JP2017036812A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device capable of improving the sealing performance of a seal by securing a seal space, and of maintaining bearing performance over a long period by enhancing the force of fitting a metallic ring.SOLUTION: A metallic ring 12, which is fitted to a base part 6b of a wheel mounting flange 6 and with which a seal member 14 is put in slide contact, includes a cylindrical fitted part 12a externally fitted to a shoulder part 4e of a hub ring 4, first and second bent parts 12b, 12c formed bent therefrom in two tiers, a disc part 12d extending from the second bent part 12c outward in the radial direction and adhered to a side face 6c of the wheel mounting flange 6, and an umbrella part 12e isolated from an outer diameter part thereof in the axial direction with respect to the wheel mounting flange 6 and extending obliquely outward in the radial direction. An elastic member 15 is integrally joined thereto over a range from the disc 12d to the umbrella part 12e with vulcanization bonding, and put in elastic contact with the side face 6c. The length of the bent part 12b of the metallic ring 12 is set smaller than the length of the second bent part 12c.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, in particular, a metal ring is fitted to a base portion of a wheel mounting flange, and a sealing performance of a seal in which a seal lip is slidably contacted with the metal ring. The present invention relates to a wheel bearing device that is improved and has an increased fitting force of a metal ring.

  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.

  Since these wheel bearing devices are arranged at sites where muddy water or the like is easily applied, a seal device is mounted to seal between the outer member and the inner member. Generally, in a sealing device, a sealing member having a sealing lip is attached to an outer member serving as a stationary member, and the sealing lip is slidably contacted with an outer peripheral surface of the inner member.

  An example of such a seal is shown in FIG. The seal 51 is disposed so as to be in sliding contact with a metal ring (deflector) 53 fitted to the base portion 52 a of the wheel mounting flange 52. The seal 51 includes a metal core 55 fitted to the inner periphery of the end of the outer member 54, and a seal member 56 integrally joined to the metal core 55 by vulcanization adhesion or the like.

  The seal member 56 is joined to the outer peripheral portion of the cored bar 55, joined to a pair of side lips 56a and 56b extending obliquely outward in the radial direction, and the inner edge of the cored bar 55, and tilted to the bearing inward side. And a grease lip 56c extending in the direction. The side lips 56 a and 56 b and the grease lip 56 c are in sliding contact with a metal ring 53 fitted to the base portion 52 a of the wheel mounting flange 52.

  The metal ring 53 is formed by press working from a steel plate having corrosion resistance, and corresponds to a cylindrical fitting portion 53a that is externally fitted to the shoulder portion 57a of the hub wheel 57 and a base portion 52a that is formed in an arc shape. From a curved portion 53b formed in an arc shape, a disk portion 53c extending radially outward from the curved portion 53b and in close contact with the side surface 52b of the wheel mounting flange 52, and an outer diameter portion of the disk portion 53c An umbrella portion 53d extending away from the wheel mounting flange 52 in the axial direction is provided, and a collar portion 53e formed to protrude radially outward from the umbrella portion 53d.

  The base 52a is formed in an arc surface having a predetermined radius of curvature r at a corner between the shoulder 57a of the hub wheel 57 and the wheel mounting flange 52. Corresponding to the arc surface, the curved portion 53b of the metal ring 53 is formed of an arc surface having a predetermined radius of curvature R, and the respective curvature radii R and r are set such that R ≧ r. Thus, when the metal ring 53 is fitted to the base 52a, the curved portion 53b of the metal ring 53 is prevented from interfering with the arc surface of the base 52a and rising. Therefore, a gap is prevented from being generated between the side surface 52b of the wheel mounting flange 52 and the disk portion 53c of the metal ring 53, and the both are brought into close contact with each other, and stable sealing is achieved by suppressing variations in the side lips 56a and 56b. Sex can be secured.

  A tapered surface 54a having a predetermined inclination angle θ1 is formed on the outer periphery of the outer end of the outer member 54. On the other hand, the umbrella portion 53d of the metal ring 53 has a predetermined inclination angle θ2 corresponding to the tapered surface 54a of the outer member 54, and is formed in a tapered shape that gradually increases in diameter toward the end portion. A slight annular gap A is formed between the tapered surface 54a and a labyrinth seal. The inclination angles θ1 and θ2 are set in a range of 15 ° to 30 °, and the gap A is set in a range of 0.05 to 1.0 mm (diameter).

  Thus, muddy water or the like enters the sliding contact portion between the seal 51 and the metal ring 53 by the labyrinth effect formed by the inner peripheral surface of the umbrella portion 53 d of the metal ring 53 and the tapered surface 54 a of the outer member 54. Even if muddy water or the like enters the inside of the metal ring 53 from the slight gap A, as shown by an arrow in the figure, it is easily caused by the centrifugal force accompanying the rotation of the metal ring 53. It is discharged outside and does not stay on the side lip 56a. Therefore, muddy water or the like can be prevented from adhering to the sliding contact surface of the side lip 56a and being worn, and a stable sealing performance can be maintained over a long period of time (see, for example, Patent Document 1).

Japanese Patent No. 5468751

  However, the metal ring 53 of such a conventional wheel bearing device does not have a sufficient fitting force, and if the following force is applied, the metal ring 53 may come out of the shoulder portion 57a of the hub wheel 57. For example, when an external force due to a collision is applied to the bent portion 53 e formed to protrude outward in the radial direction of the metal ring 53, or the hub ring 57 repeatedly receives a load from the wheel, and the load is applied to the metal ring 53. When the vibration is transmitted and deformation or vibration of the base portion 52a of the hub wheel 57 occurs, the metal ring 53 may move in the axial direction and escape. Due to the movement of the metal ring 53, the side lips 56a and 56b may be changed in the squeeze, and the sealing performance may be lowered, and the metal ring 53 may interfere with the ball 58 and cause a reduction in function. In order to improve such safety, it is necessary to improve the prevention of the metal ring 53 from coming off.

  The present invention has been made in view of such circumstances, and in a seal in which a seal lip is slidably contacted with a metal ring, the present invention focuses on a shape that enhances the fitting force of the metal ring and secures a seal space to seal the seal. An object of the present invention is to provide a wheel bearing device capable of improving the performance and increasing the fitting force of the metal ring to maintain the bearing performance over a long period of time.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the suspension on the outer periphery, and a double row outer rolling surface integrally on the inner periphery. A formed outer member and a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and a small-diameter stepped portion formed on the outer periphery, and an inner ring or a constant speed fitted to the hub ring An inner member comprising an outer joint member of a universal joint and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and both the inner member and the outer member. A double row rolling element accommodated between the running surfaces so as to be freely rollable, and a seal attached to both side openings of an annular space formed between the outer member and the inner member, The base on the inner side of the wheel mounting flange is formed in an arc shape, and this base is pressed from a steel plate. The metal ring formed by the work is fitted, and the outer seal among the seals is fitted to the inner periphery of the end of the outer member, and vulcanized adhesion to the core The seal member comprises a seal member having a side lip that is integrally joined and extends to incline radially outward, and a grease lip that inclines and extends inward of the bearing. The side lip of the seal member is in sliding contact with the metal ring. In the wheel bearing device thus formed, the metal ring is formed in two stages corresponding to the base portion from the fitting portion having a cylindrical shape fitted on the shoulder portion of the hub wheel. And a disk portion that extends radially outward from the second bent portion and is in close contact with the inner side surface of the wheel mounting flange.

  In this way, the base portion on the inner side of the wheel mounting flange is formed in an arc shape, and a metal ring formed by pressing from a steel plate is fitted to this base portion, and the seal on the outer side is attached to the outer member. Seal member having a metal core fitted to the inner periphery of the end, a side lip integrally joined to the metal core, extending obliquely outward in the radial direction, and a grease lip extending inclined toward the inner side of the bearing In the wheel bearing device in which the side lip of the seal member is slidably contacted with the metal ring, the metal ring includes a cylindrical fitting portion that is externally fitted to the shoulder portion of the hub wheel, and the fitting portion. First and second bent portions that are bent in two steps corresponding to the base portion, extend radially outward from the second bent portion, and are in close contact with the inner side surface of the wheel mounting flange. A disc part that secures a seal space and seals With improved sealing performance, it is possible to provide a wheel bearing device can be maintained over a long period of time bearing performance by increasing the fitting force of the metal ring.

  Preferably, if the length of the first bent portion of the metal ring is set smaller than the length of the second bent portion as in the invention described in claim 2, A curved part approaches a fitting part and the fitting force of a metal ring increases.

  Further, as in the invention described in claim 3, if the anti-seal sliding surface side of the first bent portion of the metal ring has a straight portion of at least 0.5 mm, the rigidity of the metal ring is increased. The fitting force increases.

  In addition, as in the invention according to claim 4, each inclination angle of the first bent portion of the metal ring, the fitting portion, and the second bent portion is set to 45 ° or less. If so, a sealing space can be secured, and the sealing performance of the seal can be improved.

  Further, as in the invention according to claim 5, at least the first bent portion and the first bent portion of the metal ring and the corner portion of the second bent portion are fitted to the first bent portion. If the corner part on the anti-seal sliding surface side with the part is formed on the arc surface, the press-fitting property of the metal ring can be improved.

  According to a sixth aspect of the present invention, an umbrella portion that is axially spaced from the outer diameter portion of the disk portion of the metal ring with respect to the wheel mounting flange and extends obliquely outward in the radial direction. Provided that the elastic member is integrally joined by vulcanization bonding from the disk portion to the umbrella portion, and is elastically contacted with the inner side surface of the wheel mounting flange. It is possible to prevent foreign matter from entering from between the disk portion and the rusting of the base portion and the metal ring mounting portion over a long period of time.

  A wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange for mounting to a suspension device on the outer periphery, and an outer member formed integrally with a double row outer rolling surface on the inner periphery, and one end A hub ring integrally having a wheel mounting flange for mounting a wheel on the part, and a outer ring member of an inner ring or a constant velocity universal joint fitted to the hub ring, and a small-diameter stepped portion formed on the outer periphery, An inner member having a double row inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member. A double row rolling element, and a seal mounted on both side openings of an annular space formed between the outer member and the inner member, and the base on the inner side of the wheel mounting flange A metal ring formed in an arc shape and pressed from a steel plate at the base The outer seal of the seals is attached to the inner periphery of the end of the outer member, and is integrally joined to the core by vulcanization bonding. In the wheel bearing device, comprising a seal member having a side lip extending inclined and a grease lip extending inclined toward the inner side of the bearing, wherein the side lip of the seal member is in sliding contact with the metal ring. A cylindrical fitting portion in which a ring is fitted on the shoulder portion of the hub wheel, and first and second bent portions formed in two steps from the fitting portion so as to correspond to the base portion And a disk portion extending radially outward from the second bent portion and being in close contact with the inner side surface of the wheel mounting flange. Bearing with improved performance and increased metal ring fitting force It is possible to provide a wheel bearing apparatus that can be maintained over the ability to long term.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a principal part enlarged view which shows the seal part of FIG. It is explanatory drawing which shows the analysis result of the drawing force of a metal ring, (a) is a comparative example which shows the conventional R-shaped metal ring, (b) is a comparative example which shows the metal ring of 1 step bending shape, (c ) Is an example showing a metal ring according to the present invention, and (d) is a modification of the metal ring of (c). It is a principal part enlarged view which shows the sealing device of the conventional wheel bearing apparatus.

  An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for attaching a wheel to one end And a hub wheel in which an inner rolling surface facing one of the double row outer rolling surfaces and a small-diameter step portion extending in the axial direction from the inner rolling surface are formed on the outer periphery, and the hub An inner member comprising an inner ring press-fitted into a ring and having an inner race surface formed on the outer periphery facing the other of the outer row rolling surfaces of the double row, and both rolling surfaces of the inner member and the outer member A double-row rolling element housed in a freely rotatable manner between, and seals mounted on both side openings of an annular space formed by the outer member and the inner member, and the wheel mounting flange. The base on the inner side is formed in an arc shape, and this base is formed by pressing from a steel plate And the outer seal of the seals is joined to the inner periphery of the end of the outer member, and the core metal is integrally joined to the outer ring. In the wheel bearing device, comprising a seal member having a side lip extending incline toward the bearing and a grease lip extending incline toward the bearing inward side, and the side lip of the seal member is in sliding contact with the metal ring, A cylindrical fitting portion in which a metal ring is fitted on the shoulder portion of the hub wheel, and first and second bent portions formed in two steps from the fitting portion so as to correspond to the base portion. A disk portion that extends radially outward from the second bent portion and is in close contact with the side surface on the inner side of the wheel mounting flange, and from the outer diameter portion of the disk portion to the wheel mounting flange. And an umbrella portion that is axially spaced apart and extends radially outward and inclined. The elastic member is integrally joined by vulcanization bonding from the disc portion to the umbrella portion, and is elastically contacted with the side surface on the inner side of the wheel mounting flange, and the length of the first bent portion of the metal ring Is set smaller than the length of the second bent portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part showing a seal portion of FIG. 1, and FIG. 3 is an analysis result of a pulling force of a metal ring. (A) is a comparative example showing a conventional R-shaped metal ring, (b) is a comparative example showing a one-step bent metal ring, and (c) is a metal according to the present invention. An example showing a ring, (d) is a variation of the metal ring of (c). In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  The wheel bearing device shown in FIG. 1 is for a drive wheel called a third generation, and is externally inserted into the inner member 1 and the inner member 1 through double-row rolling elements (balls) 3. The outer member 2 is provided. The inner member 1 includes a hub ring 4 and an inner ring 5 fixed to the hub ring 4.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A cylindrical small diameter step portion 4b extending in the axial direction from the surface 4a is formed, and a serration (or spline) 4c for torque transmission is formed on the inner periphery. In addition, hub bolts 6a for fastening the wheels are implanted in the wheel mounting flange 6 at equal intervals in the circumferential direction.

  On the other hand, the inner ring 5 is formed with the other (inner side) inner raceway surface 5a on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub wheel 4 through a predetermined shimoshiro, and the end portion of the small-diameter step portion 4b. Is fixed in the axial direction with respect to the hub wheel 4 in a state where a predetermined bearing preload is applied by a caulking portion 4d formed by plastically deforming the outer ring in a radially outward direction.

  The hub wheel 4 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the base portion 6b on the inner side of the wheel mounting flange 6 are connected 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 4d is an unquenched portion with 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. A micro crack or the like is prevented from occurring in the caulking portion 4d due to the processing.

  The outer member 2 integrally has a vehicle body mounting flange 2b to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and the double row inner rolling surface 4a of the inner member 1 on the inner periphery. Double row outer rolling surfaces 2a, 2a facing 5a are integrally formed. The outer member 2 is formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 2a and 2a have a surface hardness of 58 to 64 HRC by induction hardening. Hardened to range. The double-row rolling elements 3 and 3 are accommodated between the rolling surfaces of the outer member 2 and the inner member 1 and are held by the cages 7 and 7 so as to be freely rollable. 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. Moreover, the rolling element 3 is formed of high carbon chrome steel such as SUJ2 as in the case of the inner ring 5, and is hardened in the range of 62 to 67HRC to the core part by quenching.

  Seals 8 and 9 are attached to both side openings of the annular space formed between the outer member 2 and the inner member 1. These seals 8 and 9 prevent the grease sealed inside the bearing from leaking outside and preventing rainwater, dust, and the like from entering the bearing from the outside. The inner side seal 9 constitutes a so-called pack seal composed of an annular seal plate 10 and a slinger 11 which are substantially L-shaped in cross section and arranged to face each other.

  Here, in the present embodiment, the metal ring 12 is fitted to the inner side base portion 6 b of the wheel mounting flange 6, and the outer side seal 8 is disposed so as to be in sliding contact with the metal ring 12. As shown in an enlarged view in FIG. 2, the seal 8 is integrally joined to the core bar 13 fitted to the inner periphery of the outer end of the outer member 2 by vulcanization bonding or the like. And a seal member 14. The core 13 is made of an austenitic stainless steel plate (JIS standard SUS304, etc.) or a rust-proof cold-rolled steel plate (JIS standard SPCC, etc.), and the cross section is substantially U-shaped by pressing. Is formed.

  On the other hand, the seal member 14 is joined to the outer peripheral portion of the cored bar 13 and joined to the pair of side lips 14a and 14b extending obliquely outward in the radial direction and the inner edge part of the cored bar 13, and to the bearing inner side It has a grease lip 14c extending in an inclined manner. These side lips 14 a and 14 b and the grease lip 14 c are in sliding contact with the metal ring 12 fitted to the base portion 6 b on the inner side of the wheel mounting flange 6. In addition, the sealing member 14 wraps around and is joined to the fitting portion of the core metal 13 to form a so-called half metal structure. Thereby, airtightness is improved and foreign matter such as muddy water is prevented from entering the inside of the bearing from the fitting portion between the outer member 2 and the cored bar 13.

  The metal ring 12 is formed from a steel plate having corrosion resistance, for example, an austenitic stainless steel plate, or a cold-rolled steel plate that has been rust-proofed by pressing, and is a cylindrical shape that is externally fitted to the shoulder 4e of the hub ring 4. The fitting portion 12a, the first and second bent portions 12b and 12c bent in two steps corresponding to the arcuate base portion 6b formed from the fitting portion 12a, and the second A disc portion 12d extending radially outward from the bent portion 12c and being in close contact with the inner side surface 6c of the wheel mounting flange 6 via an elastic member 15 described later, and an outer diameter of the disc portion 12d An umbrella portion 12e that is spaced apart from the wheel mounting flange 6 in the axial direction and extends obliquely outward in the radial direction, and a flange portion 12f that protrudes radially outward from the umbrella portion 12e. Yes. The flange 12f is provided to improve the strength and rigidity of the metal ring 12, and can prevent the deformation of the metal ring 12 and can increase the size and shape accuracy.

  Moreover, in order to improve the press fit property of the metal ring 12, of the corners of the fitting part 12a and the first bent part 12b and the corners of the first bent part 12b and the second bent part 12c At least the corners on the anti-seal sliding surface side (fitting surface side) of the fitting portion 12a and the first bent portion 12b are formed as arcuate surfaces.

  In addition, as for this metal ring 12, while the plate | board thickness is set to the range of 0.4-1.0 mm, the surface roughness of the steel plate used as a raw material is set to the range of Ra0.2-0.6. As a result, a desired fitting force can be secured, a good seal sliding contact surface can be obtained, lip wear can be suppressed, and the sealing performance of the seal 8 can be maintained even when used in a poor environment. Can be planned. Note that Ra is one of JIS roughness shape parameters (JIS B0601-1994), and is an arithmetic average roughness, which means an average value of absolute value deviations from an average line.

  Moreover, in this embodiment, the elastic member (packing) 15 which consists of synthetic rubber etc. is integrally joined by the vulcanization adhesion from the disk part 12d of the metal ring 12 to the umbrella part 12e and the collar part 12f. The wheel mounting flange 6 is in elastic contact with the inner side surface 6c. Thus, foreign matter is prevented from entering from between the side surface 6c of the wheel mounting flange 6 and the disc portion 12d of the metal ring 12, and rusting of the base 6b and the mounting portion of the metal ring 12 is performed over a long period of time. Can be prevented.

  Furthermore, a tapered surface 16 having a predetermined inclination angle θ1 that gradually increases in diameter from the outer end surface of the outer member 2 toward the outer peripheral surface is formed. On the other hand, the umbrella portion 12 e of the metal ring 12 is formed in a tapered shape having a predetermined inclination angle θ 2 corresponding to the tapered surface 16 of the outer member 2, and is slightly between the tapered surface 16 of the outer member 2. An annular gap A is formed to form a labyrinth seal. The inclination angles θ1 and θ2 are set in a range of 15 ° to 30 ° so as to be substantially the same angle, and the gap A is set in a range of 0.05 to 1.0 mm (diameter).

If the inclination angles θ1 and θ2 are set to exceed 30 °, muddy water or the like is liable to enter, and if it is less than 15 °, the muddy water or the like that has entered may be difficult to drain due to centrifugal force. Further, if the gap A is less than 0.05 mm, the umbrella 12e may interfere with the outer member 2 due to dimensional variation or eccentricity of the metal ring 12 or the outer member 2, and if it exceeds 1.0 mm, the labyrinth. This is not preferable because the effect is reduced by half and muddy water or the like easily enters.
Here, “substantially the same” is, for example, a design target value, and a state where there is substantially no angular difference, that is, an angular difference caused by a processing error or the like should be allowed.

  As described above, muddy water or the like enters the sliding contact portion between the seal 8 and the metal ring 12 by the labyrinth seal constituted by the inner peripheral surface of the umbrella portion 12 e of the metal ring 12 and the tapered surface 16 of the outer member 2. Even if muddy water or the like enters the inside of the metal ring 12 from this slight annular gap A, as shown by the arrows in the figure, the centrifugal force accompanying the rotation of the metal ring 12 causes It is easily discharged to the outside and does not stay near the side lip 14a. Therefore, muddy water or the like can be prevented from adhering to the sliding contact surface of the side lip 14a and being worn, and a stable sealing performance can be maintained over a long period of time.

  Here, the third generation structure on the driven wheel side is exemplified as the wheel bearing device, but the wheel bearing device according to the present invention is not limited to this, and the second generation or the fourth generation is applicable as long as the structure is applicable. It may be a generation. Furthermore, in this embodiment, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated, of course, not only this but the double row cone which uses a tapered roller for a rolling element You may be comprised with the roller bearing.

  Here, the inventors of the present invention have earnestly researched the shape that increases the fitting force of the metal ring in the seal in which the seal lip is in sliding contact with the metal ring, based on the knowledge such as failure cases in the market. As a result of verifying the relationship between the shape of the ring and the pulling force by FEM analysis (analysis by the finite element method), an R-shaped (arc-shaped) metal ring having a conventional radius of curvature R shown in FIG. Compared to 53, the pulling force was found to be greater in the one-step or two-step bending shape shown in (b) to (d).

  Specifically, the metal ring 17 shown in (b) includes a cylindrical fitting portion 17a that is externally fitted to the shoulder portion 4e of the hub wheel 4, and a base portion 6b that is formed in an arc shape from the fitting portion 17a. One-stage bent portion 17b straddling the wheel, and a disc portion 17c that extends radially outward from the bent portion 17b and is in close contact with the inner side surface 6c of the wheel mounting flange 6 via the elastic member 15. And an umbrella part 17d that is axially spaced from the outer diameter part of the disk part 17c with respect to the wheel mounting flange 6 and that extends obliquely outward in the radial direction, and protrudes radially outward from the umbrella part 17d. The flange portion 17e is formed.

  The pulling force of the metal ring 17 is 130 to 135 when the pulling force of the R-shaped metal ring 53 shown in (a) is 100, and an increase of 30 to 35% can be expected. However, with this one-stage bending type, it is difficult to secure a sealing space in terms of design, and a desired sealing property cannot be obtained.

  On the other hand, as described above, the metal ring 12 shown in (c) is formed in a circular arc shape from the cylindrical fitting portion 12a fitted on the shoulder portion 4e of the hub wheel 4 and the fitting portion 12a. First and second bent portions 12b and 12c that are bent in two steps corresponding to the base portion 6b, and extend radially outward from the second bent portion 12c, and the inner side of the wheel mounting flange 6 The disc portion 12d that is in close contact with the side surface 6c via the elastic member 15, and the outer diameter portion of the disc portion 12d is axially separated from the wheel mounting flange 6 and is inclined radially outward. And an eaves portion 12e that extends outward in the radial direction from the umbrella portion 12e.

  Further, the metal ring 18 shown in (d) is the ratio of the length of the metal ring 12 described above and the first and second bent portions 12b and 12c basically bent in two steps, Only in the inclination angle, the cylindrical fitting portion 12a fitted on the shoulder portion 4e of the hub wheel 4 and the base portion 6b formed in an arc shape from the fitting portion 12a are arranged in two steps. The bent first and second bent portions 18a and 18b and the second bent portion 18b extend radially outward, and the elastic member 15 is provided on the inner side surface 6c of the wheel mounting flange 6. A disc portion 12d that is closely attached thereto, an umbrella portion 12e that is spaced apart from the outer diameter portion of the disc portion 12d in the axial direction with respect to the wheel mounting flange 6 and that extends obliquely outward in the radial direction, and the umbrella A flange portion 12f is formed so as to protrude radially outward from the portion 12e.

  The pulling force of these metal rings 12 and 18 is that when the pulling force of the R-shaped metal ring 53 shown in (a) is 100, the metal ring 12 shown in (c) is 135 to 140, and (d ) Is 125 to 130, and an increase of 25 to 40% is expected. Therefore, the sealing space is secured to improve the sealing performance of the seal 8 and the fitting force of the metal rings 12 and 18 is increased. A wheel bearing device capable of maintaining the bearing performance over a long period of time can be provided.

  Here, the cause of the difference in the pulling force between the metal ring 12 shown in (c) and the metal ring 18 shown in (d) is the first and second bent portions 12b and 12c of the metal ring 12. It can be considered that the ratio of the first and second bent portions 18a and 18b of the metal ring 18 is different. That is, in the metal ring 12, the length of the first bent portion 12b and the length of the second bent portion 12c are the length of the first bent portion 12b <the length of the second bent portion 12c. It can be considered that this is due to the result of adjusting the angles of the inclination angles α1 and β1. That is, by setting α1 <β1, the first bent portion 12b approaches the fitting portion 12a and the fitting force is increased.

  On the contrary, in the metal ring 18, the length of the first bent portion 18a and the length of the second bent portion 18b are the length of the first bent portion 18a> the length of the second bent portion 18b. Thus, it is considered that the result is that the first bent portion 18a is separated from the fitting portion 12a and the fitting force is reduced by α2> β2.

  In addition, the inclination angles α1, α2, β1, and β2 are preferably 45 ° or less in order to secure a sealing space. Thereby, the seal space of the seal 8 can be secured. This is because, for example, in the metal ring 12 having a two-step bent shape, the first bent portion 12b and the second bent portion 12c are set at the start positions of the first bent portion 12a in order to avoid interference with the base 6b. 12b must be moved in the axial direction, and the second bent portion 12c must be moved in the radial direction, but the second bent portion 12c is moved in the radial direction while maintaining the position of the first bent portion 12b. If it is attempted to move, the two-step bending is not established even at the same inclination angle, and a one-step bending shape is obtained, or the length of the first bent portion 12b> the length of the second bent portion 12c. End up.

  Furthermore, it is preferable to secure a straight portion having a length (fitting surface side) of the first bent portion 12b on the anti-seal sliding surface side of at least 0.5 mm. If the straight portion of the first bent portion 12b is less than 0.5 mm, it overlaps with the end portion of the fitting portion 12a. As a result, the rigidity of the metal ring 12 is reduced, and the fitting force is (a ) Of the conventional R-shaped metal ring 53 shown in FIG.

  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 second to fourth generation wheel bearing devices of the inner ring rotation type.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body mounting flange 3 Rolling body 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step part 4c Serration 4d Clamping part 4e Shoulder part 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Wheel mounting flange inner side base 6c Wheel mounting flange inner side surface 7 Cage 8 Outer side seal 9 Inner side seal 10 Seal plate 11 Slinger 12, 17, 18 Metal ring 12a, 17a Fitting portion 12b, 18a 1st bent part 12c, 18b 2nd bent part 12d, 17c Disc part 12e, 17d Umbrella part 12f, 17e Ridge part 13 Core 14 Seal member 14a, 14b Side lip 14c Grease lip 15 Elasticity Member 16 Tapered surface 17b of outer member Bending portion 51 Seal 52 Wheel mounting flange 52a Wheel mounting flange Inner side base 52b Inner side surface 53 of wheel mounting flange Metal ring 53a Fitting portion 53b Curved portion 53c Disk portion 53d Umbrella portion 53e Hook portion 54 Outer member 54a Tapered surface 55 of outer member 55 Core metal 56 Seal member 56a, 56b Side lip 56c Grease lip 57 Hub wheel 57a Hub ring shoulder A Annular gap R Curvature radius of curvature of metal ring r Radius of curvature of base θ1 Inclination angle of taper surface θ2 Inclination angle of umbrella portion α1, α2 Inclination angles β1 and β2 of the first bent part Inclined angles of the second bent part

Claims (6)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
It consists of a hub wheel that has a wheel mounting flange for mounting a wheel at one end and a small-diameter step on the outer periphery, and an outer ring member of an inner ring or constant velocity universal joint that is fitted to this hub ring. An inner member in which a double row inner rolling surface facing the double row outer rolling surface is formed on the outer periphery;
A double row rolling element housed so as to be freely rollable between both rolling surfaces of the inner member and the outer member;
A seal mounted on both side openings of the annular space formed between the outer member and the inner member;
The base portion on the inner side of the wheel mounting flange is formed in an arc shape, and a metal ring formed by pressing from a steel plate is fitted to the base portion,
Outer side seal among the seals is a metal core fitted to the inner periphery of the end portion of the outer member, and a side that is integrally joined to the metal core by vulcanization and extends obliquely outward in the radial direction. In the wheel bearing device, comprising a seal member having a lip and a grease lip extending inclinedly toward the bearing inward side, and the side lip of the seal member is in sliding contact with the metal ring,
The metal ring has a cylindrical fitting portion that is externally fitted to the shoulder portion of the hub wheel, and first and second folds formed in two steps from the fitting portion corresponding to the base portion. A wheel bearing device comprising: a curved portion; and a disk portion extending radially outward from the second bent portion and being in close contact with an inner side surface of the wheel mounting flange. .   The wheel bearing device according to claim 1, wherein a length of the first bent portion of the metal ring is set smaller than a length of the second bent portion.   The wheel bearing device according to claim 2, wherein an anti-seal sliding surface side of the first bent portion of the metal ring has a straight portion of at least 0.5 mm.   4. The wheel according to claim 1, wherein an inclination angle of each of the first bent portion of the metal ring, the fitting portion, and the second bent portion is set to 45 ° or less. Bearing device.   Of the corners of the first bent portion and the fitting portion and the second bent portion of the metal ring, at least the corner portion on the anti-seal sliding surface side of the first bent portion and the fitting portion. The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing device is formed on an arc surface.   An umbrella portion that is axially spaced from the outer diameter portion of the disk portion of the metal ring with respect to the wheel mounting flange and that extends obliquely outward in the radial direction extends from the disk portion to the umbrella portion. The wheel bearing device according to claim 1, wherein the elastic member is integrally joined by vulcanization adhesion and elastically contacts the inner side surface of the wheel mounting flange.

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