JP4519003B2 - Wheel bearing device - Google Patents

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. 3 and 4 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 splined, 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 end of the hub 29 that are crimped to the stepped portion 36 of the inner ring 30.
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, and 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) Further, since the caulking portion 29b of the hub wheel 29 is large, the caulking tool interferes with the inner ring 30 in the swing 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 pull-out resistance during assembly 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. The inner member includes a hub wheel having a hub flange for mounting the wheel on the outer periphery and an inner ring fitted on the outer periphery of the inboard side end of the hub wheel. Forming a raceway surface in each row, and an end surface facing the inboard side of the inner ring connected to the outer ring of the constant velocity joint, and an end surface facing the inboard side of the constant velocity joint facing the outboard side In a double-row angular contact ball bearing type wheel bearing device for supporting a driving wheel pressed against a surface and having a ball contact angle aligned with the back surface, the inner ring is connected to an inboard side end of the inner peripheral surface of the inner ring. Continue to the end face on the inboard side , Engages a locking surface of the small depth of the stepped portion to the extent capable of preventing the inner ring of the omission provided in the assembly process of the vehicle, facing the enlarged diameter machining of the hub wheel in the axial direction of the step portion of the inner ring to only set the plastic deformation portion, the plastic deformation portion of this shall not protrude from the end face of the inner ring, the locking surface is located on the inboard side of the straight line forming a ball contact angle in the inner ring raceway surface of inboard side In addition, the step difference between the inner ring fitting surface of the hub ring and the outer diameter surface of the plastically deformed portion is 0.13 mm or more.
According to this configuration, the step portion provided on the inner peripheral surface of the inner ring and engaged with the plastically deformed portion by the caulking process of the hub ring has a limited range of the inner peripheral edge of the inner ring. The step portion can be made as small as possible. 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 step between the fitting surface of the inner ring in the hub wheel and the outer diameter surface of the plastically deformed portion is 0.13 mm or more, sufficient inner ring slip-off resistance can be ensured. As described above, according to this wheel bearing device, without causing adverse effects on the bearing function, it is possible to ensure the withstand strength of the inner ring in the assembly process to the vehicle, and to prevent the inner ring from being lost.

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. The inner ring is a small part, has a raceway surface, and the inner diameter surface is fitted to the hub ring. Therefore, the entire life from the surface to the core is hardened by quenching treatment. And the point of improving the 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. The inner member includes a hub wheel having a hub flange for mounting the wheel on the outer periphery and an inner ring fitted on the outer periphery of the inboard side end of the hub wheel. Forming a raceway surface in each row, and an end surface facing the inboard side of the inner ring connected to the outer ring of the constant velocity joint, and an end surface facing the inboard side of the constant velocity joint facing the outboard side In a double-row angular contact ball bearing type wheel bearing device for supporting a driving wheel pressed against a surface and having a ball contact angle aligned with the back surface, the inner ring is connected to an inboard side end of the inner peripheral surface of the inner ring. Continue to the end face on the inboard side , Engages a locking surface of the small depth of the stepped portion to the extent capable of preventing the inner ring of the omission provided in the assembly process of the vehicle, facing the enlarged diameter machining of the hub wheel in the axial direction of the step portion of the inner ring to only set the plastic deformation portion, the plastic deformation portion of this shall not protrude from the end face of the inner ring, the locking surface is located on the inboard side of the straight line forming a ball contact angle in the inner ring raceway surface of inboard side In addition, since the step between the inner ring fitting surface of the hub wheel and the outer diameter surface of the plastically deformed portion is set to 0.13 mm or more, the sufficient inner ring can be assembled at the time of assembly to the vehicle without adversely affecting the bearing function. Pull-out strength is secured, and inner ring slippage can be prevented.

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 central hole 11, and the raceway surface 4 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 an enlarged sectional view in FIG. 2, a stepped inner ring fitting surface portion 15 having a smaller diameter than the outer periphery of the other portion of the hub wheel 9 is formed on the outer periphery of the inboard side end of the hub wheel 9. Then, 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 up to the inboard side end surface 10a of the inner ring 10, and A plastically deformed portion 9b that engages with a locking surface 16a facing the axial direction of the step portion 16 of the inner ring 10 is provided by tightening. The locking surface 16 a is a tapered surface inclined with respect to the axial direction of the inner ring 10. The locking surface 16a is located on the inboard side with respect to the straight line L that forms the ball contact angle on the inner ring raceway surface 4 on the inboard side.

  The plastic deformation portion 9b substantially fills the inside of the step portion 16 of the inner ring 10, but does not protrude from the end face 10a of the inner ring 10. Further, the step W between the inner ring fitting surface portion 15 of the hub wheel 9 and the outer diameter surface of the plastic deformation portion 9b is set to 0.13 mm or more. The caulking process is performed over the entire circumference by a method such as press working. This caulking process is performed so that the entire circumference of the inboard side end of the hub wheel 9 is expanded. The plastic deformation portion 9b for performing the caulking process of the hub wheel 9 is a non-heat treated portion.

  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 central hole 11 of the hub wheel 9 and 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 of this configuration, the step portion 16 is provided on the inner peripheral surface of the inner ring, and the plastic deformation portion 9b by the caulking process of the hub wheel 9 is engaged with the step portion 16, so It is possible to prevent the inner ring 10 from coming off from the hub ring 9 due to an external force generated in the attaching step.
Since the step portion 16 has a very limited range of the inner periphery of the inner ring 10, the step portion 16 can be made small while preventing the inner ring from coming off. 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, since the step between the inner ring fitting surface portion 15 of the hub wheel 9 and the outer diameter surface of the plastic deformation portion 9b is set to 0.13 mm or more, sufficient inner ring slip-off resistance can be ensured. That is, according to an experiment by the present inventors, it has been confirmed that the inner ring slip-off resistance when the step W is 0.13 mm is about 40 kN. On the other hand, it has been confirmed by experiments that an inner ring slip-off resistance of 2 tons or more is necessary to prevent the inner ring slipping when the wheel bearing device is assembled to the vehicle. Therefore, by setting the step W to 0.13 mm or more as in this embodiment, a sufficient inner ring slip-off resistance can be ensured. 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 device, since the raceway surface 4 of the hub wheel 9 is a hardened surface, the rolling life can be ensured. Since the plastic deformation part 9b which is a caulking part is a non-heat-treating part, the caulking process can be easily performed. Since the inner ring 10 is a small part and has the raceway surface 4 and the inner diameter surface is fitted to the hub ring 9, the entire surface from the surface to the core is hardened by quenching as described above. Thus, 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 of the wheel bearing device. 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 ... Plastic deformation part 10 ... Inner ring 10a ... End surface of inner ring 15 ... Inner ring fitting surface part 16 of the hub wheel ... Inner ring step part 16a ... Locking surface 16b facing the axial direction of the inner ring step part ... Inner ring inner diameter surface W ... Step difference between the inner ring fitting surface part and the plastically deformed part outer diameter surface

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 consists of a hub wheel having a hub flange for wheel mounting on the outer periphery and an inner ring fitted to the outer periphery of the inboard side end of the hub wheel, and the raceway surface of each row is formed on the hub wheel and the inner ring. The hub wheel is connected to the outer ring of the constant velocity joint, and the end surface of the inner ring facing the inboard side is pressed against the stepped surface facing the outboard side provided on the outer ring of the constant velocity joint. In a double row angular contact ball bearing type wheel bearing device in which the ball contact angle is back to back,
The hub is provided at the inboard side end on the inner peripheral surface of the inner ring up to the end surface on the inboard side of the inner ring, and is provided with a stepped portion having a depth small enough to prevent the inner ring from coming off during the assembly process to the vehicle. only set plastic deformation portion engages the engaging surface facing a diameter machining wheel in the axial direction of the step portion of the inner ring, the plastic deformation portion of this shall not protrude from the end face of the inner ring, the locking The surface is located on the inboard side with respect to the straight line forming the ball contact angle on the inner ring raceway surface on the inboard side, and the step between the inner ring fitting surface of the hub wheel and the outer diameter surface of the plastic deformation portion is 0.13 mm. A wheel bearing device characterized by the above.   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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