JP4986116B2 - Wheel bearing device - Google Patents

Description

  The present invention relates to a wheel bearing device that rotatably supports a drive wheel of a vehicle such as an automobile, and more particularly to a wheel bearing device that achieves a reduction in cost while being lightweight and compact.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes 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. This wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double-row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device, and is an outer member. 2nd generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the wheel, 3rd generation structure with one inner rolling surface formed directly on the outer periphery of the hub wheel, or constant speed with the hub wheel It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the universal joint.

  Various types of wheel bearing devices have been proposed in the past, and for example, those shown in FIG. 3 are known. The wheel bearing device 50 is referred to as a first generation structure, and includes a hub wheel 51 on which the driving wheel W and the brake rotor B are mounted at one end, and a double row rolling bearing 52 that rotatably supports the hub wheel 51. And a fixed constant velocity universal joint 53 that is connected to the hub wheel 51 and transmits the power of a drive shaft (not shown) to the hub wheel 51.

  The hub wheel 51 integrally has a wheel mounting flange 54 for mounting the driving wheel W and the brake rotor B at one end, and a cylindrical small-diameter step portion 51a extending in the axial direction from the wheel mounting flange 54 is formed. Yes.

  The double-row rolling bearing 52 is fitted to a knuckle N constituting a suspension device, and an outer ring 55 having double-row outer rolling surfaces 55a and 55a formed on the inner periphery, and a double-row outer rolling surface on the outer periphery. A pair of inner rings 56, 56 formed with an inner rolling surface 56a opposite to 55a, 55a, and a double row ball 58 accommodated so as to roll between the rolling surfaces 55a, 56a via a cage 57. , 58 and double row angular contact ball bearings.

  The constant velocity universal joint 53 is an outer joint member integrally having a cup-shaped mouth portion (not shown), a shoulder portion 59 that forms the bottom portion of the mouth portion, and a shaft portion 60 that extends in the axial direction from the shoulder portion 59. 61 is provided. The outer joint member 61 is fitted into the hub wheel 51 through serrations so as to transmit torque. Then, the shaft portion 60 is fitted into the hub wheel 51 until the shoulder portion 59 abuts against the inner ring 56 of the double row rolling bearing 52, and the fixing nut 63 is attached to the male screw 62 formed at the end of the shaft portion 60. Are fastened with a predetermined tightening torque, and the hub wheel 51 and the outer joint member 61 are coupled so as to be separable in the axial direction.

  A large torque is applied to the driving wheel W of such a vehicle through a sliding type constant velocity universal joint (not shown) from the engine when the engine rotates at a low speed, for example, when the vehicle starts, and the drive shaft is twisted. It has been known. As a result, the inner ring 56 of the double row rolling bearing 52 supporting the drive shaft is also twisted. When a large twist occurs in the drive shaft in this way, if there is a circumferential clearance between the serrations of the hub portion 51 and the shaft portion 60 of the outer joint member 61 fitted inside the hub wheel 51, the outer joint member 61. A so-called stick-slip sound is generated by a sudden slip at the contact surface between the inner ring 56 and the inner ring 56.

As a countermeasure against this, in the conventional wheel bearing device 50, the surface of the outer joint member 61 that contacts the shoulder 59 is subjected to a surface treatment that reduces the frictional resistance, and a smooth slip is obtained, resulting in a stick-slip sound. The effect which suppresses can be exhibited.
JP 2000-110840 A

  However, in this conventional wheel bearing device, the end surface or the like of the inner ring 56 is subjected to a surface treatment including a grease groove or the like, and the frictional resistance with the abutting member can be reduced to suppress stick-slip noise. It is necessary to perform such surface treatment on a plurality of parts, which increases the number of processing steps and hinders cost reduction.

  Further, in this type of wheel bearing device, the hub wheel 51 is formed by forging or casting, and thereafter, each part including the wheel mounting flange 54 is turned so that the double row rolling bearing 52 is fitted. The outer periphery of the stepped portion 51a is heat-treated and finally ground. As long as such a manufacturing process is employed, this type of conventional structure has a limitation in cost reduction.

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 that is reduced in cost and weight while being compact.
Another object of the present invention is to prevent the occurrence of stick-slip noise due to a sudden slip at the contact surface with the outer joint member by suppressing circumferential backlash between the hub wheel and the outer joint member.

In order to achieve such an object, the invention according to claim 1 of the present invention has a wheel mounting flange integrally formed at one end, and a cylindrical small-diameter step portion extending in the axial direction from the wheel mounting flange is formed. A hub wheel, a wheel bearing formed of a double row rolling bearing and press-fitted into a small-diameter step portion of the hub wheel through a predetermined squeeze, and fitted into the hub wheel so as to be able to transmit torque, via screw means. And a constant velocity universal joint separably coupled in the axial direction, wherein the hub wheel is formed by pressing from a steel plate, and the shaft portion of the outer joint member in the constant velocity universal joint serrations whose surface is hardened is formed by Rukoto not bite into the serration by press-fitted into the inner peripheral surface of the hub wheel, it is coupled with a suppressed circumferential backlash between the hub wheel and the outer joint member is made There.

As described above, the wheel mounting flange is integrally formed at one end portion, and the hub wheel having the cylindrical small diameter step portion extending in the axial direction from the wheel mounting flange is formed. And a constant velocity universal joint that is fitted in the hub wheel so as to be able to transmit torque and is separated in the axial direction through screw means. In the wheel bearing device, a hub ring is formed by pressing from a steel plate, and a serration whose surface is hardened is formed on the shaft portion of the outer joint member of the constant velocity universal joint. the Rukoto was bite by press fitting on the peripheral surface, wherein the coupling that suppresses circumferential backlash between the hub wheel and the outer joint member is made with light weight and compact, cost can be reduced It can be. Further, it is possible to prevent the occurrence of stick-slip noise due to sudden slip on the contact surface between the hub wheel and the outer joint member.

  Preferably, as in the invention described in claim 2, the wheel mounting flange protrudes by a predetermined depth in the axial direction between the mounting portion extending radially outward from the base portion of the wheel mounting flange. If it is composed of convex parts formed in this way, the strength and rigidity of the wheel mounting flange can be increased without using a thick steel plate, and the workability is improved to further reduce the cost. be able to.

  According to a third aspect of the present invention, a plurality of bolt holes for fixing the hub bolts are formed by punching at the circumferentially equidistant positions of the wheel mounting flange, and the edge portions of the bolt holes are shafts. If it is formed so as to protrude in the direction, a fitting surface of a predetermined hub bolt can be secured.

  Further, as in the invention described in claim 4, a cup-shaped pilot member formed by pressing a steel plate by supporting a wheel on the outer end of the hub wheel and press-working is fitted. If the hub wheel is fixed in a state of being sandwiched between the member and the outer joint member, the opening end of the hub wheel is closed to prevent rainwater, dust, etc. from entering the coupling portion from the outside, It can prevent that a coupling | bond part rusts.

  Further, as in the invention according to claim 5, the wheel bearing is preloaded by the crimped portion formed by plastically deforming the end portion of the small diameter step portion radially outward. If fixed to the hub wheel in the axial direction, it is possible to provide a self-retaining structure that maintains the preload applied to the wheel bearing for a long period of time and to manage the preload using a fixing bolt or the like. Therefore, it is possible to reduce the management man-hours in the assembly line and reduce the cost.

A wheel bearing device according to the present invention has a wheel mounting flange integrally formed at one end, a hub wheel formed with a cylindrical small-diameter step portion extending in the axial direction from the wheel mounting flange, and a small diameter of the hub wheel. A wheel bearing comprising a double row rolling bearing is press-fitted into the stepped portion through a predetermined shimiro, and is fitted into the hub wheel so as to be able to transmit torque, and is coupled in a separable manner in the axial direction via screw means. In a wheel bearing device including a constant velocity universal joint, the hub wheel is formed by pressing from a steel plate, and a serrated surface is hardened on a shaft portion of an outer joint member of the constant velocity universal joint. by Rukoto not bite into the serration by press-fitted into the inner peripheral surface of the hub wheel, the coupling that suppresses circumferential backlash between the hub wheel and the outer joint member is made lightweight and compact Together, it is possible to reduce the cost. Further, it is possible to prevent the occurrence of stick-slip noise due to sudden slip on the contact surface between the hub wheel and the outer joint member.

A hub wheel having a wheel mounting flange integrally formed at one end and formed with a cylindrical small diameter step portion extending in the axial direction from the wheel mounting flange, and press-fitted into the small diameter step portion of the hub wheel through a predetermined shimoshiro A wheel bearing comprising a double row rolling bearing, and a constant velocity universal joint that is fitted in the hub wheel so as to be able to transmit torque and is separated in the axial direction through screw means. In the bearing device, the hub wheel is formed by pressing from a steel plate, and the wheel mounting flange includes a mounting portion extending radially outward from a base portion of the wheel mounting flange, and a predetermined depth in the axial direction between the mounting portions. And a serration with a hardened surface formed on the shaft portion of the outer joint member of the constant velocity universal joint. The serration is pressed against the inner peripheral surface of the hub wheel. The Rukoto was bite by binding with a suppressed circumferential backlash between the hub wheel and the outer joint member have been made.

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 a longitudinal sectional view showing a single hub wheel of FIG. 1, and FIG. It is a side view. 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 first generation structure, and includes a hub wheel 1 and a wheel bearing 2 attached to the hub wheel 1. A constant velocity universal joint 3 is fitted into the hub wheel 1 so as to be able to transmit torque, and the hub wheel 1 and the constant velocity universal joint 3 are detachably integrated via a fixing bolt 4.

  The wheel bearing 2 is fitted into a knuckle 5 and has an outer ring 6 in which double row outer rolling surfaces 6a and 6a are formed on the inner periphery, and an inner side facing the double row outer rolling surfaces 6a and 6a on the outer periphery. A pair of inner rings 7, 7 formed with rolling surfaces 7a, and double-row rolling elements (balls) 9, 9 accommodated between the rolling surfaces via a cage 8 so as to be freely rollable, This is a back-to-back type double row angular contact ball bearing.

  The constant velocity universal joint 3 includes an outer joint member 10, a joint inner ring 11, a cage 12, and a torque transmission ball 13. The outer joint member 10 is integrally formed with a cup-shaped mouth portion 14, a shoulder portion 15 that forms the bottom of the mouth portion 14, and a shaft portion 16 that extends in the axial direction from the shoulder portion 15. A serration (or spline) 16a is formed on the outer periphery, and an internal thread 16b is formed on the end. Here, the serration 16a is subjected to a curing process with a surface hardness in the range of 50 to 64 HRC by induction hardening.

  The hub wheel 1 has a wheel mounting flange 17 for mounting a wheel (not shown) at one end portion on the outer side, and a cylindrical small-diameter step extending from the wheel mounting flange 17 in the axial direction via a shoulder portion 1a. The part 1b is formed by press working. The hub wheel 1 is made of a steel plate made of carburized steel such as SCr420 or SCM415 with a relatively small amount of carbon. And the surface hardness is hardened in the range of 50 to 64 HRC by carburizing and quenching. In addition, the caulking part 19 to be described later is left with raw material hardness by carburization. In addition to this, examples of the material of the hub wheel 1 include SCM440, cold rolled steel plate (JIS standard SPCC system, etc.), and carbon steel such as S45C. In the case of cold rolled steel or carbon steel, the surface hardness is set in the range of 50 to 64 HRC by induction hardening from the shoulder 1a to the small diameter step 1b. Thereby, while having sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 17, the fretting resistance of the small diameter step portion 1b is improved, and the durability of the hub wheel 1 is further improved.

  A cup-shaped pilot member 18 that supports a wheel (not shown) is fitted to the outer end of the hub wheel 1 to close the open end of the hub wheel 1. Thereby, it can prevent that rainwater, dust, etc. penetrate | invade from a exterior into a joint part, and can prevent that a joint part rusts. The pilot member 18 is formed by press working from a steel plate made of carburized steel such as SCr420 or SCM415 having a relatively small amount of carbon. And the surface hardness is hardened in the range of 50 to 64 HRC by carburizing and quenching.

  Further, the wheel bearing 2 is press-fitted into the small-diameter step portion 1b of the hub wheel 1 through a predetermined scissors, and the end portion of the small-diameter step portion 1b has a diameter in a state where the outer-side inner ring 7 abuts the shoulder portion 1a. It is fixed in the axial direction by a caulking portion 19 formed by plastic deformation outward in the direction. The shaft portion 16 is press-fitted into the hub wheel 1 until the shoulder portion 15 of the outer joint member 10 abuts against the caulking portion 19, and the hub wheel 1 is sandwiched between the pilot member 18 and the outer joint member 10. Thus, the fixing bolts 4 are connected so as to be separable in the axial direction. As a result, it is possible to provide a self-retaining structure that maintains the preload applied to the wheel bearing 2 for a long period of time, and it is possible to eliminate the trouble of managing the preload by the fixing bolt 4 and to reduce the management man-hours in the assembly line. Thus, cost reduction can be achieved.

  Here, when the shaft portion 16 is press-fitted into the hub wheel 1, the serrated surface 16 a having a hardened surface bites into the inner peripheral surface of the hub wheel 1 and suppresses circumferential play between the hub wheel 1 and the outer joint member 10. be able to. Therefore, it is possible to prevent the occurrence of a stick-slip sound due to a sudden slip at the contact surface between the caulking portion 19 and the shoulder portion 15 of the outer joint member 10. Further, as a matter of course, the processing step for forming serrations on the hub wheel 1 can be reduced, and the cost can be further reduced.

Next, the configuration of the hub wheel 1 will be described in detail with reference to FIG.
The hub wheel 1 is formed by punching a rolled steel plate into a disk-shaped material having a predetermined outer diameter, and forming a small-diameter step portion 1b by punching the bottom after deep drawing. The wheel mounting flange 17 is formed with a substantially fan-shaped mounting portion 17a extending radially outward from the base portion 20 of the wheel mounting flange 17, and a predetermined depth protruding in the axial direction between the mounting portions 17a and 17a. It is comprised with the convex part 17b which makes a substantially fan shape. Thus, since the wheel mounting flange 17 is formed in a corrugated shape composed of the mounting portion 17a and the convex portion 17b, the strength and rigidity of the wheel mounting flange 17 can be increased without using a thick steel plate. While being able to raise, workability can be improved and cost reduction can be achieved.

  In addition, bolt holes 21 for fixing hub bolts (not shown) are formed by punching at equal circumferential positions of the mounting portions 17a. In this bolt hole 21, a separate ring member 22 is joined to the inner side surface of the mounting portion 17a by welding in order to secure a predetermined fitting surface. Instead of joining the ring member 22, the bolt hole 21 may be formed by punching the edge of the bolt hole 21 after piercing.

  In the present embodiment, the hub wheel 1 is formed by plastic working such as drawing and burring and is manufactured substantially without machining, so that productivity is improved and yield is improved and cost can be reduced. . Here, the double-row angular contact ball bearing using balls as the rolling elements 9 is illustrated as the wheel bearing 2, but the present invention is not limited thereto, and a double-row tapered roller bearing using tapered rollers as the rolling elements may be used. . In addition, although the wheel bearing device having the first generation structure is illustrated here, the present invention is not limited to this, but the second generation integrally has a vehicle body mounting flange for fixing the knuckle to the outer ring of the wheel bearing. It may be a structure.

  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 includes a hub wheel and a wheel bearing press-fitted into the hub wheel, and can be applied to the wheel bearing device.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is a longitudinal cross-sectional view which shows the hub ring single-piece | unit of FIG. (B) is a side view of (a). It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1. Hub wheel 1a, 15 ... Shoulder 1b ... Small diameter step 2 ...・ ・ Wheel bearing 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joint 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fixing bolt 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Knuckle 6 ・... outer ring 6a ... outer raceway 7 ... inner ring 7a ... Inner rolling surface 8 ... Cage 9 ... Rolling element 10 ... Outer joint member 11 .... Joint inner ring 12 ... Cage 13 ... Torque transmission ball 14 ... Mouse part 16 .... Shaft 16a ... Serration 16b ... Female thread 17 ... Wheel mounting flange 17a ... Mounting part 17b ... Projection 18 ... Pilot member 19 ... caulking part 20 ... base 21 ... bolt hole 22 ... ··· Ring member 50 ··· Wheel bearing device 51 ··············· Hub wheel 51a ········· Small diameter step 52 ··· ······ Double row rolling bearing 53 ··· Constant velocity universal joint 54 ··· Wheel mounting flange 55 ··· -Outer member 55a ... Outer rolling surface 56 ... Inner ring 56a ... Inner rolling surface 57 ... ... Cage 58 ... 59 ... shoulder 60 ... shaft 61 ... outer joint member 62 ... ... Male thread 63 ... Fixing nut B ... Brake rotor N ... Knuckle W ... ······Wheel

Claims (5)

A hub wheel integrally having a wheel mounting flange at one end portion and formed with a cylindrical small-diameter stepped portion extending in the axial direction from the wheel mounting flange;
A wheel bearing that is press-fitted into a small-diameter step portion of the hub wheel through a predetermined shimoshiro and is composed of a double row rolling bearing;
A wheel bearing device including a constant velocity universal joint that is fitted into the hub wheel so as to be able to transmit torque and is separably coupled in an axial direction via screw means.
The hub ring is formed by pressing from a steel plate, and a serration with a hardened surface is formed on the shaft portion of the outer joint member of the constant velocity universal joint. The serration is press-fitted into the inner peripheral surface of the hub ring. the Rukoto was bite Te, the wheel hub and wheel bearing apparatus characterized by coupling that suppresses circumferential backlash between the outer joint member have been made.   The wheel mounting flange includes a mounting portion that extends radially outward from a base portion of the wheel mounting flange, and a convex portion that projects between the mounting portions by a predetermined depth in the axial direction. The wheel bearing device according to 1.   3. A plurality of bolt holes for fixing a hub bolt at a circumferentially equidistant position of the wheel mounting flange are formed by punching, and an edge portion of the bolt hole is formed to protrude in the axial direction. The wheel bearing apparatus described in 1.   A cup-shaped pilot member formed by pressing a hub from the steel plate and supporting the wheel on the outer end of the hub wheel is fitted, and the hub wheel is sandwiched between the pilot member and the outer joint member. The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing device is fixed in a fixed state. The wheel bearing is axially fixed to the hub wheel in a state where a preload is applied by a crimping portion formed by plastically deforming an end portion of the small diameter step portion radially outward. Item 5. A wheel bearing device according to any one of Items 1 to 4.

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