JP2005140177A - Wheel support hub unit - Google Patents

Abstract

An excessive impact load may act on a wheel-supporting hub unit due to an automobile collision or riding on a falling object during high-speed traveling. The impact load causes damage to the raceway surface of the bearing, and due to this, the performance of the bearing is significantly reduced.
An entire portion of a step portion 8 formed at an inner end portion of a hub 2 near an inner end of a step portion is projected inwardly from an inner ring 3 externally fitted to the step portion 8 and has a rectangular cross section. A spacer 18 formed in an annular shape is fitted. A caulking portion 16 is formed by caulking and expanding a portion projecting inward from the inner side surface of the spacer 18 at the inner end portion of the cylindrical portion 20, and the spacer 18 is connected to the inner end surface of the inner ring 3. The inner ring 3 is coupled and fixed to the hub 2 while being pressed against the hub 21. By using a copper-based metal or an aluminum-based metal as the material of the spacer 18, when an impact load is applied to the hub unit from the outside, the load can be reduced by the spacer 18.
[Selection] Figure 1

Description

  The present invention relates to a wheel support hub unit that rotatably supports a wheel of an automobile with respect to a suspension device.

  The wheel of the automobile is supported on the suspension device by a hub unit for supporting the wheel. FIG. 4 shows an example of a wheel support hub unit that has been widely used conventionally. The wheel support hub unit 1 includes a hub 2, an inner ring 3, an outer ring 4, and a plurality of rolling elements 5 and 5. A flange 6 for supporting the wheel is formed at the outer end of the outer peripheral surface of the hub 2. Further, a first inner ring raceway 7 is formed at an intermediate portion of the hub 2, and a step portion 8 having a smaller outer diameter is formed at the inner end portion.

  In the state where the wheel support hub unit 1 is attached to the vehicle body, the flange 6 to which the wheel is attached is usually located outside the vehicle body, and the opposite side is located inside the vehicle body. In each member of the hub unit 1, the flange 6 side is referred to as the outside, and the opposite side is referred to as the inside.

  An inner ring 3 having a second inner ring raceway 9 formed on the outer peripheral surface thereof is externally fitted to the stepped portion 8. A male threaded portion 10 is formed in the inner end of the hub 2, and the tip end of the male threaded portion 10 protrudes inward from the inner end face of the inner ring 3. The inner ring 3 is clamped and fixed to a predetermined position of the hub 2 by sandwiching the inner ring 3 between a nut 11 screwed into the male threaded portion 10 and a stepped surface 12 of the stepped portion 8. A locking recess 17 is formed on the outer peripheral surface of the distal end portion of the male screw portion 10. Then, after tightening the nut 11 with a predetermined torque, a portion of the nut 11 that is aligned with the recess 17 is caulked inward in the diametrical direction to prevent the nut 11 from loosening.

  A first outer ring raceway 13 that faces the first inner ring raceway 7 and a second outer ring raceway 14 that faces the second inner ring raceway 9 are formed on the inner peripheral surface of the outer ring 4. . A plurality of rolling elements 5 and 5 are provided between the first and second inner ring raceways 7 and 9 and the first and second outer ring raceways 13 and 14, respectively. In the illustrated example, balls are used as the rolling elements 5 and 5. However, in the case of a heavy vehicle hub unit such as a truck or a bus, tapered rollers may be used as these rolling elements. is there.

  Further, in the illustrated example, by providing a seal ring 22 between the outer peripheral surface of the outer end portion of the outer ring 4 and the outer peripheral surface of the hub 2, dust enters the space where the rolling elements 5 and 5 are installed. Or the lubricating oil or the like is prevented from leaking from this space. Further, a lid body 23 that closes the inner end opening of the outer ring 4 is attached to the inner end of the outer ring 4.

  In order to assemble the wheel support hub unit 1 as described above to an automobile, the outer ring 4 is fixed to a suspension device by an outward flange-shaped mounting portion 15 formed on the outer peripheral surface thereof, and a wheel 26 is attached to the flange 6 by bolts 26. To fix. As a result, this wheel is rotatably supported with respect to the suspension device.

  US Pat. No. 5,226,738 describes a wheel support hub unit 1 having a structure as shown in FIG. In the case of the second example of this conventional structure, a caulking portion 16 is formed by bending a portion of the inner end portion of the hub 2 that protrudes inward from the inner end surface of the inner ring 3 in the diametrically outward direction. The inner ring 3 is sandwiched between the portion 16 and the step surface 12 of the step portion 8.

  In the first example of the conventional structure shown in FIG. 4 among the wheel supporting hub units having the above-described structures, the operation of forming the locking recess 17 at the tip of the male screw 10 and the nut An operation of caulking a part of 11 inward in the diameter direction is required. For this reason, the parts manufacturing work and assembling work of the wheel supporting hub unit 1 become troublesome, and the cost increases.

  On the other hand, in the case of the second example of the conventional groove structure shown in FIG. 5 described above, the trouble of the component manufacturing work and the assembly work can be eliminated, but there are the following disadvantages. In other words, when the caulking portion 16 for fixing the inner ring 3 to the hub 2 is formed, a force directed outward in the diameter direction is applied to the inner peripheral surface of the inner ring 3 adjacent to the caulking portion 16. For this reason, the diameter of the inner ring 3 changes although it is slight. If the amount of change increases, the bearing life may be shortened due to excessive preload, preload loss, or deformation of the raceway. In particular, in order to prevent the inner ring 3 from rotating with respect to the hub 2, it is easy to increase the amount of deformation of the inner ring 3 when the caulking strength of the caulking portion 16 is sufficiently secured. The effect on the life is increased.

  For this reason, in order to eliminate the above-mentioned inconvenience, Japanese Patent Laid-Open No. 9-220904 describes a wheel support hub unit 1 having a structure as shown in FIG. In the case of the third example of this conventional structure, a portion that protrudes inward from the inner ring 3 that is externally fitted to the step portion 8 at a portion near the inner end of the step portion 8 formed at the inner end portion of the hub 2. In addition, a spacer 18 that is formed in a circular shape with a rectangular cross section by a metal having sufficient rigidity such as steel is externally fitted. The inner diameter of the spacer 18 is set to be a size that can be fitted onto the step portion 8 without a gap. In addition, a circular recess 19 is formed on the inner end surface of the hub 2 so that a cylindrical portion 20 is formed at the inner end of the hub 2. In the case of the illustrated example, the cylindrical portion 20 exists at a portion protruding inward from the inner end surface 21 of the inner ring 3 at the inner end portion of the hub 2.

  Then, the caulking portion 16 is formed by caulking and expanding the portion protruding inward from the inner side surface of the spacer 18 at the inner end portion of the cylindrical portion 20 outward in the diameter direction. The caulking portion 16 holds the spacer 18 against the inner end surface 21 of the inner ring 3, and the inner ring 3 is coupled and fixed to the hub 2. That is, the inner ring 3 and the spacer 18 are sandwiched between the caulking portion 16 and the step surface 12 of the step portion 8, so that the inner ring 3 and the spacer 18 are coupled and fixed to the hub 2.

  In the case of the wheel supporting hub unit 1 as shown in FIG. 6, even if the caulking strength of the caulking portion 16 is sufficiently increased by providing the spacer 18, the inner ring 3 is elastically deformed in the diameter direction. Can be surely prevented. That is, when the caulking portion 16 is formed, a force directed outward in the diameter direction is applied to the inner peripheral surface of the member adjacent to the caulking portion 16. In the case of the second example of the conventional structure shown in FIG. 5, the inner ring 3 receives this force, whereas in the case of the third example of the conventional structure shown in FIG. The spacer 18 that is externally fitted to the arm receives a force directed outward in the diameter direction. Therefore, the diameter of the inner ring 3 does not change with the formation of the caulking portion 16. Therefore, the preload of the rolling element 5 provided between the second inner ring raceway 9 formed on the outer peripheral surface of the inner ring 3 and the second outer ring raceway 14 formed on the inner peripheral surface of the outer ring 4 is maintained at an appropriate value. it can.

Further, JP 2000-229501 A discloses a wheel support hub unit 1 having a structure as shown in FIG. 7, and the first tapered surface portion 24 provided on the inner end surface of the inner ring 3 with this structure. Based on the engagement with the second tapered surface portion 25 provided on the outer end surface of the seat 18, the coupling force of the inner ring to the hub 2 can be increased. That is, the contact surfaces of the first and second tapered surface portions are inclined in the direction toward the axially outward side toward the inner diameter side. Therefore, when the cylindrical portion 20 formed at the inner end portion of the hub 2 is caulked (when the caulking portion is formed), a force directed outward in the diameter direction is applied to the spacer 18 so that the diameter of the spacer 18 is somewhat In the ascending lift, a force directed outward in the axial direction is applied from the spacer to the inner ring through the contact surfaces of the two tapered surface portions. That is, in this case, based on the engagement between the two tapered surface portions, the force directed outward in the diameter direction applied to the spacer 18 can be converted into the force pressing the inner ring 3 outward in the axial direction. For this reason, it is possible to increase the coupling force of the inner ring 3 to the hub 2 by applying a large axially outward force to the inner ring 3.
US Pat. No. 5,226,738 Japanese Patent Laid-Open No. 9-220904 JP 2000-229501 A

  The wheel support hub unit may be subjected to an excessive impact load due to an automobile collision or riding on a fallen object during high-speed traveling. The impact load causes damage to the raceway surface of the bearing, and due to this, the performance of the bearing is significantly reduced. Therefore, it is necessary to take measures against the wheel support hub unit having the conventional structure as described above.

  The wheel support hub unit of the present invention is similar to the wheel support hub unit of the third example of the conventional structure shown in FIG. 6 and the fourth example of the conventional structure shown in FIG. The flange for supporting the wheel at the end, the first inner ring raceway at the intermediate part directly or via a separate inner ring, and the part where the first inner ring raceway is also formed at the inner end part. Steps with reduced diameter dimensions are formed on the hub, the outer ring has a second inner ring raceway, the inner ring is fitted on the stepped part, and the inner ring is attached to the first inner ring raceway. Between the first outer ring raceway and the outer ring forming the second outer ring raceway facing the second inner ring raceway, and between the first and second inner ring raceways and the first and second outer ring raceways. And a plurality of rolling elements provided respectively.

  A spacer is externally fitted to a portion projecting inward from the inner ring at a portion near the inner end of the intermediate portion of the step portion, and at least a portion projecting inward from the spacer at the inner end portion of the hub. A cylindrical portion is formed on the inner ring, and the spacer is pressed against the inner end surface of the inner ring by a caulking portion formed by caulking the cylindrical portion outward in the diameter direction, and the inner ring is coupled and fixed to the hub. Become. In particular, in the wheel supporting hub unit of the present invention, the spacer is made of a copper-based material or an aluminum-based material.

  Based on the action of supporting the wheel rotatably with respect to the suspension device by the wheel support hub unit of the present invention configured as described above, and the presence of a spacer sandwiched between the inner ring and the caulking portion, this The wheel support hub unit of the third to fourth examples of the conventional structure shown in FIGS. 6 and 7 is capable of preventing the diameter of the inner ring from changing as the preload of each rolling element changes when the caulking portion is formed. It is the same. Furthermore, the impact load can be reduced and the bearing life can be extended based on the material of the spacer being a copper-based deposit or an aluminum-based material.

  A flange for supporting the wheel at the outer end of the outer peripheral surface, a first inner ring raceway formed in the middle part directly or via a separate inner ring, and the first inner ring raceway formed in the inner end part. Steps having outer diameters smaller than the part, hubs formed respectively, an inner ring having a second inner ring raceway on the outer peripheral surface, the outer ring fitted on the step part, and the first on the inner peripheral surface An outer ring that forms a first outer ring raceway that faces the inner ring raceway and a second outer ring raceway that faces the second inner ring raceway, the first and second inner ring raceways, and the first and second outer rings. And a plurality of transfer bodies provided between each of the tracks, and a spacer is externally fitted to a portion projecting inward from the inner ring at a portion near the inner end of the intermediate portion of the step portion, and the hub A cylindrical portion is formed at least at a portion protruding inward from the spacer at the inner end of the cylindrical portion. The spacer is pressed against the inner end surface of the inner ring by a caulking portion formed by caulking outward in the radial direction, and the impact load on the wheel support hub unit formed by coupling and fixing the inner ring to the hub is reduced. The purpose of extending the bearing life is realized by using a copper-based deposit or aluminum-based material as the spacer.

    FIG. 1 shows a first example of an embodiment of the present invention. The feature of the present invention lies in the structure of the portion for fixing the inner ring 3 to the hub 2, and the structure and operation of the other portions are the same as those of the conventional structure shown in FIG. The same reference numerals are assigned to the components, and overlapping descriptions are omitted or simplified, and the following description will focus on the features of the present invention.

  At the portion near the inner end of the intermediate portion of the step portion 8 formed at the inner end portion of the hub 2, the portion protruding inward from the inner ring 3 fitted on the step portion 8 is formed in an annular shape with a rectangular cross section. The spacer 18 is externally fitted. The inner diameter of the spacer 18 is set to a size such that the spacer 18 can be externally fitted without rattling. In addition, a circular recess 19 is formed on the inner end surface of the hub 2 so that a cylindrical portion 20 is formed at the inner end of the hub 2. In the case of the first example shown in the figure, the cylindrical portion 20 exists at a portion protruding inward from the inner end surface 21 of the inner ring 3 at the inner end portion of the hub 2.

  In the hub unit for supporting a wheel of the present invention, a portion protruding inward from the inner side surface of the spacer 18 at the inner end portion of the cylindrical portion 20 is caulked outward in the diametrical direction by, for example, a rocking press. Thus, the caulking portion 16 is formed. The caulking portion 16 holds the spacer 18 against the inner end surface 21 of the inner ring 3, and the inner ring 3 is coupled and fixed to the hub 2. That is, the inner ring 3 and the spacer 18 are sandwiched between the caulking portion 16 and the step surface 12 of the step portion 8, so that the inner ring 3 and the spacer 18 are coupled and fixed to the hub 2. If a rocking press is used for the caulking operation, there is an advantage that the load during molding can be reduced, the influence on the inside of the bearing can be eliminated, and preload management after molding can be appropriately performed.

  In the case of the first example, by providing such a spacer 18, even when the caulking strength of the caulking portion 16 is sufficiently increased, the inner ring 3 can be reliably prevented from being elastically deformed in the diametrical direction. That is, when the caulking portion 16 is formed, a force directed outward in the diameter direction is applied to the inner peripheral surface of the member adjacent to the caulking portion 16. In the case of the conventional structure shown in FIG. 6 described above, the inner ring 3 receives this force, whereas in the case of the first example, the spacer 18 that is fitted onto the hub 2 has the diametrically outer side. Receives the power suitable for Therefore, the diameter of the inner ring 3 does not change with the formation of the caulking portion 16. For this reason, the inner ring 3 is not damaged as the caulking portion 16 is formed.

  In the wheel support hub unit of the present invention, the spacer 18 is made of copper-based metal or aluminum-based metal. For this reason, when an impact load is applied to the hub unit from the outside, the load can be relieved by the spacer 18 and an effect of extending the life can be obtained.

  FIG. 2 shows a second example of the embodiment of the present invention. In this example, as in the first example, on the inner peripheral surface side of the spacer 18 made of a copper-based metal or an aluminum-based metal, an outward projecting portion 27 is formed to form a stepped shape. The protrusion 27 is fitted in a fitting groove 28 formed inward of the inner peripheral surface. By comprising in this way, in addition to the effect of the said 1st example, the positioning accuracy of the spacer 18 can be improved.

 FIG. 3 shows a third example of the embodiment of the present invention, and this example corresponds to the conventional structure shown in FIG. Based on the engagement between the first tapered surface portion 24 provided on the inner end surface of the inner ring 3 and the second tapered surface portion 25 provided on the outer end surface of the spacer 18, the coupling force of the inner ring 3 to the hub 2 can be increased. That is, the contact surfaces of the first and second taper surface portions are inclined in the direction toward the axially outward side toward the inner diameter side. For this reason, when the cylindrical portion formed at the inner end portion of the hub 2 is caulked (when the caulking portion is formed), a force directed outward in the diameter direction is applied to the spacer 18 so that the diameter of the spacer 18 is somewhat reduced. When both are spread, a force directed outward in the axial direction is applied from the spacer 18 to the inner ring 3 through the contact surfaces of the two tapered surface portions.

  That is, in the case of this example, based on the engagement between the both tapered surface portions, the force directed outward in the diameter direction applied to the spacer 18 can be converted to the force pressing the inner ring 3 outward in the saddle direction. For this reason, it is possible to increase the coupling force of the inner ring 3 with respect to the hub 2 by applying a large axially outward force to the inner ring 3. Further, the material of the spacer 18 is made of a copper-based metal or an aluminum-based metal, so that the impact load acting on the hub can be relieved as in the above embodiments, and the effect of extending the life of the bearing can be obtained.

  The hub unit for supporting wheels according to the present invention can be used as a hub unit for supporting wheels of various automobiles, and is particularly suitable for wheel supports in which roller bearings are arranged between double rows of balls as used in heavy vehicles. It can also be used for a hub unit.

It is sectional drawing which shows the 1st example of embodiment of this invention. It is sectional drawing which shows the principal part of the 2nd example of embodiment of this invention. It is sectional drawing which shows the principal part of the 3rd example of embodiment of this invention. It is sectional drawing which shows the 1st example of a conventional structure. It is sectional drawing which shows the 2nd example of conventional forging. It is sectional drawing which shows the 3rd example of a conventional structure. It is sectional drawing which shows the 4th example of the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel support hub unit 2 Hub 3 Inner ring 4 Outer ring 5 Rolling element 6 Flange 7 First inner ring raceway 8 Step part 9 Second inner ring raceway 10 Male thread part 11 Nut 12 Step surface 13 First outer ring raceway 14 Second Outer ring raceway 15 Mounting portion 16 Caulking portion 17 Locking recess 18 Spacer 21 Inner end surface 22 Seal ring 23 Lid

Claims (1)

A flange for supporting the wheel at the outer end of the outer peripheral surface, a first inner ring raceway formed in the middle portion directly or via a separate inner ring, and the first inner ring raceway formed in the inner end portion. Hubs each formed with a step portion having a smaller outer diameter than the portion,
An inner ring having a second inner ring raceway on the outer peripheral surface and fitted on the stepped portion;
An outer ring having a first outer ring raceway facing the first inner ring raceway and a second outer ring raceway facing the second inner ring raceway on the inner peripheral surface;
A plurality of transfer bodies each provided between the first and second inner ring raceways and the first and second outer ring raceways,
A spacer is externally fitted to a portion projecting inward from the inner ring at a portion near the inner end of the intermediate portion of the step portion, and a cylinder is formed at a portion projecting inward from the spacer at the inner end portion of the hub. A wheel formed by pressing the spacer against the inner end surface of the inner ring by a caulking part formed by caulking and expanding the cylindrical part outward in the diameter direction, and coupling and fixing the inner ring to the hub In the supporting hub unit,
A hub unit for supporting a wheel, wherein the spacer is made of a copper-based material or an aluminum-based material.

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