JP2020067149A - Assembling method of hub unit bearing - Google Patents

Abstract

To obtain an assembling method of a hub unit bearing which can make favorable not only a lubrication state of a rolling contact part between and among rolling faces of conical rollers held by a fall prevention cage, an outer ring raceway and an inner ring raceway, but also a lubrication state of a contact part between large-diameter side end parts of the conical rollers and a large flange part.SOLUTION: A roller assembly 17c for holding conical rollers 4c at a cage 12c being a fall prevention cage is arranged at an inside diameter side of an outer ring raceway 6c in a state that the assembly is displaced to a side at which an inside diameter of the outer ring raceway 6c becomes large with respect to an axial direction rather than a regular assembling position, a clearance 38 is thereby formed between the roller assembly 17c and the outer ring raceway 6c, and grease is discharged toward the clearance 38 from a grease sealing jig 39.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method of assembling a hub unit bearing for rotatably supporting a vehicle wheel with respect to a suspension device.

  The wheel of the automobile is rotatably supported by the hub unit bearing with respect to the suspension device. Further, a tapered roller is used as a rolling element in a hub unit bearing for rotatably supporting a heavy vehicle wheel. Further, in recent years, for the purpose of reducing the number of parts and cost, and the like, a so-called third generation hub unit bearing in which an inner ring raceway is directly formed on an outer peripheral surface of a hub ring is also used.

FIG. 15 shows an example of a conventional structure disclosed in Japanese Patent Laid-Open No. 2004-263722, as a third-generation hub unit bearing using tapered rollers as rolling elements. The hub unit bearing 1 is configured by rotatably supporting a hub 3 that rotates together with a wheel and a braking rotating body on the inner diameter side of an outer ring 2 that is fixed to a knuckle of a suspension device by a plurality of tapered rollers 4a and 4b. Has been done.
Regarding the hub unit bearing 1, the outside in the axial direction is the left side in FIG. 15 that is the outside in the width direction of the vehicle when assembled in the vehicle, and the inside in the axial direction is the center side in the width direction of the vehicle when assembled in the vehicle. 15 is the right side of FIG.

  The outer ring 2 has a substantially cylindrical shape, has a stationary flange 5 connected to a knuckle on the outer peripheral surface, and has double rows of outer ring raceways 6a and 6b on the inner peripheral surface. The double-row outer ring raceways 6a and 6b each have a conical surface shape, and their inclination directions are opposite to each other. The outer ring raceway 6a in the outer row located axially outside has a larger inner diameter toward the outer side in the axial direction, and the outer ring raceway 6b in the inner row located axially inward has a larger inner diameter toward the inner side in the axial direction.

  The hub 3 is configured by combining a hub wheel 7 and an inner ring 8, and has a rotary flange 9 for mounting wheels and a braking rotor, and double-row inner ring raceways 10a, 10b. The double-row inner ring raceways 10a and 10b each have a conical surface shape, and their inclination directions are opposite to each other. The outer ring inner ring raceways 10a located on the outer side in the axial direction are formed on the outer peripheral surface of the hub wheel 7, and the outer diameter increases toward the outer side in the axial direction. The inner row orbits 10b of the inner row located axially inward are formed on the outer peripheral surface of the inner ring 8, and the outer diameter increases toward the inner side in the axial direction. The inner ring 8 is externally fitted to a fitting shaft portion 11 provided on the axially inner side portion of the hub wheel 7.

  The tapered rollers 4a and 4b are arranged in a double row, and the tapered rollers 4a in the outer row located axially outside are arranged between the outer ring raceway 6a and the inner ring raceway 10a in the outer row and are axially inward. The tapered roller 4b in the inner row is located between the outer ring raceway 6b and the inner ring raceway 10b in the inner row. The tapered rollers 4a in the outer row are rotatably held by the cage 12a in the outer row, and the tapered rollers 4b in the inner row are rotatably held by the cage 12b in the inner row.

  The space 13 existing between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 is filled with grease. This lubricates the rolling contact portions of the tapered rollers 4a and 4b with the outer ring raceways 6a and 6b and the inner ring raceways 10a and 10b. Further, the grease filled in the space 13 lubricates the contact portion between the large-diameter side end portion of the tapered roller 4a in the outer row and the large flange portion 14a provided in the hub wheel 7, and the large diameter of the tapered roller 4b in the inner row. Lubricate the contact portion between the radial end portion and the large collar portion 14b provided on the inner ring 8. Further, in order to prevent the grease from leaking out from the space 13, the axial outer opening of the space 13 is closed by the outer sealing member 15, and the axial inner opening of the space 13 is closed by the inner sealing member 16.

The hub unit bearing 1 as described above is assembled through the following steps. This will be described below with reference to FIG.
First, the outer row tapered roller 4a and the outer row retainer 12a are combined to obtain the outer row roller assembly 17a. Subsequently, as shown in FIG. 16A, the roller assembly 17a of the outer row is arranged on the inner diameter side of the outer ring raceway 6a of the outer row of the outer ring 2. Then, the outer sealing member 15 is attached to the axially outer end portion of the outer ring 2. Then, as shown in FIG. 16B, the hub wheel 7 is inserted into the inner ring side of the outer ring 2. After that, as shown in (C1) of FIG. 16, the tapered roller 4b of the inner row, the cage 12b of the inner row, and the inner ring 8 having the small flange portion 28 are combined between the outer ring 2 and the hub wheel 7. 16 is incorporated, or as shown in FIG. 16C2, an inner row roller assembly 17b is formed by combining the inner row tapered roller 4b and the inner row retainer 12b. After that, the inner ring 8 having no small collar portion is incorporated.

  When assembling the hub unit bearing 1, the roller assembly 17a of the outer row is arranged on the inner diameter side of the outer ring raceway 6a of the outer row, as described above, in order to ensure the assemblability of the outer sealing member 15. It is necessary to insert the hub wheel 7 into the inner diameter side of the outer ring 2 with the outer sealing member 15 attached to the axially outer end portion of the outer ring 2. For this reason, the cage 12a in the outer row is required to hold the tapered rollers 4a in the outer row inward in the radial direction so as not to fall off. Therefore, as the cage 12a in the outer row, as described in Japanese Patent Application Laid-Open No. 2013-174254, a fall prevention cage having a function of preventing the tapered rollers from falling is used.

  As shown in FIG. 15 and FIG. 16 (A), the retainer 12a in the outer row having a fall-out preventing function is configured in a partially conical tube shape as a whole, and has a small-diameter annular portion 19 and a large-diameter annular ring. It includes a portion 20 and a plurality of pillar portions 21 arranged at equal intervals in the circumferential direction and axially connecting the small-diameter annular portion 19 and the large-diameter annular portion 20. The portion between the column portions 21 adjacent to each other in the circumferential direction is a pocket 22. In addition, the cages 12 a in the outer row are designed so that the tapered roller 4 a is prevented from coming off from the pocket 22 inward in the radial direction, and the shape of the column portion 21 is devised so that the opening portion of the pocket 22 inside in the radial direction is formed. The width in the circumferential direction is made smaller than the diameter of the tapered roller 4a.

JP, 2004-263722, A JP, 2013-174254, A

  However, in the retainer 12a having the fall-out prevention function, the radial dimension of the column portion 21 tends to increase. Therefore, with the roller assembly 17a of the outer row arranged on the inner diameter side of the outer ring raceway 6a of the outer row, so-called grease is discharged in the axial direction between the rolling surface of the tapered roller 4a and the outer ring raceway 6a. Even when an attempt is made to supply grease from the outside in the axial direction by the flat surface encapsulation method, the column portion 21 becomes an obstacle, and grease tends to collect near the large diameter side end of the tapered roller 4a, causing the tapered roller 4a to roll. It becomes difficult to supply a sufficient amount of grease between the surface and the outer ring raceway 6a. As a result, the contact portion between the large diameter side end of the tapered roller 4a and the large flange portion 14a of the hub wheel 7 can be satisfactorily lubricated, but the rolling surface of the tapered roller 4a and the outer ring raceway 6a and the inner ring raceway 10a are not affected. It becomes difficult to improve the lubrication condition of the rolling contact part. If the amount of grease supplied to the large-diameter side end of the tapered roller 4a and the large flange 14a of the hub wheel 7 is too large, grease may leak from the outer sealing member 15.

  Even in the case shown in (C1) of FIG. 16, such a problem is that the same retainer 12b in the inner row is used as the retainer 12b in the outer row, and the inner race assembly 18 is attached to the outer raceway 6b. Occurs when assembling and grease is enclosed in a plane. Further, as shown in (C2) of FIG. 16, the same occurs when an assembling method of incorporating the inner row roller assembly 17b between the outer ring 2 and the hub ring 7 prior to the inner ring 8 is adopted. . That is, when the inner row roller assemblies 17b are assembled prior to the inner ring 8, the inner row retainer 12b must be a fall-prevention retainer. Therefore, with the roller assembly 17b of the inner row arranged on the inner diameter side of the outer ring raceway 6b of the inner row, the grease is applied from the inner side in the axial direction between the rolling surface of the tapered roller 4b and the outer ring raceway 6b by the plane encapsulation method. Even when the tapered roller 4b is supplied, grease tends to collect near the large diameter side end of the tapered roller 4b, and it becomes difficult to supply a sufficient amount of grease between the rolling surface of the tapered roller 4b and the outer ring raceway 6b. However, there is a possibility that grease may leak from the inner sealing member 16.

  In order to solve the above problems, it is possible to apply grease to the outer ring raceways 6a (6b) in advance, for example. In this case, the rolling contact portion of the tapered roller 4a (4b) with the outer ring raceway 6a (6b) and the inner ring raceway 10a (10b) can be satisfactorily lubricated, but the tapered roller 4a (4b) can be lubricated. It becomes difficult to spread the grease sufficiently between the large-diameter side end portion and the large flange portion 14a (14b). As a result, the contact portion between the large-diameter side end portion of the tapered roller 4a (4b) and the large flange portion 14a (14b) has poor lubrication.

  In view of the above-mentioned circumstances, the present invention relates to a hub unit bearing that uses tapered rollers as rolling elements, and a rolling contact portion between the rolling surface of the tapered rollers held by the captive retainer and the outer ring raceway and the inner ring raceway. Not only can the lubrication condition of the hub unit be improved, but the lubrication condition of the contact part between the large diameter side end of the tapered roller and the large collar part can also be improved, and grease leakage from the sealing member can be prevented. It was invented to realize the.

A hub unit bearing which is a target of the hub unit bearing assembling method of the present invention includes an outer ring, a hub, a plurality of tapered rollers, and a cage.
The outer ring has an outer ring raceway on its inner peripheral surface.
The hub has an inner ring raceway on its outer peripheral surface.
The plurality of tapered rollers are arranged between the outer ring raceway and the inner ring raceway.
The cage holds the tapered rollers so that they can roll.
Further, the cage is a fall prevention cage capable of holding the tapered rollers in a radial direction so as not to fall off.

  Particularly, in the hub unit bearing assembling method of the invention, the roller assembly in which the tapered rollers are held in the captive retainer is mounted on the inner diameter side of the outer ring raceway in the outer ring raceway in the axial direction from the normal mounting position. By arranging them in a state of being shifted to the side where the inner diameter increases, a gap is formed between the roller assembly and the outer ring raceway, and grease is discharged from the grease filling jig toward the gap. including.

  In the hub unit bearing assembling method of the present invention, as the captive retainer, a small-diameter annular portion, a large-diameter annular portion having an outer diameter larger than that of the small-diameter annular portion, and at equal intervals in the circumferential direction. A plurality of pillars arranged to axially connect the small-diameter annular portion and the large-diameter annular portion, and rolling the tapered roller at a portion between the pillars adjacent to each other in the circumferential direction. A pocket for movably holding the opening on the radially inner side of the pocket is located on the inner diameter side of the tapered roller's rotation axis at least at an intermediate position in the longitudinal direction of the tapered roller. The width in the circumferential direction is smaller than the diameter of the tapered roller, and the opening on the outer side in the radial direction of the pocket is formed in the entire region in the longitudinal direction of the tapered roller from the rotation axis of the tapered roller. Is also located on the outer diameter side Ri, the circumferential width can be used smaller than the diameter of the tapered rollers.

  In the hub unit bearing assembling method of the invention, in the grease filling step, for example, the grease filling is performed in a state where the tip end portion of the grease filling jig is in contact with the axial end portion of the captive retainer. The grease can be discharged from the tip of the jig toward the gap.

In the hub unit bearing assembling method of the invention, the hub unit bearing further includes an outer sealing member for closing an axial outer opening of a space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. Can be used.
Further, the captive retainer retains the tapered rollers of the outer row in a radial direction so as not to be disengaged, and before mounting the outer sealing member on the outer ring, or mounting the outer sealing member on the outer ring. After that, the grease filling step can be performed.

  In the hub unit bearing assembling method of the present invention, the captive retainer holds the tapered rollers in the inner row in a radial direction so as not to be disengaged, and the hub ring forming the hub is inserted on the inner diameter side of the outer ring. After that, the grease filling step can be performed.

  In the present invention, in the grease filling step, the grease can be discharged from the grease filling jig toward the gap from the large diameter side end of the tapered roller.

  Alternatively, in the present invention, in the grease filling step, grease may be discharged from the grease filling jig toward the gap from the small diameter side end portion side of the tapered roller.

  According to the present invention, with respect to a hub unit bearing using tapered rollers as rolling elements, it is possible to improve the lubrication condition of the rolling contact portion of the tapered roller held by the captive retainer and the outer ring raceway and the inner ring raceway. Not only that, the lubrication condition of the contact portion between the large diameter side end portion of the tapered roller and the large flange portion can be improved, and grease leakage from the sealing member can be prevented.

FIG. 1 is a half sectional view showing a hub unit bearing assembled by an assembly method according to a first example of an embodiment. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view showing a first step of the steps of assembling the hub unit bearing according to the first example of the embodiment. FIG. 4 is a cross-sectional view showing a second step of the steps of assembling the hub unit bearing according to the first example of the embodiment. FIG. 5 is a cross-sectional view showing a fourth step of the steps of assembling the hub unit bearing according to the first example of the embodiment. FIG. 6 is a cross-sectional view showing a fifth step of the steps of assembling the hub unit bearing in the first example of the embodiment, FIG. 6A showing a case where the inner ring assembly is incorporated, and FIG. ) Indicates a case where the inner ring is assembled after the roller assembly of the inner row is assembled. FIG. 7 is a cross-sectional view showing a grease enclosing step of supplying grease to the tapered rollers of the outer row in the hub unit bearing assembling step in the first example of the embodiment. FIG. 8A is a diagram corresponding to FIG. 7, showing a second example of the embodiment, and FIG. 8B is a diagram showing a modification of the second example of the embodiment. . FIG. 9 is a diagram corresponding to FIG. 7, showing a third example of the embodiment. FIG. 10 is a diagram corresponding to FIG. 7, showing a fourth example of the embodiment. FIG. 11 is a diagram corresponding to FIG. 7, showing a fifth example of the embodiment. FIG. 12 is a view corresponding to FIG. 7, showing a fifth example of the embodiment, and FIG. 12A shows a state in which the roller assembly of the inner row is arranged at a regular assembly position, and FIG. ) Indicates a state in which the roller assembly in the inner row is moved upward by using a pulling jig. FIG. 13 is a perspective view showing a front side portion of a pull-up jig used in the fifth example of the embodiment. FIG. 14 is a diagram corresponding to FIG. 7, showing a sixth example of the embodiment. FIG. 15 is a sectional view showing an example of a conventional structure of a hub unit bearing. FIG. 16 is a cross-sectional view showing a part of the assembly process of the hub unit bearing.

[First Example of Embodiment]
A first example of the embodiment will be described with reference to FIGS.
The hub unit bearing 1a to be assembled in this example is a so-called third-generation hub unit bearing that uses tapered rollers as rolling elements, and rotatably supports the wheels of automobiles such as large SUVs and commercial vehicles. It is what you use to do.

The hub unit bearing 1a includes an outer ring 2a that does not rotate in a used state, a hub 3a that rotates together with a braking rotating body such as a wheel and a disk or a drum in a used state, double row tapered rollers 4c and 4d, and two holding members. It is provided with vessels 12c and 12d, an outer sealing member 15a, and an inner sealing member 16a.
Regarding the hub unit bearing 1a, the outboard side, which is the outer side in the axial direction, is the outer side in the width direction of the vehicle when assembled in the vehicle, that is, the left side in FIGS. 1 and 3 to 6, and the inner side in the axial direction. The board side is the right side of FIGS. 1 and 3 to 6, which is the center side in the width direction of the vehicle when assembled to the vehicle.

  The outer ring 2a is made of medium carbon steel such as S53C and has a substantially cylindrical shape. A stationary flange 5a, which is coupled to the knuckle of the suspension device, is provided at an axially intermediate portion of the outer peripheral surface of the outer ring 2a. The inner ring surface of the outer ring 2a has double rows of outer ring raceways 6c and 6d. The double-row outer ring raceways 6c and 6d each have a conical surface shape, and their inclination directions are opposite to each other. The outer ring raceway 6c in the outer row located axially outside has a larger inner diameter toward the outer side in the axial direction, and the outer ring raceway 6d in the inner row located axially inward has a larger inner diameter toward the inner side in the axial direction.

  The hub 3a is arranged coaxially with the outer ring 2a on the inner diameter side of the outer ring 2a, and is formed by combining a hub ring 7a made of medium carbon steel such as S53C and an inner ring 8a made of high carbon chrome steel such as SUJ2. ing. The outer peripheral surface of the hub 3a has double-row inner ring raceways 10c and 10d. The double-row inner ring raceways 10c and 10d each have a conical surface shape, and their inclination directions are opposite to each other. The outer ring inner ring raceway 10c positioned on the outer side in the axial direction has a larger outer diameter toward the outer side in the axial direction, and the inner ring raceway 10d on the inner row located on the inner side in the axial direction has a larger outer diameter toward the inner side in the axial direction. Become.

  The hub wheel 7a is a shaft member for externally fitting and holding the inner ring 8a, and in order from the outer side in the axial direction, the pilot portion 23, the rotary flange 9a, the large flange portion 14c, the inner ring raceway 10c of the outer row, and the fitting shaft. And a portion 11a.

  The pilot portion 23 is for externally fitting the wheel and the braking rotary body, is provided so as to project axially outward from the radial intermediate portion of the axial outer portion of the hub wheel 7a, and has a substantially cylindrical shape. have. The rotary flange 9a is for attaching a wheel and a braking rotary body, is provided on the axially outer side portion of the hub wheel 7a so as to project radially outward, and has a substantially circular ring shape. There is. The large flange portion 14c is for controlling the axial position of the tapered roller 4c in the outer row and for supporting the axial load acting on the tapered roller 4c in the outer row, and is located outside the inner ring raceway 10c in the outer row in the axial direction. Is provided adjacent to. The inner side surface of the large flange portion 14c in the axial direction inclines toward the inner side in the axial direction toward the outer side in the radial direction, and is in contact with and faces the large diameter side end portion of the tapered roller 4c in the outer row. The outer ring inner ring raceways 10c are formed in the axially intermediate portion of the outer peripheral surface of the hub wheel 7a. The fitting shaft portion 11a is provided on the inner side in the axial direction of the hub wheel 7a, and the inner ring 8a is externally fitted by interference fitting. The outer peripheral surface of the fitting shaft portion 11a and a portion of the outer peripheral surface of the hub wheel 7a that is adjacent to the inner side of the outer ring inner ring raceways 10c in the axial direction are connected via a step surface 24. Further, a caulking portion 25 bent outward in the radial direction is formed at the axially inner end portion of the fitting shaft portion 11a.

  Note that, instead of the structure in which the caulking portion 25 is formed at the axially inner end portion of the hub wheel 7a, a structure in which a nut is screwed to the axially inner end portion of the hub wheel 7a can also be adopted. Further, since the hub unit bearing 1a of the present example is for a driven wheel, the hub ring 7a has a solid shape, but the present invention is also applicable to a hub unit bearing for a drive wheel. When applied to a hub unit bearing for a drive wheel, as shown in FIG. 15, a spline hole for engaging a spline shaft, which is a drive shaft member, is provided at the center of the hub wheel 7a in the radial direction. It is formed so as to penetrate in the direction.

  The inner ring 8a has an annular shape, and is fitted onto the fitting shaft portion 11a provided on the inner side in the axial direction of the hub wheel 7a by interference fitting. Further, the axially outer end surface of the inner ring 8a is abutted against the step surface 24, and the axially inner end surface of the inner ring 8a is restrained by the caulking portion 25. The inner ring 8a has an inner ring raceway 10d in the inner row at the axially intermediate portion of the outer peripheral surface. Further, the inner ring 8a has a large flange portion 14d that projects radially outward at an axially inner portion adjacent to the inner side of the inner ring raceway 10d in the axial direction. The large flange portion 14d prevents the tapered rollers 4d in the inner row from falling off in the axial direction, and supports the axial load acting on the tapered rollers 4d in the inner row.

  The tapered rollers 4c and 4d are made of high carbon chrome steel such as SUJ2 and each have a tapered shape. The tapered rollers 4c and 4d are arranged in double rows, and the tapered rollers 4c in the outer row located axially outside are arranged between the outer ring raceway 6c in the outer row and the inner ring raceway 10c in the outer row, and The tapered roller 4d of the inner row located on the inner side in the direction is arranged between the outer ring raceway 6d of the inner row and the inner ring raceway 10d of the inner row. A preload is applied to the tapered roller 4c in the outer row and the tapered roller 4d in the inner row together with the contact angle of the back surface combination type.

  The cages 12c and 12d are called cage cages, are made of synthetic resin, and are entirely configured in a partially conical tube shape. Of the cages 12c and 12d, the cage 12c in the outer row located axially outside holds the tapered rollers 4c in the outer row rotatably, and the cage 12d in the inner row located axially inward. Holds rotatably the tapered rollers 4d in the inner row.

  Examples of the synthetic resin forming the cages 12c and 12d include polyamide-based resins such as polyamide 46 and polyamide 66, polybutylene terephthalate, polyphenylene sulfide (PPS), polyamide imide (PAI), thermoplastic polyimide, polyether ether ketone. (PEEK), polyether nitrile (PEN), etc. can be used. Moreover, rigidity and dimensional accuracy can be improved by appropriately adding 10 to 50 wt% of a fibrous filler (for example, glass fiber or carbon fiber) to these resins.

  In this example, both the outer row retainer 12c and the inner row retainer 12d have a structure for preventing the tapered rollers 4c and 4d from falling out of the pockets 22a of the retainers 12c and 12d. It is used as a container (roller fall prevention cage). The retainer 12c in the outer row and the retainer 12d in the inner row are the same parts and are different only in the assembling direction with respect to the hub unit bearing 1a. Therefore, in the following, only the outer row holders 12c will be described in detail.

  The retainer 12c is provided with an annular small-diameter annular portion 19a, an annular large-diameter annular portion 20a larger in diameter than the small-diameter annular portion 19a, and equidistantly in the circumferential direction. 19a and the large-diameter annular portion 20a are provided in the axial direction, and a plurality of pillar portions 21a are provided. The portion between the column portions 21a adjacent to each other in the circumferential direction is a pocket 22a. In the cage 12c in the outer row, the small-diameter annular portion 19a is arranged axially inside, and the large-diameter annular portion 20a having an outer diameter larger than that of the small diameter annular portion 19a is arranged axially outside. In addition, in the cage 12d in the inner row, the small-diameter annular portion 19a is arranged outside in the axial direction and the large-diameter annular portion 20a is arranged inside in the axial direction.

  The column portion 21a is inclined in a direction outward in the radial direction with increasing distance from the small-diameter annular portion 19a, and the radial dimension is increased over the entire axial length. The small-diameter side end portion of the column portion 21a is connected to the small-diameter annular portion 19a over the entire radial width, but the large-diameter side end portion of the column portion 21a has only the radially outer portion formed into the large-diameter annular portion 20a. It is connected. Therefore, the large-diameter side portion of the column portion 21a protrudes radially inward from the large-diameter annular portion 20a. The radially outer surface of the column portion 21a is arranged substantially parallel to the outer ring raceways 6c in the outer row and closely faces them. Further, the radially inner side surface of the column portion 21a is arranged substantially parallel to the inner ring raceways 10c of the outer row and closely faces each other. For this reason, the opening on the radially inner side of the pocket 22a is located on the inner diameter side of the rotation axis of the tapered roller 4c at least at an intermediate position in the longitudinal direction of the tapered roller 4c. On the other hand, the radially outer opening of the pocket 22a is located on the outer diameter side of the rotation axis of the tapered roller 4c in the entire area of the tapered roller 4c in the longitudinal direction.

In order to prevent the tapered roller 4c from coming off from the pocket 22a inward in the radial direction, as shown in FIG. 2, the cross-sectional shape of the side surface of the column portion 21a in the circumferential direction is made concave so that the tapered roller 4c is formed in the circumferential direction. Holds from both sides. In the illustrated example, of the circumferential side surfaces of the column portion 21a, the radially outer portion is the arc-shaped portion 27a and the radially inner portion is the flat portion 27b. The circumferential width W _in of the opening on the radially inner side of the pocket 22a is made smaller than the diameter D of the tapered roller 4c (W _in <D). With such a structure, the tapered rollers 4c are prevented from coming off from the pockets 22a inward in the radial direction. Further, in this embodiment, for the circumferential width _{W OUT} of the opening of the radially outer pockets 22a, is smaller than the diameter D of the tapered rollers 4c _(W OUT <D). Therefore, the tapered rollers 4c are also prevented from falling out of the pockets 22a in the radial direction. The work of incorporating the tapered roller 4c into the pocket 22a can be performed by pushing the tapered roller 4c from the radially inner side of the pocket 22a to the column portion 21a in the circumferential direction.

  The outer sealing member 15a is internally fitted and fixed to the inner peripheral surface of the outer side portion of the outer ring 2a in the axial direction. The outer sealing member 15a is configured in an annular shape as a whole, and includes a cored bar 29 made of a metal plate and a sealing material 30 made of an elastic material that is fixedly coupled to the cored bar 29. The cored bar 29 is press-fitted onto the inner peripheral surface of the outer ring 2a in the axially outer side portion. The sealing material 30 has a plurality of (three in the illustrated example) seal lips 31 a to 31 c on the radially inner side and an auxiliary lip 32 on the radially outer side. Each of the plurality of seal lips 31a to 31c has its tip portion located on a portion of the outer peripheral surface of the hub wheel 7a that is located between the axially inner side surface of the rotary flange 9a and the outer peripheral surface of the large flange portion 14c. The entire circumference is in sliding contact. The auxiliary lip 32 closely faces the radially inner portion of the inner surface of the rotary flange 9a in the axial direction with a minute gap therebetween. This prevents the grease filled in the space 13a existing between the inner peripheral surface of the outer ring 2a and the outer peripheral surface of the hub 3a from leaking out from the axially outer opening of the space 13a and prevents muddy water from the outside. Dust is prevented from entering the space 13a.

  The inner sealing member 16a is a so-called cover member, and is internally fitted and fixed to the axially inner portion of the outer ring 2a. The inner sealing member 16a is made of a metal plate and has a bottomed cylindrical shape as a whole. The inner sealing member 16a has a cylindrical fixed cylindrical portion 33 and a disk-shaped bottom plate portion 34 extending radially inward from an axial inner end of the fixed cylindrical portion 33. The inner sealing member 16a closes the axially inner opening of the outer ring 2a by press-fitting the fixed cylindrical portion 33 into the inner peripheral surface of the inner side portion of the outer ring 2a in the axial direction. This prevents the grease filled in the space 13a from leaking to the outside through the axially inner opening of the outer ring 2a, and prevents muddy water and dust from entering the space 13a. As the inner sealing member 16a, a combination seal ring mounted between the outer ring 2a and the inner ring 8a as shown in FIG. 15 may be used instead of the cover member as in this example.

The hub unit bearing 1a of this example as described above is assembled through the following first to seventh steps.
First, in the first step, as shown in FIG. 3, the tapered rollers 4c in the outer row are held inside the pockets 22a constituting the cage 12c in the outer row so as not to fall off radially inward and radially outward. Then, the outer row roller assemblies 17c are obtained. That is, in the state in which the roller assembly 17c is configured, the tapered rollers 4c are held by the cage 12c without being separated.

  In the subsequent second step, as shown in FIG. 4, the outer row roller assemblies 17c obtained in the first step are assembled to the outer ring raceways 6c of the outer row of the outer ring 2a. At this time, the roller assembly 17c of the outer row and the outer ring 2a are coaxially arranged, the axial position of the roller assembly 17c of the outer row with respect to the outer ring 2a is restricted, and the roller assembly 17c of the outer row is normally assembled. Place in position. Specifically, the roller assemblies 17c in the outer row are arranged at the axial positions in the assembled state of the hub unit bearing 1, and the rolling surfaces of the tapered rollers 4c are brought into contact with the outer ring raceway 6c. In this state, the roller assembly 17c in the outer row is separably combined with the outer ring 2a.

  In the subsequent third step, the outer sealing member 15a is attached to the axially outer portion of the outer ring 2a. Specifically, the cored bar 29 forming the outer sealing member 15a is press-fitted into the inner peripheral surface of the outer side portion of the outer ring 2a in the axial direction.

  In the subsequent fourth step, as shown in FIG. 5, the hub ring 7a is inserted into the inner ring side of the outer ring 2a from the outside in the axial direction. Then, the rolling surface of the tapered roller 4c in the outer row is brought into contact with the inner ring raceway 10c in the outer row. Further, the plurality of seal lips 31a to 31c forming the outer sealing member 15a are brought into contact with the outer peripheral surface of the hub wheel 7a over the entire circumference, and the auxiliary lip 32 is radially inward of the inner surface in the axial direction of the rotary flange 9a. To face the section closely. As a result, an intermediate assembly 35 (see FIG. 6) is obtained in which the outer ring 2a, the outer row roller assembly 17c, the outer sealing member 15a, and the hub ring 7a are combined.

  In the subsequent fifth step, as shown in FIG. 6A, the tapered roller 4d in the inner row and the cage 12d in the inner row are provided between the outer ring 2a and the hub ring 7a that form the intermediate assembly 35. The inner ring assembly 18a formed by combining the inner ring 8a having the small collar portion 28 is incorporated, or, as shown in FIG. 6B, the tapered roller 4d of the inner row and the cage 12d of the inner row are provided. After the inner row roller assembly 17d is assembled, the inner ring 8a having no small collar portion is installed. In any case, the inner ring 8a is fitted and fixed to the fitting shaft portion 11a of the hub wheel 7a by interference fitting.

  In the subsequent sixth step, the caulking portion 25 (see FIG. 1) is formed on the inner side in the axial direction of the fitting shaft portion 11a by performing, for example, swing forging. As a result, the axially inner end surface of the inner ring 8a is held down by the caulking portion 25.

  In the seventh step, the inner sealing member 16a is mounted on the inner peripheral surface of the axially inner end of the outer ring 2a. This closes the axially inner opening of the outer ring 2a.

The hub unit bearing 1a is assembled through the above-described first to seventh steps, but in this example, in particular, lubrication of the tapered roller 4c in the outer row held by the retainer 12c in the outer row, which is a captive retainer. In order to improve the condition, the following grease encapsulation process is performed between the second process and the third process.
In this example, the grease filling process for the tapered rollers 4d in the inner row will not be described, but will be described in the fourth to seventh examples of the embodiment described later.

  In the grease filling process of this example, as shown in FIG. 7, the roller assembly 17c of the outer row is assembled to the outer ring raceway 6c of the outer row at a regular assembly position, and the roller assembly 17c of the outer row is assembled. And, the central axis of the outer ring 2a is arranged in the vertical direction. Specifically, the lower surface, which is the axially inner side surface of the stationary flange 5a of the outer ring 2a, is placed on the upper surface of the support base 36 with the outer side portion of the outer ring 2a facing upward.

  Then, the small-diameter annular portion 19a of the retainer 12c is pushed up by the substantially cylindrical push-up jig 37 arranged on the inner diameter side of the outer ring 2a, and only the roller assembly 17c of the outer row is lifted up. That is, the roller assemblies 17c in the outer row are moved upward relative to the outer ring 2a. Then, the roller assemblies 17c in the outer row are arranged at a position displaced to the upper side, which is the side where the inner diameter of the outer ring raceway 6c is larger than the regular assembly position. Since the tapered roller 4c is restricted from being displaced radially outward by the column portion 21a, the rolling surface of the tapered roller 4c is spaced radially inward from the outer ring raceway 6c, and the column portion forming the cage 12c is formed. The radially outer surface of 21a is spaced radially inward from the outer ring raceway 6c. Then, a gap 38 is formed between the outer row roller assembly 17c and the outer row outer ring raceway 6c. The gap 38 axially communicates with spaces located on both sides in the axial direction of the roller assemblies 17c in the outer row, and is connected over the entire circumference. In addition, the gist of the present invention is to move the outer row roller assemblies 17c axially outward from the regular assembly position in a state of being coaxial with the outer ring 2a to create a gap 38 for enclosing grease, It is to facilitate the filling of grease. Therefore, in this example and each example of the embodiment described later, the structure in which the central axes of the roller assembly 17c (17d) and the outer ring 2a are arranged in the up-down direction is shown, and the description is also given in the arrangement direction of the central axis. However, in the case of carrying out the present invention, the arrangement direction of the center axis of the roller assembly 17c (17d) and the outer ring 2a is not limited to the vertical direction, and other directions such as horizontal direction and diagonal direction are also possible. The direction of can be adopted. When the center axes of the roller assembly 17c (17d) and the outer ring 2a are arranged in a direction other than the vertical direction, it is desirable to provide a centering mechanism 46 as shown in FIG. 8B, for example. .

  As described above, if the gap 38 is formed between the outer row roller assembly 17c and the outer row outer ring raceway 6c, a so-called plane enclosing jig arranged above the outer row roller assembly 17c is used. Grease is discharged from a substantially annular grease sealing jig 39 toward the gap 38. Specifically, the lower end which is the tip of the grease sealing jig 39 is inserted inside the upper end of the outer ring 2a (the outer end in the axial direction) without rattling. Then, the grease is discharged from the discharge port 40 in a state where the discharge port 40 opened on the lower end surface of the grease sealing jig 39 faces the radially outer side portion of the large diameter side end surface of the tapered roller 4c. As a result, as shown by the arrow X, the grease is moved radially outward along the large-diameter side end surface of the tapered roller 4c and fed into the gap 38. At this time, the tip portion of the grease sealing jig 39 is brought into contact with the upper end portion of the large-diameter annular portion 20a forming the cage 12c in the outer row. As a result, grease is discharged from the grease sealing jig 39 in a state in which the posture and the axial position of the roller assembly 17c in the outer row are regulated. Note that a structure in which a plurality of discharge ports 40 are evenly arranged in the circumferential direction can be adopted on the lower end surface of the grease sealing jig 39, or one annular discharge port 40 that is continuous in the circumferential direction can be adopted. It is also possible to adopt a structure provided only.

  After the grease is supplied to the gap 38 as described above, the push-up jig 37 is lowered to return the outer row roller assemblies 17c to the regular assembly position. Then, the 3rd process mentioned above is implemented.

  The work of lifting the roller assembly 17c in the outer row by the push-up jig 37 may be performed while the roller assembly 17c in the outer row is clamped by the push-up jig 37 and the grease enclosing jig 39 from both sides in the vertical direction. it can. In this example, since the grease enclosing jig 39 is arranged on the upper side of the roller assembly 17c in the outer row, the grease enclosing step is performed before the outer sealing member 15a is attached to the axially outer side portion of the outer ring 2a.

In this example in which the grease filling process is performed as described above, the rolling surface of the tapered roller 4c of the outer row held by the retainer 12c of the outer row, which is the retaining cage, the outer ring raceway 6c and the inner ring raceway of the outer row. Not only can the sliding contact portion with 10c be lubricated well, but the contact portion between the large diameter side end of the tapered roller 4c and the large collar portion 14c of the hub wheel 7a can be lubricated well. Further, it is possible to prevent grease leakage from the outer sealing member 15a.
That is, the roller assembly 17c of the outer row is arranged at a position displaced to the upper side, which is the side where the inner diameter of the outer ring raceway 6c is larger than the regular assembly position, and the roller assembly 17c of the outer row and the outer ring raceway of the outer row are arranged. The grease is discharged with a gap 38 formed between the grease and 6c. Therefore, a sufficient amount of grease can be applied between the rolling surface of the tapered roller 4c and the outer ring raceway 6c. Therefore, the lubrication state of the rolling contact portion between the rolling surface of the tapered roller 4c and the outer ring raceway 6c and the inner ring raceway 10c can be improved. Further, since the grease discharged from the grease sealing jig 39 adheres also to the large diameter side end face of the tapered roller 4c, a sufficient amount of grease can be applied near the large diameter side end of the tapered roller 4c. . Therefore, it is possible to improve the lubrication condition of the contact portion between the large-diameter side end portion of the tapered roller 4c and the large flange portion 14c, and it is possible to effectively prevent the contact portion from being poorly lubricated. Furthermore, since a large amount of grease does not accumulate near the large diameter side end of the tapered roller 4c, it is possible to prevent grease from leaking from the outer sealing member 15a.

[Second Example of Embodiment]
A second example of the embodiment will be described with reference to FIG.
Also in the case of this example, the grease filling process is performed for the tapered rollers 4c in the outer row, but the timing and the specific method of performing the grease filling process are different from those in the first example of the embodiment. In this example, the grease sealing step is performed after the outer sealing member 15a is assembled to the outer side portion of the outer ring 2a in the axial direction. That is, the grease filling step is performed between the third step of mounting the outer sealing member 15a and the fourth step of inserting the hub wheel 7a on the inner diameter side of the outer ring 2a.

  In the grease filling step of this example, as shown in FIG. 8A, the roller assembly 17c of the outer row is assembled to the outer ring raceway 6c of the outer row at a regular assembly position, and the outer ring 2a is axially outer side. With the outer sealing member 15a attached to the portion, the central axes of the outer row roller assemblies 17c and the outer ring 2a are arranged in the vertical direction. Specifically, the roller assembly 17c of the outer row is mounted on the upper surface of the substantially cylindrical grease sealing jig 39a arranged on the inner diameter side of the outer ring 2a with the axially outer portion of the outer ring 2a facing upward. Place. At this time, the lower end portion of the small-diameter annular portion 19a forming the outer row of retainers 12c is brought into contact with the upper end surface which is the tip end surface of the grease sealing jig 39a. Further, in this example, the outer ring 2a is not supported from below as in the case of the first example of the embodiment.

  As described above, when the outer row roller assemblies 17c are placed on the grease sealing jig 39a, the outer ring 2a is kept until the outer sealing member 15a (core 29) contacts the large-diameter annular portion 20a of the cage 12c. However, due to its own weight, it moves downward relative to the roller assembly 17c and the grease sealing jig 39a in the outer row. As a result, the roller assemblies 17c in the outer row are arranged at a position displaced to the upper side, which is the side where the inner diameter of the outer ring raceway 6c is larger than the regular assembly position. As a result, the gap 38 can be formed between the outer row roller assembly 17c and the outer row outer ring raceway 6c.

  If a gap 38 is formed between the roller assembly 17c of the outer row and the outer ring raceway 6c of the outer row, the grease enclosing jig 39a that supports the roller assembly 17c of the outer row moves toward the grease 38 toward the gap 38. Is discharged. Specifically, the grease is discharged along the inclination direction of the gap 38 from the discharge port 40a that is open to the radially outer side of the upper end surface of the grease sealing jig 39a.

  In this example as described above, the weight of the outer ring 2a can be used to shift the roller assembly 17c in the outer row from the regular assembly position. Therefore, the push-up jig 37 (see FIG. 7) used in the first example of the embodiment can be omitted. Therefore, the equipment required for the grease filling step can be simplified and the manufacturing cost of the hub unit bearing 1a can be kept low.

Further, in this example, grease is discharged from the small diameter side end portion side (lower side) of the outer row tapered rollers 4c, but the gap 38 is communicated to the large diameter side end portion side (upper side) of the tapered roller 4c. Therefore, a sufficient amount of grease can be supplied to the contact portion between the large diameter side end portion of the tapered roller 4c and the large flange portion 14c. Further, since the large-diameter annular portion 20a of the cage 12c and the outer sealing member 15a are in contact with each other, the grease that has moved to the large-diameter side end of the tapered roller 4c through the gap 38 leaks out. Can be effectively prevented. Further, since the cored bar 29 of the outer sealing member 15a is brought into contact with the large-diameter annular portion 20a, the outer sealing member 15a may be damaged by the contact with the large-diameter annular portion 20a. Absent. Further, as shown in a modified example in FIG. 8B, in the grease filling step of this example, the center axes of the roller assembly 17c and the outer ring 2a in the outer row are set in a horizontal direction (or in a vertical direction such as an oblique direction). Direction). In this case, for example, by providing the centering mechanism 46 configured by locking the projection provided on the large-diameter annular portion 20a of the retainer 12c to a part of the outer sealing member 15a, A configuration in which the roller assembly 17c is arranged coaxially with the outer ring 2a can be adopted. In this way, even when the outer rows of roller assemblies 17c and the outer ring 2a are arranged with their central axes oriented in directions other than the vertical direction, the outer rows of roller assemblies 17c are moved axially outward from their normal assembly positions. Then, a gap 38 for enclosing the grease is formed.
Other configurations and operational effects are the same as those of the first example of the embodiment.

[Third Example of Embodiment]
A third example of the embodiment will be described with reference to FIG.
Also in the case of this example, after the outer sealing member 15a is assembled to the axially outer side portion of the outer ring 2a, the grease filling step is performed for the tapered rollers 4c in the outer row, but a specific method of the grease filling step is , Which is different from the second example of the embodiment.

  In the grease filling process of this example, as shown in FIG. 9, the roller assembly 17c of the outer row is assembled to the outer ring raceway 6c of the outer row at a regular assembly position, and the outer ring 2a is sealed to the outer side in the axial direction. With the member 15a attached, the roller assemblies 17c in the outer row and the central axes of the outer races 2a are arranged vertically. Specifically, the lower surface, which is the axially outer surface of the stationary flange 5a of the outer ring 2a, is placed on the upper surface of the support base 36a with the outer side portion of the outer ring 2a facing downward.

  As described above, when the outer ring 2a is placed on the support base 36a, the roller assembly 17c of the outer row is moved until the large-diameter annular portion 20a of the retainer 12c abuts the outer sealing member 15a (core metal 29). Due to its own weight, it moves downward relative to the outer ring 2a. As a result, the roller assemblies 17c in the outer row are arranged at positions shifted downward from the regular assembly position, which is the side where the inner diameter of the outer ring raceway 6c is larger. As a result, the gap 38 can be formed between the outer row roller assembly 17c and the outer row outer ring raceway 6c.

  If the gap 38 is formed between the roller assembly 17c of the outer row and the outer ring raceway 6c of the outer row, the grease inserted into the inner diameter side of the outer ring 2a and arranged on the upper side of the roller assembly 17c of the outer row. Grease is discharged from the enclosing jig 39b toward the gap 38. Specifically, the grease is discharged along the inclination direction of the gap 38 from the discharge port 40b that is open to the radially outer portion of the lower end surface of the grease sealing jig 39b.

In this example as described above, the weight of the roller assembly 17c in the outer row can be used to shift the roller assembly 17c in the outer row from the regular assembly position. Therefore, similarly to the second example of the embodiment, the equipment required for the grease filling step can be simplified and the manufacturing cost of the hub unit bearing 1a can be kept low.
Other configurations and operations are the same as those of the first and second examples of the embodiment.

[Fourth Example of Embodiment]
A fourth example of the embodiment will be described with reference to FIG.
In this example, a grease filling step will be described which is performed for the tapered rollers 4d in the inner row when the hub unit bearing 1a shown in the first example of the embodiment is assembled.

  In this example, when assembling the hub unit bearing 1a, the above-described first to fourth steps are sequentially performed to combine the outer ring 2a, the outer row roller assembly 17c, the outer sealing member 15a, and the hub ring 7a. The intermediate assembly 35 is obtained. Then, in the following fifth step, as shown in FIG. 6B, the inner row of tapered rollers 4d and the inner row of retainers 12d are combined between the outer ring 2a and the hub ring 7a. After the roller assembly 17d of the inner row is assembled, the inner ring 8a having no small collar portion is assembled. In this example, the grease filling step is performed before the work of incorporating the inner ring 8a.

  In the grease filling step of this example, as shown in FIG. 10, the central axis of the intermediate assembly 35 is arranged in the vertical direction. Specifically, the lower surface, which is the axially inner side surface of the stationary flange 5a of the outer ring 2a, is placed on the upper surface of the support base 36 with the outer side portion of the outer ring 2a facing upward. Then, between the outer ring 2a and the hub wheel 7a, the roller assembly 17d for the inner row, which is formed by combining the tapered roller 4d for the inner row and the cage 12d for the inner row, is inserted from below. In this example, while the roller assembly 17d of the inner row is placed on the upper end surface of the annular grease enclosing jig 39c, the grease enclosing jig 39c is lifted to move the roller assembly 17d of the inner row. It is inserted between the outer ring 2a and the hub ring 7a. Then, the roller assembly 17d of the inner row is arranged on the inner diameter side of the outer ring raceway 6d of the inner row with the central axis arranged vertically.

  In this example, by adjusting the amount of rise of the grease sealing jig 39c, the roller assembly 17d in the inner row is moved to the lower side (the inner side in the axial direction) where the inner diameter of the outer ring raceway 6d is larger than the regular assembly position. ) Place it in a position displaced from. Since the tapered roller 4d is restricted from being displaced outward in the radial direction by the column portion 21a, the rolling surface of the tapered roller 4d is arranged at a position separated from the outer ring raceway 6d inward in the radial direction. The radially outer surface of the column portion 21a that constitutes 12d is arranged at a position spaced radially inward from the outer ring raceway 6d. Therefore, a gap 38a is formed between the roller assembly 17d in the inner row and the outer ring raceway 6d in the inner row. The gap 38a axially communicates with spaces located on both axial sides of the inner row of roller assemblies 17d, and is connected over the entire circumference.

  As described above, if the gap 38a is formed between the roller assembly 17d of the inner row and the outer ring raceway 6d of the inner row, from the grease enclosing jig 39c supporting the roller assembly 17d of the inner row to the gap 38a. To discharge the grease. Specifically, the grease is discharged toward the large-diameter side end surface of the tapered roller 4d from the discharge port 40c that is open to the radially outer side of the upper end surface of the grease sealing jig 39c. Then, the grease is moved radially outward along the large-diameter side end surface of the tapered roller 4d, and is fed into the gap 38a.

In this example as described above, the rolling contact portion of the tapered roller 4d of the inner row held by the retainer 12d of the inner row, which is the fall prevention cage, and the rolling contact portion of the outer ring raceway 6d and the inner ring raceway 10d of the inner row. Not only can the lubricating condition of No. 2 be improved, but also the lubricating condition of the contact portion between the large diameter side end of the tapered roller 4d and the large flange 14d of the inner ring 8a can be improved. Further, since a large amount of grease does not accumulate near the large diameter side end of the tapered roller 4d, for example, even when a combination seal ring mounted between the outer ring 2a and the inner ring 8a is used as the inner sealing member 16a, It is possible to prevent grease from leaking from the inner sealing member 16a.
Other configurations and operational effects are the same as those of the first example of the embodiment.

[Fifth Example of Embodiment]
A fifth example of the embodiment will be described with reference to FIG.
Also in the case of this example, the grease filling step is performed for the tapered rollers 4d in the inner row, and in the fifth step of the assembly process of the hub unit bearing 1a, the inner row is inserted between the outer ring 2a and the hub ring 7a. After incorporating the roller assembly 17d and before incorporating the inner ring 8a, a grease filling step is performed. However, in this example, unlike the fourth example of the embodiment, the grease filling step is performed in a state where the outer side portion of the outer ring 2a in the axial direction faces downward.

  In the grease filling step of this example, as shown in FIG. 11, the collet in which the roller assembly 17d of the inner row arranged on the inner diameter side of the outer ring raceway 6d of the inner row is inserted on the inner diameter side of the roller assembly 17d of the inner row Using a substantially cylindrical pull-up jig 41 such as a chuck, the pull-up jig 41 is pulled up. Specifically, the locking flange portion 42 formed at the front end portion (lower end portion) of the pulling jig 41 and bent outward in the radial direction is locked to the small diameter side end portion of the tapered roller 4d, and The row roller assembly 17d is pulled up. As a result, the roller assemblies 17d in the inner row are moved upward relative to the outer ring 2a. Then, the roller assembly 17d of the inner row is arranged at a position displaced to the upper side, which is the side where the inner diameter of the outer ring raceway 6d is larger than the regular assembly position. As a result, the rolling surface of the tapered roller 4d is separated from the outer ring raceway 6d inward in the radial direction, and the radially outer surface of the column portion 21a forming the cage 12d is separated from the outer ring raceway 6d inward in the radial direction. Then, a gap 38a is formed between the inner row roller assembly 17d and the inner row outer ring raceway 6d.

  As described above, when the gap 38a is formed between the roller assembly 17d in the inner row and the outer ring raceway 6d in the inner row, the gap is inserted from the grease sealing jig 39d arranged above the roller assembly 17d in the inner row. The grease is discharged toward 38a. Specifically, the grease is discharged toward the gap 38a from the discharge port 40d which is open to the radially outer side of the lower end surface of the grease sealing jig 39d.

In this example as described above, since the grease filling step is performed with the outer side portion of the outer ring 2a facing downward, the grease passes through the gap 38a between the inner row roller assembly 17d and the outer ring raceway 6d. It becomes easy to supply the grease to the roller assemblies 17c in the outer row.
Other configurations and operational effects are the same as those of the first and fourth examples of the embodiment.

[Sixth Example of Embodiment]
A sixth example of the embodiment will be described with reference to FIGS. 12 and 13.
This example is a modification of the fifth example of the embodiment, and is different from the fifth example of the embodiment only in the structure of the lifting jig 41a used when pulling up the roller assembly 17d in the inner row. .

  The pull-up jig 41a has a substantially cylindrical shape, and its front side portion is configured to be capable of expanding its diameter. Therefore, as shown in FIG. 13, a plurality of slits 43 extending in the axial direction are formed in a range from the tip (lower end) to the middle of the pulling jig 41a, and the slits 43 adjacent to each other in the circumferential direction are formed. The intervening part is a band-shaped part 44. Further, on the inner peripheral surface of the tip end portion of the band-shaped portion 44, a protrusion portion 45 protruding inward in the radial direction is provided. The protruding portion 45 has a substantially semicircular cross-sectional shape, and the radially inner side surface of the lower half portion is inclined toward the radially inner side as it goes upward. As shown in FIG. 12 (B), such a band-shaped portion 44 is formed by the protrusion 45 formed at the tip end riding on the outer peripheral edge portion of the step surface 24 formed on the outer peripheral surface of the hub wheel 7a. , Elastically deforms outward in the radial direction (expands in diameter).

  In this example, the pulling jig 41a as described above is inserted into the inner row roller assembly 17d while the inner row roller assembly 17d is arranged on the inner row outer ring raceway 6d. To do. Then, the protruding portion 45 of the strip-shaped portion 44 rides on the outer peripheral edge portion of the step surface 24, so that the front side portion of the strip-shaped portion 44 is expanded in diameter. Then, the outer peripheral surface of the belt-shaped portion 44 pushes up the small diameter side end portion of the tapered roller 4d in the inner row toward the upper side. Thereby, the roller assembly 17d of the inner row is relatively moved upward with respect to the outer ring 2a, and the roller assembly 17d of the inner row is moved to the upper side where the inner diameter of the outer ring raceway 6d is larger than the normal assembly position. Place it in a displaced position.

In this example as described above, the structure of the lifting jig 41a can be simplified. Therefore, the manufacturing cost of the hub unit bearing 1a can be kept low.
Other configurations and operational effects are the same as those of the first, fourth, and fifth examples of the embodiment.

[Seventh Example of Embodiment]
A seventh example of the embodiment will be described with reference to FIG.
Also in the case of this example, the grease filling step is performed for the tapered rollers 4d in the inner row, but as shown in FIG. 6A in the fifth step of the assembly process of the hub unit bearing 1a. , When the inner ring assembly 18a formed by combining the inner row of tapered rollers 4d, the inner row of the cage 12d and the inner ring 8a having the small collar portion 28 is assembled between the outer ring 2a and the hub ring 7a, Carry out the grease filling process.

  In the grease filling step of this example, as shown in FIG. 14, the central axis of the intermediate assembly 35 is arranged in the vertical direction. Specifically, the outer ring 2a is placed with its axially outer portion facing upward. Then, the inner ring assembly 18a is inserted from the lower side between the outer ring 2a and the hub wheel 7a by using a press-fitting jig (not shown), and the inner ring 8a constituting the inner ring assembly 18a is inserted into the fitting shaft portion 11a. Press fit (temporary press fit). Then, before the upper end portion (axial outer end portion) of the inner ring 8a hits the step surface 24, the press-fitting operation is temporarily stopped. As a result, the roller assembly 17d in the inner row is arranged at a position displaced downward from the regular assembly position, which is the side where the inner diameter of the outer ring raceway 6d is larger. Therefore, the rolling surface of the tapered roller 4d is arranged at a position radially inwardly spaced from the outer ring raceway 6d, and the radially outer surface of the column portion 21a constituting the retainer 12d has a diameter larger than the outer ring raceway 6d. It is arranged at a position separated inward in the direction. Therefore, a gap 38a is formed between the inner row roller assembly 17d and the inner row outer ring raceway 6d.

  As described above, if the gap 38a is formed between the roller assembly 17d of the inner row and the outer ring raceway 6d of the inner row, the discharge of the grease sealing jig 39c arranged below the roller assembly 17d of the inner row. The grease is discharged from the outlet 40c toward the gap 38a.

  After the grease is supplied to the gap 38a as described above, the press-fitting work by the press-fitting jig (not shown) is restarted, and the inner ring assembly 18a is press-fitted (inserted) until the upper end of the inner ring 8a hits the step surface 24. To do.

Also in the case of this example as described above, the rolling surface of the tapered roller 4d in the inner row held by the retainer 12d in the inner row, which is the fall prevention cage, the outer ring raceway 6d and the inner ring raceway 10d in the inner row Not only can the rolling contact portion be lubricated well, but the contact portion between the large diameter side end of the tapered roller 4d and the large flange portion 14d of the inner ring 8a can be lubricated well.
Other configurations and operational effects are the same as those of the first and fourth examples of the embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be applied to hub unit bearings for drive wheels as well as for driven wheels. Further, the structure of the captive retainer for preventing the tapered rollers from coming off is not limited to the structure shown in each example of the embodiment, and other structures may be adopted as long as the function can be exerted. it can. Further, the structures of the outer sealing member and the inner sealing member are not limited to the structures shown in the respective examples of the embodiment, and conventionally known sealing members of various structures can be adopted. In addition, each example of the embodiments can be implemented in an appropriate combination.

1, 1a Hub unit bearing 2, 2a Outer ring 3, 3a Hub 4a-4d Tapered roller 5, 5a Stationary flange 6a-6d Outer ring track 7, 7a Hub ring 8, 8a Inner ring 9, 9a Rotating flange 10a-10d Inner ring track 11, 11a Fitting shaft part 12a-12d Retainer 13, 13a Space 14a-14d Large collar part 15, 15a Outer sealing member 16, 16a Inner sealing member 17a-17d Roller assembly 18, 18a Inner ring assembly 19, 19a Small diameter circular ring Part 20, 20a Large-diameter annular part 21, 21a Column part 22, 22a Pocket 23 Pilot part 24 Step surface 25 Caulking part 27a Arc-shaped part 27b Flat part 28 Small collar part 29 Core metal 30 Seal material 31a-31c Seal lip 32 Auxiliary lip 33 Fixed tubular portion 34 Bottom plate portion 35 Intermediate assembly 36, 36a Support base 37 Push Upper jig 38, 38a Gap 39, 39a to 39d Grease enclosing jig 40, 40a to 40d Discharge port 41, 41a Pulling jig 42 Locking collar portion 43 Slit 44 Strip portion 45 Protrusion portion 46 Centering mechanism

Claims (3)

An outer ring having an outer ring raceway on the inner peripheral surface,
A hub having an inner ring raceway on the outer peripheral surface,
A plurality of tapered rollers arranged between the outer ring raceway and the inner ring raceway,
A retainer that rotatably holds the tapered rollers,
The retainer is a fall prevention retainer capable of holding the tapered rollers in a radial direction so as not to fall off,
A method of assembling a hub unit bearing, comprising:
A roller assembly in which the tapered rollers are held by the captive retainer is arranged on the inner diameter side of the outer ring raceway in a state of being displaced to the side where the inner diameter of the outer ring raceway becomes larger in the axial direction than the regular assembly position. Thus, a method of assembling the hub unit bearing, including a grease enclosing step of forming a gap between the roller assembly and the outer ring raceway and discharging grease from the grease enclosing jig toward the gap.   The captive retainer is arranged at equal intervals in the circumferential direction, a small-diameter annular portion, a large-diameter annular portion having an outer diameter larger than that of the small-diameter annular portion, and the small-diameter annular portion and the large-diameter annular portion. A plurality of pillar portions axially connecting the radial annular portion, and a portion between the pillar portions adjacent to each other in the circumferential direction is a pocket for rotatably holding the tapered rollers. The opening on the radially inner side of the pocket is located on the inner diameter side with respect to the rotation axis of the tapered roller at least at an intermediate position in the longitudinal direction of the tapered roller, and the circumferential width thereof is The diameter of the tapered roller is smaller than the diameter of the tapered roller, and the opening on the outer side in the radial direction of the pocket is located on the outer diameter side of the tapered roller's rotation axis in the entire lengthwise direction of the tapered roller. The circumferential width is the diameter of the tapered roller Remote small hub unit assembling method of a bearing according to claim 1.   In the grease filling step, while the tip end of the grease filling jig is in contact with the axial end portion of the captive retainer, grease is applied from the tip end of the grease filling jig toward the gap. The method of assembling the hub unit bearing according to claim 1, wherein the hub unit bearing is discharged.

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