JP2009298367A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device having high sealing performance against a large amount of muddy water or the like. <P>SOLUTION: The wheel bearing device 11 consists of an external member 15 keeping the double row outside rolling surfaces 15a, 15b in an inner periphery, an internal member 12 keeping in an outer periphery the double row inside rolling surfaces 12a, 12b opposed to the double row outside rolling surfaces 15a, 15b, a double row rolling element 16 freely rollably accommodated between both rolling surfaces of the internal member 12 and external member 15 through a retainer 17 and sealing members 21, 31 mounted in an opening of an annular gap formed between the external member 15 and internal member 12. Contact parts of the internal member 12 and external member 15 with the sealing members 21, 31 are provided with a water repellent treated layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wheel bearing device, and more particularly, to a wheel bearing device used in an environment in contact with a large amount of muddy water or dust.

  A conventional rolling bearing is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-83345 (Patent Document 1). Referring to FIG. 11, a rolling bearing 101 disclosed in the publication includes an inner ring 102 that rotates integrally with a wheel hub (not shown), an outer ring 103 that is fixed to a knuckle (not shown), an inner ring 102, and an outer ring. And a plurality of rolling elements 104 disposed between the inner ring 102 and the sealing device (sealing member) 105 that seals both ends of the inner ring 102 and the outer ring 103 in the axial direction.

The sealing member 105 seals the inside of the bearing by bringing a seal member 105a attached to the outer ring 103 and a slinger 105b attached to the inner ring 102 into sliding contact. Further, it is disclosed that a resin coating (not shown) is applied to the surface of the slinger 105b to prevent wear of the sliding contact portion due to foreign matter.
JP 2003-83345 A

  The sealing member 105 disclosed in the publication can effectively prevent intrusion of muddy water or the like into the bearing, although it can prevent wear due to intrusion of muddy water or dust (hereinafter referred to as “muddy water”). It's hard to say.

  Accordingly, an object of the present invention is to provide a wheel bearing device having high sealing performance against a large amount of muddy water or the like.

  In the wheel bearing device according to the present invention, an outer member having a double-row outer rolling surface formed on the inner periphery, and a double-row inner rolling surface facing the double-row outer rolling surface are formed on the outer periphery. Between the outer member, the inner member and the inner member and the outer member, the double row rolling elements accommodated between the rolling surfaces of the inner member and the outer member via a cage. And a sealing member attached to the opening of the annular space formed in the. A water repellent treatment layer is provided at the contact portion between the inner member and the outer member with the sealing member.

  Muddy water or the like mainly accumulates at the contact portion between the inner member and the outer member and the sealing member, and promotes wear of the sealing member and rusting of the inner member and the outer member, and enters the bearing internal space. Therefore, by selectively providing a water-repellent treatment layer in this path, muddy water and the like can be expelled from the periphery of the sealing member to the outside, and entry into the bearing can be effectively prevented.

  Preferably, a water repellent treatment layer is provided on the entire surface of the sealing member. More preferably, a water repellent treatment layer is provided on the exposed portions of the inner member and the outer member. Thereby, the penetration | invasion to sealing member periphery, such as muddy water, can be blocked | prevented more effectively.

  Preferably, the water repellent treatment layer is a fluorine coating. The fluororesin is excellent in water repellency and has high wear resistance, impact resistance, chemical resistance, corrosion resistance, weather resistance, and salt water resistance, and is suitable as a material to be applied to the surface of the seal portion.

  Preferably, the water repellent treatment layer is formed of a material containing a hydrophobic silica compound.

  According to the present invention, it is possible to obtain a wheel bearing device in which muddy water or the like is effectively prevented from entering the inside of the bearing by selectively providing a water-repellent treatment layer in a portion where muddy water or the like easily enters.

  A wheel bearing device (hereinafter referred to as “wheel hub bearing”) according to an embodiment of the present invention will be described with reference to FIGS. 1 is a view showing a wheel hub bearing 11 according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion P in FIG. 1, and FIG. 3 is an enlarged view of a portion Q in FIG.

  First, referring to FIG. 1, the wheel hub bearing 11 is disposed between an inner member 12 that functions as an inner ring, an outer member 15 that functions as an outer ring, and the inner member 12 and the outer member 15. The ball | bowl 16 as a some rolling element, the holder | retainer 17 holding the space | interval of the adjacent ball | bowl 16, and the sealing members 21 and 31 which seal the axial direction one side and other side of the wheel hub bearing 11 are provided. The wheel hub bearing 11 in this embodiment has a third generation structure and employs a double-row angular ball bearing as a bearing type.

  The inner member 12 includes an inner ring member 13 and a wheel hub 14 that holds the inner ring member 13 and a wheel (not shown). Specifically, a first inner rolling surface 12 a is provided on the outer diameter surface of the inner ring member 13, and a second inner rolling surface 12 b is provided on the outer diameter surface of the wheel hub 14. The inner ring member 13 and the wheel hub 14 are fixed by swinging and caulking the tip of the wheel hub 14 (the right side in FIG. 1).

  The outer member 15 protrudes from the first and second outer rolling surfaces 15a, 15b and the outer diameter surface at positions facing the first and second inner rolling surfaces 12a, 12b of the inner diameter surface and wheels ( And a wheel mounting flange 15c that holds a wheel (not shown), and is fixed to a knuckle (not shown).

  The inner member 12 and the outer member 15 having the above-described configuration are formed of, for example, medium carbon steel (S53C) having a carbon content of 0.40 to 0.80 wt%, and surface hardness is obtained by induction hardening. HRC is set in the range of 58-64.

  A plurality of balls 16 are provided between the first inner rolling surface 12a and the first outer rolling surface 15a and between the second inner rolling surface 12b and the second outer rolling surface 15b. Has been placed. In addition, grease as a lubricant is sealed in a space surrounded by the inner member 12, the outer member 15, and the sealing members 21 and 31 (hereinafter referred to as “bearing internal space”).

  When the automobile travels on a bad road or rainy weather, the wheel hub bearing 11 having the above configuration comes into contact with a large amount of muddy water or the like. Therefore, sealing members 21 and 31 as shown in FIGS. 2 and 3 are employed as sealing members for sealing the wheel hub bearing 11.

  Referring to FIG. 2, the sealing member 21 is a lip seal that is fitted and fixed to the inner diameter surface of the outer member 15 and slidably contacts the outer diameter surface of the inner member 12, and includes an elastic seal 22 and a core. It consists of gold 23. The elastic seal 22 has three lip portions 22a, 22b, and 22c that are in sliding contact with a position (referred to as "seal land") adjacent to the second inner rolling surface 12b of the outer diameter surface of the inner member 12. Vulcanized and bonded to the core metal 23. The core metal 23 is fitted and fixed to the inner diameter surface of the outer member 15 to fix the elastic seal 22 to the outer member 15, and also functions as a shape holding member that holds the shape of the elastic seal 22.

  Next, referring to FIG. 3, the sealing member 31 is fitted and fixed to the outer diameter surface of the inner member 12 and the inner diameter surface of the outer member 15, and the slinger 35 is also fixed. It is a high pack seal comprised with the sealing member 32 which slidably contacts. The seal member 32 includes an elastic seal 33 including an axial lip 33a and radial lips 33b and 33c, and a cored bar 34 as a shape maintaining member.

  The cored bar 34 includes a cylindrical portion 34a that fits into the inner diameter surface of the outer member 15, and an inward flange portion 34b that protrudes radially inward from one axial side (left side in FIG. 3) of the cylindrical portion 34a. Have. The elastic seal 33 is vulcanized and bonded to the core metal 34. That is, the cored bar 34 is fitted and fixed to the inner diameter surface of the outer member 15 to fix the elastic seal 33 to the outer member 15 and also functions as a shape holding member that holds the shape of the elastic seal 33.

  The slinger 35 includes a cylindrical portion 35a that is fitted and fixed to the outer diameter surface of the inner member 12, and an outward flange that protrudes radially outward from one axial end (right side in FIG. 3) of the cylindrical portion 35a. Part 35b. A magnetizing encoder 35c is attached to the outward flange portion 35b. Specifically, the magnetizing encoder 35c is a ring-shaped member made of a rubber multipole magnet in which magnetic poles are alternately arranged in the circumferential direction, and is a wall surface facing the axially outer side of the outward flange portion 35b. Is held in.

  The sealing member 31 having the above configuration seals the bearing internal space by the axial lip 33a and the outward flange portion 35b being in sliding contact with the radial lip 33b and the cylindrical portion 35a, respectively. Further, the radial lip 33c and the cylindrical portion 35a face each other with a predetermined interval, and both constitute a labyrinth.

  The elastic seals 22 and 33 are made of synthetic rubber such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluorinated rubber (FKM). On the other hand, the core bars 23 and 34 and the slinger 35 are made of stainless steel such as austenitic stainless steel (SUS304), for example. Stainless steel is effective for rust prevention of the portions (exposed portions) in contact with the outside air of the core bars 23 and 34 and the slinger 35.

  In the wheel hub bearing 11 described above, a water repellent treatment layer 18 is provided at a contact portion between the inner member 12 and the outer member 15 with the sealing members 21 and 31. Specifically, the sliding contact portions of the inner member 12 with the lip portions 22a, 22b, and 22c, the fitting portion of the inner member 12 with the slinger 35, and the fitting of the outer member 15 with the core bars 23 and 34 are performed. A water repellent treatment layer 18 is provided in the part.

  Muddy water or the like mainly penetrates into the bearing internal space by promoting wear and rust at the contact portions between the inner member 12 and the outer member 15 and the sealing members 21 and 31. Therefore, by selectively providing the water repellent treatment layer 18 in this path, muddy water and the like can be ejected from the periphery of the sealing member to effectively prevent entry into the bearing internal space.

  In addition to the configuration of FIG. 2, the water repellent treatment layers 21 a, 32 a, and 35 d may be provided on the entire surfaces of the sealing members 21 and 31. Specifically, referring to FIG. 5, after the elastic seal 22 and the core metal 23 are vulcanized and bonded, the water repellent treatment layer 21 a is formed on the entire surface of the sealing member 21. Similarly, referring to FIG. 6, after the elastic seal 33 and the cored bar 34 are vulcanized and bonded, a water repellent treatment layer 32 a is formed on the entire surface of the seal member 32. Further, a water repellent treatment layer 35d is also formed on the entire surface of the slinger 35 to which the magnetizing encoder 35c is attached.

  Further, in addition to the configuration of FIG. 2, the water repellent treatment layer 18 may be extended so as to cover the exposed portions of the inner member 12 and the outer member 15 (pointing to the “outside of the bearing internal space”). Good. Specifically, referring to FIGS. 8 and 9, the water repellent treatment layer 18 is also formed on the axial end surface of the inner member 12, the axial end surface of the outer member 15, and the outer diameter surface. Thereby, the penetration | invasion to bearing internal space, such as muddy water, can be blocked | prevented more effectively.

  At this time, it is desirable to similarly provide the water-repellent treatment layers 21 a and 31 a on the exposed portions of the sealing members 21 and 31. Alternatively, as shown in FIGS. 5 and 6, sealing members 21 and 31 having water repellent treatment layers 21a, 32a, and 35d on the entire surface may be employed.

  In order to obtain the effect of the present invention, the water-repellent treatment layer 18 may be provided only at least in contact with the sealing members 21 and 31 of the inner member 12 and the outer member 15. However, as shown in FIGS. 5 to 9, a higher effect can be expected by further providing a water-repellent treatment layer in the peripheral portion.

  The water-repellent treatment layer is formed, for example, by applying a fluororesin on the surface (referred to as “fluorine coating”). The fluororesin is excellent in water repellency and has high wear resistance, impact resistance, chemical resistance, corrosion resistance, weather resistance, and salt water resistance, and is suitable as a material to be applied to the surface of the seal portion.

  Specific examples of the fluororesin include PTFE (Poly Tetra Fluoro Ethylene), FEP (Fluorinated Ethylene Proline), PFA (Tetra Fluoroethylene PerFluor Alkylin Ethyl), and ETF.

  Further, a hydrophobic silica compound may be used as the material for the water-repellent treatment layer in place of the fluororesin.

  In each of the above embodiments, the example in which the magnetizing encoder 35c is attached to the slinger 35 has been described. However, the magnetizing encoder 35c is not an essential component of the present invention and can be omitted. That is, even if the sealing member 31 shown in FIG. 4 is used instead of FIG. 3, the sealing member 31 shown in FIG. 7 is used instead of FIG. 6, and the sealing member 31 shown in FIG. The effect of can be obtained. 3 and 6 and FIGS. 4, 7, and 10 are partially different in shape of the sealing member 31, but it goes without saying that the effect of the present invention can be obtained in either case.

  In the above-described embodiment, the example of the wheel hub bearing 11 in which the inner member 12 is the rotating side raceway and the outer member 15 is the non-rotating side raceway is shown. The present invention can also be applied to a wheel hub bearing 11 in which 12 is a non-rotating side race and the outer member 15 is a rotational side race.

  Further, in the above embodiment, the third generation structure is exemplified as the wheel hub bearing 11, but the present invention is not limited to this, and can be similarly applied to the first and second generation wheel hub bearings. .

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used in a wheel bearing device.

It is a figure which shows the wheel hub bearing which concerns on one Embodiment of this invention. It is an enlarged view of the P section of FIG. It is an enlarged view of the Q section of FIG. It is a figure which shows other embodiment of FIG. It is a figure which shows the other form of the sealing member arrange | positioned at the P section of FIG. It is a figure which shows the other form of the sealing member arrange | positioned at the Q section of FIG. It is a figure which shows other embodiment of FIG. It is a figure which shows other embodiment of FIG. It is a figure which shows other embodiment of FIG. It is a figure which shows other embodiment of FIG. It is a figure which shows the conventional rolling bearing.

Explanation of symbols

  11 Wheel hub bearing, 12, 102 Inner member, 12a, 12b Inner rolling surface, 13 Inner ring member, 14 Wheel hub, 15, 103 Outer member, 15a, 15b Outer rolling surface, 16 balls, 104 rollers, 17 Cage, 18, 21a, 31a, 32a, 35d Water repellent layer, 21, 31, 105 Sealing member, 22, 33 Elastic seal, 22a, 22b, 22c Lip part, 33a Axial lip, 33b, 33c Radial lip, 23 , 34 Core bar, 32, 105a Seal member, 35, 105b Slinger, 34a, 35a Cylindrical portion, 34b Inward flange portion, 35b Outward flange portion, 35c Magnetized encoder, 101 Rolling bearing.

Claims (5)

An outer member having a double row outer raceway formed on the inner periphery;
An inner member in which an inner rolling surface of a double row facing the outer rolling surface of the double row is formed on the outer periphery;
A double row rolling element housed between the rolling surfaces of the inner member and the outer member via a cage so as to roll freely;
In a wheel bearing device comprising: a sealing member attached to an opening of an annular space formed between the outer member and the inner member;
A bearing device for a wheel, wherein a water repellent layer is provided at a contact portion of the inner member and the outer member with the sealing member.   The wheel bearing device according to claim 1, wherein a water repellent treatment layer is provided on the entire surface of the sealing member.   The wheel bearing device according to claim 1 or 2, wherein a water-repellent treatment layer is provided on exposed portions of the inner member and the outer member.   The wheel bearing device according to claim 1, wherein the water-repellent layer is a fluorine coating.   The wheel bearing device according to claim 1, wherein the water repellent treatment layer is formed of a material containing a hydrophobic silica compound.

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