JP4131099B2 - Double row radial ball bearing - Google Patents

Description

尚、これら各軸受ａ〜ｆとも、外輪、内輪各軌道２、４の曲率半径ｒ_o 、ｒ_i と玉６の直径Ｄとの比を、（ｒ_o ／Ｄ）＝０．５３、（ｒ_i ／Ｄ）＝０．５１７５とし、接触角αを（前述した通り）４０度とした。尚、上記内輪軌道４は、円周方向に関して凸に湾曲している為、この内輪軌道４と上記玉６の転動面との接触部に存在する接触楕円の面積が小さくなり易い。この為、当該接触部の面圧上昇を抑えるべく、上述の様に内輪側の比（ｒ_i ／Ｄ）を、外輪側の比（ｒ_o ／Ｄ）に比べて小さくした。一方、この様に比（ｒ_i ／Ｄ）を小さくした分、上記接触楕円の長径（この内輪軌道４の幅方向に関する幅）が長くなり、この接触楕円の一部が上記内輪軌道４から外れ易くなる為、これを有効に防止すべく、回転輪である内輪５の肩部８の高さＨ_i は、上記玉６の直径Ｄの４２％（Ｈ_i ＝０．４２×Ｄ）とした。又、固定輪である外輪３の肩部７の高さＨ_o は、Ｈ_o ≒１．１×Ｈ_{o 、 min} とした。
この結果、上述した各軸受ａ〜ｆとも、本発明による肩部の寸法規制を行なう前に比べて、軸受全体の転がり疲れ寿命を１．５〜３倍程度伸ばす事ができた。
【００２５】
【発明の効果】
本発明の複列ラジアル玉軸受は、以上に述べた通り構成され作用するので、固定輪である外輪と回転輪である内輪との寿命のバランスを取りつつ、複列ラジアル玉軸受全体としての寿命の延長を図れる。
【図面の簡単な説明】
【図１】 複列ラジアル玉軸受の１例である、アンギュラ型の複列ラジアル玉軸受の半部断面図。
【図２】 運転時の玉の乗り上げ率が回転輪と固定輪とで等しいラジアル玉軸受の耐久試験の結果を示す図。
【図３】 アンギュラ型の複列ラジアル玉軸受を構成する外輪の半部断面図。
【図４】 同じく、１対の内輪の半部側面図。
【図５】 接触角αと、接触楕円の長半径ａ_i 、ａ_o とを表した図。
【図６】 軌道の曲率半径ｒ_i 、ｒ_o と、肩部の高さＨ_i 、Ｈ_o と、軌道の溝底と肩部の端縁との間の角度θ_Hi、θ_Hoとを表した図。
【図７】 外輪、内輪両軌道の曲率半径同士の比（ｒ_o ／ｒ_i ）と外輪側、内輪側両接触楕円の長半径同士の比（ａ_o ／ａ_i ）との関係を示すグラフ。
【図８】 外輪、内輪両軌道の曲率半径同士の比（ｒ_o ／ｒ_i ）と、外輪側の肩部の必要最低高さと内輪側の肩部の高さとの比（Ｈ_{o 、 min} ／Ｈ_i ）との関係を示すグラフ。
【符号の説明】
１ 複列ラジアル玉軸受
２ 外輪軌道
３ 外輪
４ 内輪軌道
５ 内輪
６ 玉
７ 肩部
８ 肩部
９ 保持器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a double-row radial ball bearing for rotatably supporting a wheel of an automobile with respect to a suspension device . In particular, the double-row radial ball bearing of the present invention ensures sufficient durability even when it is used under conditions where load, shaft inclination, and vibration are applied during operation.
[0002]
[Prior art]
For example, a double-row radial ball bearing 1 as shown in FIG. 1 is used to rotatably support the wheels of an automobile with respect to a suspension device. This double-row radial ball bearing 1 includes an outer ring 3 in which angular outer ring raceways 2 and 2 are formed in a double row on the inner peripheral surface, and a pair of inner rings 5 each of which forms an angular inner ring raceway 4 on the outer peripheral surface. , Balls 6 and 6 provided in a freely rollable manner while being held by the cages 9 and 9 between the outer ring raceways 2 and 2 and the inner ring raceways 4 and 4, respectively. Is provided. Then, as shown in the figure, a contact angle α in the direction indicated by a chain line γ in FIG. 1 is given to the balls 6 and 6 in a state where the axial end surfaces of the inner rings 5 and 5 are in contact with each other. . When the double-row radial ball bearing 1 configured as described above is used to rotatably support the wheel of an automobile with respect to the suspension device, for example, the outer ring 3 is internally fitted and fixed to a knuckle constituting the suspension device, and The inner rings 5 and 5 are externally fixed to a hub that rotates together with the wheels. In this case, the outer ring 3 is a fixed ring that does not rotate even when used, and the inner rings 5 and 5 are rotating wheels that rotate when used.
[0003]
By the way, a large thrust load or moment load may be applied to the double row radial ball bearing 1 as described above during the operation of the automobile in addition to the radial load. On the other hand, in such a case, the rolling members of the balls 6, 6 are caused to be elastically deformed by the structural members of the double-row radial ball bearing 1. There is a possibility of riding on the shoulders 7 and 8 on the one side in the width direction of the tracks 2 and 4. When such a ride occurs, a part of the contact ellipse existing at the contact portion between the rolling surface of each of the balls 6 and 6 and each of the tracks 2 and 4 is detached from the track 2 or 4 and the edge load is applied. Therefore, the surface pressure of the contact portion between the rolling surfaces of the balls 6 and 6 and the tracks 2 and 4 increases. When the contact portions between the rolling surfaces of the balls 6 and 6 and the tracks 2 and 4 reach the edges in the width direction of the tracks 2 and 4, the shape of the contact portions is not an ellipse (the elliptical shape). Part of the shape is missing). However, in the present specification, for convenience of explanation, the term “contact ellipse” is used even when a part of the contact ellipse deviates from the trajectory.
[0004]
Further, the increase in the surface pressure based on the edge load as described above is a ratio (= the area of the part / the area of the entire contact ellipse including the part. , "Take-up rate of balls"), the larger it becomes. Such an increase in surface pressure causes the rolling fatigue life of the double-row radial ball bearing 1 to be reduced. Therefore, when performing actual design, the load load conditions during operation are taken into consideration when the operation is performed. The riding rates of the balls 6 and 6 for the outer ring 3 and the inner rings 5 and 5 are not excessively increased (for example, can be suppressed to about several percent). In addition, the outer ring 3 and the inner rings 5 and 5 are configured so that the riding rates of the balls 6 and 6 during driving are substantially equal to each other.
[0005]
[Problems to be solved by the invention]
In the case of the double-row radial ball bearing 1 as described above, for example, when an automobile tire rides on a curbstone or the like, the climbing rate of each of the balls 6 and 6 becomes larger than the value planned in the design. there is a possibility. As a result, the outer ring raceway 2 formed on the inner peripheral surface of the outer ring 3 that is a fixed ring is peeled off early, and the life of the double row radial ball bearing 1 is shorter than the calculated value. May cause inconvenience. For this reason, provision of the technique which prevents such an inconvenience is desired.
[0006]
FIG. 2 shows the results of an experiment conducted to examine the relationship between the rolling fatigue life of a radial ball bearing (the life of a rotating wheel or a fixed wheel) and the ball climbing rate during operation. In the experiment, as a sample radial ball bearing, the rolling-up fatigue life (calculated value) is based on the assumption that the running rate (calculated value) of the balls in the outer ring and the inner ring are almost equal to each other and no ball ride-on occurs. An angular type radial ball bearing with an outer ring longer than the inner ring was used. Such a radial ball bearing was operated in a state where the outer ring was fixed and the inner ring was rotated, and the outer ring and the inner ring were loaded with balls. For this purpose, during operation, the radial ball bearing was loaded with unevenly distributed loads such as radial loads and moment loads. Incidentally, the running rate of balls during operation was changed little by little for each of 39 radial ball bearings as samples. Each of these radial ball bearings reaches the end of its life (that is, the vibration or temperature of the radial ball bearing significantly increases based on the occurrence of separation on the raceway surface of either the outer ring or the inner ring. ), And which of the outer ring and inner ring the raceway surface was checked for peeling.
[0007]
As a result of the experiment, as shown in FIG. 2, the calculated values of the life on the premise that no balls run up are longer for the outer ring than for the inner ring, but the 39 radial ball bearings used as samples were used. Among them, the majority (30) of the radial ball bearings peeled off the raceway surface (outer ring raceway) of the outer ring as a fixed ring before the raceway surface (inner raceway) of the inner ring as a rotating wheel. In general, in the case of a radial ball bearing that receives an unevenly distributed load such as a radial load or a moment load during operation, the fixed ring is more likely to peel off the raceway surface than the rotating wheel. This is because, in the case of rotating wheels, the load zone moves in the circumferential direction of the raceway surface during operation, whereas in the case of fixed wheels, the load zone moves in the circumferential direction of the raceway surface during operation. This is because it always receives a large repetitive stress at the same location on the raceway surface.
[0008]
In addition, as is apparent from the experimental results shown in FIG. 2, as the ball riding rate during driving increases, the raceway surface of the outer ring, which is a fixed ring, is peeled off before the raceway surface of the inner ring, which is a rotating wheel. It can be seen that the relative life ratio of the radial ball bearing (the value representing the life represented by the ratio of the life of a specific sample as 1) is reduced. Therefore, when analyzing the results of such an experiment, it is possible to prevent the raceway surface of the outer ring from peeling off and reduce the overall radial ball bearing by reducing the ball riding rate during operation for the outer ring, which is a fixed ring. It can be seen that the lifetime can be extended.
[0009]
As described above, as a method of reducing the running rate of the ball during driving, that is, a method of making it difficult for the rolling surface of the ball to ride on the edge in the width direction of the track, the radius of curvature of the track is increased. There are a method of reducing the area of the contact ellipse existing at the contact portion between the track and the rolling surface of the ball, and a method of increasing the height of the shoulder portion present on the side in the width direction of the track. Of these, the method of increasing the radius of curvature of the track may be difficult to adopt from the viewpoint of securing a rolling fatigue life because the surface pressure of the contact portion increases as the radius of curvature of the track increases. is there. Further, the method of increasing the height of the shoulder portion may be restricted in order to prevent interference between the shoulder portion and other members such as the cage 9 (see FIG. 1). Therefore, the design for making it difficult for the ball rolling surface to get on the edge in the width direction of the track needs to be performed while adjusting both the radius of curvature of the track and the height of the shoulder. On the other hand, in the above-described case, the life of the inner ring may be extended if the ball riding rate during driving is reduced by the same amount as that of the outer ring that is a fixed ring. is there. However, the life of the inner ring, which is a rotating wheel that has a sufficient life as it is, should be further extended. The surface pressure of the bearing increases, shortening the life from another surface (when the radius of curvature of the inner ring raceway is increased), or the shoulder and the cage interfere (when the height of the shoulder is increased) This is not preferable because of problems such as the above.
In view of the circumstances as described above, the present invention suppresses an increase in the surface pressure of the contact portion between the ball rolling surface and each track, while preventing interference between the shoulder portion and other members such as a cage. , by adjusting the height of the curvature radius and a shoulder portion of the raceway surface of the inner ring is the outer ring and the rotating ring is a fixed ring, while balancing the life of the outer ring and the inner ring, the entire double row radial ball bearings The invention was invented to extend the life of the product.
[0010]
[Means for Solving the Problems]
The double-row radial ball bearing of the present invention is similar to the double-row radial ball bearing 1 shown in FIG. 1 described above, and an outer ring in which an angular outer ring raceway is formed in a double row on the inner peripheral surface, and an angular ring on each outer peripheral surface. A pair of inner rings forming an inner ring raceway of the mold, and each of the outer ring raceways and a plurality of balls provided between the inner ring raceways so as to be freely rollable. The outer ring is a fixed ring that does not rotate even when in use, and both the inner rings are rotating wheels that rotate when in use.
In particular, in the double-row radial ball bearing of the present invention, it is used for rotatably supporting the wheel of an automobile with respect to a suspension device, and a back combination type contact is made with each of the balls arranged in the double row. The corner is given. Then, the radius of curvature of each outer ring raceway is r _o , the radius of curvature of each inner ring raceway is r _i , the diameter of each ball is D, and the rolling surface of each ball, each outer ring, each race of inner ring, the contact angle as alpha, shoulder portion provided in the width direction side of each outer ring raceway, the radial height from the groove bottom of the track and H _o, the width direction side of each inner ring raceway the provided shoulder portion, the radial height from the groove bottom of the track when the H _i, the following (1) satisfies the condition (2).
(1) The ratios (r _o / D) and (r _i / D) of the curvature radius r _o of each outer ring raceway and the curvature radius r _i of each inner ring raceway to the diameter D of each ball are (r _o / D) ₌ 0.51-0.54 and (r _i /D)=0.51-0.54, and (r _o / D)> (r _i / D) Satisfy the relationship.
(2) H _o is smaller than H _i and the expression “H _o = (1.07-1.15) × r _o (1− cos (α + sin ⁻¹ (r _i · sin ( cos ⁻¹⁾ (1-H _i / r _i ) −α) × (−7.215 (r _o / r _i ) +8.187) / r _o ))) ”.
[0012]
[Action]
According to the double-row radial ball bearing of the present invention configured as described above, the running rate of the balls during operation is smaller in the outer ring that is a fixed ring than in the inner ring that is a rotating ring , so that the outer ring raceway is early It is possible to prevent peeling. As a result, while balancing the life of the outer ring and the inner ring, thereby to extend the life of the entire double row radial ball bearings.
[0013]
The inner ring raceway of the outer ring raceway and the inner ring raceway constituting the double-row radial ball bearing is convexly curved in the circumferential direction, and therefore exists at the contact portion between the inner ring raceway and the ball rolling surface. The area of the contact ellipse is likely to be small (because the minor axis existing in the circumferential direction becomes short). For this reason, in order to suppress an increase in the surface pressure of the contact portion, it is necessary to reduce the curvature radius of the inner ring raceway close to the curvature radius of the rolling surface of the ball and to secure a sufficient area of the contact ellipse. However, when the radius of curvature of the inner ring raceway is reduced in this way, the major axis (existing in a direction perpendicular to the circumferential direction) of the contact ellipse (width in the width direction of the inner ring raceway) becomes larger. It becomes easy for the rolling surface of the ball to ride on the edge in the width direction.
[0014]
On the other hand, since the outer ring raceway is concavely curved in the circumferential direction, a contact ellipse (short diameter existing in the circumferential direction) exists in the contact portion between the outer ring raceway and the ball rolling surface. It is easy to secure the area). For this reason, even if the radius of curvature of the outer ring raceway is slightly increased, an increase in the surface pressure of the contact portion can be suppressed. In this way, in the case of the outer ring raceway, the radius of curvature can be made larger than the curvature radius of the inner ring raceway, so the major radius of the contact ellipse (width in the width direction of the outer ring raceway) becomes smaller. It becomes difficult for the rolling surface of the ball to ride on the edge in the width direction.
[0015]
In the case of a double-row radial ball bearing used for outer ring fixation and inner ring rotation, the rolling surface of the ball is less likely to ride on the width direction end edge of the outer ring raceway than the width direction end edge of the inner ring raceway. For this reason, the height of the shoulder provided on the side in the width direction of the outer ring raceway is increased. As described above, the rolling surface of the ball is unlikely to ride on the edge in the width direction of the outer ring raceway. It has become. For this reason, in order to make it difficult for the rolling surface of the ball to ride on the edge in the width direction of the outer ring raceway than the edge in the width direction of the inner raceway, the height of the shoulder portion may be slightly increased. . Therefore, even when it is necessary to consider the prevention of interference between the shoulder portion and other members such as a cage, the height of the shoulder portion can be easily increased as desired.
[0016]
【Example】
Examples of the present invention will be described below. In this embodiment, the present invention is applied to the double-row radial ball bearing 1 shown in FIG. 1, and the inner ring raceway is suppressed while suppressing an increase in the surface pressure at the contact portion between each ball 6,6 and each raceway 2,4. The height of the shoulder provided on one side in the width direction and the height of the shoulder provided on one side in the width direction of the outer ring raceway are adjusted. Accordingly, the balls 6, 6 are configured to be less likely to ride on the edge on one side in the width direction of the outer ring raceway than the edge on one side in the width direction of the inner raceway during operation. The life of the double-row radial ball bearing 1 as a whole is extended while making the life of the outer ring as the fixed ring and the inner ring as the rotating ring substantially equal to each other. The following embodiments will be described with reference to FIGS. 3 to 8 in addition to FIG. 1 described above.
[0017]
In this example , the inner rings 5 and 5 constituting the double row radial ball bearing 1 shown in FIG. 1 are rotating wheels that rotate when in use, and the outer ring 3 is a fixed ring that does not rotate even when used. It is.
In this example, the diameter D (FIG. 5) of the ball 6 is in the range of 9.5 to 12.7 mm, the pitch circle diameter of the ball row is in the range of 44 to 64.5 mm, and the outer ring and the inner ring each track 2 4 and the rolling surface of the ball 6 is 40 degrees, the radius of curvature r _o of the outer ring raceway 2 (FIGS. 3 and 6) and the radius of curvature r _i of the inner ring raceway 4. the ratio of (FIGS. 4 and 6) and the diameter D of the balls 6, the range of each (r _o /D)=0.51~0.54,(r _i /D)=0.51~0.54 The double-row radial ball bearing 1 in FIG.
[0018]
In the case of such a double-row radial ball bearing 1, the major axis direction of a contact ellipse (hereinafter referred to as “contact ellipse on the outer ring side”) present at the contact portion between the outer ring raceway 2 and the rolling surface of the ball 6. radius (hereinafter referred to as "long radius".) and the a _o (FIG. 5), the contact ellipse (hereinafter "the inner side contact ellipse existing in the contact portion between the inner ring raceway 4 and the rolling surface of the balls 6 ) Is a _i (FIG. 5), the ratio (a _o / a _i ) between the long radii a _o and a _i , and the outer ring and inner ring tracks 2, 4 Between the radius of curvature r _o and the ratio of r _i (r _o / r _i ), a linear relationship (proportional relationship) as shown in FIG. 7, that is, a relationship represented by the following equation (1): Is established.
(A _o / a _i ) = − 7.215 (r _o / r _i ) +8.187
----- (1)
The specific numerical values of the major radii a _o and a _i can be obtained by Hertz's contact theory, which is well known in the technical field of ball bearings.
[0019]
On the other hand, the height of the shoulder 8 on the inner ring side (the height in the radial direction from the groove bottom of the inner ring raceway 4 to the end of the shoulder 8 which is the end of the portion where the load can be applied) is defined as H _i ( 4 and 6), the angle θ _Hi (FIG. 6) between the groove bottom of the inner ring raceway 4 and the edge of the shoulder portion 8 centered on the center of curvature O ₄ of the inner ring raceway 4 is
θ _Hi = cos ⁻¹ (1−H _i / r _i ) −−−−− (2)
It becomes.
Further, since the contact angle between the outer ring and inner ring raceways 2 and 4 and the rolling surface of the ball 6 is α, the allowable long radius of the contact ellipse on the inner ring side (= the rolling surface of the ball 6 is the inner ring). The maximum value of the major radius a _i of the contact ellipse in a range where it does not ride on the edge of the side shoulder 8) a _{i , lim
a i, lim = r i ·} sin (θ Hi -α) ----- (3)
It becomes.
[0020]
On the other hand, when the long radius a _i of the contact ellipse on the inner ring side is the allowable long radius a _{i , lim} , the long radius a _o of the contact ellipse on the outer ring side (in this case, a _o is a _{o , ilim} ) From the above equation (1)
a _{o , ilim} = a _{i , lim} {−7.215 (r _o / r _i ) +8.187}
----- (4)
It becomes.
[0021]
The major radii a _{o , ilim} represented by the equation (4) are the allowable major radius of the contact ellipse on the outer ring side (= the rolling surface of the ball 6 rides on the edge of the shoulder 7 on the outer ring side). The height of the shoulder portion 7 on the outer ring side (the diameter from the groove bottom of the outer ring raceway 2 to the edge of the shoulder portion 7) when the contact ellipse has a long radius a _o in a range that does not exist (Directional height) H _o (Figs. 3 and 6. In this case, H _o is the minimum required height H _{o and min} ).
H _{o , min} = r _o (1-cos θ _Ho ) ----- (5)
It becomes. Note that θ _{Ho in} the right side of the equation (5) is the end of the groove bottom of the outer ring raceway 2 and the shoulder portion 7 with the center of curvature O ₂ of the outer ring raceway 2 as the center, as shown in FIG. The angle between the edges,
^{_{θ Ho = α + sin -1 (}} a o, ilim / r o) ----- (6)
It is represented by
[0022]
Here, when the above formulas (2) to (4) and (6) are substituted into the above formula (5), the required minimum heights H _{o and min} of the shoulder 7 on the outer ring side are:
_{H o, min = r o (} 1-cos (α + sin -1 (r i · sin (cos -1 (1-H i / r i) -α) × (-7.215 (r o / r i) +8 .187) / r _o )))
----- (7)
Although this equation (7) is expressed in the range of (r _o /D)=0.51 to 0.54, (r _i /D)=0.51 to 0.54, When calculation is performed for several different double-row radial ball bearings 1, a result as shown in FIG. 8 is obtained, and the following approximate expression is obtained from the linear relationship (proportional relationship) shown in this result.
H _{o , min} = H _i {−6.131 (r _o / r _i ) +7.105}
----- (8)
[0023]
Accordingly, in this embodiment, when the height of the shoulder portion 8 of the inner ring 5 is rotated wheel was H _i, the height H _o of the minimum required height H of the shoulder portion 7 of the outer ring 3 is fixed wheel _By making it larger than _{o and min} (H _o > H _{o , min} ), the plurality of balls 6 and 6 are more fixed to the fixed ring than the edge of the shoulder 8 of the inner ring 5 which is the rotating ring. The double-row radial ball bearing 1 has a long life as a structure that is difficult to ride on the edge of the shoulder 7 of the outer ring 3. For example, if H _o = (1.07-1.15) × H _{o , min} , the life of the double-row radial ball bearing 1 can be extended and the outer ring raceway 2 and the inner ring raceway 4 can be actually used. The rolling fatigue life can be made almost equal to each other (a well-balanced design can be made).
[0024]
Table 6 below shows six examples (bearings a to f) of the double-row radial ball bearing 1 designed based on the above calculation.
[Table 1]

In each of these bearings a to f, the ratio of the radius of curvature r _o , r _{i of} each of the outer ring and inner ring races 2, 4 to the diameter D of the ball 6 is (r _o /D)=0.53, (r _{i /} D) ₌ 0.5175, and the contact angle α was 40 degrees (as described above). Since the inner ring raceway 4 is convexly curved in the circumferential direction, the area of the contact ellipse existing at the contact portion between the inner ring raceway 4 and the rolling surface of the ball 6 tends to be small. For this reason, in order to suppress the increase in the surface pressure of the contact portion, the ratio (r _i / D) on the inner ring side is made smaller than the ratio (r _o / D) on the outer ring side as described above. On the other hand, this amount was reduced ratio (r _i / D) as made major axis of the contact ellipse (the width in the width direction of the inner ring raceway 4) is long, a part of the contact ellipse is disengaged from the inner ring raceway 4 In order to prevent this effectively, the height H _i of the shoulder 8 of the inner ring 5 which is a rotating wheel is set to 42% of the diameter D of the ball 6 (H _i = 0.42 × D). . Further, the height H _o of the shoulder 7 of the outer ring 3 that is a fixed ring was set to H _o ≈1.1 × H _{o , min} .
As a result, each of the bearings a to f described above was able to extend the rolling fatigue life of the entire bearing by about 1.5 to 3 times compared to before the shoulder size control according to the present invention.
[0025]
【The invention's effect】
Since the double-row radial ball bearing of the present invention is configured and operates as described above, the life of the double-row radial ball bearing as a whole is obtained while balancing the life of the outer ring that is a fixed ring and the inner ring that is a rotating ring. Can be extended.
[Brief description of the drawings]
1 is an example of a double row radial ball bearing, semi-sectional view of a double row radial ball bearings of the angular type.
FIG. 2 is a diagram showing the results of a durability test of radial ball bearings in which the running rate of balls during operation is the same for rotating wheels and fixed wheels.
FIG. 3 is a half sectional view of an outer ring constituting an angular type double-row radial ball bearing.
FIG. 4 is also a half side view of a pair of inner rings.
FIG. 5 is a diagram showing a contact angle α and major radii a _i and a _{o of} a contact ellipse.
Angle theta _Hi, and theta _Ho table between 6 curvature of the track radius r _i, and r _o, the height H _i of the shoulder, and H _o, and the edge of the groove bottom and the shoulder of the track Figure.
FIG. 7 is a graph showing the relationship between the ratio (r _o / r _i ) between the curvature radii of both the outer ring and inner ring raceways and the ratio (a _o / a _i ) between the major radii of both the outer ring side and inner ring side contact ellipses. .
[FIG. 8] The ratio (r _o / r _i ) between the radii of curvature of both the outer ring and inner ring raceways and the ratio between the required minimum height of the outer ring side shoulder and the height of the inner ring side shoulder (H _{o , min} / A graph showing the relationship with H _i ) .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Double row radial ball bearing 2 Outer ring raceway 3 Outer ring 4 Inner ring raceway 5 Inner ring 6 Ball 7 Shoulder 8 Shoulder 9 Cage

Claims (1)

An outer ring in which angular outer ring raceways are formed in a double row on the inner peripheral surface, a pair of inner rings in which angular inner ring raceways are formed on each outer peripheral surface, and the outer ring raceways between these inner ring raceways. In a double-row radial ball bearing comprising a plurality of balls each provided so as to be capable of rolling, the outer ring being a fixed ring that does not rotate even when used, and the inner ring being a rotating ring that rotates when used. This double-row radial ball bearing is to support the wheels of the automobile so as to be rotatable with respect to the suspension device, and each of the balls arranged in the double-row is provided with a back combination type contact angle, The radius of curvature of each outer ring raceway is r _o , the radius of curvature of each inner ring raceway is r _i , the diameter of each ball is D, and the contact surface between the rolling surface of each ball and each raceway of the outer ring and inner ring The angle is α, and it is provided on the lateral side of each outer ring raceway. And the shoulder portion, the radial height from the groove bottom of the track and H _o, shoulder portion provided in the width direction side of each inner ring raceway, the radial height from the groove bottom of the track If H _i ,
(1) The ratios (r _o / D) and (r _i / D) of the curvature radius r _o of each outer ring raceway and the curvature radius r _i of each inner ring raceway to the diameter D of each ball are (r _o / D) ₌ 0.51-0.54 and (r _i /D)=0.51-0.54, and (r _o / D)> (r _i / D) Satisfy the relationship
(2) H _o is smaller than H _i and the expression “H _o = (1.07-1.15) × r _o (1− cos (α + sin ⁻¹ (r _i · sin ( cos ⁻¹⁾ (1-H _i / r _i ) −α) × (−7.215 (r _o / r _i ) +8.187) / r _o ))) ”” Radial ball bearing.

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