JP5636887B2 - Tandem angular contact ball bearings - Google Patents

Description

The present invention relates to an improvement in a tandem angular ball bearing that is incorporated in a differential device for an automobile and supports a pinion shaft for a differential gear that rotates in a state where a radial load and a thrust load are applied. Specifically, it is intended to realize a structure capable of shortening the axial dimension while ensuring the load capacity.

  A pinion shaft for constituting a differential gear for automobiles is rotatably supported by a plurality of rolling bearings in a differential case. Since large radial load and thrust load are simultaneously applied to the pinion shaft during differential gear operation, it is necessary to use a bearing with sufficient load capacity in both radial and thrust directions to support the pinion shaft. is there. In addition, due to the recent trend of reducing fuel consumption in automobiles, it is possible to support large loads in both the radial and thrust directions as rolling bearings for supporting the pinion shaft with respect to the differential case, and in comparison with tapered roller bearings. As described in Patent Documents 1 to 3, it has been conventionally considered to use a tandem angular ball bearing that can keep the torque low.

  FIG. 13 shows a rotational support device for a pinion shaft for a differential gear, which is configured by a tandem angular ball bearing described in Patent Document 1. Since the structure and operation of the entire differential gear are well known and described in Patent Documents 1 and 2, the illustration and detailed description thereof will be omitted. Hereinafter, the structure of the rotation support device portion will be described. explain. A pair of ball bearings 1 and 2 are arranged inside the differential case in a state of being separated from each other, and the pinion shaft 3 is supported by these ball bearings 1 and 2. These ball bearings 1 and 2 are angular ball bearings in which the balls have contact angles, and the contact angles of these ball bearings 1 and 2 are opposite to each other. Therefore, the pinion shaft 3 is rotatably supported in the differential case in a state where not only a radial load but also a thrust load in both directions is supported.

  Of the two ball bearings 1 and 2, a tandem angular ball bearing which is a subject of the present invention is used as the ball bearing 1 on the pinion gear 4 side (the right side in FIG. 13) for supporting a relatively large radial load and thrust load. Is used. On the other hand, the ball bearing 2 on the anti-pinion gear 4 side (left side in FIG. 13) that supports only a relatively small radial load and thrust load uses a single-row angular ball bearing. However, a structure in which not only the pinion gear side but also the ball bearing on the anti-pinion gear side is a tandem angular type is described in Patent Documents 1 and 2, and is conventionally known. In the case of such a structure, the ball bearing on the anti-pinion gear side is also an object of the present invention. In any case, in addition to the radial load, the ball bearing 1 on the pinion gear 4 side supports a thrust load in a direction away from the ring gear (not shown) meshed with the pinion gear 4 (leftward in FIG. 13). On the other hand, the ball bearing 2 on the side opposite to the pinion gear 4 supports a thrust load in a direction approaching the ring gear (rightward in FIG. 13) in addition to the radial load.

  In the case of this example, the ball bearing 1 on the pinion gear 4 side, which is a tandem angular ball bearing, includes an outer ring 5, an inner ring 6, a plurality of balls 7a and 7b, and a pair of cages 8a and 8b. Prepare. Of these, the outer ring 5 is provided with double-row angular outer ring raceways 9a and 9b having different inner diameters on the inner peripheral surface. The inner diameters of these outer ring raceways 9 a and 9 b are larger in the outer ring raceway 9 a on the pinion gear 4 side and smaller in the outer ring raceway 9 b on the opposite side to the pinion gear 4. Further, the inner ring 6 is disposed concentrically with the outer ring 5 on the inner diameter side of the outer ring 5, and the outer diameters of the outer peripheral surfaces of the inner ring 6 are opposite to the outer ring raceways 9a and 9b. Double row angular type inner ring raceways 10a and 10b are provided. The outer diameters of both the inner ring raceways 10a and 10b are larger in the inner ring raceway 10a on the pinion gear 4 side and smaller in the outer ring raceway 10b on the opposite side to the pinion gear 4. Further, a plurality of balls 7a, 7b are arranged in the same direction in both rows (parallel combination type) between the outer ring raceways 9a, 9b and the inner ring raceways 10a, 10b. ) It is provided so as to be able to roll while being given a contact angle. Furthermore, both the cages 8a and 8b have different diameters, and each retains the balls 7a and 7b in both rows in a freely rollable manner. The diameters of the balls 7a and 7b in both rows may be the same or different from each other.

  The tandem angular ball bearing 1 as described above is incorporated between the inner peripheral surface of the support hole 12 of the support portion 11 of the differential case and the outer peripheral surface of the pinion shaft 3. And since the said ball bearing 1 does not involve a big sliding contact like the case of a tapered roller bearing at the time of a driving | running, dynamic torque can be restrained low and the resistance of a differential gear can be made low. Further, since the balls 7a and 7b arranged in a double row support the radial load and the thrust load generated at the meshing portion of the pinion gear 4 and the ring gear, it is possible to sufficiently secure the load capacity related to the loads in both directions.

  In order to reduce the size and weight of a differential gear incorporating a tandem angular ball bearing as described above, it is desirable to reduce the axial dimension of this tandem angular ball bearing while ensuring a load capacity. . In order to secure the load capacity, it is important to secure the diameter and number of the balls 7a and 7b. On the other hand, in order to shorten the axial dimension while securing the diameter and number of these balls 7a, 7b, the pitch (inter-row pitch) P of the balls 7a, 7b in both rows is shortened. There is a need to. In order to reduce the pitch between the balls 7a and 7b in both rows without reducing the diameter of the balls 7a and 7b, the structure of the invention described in Patent Document 4 should be adopted. Can be considered. As shown in FIG. 14, the structure of the invention described in Patent Document 4 shifts the phases of the balls 7a and 7b in both rows in the circumferential direction, and the balls 7a and 7b in both rows are single. Is held by the cage 8c. If such a structure is adopted, as is apparent from FIG. 14, a part of the balls 7a and 7b in both rows is overlapped with each other in the circumferential direction, and the pitch p between the rows 7a and 7b in both rows is set. Together with the shortening, the axial dimensions of the outer ring 5a and the inner ring 6a can be shortened.

However, the structure of the invention described in Patent Document 4 as described above has room for improvement in the following points (1) and (2).
(1) Since the difference in revolution speed (the number of revolutions per unit time, revolution angular velocity) of the balls 7a and 7b in both rows is not considered, excessive stress is applied to the cage 8c, and the cage 8c Damages such as cracks occur, and excessive slip occurs at the contact portions between the rolling surfaces of the balls 7a and 7b and the outer ring raceways 9a and 9b and the inner ring raceways 10a and 10b. In addition, such excessive slip causes a metal contact due to the oil film breakage at each of these contact portions, and significantly impairs the durability of the tandem angular ball bearing.
(2) The cage 8c is provided with rim portions 13a and 13b at both axial ends, respectively, and these rim portions 13a and 13b are more axial than the balls 7a and 7b, respectively. Protruding. For this reason, it is disadvantageous in terms of shortening the axial dimension of the tandem angular ball bearing by the amount of both the rim portions 13a and 13b.

  Patent Document 3 discloses an invention relating to a structure in which the cages in both rows are separated from each other, the balls in both rows can revolve independently of each other, and the difference in revolution speed between the rows is kept small (less than 10%). Is described. In addition to the above-mentioned Patent Document 3, Non-Patent Documents 1 and 2 describe the formula for obtaining the revolution speed (rotational speed of the cage) of the balls constituting the angular ball bearing. Patent Document 3 also describes that both rows of cages may be integrated (paragraph [0037] portion of the specification). Therefore, according to the structure of the invention described in Patent Document 3, among the problems that occur in the case of the invention described in Patent Document 4 shown in (1) and (2), (1) Problems can be reduced or eliminated. However, even in the structure of the invention described in Patent Document 3, since the rim portions are provided at both ends in the axial direction of the cage, an increase in the axial dimension of the cage itself can be avoided. However, the problem (2) cannot be solved.

JP 2004-169890 A JP 2004-245231 A JP 2009-36348 A JP 2004-308792 A

J. et al. Blend Line and other three edited by Tatsuo Yoshitake, “Handbook for Rolling Bearings”, first edition, second edition, Industrial Research Co., Ltd., August 2, 1997, p. 89-91 “NSK Technical Report”, Catalog No. 728e, NSK Ltd., p. 250

  In view of the circumstances as described above, the present invention was invented to realize a structure of a tandem angular ball bearing capable of sufficiently shortening the axial dimension while ensuring a load capacity.

Each of the tandem angular ball bearings of the present invention is for rotatably supporting a pinion shaft constituting a differential device in a differential case, and includes an outer ring , an inner ring, a plurality of balls, And a cage.
Of these, the outer ring is an angular type and has two rows of outer ring raceways having different inner diameters on the inner peripheral surface in the same direction.
Further, the inner ring is an angular type and has two rows of inner ring raceways having different outer diameters provided on the outer peripheral surface in the same direction, and is arranged concentrically with the outer ring on the inner diameter side of the outer ring.
Each of the balls is provided with a contact angle in the same direction between the outer ring raceways and the inner ring raceways in a same direction between the rows, and a plurality of pitch circle diameters. Are provided so as to be able to roll in a state where they are different from each other.
Moreover, the said holder | retainer hold | maintains each said ball | bowl so that rolling is possible.
The tandem angular ball bearing of the present invention as described above is used in an oil lubrication environment.

In particular, in the tandem angular contact ball bearing of the present invention described in claim 1, the cage is made of a synthetic resin, and is entirely in the shape of a partially conical cylinder, and has a plurality of central rim portions and a plurality of first rim portions. One pocket and a second pocket are provided.
Of these, the central rim portion is arranged at a portion between the balls arranged in both rows, and has an annular shape.
The first pockets are provided intermittently in the circumferential direction on one side of the central rim portion in the axial direction of the cage.
The second pockets are provided intermittently in the circumferential direction on the other side of the central rim portion with respect to the axial direction of the cage, with the phase in the circumferential direction being shifted from the first pocket. ing.
Further, with respect to both the first pockets and the second pockets, the portions opposite to the central rim portion with respect to the axial direction of the cage are open, and both axial edges of the cage are The first and second pockets do not protrude in the axial direction from the balls held in the pockets.
Further, at the portions facing the first and second pockets with respect to the axial direction of the cage, the inner peripheral edges are arranged between the inner peripheral surfaces of both ends of the outer ring and the outer peripheral surfaces of both ends of the inner ring. While locking to the outer peripheral surface of both ends of the inner ring, and by making each outer peripheral edge close to and opposed to the inner peripheral surface of both ends of the outer ring, it exists between the inner peripheral surface of these outer rings and the outer peripheral surface of the inner ring. A pair of closing plates are provided to close the openings at both ends of the space where each ball is installed.

On the other hand, in the tandem angular ball bearing according to claim 2, the cage is made of a synthetic resin and has a partially conical cylindrical shape, and includes a central rim portion and a small-diameter side rim portion. Each having a first pocket and a second pocket.
Of these, the central rim portion is arranged at a portion between the balls arranged in both rows, and has an annular shape.
Moreover, the said small diameter side rim | limb part is formed in the state which continues over the perimeter to the small diameter side edge part of the said holder | retainer.
The first pockets are provided intermittently in the circumferential direction on the larger diameter side than the central rim portion in the axial direction of the cage.
The second pockets are intermittently provided in the circumferential direction on the small diameter side of the central rim portion with respect to the axial direction of the cage, with the phase in the circumferential direction being shifted from the first pocket. ing.
Each of the first pockets is surrounded only on three sides of the central rim portion side portion and both side portions with respect to the circumferential direction, and the opposite side portion to the central rim portion is opened in the axial direction of the cage. The edge on the side of each first pocket with respect to the axial direction of the cage does not protrude in the axial direction from the balls held in the first pockets.
Each of the second pockets is surrounded by the entire circumference, and is open only in the radially outward direction and the radially inward direction. The shape of the opening is circular, and the inner surface is a concave part with a spherical surface. .

Furthermore, in any of the inventions described in claim 1 and claim 2, the revolution speeds (the number of revolutions per unit time, the revolution angular speed) of the balls in both rows are equal to each other.
That is, the diameter of each ball on the large-diameter row arranged between the outer ring raceway having a large inner diameter and the inner ring raceway having a large outer diameter is D _w1 mm, and the pitch circle diameter is D _pw1 mm. The contact angle is α ₁ degree,
The diameter of each ball on the small diameter side arranged between the outer ring raceway having a small inner diameter and the inner ring raceway having a small outer diameter is D _w2 mm, the pitch circle diameter is D _pw2 mm, and the contact angle is also the same. α ₂ degrees
When the rotation speed of the inner ring (the number of rotations per unit time, the rotation angular speed) is n _i min ⁻¹ and the rotation speed of the outer ring is n _e min ⁻¹ , it is expressed by the following equation (1). The relationship between the revolution speed n ₁ min ⁻¹ of each ball on the large diameter row side and the revolution speed n ₂ min ⁻¹ of each ball on the small diameter row side expressed by the following equation (2) is expressed as n ₁ = n ₂

According to the tandem angular contact ball bearing of the present invention configured as described above, it is possible to sufficiently shorten the axial dimension while securing the load capacity, and also to prevent damage to each part and ensure sufficient durability. .
That is, using a single cage, balls arranged in a double row are alternately arranged in the circumferential direction (arranged in a staggered manner), so the diameter of each of these balls is not reduced. The pitch between the balls of both rows can be shortened. Further, since it is not necessary to reduce the number of balls in both rows, it is possible to secure load capacity.
In addition, since the cage does not protrude in the axial direction from the ball held in the pocket on at least one of the pockets side, the axial direction of the tandem angular ball bearing includes this cage. Dimensions can be shortened.
Furthermore, since the revolution speeds of the balls in both rows are equal to each other, an excessive force is applied to the cage based on the difference in the revolution speeds of the balls in both rows, or the rolling surfaces of the balls No excessive slip occurs at the contact portion between the outer ring raceway and the inner ring raceway, and damage to each part can be suppressed to ensure sufficient durability.

The fragmentary sectional view which shows the 1st example of the reference example relevant to this invention . The expanded view shown in the state which took out the holder | retainer and was seen from radial direction. The fragmentary sectional view which shows the 1st example of embodiment of this invention. The fragmentary sectional view which shows the 2nd example of the reference example relevant to this invention . The fragmentary sectional view which shows the 3rd example . The fragmentary sectional view which shows the 4th example . The expanded view shown in the state which took out the holder | retainer and was seen from radial direction. The fragmentary sectional view which shows the 5th example of the reference example relevant to this invention . The fragmentary sectional view which shows the 2nd example of embodiment of this invention . The expanded view shown in the state which took out the holder | retainer and saw from radial direction. The fragmentary sectional view which shows the 6th example of the reference example relevant to this invention . The figure similar to FIG.2,7,10 which shows two examples of the arrangement | positioning state of a pocket. Sectional drawing which shows an example of the differential gear incorporating a tandem angular ball bearing. The fragmentary sectional view which shows the 2nd example of the tandem angular type ball bearing conventionally known.

[ First example of reference example related to the present invention ]
1 and 2 show a first example of a reference example related to the present invention . As shown in FIG. 1, the tandem angular ball bearing of the present reference example includes an outer ring 5b, an inner ring 6b, a plurality of balls 7A and 7B, and a single cage 8d.

Of these, the outer ring 5b has an outer peripheral surface that is a simple cylindrical surface, and two rows of outer ring raceways 9A and 9B that are angular and have different inner diameters are provided in the same direction on the inner peripheral surface. In the case of this reference example , as the diameters D _w1 and D _w2 of the balls 7A and 7B are different from each other, the curvature radii of the cross-sectional shapes of the outer ring raceways 9A and 9B are different from each other. . This is because the diameters D _w1 and D _w2 of the balls 7A and 7B arranged in two rows are different from each other in the case of the structure of this reference example . That is, in the case of this reference example , as will be described later, in order to make the revolution speeds of the balls 7A, 7B in both rows coincide with each other, the diameter D _w1 of each ball 7A, 7A on the larger pitch circle diameter D _pw1 side. _Is larger than the diameter D _w2 of the balls 7B and 7B on the small side (D _w1 > D _w2 ). Therefore, in the case of this reference example, the radius of curvature of the cross-sectional shape of the outer ring raceway 9A having a large inner diameter is made larger than the radius of curvature of the cross-sectional shape of the outer ring raceway 9B having a small inner diameter. On the other hand, as is widely known in the field of ball bearings, the radius of curvature of the cross-sectional shape of the outer ring raceway is made slightly larger than ½ of the diameter of the ball in rolling contact with the outer ring raceway. Specifically, according to the relationship between the diameters D _w1 and D _{w2 of the} balls 7A and 7B and the pitch circle diameters D _pw1 and D _pw2 of the respective rows, the cross-sectional shapes of the outer ring raceways 9A and 9B are determined. The relationship between the radius of curvature R _O and the diameter D (D _w1 , D _w2 ) of each of the balls 7A and 7B is R _O = (0.53 to 0.58) D. However, depending on the performance (load capacity, dynamic torque) required for the tandem angular ball bearing, the value of the radius of curvature R _O may be out of the above range.

Further, the inner ring 6b has an inner peripheral surface that is a simple cylindrical surface, and two rows of inner ring raceways 10A and 10B that are angular and have different outer diameters are provided in the same direction on the outer peripheral surface. . In the case of this reference example, the curvature radii of the cross-sectional shapes of the inner ring raceways 10A and 10B are also different from each other for the same reason that the curvature radii of the cross-sectional shapes of the outer ring raceways 9A and 9B are different from each other. It is Therefore, in the case of this reference example, the radius of curvature of the cross-sectional shape of the inner ring raceway 10A having a large outer diameter is made larger than the radius of curvature of the cross-sectional shape of the inner ring raceway 10B having a small outer diameter. As is widely known in the field of ball bearings, the radius of curvature of the cross-sectional shape of the inner ring raceway is slightly larger than ½ of the diameter of the ball in rolling contact with the inner ring raceway, and the inner ring raceway The radius of curvature of the outer ring raceway facing the raceway in the radial direction is slightly smaller than the curvature radius. Specifically, the relationship between the radius of curvature R _I of the cross-sectional shape of the inner ring raceways 10A and 10B and the diameter D (D _w1 , D _w2 ) of the balls 7A and 7B is expressed as R _I = (0.51 ˜0.53) D. Also for this radius of curvature R _I value, depending on the required performance, but may be outside this range. Such an inner ring 6b is concentric with the outer ring 5b on the inner diameter side of the outer ring 5b, with the outer ring raceway 9A and the inner ring raceway 10A facing each other, and the outer ring raceway 9B and the inner ring raceway 10B facing each other. It is arranged with.

Each of the balls 7A, 7B is held by the cage 8d between the outer ring raceways 9A, 9B and the inner ring raceways 10A, 10B, and a plurality of balls are provided for each row. It is provided so that it can roll freely. In this state, the balls 7A and 7B are given contact angles α ₁ and α ₂ in the same direction between the two rows. The pitch circle diameters D _pw1 and D _pw2 of the balls 7A and 7B in both rows are determined according to the difference between the inner diameters of the outer ring raceways 9A and 9B and the outer diameters of the inner ring raceways 10A and 10B. They are different from each other. That is, the pitch circle diameter D _pw1 of the row of balls 7A and 7A having a large diameter D _w1 is increased (the row is a large diameter row), and the pitch circle diameter D _pw2 of the row of balls 7B and 7B having a small diameter D _w2 2 is _used. Is made smaller (the row is a small diameter row).

Furthermore, the cage 8d is formed by injection molding a synthetic resin having oil resistance or by cutting a metal material (cylindrical material) having self-lubricating properties such as a copper-based alloy such as brass. The whole is formed in an annular shape. In the case of the present reference example , the cage 8d includes a central rim portion 14 and a plurality of first pockets 15 and 15 and a plurality of second pockets 16 and 16, respectively. . Each of the first and second pockets 15 and 16 is slightly larger than a semicircle when viewed from the radial direction of the cage 8d. The inner surfaces of the first and second pockets 15 and 16 facing the rolling surfaces of the balls 7A and 7B are smaller than ½ of the diameters D _w1 and D _w2 of the balls 7A and 7B. The concave surface is a partially spherical surface having a slightly large radius of curvature. Accordingly, the widths W ₁ and W ₂ of the openings on the axial end edge side of the cage 8d of the _first and _second pockets 15 and 16 are the diameters of the balls 7A and 7B held in the pockets 15 and 16, respectively. It is slightly smaller than D _w1 and D _w2 (W ₁ <D _w1 , W ₂ <D _w2 ).

  The first pockets 15 and 15 are formed at the large-diameter end edge of the retainer 8d, and the second pockets 16 and 16 are formed at the small-diameter end edge at equal pitches in the circumferential direction. doing. With respect to the phase in the circumferential direction, the installation positions of the first pockets 15 and 15 and the installation positions of the second pockets 16 and 16 are shifted from each other by a half pitch. Further, the back portions of the first pockets 15 and 15 and the back portions of the second pockets 16 and 16 are overlapped with each other in the circumferential direction. Accordingly, in a state in which the first pockets 15 and 15 and the second pockets 16 and 16 are partitioned, the portion between the balls 7A and 7A on the large diameter row side and the balls 7B and 7B on the small diameter row side. The central rim portion 14 provided at the axially intermediate portion of the cage 8d has a shape bent with respect to the circumferential direction.

  The balls 7A and 7A constituting the large-diameter side row with respect to the cage 8d having the above-described configuration are arranged in the first pockets 15 and 15 so as to constitute the small-diameter side row. The balls 7B and 7B are pushed into the second pockets 16 and 16 from the opening on the axial end edge side of the cage 8d, respectively. In the state after being pushed in, the balls 7A and 7B are engaged with each other by the rolling surfaces of the balls 7A and 7B and the inner surfaces of the first and second pockets 15 and 16 (by the ball guide). The radial position of the retainer 8d is restricted. A part of each of the balls 7A and 7B protrudes from the opening of each of the first and second pockets 15 and 16 in the axial direction. In other words, both end edges in the axial direction of the cage 8d do not protrude in the axial direction from the balls 7A and 7B held in the first and second pockets 15 and 16, respectively.

即ち、前記大径列側の各玉７Ａ、７Ａと前記小径列側の各玉７Ｂ、７Ｂとが同一角速度で公転運動し、これら両列の玉７Ａ、７Ｂの円周方向に関する位相がずれ動かない様にしている。 Further, in the case of the tandem angular ball bearing of this reference example , as described below, the revolving speed (the number of revolutions per unit time) of the balls 7A and 7B in both rows is regulated by regulating the dimensions and the like of each part. , Revolution angular velocities) are equal to each other.
First, as described above, the diameter of each ball 7A, 7A on the large diameter row side is D _w1 mm, the pitch circle diameter is D _pw1 mm, the contact angle is α ₁ degree, and each ball 7B on the small diameter row side is 7B. The diameter of 7B is D _w2 mm, the pitch circle diameter is D _pw2 mm, and the contact angle is α ₂ degrees.
Under these conditions, when the rotation speed of the inner ring 6b (the number of rotations per unit time, the rotation angular speed) is n _i min ⁻¹ and the rotation speed of the outer ring 5b is n ⁻⁻ _e min ⁻¹ , Revolution speed n ₁ min ⁻¹ of each ball 7A, 7A on the large diameter row side represented by the equation (1), and each ball 7B, 7B on the small diameter row side represented by the following equation (2) The relation with the revolution speed n ₂ min ⁻¹ is n ₁ = n ₂ .

That is, the balls 7A, 7A on the large-diameter row side and the balls 7B, 7B on the small-diameter row side revolve at the same angular velocity, and the phases in the circumferential direction of the balls 7A, 7B in both rows are shifted. I am not doing it.

According to the tandem angular contact ball bearing of this reference example configured as described above, it is possible to sufficiently shorten the axial dimension while securing the load capacity, and also to prevent damage to each part and ensure sufficient durability. it can.
That is, in the case of the structure of this reference example , the first and second pockets for holding the balls 7A and 7B arranged in a double row using the single holder 8d. 15 and 16 are alternately arranged in the circumferential direction. Moreover, in the case of the structure of this reference example , the back portions of the first and second pockets 15 and 16 are overlapped with each other in the circumferential direction. For this reason, the pitch p between the balls 7A and 7B in both rows can be shortened without reducing the diameters D _w1 and D _w2 of the balls 7A and 7B. In addition, since it is not necessary to reduce the number of balls 7A and 7B in both rows, it is possible to secure load capacity.

  In addition, since both ends of the cage 8d in the axial direction do not protrude in the axial direction from the balls held in the first and second pockets 15 and 16, the tandem including the cage 8d is included. The axial dimension of angular contact ball bearings can be shortened. In addition, it is possible to reduce the size and weight of various rotary machine devices incorporating the tandem angular ball bearing, such as a differential gear and a transfer for an automobile.

Further, since the revolution speeds of the balls 7A and 7B in both rows are equal to each other, an excessive force is applied to the cage 8d based on the difference in the revolution speeds of the balls 7A and 7B in both rows. It can be suppressed. In addition, the rolling contact portions of the rolling surfaces of the balls 7A and 7B and the outer ring raceways 9A and 9B and the inner ring raceways 10A and 10B are excessively large (other than spin slip, which is unavoidable when the angular ball bearing is in operation). ) Slip can be suppressed. For this reason, damage of each part can be suppressed and sufficient durability can be secured. Note that due to unavoidable manufacturing errors, etc., the dimensions D _w1 , D _pw1 , α ₁ , D _w2 , D _pw2 , α ₂ may deviate from the design values, and n ₁ = n ₂ does not completely _occur . If the difference is kept small (for example, less than 5%, preferably less than 3%, more preferably less than 1% based on the larger value), the object of the present reference example and the present invention can be achieved. Therefore, in the present specification and claims, “n ₁ = n ₂ ” includes the case where there is a deviation of less than 5% based on the larger value as described above.

[ First example of embodiment]
FIG. 3 shows a first example of an embodiment of the present invention corresponding to claim 1 . In the case of this example, each ball 7A exists between the inner peripheral surface of both ends of the outer ring 5b and the outer peripheral surface of both ends of the inner ring 6b, between the inner peripheral surface of these outer rings 5b and the outer peripheral surface of the inner ring 6b. , 7B are provided with closing plates 18a, 18b for closing the openings at both ends of the space 17. In the case of this example, as the both blocking plates 18a and 18b, non-contact type plates called shield plates are used. Then, the inner peripheral edges of the both blocking plates 18a and 18b are respectively locked to the outer peripheral surfaces of both end portions of the inner ring 6b, and the outer peripheral edges thereof are brought close to and opposed to the inner peripheral surfaces of both end portions of the outer ring 5b. The labyrinth seal is configured.

According to the structure of this example configured as described above, the amount of lubricating oil flowing through the inside of the tandem angular ball bearing can be properly regulated. That is, when excessive lubricating oil exists in the space 17, the stirring resistance of the lubricating oil based on the rotation and revolution motion of the balls 7A and 7B existing in the space 17 becomes excessive. Can be prevented. Further, even if foreign matter such as wear powder enters the space 17, the foreign matter is disposed opposite to the large-diameter side row by the pump action based on the revolution movement of the balls 7A and 7B. It discharges | emits from the clearance gap between the outer periphery of the said closing board 18a, and the edge part inner peripheral surface of the said outer ring | wheel 5b. For this reason, the foreign matter is unlikely to cause a deterioration in the durability of the tandem angular ball bearing. Since other configurations and operations are the same as those in the first example of the reference example described above, the same reference numerals are given to the equivalent parts, and duplicate descriptions are omitted.

[ Second example of reference example related to the present invention ]
FIG. 4 shows a second example of a reference example related to the present invention . In the case of the first example embodiment shown in FIG. 3 described above, the openings at both ends of the space 17, the pair of closing plates 18a, adopts the structure which closes by 18b, in the case of the present embodiment Adopts a configuration in which only the end opening on the large diameter row side (the right side in FIG. 4) of the space 17 is closed by the closing plate 18a. Further, in the case of the present reference example, the occlusion plate to be assembled to the end opening on the small diameter row side (left side in FIG. 4) of the space 17 is omitted, so that the axial direction of the outer ring 5c and the inner ring 6c on the small diameter row side is omitted. The dimensions are made shorter than in the case of the first example of the above-described embodiment to further shorten the axial dimension of the tandem angular ball bearing.
Since the configuration and operation of the other parts are the same as those in the first example of the reference example or the first example of the embodiment described above, the same parts are denoted by the same reference numerals, and redundant description is omitted. .

[ Third example of reference example related to the present invention ]
FIG. 5 shows a third example of the reference example related to the present invention . In the case of the first example embodiment shown in FIG. 3 described above, the openings at both ends of the space 17, the pair of closing plates 18a, adopts the structure which closes by 18b, in the case of the present embodiment Adopts a configuration in which only the end opening on the small diameter row side (the left side in FIG. 5) of the space 17 is closed by the closing plate 18b. Further, in the case of this reference example, the occlusion plate to be assembled to the end opening on the large diameter row side (the right side in FIG. 5) of the space 17 is omitted, so that the outer ring 5d and the inner ring 6d are arranged on the large diameter row side . The axial dimension is made shorter than in the case of the first example of the embodiment described above to further shorten the axial dimension of the tandem angular ball bearing.
Since the configuration and operation of the other parts are the same as those of the first example of the reference example or the first example of the embodiment described above, the same parts are denoted by the same reference numerals, and redundant description is omitted. .

[ Fourth Reference Example Related to the Present Invention ]
FIGS. 6-7 has shown the 4th example of the reference example relevant to this invention . In the case of this reference example , the large-diameter side rim portion 19 is formed on the large-diameter side edge of the cage 8e so as to be continuous over the entire circumference. For this reason, each first pocket 15a, 15a holding the balls 7A, 7A on the large diameter row side becomes a circle surrounded by the entire circumference. Accordingly, the balls 7A and 7A are assembled in the first pockets 15a and 15a from the radial openings of the cage 8e.
In the case of such a structure of the present reference example , the axial dimension of the cage 8e increases as compared with the case of the first example of the reference example described above, but compared with the conventional structure described in Patent Document 4 described above, Axial dimension can be shortened.
Since the configuration and operation of the other parts are the same as those of the first example of the reference example described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[ Fifth example of reference example related to the present invention ]
FIG. 8 shows a fifth example of the reference example related to the present invention . In the case of this reference example, a closing plate 18b that closes the small diameter side end opening of the space 17 is provided between the small diameter side end inner peripheral surface of the outer ring 5b and the small diameter side end outer peripheral surface of the inner ring 6b. The amount of lubricating oil that circulates inside the angular ball bearing can be regulated appropriately.
Since the configuration and operation of the other parts are the same as those of the fourth example of the reference example described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[ Second Example of Embodiment]
FIGS. 9-10 has shown the 2nd example of embodiment of this invention corresponding to only Claim 2. FIG. In the case of this example, the small-diameter rim portion 20 is formed on the small-diameter end edge of the cage 8f so as to be continuous over the entire circumference. For this reason, each second pocket 16a, 16a holding the balls 7B, 7B on the small diameter row side has a circular shape surrounded by the entire circumference. Accordingly, the balls 7B and 7B are assembled in the second pockets 16a and 16a from the radial openings of the cage 8f.
In the case of such a structure of the present example, the axial dimension of the cage 8f increases as compared with the case of the first example of the reference example described above. Directional dimensions can be shortened.
Since the configuration and operation of the other parts are the same as those of the first example of the reference example described above, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[ Sixth Reference Example Related to the Present Invention ]
FIG. 11 shows a sixth example of the reference example related to the present invention . In the case of this reference example, a blocking plate 18a is provided between the outer peripheral surface of the outer ring 5b and the outer peripheral surface of the outer ring 5b and the outer peripheral surface of the inner ring 6b. Therefore, it is possible to appropriately regulate the amount of lubricating oil flowing through the inside of the tandem angular ball bearing.
Since the configuration and operation of the other parts are the same as those of the second example of the above-described embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

In carrying out the present invention, in order to shorten the axial dimension of the cage as much as possible, as shown in FIGS. 1 to 11, the inner portions of the first pockets 15 and 15 (15a and 15a) It is preferable that the back portions of the second pockets 16 and 16 (16a and 16a) overlap each other in the circumferential direction. However, depending on the level required for shortening the axial dimension (the degree of necessity for reduction in size and weight), it may not be necessary to superimpose them. That is, as shown in FIGS. 1 to 11 and FIG. 12A, the back portions of the first pockets 15 and 15 and the back portions of the second pockets 16 and 16 are overlapped with each other in the circumferential direction. if (if "sum / 2 columns pitch <of both rows ball diameter"), in a state that combines and ball retainer made sufficiently small width W _a in the axial direction, a significant It becomes possible to reduce the size and weight. On the other hand, as shown in FIG. 12B, the back portions of the first pockets 15 and 15 and the back portions of the second pockets 16 and 16 are not overlapped with each other in the circumferential direction (“row” if between the sum / 2 "pitch ≧ of both rows of balls diameter), in a state in which the combination of the cage and balls, enough to shorten the width W _B in the axial direction, and by extension, size and The extent to which weight reduction is possible is limited. However, as described above, the structure shown in FIG. 12B can also be adopted depending on the required level for axial dimension reduction.

Further, in the case of carrying out the present invention (the invention according to claim 2) , when providing a closing plate that closes the end opening of the space in which each ball is installed, this closing plate is not limited to a non-contact type, It can also be a contact type (a seal ring provided with a seal material whose tip edge is in sliding contact with the mating surface). Further, the closing plate is not limited to a type that is locked to the outer peripheral surface of the inner ring, but may be a type that is locked to the inner peripheral surface of the outer ring.

The tandem angular ball bearing according to the present invention is incorporated in a differential device for an automobile and used to support a pinion shaft for a differential gear. However, although not within the technical scope of the present invention , the rotary shaft is supported by being incorporated in various rotary machine devices having a rotary shaft that rotates with a radial load and a thrust load, such as a transfer for an automobile. It can also be used to do.

DESCRIPTION OF SYMBOLS 1 Ball bearing 2 Ball bearing 3 Pinion shaft 4 Pinion gear 5, 5a, 5b, 5c, 5d Outer ring 6, 6a, 6b, 6c, 6d Inner ring 7a, 7b, 7A, 7B Ball 8a, 8b, 8c, 8d, 8e, 8f Cage 9a, 9b, 9A, 9B Outer ring raceway 10a, 10b, 10A, 10B Inner ring raceway 11 Support part 12 Support hole 13a, 13b Rim part 14 Central rim part 15, 15a First pocket 16, 16a Second pocket 17 Space 18a , 18b Blocking plate 19 Large diameter side rim portion 20 Small diameter side rim portion

Claims (2)

For supporting the pinion shaft constituting the differential device rotatably in the differential case,
Two outer ring raceways each having an angular shape and different inner diameters on the inner peripheral surface, outer rings provided in the same direction, and two rows of inner ring raceways each having an angular shape and different outer diameters on the outer periphery A plurality of inner rings arranged in the same direction on the inner surface of the outer ring and arranged concentrically with the outer ring on the inner diameter side of the outer ring, and the outer ring raceway and the inner ring raceways in a plurality of rows. A ball that is provided with a contact angle in the same direction between the rows and has a pitch circle diameter that is different from each other, and a single holding that holds the balls freely. A tandem angular contact ball bearing used in an oil-lubricated environment ,
The cage is made of synthetic resin, and has a partially conical cylindrical shape as a whole, and is arranged in a portion between the balls arranged in both rows, and an annular central rim portion, and the axial direction of the cage A plurality of first pockets intermittently provided in the circumferential direction on one side of the central rim portion, and the other side in the state in which the phase in the circumferential direction is shifted from each of the first pockets. A plurality of second pockets provided intermittently with respect to the direction,
With respect to both the first pocket and the second pocket, the central rim portion opposite to the axial direction of the cage is open, and both axial edges of the cage are It does not protrude in the axial direction than the balls held in the first and second pockets,
The inner peripheral edge of each inner ring is disposed between the inner peripheral surface of both ends of the outer ring and the outer peripheral surface of both ends of the inner ring at a portion facing the first and second pockets in the axial direction of the cage. Each of the balls is engaged between the outer circumferential surfaces of the outer rings and the outer circumferential surfaces of the outer rings by engaging the outer circumferential edges of the outer rings in close proximity to the inner circumferential surfaces of the outer rings. A pair of closing plates are provided to close the openings at both ends of the space where the
The diameter of each ball on the large diameter row side arranged between the outer ring raceway having a large inner diameter and the inner ring raceway having a large outer diameter is D _w1 mm, the pitch circle diameter is D _pw1 mm, and the contact angle is the same. Is α ₁ degree,
The diameter of each ball on the small diameter side arranged between the outer ring raceway having a small inner diameter and the inner ring raceway having a small outer diameter is D _w2 mm, the pitch circle diameter is D _pw2 mm, and the contact angle is also the same. α ₂ degrees
When the rotation speed of the inner ring is n _i min ⁻¹ and the rotation speed of the outer ring is n _e min ⁻¹ , the revolution of each ball on the large diameter row side represented by the following equation (1) The relationship between the speed n ₁ min ⁻¹ and the revolution speed n ₂ min ⁻¹ of each ball on the small diameter row side expressed by the following equation (2) is characterized by n ₁ = n ₂ Tandem angular contact ball bearings.

For supporting the pinion shaft constituting the differential device rotatably in the differential case,
Two outer ring raceways each having an angular shape and different inner diameters on the inner peripheral surface, outer rings provided in the same direction, and two rows of inner ring raceways each having an angular shape and different outer diameters on the outer periphery A plurality of inner rings arranged in the same direction on the inner surface of the outer ring and arranged concentrically with the outer ring on the inner diameter side of the outer ring, and the outer ring raceway and the inner ring raceways in a plurality of rows. A ball that is provided with a contact angle in the same direction between the rows and has a pitch circle diameter that is different from each other, and a single holding that holds the balls freely. A tandem angular contact ball bearing used in an oil-lubricated environment ,
The cage is made of synthetic resin, and has a partially conical cylindrical shape. The cage is arranged at a portion between the balls arranged in the two rows, and an annular central rim portion and a small-diameter side edge portion. a small diameter side rim portion formed in a state of continuous over the entire circumference, the larger diameter side than the central rim portion in the axial direction of said retainer, a plurality of first pockets arranged intermittently in the circumferential direction And on the small-diameter side , with a plurality of second pockets intermittently provided in the circumferential direction with the phase in the circumferential direction shifted from each of the first pockets,
Each of the first pockets is surrounded only on three sides of the central rim portion side portion and both side portions in the circumferential direction, and the opposite side portion to the central rim portion is open in the axial direction of the cage. the edge of each first pocket side in the axial direction of the retainer does not protrude in the axial direction than the respective balls held in the respective first pocket,
Each of the second pockets is surrounded by the entire circumference, and is open only in the radially outward direction and the radially inward direction, the shape of the opening is circular, and the inner surface is a partially spherical concave surface,
The diameter of each ball on the large diameter row side arranged between the outer ring raceway having a large inner diameter and the inner ring raceway having a large outer diameter is D _w1 mm, the pitch circle diameter is D _pw1 mm, and the contact angle is the same. Is α ₁ degree,
The diameter of each ball on the small diameter side arranged between the outer ring raceway having a small inner diameter and the inner ring raceway having a small outer diameter is D _w2 mm, the pitch circle diameter is D _pw2 mm, and the contact angle is also the same. α ₂ degrees
When the rotation speed of the inner ring is n _i min ⁻¹ and the rotation speed of the outer ring is n _e min ⁻¹ , the revolution of each ball on the large diameter row side represented by the following equation (1) The relationship between the speed n ₁ min ⁻¹ and the revolution speed n ₂ min ⁻¹ of each ball on the small diameter row side expressed by the following equation (2) is characterized by n ₁ = n ₂ Tandem angular contact ball bearings.

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