WO2008026317A1

WO2008026317A1 - Bearing device for wheel

Info

Publication number: WO2008026317A1
Application number: PCT/JP2007/000923
Authority: WO
Inventors: Isao Hirai; Takayasu Takubo; Kiyotake Shibata; Syougo Suzuki
Original assignee: Ntn Corporation
Priority date: 2006-08-28
Filing date: 2007-08-28
Publication date: 2008-03-06
Also published as: JP2008051289A

Abstract

[PROBLEMS] A bearing device for a wheel, in which air tightness at a seal fitting section is enhanced to improve sealing performance. [MEANS FOR SOLVING PROBLEMS] The bearing device for a wheel has a seal (8 (9)) installed in an opening of an annular space formed between an outer member (10) and an inner member (1). The seal (8 (9)) is constructed from a core (15 (20)) formed by press forming a steel plate and fitted in the outer member (10) by a metal-to-metal fitting, and a seal member (16 (21)) having a projection (16d (21d)) integrally joined to the core (15 (20)) and covering a portion that is projected and exposed to the outside of the outer peripheral surface of the core (15 (20)). A predetermined hardened layer (13 (14)) is formed by induction hardening from an outer rolling surface (10a) of the outer member (10) to the surface (11 (12)) on which the seal (8 (9)) is fitted. The hardened layer (13 (14)) lies over a circular tube section (15a (20a)) of the core (15 (20)) and stops near an end surface (10c (10d)) of the outer member (10).

Description

Specification

Wheel bearing device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like with respect to a suspension device. More specifically, the present invention improves the airtightness of a fitting portion of a seal attached to the bearing portion, and seals performance. The present invention relates to a bearing device for a wheel that improves the above.

Background art

[0002] Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a double row rolling bearing, and is used for a driving wheel and a driven wheel. There is. For structural reasons, an inner ring rotation method is generally used for driving wheels, and both an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. In addition, the wheel bearing device has a structure called a first generation in which a wheel bearing comprising a double-row anguilla ball bearing is fitted between a knuckle and a hub wheel constituting a suspension device. 2nd generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the side member, 3rd generation structure with one inner raceway formed directly on the outer periphery of the hub wheel, or hub wheel It is roughly classified into the 4th generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the constant velocity universal joint.

[0003] These bearings are fitted with seals to prevent leakage of grease sealed inside the bearings and to prevent rainwater and dust from entering from the outside. In recent years, the maintenance of automobiles has become more maintenance-free, and even longer bearing life has been demanded for wheel bearing devices. In addition, there are many cases in which the bearings are damaged due to intrusion of rainwater or dust into the bearings due to a sealing failure or a decrease in sealing performance. Therefore, the bearing life can be improved by improving the sealing performance of the seal.

[0004] Conventionally, various seals with improved sealing performance have been proposed. A typical example of the seal is shown in Fig. 4 (a). The seal 50 is attached to a housing 51 as two members which are assembled concentrically with each other so as to be relatively rotatable, and a rotary shaft 52 inserted into the housing 51, and is integrally formed with the rotary shaft 52. Accordingly, the annular gap between the rotating sleeve member 53 is sealed.

[0005] The seal 50 includes a metal ring 5 4 having a hollow hole formed by pressing a metal plate material by pressing or the like, and an elastic material in which rubber or the like is fixed to the metal ring 54 by baking or bonding. Members 5 and 5. The elastic member 5 5 has a main lip 5 5 a as a part, and the main lip 5 5 a slidably contacts the outer peripheral surface of the sleeve portion 5 3 b of the sleeve member 5 3, and the housing 5 The annular gap between 1 and the rotating shaft 5 2 is sealed to the sealed fluid side O and the atmosphere side A. Further, a tongue-shaped dust lip 5 5 b is provided continuously with the main lip 5 5 a, extends to the atmosphere side A, and inclines radially outward so that the flange portion 5 3 of the sleeve member 5 3 It is formed so as to be in sliding contact with a, preventing mud from the atmosphere side A from entering the inside.

[0006] In addition, the metal ring 5 4 includes a cylindrical portion 5 4 a extending in the axial direction, and an annular portion 5 4 b bent from the end of the sealed fluid side O of the cylindrical portion 5 4 a to the inner diameter side. The main lip 55a and the dust lip 55b are continuously fixed to the surface on the atmosphere side A of the metal ring 54.

[0007] The gap between the outer peripheral surface of the sleeve member 53 and the inner peripheral surface of the housing 51 is small, and an elastic member 55 is provided on the outer peripheral surface of the cylindrical portion 5 4a of the metal ring 5 4 Therefore, it is difficult to secure a space for this, and the outer peripheral surface of the cylindrical portion 54 a is directly fitted to the inner peripheral surface of the housing 51, and the seal 50 is fixed to the housing 51.

[0008] Here, a taper part 51a is provided at the edge of the opening of the housing 51, and the cylindrical part 54 is further sealed so that the elastic member 55 seals the tapered part 51a. An edge seal portion 55 c as a part of the elastic member 55 is fixed to a predetermined range of the end of the atmosphere side A of a. The edge seal portion 5 5 c is shown enlarged in FIG. However, the edge seal portion 5 5 c has a portion protruding outward from the outer peripheral surface of the cylindrical portion 5 4 a of the metal ring 5 4, and the protruding portion is formed on the housing 5 1. The taper part 5 1 a of the opening is sealed. The shape of the protruding portion is as similar as possible to the shape of the taper portion 51a of the housing 51, and the protruding portion when the seal 50 is attached to the housing 51 is that of the taper portion 51a. It is easy to follow the shape.

[0009] The predetermined range includes a width of the seal 50, a fitting area between the housing 5 1 and the cylindrical portion 5 4a, and a contact area corresponding to the use environment. The cylindrical portion 5 4 a having such a width that 0 does not come out of the housing 51 is set in a range not covered by the elastic member 55.

[0010] In addition, a concave portion 5 4c is provided on the end surface portion of the cylindrical portion 5 4a of the metal ring 54 so that the elastic member 55 can be accurately fixed, and the base of the edge seal portion 5 5c is provided. The end portion protrudes from the outer peripheral surface of the cylindrical portion 54 a so that the seal 50 is not peeled off when being attached to the housing 51.

[001 1] By adopting such a configuration, the taper portion 5 1 a normally provided at the edge of the opening facing the mounting portion of the seal 50 provided in the metal housing 51 is replaced with the seal 5 Since the edge seal portion 55 c of the 0 elastic member 55 is sealed, the leakage of the sealing fluid between the housing 51 and the seal 50 can be prevented. Patent Document 1: Japanese Laid-Open Patent Publication No. 2 0 00 _ 1 9 8 6 5

Disclosure of the invention

Problems to be solved by the invention

[0012] With such a conventional seal 50, it is possible to improve the sealing performance between the seal 50 and the housing 51 to which the seal 50 is mounted. It is mounted with a pressure input that provides a predetermined pull-out strength so that it does not come out due to an increase in the internal pressure of the bearing during operation. In this case, when the metal ring 54 of the seal 50 is press-fitted into the housing 51, the fitting surface of the housing 51 may be scratched in the axial direction.

[0013] Usually, the mating surface is ground to improve hermeticity, and has a predetermined shape. Although it has been finished every time, there is a risk of intrusion of muddy water and grease from this fitting surface due to scratches generated during press fitting. For example, as in the case of this conventional seal 50, even if a part of the elastic member 55 such as rubber is covered up to the end of the metal ring 5 4 as the edge seal portion 5 5 c, the elastic member 5 5 deteriorates and it is difficult to maintain airtightness over a long period of time.

[0014] The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a wheel bearing device in which the airtightness of the seal fitting portion is improved and the sealing performance is improved. .

Means for solving the problem

[0015] In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a plurality of outer rolling surfaces are integrally formed on the inner periphery, and the plurality of columns on the outer periphery. An inner member provided with a double row of inner rolling surfaces facing the outer rolling surface, and accommodated between the rolling surfaces of the inner member and the outer member via a cage. A wheel bearing device comprising: a plurality of rolling element groups formed in a row; and a seal mounted on an opening of an annular space formed between the outer member and the inner member. A steel plate formed by press working, and a metal core that fits between the outer member and the metal, and a seal member that is integrally joined to the metal core, and an outer side of the outer member. A predetermined hardened layer is formed by induction hardening from the rolling surface to the fitting surface of the seal, and this hardened layer is fitted to the core metal. Beyond the section, it is stopped in the vicinity of the end face of the outer member.

[001 6] In this way, in the wheel bearing device including the seal mounted on the opening of the annular space formed between the outer member and the inner member, the seal can press the steel plate. The outer member and the metal are fitted to each other, and the seal member integrally joined to the metal, and from the outer rolling surface of the outer member to the seal fitting surface. As a result, a predetermined hardened layer is formed by induction hardening, and this hardened layer is stopped in the vicinity of the end face of the outer member beyond the fitting part of the core metal. To prevent strength and to prevent the streaks in the axial direction from being attached to the mating surface by press-fitting the cored bar. And stable airtightness can be ensured.

[001 7] Preferably, as in the invention according to claim 2, the counter part of the outer rolling surface is abolished or reduced, and the groove bottom is secured to such an extent that the groove diameter of the outer rolling surface can be easily measured. If a smooth connecting portion is formed between the groove bottom and the fitting surface, the quenching portion can be smoothed, the cracking due to abnormal heating can be prevented, and the range of the hardened layer can be easily controlled. Thus, a desired quenching pattern can be obtained.

[0018] Further, as in the invention according to claim 3, the cored bar has a cylindrical part that is press-fitted into the fitting surface via a predetermined shimiro, and the seal member is formed of the cylindrical part. If the protrusion protrudes outward from the outer peripheral surface and has a protrusion joined so as to cover the exposed portion of the metal core, the protrusion closes the opening of the fitting surface and Airtightness can be further enhanced.

[001 9] Further, as in the invention described in claim 4, if the fitting surface is regulated to a predetermined accuracy by grinding, the airtightness of the seal fitting portion can be enhanced.

[0020] Preferably, as in the invention according to claim 5, if the fitting surface is ground simultaneously with the outer rolling surface by a general-purpose grindstone, the coaxiality of the fitting surface can be obtained. The seal can be further improved in airtightness.

The invention's effect

[0021] A wheel bearing device according to the present invention includes an outer member in which a double-row outer rolling surface is integrally formed on an inner periphery, and a double-row facing the outer rolling surface of the double row on an outer periphery. An inner member provided with an inner rolling surface of the inner member, and a double row rolling element group that is movably accommodated via a cage between the inner member and the outer member. In a wheel bearing device comprising a seal mounted in an opening of an annular space formed between the outer member and the inner member, the seal is formed by pressing a steel plate, The outer member and the metal core are fitted to each other, and the seal member is integrally joined to the metal core, and the outer member rolling from the outer rolling surface of the outer member to the seal fitting surface. Thus, a predetermined hardened layer is formed by induction hardening, and this hardened layer exceeds the fitting portion of the core metal, Since being stopped in the vicinity of the surface, Prevents burning cracks and cracks due to impact loads to ensure strength, and press-fitting the cored bar prevents axial streaks from being attached to the mating surface, ensuring stable airtightness over a long period of time Sex can be secured.

BEST MODE FOR CARRYING OUT THE INVENTION

[0022] An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel for attaching a wheel to one end A hub wheel having an integral mounting flange and formed on the outer periphery thereof with one inner rolling surface facing the double-row outer rolling surface and a small-diameter step portion extending axially from the inner rolling surface; And an inner member comprising an inner ring that is press-fitted into a small-diameter step portion of the hub wheel and has an outer ring formed on the outer periphery thereof that faces the outer row rolling surface of the double row, and the inner member and the outer member. An opening in an annular space formed between the outer member and the inner member, and a double row rolling element group accommodated by the rolling member via a cage between both rolling surfaces of the member. In the wheel bearing device provided with a seal mounted on the steel plate, the seal is formed by pressing a steel plate. A cored bar that fits the outer member and the same metal, and a projecting part that is integrally joined to the cored bar and that protrudes outward from the outer peripheral surface of the cored bar and covers the exposed part. A predetermined hardened layer is formed by high-frequency quenching from the outer rolling surface of the outer member to the fitting surface of the seal, and the hardened layer is a fitting portion of the cored bar. And is stopped near the end face of the outer member.

Example

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is an enlarged view of a main part showing a seal fitting portion on the outer side of FIG. 1, and FIG. ) Is the main part enlarged view showing the seal fitting part on the inner side, FIG. 3 is a modified example of FIG. 2, and (a) is the main part enlarged showing the seal fitting part on the outer side. FIG. 4B is an enlarged view of a main part showing a seal fitting part on the inner side. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing). [0024] This wheel bearing device is for a drive wheel, and is composed of an inner member 1 and an outer member 10 and a double row rolling element (pole) 7 that is housed so as to roll between the members 1 and 10. , 7 groups, and a configuration called third generation. The inner member 1 includes a hub ring 2 and an inner ring 3 press-fitted into the hub ring 2 through a predetermined shim opening.

[0025] The hub wheel 2 integrally has a wheel mounting flange 4 for mounting a wheel at one end, and one (outer side) inner rolling surface 2a and an inner rolling surface 2a on the outer periphery. A cylindrical small diameter step 2b extending in the axial direction is formed, and a torque transmission selection (or spline) 2c is formed on the inner periphery. Hub ports 5 are also planted at the circumferentially equidistant positions of the wheel mounting flanges 4. Further, the inner ring 3 is formed with the other (inner one side) inner rolling surface 3 a on the outer periphery.

[0026] The hub wheel 2 is formed of medium and high carbon steel containing carbon 0.4 to 0.80 wt% such as S 53 C, and includes an inner rolling surface 2a and an outer seal 8 described later. The surface is hardened in the range of 58 to 64 HRC by induction hardening from the base 4a of the wheel mounting flange 4 to the small-diameter step portion 2b, which is the seal land portion. On the other hand, the inner ring 3 and the rolling element 7 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core by quenching.

[0027] The outer member 10 is integrally provided with a vehicle body mounting flange 1 Ob for being attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and on the inner periphery of the inner member 1 on the inner periphery. Double row outer rolling surfaces 10 a and 10 a facing the rolling surfaces 2 a and 3 a are integrally formed. Between these rolling surfaces 10 a, 2 a and 10 a, 3 a, double row rolling elements 7, 7 are accommodated in a freely rolling manner via a cage 6. This outer member 10 is formed of medium and high carbon steel containing carbon 0.40 to 0.80 wt% such as S 53 C, double row outer rolling surface 1 O a, 10 a and seal Predetermined hardened layers 1 3 and 14 in the range of 5 8 to 6 4 HRC are formed on the surfaces of the fitting surfaces 11 and 12 on which 8 and 9 are mounted by induction hardening.

[0028] Seals 8 and 9 are attached to both ends of the outer member 10 so that the outer member 10 and the inner member are inward. The opening of the annular space formed between the member 1 and the member 1 is sealed. The seals 8 and 9 prevent the lubricating grease sealed inside the bearing from leaking to the outside and preventing rainwater and dust from entering the bearing from the outside. Here, a double-row anguillare ball bearing using a pole for the rolling element 7 is illustrated, but the present invention is not limited to this, and a double-row tapered roller bearing using a tapered roller for the rolling element 7 may be used. .

[0029] Here, the seal 8 on the outer side of the seals 8 and 9 is integrated with the core metal 15 and the core metal 15 by vulcanization bonding or the like, as shown in an enlarged view in FIG. 2 (a). And a seal member 16 joined to the. The metal core 15 can be pressed from austenitic stainless steel (JIS standard SUS 304 series, etc.) or cold-rolled cold-rolled steel (JIS standard SPCC, etc.). The cylindrical portion 15 a having a substantially U-shaped cross section and press-fitted into the fitting surface 11 of the outer member 10 through a predetermined shim opening, and the radial direction from the cylindrical portion 15 a It consists of an inner part 15b extending inward. In this way, since the core 15 is formed of a steel plate having a flaw proofing capability, the durability of the seal 8 can be improved by preventing flaming over a long period of time.

[0030] The seal member 16 is made of an elastic member such as nitrile rubber, and has a pair of side lips 16a, 16b and a radial lip 16c that are in sliding contact with the base 4a having a circular cross section. have. The side lips 16a and 16b are formed so as to be inclined radially outward toward the tip, and the tip is in sliding contact with the base 4a with a predetermined squeeze mouth, and rainwater, dust, etc. are externally applied. Prevents intrusion into the bearing. In addition, the radial lip 16 c is formed with its tip inclined toward the inner side of the bearing to prevent the grease enclosed in the bearing from leaking to the outside.

[0031] It should be noted that the sealing member 16 protrudes outward from the outer peripheral surface of the cylindrical portion 15a of the core bar 15 and is a protruding portion 16d joined so as to cover the exposed portion of the core bar 15 have. This projecting portion 16 6d force closes the opening of the fitting surface 11. Thereby, the airtightness of the fitting part of the seal 8 can be enhanced.

[0032] Here, in the present embodiment, as described above, the outer-side outer rolling surface 1 0 A predetermined hardened layer 13 is formed from a to the fitting surface 11 of the seal 8 through the counter portion 17. This hardened layer 13 is stopped in the vicinity of the outer end face 10 c of the outer member 10 beyond the cylindrical portion 15 a of the core bar 15. Then, the outer surface 10 a and the outer member 10 are fitted to each other and the outer surface 10 a is ground simultaneously with the outer surface 10 a by the fitting surface 11 of the outer member 10 to be fitted between the metal and the metal, and is regulated to a predetermined accuracy. This prevents cracking due to burning cracks and impact loads, ensures strength, and prevents press-fitting of the cored bar 15 from causing axial streaks on the fitting surface 11. Simultaneous grinding provides a concentricity on the mating surface 11 and ensures stable airtightness over a long period of time. Further, even if the protruding portion 16 d of the sealing member 16 is deteriorated over time, the airtightness is not impaired. Here, the counter unit 17 is projected by a predetermined amount from the groove bottom of the outer rolling surface 10 a so that the rolling element 7 fitted to the outer rolling surface 10 a does not fall off when the bearing is assembled. Refers to the convex part formed.

[0033] On the other hand, the seal 9 on the inner side is composed of a slinger 18 and an annular seal plate 19 arranged to face each other, as shown in an enlarged view in FIG. 2 (b). Slinger 18 can be produced by pressing from a ferritic stainless steel plate (JIS standard SUS 4 30 system, etc.), or a cold-rolled steel plate (JIS standard SPCC system, etc.) that has been subjected to anti-corrosion treatment. The cross section is formed in a substantially L-shape, and includes a cylindrical portion 18 a that is press-fitted into the inner ring 3, and a standing plate portion 18 b that extends radially outward from the cylindrical portion 18 a. As a result, the slinger 1 8 can be prevented from generating and the durability of the seal 9 can be improved.

The seal plate 19 is formed in a substantially L-shaped cross section and is attached to the outer member 10. The seal plate 19 includes a metal core 20 and a seal member 21 integrally joined to the metal core 20 by vulcanization adhesion or the like. The core bar 20 can be pressed from austenitic stainless steel (JIS standard SUS 304 series, etc.) or cold-rolled cold-rolled steel (JIS standard SPCC, etc.). A cylindrical portion 20 a that is press-fitted into the fitting surface 12 of the outer member 10 through a predetermined shim opening, and a vertical plate portion that extends radially inward from the cylindrical portion 20 a. 2 0 and b The

[0035] The seal member 21 is made of an elastic member such as nitrile rubber. The side lip 2 1a is in sliding contact with the standing plate portion 18b of the slinger 18 and the radial lip 2 1b is in sliding contact with the cylindrical portion 18a. 2 1 c. The side lip 21a is formed so as to be inclined to the outer diameter side from the vertical plate portion 20b of the metal core 20. The tip is slidably contacted with the vertical plate portion 18b of the slinger 18 with a predetermined shim opening. It prevents rainwater and dust from entering the bearing from the outside. The bifurcated radial lip 2 1 b, 2 1 c is in sliding contact with the cylindrical portion 18 a of the slinger 18 with a predetermined squeegee opening and passes through the side lip 2 1 a. Intrusion of rainwater, dust, etc., and leakage of grease sealed inside the bearing are prevented.

[0036] Further, the seal member 21 is joined so as to wrap around the outer surface of the end portion of the cylindrical portion 20a of the core 20 and protrude outward from the outer peripheral surface and cover the exposed portion of the core 20 It has a protruding part 21 1 d. This projecting portion 21 d is brought into close contact with the opening of the fitting surface 12, thereby improving the airtightness. Furthermore, a labyrinth seal is formed by the outer edge of the standing plate portion 18 b of the slinger 18 and the core bar 20 facing each other through a slight radial clearance, and rainwater, dust, etc. are directly applied to the side lip 21 from the outside. Prevents falling on a and improves sealing performance.

[0037] Here, a predetermined hardened layer 14 is formed from the outer rolling surface 10a on the inner side to the fitting surface 12 of the seal 9 via the counter portion 22. . This hardened layer 14 is stopped in the vicinity of the end face 10 d on the inner side of the outer member 10, exceeding the cylindrical portion 20 a of the core bar 20, similarly to the hardened layer 13 on the outer side described above. It has been. Then, the fitting surface 12 of the outer member 10 for fitting the metal core 20 and the metal is simultaneously ground with the outer rolling surface 10 a by a general-purpose grindstone and is regulated to a predetermined accuracy. This ensures strength by preventing cracking due to fire cracking and impact load, and also prevents axial streaks from being attached to the mating surface 12 2 by press-fitting the core bar 20 while fitting. The coaxiality of surface 12 can be obtained, and stable airtightness can be secured over a long period of time.

[0038] Here, when forming the hardened layers 1 3 and 1 4 by induction hardening, As shown in Fig. 3, these force counters are used to prevent abnormal heat from concentrating on the counter parts 1 7 and 2 2 of the outer member 10 where the gear protrudes and causing abnormal heating. 1 7 and 2 2 may be abolished or formed smaller. It should be noted that the same parts, the same parts, or the parts having the same functions as those in the embodiment described above are denoted by the same reference numerals and detailed description thereof is omitted.

As shown in FIG. 3 (a), the outer end of the outer member 10 0 ′ has a groove bottom secured to such an extent that the groove diameter of the outer rolling surface 10 a can be easily measured. A fitting surface 11 is formed from the groove bottom through a cylindrical connecting portion 23. As shown in FIG. 3 (b), as in (a), the end on the inner side of the outer member 10 'is also connected to the fitting surface 12 from the groove diameter of the outer rolling surface 10a. A smooth connecting portion 2 4 inclined toward is formed. This makes it possible to smooth the quenching site and prevent abnormal heating, and to easily control the range of the hardened layers 13 and 14 and obtain a desired quenching pattern.

[0040] The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example and within the scope not departing from the gist of the present invention. Of course, the present invention can be implemented in various forms, and the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims, Includes all changes.

Industrial applicability

[0041] The wheel bearing device according to the present invention can be applied to the first to fourth generation wheel bearing devices provided with a seal that fits the outer member and the metal.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention.

FIG. 2 (a) is an enlarged view of the main part showing the outer side seal fitting portion of FIG.

(b) is an enlarged view of the main part showing the seal fitting part on the inner side as in the above.

[FIG. 3] (a) is an enlarged view of a main part showing a modification of FIG. 2 (a). (B) is an enlarged view of the main part showing a modification of FIG. 2 (b). FIG. 4 (a) is a longitudinal sectional view showing a seal of a conventional wheel bearing device. (B) is an enlarged view of the main part of (a).

Explanation of symbols

1--■ ■ ■ Inner material

2 ■ ■ ■ ■ ■ Hub wheel

2 a, 3 a ■ ■ ■ Inside rolling surface

2 b ■ ■ ■ ■ Small diameter step

2 c ■ ■ ■ ■ Selection

3 ■ ■ ■ ■ ■ ¾ wheel

4 ■ ■ ■ ■ ■ Wheel mounting flange

4 a ■ • · ■ Base

5 ■ ■ ■ ■ ■ Hubport

6 ■ ■ ■ ■ ■ Cage

7 ■ ■ ■ ■ ■ Rolling elements

8 ■ ■ ■ ■ ■ Outer seal

9 ■ ■ ■ ■ ■ Inner seal

1 0, 1 0 '• · ■ Outer member

1 0 a ■ ■ ■ Outer rolling surface

1 0 b ■ ■ ■ Body mounting flange

1 0 c ■ ■ ■ Outer end face of outer member

1 0 d ■ ■ ■ Outer member inner end face

1 1, 1 2

1 3, 1 4 ■ ■ Hardened layer

1 5, 20 ■ ■ ■ Core

1 5 a, 1 8 a, 20 a-■ ■ ■ ■ ■ Cylindrical part

1 5 b ■ ■ ■ Inside

1 6, 2 1 ■ ■ ■ Sealing material

1 6 a, 1 6 b, 2 1 a-■ ■ ■ ■ ■ Side lip Radial lip Protruding part Counter part Slinger Standing plate part Seal plate Connecting part Seal Housing Taper part Rotating shaft Sleeve member Flange part Sleeve part Metal ring Cylindrical part Circular part Recessed part

Elastic member Main lip Dustrip Edge seal part Atmosphere side Sealed fluid side

Claims

The scope of the claims

[1] An outer member in which a double row outer rolling surface is integrally formed on the inner periphery,

An inner member provided on the outer periphery with a double-row inner rolling surface facing the double-row outer rolling surface;

A double row rolling element group accommodated in a freely rolling manner via a cage between both rolling surfaces of the inner member and the outer member;

In a wheel bearing device comprising a seal attached to an opening of an annular space formed between the outer member and the inner member,

The seal is formed by pressing a steel plate, and includes a core bar that fits between the outer member and the metal, and a seal member integrally joined to the core bar.

A predetermined hardened layer is formed by induction quenching from the outer rolling surface of the outer member to the fitting surface of the seal, and the hardened layer exceeds the fitting portion of the core metal, and the outer member A wheel bearing device characterized by being stopped near the end face of the wheel.

[2] The counter part of the outer rolling surface is abolished or reduced, and a groove bottom is secured to the extent that the groove diameter of the outer rolling surface can be easily measured, and sliding between the groove bottom and the fitting surface. The wheel bearing device according to claim 1, wherein a simple connecting portion is formed.

[3] The core metal has a cylindrical portion that is press-fitted into the fitting surface through a predetermined shim opening, and the seal member protrudes outside the outer peripheral surface of the cylindrical portion, The wheel bearing device according to claim 1, further comprising a protruding portion joined so as to cover the exposed portion of gold.

4. The wheel bearing device according to any one of claims 1 to 3, wherein the fitting surface is regulated to a predetermined accuracy by grinding.

5. The wheel bearing device according to claim 4, wherein the fitting surface is ground simultaneously with the outer rolling surface by a general-purpose grindstone.