JP2017062019A - Bearing for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of preventing degradation of rolling fatigue life by reducing deformation of an opening portion of an outer member while minimizing increase of the total weight.SOLUTION: In a bearing device 1 for a wheel including an outer member 2 integrally having a car body mounting flange 2e, and integrally provided with double row outer rolling faces 2c and 2d, an inner member integrally having a wheel mounting flange 3b for mounting the wheel, composed of a hub ring 3 having a small-diameter step portion 3a, and at least one inner ring 4 press-fitted to the small-diameter step portion 3a of the hub ring 3, and provided with double row inner rolling faces 3c and 4a opposed to the double row outer rolling faces 2c and 2d, and double row rolling elements 5a and 5b rollably accommodated between the rolling faces, a belt-shaped portion 2f radially projecting by a projection amount p1 with a prescribed width w1 so that at least partially overlapped radially to the outer rolling face 2d at the wheel mounting flange side, of the outer member, is formed on an outer peripheral face of the outer member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wheel bearing device. More specifically, the present invention relates to a wheel bearing device that improves the life of an outer member.

  2. Description of the Related Art Conventionally, a wheel bearing device that rotatably supports a wheel in a suspension device such as an automobile is known. In a wheel bearing device, a hub wheel connected to a wheel is rotatably supported by an outer member via a rolling element. The wheel bearing device is fixed to a knuckle of a vehicle via a mounting flange of an outer member. That is, the wheel bearing device rotatably supports the hub wheel to which the wheel is connected in a state where the outer member is fixed to the knuckle of the vehicle. As the wheel bearing device, a double-row angular contact ball bearing having a desired bearing rigidity and a small rotational torque from the viewpoint of improving fuel efficiency is often used. The wheel bearing device constitutes an angular ball bearing by giving a predetermined contact angle to a rolling element and bringing it into contact with an outer member and a hub wheel. On the outer member of the wheel bearing device, the rolling element row rolls in the vicinity of the opening on the wheel mounting flange side (outer side) of the hub wheel and in the vicinity of the opening on the mounting flange side (inner side) of the outer member. A surface is formed. The outer member supports the load from the wheel on the rolling surface via the rolling elements supporting the hub wheel.

  In such a wheel bearing device, when the vehicle is stationary or moving back and forth, the load from the vehicle acts on the approximate center of the double row angular ball bearing. On the other hand, when the vehicle turns, the radial load or the axial load applied to the wheel on the opposite side of the turning direction (left side of the vehicle in the case of right turn) increases. Therefore, there is a wheel bearing device that increases the rigidity of the outer rolling element row to increase the bearing rigidity and prevent the rolling fatigue life from decreasing. For example, as described in Patent Document 1.

  In the wheel bearing device described in Patent Document 1, the outer side rolling element row has a pitch circle diameter larger than that of the inner side rolling element row among the double row rolling element rows. The number of rolling elements in the rolling element row is increased, and the rigidity of the rolling element row is increased. However, in the wheel bearing device, the diameter of the outer-side opening of the outer member increases as the pitch circle diameter of the outer rolling element row increases. In addition, each opening of the outer member is formed with a fitting portion for providing a seal member for preventing rainwater and the like from entering the outer member, a reference surface for processing, and the like. For this reason, the wheel bearing device has an outer side separated from the mounting flange fixed to the knuckle when a radial load or an axial load applied to the outer rolling surface of the outer member increases due to turning of the vehicle. There was a possibility that the opening part of the roller was deformed into an approximately elliptical shape, and the roundness of the rolling surface was deteriorated and the rolling fatigue life was reduced.

JP 2008-155837 A

  The present invention has been made in view of the above situation, and can reduce the deformation amount of the opening of the outer member while minimizing the increase in the overall weight, thereby preventing the rolling fatigue life from being lowered. The object is to provide a wheel bearing device.

  That is, an outer member integrally having a vehicle body mounting flange on the outer periphery and a double row annular outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for mounting a wheel on one end are integrated. A hub ring having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and facing the outer surface of the double row on the outer periphery. An inner member in which a double-row annular inner rolling surface is formed, and a double-row rolling element housed in a freely rolling manner between the inner member and the outer member. The outer peripheral surface of the outer member has a predetermined width so that at least a part of the outer member overlaps the outer raceway surface of the outer member on the wheel mounting flange side in the radial direction of the outer member. In this way, a band-shaped part protruding by a predetermined amount in the radial direction is formed. .

  The belt-shaped portion is formed so as to overlap with a portion of the outer rolling surface that is closest to the outer peripheral surface of the outer member in the radial direction of the outer member.

  The belt-like portion is formed so as to overlap with the maximum outer diameter portion of the annular outer rolling surface in the radial direction of the outer member.

  The belt-shaped portion is formed so as to cover a portion where a straight line passing through a rolling element contact point of the outer rolling surface and a rolling element contact point of the inner rolling surface intersects with an outer peripheral surface of the outer member. .

  As effects of the present invention, the following effects can be obtained.

  According to the wheel bearing device, the thickness of the portion of the outer member near the opening on the wheel mounting flange side where the thickness of the outer member is reduced by the outer rolling surface is increased. As a result, it is possible to reduce the amount of deformation of the outer member opening while minimizing the increase in the overall weight and prevent the rolling fatigue life from decreasing.

  According to the wheel bearing device, the thickness of the outer member in the vicinity of the opening on the wheel mounting flange side and where the thickness of the outer member is reduced most by the outer rolling surface is increased. As a result, it is possible to reduce the amount of deformation of the outer member opening while minimizing the increase in the overall weight and prevent the rolling fatigue life from decreasing.

  According to the wheel bearing device, the thickness of the portion of the outer member near the opening on the wheel mounting flange side where the outer rolling surface receives the force is increased. As a result, it is possible to reduce the amount of deformation of the outer member opening while minimizing the increase in the overall weight and prevent the rolling fatigue life from decreasing.

The perspective view which shows the whole structure in 1st embodiment of the wheel bearing apparatus. Sectional drawing which shows the whole structure in 1st embodiment of the wheel bearing apparatus (A arrow directional view in FIG. 1). The expanded fragmentary sectional view which shows the shape of the outward member in 1st embodiment of the wheel bearing apparatus. The expanded partial sectional view which shows the shape of the outward member in other embodiment of 1st embodiment of the wheel bearing apparatus. (A) Sectional drawing which shows the whole structure before the strip | belt-shaped part in 2nd embodiment of a wheel bearing apparatus is formed (b) Sectional drawing which shows the whole structure after a strip | belt-shaped part is similarly formed. The expanded partial sectional view which shows the shape of the outward member in 3rd embodiment of the wheel bearing apparatus. The expanded fragmentary sectional view which shows the shape of the outward member in 4th embodiment of the wheel bearing apparatus.

  Below, the wheel bearing apparatus 1 which is 1st embodiment of the wheel bearing apparatus is demonstrated using FIG. 1 and FIG.

  As shown in FIGS. 1 and 2, the wheel bearing device 1 supports a wheel rotatably in a suspension device of a vehicle such as an automobile. The wheel bearing device 1 includes an outer member 2, a hub wheel 3, an inner ring 4, two rows of one side ball row 5a (see FIG. 2), which is a rolling row, another side ball row 5b (see FIG. 2), one A side (inner side) seal member 6 (see FIG. 2) and an other side (outer side) seal member 8 (see FIG. 2) are provided.

  As shown in FIG. 2, the outer member 2 supports the inner members (hub wheel 3 and inner ring 4). The outer member 2 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a substantially cylindrical shape. At one end (inner side) end of the outer member 2, a one-side opening 2a into which the one-side seal member 6 can be fitted is formed. The other side (outer side) end of the outer member 2 is formed with an other side opening 2b into which the other side sealing member 8 can be fitted. On the inner peripheral surface of the outer member 2, an annular one side outer rolling surface 2c on which the one side ball row 5a rolls is formed in the vicinity of the one side opening 2a. Similarly, on the inner peripheral surface of the outer member 2, the outer rolling surface 2d on the other side of the ring (the wheel mounting flange 3b described later) on which the other side ball row 5b rolls in the vicinity of the other side opening 2b. Is formed. The outer rolling surface 2c on one side and the outer rolling surface 2d on the other side are formed to be parallel to each other in the circumferential direction. The outer rolling surface 2d on the other side is formed to have a larger pitch circle diameter than the outer rolling surface 2c on the one side. In addition, you may comprise equally the pitch circle diameter of the outer side rolling surface 2c of one side, and the outer side rolling surface 2d of the other side. A hardened layer having a surface hardness in the range of 58 to 64 HRC is formed by induction hardening on the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side. A vehicle body attachment flange 2e for being attached to a knuckle of a suspension device (not shown) is integrally formed on the outer peripheral surface on one side of the outer member 2. One side surface and the other side surface which are attachment surfaces of the vehicle body attachment flange 2e are subjected to machining such as cutting. On the outer peripheral surface of the other side of the outer member 2 (outer side, wheel mounting flange 3b described later), a predetermined amount in the radial direction with a predetermined width from the end of the other side opening 2b toward one side in the axial direction. A protruding annular belt-like portion 2f is integrally formed.

  The hub wheel 3 constituting the inner member rotatably supports a vehicle wheel (not shown). The hub wheel 3 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a bottomed cylindrical shape. At one end (inner side) of the hub wheel 3, a small-diameter step portion 3a having a reduced diameter on the outer peripheral surface is formed. A wheel attachment flange 3b for attaching a wheel is integrally formed at the other end (outer side) of the hub wheel 3. An annular inner raceway surface 3c and an annular seal sliding surface 3d are formed in the circumferential direction on the outer peripheral surface of the other side of the hub wheel 3 (the wheel mounting flange 3b side). Hub bolts 3e are provided at the circumferentially equidistant positions on the wheel mounting flange 3b.

  An inner ring 4 constituting an inner member is press-fitted into the small-diameter stepped portion 3 a at one end of the hub wheel 3. The inner ring 4 is made of high carbon chrome bearing steel such as SUJ2, and is hardened in the range of 58 to 64 HRC to the core part by quenching. On the outer peripheral surface of the inner ring 4, an annular inner rolling surface 4a is formed in the circumferential direction. The inner raceway surface 3 c of the hub wheel 3 is formed to have a larger pitch circle diameter than the inner raceway surface 4 a of the inner race 4. In addition, you may comprise the pitch circle diameter of the inner side rolling surface 3c and the inner side rolling surface 4a equally. The inner ring 4 is integrally fixed to one end of the hub ring 3 in a state where a predetermined preload is applied by press-fitting. That is, the inner raceway 4 a is constituted by the inner race 4 on one side of the hub race 3. The hub wheel 3 has a surface hardness of 58 to 64 HRC by induction hardening from the small diameter step 3a on one side to the inner rolling surface 3c on the other side. Thereby, the hub wheel 3 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 3b, and the durability of the hub wheel 3 is improved. The hub ring 3 has an inner rolling surface 4a formed on the inner ring 4 at one end and an outer rolling surface 2c on one side of the outer member 2, and is formed on the other side. The surface 3c is disposed so as to face the outer rolling surface 2d on the other side of the outer member 2.

  The one side ball row 5a and the other side ball row 5b, which are rolling rows, support the hub wheel 3 rotatably. In the one-side ball row 5a and the other-side ball row 5b, a plurality of balls, which are rolling elements, are held in an annular shape by a cage. The one-side ball row 5a and the other-side ball row 5b are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core portion by quenching. The other side ball row 5b is configured to have a larger pitch circle diameter than the one side ball row 5a. Note that the pitch circle diameters of the one-side ball row 5a and the other-side ball row 5b may be configured to be equal. The one-side ball row 5a is sandwiched between an inner rolling surface 4a formed on the inner ring 4 and an outer rolling surface 2c on one side of the outer member 2 facing the inner rolling surface 4a. Yes. The other side ball row 5b is sandwiched between the inner raceway surface 3c formed on the hub wheel 3 and the outer raceway surface 2d on the other side of the outer member 2 facing the outer raceway 2c. ing. That is, the one side ball row 5 a and the other side ball row 5 b support the hub wheel 3 and the inner ring 4 so as to be rotatable with respect to the outer member 2. In the wheel bearing device 1, a double-row angular ball bearing is constituted by the outer member 2, the hub wheel 3, the inner ring 4, the one-side ball row 5 a, and the other-side ball row 5 b. In the present embodiment, the wheel bearing device 1 is configured with a double-row angular contact ball bearing, but is not limited thereto, and may be configured with a double-row tapered roller bearing or the like.

  The one side (inner side) seal member 6 closes the gap between the outer member 2 and the inner ring 4. The one-side seal member 6 includes a substantially cylindrical seal plate and a substantially cylindrical slinger. The one-side seal member 6 is formed by adding a plurality of one-side seal lips made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) to a seal plate made of a ferritic stainless steel plate (JIS standard SUS430 series or the like). Sulfur bonded. The slinger is composed of a steel plate equivalent to the seal plate. A magnetic encoder 7 is bonded to the outside (inner side) of the slinger. In the one-side seal member 6, a seal plate is fitted into the one-side opening 2a of the outer member 2, and a slinger is fitted into the inner ring 4 to constitute a pack seal. The one-side seal member 6 is configured to be slidable with respect to the slinger when the one-side seal lip of the seal plate comes into contact with the slinger through the oil film. Thereby, the one-side seal member 6 prevents the leakage of the lubricating grease from the inside of the outer member 2 and the intrusion of rainwater, dust and the like from the outside.

  The other side (outer side) seal member 8 closes the gap between the outer member 2 and the hub wheel 3. The other side sealing member 8 has a plurality of other side sealing lips made of synthetic rubber such as nitrile rubber, and is integrally joined to a metal core formed in a substantially cylindrical shape by vulcanization adhesion. The other-side seal member 8 has a cylindrical portion fitted into the other-side opening 2 b of the outer member 2, and a plurality of other-side seal lips are in contact with the seal sliding surface 3 d of the hub wheel 3. The other side seal member 8 is configured to be slidable with respect to the hub wheel 3 when the other side seal lip comes into contact with the seal sliding surface 3d of the hub wheel 3 through an oil film. Thereby, the other side sealing member 8 prevents the leakage of the lubricating grease from the inside of the outer member 2 and the intrusion of rainwater, dust, etc. from the outside.

  In the wheel bearing device 1 configured as described above, the outer member 2, the hub wheel 3, the inner ring 4, the one-side ball row 5a, and the other-side ball row 5b constitute a double-row angular ball bearing. Is rotatably supported by the outer member 2 via the one side ball row 5a and the other side ball row 5b. In the wheel bearing device 1, the gap between the one side opening 2 a of the outer member 2 and the inner ring 4 is closed by the one side seal member 6, and the other side opening 2 b of the outer member 2 and the hub ring 3 are closed. The other side sealing member 8 closes the gap. Thus, the wheel bearing device 1 is configured such that the hub wheel 3 supported by the outer member 2 can rotate while preventing leakage of lubricating grease from the inside and intrusion of rainwater, dust, and the like from the outside. Has been.

  Next, the shape of the outer member 2 will be described in detail with reference to FIG. Here, from the other side end of the outer member 2 in the present embodiment to the position of the maximum outer diameter D of the outer rolling surface 2d on the other side (wheel mounting flange 3b side, see FIG. 2) formed in an annular shape. The axial width is defined as the maximum outer diameter width Wa. The maximum outer diameter width Wa is from the other end of the outer member 2 to the bottom of the outer rolling surface 2d on the other side that is recessed most on the outer circumferential surface side of the outer member 2 among the outer rolling surfaces 2d on the other side. The width in the axial direction.

  As shown in FIG. 3, on the outer peripheral surface of the outer member 2 formed in a substantially cylindrical shape, a vehicle body attachment flange for attaching to a knuckle of a suspension device (not shown) in the vicinity of one outer rolling surface 2c. 2e is formed. Further, in the vicinity of the outer rolling surface 2d on the other side of the outer peripheral surface of the outer member 2, a belt-like portion 2f (light ink portion) is formed. The band-shaped part 2f is formed in a band shape protruding from the other end of the outer member 2 by a predetermined protrusion amount p1 in the radial direction with a predetermined band width w1. The band-like portion 2f is formed over the entire circumference at the other end of the outer peripheral surface of the outer member 2 (see the thin ink portions in FIGS. 1 and 2). The outer peripheral surface of the band-like portion 2f is subjected to machining such as cutting.

  The band-like portion 2f of the outer member 2 is larger than the maximum outer diameter width Wa that is the axial width from the other end of the outer member 2 to the position of the maximum outer diameter D of the outer rolling surface 2d on the other side. A width w1 is formed (Wa <w1). That is, the belt-like portion 2f overlaps with the position of the maximum outer diameter D of the outer rolling surface 2d on the other side of the outer member 2 in the radial direction (in a side view in a direction perpendicular to the axial direction of the outer member 2). A width w1 is formed. Thereby, the strip | belt-shaped part 2f is formed so that the bottom part of the outer side rolling surface 2d of the other side of the outer member 2 may be covered. In the present embodiment, the belt-like portion 2f is formed so as to cover the thinnest portion of the portion where the outer rolling surface 2d on the other side of the outer member 2 is formed. Further, the belt-like portion 2f protrudes with a predetermined amount in which the thickness t1 of the outer member 2 at the position of the maximum outer diameter D of the outer rolling surface 2d on the other side is equal to or greater than a reference value (for example, about 5 mm to 8 mm). It is formed to protrude outward in the radial direction by an amount p1. Thereby, as for the outer member 2, the thinnest thickness t1 becomes a reference value or more in the part in which the outer side rolling surface 2d of the other side is formed. The wheel bearing device 1 in which the belt-like portion 2f is formed has a roundness deterioration amount of the outer raceway surface 2d on the other side as compared with the conventional wheel bearing device in which the belt-like portion 2f is not formed. About 21% improvement. As a result, the bearing rolling fatigue life of the wheel bearing device 1 in the present embodiment is improved by about 6% compared to the conventional wheel bearing device.

  Of the outer member 2 of the wheel bearing device 1 configured as described above, the range including the outer rolling surface 2c on one side from the one side end is connected to a knuckle on the vehicle side (not shown) via the vehicle body mounting flange 2e. Since it is fixed, a certain level of bearing rigidity is ensured. On the other hand, in the range of the width w1 from the other end of the outer member 2 of the wheel bearing device 1, a certain level of bearing rigidity is ensured by the belt-like portion 2f. Therefore, in the wheel bearing device 1, even when the radial load or the axial load increases, the deformation amount in the range of the width w1 from the other side end of the outer member 2 is suppressed. That is, in the wheel bearing device 1, the deterioration of the roundness of the rolling surface of the outer rolling surface 2 d due to the deformation of the other side opening 2 b of the outer member 2 is suppressed by providing the band-shaped portion 2 f. Further, in the wheel bearing device 1, only the range of the width w <b> 1 from the other side end of the outer member 2 is covered with the belt-like portion 2 f. Thereby, it is possible to reduce the deformation amount of the other side opening 2b of the outer member 2 while minimizing an increase in the overall weight, and to prevent a decrease in rolling fatigue life.

  Further, as another embodiment of the shape of the outer member 2 in the first embodiment, a band-like portion 2g may be formed on the outer member 2 as shown in FIG. Here, the width in the axial direction from the other side end of the outer member 2 to the edge on the wheel mounting flange 3b side of the outer rolling surface 2d on the other side is defined as an offset width Wb. The offset width Wb is a width from the other side end of the outer member 2 to a portion closest to the other side end of the outer rolling surface 2d on the other side.

  The band-like portion 2g of the outer member 2 is larger than an offset width Wb that is an axial width from the other end of the outer member 2 to the edge on the wheel mounting flange 3b side of the outer rolling surface 2d on the other side, The outer side rolling surface 2d on the other side is formed to have a width w2 that is equal to or smaller than the maximum outer diameter width Wa that is the axial width to the position of the maximum outer diameter D (Wb <w2 ≦ Wa). That is, the belt-like portion 2g overlaps with the outer peripheral surface of the outer member 2 in a radial direction (in a side view in a direction perpendicular to the axial direction of the outer member 2) with a part of the other outer rolling surface 2d on the other side. The width w2 is formed. Thereby, the strip | belt-shaped part 2g is formed so that a part of part in which the outer side rolling surface 2d of the other side of the outer member 2 is formed may be covered.

  Regarding the range of the outer member 2 of the wheel bearing device 1 configured as described above, which is larger than the offset width Wb of the outer rolling surface 2d on the other side from the other end, is equal to or less than the maximum outer diameter width Wa. The bearing rigidity of a certain level or more is ensured by 2g. Therefore, in the wheel bearing device 1, the deterioration of the roundness of the rolling surface of the outer rolling surface 2 d due to the deformation of the other side opening 2 b of the outer member 2 is suppressed by providing the belt-like portion 2 g. Thereby, it is possible to reduce the deformation amount of the other side opening 2b of the outer member 2 while minimizing an increase in the overall weight, and to prevent a decrease in rolling fatigue life.

  Next, a wheel bearing device 9 which is a second embodiment of the wheel bearing device will be described with reference to FIG. In addition, the wheel bearing device according to each of the following embodiments is applied to the wheel bearing device 1 in the wheel bearing device 1 shown in FIGS. The same reference numerals are used to indicate the same parts, and in the following embodiments, the same points as those of the above-described embodiments will not be described in detail, and different portions will be mainly described.

  As shown in FIG. 5, the wheel bearing device 9 includes an outer member 10, a hub wheel 3, an inner ring 4, two rows of one-side ball rows 5 a and other-side ball rows 5 b that are rolling rows. The wheel bearing device 9 includes a double-row angular ball bearing composed of the outer member 10, the hub wheel 3, the inner ring 4, the one-side ball row 5a, and the other-side ball row 5b. The one-side ball row 5a is sandwiched between an inner rolling surface 4a formed on the inner ring 4 and an outer rolling surface 10c on one side of the outer member 10 facing the inner rolling surface 4a. Yes. The other-side ball row 5b is sandwiched between the inner rolling surface 3c formed on the hub wheel 3 and the outer rolling surface 10d on the other side of the outer member 10 facing the inner rolling surface 3c. ing. That is, the one side ball row 5 a and the other side ball row 5 b support the hub wheel 3 and the inner ring 4 so as to be rotatable with respect to the outer member 10.

  Next, the shape of the outer member 10 will be described in detail. Here, the width in the axial direction from the other side end of the outer member 10 to the portion closest to the outer peripheral surface of the outer member 10 on the outer rolling surface 10d on the other side is defined as a minimum thickness Wc. The minimum thickness width Wc is the width in the axial direction from the other end of the outer member 10 to the thickness t2 where the outer member 10 has the smallest thickness on the outer rolling surface 10d on the other side.

  As shown in FIG. 5A, the outer peripheral surface of the outer member 10 overlaps with the outer rolling surface 10d on the other side in the radial direction (in a side view in a direction perpendicular to the axial direction of the outer member 10). The diameter is gradually reduced from the portion toward the other end. Thereby, the outer member 10 is thickest among the parts in which the outer rolling surface 10d on the other side is formed at the position on the other side of the position of the maximum outer diameter D of the outer rolling surface 10d on the other side. A portion having a thin wall thickness t2 is formed. That is, the position of the thinnest thickness t2 in the outer member 10 is formed at the position of the minimum thickness width Wc from the other side end of the outer member 10.

  As shown in FIG. 5 (b), a belt-like portion 10f (light ink portion) is formed in the vicinity of the outer rolling surface 10d on the other side of the outer peripheral surface of the outer member 10. The band-shaped portion 10f of the outer member 10 has a minimum wall thickness that is the axial width from the other side end of the outer member 10 to the thinnest thickness t2 in the portion where the outer rolling surface 10d on the other side is formed. The width w3 is larger than the thickness width Wc. That is, the band-shaped portion 10f is formed on the outer peripheral surface of the outer member 10 at the position and the radial direction of the thinnest thickness t2 of the outer rolling surface 10d on the other side (direction perpendicular to the axial direction of the outer member 10). (In a side view of FIG. 5), an overlapping width w3 is formed. Thereby, the strip | belt-shaped part 10f is formed so that the thinnest part may be covered among the parts in which the outer side rolling surface 10d of the other side of the outer member 10 is formed. Further, the belt-like portion 10f protrudes outward in the radial direction by a protrusion amount p2 that is a predetermined amount in which the thinnest thickness t2 of the outer rolling surface 10d on the other side becomes a reference value or more (for example, about 5 mm to 8 mm). Is formed. Thereby, as for outer member 10, thickness t2 of the thinnest part in outside rolling surface 10d of the other side from the other side end becomes more than a standard value.

  In the outer member 10 of the wheel bearing device 9 configured as described above, in a range from the other side end to the width w3, the belt-shaped portion 10f ensures a certain level of bearing rigidity. Therefore, in the wheel bearing device 9, the deterioration of the roundness of the rolling surface of the outer rolling surface 10 d on the other side due to the deformation of the other side opening 10 b of the outer member 10 is suppressed by providing the belt-like portion 10 f. . Thereby, the deformation amount of the other side opening 10b of the outer member 10 can be reduced while suppressing an increase in the overall weight to a minimum, and a reduction in rolling fatigue life can be prevented.

  Next, a wheel bearing device 11 which is a third embodiment of the wheel bearing device will be described with reference to FIG.

  As shown in FIG. 6, the wheel bearing device 11 includes an outer member 12, a hub wheel 3, an inner ring 4, two rows of one-side ball rows 5 a and other-side ball rows 5 b that are rolling rows. In the wheel bearing device 11, a double row angular ball bearing is constituted by the outer member 12, the hub wheel 3, the inner ring 4, the one side ball row 5a, and the other side ball row 5b. The one-side ball row 5a is sandwiched between an inner rolling surface 4a formed on the inner ring 4 and an outer rolling surface 12c on one side of the outer member 12 facing the inner rolling surface 4a. Yes. The other-side ball row 5b is sandwiched between an inner rolling surface 3c formed on the hub wheel 3 and an outer rolling surface 12d on the other side of the outer member 12 facing the inner rolling surface 3c. ing. That is, the one side ball row 5 a and the other side ball row 5 b support the hub wheel 3 and the inner ring 4 so as to be rotatable with respect to the outer member 12.

  Next, the shape of the outer member 12 will be described in detail. Here, the axial width from the edge on one side (the vehicle body mounting flange 12e side) of the outer rolling surface 12d on the other side of the outer member 12 to the edge on the other side of the outer rolling surface 12d on the other side is rolled. The running surface width Wd. That is, the rolling surface width Wd is the groove width of the outer rolling surface 12d on the other side.

  In the vicinity of the outer rolling surface 12d on the other side of the outer peripheral surface of the outer member 12, a belt-like portion 12f (light ink portion) is formed. The strip 12f of the outer member 12 is formed to have a width w4 that is larger than the rolling surface width Wd that is the width in the axial direction from one edge of the other outer rolling surface 12d to the other edge. (Wd <w4). That is, the belt-like portion 12f is formed in a width w4 that overlaps the outer peripheral surface of the outer member 12 with the outer rolling surface 12d on the other side in the radial direction (in a side view perpendicular to the axial direction of the outer member 12). Is done. Thereby, the strip | belt-shaped part 12f is formed so that the part in which the outer side rolling surface 12d of the other side of the outer member 12 is formed may be covered.

  About the range of width w4 among the outer members 12 of the wheel bearing device 11 configured in this way, a bearing rigidity of a certain level or more is ensured by the belt-like portion 12f. Therefore, the wheel bearing device 11 is provided with the belt-like portion 12f, so that deterioration of the rolling surface roundness of the outer rolling surface 12d on the other side due to the deformation of the other opening 2b of the outer member 12 is suppressed. . Further, in the wheel bearing device 11, only the range of the width w4 from the other end of the outer member 12 is covered with the belt-like portion 12f. Thereby, the deformation amount of the other side opening 12b of the outer member 12 can be reduced while suppressing the increase in the overall weight to the minimum, and the decrease in the rolling fatigue life can be prevented.

  Next, a wheel bearing device 13 that is a fourth embodiment of the wheel bearing device will be described with reference to FIG.

  As shown in FIG. 7, the wheel bearing device 13 includes an outer member 14, a hub wheel 3, an inner ring 4, two rows of one-side ball rows 5 a and other-side ball rows 5 b that are rolling rows. In the wheel bearing device 13, a double row angular ball bearing is constituted by the outer member 14, the hub wheel 3, the inner ring 4, the one side ball row 5 a, and the other side ball row 5 b. The one-side ball row 5a is sandwiched between an inner rolling surface 4a formed on the inner ring 4 and an outer rolling surface 14c on one side of the outer member 14 facing the inner rolling surface 4a. Yes. The other-side ball row 5b is sandwiched between the inner rolling surface 3c formed on the hub wheel 3 and the outer outer rolling surface 14d on the other side of the outer member 14 facing the inner rolling surface 3c. ing. That is, the one side ball row 5 a and the other side ball row 5 b support the hub wheel 3 and the inner ring 4 so as to be rotatable with respect to the outer member 14.

  Next, the shape of the outer member 14 will be described in detail. Here, on the outer side rolling surface 14d on the other side of the outer member 14, the rolling element contact point where one ball in the other side ball row 5b which is a rolling element is in contact is defined as an outer contact point P1. Similarly, on the inner raceway surface 3c of the hub wheel 3, a rolling element contact point where one ball of the other side ball row 5b which is a rolling element is in contact is defined as an inner contact point P2. The width from the other end of the outer member 14 to the position where the contact angle line L passing through the outer contact point P1 and the inner contact point P2 intersects the outer peripheral surface of the outer member 14 is defined as a contact angle width We. The contact angle line L indicates the direction in which the force applied to the outer member 14 from the other side ball row 5b is transmitted.

  In the vicinity of the outer rolling surface 14d on the other side of the outer peripheral surface of the outer member 14, a belt-like portion 14f (light ink portion) is formed. The band-like portion 14f of the outer member 14 is formed to have a width w5 that is larger than a contact angle width We that is an axial width from the other side end of the outer member 14 to a position where the outer peripheral surface and the contact angle line L intersect. (We <w5). That is, the belt-like portion 14f is radially formed on the outer peripheral surface of the outer member 14 on the outer rolling surface 14d on the other side and the contact angle line L (in a side view perpendicular to the axial direction of the outer member 14). Overlapping width w5 is formed. Thereby, the belt-like portion 14f is formed so as to cover a portion where the outer rolling surface 14d on the other side of the outer member 14 is formed and a portion where the outer member 14 receives the force from the other-side ball row 5b. ing.

  About the range of the width | variety w5 among the outer members 14 of the wheel bearing device 13 configured as described above, a certain level or more of bearing rigidity is secured by the belt-like portion 14f. Therefore, the wheel bearing device 13 is provided with the belt-like portion 14f, so that deterioration of the rolling surface roundness of the outer rolling surface 14d on the other side due to the deformation of the other opening 14b of the outer member 14 is suppressed. . Further, in the wheel bearing device 13, only the range of the width w5 from the other side end of the outer member 14 is covered with the belt-like portion 14f. Thereby, it is possible to reduce the deformation amount of the other side opening 14b of the outer member 14 while minimizing the increase in the overall weight and prevent the rolling fatigue life from decreasing.

  The wheel bearing device according to each embodiment has been described as a third-generation wheel bearing device in which the inner rolling surface 3c of the one-side ball row 5a is directly formed on the outer periphery of the hub wheel 3. The second generation structure in which the pair of inner rings 4 are press-fitted and fixed to the hub ring 3 may be used. In addition, the above-described embodiments are merely representative examples of the present invention, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Wheel bearing apparatus 2 Outer member 2d Outer rolling surface 2e Car body mounting flange 2f Belt-like part 3 Hub wheel 3b Wheel mounting flange 4 Inner ring 5a One side ball row 5b Other side ball row

Claims (4)

An outer member integrally having a vehicle body mounting flange on the outer periphery, and a double-row annular outer rolling surface formed integrally on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end portion and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double-row annular inner raceway facing the outer raceway of the double-row is formed on the outer periphery,
In a wheel bearing device comprising: a double row rolling element that is slidably accommodated between the rolling surfaces of the inner member and the outer member,
The outer member protrudes by a predetermined amount in the radial direction with a predetermined width so that at least a part of the outer member overlaps the outer rolling surface on the wheel mounting flange side of the outer member in the radial direction of the outer member. A wheel bearing device in which a belt-like portion is formed.   2. The wheel bearing device according to claim 1, wherein the belt-shaped portion is formed so as to overlap with a portion of the outer rolling surface that is closest to an outer peripheral surface of the outer member in a radial direction of the outer member. .   3. The wheel bearing device according to claim 1, wherein the belt-shaped portion is formed so as to overlap with a maximum outer diameter portion of the annular outer rolling surface in a radial direction of the outer member.   2. The belt-shaped portion is formed so as to cover a portion where a straight line passing through a rolling element contact point of the outer rolling surface and a rolling element contact point of the inner rolling surface intersects with an outer peripheral surface of the outer member. The wheel bearing device according to any one of claims 1 to 3.

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