JP2000130444A - Double row rolling bearing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure lightening weight and having sufficient durability. SOLUTION: An outer peripheral surface 18 of an outer ring 6 is a tapered surface gradually decreasing an external diameter from one end part toward the other end part. A flange part 9 and a cylindrical surface part 21 are respectively formed in one end part and the other end part of this outer ring 6. The other end part of the outer ring 6 is reinforced by externally fitting a retaining ring 22 to this cylindrical surface part 21 by interference fitting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The double-row rolling bearing unit according to the present invention is used, for example, when a vehicle wheel is rotatably supported by a suspension device.

[0002]

2. Description of the Related Art A double-row rolling bearing unit is used to rotatably support a vehicle wheel with respect to a suspension system. For example, in order to rotatably support wheels of a large vehicle with respect to a suspension, a double-row tapered roller bearing unit, which is a kind of the double-row rolling bearing unit and has a large load capacity, is used. FIG. 14 shows a conventional double-row tapered roller bearing of the type disclosed in Japanese Unexamined Patent Publication No.
No. 00035 is disclosed. The structure shown in FIG. 14 is for rotatably supporting a wheel 2 constituting a wheel around an end portion of an axle 1 constituting a suspension device by a double-row tapered roller bearing unit 3. The upper half of FIG. 14 shows a state in which a disk rotor 4 for forming a disk brake is connected and fixed, and the lower half thereof shows a state in which a drum 5 for forming a drum brake is connected and fixed. Are respectively shown.

The double-row tapered roller bearing unit 3 includes an outer ring 6 and an inner ring assembly 7 which are arranged concentrically with each other, and a plurality of tapered rollers 8, 8 each of which is a rolling element. The outer ring 6 is formed into a cylindrical shape by forging a carbon steel material. The outer ring 6 has a flange 9 on an outer peripheral surface at one end (the left end in FIG. 14) and a double row on an inner peripheral surface. Have outer ring raceways 10, 10, respectively. Each of these outer raceways 10, 10 has a conical concave shape, and
Are inclined in such a direction that the inner diameter increases toward the axial end. Further, the outer peripheral surface of the outer ring 6 is provided with the flange 9
The outer ring 6 is formed as a tapered surface that is inclined in a direction in which the outer diameter becomes smaller as the distance from the outer ring increases, so that the outer ring 6 can be easily extracted from the mold when forging.

[0004] The inner race assembly 7 is formed by abutting axial end faces of a pair of inner race elements 11, 11.
The whole is cylindrical. Each of these inner ring elements 11,
An inner raceway 12 having a conical convex shape is formed on an outer peripheral surface of the eleventh. The inner ring assembly 7 has such a 1
The pair of inner ring elements 11, 11 are
The inner raceways 12 are combined in a state where the small-diameter end faces of the inner raceways 12 abut each other. Accordingly, on the outer peripheral surface of the inner ring assembly 7, there are multiple rows of inner ring raceways 12, 12 that are inclined in such a manner that the outer diameter increases toward the axial end. Further, each of the tapered rollers 8, 8 is rotatably held between the outer raceways 10, 10 and the inner raceways 12, 12 by a plurality of cages 13, 13. Provided.

[0005] With the above-described structure, wheels including the wheel 2 can be rotatably supported around the axle 1 constituting the suspension system. The structure shown in FIG. 14 incorporates a rotation speed detection device for detecting the rotation speed of the wheels. Therefore, the other end of the outer ring 6 (the right end in FIG. 14).
Alternatively, the tone wheel 14 is externally fitted and fixed to the shoulder of the flange portion 9, and a sensor 15 supported on a fixed portion such as a suspension device is opposed to the tone wheel 14.

[0006]

In the case of a conventional double-row rolling bearing unit including the double-row tapered roller bearing unit shown in FIG. 14, it has been difficult to achieve both reduction in weight and securing of durability. . The reason is as follows. In other words, for example, the outer peripheral surface of the outer race 6 constituting the double row tapered roller bearing unit 3 shown in FIG. 14 has an outer diameter that goes from one end where the flange 9 is provided to the other end (the right end in FIG. 14). The tapered surface is inclined in the direction in which it becomes smaller. The reason for this is that, when the outer race 6 is formed by forging a metal material such as carbon steel to form the outer race 6, a draft is provided to facilitate removal of the processed outer race 6 from the mold. With the provision of such a draft angle, the thickness of the other end of the outer ring 6 becomes smaller than the thickness of the one end.

For this reason, in order to reduce the weight of the double row rolling bearing unit such as the double row tapered roller bearing unit 3 and the like, if the thickness of the outer ring 6 is reduced, the thickness of the other end of the outer ring 6 is equivalent. Will be smaller. Since a radial load applied between the axle 1 and the wheel 2 is applied to the other end via a plurality of tapered rollers 8, when the wall thickness is too small, the other end is There is a possibility that the amount of elastic deformation becomes so large that it cannot be ignored. When the amount of elastic deformation is increased, the other end may be damaged, such as a crack, with use over a long period of time, or may be provided on the inner diameter side of the other end. There is a possibility that the sealing performance of the seal ring 16 may be deteriorated.

Conventionally, therefore, the outer ring 6 is made to have a sufficient thickness even at the other end where the outer ring 6 has the smallest thickness so as to prevent the above-mentioned damage and prevent deterioration of the sealing performance. I was planning. For this reason, it is inevitable that the weight of the double row rolling bearing unit such as the double row tapered roller bearing unit 3 increases.

In the case of the structure shown in the upper half of FIG.
Although the tone wheel 14 is externally fitted and fixed to the other end of the outer ring 6, it is not intended that the tone wheel 14 reinforce the other end. That is, since the gear wheel-shaped unevenness is formed on the axial end surface of the tone wheel 14 for detecting the rotation speed, when a large tensile stress is applied to the tone wheel 14, a crack is generated from the uneven portion. Easy to do. Therefore, this tone wheel 1
4, it is difficult to reinforce the other end of the outer ring 6. For this reason, it cannot contribute to weight reduction of the double row rolling bearing unit such as the double row tapered roller bearing unit 3 and the like.

In addition, the tone wheel 14 is provided at a portion deviated from the outer raceway 10 to the other end (the right side in FIG. 14). For this reason, even if the tensile strength of the tone wheel 14 is sufficient, not only does the tone wheel 14 not support the radial load applied to the outer raceway 10 from the tapered rollers 8, but also the other end of the outer race 6. A force in the shear direction is applied to the deviated portion by the tone wheel 14 and the tapered rollers 8, 8. On the basis of the force in the shearing direction, damage such as a crack or the like is rather caused at the base end (the left end in FIG. 14) of the step 17 formed at the other end of the outer ring 6 for providing the tone wheel 14. It is easy to occur. The double row rolling bearing unit of the present invention has been invented in view of the above-described circumstances to realize a structure capable of achieving both weight reduction and durability.

[0011]

The double row rolling bearing unit according to the first aspect of the present invention includes an outer ring, an inner ring assembly, and a plurality of rolling elements. Of these, the outer ring is made entirely cylindrical, with a flange part on the outer peripheral surface, a double row outer ring raceway on the inner peripheral surface,
Have each. Further, the outer peripheral surface of the outer race is a tapered surface inclined in a direction in which the outer diameter decreases as the distance from the flange portion increases. The inner ring assembly has a double-row inner ring raceway on the outer peripheral surface. Further, the plurality of rolling elements are:
Between the outer raceway and the inner raceway, a plurality of rolling units are provided so as to be freely rotatable while being held by retainers as necessary.

In particular, in the double row rolling bearing unit according to the first aspect, a cylindrical surface portion is provided at the end of the outer ring at a small diameter side portion of the tapered surface, and the outer ring raceway is provided near the end. Is formed up to the portion located around the portion near the end of. Then, a cylindrical restraining ring is externally fitted to the cylindrical surface portion by interference fitting in a state where at least a part of the restraining ring is located around an end portion of the outer raceway provided near the end portion. ing.

On the other hand, the double row rolling bearing unit according to the second aspect also includes an outer ring, an inner ring assembly, and a plurality of rolling elements. The outer ring of these is made entirely cylindrical.
A flange portion is provided on a part of the outer peripheral surface, and a double-row outer raceway is provided on the inner peripheral surface. The inner ring assembly has a double-row inner ring raceway on the outer peripheral surface. Further, the plurality of rolling elements are provided between the respective outer raceways and the inner raceways so as to be capable of rolling by a plurality of rolling bodies while being held by retainers as necessary.

In particular, in the double row rolling bearing unit according to the second aspect, a thick portion protruding diametrically outward of the outer ring is provided at a portion of the outer ring that is separated from the flange portion at an end portion. The outer raceway is formed from the end face of the outer race to a portion of the outer raceway provided near the end of the outer race, the part being located around the end race.

[0015]

In the case of the double row rolling bearing unit of the present invention constructed as described above, the strength of the end portion of the outer ring can be sufficiently ensured even if the thickness of the outer ring is reduced. For this reason, it is possible to realize a structure that can achieve both weight reduction and durability.

[0016]

1 and 2 show a first embodiment of the present invention corresponding to claim 1. FIG. 1 is an example of an embodiment of a double-row rolling bearing unit of the present invention.
The double-row tapered roller bearing unit 3a includes an outer ring 6 and an inner ring assembly 7, which are arranged concentrically with each other, and a plurality of tapered rollers 8 each of which is a rolling element, similarly to the above-described conventional double-row tapered roller bearing unit. , 8. The outer ring 6 is formed into a cylindrical shape by forging a metal material such as carbon steel such as bearing steel, and a flange portion 9 is formed on the outer peripheral surface of one end (the left end in FIG. 1). , Each having a double-row outer raceway 10 on its inner peripheral surface. Each of these outer raceways 10, 10 has a conical concave shape, and is inclined in such a direction that the inner diameter increases toward the axial end of the outer race 6. In other words, the cross-sectional shape of the axially intermediate portion of the outer ring 6 is a mountain shape. Further, the outer peripheral surface 18 of the outer ring 6 is a tapered surface that is inclined in a direction in which the outer diameter decreases as the outer ring 6 moves away from the flange portion 9, so that the outer ring 6 can be easily extracted from a mold when forging the outer ring 6. I am doing it.

The inner race assembly 7 is formed by abutting the axial end surfaces of the pair of inner race elements 11, 11 with each other.
The whole is cylindrical. Each of these inner ring elements 11,
An inner raceway 12 having a conical convex shape is formed on an outer peripheral surface of the eleventh. The inner ring assembly 7 has such a 1
The pair of inner ring elements 11, 11 are
The inner raceways 12 are combined in a state where the small-diameter end faces of the inner raceways 12 abut each other. Accordingly, on the outer peripheral surface of the inner ring assembly 7, there are multiple rows of inner ring raceways 12, 12 that are inclined in such a manner that the outer diameter increases toward the axial end. In the illustrated example, the pair of inner ring elements 11, 1
In a state where the axial end faces of the inner ring elements 1 abut each other, a coupling ring 19 is bridged between the inner ring elements 11, 11 so that the inner ring elements 11, 11 are not inadvertently separated from each other.

A plurality of the tapered rollers 8, 8 are rolled between the outer raceways 10, 10 and the inner raceways 12, 12 while being held by a plurality of cages 13, 13, respectively. It is provided movably. Further, seal rings 20a and 20b are provided between inner peripheral surfaces of both ends of the outer ring 6 and outer peripheral surfaces of shoulders provided at large-diameter ends of the inner ring elements 11 and 11, respectively. In the illustrated example, a single seal ring is used for the seal ring 20a on one end, and a combined seal ring is used for the seal ring 20b on the other end. The configuration described above is the same as that of a double-row tapered roller bearing unit that has been generally implemented conventionally.

In particular, in the double-row tapered roller bearing unit 3a of the present invention, a cylindrical surface portion 21 is provided at the other end of the outer ring 6.
Is formed concentrically with the outer ring 6 by, for example, machining the outer ring 6 by forging and then machining using a lathe or the like. The cylindrical surface portion 21 is formed up to a portion of the outer ring raceway 10 provided near the other end of the outer ring 6 (to the right in FIG. 1) and located around a portion near the other end. That is, around the portion near the other end of the outer raceway 10, a base end (the left end in FIG. 1) of the cylindrical surface portion 21, more preferably a base half (the left half in FIG. 1) is present. I am doing it.

The outer diameter D ₂₁ of the cylindrical surface portion 21 is within a range that does not change in the axial direction from the base end to the distal end (the right end in FIG. 1) of the cylindrical surface portion 21. Increase as much as possible. That is, as described above, the outer peripheral surface 18 of the outer race 6 is a tapered surface whose outer diameter decreases from one end to the other end. Therefore, in order to form the cylindrical surface portion 21, the other end of the outer ring 6 needs to be cut from the state shown by the chain line in FIG. 2 to the state shown by the solid line. During this scraping, the outer diameter D ₂₁ of the cylindrical surface portion 21 so as not be too small compared to the outer diameter D ₆ of the other edge portion of at the outer ring 6 previously scraping.

Then, a cylindrical restraining ring 22 is fitted on the cylindrical surface portion 21 as described above. This holding ring 22
Is externally fitted to the cylindrical surface portion 21 by shrink fitting or press fitting. Then, in a state of being externally fitted to the cylindrical surface portion 21, at least a part of the pressing ring 22 is positioned around a portion near the other end of the outer raceway 10 provided near the other end. . That is, the above-mentioned holding ring 2
2, and more preferably one half (the left half in FIG. 1) is present. The material of the restraining ring 22 is the same as or similar to the material of the outer ring 6 in properties such as expansion coefficient and Young's modulus. Therefore,
For example, when the outer ring 6 is made of carbon steel, it is preferable that the holding ring 22 is also made of carbon steel.

In the case of the double-row tapered roller bearing unit 3a of the present invention configured as described above, the strength of the other end of the outer ring 6 can be sufficiently ensured even if the thickness of the outer ring 6 is reduced. . For this reason, it is possible to realize a structure that can achieve both weight reduction and durability. That is, since the other end of the outer ring 6 that is easily elastically deformed based on a radial load applied during use is reinforced by the pressing ring 22, the amount of elastic deformation of the other end is suppressed to a negligible level. Can be. For this reason, it is possible to prevent the damage such as a crack from occurring at the other end, and also to prevent a gap from being generated at the fitting portion of the seal ring 20b, thereby deteriorating the sealing performance of the seal ring 20b. Things can be prevented. Thus, the durability of the double-row tapered roller bearing unit 3a can be ensured.

Further, in the case of the double-row tapered roller bearing unit 3a of the present invention, a part, more preferably, one half of the retaining ring 22 exists around the other end of the outer raceway 10. Therefore, it is possible to prevent a force in the shear direction from being applied to the portion near the other end based on the radial load applied to the portion near the other end of the outer ring 6 from each of the tapered rollers 8, 8. As a result, it is possible to effectively prevent the outer ring 6 from being damaged such as a crack.

Next, FIG. 3 shows a second embodiment of the present invention corresponding to claim 1. In the case of the first example described above, the gap 2 is formed between the step surface 23 at the back end of the cylindrical surface portion 21 formed at the other end of the outer ring 6 and the restraining ring 22.
4 (FIG. 1). On the other hand, in the case of the present example, the end surface of the pressing ring 22 abuts against the step surface 23. For this reason, the strength of the other end of the outer ring 6 can be further improved. Other configurations and operations are the same as those described in the first embodiment.
Since this is the same as in the case of the example, the same reference numerals are given to the same parts, and the duplicate description will be omitted.

Next, FIG. 4 shows a third embodiment of the present invention corresponding to claim 1. In the case of this example, an outward flange-like flange 25 is provided on the outer peripheral surface of the base end (the left end in FIG. 4) of the holding ring 22a. When such a retaining ring 22a is externally fitted to the cylindrical surface portion 21 at the other end of the outer ring 6, the tip of the tool is abutted against the flange 25. Other configurations and operations are the same as those of the above-described second example, and therefore, the same reference numerals are given to the same parts, and the duplicate description will be omitted.

Next, FIG. 5 shows a fourth embodiment of the present invention corresponding to claim 1. In the case of this example, the tone wheel 14a is externally fitted and fixed to the restraining ring 22 so that the rotation speed of the outer ring 6 can be detected. The tone wheel 14a is made of a magnetic metal plate, has a shape like a cage for a roller bearing, and has a magnetic characteristic of an outer peripheral surface.
They are alternately and equally spaced in the circumferential direction.
Since the configuration and operation of the other parts are the same as those of the second example shown in FIG. 3 described above, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 6 shows a fifth embodiment of the present invention corresponding to claim 1. In the case of the present example, the tone wheel 14b, which is formed in a substantially L-shaped cross section by a steel plate and is entirely annular, is externally fitted and fixed to the pressing ring 22. The tone wheel 14b changes the magnetic properties of the side face alternately and at equal intervals in the circumferential direction. The configuration and operation of the other portions are the same as those of the fourth example shown in FIG. 5 described above, and therefore, the same reference numerals are given to the same portions, and duplicate description will be omitted.

Next, FIG. 7 shows a sixth embodiment of the present invention corresponding to claim 1. In the case of this example, the pressing ring 22a having the flange 25 on the outer peripheral surface of the base end portion
In addition, a tone wheel 14c formed of a steel plate and having a substantially U-shaped cross section and formed entirely in an annular shape is externally fitted and fixed. The tone wheel 14c changes the magnetic characteristics of the outer peripheral surface alternately and at equal intervals in the circumferential direction. In the case of the present example, after the retaining ring 22a is externally fitted to the outer ring 6, the tone wheel 14c is externally fitted to the retaining ring 22a until the edge of the tone wheel 14c comes into contact with the flange 25. The configuration and operation of the other parts are the same as those of the fifth example shown in FIG. 6 described above, and therefore, the same reference numerals are given to the same parts, and duplicate description will be omitted.

FIG. 8 shows a seventh embodiment of the present invention corresponding to claim 1. In the case of this example, the pressing ring 22a having the flange 25 on the outer peripheral surface of the base end portion
Further, a tone wheel 14b similar to the fifth example shown in FIG. 6 described above is externally fitted and fixed. In the case of the tone wheel 14b in which the magnetic characteristics of the side surface are changed, this tone wheel 1
The sensor is opposed to 4b in the thrust direction via a minute gap. Therefore, it is important to position the tone wheel 14b with respect to the outer ring 6 in the axial direction. The structure of this example can satisfy such requirements.
Since the configuration and operation of the other parts are the same as those of the sixth example shown in FIG. 7 described above, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

Next, FIG. 9 shows an eighth embodiment of the present invention corresponding to claim 1. The above first to first
In each of the seven cases, one restraining ring 22 and 22a was externally fixed to the cylindrical surface portion 21 provided at the other end of the outer ring 6. On the other hand, in the case of the present example, two restraining rings 22b and 22c of a cylindrical restraining ring 22b and a ring-shaped restraining ring 22c are tightly fitted, respectively.
The outer ring 6 is externally fitted and fixed to a cylindrical surface 21 provided at the other end. Since the configuration and operation of the other parts are the same as those of the above-described respective examples, the same reference numerals are given to the same parts, and redundant description will be omitted.

Next, FIG. 10 shows a ninth embodiment of the present invention corresponding to claim 1. In the case of the present example, an inward flange-shaped flange 27 is provided on the inner peripheral surface of the distal end (right end in FIG. 10) of the restraining ring 22d. The pressing ring 22d is pressed into the cylindrical surface 21 provided at the other end of the outer ring 6 by interference fitting until the flange 27 abuts on the other end of the outer ring 6. Other configurations and operations are the same as those of the above-described respective examples, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

Next, FIG. 11 shows a tenth example of the embodiment of the present invention corresponding to claim 1. In the case of this example, the flange portion 9a is formed on the outer peripheral surface of the intermediate portion of the outer ring 6b, and the hub 28 and the inner ring 2 are formed as the inner ring assembly 7a.
9 is used. The outer ring 6b is connected to the outer end of the hub 28 (the end that is the outer side in the width direction when assembled to a vehicle, and the left end in FIG. 11).
Is provided with a flange portion 30 for supporting and fixing the wheel at a portion protruding from the outer end opening. In the case of such a structure,
A large radial load is applied to the outer end of the outer ring 6b.
Therefore, in the case of this example, a cylindrical surface portion 21 is formed at the outer end portion of the outer ring 6b, and a holding ring 22 is formed on the cylindrical surface portion 21.
Are externally fitted and fixed by interference fit. Also, as retainers 13a, 13a for holding the respective tapered rollers 8, 8,
Uses synthetic resin. Other configurations and operations are the same as those of the above-described respective examples, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

Next, FIG. 12 shows an eleventh embodiment of the present invention corresponding to claim 4. In the case of this example, a double-row outer raceway 10 formed on the inner peripheral surface of the outer race 6c
a, 10a and a plurality of rows of inner raceways 12a, 12a formed on the outer peripheral surface of the inner race assembly 7 are each formed into an arc-shaped cross section.
It has an angular track surface. A plurality of rolling balls 31 are provided between the outer raceways 10a and the inner raceways 12a. In the case of this example, the inner ring assembly 7 is a stationary wheel, and the outer ring 6c is a rotating wheel.

In order to carry out the present invention with a double row rolling bearing unit having such a structure, in the case of this embodiment, the outer race 6c is used.
A cylindrical surface portion 21 is formed at the inner end of the cylindrical surface portion 21.
Further, a cylindrical holding ring 22 is externally fitted and fixed by interference fitting. The proximal end (the left end in FIG. 12) of the cylindrical surface 21 is exposed from the outer edge of the pressing ring 22. Therefore, the outer diameter of the outer ring 6c is slightly smaller in this portion than in the adjacent portion. This includes a coil spring 32 for controlling the operation of the brake drum,
This is to prevent interference with the outer ring 6c.

In the direction of the contact angle between the balls 31, 31 indicated by chain lines α, α in FIG. 12, the thick portion deviating from the cylindrical surface portion 21 (in the case of the outer row on the left side in FIG. 12). Alternatively, the retaining ring 22 (in the case of the inner row on the right side in FIG. 12) is provided. Therefore, each ball 31,
The thickness of the outer ring 6c for supporting the load applied to the outer ring 6c from the outer ring 6c is sufficiently ensured for both the outer row and the inner row, so that the durability of the outer ring 6c can be sufficiently ensured.
Other configurations and operations are the same as those of the above-described respective examples, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 13 shows a twelfth embodiment of the present invention corresponding to claim 2. In the case of the double row tapered roller bearing unit 3b of this example, a thick portion 26 is provided at the other end (the right end in FIG. 13) of the outer ring 6a so as to project outward in the diameter direction of the outer ring 6a. This thick part 26
Are formed on the outer ring 6 in the first to ninth examples and the eleventh example described above.
This is the same as the position where 2c and 22d (see FIGS. 1 to 10 and 12) are externally fitted. That is, the thick portion 26 is formed of the outer ring 6a.
From the other end surface (the right end surface in FIG. 13) to the portion of the outer ring raceway 10 provided near the other end portion (the right side in FIG. 13) of the outer ring 6a and located around the other end portion. I have.

In the case of the double row tapered roller bearing unit 3b of this embodiment as described above, the strength of the other end of the outer ring 6a is sufficient even if the thickness of the outer ring 6a (at the middle portion in the axial direction) is reduced. Can be secured. For this reason, it is possible to realize a structure that can achieve both weight reduction and durability.

[0038]

The double-row rolling bearing unit according to the present invention is constructed and operates as described above. However, since both weight reduction and ensuring durability can be achieved, the power performance and the fuel consumption performance by reducing the weight of the vehicle are improved. It can contribute to improvement.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A of FIG. 1 showing only an outer ring taken out.

FIG. 3 is a sectional view showing a second example of the embodiment of the present invention.

FIG. 4 is a sectional view showing the third example.

FIG. 5 is a sectional view showing the fourth example.

FIG. 6 is a sectional view showing the fifth example.

FIG. 7 is a sectional view showing a sixth example.

FIG. 8 is a sectional view showing a seventh example.

FIG. 9 is a half sectional view showing the eighth example.

FIG. 10 is a half sectional view showing the ninth example.

FIG. 11 is a half sectional view showing the tenth example.

FIG. 12 is a sectional view showing an eleventh example;

FIG. 13 is a sectional view showing a twelfth example;

FIG. 14 is a cross-sectional view of a wheel support unit incorporating a conventional double-row rolling bearing unit.

[Explanation of symbols]

 Reference Signs List 1 axle 2 wheel 3, 3a, 3b double row tapered roller bearing unit 4 disk rotor 5 drum 6, 6a, 6b, 6c outer ring 7 inner ring assembly 8 tapered roller 9, 9a flange portion 10 outer ring raceway 11 inner ring element 12, 12a inner ring Track 13 Cage 14, 14 a, 14 b, 14 c Tone wheel 15 Sensor 16 Seal ring 17 Step 18 Outer peripheral surface 19 Coupling ring 20 a, 20 b Seal ring 21 Cylindrical surface 22, 22 a, 22 b, 22 c, 22 d Suppression ring 23 Step surface 24 Gap 25 Flange 26 Thick part 27 Flange 28 Hub 29 Inner ring 30 Flange 31 Ball 32 Coil spring

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F16C 41/00 F16C 41/00 (72) Inventor Kunio Nakamoto 1-50-50 Kumeinuma Shinmei Kugenuma, Fujisawa-shi, Kanagawa Nippon Seiko Incorporated F term (reference) 3J101 AA02 AA16 AA25 AA32 AA43 AA54 AA62 BA54 BA56 BA64 BA77 FA23 FA31 FA51 FA60 GA03

Claims (4)

[Claims] 1. The entirety is formed in a cylindrical shape, and has a flange portion on a part of an outer peripheral surface, a double row of outer raceways on an inner peripheral surface, and the outer diameter increases as the outer peripheral surface moves away from the flange portion. An outer ring that is a tapered surface inclined in a direction to become smaller, an inner ring assembly having a double row of inner ring raceways on the outer peripheral surface, and a plurality of the respective outer ring raceways and each of the inner ring raceways that can roll freely. In the double row rolling bearing unit provided with the provided rolling elements, a cylindrical surface portion is provided at a small diameter side portion of the tapered surface at an end portion of the outer ring, and an end portion of an outer ring raceway provided near the end portion. Is formed up to the portion located around the periphery, a cylindrical retaining ring on this cylindrical surface portion, at least a part of the retaining ring around the end portion of the outer ring raceway provided near the end portion In the position, it must be fitted outside by interference fit Double row rolling bearing unit characterized by the following. 2. An inner ring assembly which is entirely cylindrical and has a flange portion on a part of the outer peripheral surface, a double row of outer ring raceways on the inner peripheral surface, and a double row inner ring raceway on the outer peripheral surface. In a double-row rolling bearing unit comprising a three-dimensional structure and a plurality of rolling elements respectively provided between the outer raceways and the inner raceways, the flanges are provided at the ends of the outer races. A portion of the outer ring raceway provided near the end of the outer ring from the end face of the outer ring to a thick portion protruding outward in the diametrical direction of the outer ring in a portion deviated from the outer ring portion. A double row rolling bearing unit characterized by being formed up to. 3. The double-row inner raceway has a conical concave shape and is inclined in a direction in which the inner diameter increases toward the axial end, and the double-row inner raceway has a conical convex shape. The double row rolling bearing unit according to any one of claims 1 to 2, wherein the rolling element is inclined in a direction in which the outer diameter increases toward the axial end, and the rolling element is a tapered roller. 4. The double-row rolling bearing unit according to claim 1, wherein each of the double-row outer raceway and the inner raceway has an arc-shaped cross section, and the rolling element is a ball.