JP4993341B2 - Wheel bearing device - Google Patents

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that achieves higher rigidity and longer bearing life.

  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. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Further, the 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. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. 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 speed universal joint.

  In such a wheel bearing device, conventionally, both rows of bearings have the same specification, so that they have sufficient rigidity when stationary, but the optimum rigidity is not always obtained when the vehicle turns. That is, the position of the vehicle weight when stationary is determined so that it acts on the approximate center of the double row rolling bearing, but when turning, the opposite side of the turning direction (when turning right, the vehicle A large radial load or axial load is applied to the left axle. Therefore, at the time of turning, it is effective to increase the rigidity of the outer bearing row rather than the inner bearing row. Then, what is shown in FIG. 7 is known as a wheel bearing apparatus which improved the rigidity at the time of turning, without enlarging an apparatus.

  This wheel bearing device 50 has a vehicle body mounting flange 51c integrally attached to a knuckle (not shown) on the outer periphery, and an outer side in which double row outer rolling surfaces 51a and 51b are formed on the inner periphery. A member 51 and a wheel mounting flange 53 for mounting a wheel (not shown) at one end are integrally formed, and one inner rolling surface 52a facing the double row outer rolling surfaces 51a and 51b on the outer periphery. The hub wheel 52 having a small-diameter step portion 52b extending in the axial direction from the inner rolling surface 52a and the small-diameter step portion 52b of the hub wheel 52 are externally fitted to the double-row outer rolling surfaces 51a and 51b. An inner member 55 composed of an inner ring 54 formed with the other inner rolling surface 54a facing each other, double rows of balls 56, 57 accommodated between both rolling surfaces, and these double rows of balls 56, 57 A retainer 58 for freely rolling It is composed of a double row angular contact ball bearing with a 9.

  The inner ring 54 is fixed in the axial direction by a caulking portion 52c formed by plastically deforming a small diameter step portion 52b of the hub wheel 52 radially outward. Seals 60 and 61 are attached to the opening of the annular space formed between the outer member 51 and the inner member 55, leakage of the lubricating grease sealed inside the bearing, and rainwater from the outside into the bearing. And dust are prevented from entering.

Here, the pitch circle diameter D1 of the outer side ball 56 is set larger than the pitch circle diameter D2 of the inner side ball 57. Along with this, the inner rolling surface 52a of the hub wheel 52 is expanded in diameter than the inner rolling surface 54a of the inner ring 54, and the outer rolling surface 51a on the outer side of the outer member 51 is also rolled on the inner side. The diameter is larger than that of the surface 51b. The outer side balls 56 are accommodated more than the inner side balls 57. In this way, by setting the pitch circle diameters D1 and D2 to D1> D2, the rigidity is improved not only when the vehicle is stationary but also when turning, and the life of the wheel bearing device 50 can be extended. it can.
JP 2004-108449 A

  However, in the case of such a conventional wheel bearing device 50, the rigidity of the inner side bearing row is insufficient with respect to the rigidity of the outer side bearing row, and the pitch circle diameter D1 of the outer side ball 56 is less than the inner side. Since the diameter is set larger than the pitch circle diameter D2 of the ball 57, a step portion is provided between the outer side inner rolling surface 52a and the small-diameter step portion 52b into which the inner ring 54 is press-fitted in the hub wheel 52. 62 is formed. That is, since a step portion 62 composed of at least a step difference (D1-D2) / 2 between the diameters of both pitch circle diameters D1 and D2 is formed, the outer rolling surface 51a on the outer side of the outer member 51 in the assembly process of the apparatus. There is a risk that the outer-side ball 56 temporarily assembled through the cage 58 may come into contact with the stepped portion 62 of the hub wheel 52. The stepped portion 62 is changed to various shapes and sizes in consideration of the rigidity of the hub wheel 52, but the ball 56 contacts the stepped portion 62 of the hub wheel 52 including the counter portion 63 of the inner rolling surface 52a. As a result, a minute flaw is generated in the ball 56, and not only the acoustic characteristics of the bearing are deteriorated, but also there is a possibility of causing a short life.

  The present invention has been made in view of such circumstances, and solves the conflicting problems of light weight, compactness and high rigidity of the device, prevents the occurrence of ball scratches during assembly, and the acoustic characteristics of the bearing. An object of the present invention is to provide a wheel bearing device that improves the service life and extends the service life.

In order to achieve the object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the knuckle on the outer periphery, and a double row outer rolling surface is formed on the inner periphery. An outer member, and a wheel mounting flange for mounting a wheel at one end are integrally formed, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axis from the inner rolling surface Hub wheel formed with a small-diameter step portion extending in the direction, and the other inner rolling surface that is press-fitted into the small-diameter step portion of the hub wheel through a predetermined shimoshiro and faces the outer rolling surface of the double row on the outer periphery In a wheel bearing device comprising: an inner member formed of an inner ring formed with an inner ring; and a double row rolling element that is slidably accommodated between both rolling surfaces of the inner member and the outer member. Out of the double row rolling elements, the outer side rolling element is a ball and the inner side rolling element. The pitch diameter of the inner side tapered roller is set to be smaller than the pitch diameter of the outer side ball, and the corners of the outer peripheral surface of the hub ring are flattened and smooth. together that are formed in a circular arc shape, the shaft-like portion extending in the axial direction over the groove bottom portion of the inner raceway surface of the wheel hub to the cylindrical portion is formed, matched against the said inner ring and the shaft-like portion A tapered step portion is formed between the shoulder portion and a mortar-like recess is formed at the outer end of the hub wheel, and the depth of the recess is determined by the inner rolling surface. The depth of the groove to the vicinity of the step portion was adopted .

Thus, an outer member having a vehicle body mounting flange on the outer periphery, a hub wheel having a wheel mounting flange at one end, an inner member made of an inner ring press-fitted into the hub wheel, and the inner member and the outer member. In a third-generation wheel bearing device comprising a double row rolling element housed between members, the outer side rolling element of the double row rolling element is a ball and the inner side rolling element is a tapered roller. Yes, the pitch diameter of the inner side tapered rollers is set smaller than the pitch diameter of the outer side balls, and the corners of the outer peripheral surface of the hub wheel are flattened to form a smooth arc shape. both that is, shaft-like portion extending in the axial direction over the cylindrical portion from the groove bottom of the inner raceway surface of the hub wheel is formed a taper between a shoulder which is matched to the shaft-like portion and the inner ring Shaped step and outer hub ring The conical recess is formed at the end portion, the depth of this recess, so there is a depth of up to about stepped portion beyond the groove bottom of the inner raceway surface, there is ensured a weight and size, It is possible to provide a wheel bearing device that prevents the occurrence of ball scratches during assembly, improves the acoustic characteristics of the bearing, increases the rigidity, and extends the life of the bearing.

  Preferably, as in the invention according to claim 2, the shaft is formed in a state in which the inner ring is applied with a predetermined preload by a crimped portion formed by plastically deforming an end portion of the small diameter step portion radially outward. If it is fixed in the direction, the weight and size can be further reduced, and the initially set preload can be maintained over a long period of time.

  Moreover, if the groove shoulder part and counter part of the inner side rolling surface on the outer side are formed by simultaneous grinding with the rolling surface by a general-purpose grindstone after heat treatment, as in the invention described in claim 3, The part can be formed more smoothly.

The invention according to claim 4, since the outer shape before Symbol hub wheel is formed to have a substantially uniform wall thickness corresponding to the recess, light weight without sacrificing the rigidity of the device Can be achieved.

The wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange to be attached to the knuckle on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel at one end. A wheel mounting flange is integrally formed, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface is formed. And an inner ring formed by press-fitting the hub wheel into a small-diameter step portion of the hub ring via a predetermined scissors and having the other inner rolling surface facing the outer rolling surface of the double row formed on the outer periphery. In a wheel bearing device comprising a member and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member, an outer of the double row rolling elements is provided. The rolling elements on the side are balls, and the rolling elements on the inner side are tapered rollers. With a pitch circle diameter of the tapered rollers over side is set smaller in diameter than the pitch circle diameter of the outer side of the ball, the corner portion of the outer peripheral surface of the hub wheel is formed into a smooth arcuate shape is plane crush In addition, a shaft-shaped portion extending in the axial direction from the groove bottom portion of the inner raceway surface of the hub wheel to the small-diameter step portion is formed, and between the shaft-shaped portion and a shoulder portion that is abutted against the inner ring. And a mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of the recess exceeds the groove bottom of the inner rolling surface and Since the depth is close to the step, it is lighter and more compact, prevents ball damage during assembly, improves the acoustic characteristics of the bearing, and achieves higher rigidity and longer bearing life. A wheel bearing device can be provided.

A body mounting flange for mounting to the knuckle 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 the wheel on one end is integrated. A hub wheel having one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, a small diameter step portion extending in the axial direction from the inner rolling surface, and a small diameter of the hub wheel An inner member consisting of an inner ring that is press-fitted into a stepped portion and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and both rolling of the inner member and the outer member A plurality of balls that are rotatably accommodated between the surfaces, and the inner ring is pivoted with respect to the hub ring by a caulking portion formed by plastically deforming an end of the small diameter step portion radially outward. In the wheel bearing device fixed in the direction, the outer side rolling of the double row rolling elements Is a ball, the inner side rolling element is a tapered roller, the pitch circle diameter of the inner side tapered roller is set smaller than the pitch circle diameter of the outer side ball, and the outer peripheral surface of the hub ring corners together being surface crush that is formed into a smooth arcuate shape, shaft-like portion extending in the axial direction from the groove bottom of the inner raceway surface of the hub wheel over the cylindrical portion is formed, this A tapered step portion is formed between the shaft-like portion and a shoulder portion that is abutted against the inner ring, and a mortar-like recess is formed at the outer end of the hub wheel. The depth is the depth that extends beyond the groove bottom of the inner rolling surface to the vicinity of the stepped portion .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a reference example of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part of the hub wheel of FIG. 1, and FIG. 3 is an explanatory view showing an assembled state. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  This wheel bearing device is for a driven wheel called the third generation, and includes an inner member 1 and an outer member 2, and a plurality of balls 3 accommodated so as to roll between both members 1 and 2. A tapered roller 4 is provided. The inner member 1 includes a hub ring 5 and an inner ring 6 press-fitted into the hub ring 5 through a predetermined shimiro.

  The hub wheel 5 integrally has a wheel mounting flange 7 for mounting a wheel (not shown) at one end portion, one (outer side) arcuate inner rolling surface 5a on the outer periphery, and this inner rolling. A small-diameter step portion 5b is formed through an axial portion 8 extending in the axial direction from the surface 5a. Hub bolts 7a are planted on the wheel mounting flange 7 in a circumferentially uniform manner, and circular holes 7b are formed between the hub bolts 7a. The circular hole 7b not only contributes to weight reduction, but also a fastening jig such as a wrench can be inserted from the circular hole 7b in the assembly / disassembly process of the apparatus, and the work can be simplified.

  The inner ring 6 is formed with the other (inner side) tapered inner rolling surface 6a on the outer periphery, a large collar 6b for guiding the tapered roller 4 to the large diameter side of the inner rolling surface 6a, and a small diameter side In addition, a small scissors 6c for preventing the tapered roller 4 from falling off is formed. The inner ring 6 is press-fitted into the small-diameter step portion 5b of the hub wheel 5 through a predetermined shimiro, and a predetermined preload is applied by a crimping portion 9 formed by plastically deforming an end portion of the small-diameter step portion 5b. In the applied state, it is fixed in the axial direction. As a result, it is possible to reduce the weight and size, and to maintain the initially set preload over a long period of time.

  The hub wheel 5 is formed of medium-high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 5a and an inner side of a wheel mounting flange 7 on which an outer seal 12 described later is in sliding contact. The surface hardness is hardened in the range of 58 to 64 HRC by induction hardening from the base 7c to the small diameter step 5b. The caulking portion 9 is kept in the surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 7, and the fretting resistance of the small-diameter step portion 5 b serving as the fitting portion of the inner ring 6 is improved, and caulking is performed. There is no generation of minute cracks or the like during processing, and the plastic processing of the crimped portion 9 can be performed smoothly. The inner ring 6, the ball 3 and the tapered roller 4 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64HRC to the core by quenching.

  The outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and an outer member facing the inner rolling surface 4a of the hub wheel 4 on the inner periphery. An arcuate outer rolling surface 2a on the side and an inner tapered outer rolling surface 2b facing the inner rolling surface 5a of the inner ring 5 are integrally formed. This outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 2a and 2b have a surface hardness in the range of 58 to 64HRC by induction hardening. Has been cured. And the some ball | bowl 3 and the tapered roller 4 are accommodated rotatably via the holder | retainer 10 and 11 between both rolling surface 2a, 4a and 2b, 5a. In addition, a seal 12 and a magnetic encoder 13 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1, and leakage of grease sealed inside the bearing to the outside Prevents rainwater and dust from entering the bearing.

  In the present embodiment, the pitch circle diameter PCDi of the four rows of inner side tapered rollers is set to be smaller than the pitch circle diameter PCDo of the three rows of balls on the outer side. As a result, the outer diameter D on the inner side of the outer member 2 can be set to a small diameter. By using the tapered rollers 4, the knuckle size can be reduced without reducing the basic load rating of the inner rolling element row. The rigidity of the rolling element row portion on the inner side is increased while reducing the size and weight of the device.

  A mortar-shaped recess 14 is formed at the outer end of the hub wheel 5 in the forging process in order to reduce the weight. The depth of the recess 14 extends to the vicinity of the groove bottom of the inner side rolling surface 5a on the outer side. Then, the outer shape of the hub wheel 5 is formed so as to be uniform in thickness corresponding to the recess 14, and is stepped from the reduced diameter portion 15 that gradually decreases in diameter from the inner rolling surface 5 a toward the inner side. The shaft-shaped portion 8 formed to have a small diameter through the portion 8a and the shoulder portion 8b with which the inner ring 6 is abutted lead to the small-diameter step portion 5b.

  On the other hand, in the outer member 2, with the difference in pitch circle diameters PCDo and PCDi, the outer-side outer rolling surface 2a has a diameter larger than the inner-side outer rolling surface 2b, and the outer-side outer rolling surface 2a. From the shoulder 17 on the small diameter side through the cylindrical shoulder 16 and the stepped portion 16a to the outer rolling surface 2b on the inner side.

  Here, the corners of the outer peripheral surface of the hub wheel 5 are flattened to form a smooth arc shape. That is, the base portion 7c of the wheel mounting flange 7, the corner portion (groove shoulder portion) A of the inner side rolling surface 5a on the outer side, and the corner portion B of the step portion 8a have a predetermined chamfered shape / dimension having a corner radius R. Is formed. Specifically, as shown in an enlarged view in FIG. 2, the corner portion A has a chamfered axial dimension La of 0.15 to 0.8 mm, preferably 0.15 to 0.3 mm, and a radial dimension Lr. Is 0.15 to 0.8 mm, preferably 0.15 to 0.3 mm, and the angle R is set to 0.15 to 2.0 R, preferably 0.45 to 0.7 R. Each connecting portion is formed smoothly. If the corner radius R is less than 0.15 mm, the ball 3 is easily scratched. On the other hand, if the corner radius R exceeds 2.0 R, the contact ellipse of the ball 3 rides on the inner rolling surface 5a. It is not preferable because it is easy to come off. Further, the corner portion B has a chamfered axial dimension La and a radial dimension Lr of 0.5 to 5 mm, and a corner radius R of 1.0 to 10R, and each joint portion is smoothly formed. .

  Further, a counter portion C having a diameter larger than the groove bottom diameter and a predetermined width is formed in the vicinity of the groove bottom portion of the inner rolling surface 5a. A diameter-reduced portion 15 comprising a tapered surface or a circular arc surface having a predetermined radius of curvature from the counter portion C toward the inner side is formed, and a step portion 8a is formed from the diameter-reduced portion 15 via a corner portion B. Is formed. The counter portion C is also formed in a smooth arc shape having an angular radius R of 1.0 to 5R.

  In this way, by rounding the corners A, B, and C of the outer peripheral surface of the hub wheel 5, in the assembly of the bearing as shown in FIG. Since it is possible to prevent the ball 3 from being damaged even if it contacts B and C, the acoustic characteristics of the bearing can be improved and the life can be extended.

  Further, since the base portion 7c of the wheel mounting flange 7 and the corner portion A of the inner side rolling surface 5a on the outer side are smoothly rounded, the lip of the seal 12 is prevented from being damaged even if it contacts the corner portion A. It is possible to improve the reliability of the quality and the sealing performance. Further, when a large moment load is applied to the device, it is possible to prevent the occurrence of edge load even if the contact ellipse due to the contact between the inner rolling surface 5a and the ball 3 hits the corner A, The life of the bearing can be extended.

  Of these corners A, B, and C, the corners A and C are ground together with the inner rolling surface 5a by a general-purpose grindstone after heat treatment, and the corner B of the step 8a is cut by a cutting tool or the like. And is formed into a smooth arc shape. Further, by simultaneously grinding the counter portion C with the inner rolling surface 5a, it is possible to prevent the occurrence of burrs and the like, and it is possible to process the outer diameter of the counter portion C with extremely high accuracy without variation. . In addition to the inner rolling surface 5a of the hub wheel 5, not shown, in this embodiment, the corners of the outer rolling surface 2a of the outer member 2 (groove shoulder) and the counter portion are also corner portions. Is flattened and formed into a smooth arc shape. As a result, it is possible to prevent the occurrence of ball scratches during assembly and to suppress the occurrence of edge load even when the contact ellipse due to the contact between the outer rolling surface 2a and the ball 3 hits the corner, Can be further extended.

Figure 4 is a longitudinal cross-sectional view showing an implementation form of the wheel bearing apparatus of the present invention, FIG 5 is a fragmentary enlarged view of the hub of FIG. 4, FIG. 6 is an explanatory view showing an assembled state. Note that this embodiment is basically different from the above-described reference example (FIG. 1) only in the configuration of the hub wheel, and the same reference numerals are given to other identical parts, identical parts, or parts having the same function. In addition, the detailed description is omitted.

  This wheel bearing device is for a driven wheel called a third generation, and includes an inner member 18 and an outer member 2, a plurality of balls 3 accommodated in a freely rolling manner between the two members 18 and 2, and A tapered roller 4 is provided. The inner member 18 includes a hub ring 19 and an inner ring 6 that is press-fitted into the hub ring 19 through a predetermined shimiro.

  The hub wheel 19 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is formed deeper than the mortar-shaped recess 14 (shown by a two-dot chain line) at the end on the outer side. A recessed portion 20 is formed. The depth of the recess 20 is set to a depth extending beyond the groove bottom of the inner rolling surface 5a to the vicinity of the stepped portion 21. The outer shape of the hub wheel 19 is formed so as to have a uniform thickness corresponding to the recess 20, and the shaft-shaped portion 22 extending in the axial direction from the groove bottom portion of the inner rolling surface 5 a, and the tapered shape. The small diameter step portion 5b is reached through the step portion 21 and the shoulder portion 8b with which the inner ring 6 is abutted.

Also in this embodiment, the pitch circle diameter PCDi of the four inner side tapered rollers is set smaller than the pitch circle diameter PCDo of the three outer side balls, as in the above-described reference example. The bearing rigidity on the inner side increases. In addition, a deep recess 20 is formed at the outer side end of the hub wheel 19 and is formed in a contour shape corresponding to the recess 20 so as to have a uniform thickness. Can be reduced in weight.

  Here, the corners of the outer peripheral surface of the hub wheel 19 are flattened to form a smooth arc shape. That is, the base portion 7c of the wheel mounting flange 7 and the corner portion A of the inner side rolling surface 5a on the outer side, the corner portion D of the shaft-like portion 22 and the tapered step portion 21, the tapered step portion 21 and the shoulder portion 8b. Are formed in a predetermined chamfered shape and dimension each having a corner radius R. Specifically, as shown in an enlarged view in FIG. 5, the corner portion A has a chamfered axial dimension La of 0.15 to 0.8 mm, preferably 0.15 to 0.3 mm, and a radial dimension Lr. Is 0.15 to 0.8 mm, preferably 0.15 to 0.3 mm, and the angle R is set to 0.15 to 2.0 R, preferably 0.45 to 0.7 R. Each connecting portion is formed smoothly. Further, the corner portions D and E are set such that the chamfered axial dimension La and the radial dimension Lr are 0.5 to 5 mm, and the corner radius R is 1.0 to 10R, and each joint portion is smoothly formed. ing.

  In this way, by rounding the corners A, C, D, and E of the outer peripheral surface of the hub wheel 19, the outer side ball 3 becomes the corner portion of the outer peripheral surface of the hub wheel 19 in the assembly of the bearing as shown in FIG. 6. It is possible to prevent the ball 3 from being damaged even if it contacts A, C, D, and E, thereby improving the acoustic characteristics of the bearing and extending its life.

  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 wheel bearing device having a third generation structure regardless of whether it is for driving wheels or driven wheels.

It is a longitudinal cross-sectional view which shows the reference example of the wheel bearing apparatus which concerns on this invention. It is a principal part enlarged view which shows the hub wheel of FIG. It is explanatory drawing which shows an assembly state same as the above. The implementation form of a wheel bearing apparatus of the present invention is a longitudinal sectional view showing. It is a principal part enlarged view which shows the hub wheel of FIG. It is explanatory drawing which shows an assembly state same as the above. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1, 18 ... Inner member 2 ... Outer member 3 ... ····························································································································・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 5b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 6b ················· 6c ·············································· 7 ... Wheel mounting flange 7a ... Hub bolt 7b ... Round hole 7c ... ·········· Bases 8 and 22 ···················· Shafts 8a, 16a, 21 ... ··· Steps 8b and 16, 7 ········ Shoulder 9 ································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Magnetic encoder 14, 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Concave 15 ... Reduced diameter part 50 ... Wheel bearing device 51 ...・ ・ ・ ・ ・ ・ Outer member 51a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 51b on the outer side ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer on the inner side Rolling surface 51c ..... Body mounting flange 52 ..... Hub wheels 52a, 54a ... .... Inner rolling surface 52b ... Small diameter step 52c ... ·····································… ... Inner members 56, 57 ... Balls 58, 59 ... Cage 60 , 61 ..... Seal A, B, D, E ..... Corner C ...・ Counter part D1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle diameter of outer side ball D2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle of inner side ball Diameter La ········ Chamfered axial dimension Lr ······ Chamfered radial dimension PCDo ··· .... Pitch circle diameter PCDi of outer side ball・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle diameter R of inner side ball ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Round angle

Claims (4)

An outer member integrally having a vehicle body mounting flange to be attached to the knuckle on the outer periphery, and a double row outer rolling surface formed on the inner periphery;
A wheel mounting flange for mounting a wheel at one end is integrally formed, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a small diameter step extending in the axial direction from the inner rolling surface A hub ring formed with a portion, and an inner ring that is press-fitted into a small-diameter step portion of the hub ring through a predetermined squeeze and has the other inner rolling surface opposed to the double-row outer rolling surface on the outer periphery. An inner member comprising:
In the wheel bearing device including the inner member and a double-row rolling element that is accommodated in a freely rolling manner between both rolling surfaces of the outer member,
Out of the double row rolling elements, the outer side rolling element is a ball and the inner side rolling element is a tapered roller, and the pitch circle diameter of the inner side tapered roller is smaller than the pitch circle diameter of the outer side ball. is set to the corners of the outer peripheral surface of the front SL wheel hub, both being surfaces crush that is formed into a smooth arcuate shape, over the cylindrical portion from the groove bottom of the inner raceway surface of the hub wheel An axial portion extending in the axial direction is formed, a tapered step portion is formed between the shaft portion and a shoulder portion that abuts against the inner ring, and a mortar is formed at the outer end of the hub wheel. A wheel bearing device characterized in that a recess having a shape is formed, and the depth of the recess extends beyond the groove bottom of the inner rolling surface to the vicinity of the stepped portion .   The wheel according to claim 1, wherein the inner ring is fixed in the axial direction in a state where a predetermined preload is applied by a caulking portion formed by plastically deforming an end portion of the small diameter step portion radially outward. Bearing device.   3. The wheel bearing device according to claim 1, wherein a groove shoulder portion and a counter portion of the inner side rolling surface on the outer side are formed by simultaneous grinding with the rolling surface by a general-purpose grindstone after heat treatment. A bearing device for a wheel according to claim 1, outer shape before Symbol hub wheel is formed to have a substantially uniform wall thickness corresponding to the recess.

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