Patent Publication Number: US-2007104402-A1

Title: Seal device with sensor and rolling bearing device using the same

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to a seal device mounting a sensor device and a rolling bearing device using the seal device.  
      Since vehicles need various kinds of information for performing control, it has been proposed that a hub unit (a rolling bearing device) has a sensor device provided therein. The hub unit includes a wheel-side raceway member to which a wheel is attached, a body-side raceway member which is fixed to a body side, and two lines of rolling elements arranged between both of the wheel-side raceway member and the body-side raceway member.  
      As such a rolling bearing device, Patent Document 1 discloses a rolling bearing device including an outer ring, an inner ring, rolling elements arranged between both of the outer and inner rings, and seal disposed between the end portions of both of the outer and inner rings. On the end surface of the outer ring, a sensor supporting member having a sensor provided thereon is attached. Further, a ring-shaped magnet is fixed on the axial outer surface of a slinger fixed to the inner ring.  
      When such a rolling bearing device is applied to a hub unit of a vehicle, the axial dimension thereof needs to be reduced to less than a predetermined value. In the rolling bearing device of Patent Document 1, the ring-shaped magnet and the sensor supporting member are formed so as to project more than the bearing device in the axial direction, which makes it difficult to apply the rolling bearing device to a hub unit of a vehicle.  
      Accordingly, it is considered that a sensor is resin-molded to core metal composing a seal device so as to reduce an axial dimension. In this case, however, a gap can occur between resin and the core metal holding the resin as the resin contracts, the core metal and the resin can be separated from each other, or water can invade into the bearing from the boundary between the core metal and the resin. Therefore, prevention measures are needed.  
      Considering the above-described situation, the present applicants propose a seal device with a sensor in Patent Document 2, as shown in  FIG. 3 . The seal device with a sensor includes a cylindrical fitting portion  61 , a flange portion  62 , a cylindrical portion  63  for preventing water from invading, and an inner flange portion  64 . The cylindrical fitting portion  61  includes a fixed seal member  8  that has core metal  21  fitted and fixed to a fixed member  3  and a sensor  11  resin-molded to the core metal  21 ; and a rotated seal member  9  that has a cylindrical portion  32 , of which the axial inner portion is fitted and fixed to a rotating member  4 , and a flange portion  33  which continues into the axial outer end portion of the cylindrical portion  32  so as to extend toward the fixed seal member  8 . The core metal  21  of the fixed seal member  8  is fitted and fixed to the fixed member  3 . The flange portion  62  continues into the axial inner end portion of the cylindrical fitting portion  61  so as to extend toward the cylindrical portion  32  of the rotated seal member  9 . The cylindrical portion  63  for preventing water from invading continues into the flange portion  62  so as to extend outward in the axial direction thereof. The inner flange portion  64  continues into the cylindrical portion  63  for preventing water from invading so as to extend inward. Insert molding is performed so that the axial outer end portion of the cylindrical fitting portion  61  is positioned within resin, and a fitting portion  71  of elastic seal  65  having a plurality of lips  72 ,  73 , and  74  is attached to at least one of the axial outer end portion of the cylindrical portion  63  for preventing water from invading and the axial outer end portion of the rotated seal member  9 . The rotated seal member  9  has a pulsar  60  including a support member  66  and a magnetized body  67 . The support member  66  of the pulsar  60  includes a small-diameter cylindrical portion  69  which is fitted and fixed to the outer circumference of the cylindrical portion  32  of the rotated seal member  9 ; a large-diameter cylindrical portion  68  having the magnetized body  67  provided on the outer circumference thereof; and a connecting portion  70  which connects the large-diameter cylindrical portion  68  and the small-diameter cylindrical portion  69 .  
      The support member  66  of the pulsar  60  comprises the large-diameter cylindrical portion  68 , the small-diameter cylindrical portion  69 , and the connecting portion  70 . The small-diameter cylindrical portion  69  is pressed into the rotated seal member  9 . When the pressing is performed, the right end position of the large-diameter cylindrical portion  68  and the right end position of the cylindrical portion  32  of the slinger  31  composing the rotated seal member  9  are on the same plane. Further, the right end position of the large-diameter cylindrical position  68  is slightly shifted more leftward than the right surface of the flange portion  62  of the fixed seal member  8 , and the right end of the small-diameter cylindrical portion  69  is positioned more rightward than the large-diameter cylindrical portion  68 .  
      As such, a required seal property is secured by combining the fixed seal member  8  and the rotated seal member  9 . Further, as the output of the sensor  11  within the resin member  22  is drawn out by wiring units such as a connector portion  27 , a connector pin  28 , a connector  29 , a lead line  30  and the like, it is possible to obtain such a seal device that has an excellent seal property and the sensor  11  mounted therein.  
      As for the seal property, a gap easily occurs in the interface between the core metal  21  and the resin member  22  due to the contraction of resin at the time of insert molding, a difference in expansion rate between metal and resin, and the repeated intrusion of muddy water, and water or the like can invade into the bearing from a position A of  FIG. 3 . Therefore, a bearing function can be degraded, and a lifetime can be reduced. However, the water invading from the position A of  FIG. 3  is blocked by the fitting between the cylindrical portion  61  of the core metal  21  and the fixed raceway member  3  so as not to move rightward. The water invading leftward from the space between the outer periphery of the cylindrical portion  61  of the core metal  21  and the resin member  22  is sealed by the elastic seal  65  such that water is prevented from invading into the bearing.  
      Patent Document 1; JP-A-5-26233  
      Patent Document 2: JP-A-2006-291977  
      According to the seal device with a sensor disclosed in Patent Document 2, the axial dimension thereof is reduced, and the separation between the core metal and the resin member and the intrusion of water from the boundary between the core metal and the resin member can be prevented. As shown in  FIG. 3 , however, the axial inner end portion of the cylindrical portion  32  of the slinger  31  composing the rotated seal member  9  is fitted and fixed to the rotating member  4  and the small-diameter portion  69  of the support member  66  of the pulsar is fitted and fixed to the middle of the cylindrical portion  32  of the slinger  31 , which means that the fitting portions thereof are deviated from each other in the axial direction. Therefore, the rigidity of the fitting portion between the rotated seal member  31  and the rotating member  4  becomes relatively low. When the rigidity of the fitting portion is low, it is highly likely that water invades from the fitting portion. Therefore, it is desired to enhance the rigidity of the fitting portion without any demerit occurring.  
     SUMMARY OF THE INVENTION  
      An object of the present invention is to provide a seal device with a sensor and a rolling bearing device using the seal device. In the seal device and the rolling bearing device, the axial dimensions thereof can be reduced, and the separation between core metal and resin member and the intrusion of water from the boundary between the core metal and the resin member can be prevented. Further, the rigidity of the fitting portion between a rotated seal member and a rotating member can be enhanced.  
      In order to achieve the object, the present invention is characterized by having the following arrangement.  
      1. A seal device with a sensor comprising:  
      a fixed member;  
      a rotating member rotatable with respect to the fixed member;  
      a core metal including a cylindrical fitting portion which is insert-molded to the fixed member so that an axial outer end portion of the cylindrical fitting portion is positioned within resin, a first flange portion that continues to an axial inner end portion of the cylindrical fitting portion, and a first cylindrical portion for preventing water from invading which continues to the first flange portion so as to extend outward in an axial direction;  
      a sensor resin-molded to the core metal;  
      a rotating seal member that including a second cylindrical portion having an axial inner portion fitted and fixed to the rotating member, and a second flange portion which continues to an axial outer end portion of the second cylindrical portion so as to extend toward the fixed member;  
      an elastic seal provided in at least one of the axial outer end portion of the first cylindrical portion and an axial outer end portion of the rotating seal member; and  
      a pulsar that includes a support member and a magnetized body and is provided in the rotating seal member,  
      wherein the support member includes a small-diameter cylindrical portion that is fitted and fixed to the second cylindrical portion, a large-diameter cylindrical portion on which the magnetized body is provided, and a connecting portion that connects the large-diameter cylindrical portion to the small-diameter cylindrical portion, and  
      wherein the support member is fitted and fixed to an axial inner end portion of the second cylindrical portion so that the connected portion is set inward in the axial direction.  
      The fixing member may be set to an outer ring or inner ring of a rolling bearing, and the rotating member may be set to an inner ring or outer ring of a rolling bearing. However, this is not limited thereto.  
      The core metal may be formed of one rigid ring or more than two rigid rings. However, regardless of whether the core metal is formed of one rigid ring or more than two rigid rings, the core metal is set to have the large-diameter cylindrical portion and the small-diameter cylindrical portion such that the resin-molded sensor is positioned between both of the cylindrical portions.  
      The elastic seal is provided in the flange portion of the rotated seal member so as to come in sliding contact with the cylindrical portion for preventing water from invading. Alternately, the elastic seal is provided in the flange portion provided in the axial outer end portion of the cylindrical portion for preventing water from invading so as to come in sliding contact with the cylindrical portion of the rotated seal member and/or the flange portion.  
      The elastic seal may be provided in both of the outer ends of the rotated seal member and the cylindrical portion for preventing water from invading. Further, the elastic seal is provided not only between both of the outer ends of the rotated seal member and the cylindrical portion for preventing water from invading, but also between both of the inner ends thereof, if necessary.  
      The sensor is set to a magnetic sensor using an MR element or hole element. However, it is not limited thereto. Typically, a pulsar applying a signal to a magnetic sensor is provided in the cylindrical portion of the rotated seal member so as to face the magnetic sensor.  
      The core metal and the resin member are insert-molded. At this time, the outer end portion of the cylindrical fitting portion is positioned within the resin. That is, the core metal is not closely attached only on the surface of the resin, but the end portion of the core metal is inserted into the resin.  
      The rotated seal member has the pulsar including the support member and the magnetized body. The support member of the pulsar comprises the small-diameter cylindrical portion fitted and fixed to the outer circumference of the cylindrical portion of the rotated seal member, the large-diameter cylindrical portion having the magnetized body provided on the outer circumference thereof, and the connecting portion connecting the large-diameter cylindrical portion and the small-diameter cylindrical portion.  
      The small-diameter cylindrical portion of the support member of the pulsar is fitted and fixed to the axial inner portion of the cylindrical portion of the rotated seal member such that the connecting portion is set inward in the axial direction. Then, the fitting portion between the cylindrical portion of the rotated seal member and the rotating member is reinforced by the small-diameter cylindrical member of the support member of the pulsar, which makes it possible to enhance the rigidity thereof.  
      Preferably, the small-diameter cylindrical portion of the support member of the pulsar has a smaller axial length than the large-diameter cylindrical portion. The large-diameter cylindrical portion needs to have a certain axial length such that the magnetized body is provided therein. Further, in terms of rigidity, it is preferable that the small-diameter cylindrical portion is set to have the same axial length as the large-diameter cylindrical portion. In this case, however, it is difficult to perform press molding. When the small-diameter cylindrical portion of the support member of the pulsar is fitted and fixed to the rotated seal member such that the connecting portion is set inward in the axial direction, the rigidity can be sufficiently enhanced even though the axial length of the small-diameter cylindrical portion is set to be smaller than the large-diameter cylindrical portion. As such, it is possible to enhance the rigidity without degrading the productivity.  
      The seal device with a sensor is preferably used in a rolling bearing device which includes a rolling bearing that comprises a fixed ring serving as a fixed member, a rotating ring serving as a rotating member, and rolling elements arranged between both of the rings; and a seal device which is integrally provided in the rolling bearing.  
      In this case, the fixed ring may be set to an outer ring, and the rotating ring may be set to an inner ring. Alternately, the fixed ring may be set to an inner ring, and the rotating ring may be set to an outer ring.  
      The fixed ring is set to a body-side raceway member having an attaching portion with a body and the rotating ring is set to a wheel-side raceway member having a ring attaching portion, so that the rolling bearing device is preferably used as a hub unit.  
      The seal device with a sensor according to the present invention includes the fixed seal member and the rotated seal member, and the fixed seal member has a sensor resin-molded to the core metal. Therefore, the sensor is mounted into the seal device. For example, when the sensor is attached to the rolling bearing, the sensor is easily embedded in the rolling bearing. Further, it is possible to reduce the axial dimension of the rolling bearing device with a sensor. Furthermore, since the outer end portion of the cylindrical fitting portion is insert-molded so as to be positioned within the resin, the core metal is not removed from the resin by a torque at the time of rotation. In addition, the elastic seal is provided in at least one of the axial outer end portion of the cylindrical portion for preventing water from invading and the axial outer end portion of the rotated seal member, the elastic seal coming in sliding contact with the other. Therefore, although water invades from the gap occurring between the core metal and the resin after the cylindrical fitting portion of the core metal is fitted and fixed to the fixed member, the water is delivered outward in the axial direction from the space between the resin and the cylindrical portion for preventing water from invading through between the cylindrical fitting portion and the resin and between (the outer surface in an axial direction of) the flange portion and the resin. Therefore, the water is prevented from invading into a device having the seal device with a sensor attached thereto. Further, the fitting portion between the cylindrical portion of the rotated seal member and the rotating member is reinforced by the small-diameter cylindrical portion of the support member of the pulsar, which makes it possible to enhance the rigidity thereof. Therefore, it is possible to further enhance a seal property. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a vertical sectional view illustrating a sealing device with a sensor and a rolling bearing device according to an embodiment of the invention.  
       FIG. 2  is an enlarged vertical sectional view of  FIG. 1 .  
       FIG. 3  is an enlarged vertical sectional view illustrating a sealing device with a sensor and a rolling bearing device which is compared with the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Hereinafter, a preferred embodiment of the present invention will be described with reference to accompanying drawings.  
       FIGS. 1 and 2  are diagrams illustrating a seal device with a sensor and a rolling bearing device using the seal device according to an embodiment of the invention. In the following descriptions, the left and right sides are referred to as the left and right sides of  FIG. 1 , respectively. Further, the left side becomes the inside of a rolling stock, and the right side becomes the outside of the rolling stock.  
      The rolling bearing device includes a hub unit  1 , a sensor device  2  provided in the hub unit  1 , and a pulsar  10  which is a portion to be detected.  
      The hub unit  1  includes a body-side raceway member  3  fixed to a body side, a wheel-side raceway member  4  on which a wheel is attached, a plurality of balls  5  serving as rolling elements which are arranged in two lines between both of the members  3  and  4 , and a holder  6  which holds the respective lines of balls  5 .  
      The body-side raceway member  3  having a function of an outer ring (fixed ring) of a bearing includes a cylindrical portion  12  having two lines of outer-ring raceways  12  formed on the inner periphery thereof and a flange portion  13  which is provided in the vicinity of the left end of the cylindrical portion  12  and is attached to a suspension (body) by a bolt.  
      The wheel-side raceway member  4  comprises a hollow shaft  14  including a large-diameter portion  15  having a first raceway groove  15   a  and a small-diameter portion  16  having a smaller diameter than the first raceway groove  15   a ; and an inner ring  17  which is fitted into the outer circumference of the small-diameter portion  16  of the hollow shaft  14  and of which the right surface comes in close contact with the left surface of the large-diameter portion  15  of the hollow shaft  14 . On the inner periphery of the hollow shaft  14 , a serration is provided. In the vicinity of the right end of the hollow shaft  14 , a flange portion  18  is provided to which a plurality of bolts for attaching a wheel are fixed. The inner ring  17  having a raceway groove  17   a  formed thereon such that the raceway groove  17   a  is set in parallel to the raceway groove  15   a  of the hollow shaft  14 . Further, the inner ring  17  has a shoulder portion  17   b  formed in the left portion thereof. Between the right end of the body-side raceway member  3  and the hollow shaft  4 , a seal member  20  is formed of elastic seal and core metal.  
      Between the shoulder portion  17   b  of the inner ring  17  and the left end portion of the body-side raceway member  3 , the seal device  7  according to the invention is provided.  
      The seal device  7  includes a fixed seal member  8  fixed to the body-side raceway member  3  and a rotated seal member  9  fixed to the wheel-side raceway member  4 .  
      The stationary seal member  8  includes core metal  21 , a resin member  22  integrated with the core metal  21  through insert molding, a sensor  11  resin-molded to the core metal  21 , and elastic seal  23  bonded to the core metal  21 .  
      The resin member  22  is formed in a ring shape. The outer diameter of the ring-shaped portion is set to be substantially equal to that of the left end portion of the fixed raceway member  3 . Further, on the ring-shaped portion, a projecting portion  26  is provided so as to project leftward and outward in the diameter direction. In the upper end portion of the projecting portion  26 , a connector portion  27  for attaching a harness connecting the sensor  11  and a processing unit provided in the body side is integrally formed. The connector portion  27  having a signal connector pin  28  provided therein such that the sensor  11  and the connector pin  28  are connected through a connector  29  and a lead line  30  (or only a lead line).  
      The rotated seal member  9  includes a slinger  31  fitted and fixed to the shoulder portion  17   b  of the inner ring  17  of the wheel-side raceway member  4  and the pulsar  10  fixed to the slinger  31 .  
      Wiring units, such as the sensor  11 , the connector portion  27  retrieving an output of the sensor  11  to the outside, the connector pin  28 , the connector  29 , the lead line  30  and the like, and a processing unit (not shown) constitutes a sensor device  2 . The sensor  11  comprises a magnetic sensor, and the sensing surface thereof is set to face the outer periphery of a pulsar  10  from the outward direction in the diameter direction.  
      Referring to  FIG. 2 , the seal device  7  will be described in more detail.  
      The core metal  21  of the fixed seal member  8  is formed of one rigid ring. The core metal  21  includes a cylindrical fitting portion  61  which is fitted and fixed to the left end portion of the body-side raceway member  3 , an outer flange portion  62  continuing into the axial inner end portion (right end portion) of the cylindrical portion  61  so as to extend inward (a direction directed to the rotated seal member  9 ), a cylindrical portion  63  for preventing water from entering which continues into the outer cylindrical flange portion  62  so as to extend outward (leftward) in the axial direction, and an inner flange portion  64  which continues into the cylindrical portion  63  for preventing water from entering so as to extend in the inward direction. On the inner peripheral edge of the inner flange portion  64 , elastic seal  65  is bonded. The left portion of the cylindrical fitting portion  61  is formed to project more leftward than the left end of the body-side raceway member  3  and is inserted into the resin member  22 . The cylindrical portion  63  for preventing water from entering is abutted on the inner periphery of the resin member  22 , and the left end thereof is positioned more leftward than the resin member  22 . The core metal  21  is made of nonmagnetic metal, such as SUS304, such that a magnetic line is easily put into the detecting surface of the magnetic sensor  11 .  
      The slinger  31  comprises a cylindrical portion  32 , of which the axial inner end portion (right end portion) is fitted and fixed to the shoulder portion  17   b  of the inner ring  17  of the wheel-side raceway member  4 , and an outward flange portion  33  which continues into the axial outer end portion (left end portion) of the cylindrical portion  31  in the axis direction so as to extend toward the fixed seal member  8 . Between the outward flange portion  33  and the inner flange portion  64  of the core metal  21  of the fixed seal member  8 , a space is formed in which the elastic seal  65  can be housed.  
      The pulsar  10  of the rotated seal member  9  has N poles and S poles alternately disposed so as to generate a magnetic force so that the sensor  11  combined therewith outputs a rotation signal. Accordingly, the pulsar  10  comprises a ring-shaped support member  35  and a magnetized body  36  bonded to the support member. The support member  35  is made of magnetic metal such as SUS430. The magnetized body  36  is formed by magnetizing magnetic powder, with rubber being set to binder.  
      The support member  35  of the pulsar  10  comprises a small-diameter cylindrical portion  37  which is fitted and fixed to the outer circumference of the cylindrical portion  32  of the slinger  31  of the rotated seal member  9 , a large-diameter cylindrical portion  38  having the magnetized body  36  provided on the outer circumference thereof, and a connecting portion  39  which connects the large-diameter cylindrical portion  38  and the small-diameter cylindrical portion  37 . The axial length of the small-diameter cylindrical portion  37  is smaller than that of the large-diameter cylindrical portion  38 . The magnetized body  36  is provided on the outer circumference of the large-diameter cylindrical portion  38  so as to face the sensor  11 . The gap between the magnetized body  36  and the cylindrical portion  63  for preventing water from entering is set to as a small value as possible in the range where both of the magnetized body  36  and the cylindrical portion  63  do not come in contact with each other.  
      In the support member  35  of the pulsar  10 , the small-diameter cylindrical portion  37  is fitted and fixed to the axial inner portion of the cylindrical portion  32  of the slinger  31  such that the connecting portion  39  is set inward in the axis direction. In this embodiment, the connecting portion  39  of the support member  35  of the pulsar  10  and the axial inner end surface of the cylindrical portion  32  of the slinger  31  are on the same plane. Accordingly, the fitting portion between the cylindrical portion  32  of the slinger  31  and the wheel-side raceway member  4  is reinforced by fitting the small-diameter cylindrical portion  37  of the support member  35  of the pulsar  10  into the inner end portion of the cylindrical portion  32  of the slinger  31 , thereby improving the rigidity thereof.  
      The sensor  11  is positioned within the resin member  22  filled between the cylindrical portion  61  which is a large-diameter cylindrical portion and the cylindrical portion  63  which is a small-diameter cylindrical portion.  
      In the outer end portion of the cylindrical portion  61  of the core metal  21  of the fixed seal member  8 , a notched portion  47  for leading wiring lines  30  is provided. The wiring lines  30  connect the sensor  11  and a signal processing unit.  
      The elastic seal  65  includes a U-shaped fitting portion  71  which is fitted in the inner peripheral edge of the inner flange portion  64  of the core metal  21 ; an axial lip  72  which extends leftward from the left surface of the fitting portion  71  so as to come in sliding contact with the flange portion  33  of the slinger  31 ; a first radial lip  73  which extends leftward and inward in the diameter direction from the bottom surface of the fitting portion  71  so as to come in sliding contact with the cylindrical portion  32  of the slinger  31 ; and a second radial lip  74  which extends inward in the diameter direction from the bottom surface of the fitting portion  71  so as to come in sliding contact with the cylindrical portion  32  of the slinger  31 .  
      The core metal  21  of the fixed seal member  8  and the resin member  22  are integrated by insert molding.  
      In the interface between the core metal  21  and the resin member  22 , a gap easily occurs due to the contraction of resin at the time of insert molding, a difference in expansion rate between metal and resin, and the repeated intrusion of muddy water. Further, water can invade into the bearing from a position A shown in  FIG. 2 . Accordingly, a bearing function can be degraded, and a lifetime can be reduced. According to the seal device  7  of this embodiment, the intrusion of water from the position A of  FIG. 2  is prevented by the fitting between the cylindrical portion  61  of the core metal  21  and the fixed raceway member  3  such that the water cannot move rightward but invades leftward from the space between the outer periphery of the cylindrical portion  61  of the core metal  21  and the resin member  22 . As described above, the gap can occur in the boundary between the resin member  22  and the core metal  21 . Therefore, invading water can enter into the left end portion of the cylindrical portion  63  through the left end and the inner periphery of the cylindrical portion fitting  61  and the left end of the flange portion  62 . However, since the elastic seal  65  is present in the position, water is prevented from invading into the bearing. As such, it is possible to reliably prevent water from invading even though an O-ring is not used. Further, since the cylindrical portion  61  of the core metal  21  of the fixed seal member  8  is fitted and fixed to the body-side raceway member  3 , the core metal  21  is prevented from sliding on the fixed seal member  8  due to the torque accompanied by the sliding of the elastic seal  65 . Further, since insert molding is performed in a state where the left portion of the cylindrical portion  61  of the core metal  21  of the fixed seal member  8  is inserted into the resin member  22 , the sliding between the core metal  21  and the resin member  22  is also prevented.  
      As for the fitted position of the pulsar  10  with respect to the slinger  31 , the connecting portion  39  of the support member  35  is set inward in the axial direction in a state where the axial inner portion of the cylindrical portion  32  of the slinger  31  composing the rotated seal member  9  is fitted and fixed to the wheel-side raceway member  4 . Therefore, the fitting portion of the small-diameter cylindrical portion  37  of the support member  35  is superimposed on the fitting portion between the slinger  31  and the wheel-side raceway member  4 . As for the fitted position of the pulsar  60  with respect to the slinger  31  in the example shown in  FIG. 3 , the connecting portion  39  of the support member  35  is set outward in the axial direction, while the fitting between the slinger  31  and the wheel-side raceway member  4  is performed the same as  FIG. 2 . Therefore, the fitting portion of the small-diameter cylindrical portion  37  of the support member  35  is deviated from the fitting portion between the slinger  31  and the wheel-side raceway member  4 . Accordingly, in the seal device of  FIG. 3 , the rigidity of the fitting portion between the cylindrical portion  32  of the slinger  31  and the wheel-side raceway member  4  is relatively low. Further, in the seal device of  FIG. 2 , the rigidity of the fitting portion between the cylindrical portion  32  of the slinger  31  and the wheel-side raceway member  4  is relatively high, as the fitting portion is reinforced by the small-diameter cylindrical portion  37  of the support member  35  of the pulsar  10 . Therefore, in the seal device of  FIG. 2 , the construction of the pulsar  10  is not changed from that of  FIG. 3 , but only a direction at the time of pressing is changed. Then, a high seal property is maintained so as to prevent water from invading from a position B of  FIG. 3 . Further, a seal property is further enhanced.  
      The hub unit  1  of this embodiment is shown as a driving ring having a serration provided in the hollow shaft  14  such that the bearing portion of a constant-velocity joint can be inserted. However, the hub unit  1  can be set as a driven ring, as the hollow shaft is replaced with the rotation shaft of a driven ring. Although the description has been made with the hub unit  1  being exemplified, the seal device  7  can be applied to various rolling bearing devices or various rotary equipments which relatively performs rotation, in addition to the hub unit  1 .