JP2007276780A - Vehicle bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle bearing device capable of simplifying a structure of a calked part when a constant velocity joint is installed to a hub unit. <P>SOLUTION: In the vehicle bearing device, a shaft 4 of the constant velocity joint 3 is spline-fitted to an insertion hole 2 of the hub unit 1 supported on a vehicle body side by a double-row rolling bearing 5, and after a vehicle inner side end in the hub unit 1 is enlarged in diameter, it is calked to the vehicle inner side end surface of an inner ring 20 of the bearing 5. A cross section shape along an axis 6 direction on the vehicle inner side of the calked part is formed in a projection curve surface projected to the vehicle inner side, and when the shaft 4 is connected to the hub unit 1 while making them relatively closer to each other in an axial direction, a flat end surface opposed to the hub unit 1 side in the constant velocity joint 3 is abutted on the projection curve surface of the calked part and presses it to the vehicle outer side, and thereby, the projection curve surface is slightly plastically deformed. Thereby, the calked part and the vehicle outer side end surface of the constant velocity joint 3 are surface-contacted with each other over the whole periphery. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular bearing device to which a disc rotor and wheels of a disc brake device in a vehicle such as an automobile are attached.

  Conventionally, as this type of vehicle bearing device, a wheel mounting hub unit that is rotatably supported around a shaft center on a double row rolling bearing supported on the vehicle body side, and the hub unit along the shaft center is provided. A shaft part for spline fitting from the vehicle inner side is provided on one end side in the through hole formed in this way, and the other end side is configured with a constant velocity joint that interlocks and connects the drive shaft to the hub unit Is well known.

In the hub unit, a double row rolling bearing for rotatably supporting the hub unit on the vehicle side is disposed at a location on the vehicle inner side. The inner ring of the double row rolling bearing may be a separate one from the hub unit. In that case, the inner ring and the hub unit are fixed together so that the inner ring does not come off the hub unit in the fixed state. In order to do so, conventionally, the hub inner side end portion of the hub unit that is formed in a cylindrical shape with an insertion hole is increased in diameter, and the increased diameter portion is connected to the inner ring from the vehicle inner side. What is shown is known (for example, see Patent Document 1). Furthermore, the regulation of the position of the constant velocity joint, which has been spline fitted to the hub unit insertion hole, toward the vehicle outer side is performed by attaching the constant velocity joint to the caulking portion, which is the enlarged diameter portion where the caulking is performed. It is made by letting. Then, in order to stabilize the posture of the constant velocity joint in the contacted state, a flat surface perpendicular to the axial center is cut to the caulking portion in accordance with the flat end surface of the constant velocity joint to which the caulking portion is applied in advance. Those formed by processing or the like are well known.
JP 2000-87979 A

  However, it is troublesome to form the caulking portion on the flat surface by cutting or the like, and if the end surface of the constant velocity joint is brought into contact with the caulking portion in the flat surface state, the caulking portion is caulked. Because the contact area with the part is large, the force acting on the inner ring of the bearing from the caulking part is relatively large even if the surface pressure received by the caulking part from the constant velocity joint is small. There is a possibility that the rolling element may come into strong contact with the outer ring side, so that there is a possibility that rolling friction of the rolling element may increase.

  The present invention provides a vehicular bearing device capable of simplifying the structure of the caulking portion when assembling the constant velocity joint to the hub unit and preventing the rolling friction of the rolling elements of the bearing from becoming unduly large. Objective.

  According to a first aspect of the present invention, there is provided a vehicle bearing device including a wheel mounting hub unit supported on a double-row rolling bearing supported on a vehicle body side so as to be rotatable around an axis, and the hub unit having the shaft center on the axis. A shaft portion that is spline-fitted from the vehicle inner side to the insertion hole formed along the inner side is provided on one end side, and the other end side is configured with a constant velocity joint that interlocks and interlocks with the hub unit. In addition, the inner ring in the double row rolling bearing is disposed near the constant velocity joint, and the hub inner side end of the hub unit is expanded on the inner side end surface of the inner ring, and then the hub unit is caulked. And the inner ring integrated with the inner ring, the cross-sectional shape along the axial direction of the vehicle inner side of the caulking portion for caulking the inner ring from the vehicle inner side is the vehicle inner side A convex curved surface projecting, and when the shaft portion is moved relative to the hub unit in the axial direction toward the vehicle outer side and connected to the hub unit side of the constant velocity joint. The opposing flat end surface is brought into contact with the convex curved surface of the caulking portion and pressed toward the vehicle outer side, thereby causing the convex curved surface to be slightly plastically deformed, and the caulking portion and the vehicle outer side end surface of the constant velocity joint, Is in surface contact over the entire circumference.

  According to the configuration of the first aspect of the present invention, it is not necessary to previously form a flat surface for restricting contact of the end surface of the constant velocity joint to the caulking portion by cutting or the like. Can be omitted. Also, when caulking, it is set so that the force acting from the caulking location on the inner ring of the double row rolling bearing can only be in close contact with the caulking portion, or so that a slight pressing force acts somewhat on the inner ring side. If this is the case, even if the contact portion of the caulking portion with the end face of the constant velocity joint is formed to be somewhat flat due to plastic deformation, an unreasonably large force does not act on the inner ring side. Is maintained well without being unduly large. Furthermore, when fixing the shaft portion of the constant velocity joint to the hub unit, the end surface on the hub unit side of the constant velocity joint is pressed against the caulking portion, and the convex curved surface of the caulking portion is plastically deformed to be somewhat flat. By doing so, the contact state of the constant velocity joint with the hub unit can be brought into surface contact around the entire circumference of the axis, so when steering the vehicle, the moment generated by the force transmitted from the wheel, that is, the axis is Because the contact between the constant velocity joint and the constant velocity joint is a surface contact even with respect to the moment acting between the center double row rolling bearing and the constant velocity joint, the relative relationship between the bearing and the constant velocity joint due to the moment It is possible to prevent the rotational displacement from occurring.

  A vehicle bearing device according to a second aspect of the present invention is the vehicle bearing device according to the first aspect, wherein a vehicle outer side end portion of the shaft portion that is spline-fitted to the insertion hole of the hub unit is used as the vehicle of the insertion hole. The shaft portion is fixed to the hub unit by protruding from the outer side end portion and screwing and fastening a nut to a male screw portion formed in the protruding portion.

  According to the configuration of the second aspect of the present invention, the shaft portion can be easily fixed to the hub unit by screwing and fastening the nut to the male screw portion of the shaft portion, so that it can be manufactured at low cost. .

  A vehicle bearing device according to a third aspect of the present invention is the vehicle bearing device according to the first aspect, wherein the shaft portion is spline-fitted into the insertion hole of the hub unit at a vehicle outer side end portion. A screw hole is formed, and a bolt is screwed into the screw hole from the vehicle outer side to fasten the shaft portion to the hub unit.

  According to the configuration of the third aspect of the present invention, the bolt can be easily fixed to the hub unit by screwing the bolt into the screw hole of the shaft, so that it can be manufactured at low cost.

  A vehicle bearing device according to a fourth aspect of the present invention is the vehicle bearing device according to the first aspect, wherein the end portion on the vehicle outer side of the shaft portion that is spline-fitted into the insertion hole of the hub unit is provided. The shaft unit is fixed to the hub unit by caulking the end of the hub unit on the vehicle outer side.

  According to the fourth aspect of the present invention, the shaft portion is fixed to the hub unit by a simple process of caulking the vehicle outer side end portion of the shaft portion to the vehicle outer side end portion of the hub unit. Therefore, it can be manufactured at low cost.

  A vehicle bearing device according to a fifth aspect of the present invention is the vehicle bearing device according to the second aspect, wherein the male screw portion forming portion of the projecting portion of the shaft portion is the same as the constant velocity joint. Up to a position where the nut screwed to the protruding portion is regulated by the end surface of the hub unit with the shaft portion being spline fitted to the insertion hole so that the end surface contacts the convex curved surface of the caulking portion In addition to the screw forming portion for fastening, at least a screw forming portion required for screwing and fastening the nut further than the restriction position and deforming the convex curved surface of the caulking portion into a flat surface is provided. This is a characteristic configuration.

  According to the fifth aspect of the present invention, the shaft portion is spline-fitted into the insertion hole of the hub unit so that the flat end surface of the constant velocity joint on the vehicle outer side contacts the convex curved surface of the caulking portion. In this state, the nut is screwed into the male screw portion of the projecting portion of the end portion on the vehicle outer side of the shaft portion, so that the position of the projecting portion is reached to the position where the nut is positioned on the end surface on the vehicle outer side of the hub unit. Since the male screw portion is provided with a screw forming portion so that the nut can be screwed and fastened, the nut is fastened to the screw forming portion. Since the part is pulled toward the vehicle outer side, the caulking part is slightly deformed into a flat surface by the flat end surface on the vehicle outer side of the constant velocity joint, and the caulking part can be easily fixed by tightening the nut. The desired flat surface It can be formed. As shown in FIG. 1, the length of the insertion hole 2 of the hub unit 1 in the vehicle inside / outside direction (the length from the rear end of the caulking portion 23 before the nut fastening to the vehicle outer side end surface of the insertion hole 2). However, by setting the length from the end face 24 of the shaft portion of the constant velocity joint to the formation of the male screw portion 25 small, a small amount of the caulking portion by tightening the nut can be obtained without using a special nut. Flattening can be achieved at a low cost. That is, the length of the insertion hole 2 of the hub unit 1 in the vehicle inside / outside direction and the length from the end surface 24 of the shaft portion of the constant velocity joint to the formation of the male screw portion 25 are the same or the former length. However, if the length is shorter than the latter length, a special nut such as a cap nut must be used, resulting in an increase in cost, but this can be solved.

  As described above, according to the vehicle bearing device of the first aspect of the present invention, the caulking portion is formed in a curved state, and in the state where the end surface of the constant velocity joint is applied to the caulking portion, The constant velocity joint and the caulking portion are in a line contact state. However, when the constant velocity joint is fastened with a screw member or the like so as to be close to the hub unit, the caulking portion is brought into contact with the end surface of the constant velocity joint. At the same time, it is plastically deformed, and the caulked portion and the end face of the constant velocity joint are brought into surface contact with each other, so that no undue rattling or gap is generated between the hub unit and the constant velocity joint. At the same time, the curved end edge at the time when the caulking is finished can be made into a flat surface state without further cutting or the like, so that the labor of processing can be omitted. Also, when caulking, it is set so that the force acting from the caulking location on the inner ring of the double row rolling bearing can only be in close contact with the caulking portion, or so that a slight pressing force acts somewhat on the inner ring side. If this is the case, even if the contact portion of the caulking portion with the end face of the constant velocity joint is formed to be somewhat flat due to plastic deformation, an unreasonably large force does not act on the inner ring side. Is maintained well without being unduly large. Furthermore, when fixing the shaft portion of the constant velocity joint to the hub unit, the end surface on the hub unit side of the constant velocity joint is pressed against the caulking portion, and the convex curved surface of the caulking portion is plastically deformed to be somewhat flat. By doing so, the contact state of the constant velocity joint with the hub unit can be brought into surface contact around the entire circumference of the axis, so when steering the vehicle, the moment generated by the force transmitted from the wheel, that is, the axis is Because the contact between the constant velocity joint and the constant velocity joint is a surface contact even with respect to the moment acting between the center double row rolling bearing and the constant velocity joint, the relative relationship between the bearing and the constant velocity joint due to the moment It is possible to prevent the rotational displacement from occurring.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of an embodiment according to claims 1 and 2 of the present invention.

  As shown in FIG. 1, a shaft portion 4 of a constant velocity joint 3 is spline-fitted into an insertion hole 2 of a hub unit 1 for attaching a wheel, and the hub unit 1 is a double row rolling bearing supported on the vehicle body side. 5 is rotatably supported around an axis 6.

  A mounting flange 7 projecting radially outward is formed on the outer peripheral surface of the hub unit 1, and a disk rotor and a wheel of a disk brake device (not shown) are fixed to the circumferential position of the mounting flange 7. The mounting bolt 8 is penetrated.

  The constant velocity joint 3 is connected to the hub unit 1 so as to be able to tilt relative to the hub unit 1, and a well-known member called a Zepper type (Barfield type) is used. The specific configuration of the constant velocity joint 3 includes a ball 10 for tilting and guiding the hub unit 1 with respect to the drive shaft 9, an inner ring 11, a cage 12 for holding the ball 10, etc. (Hereinafter referred to as an outer ring) 13 and the shaft portion 4 integrally connected to the small-diameter side (vehicle outer side) of the outer ring 13. In FIG. 1, the end surface on the small diameter side of the outer ring 13 is in contact with the end surface on the vehicle inner side of the hub unit 1.

  Reference numeral 14 denotes a sealing boot for sealing the constant velocity joint 3, and one end covers the open side of the outer ring 13 of the constant velocity joint 3, and the other end is disposed so as to cover the middle of the drive shaft 9. .

  The double row rolling bearing 5 includes a plurality of balls 15 and 16 as rolling elements arranged in two rows, two crown type cages 17 for holding these balls 15 and 16, an inner ring and an outer ring 18. In addition, as an inner ring raceway, an annular inner ring member 20 fitted to the vehicle inner side of the hub unit 1 and the hub unit 1 is used. That is, the outer peripheral surface of the hub unit 1 is used as the raceway surface of one ball 15 row, and the outer peripheral surface of the annular inner ring member 20 is used as the raceway surface of the other ball 16 row. A radially outward mounting flange 21 that is bolted to a vehicle body or the like is formed on the outer peripheral surface of the outer ring 18 of the double row rolling bearing 5.

  Further, the outer ring 18 of the double row rolling bearing 5 is arranged such that the end surface on the vehicle outer side is close to the mounting flange 7 of the hub unit 1.

  Further, the outer side and the inner side of the double row rolling bearing 5 and the outer peripheral surface of the hub unit 1 (annular inner ring member 20) are sealed with a contact type sealing material 22.

  As shown in FIG. 2, in order to fix and hold the annular inner ring member 20 as the inner ring on the vehicle inner side of the double row rolling bearing 5 to the hub unit 1, the vehicle inner side end portion of the hub unit 1 is plastically deformed. The caulked portion 23 is configured by caulking the enlarged diameter portion toward the vehicle inner side of the annular inner ring member 20 after the diameter is increased. When the caulking portion 23 is caulked, the force acting from the caulking portion on the inner ring of the double row rolling bearing during caulking can be in close contact with the caulking portion, or somewhat closer to the inner ring side. As shown in FIG. 2, the vehicle inner side end surface of the caulking portion 23 has a curved shape in which the cross-sectional shape along the direction of the axis 6 is convex toward the vehicle inner side. It has become. Then, the shaft portion 4 of the constant velocity joint 3 is inserted into the insertion hole 2 in a spline-fitted state without machining the end surface while being caulked, and the vehicle outer side end surface of the outer ring 13 of the constant velocity joint 3 is inserted. In a state in which 24 is in contact with the caulking portion 23, a nut 26 is then attached to a male screw portion 25 that is screwed to a protruding shaft portion as a protruding portion protruding from the vehicle outer side end portion of the insertion hole 2 of the shaft portion 14. The end face 24 is pressed against the caulking portion 23 toward the outer side of the vehicle body by the screwing of the nut 26, whereby the curved portion of the caulking portion 23 is plastically deformed. Thus, as shown in FIG. However, the flat surface is formed by the nut 26 with such a force that the ball 16 does not improperly contact the annular inner ring member 20 and the outer ring 18 by the pressing force acting on the annular inner ring member 20 from the caulking portion 23. Will be concluded. As a result, the caulking portion 23 and the vehicle outer side end surface 24 of the outer ring 13 can be brought into surface contact with each other with a predetermined area, and the width of the caulking portion 23 is substantially the same in the radial direction over the entire circumference around the axis 6. Since contact is made so as to be a contact surface, even when steering is performed as a vehicle, the vehicle can sufficiently withstand a moment generated in the annular inner ring member 20 due to the steering. As shown in FIG. 1, the protruding shaft portion where the male screw portion 25 is formed is a portion that protrudes toward the vehicle outer side with a smaller diameter than the portion where the spline is formed at the vehicle outer side end portion of the shaft portion 4. Say. In the state where the shaft portion 4 is spline-fitted into the insertion hole 2 and the end face 14 of the constant velocity joint 3 is in contact with the caulking portion 23, the axial direction range of the male screw portion 25 formed on the protruding shaft portion In addition to the portion that protrudes from the insertion hole 2 toward the vehicle outer side, the caulking portion 23 is further tightened to the portion of the insertion hole 2 of the hub unit 1 that is in the insertion hole 2 than the end position on the vehicle outer side. Is set so that a very small flat surface can be formed. Accordingly, even when the nut 26 is fastened to the male screw portion 25 and the nut 26 is in contact with the hub unit 1 and the position is restricted, if the screw 26 is further screwed and fastened, the nut 26 connects the shaft 4 to the vehicle. By pulling toward the outer side, the convex curved surface of the caulking portion 23 which is in contact with the end surface 24 is slightly plastically deformed into a flat surface.

  Next, a procedure for assembling the constant velocity joint 3 to the hub unit 1 will be described. First, the vehicle outer side of the shaft portion 4 of the constant velocity joint 3 is aligned with the insertion hole 2 and pushed into this. Then, the shaft portion 4 is spline-fitted with the insertion hole 2 so that the hub unit 1 and the shaft portion 4 are integrally attached to the shaft center 6 so as to be rotatable. Next, when the nut 26 is screwed and fastened to the male screw portion 25, the constant velocity joint 3 itself comes close to the hub unit 1, and the end surface 24 of the constant velocity joint 3 is the curved surface of the caulking portion 23. Since the contact portion with the end surface 24 of the caulking portion 23 is slightly plastically deformed to become a flat surface in accordance with the end surface 24, the line contact state becomes a surface contact state.

(Another embodiment)
Next, an example of another embodiment will be described below. Note that the description of the same structure as the above embodiment is omitted, and the same reference numerals are given.

  As shown in FIG. 4, the shaft portion 4 of the constant velocity joint 3 is spline-fitted along the axis 6 to the insertion hole 2 formed in the hub unit 1. Unlike the above-described embodiment, the shaft portion 4 is formed in a cylindrical shape having a bottom on the vehicle inner side. Then, in order to fix the annular inner ring member 20 of the double-row rolling bearing 5 that rotatably supports the hub unit 1 around the axis 6 to the hub unit 1, the vehicle inner of the hub unit 1 is the same as in the above embodiment. The side end portion is expanded in diameter by a caulking jig, and the annular inner ring member 20 is caulked at the expanded diameter portion. In the caulking portion 23, the cross-sectional shape in the axial direction of the vehicle inner side end surface is a protruding curved surface shape, similar to the caulking portion 23 shown in FIG. 2 in the above embodiment. When the shaft portion 4 is spline-fitted into the insertion hole 2 and the caulking portion 23 and the end face 24 of the constant velocity joint 3 are in contact with each other, the vehicle outer side end portion of the insertion hole 2 It protrudes somewhat from the vehicle outer side end. Then, in order to fix the shaft portion 4 to the hub unit 1, the outer side end portion of the shaft portion 4 is enlarged by a caulking jig, and the enlarged diameter portion 27 is the vehicle outer in the insertion hole 2 of the hub unit 1. Crimp to the side edge. By this caulking, the outer ring 13 of the constant velocity joint is also drawn toward the hub unit 1, so that the end surface 24 of the constant velocity joint 3 is pressed against the caulking portion 23 toward the hub unit 1. As a result, the protruding curved surface shape in the caulking portion 23 is slightly plastically deformed to be somewhat flat so as to be similar to the caulking portion 23 shown in FIG. 3 in the above embodiment. As a result, the end face 24 and the caulking portion 23 are in surface contact over the entire circumference in the circumferential direction centered on the axis 6, and between the hub unit and the outer ring 13 of the constant velocity joint 3 as the vehicle steers. It will be able to withstand the acting moment.

(Another embodiment 2)
As shown in FIG. 5, in the structure similar to the above embodiment, the vehicle outer side end surface 24 of the outer ring 13 of the constant velocity joint 3 is spline fitted to the hub unit 1 and the convex curved surface of the caulking portion 23. In the state of contact, the vehicle outer side end surface of the shaft portion 4 is configured to be located a predetermined distance inward from the vehicle outer side end in the insertion hole 2 of the hub unit, and the shaft center 4 is centered from the vehicle outer side end portion. A single screw hole 27 is formed around the center. Bolts 28 are screwed into the screw holes 27, and the bolts 28 are fastened so that the heads of the bolts 28 are regulated to contact the end face 29 of the hub unit 1 on the vehicle outer side. The constant velocity joint 3 is fixed to the hub unit 1. Even when the bolt 28 is fastened, the vehicle outer side end of the shaft portion 4, which is restrained against the caulking portion 23, is positioned in the insertion hole 2 even before the bolt 28 is fastened. By further tightening than the state of just contacting with the end portion 24, the end surface 24 of the outer ring 13 contacting the caulking portion 23 slightly plastically deforms the caulking portion 23 to bring it into a surface contact state. .

Cross-sectional plan view showing a bearing device for a vehicle Enlarged cross-sectional plan view of the main part before assembling the power joint Expanded cross-sectional plan view of the main part with the power joint assembled Cross-sectional plan view showing a bearing device for a vehicle in another embodiment Cross-sectional plan view showing a vehicular bearing device according to still another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub unit 2 Insertion hole 3 Constant velocity joint 4 Shaft part 5 Double row rolling bearing 6 Axis 9 Drive shaft 20 Annular inner ring member (inner ring)
23 Caulking part 24 End face 25 Male screw part 26 Nut 27 Screw hole 28 Bolt

Claims (5)

A hub unit for wheel mounting, which is supported on a double row rolling bearing supported on the vehicle body so as to be rotatable around the shaft center, and a spline from the vehicle inner side to an insertion hole formed along the shaft center in the hub unit. A shaft portion to be fitted is provided on one end side, and a drive shaft is connected to the other end side with a constant velocity joint interlockingly connected to the hub unit, and an inner ring in the double row rolling bearing is formed at the constant velocity A bearing device for a vehicle, which is disposed near a joint, and is integrated with the hub unit and the inner ring by caulking after expanding the vehicle inner side end of the hub unit on the inner side end surface of the inner ring. And
A cross-sectional shape of the caulking portion that caulks the inner ring from the vehicle inner side along the axial direction on the vehicle inner side is formed as a convex curved surface that protrudes toward the vehicle inner side, and the shaft portion is connected to the hub unit. When connecting and moving relatively toward the vehicle outer side in the axial direction, the flat end surface facing the hub unit side of the constant velocity joint is brought into contact with the convex curved surface of the caulking portion to be on the vehicle outer side A vehicular bearing device, wherein the convex curved surface is slightly plastically deformed by pressing to make the caulking portion and the vehicle outer side end surface of the constant velocity joint in surface contact over the entire circumference. The vehicle bearing device according to claim 1,
The vehicle outer side end portion of the shaft portion that is spline-fitted into the insertion hole of the hub unit protrudes from the vehicle outer side end portion of the insertion hole, and a nut is screwed and fastened to a male screw portion formed in the protruding portion. By doing so, the shaft portion is fixed to the hub unit. The vehicle bearing device according to claim 1,
A screw hole is formed in a vehicle outer side end portion of the shaft portion that is spline-fitted into the insertion hole of the hub unit, and a bolt is screwed into the screw hole from the vehicle outer side to fasten the shaft portion. A vehicle bearing device characterized by being fixed to a hub unit. The vehicle bearing device according to claim 1,
A vehicle outer side end portion of the shaft portion that is spline-fitted into the insertion hole of the hub unit is caulked to a vehicle outer side end portion of the hub unit, and the shaft portion is fixed to the hub unit. A vehicle bearing device. The vehicle bearing device according to claim 2,
The male screw part forming part of the projecting part of the shaft part is a state in which the shaft part is spline-fitted to the insertion hole so that the end surface of the constant velocity joint is in contact with the convex curved surface of the caulking part In addition to the screw forming portion for fastening the nut screwed to the projecting portion to a position regulated by the end face of the hub unit, the nut is screwed and fastened further than the regulation position, and the caulking portion A vehicular bearing device comprising at least a screw forming portion required to deform the convex curved surface to a flat surface.

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