JP2007001341A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel attempting to lighten a hub wheel and to improve corrosion prevention of pilot parts. <P>SOLUTION: This bearing device for the wheel is provided with the brake pilot part 11 and the wheel pilot part 12 extending to the outboard side from a wheel mounting flange 4 and guiding a brake rotor and the wheel, this wheel pilot part 12 is made into a split shape separated in the circumferential direction, a cylindrical fitting surface 14 is formed on an inner peripheral surface of the brake pilot part 11, a cap 15 formed by stamping a steel plate having corrosion resistance is installed on this fitting surface 14, the cap 15 is constituted of a cylinder part 15a internally fitted on the fitting surface 14, a polymerized part 15b extending outward in the diametrical direction from it and a bottom part 15c continued to it and the polymerized part 15b is press-fitted in the cap 15 until it collides against an end surface of the wheel pilot part 12 and blocks an opening part on the outboard side of the hub wheel 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention 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, and more particularly to a wheel bearing device that reduces the weight of a hub wheel and improves rust prevention of a pilot part. It is.

  A wheel bearing device that rotatably supports a wheel with respect to a suspension device of an automobile has been made lighter and more compact for improving fuel efficiency, not to mention cost reduction. These wheel bearing devices are constituted by unitizing a hub wheel and a double row rolling bearing, and as a typical example, both the inner member and the outer member have a flange integrally, For a wheel referred to as a third generation, in which one inner rolling surface of the rolling bearing is formed directly on the hub wheel and the other inner rolling surface is formed on a separate inner ring press-fitted into the hub wheel. Bearing devices are known.

  FIG. 6 shows a third-generation wheel bearing device on the drive wheel side, which includes an outer member 51, an inner member 54 including a hub wheel 52 and an inner ring 53 press-fitted into the hub wheel 52. And double-row rolling elements 55 and 55 accommodated between the two members. The hub wheel 52 integrally has a wheel mounting flange 56 for mounting a wheel (not shown) at one end thereof, an inner rolling surface 52a on the outer periphery, and a small diameter extending in the axial direction from the inner rolling surface 52a. A stepped portion 52b is formed. Further, hub bolts 57 for fixing the wheels are implanted in the circumferentially equidistant positions of the wheel mounting flanges 56. An inner ring 53 having an inner rolling surface 53a formed on the outer periphery is press-fitted into the small-diameter step portion 52b of the hub wheel 52, and the end portion of the small-diameter step portion 52b of the hub wheel 52 is plastically deformed outward in the radial direction. The caulking portion 52c formed in this manner prevents the inner ring 53 from coming off in the axial direction with respect to the hub wheel 52.

  The outer member 51 integrally has a vehicle body mounting flange 51b on the outer periphery, and double row outer rolling surfaces 51a and 51a are formed on the inner periphery. And between the inner side rolling surfaces 52a and 53a which oppose this double row outer side rolling surfaces 51a and 51a, the double row rolling elements 55 and 55 are accommodated so that rolling is possible.

  Here, on the side surface of the hub wheel 52 on the outboard side, a brake pilot portion 58 and a wheel pilot portion 59 serving as a guide portion when a brake rotor (not shown) and wheels are mounted are projected. The wheel pilot portion 59 is covered with a cap 60 made of a metal that hardly corrodes, such as a stainless steel plate. The cap 60 has a circular shape with a substantially U-shaped cross section, and integrally includes a top plate portion 60a and a cylindrical portion 60b, and an opening 61 is formed in the top plate portion 60a. The cylindrical portion 60 b of the cap 60 is press-fitted into the outer periphery of the wheel pilot portion 59, and the cap 60 is fixed to the wheel pilot portion 59.

  As described above, since the cap 60 covers the outer peripheral portion of the wheel pilot portion 59, rusting of the outer peripheral portion can be prevented, and adhesion between the wheel and the hub wheel 52 can be prevented. Moreover, since the opening part 61 is provided in the cap 60, even if the cap 60 is attached, it becomes possible to tighten and remove the hub wheel 52 and the axle nut (not shown) (Patent Document). 1).

  The hub wheel 52 includes a brake pilot portion 58 and a wheel pilot portion 59 that are continuous over the entire circumference, and there is room for further weight reduction. That is, the brake pilot portion 58 is a cylindrical portion that protrudes to the side surface on the outboard side of the hub wheel 52, and the wheel pilot portion 59 is a portion that further protrudes with a slightly smaller diameter from the brake pilot portion 58. Here, the applicant has obtained the wheel bearing device shown in FIG. 7 that is further reduced in weight by dividing the cylindrical portion serving as the wheel pilot portion 59 into a plurality of projecting pieces separated in the circumferential direction. Already proposed.

  This wheel bearing device is for a driven wheel and has an outer member 70 integrally formed with a vehicle body mounting flange 70b on the outer periphery and double row outer rolling surfaces 70a, 70a formed on the inner periphery, A wheel mounting flange 71 is integrally formed at the end, one inner rolling surface 72a facing the outer rolling surfaces 70a, 70a of the double row on the outer periphery, and an axis extending in the axial direction from the inner rolling surface 72a A hub wheel 72 having a small-diameter stepped portion 72b formed therein, and the other inner rolling surface 73a that is press-fitted into the small-diameter stepped portion 72b of the hub wheel 72 and faces the double-row outer rolling surface 70a on the outer periphery. An inner member 74 composed of the formed inner ring 73 and double-row rolling elements 75 and 75 accommodated between both facing rolling surfaces are provided. The inner ring 73 is fixed to the hub wheel 72 by a caulking portion 72c formed by plastically deforming an end portion of the small-diameter stepped portion 72b of the hub wheel 72 radially outward.

  Seals 76 and 77 are attached to the opening of the annular space formed by the outer member 70 and the inner member 74, and the grease sealed inside the bearing flows out to the outside, and rainwater, dust, etc. from the outside Is prevented from entering the bearing.

  Hub bolts 71a are planted at the circumferentially equidistant positions of the wheel mounting flanges 71 in the hub wheel 72, and the brake rotor 78 and the wheels 79 are sequentially stacked on the side surface of the wheel mounting flange on the outboard side. It is done.

  The hub wheel 72 extends to the outboard side from the wheel mounting flange 71, and is provided with a brake pilot portion 80 that guides the inner diameter surface of the brake rotor 78. Further, a wheel pilot portion 81 that further extends from the brake pilot portion 80 and guides the inner surface of the wheel 79 is provided. The brake pilot portion 80 is formed continuously around the entire circumference as a cylindrical protruding portion concentric with the hub wheel 72. Further, the wheel pilot portion 81 has a slightly smaller diameter than the brake pilot portion 80, and is provided with a plurality of protruding piece-like partial wheel pilot portions separated in the circumferential direction by providing notches at a plurality of locations in the circumferential direction. It is divided into 81a.

As described above, the brake pilot portion 80 of the hub wheel 72 is formed in a cylindrical shape continuously around the entire circumference, but the wheel pilot portion 81 extending beyond the hub pilot portion 72 includes a plurality of partial wheel pilot portions 81a and 81a. Therefore, it is possible to reduce the weight of the hub wheel 72 without causing functional trouble (Patent Document 2).
JP 2004-114855 A JP 2005-59831 A

  In the former conventional wheel bearing device described above, the cap 60 is fixed to the wheel pilot portion 59 of the hub wheel 52 and covers the outer peripheral portion of the wheel pilot portion 59, so that rusting of the outer peripheral portion can be prevented. Can be prevented from adhering to the hub wheel 52, but it is difficult to apply to the latter conventional wheel bearing device which is reduced in weight. That is, since the wheel pilot portion 81 is a split type, the press-fitting surface of the cap 60 is intermittent, and the cap 60 is deformed between the partial wheel pilot portion 81a and the notch portion, and is stable due to a difference in surface pressure. And cannot be press-fitted.

  In such a split-type wheel pilot part 81, it is possible to replace with an aluminum wheel, a wheel cap or the like without using the cap 60. However, this is not only a cause of cost increase but also this kind of aluminum wheel. And wheel caps are easy to access by the user, and are likely to be used without a cap function after being replaced or removed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device in which the hub wheel is reduced in weight and the pilot portion is improved in rust prevention.

  In order to achieve such an object, the invention according to claim 1 of the present invention is opposed to the outer member having a double row outer rolling surface formed on the inner periphery, and the double row outer rolling surface. An inner member formed with a double row inner rolling surface, and a double row rolling element accommodated in a freely rolling manner between the inner member and the outer member. A wheel mounting flange is integrally formed at one end of the side member or the inner member, and a brake rotor and a wheel are sequentially stacked on the side surface of the wheel mounting flange on the outboard side. A cylindrical brake pilot portion extending to the side for guiding the inner diameter surface of the brake rotor, and a wheel pilot portion extending further from the brake pilot portion for guiding the inner diameter surface of the wheel are provided. In the wheel bearing device in which the portion is divided into a plurality of partial wheel pilot portions separated in the circumferential direction, a cylindrical fitting surface is formed on the inner circumferential surface of the brake pilot portion, and the fitting surface A configuration was adopted in which a cap formed in a cup shape with a material having corrosion resistance was mounted.

  As described above, the wheel mounting flange is integrally formed at one end of the outer member or the inner member, and the brake rotor and the wheel are sequentially stacked on the side surface on the outboard side of the wheel mounting flange. A brake pilot portion and a wheel pilot portion that extend further to the outboard side and guide the inner surface of the brake rotor and the wheel are provided, and the wheel pilot portion is provided in a plurality of partial wheel pilot portions that are separated in the circumferential direction. In the divided wheel bearing device, a cylindrical fitting surface is formed on the inner peripheral surface of the brake pilot portion, and the cylindrical portion is fitted into the fitting surface. Since the cap formed on is attached, the cap is strong even if the wheel pilot part is a split type. To, and can be stably fixed, rain water or dusts can be prevented from entering the interior from the pilot portion, such as a fixed nut can be prevented from sticking to rusting.

  Preferably, as in the invention described in claim 2, if the cap is formed by pressing from a steel plate, the cap has sufficient rigidity and can maintain strength and durability over a long period of time. it can.

  More preferably, as in the invention described in claim 3, the cap includes a cylindrical portion, a superposed portion extending radially outward from the cylindrical portion, and a bottom formed continuously to the superposed portion. As long as the cap is fitted until the overlapping portion abuts the end surface of the wheel pilot portion, the cap has sufficient rigidity even if a thin steel plate is used as the material, and the press-fitting work of the cap is easy. In addition, it is possible to improve the rust prevention of the pilot portion without moving over a long period of time.

  According to a fourth aspect of the present invention, the cylindrical portion of the cap is formed with a plurality of claw portions that are inclined at a predetermined angle radially outward by cutting and raising, and the fitting surface If the annular groove is formed in the annular groove and the claw portion is engaged with the annular groove, the cap can be securely fixed and the pilot portion can be further improved in rust prevention.

  Further, in the invention according to claim 5, if the inner peripheral surfaces of the brake pilot portion and the wheel pilot portion remain forged, and only the fitting surface is finished by machining, the number of processing steps is minimized. The cost can be reduced.

  The wheel bearing device according to the present invention includes an outer member having a double-row outer rolling surface formed on an inner periphery, and a double-row inner rolling surface facing the double-row outer rolling surface. An inner member, and a double row rolling element that is rotatably accommodated between the rolling surfaces of the inner member and the outer member, and is provided at one end of the outer member or the inner member. A wheel mounting flange is integrally formed, and a brake rotor and a wheel are attached to a side surface on the outboard side of the wheel mounting flange so as to be overlapped in order, and extend to the outboard side from the wheel mounting flange to extend the inner diameter surface of the brake rotor. A cylindrical brake pilot portion for guiding the wheel, and a wheel pilot portion that extends further from the brake pilot portion and guides the inner diameter surface of the wheel, and a plurality of wheel pilot portions separated in the circumferential direction are provided. In the wheel bearing device divided into partial wheel pilot portions, a cylindrical fitting surface is formed on the inner peripheral surface of the brake pilot portion, and a cylindrical portion fitted into the fitting surface is provided, and has corrosion resistance. A cap formed in a cup shape with a material having a cap is attached, so that even if the wheel pilot part is a split type, the cap can be firmly and stably fixed. Etc. can be prevented from entering the inside, and the fixing nut or the like can be prevented from rusting and sticking.

  A vehicle body mounting flange is integrally formed on the outer periphery, an outer member having a double row outer rolling surface formed on the inner periphery, a wheel mounting flange is integrally formed on one end, and the double row outer rolling is formed on the outer periphery. One inner rolling surface facing the running surface, a hub ring formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and a small-diameter stepped portion of the hub wheel are press-fitted into the hub ring. An inner member composed of an inner ring on which the other inner rolling surface facing the outer rolling surface of the row is formed, and is accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member. A plurality of rolling elements, and a brake rotor and a wheel are attached to the side surface on the outboard side of the wheel mounting flange in an overlapping manner in order, and extend to the outboard side from the wheel mounting flange to extend the inner diameter of the brake rotor. A cylindrical brake pilot that guides the surface; and A wheel pilot device that further extends from the brake pilot portion of the wheel and guides the inner surface of the wheel is provided, and the wheel pilot portion is divided into a plurality of partial wheel pilot portions that are separated in the circumferential direction. In the above, a cylindrical fitting surface is formed by machining on the inner peripheral surface of the brake pilot portion, and a cap formed by pressing a corrosion-resistant steel plate is attached to the fitting surface, and the cap is A cylindrical portion fitted into the fitting surface, a superposed portion extending radially outward from the cylindrical portion, and a bottom formed continuously to the superposed portion, wherein the superposed portion is the wheel pilot. It press-fits until it abuts against the end face of the part, and closes the opening on the outboard side of the hub wheel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 shows a state in which a cap according to the present invention is mounted. It is a principal part enlarged view. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).

  The wheel bearing device includes an inner member 1, an outer member 10, and double-row rolling elements (balls) 6, 6 accommodated between the members 1, 10 so as to roll freely. The inner member 1 includes a hub ring 2 and a separate inner ring 3 that is externally fitted to the hub ring 2. The hub wheel 2 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end portion on the outboard side, and the wheel is fixed at a circumferentially equidistant position of the wheel mounting flange 4. The hub bolt 5 is planted. Further, an inner rolling surface 2a and a cylindrical small-diameter step portion 2b extending in the axial direction from the inner rolling surface 2a are formed on the outer periphery of the hub wheel 2, and a serration (or spline) for torque transmission is formed on the inner periphery. ) 2c is formed. The inner ring 3 having the inner raceway surface 3a formed on the outer periphery is press-fitted into the small-diameter step portion 2b, and the end portion of the small-diameter step portion 2b is plastically deformed outward in the radial direction. The inner ring 3 is fixed in the axial direction, and the inner ring 3 is prevented from coming off in the axial direction with respect to the hub ring 2.

  The outer member 10 integrally has a vehicle body mounting flange 10b for mounting to a vehicle body (not shown) on the outer periphery, and double row outer rolling surfaces 10a, 10a are formed on the inner periphery. And the double row rolling elements 6 and 6 are accommodated between each rolling surface 10a, 2a and 10a, 3a, and these double row rolling elements 6 and 6 are rollably hold | maintained by the holder | retainers 7 and 7. ing. In addition, sealing devices 8 and 9 are attached to the end of the outer member 10 to prevent leakage of lubricating grease sealed in the bearing and prevent rainwater and dust from entering the bearing. is doing.

  Here, the wheel bearing device referred to as the third generation in which the inner raceway surface 2a is directly formed on the outer periphery of the hub wheel 2 is illustrated, but the wheel bearing device according to the present invention is not limited to such a structure. For example, although not shown, a first generation or second generation structure in which a pair of inner rings are press-fitted into a small diameter step portion of the hub ring may be used. In addition, although the double row angular contact ball bearing which used the rolling elements 6 and 6 as the ball | bowl was illustrated, it is not restricted to this, The double row tapered roller bearing which uses a tapered roller for a rolling element may be sufficient.

  The hub wheel 2 is made of medium carbon steel containing carbon of 0.40 to 0.80% by weight such as S53C, and the seal on which the sealing device 8 on the outboard side including the inner rolling surface 2a on the outboard side slides. The surface hardness is hardened to the range of 58 to 64 HRC by induction hardening over the land portion and the small diameter step portion 2b. The caulking portion 2d is an unquenched portion having a material surface hardness of 25 HRC or less after forging. On the other hand, the inner ring 3 is made of high carbon chrome bearing steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  Further, the outer member 10 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the sealing devices 8 and 9 including the double row outer raceway surfaces 10a and 10a are fitted. The surface hardness is hardened in the range of 58 to 64 HRC by induction hardening over the inner diameter surface of the end portion to be joined.

  Here, the hub wheel 2 is provided with a brake pilot portion 11 that extends to the outboard side from the wheel mounting flange 4 and guides an inner diameter surface of a brake rotor (not shown). Further, a wheel pilot portion 12 is provided which further extends from the brake pilot portion 11 and guides an inner diameter surface of a wheel provided to overlap the brake rotor.

  The brake pilot portion 11 is formed as a cylindrical projecting portion concentric with the hub wheel 2 and is continuous over the entire circumference, and an outer diameter surface serving as a guide surface is a cylindrical surface. On the other hand, the wheel pilot portion 12 has a slightly smaller diameter than the brake pilot portion 11, and is provided with notches 13 at a plurality of locations in the circumferential direction, and a plurality of protruding piece-like partial wheel pilots separated in the circumferential direction. It is divided into parts 12a and 12a.

  On the inner peripheral surfaces of the brake pilot portion 11 and the wheel pilot portion 12, as shown in an enlarged view in FIG. Fifteen fitting surfaces 14 are formed (indicated by hatching in the figure). That is, the inner peripheral surfaces of the brake pilot portion 11 and the wheel pilot portion 12 remain forged, and only the fitting surface 14 is finished by machining to form the entire circumference, so that the number of processing steps is reduced. The cost can be reduced to a minimum. A cap 15 is fitted to the fitting surface 14 as shown in FIG.

  The cap 15 is formed by pressing from a corrosion-resistant steel plate, for example, an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). It is formed in a cup shape. The cap 15 includes a cylindrical portion 15a that is press-fitted into the fitting surface 14, an overlapping portion 15b that extends radially outward from the cylindrical portion 15a, and a bottom portion 15c that is formed continuously with the overlapping portion 15b. Become. The cap 15 is press-fitted until the overlapping portion 15 b abuts against the end face of the wheel pilot portion 12 to close the opening on the outboard side of the hub wheel 2.

  The cap 15 is not limited to a steel plate, but may be formed by injection molding a synthetic resin such as polyamide (PA) 66 reinforced with glass fiber (GF) or carbon fiber (CF). It is preferably made of a stainless steel plate having sufficient rigidity and capable of maintaining strength and durability over a long period of time.

  In the present embodiment, since the overlapping portion 15b extending radially outward is formed in the cap 15, it has sufficient rigidity even if a thin steel plate is used as a material, and the press-fitting work of the cap 15 is facilitated. Further, it is possible to improve the rust prevention of the pilot part without moving over a long period of time. That is, it is possible to prevent rainwater, dust, and the like from entering the fixing nut (not shown) and the serration 2c from the pilot portion, and prevent the fixing nut and the serration 2c from being rusted and fixed.

  Further, here, since the wheel pilot portion 12 is a split type, it is possible to prevent the outer peripheral portion from being rusted and the wheel and the hub wheel 2 are fixed and cannot be separated, and the fitting surface 14 is a machine. Since it is formed in the cylindrical surface by processing, the cap 15 can be fixed firmly and stably.

  FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, and FIG. 5 is an enlarged view of a main part of FIG. This embodiment is a wheel bearing device on the driven wheel side, and the same reference numerals are given to the same parts or parts having the same mechanism as those of the above-described embodiment, and detailed description thereof is omitted.

  This wheel bearing device includes an outer ring (outer member) 16, a pair of inner rings (inner members) 3, 3, and double row rolling elements 6, 6 accommodated between these members. The outer ring 16 is formed of medium carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and integrally has a wheel mounting flange 4 at an end portion on the outboard side, and has a double row outer side on the inner periphery. Rolling surfaces 16a and 16a are formed. And these double row outer side rolling surfaces 16a and 16a are hardened by induction hardening in the range of the surface hardness of 58-64HRC.

  The pair of inner rings 3, 3 are press-fitted into the axle shaft 17 and fixed in the axial direction via a fixing nut 18. In addition, seals 8 and 9 are attached to the opening of the annular space formed between the inner ring 3 and the outer ring 16 to prevent leakage of the lubricating grease sealed inside the bearing, and external rainwater, dust, etc. Prevents entry into the interior.

  The outer ring 16 is provided with a brake pilot portion 11 and a wheel pilot portion 12 that extend to the outboard side from the wheel mounting flange 4. The brake pilot portion 11 is formed as a cylindrical projecting portion concentric with the hub wheel 2, and the wheel pilot portion 12 is formed with a slightly smaller diameter than the brake pilot portion 11 and is a split type separated in the circumferential direction. ing.

  The cap 19 is formed by pressing a corrosion-resistant steel plate, for example, an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). It is formed in a cup shape. The cap 19 includes a cylindrical portion 19a, an overlapping portion 15b extending radially outward from the cylindrical portion 19a, and a bottom portion 15c formed continuously from the overlapping portion 15b.

  A plurality of claw portions 20 are formed in the circumferential direction at the end of the cylindrical portion 19a of the cap 19 and inclined by a predetermined angle outward in the radial direction by cutting and raising. On the other hand, an annular groove 21 is formed on the inner peripheral surface of the cylindrical brake pilot portion 11 by machining such as turning. The cap 19 is press-fitted in a state where the claw portion 20 is elastically deformed until the overlapping portion 15b abuts against the end face of the wheel pilot portion 12, and the claw portion 20 is elastically restored at the position of the annular groove 21 to enter the annular groove 21. Engage.

  In the present embodiment, a plurality of claw portions 20 are formed on the cylindrical portion 19 a of the cap 19 and engaged with the annular groove 21 formed on the inner peripheral surface of the brake pilot portion 11, so that the cap 19 is securely attached to the outer ring 16. The pilot portion can be further improved in rust prevention.

  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.

  In the wheel bearing device according to the present invention, a brake pilot portion and a wheel pilot portion project from the side surface of the hub wheel on the outboard side, and the wheel pilot portion is separated in the circumferential direction to reduce the weight of the hub wheel. The present invention can be applied to the first-generation to third-generation wheel bearing devices that are divided.

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. FIG. 2 is an enlarged view of a main part showing a state where the cap according to the present invention is mounted. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a longitudinal cross-sectional view which shows the other conventional wheel bearing apparatus.

Explanation of symbols

1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 2a, 3a ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ Inner rolling surface 2b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 2c ・ ・ ・ ・ ・ Serration 2d ・ ・ ・········································ 3 Flange 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolt 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling element 7 ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ Cage 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outboard side seal 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inboard side Seal 10 ... Outer members 10a, 16a ... Outer rolling surface 10・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 11 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Brake pilot 12・ ・ Wheel pilot part 12a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Partial wheel pilot part 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Notch 14 ・ ・ ・ ・ ・ ・·········· Fitting surfaces 15, 19 ················· Caps 15a, 19a ········· Cylindrical portion 15b ···・ ・ ・ ・ ・ ・ ・ ・ Polymerized part 15c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bottom 16 ・ ・ ・ ・ ・ ・ ・ ・ Outer ring 17 ・ ・ ・ ・ ・ ・ ・ ・Axle shaft 18 ... Fixing nut 20 ... Claw 21 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Annular groove 5 , 70 ... Outer member 51a, 70a ... Outer rolling surface 51b, 70b ... Car body mounting flange 52, 72... Hub wheels 52a, 53a, 72a, 73a .. Inner rolling surfaces 52b, 72b... Small diameter steps 52c, 72c.・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping parts 53 and 73 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rings 54 and 74・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling elements 56, 71 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flanges 57, 71a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolts 58, 80 ・·············································· Brake pilot part 59, 81 ... a ... top plate part 60b ... cylindrical part 61 ... Openings 76, 77 ... Seal 78 ... Brake rotor 79 ...・ ・ Wheel 81a ・ ・ ・ ・ ・ ・ ・ ・ ・ Partial wheel pilot

Claims (5)

An outer member having a double row outer raceway formed on the inner periphery;
An inner member in which a double row inner rolling surface facing the double row outer rolling surface is formed;
A double row rolling element housed in a freely rolling manner between the rolling surfaces of the inner member and the outer member;
A wheel mounting flange is integrally formed at one end portion of the outer member or the inner member, and a brake rotor and a wheel are sequentially stacked on the side surface on the outboard side of the wheel mounting flange. A cylindrical brake pilot portion extending toward the outboard side and guiding the inner diameter surface of the brake rotor, and a wheel pilot portion extending further from the brake pilot portion and guiding the inner diameter surface of the wheel are provided. In the wheel bearing device in which the portion is divided into a plurality of partial wheel pilot portions separated in the circumferential direction,
A cylindrical fitting surface is formed on the inner peripheral surface of the brake pilot portion, and a cap formed in a cup shape with a corrosion-resistant material is provided, and the cylindrical portion is fitted into the fitting surface. A bearing device for a wheel.   The wheel bearing device according to claim 1, wherein the cap is formed from a steel plate by pressing.   The cap includes a cylindrical portion, a superposed portion extending radially outward from the cylindrical portion, and a bottom formed continuously to the superposed portion, and the superposed portion abuts against an end surface of the wheel pilot portion. The wheel bearing device according to claim 2, wherein the cap is fitted until it is.   In the cylindrical portion of the cap, a plurality of claw portions inclined in the radial direction by a predetermined angle by cutting and raising are formed in the circumferential direction, and an annular groove is formed in the fitting surface. The wheel bearing device according to claim 2 or 3, wherein the claw portion is engaged.   The wheel bearing device according to any one of claims 1 to 4, wherein the inner peripheral surfaces of the brake pilot portion and the wheel pilot portion remain forged and only the fitting surface is finished by machining.

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