JP2008128381A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device having a longer life while preventing the entry of mud water into a bearing. <P>SOLUTION: A double row rolling bearing 2 comprises: an outer ring 4 having double row outside rolling surfaces 4a, 4a formed on the inner periphery; a pair of inner rings 5, 5 having double row inside rolling surfaces 5a, 5a formed on the outer periphery and opposed to the double row outside rolling surfaces; and double row rolling elements (balls) 6, 6 rollingly stored between both rolling surfaces. The outer ring 4 and the inner ring 5 are each formed of a stainless steel flat or pipe material having rust preventing capability, as a raw material, with pressing work. Seals 31, 34 are mounted in opening portions on the inner side and on the outer side formed between cylindrical portions 4c, 4c of the outer ring 4 and collar portions 5d, 5d of the inner rings 5, 5, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like.

  2. Description of the Related Art 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 rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used.

  The bearing includes an inner member having a rolling surface formed on the outer side, an outer member having a rolling surface formed on the inner side, and a rolling element that is arranged to freely roll between both rolling surfaces. Become. Conventionally, the inner member and the outer member are formed by turning or the like, but a method of press-molding the inner member and the outer member from a plate material or a pipe material has been devised with the aim of reducing the weight and cost. .

Patent Document 1 and Patent Document 2 show examples in which the inner member and the outer member are formed of a plate material or a pipe material. In Patent Document 1, the inner member is composed of a pair of inner rings, and a ball is rotatably disposed between the inner ring and the outer member. In this example, a preload is applied by placing a weight on the inner ring from the axial direction. Further, in Patent Document 2, double rows of balls are arranged in an annular shape at the annular curved portion of the inner member, and an annular recess is formed in the outer member by a hydraulic press roller. A preload is applied between the inner member, the outer member, and the ball during the press forming.
Japanese Utility Model Publication No. 6-1835 Japanese Patent Laid-Open No. 1-210612

  However, when muddy water or the like is applied to the wheel bearing device shown in Patent Document 1 or Patent Document 2, the muddy water or the like enters the bearing from the gap between the inner member and the outer member, which adversely affects the life of the bearing. give. Also, the lubricating grease sealed inside the bearing may leak and adversely affect the life of the bearing.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a long-life wheel bearing device that prevents muddy water and the like from entering the bearing.

  In order to achieve such an object, the present invention includes an outer ring made of a press plate having a double-row outer rolling surface formed on the inner periphery, and a double-row inner rolling facing the outer surface of the double row on the outer periphery. A cylindrical portion that includes a pair of inner rings made of a press plate on which running surfaces are formed, and a double-row rolling element that is rotatably accommodated between the both rolling surfaces, and that extends outward in the axial direction on the outer ring. An inner side and an outer side opening formed by a cylindrical portion of the outer ring and a flange portion of the inner ring, and a flange portion extending radially outward is formed at an axially outer end portion of the inner ring. A seal is attached to each of the parts, and a hub ring fitted into the inner ring and an outer joint member of a constant velocity universal joint fitted to the hub ring are fixed by fixing means, and the hub ring A configuration is adopted in which a preload is applied to the flange portions of the pair of inner rings by the shoulder portions of the outer joint member and the shoulder portions of the outer joint member.

  As described above, since the seal is attached to the opening of the cylindrical portion of the outer ring and the flange portion of the inner ring, leakage of the lubricating grease enclosed in the bearing and rainwater, dust, etc. enter the bearing from the outside. Therefore, a long-life wheel bearing device can be provided. In addition, since the preload can be applied to the bearing by the shoulder portion of the hub wheel and the shoulder portion of the outer joint member, high bearing performance can be realized and a long-life wheel bearing device can be provided.

  Further, according to the present invention, the seal includes a core metal press-fitted into the inner peripheral surface of the cylindrical portion of the outer ring, and a seal member joined to the core metal and having a plurality of seal lips. The seal lip provided on the outer-side seal can be slidably contacted with the shoulder portion of the hub wheel, and the seal lip provided on the inner-side seal can be slidably contacted with the side surface of the flange portion. Since the seal lip provided on the outer seal is slidably contacted with the shoulder portion of the hub wheel, it is not necessary to prepare another slidable contact surface, and the apparatus can be made compact.

  Further, according to the present invention, the seal includes a core metal press-fitted into the inner peripheral surface of the cylindrical portion of the outer ring, and a seal member joined to the core metal and having a plurality of seal lips. The seal lips provided on the outer side and inner side seals may be slidably contacted with the side surfaces of the flanges. Thereby, since the outer side seal and the inner side seal can be made of the same member, cost reduction can be realized.

  In the present invention, the seal includes a core metal press-fitted into an inner peripheral surface of the cylindrical portion of the outer ring, and a seal member joined to the core metal and having a plurality of seal lips. A plate having a substantially L-shaped cross section is arranged over a part of the outer diameter portion and the side surface of each of the seals, and the seal lips provided on the outer side and inner side seals of the seals are in sliding contact with the side surfaces of the plates, respectively. Can also be done. Thereby, a suitable sliding contact surface with less friction can be ensured.

  In the present invention, the plate may be made of a stainless steel plate. Since it is a stainless steel plate, there is no deterioration in bearing performance due to rust, and the device can have a long service life.

  In the present invention, the clearance between the inner peripheral surface of the cylindrical portion of the outer ring or the inner peripheral surface of the core metal and the outer peripheral surface of the plate may be 1 mm or less. As a result, even if muddy water or foreign matter enters the inside of the seal lip, the clearance is narrow so that it does not enter further inside.

  A wheel bearing device according to the present invention includes a press plate outer ring having a double row outer rolling surface formed on the inner periphery, and a double row inner rolling facing the outer surface of the double row on the outer periphery. A pair of inner rings made of a press plate having a surface formed thereon, and a double row rolling element that is rotatably accommodated between the two rolling surfaces, and a cylindrical portion that extends axially outward in the outer ring. An inner side and an outer side opening formed by a cylindrical portion of the outer ring and a flange portion of the inner ring formed with a flange portion extending radially outward at an axially outer end portion of the inner ring. The hub ring fitted into the inner ring and the outer joint member of the constant velocity universal joint fitted to the hub ring are fixed by a fixing means, and the hub ring of the hub ring is fixed to the hub ring. A preload is applied to the flanges of the pair of inner rings by the shoulder and the shoulder of the outer joint member. And leakage of lubricating grease which is, from outside prevents the rain water or dusts into the bearing from entering, it is possible to provide a bearing device for a high life wheel.

  A pair of press plate outer rings formed with a double row outer rolling surface on the inner periphery and a press plate pair formed with a double row inner rolling surface opposite to the double row outer rolling surface on the outer periphery. An inner ring and a double-row rolling element accommodated between the two rolling surfaces so as to be freely rollable, and a cylindrical portion extending outward in the axial direction is formed on the outer ring. A flange extending radially outward is formed at the end of the inner ring, and a seal is attached to each of the inner and outer openings formed by the cylindrical portion of the outer ring and the flange of the inner ring, A hub ring fitted into the inner ring and an outer joint member of a constant velocity universal joint fitted to the hub ring are fixed by fixing means, and a shoulder portion of the hub ring and a shoulder portion of the outer joint member A preload is applied to the buttocks of the pair of inner rings.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side of the drawing in FIG. 1), and the side closer to the center is referred to as the inner side (right side of the drawing in FIG. 1).

  In the wheel bearing device according to the present invention, the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 are detachably unitized.

  As shown in FIG. 2, the double-row rolling bearing 2 is opposed to the outer ring 4 in which double-row outer rolling surfaces 4a and 4a are formed on the inner circumference, and the double-row outer rolling surface on the outer circumference. It is composed of a pair of inner rings 5 and 5 in which double row inner rolling surfaces 5a and 5a are formed, and double row rolling elements (balls) 6 and 6 accommodated so as to be freely rollable between both rolling surfaces. ing. The outer ring 4 and the inner ring 5 are formed by press working using a flat plate or pipe material such as case-hardened steel, bearing steel, or stainless steel having rust prevention ability.

  The outer peripheral surface of the outer ring 4 has a substantially cylindrical shape, and is press-fitted and fixed to a knuckle 7 arranged at the top and bottom of the figure. A protrusion 7 a is formed on the inner side of the knuckle 7 in the radial direction. The protrusion 7 a abuts against the side surface of the outer ring 4 so that the outer ring 4 is aligned. The cross-sectional height of the protrusion 7 a is substantially equal to the height of the side surface of the outer ring 4.

  An annular convex portion 4b that protrudes radially inward is formed by pressing or rolling at a substantially central portion of the inner peripheral surface of the outer ring 4. The inner peripheral surface of the annular convex portion 4b is a flat surface extending in the axial direction. Double row outer rolling surfaces 4a, 4a having a substantially arc-shaped cross section are formed on the inner peripheral surfaces on both sides of the annular convex portion 4b. Cylindrical portions 4c and 4c extending in the axial direction are formed on both sides of the outer rolling surfaces 4a and 4a. The thickness of the cylindrical portions 4c and 4c is thinner than the thickness of the outer rolling surfaces 4a and 4a. At least both outer rolling surfaces 4a and 4a of the outer ring 4 are subjected to a surface hardening process such as submerged or carburized and quenched.

  The inner rings 5 and 5 are arranged so that the same shape is abutted symmetrically. There is no gap in the butting portion 5b. The inner rings 5 and 5 are formed with cylindrical portions 5c and 5c extending in the axial direction from the butted portion 5b. Inner rolling surfaces 5a and 5a having a substantially arc-shaped cross section are formed on the outer peripheral surfaces on the sides of the cylindrical portions 5c and 5c, respectively. On both sides of the inner rolling surfaces 5a and 5a, flanges 5d and 5d extending outward in the radial direction are formed. At least both inner rolling surfaces 5a and 5a of the inner rings 5 and 5 are subjected to a surface hardening process such as submerged or carburized and quenched.

  Between the outer rolling surfaces 4a, 4a and the inner rolling surfaces 5a, 5a, double-row rolling elements 6, 6 are accommodated, respectively. The rolling elements 6 and 6 are held by the cages 8 and 8 so as to freely roll. In this example, a ball is used as the rolling element 6. However, a double row tapered roller bearing using a tapered roller as the rolling element 6 may be used.

  Seals 31 and 34 are attached to the inner and outer openings formed between the cylindrical portions 4c and 4c of the outer ring 4 and the flange portions 5d and 5d of the inner rings 5 and 5, respectively. The seals 31 and 34 include core bars 32 and 35 having a substantially L-shaped cross section, and seal members 33 and 36 joined to the core bars 32 and 35. The core bars 32 and 35 are formed by press working from a plate material or a pipe material having rust prevention ability. The outer peripheral surfaces of the core bars 32 and 35 are press-fitted and fixed to the inner peripheral surfaces of the cylindrical portions 4 c and 4 c of the outer ring 4. The seal members 33 and 36 include joint portions 33a and 36a joined to the core bars 32 and 35, two seal lips 33b and 36b, and seal lips 33c and 36c. The end portions of the seal lip 33b and the seal lip 33c are in sliding contact with the side surface of the flange portion 5d of the inner ring 5 on the inner side. The ends of the seal lip 36b and the seal lip 36c are in sliding contact with the shoulder 1e of the hub wheel 1. The seal lips 33b and 36b and the seal lips 33c and 36c can suitably prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater, dust and the like into the bearing from the outside.

  On the inner side of the hub wheel 1, a small-diameter step portion 1a having a cylindrical shape extending in the axial direction is formed. Inner rings 5 and 5 are fitted to the outer peripheral surface of the small diameter step portion 1a. The outer peripheral surface of the small diameter step portion 1a and the cylindrical portions 5c and 5c of the inner rings 5 and 5 are fitted with no gap.

  A wheel mounting flange 1 b for mounting a wheel (not shown) is formed at the outer end of the hub wheel 1. Hub bolt insertion holes 1c are equally formed in the circumferential direction of the wheel mounting flange 1b. A hub bolt (not shown) for fixing the wheel is planted in the hub bolt insertion hole 1c. On the inner periphery of the hub wheel 1, a serration (or spline) 1d for torque transmission is formed. The shoulder 1e of the hub wheel 1 is in contact with the side surface of the flange portion 5d of the inner ring 5 on the outer side. The hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the outer peripheral surface of the small-diameter stepped portion 1a is hardened by induction hardening to a surface hardness of 58 to 64 HRC. Has been.

  The constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring 15, a cage 16 and a torque transmission ball 17. The outer joint member 14 includes a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom of the mouth portion 18, a shaft portion 20 that extends in the axial direction from the shoulder portion 19, and a male screw portion 21 that further extends in the axial direction. And having. Curved track grooves 18 a and 15 a extending in the axial direction are formed on the inner periphery of the mouse portion 18 and the outer periphery of the joint inner ring 15, respectively. A torque transmission serration (or spline) 20 a is formed on the outer periphery of the shaft portion 20 of the outer joint member 14. The shoulder portion 19 of the outer joint member 14 is in contact with the side surface of the flange portion 5d of the inner ring 5 on the inner side. The outer joint member 14 is made of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and the outer circumferential surface extending from the shoulder portion 19 to the shaft portion 20 including the track grooves 18a and 15a is induction-hardened. The surface hardness is set in the range of 58 to 64 HRC.

  The shaft portion 20 of the outer joint member 14 is fitted to the inner periphery of the hub wheel 1. Torque is transmitted when the serration 20 a of the shaft portion 20 of the outer joint member 14 meshes with the serration 1 d of the hub wheel 1. The outer joint member 14 fitted in the hub wheel 1 is fixed with a constant torque by screwing a spindle nut 22 into the male thread portion 21 thereof. At this time, the shoulder portion 1e of the hub wheel 1 contacts the side surface of the flange portion 5d of the inner ring 5 on the outer side, and the shoulder portion 19 of the outer joint member 14 contacts the side surface of the flange portion 5d of the inner ring 5 on the inner side. Therefore, when the spindle nut 22 is tightened, the inner rings 5 and 5 are pressurized from both sides, and a preload is applied to the bearing 2.

Next, another embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a longitudinal sectional view showing a main part of a second embodiment of the wheel bearing device according to the present invention. Note that the same components and parts as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this example, seals 31 and 41 are attached to the inner side and outer side openings formed between the cylindrical portions 4c and 4c of the outer ring 4 and the flange portions 5d and 5d of the inner rings 5 and 5, respectively. Yes. The inner seal 31 is the same as in the first embodiment. The seal 41 includes a core bar 42 having a substantially L-shaped cross section and a seal member 43 joined to the core bar 42. The cored bar 42 is formed by press working from a plate material or pipe material having rust prevention ability. The outer peripheral surface of the core metal 42 is press-fitted and fixed to the inner peripheral surface of the cylindrical portion 4 c of the outer ring 4. The seal member 43 includes a joint portion 43a joined to the core metal 42, two seal lips 43b, and a seal lip 43c. The end portions of the seal lip 43b and the seal lip 43c are in sliding contact with the side surface of the flange portion 5d of the inner ring 5 on the outer side. With the seal lip 43b and the seal lip 43c, it is possible to suitably prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rain water, dust and the like into the bearing from the outside.

Next, another embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 4 is a longitudinal sectional view showing a main part of a third embodiment of the wheel bearing device according to the present invention. Note that the same components and parts as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  Seals 31 and 41 are attached to the inner side and outer side openings formed between the cylindrical portions 4c and 4c of the outer ring 4 and the flanges 5d and 5d of the inner rings 5 and 5, respectively. In this example, plates 51 and 52 having a substantially L-shaped cross section are disposed over the outer diameter portion of the flange portions 5d and 5d of the inner and outer inner rings 5 and 5 and part of the side surfaces. The plates 51 and 52 include cylindrical portions 51a and 52a extending in a cylindrical shape in the axial direction, and flange portions 51b and 52b extending radially inward. The cylindrical portions 51a and 52a are press-fitted and fixed to the outer diameter portions of the flange portions 5d and 5d. The flange portions 51b and 52b are in contact with the side surfaces of the flange portions 5d and 5d. The plates 51 and 52 are formed by pressing a stainless steel plate. Further, the clearance between the inner peripheral surface of the cylindrical portion 4c of the outer ring 4 or the inner peripheral surfaces of the cores 32 and 42 and the outer peripheral surfaces of the cylindrical portions 51a and 52a of the plates 51 and 52 is 1 mm or less, more preferably 0. 3 mm or more and 0.8 mm or less. Seal lips 33b and 33c are in sliding contact with the inner side surface of the flange portion 51b. On the other hand, seal lips 43b and 43c are in sliding contact with the outer side surface of the flange portion 52b.

  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 various modifications can be made without departing from the scope of the present invention. Of course, 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 and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a so-called second-generation wheel bearing device that rotatably supports a wheel of an automobile or the like.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows the principal part of 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the principal part of 3rd Embodiment of the wheel bearing apparatus which concerns on this invention.

Explanation of symbols

1 ... hub wheel 1a ... small diameter step 1b ... Wheel mounting flange 1c ... Hub bolt insertion hole 1d ... ··· Serration 1e ··············································································· ··············· Constant velocity universal joint 4・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 4b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Annular convex part 4c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Cylindrical part 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 5a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 5・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Matching part 5c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cylindrical part 5d ・ ・ ・ ・ ・ ・ ・ ・ ・ ・······························································ knuckle 7a ······································· 8 ··········· Outer joint member 15 ····························· Joint inner rings 15a, 18a ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cage 17 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 18・ ・ ・ ・ ・ ・ ・ Mouse part 19 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ Shaft 20a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Serration 21 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Male thread 22 ··························································································· Seal 32, 35, 42 33, 36, 43 ·············· Seal members 33a, 36a, 43a ········· Junctions 33b, 33c, 36b, 36c, 43b, 43c ···

Claims (6)

A pair of press plate outer rings formed with a double row outer rolling surface on the inner periphery and a press plate pair formed with a double row inner rolling surface facing the outer surface of the double row on the outer periphery. An inner ring and a double row rolling element accommodated so as to be freely rollable between the both rolling surfaces,
A cylindrical portion extending outward in the axial direction is formed on the outer ring, and a flange portion extending radially outward is formed at an axially outer end portion of the inner ring, and the cylindrical portion of the outer ring and the flange portion of the inner ring Seals are attached to the inner and outer openings formed in
A hub ring fitted into the inner ring and an outer joint member of a constant velocity universal joint fitted to the hub ring are fixed by fixing means, and a shoulder portion of the hub ring and a shoulder of the outer joint member The wheel bearing device is characterized in that a preload is applied to the flanges of the pair of inner rings.   The seal includes a core metal press-fitted into the inner peripheral surface of the cylindrical portion of the outer ring, and a seal member joined to the core metal and having a plurality of seal lips. The wheel bearing device according to claim 1, wherein the seal lip provided is slidably contacted with a shoulder portion of the hub wheel, and the seal lip provided on the inner seal is slidably contacted with a side surface of the flange portion.   The seal includes a metal core press-fitted into the inner peripheral surface of the cylindrical portion of the outer ring, and a seal member joined to the metal core and having a plurality of seal lips. The seal includes an outer side and an inner side. The wheel lip device according to claim 1, wherein seal lips provided on the seal of each of the seals are slidably contacted with side surfaces of the flange portion.   The seal includes a core bar press-fitted into the inner peripheral surface of the cylindrical portion of the outer ring, a seal member joined to the core bar and having a plurality of seal lips, and an outer diameter portion and a side surface of the flange portion. 2. A plate having a substantially L-shaped cross section is disposed over a portion of the seal, and seal lips provided on the seal on the outer side and on the inner side of the seal are in sliding contact with the side surfaces of the plate, respectively. Wheel bearing device.   The wheel bearing device according to claim 4, wherein the plate is made of a stainless steel plate.   The wheel bearing device according to claim 4 or 5, wherein a clearance between an inner peripheral surface of the cylindrical portion of the outer ring or an inner peripheral surface of the core metal and an outer peripheral surface of the plate is 1 mm or less.

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