JP2008132827A - Hub unit for supporting wheel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub unit for supporting a wheel capable of surely preventing slipping-out of an inner ring without requiring an expensive device, and its manufacturing method. <P>SOLUTION: This hub unit 20 is provided with a hub 21 provided with an outer ring 22 having a plurality of rows of outer ring raceway surfaces 33 and 34 on an inner peripheral surface, a hub wheel 25 having an inner ring raceway surface 32 corresponding to the one outer ring raceway surface 34 on an outer peripheral surface, and an inner ring 30 fitted in a small diameter step part 29 of the hub wheel 25 and having an inner ring raceway surface 31 corresponding to the other outer ring raceway surface 33 on an outer peripheral surface, and a plurality of rolling elements 23 disposed to roll between the inner ring raceway surfaces 31 and 32 of the hub 21 and the outer ring raceway surfaces 33 and 34. A radial direction gap g is provided between an inboard side outer peripheral surface 41 of the small diameter step part 29 of the hub wheel 25 and an inner peripheral surface of the inner ring 30. The hub wheel 25 has a projecting part 45 projecting into the radial direction gap g by plastically deforming an annular groove 44 formed on the inner peripheral surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel support hub unit for rotatably supporting a wheel of an automobile or the like with respect to a suspension device and a method for manufacturing the same.

  FIG. 5 shows a conventional hub unit for driving wheels. The wheel support hub unit 1 includes a hub 4 having a hub ring 2 and an inner ring 3, an outer ring 5, and a plurality of balls 6 interposed between the hub 4 and the outer ring 5 in a double row. The hub unit 1 is coupled to the constant velocity joint 7 by fastening the spline shaft 8 of the constant velocity joint 7 to the hub wheel 2.

  The inner ring 3 is abutted against the housing end surface 9 of the constant velocity joint 7, and is coupled to the hub wheel 2 by fastening a nut 11 to the screw portion 10 at the tip of the spline shaft 8.

  In general, the assembly process of the hub unit 1 and the constant velocity joint 7 is performed by a sub-assembly manufacturer. Conventionally, the hub unit 1 is attached by the fitting force of the inner ring 3 on the fitting surface with the hub ring 2. Shipped in a state to the sub-assembly manufacturer.

  For this reason, if the hub unit 1 is supplied to a sub-assembly manufacturer with many peripheral parts assembled, the inner ring 3 may come out of the hub ring 2 only with the fitting force between the inner ring 3 and the hub ring 2. There is.

  As a countermeasure against brake judder, the rotor surface may be turned after the brake rotor is assembled to the hub unit 1 and before the constant velocity joint 7 is assembled. May occur.

  If the inner ring 3 is pulled out, the contact position between the ball 6 and the raceway surface is not normal, the ball 6 protrudes from the end of the raceway surface and rolls, and the surface of the ball 6 and the raceway surface are damaged. , Leading to abnormal noise and reduced life. In addition, the sliding position of the sealing lip of the sealing member 12 is not normal, so that the sealing lip is scratched or the lip is reversed. As a result, water can enter the bearing or cause grease leakage from the bearing. It becomes.

As a measure to prevent the inner ring 3 from coming off, the inner ring was formed with irregularities on the inner diameter of the inner ring to increase the diameter of the small-diameter step of the hub ring, or the diameter of the tip of the small-diameter step of the hub ring was increased to the inner diameter of the inner ring. It has been proposed to engage with a stepped portion (see, for example, Patent Documents 1 and 2).
JP 2003-65347 A JP 2006-161970 A

  However, in the hub units described in Patent Documents 1 and 2, a rotary forging machine is required to increase the diameter of the stepped portion of the hub wheel, and the introduction of the device is expensive. Further, when the diameter of the small-diameter step portion of the hub wheel is expanded by the device, the inner ring may be deformed when the pressing force is increased.

  The present invention has been made to eliminate such inconveniences, and does not require an expensive device such as a rotary forging machine, and a wheel support hub unit capable of reliably preventing the inner ring from coming off, and its An object is to provide a manufacturing method.

The above object of the present invention is achieved by the following configurations.
(1) an outer ring having a double-row outer ring raceway surface on the inner circumferential surface;
A hub ring having an inner ring raceway surface corresponding to one of the double row outer ring raceway surfaces on the outer peripheral surface, and fitted in the axial end of the hub ring on the inboard side, and is fitted to the other of the double row outer ring raceway surfaces. A hub comprising an inner ring having a corresponding inner ring raceway surface on the outer peripheral surface;
A plurality of rolling elements arranged to be rollable between the inner ring raceway surface of the hub and the outer ring raceway surface of the outer ring;
A wheel supporting hub unit comprising:
A radial clearance is provided between the inboard-side outer peripheral surface of the axial end portion of the hub wheel and the inner peripheral surface of the inner ring,
The hub wheel includes a hub unit for supporting a wheel, wherein a groove formed on an inner peripheral surface of the hub wheel has a projecting portion that projects into the radial gap as a result of plastic deformation.
(2) The inboard side outer peripheral surface of the hub wheel is formed to have a smaller diameter than the inner diameter of the inner ring by a step formed on the outboard side from the groove. Hub unit for wheel support.
(3) An outer ring having a double row outer ring raceway surface on the inner peripheral surface, a hub ring having an inner ring raceway surface corresponding to one of the double row outer ring raceway surfaces on the outer peripheral surface, and an inboard side of the hub ring. A hub that is fitted into an axial end and has an inner ring having an inner ring raceway surface corresponding to the other of the double row outer ring raceway surfaces on the outer peripheral surface; the inner ring raceway surface of the hub; and the outer ring raceway surface of the outer ring; A plurality of rolling elements disposed so as to be capable of rolling between, and a method of manufacturing a wheel supporting hub unit comprising:
Forming a groove in the inner peripheral surface of the hub wheel;
The groove is plastically deformed by compressing the axial end portion of the hub wheel in the axial direction, and is provided between the inboard side outer peripheral surface of the axial end portion of the hub wheel and the inner peripheral surface of the inner ring. Projecting the outer portion of the groove into a radial gap, and preventing the inner ring from coming off from the hub ring,
A method for manufacturing a wheel support hub unit.

  According to the wheel support hub unit of the present invention and the manufacturing method thereof, a groove is formed on the inner peripheral surface of the hub wheel, and the axial end of the hub wheel is compressed in the axial direction to plastically deform the groove. An outer portion of the groove is projected in a radial gap provided between the inboard side outer peripheral surface of the hub wheel and the inner peripheral surface of the inner ring. Thus, an expensive device such as a rotary forging machine is not required, and the inner ring can be reliably prevented from coming off.

  Hereinafter, a wheel support hub unit and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

  The wheel support hub unit 20 of the present embodiment is for a drive wheel, and includes a hub 21 and an outer ring 22 and balls 23 as a plurality of rolling elements, as shown in FIG. The hub 21 includes a hollow hub wheel 25, and the hub wheel 25 is an end portion on the outboard side of the outer peripheral surface (an end portion on the outer side in the vehicle width direction in the assembled state in the automobile: the right end portion in FIG. 1). The wheel mounting flange 26 extends radially outward. A plurality of studs 27 are attached to the wheel mounting flange 26 at substantially equal intervals in the circumferential direction on the side surface on the outboard side for mounting a wheel (not shown), a brake rotor, and the like. Furthermore, a spline groove 28 that engages with a spline shaft of a constant velocity joint (not shown) is formed on the inner peripheral surface of the hub wheel 25 as in FIG.

  A small-diameter step portion 29 is formed at an end portion in the axial direction on the inboard side of the hub wheel 25 (an end portion on the inner side in the vehicle width direction in the assembled state in the automobile: the left end portion in FIG. 1). An inner ring 30 is fitted into the inner ring 30. An inner ring raceway surface 31 is formed on the outer peripheral surface of the inner ring 30, and an inner ring raceway surface 32 is formed on the outer peripheral surface in the axial direction of the hub ring 25.

  An outer ring raceway surface 33 corresponding to the inner ring raceway surface 31 of the inner ring 30 and an outer ring raceway surface 34 corresponding to the inner ring raceway surface 32 of the hub ring 25 are formed on the inner peripheral surface of the outer ring 22, and a wheel mounting flange 26 is formed. A suspension device mounting flange 35 extending radially outward is provided at the end of the outer ring 22 on the side away from the outer ring 22.

  A plurality of balls 23 are arranged between the double-row inner ring raceway surfaces 31 and 32 and the double-row outer ring raceway surfaces 33 and 34 so as to roll in the circumferential direction via the cage 24. In the illustrated example, the balls 23 are used as the rolling elements. However, in the case of a heavy wheel support hub unit, tapered rollers may be used as the rolling elements.

  Further, a seal that seals the annular space between the outer ring 22, the hub ring 25, and the inner ring 30 between the inner peripheral surface of both ends of the outer ring 22 and the outer peripheral surfaces of the hub ring 25 and the inner ring 30 facing the inner peripheral surface. The members 36 and 37 are disposed to prevent leakage of grease filled inside and intrusion of water and foreign matters from the outside.

  In order to assemble the wheel supporting hub unit 20 as described above to the automobile, the suspension device mounting flange 35 of the outer ring 22 is fixed to the suspension device, and the stud 27 and nut (on the wheel mounting flange 26 of the hub wheel 25 on the rotating wheel side are fixed. The brake rotor and the wheel are fixed via a not-shown) or the like. Thereby, a wheel can be rotatably supported with respect to a suspension apparatus.

  Here, in the present embodiment, as shown in FIG. 2B, an interference fit is provided between the outer peripheral surface 40 of the small diameter step portion 29 of the hub wheel 25 and the inner peripheral surface of the inner ring 30. The dimensions are set to prevent the occurrence of creep in the configuration in which the hub 21 side rotates.

  Further, the small diameter step portion 29 of the hub wheel 25 is provided with a step 42 between the outboard side outer peripheral surface 40 and the inboard side outer peripheral surface 41, and the inboard side outer peripheral surface 41 of the small diameter step portion 29 and the inner ring 30. The dimensions are set so that there is a clearance fit between the inner peripheral surface. Thus, a radial gap g is provided between the inboard side outer peripheral surface 41 of the small diameter step portion 29 and the chamfered portion 43 of the inboard side inner peripheral surface of the inner ring 30.

  And in the said radial direction gap g, the protrusion 45 protrudes by plastically deforming the V-shaped annular groove 44 in the cross section processed into the inboard side inner peripheral surface of the small diameter step portion 29 of the hub wheel 25. It is formed to prevent the inner ring 30 from coming off.

  As shown in FIG. 2A, the annular groove 44 of the hub wheel 25 is formed at a position overlapping with the chamfered portion 43 of the inner ring 30 in the axial direction before plastic deformation. Further, the inboard side portion 46 of the small-diameter step portion 29 of the hub wheel 25 in which the annular groove 44 is formed has an inner peripheral surface from the spline groove 28 so as to reduce the pressing force for plastically deforming the annular groove 44. It is thin and has a large diameter.

  When the inner ring 30 is fixed to the hub ring 25, first, the inner ring 30 is press-fitted into the small diameter step portion 29 of the hub ring 25. At this time, since the clearance between the inboard side outer peripheral surface 41 of the small diameter step portion 29 and the inner peripheral surface of the inner ring 30 is a clearance fit, the annular groove 44 is prevented from buckling when the inner ring 30 is press-fitted. ing.

  Thereafter, by compressing the inboard side portion 46 of the small-diameter step portion 29 of the hub wheel 25 in the axial direction, the annular groove 44 is plastically deformed, and the outer portion of the annular groove 44 is buckled outward, and the inner ring 30 is fitted. By projecting larger than the inner diameter of the mating surface, it projects into the radial gap g. Thereby, the inner ring 30 is crimped by the protruding portion 45 protruding into the radial gap g, and the inner ring 30 is prevented from coming off.

  The end surface 47 of the inboard side portion 46 is sized and designed to be the same as or closer to the outboard of the inboard side end surface 30a of the inner ring 30 after the annular groove 44 is plastically deformed. As a result, as shown in FIG. 2B, when the constant velocity joint CVJ is fastened to the hub unit, the housing end surface S of the constant velocity joint CVJ interferes with the inboard side end portion 46 of the hub wheel 25. Without contact with the inboard side end surface 30a of the inner ring 30.

  Therefore, in the present embodiment, the annular groove 44 is formed in the inboard side inner peripheral surface of the small diameter step portion 29 of the hub wheel 25 and the inboard side portion 46 of the small diameter end portion 29 of the hub wheel 25 is compressed in the axial direction. As a result, the annular groove 44 is plastically deformed, and the outer portion of the annular groove 44 is projected into a radial gap g provided between the inboard-side outer peripheral surface 41 of the hub wheel 25 and the inner peripheral surface of the inner ring 30. . Accordingly, an expensive device such as a conventionally used rotary forging machine is not required, and the inner ring 30 can be reliably prevented from coming off by the projecting portion 45 projecting into the radial gap g. It is possible to prevent the ball damage due to the ball, the abnormal noise accompanying the ball damage, the life reduction, etc., and the damage of the seal member can be prevented.

  Further, since the inner ring 30 is crimped by compressing the inboard side portion 46 of the small diameter end portion 29 in the axial direction, the hub ring 25 is greatly displaced in the axial direction. For this reason, it is possible to easily confirm whether the inner ring 30 has been crimped by checking the axial displacement amount of the hub ring 25 by, for example, providing a portal cage in the mass production line and passing through the hub 21. it can.

  In addition, strict centering (positioning) is not required, and the mold is moved in the axial direction, compared to a method of caulking the inner ring 30 by moving the mold in the circumferential direction, such as a rotary forging machine. Therefore, the cycle time can be shortened.

  The inboard-side outer peripheral surface 41 of the small-diameter step portion 29 of the hub wheel 25 is formed with a diameter smaller than the inner diameter of the inner ring 30 by a step 42 formed on the outboard side with respect to the annular groove 44. It is possible to prevent the annular groove 44 from buckling during press-fitting.

  Although the protrusion 45 of the hub wheel 25 is preferably in contact with the chamfered portion 43 of the inner ring 30, these axial gaps are obtained from the relationship between the ball diameter D, the groove curvature R of the inner ring 30, and the groove shoulder height H. (See FIG. 2A), there may be a gap between the protruding portion 45 and the chamfered portion 43 as long as the ball 23 does not run on the shoulder of the groove.

  In the present embodiment, the radial gap g is formed between the inboard-side outer peripheral surface 41 of the small-diameter stepped portion 29 of the hub wheel 25 and the chamfered portion 43 of the inner ring 30, but the book shown in FIG. As in the modification of the embodiment, a step 50 is provided on the inboard side inner peripheral surface of the inner ring 30, and between the inboard side outer peripheral surface 41 of the small diameter step portion 29 and the large diameter inner peripheral surface 51 of the inner ring 30. A radial gap g may be formed. In this case, the step 50 of the inner ring 30 is formed between the step 42 of the hub wheel 25 and the annular groove 44 in a state where the inner ring 30 is press-fitted into the hub wheel 25 as shown in FIG. .

  Further, as in another modification shown in FIG. 4, the radial gap g is formed by forming the groove 60 at a position corresponding to the annular groove 44 on the inboard side inner peripheral surface of the inner ring 30. It may be provided between the inboard side outer peripheral surface 41.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, the cross-sectional shape of the annular groove of the present invention is not limited to a V shape such as a U shape, and may be any shape that allows the plastic deformation.

  Furthermore, in the above embodiment, the wheel support hub unit for driving wheels is taken as an example, but the present invention may be applied to a wheel support hub unit for driven wheels.

It is sectional drawing for demonstrating the hub unit for wheel support which is one Embodiment of this invention. It is the II section enlarged sectional view of Drawing 1, (a) shows the state before plastic deformation, and (b) shows the state after plastic deformation. It is sectional drawing corresponding to FIG. 2 for demonstrating the hub unit for wheel support which is a modification of this invention, (a) shows the state before plastic deformation, (b) shows the state after plastic deformation. . It is sectional drawing for demonstrating the wheel support hub unit which is the other modification of this invention. It is sectional drawing for demonstrating an example of the hub unit for wheel support conventionally.

Explanation of symbols

20 Wheel support hub unit 21 Hub 22 Outer ring 23 Ball (rolling element)
25 Hub wheel 29 Small diameter step (Axial end on the inboard side)
30 Inner ring 31, 32 Inner ring raceway surface 33, 34 Outer ring raceway surface 40 Outboard side outer peripheral surface 41 Inboard side outer peripheral surface 42 Step 43 Chamfered portion 44 Annular groove (groove)
45 Projection 50 Step 51 Large diameter inner peripheral surface g Radial gap

Claims (3)

An outer ring having a double-row outer ring raceway surface on the inner circumferential surface;
A hub ring having an inner ring raceway surface corresponding to one of the double row outer ring raceway surfaces on the outer peripheral surface, and fitted into the axial end of the hub ring on the inboard side, and fitted to the other of the double row outer ring raceway surfaces. A hub comprising an inner ring having a corresponding inner ring raceway surface on the outer peripheral surface;
A plurality of rolling elements arranged to be rollable between the inner ring raceway surface of the hub and the outer ring raceway surface of the outer ring;
A wheel supporting hub unit comprising:
A radial clearance is provided between the inboard-side outer peripheral surface of the axial end portion of the hub wheel and the inner peripheral surface of the inner ring,
The hub wheel includes a hub unit for supporting a wheel, wherein a groove formed on an inner peripheral surface of the hub wheel has a protruding portion that protrudes into the radial gap as a result of plastic deformation.   2. The wheel support according to claim 1, wherein an inboard side outer peripheral surface of the hub wheel is formed to have a smaller diameter than an inner diameter of the inner ring by a step formed on an outboard side from the groove. Hub unit. An outer ring having a double row outer ring raceway surface on the inner peripheral surface, a hub ring having an inner ring raceway surface corresponding to one of the double row outer ring raceway surfaces on the outer peripheral surface, and an axial end on the inboard side of the hub ring Between the inner ring raceway surface of the hub and the outer ring raceway surface of the outer ring, the hub having an inner ring having an inner ring raceway surface on the outer peripheral surface corresponding to the other of the double row outer ring raceway surfaces. A plurality of rolling elements arranged so as to be capable of rolling, and a manufacturing method of a wheel supporting hub unit comprising:
Forming a groove in the inner peripheral surface of the hub wheel;
The groove is plastically deformed by compressing the axial end of the hub wheel in the axial direction, and is provided between the inboard side outer peripheral surface of the axial end of the hub wheel and the inner peripheral surface of the inner ring. Projecting the outer portion of the groove into a radial gap, and preventing the inner ring from coming off from the hub ring,
A method for manufacturing a wheel support hub unit.

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