JP2013112011A - Rolling bearing unit for supporting wheel - Google Patents

Abstract

[PROBLEMS] To secure the necessary strength and rigidity by devising the shape of a main body 28 made of a light alloy with a structure including an outer ring 6a configured by combining an iron-based alloy and a light alloy. A structure that can achieve further weight reduction is realized.
Reinforcing ribs 33 and 33 are formed on the outer peripheral surface of a main body portion 28 on the outer side in the axial direction of a stationary flange 12a at the same plural positions as each screw hole or through hole in the circumferential direction. While reducing the weight of the outer ring 6a. The strength and rigidity of the outer ring 6a are ensured.
[Selection] Figure 1

Description

  The present invention relates to an improvement of a wheel bearing rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device. Specifically, some of the components are made of light alloys such as aluminum-based alloys and magnesium-based alloys for weight reduction, while further reducing weight while ensuring the required strength and rigidity. It is intended to realize a structure that can be achieved.

  A wheel 1 constituting a wheel of an automobile and a rotor 2 constituting a disc brake that is a braking rotating member and a braking device are described in, for example, Patent Document 1 and have a structure as shown in FIG. The knuckle 3 which comprises is supported rotatably. For this purpose, an outer ring 6 constituting the wheel bearing rolling bearing unit 5 is fixed to a circular support hole 4 formed in the knuckle 3 by a plurality of bolts 7. Further, the wheel 1 and the rotor 2 are coupled and fixed to a hub 8 which is an inner ring equivalent member constituting the wheel support rolling bearing unit 5 by a plurality of studs 9 and nuts 10. Further, double-row outer ring raceways 11a and 11b are formed on the inner peripheral surface of the outer ring 6, and a stationary side flange 12 is formed on the outer peripheral surface. Such an outer ring 6 is supported and fixed to the knuckle 3 by connecting the stationary flange 12 to the knuckle 3 with the bolts 7.

  The hub 8 includes a hub body 13 and an inner ring 14. A rotation-side flange 15 is formed on a part of the outer peripheral surface of the hub main body 13 at a portion protruding from the outer end opening of the outer ring 6. Note that “outside” with respect to the axial direction refers to the left side of FIGS. On the contrary, the right side of FIGS. 1 and 3-8, which is the center side in the width direction of the vehicle in the assembled state in the automobile, is referred to as “inside” in the axial direction. A positioning cylinder portion 16 called a pilot portion is provided concentrically with the hub body 13 at the outer end portion of the hub body 13. The wheel 1 and the rotor 2 are fixedly coupled to the outer surface of the rotation side flange 15 by the studs 9 and nuts 10 in a state in which the wheel 1 and the rotor 2 are externally fitted to the positioning cylinder portion 16 and positioned in the radial direction. doing.

  Further, an inner ring raceway 17a facing the outer ring raceway 11a on the outer side of the outer ring raceways 11a, 11b in the double row is formed at an intermediate portion of the outer peripheral surface of the hub body 13, and a small diameter step portion 18 is also formed at the inner end. Each is formed. The inner ring 14 is externally fitted to the small diameter step portion 18. An inner ring raceway 17b is formed on the outer peripheral surface of the inner ring 14 to face the inner outer ring raceway 11b of the double row outer ring raceways 11a and 11b. Such an inner ring 14 is fixed to the hub body 13 by a caulking portion 19 formed by plastically deforming the inner end portion of the hub body 13 radially outward. A plurality of balls 20, 20 are provided between the outer ring raceways 11a, 11b and the inner ring raceways 17a, 17b, respectively, so that they can roll. In this state, the balls 20, 20 are provided with a contact angle of a back combination type in the opposite direction between the two outer ring raceways 11a, 11b and the inner ring raceways 17a, 17b. In contact with rolling. In this state, a predetermined preload is applied to the balls 20 and 20. With this configuration, the hub 8 is supported on the inner diameter side of the outer ring 6 so as not to rattle and rotatably while supporting a radial load and an axial load. Further, both end openings of the cylindrical space in which the balls 20 and 20 are installed are sealed by seal rings 21a and 21b, respectively.

  Furthermore, since the illustrated example is a wheel support rolling bearing unit 5 for driving wheels (front wheels of FF vehicles, rear wheels of FR and RR vehicles, all wheels of 4WD vehicles), the hub 8 has a central portion. The spline hole 22 is formed. A spline shaft 24 fixed to the outer end face of the constant velocity joint outer ring 23 is inserted into the spline hole 22. At the same time, a nut 25 is screwed onto the tip of the spline shaft 24 and further tightened, whereby the hub body 13 is sandwiched between the nut 25 and the constant velocity joint outer ring 23.

FIG. 8 shows a wheel support rolling bearing unit 5d for driven wheels (rear wheel of FF vehicle, front wheel of FR vehicle and RR vehicle). Since the wheel-supporting rolling bearing unit 5d is for a driven wheel, no spline hole is provided at the center of the hub body 13a constituting the hub 8a. The structure and operation of the other parts are the same as in the case of the wheel support rolling bearing unit 5 for driving wheels described above.
In addition, although illustration is omitted, a wheel support rolling bearing unit in which the outer ring equivalent member is a hub that rotates together with the wheel and the inner ring equivalent member is a stationary side race ring that is supported and fixed to the suspension device is also described in Patent Document 2, for example. For example, it has been widely known.

  Regardless of whether it is for a driving wheel or a driven wheel, whether it is an inner ring rotating type or an outer ring rotating type, the wheel bearing rolling bearing units 5, 5d are more than the springs constituting the suspension device. Since it is a so-called unsprung load provided on the road surface side, it is desired to reduce the weight as much as possible in order to improve traveling performance centering on ride comfort and traveling stability. In view of such circumstances, for example, Patent Document 3 discloses a wheel support in which a portion of the outer ring provided with both outer ring raceways is made of an iron-based alloy and a portion other than the both outer ring raceways is made of a light alloy. A rolling bearing unit for use is described. However, since the structure described in the above-mentioned Patent Document 3 is only intended to reduce the weight by material contrivance, if the strength and rigidity of the light alloy part are sufficiently secured, the volume of the light alloy part It is difficult to reduce the weight sufficiently.

JP 2009-299759 A JP 7-167138 A JP 2010-209964 A

  In view of the circumstances as described above, the present invention has a structure including an outer ring equivalent member configured by combining an iron-based alloy and a light alloy, and devise the shape of the portion made of the light alloy. Thus, the invention has been invented to realize a wheel bearing rolling bearing unit that can further reduce the weight while ensuring the necessary strength and rigidity.

The wheel bearing rolling bearing unit of the present invention includes an outer ring equivalent member, an inner ring equivalent member, and a plurality of rolling elements.
Of these, the outer ring equivalent member has a double row outer ring raceway on the inner peripheral surface, and a part including the part provided with both outer ring raceways is made of an iron-based alloy, and the remaining part including at least the portion near the outer diameter is provided. The flange portion is formed in a state of being made of a light alloy and projecting radially outward from the outer peripheral surface of the remaining portion.
The inner ring equivalent member has a double row of inner ring raceways on the outer peripheral surface.
Further, a plurality of rolling elements are provided between the inner ring raceways and the outer ring raceways so as to be freely rollable in both rows.
In particular, in the rolling bearing unit for supporting a wheel according to the present invention, reinforcing ribs are formed at a plurality of circumferential positions on the axial side surface of the flange portion to ensure the strength and rigidity of the outer ring equivalent member. Yes.

When implementing such a wheel-supporting rolling bearing unit of the present invention, a back contact type contact angle is imparted to the rolling elements of both rows, for example, as in the invention described in claims 2 to 3.
In this case, for example, as in the invention described in claim 2, the outer ring raceways are formed on the inner peripheral surfaces of a pair of outer ring elements independent of each other. The outer ring elements are held in the remaining portion in a state where a small diameter portion formed near the inner diameter portion of the remaining portion and having a smaller inner diameter than both axial side portions is sandwiched from both axial directions.
Alternatively, as in the invention described in claim 3, the both outer ring raceways are formed at two positions separated in the axial direction of the inner peripheral surface of one outer ring element. Then, the outer ring element is formed in the axially intermediate part of the outer peripheral surface of the outer ring element, with the concave and convex engaging portions protruding or recessed in the radial direction with respect to both axial side parts embedded in the remaining part. Is held on the inner diameter side of the remaining portion.
Further, when the invention described in claim 3 is carried out, preferably, as in the invention described in claim 4, the concave-convex engaging portion is projected or recessed with respect to a portion adjacent in the axial direction. In addition to the shape to enter, the shape is such that irregularities are repeated in the circumferential direction.

Further, when the rolling bearing unit for supporting a wheel of the present invention as described above is implemented, for example, as in the invention described in claim 5, a plurality of circumferential direction portions of the remaining portion of the outer ring equivalent member closer to the outer diameter The outer ring equivalent member is supported and fixed to the suspension device, or a screw hole or a through hole for screwing or inserting a bolt for coupling and fixing the wheel to the outer ring equivalent member is formed. And each said reinforcement rib is formed in the same position as each said screw hole or a through-hole in the phase regarding the circumferential direction.
Furthermore, when the rolling bearing unit for supporting a wheel according to the present invention is implemented, the remaining part of the outer ring equivalent member and a member constituting a suspension device such as a knuckle are integrated as in the invention described in claim 6, for example. And

  As described above, in the case of the rolling bearing unit for supporting a wheel according to the present invention, a plurality of locations in the circumferential direction are provided on the flange portion of the remaining portion of the outer ring equivalent member, which is a portion close to the outer diameter of the outer ring equivalent member made of light alloy. Reinforcing ribs are formed. For this reason, the section modulus of the remaining portion made of a light alloy is increased to ensure the strength and rigidity of the outer ring equivalent member including the remaining portion. As a result, it is possible to further reduce the weight of the wheel bearing rolling bearing unit while ensuring the necessary strength and rigidity.

According to the second aspect of the present invention, the outer ring element having a simple shape can be used to provide the double-row outer ring raceway on the inner peripheral surface of the outer ring equivalent member, so that the manufacturing cost can be kept low.
On the other hand, according to the third aspect of the present invention, it is easy to ensure the coupling strength between the outer ring element and the remaining portion of the outer ring equivalent member made of a light alloy. In this case, according to the structure of the invention described in claim 4, it is possible to reliably prevent creep, which is a phenomenon in which the outer ring element and the remaining portion rotate relative to each other.

According to the fifth aspect of the present invention, the direction of the action of the moment applied to the remaining portion made of the light alloy among the outer ring equivalent members in the installation portion of the bolt for connecting the suspension device and the outer ring equivalent member. In addition, by providing the reinforcing rib, it is possible to prevent the remaining portion from being damaged such as a crack by this moment.
Further, according to the invention described in claim 6, the bolt itself for connecting the member constituting the suspension device such as a knuckle and the member corresponding to the outer ring becomes unnecessary, and the above-described unsprung load can be further reduced. I can plan.

Sectional drawing which shows the 1st example of embodiment of this invention. Similarly, the side view seen from the right side of FIG. Similarly perspective view. FIG. 2 is a partial cross-sectional view (a) corresponding to the lower right portion of FIG. 1 and partial cross-sectional views (b) and (c) showing two examples of a state in which a sleeve with a flange is installed on the main body. The fragmentary sectional view equivalent to the upper right part of FIG. 1 which shows the 2nd example of embodiment of this invention. Sectional drawing which shows the 3rd example of embodiment of this invention. Sectional drawing which shows the 1st example of a conventional structure. Sectional drawing which shows the 2nd example.

[First example of embodiment]
1 to 4 show a first example of an embodiment of the present invention corresponding to claims 1, 2, and 5. FIG. The wheel support rolling bearing unit 5a of this example includes an outer ring 6a that is an outer ring equivalent member, a hub 8a that is an inner ring equivalent member, and a plurality of balls 20a and 20a, each of which is a rolling element. Since the wheel-supporting rolling bearing unit 5a of this example is for an inner ring rotating type driven wheel, the outer peripheral surface of the outer ring 6a has a flange portion described in the claims at an inward portion in the axially intermediate portion. The stationary side flange 12a corresponding to is formed. Further, a rotation-side flange 15a is formed on the outer peripheral surface of a portion of the hub 8a that protrudes outward in the axial direction from the outer ring 6a. The rotation-side flange 15a is internally fitted and fixed with studs 9a and 9a for connecting the wheel 1 and the disk 2 (see FIG. 7) to the rotation-side flange 15a.

  The outer ring 6a has double-row outer ring raceways 11a and 11b on the inner peripheral surface, each made of bearing steel, and a pair of outer ring elements 27a and 27b corresponding to a part of the claims. Similarly, the main body 28 corresponding to the remaining portion is combined. The outer ring raceways 11a and 11b are formed on the inner peripheral surfaces of the outer ring elements 27a and 27b, respectively. The inner peripheral surface of the main body 28 has a stepped cylindrical shape composed of a small-diameter portion 29 provided at an axially intermediate portion and large-diameter portions 30a and 30b provided on both axial sides of the small-diameter portion 29. . Both end edges in the axial direction of the small-diameter portion 29 and end edges of both the large-diameter portions 30a and 30b are made continuous by a step surface that exists in a direction perpendicular to the central axis of the outer ring 6a. The outer ring elements 27a and 27b are held and fixed on the inner diameter sides of the large diameter portions 30a and 30b.

  The main body 28 as described above is integrally formed by casting a light alloy such as an aluminum alloy or a magnesium alloy (including die-cast molding or molten metal forging) or by forging the material. Yes. In the case of manufacturing by casting, both the outer ring elements 27a and 27b are cast (molded) on the inner diameter side of both the large diameter portions 30a and 30b. At this time, the shoulder portions (portions where the inner diameter is reduced) of both the outer ring elements 27a and 27b are positioned on the small diameter portion 29 side (the shoulder portion side end surface is abutted against the step surface). Since the linear expansion coefficient of the light alloy constituting the main body portion 28 is higher than the linear expansion coefficient of the bearing steel constituting the outer ring elements 27a and 27b, the outer peripheral surfaces of the outer ring elements 27a and 27b are formed after insert molding. And the inner peripheral surfaces of both large-diameter portions 30a and 30b are in contact with each other at a high surface pressure based on the thermal contraction of the main body portion 28, and both the outer ring elements 27a and 27b are disposed on the inner diameter side of the main body portion 28. It is held without wobbling. However, in this case, there is a possibility that the hardness of the outer ring raceways 11a and 11b formed on the inner peripheral surfaces of the outer ring elements 27a and 27b may be insufficient due to the heat generated when casting the main body 28. Therefore, if necessary, after casting the main body 28, both the outer ring raceways 11a and 11b are quenched and hardened by high-frequency heat treatment. On the other hand, when the main body 28 is manufactured by forging, the outer ring elements 27a and 27b are fitted and fixed to the large-diameter portions 30a and 30b of the processed main body 28 by interference fitting. In this case, if necessary, the outer ring elements 27a and 27b are cooled and fitted in a cooled state, the main body 28 is fitted in a heated state, and the main body 28 is heated. Any one of cold shrink fitting that fits the outer ring elements 27a and 27b in a cooled state is performed.

  On the other hand, the hub 8a includes a hub body 13a made of steel such as medium carbon steel, and an inner ring 14a externally fitted to a small-diameter step portion 18a provided near the inner end of the hub body 13a in the axial direction. The inner end portion of 13a is coupled and fixed in a non-separable manner by a caulking portion 19a formed by plastically deforming radially outward. Double row inner ring raceways 17a and 17b are provided on the outer peripheral surface of the hub 8a. These inner ring raceways 17a and 17b are provided in a direction in which the outer diameter on the axial center side of the hub 8a is small and the outer diameters on both ends are also increased.

  Each of the balls 20a and 20a can freely roll between the outer ring raceways 11a and 11b and the inner ring raceways 17a and 17b while being held by a retainer (not shown) in each row. Is provided. In this state, a preload is applied to each of the balls 20a and 20a together with a back contact type contact angle. Incidentally, both end openings in the axial direction of the inner space 31 that exist between the inner peripheral surface of the outer ring 6a and the outer peripheral surface of the hub 8a and in which the balls 20a, 20a are arranged are the axial outer end openings. The seal ring 21a and the axially inner end opening are closed by the cover 32, respectively.

  Further, in the case of this example, a plurality of circumferential positions (for example, four positions) on the outer peripheral surface of the stationary flange 12a are projected outward in the radial direction, and screw holes or through-holes 35 are respectively formed in these projected portions. , 35 are formed. These screw holes or through-holes 35, 35 are for screwing or inserting bolts 7 (see FIG. 7) for connecting the stationary flange 12a and the components of the suspension device such as the knuckle 3. is there. When a screw hole is formed in the stationary side flange 12a, the tip of the bolt 7 inserted through the through hole provided on the knuckle 3 side is screwed into this screw hole and further tightened. On the other hand, when the through holes are formed in the stationary flange 12a, the tip portions of the bolts 7 inserted through the through holes are screwed into the screw holes formed in the knuckle and further tightened.

  In particular, in the case of the wheel support rolling bearing unit 5a of the present example, the outer ring 6a is secured while ensuring the strength and rigidity required for the outer ring 6a by devising the shape of the stationary flange 12a. In order to further reduce weight. That is, in the case of this example, the reinforcing ribs 33 are formed at a plurality of locations in the circumferential direction on the outer surface in the axial direction of the stationary flange 12a. These reinforcing ribs 33 and 33 are formed at the same positions as the screw holes or through-holes 35 and 35 in the phase in the circumferential direction, and the joint surface between the reinforcing rib 33 and the outer ring 6a and the stationary flange 12a. Is provided with a corner R portion 34 to ensure the strength and rigidity of the outer ring 6a. In short, by forming these reinforcing ribs 33, 33, the volume of the outer ring 6a provided with the stationary side flange 12a is suppressed to reduce the weight, and based on the presence of the reinforcing ribs 33, 33, the outer ring By ensuring the section modulus of 6a, etc., the strength and rigidity of the radial direction of the outer ring 6a and the acting direction of the moment are ensured.

  When a screw hole is formed in the stationary flange 12a and the tip of the bolt 7 is screwed into the screw hole and tightened, the screw hole is directly formed on the stationary flange 12a made of light alloy. However, if it is necessary to increase the tightening torque of the bolt 7 sufficiently to increase the coupling strength of the bolt 7, as shown by the chain line in FIG. It is preferable to embed and support (insert molding) a cylindrical sleeve 36 having an internal thread formed on the inner peripheral surface thereof in a part of the stationary side flange 12a. In this case, it is preferable to use a sleeve 36 having an outward flange-shaped flange portion 38 as shown in FIGS. If this flange portion 38 is brought into contact with the outer side surface in the axial direction, which is the side surface opposite to the head portion of the bolt 7, of both side surfaces in the axial direction of the stationary flange 12 a, the bolt 7 is tightened. Accordingly, the thrust force applied to the sleeve 36 can be reliably supported. As shown in FIG. 4 (b), the flange 38 can be left protruding from the axially outer surface of the stationary flange 12a, but as shown in FIG. 4 (c). Moreover, it is advantageous in preventing interference with adjacent members if it is embedded in the stationary flange 12a so as not to protrude from the outer surface in the axial direction. The method for supporting the sleeve 36 on a part of the stationary flange 12a is appropriately selected according to the shape of the sleeve 36. When a cylindrical sleeve 36 as shown in FIG. 4A is used, this sleeve is held and fixed to a part of the stationary side flange 12a by insert molding. On the other hand, when using the sleeve 36 having the flange portion 38 as shown in FIGS. 4B and 4C, it is fitted to the through hole 35 formed by casting as well as by insert molding. You can also do it. The fitting in this case is preferably an interference fit, but may be a gap fit.

As described above, in the case of the rolling bearing unit 5a for supporting a wheel according to the present invention, the stationary flange 12a is provided on the outer peripheral surface of the main body 28 made of light alloy, which is a portion closer to the outer diameter of the outer ring 6a. Reinforcing ribs 33 and 33 are formed at a plurality of locations in the circumferential direction of the axially outer side surface of the side flange 12a. For this reason, the section modulus of the main body 28 is increased to ensure the strength and rigidity of the outer ring 6 a including the main body 28. As a result, the wheel support rolling bearing unit 5a can be further reduced in weight while ensuring the required strength and rigidity.
Further, according to the structure of this example, a pair of outer ring elements 27a and 27b, each having a simple shape, can be used to provide double row outer ring raceways 11a and 11b on the inner peripheral surface of the outer ring 6a. Manufacturing costs can be kept low.

[Second Example of Embodiment]
FIG. 5 shows a second example of an embodiment of the present invention corresponding to claims 1, 3 and 4. In the case of the wheel support rolling bearing unit 5b of this example, the double row outer ring raceways 11a and 11b provided on the inner peripheral surface of the outer ring 6b are separated in the axial direction of the inner peripheral surface of one outer ring element 27c. It is formed at two positions. A protrusion 37 corresponding to the concave-convex engaging portion described in the claims is continuously or intermittently provided in the axial direction intermediate portion of the outer peripheral surface of the outer ring element 27c made of bearing steel in the circumferential direction. Is formed. Then, a body 28a made of a light alloy is formed on the outer diameter side of the outer ring element 27c in a state where the outer ring element 27c is molded, and the outer ring element 27c is held on the inner diameter side of the main body 28a. Yes. In this state, the outer ring element 27c and the main body portion 28a are firmly coupled by wrapping the protruding portion 37 with a light alloy constituting the main body portion 28a. Furthermore, if this protrusion 37 is formed intermittently in the circumferential direction, relative rotation (creep) between the outer ring element 27c and the main body 28a can be reliably prevented.
In the case of this example, the rigidity of the outer ring raceways 11a and 11b can be increased by integrating the outer ring elements 27c having the both outer ring raceways 11a and 11b.
Since the configuration and operation of the other parts are the same as in the case of the first example of the embodiment described above, illustration and description regarding the equivalent parts are omitted.

[Third example of embodiment]
FIG. 6 shows a third example of an embodiment of the present invention corresponding to claims 1, 2, and 6. In the case of the wheel support rolling bearing unit 5c of this example, the main body portion 28c constituting the outer ring 6c and the knuckle 3a constituting the suspension device are integrated. According to such a structure of this example, the bolt 7 (see FIG. 7) for connecting the main body portion 28c and the knuckle 3a becomes unnecessary, the strength and rigidity are further improved, and the unsprung load of Further reduction can be achieved.
Since the configuration and operation of the other parts are the same as those of the first and second examples of the above-described embodiment, the overlapping description is omitted.

In the illustrated examples, the present invention is shown when the present invention is applied to a wheel bearing rolling bearing unit for an inner ring type driven wheel, but the present invention is an outer ring type for a driven wheel, or The present invention can also be applied to a wheel bearing rolling bearing unit for an inner ring rotating type driving wheel.
Further, the pitch circle diameter, the ball diameter, and the number of balls of the balls arranged in a double row are not necessarily the same, and may be different from each other.
Furthermore, a tapered roller can be used instead of a ball as each rolling element. Furthermore, the rolling elements constituting the row on the side receiving a large load may be tapered rollers, and the rolling elements constituting the other row may be balls. In any case, the number of rolling elements may be different between both rows.
As in the present invention, the raceway surface portion is made of an iron-based alloy and the other portions are made of a light alloy, and the inner ring equivalent member such as a hub is reduced in weight while ensuring the necessary strength and rigidity. You can also plan.

If you use ceramic balls as rolling elements, resin cages, and aluminum alloy covers to reduce the weight of parts other than the outer and inner rings, the weight of the rolling bearing unit for supporting the wheels will be further reduced. I can do it.
Also, when the temperature of the rolling bearing unit for supporting the wheel rises, the thermal expansion coefficient of the aluminum alloy is larger than that of iron, so the fitting force between the cover that closes the axial inner end opening and the outer ring is weakened. The cover may be displaced in the axial direction. Therefore, it is preferable to use a material such as an aluminum alloy having a thermal expansion coefficient equivalent to that of the outer ring as the cover material. When the cover is made of an iron-based material, an elastic material such as rubber can be vulcanized or coated with an adhesive on the outer periphery of the cover fitted with the outer ring.

1 Wheel 2 Disc 3, 3a Knuckle 4 Support hole 5, 5a, 5b, 5c, 5d Rolling bearing unit for wheel support 6, 6a, 6b, 6c Outer ring 7 Bolt 8, 8a Hub 9, 9a Stud 10 Nut 11a, 11b Outer ring Track 12, 12a Stationary flange 13, 13a Hub body 14, 14a Inner ring 15, 15a Rotating flange 16 Positioning portion 17a, 17b Inner ring track 18, 18a Small diameter step portion 19, 19a Caulking portion 20, 20a Ball 21a, 21b Seal ring 22 spline hole 23 outer ring for constant velocity joint 24 spline shaft 25 nut 27a, 27b, 27c outer ring element 28, 28a, 28c main body part 29 small diameter part 30a, 30b large diameter part 31 internal space 32 cover 33 reinforcing rib 34 corner R part 35 35a Screw hole or through hole 6 sleeve 37 ridges 38 flange portion

Claims (6)

  An outer ring equivalent member having a double row outer ring raceway on the inner peripheral surface, an inner ring equivalent member having a double row inner ring raceway on the outer peripheral surface, and a plurality of both outer ring raceways between the inner ring raceway and the outer ring raceways. Rolling elements provided so as to be capable of rolling individually, and a part of the outer ring equivalent member including the part where the outer ring raceways are provided is made of an iron-based alloy, and the remaining part including at least a part near the outer diameter is provided. In a rolling bearing unit for wheel support that is made of a light alloy and has a flange portion that protrudes radially outward from the outer peripheral surface of the remaining portion, a plurality of circumferential positions on the axial side surface of the flange portion A rolling bearing unit for supporting a wheel, characterized in that reinforcing ribs are formed on the outer ring to ensure the strength and rigidity of the outer ring equivalent member.   A contact angle of a back contact type is given to the rolling elements of both rows, and both the outer ring raceways are formed on inner peripheral surfaces of a pair of independent outer ring elements, and a portion closer to the inner diameter of the remaining part 2. The wheel support according to claim 1, wherein the outer ring elements are held by the remaining portion in a state in which a small-diameter portion having a smaller inner diameter than both side portions in the axial direction is sandwiched from both sides in the axial direction. Rolling bearing unit.   A contact angle of a back contact type is given to the rolling elements of both rows, and both the outer ring raceways are formed at two positions separated in the axial direction of the inner circumferential surface of one outer ring element, The outer ring element is formed in the axially intermediate portion of the outer peripheral surface of the outer ring element, and the concave and convex engaging portions protruding or recessed in the radial direction with respect to both axial side portions are embedded in the remaining part. The wheel bearing rolling bearing unit according to claim 1, wherein is held on the inner diameter side of the remaining portion.   4. The wheel support according to claim 3, wherein the uneven engaging portion has a shape in which unevenness is repeated in the circumferential direction in addition to a shape protruding or recessed with respect to a portion adjacent in the axial direction. Rolling bearing unit.   The outer ring equivalent member is supported and fixed to a suspension device at a plurality of locations in the circumferential direction near the outer diameter of the remaining portion of the outer ring equivalent member, or a bolt for connecting and fixing the wheel to the outer ring equivalent member is screwed or Screw holes or through-holes for insertion are formed, and the reinforcing ribs are formed at the same positions as the screw holes or through-holes in a phase in the circumferential direction. The rolling bearing unit for wheel support described in any one of these.   The wheel bearing rolling bearing unit according to any one of claims 1 to 4, wherein a remaining part of the outer ring equivalent member and a member constituting the suspension device are integrated.

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