JP2005265093A - Double row obliquely contacting ball bearing and rotating shaft support structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a bearing function by allowing relative displacement of an outer ring 2 and an inner ring 3 with making the outer ring 2 and the inner ring 3 unseparatable in a double row obliquely contacting ball bearing 1 having double row balls 4A, 4B put between a large diameter raceway part 2a and a small diameter raceway part 2b provided on an inner circumference surface of the outer ring and a large diameter raceway part 3a and a small diameter raceway part 3b provided on an outer circumference surface of the inner ring 3, and having contact angles θ1, θ2 in same direction . <P>SOLUTION: A first and a second allowance part 3f, 3g allowing balls 4A, 4B of each row to roll in an axial direction are provided on an inner end side of the large diameter raceway part 3a of the inner ring 3 and an outer end side of the small diameter raceway part 3b of the inner ring 3 and a first and a second regulation part (a first and a second curved inclined surface 3h, 3i) regulating movement of balls 4A, 4B of each row in the axial direction to less than predetermined amount are provided on end parts of each allowance part 3f, 3g. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a double-row oblique contact ball bearing in which the inclinations of the contact angles are the same, and a rotary shaft support structure using the double-row oblique contact ball bearing.

  For example, in transmissions, differentials, and the like mounted on vehicles such as automobiles, their appropriate rotating shafts are supported on the inner periphery of the housing via two tapered roller bearings (see, for example, Patent Document 1). However, since the tapered roller bearing has a large contact area between the outer ring and the inner ring and the tapered roller, and slip occurs between the large flanges of the inner ring, the rotational resistance is relatively large.

  Therefore, it is conceivable to use a ball bearing having a smaller rotational resistance than a tapered roller bearing, but it is preferable to use a double row oblique contact ball bearing having a large load capacity for an axial load or a radial load. Among these double row oblique contact ball bearings, there is a so-called tandem type in which the inclinations of the contact angles are the same. An example of this tandem double row oblique contact ball bearing is shown in FIG. In order to make the outer ring 81 and the inner ring 91 non-separable in the axial direction, the inner diameter of the large diameter shoulder portion 84 of the outer ring 81 is made slightly smaller than the inner diameter of the bottom portion of the large diameter track portion 82 and the inner diameter of the medium diameter shoulder portion 85. Is slightly smaller than the inner diameter of the bottom portion of the small-diameter track portion 83, and the outer diameter of the medium-diameter shoulder portion 94 of the inner ring 91 is slightly larger than the outer diameter of the bottom portion of the large-diameter track portion 92 and the small-diameter shoulder portion 95 The outer diameter is slightly larger than the outer diameter of the bottom of the small-diameter track portion 93. That is, the large-diameter shoulder portion 84 and the medium-diameter shoulder portion 85 of the outer ring 81 and the medium-diameter shoulder portion 94 and the small-diameter shoulder portion 95 of the inner ring 91 are hooked to make the balls 80A and 80B in each row immovable in the axial direction. Thus, the outer ring 81 and the inner ring 91 are not separated in the axial direction.

In recent years, transmission and differential housings are sometimes made of light alloys (for example, aluminum alloys and magnesium alloys) instead of ferrous metals to reduce the weight. Because it is made of metal, when a pre-position preload is applied to the double row oblique contact ball bearing used to support the rotary shaft, the double row oblique contact ball bearing at high temperatures due to the difference in linear expansion coefficient between the housing and the rotary shaft There is a tendency for the preload to be lost. As shown in FIG. 5, such preload loss occurs due to the action of the forces F1 and F2 in the direction of the arrows that separate the outer ring 81 and the inner ring 91 in the axial direction. The phenomenon that 80B rides on the respective edges of the large-diameter shoulder portion 84 and the medium-diameter shoulder portion 85 of the outer ring 81 and the medium-diameter shoulder portion 94 and the small-diameter shoulder portion 95 of the inner ring 91 causes rolling of the balls 80A and 80B. Operation may be hindered.
JP-A-8-74845 (FIG. 7)

  In the double row oblique contact ball bearing in which the inclination of the contact angle is the same, the outer ring and the inner ring are not separated from each other, and relative displacement in the axial direction thereof is allowed. As a problem to be solved, it is necessary to ensure the rolling function in the circumferential direction of the ball and to ensure the bearing function when a force in the direction of pulling them apart in the axial direction is applied.

  The present invention interposes a plurality of balls between each of the large and small diameter track portions provided on the inner peripheral surface of the outer ring and each of the large and small diameter track portions provided on the outer peripheral surface of the inner ring. A double row oblique contact ball bearing having the same inclination of the contact angle of the ball, and in the inner ring, the axial direction of the ball on each of the inner end side of the large diameter raceway portion and the outer end side of the small diameter raceway portion Provided with first and second permissible portions that allow rolling to the end, and provided with first and second restricting portions that restrict movement of the ball in the axial direction by a predetermined amount or more at the end portions of the permissible portions. It is characterized by.

  According to the present invention, when a force is applied to pull the outer ring and the inner ring apart in the axial direction, the balls in each row roll in the axial direction on the first and second permissible portions of the inner ring, and the outer ring and the inner ring Can be separated in the axial direction by a predetermined amount. Even in this state, the balls in each row can smoothly roll in the circumferential direction, so that a radial load can be received. In addition, since the movement of the ball in the axial direction over a predetermined amount is restricted by the first and second restricting portions, the outer ring and the inner ring do not need to be separated.

  In the present invention, the outer ring and the inner ring can be separated from each other, and the relative displacement in the axial direction is allowed, and when the force in the direction of separating the outer ring and the inner ring in the axial direction is applied, The rolling motion in the circumferential direction of the ball is ensured, and the bearing function can be secured.

  Hereinafter, the present invention will be described based on the best embodiment shown in the drawings. FIG. 1 is a cross-sectional view showing the upper half of the double row oblique contact ball bearing, and FIG. 2 is a view showing a state when the outer ring and the inner ring are pulled apart in the axial direction.

  The double-row oblique contact ball bearing 1 shown in the figure has a configuration including an outer ring 2, an inner ring 3, two rows of balls 4A and 4B, and two cages 5 and 6, and the diameter of the two rows of balls 4A and 4B. The pitch circle diameter D1 of the balls 4A in one row is made larger than the pitch circle diameter D2 of the balls 4B in the other row, and the contact angles θ1 and θ2 of the balls 4A and 4B in the two rows are made the same so The angles θ1 and θ2 are inclined in the same direction. The double row oblique contact ball bearing 1 having such a configuration is referred to as a tandem type. However, even when the diameters and contact angles θ1 and θ2 of the two rows of balls 4A and 4B are different, they are called tandem double row oblique contact ball bearings.

  The outer ring 2 has a shape in which the inner peripheral surface has a diameter reduced stepwise in the axial direction, and specifically includes a large-diameter track portion 2a and a small-diameter track portion 2b arranged in the axial direction. A large-diameter shoulder portion 2c is formed on the outer end side, a small-diameter shoulder portion 2d is formed on the outer end side of the small-diameter track portion 2b, and a medium-diameter shoulder portion 2e is further interposed between the large-diameter track portion 2a and the small-diameter track portion 2b. , Each provided. The inner diameter of the large-diameter shoulder 2c is the same as the inner diameter of the bottom of the large-diameter track 2a. The inner diameter of the small-diameter shoulder portion 2d is smaller than the inner diameter of the bottom portion of the small-diameter track portion 2b. The inner diameter of the medium diameter shoulder 2e is larger than the inner diameter of the small diameter shoulder 2d and slightly smaller than the inner diameter of the bottom of the small diameter track 2b. The large-diameter track portion 2a is formed of a curved slope provided at the step portion between the large-diameter shoulder portion 2c and the medium-diameter shoulder portion 2e, and the small-diameter track portion 2b is provided at the step portion between the medium-diameter shoulder portion 2e and the small-diameter shoulder portion 2d. It consists of a curved slope.

  The inner ring 3 has a shape in which the outer peripheral surface is reduced in a stepped shape in the axial direction, and specifically includes a large-diameter track portion 3a and a small-diameter track portion 3b arranged in the axial direction. A large-diameter shoulder 3c is formed on the end side, a small-diameter shoulder 3d is disposed on the outer end side of the small-diameter track portion 3b, and a medium-diameter shoulder portion 3e is disposed between the large-diameter track portion 3a and the small-diameter track portion 3b. Each is provided. The outer diameter of the large-diameter shoulder 3c is larger than the outer diameter of the bottom of the large-diameter track 3a. The outer diameter of the small diameter shoulder portion 3d is smaller than the outer diameter of the medium diameter shoulder portion 3e and slightly larger than the outer diameter of the bottom portion of the small diameter track portion 3b. The outer diameter of the medium diameter shoulder 3e is smaller than the outer diameter of the large diameter shoulder 3c and slightly larger than the outer diameter of the bottom of the large diameter track 3a. The large-diameter track portion 3a is formed of a curved slope provided at the step portion between the large-diameter shoulder portion 3c and the medium-diameter shoulder portion 3e, and the small-diameter track portion 3b is provided at the step portion between the medium-diameter shoulder portion 3e and the small-diameter shoulder portion 3d. It consists of a curved slope.

  The balls 4A in a row that are interposed between the large-diameter track portion 2a of the outer ring 2 and the large-diameter track portion 3a of the inner ring 3 and whose pitch circle diameter D1 is increased are referred to as large-diameter rows. Further, the balls 4B in a row that are interposed between the small-diameter track portion 2b of the outer ring 2 and the small-diameter track portion 3a of the inner ring 3 and have a smaller pitch circle diameter D2 are referred to as small-diameter rows. The large diameter row 4A and the small diameter row 4B are separately held by, for example, cages 5 and 6 called crown type cages, and each ball is arranged at equal intervals in the circumferential direction.

  In such a tandem type double row oblique contact ball bearing 1, first, which allows the middle diameter shoulder 3 e and the small diameter shoulder 3 d of the inner ring 3 to roll the balls 4 A and 4 B in each row in the axial direction, Second permission portions 3f and 3g are provided.

  The first allowable portion 3f of the medium-diameter shoulder portion 3e is formed of a circumferential surface having the same outer diameter as that of the bottom portion of the large-diameter track portion 3a and continuing toward the large-diameter track portion 3a. The second allowable portion 3g of the small-diameter shoulder portion 3d is formed of a circumferential surface that has the same outer diameter as that of the bottom of the small-diameter track portion 3b and continues toward the small-diameter track portion 3b. Both the allowing portions 3f and 3g are set to a predetermined length along the direction along the rotation axis.

  A first curved slope 3h having a curvature substantially the same as the curvature of the balls 4B in the small diameter row is formed at the step portion between the medium diameter shoulder 3e and the first allowance 3f. A second curved slope 3i having a curvature substantially the same as the curvature of the balls 4A in the large-diameter row is formed at a step portion between the small-diameter shoulder 3d and the allowable portion 3g. These curved slopes 3h and 3i serve as first and second restricting portions that restrict movement of the balls 4A and 4B in each row by a predetermined amount or more in the axial direction.

  In the double row oblique contact ball bearing 1 described above, the small diameter ball 4B is hooked in the axial direction on the medium diameter shoulder 2e of the outer ring 2, while the large diameter ball 4A is connected to the large diameter raceway portion of the inner ring 3. 3a and the first permissible portion 3f, and the balls 4B in a small diameter row are placed in the small diameter raceway portion 3b and the second permissible portion 3g of the inner ring 3, respectively, and axially enter the first and second curved slopes 3h and 3i. Since the rolling range is restricted, the bearing components are not separated. In addition, as shown in FIG. 2, when forces F1 and F2 that pull the outer ring 2 and the inner ring 3 apart in the axial direction are applied, the balls 4A and 4B in each row are the first and second allowable portions 3f of the inner ring 3. , 3g roll in the axial direction so that the outer ring 2 and the inner ring 3 can be separated by a predetermined amount in the axial direction. Even in this state, the balls 4A and 4B in each row can smoothly roll in the circumferential direction, so that a radial load can be received.

  The double-row oblique contact ball bearing 1 having such a configuration is assembled by using the large-diameter rows of balls 4A and the cage 6 held by the cage 5 on the outer circumferences of the large-diameter raceway portion 3a and the small-diameter raceway portion 3b of the inner ring 3. This is done by attaching the balls 4B of the small-diameter rows that are held and shrink-fitting the outer ring 2 to this assembly.

  By the way, the tandem type double row oblique contact ball bearing 1 described above can be used in a transmission as shown in FIG. A rotary shaft 12 with a gear 13 is rotatably supported in the two-piece housings 10 and 11 of the transmission via a tandem double row oblique contact ball bearing 1 and a tapered roller bearing 14 shown in FIG. . The double-row oblique contact ball bearing 1 and the tapered roller bearing 14 are assembled in a front combination, and a fixed position preload is applied to these bearings 1 and 14.

  Specifically, this fixed position preload is obtained by bringing the back surface of the outer ring 2 of the double row oblique contact ball bearing 1 into contact with the radially inwardly stepped portion 10a of the housing 10 and the back surface of the inner ring 3 of the double row deep groove ball bearing 1 and In a state where the back surface of the inner ring 14 b of the tapered roller bearing 14 is in contact with both side surfaces of the gear 13, the dimension is previously set between the back surface of the outer ring 14 a of the tapered roller bearing 14 and the step portion 11 a radially inward of the housing 11. This is performed by sandwiching the spacer 15 adjusted in the above.

  In such a structure, when the housings 10 and 11 are made of a light alloy (for example, an aluminum alloy or a magnesium alloy) and the rotating shaft 12 is made of an iron-based metal, the bearings 1 and 1 are heated at high temperatures due to a difference in their linear expansion coefficients. Since the preload applied to No. 14 tends to be released, it is appropriately set empirically in consideration of the preload at normal temperature and the degree of preload loss at high temperature.

  Here, if a preload loss occurs at a high temperature, a force that separates the outer ring 2 and the inner ring 3 of the double row oblique contact ball bearing 1 in the axial direction works. At this time, as described above, the double row oblique contact Since the balls 4A and 4B in each row roll in the axial direction on the first and second permissible portions 3f and 3g of the inner ring 3 of the ball bearing 1, it is possible to prevent the occurrence of ball climbing as in the conventional example. Therefore, even in this state, the balls 4A and 4B in each row can smoothly roll in the circumferential direction, so that a radial load can be received and the rotation of the rotary shaft 12 can be stably supported.

  In addition, the tandem double-row oblique contact ball bearing 1 described above can be used to support a differential side gear as shown in FIG.

  As shown in the figure, a differential case 21 with a ring gear 20 is rotatably supported on a housing 22 via a tandem double row oblique contact ball bearing 1 and a tapered roller bearing 23 shown in FIG.

  The differential case 21 has a two-piece structure composed of a case main body 24 and a lid-like member 25, in which two pinion gears, two side gears (not shown) are accommodated and arranged. The case body 24 is formed with a cylindrical boss portion 24a through which the axle shaft 26 on one side is inserted. The lid-like member 25 is formed with a cylindrical boss portion 25a through which the other axle shaft 27 is inserted. Both boss portions 24a and 25a are provided coaxially. The ring gear 20 is bolted to the outer diameter side of the lid-like member 25.

  The housing 22 is provided with cylindrical portions 22a and 22b through which the boss portions 24a and 25a of the case main body 24 and the lid-like member 25 of the differential case 21 are inserted.

  The tapered roller bearing 23 is provided between the one cylindrical portion 22a of the housing 22 and the one boss portion 24a of the differential case 21, and the tandem type double row is provided between the other cylindrical portion 22b and the other boss portion 25a of the differential case 21. The oblique contact ball bearing 1 is incorporated. These both bearings 1 and 23 are a front combination.

  The back surface of the outer ring 23 a of the tapered roller bearing 23 is brought into contact with the stepped side surface 22 c provided on the one cylindrical portion 22 a of the housing 22, and the back surface of the inner ring 23 b is provided on the boss portion 24 a of the case main body 24 of the differential case 21. It is made to contact | abut to a certain step part side surface 24b. The back surface of the outer ring 2 of the double row oblique contact ball bearing 1 is brought into contact with the stepped side surface 22 d of the other cylindrical portion 22 b of the housing 22, and the back surface of the inner ring 3 is brought into contact with the outer surface 25 b of the lid-like member 25. In this state, by adjusting the dimensions of the bearings 1, 23, the differential case 21, and the housing 22, a fixed position preload is applied to the bearings 1, 23.

  In the above configuration, the differential case 21 and the bearing ring materials of the two bearings 1 and 23 are made of an iron-based metal to ensure their strength, while the housing 22 is made of a light alloy (for example, an aluminum alloy or magnesium for weight reduction). Alloy). In this case, since there is a difference in the linear expansion coefficient between the ferrous metal and the light alloy, the preload applied to the bearings 1 and 23 tends to be released due to the difference in the thermal expansion coefficient between the differential case 21 and the housing 22 at high temperatures. However, even in that case, since the balls 4A and the balls 4B of each row of the double row oblique contact ball bearing 1 can roll in the circumferential direction, it is possible to prevent the occurrence of an operational failure in the differential.

  3 and 4, the tapered roller bearings 14 and 23 are replaced with the tandem double row oblique contact ball bearing 1 shown in FIG. 1. In this case, it is more effective in reducing rotational resistance than when the tapered roller bearings 14 and 23 are used. Moreover, the use object of the double row oblique contact ball bearing 1 of this invention can be used for the appropriate rotating shaft support part etc. of the transfer mounted in a four-wheel drive vehicle other than the above.

Sectional drawing which shows the upper half of the double row oblique contact ball bearing which concerns on the best form of this invention The figure which shows a state when the outer ring and inner ring of FIG. 1 are pulled apart in the axial direction Sectional drawing which shows the usage example of the double row oblique contact ball bearing shown in FIG. Sectional drawing which shows the other usage example of the double row oblique contact ball bearing shown in FIG. Sectional view showing the upper half of a conventional tandem double row oblique contact ball bearing

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Double row oblique contact ball bearing, 2 ... Outer ring, 2a ... Large diameter track part, 2b ... Small diameter track part, 2c ... Large diameter shoulder part, 2d ... Small diameter shoulder part, 2e ... Medium diameter shoulder part, 3 ... Inner ring, 3a: Large diameter raceway part, 3b ... Small diameter raceway part, 3c ... Large diameter shoulder part, 3d ... Small diameter shoulder part, 3e ... Medium diameter shoulder part, 3f ... First allowance part, 3g ... Second allowance part, 3h ... First 1 curved slope (first restriction portion), 3i... 2 curved slope (second restriction portion), 4A .large diameter row ball, 4B .small diameter row ball.

Claims (5)

A plurality of balls are interposed between the large-diameter and small-diameter track portions provided on the inner peripheral surface of the outer ring and the large-diameter and small-diameter track portions provided on the outer peripheral surface of the inner ring, respectively. A double row oblique contact ball bearing with the same inclination,
In the inner ring, first and second permissible portions that allow the balls to roll in the axial direction are provided on the inner end side of the large-diameter raceway portion and the outer end side of the small-diameter raceway portion, respectively. A double row oblique contact ball bearing characterized in that first and second restricting portions for restricting the movement of the ball in the axial direction by a predetermined amount or more are provided at the end portion of the ball. In the inner ring,
A large-diameter shoulder that is larger than the outer diameter of the bottom of the large-diameter track portion is provided at the outer end of the large-diameter track portion, and the large-diameter track portion is disposed between the large-diameter track portion and the small-diameter track portion. A medium-diameter shoulder that is smaller than the diameter and larger than the outer diameter of the bottom of the large-diameter track portion is smaller than the outer diameter of the medium-diameter shoulder portion and larger than the outer diameter of the bottom of the small-diameter track portion at the outer end of the small-diameter track portion. Each has a small diameter shoulder,
A circumferential surface that is the same as the outer diameter of the bottom of the large-diameter track portion and that is continuous with the large-diameter track portion is provided as the first allowance portion on the medium-diameter shoulder portion. The step portion with the part is the first restriction part,
A circumferential surface continuous with the small-diameter track portion having the same outer diameter as the bottom diameter of the small-diameter track portion is provided as the second allowance portion on the small-diameter shoulder portion, and a step between the small-diameter shoulder portion and the second allowance portion The double row oblique contact ball bearing according to claim 1, wherein the portion is the second restricting portion. In the inner ring,
The large-diameter track portion is configured by a curved slope provided in the step portion between the large-diameter shoulder portion and the medium-diameter shoulder portion, and the small-diameter track portion is provided in the step portion between the medium-diameter shoulder portion and the small-diameter shoulder portion. The double row oblique contact ball bearing according to claim 2, wherein the double row oblique contact ball bearing is configured by a curved slope. In the outer ring,
A large-diameter shoulder having an inner diameter that is substantially the same as the inner diameter of the bottom of the large-diameter track portion at the outer end of the large-diameter track portion, and an inner diameter of the bottom portion of the small-diameter track portion at the outer end of the small-diameter track portion A small small-diameter shoulder is further provided between the large-diameter track and the small-diameter track, and a medium-diameter shoulder that is larger than the inner diameter of the small-diameter shoulder and smaller than the inner diameter of the bottom of the small-diameter track,
The large-diameter track portion is constituted by a curved slope provided at a step portion between the large-diameter shoulder portion and the medium-diameter shoulder portion,
The double-row oblique contact ball bearing according to any one of claims 1 to 3, wherein the small-diameter track portion is configured by a curved slope provided at a step portion between a small-diameter shoulder portion and a medium-diameter shoulder portion. A rotating shaft made of metal is supported on the inner circumference of a housing made of a metal having a larger linear expansion coefficient than the metal via two oblique contact type rolling bearings, and the two oblique contact type rolling bearings are combined as a frontal combination. A shaft support structure,
In the oblique contact type rolling bearing, the back surface of each outer ring is brought into contact with the respective side surfaces along the radial direction of two radially inwardly provided step portions provided on the housing, while the back surface of each inner ring is A fixed position preload is applied in a state of being in contact with each side surface along the radial direction of the radially outward step portion provided on the rotating shaft,
5. The rotating shaft support structure according to claim 1, wherein at least one of the oblique contact type rolling bearings is the double row oblique contact ball bearing according to any one of claims 1 to 4.

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