JP2008064185A - Seal ring and wheel support hub unit having seal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal ring capable of preventing ingress of foreign matters such as mud water in an annular space with a moving object or the like arranged therein, enhancing the performance of preventing leakage of grease filled in the annular space outside, and reducing the friction and the wear, and a wheel support hub unit having the seal ring. <P>SOLUTION: A seal ring 14a incorporated into a wheel support hub unit comprises a core 15, a slinger 16, and a seal member 17. The seal member 17 is formed of a resin elastic body such as a rubber, and has three outer, intermediate and inner seal lips 22, 23, 24 on its fore end. A spiral groove 50a is formed in an end face outside the axial direction continuous from the outer seal lip 22 to the intermediate seal lip 23 over the entire circumferential direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seal ring that closes an open end of a wheel support hub unit to support, for example, a vehicle (automobile) wheel on a suspension device, and a wheel support hub unit including the seal ring.

  Rolling bearings such as ball bearings, cylindrical roller bearings, and tapered roller bearings are incorporated in the rotation support portions of various mechanical devices (see, for example, Patent Document 1). In addition, a seal ring is incorporated in such a rolling bearing to prevent the grease filled in the annular space inside the rolling bearing from leaking to the outside and to prevent rainwater, mud, dust, etc. existing outside. It prevents mud salt water containing various foreign substances from rolling into the bearings.

  For example, as shown in FIGS. 4 and 5, two types of seal rings are known as incorporated in a wheel support hub unit for supporting a vehicle (automobile) wheel on a suspension device.

  As shown in FIG. 4, one of the seal rings 114 a includes a core metal 115, a slinger 116, and a seal member 117. The cored bar 115 includes a cored bar cylindrical part 118 fitted to the inner peripheral surface of the end of the outer ring 101, and a cored bar annular plate part extending radially inward from the axially inner end of the cored bar cylindrical part 118 117 and is formed in a substantially L-shaped cross section. In addition, the axial direction said here has shown the left-right direction of the figure, and the radial direction has shown the up-down direction of the figure.

  In addition, the slinger 116 is arranged so as to face the core metal 115 and is fitted to the outer peripheral surface of the end portion of the inner ring 105, and the diameter of the slinger 116 from the axially outer end portion of the slinger cylindrical portion 120. And a slinger annular plate portion 121 extending outward in the direction, and having a substantially L-shaped cross section.

  The seal member 117 is fixed to the outer peripheral surface and end surface of the core metal 115 in the axial direction, and the tip of the seal member is the outer peripheral surface of the slinger cylindrical portion 120 of the slinger 116 and the shaft of the slinger annular plate portion 121. It is in sliding contact with the inner end surface. Thus, one end of the opening of the annular space where the rolling elements 103 are arranged is closed.

  Furthermore, the other seal ring 114b is composed of a core metal 125 and a seal member 126, as shown in FIG. Among these, the core metal 125 includes a core metal cylindrical portion 125a fitted to the inner circumferential surface of the outer end of the outer ring 101 in the axial direction, and an axial outer end edge of the core metal cylindrical portion 125a (left end edge in FIG. 5). And a support plate portion 125b that is bent inward in the radial direction and is substantially S-shaped in cross section and formed entirely in an annular shape.

  The seal member 126 is formed of a resin elastic body such as rubber, for example, and is fixed to the outer circumferential surface of the cored bar 125 in the axial direction. The distal end portion (seal lip) of the seal member 126 extends from the inner surface of the base end portion of the mounting flange 109 for mounting the wheel support hub unit to the wheel, from the inner surface of the base end portion and the outer peripheral surface of the intermediate portion of the hub body 104. It is slid over the circumference.

  By these seal rings 114a and 114b, the sealing performance in the annular space inside the wheel supporting hub unit is realized.

On the other hand, the wheel support hub unit for supporting the wheels of the vehicle, in which the seal rings 114a and 114b as described above are incorporated, includes rainwater, tap water (such as when washing a car), muddy water (such as an unpaved road), salt water ( Used in snow-melting agents) and exposed to mud salt water such as water vapor. For this reason, each of the above-described seal rings 114a and 114b is required to have sufficient mud salt water resistance, specifically, sealing performance, wear resistance, corrosion resistance, and the like.
JP 2003-222145 A

  However, the seal rings 114a and 114b are used in a situation where the axle of the vehicle is submerged, the backlash of the axle bearing is large, and the seal members 117 and 126 are deteriorated due to aging. There is a possibility that the wear resistance, corrosion resistance and the like are not sufficiently satisfied. In this case, the muddy salt water infiltrates into the wheel support hub unit, and the oil film due to the grease filled between the rolling elements and the inner and outer rings is broken to cause a metal contact state.

  If the driving | operation in such a state continues, peeling will generate | occur | produce on the rolling-element surface. In the initial peeling, it appears as an abnormal sound, but depending on the running state of the vehicle, it may be mixed with other sounds, and the abnormal sound cannot often be detected. If the separation further progresses, vibration will gradually occur, leading to discomfort to the driver of the vehicle, but if the vehicle continues to run without being able to identify the abnormality, the operation will eventually be stopped by burning the wheel support hub unit. In the worst case, the vehicle may not be able to travel due to damage to the wheel supporting hub unit.

  Here, the intrusion of the muddy salt water in the conventional wheel support hub unit will be described more specifically.

  When the seal ring is exposed to muddy salt water, muddy water or salt water adheres to the tip of the seal member and the sliding contact portion of the seal member, but since the vehicle repeatedly runs and stops, the adhering muddy salt water dries. May be in a state. If traveling is started again in this state, the adhering and dried mud and salt function as an abrasive, and the seal member may be worn. Then, the tip of the radially outermost seal member (hereinafter also referred to as the tip of the outer seal member), which is the seal member first exposed to the muddy salt water, gradually wears, and the specified tightening allowance is worn. As a result, muddy water enters the seal ring.

  In the conventional seal ring described above, the infiltrated muddy salt water does not immediately reach the inside of the wheel support hub unit, but gradually advances to the inside, but the tip end of the seal member inside the outer seal member tip. As for the muddy salt water that has passed through and attached to the slinger, the progress to the inside does not proceed due to, for example, the centrifugal force caused by the rotation while the vehicle is running. On the other hand, the material adhering to the front end of the outer seal member travels along the front end of the outer seal member and gradually proceeds to the inside. Then, it reaches the inner seal member front end from the outer seal member front end, and the inner seal member front end wears in the same manner, and finally, the salt water passes through the inner seal member front end. Will be. The passed mud salt water reaches the inside of the wheel supporting hub unit in a short time. When foreign matter such as mud salt water enters the inside, components for holding the wheels such as rolling elements and cages in a freely rotatable manner are corroded and damaged, which adversely affects the running of the vehicle.

  The present invention has been made in view of the above-described circumstances, and its purpose is to further prevent entry of foreign matter such as muddy water into the annular space in which the rolling elements are arranged, and to fill the annular space. Another object of the present invention is to provide a seal ring that improves the performance of further preventing leakage of grease to the outside and reduces friction and wear, and a wheel support hub unit including the seal ring.

  In order to achieve the above-mentioned object, the rolling bearing according to the present invention is characterized by the following (1) and (2).

(1) In a seal ring including a seal lip that closes an annular space existing between an outer peripheral surface of an inner ring equivalent member and an inner peripheral surface of an outer ring equivalent member that rotate relative to each other,
The seal lip has a spiral groove.
(2) an outer ring equivalent member having an outer ring raceway on the inner peripheral surface;
An inner ring equivalent member having an inner ring raceway on the outer peripheral surface;
A plurality of rolling elements provided between the outer ring raceway and the inner ring raceway so as to be freely rollable;
A wheel support hub unit comprising: a seal ring that closes an end opening of an annular space existing between an inner peripheral surface of the outer ring equivalent member and an outer peripheral surface of the inner ring equivalent member;
The seal ring is the seal ring described in (1).

  According to the present invention, it is possible to further prevent foreign matters such as muddy water from entering the annular space in which the rolling elements are arranged, and to further prevent the grease filled in the annular space from leaking to the outside. Can be improved, and low friction and low wear can be achieved. That is, according to the present invention, it is possible to improve the running performance centering on the fuel efficiency performance and acceleration performance of the vehicle.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view of a wheel support hub unit according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part of a seal ring according to an embodiment of the present invention, and FIG. 3 is the other seal according to an embodiment of the present invention. It is principal part sectional drawing of a ring.

  FIG. 1 shows a structure for rotatably supporting a drive wheel of a vehicle (automobile) on a suspension device as an example of a wheel support bearing device having a seal ring according to the present invention.

  The wheel support bearing device includes an outer ring 1 corresponding to an outer ring equivalent member, a hub 2 corresponding to an inner ring equivalent member, and balls 3 and 3 as a plurality of rolling elements. Of these, the hub 2 is configured by combining the hub body 4 and the inner ring element 5. The balls 3, 3 are formed by a double row outer ring raceway 6, 6 formed on the inner peripheral surface of the outer ring 1 and a double row inner ring raceway 7, 7 formed on the outer peripheral surface of the hub 2. A plurality of them are arranged so as to be freely rollable. When the wheel supporting hub unit is used, that is, when the wheel is rotatably supported by the vehicle suspension device, the outer ring 1 is fixed to the knuckle 8 constituting the suspension device and provided on the hub body 4. The wheel is fixed to the mounting flange 9 provided. Further, the structure shown in FIG. 1 is a structure for supporting a drive wheel among wheels, and a spline shaft 12 in which a constant velocity joint 11 is connected to a spline hole 10 provided in the central portion of the hub body 4. It is inserted.

  In such a wheel support hub unit, the annular space 13 in which the balls 3 and 3 are arranged is filled with grease, the rolling surfaces of the balls 3 and 3, the outer ring raceways 6 and 6, and the inner ring raceway 7. , 7 and the rolling contact portion is lubricated. Further, seal rings 14 a and 14 b are respectively provided between the inner peripheral surfaces of both ends of the outer ring 1, the outer peripheral surface of the outer side in the axial direction of the inner ring element 5, and the outer peripheral surface of the hub body 4 in the axial direction. It is arrange | positioned and the both-ends opening part of the said annular space 13 is block | closed.

  Of these seal rings 14a and 14b, a seal ring 14a that closes an opening (on the right side in FIG. 1) located on the constant velocity joint 11 side outside the annular space 13 in the axial direction is configured as shown in FIG. . That is, the seal ring 14 a is called a combination seal ring, and includes a metal core 15, a slinger 16, and a seal member 17. The cored bar 15 includes a cored bar cylindrical part 18 fitted to the inner peripheral surface of the end part of the outer ring 1 and a core extending radially inward from the axially inner end of the cored bar cylindrical part 18. It is provided with a gold ring plate portion 19 and is formed in a substantially L-shaped cross section.

  In addition, the slinger 16 is disposed so as to face the core metal 15, and a slinger cylindrical portion 20 that is fitted on the outer peripheral surface of the end portion of the inner ring element 5, and an axially outer end of the slinger cylindrical portion 20. And a slinger annular plate portion 21 extending radially outward from the portion, and having a substantially L-shaped cross section.

  Further, the seal member 17 is formed of a resin elastic body such as rubber, for example, and includes three seal lips 22, 23, and 24 on the front end portion, that is, the three seal lips 22. , 23 and 24 are fixed to the core 15 at the base end. Then, with respect to the radial direction of the annular space 13, the tip edge of the outer seal lip 22 located on the outermost side is slid over the end surface on the axially inner side of the slinger annular plate portion 21 constituting the slinger 16 in the circumferential direction. The leading edges of the middle and inner seal lips 23, 24, which are the remaining two seal lips, are brought into sliding contact with the outer peripheral surface of the slinger cylindrical portion 20 constituting the slinger 16 over the entire circumference. Yes.

  A spiral groove 50a is provided over the entire circumferential direction on the end surface on the axially outer side that continues from the outer seal lip 22 to the intermediate seal lip 23.

  On the other hand, the seal ring 14b that closes the opening at the other end of the annular space 13 that is located at the base end of the mounting flange 9 is configured as shown in FIG. 3 and includes a metal core 25 and a seal member 26. Is done. The cored bar 25 includes a cored bar cylindrical part 25a fitted to the inner peripheral surface of the outer end of the outer ring 1 in the axial direction, and an axially outer end edge of the cored bar cylindrical part 25a (the left end edge in FIG. 5). ), And a support plate portion 25b that is bent inward in the radial direction and has a substantially S-shaped cross section and is formed in an annular shape as a whole.

  The seal member 26 is formed of, for example, a resin elastic body such as rubber, and includes three seal lips 27, 28, and 29 on the outer side, the middle side, and the inner side. Has been. Then, the distal end edge of the outer seal lip 27, which is called a side lip and is provided on the outermost diameter side so as to protrude outward in the axial direction, is placed on the inner peripheral surface of the base end portion of the mounting flange 9 over the entire circumference. The leading edges of the remaining two seal lips 30 and 31 are moved all around from the continuous portion of the inner peripheral surface of the base end portion to the outer peripheral surface of the intermediate portion of the hub body 4 to the outer peripheral surface of the intermediate portion. Slid and touched.

  An axially outer end face continuous from the outer seal lip 27 to the intermediate seal lip 28 is provided with a spiral groove 50b over the entire circumferential direction.

  Therefore, the middle and inner seal lips 23, 24, 28, 29 in which the muddy salt water that has passed through the outer seal lips 22, 27 is disposed inside the outer seal lips 22, 27 by the spiral grooves 50 a, 50 b. It is possible to extend the path that passes through and reaches the annular space 13. As a result, the muddy salt water that has passed through the outer seal lips 22 and 27 tries to travel along the inner end faces of the outer seal lips 22 and 27, but does not travel straight as it is, and is annular along the spiral grooves 50a and 50b. Since it proceeds in the direction of the space 13, the arrival time of the annular space 13 can be greatly extended.

  Therefore, according to this embodiment, since the spiral grooves 50a and 50b are provided in the seal lips 17 and 26, even if muddy salt water enters the inside of the seal lip, the inside of the annular space 13 in which rolling elements are arranged It is possible to extend the time for the mud salt water to reach several tens of times that of the conventional seal ring, and as a result, the life of the wheel supporting hub unit can be improved.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved. For example, since the seal member does not rotate, the direction of the spiral groove may be either right-handed or left-handed. Further, the position where the spiral groove is provided may be provided anywhere as long as it is inside the outer seal lip.

It is sectional drawing of the hub unit for wheel support which concerns on this invention. It is an expanded principal part sectional drawing of the A section of FIG. 1 which shows the seal ring which concerns on this invention. It is an expanded principal part sectional drawing of the B section of FIG. 1 which shows another seal ring which concerns on this invention. It is principal part sectional drawing of the seal ring integrated in the hub unit for wheel support which shows a prior art example. It is principal part sectional drawing of another seal ring integrated in the hub unit for wheel support which shows a prior art example.

Explanation of symbols

1 Outer ring (outer ring equivalent member)
2 Hub (inner ring equivalent member)
5 Inner ring element (inner ring equivalent member)
14a, 14b Seal ring 15, 25 Core metal 16, Slinger 17, 26 Seal member 50a, 50b Spiral groove

Claims (2)

In a seal ring having a seal lip that closes an annular space existing between the outer peripheral surface of the inner ring equivalent member and the inner peripheral surface of the outer ring equivalent member that rotate relative to each other,
The seal ring, wherein the seal lip has a spiral groove. An outer ring equivalent member having an outer ring raceway on the inner peripheral surface;
An inner ring equivalent member having an inner ring raceway on the outer peripheral surface;
A plurality of rolling elements provided between the outer ring raceway and the inner ring raceway so as to be freely rollable;
A wheel support hub unit comprising: a seal ring that closes an end opening of an annular space existing between an inner peripheral surface of the outer ring equivalent member and an outer peripheral surface of the inner ring equivalent member;
The wheel support hub unit according to claim 1, wherein the seal ring is the seal ring according to claim 1.

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