction control system (TCS) and stability control system (SCS). This encoder may be mounted on a hub flange in a suspension system together with a sensor, and is used to detect a number of revolutions for each of the vehicle wheels. The encoder is mounted on each of four wheels, such as front, rear, right and left wheels, together with the sensor, and may be used to detect any difference in a number of revolutions between each of the wheels. In response to such difference, the encoder may turn a drive system or brake system on and off, thereby controlling behavior of the vehicle to ensure that the vehicle can be running with stability and safety in case some emergency situation should occur.  
         [0006]     Lubrication oil may leak from bearing units on the automotive vehicle on which the safety running devices are installed as described above, and seals are required to avoid such leaks. Most of the sealing devices include integrated sealing and rotation detecting capabilities, and may be mounted in a gap or space that is available on the bearing units to meet such needs.  
         [0007]     Typically, a sealing device that has been proposed for those recent years provides a rotation detecting function as well as encoder function, and has been used widely for practical purposes.  
         [0008]     The typical encoder-equipped sealing device that has been proposed and practically used will be described below by referring to  FIG. 8 .  
         [0009]     Two units  41 ,  42  of the encoder-equipped sealing device are shown in  FIG. 8 , in which each of the units includes two seal elements  3 ,  2  combined together.  
         [0010]     Specifically, the seal element  3  includes a metal core  31  having a substantially L-shaped cross section, wherein the metal core  31  has a cylindrical portion  31  a and a flange portion  31   b  extending from one end of the cylindrical portion  31   a  in a direction perpendicular to a direction in which the cylindrical portion  31   a  extends. The seal element  3  further includes an elastic seal portion  6  on the flange portion  31   b  that is arranged in a space defined by the cylindrical portion  31   a  and flange portion  31   b.    
         [0011]     Similarly to the seal element  3 , the seal element  2  includes a metal core  21  having a substantially L-shaped cross section, wherein the metal core  21  has a cylindrical portion  21   a  and a flange portion  21   b  extending from one end of the cylindrical portion  21   a  in a direction perpendicular to a direction in which the cylindrical portion  21   a  extends. The seal element  2  further includes a magnet-based encoder  1  that is arranged on the flange portion  21   b.    
         [0012]     It may be seen from  FIG. 8  that the seal element  3  and seal element  2  are combined such that the space defined by the cylindrical portion  31   a  and flange portion  31   b  of the seal element  3  and the space defined by the cylindrical portion  21   a  and flange portion  21   b  of the seal element  2  face opposite each other.  
         [0013]     The encoder-equipped sealing device that includes combined seal elements  3  and  2  may be mounted on any area that needs to be sealed, such as an appropriate area in a bearing unit on an automotive vehicle, and a sensor  11  shown by dot-dash lines in  FIG. 2  may be mounted adjacently to the encoder  1  so that it can face opposite the encoder  1 . It may be seen from  FIG. 8  that in unit  41 , for example, the seal element  2  including the encoder  1  may be mounted on a rotational element, such as an inner or outer race of a bearing unit, wherein pulses that are magnetically generated by the encoder  1  may be detected by the sensor  11 .  
         [0014]     All of the encoder-equipped sealing devices that have been described above may be maintained in storage before they are actually used, such as being mounted on areas of bearing units on an automotive vehicle that need to be sealed, and each of the devices has the seal elements  2 ,  3  completely assembled together. In storage, these individual devices are maintained like a stack in which the devices are placed one over another such that they can be oriented in one particular direction, for convenience of easy handling by appropriate handling tools. It may be seen from  FIG. 8  that two units  41 ,  42  of the encoder-equipped sealing device, for example, are placed one over the other in a horizontal direction such that each encoder  1  is located on the right side, and is oriented in one particular direction.  
         [0015]     Plural units of the encoder-equipped sealing device that are placed one over the other such that they are oriented in one particular direction, as shown in  FIG. 8 , are loaded in a magazine, and they are transported or stored while being placed one over another such that they are oriented in one particular direction in the magazine. When they are actually used, they are removed from respective magazines, and are mounted on areas of a bearing unit that need to be sealed.  
         [0016]     In the plural units of the encoder-equipped sealing device that are placed one over the other so that they are oriented in one particular direction as shown in  FIG. 8 , the encoder  1  in unit  41 , for example, produces a strong magnetic force that attracts metal core  31  on the seal element  3  in the other unit  42  magnetically. This may cause cohesion by magnetic attraction to occur between the seal element  2  in unit  41  and the seal element  3  in the other unit  42 .  
         [0017]     When such cohesion occurs, the two units may attract each other magnetically within the magazine, from which it is difficult to remove the units by using any appropriate fitting device that mounts the units on an area that needs to be sealed, such as an appropriate area in a bearing unit. This may cause the fitting device to become non-operational or may affect a working efficiency of the fitting device remarkably.  
         [0018]     In another encoder-equipped sealing device that is proposed to address the problem described above, which is disclosed in Japanese patent application as published under No. 2001-141069, a seal portion is extended to provide a projection thereon. An object of providing this projection is to keep the two units of the encoder-equipped sealing device that are located adjacent each other spaced away from each other. As this projection is formed as part of an elastic seal portion, the projection thus obtained is not sufficient to prevent cohesion by magnetic attraction that occurs between the two units.  
       SUMMARY OF THE INVENTION  
       [0019]     In order to eliminate serious disadvantages and problems associated with the prior art encoder-equipped sealing devices described above, it is an object of the present invention to provide an encoder-equipped sealing device that has a simple construction and prevents cohesion by magnetic attraction that might otherwise occur between two units of the encoder-equipped sealing device that are located adjacent each other. That is to say, the object of the present invention is to provide encoder-equipped sealing devices by which an encoder-equipped sealing device can be removed from a magazine without being caught by another encoder-equipped sealing device, and then may be mounted securely on an area that needs to be sealed, such as an appropriate area in a bearing unit, even if plural units of the encoder-equipped sealing device are placed one over another such that they are oriented in one particular direction, as shown in  FIG. 8 , and loaded in a magazine.  
         [0020]     The problems mentioned above may be solved by providing an encoder-equipped sealing device in accordance with the present invention that is constructed as described below.  
         [0021]     The encoder-equipped sealing device that is proposed by the present invention comprises two seal elements  3 ,  2  combined together, wherein each of the elements  3 ,  2  includes a metal core  31 ,  32  having a substantially L-shaped cross section, with each of the metal cores  31 ,  32  having a cylindrical portion  31   a,    21   a  and a flange portion  31   b,    21   b  provided on one end of the cylindrical portion  31   a,    21   a  and extending in a direction perpendicular to a direction in which the cylindrical portion  31   a,    21   a  extends.  
         [0022]     One seal element  3  and the other seal element  2  are combined together such that a space defined by the cylindrical portion  31   a  and flange portion  31   b  of the one seal element  3 , and the space defined by the cylindrical portion  21   a  and flange portion  21   b  of the other seal element  2 , face opposite each other.  
         [0023]     The one seal element  3  further includes an elastic seal portion  6  on the flange portion  31   b  that is arranged in the space defined by its cylindrical portion  31   a  and flange portion  31   b,  and the other seal element  2  further includes a magnet-based encoder  1  on the flange portion  21   b.    
         [0024]     For the above-described encoder-equipped sealing device, the present invention proposes the following seven embodiments.  
         [0025]     In an encoder-equipped sealing device according to a first embodiment of the present invention, that is shown in  FIG. 1 , one seal element  3  further includes a projecting portion  4   a  on an end of cylindrical portion  31   a  on a side on which flange portion  31   b  is located, wherein the projecting portion  4   a  extends beyond a side of the flange portion  31   b  opposite a side on which seal portion  6  is located and in a direction in which the cylindrical portion  31   a  extends.  
         [0026]     In an encoder-equipped sealing device according to a second embodiment of the present invention, that is shown in  FIG. 2  and is a variation of the encoder-equipped sealing device according to the first embodiment, one seal element  3  includes an end  4   b  at an end of cylindrical portion  31   a  on which flange portion  31   b  is located, and wherein the end  4   b  forms a projecting portion by folding a base end of the flange portion  31   b  and the end of the cylindrical portion  31   a  so as to overlap each other in a direction in which the cylindrical portion  31   a  extends.  
         [0027]     In an encoder-equipped sealing device according to a third embodiment of the present invention, that is shown in  FIG. 3 , one seal element  3  further includes a projecting portion  4   c  extending beyond a side of flange portion  31   b  opposite a side on which seal portion  6  is located and extending in a direction in which cylindrical portion  31   a  extends.  
         [0028]     In an encoder-equipped sealing device according to a fourth embodiment of the present invention, that is shown in  FIG. 5 , an end portion  4   d  of cylindrical portion  31   a  of one seal element  3  extending toward the other seal element  2  extends in a direction in which cylindrical portion  31   a  extends and beyond a side of the other seal element  2  opposite a side on which the other seal element  2  faces opposite the one seal element  3 .  
         [0029]     In an encoder-equipped sealing device according to a fifth embodiment of the present invention, that is shown in  FIG. 4 , one seal element  3  further includes a recess  4   f  that is formed on a side of flange portion  31   b  opposite a side on which seal portion  6  is located, wherein the recess  4   f  extends toward the side on which the seal portion  6  is located.  
         [0030]     In an encoder-equipped sealing device according to a sixth embodiment of the present invention, that is shown in  FIG. 6 , encoder  1  is arranged on a side of flange portion  21   b  of seal element  2  opposite a side on which the flange portion  21   b  faces opposite seal element  3 , and wherein the flange portion  21   b  includes a projecting portion  4   e  that extends beyond a surface of the encoder  1  and in a direction in which cylindrical portion  21   a  extends.  
         [0031]     In an encoder-equipped sealing device according to a seventh embodiment of the present invention, that is shown in  FIG. 7 , one seal element  3  includes an elastic lateral side portion  5  formed on a side of flange portion  31   b  opposite a side on which seal portion  6  is located, and wherein the elastic lateral side portion  5  has undulations  4   g  formed thereon  
         [0032]     In any of these above-described embodiments, seal portion  6  may be formed from any elastic material such as synthetic rubber, synthetic resin and the like, and annular metal core  21 ,  31  may be formed from iron or stainless steel. The encoder  1  is a multi-pole magnet that may be formed like an annular magnet from a mixture composed of any elastic material, such as synthetic rubber, synthetic resin or like, and any ferromagnetic material such as ferrite, rare earth or the like, in powdery forms. The annular magnet has N polarities and S polarities magnetized alternately around its circumference. The above-described seal portion, annular metal core, and encoder are known and used in the conventional encoder-equipped sealing device comprised by incorporating an encoder and sealing elements combined together, and mounted on a bearing unit in an automotive vehicle&#39;s wheel.  
         [0033]     The encoder-equipped sealing devices that have been described in connection with the above-described embodiments are used together with a sensor that may be disposed adjacent and opposite encoder  1  so that it can detect pulses that are generated magnetically by the encoder  1 . This magnet-based encoder  1  that is located on a seal element mounted on a rotational element on an automotive vehicle is rotated as the rotational element rotates, and the pulses from the encoder  1  rotating as the before described are detected by the sensor. Thereby, a number of revolutions are detected by the sensor. It may be understood from the foregoing description that the encoder-equipped sealing device of the present invention has the encoder  1  incorporated therein.  
         [0034]     In any of the first, second, third, fourth and sixth embodiments of the present invention, when plural units of the encoder-equipped sealing device of the present invention are placed one over another adjacent each other so that they are oriented in one particular direction, for example, when two units  51 ,  52  of the encoder-equipped sealing device are placed one over another adjacent each other so that they are oriented in one particular direction as shown in  FIG. 1 , these two adjacent units  51  and  52  can be kept spaced away from each other by the cylindrical portion or flange portion of the metal core. This can maintain a gap between the two adjacent units  51  and  52  constant, and physical cohesion by magnetic attraction that would occur between the two units  51  and  52  can thus be prevented effectively.  
         [0035]     In the fifth embodiment, when plural units of the encoder-equipped sealing device of the present invention are placed one over another adjacent each other so that they are oriented in one particular direction, for example, when two units  51 ,  52  of the encoder-equipped sealing device are placed one over the other adjacent each other so that they are oriented in one particular direction as shown in  FIG. 1 , an area of contact between the encoder and the flange portion of the metal core can be kept as small as possible, and physical cohesion by magnetic attraction that would occur between the two units can thus be prevented effectively.  
         [0036]     In the seventh embodiment, when plural units of the encoder-equipped sealing device of the present invention are placed one over another adjacent each other so that they are oriented in one particular direction, for example, when two units  51 ,  52  of the encoder-equipped sealing device are placed one over the other adjacent each other so that they are oriented in one particular direction as shown in  FIG. 1 , a gap between these two adjacent units can be kept constant by the elastic lateral side portion  5  having the undulations  4   g  formed thereon, and physical cohesion by magnetic attraction that would occur between the two units can thus be prevented effectively.  
         [0037]     It may be understood from the above description that when plural units of the encoder-equipped sealing device of the present invention are placed one over another so that they are oriented in one particular direction as shown in  FIG. 1 , cohesion by magnetic attraction that might otherwise occur between adjacent units can be prevented effectively. Accordingly, even if the plural units of the encoder-equipped sealing device are loaded in a magazine, with the units being placed one over another so that they are oriented in one particular direction, each encoder-equipped sealing device can be removed from the magazine without being caught by an adjacent encoder-equipped sealing device, and can then be mounted securely onto an area that needs to be sealed, such as an appropriate area in a bearing unit.  
         [0038]     That is to say, even if plural units of the encoder-equipped sealing device are placed one over another so that they are oriented in one particular direction, each encoder-equipped sealing device can be slid relative to an adjacent encoder-equipped sealing device without causing any problems. Also, either of these two units that are located adjacently can be moved away from the other without causing any problems, so that each of the encoder-equipped sealing devices can be handled after being detached. Thus, the encoder-equipped sealing device of the present invention can be slid smoothly out of a magazine equipped in a fitting tool, without causing any problems such as being caught or stuck. Thus, the encoder-equipped sealing device can be mounted on an area that needs to be sealed, such as an appropriate area in a bearing unit, with highest reliability. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0039]      FIG. 1  is a cross sectional view of an encoder-equipped sealing device in accordance with a first embodiment of the present invention, showing that two units of the encoder-equipped sealing device, for example, are placed adjacent each other in a horizontal direction so that they are oriented in one particular direction, although some non-critical parts are not shown;  
         [0040]      FIG. 2  is a cross sectional view of the encoder-equipped sealing device in accordance with a second embodiment of the present invention, with some non-critical parts not being shown;  
         [0041]      FIG. 3  is a cross sectional view of the encoder-equipped sealing device in accordance with a third embodiment of the present invention, with some non-critical parts not being shown;  
         [0042]      FIG. 4  is a cross sectional view of the encoder-equipped sealing device in accordance with a fifth embodiment of the present invention, with some non-critical parts not being shown;  
         [0043]      FIG. 5  is a cross sectional view of the encoder-equipped sealing device in accordance with a fourth embodiment of the present invention, with some non-critical parts not being shown;  
         [0044]      FIG. 6  is a cross sectional view of the encoder-equipped sealing device in accordance with a sixth embodiment of the present invention, with some non-critical parts not being shown;  
         [0045]      FIG. 7  is a side elevational view of the encoder-equipped sealing device in accordance with a seventh embodiment of the present invention, with some parts being shown in cross section; and  
         [0046]      FIG. 8  is a cross sectional view of an encoder-equipped sealing device in accordance with the prior art, showing that two units of the encoder-equipped sealing device are placed adjacent each other in a horizontal direction so that they are oriented in one particular direction, although some non-critical parts are not shown. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0047]     Several preferred embodiments of the present invention are now described below by referring to the accompanying drawings.  
         [0048]     It should be noted that the encoder-equipped sealing device according to the prior art that has been described so far by referring to  FIG. 8  and an encoder-equipped sealing device according to various embodiments of the present invention that will be described below by referring to  FIGS. 1 through 7  contain some common parts, elements or members. In the following description, these common parts, elements or members are given same reference numerals, and are not described to avoid duplication.  
         [0049]     Referring first to  FIG. 1 , an encoder-equipped sealing device according to a first embodiment of the present invention is described. In encoder-equipped sealing devices  51  and  52 , seal element  3  includes a projecting portion  4   a  on an end of cylindrical portion  31   a  on a side on which flange portion  31   b  is located. The projecting portion  4   a  extends beyond a side of the flange portion  31   b  opposite a side on which seal portion  6  is located and in a direction in which the cylindrical portion  31   a  extends. That is to say, the projecting portion  4   a  extends beyond the left side of the flange portion  31   b  in  FIG. 1 .  
         [0050]     In the embodiment shown in  FIG. 1 , an end of the cylindrical portion  31   a  that is located on the left side and a base end of the flange portion  31   b  are formed in such a manner as to extend toward the left side. This before described portion extends toward the left side in  FIG. 1  and forms the projecting portion  4   a.    
         [0051]     Referring next to  FIG. 2 , an encoder-equipped sealing device according to a second embodiment of the present invention is described. This second embodiment is based on an inventive concept on which the first embodiment is based.  
         [0052]     In the encoder-equipped sealing device shown in  FIG. 2 , seal element  3  includes an end  4   b  at an end of cylindrical portion  31   a  on which flange portion  31   b  is located. The end  4   b  forms a projecting portion as shown in  FIG. 2 . The end  4   b  is formed by folding a base end of the flange portion  31   b  and the end of the cylindrical portion  31   a,  thereby overlapping each other in a direction in which the cylindrical portion  31   a  extends as shown in  FIG. 2 .  
         [0053]     Referring next to  FIG. 3 , an encoder-equipped sealing device according to a third embodiment of the present invention is described.  
         [0054]     In the encoder-equipped sealing device shown in  FIG. 3 , seal element  3  includes a projecting portion  4   c  extending beyond a side of flange portion  31   b  opposite a side on which seal portion  6  is located and extending in a direction in which cylindrical portion  31   a  extends. That is to say, the projecting portion  4   c  extends beyond the left side of the flange portion  31   b  in  FIG. 3 .  
         [0055]     In the third embodiment shown in  FIG. 3 , the projecting portion  4   c  is formed by bending an end of the flange portion  31   b  toward the left side in  FIG. 3 . It should be noted that this embodiment may be varied such that the projecting portion  4   c  can be located on a middle portion of the flange portion  31   b.    
         [0056]     Referring next to  FIG. 5 , an encoder-equipped sealing device according to a fourth embodiment of the present invention is described.  
         [0057]     In the encoder-equipped sealing device shown in  FIG. 5 , end portion  4   d  of cylindrical portion  31   a  of the seal element  3  extending toward another seal element  2  extends in a direction in which the cylindrical portion  31   a  extends. And, the end portion  4   d  further extends beyond a side of the other seal element  2  opposite the side on which the other seal element  2  faces opposite the seal element  3 . That is to say, the end portion  4   d  of the cylindrical portion  31   a  of the seal element  3  extends beyond the right side of the seal element  2  in the direction in which the cylindrical portion  31   a  extends.  
         [0058]     In the fourth embodiment shown in  FIG. 5 , an encoder  1  is arranged on a side (right side in  FIG. 5 ) of flange portion  21   b  opposite a side on which the flange portion  21   b  faces the seal element  3 . Since the end portion  4   d  of the cylindrical portion  31   a  of the seal element  3  extends beyond the side (right side in  FIG. 5 ) of the seal element  2  opposite the side on which the seal element  2  faces the seal element  3 , the end portion  4   d  extends beyond the right side of the encoder  1  in  FIG. 5  and in the direction in which the cylindrical portion  31   a  extends.  
         [0059]     Referring next to  FIG. 6 , an encoder-equipped sealing device according to a sixth embodiment of the present invention is described.  
         [0060]     In the encoder-equipped sealing device shown in  FIG. 6 , encoder  1  is arranged on a side of flange portion  21   b  of seal element  2  opposite a side on which the flange portion  21   b  faces opposite seal element  3 . That is to say, the encoder  1  is disposed on the right side of the flange portion  21   b  of the seal element  2 . And, the flange portion  21   b  includes a projecting portion  4   e  that extends beyond a surface of the encoder  1  and in a direction in which cylindrical portion  21   a  extends.  
         [0061]     In the sixth embodiment shown in  FIG. 6 , the projecting portion  4   e  is formed by bending the end of the flange portion  21   b,  and the projecting portion  4   e  extends beyond the right side of the encoder  1  and in the direction in which the cylindrical portion  21   a  extends.  
         [0062]     In any of the embodiments described above by referring to  FIGS. 1, 2 ,  3 ,  5  and  6 , when two units of the encoder-equipped sealing device as designated by  51 ,  52  are placed one over the other adjacently to each other in a particular direction as shown in  FIG. 1  so that these units are oriented in one particular direction, projecting portion  4   a,  end portion  4   b  forming projecting portion, the projecting portion  4   c,  the end  4   d  and the projecting portion  4   e  can exist between the two adjacent units  51  and  52 .  
         [0063]     These projecting portions and ends that exist between the two adjacent units  51  and  52  can prevent the encoder  1  in one unit and the flange portion  31   b  in the other unit from contacting each other over a wide area, as opposed to the case shown in  FIG. 8 .  
         [0064]     Thus, a magnetic force produced from the encoder  1  in unit  51  against the flange portion  31   b  in unit  52  can be reduced greatly.  
         [0065]     This can prevent cohesion by magnetic attraction from occurring between two adjacent units  51  and  52 .  
         [0066]     In particular, in each of the embodiments shown in  FIGS. 5 and 6 , the end portion  4   d  or projecting portion  4   e  in one unit can abut the flange portion  31   b  in the other adjacent unit, which can prevent the encoder  1  in unit  51  from contacting the flange portion  31   b  in unit  52 . Thus, those embodiments are very advantageous in that cohesion by magnetic attraction between the two adjacent units  51  and  52  can be prevented.  
         [0067]     It should be noted that in each of the embodiments shown in  FIGS. 1, 2  and  3 , an area of contact between the encoder  1  in unit  51  and the flange portion  31   b  in unit  52  can be made as small as possible by modifying a size of the flange portions  21   b,    31   b  as viewed vertically in respective figures, a size of the encoder  1 , a size of the projecting portion  4   a,  and a size of end  4   b  forming a projecting portion, respectively.  
         [0068]     In each of the embodiments shown in  FIGS. 5 and 6 , respective end portion  4   d  and projecting portion  4   e  may be extended further toward the right side in  FIGS. 5 and 6 , respectively. In this way, a gap between the encoder  1  and sensor  11 , located adjacently to and opposite the encoder  1 , can be covered like an umbrella by the end portion  4   d  and projecting portion  4   e. Thus, the gap between the encoder  1  and sensor  11  can be protected from any foreign matter that might otherwise enter the gap.    
         [0069]     In each of the embodiments described so far by referring to  FIGS. 1, 2 ,  3 ,  5  and  6 , a gap between the units  51  and  52  that are located adjacently to each other is determined by presence of the projecting portion  4   a,  the end portion  4   b  forming the projecting portion, the projecting portion  4   c,  the end portion  4   d,  and the projecting portion  4   e.  Thus, these projecting portions  4   a - 4   e,  which are made of metal, can maintain the gap between the adjacent units  51  and  52  constant as it is originally designed.  
         [0070]     Referring to  FIG. 4 , the encoder-equipped sealing device according to a fifth embodiment of the present invention is now described.  
         [0071]     In the encoder-equipped sealing device shown in  FIG. 4 , seal element  3  includes a recess  4   f  that is formed in a side of flange portion  31   b  opposite a side on which seal portion  6  is located. The recess  4   f  extends toward a side on which the seal portion  6  is located. That is to say, the recess  4   f  is formed at the left side of flange portion  31   b  in  FIG. 4 , and the recess  4   f  extends toward the right side in  FIG. 4 .  
         [0072]     When two units  51 ,  52  of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction, as shown in  FIG. 1 , presence of the recess  4   f  can maintain an area of contact between the encoder  1  in one unit  51  and the flange portion  31   b  in the other unit  52  as small as possible. This can reduce a magnetic force attracting two units  51  and  52 , and can thus prevent the two units from attracting each other magnetically. This recess  4   f  may be formed by using a knurling process, for example.  
         [0073]     Referring next to  FIG. 7 , an encoder-equipped sealing device according to a seventh embodiment of the present invention is described.  
         [0074]     In the encoder-equipped sealing device shown in  FIG. 7 , seal element  3  includes an elastic lateral side portion  5  formed on a side of flange portion  31   b  opposite a side on which seal portion  6  is located. The elastic lateral side portion  5  has undulations  4   g  formed thereon. This elastic lateral side portion  5  may be made of any elastic material, such as synthetic rubber, synthetic resin and the like.  
         [0075]     When two units  51 ,  52  of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction, as shown in  FIG. 1 , the elastic lateral side portion  5  having the undulations  4   g  thereon can maintain a gap between the two units  51  and  52  constant, thereby preventing cohesion by magnetic attraction that might occur between the two units  51  and  52 .  
         [0076]     In the embodiment shown in  FIG. 7 , it should be noted that the elastic lateral side portion  5  having the undulations  4   g  thereon exists between the encoder  1  in one unit  51  and metal flange portion  31   b  in the other unit  52  that is located adjacently to unit  51 . The elastic lateral side portion  5  can maintain the encoder  1  in the one unit  51  in soft contact with the metal flange portion  31   b  in the other unit  52 , which will prevent the encoder  1  from being deformed or having high molecular cohesion with the metal flange portion  31   b.    
         [0077]     In each of the embodiments shown in  FIGS. 1 through 7 , it should be noted that the seal portion  6  includes radial lips  6   a,    6   b  extending from a side, at which cylindrical portion  31   a  exists, toward a forward end of the flange portion  31   b  and in a direction in which the cylindrical portion  31   a  extends, so as to extend obliquely, and a side lip  6   c  extending from a forward end of the flange portion  31   b  toward the cylindrical portion  31   a  and in a direction in which the cylindrical portion  31   a  extends, so as to extend obliquely.  
         [0078]     It should also be noted that when seal element  3  and seal element  2  are combined such that a space defined by the cylindrical portion  31   a  and flange portion  31   b  of the seal element  3 , and a space defined by the cylindrical portion  21   a  and flange portion  21   b  of the seal element  2 , can face opposite each other, the radial lips  6   a,    6   b  can abut a circumferential surface of the cylindrical portion  21   a,  and the side lip  6   c  can abut an inner surface of the flange portion  21   b.    
         [0079]     The seal portion  6  may be made of any elastic material such as synthetic rubber, synthetic resin and the like, as it is known to the art. It should be understood that the present invention is not limited to the embodiments of the seal portion  6  described above by referring to  FIGS. 1 through 7 .  
         [0080]     The encoder-equipped sealing device of the present invention is used by mounting it on a bearing unit of an automotive vehicle, which comprises an inner race and outer race rotating relative to each other, for example.  
         [0081]     In each of the embodiments described so far by referring to  FIGS. 1 through 7 , it is assumed that the seal element  2  in the encoder-equipped sealing device  51  is mounted on a rotational element on an automotive vehicle. For example, the encoder-equipped sealing device according to each of these embodiments has been described, assuming that the encoder-equipped sealing device is mounted on the bearing unit while mounting the seal element  2  in the encoder-equipped sealing device  51  on the rotational element, such as an inner race. It should be understood, however, the encoder-equipped sealing device according to each of the embodiments described and shown can be mounted on a bearing unit, comprising an inner race and outer race rotating relative to each other, while mounting the seal element  2  in the encoder-equipped sealing device  51  on the outer race, which is a rotational element, although this is not shown.  
         [0082]     Although the present invention has been described with reference to several particular preferred embodiments thereof by referring to the accompanying drawings, it should be understood that the present invention is not limited to these embodiments, and various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Technology Category: 2