JP2006057676A - Supporting structure of bearing, and supporting method of bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting structure capable of successfully supporting a knuckle on a bearing and making the supporting structure which is light-weighted and inexpensive. <P>SOLUTION: The supporting structure of the bearing 20 supports the bearing 20 to support an axle shaft in a bearing support 2 of the knuckle 1, and comprises a bearing bush 10 pressed into the bearing support 2. The bearing bush 10 is pressed into the bearing support 2. The bearing 20 is pressed into the bearing bush 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing support structure and a bearing support method for supporting a bearing that supports an axle on a bearing support portion of an automobile knuckle.

Conventionally, spheroidal graphite cast iron (FCD) is generally used for automobile knuckles (hereinafter simply referred to as “knuckles”), and a bearing for supporting an axle is press-fitted into a bearing support portion of the knuckle. The support structure of being supported was taken (for example, refer patent document 1).
Such a bearing support structure requires various measures such as management of bearing tightening allowance, response to fretting wear, and a structure for preventing slipping, but the structure is simple, inexpensive and lightweight. Had the advantage of being.

A bearing support structure is also known in which a bearing is integrated with a hub and attached to the knuckle for the purpose of enhancing the assembly of the bearing to the knuckle and the rigidity of the drive system (see, for example, Patent Document 2). .
JP-A-2-190226 (page 2, lower left column, third line to page 4, upper left column, fourth line, FIGS. 2 to 3) JP 2001-199202 A (paragraphs 0018 to 0023, FIG. 1)

  Incidentally, in recent years, aluminum alloy knuckles have come to be used with the weight reduction of automobile bodies. Since these knuckles are made of an aluminum alloy, in order to have the function as a knuckle, it is necessary to respond to fretting wear, to improve strength and to cope with electric corrosion or thermal expansion. It becomes.

  In particular, an aluminum alloy knuckle has a large difference in thermal expansion from the outer ring of the bearing and is likely to cause fretting wear. Therefore, when the bearing is press-fitted into the knuckle, it is necessary to make a large press-fitting allowance. The press-fitting allowance can be specified from the proof stress and sag resistance predicted by the material of the aluminum alloy, but if it is too small, fretting wear or tapping wear tends to occur, which is a big problem in terms of durability. Become.

For this reason, in the past, it is difficult to cause such a problem, and it is the current situation that many of the above-mentioned bearings integrated with a hub are used, but such a support structure has an integrated structure. As a result, the weight increases and the cost increases.
Moreover, in such an integrated structure, the material of the knuckle is made of an aluminum alloy for the purpose of reducing the weight, but conversely, it becomes necessary to increase the strength of the hub itself, resulting in an increase in weight. It had the disadvantage that it would end up.

  In particular, development of a lightweight and inexpensive bearing support structure has been desired for automobiles that have improved fuel efficiency through weight reduction of vehicles.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bearing support structure and a bearing support method that can favorably support a bearing on a knuckle and that can realize a lightweight and inexpensive support.

  In order to solve the above problems, a bearing support structure according to the present invention is a bearing support structure for supporting a bearing supporting an axle on a bearing support portion of a knuckle, and is a bearing bush press-fitted into the bearing support portion. The bearing bush is press-fitted into the bearing support portion, and the bearing is press-fitted into the bearing bush. Note that the press-fitting includes a light press-fitting state in which the bearing is temporarily fixed to the bearing bush.

  According to such a bearing support structure, the bearing bush is press-fitted into the bearing support, and the bearing is press-fitted into the bearing bush press-fitted into the bearing support, and the bearing is connected to the knuckle via the bearing bush. It will be supported by the bearing support part. That is, the bearing is supported by the bearing bush and the bearing support portion with the holding force shared, and a support state in which stress is concentrated only on the bearing support portion is avoided.

  As a result, the fretting wear and tapping wear that occurs when the press-fitting allowance is set to a large value or when the press-fitting allowance is too small, as in the conventional case where the bearing is directly press-fitted into the bearing support. Therefore, it is not necessary to perform mounting in consideration of the above, and the bearing can be favorably supported by the knuckle.

  Furthermore, since it can be a simple support structure in which the bearing is press-fitted and supported to the bearing support portion via the bearing bush, there is no need to use a conventional weight structure in which the hub and the bearing are integrated. And an inexpensive support structure.

  The bearing support structure of the present invention is a bearing support structure for supporting a bearing supporting an axle on a bearing support portion of a knuckle, and includes a bearing bush inserted into the bearing support portion in a loose state. The bearing bush is inserted into the bearing support, and the bearing bush is press-fitted into the bearing bush, whereby the bearing bush is press-fitted into the bearing support.

  According to such a bearing support structure, the bearing bush is inserted into the bearing support portion in a loose state, and the bearing is press-fitted into the bearing bush inserted into the bearing support portion. By the press-fitting, the bearing bush that has been inserted in the loose state is tightened to the bearing support portion of the knuckle, and as a result, the bearing is supported with respect to the bearing support portion. That is, the bearing is supported by the bearing bush and the bearing support portion with the holding force shared, and a support state in which stress is concentrated only on the bearing support portion is avoided.

  As a result, the fretting wear and tapping wear that occurs when the press-fitting allowance is set to a large value or when the press-fitting allowance is too small, as in the conventional case where the bearing is directly press-fitted into the bearing support. Therefore, it is not necessary to perform mounting in consideration of the above, and the bearing can be favorably supported by the knuckle.

Furthermore, since it can be a simple support structure in which the bearing is press-fitted and supported to the bearing support portion via the bearing bush, there is no need to use a conventional weight structure in which the hub and the bearing are integrated. And an inexpensive support structure.
In addition, the press-fitting process can be performed only once when the bearing is attached, and the number of assembling processes can be reduced. Further, since the bearing is supported by the bearing support portion via the bearing bush in one press-fitting process, an advantage that the assembling workability is improved can be obtained.

Furthermore, it is preferable that the bearing bush is formed with a flange stopper.
By providing such a flange stopper, positioning when the bearing bush is attached to the bearing support portion can be performed, and the attachment property of the bearing bush is improved.

  Further, the flange stopper may be provided with a detent portion that engages with the bearing support portion, and further, a stopper that regulates the amount of press-fitting of the bearing may be provided on the inner peripheral surface of the bearing bush.

  Thus, by providing the rotation stopper on the flange stopper, the fixing strength of the bearing bush to the bearing support can be increased, and by providing a stopper on the inner peripheral surface of the bearing bush, the press-fitting amount of the bearing can be reduced. As a result, the assembly workability can be improved.

  Further, a weak cross section can be provided between the flange stopper and the outer peripheral surface or the inner peripheral surface of the bearing bush. By providing such a concave portion, a flange stopper having increased rigidity can be provided. And the portion where the outer peripheral surface or the inner peripheral surface is formed can be cut off, whereby a good press-fitting of the bearing bush can be realized. Therefore, long-term maintenance of a good support state of the bearing can be realized.

  The bearing support method of the present invention is a bearing support method for supporting a bearing for supporting an axle on a bearing support portion of a knuckle, and a bearing bush is press-fitted or loosened into the bearing support portion. Inserting the bearing into the bearing bush press-fitted or inserted into the bearing support portion by this step, thereby bringing the bearing bush into a press-fit state with respect to the bearing support portion. It is characterized by having.

  According to such a bearing support method, after the bearing bush is press-fitted or loosely inserted into the bearing support portion, the bearing is supported by the bearing support portion by press-fitting the bearing into the bearing bush. It becomes. That is, the bearing is supported by the bearing support portion via the bearing bush, and the bearing bush functions as a cushion between the bearing and the bearing support portion. As a result, a force due to the press-fitting of the bearing is not directly applied to the bearing support portion, and the bearing is supported in a state where the holding force is shared between the bearing bush and the bearing support portion. Therefore, an increase in stress on the bearing support portion is absorbed, and an advantage that the bearing is favorably supported on the knuckle can be obtained.

  In addition, since the bearing can be supported by a simple support method in which the bearing is press-fitted and supported to the bearing support portion via the bearing bush, it is necessary to use a conventional weight structure in which the hub and the bearing are integrated. Therefore, it is possible to realize a lightweight and inexpensive support.

  ADVANTAGE OF THE INVENTION According to this invention, the bearing support structure and the support method of a bearing which can support a bearing favorably to a knuckle and can implement | achieve lightweight and cheap support are obtained.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.
<First Embodiment>
In the drawings to be referred to, FIG. 1 is a schematic view showing a wheel portion of an automobile to which a bearing support structure according to a first embodiment of the present invention is applied, and FIG. 2 is also for explaining the bearing support structure. FIG. 3 is a partially sectional view for explaining the bearing support structure, and FIG. 4 is an enlarged sectional view showing the main part for explaining the bearing support structure. .

  As shown in FIG. 1, a front wheel (drive side wheel) portion of an automobile to which the bearing support structure of the present embodiment is applied includes a knuckle 1, an axle S supported by the knuckle 1, and the axle S And an attached wheel hub H. The knuckle 1 is provided with a knuckle arm 4 having a connecting portion 3 connected to a plurality of suspension arms A. Further, a tire wheel TW with a tire T attached thereto is attached to the wheel hub H by bolts (not shown). Further, a shock absorber K is disposed in the vicinity of the knuckle 1 and the suspension arm A.

  The knuckle 1 is made of an aluminum alloy casting, and as shown in FIG. 2, a cylindrical bearing support portion 2 is formed at the center. A bearing bush 10 is press-fitted into the bearing mounting surface 2 ′ of the bearing support portion 2, and a bearing 20 is press-fitted into and supported by the press-fitted bearing bush 10. Yes.

  The bearing bush 10 is formed using a material having a thermal expansion coefficient close to that of an aluminum alloy material, for example, an aluminum MMC (Metal Matrix Composite) material or a stainless steel material. Therefore, the bearing bush 10 having higher strength and better sag resistance than the aluminum alloy material can be obtained. The bearing bush 10 may be formed using a steel material or the like, or may be formed using an aluminum alloy material.

  As shown in FIG. 2, the bearing bush 10 includes a cylindrical portion 10a and a flange stopper 10b formed integrally with an end portion (non-pressure inlet side) of the cylindrical portion 10a. As described above, the bearing 20 is press fitted into the cylindrical portion 10a and attached. As shown in FIG. 3, a stopper 10 c that contacts the end of the press-fitted bearing 20 and regulates the press-fitting amount of the bearing 20 is provided in the cylindrical portion 10 a.

  Further, as shown in FIG. 4, a weak cross-sectional portion 10d (concave portion) is provided at the boundary portion between the cylindrical portion 10a and the flange stopper 10b of the bearing bush 10 over the entire circumference of the cylindrical portion 10a. Note that the weak cross section 10d does not necessarily extend over the entire circumference, and may be provided intermittently or may penetrate therethrough. Further, the weak cross section 10d may be provided not only on the outer peripheral surface side but also on the inner peripheral surface side.

  As shown in FIG. 2, the insertion of the bearing bush 10 into the bearing support portion 2 is performed from the side of the knuckle 1 (not shown) (see FIG. 1). As shown in FIG. 3, a stepped portion 2 a into which the flange stopper 10 b of the bearing bush 10 fits flush is formed at the opening edge on the side over the entire periphery of the opening edge.

  The bearing 20 is a ball bearing made of steel or the like. In the present embodiment, the bearing 20 has two rows of balls 21, and the outer ring 22 is sized so as to be press-fitted into the cylindrical portion 10 a of the bearing bush 10. Is formed.

Next, assembly of the bearing 20 in such a support structure for the bearing 20 will be described with reference to FIGS.
First, as shown in FIG. 5A, the bearing bush 10 is press-fitted into the bearing support portion 2 of the knuckle 1. Next, as shown in FIG. 5B, the bearing 20 is press-fitted into the cylindrical portion 10a of the press-fitted bearing bush 10. At this time, the bearing 20 is press-fitted to a position where it comes into contact with the stopper 10 c in the cylindrical portion 10 a of the bearing bush 10.
As a result, the bearing 20 is supported by the bearing support 2 via the bearing bush 10.

Here, the relationship between the tightening allowance of each part and the stress that change when the bearing 20 is assembled will be described with reference to FIGS. 6 and 7A and 7B.
In FIG. 6, straight lines A to C indicate the relationship between the tightening allowance and stress in each member, the straight line A indicates the relationship in the bearing support portion 2 of the knuckle 1, and the straight line B indicates the relationship in the bearing bush 10. The straight line C indicates the relationship of the bearing 20 in the outer ring 22.

  First, as shown in FIG. 7A, the relationship between the tightening allowance and the stress in a state where the bearing bush 10 is press-fitted into the bearing support portion 2 will be described. When the bearing bush 10 is press-fitted into the bearing support portion 2, the bearing support portion 2 has a tightening press-fit management width indicated by a symbol A (A) in the straight line A, as shown in FIG. The bearing bush 10 has a press-fit management width of a tightening margin indicated by a symbol B (A) in the straight line B.

In this state, as shown in FIG. 7B, when the bearing 20 is press-fitted into the bearing bush 10, a positive stress (tensile force) is generated in the bearing support portion 2, and the bearing support portion 2 As shown in FIG. 6, the press-fit management width indicated by the symbol A (A) shifts to the press-fit management width indicated by the symbol A (B). That is, the stress and the tightening allowance are large values.
At this time, the stress in the bearing bush 10 is changed from a negative stress (compressive force) to a positive stress (tensile force) by press-fitting the bearing 20, and the bearing bush 10 is shown in FIG. The process shifts from the press-fit management width indicated by the symbol B (A) to the press-fit management width indicated by the symbol B (B).

  Further, as shown in FIG. 6, the bearing 20 (outer ring 22) is in a state in which the bearing 20 is press-fitted into the bearing bush 10, and has a tightening press-fit management width indicated by a symbol C (b) in the straight line C. It will be held by the bush 10.

  Here, as a comparative example, the relationship between the tightening allowance and the stress when the bearing 20 is directly press-fitted into the bearing support 2 will be described. The press-fitting management width is indicated by a reference D in FIG. It is the press-fit management width of the tightening allowance. That is, with this press-fit management width, there is a possibility that the press-fit management width may overlap the proof strength limit region of the knuckle 1 whose range is indicated by hatching in FIG. 6, and the purpose of favorably supporting the bearing 20 will not be achieved.

  On the other hand, in this embodiment, the press-fit management width of the bearing support portion 2 is indicated by the reference A (B) from the press-fit management width indicated by the reference A (A) in the figure before and after press-fitting the bearing 20. Although the transition to the press-fit control width shown in Fig. 2 is applied, the press-fit control width A (B) after the transition has a lower stress and tightening margin than the knuckle 1 yield strength limit area, and overlaps the yield limit area. There is no. That is, the increase in stress applied to the bearing support portion 2 is absorbed by the bearing bush 10, and as a result, the bearing 20 can be supported favorably in a stable state.

  In the present embodiment, the inner diameter dimension of the bearing support portion 2, the outer diameter dimension and the inner diameter dimension of the cylindrical portion 10a, and the outer ring 22 dimension of the bearing 20 are adjusted so as to obtain the above result. Yes.

  According to the support structure of the bearing 20 of the present embodiment described above, the bearing 20 is supported by the bearing support portion 2 of the knuckle 1 via the bearing bush 10, and the bearing bush 10 and the bearing support portion 2 support the bearing 20. The holding force is shared and supported. Therefore, stress does not concentrate only on the bearing support portion 2 in supporting the bearing 20.

  As a result, as in the conventional case, when the bearing 20 is directly press-fitted into the bearing support portion 2, the press-fitting allowance is set to be large, or the fretting wear caused by the press-fitting allowance is too small. It is not necessary to perform attachment in consideration of wear or the like, and the bearing 20 can be favorably supported on the knuckle 1.

  Furthermore, since a simple support structure in which the bearing 20 is press-fitted and supported on the bearing support portion 2 via the bearing bush 10 can be used, it is necessary to use a conventional weight structure in which the hub and the bearing are integrated. This eliminates the need for a light and inexpensive support structure.

  Furthermore, since the bearing bush 10 is formed with the flange stopper 10b, positioning when the bearing bush 10 is attached to the bearing support portion 2 can be performed, and the attachment property of the bearing bush 10 is improved.

  Further, since the weak cross-sectional portion 10d is provided between the flange stopper 10b and the cylindrical portion 10a in the bearing bush 10, the degree of force applied between the flange stopper 10b and the cylindrical portion 10a having increased rigidity can be reduced. Can be cut, and thereby a good press fit of the bearing bush 10 is achieved. Therefore, long-term maintenance of a good support state of the bearing 20 can be realized.

  Furthermore, the bearing 20 is held against the bearing bush 10 which has higher strength and better sag resistance than the aluminum alloy material as compared with the case where the bearing 20 is directly attached to the aluminum alloy knuckle 1, so that it is in a stable state. The advantage of being supported by is obtained.

  Further, when the bearing bush 10 is formed of a material whose thermal expansion is close to that of an aluminum alloy material, such as an aluminum MMC material or a stainless steel material, there is also an advantage that a change in tightening margin can be suppressed to a small extent.

<Second Embodiment>
Next, a bearing support structure according to a second embodiment of the present invention will be described with reference to FIG. 3 again. The present embodiment is different from the first embodiment in that the bearing bush 10 is inserted into the bearing support portion 2 in a loose state and the bearing 20 is press-fitted into the bearing bush 10.

  That is, the assembly of the bearing 20 is performed by first inserting the bearing bush 10 into the bearing support portion 2 in a loose state and press-fitting the bearing 20 there. The bearing bush 10 inserted in the state is fastened to the bearing support portion 2 and the bearing 20 is held by the bearing bush 10. That is, also in the present embodiment, the bearing 20 is supported by the bearing bush 10 and the bearing support portion 2 with a holding force shared, and a support state in which stress is concentrated only on the bearing support portion 2 is avoided. .

  Therefore, also in the present embodiment, as described with reference to FIG. 6, the press-fit management width of the bearing support portion 2 after the press-fit of the bearing 20 is indicated by the symbol A (b) in FIG. It is avoided to overlap the proof stress limit area. In other words, the increase in stress applied to the bearing support portion 2 is absorbed by the bearing bush 10 even in this case, and as a result, the bearing 20 can be favorably supported in a stable state.

  As a result, as in the conventional case, when the bearing 20 is directly press-fitted into the bearing support portion 2, the press-fitting allowance is set to be large, or the fretting wear caused by the press-fitting allowance is too small. It is not necessary to perform attachment in consideration of wear or the like, and the bearing 20 can be favorably supported on the knuckle 1.

  Furthermore, since the press-fitting process is performed only once when the bearing 20 is attached, there is an advantage that the number of assembling processes is reduced as compared with the first embodiment. Moreover, since the bearing 20 is supported by the bearing support part 2 via the bearing bush 10 by one press-fitting process, the advantage that an assembly workability | operativity improves is also acquired.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications.
For example, as shown in FIG. 8A, the bearing bush 10 does not necessarily have to be provided with a flange stopper. Further, the bent portion 10e may be formed at the end portion, and the stopper 10c may be provided. Further, a circlip groove 11 may be provided to fix the bearing 20 (not shown).
Moreover, as shown in FIG.8 (b), the ring member 12 may be fixed to the edge part of the cylindrical part 10a by welding etc., and a flange may be formed.

Further, the flange stopper 10b is not limited to an annular shape, and may be configured by forming a tongue-like portion as shown in FIG. 8 (c).
In this case, the tongue-like portion can be formed by press molding or the like.
The stopper 10c can also be formed by performing inner diameter processing.

Further, as shown in FIG. 8 (d), the flange stopper 10b is formed with a concave portion 13 that acts as a rotation preventing portion, and is fitted into the opposing bearing support portion 2 (see FIG. 3). May be.
Moreover, as shown in FIG.8 (e), the volt | bolt 14 for fixation may be attached to the flange stopper 10b, and you may comprise so that it can fix to the bearing support part 2 (refer FIG. 3).
In this case, a bolt 14 having a long overall length (not shown) is used as the fixing bolt 14 and is passed through the pressure inlet side of the bearing 20 of the bearing support portion 2 and is screwed into a nut or the like to be fastened. May be.
By setting it as such a structure, the bearing bush 10 can be fixed to the bearing support part 2 reliably. As the bolt 14, it is desirable to use a material having a high coefficient of thermal expansion or a low spring constant, for example, a material made of stainless steel or titanium. By using the bolt 14 formed of such a material, it is possible to improve the followability to the thermal expansion of the knuckle 1.

It is the schematic diagram which showed the wheel part of the motor vehicle to which the support structure of the bearing of the 1st Embodiment of this invention is applied. FIG. 6 is an exploded perspective view (partially omitted) for explaining the bearing support structure. It is a fragmentary sectional view for demonstrating the support structure of a bearing similarly. It is the expanded sectional view which showed the principal part for demonstrating the support structure of a bearing similarly. (A) (b) is explanatory drawing at the time of assembling a bearing. It is the figure which showed the relationship between the interference of each member and stress which change at the time of the assembly | attachment of a bearing. (A) (b) is a supplementary explanatory drawing in demonstrating the relationship between the interference of each member, and stress. (A)-(e) is explanatory drawing which showed the modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Knuckle 2 Bearing support part 2a Step part 10 Bearing bush 10a Cylindrical part 10b Flange stopper 10c Stopper 10d Concave part 20 Bearing

Claims (7)

A bearing support structure for supporting a bearing supporting an axle on a bearing support portion of an automotive knuckle,
A bearing bush press-fitted into the bearing support;
A bearing support structure, wherein the bearing bush is press-fitted into the bearing support portion, and the bearing is press-fitted into the bearing bush. A bearing support structure for supporting a bearing supporting an axle on a bearing support portion of an automotive knuckle,
A bearing bush that is inserted in a loose state into the bearing support portion,
A bearing support structure, wherein the bearing bush is inserted into the bearing support, and the bearing bush is press-fitted into the bearing support by inserting the bearing into the bearing bush.   The bearing support structure according to claim 1, wherein a flange stopper is formed on the bearing bush.   The bearing support structure according to claim 3, wherein an anti-rotation portion that engages with the bearing support portion is provided on the flange stopper or the outer peripheral surface of the bearing bush.   The bearing support structure according to any one of claims 1 to 4, wherein a bearing stopper for regulating a press-fitting amount of the bearing is provided on an inner peripheral surface of the bearing bush.   The bearing support structure according to any one of claims 1 to 5, wherein a weak cross section is provided between the flange stopper and an outer peripheral surface or an inner peripheral surface of the bearing bush. A bearing support method for supporting a bearing for supporting an axle on a bearing support portion of a knuckle,
Inserting a bearing bush into the bearing support portion in a press-fit or loose state;
A step of press-fitting the bearing into the bearing bush press-fitted or inserted into the bearing support portion by this step so that the bearing bush is press-fitted into the bearing support portion; and
A method for supporting a bearing, comprising:

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