JP6967831B2 - Bearing device for wheels - Google Patents

Description

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

Conventionally, a wheel bearing device that rotatably supports a wheel in a suspension device such as an automobile is known. In the wheel bearing device, the hub wheel connected to the wheel is rotatably supported by an outer member via a rolling element. The wheel bearing device is fixed to the knuckle of the vehicle via the mounting flange of the outer member. That is, the wheel bearing device rotatably supports the hub wheel to which the wheel is connected with the outer member fixed to the knuckle of the vehicle. Double-row angular contact ball bearings having desired bearing rigidity and small rotational torque are often used in wheel bearing devices from the viewpoint of improving fuel efficiency. The wheel bearing device constitutes an angular contact ball bearing by imparting a predetermined contact angle to the rolling element and bringing it into contact with the outer member and the hub wheel. For the outer member of the wheel bearing device, the rolling element row is rotated between the vicinity of the opening on the wheel mounting flange side (outer side) of the hub wheel and 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 element that supports the hub wheel.

In such a wheel bearing device, when the vehicle is stationary or moving forward and backward, the load from the vehicle acts on substantially the center of the double row angular contact ball bearings. On the other hand, when the vehicle turns, the radial load and the axial load applied to the wheels on the opposite side of the turning direction (the left side of the vehicle in the case of a right turn) increase. Therefore, some wheel bearing devices increase the bearing rigidity by increasing the rigidity of the rolling element row on the outer side to prevent a decrease in rolling fatigue life. For example, as described in Patent Document 1.

In the wheel bearing device described in Patent Document 1, the pitch circle diameter of the rolling element row on the outer side of the double row rolling element row is made larger than the pitch circle diameter of the rolling element row on the inner side, so that the pitch circle diameter is larger than that on the outer side. The number of rolling elements in the rolling element row has increased, and the rigidity of the rolling element row has been increased. However, in the wheel bearing device, the diameter of the opening on the outer side of the outer member also increases as the pitch circle diameter of the rolling element row on the outer side increases. Further, each opening of the outer member is formed with a fitting portion for providing a sealing member for preventing rainwater or the like from entering the inside of the outer member, a reference surface for processing, and the like. Therefore, in the wheel bearing device, when the radial load or axial load applied to the rolling surface on the outer side of the outer member increases due to the turning of the vehicle, the outer side separated from the mounting flange fixed to the knuckle. There was a possibility that the opening of the wheel would be deformed into a substantially elliptical shape, the roundness of the rolling surface would be deteriorated, and the rolling fatigue life would be shortened.

Japanese Unexamined Patent Publication No. 2008-155833

The present invention has been made in view of the above circumstances, and it is possible to reduce the amount of deformation of the opening of the outer member while suppressing the increase in the total weight to the minimum and prevent the rolling fatigue life from being shortened. It is an object of the present invention to provide a bearing device for wheels.

That is, an outer member having a vehicle body mounting flange integrally on the outer circumference and a double-row annular outer rolling surface integrally formed on the inner circumference, and a wheel mounting flange for mounting a wheel at one end are integrally formed. It consists of a hub wheel having a small diameter step portion extending in the axial direction on the outer periphery thereof, and at least one inner ring press-fitted into the small diameter step portion of the hub wheel, and facing the outer rolling surface of the double row on the outer periphery. An inner member having a double-row annular inner rolling surface formed therein, and a double-row rolling element rotatably accommodated between the rolling surfaces of the inner member and the outer member. In the wheel bearing device provided with, at least a part of the outer peripheral surface 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 band-shaped portion is formed that protrudes by a predetermined amount in the radial direction.

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

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

As the effect of the present invention, the following effects are exhibited.

According to the wheel bearing device, the wall thickness of the portion of the outer member near the opening on the wheel mounting flange side where the wall 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 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

According to the wheel bearing device, the wall thickness of the portion of the outer member near the opening on the wheel mounting flange side where the wall thickness of the outer member is most 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 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

According to the wheel bearing device, the wall 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 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

The perspective view which shows the whole structure in the 1st Embodiment of the bearing device for a wheel. FIG. 3 is a cross-sectional view (A arrow view in FIG. 1) showing an overall configuration of the wheel bearing device according to the first embodiment. The enlarged partial sectional view which shows the shape of the outer member in 1st Embodiment of a bearing apparatus for a wheel. An enlarged partial cross-sectional view showing the shape of an outer member in another embodiment of the first embodiment of a wheel bearing device. (A) Cross-sectional view showing the overall configuration before the band-shaped portion is formed in the second embodiment of the wheel bearing device (b) Cross-sectional view showing the overall configuration after the band-shaped portion is also formed. FIG. 3 is an enlarged partial cross-sectional view showing the shape of the outer member in the third embodiment of the wheel bearing device. FIG. 3 is an enlarged partial cross-sectional view showing the shape of the outer member in the fourth embodiment of the wheel bearing device.

Hereinafter, the wheel bearing device 1 which is the first embodiment of the wheel bearing device will be described with reference to FIGS. 1 and 2.

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

As shown in FIG. 2, the outer member 2 supports the inner member (hub ring 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. A one-side opening 2a into which the one-side seal member 6 can be fitted is formed at one side (inner side) end of the outer member 2. At the other side (outer side) end of the outer member 2, an other side opening 2b into which the other side seal member 8 can be fitted is formed. On the inner peripheral surface of the outer member 2, an annular 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 side 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 so as to be parallel to each other in the circumferential direction. The outer rolling surface 2d on the other side is formed so that the diameter of the pitch circle is larger than that of the outer rolling surface 2c on the one side. The pitch circle diameters of the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side may be equal to each other. A cured layer having a surface hardness in the range of 58 to 64 HRC is formed on the outer rolling surface 2c on one side and the outer rolling surface 2d on the other side by induction hardening. On the outer peripheral surface on one side of the outer member 2, a vehicle body mounting flange 2e for mounting on a knuckle of a suspension device (not shown) is integrally formed. One side surface and the other side surface, which are the mounting surfaces of the vehicle body mounting flange 2e, are machined by cutting or the like. On the outer peripheral surface of the other side of the outer member 2 (outer side, wheel mounting flange 3b side 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. The protruding annular band-shaped portion 2f is integrally formed.

The hub wheel 3 constituting the inner member rotatably supports a wheel of a vehicle (not shown). The hub ring 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. A small diameter step portion 3a having a reduced diameter is formed on the outer peripheral surface at one side end portion (inner side) of the hub ring 3. A wheel mounting flange 3b for mounting a wheel is integrally formed at the other end (outer side) of the hub wheel 3. On the outer peripheral surface of the other side of the hub wheel 3 (wheel mounting flange 3b side), an annular inner rolling surface 3c and an annular seal sliding surface 3d are formed in the circumferential direction. The wheel mounting flange 3b is provided with hub bolts 3e at positions that are evenly distributed around the circumference.

The inner ring 4 constituting the inner member is press-fitted into the small diameter step portion 3a at one side end of the hub ring 3. The inner ring 4 is made of high carbon chrome bearing steel such as SUJ2, and is hardened to the core in the range of 58 to 64 HRC by quenching. An annular inner rolling surface 4a is formed on the outer peripheral surface of the inner ring 4 in the circumferential direction. The inner rolling surface 3c of the hub ring 3 is formed so that the pitch circle diameter is larger than that of the inner rolling surface 4a of the inner ring 4. The pitch circle diameters of the inner rolling surface 3c and the inner rolling surface 4a may be equal to each other. The inner ring 4 is integrally fixed to one side end of the hub ring 3 in a state where a predetermined preload is applied by press fitting. That is, on one side of the hub ring 3, the inner rolling surface 4a is formed by the inner ring 4. The surface hardness of the hub ring 3 is hardened in the range of 58 to 64 HRC by induction hardening from the small diameter step portion 3a on one side to the inner rolling surface 3c on the other side. As a result, 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. In the hub ring 3, the inner rolling surface 4a formed on the inner ring 4 at one side end faces the outer rolling surface 2c on one side of the outer member 2, and the inner rolling surface 4a is formed on the other side. The surface 3c is arranged 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, rotatably support the hub wheel 3. 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 to the core in the range of 58 to 64 HRC by quenching. The other side ball row 5b is configured to have a larger pitch circle diameter than the one side ball row 5a. The pitch circle diameters of the one-side ball row 5a and the other-side ball row 5b may be equal. The one-side ball row 5a is rotatably sandwiched between the inner rolling surface 4a formed on the inner ring 4 and the outer rolling surface 2c on one side of the outer member 2 facing the inner rolling surface 4a. There is. The other side ball row 5b is rotatably sandwiched between the inner rolling surface 3c formed on the hub wheel 3 and the outer rolling surface 2d on the other side of the outer member 2 facing the inner rolling surface 3c. ing. That is, the one-side ball row 5a and the other-side ball row 5b rotatably support the hub ring 3 and the inner ring 4 with respect to the outer member 2. The wheel bearing device 1 comprises a double row angular contact ball bearing from an outer member 2, a hub wheel 3, an inner ring 4, a one-side ball row 5a, and a other-side ball row 5b. In the present embodiment, the wheel bearing device 1 is configured with a double-row angular contact ball bearing, but the present invention is not limited to this, and a double-row conical roller bearing or the like may be used.

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 a seal plate made of a ferritic stainless steel plate (JIS standard SUS430 series, etc.) and a plurality of one-side seal lips made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber). It is vulcanized. The slinger is composed of a steel plate equivalent to a sealing plate. A magnetic encoder 7 is adhered to the outside (inner side) of the slinger. In the one-side seal member 6, the seal plate is fitted into the one-side opening 2a of the outer member 2, and the slinger is fitted into the inner ring 4, forming a pack seal. The one-side seal member 6 is configured to be slidable with respect to the slinger by contacting the one-side seal lip of the seal plate with the slinger via an oil film. As a result, the one-side sealing member 6 prevents the lubricating grease from leaking 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 ring 3. In the other side sealing member 8, a plurality of other side sealing lips made of synthetic rubber such as nitrile rubber are integrally joined to a core metal formed in a substantially cylindrical shape by vulcanization adhesion. The other side seal member 8 has a cylindrical portion fitted in the other side opening 2b of the outer member 2, and a plurality of other side seal lips are in contact with the seal sliding surface 3d of the hub ring 3. The other-side seal member 8 is configured to be slidable with respect to the hub ring 3 when the other-side seal lip comes into contact with the seal sliding surface 3d of the hub ring 3 via the oil film. As a result, the other side sealing member 8 prevents the lubricating grease from leaking from the inside of the outer member 2 and the intrusion of rainwater, dust, and the like from the outside.

In the wheel bearing device 1 configured as described above, a double row angular contact ball bearing is configured from 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, and the hub wheel 3 is formed. Is rotatably supported by the outer member 2 via the ball row 5a on one side and the ball row 5b on the other side. Further, in the wheel bearing device 1, the gap between the one-side opening 2a of the outer member 2 and the inner ring 4 is closed by the one-side sealing member 6, and the other-side opening 2b of the outer member 2 and the hub ring 3 are closed. The gap between the two and the other side is closed by the sealing member 8. As a result, the wheel bearing device 1 is configured so 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, etc. from the outside. Has been done.

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 width in the axial direction 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 which is recessed toward the outer peripheral surface side of the outermost member 2 among the outer rolling surfaces 2d on the other side. Width in the axial direction of.

As shown in FIG. 3, on the outer peripheral surface of the outer member 2 formed in a substantially cylindrical shape, a vehicle body mounting flange for mounting on a knuckle of a suspension device (not shown) in the vicinity of the outer rolling surface 2c on one side. 2e is formed. Further, a band-shaped portion 2f (thin ink portion) is formed in the vicinity of the outer rolling surface 2d on the other side of the outer peripheral surface of the outer member 2. The band-shaped portion 2f is formed in a band shape that protrudes from the other side end of the outer member 2 by a predetermined protrusion amount p1 in the radial direction with a predetermined band width w1. The band-shaped portion 2f is formed on the other side end portion of the outer peripheral surface of the outer member 2 over the entire circumference (see the light black portion in FIGS. 1 and 2). The outer peripheral surface of the strip-shaped portion 2f is machined by cutting or the like.

The band-shaped portion 2f of the outer member 2 is larger than the maximum outer diameter width Wa, which is the axial width from the other side 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. It is formed to have a width w1 (Wa <w1). That is, the strip-shaped 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 the side view in the direction perpendicular to the axial direction of the outer member 2). It is formed to have a width w1. As a result, the strip-shaped portion 2f is formed so as to cover the bottom portion of the outer rolling surface 2d on the other side of the outer member 2. In the present embodiment, the strip-shaped portion 2f is formed so as to cover the portion having the thinnest wall thickness among the portions on which the outer rolling surface 2d on the other side of the outer member 2 is formed. Further, the strip-shaped portion 2f is a protrusion having a predetermined amount such that the wall 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 more than the reference value (for example, about 5 mm to 8 mm). It is formed so as to project outward by the amount p1 in the radial direction. As a result, in the outer member 2, the thinnest wall thickness t1 at the portion where the outer rolling surface 2d on the other side is formed becomes equal to or more than the reference value. The wheel bearing device 1 in which such a strip-shaped portion 2f is formed has a roundness deterioration amount of the outer rolling surface 2d on the other side as compared with the conventional wheel bearing device in which the strip-shaped portion 2f is not formed. It has improved by about 21%. As a result, the bearing rolling fatigue life of the wheel bearing device 1 in the present embodiment is improved by about 6% as compared with the conventional wheel bearing device.

The range including the outer rolling surface 2c on one side from one side end of the outer member 2 of the wheel bearing device 1 configured as described above is a knuckle on the vehicle side (not shown) via the vehicle body mounting flange 2e. Since it is fixed, the bearing rigidity above a certain level is secured. On the other hand, in the range of the width w1 from the other side end of the outer member 2 of the wheel bearing device 1, the bearing rigidity of a certain level or more is secured by the band-shaped portion 2f. Therefore, even if the radial load or the axial load increases, the wheel bearing device 1 suppresses the amount of deformation in the range of the width w1 from the other side end of the outer member 2. That is, by providing the band-shaped portion 2f in the wheel bearing device 1, deterioration of the rolling surface roundness of the outer rolling surface 2d due to the deformation of the other side opening 2b of the outer member 2 is suppressed. Further, in the wheel bearing device 1, only the range of the width w1 from the other side end of the outer member 2 is covered with the band-shaped portion 2f. As a result, it is possible to reduce the amount of deformation of the other side opening 2b of the outer member 2 while suppressing the increase in the total weight to the minimum, and prevent the rolling fatigue life from being shortened.

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

The strip-shaped portion 2g of the outer member 2 is larger than the offset width Wb, which is the axial width from the other side end of the outer member 2 to the edge of the outer rolling surface 2d on the other side on the wheel mounting flange 3b side. It is formed in a width w2 equal to or less than the maximum outer diameter width Wa, which is the width in the axial direction to the position of the maximum outer diameter D of the outer rolling surface 2d on the other side (Wb <w2 ≦ Wa). That is, the strip-shaped portion 2g overlaps the outer peripheral surface of the outer member 2 in the radial direction (in the side view in the direction perpendicular to the axial direction of the outer member 2) with the other side portion of the outer rolling surface 2d on the other side. It is formed in the width w2. As a result, the strip-shaped portion 2g is formed so as to cover a part of the portion where the outer rolling surface 2d on the other side of the outer member 2 is formed.

Of the outer member 2 of the wheel bearing device 1 configured as described above, the band-shaped portion is larger than the offset width Wb of the outer rolling surface 2d on the other side from the other side end and is equal to or less than the maximum outer diameter width Wa. Bearing rigidity above a certain level is ensured by 2 g. Therefore, in the wheel bearing device 1, by providing the band-shaped portion 2g, deterioration of the rolling surface roundness of the outer rolling surface 2d due to the deformation of the other side opening 2b of the outer member 2 is suppressed. As a result, it is possible to reduce the amount of deformation of the other side opening 2b of the outer member 2 while suppressing the increase in the total weight to the minimum, and prevent the rolling fatigue life from being shortened.

Next, the wheel bearing device 9 which is the second embodiment of the wheel bearing device will be described with reference to FIG. The wheel bearing device according to each of the following embodiments is the name used in the description as being applied in place of the wheel bearing device 1 in the wheel bearing device 1 shown in FIGS. 1 to 4. By using drawing numbers and symbols, the same thing is pointed out, and in the following embodiments, the same points as those of the embodiments already described will be omitted, and the differences 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, a two-row one-side ball row 5a, a other-side ball row 5b, and the like, which are rolling rows. The wheel bearing device 9 comprises a double row angular contact ball bearing from an outer member 10, a hub wheel 3, an inner ring 4, a one-side ball row 5a, and a other-side ball row 5b. The one-side ball row 5a is rotatably sandwiched between the inner rolling surface 4a formed on the inner ring 4 and the outer rolling surface 10c on one side of the outer member 10 facing the inner rolling surface 4a. There is. The other side ball row 5b is rotatably 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 5a and the other-side ball row 5b rotatably support the hub ring 3 and the inner ring 4 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 of the outer rolling surface 10d on the other side closest to the outer peripheral surface of the outer member 10 is defined as the minimum wall thickness width Wc. The minimum wall thickness width Wc is the width in the axial direction from the other side end of the outer member 10 to the thinnest wall thickness t2 of 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 the side view in the direction perpendicular to the axial direction of the outer member 10). It is formed so as to gradually reduce the diameter from the portion toward the other side end. As a result, the outer member 10 has the thickest portion of the portion where the outer rolling surface 10d on the other side is formed at a position on the other side of the position of the maximum outer diameter D of the outer rolling surface 10d on the other side. Is formed with a thin wall thickness t2. That is, the position of the thinnest wall thickness t2 of the outer member 10 is formed at the position of the minimum wall thickness width Wc from the other side end of the outer member 10.

As shown in FIG. 5B, a band-shaped portion 10f (thin 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 strip-shaped portion 10f of the outer member 10 has a minimum thickness in the axial direction, which is the thinnest wall thickness t2 among the portions where the outer rolling surface 10d on the other side is formed from the other side end of the outer member 10. It is formed in a width w3 larger than the thick width Wc. That is, the strip-shaped portion 10f is located on the outer peripheral surface of the outer member 10 in the radial direction with the position of the thinnest wall thickness t2 of the outer rolling surface 10d on the other side (direction perpendicular to the axial direction of the outer member 10). It is formed in the overlapping width w3 (in the side view of). As a result, the strip-shaped portion 10f is formed so as to cover the portion having the thinnest wall thickness among the portions on which the outer rolling surface 10d on the other side of the outer member 10 is formed. Further, the strip-shaped portion 10f protrudes outward in the radial direction by a predetermined amount such that the thinnest wall thickness t2 of the outer rolling surface 10d on the other side is equal to or more than the reference value (for example, about 5 mm to 8 mm). It is formed. As a result, in the outer member 10, the wall thickness t2 of the portion having the thinnest wall thickness on the outer rolling surface 10d on the other side from the other side end becomes equal to or more than the reference value.

In the range of the width w3 from the other side end of the outer member 10 of the wheel bearing device 9 configured as described above, the bearing rigidity of a certain level or higher is secured by the band-shaped portion 10f. Therefore, in the wheel bearing device 9, by providing the band-shaped portion 10f, deterioration of the rolling surface roundness of the outer rolling surface 10d on the other side due to the deformation of the other side opening 10b of the outer member 10 is suppressed. .. As a result, it is possible to reduce the amount of deformation of the other side opening 10b of the outer member 10 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

Next, the wheel bearing device 11 which is the 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, a two-row one-side ball row 5a, a other-side ball row 5b, and the like, which are rolling rows. The wheel bearing device 11 comprises a double row angular contact ball bearing from an outer member 12, a hub wheel 3, an inner ring 4, a one-side ball row 5a, and a other-side ball row 5b. The one-side ball row 5a is rotatably sandwiched between the inner rolling surface 4a formed on the inner ring 4 and the outer rolling surface 12c on one side of the outer member 12 facing the inner rolling surface 4a. There is. The other side ball row 5b is rotatably sandwiched between the inner rolling surface 3c formed on the hub wheel 3 and the 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 5a and the other-side ball row 5b rotatably support the hub ring 3 and the inner ring 4 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 of one side (vehicle body mounting flange 12e side) of the outer rolling surface 12d on the other side of the outer member 12 to the other edge of the outer rolling surface 12d on the other side is changed. The running surface width is Wd. That is, the rolling surface width Wd is the groove width of the outer rolling surface 12d on the other side.

A band-shaped portion 12f (thin ink portion) is formed in the vicinity of the outer rolling surface 12d on the other side of the outer peripheral surface of the outer member 12. The strip-shaped portion 12f of the outer member 12 is formed to have a width w4 larger than the rolling surface width Wd, which is the axial width from one edge of the outer rolling surface 12d on the other side to the other edge. Yes (Wd <w4). That is, the strip-shaped portion 12f is formed to have a width w4 that overlaps the outer peripheral surface of the outer member 12 in the radial direction (in the side view in the direction perpendicular to the axial direction of the outer member 12) with the outer rolling surface 12d on the other side. Will be done. As a result, the strip-shaped portion 12f is formed so as to cover the portion where the outer rolling surface 12d on the other side of the outer member 12 is formed.

In the range of the width w4 of the outer member 12 of the wheel bearing device 11 configured as described above, the bearing rigidity of a certain level or higher is secured by the band-shaped portion 12f. Therefore, in the wheel bearing device 11, by providing the band-shaped portion 12f, deterioration of the rolling surface roundness of the outer rolling surface 12d on the other side due to the deformation of the other side 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 side end of the outer member 12 is covered with the band-shaped portion 12f. As a result, it is possible to reduce the amount of deformation of the other side opening 12b of the outer member 12 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

Next, the wheel bearing device 13 which is the fourth embodiment of the wheel bearing device will be described with reference to FIG. 7.

As shown in FIG. 7, the wheel bearing device 13 includes an outer member 14, a hub wheel 3, an inner ring 4, a two-row one-side ball row 5a, a other-side ball row 5b, and the like, which are rolling rows. The wheel bearing device 13 comprises a double row angular contact ball bearing from an outer member 14, a hub wheel 3, an inner ring 4, a one-side ball row 5a, and a other-side ball row 5b. The one-side ball row 5a is rotatably sandwiched between the inner rolling surface 4a formed on the inner ring 4 and the outer rolling surface 14c on one side of the outer member 14 facing the inner rolling surface 4a. There is. The other side ball row 5b is rotatably sandwiched between the inner rolling surface 3c formed on the hub wheel 3 and the 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 5a and the other-side ball row 5b rotatably support the hub ring 3 and the inner ring 4 with respect to the outer member 14.

Next, the shape of the outer member 14 will be described in detail. Here, on the outer rolling surface 14d on the other side of the outer member 14, the rolling element contact point with which one of the balls in the other side ball row 5b, which is the rolling element, is in contact is defined as the outer contact point P1. Similarly, on the inner rolling surface 3c of the hub wheel 3, the rolling element contact point with which one of the balls in the other side ball row 5b, which is the rolling element, is in contact is defined as the 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 and the outer peripheral surface of the outer member 14 intersect is defined as the 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.

A band-shaped portion 14f (thin ink portion) is formed in the vicinity of the outer rolling surface 14d on the other side of the outer peripheral surface of the outer member 14. The band-shaped portion 14f of the outer member 14 is formed to have a width w5 larger than the contact angle width We, which is the width in the axial direction from the other side end of the outer member 14 to the position where the outer peripheral surface and the contact angle line L intersect. (We <w5). That is, the strip-shaped portion 14f is radially on the outer peripheral surface of the outer member 14 with the outer rolling surface 14d on the other side and the contact angle line L (in the side view in the direction perpendicular to the axial direction of the outer member 14). It is formed in the overlapping width w5. As a result, the band-shaped portion 14f is formed so as to cover the portion where the outer rolling surface 14d on the other side of the outer member 14 is formed and the portion where the outer member 14 receives the force from the other side ball row 5b. ing.

In the range of the width w5 of the outer member 14 of the wheel bearing device 13 configured as described above, the bearing rigidity of a certain level or higher is secured by the band-shaped portion 14f. Therefore, in the wheel bearing device 13, by providing the band-shaped portion 14f, deterioration of the rolling surface roundness of the outer rolling surface 14d on the other side due to the deformation of the other side 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 band-shaped portion 14f. As a result, it is possible to reduce the amount of deformation of the other side opening 14b of the outer member 14 and prevent a decrease in rolling fatigue life while suppressing an increase in the total weight to a minimum.

The wheel bearing device according to each embodiment has been described above as a wheel bearing device having a third generation structure 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. However, the structure may be a second generation structure in which a pair of inner rings 4 are press-fitted and fixed to the hub wheel 3. In addition, the above-described embodiment merely shows a typical embodiment of the present invention, and can be variously modified and carried out within a range that does not deviate from the gist of the present invention.

1 Wheel bearing device 2 Outer member 2d Outer rolling surface 2e Body mounting flange 2f Band-shaped 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 that has a vehicle body mounting flange integrally on the outer circumference and a double-row annular outer rolling surface integrally formed on the inner circumference.
From a hub wheel that has a wheel mounting flange integrally at one end and has a small diameter step portion extending in the axial direction on the outer circumference, and at least one inner ring press-fitted into the small diameter step portion of the hub ring. An inner member having a double-row annular inner rolling surface formed on the outer periphery thereof facing the double-row outer rolling surface.
In a wheel bearing device including a double-row rolling element rotatably accommodated between the rolling surfaces of the inner member and the outer member.
At least a part of the outer peripheral surface of the outer member overlaps the outer rolling surface on the wheel mounting flange side of the outer member in the radial direction with a predetermined width by a predetermined amount in the radial direction. The protruding band-shaped portion is formed integrally with the outer member, and is formed.
The vehicle body mounting flange is provided on the outer peripheral surface of the outer member, a cylindrical outer peripheral surface provided near the inner side end portion in the axial direction, and an outer peripheral surface in the axial direction with respect to the cylindrical outer peripheral surface. It is arranged between the band-shaped portion and the vicinity of the contact point on the outermost side of the contact portion with which the rolling element is in contact on the outer rolling surface on the inner side of the outer member.
In the strip-shaped portion, the radial thickness of the outer member including the strip-shaped portion is thicker than the radial thickness of the outer member on the cylindrical outer peripheral surface, and the strip-shaped portion is the outer periphery of the outer member. A wheel bearing device formed on the surface from the outer end in the axial direction toward the inner side in the axial direction. The wheel bearing device according to claim 1, wherein the strip-shaped portion is formed so as to overlap with a portion of the outer rolling surface closest to the outer peripheral surface of the outer member in the radial direction of the outer member. .. The wheel bearing device according to claim 1 or 2, wherein the strip-shaped portion is formed so as to overlap the maximum outer diameter portion of the annular outer rolling surface in the radial direction of the outer member. Claim 1 in which the strip-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 3.

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