JP2013249927A - Seal structure of wheel bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure of a wheel bearing capable suppressing rotating resistance of the wheel bearing low while securing high sealing property in the wheel bearing.SOLUTION: A constitution in which a side lip 15c of a seal member 15 and an outer peripheral side end part of a slinger 16 are formed obliquely relative to an axial direction and the side lip 15c does not touch the slinger 16 is adopted as a seal structure of a wheel bearing 12 constituted by fixing the seal member 15 to a fixing side of the wheel bearing 12 rotatably supporting a wheel 2 of a vehicle and fixing the slinger 16 covering the seal member 15 from the outside to the rotation side of the wheel bearing 12.

Description

  The present invention relates to a seal structure for a wheel bearing that rotatably supports a vehicle wheel.

  For example, a wheel of a front wheel of a vehicle is supported by a wheel bearing so as to be rotatable with respect to a knuckle, and the wheel bearing is provided with a seal member. (See, for example, Patent Documents 1 and 2). FIG. 4 shows a conventional example of a wheel bearing seal structure.

  That is, FIG. 4 is a partial cross-sectional view showing a conventional example of a seal structure of a wheel bearing. A wheel bearing 112 that rotatably supports a wheel (not shown) is disposed between an inner ring 112a and an outer ring 112b that are concentrically arranged. A plurality of balls (steel balls) 112c (only one is shown in FIG. 4) is arranged to be able to roll, and the inner periphery of the inner ring 112a is fitted to the outer periphery of a rotating shaft (not shown), The outer periphery of the outer ring 112b is fitted to the inner periphery of a knuckle (not shown) on the fixed side.

  A seal member 115 is provided at the inner end in the axial direction between the inner ring 112 a and the outer ring 112 b of the wheel bearing 112, and the seal member 115 is a slinger fixed to the outer periphery of the inner ring 112 a of the wheel bearing 112. 116 is covered from the outside by 116. Here, the seal member 115 is configured by baking an elastic body 115B such as rubber on a metal core 115A having an L-shaped cross section, and the outer periphery of the core 115A is the inner ring of the outer ring 112b of the wheel bearing 112. The outer ring 112b on the fixed side is fixed by being fitted around the circumference.

  Further, in the seal member 115, the first lip 115a and the second lip 115b formed in a bifurcated shape on the inner peripheral portion of the elastic body 115B are in close contact with the outer periphery of the cylindrical portion 116A of the slinger 116, and the elastic body 115B The front end portion of the side lip 115c extending obliquely and integrally from the radial intermediate portion is in close contact with the inner surface of the ring-shaped flange portion 116B of the slinger 116. As described above, the first lip 115a, the second lip 115b, and the side lip 115c formed on the elastic body 115B of the seal member 115 are in close contact with the slinger 116, thereby ensuring a high sealing function for the seal member 115. The seal function 115 prevents water and foreign matter from entering the wheel bearing 112.

JP-A-6-247268 Japanese Patent Laid-Open No. 9-042300

  By the way, in recent years, a vehicle is required to have low fuel consumption. However, as shown in FIG. 4, there are three lip 115a, second lip 115b and side lip 115c of the seal member 115 used for sealing the wheel bearing 112. If it is in close contact with the slinger 116, the frictional resistance generated in these close contact portions is increased and the rotational resistance of the wheel bearing 112 is increased, which is disadvantageous for vehicles aiming at low fuel consumption.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wheel bearing seal structure that can keep the rotational resistance of the wheel bearing low while ensuring high sealing performance for the wheel bearing. There is.

  In order to achieve the above object, according to the first aspect of the present invention, a seal member is fixed to a fixed side of a wheel bearing that rotatably supports a vehicle wheel, and a slinger that covers the seal member from the outside is provided on the wheel bearing. As the seal structure of the wheel bearing fixed to the rotation side, the side lip of the seal member and the outer peripheral side end of the slinger are formed obliquely with respect to the axial direction, and the side lip is not in contact with the slinger. It is characterized by adopting the configuration to do.

  According to a second aspect of the present invention, in the first aspect of the invention, the outer peripheral side end portion of the side lip of the seal member is formed obliquely outward in the radial direction toward the outer side in the axial direction, and the outer periphery of the slinger The side end is formed obliquely so as to extend radially outward toward the inner side in the axial direction, and the outer peripheral side end of the side lip and the outer peripheral side end of the slinger are overlapped in the axial direction. To do.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the inner peripheral surface of the outer peripheral side end portion of the seal member is a slope inclined in the same direction as the inclination direction of the side lip. To do.

  According to the first aspect of the present invention, since the outer peripheral side end portions of the side lip and slinger of the sealing member are formed obliquely with respect to the axial direction, the side lip and slinger are not in contact with the slinger. The labyrinth effect caused by the labyrinth formed between the water and foreign matter is prevented from entering the wheel bearing from the outside. Even if water or foreign matter passes through the gap between the side lip and the slinger, the water or foreign matter is easily discharged. Further, since the side lip of the seal member does not come into contact with the slinger, the rotational resistance of the wheel bearing is kept low, and the fuel efficiency of the vehicle is improved.

  According to invention of Claim 2, since the side lip and slinger of a sealing member incline in the mutually opposite direction, since both outer peripheral side edge parts overlap in an axial direction, the labyrinth effect by a maze structure As a result, the penetration of water and foreign matter from the outside into the wheel bearing can be more effectively prevented. Even if water or foreign matter passes through the gap between the side lip and the slinger, the water or foreign matter flows down along the slopes of the side lip and slinger due to its own weight, and is easily discharged to the outside. Is done.

  According to the invention of claim 3, since the inner peripheral surface of the outer peripheral side end portion of the seal member is an inclined surface inclined in the same direction as the inclination direction of the side lip, it enters from the gap between the side lip and the slinger and is caused by its own weight. The water and foreign matter that flow down along the slopes of the side lip and slinger are received by the slinger from the side lip that alternately inclines in the opposite direction, and are received by the slope at the outer peripheral end of the seal member from the slinger to the outside. And discharged smoothly.

It is a longitudinal cross-sectional view of the front-wheel part of a vehicle. It is an expanded sectional view of the wheel bearing part of FIG. It is a fragmentary sectional view which shows the seal structure of the wheel bearing which concerns on this invention. It is a fragmentary sectional view which shows the prior art example of the seal structure of a wheel bearing.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a longitudinal sectional view of a front wheel portion of a vehicle, FIG. 2 is an enlarged sectional view of a wheel bearing portion of FIG. 1, and FIG. 3 is a partial sectional view showing a seal structure of a wheel bearing according to the present invention. Each pair of left and right front wheels 1 (only one is shown in FIG. 1) is composed of a wheel 2, a rim 3 bound to the outer periphery thereof, and a tire 4 fitted to the rim 3 as shown in FIG. Yes. The front wheel 1 is supported by the center portion of the wheel 2 being connected to the hub 5 by a plurality of bolts 6 and nuts 7 (only one is shown in FIG. 1).

  One end of the drive shaft 8 extending in the left-right direction is screwed through the center of the hub 5, and the hub 5 is connected to the drive shaft 8 by a nut 9 that is screwed into the end of the drive shaft 8. ing. A knuckle 11 is attached to the ends of the left and right suspension arms 10 extending from the vehicle body, and a hub 5 is rotatably supported on the knuckle 11 via a wheel bearing 12. The knuckle 11 is connected to the end of a steering tie rod 14 via a ball joint 13.

  As shown in detail in FIG. 2, the wheel bearing 12 is configured by rolling a plurality of balls (steel balls) 12 c between the inner ring 12 a and the outer ring 12 b that are concentrically arranged. An inner ring (inner diameter) of the inner ring 12a is fitted to the outer circumference (outer diameter) of the drive shaft 8, and an outer circumference (outer diameter) of the outer ring 12b is fitted to the inner circumference (inner diameter) of the knuckle 11. Yes.

  Thus, a seal member 15 is provided between the inner ring 12a and the outer ring 12b at the axial end of the wheel bearing 12, and as shown in detail in FIG. 3, the seal member 15 and the seal member The seal structure according to the present invention is configured by a slinger 16 that is disposed on the side of the seal member 15 at a position on the axial end side with respect to 15 and covers the seal member 15 from the outside. The details of the seal structure according to the present invention will be described below with reference to FIG.

  The seal member 15 is configured by baking an elastic body 15B such as rubber on a metal core 15A having an L-shaped cross section, and the outer periphery (outer diameter) of the core 15A is the outer ring 12b of the wheel bearing 12. By being fitted to the inner periphery (inner diameter), it is fixed to the outer ring 12b on the fixed side. In the seal member 15, the first lip 15a and the second lip 15b formed in a bifurcated shape on the inner peripheral portion (inner diameter portion) of the elastic body 15B are in close contact with the outer periphery (outer diameter) of the cylindrical portion 16A of the slinger 16. The side lip 15c extends obliquely and integrally from the radial intermediate portion of the elastic body 15B. That is, the side lip 15 c has the same axial center as the wheel bearing 12 and is formed in a tapered shape that increases in diameter toward the slinger 16.

  On the other hand, the metal slinger 16 is fitted on the outer periphery (outer diameter) of the inner ring 12a of the wheel bearing 12, and the cylindrical portion 16A and the outer end of the cylindrical portion 16A (the axially outer end of the wheel bearing 12). A ring-shaped flange portion 16B that extends (extends) by bending at a right angle from the portion) radially outward. The outer peripheral edge of the flange portion 16B is bent to form an inclined portion 16a that is inclined obliquely toward the seal member 15 as shown. That is, the outer peripheral edge portion of the flange portion 16 </ b> B has a tapered shape that has the same axis as the wheel bearing 12 and expands toward the seal member 15.

  Thus, in the sealing structure according to the present invention, as shown in FIG. 3, the side lip 15c of the sealing member 15 and the slope 16a of the outer peripheral edge of the slinger 16 are formed obliquely with respect to the axial direction of the wheel bearing 12. The side lip 15 c of the seal member 15 is not in contact with the slinger 16. Specifically, in each cross section including the shaft of the wheel bearing 12, the outer peripheral edge portion of the side lip 15c of the seal member 15 is formed obliquely so as to go radially outward toward the axially outer side of the wheel bearing 12. The slanted portion 16a at the outer peripheral side end portion of the slinger 16 has a larger diameter than the side lip 15c and is formed obliquely toward the radially outer side toward the inner side in the axial direction of the wheel bearing 12. That is, the side lip 15c of the seal member 15 and the slanted portion 16a of the slinger 16 are opposed to each other by inclining in the opposite direction by increasing the diameter in the axial direction toward each other. When the portion enters the inner diameter portion (inner space) of the slope portion 16a and is disposed close to the bent portion (small diameter portion of the slope portion 16a) of the outer peripheral edge portion of the flange portion 16B, the outer peripheral edge portion of the side lip 15c and the slinger 16 The slope portions 16a overlap each other in the axial direction. In the present embodiment, the inner surface of the outer peripheral portion of the elastic body 15B of the seal member 15 is an inclined surface 15d inclined in the same direction as the inclined direction of the side lip 15c. That is, the inner side surface is formed in a tapered shape having the same axis as the wheel bearing 12 and having a diameter increasing toward the side (outside) where the slinger 16 is disposed.

  Next, the operation of the seal structure configured as described above will be described.

  When the front wheel 1 is rotated by receiving rotational power from the drive shaft 8, the inner ring 12a of the wheel bearing 12 rotates together with the hub 5. Therefore, the slinger 16 fitted to the outer periphery of the inner ring 12a rotates together with the inner ring 12a while being fixed. The seal member 15 fitted to the inner periphery of the outer ring 12b on the side is kept stationary, and the first lip 15a and the second lip 15b formed on the inner periphery (inner diameter portion) of the elastic body 15B The desired seal function is achieved by sliding contact with the outer periphery (outer diameter) of the cylindrical portion 16A, and water and foreign matter are prevented from entering the wheel bearing 12 from the outside.

  Thus, in the present embodiment, the side lip 15c of the sealing member 15 and the slope 16a of the outer peripheral edge of the slinger 16 are formed obliquely with respect to the axial direction, so the side lip 15c is not in contact with the slinger 16 Even so, the labyrinth effect caused by the labyrinth formed between the side lip 15c and the slope 16a of the slinger 16 prevents water and foreign matter from entering the wheel bearing 12 from the outside. And even if water and a foreign material have passed through the gap between the side lip 15c and the slinger 16, these water and the foreign material are easily discharged.

  More specifically, the opening area is reduced by providing the inclined surface portion 16a, and the amount of water and foreign matter entering the slinger 16 and the seal member 15 beyond the slinger 16 is reduced by the inclined surface portion 16a that rotates together with the inner ring 12a. be able to. Since the side lip 15c of the seal member 15 and the inclined surface portion 16a of the slinger 16 are inclined in opposite directions, the end portion of the side lip 15c and the inclined surface portion 16a of the slinger 16 are overlapped in the axial direction. The water or foreign matter that enters between the slinger 16 and the seal member 15 beyond 16 is received by the outer diameter surface of the side lip 15c (more specifically, the groove at the root of the side lip 15c), and the inner side of the side lip 15c. The amount of water or foreign matter entering the space can be reduced. Further, the labyrinth effect by the labyrinth structure constituted by the slinger 16 and the side lip 15c is enhanced, and the entry of water and foreign matter from the outside into the wheel bearing 12 can be more effectively prevented.

  Even if water or foreign matter has passed through the gap between the side lip 15c and the slinger 16 of the seal member 15 and water or foreign matter has entered the inner diameter side space of the side lip 15c, the water or foreign matter will remain in the seal member. Falls on the side lip 15c formed in an inclined state by its own weight as indicated by a broken line arrow in FIG. However, the fallen foreign matter moves along the slope of the side lip 15c formed in an inclined state and falls onto the slope 16a of the slinger 16 from the tip of the side lip 15c. And the fallen foreign material moves along the slope part 16a which inclines in the reverse direction, and is discharged | emitted outside from the front-end | tip of the slope part 16a. At this time, since the slope portion 16a rotates together with the inner ring 12a, it is more effectively discharged by centrifugal force. That is, water and foreign matter flow downward along the slopes of the side lip 15c and the slinger 16 and are easily discharged to the outside.

  Further, in the present embodiment, the inner diameter side surface of the outer peripheral portion of the seal member 15 is the inclined surface 15d inclined in the same direction as the inclined direction of the side lip 15c, so that it enters from the gap between the side lip 15c and the slinger 16. Water or foreign matter that flows down along the slopes of the side lip 15c and slinger 16 due to its own weight flows through the slope 15d without collecting on the inner diameter side surface of the outer peripheral portion of the seal member 16, and is smoothly discharged from the slope 15d to the outside. Is done.

  Further, in the present embodiment, since the side lip 15c of the seal member 15 does not contact the slinger 16, the rotational resistance of the wheel bearing 12 can be kept low, and the fuel efficiency of the vehicle can be improved.

1 Front wheel 2 Wheel 8 Drive shaft (rotary shaft)
DESCRIPTION OF SYMBOLS 12 Wheel bearing 15 Seal member 15A Seal member core 15B Seal member elastic body 15a Seal member first lip 15b Seal member second lip 15c Seal member side lip 15d Seal member slope 16 Slinger 16A Slinger cylindrical portion 16B Slinger flange 16a Slinger slope

Claims (3)

A wheel bearing seal structure in which a seal member is fixed to a fixed side of a wheel bearing that rotatably supports a vehicle wheel, and a slinger that covers the seal member from the outside is fixed to the rotary side of the wheel bearing. ,
A seal structure for a wheel bearing, wherein the side lip of the seal member and the outer peripheral side end of the slinger are formed obliquely with respect to the axial direction, and the side lip is not in contact with the slinger.   An outer peripheral side end of the side lip of the seal member is formed obliquely outward in the radial direction toward the outer side in the axial direction, and an outer peripheral side end of the slinger is directed outward in the radial direction toward the inner side in the axial direction. 2. The wheel bearing seal structure according to claim 1, wherein the outer peripheral side end of the side lip and the outer peripheral side end of the slinger are overlapped in the axial direction. 3. The wheel bearing seal structure according to claim 1, wherein an inner peripheral surface of an outer peripheral side end portion of the seal member is an inclined surface inclined in the same direction as an inclination direction of the side lip.

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