JP2007261577A5 - - Google Patents

Description

Drive wheel bearing device and manufacturing method thereof

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive wheel bearing device for supporting a drive wheel of an automobile or the like and a method for manufacturing the same, and in particular, a drive wheel bearing device in which a hub wheel, a constant velocity universal joint, and a double row rolling bearing are unitized. And a manufacturing method thereof.

  Driving wheels of automobiles such as rear wheels of FR vehicles, front wheels of FF vehicles, or all wheels of 4WD vehicles are supported on a suspension device by a bearing device for driving wheels. In recent years, bearing devices for drive wheels have a tendency to unitize a hub wheel, a constant velocity universal joint, and a bearing portion in order to reduce weight and size.

  FIG. 6 is a longitudinal sectional view showing a conventional drive wheel bearing device, in which a hub wheel 50, a bearing portion 60, and a constant velocity universal joint 70 are formed as a unit. The hub wheel 50 integrally has a wheel mounting flange 51 for mounting a wheel (not shown), and a hub bolt 52 for fixing the wheel is implanted at a circumferentially equidistant position of the wheel mounting flange 51. Yes.

  The bearing portion 60 includes an outer member 61, an inner member 62, and double-row rolling elements 63, 63. The outer member 61 is integrally provided with a vehicle body mounting flange 64 for mounting to a vehicle body (not shown) on the outer periphery. And the double-row rolling surfaces 61a and 61a are formed on the inner periphery. On the other hand, the inner member 62 forms double-row rolling surfaces 50a and 71a facing the rolling surfaces 61a and 61a of the outer member 61 described above. One rolling surface 50 a is integrally formed on the outer periphery of the hub wheel 50, and the other rolling surface 71 a is integrally formed on the outer periphery of the outer joint member 71 of the constant velocity universal joint 70. Double-row rolling elements 63 and 63 are accommodated between the rolling surfaces 61a and 50a and 61a and 71a, respectively, and are held by rollers 65 and 65 so as to be freely rollable. In this case, the inner member 62 refers to the hub wheel 50 and the outer joint member 71. Seals 66 and 67 are attached to the end portion of the bearing portion 60 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside.

  The constant velocity universal joint 70 includes an outer joint member 71, a joint inner ring (not shown), a cage, and a torque transmission ball. The outer joint member 71 has a cup-shaped mouth portion 72 and a shaft portion 73 extending in the axial direction from the mouth portion 72, and a curved track groove 72 a extending in the axial direction is formed on the inner periphery of the mouth portion 72. ing.

  The shaft portion 73 of the outer joint member 71 formed in a hollow shape is fitted into the hub wheel 50, the uneven portion 53 is formed on the inner peripheral surface of the hub wheel 50, the diameter of the shaft portion 73 is expanded, and the uneven portion 53 is formed. The hub wheel 50 and the outer joint member 71 are plastically coupled by biting and crimping the fitting portion.

In the conventional drive wheel bearing device described above, the looseness of the fitting portion can be prevented and the wear of the fitting portion can be suppressed compared to torque transmission means such as serrations, so that the durability and handling stability of the device can be reduced. Can be improved. In addition, since this coupling portion has both the torque transmission means and the coupling means for the hub wheel and the outer joint member, a fixing means such as a fastening nut is not required, and the apparatus can be further reduced in weight and size.
Japanese Patent Laid-Open No. 2001-18605

  However, in such a drive wheel bearing device, when an excessive bending moment load is generated during turning of the vehicle, the butt portion between the hub wheel and the outer joint member becomes a node and receives a repeated bending load. At this time, excessive stress is generated in the in-row portion of the hub wheel and the shaft portion of the outer joint member, particularly in the corner portion of the shaft portion, and there is a fear that durability is lowered. Further, the in-brow part and the shaft part may be deformed by repeated bending loads, and abnormal wear may occur in the butt part. This wear may cause wear powder to enter the bearing and cause a reduction in service life.

  The present invention has been made in view of such circumstances, and it is intended for a drive wheel that has improved durability by suppressing the occurrence of such excessive stress and wear while reducing the weight and size of the device by plastic bonding. It aims at providing a bearing device and its manufacturing method.

In order to achieve such an object, the present invention includes a hub wheel having a wheel mounting flange at one end, a cup-shaped mouth portion, a shoulder portion forming the bottom portion of the mouth portion, and a shaft portion extending in the axial direction from the shoulder portion. A constant velocity universal joint having a hollow outer joint member integrally formed and a double row rolling bearing that rotatably supports the wheel with respect to the vehicle body are unitized, and the inner rolling surface of the double row rolling bearing is One of them is formed on the outer peripheral surface of the hub wheel, and the other is formed on the outer peripheral surface of the outer joint member, and the end surface of the hub wheel is abutted against the shoulder of the outer joint member to fit both members, By forming a hardened concave and convex portion on the inner peripheral surface of the hub wheel at the fitting portion, and expanding the biting portion of the outer joint member into the concave and convex portion, the hub wheel and the hub Drive wheel with plastic joint integrally with outer joint member Enlarged in the manufacturing method of the bearing device, a step of placing the cradle the wheel hub, the fitting portion between the hub wheel by inserting the mandrel from the inboard side of the outer joint member on the outboard side direction The structure provided with the process to make was adopted.

Further, the present invention includes a hub wheel having a wheel mounting flange at one end, the mouth portion of the cup, a shoulder portion forming the bottom of the mouth portion, a hollow shape having a shaft portion extending axially from the shoulder portion integrally respectively A constant velocity universal joint having an outer joint member and a double row rolling bearing that rotatably supports a wheel with respect to the vehicle body are unitized, and one of the inner rolling surfaces of the double row rolling bearing is connected to the hub. On the outer peripheral surface of the ring, the other is formed on the outer peripheral surface of the outer joint member. The end surface of the hub wheel is abutted against the shoulder of the outer joint member, and both members are fitted. The hub wheel and the outer joint member are formed by forming a hardened uneven portion on the inner peripheral surface of the hub wheel and enlarging the fitting portion of the outer joint member into the uneven portion. In a bearing device for a drive wheel that is integrally plastically bonded. , By inserting the mandrel from the inboard side of the outer joint member on the outboard side direction, characterized in that it is expanded the fitting portion between the hub wheel.

Method for producing a driving wheel bearing apparatus of the present invention, by placing the wheel hub, inserting the mandrel from the inboard side of the outer-side joint member to the outboard side direction in the cradle, the hub wheel in the pushing force The in-row portion is compressed in the axial direction by the shoulder portion and the cradle of the outer joint member, and the fitting portion is expanded in this state, so that compressive stress remains even after plastic bonding. Therefore, during such plastic coupling, no axial clearance is generated at the butted portion of the inrow portion and the shoulder portion, and the internal clearance of the double row rolling bearing can maintain the initially set negative clearance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a drive wheel bearing device according to the present invention.

  This drive wheel bearing device comprises a hub wheel 1, a double row rolling bearing 2 and a constant velocity universal joint 3 as a unit. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).

  The hub wheel 1 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end portion on the outboard side. Concave and convex portions 5 are formed on the inner peripheral surface of the hub wheel 1, and a hardened layer 10 is formed with a surface hardness in the range of 54 to 64 HRC by heat treatment (indicated by cross-hatching in the figure). As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable.

  In addition, the uneven | corrugated | grooved part 5 can illustrate the shape which orthogonally crossed the groove | channel of several rows as shown in FIG. (A) is a spiral groove 6 inclined with respect to each other, and (b) is a crossed groove 6 ′ of an annular groove independent of an axial groove, and an iris knurl can be formed. Moreover, the convex part of the uneven part 5 is formed in a spire shape such as a triangular shape in order to ensure good bite.

  The double-row rolling bearing 2 includes an outer member 7, an inner member 8, and double-row rolling elements 9, 9. The outer member 7 is a vehicle body mounting flange for mounting to the vehicle body (not shown) on the outer periphery. 7a is integrally formed, and double row outer rolling surfaces 7b and 7b are formed on the inner periphery. On the other hand, the inner member 8 refers to the hub wheel 1 and an outer joint member 14 to be described later. The inner rolling surface 1a on the outboard side facing the outer rolling surfaces 7b and 7b of the outer member 7 is connected to the hub wheel 1. An inner rolling surface 14a on the inboard side is formed on the outer periphery and on the outer periphery of the outer joint member 14, respectively. Double row rolling elements 9, 9 are accommodated between the rolling surfaces 7b, 1a and 7b, 14a, respectively, and are held by the retainers 11, 11 so as to be freely rollable. Seals 12 and 13 are attached to the ends of the double-row rolling bearing 2 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside.

  In the hub wheel 1, as shown in FIG. 3A, the seal land portion 18 in which the seal lip of the seal 12 is in sliding contact, the inner rolling surface 1 a, and the inrow portion 1 b in contact with the shoulder portion 16 of the outer joint member 14. A hardened layer 10 ′ is formed on the surface and further on the end face 19 of the in-row part 1 b by induction hardening (indicated by cross hatching in the figure).

  FIG. 3B shows an enlarged end portion of the in-row portion 1b. The hardened layer 10 'is set so as to partially reach the end surface 19 and the inner end portion of the in-row portion 1b. As a result, it is possible to suppress wear between the in-row portion 1b fitted on the cylindrical surface and the small-diameter step portion 17a of the outer joint member 14 described later. Further, a grease reservoir portion 20 is formed on the inner diameter side of the end surface 19 of the in-row portion 1b. Here, the shape in which the concave portion is formed on the end surface 19 is illustrated, but the shape is not limited to this, and for example, a large chamfer may be formed on the inner diameter side to form the grease reservoir portion. Here, the double-row rolling bearing 2 is exemplified as a double-row angular contact ball bearing in which the rolling elements 9 and 9 are balls. .

Since grease is interposed abutment surface of the shoulder portion 16 of the end face 19 and the outer joint member 14 of the hub wheel 1, thereby suppressing the abrasion of the butt portion, when transmitting torque through the outer joint member 14 In addition, the shaft portion 17 of the outer joint member 14 is twisted, so that it is possible to suppress the generation of relative slip noise, so-called stick-slip noise, with the end surface 19 of the hub wheel 1 . Further, by providing the end face 1 9 grease reservoir portion 20 of the hub wheel 1, it is possible to further suppress the wear and stick-slip sound generation.

The cylindrical in-row part 1b extending in the axial direction from the inner raceway surface 1a of the hub wheel 1 is formed, and the hardened layer 10 is formed on the surface from the inner raceway surface 1a to the end face 19 including the in-row part 1b . Even when the bending moment load is excessive, it has sufficient durability, and the end face 19 is worn by repeated bending loads, and the wear powder does not enter the inside of the bearing to reduce the bearing life. Further, by forming the hardened layer 10 on the surface extending to the end inner diameter of the spigot portion 1b from the end face 19 of the hub wheel 1, the wear of the shaft portion 17 of the outer joint member 14 to be fitted in the spigot portion 1b and the cylindrical surface Is suppressed.

As shown in FIG. 5, the constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring (not shown), a cage, and a torque transmission ball. The outer joint member 14 has a cup-shaped mouth portion 15, a shoulder portion 16 that forms the bottom portion of the mouth portion 15, and a shaft portion 17 that extends from the shoulder portion 16 in the axial direction. A curved track groove 15a extending in the axial direction is formed.

The outer joint member 14 is formed in a hollow shape, and the inner rolling surface 14 a described above is formed on the outer periphery of the shoulder portion 16. The shaft portion 17 of the outer joint member 14 has a small diameter step portion 17a and a fitting portion 17b. The end surface 19 of the inrow portion 1b of the hub wheel 1 press-fitted into the small-diameter step portion 17a is abutted against the shoulder portion 16 of the outer joint member 14, and the fitting portion 17b is fitted into the hub wheel 1. Thereafter, the fitting portion 17b is expanded in diameter by an appropriate means such as inserting / withdrawing a mandrel into / from the inner diameter of the fitting portion 17b, so that the concave / convex portion 5 of the hub wheel 1 is bitten into the hub wheel 1 and the outer joint member 14. And are plastically connected. As a result, since this coupling portion has both the torque transmission means and the coupling means for the hub wheel 1 and the outer joint member 14, it is necessary to form torque transmission means such as conventional serrations on the hub wheel 1 and the outer joint member 14. In addition, since fixing means such as a fastening nut is not required, the apparatus can be further reduced in weight and size. In addition, the plastic connection can reduce the weight and size of the apparatus, and even if an excessive bending moment load occurs when the vehicle turns, excessive stress is applied to the shaft portion 17 of the outer joint member 14 and the corner portion of the shaft portion 17. Generation | occurrence | production can be suppressed and it has sufficient durability.

4A and 4B, the hub wheel 1 constituting the inner member 8 is placed on the cradle B, and the mandrel M is moved from the inboard side of the outer joint member 14 to the outboard side direction. The inrow portion 1b of the hub wheel 1 is compressed in the axial direction by the shoulder portion 16 and the cradle B of the outer joint member 14 by the pushing force, and in this state, the fitting portion 17b (cross-hatching portion) is compressed. ) Is expanded, compressive stress remains after plastic bonding. Therefore, at the time of such plastic coupling, there is no axial clearance at the butted portion of the inrow portion 1b and the shoulder portion 16, and the internal clearance of the double row rolling bearing 2 maintains the initially set negative clearance. Can do.

In the outer joint member 14, as shown in FIG. 5, a track groove 15 a formed in the inner periphery of the mouth portion 15, a seal land portion 21 in sliding contact with the seal 13, an inner rolling surface 14 a, and a small diameter step of the shaft portion 17. A hardened layer 10 ″ is formed on the surface over the portion 17a. Quenching by high-frequency induction heating is suitable as the hardening treatment. Further, the fitting portion 17b whose diameter is expanded has a material surface hardness after forging of 24 HRC. It is preferable to set the following unquenched portion, and set the hardness difference between the surface hardness 54 to 64 HRC of the uneven portion 5 of the hub wheel 1 to 30 HRC or more. In addition, it is possible to deeply bite and firmly plastically bond the two without collapsing the tip of the concavo-convex portion 5.

  When an excessive bending moment load is generated during turning of the vehicle, the butt portion between the hub wheel 1 and the outer joint member 14 becomes a node and receives a repeated bending load. At this time, excessive stress is generated in the in-row part 1b of the hub wheel 1 and the shaft part 17 of the outer joint member 14, particularly the corner part 22 of the small-diameter stepped part 17a, and the durability may be reduced. In addition, the repeated bending load may deform the in-row part 1b and the small-diameter stepped part 17a to cause abnormal wear at the butt part, and the wear powder may enter the bearing, leading to a decrease in the service life. However, the strength and durability against torsional torque are improved by forming the hardened layer 10 ″ on the surface of the small diameter step portion 17a including the corner portion 22 from the inner rolling surface 14a as in this embodiment. In addition, the occurrence of wear can be suppressed even if relative slip occurs in the butted portion of the inrow portion 1b and the shoulder portion 16 due to repeated bending loads.

  Although not shown, an end cap is attached to the inner diameter of the hollow outer joint member 14 to prevent leakage of the lubricating grease sealed in the mouth portion 15 to the outside and dust intrusion from the outside.

  The in-row portion 1b of the hub wheel 1 and the small-diameter step portion 17a of the outer joint member 14 are fitted on a cylindrical surface, and have sufficient rigidity against repeated bending loads. Normally, this type of in-row part for fitting is generally provided with a radial clearance of 0.5 to 1.0 mm as a guide surface during assembly. This radial clearance is set as small as possible, with a slight sacrifice in performance. From the processing capability of the in-row part 1b and the small-diameter stepped part 17a and the durability test results, the radial clearance of this fitting part includes 0.5 mm to -0.1 mm, preferably 0.35, including some tightening allowance. It was verified that setting to -0.05 mm is effective in improving durability.

The radial clearance between the in-row part 1b of the hub wheel 1 and the shaft part 17 of the outer joint member 14 was set to 0.5 mm or less. Thereby, it is possible to suppress the deformation of the in-row part 1b with respect to repeated bending loads, and to reliably receive the load on the cylindrical surface, so that the durability of the apparatus can be significantly improved.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The drive wheel bearing device manufacturing method according to the present invention can be applied to a drive wheel bearing device manufacturing method in which a hub wheel, a constant velocity universal joint, and a double row rolling bearing are unitized.

It is a longitudinal section showing an embodiment of a bearing device for drive wheels concerning the present invention. (A) is a longitudinal cross-sectional view which shows the uneven | corrugated | grooved part shape of the hub ring which concerns on this invention, and shows the iris knurl shape comprised by the mutually inclined helical groove. (B) shows the iris knurl shape comprised by the crossing groove | channel of an annular groove independent of an axial direction groove | channel same as the above. (A) is a longitudinal cross-sectional view of the hub wheel of the bearing apparatus for drive wheels which concerns on this invention. (B) is a principal part expanded sectional view of (a). (A) is explanatory drawing which shows the plastic coupling method of the bearing apparatus for drive wheels which concerns on this invention. (B) is the principal part enlarged view of (a). It is a longitudinal cross-sectional view of the outer joint member of the bearing apparatus for drive wheels which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional bearing apparatus for drive wheels.

Explanation of symbols

1. Hub wheel 1a, 14a ... Inner rolling surface 1b ... In-row part 2 ... ········ Double row rolling bearing 3 ··············································· Wheel mounting flange 5 ········ Uneven portion 6, 6 '······································ · · Body mounting flange 7b · · · Outer rolling surface 8 · · · · · Inner member 9 ··· Rolling elements 10, 10 ', 10 "... Hardened layer 11 ... Cage 12, 13 ... Seal 14 ... ... Outer joint member 15 ... Mouse part 15a ... Truck Groove 16 ... shoulder 17 ... shaft 17a ... small diameter step 17b ... ······ Fitting portions 18, 21 ······· Seal land portion 19 ···································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Corner 50 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheels 50a, 61a, 71a ・ ・ Rolling surface 51 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel Mounting flange 52 ········································································ ... outer member 62 ... inner member 63 ... rolling element 64 ... car body Mounting flange 65 ... Cage 66, 67 ...・ ・ ・ ・ ・ Seal 70 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joint 71 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 72 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse Part 72a ... Track groove 73 ... Shaft part B ... Base M ... .... Mandrels

Claims (2)

A hub wheel having a wheel mounting flange at one end, a cup-shaped mouth portion, a shoulder portion forming the bottom portion of the mouth portion, and a hollow outer joint member integrally including a shaft portion extending in the axial direction from the shoulder portion are provided. A constant velocity universal joint and a double row rolling bearing that rotatably supports a wheel with respect to the vehicle body are unitized, and one of the inner rolling surfaces of the double row rolling bearing is an outer peripheral surface of the hub wheel. The other is formed on the outer peripheral surface of the outer joint member, the end surface of the hub ring is abutted against the shoulder of the outer joint member, and the two members are fitted together. A drive in which the hub wheel and the outer joint member are integrally plastically bonded by forming a hardened concave and convex portion on the peripheral surface and expanding the fitting portion of the outer joint member into the concave and convex portion. In the manufacturing method of the wheel bearing device,
Placing the hub wheel on a cradle, and inserting a mandrel from the inboard side of the outer joint member to the outboard side direction to expand the fitting portion with the hub wheel. A manufacturing method of a bearing device for a drive wheel, which is characterized. A hub wheel having a wheel mounting flange at one end, a cup-shaped mouth portion, a shoulder portion forming the bottom portion of the mouth portion, and a hollow outer joint member integrally including a shaft portion extending in the axial direction from the shoulder portion are provided. A constant velocity universal joint and a double row rolling bearing that rotatably supports a wheel with respect to the vehicle body are unitized, and one of the inner rolling surfaces of the double row rolling bearing is an outer peripheral surface of the hub wheel. The other is formed on the outer peripheral surface of the outer joint member, the end surface of the hub ring is abutted against the shoulder of the outer joint member, and the two members are fitted together. A drive in which the hub wheel and the outer joint member are integrally plastically bonded by forming a hardened concave and convex portion on the peripheral surface and expanding the fitting portion of the outer joint member into the concave and convex portion. In the wheel bearing device,
By inserting the outboard side direction between Ndoreru from the inboard side of the outer joint member, the driving wheel bearing apparatus characterized in that is expanded the fitting portion between the hub wheel.