JP4519005B2 - 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. 4 and 5 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 33 a of the outer ring 33 of the constant velocity joint is inserted into the through hole 31 in the center of the hub wheel 29 and is spline-fitted, and the step surface 33 b of the constant velocity joint outer ring 33 is formed on the inboard side end surface 30 a of the inner ring 30. Pressed. 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.
(4) When the caulking portion 29b at the end of the inboard side of the hub wheel 29 is swaged, the inner ring 30 expands, which causes deformation of the raceway surface 24 of the inner ring 29, leading to a decrease in life.
Further, by crimping the crimping portion 29b, the inner diameter portion (pilot inner diameter portion 29ba) at the inboard side end is deformed in a reduced diameter. Therefore, when inserting the stem portion 33a of the constant velocity joint outer ring 33 into the through hole 31 of the hub wheel 29, the pilot inner diameter portion 29ba which is the inlet portion of the through hole of the hub wheel 29 serving as the guide portion of the stem portion 33a. And the constant velocity joint outer ring 33 becomes difficult to attach to the hub wheel 29.

  An object of the present invention is to provide a wheel bearing device that can prevent an inner ring from being lost in an assembly process to a vehicle without adversely affecting the bearing function, and can improve the assembly to the vehicle.

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 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. The hub ring and the inner ring are formed with raceways of the respective rows, and the hub ring is connected to the outer ring of the constant velocity joint, and the end surface facing the inboard side of the inner ring is provided on the outer ring of the constant velocity joint. In the wheel bearing device for driving wheel support that is pressed against the stepped surface facing the outboard side, it continues to the inboard side end of the inner peripheral surface of the inner ring up to the inboard side end surface of the inner ring, and is assembled to the vehicle. Can prevent the inner ring from coming off in the process Extent provided with a step portion of the small depth, the inner surface of the stepped portion, and a straight portion formed of the cylindrical surface, a shape formed by the end of the straight portion and the inner peripheral surface subsequent stepped portion end surface of the inner ring, the only set plastic deformation portion engaging said stepped portion end surface of the step portion of the inner ring by caulking of the wheel hub, the plastic deformation portion of this will not protrude from the end face of the inner ring, and the said step portion It is characterized by not contacting the straight part.
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 while securing the proof stress. 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.
The step portion of the inner ring is small as described above, but the plastic deformation portion of the hub ring engaged with the step portion is not in contact with the straight portion of the step portion. The amount by which the inner ring expands due to the caulking process such as caulking can be reduced. For this reason, the influence on the deformation of the raceway surface of the inner ring due to the caulking process is avoided, and the deterioration of the bearing function such as the life reduction due to the deformation of the raceway surface of the inner ring is prevented.
In this way, the inner ring can be prevented from coming off in the assembly process to the vehicle without adversely affecting the bearing function, and the assembly to the vehicle can be improved.

Stepped portion end surface of the stepped portion provided on the inner peripheral surface of the inner ring is a tapered surface. If it is a taper surface, the plastically deformed portion is engaged with the inner end surface of the stepped portion without a gap due to the plastic flow during the caulking process, and reliable engagement can be achieved.

In the present invention, the through hole of the hub wheel has a spline groove that meshes with a spline on the outer periphery of the stem portion of the constant velocity joint on the inner peripheral surface, and the spline groove on the inner peripheral surface of the through hole is formed. A portion on the inboard side with respect to the general diameter portion, a large diameter step portion which becomes an inner peripheral surface of the plastic deformation portion, and an intermediate diameter step which is smaller in diameter than the large diameter step portion and larger in diameter than the general diameter portion. It is good also as a two-step stepped shape which consists of a part.
By making the inboard side end of the hub wheel into a two-stepped shape as described above, when the plastic deformation portion is crimped, the inlet portion of the general diameter portion of the hub wheel through hole is in a reduced diameter state. Is prevented from being deformed. Therefore, when the stem portion of the constant velocity joint is inserted into the hub wheel through hole, no interference occurs and the connection with the constant velocity joint can be performed reliably. In addition, the plastic deformation portion of the hub wheel can be crimped without considering the interference, and the crimping can be easily performed. Even if the intermediate diameter step portion is deformed into a reduced diameter state, the difference in diameter from the outer diameter of the stem portion is large, so that the problem of interference does not occur. The intermediate diameter step portion serves as a guide when the stem portion of the constant velocity joint is inserted, and the assemblability is further improved.

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. A rolling element, and the inner member includes 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. The hub ring and the inner ring are formed with raceways of the respective rows, and the hub ring is connected to the outer ring of the constant velocity joint, and the end surface facing the inboard side of the inner ring is provided on the outer ring of the constant velocity joint. In the wheel bearing device for driving wheel support that is pressed against the stepped surface facing the outboard side, it continues to the inboard side end of the inner peripheral surface of the inner ring up to the inboard side end surface of the inner ring, and is assembled to the vehicle. Can prevent the inner ring from coming off in the process Extent provided with a step portion of the small depth, the inner surface of the stepped portion, and a straight portion formed of the cylindrical surface, a shape formed by the end of the straight portion and the inner peripheral surface subsequent tapered surface of the inner ring, the hub only set plastic deformation portions for engagement by the caulking of the ring to the tapered surface of the stepped portion of the inner ring, the plastic deformation portion of this will not protrude from the end face of the inner ring, and the straight portion of the step portion Since the inner ring can be prevented from being deformed by caulking of the plastically deformed portion, and the contact area with the step surface of the constant velocity joint outer ring can be secured without adversely affecting the bearing function. It is possible to prevent the inner ring from being removed in the assembly process, and to improve the assembly to the vehicle.

An 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 raceway surfaces 3 and 4 has an arc shape in cross section, and each of the raceway surfaces 3 and 4 is formed such that the rolling element 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 in the center, 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 peripheral surface of the inner ring 10 up to the end surface 10a on the inboard side of the inner ring 10. The inner surface of the stepped portion 16 has a shape including a straight portion 16a formed of a cylindrical surface and a tapered surface 16b that is an inner end surface of the stepped portion that extends from the end portion of the straight portion 16a to the inner peripheral surface of the inner ring 10. The tapered surface 16b is located on the inboard side with respect to the straight line L forming the rolling element contact angle (ball contact angle). In addition, it is good also as a step part inner end surface which consists of a surface perpendicular | vertical to a bearing axial direction instead of the taper surface 16b.

  A plastic deformation portion 9b that engages with the tapered surface 16b of the stepped portion 16 of the inner ring 10 is provided at the inboard side end of the hub wheel 9 by caulking. 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 plastically deformed portion 9 b is not in contact with the straight portion 16 a of the step portion 16 of the inner ring 10. 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 inner peripheral surface of the through-hole 11 of the hub wheel 9 has a large-diameter step portion 11b in which the portion on the inboard side of the general diameter portion 11a in which the spline groove is formed becomes the inner peripheral surface of the plastic deformation portion 9b. The intermediate diameter step portion 11c is smaller in diameter than the large diameter step portion 11b and larger in diameter than the general diameter 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 through hole 11 of the hub wheel 9, and the spline on the outer periphery of the stem portion 13a. 13 aa and the spline groove on the inner peripheral surface of the through hole 11 are spline-fitted, and the constant velocity joint outer ring 13 is coupled to the inner member 2 by tightening a nut 14 that is screwed to the tip of the stem portion 13 a. 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 10, and the plastic deformation portion 9 b due to the caulking process of the hub ring 9 is formed on the tapered surface 16 b that becomes the step portion inner end surface of the step portion 16. Since they are engaged, 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 to the vehicle.
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. 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. .

  Further, the inner surface of the stepped portion 16 in the inner ring 10 is formed by a straight portion 16 a made of a cylindrical surface and a tapered surface 16 b that continues from the end of the straight portion 16 a to the inner peripheral surface of the inner ring 10. Since the plastically deformed portion 9b is not in contact with the straight portion 16a of the inner ring stepped portion 16, the amount by which the inner ring 10 is expanded by caulking, such as by expanding and crimping the plastically deformed portion 9b, can be kept small. For this reason, the influence of the deformation | transformation to the raceway surface 4 of the inner ring | wheel 10 by the said crimping process is avoided, and the fall of bearing functions, such as the lifetime reduction by the deformation | transformation of the inner ring raceway surface 4, is prevented. That is, as in the comparative example of FIG. 3, when the plastic deformation portion 9b of the hub wheel 9 is brought into contact with the straight portion 16a of the inner ring step portion 16, the inner ring 10 is pressed from the inner diameter side by crimping the plastic deformation portion 9b. The inner ring 10 may be expanded in diameter, and the inner ring raceway surface 4 may be deformed by the increased diameter. Such deformation is prevented by providing a gap between the plastic deformation portion 9b and the straight portion 16a of the inner ring step portion 16.

  Further, since the inboard side end of the through hole 11 of the hub wheel 9 has a two-stepped shape as described above, when the plastic deformation portion 9b of the hub wheel 9 is crimped, the hub wheel through hole 11 is prevented from being deformed into the reduced diameter state. Therefore, when the stem portion 13a of the constant velocity joint outer ring 13 is inserted into the hub wheel through hole 11, there is no interference with the inlet portion of the through hole 11 serving as a pilot portion with respect to the stem portion 13a, and the constant velocity joint outer ring 13 is inserted. Can be reliably connected. Further, the plastic deformation portion 9b of the hub wheel 9 can be crimped without considering the interference, and the crimping can be easily performed.

  Furthermore, 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 a partial expanded sectional view which shows a comparative example with the bearing apparatus for wheels. 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 DESCRIPTION OF SYMBOLS 11 ... Through-hole 11a ... Spline groove 11b ... Large diameter level | step-difference part 11c of a through-hole ... Middle diameter level | step-difference part 13 of a through-hole ... Constant velocity joint outer ring 13a ... Stem part 13aa of a constant velocity joint outer ring ... Spline 16 of a stem part ... Inner ring Step portion 16a ... Straight portion 16b of inner ring step portion ... Tapered surface of inner ring step portion (inner end surface of step portion)

Claims (3)

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 includes 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. A raceway surface of each row is formed, and the end surface facing the inboard side of the inner ring is coupled to the outer ring of the constant velocity joint, and the step surface facing the outboard side provided on the outer ring of the constant velocity joint In the wheel bearing device for driving wheel support to be pressed,
A stepped portion having a depth small enough to prevent the inner ring from coming off in the assembly process to the vehicle is provided at the inboard side end of the inner ring on the inner peripheral surface of the inner ring. The inner surface of the portion is formed by a straight portion made of a cylindrical surface and a tapered surface that continues from the end of the straight portion to the inner peripheral surface of the inner ring, and the stepped portion of the inner ring is formed by caulking the hub ring. plastically deformed portion of the set only to be engaged with the tapered surface, the plastic deformation portion of this is for the wheel, characterized in that it is assumed that the does not protrude from the end face of the inner ring, and not in contact with the straight portion of the step portion Bearing device.   In Claim 1, the said through-hole of the said hub ring has the spline groove | channel which meshes with the spline of the outer periphery of the stem part of a constant velocity joint in an internal peripheral surface, and the said spline groove | channel in the internal peripheral surface of the said through-hole is formed. The portion on the inboard side of the general diameter portion is a large-diameter step portion that becomes an inner peripheral surface of the plastic deformation portion, and an intermediate diameter that is smaller than the large-diameter step portion and larger than the general-diameter portion. A wheel bearing device having a stepped shape with two steps formed by a stepped portion.   3. The hub ring 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 entirely hardened by quenching. Hardened wheel bearing device.

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