JP7440349B2 - Rolling bearing unit for wheel support - Google Patents

Description

The present invention relates to a wheel supporting rolling bearing unit used to rotatably support the wheels of an automobile relative to a suspension system, and a method for assembling the same.

Conventionally, as a wheel supporting rolling bearing unit (hereinafter also referred to as a "rolling bearing unit") that rotatably supports an automobile wheel relative to a suspension system, a cylindrical bearing unit is used between two rows of balls between an inner ring and an outer ring. One in which roller rows are arranged is known (for example, see Patent Document 1).

This type of rolling bearing unit adopts a structure in which a row of cylindrical rollers (cylindrical roller bearings) is arranged between each ball row of double row ball bearings, so it has a much higher performance than a rolling bearing unit with only double row ball bearings. It is possible to obtain a large bearing load rating, the ability to bear a large moment load (load on the outside of the swing), and high moment rigidity.

As shown in FIG. 8, in the hub unit bearing 100 described in Patent Document 1, a hub inner ring 114 having an integrally formed flange 113 for fixing a wheel, and a flange 111 for fixing a wheel support member are integrally formed. The hub outer ring 112 includes a first ball row 116 and a second ball row 118 that roll between the hub inner ring 114 and the hub outer ring 112. Furthermore, a cylindrical roller bearing 121 made of cylindrical rollers 120 is arranged between these two rows of balls 116 and 118. The inner ring of the second ball row 118 is a single inner ring 127, and the cylindrical roller 120 has a stepped end surface 132 of the inner ring outer peripheral surface 131 that connects the side end 133 of the single inner ring 127 and the inner ring outer ball raceway 129 of the first ball row 116. Movement in the axial direction is regulated by this. This results in a hub unit bearing that has high rigidity, low frictional resistance, and is easy to manufacture.

Japanese Patent Application Publication No. 2005-76874

By the way, in the hub unit bearing 100 described in Patent Document 1, the cylindrical rollers 120 are assembled with the hub inner ring 114 assembled to the hub outer ring 112. That is, first, the first ball row 116 is assembled to the outboard side end of the hub outer ring 112, then the seal ring 138 is attached, and in this state, the hub inner ring 114 is attached to the inner circumference of the hub outer ring 112 from the outboard side. Insert it on the side. Thereafter, a plurality of cylindrical rollers 120 are inserted between the outer roller rolling surface 125 of the hub outer ring 112 and the inner roller rolling surface 130 of the hub inner ring 114.

However, when the cylindrical roller bearing 121 is configured by inserting a plurality of cylindrical rollers 120 into the annular space between the inner peripheral surface of the hub outer ring 112 and the outer peripheral surface of the hub inner ring 114, the radial clearance is extremely small (for example, 10 μm). (below). Therefore, the insertion work of the cylindrical rollers 120 is performed by aligning the center axes of the hub inner ring 114 and the hub outer ring 112 completely, and by keeping the center axes of the cylindrical rollers 120 parallel to the center axes of the hub inner ring 114 and the hub outer ring 112. It was necessary and extremely difficult. Moreover, even if the central axes of the hub inner ring 114 and the hub outer ring 112 are perfectly aligned and the central axes of the cylindrical rollers 120 and the central axes of the hub inner ring 114 and the hub outer ring 112 are kept parallel, the outer ring Since the grinding lines on the roller raceway surface 125 and the inner roller raceway surface 130 are circumferential when viewed from the bearing center axis, they act as insertion resistance when inserting the cylindrical rollers 120, making it difficult to insert the cylindrical rollers 120. It could have been difficult.

In view of the above-mentioned circumstances, the present invention provides a rolling bearing unit for supporting a wheel and a method for assembling the same, which is capable of carrying a large moment load, has high moment rigidity, and is easy to assemble. The purpose is to

The above object of the present invention is achieved by the following configuration.
(1) an outer ring having first to third outer ring raceways on the inner peripheral surface;
a hub having first to third inner raceways on its outer peripheral surface and a rotating side flange for supporting and fixing the wheel;
They are respectively disposed in a rotatable manner between the first outer ring raceway and the first inner ring raceway, and between the second outer ring raceway and the second inner ring raceway, and constitute first and second ball rows, respectively. With multiple balls,
A plurality of cylinders are located between the first and second ball rows in the axial direction, are rollably arranged between the third outer ring raceway and the third inner ring raceway, and constitute a cylindrical roller row. Koroto,
A rolling bearing unit for supporting a wheel, comprising:
A stepped portion is provided on the inner circumferential surface of the outer ring at least on one side in the axial direction of the third outer ring raceway to restrict axial movement of the cylindrical roller,
The cylindrical roller row is a rolling bearing unit for supporting a wheel, which is assembled to the outer ring in a state that exhibits a keystone effect.
(2) The inner circumferential surface of the outer ring is provided with a pair of stepped portions on both sides of the third outer ring raceway in the axial direction to restrict movement of the cylindrical roller in the axial direction. Rolling bearing unit for wheel support.
(3) The inner circumferential surface of the outer ring is provided with the stepped portion on one side of the third outer ring raceway in the axial direction for restricting movement of the cylindrical roller to one side in the axial direction, and
The wheel support according to (1), wherein the outer peripheral surface of the hub is provided with a stepped portion on one side of the third inner raceway in the axial direction to restrict movement of the cylindrical roller to the other side in the axial direction. rolling bearing unit.
(4) the hub includes a first inner ring having the first inner raceway on its outer peripheral surface; and a second inner ring having the second inner raceway on its outer peripheral surface;
(1)-( The rolling bearing unit for wheel support according to any one of 3).
(5) The hub includes a first inner ring having the first inner raceway on the outer peripheral surface, a second inner ring having the second inner raceway on the outer peripheral surface, and a second inner race having the third inner raceway on the outer peripheral surface. A rolling bearing unit for supporting a wheel according to any one of (1) to (3), comprising a third inner ring provided for.
(6) A method for assembling a rolling bearing unit for supporting a wheel according to any one of (1) to (5), comprising:
Assembling the plurality of cylindrical rollers to the third outer ring raceway of the outer ring by inserting the plurality of cylindrical rollers into the inner circumferential surface of the outer ring in a state that exhibits a keystone effect;
Assembling the cylindrical rollers to the third inner raceway of the hub by inserting the hub into the outer ring with the plurality of cylindrical rollers assembled;
A method for assembling a rolling bearing unit for supporting a wheel.

According to the wheel supporting rolling bearing unit and assembly method of the present invention having the above-described configuration, the plurality of cylindrical rollers constituting the cylindrical roller row are assembled on the outer ring side in advance, and then the hub is mounted on the inner peripheral side of the outer ring. Since the cylindrical rollers can be inserted into the outer ring, normal assembly procedures can be used after the cylindrical rollers are assembled to the outer ring, making assembly easy.
Therefore, according to the rolling bearing unit for supporting a wheel and the assembly method of the present invention, it is possible to have a load capacity for a large moment load, high moment rigidity, and easy assembly.

FIG. 1 is a half-sectional view of a rolling bearing unit for supporting a wheel according to a first embodiment of the present invention. It is a half sectional view showing the 1st modification of the rolling bearing unit for wheel support concerning a 1st embodiment of the present invention. It is a half sectional view showing the 2nd modification of the rolling bearing unit for wheel support concerning a 1st embodiment of the present invention. FIG. 3 is a half-sectional view of a wheel supporting rolling bearing unit according to a second embodiment of the present invention. It is a half sectional view showing the 1st modification of the rolling bearing unit for wheel support concerning a 2nd embodiment of the present invention. It is a half sectional view of the rolling bearing unit for wheel support concerning a 3rd embodiment of the present invention. It is a half sectional view showing a first modification of a wheel supporting rolling bearing unit according to a third embodiment of the present invention. FIG. 2 is a sectional view of a conventional rolling bearing unit for supporting a wheel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Wheel supporting rolling bearing units (hereinafter also referred to as "rolling bearing units") according to each embodiment of the present invention will be described in detail with reference to the drawings. Note that in the following figures (FIGS. 1 to 7), the outside in the axial direction refers to the outside in the width direction of the vehicle body when assembled to the automobile, and the left side in each figure. On the other hand, the center side in the width direction, which is the right side of each figure, is called the inner side in the axial direction.

<First embodiment>
FIG. 1 is a half-sectional view of the rolling bearing unit of the first embodiment. In the rolling bearing unit 1, the outer ring 2 and the hub 3 are arranged concentrically with each other. Between the first and second outer ring raceways 4a, 4b provided on the inner peripheral surface of the outer ring 2 and the first and second inner ring raceways 5a, 5b provided on the outer peripheral surface of the hub 3, a first A plurality of balls 6 constituting the ball row 30 and the second ball row 31 are rotatably arranged in both rows. Also, in the axial direction, between a third outer ring raceway 4c between the first and second outer ring raceways 4a and 4b and a third inner ring raceway 5c between the first and second inner ring raceways 5a and 5b. A plurality of cylindrical rollers 41 constituting a cylindrical roller row 40 are arranged so as to be freely rollable. With this configuration, the hub 3 is rotatably supported inside the outer ring 2 which is supported and fixed to the suspension system.

The outer ring 2 has a stationary side flange 10 on the outer peripheral surface of the outer ring near the inner end in the axial direction for coupling and fixing the outer ring 2 to a knuckle of a suspension device (not shown). Further, the hub 3 has a rotating side flange 11 for supporting and fixing the wheel on a portion of the outer circumferential surface near the outer end in the axial direction. The hub 3 includes a first inner ring raceway 5a in an axially outer row, a third inner ring raceway 5c in an axially intermediate row, a hub body 8 in which a rotating side flange 11 is formed, and a second inner ring in an axially inner row. It is formed by combining an inner ring 9 forming a raceway 5b. The inner ring 9 is externally fitted and fixed to a stepped surface 15 formed with a small diameter at the axially inner end of the hub body 8 .

The rolling bearing unit 1 is for a drive wheel, and a spline hole 14 is provided in the radial center of the hub body 8 for inserting a drive shaft of a constant velocity joint (not shown) from the inside in the axial direction for spline engagement. It is being
Further, between the inner circumferential surface of the outer ring 2 and the outer circumferential surface of the hub 3, an annular space 7 in which the balls 6 and cylindrical rollers 41 are installed has a sealing member 12 provided at the axially outer end opening and an axially inner inner circumferential surface. The entire circumference is closed by a combination seal ring 13 provided at the end opening.

The first ball row 30 and the second ball row 31 have the same pitch circle diameter and are arranged in a back-to-back arrangement. In addition, in order to increase the distance between the first and second ball rows 30 and 31, the holder 32 that holds each ball 6 of the first ball row 30 and the second ball row is a large-diameter ring. The small-diameter ring portion supports the plurality of pillar portions in a cantilevered manner.

Further, the cylindrical roller rows 40 protrude radially inward from the third outer ring raceway 4c on both sides of the third outer ring raceway 4c of the outer ring 2 in the axial direction, and restrict movement of the cylindrical rollers 41 in both axial directions. A pair of step portions 42 and 43 are provided. Although the gaps between the step portions 42 and 43 and both end surfaces of the cylindrical roller 41 are exaggerated in FIG. 1, the actual gaps are small.

In this rolling bearing unit 1, the plurality of cylindrical rollers 41 constituting the cylindrical roller row 40 are inserted into the inner circumferential side of the outer ring 2 in a full roller type state that exhibits a keystone effect, and are inserted into the inner circumferential side of the outer ring 2. It is assembled on the inner peripheral surface of 4c. That is, the cylindrical roller row 40 is arranged so that the cylindrical rollers 41 exhibit a keystone effect in a full-roller state, that is, in a state in which the center axes of all the cylindrical rollers 41 are parallel to the center axes of the hub 3 and the outer ring 2. The diameter, the number of cylindrical rollers 41, and the pitch diameter of the cylindrical rollers 41 are set.

For example, when the diameter of the cylindrical rollers 41 is D, and the cylindrical rollers 41 are full rollers and are arranged in a state where the cylindrical rollers 41 are in contact with each other except for one place and also in contact with the outer ring raceway 4c, the rollers are in contact with each other. If the distance between the cylindrical rollers 41 at one location not covered is L, then "D>L". That is, the circumscribed circle diameter of the cylindrical rollers 41 is set to be larger than the inner diameter of the step portions 42 and 43 when all the cylindrical rollers 41 are in contact with each other, thereby producing a keystone effect. The cylindrical rollers 41 are assembled on the inner peripheral surface of the outer ring 2 in a full roller type state.

Therefore, when assembling the cylindrical rollers 41, after assembling all the cylindrical rollers 41 on the inner peripheral surface of the outer ring 2, if the cylindrical rollers 41 are distributed approximately equally on the circumference, the outer ring 2 can be assembled. The cylindrical rollers 41 will not easily come off from the outer ring 2 even if it is placed horizontally (even if the central axis is horizontal).

In this way, by combining the outer ring 2 and the cylindrical rollers 41 together in a state where the keystone effect is exerted, the outer ring 2 and the cylindrical rollers 41 do not fall off from the outer ring 2 even when the hub body 8 is not inserted. . In addition, since a pair of stepped portions 42 and 43 are provided on both sides of the third outer ring raceway 4c in the axial direction, the outer ring is arranged so that the axial direction of the outer ring 2 is vertical when the hub body 8 is not inserted. 2, the cylindrical rollers 41 are positioned in the axial direction on the outer ring 2 and do not fall off from the outer ring 2.

Note that the cylindrical roller row 40 can exhibit the keystone effect even when a spacer is interposed between adjacent cylindrical rollers 41 in addition to the full roller type.

The cylindrical roller row 40 is assembled to the outer ring 2 as described above, and then the hub body 8 is inserted into the inner peripheral side of the cylindrical roller row 40. The cylindrical rollers 41 of the cylindrical roller row 40 are rotatably held between the third inner raceway 5c and the third outer raceway 4c.

Next, the assembly procedure of this rolling bearing unit 1 will be explained.
In order to obtain this rolling bearing unit 1, first, a plurality of cylindrical rollers 41 are assembled to the inner circumferential surface of the outer ring 2 in a state that exhibits a keystone effect, thereby forming a cylindrical roller row 40.

Next, the first ball row 30 is assembled to the outboard side end of the outer ring 2. That is, a set of a plurality of balls 6 and a retainer 32 is assembled to the first outer ring raceway 4a. Then, the seal member 12 is attached to the outboard side end of the outer ring 2, and in this state, the hub body 8 is inserted from the outboard side into the inner peripheral side of the outer ring 2 to which the cylindrical roller row 40 is assembled.

At this time, before the hub body 8 is assembled, the cylindrical roller row 40 is previously assembled integrally with the inner periphery of the outer ring 2 and there is no risk of it falling off, so the hub body 8 can be inserted smoothly. . As a result, the first ball row 30 is held between the first outer ring raceway 4a and the first inner ring raceway 5a, and at the same time, the cylindrical roller row 40 assembled to the outer ring 2 is moved to the third outer ring. It is held between the raceway 4c and the third inner raceway 5c.

After that, a set of a plurality of balls 6 and a retainer 32 constituting the second ball row 31 are assembled to the second outer ring raceway 4b of the outer ring 2, and the inner ring 9 is moved from the inboard side to the inner peripheral side of the outer ring 2. Insert the inner ring 9 into the stepped surface 15 of the hub body 8 and fix it. Thereby, the second ball row 31 is held between the second outer raceway 4b and the second inner raceway 5b.

Finally, the combination seal ring 13 on the inboard side is assembled so as to seal the inboard side end opening of the annular space 7 between the outer ring 2 and the inner ring 9, thereby completing the rolling bearing unit 1. be able to.

According to the rolling bearing unit 1 of the present embodiment having the above-described configuration, the hub body 8 is inserted into the inner ring of the outer ring 2 with the plurality of cylindrical rollers 41 constituting the cylindrical roller row 40 assembled in advance on the outer ring 2 side. It can be inserted on the circumferential side. Therefore, after assembling the cylindrical rollers 41 to the outer ring 2, a normal assembly procedure can be adopted and assembly can be easily performed.
Further, since the rolling bearing unit 1 includes the first and second ball rows 30 and 31 and the cylindrical roller row 40, it can have a load capacity for large moment loads and high moment rigidity.

Note that, without changing the overall wall thickness of the outer ring 2, a reinforcing portion 44 may be provided only on the outer peripheral side of the cylindrical roller row 40, where a large load is applied to the outer ring 2, as shown by the chain double-dashed line in FIG. good. The reinforcing portion 44 may be provided continuously in the circumferential direction, or may be provided discontinuously in the circumferential direction.

<First modification of the first embodiment>
FIG. 2 is a half-sectional view showing a first modification of the rolling bearing unit of the first embodiment.
The rolling bearing unit 1a of the first modification differs from the above embodiment in that the third inner ring raceway 5c on which the cylindrical rollers 41 roll is provided in the inner ring 9a.

In the rolling bearing unit 1a of the first modification, the step surface 15 of the hub body 8 is formed beyond the axial position of the third inner ring raceway 5c from the inboard side. On the other hand, the inner ring 9a is formed with an extension 50 that extends beyond the cylindrical roller row 40 to the outboard side so as to form a third inner ring raceway 5c in addition to the second inner ring raceway 5b. It is fitted and fixed to the stepped surface 15.

In this case, the second inner ring raceway 5b of the inner ring 9 is formed continuously up to the third inner ring raceway 5c with approximately the same outer diameter in FIG. It can also be made smaller in diameter than the orbit 5b. By making the third inner ring raceway 5c smaller in diameter than the second inner ring raceway 5b, if commercially available cylindrical rollers (standard dimensions are in Φ1 mm increments) can be used for the cylindrical rollers 41, costs can be reduced.

When assembling this rolling bearing unit 1a, first, a plurality of cylindrical rollers 41 are assembled to the inner circumferential surface of the outer ring 2 in a state that exhibits a keystone effect, thereby forming a cylindrical roller row 40.

Next, the first ball row 30 is assembled to the outboard side end of the outer ring 2, and the seal member 12 is attached, and in this state, the hub body 8 is inserted from the outboard side to the inner peripheral side of the outer ring 2. do. Thereby, the first ball row 30 is held between the first outer raceway 4a and the first inner raceway 5a.

Also, a set of a plurality of balls 6 and a retainer 32 constituting the second ball row 31 are assembled to the second outer ring raceway 4b of the outer ring 2, and the inner ring 9a is attached to the step surface 15 of the hub body 8 from the inboard side. Fit and fix.

Thereby, the second ball row 31 is held between the second outer ring raceway 4b and the second inner ring raceway 5b, and at the same time, the cylindrical roller row 40 assembled in advance on the outer ring 2 is moved to the third ball row 31. It is held between the outer ring raceway 4c and the third inner ring raceway 5c. At this time, before the inner ring 9a is assembled, the cylindrical roller row 40 is previously assembled integrally with the inner circumferential surface of the outer ring 2, so there is no risk of it falling off, so the inner ring 9a can be inserted smoothly. .

Finally, the combination seal ring 13 on the inboard side is assembled so as to seal the inboard side end opening of the annular space 7 between the outer ring 2 and the inner ring 9a, thereby completing the rolling bearing unit 1a. be able to.

Therefore, according to the rolling bearing unit 1a, the hub body 8 can be inserted into the inner peripheral side of the outer ring 2 with the plurality of cylindrical rollers 41 constituting the cylindrical roller row 40 assembled on the outer ring 2 side in advance. Therefore, after assembling the cylindrical rollers 41 to the outer ring 2, a normal assembly procedure can be adopted and assembly can be easily performed.

Moreover, according to the rolling bearing unit 1a of this modification, the third inner ring raceway 5c of the cylindrical rollers 41 is provided in the inner ring 9a. Therefore, the third inner ring raceway 5c can be made of bearing steel that has a longer life than medium carbon steel (the material of the hub body 8), thereby improving the rolling life of the cylindrical roller bearing part and improving the dent resistance. can also be increased.

<Second modification of the first embodiment>
FIG. 3 is a half-sectional view showing a second modification of the rolling bearing unit of the first embodiment.
The rolling bearing unit 1b of the second modification is for a driven wheel, and has a hub 3 formed solidly. Further, the first and second ball rows 30 and 31 employ different PCDs (pitch diameters). That is, the pitch circle diameter of the first ball row 30 is set larger than the pitch circle diameter of the second ball row 31. Furthermore, in this embodiment, the diameter of the balls 6 in the first ball row 30 is set smaller than the diameter of the balls 6 in the second ball row 31, and the number of balls in the first ball row 30 is set to be smaller than the diameter of the balls 6 in the second ball row 31. The number of balls is set to be larger than the number of balls in ball row 31.

Therefore, on the inner circumferential surface of the outer ring 2, a step is provided only on one side (inboard side) in the axial direction of the third outer ring raceway 4c to restrict movement of the cylindrical rollers 41 to one side (inboard side) in the axial direction. A section 43 is provided.

On the other hand, on the outer circumferential surface of the hub 3, the third inner ring raceway 5c protrudes from the third inner ring raceway 5c on one side in the axial direction (outboard side), and the cylindrical rollers 41 protrude on the other axial side (outboard side). A stepped portion 51 is provided to restrict movement toward the board side). Specifically, this stepped portion 51 has an outer diameter of an extension portion 50 of the inner ring 9a that is fitted and fixed to the stepped portion 15 of the hub body 8, and an outer circumferential surface of the hub body 8 that is connected to the first inner ring raceway 5a. It is formed by the difference in diameter.

In the rolling bearing unit 1b of this embodiment, the inner ring 9a is fitted and fixed to the stepped surface 15 of the hub body 8 by caulking the inboard side end of the hub body 8. Further, a bottomed cylindrical cap 60 is attached to the inner circumferential surface of the inboard side end of the outer ring 2, and closes the opening of the inboard side end of the outer ring 2. Further, an encoder 61 is attached to the outer peripheral surface of the shoulder portion of the inner ring 9 via a slinger 62.

When assembling the rolling bearing unit 1b, first, all the cylindrical rollers 41 are assembled at once on the inner circumferential surface of the outer ring 2 in a state that exerts a keystone effect (all the axially outer sides of the outer ring raceway 4c of the outer ring 2 are attached to the outer ring). Since it has a larger diameter than the raceway 4c, it is possible to assemble all the cylindrical rollers 41 at once), forming a cylindrical roller row 40. At this time, the cylindrical rollers 41 are assembled with the outer ring 2 with its inboard side end face facing down. In this case, the cylindrical rollers 41 can be positioned in the axial direction by the inboard step portion 43 provided on the inner peripheral surface of the outer ring 2. Furthermore, by keeping the outer ring 2 in that position, the cylindrical rollers 41 are held without falling off.

Next, with the inboard end of the outer ring 2 facing down, the first ball row 30 is assembled to the outboard end of the outer ring 2, and the seal member 12 is attached. The hub body 8 is inserted into the inner peripheral side of the outer ring 2 from the board side. Thereby, the first ball row 30 is held between the first outer raceway 4a and the first inner raceway 5a.

Thereafter, a set of a plurality of balls 6 and a retainer 32 constituting the second ball row 31 is assembled onto the second outer ring raceway 4b of the outer ring 2. Further, the inner ring 9a is inserted from the inboard side so that the extension portion 50 of the inner ring 9a is located on the inner peripheral side of the cylindrical rollers 41, and is fitted and fixed to the stepped surface 15 of the hub body 8. Thereafter, by crimping the inboard end of the hub body 8, the inner ring 9a is securely fixed to the hub body 8 by the crimping portion 63.

Thereby, the second ball row 31 is held between the second outer ring raceway 4b and the second inner ring raceway 5b, and at the same time, the cylindrical roller row 40 assembled in advance on the outer ring 2 is moved to the third ball row 31. It is held between the outer ring raceway 4c and the third inner ring raceway 5c. At this time, before the inner ring 9 is assembled, the cylindrical roller row 40 is in a state where the keystone effect is exhibited, so that it does not fall off from the outer ring 2, and the inner ring 9 can be inserted smoothly.

Therefore, according to the rolling bearing unit 1b, the hub body 8 can be inserted into the inner circumferential side of the outer ring 2 with the plurality of cylindrical rollers 41 constituting the cylindrical roller row 40 being assembled on the outer ring 2 side in advance. Therefore, after assembling the cylindrical rollers 41 to the outer ring 2, a normal assembly procedure can be adopted and assembly can be easily performed.

In the rolling bearing unit 1b of the second modification, the third inner ring raceway 5c of the cylindrical rollers 41 is formed on the outer peripheral surface of the extension part 50 of the inner ring 9a, but the base end is formed on the outer peripheral surface of the hub body 8. Two step surfaces are provided from the side toward the tip side, and the first step surface is used as the third inner ring raceway 5c similarly to the rolling bearing unit 1, and the second step surface is used as the third inner raceway 5c for fitting the inner ring 9. It can also be used as a face. In that case, the second inner ring raceway 5b may be formed in the inner ring 9.

In addition, when the step portion 43 that restricts the axial movement of the cylindrical roller 41 is provided only on one side in the axial direction (step portion 43 on the inboard side) as in the rolling bearing unit 1b, the keystone state of the cylindrical roller 41 is may become unstable. Therefore, in such a case, a locking means for the cylindrical rollers 41 having lubricating properties, such as Lubeguard (registered trademark) 44 (special solid lubricant), can also be used.

<Second embodiment>
Next, a rolling bearing unit according to a second embodiment will be described. As shown in FIG. 4, the rolling bearing unit 1c is a second generation rolling bearing unit, and a hub body having a rotating side flange constituting the hub is not shown.

In the rolling bearing unit 1c, the hub includes a first inner ring 20 having a first inner ring raceway 5a forming a first ball row 30 on its outer peripheral surface, and a second inner ring raceway forming a second ball row 31. 5b on the outer peripheral surface, the second inner ring 21 is provided with an extension part 50 extending to the cylindrical roller row 40, and a third inner ring raceway is provided on the outer peripheral surface of the extension part 50. 5c is formed.
Further, in this case, the first inner ring 20 and the second inner ring 21 are fitted and fixed to a hub body (not shown). Further, the extension portion 50 on which the third inner ring raceway 5c is formed may be formed on the first inner ring 20.

On the other hand, the outer ring 2 includes a stationary side flange 10, and step portions 42 and 43 are provided on both sides of the third outer ring raceway 4c in the axial direction.

When assembling such a rolling bearing unit 1c, as in the rolling bearing unit 1a of FIG. A roller row 40 is configured.

Next, the first ball row 30 is assembled to the outboard side end of the outer ring 2, and the first inner ring 20 is inserted into the inner peripheral side of the outer ring 2. At this time, the locking pawl 33 provided on the inner diameter part of the retainer 32 locks into the locking groove 20a of the inner ring 20, thereby causing the first ball row 30 to connect with the first outer ring raceway 4a. 1 and the inner ring raceway 5a. Also, the second ball row 31 is assembled to the inboard end of the outer ring 2, and the second inner ring 21 is inserted into the inner circumference of the outer ring 2 (similarly, the second ball row 31 is assembled to the inboard end of the outer ring 2). The locking pawl 33 is locked in the locking groove 21a of the second inner ring 21, and the second ball row 31 is held between the second outer ring raceway 4b and the second inner ring raceway 5b) . At this time, the extension portion 50 of the second inner ring 21 is inserted into the inner circumferential side of the cylindrical roller row 40 assembled on the inner circumferential surface of the outer ring 2 . Thereby, the second ball row 31 is held between the second outer ring raceway 4b and the second inner ring raceway 5b, and the cylindrical roller row 40 is held between the third outer ring raceway 4c and the third inner ring raceway 5c. is held between. Thereafter, the combination seal rings 13 are inserted into the openings at both ends of the rolling bearing unit 1c, and the rolling bearing unit 1c of FIG. 4 is completed.
In this embodiment, after the plurality of cylindrical rollers 41 are assembled to the inner circumferential side of the inner ring 2, the second inner ring 21 is assembled to the inner circumferential side of the outer ring 2 before the first inner ring 20. may be inserted into.

During the above assembly, before the second inner ring 21 is assembled, the cylindrical roller row 40 is already assembled integrally with the inner circumference of the outer ring 2 with a keystone effect, so there is no risk of it falling off, so it is smooth. The second inner ring 21 can be inserted.

According to this rolling bearing unit 1c, the second inner ring 21 can be inserted into the inner peripheral side of the outer ring 2 with the plurality of cylindrical rollers 41 constituting the cylindrical roller row 40 assembled on the outer ring 2 side in advance. . Therefore, after assembling the cylindrical rollers 41 to the outer ring 2, a normal assembly procedure can be adopted and assembly can be easily performed.

<Modified example of second embodiment>
FIG. 5 is a half sectional view showing a modification of the rolling bearing unit of the second embodiment.
The rolling bearing unit 1d of this modification has a point that a third inner ring 22 having a third inner ring raceway 5c on which cylindrical rollers 41 roll is separately provided between the first inner ring 20 and the second inner ring 21. This embodiment is different from the above embodiment.

When assembling this rolling bearing unit 1d, first, a plurality of cylindrical rollers 41 are assembled on the inner circumferential surface of the outer ring 2 in a state where a keystone effect is exerted to form a cylindrical roller row 40. Thereafter, one of the first inner ring 20 and the second inner ring 21 is assembled to the inner peripheral side of the outer ring 2 to complete the first or second ball row 30, 31. Next, the third inner ring 22 is inserted from the opposite side into the inner circumferential side of the outer ring 2 to which the cylindrical roller row 40 is assembled, and the cylindrical rollers 41 are inserted into the third outer ring raceway 4c and the third inner ring raceway 5c. hold between. Finally, the other of the first inner ring 20 and the second inner ring 21 is assembled to the inner peripheral side of the outer ring 2 to complete the other of the first or second ball rows 30, 31.

Therefore, also when assembling the rolling bearing unit 1d, after assembling the cylindrical rollers 41 to the outer ring 2, a normal assembly procedure can be adopted, and the assembly can be easily performed.

<Third embodiment>
Next, a rolling bearing unit according to a third embodiment will be described. As shown in FIG. 6, the rolling bearing unit 1e is a first generation rolling bearing unit, and the outer ring 2a is formed with first to third outer ring raceways 4a to 4c, and is provided with a stationary side flange. It is fitted and fixed into a housing (not shown). Further, the outer ring 2a includes step portions 42 and 43 on both sides of the third outer ring raceway 4c in the axial direction, similarly to the above embodiment.

In this case, the assembly of the rolling bearing unit 1e is similar to that of the rolling bearing unit 1c of the second embodiment described above, and the same effects can be achieved.

<Modified example of third embodiment>
FIG. 7 is a half-sectional view showing a modification of the rolling bearing unit of the third embodiment.
Similar to the modification of the second embodiment, the rolling bearing unit 1f of this modification includes a third inner raceway 5c on which cylindrical rollers 41 roll between the first inner ring 20 and the second inner ring 21. This embodiment differs from the above embodiment in that a third inner ring 22 is separately provided.

Therefore, the assembly of the rolling bearing unit 1f is similar to that of the rolling bearing unit 1d of the modification of the second embodiment described above.

Note that the present invention is not limited to the embodiments described above, and can be modified, improved, etc. as appropriate.

1, 1a, 1b, 1c, 1d, 1e, 1f Rolling bearing unit for wheel support (rolling bearing unit)
2 Outer ring 3 Hub 4a First outer ring raceway 4b Second outer ring raceway 4c Third outer ring raceway 5a First inner ring raceway 5b Second inner ring raceway 5c Third inner ring raceway 6 Ball 8 Hub body 9 Inner ring 10 Stationary side Flange 11 Rotating side flange 12 Seal member 13 Combination seal ring 20 First inner ring 21 Second inner ring 22 Third inner ring 30 First ball row 31 Second ball row 40 Cylindrical roller row 41 Cylindrical rollers 42, 43 Steps Part 44 Lubguard (registered trademark)
50 Extension part 51 Step part

Claims (3)

an outer ring having first to third outer ring raceways on the inner peripheral surface;
a hub having first to third inner raceways on its outer peripheral surface and a rotating side flange for supporting and fixing the wheel;
They are respectively disposed in a rotatable manner between the first outer ring raceway and the first inner ring raceway, and between the second outer ring raceway and the second inner ring raceway, and constitute first and second ball rows, respectively. With multiple balls,
A plurality of cylinders are located between the first and second ball rows in the axial direction, are rollably arranged between the third outer ring raceway and the third inner ring raceway, and constitute a cylindrical roller row. Koroto,
A rolling bearing unit for supporting a wheel, comprising:
The hub includes a first inner ring having the first inner raceway on an outer peripheral surface, and a second inner ring having the second inner raceway on an outer peripheral surface,
One of the first inner ring and the second inner ring is provided with an extension part extending to the cylindrical roller row, and the third inner ring raceway is formed on the outer peripheral surface of the extension part,
A stepped portion is provided on the inner circumferential surface of the outer ring at least on one side in the axial direction of the third outer ring raceway to restrict axial movement of the cylindrical roller,
The cylindrical roller row is a rolling bearing unit for supporting a wheel, which is assembled to the outer ring in a state that exhibits a keystone effect. The wheel supporting wheel according to claim 1, wherein the inner circumferential surface of the outer ring is provided with a pair of stepped portions on both sides of the third outer ring raceway in the axial direction for regulating movement of the cylindrical roller in the axial direction. Rolling bearing unit. The inner circumferential surface of the outer ring is provided with the stepped portion on one side of the third outer ring raceway in the axial direction for restricting movement of the cylindrical roller to one side in the axial direction, and
The wheel support according to claim 1, wherein the outer peripheral surface of the hub is provided with a stepped portion on one side of the third inner raceway in the axial direction to restrict movement of the cylindrical roller to the other side in the axial direction. rolling bearing unit .

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