JP2003294032A - Double-row rolling bearing and assembling method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in a tandem type double-row ball bearing, in which there are difficulties to give uniform preload onto balls on both rows of the double-row ball bearing in spite of a difference in dimensional tolerances for respective rows. <P>SOLUTION: The double-row rolling bearing comprises a first assembled unit 21 and a second assembled unit 22. The double-row rolling bearing is assembled through an axial direction so that balls 18 of the second assembled unit 22 are fitted on a raceway surface 18b of an outer ring at a small diameter side of an outer ring member 11, and that balls 17 of a first assembled unit 21 are fitted on a raceway surface 17b of an outer ring at a large diameter side of the outer ring member 11, and a nut 42 is screwed on a screw portion 40 of a shaft portion 9. Thus, load given by the nut to a thrust direction, which acts on a first inner ring member 13A, is directly transmitted to a second inner ring member 13B. The balls 17 are surely kept in contact with the raceway surface 17b of the outer ring at the large diameter side of the outer ring member 11 and a raceway surface 17a of a first inner ring of the first inner ring member 13A, and preload is surely given to the balls 17 of the first assembled unit 21 and the balls 18 of the second assembled unit 22. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-row ball bearing and a method for assembling the double-row ball bearing used in a differential device mounted on a vehicle, for example.

[0002]

2. Description of the Related Art FIG. 8 shows a sectional structure of a conventional differential device 100. The differential device 100 has a differential case 101.
A pinion shaft (drive pinion) 102 is provided therein. The pinion shaft 102 is rotatably supported around the shaft center by a pair of single-row tapered roller bearings 103 and 104 which are spaced apart from each other in the shaft center direction. A companion flange 105 connected to a propeller shaft (not shown) is provided at the end of the pinion shaft 102.

In the above differential device 100,
The bearings that rotatably support the pinion shaft 102 are tapered roller bearings 103 and 104. Particularly, the tapered roller bearing 103 on the side of the pinion gear 106 having a large thrust load
There is a great frictional resistance. Therefore, there is a problem that the rotational torque becomes large and the efficiency of the differential device 100 is reduced. Therefore, it is conceivable to use a tandem type double-row ball bearing (for example, a double-row angular contact ball bearing) in consideration of assemblability, instead of the tapered roller bearing 103 for the pinion gear 106 side bearing.

[0004]

As described above, when a tandem type double row ball bearing is used in place of the tapered roller bearing 103, due to differences in dimensional tolerances, etc. It is difficult to evenly apply preload.

[0005]

In order to solve the above-mentioned problems, a double row rolling bearing of the present invention comprises a single bearing ring having a large diameter side raceway surface and a small diameter side raceway surface which are axially separated from each other. The other bearing ring that faces the single bearing ring in the radial direction, and an assembly including a rolling element group arranged between the two bearing rings, wherein the assembly is in the axial direction with respect to the single bearing ring. The first assembly includes a first assembly and a second assembly that are assembled from the same direction, and the first assembly has a first raceway surface that radially opposes a large diameter raceway surface of a single bearing ring. A first race, and a first rolling element group fitted between the large diameter side raceway surface and the first raceway surface, wherein the second assembly is the small diameter side of a single raceway ring. A second race having a second raceway surface that faces the raceway surface in the radial direction, and a second rolling element that is fitted between the small diameter raceway surface and the second raceway surface. It contains.

In the above-mentioned double-row rolling bearing, the first assembly and the second assembly are assembled from the same direction in the axial direction with respect to the single bearing ring, so that the rolling elements of each assembly are assembled. The group is assembled so as to be fitted to each of the large diameter side raceway surface and the small diameter side raceway surface of the single bearing ring.

In order to solve the above-mentioned problems, in the double-row rolling bearing of the present invention, the first assembly and the second assembly are assembled from the axial direction, and the first assembly is Is a single first ring having a large diameter raceway surface and a small diameter raceway surface, and a raceway surface that faces one of the large diameter raceway surface and the small diameter raceway surface in the radial direction. A second race having, and a first rolling element group arranged between the first race and the second race, wherein the second assembly has a large diameter raceway surface and a small diameter. A third raceway ring having a raceway surface that faces the other raceway surface of the side raceway surface in the radial direction, and the large raceway surface and the small diameter side that are assembled to the third raceway ring. The second rolling element group is fitted to the other of the raceway surfaces from the axial direction.

The double-row rolling bearing is mounted on the first assembly so that the rolling element of the second assembly is fitted to the other raceway surface of the first bearing ring of the first assembly. Assemble by assembling the second assembly from the axial direction.

Such a double-row ball bearing is preferably used as a bearing for supporting a pinion shaft of a differential device for a vehicle, but is not limited to this. That is, a part of the components of the double-row rolling bearing is attached to one of the shaft and the housing, the other components of the double-row rolling bearing are attached to the other of the shaft and the housing, and the shaft is inserted into the housing. Any device having a configuration can be applied.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the double-row rolling bearing of the present invention is applied to a pinion shaft supporting bearing of a differential device attached to a vehicle will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a sectional view showing a schematic structure of a differential device, FIG. 2 is a sectional view of a double-row rolling bearing portion after the differential device is assembled, and FIG. 3 is a process of assembling the differential device. FIG.

As shown in FIG. 1, the differential device 1 has a differential case 2. The differential case 2 is composed of a front case 3 and a rear case 4, and both 3 and 4 are attached by bolts and nuts 2a. Annular walls 27 and 28 for mounting bearings are formed inside the front case 3. The differential case 2 has a differential transmission mechanism 5 for differentially interlocking left and right wheels, and a pinion shaft (drive pinion) 7 having a pinion gear 6 on one side. The pinion gear 6 is the ring gear 8 of the differential transmission mechanism 5.
Is meshed with. The shaft portion 9 of the pinion shaft 7 is formed in a stepped shape so that the other side has a smaller diameter than the one side.

The shaft portion 9 of the pinion shaft 7 has, on one side thereof, an annular wall 2 of the front case 3 via a double row rolling bearing 10.
7 is rotatably supported around the axis. The shaft portion 9 of the pinion shaft 7 is rotatably supported on the other side by an annular wall 28 of the front case 3 via a tapered roller bearing 25 so as to be rotatable about its axis.

As shown in FIG. 3, double-row rolling bearing 10
Is a large diameter outer ring raceway surface 17b and a small diameter outer ring raceway surface 1
It is composed of an outer ring member 11 as a single race having 8b, a first assembly 21 and a second assembly 22. The double row rolling bearing 10 is configured by assembling the first assembly 21 and the second assembly 22 to the outer ring member 11.

The outer ring member 11 is fitted on the inner peripheral surface of the annular wall 27. As the outer ring member 11, a shoulder pad outer ring is used. The outer ring member 11 has a flat surface portion 11b between the large diameter outer ring raceway surface 17b and the small diameter side outer ring raceway surface 18b, which has a smaller diameter than the large diameter outer ring raceway surface 17b and is continuous with the small diameter outer ring raceway surface 18b. Has been done. With this configuration, the inner peripheral surface of the outer ring member 11 is formed in a step shape.

The first assembly 21 includes a first inner ring member 13A having a first inner ring raceway surface 17a radially opposed to the large diameter outer ring raceway surface 17b of the outer ring member 11, and a large diameter outer ring raceway. It has a first ball group 15 fitted between the surface 17b and the first inner ring raceway surface 17a. This first ball group 15
The first retainer 19 holds them at equal positions in the circumferential direction. The shoulder inner ring is used as the first inner ring member 13A.

The second assembly 22 includes a second inner ring member 13B having a second inner ring raceway surface 18a radially opposed to the small diameter side outer ring raceway surface 18b of the outer ring member 11, and a small diameter outer ring raceway surface 18b. And the second inner ring raceway surface 18a. This second ball group 16
The second retainer 20 holds them at equal positions in the circumferential direction. As the second inner ring member 13B, a shoulder cushion inner ring having a relatively smaller diameter than that of the first inner ring member 13A is used. The diameter of the shoulder portion of the second inner ring member 13B is formed to be larger than the diameter of the shoulder recess portion of the first inner ring member 13A.

The first inner ring member 13A is press fitted into the pinion shaft 7. The end surface of the first inner ring member 13A is in contact with the end surface of the pinion gear 6 in the axial direction.
The second inner ring member 13B is loosely fitted on the pinion shaft 7. That is, the inner diameter of the second inner ring member 13B is
It is set to be larger than the inner diameter of the first inner ring member 13A.

The diameter of the balls 17 in the first ball group 15 is larger than the diameter of the balls 18 in the second ball group 16. The double-row rolling bearing 10 having such a structure is provided for each ball group 1
The pitch circle diameters D1 and D2 of 5 and 16 are different from each other.
That is, the pitch circle diameter D1 of the first ball group 15 is set larger than the pitch circle diameter D2 of the second ball group 16. In this way, the double row rolling bearing 1 having the step circle-shaped inner ring members 13A, 13B having different pitch circle diameters D1, D2
0 is called a tandem type double row rolling bearing.

The tapered roller bearing 25 includes a single outer ring member 12
A single inner ring member 14 arranged radially inward of the outer ring member 12; a plurality of single row tapered rollers 26 interposed between the outer ring member 12 and the inner ring member 14; It has a cage 25a that holds the rollers 26 at circumferentially equidistant positions. The outer ring member 12 of the tapered roller bearing 25 is fitted to the inner peripheral surface of the annular wall 28. The inner ring member 14, the cage 25a, and the plurality of single-row tapered rollers 26 are separately assembled from the outer ring member 12 and are assembled to the outer ring member 12. An outer raceway surface of the tapered roller 26 is formed on the inner peripheral surface of the outer race member 12, and an inner raceway surface of the tapered roller 26 is formed on the outer peripheral surface of the inner race member 14. The inner ring member 14 of the tapered roller bearing 25 is press-fitted in the shaft portion 9 of the pinion shaft 7.

The second inner ring member 13 of the double row rolling bearing 10
A plastic spacer 33 for setting a preload is interposed between B and the end surface of the inner ring member 14 of the tapered roller bearing 25 in the axial direction. The plastic spacer 33 is externally fitted in the shaft portion 9 of the pinion shaft 7.

The outer wall of the front case 3 and the annular wall 2 on one side
7, an oil circulation passage 30 is formed, an oil inlet 31 of the oil circulation passage 30 is opened to the ring gear 8 side of the oil circulation passage 30, and an oil outlet 32 of the oil circulation passage 30 is an annular wall 27. , 28 are opened.

The differential device 1 has a companion flange 34. This companion flange 3
Reference numeral 4 has a body portion 35 and a flange portion 36 formed integrally with the body portion 35. The body portion 35 is fitted on the other side of the shaft portion 9 of the pinion shaft 7, that is, on the drive shaft side (not shown). A shield plate 37 is interposed between one end surface of the body portion 35 and the end surface of the inner ring member 14 of the tapered roller bearing 25. An oil seal 38 is arranged between the outer peripheral surface of the body portion 35 and the inner peripheral surface of the other opening of the front case 3. A seal protection cup 39 for covering the oil seal 38 is attached to the other side opening of the front case 3. A threaded portion 40 is formed on the other outer end of the shaft portion 9, and the threaded portion 40 projects into the central recess 41 of the flange portion 36. A nut 42 is screwed onto the screw portion 40.

In this way, by screwing the nut 42 onto the threaded portion 40 and deforming the plastic spacer 33, the inner ring members 13A and 13B of the double row rolling bearing 10 and the inner ring member 14 of the tapered roller bearing 25 are connected to the pinion gear 6. Of the double row rolling bearing 10 and the tapered roller bearing 25, which are sandwiched in the axial direction by the end surface of the companion flange 34 and the end surface of the companion flange 34.
The predetermined preload is applied to the tapered roller 26 of FIG.

In the differential device 1 having the above-mentioned structure, the lubricating oil 43 is stored at the level L in the differential case 2 when the operation is stopped. The oil 43 is sprung up as the ring gear 8 rotates during operation, and passes through the oil circulation passage 30 in the front case 3 to form the double row rolling bearing 10 and the tapered roller bearing 2.
5, the double-row rolling bearing 1 is guided so as to be supplied to the upper part.
0 and the tapered roller bearing 25 are circulated in the differential case 2 so as to be lubricated.

Next, a method of assembling such a differential device 1 will be described. First, for the first inner ring member 13A in the double row rolling bearing 10, the first ball group 15
Is attached to the first retainer 19 to form a first assembly 21. Further, the second ball group 16 is assembled to the second inner ring member 13B while being held by the second cage 20 to form a second assembly 22.

Then, with the front case 3 and the rear case 4 still separated, the outer ring member 11 of the double-row rolling bearing 10 is assembled into the front case 3. At this time, the outer ring member 11 is press-fitted from one side opening of the front case 3 to a predetermined axial position corresponding to a step portion formed on the annular wall 27. In addition, the outer ring member 12 of the tapered roller bearing 25 is attached to the annular wall 28 from the opening on the other side of the front case 3.
It is press-fitted to a predetermined position in the axial direction, which corresponds to the stepped portion formed in.

Separately from this, the first assembly 21 is assembled to the shaft portion 9 of the pinion shaft 7. That is, the first assembly 21
The first inner ring member 13A is press-fitted into the shaft portion 9 of the pinion shaft 7, and the first assembly 21 is positioned on the pinion gear 6 side of the shaft portion 9 of the pinion shaft 7. Furthermore, the second assembly 22
The second inner ring member 13B is inserted (clearance fit) into the shaft portion 9 of the pinion shaft 7, and the end surfaces of both inner ring members 13A and 13B are brought into contact with each other.

The pinion shaft 7 to which the first assembly 21 and the second assembly 22 are attached as described above is attached to the second assembly 22 from the small diameter side and the one side opening of the front case 3. The ball 18 is the outer ring raceway surface 18b on the small diameter side of the outer ring member 11.
The ball 17 of the first assembly 21 is inserted so as to fit into the outer ring raceway surface 17b of the outer ring member 11 on the large diameter side. As a result, the balls 17 of the first assembly 21 and the balls 18 of the second assembly 22 are assembled to the outer ring member 11 in the same axial direction.

Next, the plastic spacer 33 is externally fitted and inserted into the shaft portion 9 of the pinion shaft 7 from the other side opening of the front case 3. Then, the inner ring member 14 in the tapered roller bearing 25,
The assembly of the cage 25a and the tapered roller 26 is attached to the shaft portion 9 of the pinion shaft 7 through the other opening of the front case 3. In this case, the inner ring member 14 of the assembly is attached to the pinion shaft 7
The tapered roller 26 is fitted into the outer ring raceway surface of the outer ring member 12 while being press-fitted into the shaft portion 9.

Thereafter, the shielding plate 37 is inserted through the other side opening of the front case 3 into the shaft portion 9 of the pinion shaft 7, an oil seal 38 is attached, and a seal protection cup 39 is attached to the other side opening portion of the front case 3. The body portion 35 of the companion flange 34 is inserted into the seal protection cup 39, and its end face is brought into contact with the shield plate 37. Subsequently, the nut 42 is screwed onto the threaded portion 40 of the shaft portion 9 to deform the plastic spacer, whereby the balls 17 of both rows in the first assembly 21 and the second assembly 22 of the double-row rolling bearing 10 are deformed. , 18 and the tapered roller 26 of the tapered roller bearing 25 are applied with a predetermined preload.

At this time, the first inner ring member 13A of the first assembly 21 of the double-row rolling bearing 10 is press-fitted into the shaft portion 9 of the pinion shaft 7, and the second inner ring member 13B of the second assembly 22. Are loosely fitted to the shaft portion 9. Therefore, when the nut 42 is screwed onto the threaded portion 40 of the shaft portion 9, the load in the thrust direction acting on the first inner ring member 13A is directly transmitted to the second inner ring member 13B. As a result, the balls 17 surely contact the large diameter outer ring raceway surface 17b of the outer ring member 11 and the first inner ring raceway surface 17a of the first inner ring member 13A, and the small diameter outer ring raceway of the outer ring member 11 is made. Surface 18b and second inner ring raceway surface 13
The ball 18 surely contacts the second inner ring raceway surface 18a of B.

Therefore, the balls 17 in the first assembly 21 and the balls 18 in the second assembly 22 can be surely and almost evenly preloaded with a preload, and the required rigidity is secured. can do.

Further, according to the first embodiment of the present invention, the double row rolling bearing 10 having a small frictional resistance is used as the rolling bearing on the side of the pinion gear 6 on which a large thrust load acts. As a result, the rotational torque becomes smaller than that of the conventionally used tapered roller bearing, and the efficiency of the differential device 1 can be improved. Moreover, since the double row rolling bearing 10 is used instead of the single row ball bearing, the load capacity can be increased as compared with the single row ball bearing, and sufficient supporting rigidity can be obtained.

In addition, as the double row rolling bearing 10, the pitch circle diameter D1 of the first ball group 15, that is, the ball group 15 on the pinion gear 6 side, and the pitch circle diameter D2 of the second ball group 16 are used.
By using the tandem-type double-row rolling bearing 10 that is larger than the above, it is possible to increase the number of balls 17 in the ball group 16 on the pinion gear 6 side on which a larger thrust load is exerted, and therefore, the load capacity is increased. It can be made even larger.

(Second Embodiment) Next, FIG. 4 and FIG.
The second embodiment of the present invention will be described with reference to FIG. Figure 4
FIG. 5 is a cross-sectional view of the double-row rolling bearing portion after assembly of the differential device, and FIG. 5 is an explanatory diagram during assembly of the differential device. For the overall configuration of the differential device, refer to the overall configuration diagram of FIG.

The double row rolling bearing 10 that rotatably supports one side of the shaft portion 9 of the pinion shaft 7 about the axis is an outer ring member 50, a first assembly 51A, and a second assembly 51B.
Composed of.

The outer ring member 50 is a large diameter outer ring raceway surface 50a.
And a small diameter side outer ring raceway surface 50b. First assembly 51
A is a first inner ring member 52 having a first inner ring raceway surface 52a facing the large diameter outer ring raceway surface 50a, and a cylindrical roller as a first rolling element group incorporated in this first inner ring member 52. The group 54 and the first cage 56 that holds the cylindrical rollers 55 of the group of cylindrical rollers 54 in the circumferentially equidistant positions. The first inner ring member 52 is press fitted into the pinion shaft 7. The end surface of the first inner ring member 52 is in contact with the end surface of the pinion gear 6 in the axial direction.

The second assembly 51B includes a second inner ring member 53.
And a ball group 58 as a second rolling element group incorporated in the second inner ring member 53, and a second cage 57 for holding the balls 59 of the ball group 58 in the circumferentially equidistant positions. Have and. Both the first inner ring member 52 and the second inner ring member 53 are shoulder inner rings. Second inner ring member 5
3 is loosely fitted on the pinion shaft 7.

The pitch circle diameter D3 of the cylindrical roller group 54 is set to be larger than the pitch circle diameter D4 of the ball group 58. The diameter of the shoulder portion of the second inner ring member 53 is formed to be larger than the diameter of the shoulder recess portion of the first inner ring member 52.

The structure of the other parts of the differential device 1 is the same as that of the first embodiment, and therefore its explanation is omitted.

A method of assembling the differential device 1 having the above structure will be described. First, the double row rolling bearing 10
In the above, the first inner ring member 52 is assembled with the cylindrical roller group 54 held by the first cage 56 to form a first assembly 51A. In addition, the second inner ring member 53
On the other hand, the ball group 58 is held in the second holder 57 and assembled to form a second assembly 51B.

Next, with the front case 3 and the rear case 4 still separated, the outer ring member 50 of the double-row rolling bearing 10 is assembled into the front case 3. At this time, the outer ring member 50 is press-fitted from one side opening of the front case 3 to a predetermined axial position corresponding to a step formed on the annular wall 27. In addition, the outer ring member 12 of the tapered roller bearing 25 is attached to the annular wall 28 from the opening on the other side of the front case 3.
It is press-fitted to a predetermined position in the axial direction, which corresponds to the stepped portion formed in.

Separately from this, the first assembly 51A is assembled to the shaft portion 9 of the pinion shaft 7. That is, the first assembly 5
The first inner ring member 52 in 1A is press-fitted into the shaft portion 9 of the pinion shaft 7, and the first assembly 51A is positioned on the pinion gear 6 side of the shaft portion 9 of the pinion shaft 7. Further, the second inner ring member 53 in the second assembly 51B is inserted (clearance fit) into the shaft portion 9 of the pinion shaft 7, and the inner ring member 52,
The end faces of 53 are brought into contact with each other.

The pinion shaft 7 to which the first assembly 51A and the second assembly 51B are attached as described above is connected to the second assembly 51B from the small diameter side and from the one side opening of the front case 3. The ball 59 is inserted into the outer ring member 50 so that it fits into the small-diameter outer ring raceway surface 50b, and the roller of the first assembly 51A fits into the large-diameter outer ring raceway surface 50a of the outer ring member 50. As a result, the cylindrical roller 55 of the first assembly 51A and the ball 59 of the second assembly 51B are assembled to the outer ring member 50 in the same axial direction.

Next, the plastic spacer 33 is externally fitted and inserted into the shaft portion 9 of the pinion shaft 7 from the other side opening of the front case 3. Then, the inner ring member 14 in the tapered roller bearing 25,
The assembly of the cage 25a and the tapered roller 26 is attached to the shaft portion 9 of the pinion shaft 7 through the other opening of the front case 3. In this case, the inner ring member 14 of the assembly is attached to the pinion shaft 7
The tapered roller 26 is fitted into the outer ring raceway surface of the outer ring member 12 while being press-fitted into the shaft portion 9.

Thereafter, the shield plate 37 is inserted through the other side opening of the front case 3 into the shaft portion 9 of the pinion shaft 7, an oil seal 38 is attached, and a seal protection cup 39 is attached to the other side opening portion of the front case 3. The body portion 35 of the companion flange 34 is inserted into the seal protection cup 39, and its end face is brought into contact with the shield plate 37. Subsequently, the nut 42 is screwed onto the threaded portion 40 of the shaft portion 9 to deform the plastic spacer 33, whereby the second assembly 51 of the double row rolling bearing 10 is formed.
A predetermined preload is applied to the ball 59 in B and the tapered roller 26 of the tapered roller bearing 25.

At this time, the first inner ring member 52 of the first assembly 51A of the double-row rolling bearing 10 is press-fitted into the shaft portion 9 of the pinion shaft 7, and the second inner ring member 53 of the second assembly 51B. Are loosely fitted to the shaft portion 9. Therefore, when the nut 42 is screwed onto the threaded portion 40 of the shaft portion 9, the load in the thrust direction acting on the first inner ring member 52 is directly transmitted to the second inner ring member 53. As a result, the balls 59 are surely brought into contact with the small-diameter outer ring raceway surface 50b of the outer ring member 50. Therefore, it is possible to reliably apply the preload to the balls 59 in the second assembly 51B and to secure the required rigidity.

By the way, in the double-row rolling bearing 10, the outer ring member 50 and the first assembly 51A form a cylindrical roller 55.
Has a bearing function. In the double row rolling bearing 10, the outer ring member 50 and the second assembly 51B have a function of an angular ball bearing. Therefore, the radial load acting on the double-row rolling bearing 10 is mainly borne by the outer ring member 50 and the first assembly 51A, and the thrust load is mainly borne by the outer ring member 50 and the second assembly 51B. Will be borne by.

Further, according to the second embodiment, as the rolling bearing on the side of the pinion gear 6 on which a large thrust load acts, a rolling bearing formed by combining a cylindrical roller bearing and an angular ball bearing is used instead of the conventional tapered roller bearing. ing. As a result, the contact area between the rolling elements and the raceway can be made smaller than that in the case of using the tapered roller bearing, so that the rotating torque becomes smaller than that of the tapered roller bearing and the efficiency of the differential device 1 is improved. be able to. Moreover, since the double-row rolling bearing 10 is not a single-row ball bearing but a combination of a cylindrical roller bearing and an angular ball bearing, the load capacity can be made larger than that of a single-row ball bearing, which is sufficient. Supporting rigidity is obtained.

(Third Embodiment) Next, FIG. 6 and FIG.
A third embodiment of the present invention will be described with reference to FIG. Figure 6
FIG. 7 is a cross-sectional view of the double-row rolling bearing portion after assembly of the differential device, and FIG. 7 is an explanatory diagram during assembly of the differential device. For the overall configuration of the differential device, refer to the overall configuration diagram of FIG.

The double row rolling bearing 10 which rotatably supports one side of the shaft portion 9 of the pinion shaft 7 around the axis is composed of a first assembly 60 and a second assembly 61.

The first assembly 60 includes a large diameter raceway surface 63 on the large diameter side.
a and a single outer ring member 63 having a small diameter side large diameter raceway surface 63b, one inner ring member 64 having an inner ring raceway surface 64a radially opposed to the small diameter side large diameter raceway surface 63b, and a small diameter of the outer ring member 63. It has a side large diameter raceway surface 63b and a first ball group 65 arranged between the inner ring raceway surface 64a of one inner ring member 64. The balls 65a forming the first ball group 65 are held by the first retainer 65b at equal positions in the circumferential direction. One inner ring member 64 is loosely fitted on the pinion shaft 7. This first assembly 60
Has the structure of a deep groove ball bearing.

The second assembly 61 is assembled to the other inner ring member 66 having an inner ring raceway surface 66a that faces the large diameter side large diameter raceway surface 63a in the radial direction, and to the other inner ring member 66. , And a second ball group 67 fitted to the large diameter side large diameter raceway surface 63a. The balls 67a forming the second ball group 67 are held by the second cage 68 at equal positions in the circumferential direction. As the other inner ring member 66, a shoulder set inner ring is used, and this inner ring member 66 is press-fitted into the shaft portion 9 of the pinion shaft 7. The end surface of the other inner ring member 66 is in contact with the end surface of the pinion gear 6 in the axial direction. The pitch circle diameter D5 of the second ball group 67 is set to be larger than the pitch circle diameter D6 of the first ball group 65.

The outer ring member 63 serves as the first bearing ring, one inner ring member 64 serves as the second bearing ring, the first ball group 65 serves as the first rolling element group, and the other inner ring member 66 serves as the other inner ring member 66. The second ball group 67 corresponds to the third race, and the second ball group 67 corresponds to the second rolling element group.

The structure of the other parts of the differential device 1 is the same as that of the first embodiment, and therefore its explanation is omitted.

A method of assembling the differential device 1 having the above structure will be described. First, the double row rolling bearing 10
In the above, the outer ring member 63, the first cage 65b, the first ball group 65, and the first inner ring member 64 are assembled into a first assembly 60. Further, the second ball group 67 is assembled to the other inner ring member 66 while being held by the second retainer 68 to form the second assembly 61.

Next, with the front case 3 and the rear case 4 still separated, the outer ring member 63 of the first assembly 60 of the double-row rolling bearing 10 is assembled into the front case 3. At this time, the outer ring member 63 is attached to the front case 3
It is press-fitted from one side opening to a predetermined position in the axial direction corresponding to a step formed on the annular wall 27. Further, the outer ring member 12 of the tapered roller bearing 25 is press-fitted from the other side opening of the front case 3 to a predetermined axial position corresponding to a step formed on the annular wall 28.

Separately from this, the second assembly 61 is assembled to the shaft portion 9 of the pinion shaft 7. That is, the second assembly 61
The other inner ring member 66 in the shaft portion 9 of the pinion shaft 7.
Then, the second assembly 61 is positioned on the side of the pinion gear 6 of the shaft portion 9 of the pinion shaft 7.

From the small diameter side of the pinion shaft 7 to which the second assembly 61 is attached as described above and from one side opening of the front case 3, the balls 67a of the second assembly 61 are attached to the outer ring member 63. It is inserted so as to fit on the large diameter side raceway surface 63a. As a result, the second assembly 61 is assembled to the first assembly 60 to form the double-row rolling bearing 10. At this time, a predetermined axial gap is provided between one inner ring member 64 and the other inner ring member 66, and a thrust load acts from the other inner ring member 66 to the first inner ring member 64. Set it so that it does not exist.

Next, the plastic spacer 33 is externally fitted and inserted into the shaft portion 9 of the pinion shaft 7 through the other side opening of the front case 3. Then, the inner ring member 14 in the tapered roller bearing 25,
The assembly of the cage 25a and the tapered roller 26 is attached to the shaft portion 9 of the pinion shaft 7 through the other opening of the front case 3. In this case, the inner ring member 14 of the assembly is attached to the pinion shaft 7
The tapered roller 26 is fitted into the outer ring raceway surface of the outer ring member 12 while being press-fitted into the shaft portion 9.

Thereafter, the shielding plate 37 is inserted through the other side opening of the front case 3 into the shaft portion 9 of the pinion shaft 7, an oil seal 38 is attached, and a seal protection cup 39 is attached to the other side opening portion of the front case 3. The body portion 35 of the companion flange 34 is inserted into the seal protection cup 39, and its end face is brought into contact with the shield plate 37. Subsequently, the nut 42 is screwed onto the threaded portion 40 of the shaft portion 9, whereby the double-row rolling bearing 1
A predetermined preload is applied to the balls 67a of the second assembly 61 of 0 and the tapered rollers 26 of the tapered roller bearing 25.

As described above, the first assembly 60 is a deep groove ball bearing, and the first inner ring member 64 and the other inner ring member 66 are provided.
Between the inner ring member 66 and the first inner ring member 64 so as to prevent a thrust load from acting on the other inner ring member 66, so that a double-row rolling bearing is formed. In 10 the part which gives the preload is the second ball group 6
7 and therefore, the preload control in the double row rolling bearing 10 is facilitated.

By the way, the first assembly 60 of the double-row rolling bearing 10 has the function of a deep groove ball bearing. The second assembly 61 of the double-row rolling bearing 10 has the function of an angular ball bearing. Therefore, the double row rolling bearing 10
The radial load acting on the
The load in the thrust direction is to be borne by the second assembly 61, so that the required rigidity can be secured.

Further, according to the third embodiment, as the rolling bearing on the side of the pinion gear 6 on which a large thrust load acts, a rolling bearing formed by combining a deep groove ball bearing and an angular ball bearing is used instead of the conventional tapered roller bearing. ing.
As a result, the contact area between the rolling elements and the raceway can be made smaller than that of a bearing using tapered rollers, so that the rotating torque becomes smaller than that of a tapered roller bearing, and the efficiency of the differential device 1 can be improved. You can Moreover, the double row rolling bearing 10 is not a single row ball bearing but a combination of a deep groove ball bearing and an angular ball bearing.
The load capacity can be increased compared to a single row rolling bearing, and sufficient support rigidity can be obtained.

In addition, as the double row rolling bearing 10, a tandem type double row rolling in which the pitch circle diameter of the second ball group 67 on the pinion gear 6 side is made larger than the pitch circle diameter of the first ball group 65. By using the bearing 10, the second ball group 6 on the side of the pinion gear 6 on which a larger thrust load acts
It is possible to increase the number of balls in 7 and thus
The load capacity can be further increased.

[0067]

As is apparent from the above description, according to the present invention, it becomes easy to control the preload on the rolling elements of each row of the double row rolling bearing. Alternatively, the preload can be evenly applied to the rolling elements in each row.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of a differential device showing a first embodiment of the present invention.

FIG. 2 is likewise an enlarged sectional view of a main part.

FIG. 3 is a sectional view showing a state in the middle of assembling the double-row rolling bearing.

FIG. 4 is an enlarged sectional view of an essential part of a double-row rolling bearing showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing a state in which the double-row rolling bearing is in the middle of assembling.

FIG. 6 is an enlarged sectional view of an essential part of a double row rolling bearing showing a third embodiment of the present invention.

FIG. 7 is a sectional view showing a state in which the double row rolling bearing is in the middle of assembling.

FIG. 8 is a cross-sectional view showing the overall configuration of a differential device showing a conventional example.

[Explanation of symbols]

1 differential device 7 pinion shaft 10 Double row rolling bearing 11 Outer ring member 13A First inner ring member 13B Second inner ring member 15 First ball group 16 Second ball group 17a First inner ring raceway surface 17b Large diameter outer ring raceway surface 18a Second inner ring raceway surface 18b Small diameter outer ring raceway surface 21 First Assembly 22 Second assembly 25 tapered roller bearing 27 Ring wall 34 companion flange D1 pitch circle diameter D2 pitch circle diameter

Continued front page    (72) Inventor Hideo Ueda             3-5-8 Minamisenba, Chuo-ku, Osaka Koyo             Within Seiko Co., Ltd. F term (reference) 3J017 AA10 BA10 HA10                 3J101 AA03 AA13 AA24 AA32 AA43                       AA54 AA62 AA77 BA53 BA54                       BA56 FA41 GA02

Claims (4)

[Claims] 1. A single bearing ring having a large-diameter side raceway surface and a small-diameter side raceway surface that are axially separated from each other, and the other raceway ring that faces the single raceway ring in the radial direction and between both raceways. A double row rolling bearing having an assembly including a rolling element group, wherein the assembly is a first assembly and a second assembly that are assembled in the same axial direction with respect to a single bearing ring. The first assembly includes a first race having a first raceway surface that faces a large raceway surface of a single raceway in a radial direction, and the large raceway surface and a first raceway. A first rolling element group that fits between the first raceway surface and a first raceway surface, and the second assembly has a second raceway surface that radially faces the small diameter side raceway surface of the single raceway ring. A double-row rolling bearing comprising a second raceway ring and a second rolling element group fitted between the small diameter side raceway surface and the second raceway surface. 2. A single bearing ring having a large-diameter side raceway surface and a small-diameter side raceway surface, which are axially separated from each other, and another raceway ring radially facing the single raceway ring and between the two raceway rings. A method of assembling a double row rolling bearing having an assembly including a group of rolling elements, wherein a first raceway surface having a first raceway surface radially opposed to a large diameter raceway surface of the single raceway ring is provided. A first assembly including a bearing ring and a first rolling element group fitted between the large diameter side raceway surface and the first raceway surface, and a radial direction on the small diameter side raceway surface of a single bearing ring. A second race having a second raceway surface facing each other, and a second assembly including a second rolling element group fitted between the small diameter side raceway surface and the second raceway surface. A method for assembling a double-row rolling bearing, characterized in that the single-race ring is assembled from the same axial direction. 3. A double row rolling bearing comprising a first assembly and a second assembly assembled from the axial direction, wherein the first assembly comprises a large diameter side raceway surface and a small diameter rolling bearing. A single first race ring having a side raceway surface, a second raceway ring having a raceway surface radially opposed to one of the large diameter side raceway surface and the small diameter side raceway surface, and A first rolling element group arranged between one raceway ring and a second raceway ring, and the second assembly is the other raceway of the large diameter side raceway surface and the small diameter side raceway surface. A third raceway ring having a raceway surface that faces each other in the radial direction, and the other raceway surface of the large diameter side raceway surface and the small diameter side raceway surface that is assembled to the third raceway wheel And a second group of rolling elements fitted in the axial direction to the double row rolling bearing. 4. A method for assembling a double row rolling bearing, which comprises assembling a first assembly and a second assembly from the axial direction, the single-row rolling bearing having a large diameter side raceway surface and a small diameter side raceway surface. A first raceway ring, a second raceway ring having a raceway surface radially opposed to one of the large diameter side raceway surface and the small diameter side raceway surface, the first raceway wheel and the first raceway wheel A first assembly including a first rolling element group arranged between two races, and a raceway that radially opposes the other raceway surface of the large diameter side raceway surface and the small diameter side raceway surface. A third race having a surface, and a third race that is assembled to the third race and that is fitted to the other raceway surface of the large diameter raceway surface and the small diameter raceway surface from the axial direction. A method for assembling a double row rolling bearing, characterized in that the second assembly including the second rolling element group is assembled from the axial direction.