JP2008144946A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device reduced in weight while maintaining its strength and having improved forgeability. <P>SOLUTION: An outer member 7 is formed of medium-high carbon steel containing 0.40-0.80 weight percent of carbon such as S53C. The outer member 7 has a vehicle body mounting flange 7b integrally formed on its outer periphery. An outer side surface of the vehicle body mounting flange 7b is tapered in such a manner that the thickness of the flange 7b gradually decreases radially outwardly. The taper angle is set to be 5 degrees. Female screws 7c for engaging with bolts for attaching a vehicle body (not shown) are formed at several portions of the vehicle body mounting flange 7b. <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.

  Patent Document 1 shows an example of a wheel bearing device using the double-row angular contact ball bearing. This wheel bearing device is fitted to an outer member having a double row outer raceway formed on the inner periphery, a hub wheel having a small diameter step portion formed on the outer periphery, and a small diameter step portion of the hub wheel. An inner member in which a double row inner rolling surface facing the outer row rolling surface of the double row is formed on the outer periphery, and between both rolling surfaces of the inner member and the outer member. A plurality of rolling elements (balls) accommodated in a rollable manner via a cage.

The outer member of such a wheel bearing device integrally has a vehicle body mounting flange to be attached to the suspension device on the outer periphery. A female thread for fastening a bolt for mounting the suspension device is formed on the vehicle body mounting flange. The thickness of the vehicle body mounting flange is substantially constant from the base to the tip.
JP 2006-218912 A

  However, since the thickness of the body mounting flange is substantially constant from the base to the tip, it is possible to reduce the weight by reducing the overall thickness from the base to the tip in order to maintain strength. difficult. Further, since the wall thickness is constant, it is necessary to flow the same thickness as that of the base portion at the front end of the flange which is difficult to flow during forging, and forging workability is poor.

  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 having good forging workability while reducing the weight while maintaining the strength.

  In order to achieve such an object, the present invention has an outer member integrally formed with a vehicle body mounting flange to be attached to a suspension device on the outer periphery, and an outer member formed with a double row outer rolling surface on the inner periphery, and one end portion. A hub ring integrally having a wheel mounting flange for mounting a wheel on the outer periphery, and a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring An inner member having a double-row inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and a cage between the inner member and the outer member. In a wheel bearing device comprising a double row rolling element housed so as to be freely rollable via the outer side surface of the vehicle body mounting flange, the wall thickness decreases as it goes radially outward. A tapered configuration is adopted.

  Thus, since the body mounting flange has a tapered shape, the apparatus can be reduced in weight, and it is not necessary to flow the same amount of meat as the base portion at the front end of the flange that is difficult to flow during forging, and forging workability is good. .

  Moreover, this invention can be set as the structure whose taper angle of the side surface of the outer side of the said vehicle body mounting flange is 5 degree | times or more and less than 10 degree | times. As a result, a wheel bearing device that is lightweight and has good forgeability can be provided. The reason why it is set to 5 degrees or more is that, if this thickness is removed, weight can be reduced and forging processability is improved. The reason why the angle is less than 10 degrees is that if the taper angle is further increased, the tapping tool for female thread machining of the vehicle body mounting flange may be damaged.

  In the present invention, the taper angle of the outer side surface of the vehicle body mounting flange is 10 degrees or more, and a straight shape portion is provided by machining on the outer side surface of the vehicle body mounting flange. You can also. Since the straight shape portion is provided, even if the taper angle is 10 degrees or more, the tapping tool for female thread machining of the vehicle body mounting flange is not damaged.

  Moreover, this invention can be set as the structure by which the internal thread which fastens the volt | bolt which attaches the said suspension apparatus to the said vehicle body attachment flange is formed. Thereby, even if the outer side surface of the vehicle body mounting flange is tapered, the suspension device can be brought into contact with the flat inner side surface and fastened with a bolt.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a suspension device on an outer periphery, an outer member having a double row outer rolling surface formed on an inner periphery, and one end portion. From a hub ring integrally having a wheel mounting flange for mounting a wheel and having a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring And an inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cage is provided between both rolling surfaces of the inner member and the outer member. And a double-row rolling element housed in a freely rolling manner via a taper whose wall thickness decreases as the outer side surface of the vehicle body mounting flange goes radially outward. Because it has a shape, while reducing the weight while maintaining strength, forging It is possible to provide a workability good wheel bearing apparatus.

  A body mounting flange for mounting to the suspension device on the outer periphery is integrated, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end A hub ring having a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring. An inner member in which a double row of inner rolling surfaces facing the running surface is formed, and a compound member that is rotatably accommodated via a cage between both rolling surfaces of the inner member and the outer member. In the wheel bearing device including a row of rolling elements, a side surface on the outer side of the vehicle body mounting flange has a tapered shape with a thickness that decreases toward the outside in the radial direction.

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. In the following description, the side closer to the outer side of the vehicle in a 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).

  This wheel bearing device has a so-called third generation configuration including a hub wheel 1 and a double row rolling bearing 2. The double-row rolling bearing 2 includes an outer member 7, an inner member 8, and double-row rolling elements (balls) 9 and 9.

  The outer member 7 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. The outer member 7 integrally has a vehicle body mounting flange 7b on the outer periphery. The side surface on the outer side of the vehicle body mounting flange 7b has a tapered shape in which the wall thickness decreases as going outward in the radial direction. The taper angle is 5 degrees. The body mounting flange 7b is provided with several female screws 7c for fastening bolts for mounting a vehicle body (not shown). Double rows of outer rolling surfaces 7 a and 7 a are formed on the inner periphery of the outer member 7. The double row outer rolling surfaces 7a, 7a are subjected to a hardening process with a surface hardness of 58 to 64 HRC by induction hardening.

  On the other hand, the inner member 8 is formed with double-row inner rolling surfaces 1a and 5a facing the outer rolling surfaces 7a and 7a of the outer member 7 described above. Of these double-row inner rolling surfaces 1a, 5a, one (outer side) inner rolling surface 1a is on the outer periphery of the hub wheel 1, and the other (inner side) inner rolling surface 5a is on the outer periphery of the inner ring 5, respectively. It is integrally formed. In this case, the inner member 8 refers to the hub wheel 1 and the inner ring 5. And the double row rolling elements 9 and 9 are accommodated between these both rolling surfaces, respectively, and are hold | maintained by the holder | retainers 10 and 10 so that rolling is possible. Further, seals 11 and 12 are attached to the opening of the annular space formed between the outer member 7 and the inner member 8, and leakage of the lubricating grease sealed inside the bearing and the inside of the bearing from the outside. Prevents intrusion of rainwater and dust.

  The hub wheel 1 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end on the outer side, and hub bolts 4a for fixing the wheel in the circumferential direction of the wheel mounting flange 4 are planted. It is installed. And the inner side rolling surface 1a and the cylindrical small diameter step part 1b extended in an axial direction from this inner side rolling surface 1a are formed in the outer periphery via the seal land part 13 used as the base of the wheel mounting flange 4. FIG. The inner ring 5 is press-fitted into the small-diameter step portion 1b via a predetermined scissors, and further, a bearing preload is applied by a crimping portion 6 formed by plastically deforming an end portion of the small-diameter step portion 1b radially outward. In this state, it is fixed to the hub wheel 1 in the axial direction. On the inner periphery of the hub wheel 1, a serration (or spline) 1c for torque transmission is formed.

  The hub wheel 1 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the outer periphery extends from the seal land portion 13 to which the outer seal 11 is in sliding contact to the inner rolling surface 1a and the small diameter step portion 1b. The surface is hardened by induction hardening to a surface hardness in the range of 58 to 64 HRC. In addition, the crimping part 6 is made into the surface hardness after a forge process. Further, the inner ring 5 and the rolling element 9 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. As a result, not only the wear resistance of the seal land 13 is improved, but also the mechanical strength against the rotational bending load applied to the wheel mounting flange 4 is sufficient, and the durability of the hub wheel 1 is further improved. To do. Further, fretting wear occurring on the fitting surface between the small diameter step 1b and the inner ring 5 can be minimized.

  Here, the third generation structure in which the inner raceway surface 1a is directly formed on the outer periphery of the hub wheel 1 is illustrated. However, the present invention is not limited to this, but a pair of inner rings are press-fitted into the hub wheel. It may be the first generation, the second generation structure, or the fourth generation in which the inner raceway is formed on the outer periphery of the hub wheel and the constant velocity universal joint. Moreover, although the structure which consists of a double row angular contact ball bearing which used the ball for the rolling element 9 was illustrated, the double row tapered roller bearing which used the tapered roller for the rolling element 9 may be sufficient.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 is an enlarged view showing a main part of a second embodiment of the wheel bearing device according to the present invention.

  As shown in FIG. 2, the outer member 27 integrally has a vehicle body mounting flange 27b on the outer periphery. On the outer side surface of the vehicle body mounting flange 27b, a tapered portion 27d having a thickness that decreases radially outward is formed. The taper angle is 10 degrees. The side surface on the outer side of the vehicle body mounting flange 27b is provided with a straight portion 27e so that the thickness of the vehicle body mounting flange 27b is constant by machining after being tapered at a taper angle of 10 degrees. The body mounting flange 27b is provided with several female screws 27c for fastening bolts for mounting a vehicle body (not shown). Thus, since the straight-shaped part 27e is provided, even if the taper angle is 10 degrees or more, the tapping tool for female thread machining of the vehicle body mounting flange is not damaged.

  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 is applied to a wheel bearing device having a first to fourth generation structure in which a vehicle body mounting flange is formed on the outer periphery of an outer member regardless of whether it is for driving wheels or driven wheels. Can do.

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 which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention.

Explanation of symbols

1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 1a, 5a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 1b ・ ・ ・ ・ ・ ・・ ・ ・ ・ Small diameter step 1c ・ ・ ・ ・ ・ ・ Serration 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double-row rolling bearing 4 ..... Wheel mounting flange 4a ..... Hub bolt 5 ... Inner ring 6 ... caulking part 7, 27 ... outer member 7a ... ····· Outside rolling surface 7b, 27b ············ Body mounting flange 7c, 27c・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling element 10 ・ ・ ・····························································· Seal 13 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Tapered portion 27e ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Straight shape portion

Claims (4)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and having a double row outer rolling surface formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and a small-diameter stepped portion formed on the outer periphery, and an inner ring fitted to the small-diameter stepped portion of the hub wheel or the outer side of the constant velocity universal joint An inner member formed of a joint member, and formed on the outer periphery with a double-row inner rolling surface facing the double-row outer rolling surface;
In a wheel bearing device comprising: a double row rolling element that is accommodated so as to roll freely between both rolling surfaces of the inner member and the outer member via a cage,
The wheel bearing device according to claim 1, wherein a side surface of the outer side of the vehicle body mounting flange has a tapered shape with a thickness that decreases in a radially outward direction.   2. The wheel bearing device according to claim 1, wherein a taper angle of an outer side surface of the vehicle body mounting flange is not less than 5 degrees and less than 10 degrees.   2. The wheel bearing device according to claim 1, wherein a taper angle of an outer side surface of the vehicle body mounting flange is 10 degrees or more, and a straight shape portion is provided by machining on the outer side surface of the vehicle body mounting flange. . The wheel bearing device according to any one of claims 1 to 3, wherein an internal thread for fastening a bolt for attaching the suspension device to the vehicle body attachment flange is formed.

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