JP2007127244A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device, implementing both weight reduction/compactification and high stiffness of a device, preventing the occurrence of a ball flaw in assembly, improving acoustic characteristics, and elongating service life. <P>SOLUTION: The wheel bearing device is constituted of a double row angular contact ball bearing integrally provided with a wheel mounting flange 6 at one end part thereof. A pitch diameter PCDo of balls 3 on an outer side out of a double row balls 3, 3 is set to be larger than a pitch diameter PCDi of the balls 3 on an inner side, an outer diameter of all of the double row balls 3 is the same, the number of the balls 3 on the outer side is larger than that on the inner side, and corner parts A to C on an outer peripheral face of a hub ring 4 are chamfered and formed in smooth circular arcs. Therefore, the occurrence of the ball flaw in assembly is suppressed to improve the acoustic characteristics of the bearing, the stiffness is enhanced, and the service life is elongated. <P>COPYRIGHT: (C)2007,JPO&INPIT

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. In this double row angular contact ball bearing, a plurality of balls are interposed between a fixed ring and a rotating ring, and a predetermined contact angle is given to the balls so as to contact the fixed ring and the rotating ring.

  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 formed with 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 surface 51a, 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 the 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 to be 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 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. A step 62 is formed between the inner-side rolling surface 52a on the outer side and the small-diameter step 52b into which the inner ring 54 is press-fitted. 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 includes an outer member having a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange for mounting the wheel at one end. An inner member having a single-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and between both rolling surfaces of the inner member and the outer member. In a wheel bearing device including a double row ball accommodated in a freely rolling manner, a pitch circle diameter of an outer side ball of the double row balls is larger than a pitch circle diameter of an inner side ball. In addition to the setting, a configuration was adopted in which corners of the outer peripheral surface of the inner member were flattened and formed into a smooth arc shape.

  In this way, in the wheel bearing device constituted by the double row angular ball bearing having the wheel mounting flange at one end, the pitch circle diameter of the outer side ball of the double row balls is the pitch circle of the inner side ball. The diameter of the inner member is set to be larger than the diameter, and the corners of the outer peripheral surface of the inner member are flattened and formed into a smooth arc shape. It is possible to provide a wheel bearing device that can improve acoustic characteristics, increase rigidity, and extend the life of the bearing.

  Preferably, as in the invention described in claim 2, if the outer diameters of the double row balls are the same and the number of balls on the outer side is set larger than the number of balls on the inner side, A desired bearing life can be ensured while achieving high rigidity.

  More preferably, as in the invention according to claim 3, if the groove shoulder portion and the 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. The connecting portion can be formed more smoothly.

  Further, in the invention according to claim 4, the inner member integrally has a wheel mounting flange at one end, and one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, A hub wheel formed with a small-diameter step portion extending in the axial direction from the inner rolling surface, and the other inner rolling member that is press-fitted into the small-diameter step portion of the hub wheel and faces the outer surface of the double row on the outer periphery. A mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of the recess is at least near the groove bottom of the inner raceway surface of the hub wheel. Since the outer shape of the hub wheel is formed so as to have a substantially uniform thickness corresponding to the recess, it is possible to simultaneously solve the conflicting problems of lightening, compactness and high rigidity of the device. Can do.

  Preferably, as in the invention described in claim 5, an axial 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. A tapered step is formed between the inner ring and the shoulder to be abutted, and the depth of the recess is set to a depth that extends beyond the groove bottom of the inner rolling surface to the vicinity of the step. If so, further weight reduction can be achieved.

  Further, as in the invention described in claim 6, the ratio d / PCDi of the outer diameter d of the ball to the pitch circle diameter PCDi of the inner side ball is 0.14 ≦ (d / PCDi) ≦ 0.25. If it is prescribed | regulated in the range of this, bearing life can be ensured, achieving high rigidity.

  The wheel bearing device according to the present invention integrally has an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end, and the outer periphery includes An inner member in which a double row inner rolling surface facing the outer rolling surface of the row is formed, and a double row accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member In the wheel bearing device comprising: a plurality of balls, a pitch circle diameter of an outer side ball of the double row balls is set larger than a pitch circle diameter of an inner side ball, and the inner member Since the corners of the outer peripheral surface are flattened and formed into a smooth arc shape, the occurrence of ball scratches during assembly is suppressed, and the acoustic characteristics of the bearing are improved. It is possible to provide a wheel bearing device with a long life.

  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 of the double row balls The pitch circle diameter of the inner side balls is set to be larger than the pitch circle diameter of the inner side balls, the outer diameters of the double row balls are the same, and the number of the outer side balls is larger than the number of the inner side balls. In addition to being set a lot, the corners of the outer peripheral surface of the hub wheel are flattened to form a smooth arc shape.

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 the hub wheel of FIG. 1, and FIG. 3 is an explanatory view showing an assembled state. is there. 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 is for a driven wheel called a third generation, and includes an inner member 1, an outer member 2, and a double row of balls 3 accommodated between the members 1 and 2 so as to roll freely. 3 are provided. The inner member 1 includes a hub ring 4 and an inner ring 5 that is press-fitted into the hub ring 4 through a predetermined scissors.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at one end, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface 4a. A small-diameter step 4b is formed through an axial portion 7 extending in the axial direction. Hub bolts 6a are implanted in the wheel mounting flange 6 at equal intervals in the circumferential direction, and circular holes 6b are formed between the hub bolts 6a. The circular hole 6b can not only contribute to weight reduction, but also a fastening jig such as a wrench can be inserted from the circular hole 6b in the assembly / disassembly process of the apparatus, and the work can be simplified.

  The inner ring 5 is formed by forming the other (inner side) inner rolling surface 5a on the outer periphery and press-fitting into the small-diameter step 4b of the hub wheel 4 and plastically deforming the end of the small-diameter step 4b. It is fixed in the axial direction by the caulking portion 8.

  The hub wheel 4 is formed of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and the inner raceway surface 4a and the inner side base portion 6c of the wheel mounting flange 6 to the small diameter step portion 4b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. The caulking portion 8 is kept in the surface hardness after forging. This has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6, improves the fretting resistance of the small-diameter stepped portion 4b serving as the fitting portion of the inner ring 5, and performs caulking. There is no occurrence of minute cracks or the like during processing, and the plastic processing of the crimped portion 8 can be performed smoothly. The inner ring 5 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) on the outer periphery, and the outer side outer rolling facing the inner rolling surface 4a of the hub wheel 4 on the inner periphery. The surface 2a and the inner side outer rolling surface 2b facing the inner rolling surface 5a of the inner ring 5 are integrally formed. Double-row balls 3 and 3 are accommodated between these rolling surfaces, and are held by the cages 9 and 10 so as to roll freely. This outer member 2 is formed of medium 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 seal | sticker 11 is mounted | worn with the outer side edge part of the annular space formed between the outer member 2 and the inner member 1, and the rotational speed of a wheel is detected in an inner side edge part (inner ring 5). The magnetic encoder 12 is fixed, and a cap (not shown) that covers the open end of the outer member 2 is mounted. The seal 9 and the cap prevent leakage of grease sealed inside the bearing and intrusion of rainwater, dust, and the like from the outside into the bearing. In addition, although the 3rd generation structure was illustrated here, the wheel bearing apparatus which concerns on this invention is not restricted to this, A 1st and 2nd generation, or a 4th generation structure may be sufficient.

  In the present embodiment, the pitch circle diameter PCDo of the outer side ball 3 is set larger than the pitch circle diameter PCDi of the inner side ball 3. The outer diameter d of the double-row balls 3 and 3 is the same, but due to the difference in the pitch circle diameters PCDo and PCDi, the number of the outer side balls 3 is set larger than the number of the inner side balls 3. ing.

  A mortar-shaped recess 13 is formed at the outer side end of the hub wheel 4 in the forging process in order to reduce the weight. The depth of the recess 13 is set to the vicinity of the groove bottom of the inner side rolling surface 4a on the outer side. The outer shape of the hub wheel 4 is formed so as to have a uniform thickness corresponding to the recess 13 and gradually decreases from the inner rolling surface 4a toward the inner side. The shaft-shaped portion 7 formed to have a small step diameter through 7a and the shoulder portion 7b with which the inner ring 5 is abutted to the small diameter step portion 4b. Further, with the difference in pitch circle diameters PCDo and PCDi, the inner raceway surface 4a of the hub wheel 4 is enlarged in diameter than the inner raceway surface 5a of the inner race 5, and the groove bottom diameter of this inner raceway surface 5a and the shaft shape are increased. The outer diameter of the part 7 is set to substantially the same dimension.

  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. To the outer side rolling surface 2b on the inner side, following the shoulder 16 on the small diameter side via the cylindrical shoulder 15 and the step 15a. The groove bottom diameter of the outer rolling surface 2b and the inner diameter of the shoulder 15 on the large diameter side are set to be approximately the same size.

  In the wheel bearing device having such a configuration, the pitch circle diameter PCDo of the outer side ball 3 is set to be larger than the pitch circle diameter PCDi of the inner side ball 3, and the number of balls 3 is set to be larger on the outer side. Therefore, the bearing rigidity of the outer side portion is increased compared to the inner side, and the life of the bearing can be extended. Furthermore, a recess 13 is formed at the outer end of the hub wheel 4 and the outer shape is formed so as to have a uniform thickness corresponding to the recess 13. The conflicting problem of high rigidity can be solved.

  In the present embodiment, the ratio d / PCDi of the outer diameter d of the ball 3 to the pitch circle diameter PCDi of the inner ball 3 is defined within a predetermined range after improving the bearing rigidity of the outer side portion. Yes. Here, it is defined in the range of 0.14 ≦ (d / PCDi) ≦ 0.25.

  That is, even if the pitch circle diameter PCDi is the same, the bearing rigidity is increased by reducing the outer diameter d of the balls 3 and increasing the number thereof, so that the smaller the outer diameter d of the balls 3 is from the viewpoint of rigidity. Although the rolling fatigue life decreases as the outer diameter d of the ball 3 decreases, it is preferable that the outer diameter d of the ball 3 is larger from the viewpoint of life. Here, when the relationship between the pitch circle diameter PCDi and the outer diameter d of the ball 3 is obtained by FEM analysis (analysis by the finite element method), when d / PCDi exceeds 0.25, the wheel bearing device is rigid. On the other hand, it was found that when d / PCDi is less than 0.14, the rolling fatigue life is insufficient as a wheel bearing device. Therefore, the pitch circle diameter PCDo of the outer side ball 3 is increased to improve the bearing rigidity of the outer side portion, and the relationship between the pitch circle diameter PCDi of the inner side ball 3 and the outer diameter d of the ball 3 is increased. Is defined in the range of 0.14 ≦ (d / PCDi) ≦ 0.25, the bearing life can be ensured while achieving high rigidity.

  Here, in this embodiment, the corner | angular part of the outer peripheral surface in the hub ring 4 is crushed and it is formed in the smooth circular arc shape. That is, as shown in an enlarged view in FIG. 2, the base portion 6c of the wheel mounting flange 6, the corner portion (groove shoulder portion) A of the inner side rolling surface 4a on the outer side, and the corner portion B of the step portion 7a are It is formed in a predetermined chamfered shape / dimension having R. Specifically, 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 of 0.15 to 0.8 mm, preferably Is formed to be 0.15 to 0.3 mm, and the corner radius R is set to 0.15 to 2.0R, preferably 0.45 to 0.7R, and each joint portion is formed smoothly. Yes. 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 4a. 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 4a. The counter portion C includes a cylindrical portion C1 that extends slightly in the axial direction from the inner rolling surface 4a, and a tapered surface that is reduced in diameter from the cylindrical portion C1 toward the inner side or an arc surface that has a predetermined radius of curvature. The diameter part C2 is comprised, The step part 7a is formed through the corner | angular part B from this reduced diameter part C2. 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 4, in the assembly of the bearing as shown in FIG. Since it can suppress that the ball | bowl 3 generate | occur | produces even if it contacts B and C, while improving the acoustic characteristic of a bearing, it can attain lifetime improvement.

  In addition, in the corner portion A of the base portion 6c of the wheel mounting flange 6 and the inner side rolling surface 4a on the outer side, the lip of the seal 11 can be prevented from coming into contact with the corner portion A and being damaged, and the reliability of quality can be prevented. And the sealing performance can be improved. Further, when a large moment load is applied to the device, even if a contact ellipse due to contact between the inner rolling surface 4a and the ball 3 is applied to the corner portion A, the occurrence of edge load can be suppressed. It is possible to extend the service life.

  Of these corners A to C, the corners A and C are ground simultaneously with the inner rolling surface 4a by a general-purpose grindstone after heat treatment, and the corner B of the stepped portion 7a is cut and smoothed by a cutting tool or the like. It is formed in a circular arc shape. In addition, since the counter part C is ground simultaneously with the inner rolling surface 4a, it is possible to prevent the occurrence of burrs and the like, and the outer diameter of the counter part C can be processed with high accuracy without variation. In addition to the inner rolling surface 4a of the hub wheel 4, not shown, in this embodiment, the corners of the inner rolling surface 5a of the inner ring 5 and the outer rolling surfaces 2a, 2b of the outer member 2 ( The corners of the groove shoulder and the counter are also flattened to form a smooth arc. This prevents the occurrence of ball scratches during assembly and suppresses the occurrence of edge load even when the contact ellipse due to the contact between the rolling surfaces 5a, 2a, 2b and the ball 3 hits the corner. The bearing life can be further extended.

  4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 5 is an enlarged view of a main part of the hub wheel of FIG. 4, and FIG. 6 is an explanatory view showing an assembled state. . Note that this embodiment basically differs from the above-described embodiment (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 20 and an outer member 2, and a double row of balls 3 accommodated between the members 20 and 2 so as to roll freely. 3 are provided. The inner member 20 includes a hub ring 21 and an inner ring 5 that is press-fitted into the hub ring 21 through a predetermined shimiro.

  The hub wheel 21 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is formed deeper than the mortar-shaped recess 13 (shown by a two-dot chain line) at the outer end. A recessed portion 22 is formed. The depth of the recess 22 is set to a depth from the inner rolling surface 4a to the vicinity of the step portion 24 beyond the groove bottom. The outer shape of the hub wheel 21 is formed so as to have a uniform thickness corresponding to the recess 22, and the shaft-shaped portion 23 extending in the axial direction from the groove bottom portion of the inner rolling surface 4 a, and the tapered shape. The small diameter step portion 4b is reached through the step portion 24 and the shoulder portion 7b with which the inner ring 5 is abutted. And with the difference in pitch circle diameters PCDo and PCDi, the inner raceway surface 4a of the hub wheel 21 is expanded in diameter than the inner raceway surface 5a of the inner race 5, and the outer diameter of the shaft portion 23 is the inner raceway surface. The diameter is set larger than the groove bottom diameter of 5a.

  Also in the present embodiment, as in the above-described embodiment, the bearing rigidity of the outer side portion is increased compared to the inner side, the life of the bearing can be extended, and a deep recess is formed at the outer side end of the hub wheel 21. Since the portion 22 is formed and the outer shape is formed so as to have a uniform thickness corresponding to the recess 22, it is possible to achieve further weight reduction as well as high rigidity.

  Further, the corners of the outer peripheral surface of the hub wheel 21 are flattened to form a smooth arc shape. That is, as shown in an enlarged view in FIG. 5, the base portion 6c of the wheel mounting flange 6, the corner portion A of the inner side rolling surface 4a on the outer side, the tapered step portion 24, the shaft portion 23, and the shoulder portion 7b. Are formed in a predetermined chamfered shape / dimension having a corner radius R. Specifically, the corners D and E have 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 is smooth. Is formed.

  By rounding the corners A, C, D, E of the outer peripheral surface of the hub wheel 21 in this way, in the assembly of the bearing as shown in FIG. Even if it contacts with A, C, D, E, it can suppress that the ball | bowl 3 generate | occur | produces, and while improving the acoustic characteristic of a bearing, it can attain lifetime improvement.

  In the above-described embodiment, the double row balls 3 and 3 have the same outer diameter d, but the outer diameters d of the balls 3 and 3 may be different. For example, the ball 3 arranged on the outer side may be made smaller in outer diameter d than the ball 3 arranged on the inner side, and the number of balls may be set larger.

  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 first to fourth generation structure regardless of whether it is for driving wheels or driven wheels.

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 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 2nd Embodiment 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. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1, 20 ... Inner member 2 ... Outer member 3 ... ······· Balls 4, 21 ·································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 5b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Large diameter side Outer diameter surface 5c ......... Small diameter side end face 6 ... Wheel mounting flange 6a ... ····························································· ......・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft-shaped parts 7a, 15a, 24 ......... Steps 7b, 15, 16 ......... Shoulder ························································ 9 ... Seal 12 ... Magnetic encoder 13, 22 ... Recess 14 ... ··························································································· Wheel bearing device 51 ... outer member 51a ... outer rolling surface 51b on the outer side ... Outer rolling surface 51c on the inner side ... Car body mounting flange 52 ... Hub wheels 52a, 54a ...・ ・ ・ ・ ・ ・ Inner rolling surface 52b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter 52c ··············································· Wheel mounting flange 54 .... Inner ring 55 ... Inner members 56, 57 ... Balls 58, 59 ...・ ・ ・ ・ ・ Retainer 60, 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal A, B, D, E ・ ・ ・ ・ ・ ・ ・ ・ Corner C ・ ・ ・ ・ ・ ・ ・ ・··········································································· ...... ················ Pitch circle diameter D2 of the ball on the outer side ...・ ・ ・ ・ ・ ・ ・ ・ Ball outer diameter La ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Chamfering axial dimension Lr ... Chamfering radial dimension PCDo ... Pitch circle diameter PCDi of outer side ball・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle diameter R of inner side ball ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Round angle

In order to achieve the object, the invention according to claim 1 of the present invention includes an outer member having a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange for mounting the wheel at one end. An inner member having a single-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and between both rolling surfaces of the inner member and the outer member. In a wheel bearing device including a double row ball accommodated in a freely rolling manner, a pitch circle diameter of an outer side ball of the double row balls is larger than a pitch circle diameter of an inner side ball. together is set, a corner portion of the outer peripheral surface between the inner raceway surfaces of the double row from the base of the inner side of the wheel mounting flange in said inner member is formed on the rounding et al are smoothly arcuate configuration It was adopted.

In this way, in the wheel bearing device constituted by the double row angular ball bearing having the wheel mounting flange at one end, the pitch circle diameter of the outer side ball of the double row balls is the pitch circle of the inner side ball. while being set to a diameter larger than the diameter, to the wheel from said inner side of the base of the mounting flange double-row angular portion of the outer peripheral surface between the inner raceway surface is been found rounded smooth arcuate in the inner member As a result, it is possible to provide a wheel bearing device that suppresses the occurrence of ball scratches during assembly to improve the acoustic characteristics of the bearing, and achieves high rigidity and a long life of the bearing.

The wheel bearing device according to the present invention integrally has an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end, and the outer periphery includes An inner member in which a double row inner rolling surface facing the outer rolling surface of the row is formed, and a double row accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member In the wheel bearing device comprising: a plurality of balls, a pitch circle diameter of an outer side ball of the double row balls is set larger than a pitch circle diameter of an inner side ball, and the inner member the so corner portion of the outer peripheral surface between the inner raceway surfaces of the double row from the base of the inner side of the wheel mounting flange is formed on the rounding et al are smoothly arcuate in the occurrence of ball scratches during assembly Suppresses and improves the acoustic characteristics of the bearing, while increasing rigidity and shaft It is possible to provide a wheel bearing apparatus which attained the life of.

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 of the double row balls The pitch circle diameter of the inner side balls is set to be larger than the pitch circle diameter of the inner side balls, the outer diameters of the double row balls are the same, and the number of the outer side balls is larger than the number of the inner side balls. with many being set, and is formed into a smooth arcuate shape the wheel corners of the outer peripheral surface of the mounting flange from the base of the inner side between the cylindrical portion is rounded up being in the wheel hub.

Here, in this embodiment, the corner | angular part of the outer peripheral surface in the hub ring 4 is squashed (rounded), and is formed in the smooth circular arc shape. That is, as shown in an enlarged view in FIG. 2, the base portion 6c of the wheel mounting flange 6, the corner portion (groove shoulder portion) A of the inner side rolling surface 4a on the outer side, and the corner portion B of the step portion 7a are It is formed in a predetermined chamfered shape / dimension having R. Specifically, 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 of 0.15 to 0.8 mm, preferably Is formed to be 0.15 to 0.3 mm, and the corner radius R is set to 0.15 to 2.0R, preferably 0.45 to 0.7R, and each joint portion is formed smoothly. Yes. 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 4a. 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. .

In order to achieve the object, the invention according to claim 1 of the present invention includes an outer member having a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange for mounting the wheel at one end. An inner member having a single-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and between both rolling surfaces of the inner member and the outer member. In a wheel bearing device including a double row ball accommodated in a freely rolling manner, a pitch circle diameter of an outer side ball of the double row balls is larger than a pitch circle diameter of an inner side ball. In addition, a configuration was adopted in which corner portions of the outer peripheral surface between the inner side base portion of the wheel mounting flange in the inner member and the inner rolling surface of the double row were formed in a smooth arc shape .

In this way, in the wheel bearing device constituted by the double row angular ball bearing having the wheel mounting flange at one end, the pitch circle diameter of the outer side ball of the double row balls is the pitch circle of the inner side ball. The diameter is set larger than the diameter, and the corner of the outer peripheral surface between the inner side base of the wheel mounting flange of the inner member and the inner rolling surface of the double row is formed in a smooth arc shape. Therefore, it is possible to provide a wheel bearing device that suppresses the occurrence of ball scratches during assembly to improve the acoustic characteristics of the bearing, and achieves high rigidity and a long life of the bearing.

The wheel bearing device according to the present invention integrally has an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end, and the outer periphery includes An inner member in which a double row inner rolling surface facing the outer rolling surface of the row is formed, and a double row accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member In the wheel bearing device comprising: a plurality of balls, a pitch circle diameter of an outer side ball of the double row balls is set larger than a pitch circle diameter of an inner side ball; Since the corner portion of the outer peripheral surface between the inner side base portion of the wheel mounting flange and the inner side rolling surface of the double row is formed in a smooth arc shape, the occurrence of ball scratches during assembly is suppressed and the bearing Improves the acoustic characteristics of the machine, increases rigidity and increases the service life of the bearing It is possible to provide a wheel bearing apparatus which attained.

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 of the double row balls The pitch circle diameter of the inner side balls is set to be larger than the pitch circle diameter of the inner side balls, the outer diameters of the double row balls are the same, and the number of the outer side balls is larger than the number of the inner side balls. In addition to being set, a corner portion of the outer peripheral surface between the base portion on the inner side of the wheel mounting flange in the hub wheel and the small diameter step portion is formed in a smooth arc shape .

In order to achieve such an object, the invention according to claim 1 of the present invention integrally has an outer member having a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange at one end, 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 step portion of the hub ring; An inner member made of an inner ring that is press-fitted and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and between both rolling surfaces of the inner member and the outer member In a wheel bearing device including a double row ball accommodated in a freely rolling manner, a pitch circle diameter of an outer side ball of the double row balls is larger than a pitch circle diameter of an inner side ball. while being set, in the wheel mounting flange includes a counter unit in the wheel hub Adopting a configuration in which the corner portion of the outer peripheral surface of the shoulder portion of the cylindrical portion from the base of the over side is formed into a smooth arcuate shape.

In this way, in the wheel bearing device constituted by the double row angular ball bearing having the wheel mounting flange at one end, the pitch circle diameter of the outer side ball of the double row balls is the pitch circle of the inner side ball. Since the diameter is set to be larger than the diameter, the corner of the outer peripheral surface of the shoulder portion of the small diameter step portion is formed in a smooth arc shape from the inner side base portion of the wheel mounting flange including the counter portion in the hub wheel . In addition, it is possible to provide a wheel bearing device that suppresses the occurrence of ball scratches during assembly and improves the acoustic characteristics of the bearing, as well as increasing rigidity and extending the life of the bearing.

Further, as in the invention described in claim 4 , the ratio d / PCDi of the outer diameter d of the ball to the pitch circle diameter PCDi of the inner side ball is 0.14 ≦ (d / PCDi) ≦ 0.25. If it is prescribed | regulated in the range of this, bearing life can be ensured, achieving high rigidity.

The wheel bearing device according to the present invention has an outer member in which a double row outer rolling surface is formed on the inner periphery, and a wheel mounting flange at one end integrally, and the double row outer rolling on the outer periphery. One inner rolling surface facing the surface, a hub wheel formed with a small-diameter step portion extending in the axial direction from the inner rolling surface, and a small-diameter step portion of the hub wheel, and press-fitted into the outer periphery of the double row An inner member composed of an inner ring formed with the other inner rolling surface facing the outer rolling surface, and a double row accommodated in a freely rolling manner between both rolling surfaces of the inner member and the outer member of the wheel bearing device and a ball, while being set greater than the pitch circle diameter of the ball pitch circle diameter of the outer side of the ball of the inner side of the ball of the double row, in the wheel hub the small diameter stepped from the inner side of the base of the wheel mounting flange includes a counter unit Since the corner portions of the outer peripheral surface of the shoulder portion is formed into a smooth arcuate shape, to suppress the occurrence of the ball scratches during assembly improves the acoustic characteristics of the bearing, high rigidity and long service life of the bearing It is possible to provide a wheel bearing device that achieves the above.

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 of the double row balls The pitch circle diameter of the inner side balls is set to be larger than the pitch circle diameter of the inner side balls, the outer diameters of the double row balls are the same, and the number of the outer side balls is larger than the number of the inner side balls. In addition, the corner of the outer peripheral surface of the shoulder portion of the small diameter step portion is formed in a smooth arc shape from the base portion on the inner side of the wheel mounting flange including the counter portion in the hub wheel .

Claims (6)

An outer member having a double row outer raceway formed on the inner periphery;
An inner member having a wheel mounting flange for attaching a wheel to an end portion integrally, and formed with a double-row inner rolling surface facing the outer rolling surface of the double-row on the outer periphery;
In the wheel bearing device comprising this inner member and a double row of balls accommodated so as to roll between both rolling surfaces of the outer member,
The pitch circle diameter of the outer side balls of the double row balls is set larger than the pitch circle diameter of the inner side balls, and the corners of the outer peripheral surface of the inner member are crushed. A wheel bearing device characterized by being formed in a smooth arc shape.   The wheel bearing device according to claim 1, wherein the outer diameters of the double row balls are the same, and the number of the outer side balls is set to be larger than the number of the inner side balls.   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.   The inner member integrally has a wheel mounting flange at one end, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a small diameter extending in the axial direction from the inner rolling surface. A hub ring formed with a stepped portion, and an inner ring press-fitted into a small-diameter stepped portion of the hub wheel and formed with the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, A mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of the recess is at least near the groove bottom of the inner raceway surface of the hub wheel, and the outer shape of the hub wheel is the recess. The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing device is formed so as to have a substantially uniform thickness corresponding to the location.   A shaft-like 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 a taper shape is formed between the shaft-like portion and a shoulder portion that abuts against the inner ring. 5. The wheel bearing device according to claim 4, wherein the step portion is formed and the depth of the recess is a depth that extends beyond the groove bottom of the inner rolling surface to the vicinity of the step portion.   The ratio d / PCDi of the outer diameter d of the ball to the pitch circle diameter PCDi of the inner side ball is defined in a range of 0.14 ≦ (d / PCDi) ≦ 0.25. A wheel bearing device according to claim 1.

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