JP2006336758A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an inner ring from coming off in an assembling step without affecting bearing functions. <P>SOLUTION: This bearing device comprises an outer member 1 having a double row raceway surface 3 on its inner periphery, an inner member 2 having a raceway surface 4 facing the raceway surface 3, and double row rolling elements 5 interposed between the raceway surfaces 3 and 4 facing each other, and supports a drive wheel. The inner member 2 comprises a hub wheel 9 having a hub flange 9a on its outer periphery and an inner ring 10 fitted to the inboard side end outer periphery of the hub wheel 9. The raceway surface 4 for each row is formed on the hub wheel 9 and the inner ring 10. A step part 16 continued to the inboard side end face 10a of the inner ring 10 and having a depth equal to the height of the inner peripheral edge of the end face 10a is formed at the inner peripheral surface inboard side end of the inner ring 10. A caulked tube part 9b formed on the hub ring 9 is processed to increase its diameter and engaged with the locking surface of the inner ring 10 facing in the axial direction of the step part 16. The caulked tube part 9b must not be projected from the end face 10a of the inner ring 10. The wall thickness t of the caulked tube part 9b is set to 1.5 to 4 mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel serving as a driving wheel of an automobile or the like.

  Conventionally, as a wheel bearing device for driving wheel support, what is shown in FIGS. 7 and 8 has been proposed (for example, Patent Document 1). This is because a ball 25 is interposed in a double row between the raceway surfaces 23 and 24 of the outer member 21 and the inner member 22 facing each other, and the inner member 22 is a hub having a wheel mounting hub flange 29a on the outer periphery. This is a type constituted by a ring 29 and an inner ring 30 fitted to the outer periphery of the inboard side end of the hub ring 29. The stem portion 33a of the outer ring 33 of the constant velocity joint is inserted into the central hole 31 of the hub wheel 29 and is spline-fitted, and the step surface 33b of the constant velocity joint outer ring 33 is pressed against the inboard side end surface 30a of the inner ring 30. It is done. In this state, the inner member 22 is tightened by the constant velocity joint outer ring 33 and the nut 34 by screwing the nut 34 into the tip of the stem portion 33a.

In this proposed example, the inner ring 30 is externally fitted to the step 35 formed on the outer periphery of the end portion on the inboard side of the hub wheel 29, and the step portion 36 is formed on the inner periphery of the end portion on the inboard side of the inner ring 30. The inboard side end of the hub wheel 29 is crimped to the step portion 36 of the inner ring 30. As a result, the inner ring 30 is prevented from coming off due to an external force generated during assembly to the vehicle.
JP-A-9-164803

However, the above-described wheel bearing device has the following problems.
(1) Since the caulking portion 29b of the hub wheel 29 is large, the radial step of the step portion 36 formed at the inboard side end portion of the inner ring 30 needs to have a radius difference of about 5 to 7 mm. When the step of the stepped portion 36 is increased in this way, the area of the inboard side end surface 30a of the inner ring 30 is reduced, so that the contact surface pressure with the stepped surface 33b of the constant velocity joint outer ring 33 is increased. Therefore, it causes wear and abnormal noise.
(2) When the caulking portion 29b of the hub ring 29 is to be stored inside (outboard side) from the inboard side end of the inner ring 30, the axial length of the step portion 36 of the inner ring 30 is set to about 7 to 8 mm. There is a need. As described above, when the axial length of the inner ring step portion 36 is increased, the inner ring step portion 36 tends to be positioned on a straight line that forms the ball contact angle. Therefore, deformation of the inner ring due to a load load during operation increases, resulting in a short life. There is a possibility. Further, when the axial length of the inner ring step portion 36 is increased, the fitting length (area) of the inner ring 30 with respect to the hub ring 29 is reduced accordingly, so that inner ring creep occurs and the bearing life may be reduced. . These problems can be avoided by increasing the width of the entire inner ring, but this requires extra space in the axial direction.
(3) Since the caulking portion 29b of the hub wheel 29 is large, the caulking tool interferes with the inner ring 30 in the rocking caulking process, and the machining is difficult.

  An object of the present invention is to provide a wheel bearing device capable of ensuring a sufficient inner ring slip-off resistance in an assembling process while ensuring assemblability to a vehicle without adversely affecting the bearing function.

The wheel bearing device of the present invention includes an outer member having a double-row raceway surface on the inner periphery, an inner member having a raceway surface facing these raceway surfaces, and a double-row interposed between the opposing raceway surfaces. A rolling element, and the inner member includes a hub wheel having a wheel flange on the outer periphery and a through hole in the center, and an inner ring fitted to the outer periphery of the inboard side end of the hub wheel. In the wheel bearing device for driving wheel support in which the raceway surface of each row is formed on the hub wheel and the inner ring,
The inboard side end of the inner ring continues to the inboard side end face of the inner ring, and a step portion having a depth corresponding to the inner peripheral edge of the end ring is provided. A caulking tube portion is formed in which the inner peripheral surface is a stepped surface portion having a diameter larger than that of the inner peripheral surface of the through-hole, and the caulking tube portion is formed near the outboard side end of the inner ring step portion. It extends to the inboard side up to the vicinity of the end face, and its radial thickness is 1.5 to 4 mm, and this caulking tube portion is plastically deformed by expanding the diameter, so that the axial direction of the step portion of the inner ring It is characterized by being engaged with a locking surface facing the surface.
According to this configuration, the stepped portion that is provided on the inner peripheral surface of the inner ring and engages the caulking tube portion of the hub ring has a limited range of the inner peripheral edge of the inner ring, so that the inner ring is prevented from being pulled out. The step portion can be made small. For this reason, the decrease in the area of the inner ring end face can be reduced while providing the stepped portion, the increase of the contact surface pressure with the stepped surface of the constant velocity joint outer ring is suppressed, and the occurrence of wear and noise can be prevented.
In this case, since the inner peripheral surface of the caulking tube portion of the hub wheel is a stepped surface portion having a larger diameter than the inner peripheral surface of the through hole of the hub wheel, the caulking tube portion is thinned and its diameter is increased. Can be done easily. In addition, since the inner periphery of the crimped tube portion is a stepped surface portion and has a large diameter, the stem portion base end that gradually increases in diameter when the stem portion of the constant velocity joint is inserted into the through hole of the hub wheel Interference is avoided. Interference at the base end of the stem portion needs to avoid interference because the hub ring may be pushed up in the radial direction and the inner ring may be deformed when the nut at the tip end of the stem portion is tightened.
Since the inner diameter of the stepped surface portion increases as the thickness of the caulking tube portion decreases, it is ensured that interference with the stem base end of the constant velocity joint is ensured. Can be avoided.
The thickness of the caulking tube is preferably thinner from the viewpoint of avoiding the above interference, but as the caulking tube is expanded, the hub pilot, which is the inlet portion of the through hole of the hub wheel, becomes thinner. The reduced diameter of the inner diameter of the part increases. When the inner diameter of the hub pilot portion is reduced, the stem portion pilot portion of the constant velocity joint which is a portion fitted to the hub pilot portion becomes difficult to fit. Therefore, in order to suppress the diameter reduction of the inner diameter of the hub pilot portion during the diameter expansion process, the thickness of the crimped tube portion needs to be 1.5 mm or more.
The wall thickness of the caulking cylinder part also affects the proof strength of the inner ring when the bearing is assembled to the vehicle.If it is too thin, the required proof strength cannot be obtained, but if the thickness is 1.5 mm or more, Pull-out resistance is secured.
According to this steel wheel bearing device, it is possible to prevent the inner ring from being removed in the assembly process to the vehicle without adversely affecting the bearing function.

In this invention, the raceway surface of the hub ring may be a hardened surface hardened surface, the caulking portion may be a non-heat treated portion, and the inner ring may be hardened by quenching the entire surface from the surface to the core portion. .
It is preferable that the raceway surface of the hub ring has a high hardness as a surface-hardened surface from the viewpoint of improving the rolling life. It is preferable to do. Since the inner ring is a small part and has a raceway surface, and the inner peripheral surface is fitted to the hub ring, it is assumed that the entire surface to the core is hardened by quenching. This is preferable in terms of improving the life and wear resistance of the fitting surface.

  The wheel bearing device of the present invention includes an outer member having a double-row raceway surface on the inner periphery, an inner member having a raceway surface facing these raceway surfaces, and a double-row interposed between the opposing raceway surfaces. A rolling element, and the inner member includes a hub wheel having a wheel flange on the outer periphery and a through hole in the center, and an inner ring fitted to the outer periphery of the inboard side end of the hub wheel. In the wheel bearing device for driving wheel support in which the raceway surfaces of the respective rows are formed on the hub wheel and the inner ring, the end surface on the inboard side of the inner ring on the inboard side end of the inner peripheral surface of the inner ring A step portion having a depth corresponding to the inner peripheral edge of the end surface is provided, and the inner peripheral surface is a step surface portion having a larger diameter than the inner peripheral surface of the through hole at the inboard side end of the hub wheel. A clamping tube portion is formed. It extends to the inboard side from the vicinity to the end face of the inner ring, the radial thickness is 1.5 to 4 mm, and the stepped portion of the inner ring is plastically deformed by expanding the caulking tube portion. Since it is engaged with the locking surface facing the axial direction of the portion, it is possible to ensure sufficient inner ring slip-off resistance in the assembling process while ensuring assemblability to the vehicle without adversely affecting the bearing function.

A first embodiment of the present invention will be described with reference to FIGS. This embodiment is a third generation type inner ring rotation type and is applied to a wheel bearing device for driving wheel support. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.
The wheel bearing device includes an outer member 1 having a double-row raceway surface 3 formed on the inner periphery, an inner member 2 having a raceway surface 4 opposed to each raceway surface 3, and these outer members 1. And the double row rolling elements 5 interposed between the raceway surfaces 3 and 4 of the inner member 2. This wheel bearing device is a double-row angular ball bearing type, and the rolling elements 5 are formed of balls, and are held by a cage 6 for each row. Each of the track surfaces 3 and 4 has an arc shape in cross section, and each of the track surfaces 3 and 4 is formed so that the ball contact angle θ is aligned with the back surface. Both ends of the bearing space between the outer member 1 and the inner member 2 are sealed by seals 7 and 8, respectively.

The outer member 1 is a member on the fixed side, and has a flange 1a attached to the knuckle in the suspension device (not shown) of the vehicle body on the outer periphery, and the whole is an integral part.
The inner member 2 is a member on the rotation side, and has a hub wheel 9 having a hub flange 9a for wheel attachment on the outer periphery, and an inner ring 10 fitted to the outer periphery of the inboard side end of the hub wheel 9; It becomes. The hub ring 9 and the inner ring 10 are formed with the raceway surfaces 4 in each row. The hub wheel 9 has a through hole 11, and the raceway surface 4 of the hub wheel 9 is a surface hardened surface by quenching. The entire inner ring 10 from the surface to the core is hardened by a quenching process.

  As shown in enlarged sectional views in FIGS. 2 and 3, a stepped inner ring fitting surface portion having a smaller diameter than the outer periphery of the other portion of the hub wheel 9 is provided on the outer periphery of the inboard side end of the hub wheel 9. 15 is formed, and the inner ring 10 is fitted to the inner ring fitting surface portion 15. A stepped portion 16 having a depth corresponding to the inner peripheral edge of the end surface 10a is provided at the inboard side end of the inner ring 10 to the end surface 10a on the inboard side of the inner ring 10. The step portion 16 is located on the inboard side with respect to the straight line L that forms the contact angle of the inner ring raceway surface 4. The inner peripheral surface of the stepped portion 16 is a cylindrical surface, and a locking surface 16a facing in the axial direction is provided at the end of the outboard. The locking surface 16 a is a tapered surface inclined with respect to the axis of the inner ring 10.

At the inboard side end of the hub wheel 9, there is provided a crimping cylinder portion 9 b that is crimped by diameter expansion processing and engaged with a locking surface 16 a that faces the axial direction of the step portion 16 of the inner ring 10.
The caulking tube portion 9b is a portion formed by providing a step surface portion 9ba whose inner peripheral surface is larger in diameter than the inner peripheral surface of the through hole 11 at the inboard side end of the hub wheel 11 as shown in FIG. The shape before caulking is a right cylindrical shape. The axial range in which the step surface portion 9ba is provided is a portion closer to the inboard side than the vicinity of the outboard side end of the step portion 16 of the inner ring 10. Further, the crimping tube portion 9 b has an end surface that does not protrude from the end surface 10 a of the inner ring 10. The wall thickness t of the crimping tube portion 9b is 1.5 to 4 mm. The crimping tube portion 9b is a non-heat treatment portion.
The caulking cylinder portion 9b is in a state after caulking, and the inside of the step portion 16 of the inner ring 10 is substantially satisfied by plastic deformation. A gap may be formed between the outer peripheral surface of the crimping tube portion 9 b and the inner peripheral surface of the step portion 16. The diameter expansion process is performed over the entire circumference by a method such as pressing.

  The wheel bearing device of the present invention is applied to, for example, a general passenger car ranging from a small passenger car to a large passenger car, and has a size of each part applied to these general passenger cars.

  In assembling the wheel bearing device to the vehicle, the stem portion 13a of the outer ring 13 serving as one joint member of the constant velocity joint 12 is inserted into the through hole 11 of the hub wheel 9 and is spline-fitted. The constant velocity joint outer ring 13 is coupled to the inner member 2 by tightening the nut 14 that is screwed into the tip of the portion 13a. At this time, the step surface 13 b facing the outboard side provided in the constant velocity joint outer ring 13 is pressed against the end surface 10 a facing the inboard side of the inner ring 10, and the inner member 2 is formed by the constant velocity joint outer ring 13 and the nut 14. Is tightened. The hub flange 9a for wheel attachment is located at the end of the hub wheel 9 on the outboard side, and a wheel (not shown) is attached to the hub flange 9a with a bolt 17 via a brake rotor.

According to the wheel bearing device with this configuration, the stepped portion 16 is provided on the inner peripheral surface of the inner ring 10, and the caulking tube portion 9b of the hub wheel 9 is engaged with the stepped portion 16 by diameter expansion processing. It is possible to prevent the inner ring 10 from coming off from the hub wheel 9 due to an external force generated in the assembly process.
Since the stepped portion 16 has a very limited range of the inner periphery of the inner ring 10, the stepped portion 16 can be made as small as possible while ensuring the slip-off resistance of the inner ring 10. For this reason, there is little decrease in the area of the end surface 10a of the inner ring 10 while providing the stepped portion 16, the increase in contact surface pressure with the step surface 13b of the constant velocity joint outer ring 13 is suppressed, and the occurrence of wear and noise can be prevented. .

In particular, the inner peripheral surface of the caulking tube portion 9b of the hub wheel 9 is a stepped surface portion 9ba having a larger diameter than the inner peripheral surface of the through hole 11 of the hub wheel 9, and the wall thickness t of the caulking tube portion 9b is set to 1. Since it is set to 5 to 4 mm, sufficient inner ring slip-off resistance can be secured while assembling to the vehicle is secured for the following reasons.
(1) Since the inner peripheral surface of the caulking tube portion 9b of the hub wheel 9 is a step surface portion 9ba having a larger diameter than the inner peripheral surface of the through hole 11 of the hub wheel 9, the caulking tube portion 9b is thinned. The diameter can be easily expanded. Further, since the inner periphery of the crimping tube portion 9b is a stepped surface portion 9ba and has a large diameter, when the stem portion 13a of the constant velocity joint 12 is inserted into the through hole 11 of the hub wheel 9 as shown in FIG. Clearance δ is ensured, and interference with stem portion base end 13c, which gradually increases in diameter, is avoided. The interference of the stem base end 13c may push up the hub wheel in the radial direction and deform the inner ring 10 when the nut 14 (FIG. 1) at the tip of the stem part 13 is tightened. Therefore, it is necessary to avoid interference.
In terms of dimensions, when the wall thickness t of the crimping tube portion 9b is 4 mm or more, the inner diameter of the stepped surface portion 9ba, which is the inner peripheral surface of the crimping tube portion 9b, becomes small. δ cannot be obtained, and the constant velocity joint outer ring 13 and the crimping tube portion 9b interfere with each other. In order to avoid this interference, when the locking surface 16a facing the axial direction of the inner ring step portion 16 and the crimping tube portion 9b of the hub wheel 9 are retracted to the outboard side, the inner ring step portion 16 has a ball contact angle θ. There is a possibility that it will fall on the straight line L formed, resulting in a short life.

(2) When the diameter of the crimping tube portion 9b of the hub wheel 9 is increased, the inner diameter of the hub pilot portion 11a that is the inlet portion of the through hole 11 of the hub wheel 9 is reduced. In this case, as shown in FIG. 4, the relationship between the wall thickness t of the caulking tube portion 9 b and the reduced diameter of the inner diameter of the hub pilot portion 11 a, the hub t as the wall thickness t of the caulking tube portion 9 b decreases. The amount of reduction in the inner diameter of the pilot portion 11a increases. That is, the outer diameter of the inner ring fitting surface portion 15 of the hub wheel 9 slightly expands due to the diameter-enlarged caulking of the caulking cylinder portion 9b. However, since the inner ring 10 is fitted, the hub ring 9 contracts toward the inner diameter side due to the ring rigidity (radial rigidity) of the inner ring 10, and the inner diameter of the hub pilot portion 11a becomes smaller. In this case, as the wall thickness t of the crimping tube portion 9b is thinner, the rigidity of the inner ring 10 is relatively increased, so that the amount of reduction in the inner diameter of the hub pilot portion 11a is increased.
Considering the gap between the inner diameter of the hub pilot portion 11a and the outer diameter of the stem pilot portion 13aa of the constant velocity joint 12 that is a portion fitted to the hub pilot portion 11a, when the wall thickness t is less than 1.5 mm, Since the inner diameter of the hub pilot portion 11a is large and it becomes difficult to insert the stem portion 13a of the constant velocity joint 12, the wall thickness t needs to be 1.5 mm. Further, the wall thickness t of the caulking tube portion 9b also affects the proof strength of the inner ring 10 when the bearing is assembled to the vehicle. As shown in FIG. 5, the proof strength decreases as the thickness t decreases. However, if the wall thickness is 1.5 mm or more, the pull-out resistance of the inner ring 10 is sufficiently ensured.

For these reasons, it is desirable that the wall thickness t of the crimping tube portion 9b be 1.5 to 4 mm in order to ensure sufficient inner ring pulling resistance while ensuring ease of assembly into the vehicle.
Thus, according to this wheel bearing device, it is possible to prevent the inner ring from being lost in the assembly process to the vehicle without adversely affecting the bearing function.

  Moreover, in this wheel bearing apparatus, since the raceway surface 4 in the hub wheel 9 is a hardened surface, the rolling life can be ensured. Since the caulking tube portion 9b for performing the diameter expansion processing is a non-heat treatment portion, the diameter expansion processing can be easily performed. Since the inner ring 10 is a small part and has a raceway surface 4 and the inner peripheral surface is fitted to the hub wheel 9, the entire surface from the surface to the core is hardened by quenching as described above. By doing so, the rolling life is excellent and the wear resistance of the fitting surface is excellent.

It is sectional drawing of the wheel bearing apparatus concerning one Embodiment of this invention. It is a partial expanded sectional view before hub wheel caulking of the bearing device for the wheels. It is a partial expanded sectional view after hub wheel caulking of the bearing device for the wheels. It is a graph which shows the relationship between the thickness of a hub ring crimping cylinder part, and hub ring pilot inner diameter reduction amount. It is a graph which shows the relationship between the wall thickness of the crimping cylinder part of a hub ring, and an inner ring fall-out proof strength. It is explanatory drawing which shows the interference relationship between the crimping cylinder part of a hub ring, and a constant velocity joint outer ring | wheel. It is sectional drawing of a prior art example. It is a partial expanded sectional view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 3 ... Outer member raceway surface 4 ... Inner member raceway surface 5 ... Rolling element 9 ... Hub ring 9a ... Hub flange 9b ... Clamping cylinder part 9ba ... Clamping cylinder part Inner ring surface 10 ... Inner ring 10a ... Inner ring end face 11 ... Through-hole 16 ... Inner ring stepped part 16a ... Axial surface t of inner ring stepped part ... Thickness of the crimped tube part

Claims (2)

An outer member having a double-row raceway surface on the inner periphery, an inner member having a raceway surface facing these raceway surfaces, and a double-row rolling element interposed between the opposing raceway surfaces, The member is composed of a hub wheel having a hub flange for wheel mounting on the outer periphery and a through hole in the center, and an inner ring fitted to the outer periphery of the inboard side end of the hub wheel. In the wheel bearing device for driving wheel support in which the raceway surface of each row is formed,
The inboard side end of the inner ring continues to the inboard side end face of the inner ring, and a step portion having a depth corresponding to the inner peripheral edge of the end ring is provided. A caulking tube portion is formed in which the inner peripheral surface is a stepped surface portion having a diameter larger than that of the inner peripheral surface of the through-hole, and the caulking tube portion is formed near the outboard side end of the step portion of the inner ring. It extends to the inboard side up to the vicinity of the end face, and its radial thickness is 1.5 to 4 mm, and this caulking tube portion is plastically deformed by expanding the diameter, so that the axial direction of the step portion of the inner ring A wheel bearing device, wherein the wheel bearing device is engaged with a locking surface facing the wheel.   2. The wheel according to claim 1, wherein the raceway surface of the hub wheel is a hardened surface hardened surface, the crimping portion is a non-heat treated portion, and the inner ring is hardened by quenching the entire surface from the surface to the core portion. Bearing device.

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