JP2008101662A - Wheel bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle bearing unit, which is equipped with a sealing mechanism to surely seal a clearance between near a hub flange of an inward member and an outer ring. <P>SOLUTION: The wheel bearing unit 1a comprises the outer ring 20 fixed to a vehicle body B side, the inward member 30 having the hub flange 42 attached by the wheel W, and double-row roll bodies 51, 52 arranged between the outer ring 20 and the inward member 30. A first sealing mechanism 60 attached to the inner peripheral surface 20b of the outer ring 20, and a second sealing mechanism 70 attached to the outer peripheral side 20a of the outer ring 20 to seal the clearance between the outer peripheral surface 20a of the outer ring 20 and the hub flange 42 are provided axially outward from the roller 51 of the vehicle outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing unit including a seal mechanism that seals a gap between an outer ring and a hub flange of an inner member. In the present specification, the term “wheel” is a generic term for all wheels that are rotatably supported via bearings, such as wheels for motorcycles and wheels for railway vehicles. .

Conventionally, in a wheel bearing unit, in addition to a seal mechanism that seals the inside of the bearing, a seal mechanism that seals the gap between the outer ring and the hub flange has been provided, so that muddy water can flow from the outer peripheral surface of the outer ring to the inside of the bearing unit. Prevents intrusion.
Such a seal member is formed integrally with a first annular portion fitted along the inner peripheral surface of the outer ring and a portion protruding from the outer ring of the first annular portion, and is fitted along the side surface of the outer ring. And a second annular portion to be joined.
And in patent document 1, the said 2nd annular part is equipped with the lip part which seals the clearance gap with a hub flange, and intrusion to the inside of bearing units, such as muddy water, is prevented, and in patent document 2, the said 1st The second annular portion includes a weir member protruding radially from the outer periphery of the outer ring, and muddy water or the like is blocked by the weir member to prevent the muddy water or the like from entering the bearing unit.
Special table 2001-510534 JP 2003-49852 A

  However, the conventional seal mechanism provided in the vehicle bearing unit has a configuration in which the annular portion of the seal mechanism is fitted to the inner peripheral surface of the outer ring. If the second annular portion fitted together is easily deformed, and the second annular portion is deformed and the fitting along the side surface of the outer ring is not realized, the lip provided in the second annular portion Since the portion does not slide in contact with the hub flange, or a gap is generated between the second annular portion and the side surface of the outer ring, there is a problem that muddy water or the like enters the bearing unit.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a vehicle bearing unit having a seal mechanism capable of reliably sealing a gap between an outer ring and a hub flange of an inner member. Is to provide.

  In order to achieve the above object, a first invention of the present invention is an outer ring fixed to the vehicle body side, an inner member having a hub flange to which the wheel is attached, and between the outer ring and the inner member. In a wheel bearing unit comprising a plurality of rolling elements arranged in a row, a first seal mechanism that is attached to the outer peripheral side of the outer ring and a first seal mechanism that is attached to the inner peripheral side of the outer ring on the outer side in the axial direction from the rolling element outside the vehicle. The wheel bearing unit includes a second seal mechanism that seals a gap between the outer peripheral surface of the outer ring and the hub flange.

  In a second aspect based on the first aspect, the wheel bearing unit includes a first outer ring raceway and a second outer ring raceway on the outer ring, a hub and an inner ring on the inner member, and the hub includes a hub. The inner ring includes a flange and a first inner ring raceway, the inner ring includes a second inner ring raceway, and the rolling elements include the first outer ring raceway, the first inner ring raceway, and the second outer ring raceway and the The wheel bearing unit is characterized by being arranged between the second inner ring raceway and the second inner ring raceway.

  According to the present invention, it is possible to provide a vehicle bearing unit capable of reliably sealing the gap between the outer ring and the hub flange of the inner member.

Hereinafter, a vehicle bearing unit according to an embodiment of the present invention will be described with reference to the drawings. In addition, this embodiment is only one embodiment of the present invention, and is not construed as being limited to these, and can be designed within the scope of the present invention.
Further, in the embodiment described below, a ball bearing or a roller bearing is adopted as a form of a bearing used in a vehicle bearing unit as an embodiment of its use, but the shape of the bearing is limited to this. As long as the wheel is supported rotatably via a bearing, other specification forms may be used within the scope of the present invention even if other bearing forms are selected depending on the use environment. Applies to
In the figure, the alternate long and short dash line is the center line of the vehicle bearing unit, and only the upper half of the center line is shown in the figure.

A first embodiment of a vehicle bearing unit 1a according to the present invention is shown in FIG.
The vehicle bearing unit 1a includes an outer ring 20 fixed to the vehicle body side (see arrow B), an inner member 30 having a hub flange 42 to which a wheel (see broken line W in the figure) is attached, the outer ring 20 and the inner ring Double-row rolling elements 51 and 52 arranged between the side members 30, a first seal mechanism 60 attached to the inner peripheral surface 20 b of the outer ring 20 on the outer side in the axial direction from the rolling elements outside the vehicle, and the outer ring The second seal mechanism 70 is attached to the outer peripheral surface 20a of the outer ring 20 and seals the gap between the outer peripheral surface 20a of the outer ring 20 and the hub flange 42.

An inner peripheral surface 20 b of the outer ring 20 includes a first outer ring raceway 21 and a second outer ring raceway 22, a second inner peripheral face 20 c disposed outside the first outer ring raceway 21, and the second outer ring raceway 22. And a third inner peripheral surface 20d disposed on the outer side of the first outer peripheral surface.
The second outer circumferential surface 20 c is provided horizontally from the part of the first outer ring raceway 21 toward the wheel W continuously through a stepped portion, and has a larger diameter than the first outer ring raceway 21. ing.
The third outer peripheral surface 20d is provided horizontally horizontally from the part of the second outer ring raceway 22 through the stepped portion toward the vehicle body B, and is formed to have a larger diameter than the second outer ring raceway 22. ing.

The inner member 30 includes an inner ring 31 and a hub 40.
The outer peripheral surface 31 a of the inner ring 31 includes a second inner ring raceway 32 that is disposed relative to the second outer ring raceway 22 of the outer ring 20, and a second outer peripheral surface 31 b that is disposed outside the second inner ring raceway 32. It consists of
The second outer peripheral surface 31 b is provided horizontally toward the vehicle body B side continuously from a part of the second inner ring raceway 32, and has a larger diameter than the second inner ring raceway 32.
The hub 40 has, on its outer peripheral surface 40 a, a first inner ring raceway 41 disposed opposite to the first outer ring raceway 21 of the outer ring 20, and a second outer peripheral surface disposed on the outer side of the first outer ring raceway 21. 40c, and the recessed part 40b which can incorporate the said inner ring | wheel 31 so that the outer peripheral surface 31a of the said inner ring | wheel 31 and the outer peripheral surface 40a of the hub 40 may become the same surface.
The second outer circumferential surface 40 c is provided horizontally from the first inner ring raceway 41 toward the wheel W side, and has a larger diameter than the first inner ring raceway 41.
Balls 51, 51... Are provided as rolling elements (rolling elements outside the vehicle) between the first outer ring raceway 21 and the first inner ring raceway 41, and the second outer ring raceway 22 and the second inner ring. Balls 52, 52... Are arranged as rolling elements (rolling elements inside the vehicle) between the tracks 32.

A disc-shaped hub flange 42 extends from the wheel W side of the second outer peripheral surface 40c of the hub 40 toward the radial direction of the center line of the vehicle bearing unit 1 (see the alternate long and short dash line in the figure). .
A portion of the hub flange 42 that extends from the second outer peripheral surface 40c of the hub 40, that is, the vicinity 45 of the hub flange 42 has a surface portion 40d that extends from the second outer peripheral surface 40c of the hub 40. The outer peripheral surface 46 is formed such that the outer diameter of the outer peripheral surface 20a of the outer ring 20 is slightly larger (reference numeral in the figure). 73).
The outer peripheral surface 46 in the vicinity 45 of the hub flange 42 has a continuous circumferential groove 47.
The hub flange 42 is provided with a plurality of through holes 44 in parallel with the center line of the vehicle bearing unit 1a (see the chain line in the figure).
A wheel mounting bolt 43 is fitted in the through hole 44. When the wheel mounting bolt 43 passes through a bolt hole (not shown) of the wheel W and is fixed with a nut (not shown), the wheel W is fixed to the hub flange 42 and can rotate. Supported by

Next, the first sealing mechanism 60 will be described.
The first seal mechanism 60 is configured by a seal body 61 that is fitted on the second inner peripheral surface 20c of the outer ring 20 on the axially outer side from the rolling elements 51, 51. A contact seal portion is formed by the second outer peripheral surface 40c of the hub 40 and the surface portion 40d extending from the second outer peripheral surface 40c.
The seal body 61 is composed of a cylindrical cored bar 61c fitted to the second inner peripheral surface 20c of the outer ring 20 from the wheel W side, and an elastic material 61d covering the cored bar 61c.
The metal core 61c has a cylindrical portion 61e in which the entire inner peripheral surface thereof is fitted to the second inner peripheral surface 20c of the outer ring 20, and a wheel W side end portion of the cylindrical portion 61e inward (in the direction of arrow C in the figure). It is formed in a substantially L shape in sectional view with a flange 61f extending in an orthogonal shape toward the surface and having an S shape in sectional view.
The elastic member 61d covers the outer peripheral surface (the wheel W side surface) of the flange 61f of the cored bar 61c and includes a plurality of seal lips (hereinafter also simply referred to as lips).
For example, in the present embodiment, two lips 61a, 61a that are continuous in the circumferential direction from the outer peripheral surface of the flange 61f of the cored bar 61c toward the surface part 40d of the hub 40, and the tip end part of the flange 61f of the cored bar 61c ( Lips 61b that continue in the circumferential direction from the end of the bearing toward the second outer peripheral surface 40c of the hub 40 are respectively extended on the ridges.
And the front-end | tip part of the said lips 61a and 61a is distribute | arranged to the surface part 40d of the said hub 40, and slides upwards. As described above, the tip portions of the lips 61a and 61a are in sliding contact with the surface portion 40d of the hub 40 so as to function as dust seals on the axially outer side (wheel W side) of the rolling element 51 outside the vehicle.
The tip of the lip 61b is disposed in sliding contact with the second outer peripheral surface 40c of the hub 40 in the inward direction of the bearing. As described above, the tip end portion of the lip 61b is in sliding contact with the second outer peripheral surface 40c of the hub 40 in the inward direction of the bearing, so that the rolling element 51 outside the vehicle is axially outside (wheel W side). Functions as an oil seal.

Although not an essential constituent element of the present invention, in the first embodiment, the seal member 62 is disposed on the inner side in the axial direction (vehicle body B side) than the rolling element 52 on the vehicle inner side (vehicle body B side).
In the first embodiment, the seal member 62 seals a gap between the third inner peripheral surface 20 d of the outer ring 20 and the second outer peripheral surface 31 b of the outer ring 31.
The seal member 62 includes a cylindrical cored bar 62c having an L-shaped cross-section that is fitted to the third inner peripheral surface 20d of the outer ring 20, an elastic material integrated with the cored bar 62c, and a first member of the inner ring 31. And a cylindrical slinger 62d having an L-shaped cross section fitted to the second outer peripheral surface 31b. The core metal 62c fitted to the third inner peripheral surface 20d of the outer ring 20 and the slinger 62d fitted to the second outer peripheral surface 31b of the inner ring 31 face each other with an L-shaped inner angular surface. Arranged. The elastic member integrated with the core metal fitted to the third inner peripheral surface 20d of the outer ring 20 has a plurality of lips that are in sliding contact with the slinger 62d fitted to the second outer peripheral surface 31b of the inner ring 31. Depending on the direction in which the lip extends, an oil seal 62b directed toward the wheel W and dust seals 62a and 62a directed toward the vehicle body B are formed and sealed on the vehicle body B side relative to the rolling element 52. To do.

Next, the second seal mechanism 70 that seals the gap between the outer ring 20 and the vicinity 45 of the hub flange 42 of the hub 40 will be described.
The second seal mechanism 70 is constituted by a seal body 74 fitted to the outer peripheral surface 20 a of the outer ring 20, and the outer peripheral surface 46 in the vicinity 45 of the hub flange 42 and the peripheral surface arranged on the outer peripheral surface 46. A non-contact seal portion is formed with the groove 47.

The seal body 74 is a non-contact seal body made of a cylindrical metal fitted to the outer peripheral surface 20a of the outer ring 20 from the wheel W side, and is fitted to a predetermined position of the outer peripheral surface 20a of the outer ring 20. Sometimes, the length is formed so as to cover the outer peripheral surface 46 in the vicinity 45 of the hub flange 42.
The end 71 on the hub flange 42 side of the seal body 74 has a seal lip 72. The seal lip 72 is formed by bending the seal body 74 in a V shape in the direction of the center of the outer ring 20 (in the direction of arrow C in the figure) to form a convex portion. The shaped tip is inserted in a non-contact manner into the circumferential groove 47 in the vicinity 45 of the hub flange 42. Accordingly, the protruding length of the seal lip 72 is formed in accordance with the depth of the circumferential groove 47.

Further, since the outer peripheral surface 20a of the outer ring 20 is formed to have a slightly larger diameter than the outer peripheral surface 46 in the vicinity 45 of the hub flange 42 (see reference numeral 73 in the figure), it fits into the outer peripheral surface 20a of the outer ring 20. The inner peripheral surface of the mating seal body 74 and the outer peripheral surface 46 in the vicinity 45 of the hub flange 42 are different in diameter from the outer peripheral surface 20a of the outer ring 20 and the outer peripheral surface 46 in the vicinity 45 of the hub flange 42. A corresponding gap is generated, and a non-contact state is maintained.
With such a configuration, the inner peripheral surface of the seal body 74, the outer peripheral surface 46 in the vicinity 45 of the hub flange 42, and the seal lip 72 and the peripheral groove 47 constitute a labyrinth seal to become a seal mechanism, and for wheels. It prevents muddy water or the like from entering the bearing unit 1a.
In this embodiment, the seal lip 72 is formed by bending the seal body 74 into a V-shaped cross section. However, the seal lip 72 may be inserted into the peripheral groove 47 in the vicinity 45 of the hub flange 45 in a non-contact state. Any other shape may be used, and can be selected according to the shape of the circumferential groove 47. For example, a trapezoidal shape may be used, or a convex member may be integrated with the seal body 74.
Furthermore, in this embodiment, the labyrinth seal is formed by the single seal lip 72 and the single circumferential groove 47. However, by providing a plurality of pairs of the seal lip 72 and the circumferential groove 47, a complicated labyrinth seal can be obtained. Forming is also within the scope of the present invention.

In this embodiment, the material of the seal body 74 of the seal mechanism 70 is made of metal, for example, stainless steel metal. However, any material can be used as long as the material has a strength sufficient to obtain the effect of the seal mechanism. It may be, and can be freely selected according to conditions such as the use environment, durability, and weather resistance of the wheel bearing unit 1a.
In addition, although the structure of a present Example is an example of the bearing unit which used the ball | bowl as a rolling element, it is applicable also to the bearing unit which used the roller as a rolling element.
(Modification 1)

In the first embodiment, the inner peripheral surface of the seal body 74, the outer peripheral surface 46 in the vicinity 45 of the hub flange 42, and the seal lip protrusion 72 and the peripheral groove 47 are separated by a labyrinth seal (non-contact). In the first modification of the first embodiment, the inner peripheral surface of the seal body 74 and the outer peripheral surface 46 in the vicinity 45 of the hub flange 42, and the seal lip convex portion 72 and the peripheral portion are arranged. It is good also as what forms the seal part of a contact by arranging so that the groove | channel 47 may slidably contact, respectively.
In that case, at least an inner peripheral surface of the seal body 74 of the seal mechanism 70 is provided with an elastic material, and the elastic material is provided on the outer peripheral surface 46 and the peripheral groove in the vicinity 45 of the hub flange 42. By being in sliding contact with 47, a seal mechanism is formed.
According to such a configuration, a seal mechanism having higher sealing performance than the labyrinth seal of the first embodiment is realized.
Note that the elastic material disposed on at least the inner peripheral surface of the seal body 74 is, as an example, a rubber-based material in the first modification of the first embodiment, but if the effect of the seal mechanism is obtained, how Any material may be used, and the material can be freely selected according to conditions such as the use environment, durability, and weather resistance of the wheel bearing unit 1a.
Since other configurations and effects are the same as those in the first embodiment, description thereof is omitted.

A wheel bearing unit 1b according to the second embodiment is shown in FIG.
The wheel bearing unit 1b according to the second embodiment is different from the second seal mechanism according to the first embodiment in the form of the second seal mechanism 80.
The second seal mechanism is different from the first embodiment in the shape of the vicinity 45 of the hub flange 42 and the shape of the seal body fitted to the outer peripheral surface 20a of the outer ring 20.
Since other configurations and effects are the same as those of the first embodiment, the description thereof will be omitted. Here, the second seal mechanism 80 that is a characteristic part of the second embodiment will be described.

The second seal mechanism 80 is constituted by a seal body 81a, and a lip 85 of the seal body 81a is brought into contact with a side surface 48 in the vicinity 45 of the hub flange 42 to form a contact seal portion.
The vicinity 45 of the hub flange 42 includes a surface portion 40d extending from the second outer peripheral surface 40c of the hub 40, and a side surface 48 formed with a gentle inclination from the surface portion 40d toward the through hole 44 of the hub flange 42. Is provided. The side surface 48 is formed outside the outer peripheral surface 20a of the outer ring 20 in the outer diameter direction (the arrow D direction in the figure).
The seal body 81 a is constituted by a cylindrical cored bar 81 fitted from the wheel W side to the outer peripheral surface 20 a of the outer ring 20 and an elastic material 82 covering the cored bar 81.
The metal core 81 has a cylindrical portion 83 in which the entire inner peripheral surface thereof is fitted to the wheel-side outer peripheral surface 20a of the outer ring 20, and a wheel W-side end portion 83a of the cylindrical portion 83 that extends orthogonally with the outer side facing outward. The disk-shaped flange 83b is formed in a substantially L shape in cross section.
The elastic member 82 covers the entire region other than the inner peripheral surface of the cylindrical portion of the cored bar 81 and continues in the circumferential direction from the outer diameter position 86 of the flange of the cored bar 81 toward the side surface 48 of the hub flange 42. A lip 84 extends from the ridge.

  The front end portion 85 of the lip 84 is disposed in sliding contact with the side surface 48 in the vicinity 45 of the hub flange 42, and the front end portion 85 of the lip 84 is in sliding contact with the side surface 48 in the vicinity 45 of the hub flange 42. Thus, the gap between the outer peripheral surface 20a of the outer ring 20 and the vicinity 45 of the hub flange 42 is sealed by the contact seal portion, and muddy water or the like can be prevented from entering the bearing unit.

The material of the cored bar 81 is the same as the material constituting the sealing body 70 of the first embodiment, and the material of the elastic member 82 is the elastic material of the first modification of the first embodiment. The wheel bearing unit 1b can be freely selected according to the usage environment, durability, weather resistance, and other conditions.
The elastic member 82 only needs to form the lip 84 at least at the flange outer diameter position 86 of the cored bar 81 on the hub flange 42 side, and does not necessarily have to cover the entire cored bar 81.

Further, in the second embodiment, the end portion 83 on the wheel W side of the cored bar 81 is bent in an L-shaped cross section toward the radial direction of the outer ring 20, but the direction in which the cored bar 81 is bent. Is not limited to this, and may be bent in a L-shaped cross section toward the center direction of the outer ring 20 (the direction opposite to the arrow D in the figure).
In this case, the lip 84 is extended from the end of the cored bar 81 on the hub flange 42 side toward the side surface 48 of the hub flange 42.
Furthermore, in this embodiment, one lip 84 and the side surface 48 in the vicinity 45 of the hub flange 42 are in sliding contact to form a seal. However, by providing a plurality of lips 84, a multiplexed seal can be formed. Are also within the scope of the present invention.

A wheel bearing unit 1c according to the third embodiment is shown in FIGS. FIG. 4 is an enlarged view of a main part of FIG.
The vehicle bearing unit 1c includes an outer ring 20 fixed to the vehicle body side (arrow B side in the figure), an inner member 30 having a hub flange 42 to which a wheel W (broken line part in the figure) is attached, Double-row rolling elements 51 and 52 arranged between the inner member 40 and a first seal mechanism 60 attached to the inner peripheral surface 20b of the outer ring 20 outside the rolling elements on the outside of the vehicle in the axial direction. And a second seal mechanism 90 that is attached to the outer peripheral surface 20a of the outer ring 20 and seals the gap between the outer peripheral surface 20a of the outer ring 20 and the hub flange 42.

In Example 3, since a tapered roller bearing is provided as an example of the wheel bearing unit 1c, the configuration of the bearing portion will be described below. In addition, the structure of a present Example is applicable even if it is a bearing unit using the ball | bowl as a rolling element.
An inner peripheral surface 20 b of the outer ring 20 includes a first outer ring raceway 21 and a second outer ring raceway 22, a second inner peripheral face 20 c disposed outside the first outer ring raceway 21, and the second outer ring raceway 22. And a third inner peripheral surface 20d disposed on the outer side of the first outer peripheral surface.
The second outer peripheral surface 20 c is provided horizontally from the first outer ring raceway 21 continuously through the inclined portion toward the wheel W side, and has a larger diameter than the first outer ring raceway 21.
The third outer peripheral surface 20d is provided horizontally from the second outer ring raceway 22 through the inclined portion toward the vehicle body B side, and has a larger diameter than the second outer ring raceway 22.

The inner member 30 includes a first inner ring 31, a second inner ring 33, and a hub 40.
An outer peripheral surface 31 a of the first inner ring 31 has a second inner ring raceway 32 disposed opposite to the second outer ring raceway 22 of the outer ring 20 and a second inner ring raceway 32 disposed outside the second inner ring raceway 32. It is comprised by the outer peripheral surface 31b.
The second outer peripheral surface 31 b is provided horizontally toward the vehicle body B side continuously from a part of the second inner ring raceway 32, and has a larger diameter than the second inner ring raceway 32.
The outer peripheral surface 33 a of the second inner ring 33 has a first inner ring raceway 34 disposed opposite to the first outer ring raceway 21 of the outer ring 20 and a second inner ring raceway 34 disposed outside the second inner ring raceway 34. It is comprised with the outer peripheral surface 33b.
The second outer peripheral surface 33 b is provided horizontally from the first inner ring raceway 34 toward the vehicle body B side, and has a larger diameter than the second inner ring raceway 34.
The hub 40 has the first inner ring 31 and the second inner ring so that the outer peripheral surface 31a of the first inner ring 31 and the outer peripheral surface 33a of the second inner ring 33 are flush with the outer peripheral surface 40a. A recess 40b into which 33 can be incorporated is provided.
And between the said 1st outer ring track 21 and the said 1st inner ring track 34, rollers 51, 51 ... as a rolling element (rolling element outside the vehicle), the second outer ring track 22 and the second inner ring. Between the track 32, rollers 52, 52... Are arranged as rolling elements (rolling elements inside the vehicle).

  The vicinity 45 of the hub flange 42 includes a surface portion extending from the wheel W side of the recess 40 b of the hub 40, and a side surface 48 formed with a gentle inclination from the surface portion toward the through hole 44 of the hub flange 42. Is provided. The side surface 48 is formed on the outer side in the outer diameter direction (the direction opposite to the arrow E direction in the drawing) from the outer peripheral surface 20a of the outer ring 20.

Next, the first sealing mechanism 60 will be described.
The first seal mechanism 60 includes a seal member 61 disposed between the second inner peripheral surface 20c of the outer ring 20 and the second outer peripheral surface 33b of the second inner ring. It is arranged between the inner peripheral surface 20c and the second outer peripheral surface 33b of the second inner ring to form a contact seal portion.

As shown in FIG. 4, the seal member 61 includes a cylindrical second metal core 63 having an L-shaped cross section that is fitted to the second inner peripheral surface 20 c of the outer ring 20, and the second metal core 63. The elastic body 64 is integrated with the cylindrical slinger 66 having an L-shaped cross section that is fitted to the outer peripheral surface 33 b of the second inner ring 33.
The second core metal 63 is formed by bending an end 63a of the vehicle body B side in the center direction of the outer ring 20 (in the direction of arrow E in the figure) into an L-shaped cross section. The wheel W side end portion of 63 has a concave groove 65 having a cross-sectional arrowhead shape (> shape) continuously recessed in the circumferential direction.
The slinger 66 has a vehicle body B-side end 66b bent in a L-shaped cross section in the radial direction of the outer ring 20 (opposite to the arrow E in the figure), and the end 66b and the second The end 63a of the cored bar 63 is disposed to face the cored bar 63.
The elastic body 64 integrated with the second core metal 63 has a plurality of lips that are in sliding contact with the slinger 66 and seals it on the axially outer side (wheel W side) of the rolling element 51 outside the vehicle. Depending on the extending direction of each lip, an oil seal 64b directed toward the vehicle body B and dust seals 64a and 64a directed toward the wheel W are formed.

Next, the second sealing mechanism 90 that seals between the outer periphery 20a of the outer ring 20 and the hub flange 42 of the inner member 40 will be described.
The second seal mechanism 90 is configured by a seal body 90a fitted to the outer peripheral surface 20a of the outer ring 20, and contacts the side surface 48 in the vicinity 45 of the hub flange 42 to form a contact seal portion.
The seal body 90 a is configured by a cylindrical cored bar 91 that is fitted from the wheel W side to the outer peripheral surface 20 a of the outer ring 20, and an elastic material 92 that covers the cored bar 91.
The metal core 91 has a cylindrical portion 91a in which the entire inner peripheral surface thereof is fitted to the outer peripheral surface of the outer ring 20 on the wheel W side, and a wheel W side end 97 of the cylindrical portion 91a inward (in the direction of arrow E in the figure). The outer ring 20 is formed in a substantially L shape in sectional view with a disk-shaped inward flange 93 extending along the wheel W side end of the outer ring 20.
The elastic member 92 covers the entire region other than the inner peripheral surface (the wheel W side outer peripheral surface and the wheel W side end portion of the outer ring 20) of the core bar 81, and the wheel W side end portion of the cylindrical portion of the core bar 91. A lip 94 continuous in the circumferential direction extends from the position 97 toward the surface portion near the side surface 48 of the hub flange 42, and extends from the ridge.

The front end portion 95 of the lip 94 is disposed in sliding contact with the surface portion near the side surface 48 of the vicinity 45 of the hub flange 42, and the front end portion 95 of the lip 94 is disposed on the side surface 48 of the vicinity 45 of the hub flange 42. By sliding in contact with the near surface portion, the gap between the outer peripheral surface 20a of the outer ring 20 and the vicinity 45 of the hub flange 42 is sealed by the contact seal portion, and muddy water or the like can be prevented from entering the inside of the bearing unit. it can. As in the second embodiment, it is also possible to adopt a form in which the tip portion 95 of the lip 94 is in sliding contact with the side surface 48.
Further, in this embodiment, one lip 94 is slidably brought into contact with the surface portion near the side surface 48 in the vicinity 45 of the hub flange 42 to form a seal, but by providing a plurality of lips 94, a multiplexed seal is formed. It is also within the scope of the present invention.

  Further, the front end portion 96 of the flange 93 of the metal core 91 is formed to a length slightly exceeding the thickness of the end portion 20 e of the outer ring 20. The elastic body 92 that covers the cored bar 91 extends toward the vehicle body B direction at the distal end portion 96 of the cored bar 91, and the extended distal end has a convex shape ( > Shape) is protruded continuously in the circumferential direction.

Furthermore, the seal structure according to the third embodiment includes a joint structure in which the seal body 90a and the core metal 63 are combined together.
In the joining structure, the protrusion 99 included in the tip of the elastic body 92 integrated with the core 91 of the seal body 90a is fitted to the arrowhead-shaped recess 65 included in the wheel W side end of the core 63. (See reference numeral 98) to form a joint structure, and the cored bar 91 and the cored bar 63 are integrated.
By adopting such a joining structure, it becomes possible to form a wall by the core bars 91 and 63 from the outer peripheral surface 20a of the wheel W side end portion 20e of the outer ring 20 to the inner peripheral surface 20b, and more completely. A simple sealing mechanism. Further, since the cored bar 63 is not extended on the side surface of the outer ring 20, there is no inconvenience that the cored bar 63 is deformed in the operation of fitting the cored bar 63 to the inner peripheral surface 20 b of the outer ring 20. .

The materials of the core bars 63 and 91 and the slinger 66 are the same as the materials constituting the seal body of the first embodiment, and the materials of the elastic members 64 and 92 are modified examples of the first embodiment. It is the same as the elastic body shown in FIG. 1, and can be freely selected according to conditions such as the use environment, durability, and weather resistance of the wheel bearing unit 1c.
(Modification 1)

A wheel bearing unit 1d according to Modification 1 of Embodiment 3 is shown in FIGS. FIG. 6 is an enlarged view of a main part of FIG.
In the third embodiment, the inner member 30 includes the first inner ring 31, the second inner ring 33, and the hub 40. However, in the first modification of the third embodiment, the inner member 30 is the first inner ring 31. The inner ring 31 and the hub 40 are configured.
In that case, the outer peripheral surface 40a of the hub 40 is continuously connected to the first inner ring raceway 40d disposed relative to the first outer ring raceway 21 of the outer ring 20 and a part of the first inner ring raceway 40d. A second outer peripheral surface 40c that is provided horizontally toward the side and has a larger diameter than the second inner ring raceway 34, and a recess 40b that incorporates the first inner ring 31.
In the case of the configuration as in the first modification, the seal member 61 of the first seal mechanism 60 is an elastic unit integrated with the second core metal 63 without using the slinger 66. The dust seals 67 and 67 of the material 64 are formed to extend to the vicinity 45 of the hub 40.
According to such a configuration, the tip portions 68 and 68 of the dust seals 67 and 67 of the elastic material 64 are in sliding contact with the side surface 48 in the vicinity 45 of the hub flange 42 to form a seal structure, and oil extending in the direction of the vehicle body B is provided. Together with the seal 69, the inside of the bearing can be sealed.
Since other configurations and effects are the same as those in the third embodiment, description thereof is omitted.

A wheel bearing unit 1e according to the fourth embodiment is shown in FIG.
The wheel bearing unit 1e according to the fourth embodiment is different from the second seal mechanism according to the first embodiment in the form of the second seal mechanism 100.
The second seal mechanism 100 is different from the first embodiment in the shape of the vicinity 45 of the hub flange 42 and the shape of the seal body.
Further, the wheel bearing unit 1e of the fourth embodiment is configured to include the sensor 120 through the outer ring 20 and the second seal mechanism as an example, but is not limited to such a configuration. Even the configuration without the sensor 120 is applied to other specification forms within the scope of the present invention.
Since other configurations and effects are the same as those in the first embodiment, description thereof is omitted, and here, the second seal mechanism 100 that is a characteristic part of the fourth embodiment will be described.

The second seal mechanism 100 is configured by a seal body 105 fitted to the outer peripheral surface 20a of the outer ring 20, and forms a non-contact seal portion with the side surface 48 in the vicinity 45 of the hub flange 42, and A contact seal portion is formed between the outer peripheral surface 20 a of the outer ring 20 and the elastic body 110 disposed between the seal body 105.
In the vicinity 45 of the hub flange 42, the side surface 48 has a gentle inclination from the vicinity of the through hole 44 toward the outer peripheral surface 20 a of the outer ring 20. It faces the end 20e with a predetermined gap.
The seal body 105 is a non-contact seal body made of a cylindrical metal that is fitted to the outer circumferential surface 20 a of the outer ring 20 from the wheel W side. The seal body 105 is fitted to the outer circumferential surface 20 a of the outer ring 20. An end 101 on the vehicle body B side, a stepped portion 102 having a crank shape viewed from the end 101 in the radial direction (the direction of arrow F in the figure), and extending from the stepped portion 102 to the wheel W side. And an end portion 103. The end 103 has a predetermined gap between the outer ring 20 and the outer peripheral surface 20a.
The end portion 103 on the wheel W side extends to cover the vicinity 45 of the hub flange 42, and the tip end 104 on the hub flange 42 side of the end portion 103 is connected to the hub flange 42. It is arranged so as to leave a slight gap close to the side surface 48 of the neighborhood 45.

  The tip 104 on the hub flange 42 side of the seal body 105 and the side surface 48 in the vicinity 45 of the hub flange 42 constitute a labyrinth seal by the slight gap to form a seal mechanism (non-contact seal portion). This prevents muddy water and the like from entering the interior bearing unit 1e.

Furthermore, in the fourth embodiment, a ring-shaped elastic body 110, for example, a rubber O-ring is fitted in the gap between the end portion 103 on the wheel W side of the seal body 105 and the outer peripheral surface 20a of the outer ring 20. It is. As described above, by arranging the ring-shaped elastic body 110, the joint portion between the vehicle body B side end portion 101 of the front seal body 105 and the outer peripheral surface 20a of the outer ring 20 can be sealed (contact seal portion). This makes it possible to prevent muddy water and the like from entering the joint surface.
(Modification 1)

FIG. 8 shows a wheel bearing unit 1f according to the first modification of the fourth embodiment.
In the fourth embodiment, the end portion 104 on the hub flange 42 side of the seal body 105 of the second seal mechanism 100 and the side surface 48 in the vicinity 45 of the hub flange 42 constitute a labyrinth seal with a slight gap. However, in the first modification of the fourth embodiment, the sealing body 105 is covered with the elastic body 130, and the elastic body 130 and the side face 48 in the vicinity 45 of the hub flange 42 are in sliding contact with each other. Forming part.
Specifically, a lip 132 is extended from the wheel W side end portion 131 of the elastic body 130 toward the side surface 48 in the vicinity 45 of the hub flange 42, and the tip portion 133 of the lip 132 is connected to the hub flange. 42 is in sliding contact with a side surface 48 in the vicinity 45 of 42.
In this case, a seal mechanism with higher sealing performance than the labyrinth seal of the fourth embodiment is realized.
Since other configurations and effects are the same as those of the fourth embodiment, description thereof is omitted.

Explanatory drawing which shows the wheel bearing unit by Example 1 of this invention. Explanatory drawing which shows the wheel bearing unit by Example 2 of this invention. Explanatory drawing which shows the wheel bearing unit by Example 3 of this invention. The principal part enlarged view of FIG. Explanatory drawing which shows the wheel bearing unit by the modification 1 of Example 3 of this invention. The principal part enlarged view of FIG. Explanatory drawing which shows the wheel bearing unit by Example 4 of this invention. Explanatory drawing which shows the wheel bearing unit by the modification 1 of Example 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Wheel bearing unit 20 Outer ring 20a Outer peripheral surface 20b Inner peripheral surface 30 Inner member 42 Hub flange 51, 52 Rolling element 60 First seal mechanism 70 Second seal mechanism B Vehicle body W Wheel

Claims (2)

An outer ring fixed to the vehicle body side,
An inner member having a hub flange to which a wheel is attached;
In a wheel bearing unit comprising a double row rolling element disposed between the outer ring and the inner member,
A first seal mechanism attached to the inner peripheral surface of the outer ring on the outer side in the axial direction from the rolling elements on the outside of the vehicle;
A second seal mechanism attached to the outer peripheral surface of the outer ring and sealing a gap between the outer peripheral surface of the outer ring and the hub flange;
A wheel bearing unit characterized by that. The outer ring has a first outer ring raceway and a second outer ring raceway,
The inner member has a hub and an inner ring,
The hub includes a hub flange and a first inner ring raceway,
The inner ring includes a second inner ring raceway,
Rolling elements are respectively disposed between the first outer ring raceway and the first inner ring raceway, and the second outer ring raceway and the second inner ring raceway.
The wheel bearing unit according to claim 1.

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