JP2008057776A - Angular ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an angular ball bearing without sharing a rolling body load only by at least one groove shoulder part of an inner race and an outer race, when forming a groove for storing a seal. <P>SOLUTION: This angular ball bearing 100 of a single row of a narrow width, has at least one of the inner race 102 forming a recessed step part 122b having a diameter smaller than an inner race groove shoulder part 102c in a part in at least the circumferential direction and the outer race 101 forming a recessed step part having a diameter larger than an outer race groove shoulder part in a part in at least the circumferential direction, and is formed by rollingly arranging a large number of balls 103 between a raceway groove 101a of the outer race 101 and a raceway groove 102a of the inner race 102. A contact angle θ is set so that an extension line L1 in the normal direction in contact parts P1 and P2 between the balls 103, the outer race and the inner race, does not interfere with the recessed step part 122b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ball bearing used in, for example, industrial machines, machine tools, robots, medical equipment, semiconductor / liquid crystal manufacturing apparatuses, optical and optoelectronic apparatuses, and in particular, radial loads and axial loads in both directions, particularly large moment loads. The present invention relates to an angular ball bearing that acts as

  In general, angular ball bearings are not equipped with seals like deep groove ball bearings. Therefore, for example, as shown in FIG. 19, single-row angular ball bearings 3A and 3B are arranged in two rows between the housing 1 and the shaft 2, and the inner ring presser 4 and the bearing are constituted by the inner ring 3a as a spacer. When the outer ring 3b is fixed with the outer ring retainer 6 while being fixed with the nut 5, the extension line L1 in the normal direction of the contact point representing the contact angle of the angular ball bearings 3A, 3B is the shoulder portion of only the inner ring 3a and the outer ring 3b. It passes through 3c and 3d and passes through the shaft 2, the inner ring presser 4, the housing 1, or the outer ring presser 6.

  When an external load is applied as a load to the angular ball bearings 3A, 3B, so-called rolling occurs at the contact portion between the rolling element 3e, which is a ball interposed between the inner ring 3a and the outer ring 3b, and the inner ring 3a and the outer ring 3b. As indicated by arrows in FIG. 19, the moving body load is generated from the rolling element 3e toward the inner ring 3a and the outer ring 3b between the contact parts in the normal direction of the contact part representing the contact angle. In particular, when the ratio of the moment load is large, the rolling element load of a part of the rolling elements 3e (mainly at a position opposite to 180 °) becomes extremely large.

  In the angular ball bearing having no seal as shown in FIG. 19, when the contact angle is about 30 ° as shown in FIG. 19 (a), the direction of the rolling element load is the angular ball bearings 3A and 3B. Both pass through the shoulder 3c of the inner ring 3a and the bearing mounting portion of the shaft 2, and when the contact angle is about 60 ° as shown in FIG. In the angular ball bearing 3A, the inner ring 3a passes through the shoulder 3c and passes through the step 3f serving as the inner ring presser of the shaft 2, and in the angular ball bearing 3B, the inner ring 3a passes through the shoulder 3c. The bearing mounting portion of the shaft 2 is reached through the presser 4.

  As described above, in the angular ball bearings 3A and 3B having no seal, the inner ring 3a and the outer ring 3b are backed up by the shaft 2, the housing 1, the inner ring presser 4 and the outer ring presser 6 which are in contact with them. Since the outer ring 3b only has the shoulder portions 3c and 3d not bearing the rolling element load, the groove shoulder portions 3c and 3d are not deformed and can support the rolling element load.

For this reason, as shown in Patent Document 1, in a single row ball bearing in which a large number of balls are rotatably disposed between the outer ring raceway groove and the inner ring raceway groove, the axial sectional width B and radius Even in the case of a narrow angular contact ball bearing with a cross-sectional dimension ratio (B / H) to (B / H) <0.63 with respect to the direction cross-section height H, if no seal is provided, only the shoulder of the inner ring or the outer ring Thus, the rolling element load is not borne, and the shoulder of the groove is not deformed, and the rolling element load can be supported.
JP 2006-105385 A (first page, FIG. 1)

However, in the narrow angular contact ball bearing disclosed in Patent Document 1, as shown in FIG. 11, when the contact angle is increased as a sealed angular contact ball bearing, the normal direction in the contact portion of the ball is increased. The extension line will pass through the groove part that accommodates the seal, and it will bear the rolling element load only at the shoulder part of the inner ring groove that is not backed up. In addition to the elastic deformation of the contact part of the ball and inner ring and outer ring groove Elastic deformation of the shoulder of the groove occurs, leading to a decrease in rigidity. In addition, when the rolling element load is large, there are unsolved problems such as breakage or chipping in the groove shoulder.
Accordingly, the present invention has been made paying attention to the unsolved problems of the conventional example described above, and when a groove or the like for storing a seal is formed, the rolling element load is applied only to the shoulder of at least one of the inner ring and the outer ring. It is an object of the present invention to provide an angular contact ball bearing that does not bear the load.

  In order to achieve the above object, the invention according to claim 1 is directed to an inner ring in which a concave step portion having a diameter smaller than that of the inner ring groove shoulder is formed in at least a part in the circumferential direction, and at least a part in the circumferential direction. And at least one of the outer rings formed with a concave step portion having a diameter larger than the shoulder portion of the outer ring groove, and a large number of balls are rotatably disposed between the race groove of the outer ring and the race groove of the inner ring. In the narrow single-row angular contact ball bearing, the contact angle is set so that the extension line in the normal direction in the contact portion between the ball and the outer ring and the inner ring does not interfere with the concave stepped portion. .

  The invention according to claim 2 includes an inner ring in which a concave step portion having a diameter smaller than that of the inner ring groove shoulder is formed at least in a part in the circumferential direction, and an outer ring groove shoulder in at least a part in the circumferential direction. The outer ring is formed with a concave step portion having a large diameter, and a plurality of balls are arranged between the raceway groove of the outer ring and the raceway groove of the inner ring so as to be freely rollable. In the row of angular contact ball bearings, a contact angle is set so that an extension line in a normal direction at a contact portion between the ball and the outer ring and the inner ring does not interfere with the concave stepped portion.

Furthermore, the invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the concave step portion is constituted by a groove into which the annular seal body is inserted and an opposing seal labyrinth portion.
Furthermore, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein an annular seal body is inserted into one of the concave steps of the inner ring and the outer ring, and the annular seal is provided. The body is configured to be in contact with or not in contact with the concave portions of the inner ring and the outer ring corresponding to the inserted side.

Here, as the narrow angular contact ball bearing, a size not applicable to a standard angular contact ball bearing (78xx, 79xx, 70xx, 72xx, 73xx series, etc.), that is, in the case of at least a single row angular contact ball bearing, for example, an axial sectional width B is a single row angular contact ball bearing with a cross-sectional dimension ratio (B / H) of B and radial cross section height H (B / H) <0.63, and in the case of a double row angular contact ball bearing, This is a narrow double-row angular contact ball bearing in which the cross-sectional dimension ratio (B2 / H2) between the cross-sectional width B2 and the radial cross-sectional height H2 is (B2 / H2) <1.2.
Further, the contact angle of the angular ball bearing varies depending on the height of the shoulders of the inner and outer rings, the ratio of the ball diameter and the bearing width, and the shape and size of the seal groove, but is generally 60 ° or less, preferably 50 ° or less. More preferably, the angle is 40 ° or less, but if it is less than 20 °, the allowable axial load and the allowable moment load decrease, which is not preferable.

  According to the present invention, in the case of narrow single-row angular contact ball bearings and double-row angular contact ball bearings, the extension line in the normal direction at the contact portion between the balls and the outer ring and the inner ring does not interfere with the recessed step portion. Since the contact angle is set at the inner ring and at least one of the outer ring, it is possible to reliably prevent the load of the rolling element from being loaded only by the shoulder portion, and the groove shoulder portion is deformed by a narrow angular ball bearing having a seal. The effect that it can support a rolling element load without doing is acquired.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part for explaining a single row ball bearing which is an example of an embodiment of the first aspect of the present invention (corresponding to claim 1), and FIG. 2 shows the single row ball bearing of FIG. It is principal part sectional drawing which shows the state which combined 2 rows.
As shown in FIG. 1, a single row ball bearing 100 as an example of an embodiment of the first aspect of the present invention (corresponding to claim 1) includes a raceway groove 101a of an outer ring 101 and a raceway groove 102a of an inner ring 102. In the single-row angular contact ball bearing 100 in which a large number of balls 103 are movably disposed between them, an axial sectional width B and a radial sectional height H (= (outer ring outer diameter D−inner ring inner diameter d) / The cross-sectional dimension ratio (B / H) to 2) is (B / H) <0.63.

Here, in this embodiment, as shown in FIG. 2, the angular ball bearing 100 is used as a two-row back surface combination and replaced with a double row angular contact ball bearing of 7208A (contact angle 30 °).
The 7208A angular contact ball bearing has an inner ring inner diameter φ40 mm, an outer ring outer diameter φ80 mm, and an axial sectional width (bearing single body width) B of 18 mm, so the sectional dimension ratio (B / H) = 0.9. Therefore, in the angular ball bearing 100 of the present embodiment, the sectional dimension ratio (B / H) = 0.45 (the inner ring inner diameter and the outer ring outer diameter remain the same, and the axial sectional width (bearing single body width) is 9 mm). Yes. As a result, a radial load, an axial load in both directions, and a moment load can be received, and space saving, a reduction in torque, and a further increase in rigidity can be achieved in the axial dimension.
Of course, if necessary, the cross-sectional dimension ratio (B / H) of the angular ball bearing 100 may be set to be less than 0.45 or more than 0.45 (where (B / H) <0.63). Absent.

Thus, the reason why B / H <0.63 is as follows.
3 and 4 are standard thin ball bearings (bearing inner diameter: φ38.1 mm, bearing outer diameter: φ47.625 mm, bearing width: 4.762 mm, cross-sectional dimension ratio (B / H)) = 1) as a reference, the inner and outer ring rings are deformed in the radial direction when the bearing inner diameter is changed without changing the bearing outer diameter and bearing width (that is, when the value of (B / H) is changed). properties (see FIG. 5: the inner ring of illustration) and radial cross-sectional secondary moment I: shows the result of comparison (see FIG. 6 calculated as I = bh ^3/12).

  7 and 8 are also used as standard thin ball bearings (bearing inner diameter: φ63.5 mm, bearing outer diameter: φ76.2 mm, bearing width: 6.35 mm, cross-sectional dimension ratio (B / H) = 1) as a reference, the radius of the inner and outer ring rings when the bearing inner diameter is changed without changing the bearing outer diameter and bearing width (that is, when the value of (B / H) is changed) The result of having compared the deformation characteristic of a direction and the cross-sectional secondary moment I of the radial direction is shown.

In any of the bearings, (B / H) = 0.63, and the change in the rigidity increase rate gradient is remarkable. That is, the increase in the secondary moment I of the cross section becomes significant, and the decrease in the deformation amount of the inner and outer ring in the radial direction becomes saturated.
Therefore, in this embodiment, it is possible to prevent bearing deformation due to lathe processing during inner / outer ring production or processing force during polishing processing, which is a problem with conventional ultra-thin bearings, and bearing accuracy such as roundness and uneven thickness Can be improved.

  Deformation of inner and outer rings when bearings are fixed with inner ring retainers and outer ring retainers (especially when they are assembled with a clearance fit with the shaft or housing). In addition, it is possible to prevent torque defects and rotational accuracy defects caused by deformation, or problems such as increased heat generation, wear and seizure.

Single-row ball bearings are difficult to apply preload or moment load in one row, but by combining multiple rows of two or more rows, radial load, axial load and moment load can be applied. It becomes possible to do.
Further, since each ball always contacts the inner and outer raceway grooves at two points, an increase in torque due to a large spin of the ball can be suppressed as in a four-point contact ball bearing. Since the rolling resistance is lower than that of the bearing, a reduction in torque can be realized.

FIG. 9 is a comparison data of the relative inclination angle of the inner and outer rings when a moment load is applied to the bearings of the single-row product of the present invention (two-row rear combination bearing with a contact angle of C shape) and the cross roller bearing. is there.
Here, the main dimensions of the measuring bearing are
Invention product:
Inner ring inner diameter: φ170
Outer ring outer diameter: φ215
Single unit width: 13.5mm
Rolling element pitch circle diameter: φ192.5
Contact angle 35 °
(B / H = 0.60)
Cross roller bearing:
Inner ring inner diameter: φ130
Outer ring outer diameter: φ230
Assembly width: 30mm
Rolling element pitch circle diameter: φ189.7
It is.

As is apparent from FIG. 9, for both the present invention product and the cross roller bearing in which the pitch circle diameters of the rolling elements are substantially the same, the comparison data of the moment stiffness is about the present invention product about the cross roller bearing. It was confirmed that the moment rigidity was maintained 1.3 times.
In addition to the above experiments, the product of the present invention and the cross roller bearing were assembled into the shaft and housing, and then rotated at a low speed by a motor (belt drive). In the case of the cross roller bearing, rotation irregularity due to torque fluctuation was actually confirmed.

Furthermore, when the width dimension is about half that of the conventional standard single row ball bearing, the ball diameter is also about half that of the conventional ball bearing, but conversely, the number of balls per row is increased, and the bearing rigidity is conventional. Increased against ball bearings. In addition, when applied to the arm joint of a turning robot, etc., low-speed oscillating rotation is almost the case, so even if the bearing load capacity is reduced by reducing the ball diameter, the rolling fatigue life time is practical. There is no problem.
Other industrial machines, machine tools, robots, medical equipment, semiconductor / liquid crystal manufacturing equipment, optical and optoelectronic equipment, etc., have many applications with low rotation speeds and rocking rotations, so rolling fatigue life time becomes a problem. There is almost no.

  FIG. 10 is a comparison of calculated moment stiffness of various bearings. For the same size (calculation example is equivalent to bearing name No. 7906A (contact angle 30 °) and the inner and outer diameter dimensions are the same: inner ring inner diameter φ30 mm, outer ring outer diameter φ47 mm), the single row narrow angular contact ball according to claim 1 The invention examples A to E in which the bearings (contact angle 30 °: bearing calculation example) are combined in two rows and the raceway groove radius of curvature of the inner and outer rings (Da is the ball diameter) are changed. The moment rigidity is higher than that of the two-row combined angular ball bearing and the four-point contact ball bearing. For example, the present invention example B is 2.4 times that of the cross roller bearing, and 1 of the conventional standard two-row combined angular ball bearing. It is possible to maintain a moment rigidity 3.3 times that of a 4-point contact ball bearing.

The design preload clearances are -0.010 mm for the invention examples A to E, standard two-row combination angular contact ball bearings and 4-point contact ball bearings, and -0.001 mm for the cross roller bearings, which are standard in practical use. Calculated as a value.
In addition, the appropriate ball diameter of the narrow ball bearing in the present embodiment varies depending on the presence or absence of a seal or the like, but in order to increase rigidity, if the ball diameter is extremely reduced, the ball and the inner and outer ring raceway grooves Since the contact pressure between the contact portions increases and the pressure scar resistance may be lowered, approximately 30 to 90% of the bearing width (B) or (B2 / 2) is desirable.

In this embodiment, an annular seal body 120 is provided on one side of the single row ball bearing 100, and a cage 130 for positioning a large number of balls 103 in the circumferential direction is provided.
That is, as shown in FIG. 1, seal housing grooves 121 and 122 serving as concave steps for housing the annular seal body 120 are disposed on, for example, the right side end surfaces of the outer ring 101 and the inner ring 102.

The annular seal body 120 is composed of a reinforced rubber seal (for example, nitrile rubber / acrylic rubber or fluororubber) 126 reinforced by a metal core 125 formed in an inverted L shape. The rubber seal 126 has a fitting portion 126 a that fits the outer ring 101 on the outer peripheral portion, and a lip portion 126 b that contacts the inner ring 102 on the inner peripheral portion.
The seal housing groove 121 of the outer ring 101 has a relatively shallow step portion 121a on the right end side of the inclined inner peripheral surface 101b connected to the raceway groove 101a of the outer ring 101, and an annular shape formed in the circumferential direction at the bottom portion of the step portion 121a. It is set as the structure which has the shallow fitting recessed part 121b which pushes in and inserts the fitting part 126a of the seal body 120. FIG.

  Further, the seal housing groove 122 of the inner ring 102 has a relatively deep step portion 122a on the right end side of the groove 102a on the right side of the raceway groove 102a on the cylindrical outer peripheral surface 102b connected to the left and right ends of the raceway groove 102a of the inner ring. A shallow housing recess 122b that is in contact with a lip 126b formed on the inner peripheral surface of the annular seal body 120 formed in the circumferential direction is formed on the bottom surface of the stepped portion 122a.

Furthermore, the retainer 130 has a pair of annular portions 132 a and 132 b extending in the axial direction across the pocket portion 131 that accommodates the ball 103, and these annular portions 132 a and 132 b are the cylindrical outer peripheral surface 102 b of the inner ring 102. Is installed as a guide surface.
The annular portion 132b on the annular seal body 120 side is connected to the intersection edge portion 123 on the inner circumferential surface facing the intersection edge portion 123 formed at the intersection between the cylindrical outer circumferential surface 102b of the inner ring 102 and the seal housing groove 122. A concave groove 133 having a semicircular cross section that avoids contact is formed in the circumferential direction.

  The cage 130 is made of a metal material such as a copper alloy manufactured by cutting, a synthetic resin material such as polyamide, polyacetal, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or glass fiber or carbon fiber. It is made of a synthetic resin material containing a reinforcing material with a reinforcing material added. When the cage 130 is formed of a resin material, either cutting molding or injection molding can be applied.

  As described above, since the concave groove 133 is formed in the circumferential direction on the inner peripheral surface facing the intersection edge portion 123 formed on the right end side of the guide surface of the cage 130, the intersection edge portion 123 is formed in the cage. The retainer 130 can be reliably prevented from coming into contact with the inner peripheral surface of the ring 130, while ensuring the strength by increasing the width of the annular portion 132b on the annular seal body 120 side to increase the cross-sectional area. Can be reliably prevented.

  In addition, in the case of grease lubrication, the concave groove 133 provided in a part of the guide surface can serve as a reservoir for holding grease, and in addition, since it is located in the vicinity of the guide surface, There is also an effect of appropriately supplying the lubricating oil, and the wear resistance can be maintained for a long time from the viewpoint of the lubrication characteristics. This effect becomes more conspicuous when concave grooves 133 and 134 are formed in both annular portions 132a and 132b as shown in FIG.

  Normally, when the annular seal body 120 is disposed on at least one side of the ball bearing 100, the inner diameter surface of the outer ring 101 and the outer diameter surface of the inner ring 102 are used as the guide surfaces of the cage 130. Since the intersection edge portion 123 is formed at a position where the groove 122 is in contact with the groove 122, the cage 130 is worn due to the contact between the intersection edge portion 123 and the annular portion 132b of the cage 130.

In order to prevent the wear of the cage 130, conventionally, when the inner ring guide is used, as shown in FIG. 11, the axial length or width of the annular portion 132b on the intersection edge portion 123 side of the cage 130 is shown. It is considered that the annular portion 132b and the intersection edge portion 123 do not come into contact with each other.
However, in the case of the narrow ball bearing 100 as in this embodiment, there is a problem that the width of the annular portion 132b becomes very thin and sufficient strength cannot be ensured.

For this purpose, as shown in FIG. 12, it is necessary to increase the width of the annular portion 132b to ensure the strength, but in this case, as described above, the intersection with the inner peripheral surface of the annular portion 132b. Since the edge portion 123 is opposed, when the cage 130 is inclined with respect to the guide-side raceway during rotation of the ball bearing 100, the inner peripheral surface of the annular portion 132b is edged to the intersection edge portion 123. As a result, the cage 130 is worn.
In particular, since the seal receiving grooves 121 and 122 are often heat-treated surfaces after cutting, the surface roughness is poor, and burrs are likely to be formed at the intersecting portions that come into contact with the cage 130, so that wear occurs. It's easy to do.

  Furthermore, since the ball bearing 100 according to the present invention has a structurally very small ball diameter with respect to the ball pitch circle diameter of the bearing, the cross section of the annular portion 132b of the cage 130 is correspondingly reduced. The radial strength of the cage 130 (the radial strength of the annular portion 132b) is also reduced. In addition to this, the application of the ball bearing 100 according to the present invention is likely to cause a large moment load to be applied during rotation of the bearing, and the bearing is liable to tilt due to its usage conditions. Therefore, due to the change in the contact angle of each ball 103, the revolution speed of each ball 103 varies, and the deformation of the cage 130 due to the tension force between the ball 103 and the pocket portion 131 also increases, so it is easier to hit the edge. Further, the surface pressure of the contact portion also increases and wear tends to proceed.

  However, as described above, in the present embodiment, as shown in FIG. 1, the width of the annular portion 132 b on the annular seal body 120 side of the cage 130 is increased to increase the cross-sectional area and Since the concave groove 133 is formed in a portion that may contact the intersection edge 123 at the boundary with the cylindrical surface 102b serving as the guide surface, even if the cage 130 is inclined, the intersection edge 123 and the concave shape are formed. Since a sufficient space can be ensured between the groove portion 133 and the concave groove portion 133 and the intersection edge portion 123 can be reliably prevented from being contacted, and the wear of the cage 130 can be reliably prevented. .

  In the present embodiment, the normal extension line L1 at the contact portion P1 that contacts the raceway groove 101a of the outer ring 101 of the ball 103 and the contact portion P2 that contacts the raceway groove 102a of the inner ring 102 interferes with the housing recess 122b. In order to prevent this, the contact angle θ is set to 35 °. For this reason, the distance Δ between the parallel line L2 parallel to the extension line L1 and in contact with the storage recess 122b is Δ> 0. Here, the contact angle θ varies depending on the height of the shoulder of the inner ring and the outer ring, the ratio of the ball diameter and the bearing width, and the shape and size of the seal recess 122b, but is generally 60 ° or less, preferably 50 ° or less. More preferably, the angle is 40 ° or less, but if it is less than 20 °, the allowable axial load and the allowable moment load decrease, which is not preferable.

  In this way, by setting the contact angle θ, the contact line P1 and the extension line L1 in the normal direction of the P2 which is the direction in which the rolling element load is applied are separated by a distance Δ from the storage recess 122b in which the annular seal body 120 is stored. (> 0), the inner ring 102 is backed up by the inner ring presser 140 shown by the chain line in FIG. In addition, a rolling element load can be received by a shaft (not shown) fitted in the inner ring 102, and the rolling shoulder load can be received without causing deformation of the groove shoulder portion 102c and causing a decrease in rigidity. Therefore, even when a large angular load is applied to a narrow angular ball bearing, the groove shoulder 102c is not broken or chipped, and the bearing life can be extended.

In addition, although the said embodiment demonstrated the case where the annular seal body 120 was arrange | positioned on the right side of the ball bearing 100, it is not limited to this, The annular seal body 120 is arrange | positioned on the left side of the ball bearing 100. Alternatively, the annular seal body 120 may be disposed on both sides.
Moreover, although the case where the concave groove part 133 formed in the annular part 132b is formed in a semicircular cross section has been described in the above modification, the present invention is not limited to this, and is not limited to this. Any shape can be used as long as contact with the intersection edge portion 123 such as a shape can be avoided.

Further, in the above modification, the case where the annular seal body 120 contacts the inner ring seal housing groove 122 has been described. However, the present invention is not limited to this, and a non-contact rubber seal that does not contact the inner ring seal housing groove 122 shown in FIG. A metal seal that is caulked in a mold (with a metal core) or an outer ring seal groove can be applied.
Furthermore, in the above embodiment, the case where the guide surface of the cage 130 is the outer peripheral surface of the inner ring 102 has been described. However, the present invention is not limited to this, and the inner peripheral surface of the outer ring 101 is used as the guide surface. May be.

  Furthermore, although the said embodiment demonstrated the case where the concave groove part 133 was formed in the annular part 132b by the side of the annular seal body 120 among the annular parts 132a and 132b of the holder | retainer 130, it is not limited to this. As shown in FIG. 13, the annular groove 132a on the opposite side of the annular seal body 120 also has a concave groove at a plane symmetrical position sandwiching the concave groove 133 of the annular portion 132b and the vertical plane passing through the center of each ball 103. 134 may be provided. As described above, when the concave groove portions are formed in the left and right annular portions 132a and 132b, it is possible to assemble from any direction without confirming the formation position of the concave groove portions of the retainer 130 during the assembly, thereby improving the assembling work. be able to.

In addition to this embodiment, as shown in FIG. 16, the cage has an annular seal body 104 attached to one end in the axial direction (end opposite to the end face on the combination side), and the ball 103 is attached. When two rows of angular ball bearings 100 having cages 110 that are held so as to be able to roll are combined on the back side, as shown in FIGS. 17 and 18, an annular part 111 and one end part of the annular part 111 are provided. A plurality of pillar portions 112 projecting in the axial direction at a plurality of substantially equal intervals in the circumferential direction, and pocket portions 113 formed between the respective pillar portions 112 to hold the balls 103 so as to roll in the circumferential direction. A retainer having a flexible inner ring outer diameter surface and a cantilever ring structure in which the outer ring inner diameter surface is not used as a guide surface, that is, a ball guide crown-shaped cage 110 that is not in contact with the inner ring / outer ring may be employed. When two single-row ball bearings are combined in this way, as shown in FIG. 16, if the axial pitch of the balls 103 is shifted as much as possible on the opposite side of the end face on the combination side (X ₁ > X ₂ ), the cage A structure in which the axial thickness of the ring portion increases can be obtained, and the distance between the operating points for increasing the moment rigidity can be increased. Further, a full-ball angular contact ball bearing without a cage may be applied.

In the above embodiment, the pitch circle diameter of the balls 103 is as shown in the following formula (1). However, when it is desired to increase the moment stiffness by increasing the number of balls per row of the bearing, the following formula (2) The pitch circle diameter of the ball 103 may be shifted to the outer ring side, or the following equation (3) may be used as necessary to shift the pitch circle diameter of the ball 103 toward the inner ring 102 side. (Not shown).
Ball pitch circle diameter = (inner ring inner diameter + outer ring outer diameter) / 2 (1)
Ball pitch circle diameter> (inner ring inner diameter + outer ring outer diameter) / 2 (2)
Ball pitch circle diameter <(inner ring inner diameter + outer ring outer diameter) / 2 (3)

  If necessary, the ball pitch circle diameters of the left and right ball bearings to be combined may not be the same value, and the diameters of the balls 103 of the left and right ball bearings to be combined may not be the same value. In addition, the sectional dimension ratio (B / H) of the two ball bearings to be combined is not the same. For example, the smaller ball diameter is (B / H) = 0.28, and the larger ball diameter is (B / H). ) = 0.62. Further, the axial pitch of the balls 103 may not be the center of the axial direction, and the axial pitch of the balls 103 may be shifted in the axial direction in order to secure the distance between the application points of the moment and the moment of attachment of the seal and the cage. Good.

Next, with reference to FIG. 15, a double-row angular contact ball bearing which is an example of an embodiment of the second aspect (corresponding to claim 2) of the present invention will be described.
In this double row angular contact ball bearing 200, a large number of balls 203 are rotatably arranged between the double row raceway grooves 201a and 201b of the outer ring 201 and the double row raceway grooves 202a and 202b of the inner ring 202, and an axial cross-section. The cross-sectional dimension ratio (B2 / H2) between the width B2 and the radial sectional height H2 (= (outer ring outer diameter D2—inner ring inner diameter d2) / 2) is (B2 / H2) <1.2, The pitch circle diameter is set at the center of the radial section height.

And the seal | sticker accommodation groove | channels 121 and 122 similar to 1st Embodiment are each formed in the right-and-left side surface of the outer ring | wheel 201 and the inner ring | wheel 202, and the cyclic | annular seal body 120 is accommodated in these seal | sticker accommodation grooves 121 and 122 by right and left object. .
Here, in this embodiment, a case where the double row ball bearing 200 is replaced with a double row combination angular ball bearing of 7208A (contact angle 35 °) is taken as an example.

  7208A has an inner ring inner diameter φ40 mm, an outer ring outer diameter φ80 mm, and an axial cross-sectional width (bearing single body width): B is 18 mm, so the cross-sectional dimension ratio (B / H) = 0.9. Therefore, in the angular ball bearing 200 of the present embodiment, the cross-sectional dimension ratio (B2 / H2) = 0.90 (the inner ring outer diameter and the outer ring outer diameter remain the same, and the axial sectional width (bearing unit width): B2 is 18 mm. ) As a result, it is possible not only to receive radial load, axial load in both directions, and moment load, but also to reduce space by 1/2 in the axial dimension, lower torque, and higher rigidity. .

Of course, if necessary, the cross-sectional dimension ratio (B2 / H2) may be set to be less than 0.90 or more than 0.90 (provided that (B2 / H2) <1.2).
The contact angle of the angular ball bearing 200 is set to 35 °, for example, as in the first embodiment described above, and the contact portions of the ball 203 with the outer ring 201 and the raceway grooves 201a, 201b and 202a, 202b of the inner ring 202 are set. The extension line L1 in the normal direction of P1 and P2 is set so as to pass through a position separated by a predetermined distance Δ (> 0) with respect to the housing recess 122b.

  Even in the second embodiment, the contact angle θ is set so that the extension line L1 in the normal direction of the contact portions P1 and P2 does not interfere with the housing recess 122b of the seal housing groove 122. When a large rolling element load is applied, the rolling element load is not borne only by the groove shoulder, but is received by the inner ring 202 backed up by the inner ring presser and a shaft (not shown) inserted therein. Therefore, the deformation of the groove shoulder can be suppressed, and the fracture or chipping of the groove shoulder can be surely prevented, and the life of the narrow double row angular bearing can be prolonged.

In the second embodiment, in order to increase the moment rigidity, the double-row angular contact ball bearing 200 is used to shift the ball pitch circle diameter to the outer diameter side, or the double-row angular contact ball bearing 200 is used to change the ball diameter and ball pitch of each row. The circle diameter may be changed.
Alternatively, a double row full ball angular contact ball bearing without a cage may be used.
In any case, in addition to the structure of the annular seal body, the cage, etc. and whether or not it is mounted, the application example related to the structure is the same as the single row ball bearing described in the first embodiment. Moreover, you may use on any conditions of a preload and a clearance gap similarly to embodiment of the said 1st aspect.

  In the first embodiment, the case has been described in which the housing recesses 121b and 122b for housing the annular seal body 120 connected to the shoulder portion 102c on the inner ring 102 side are formed. However, the present invention is not limited to this. Instead, this is also the case when the concave portion for accommodating the annular seal body 120 is formed by connecting the outer ring 101 and the inner ring 102 to the shoulders as a shape reversed left and right by a vertical line passing through the center of the ball 103 in FIG. The invention can be applied. Here, the annular seal body 120 may be provided on both the left and right sides.

  Furthermore, in the said 1st and 2nd embodiment, although the accommodation recessed part 121b, 122b which accommodates the cyclic | annular sealing body 120 was demonstrated covering the perimeter of the circumferential direction, it is limited to this. The present invention can also be applied to a case where the housing recess is formed in a part of the circumferential direction. Furthermore, the storage recess is not limited to the one for storing the annular seal body 120, and a storage recess used for any application can be applied.

It is principal part sectional drawing for demonstrating the single row angular contact ball bearing which is an example of embodiment of the 1st aspect (corresponding to Claim 1) of this invention. It is principal part sectional drawing which shows the state which combined the single row angular contact ball bearing of FIG. 1 with 2 rows. It is a graph which shows the relationship between a cross-sectional dimension ratio (B / H) and the deformation amount of the inner and outer ring | wheels of a radial direction. It is a graph which shows the relationship between a cross-sectional dimension ratio (B / H) and a cross-sectional secondary moment I. It is explanatory drawing for demonstrating the deformation amount of the radial direction of an inner ring | wheel. It is explanatory drawing for demonstrating the calculation method of the cross-sectional secondary moment of an inner ring | wheel. It is a graph which shows the relationship between a cross-sectional dimension ratio (B / H) and the deformation amount of the inner and outer ring | wheels of a radial direction. It is a graph which shows the relationship between a cross-sectional dimension ratio (B / H) and a cross-sectional secondary moment I. It is a graph which shows the comparison of the moment rigidity of this invention product and a cross roller bearing. It is a graph which shows the comparison of the calculated moment rigidity in various bearings. It is principal part sectional drawing for demonstrating the single row angular contact ball bearing which is other embodiment of the 1st aspect of this invention. It is principal part sectional drawing for demonstrating the single row angular contact ball bearing of the 1st aspect of this invention. It is principal part sectional drawing for demonstrating the modification of the single row angular contact ball bearing of the 1st Embodiment of this invention. It is principal part sectional drawing for demonstrating the single row angular contact ball bearing of the other modification of the 1st aspect of this invention. It is principal part sectional drawing for demonstrating the double row angular contact ball bearing of the 2nd aspect of this invention. It is principal part sectional drawing which shows the state which combined the single row ball bearing which shows the other example of the single row angular ball bearing of the 1st aspect of this invention in two rows. It is sectional drawing in alignment with the radial direction of a holder | retainer. It is the fragmentary perspective view which looked at the holder | retainer from radial direction inner side. It is explanatory drawing which shows the conventional angular contact ball bearing.

Explanation of symbols

100 single row ball bearing 101 outer ring 101a outer ring raceway groove 102 inner ring 102a inner ring raceway groove 102c groove shoulder 103 ball 120 annular seal body 121, 122 seal receiving groove 123 intersection edge part 130 cage 131 pocket part 132a, 132b annular part 133 Concave groove 200 Double row ball bearing 201 Outer ring 201a, 201b Outer ring raceway groove 202 Inner ring 202a, 202b Inner ring raceway groove 203 Ball

Claims (4)

An inner ring in which a concave step portion having a diameter smaller than that of the inner ring groove shoulder portion is formed at least in a part of the circumferential direction, and a concave step portion having a diameter larger than that of the outer ring groove shoulder portion is formed in at least a part of the circumferential direction. In the narrow single row angular contact ball bearing provided with at least one of the outer ring and a large number of balls rotatably arranged between the race groove of the outer ring and the race groove of the inner ring,
A single row angular contact ball bearing, wherein a contact angle is set so that an extension line in a normal direction at a contact portion between the ball and the outer ring and the inner ring does not interfere with the concave stepped portion. An inner ring in which a concave step portion having a diameter smaller than that of the inner ring groove shoulder portion is formed at least in a part of the circumferential direction, and a concave step portion having a diameter larger than that of the outer ring groove shoulder portion is formed in at least a part of the circumferential direction. In the narrow double-row angular contact ball bearing provided with at least one of the outer ring and a large number of balls rotatably arranged between the race groove of the outer ring and the race groove of the inner ring,
A double row angular contact ball bearing, wherein a contact angle is set so that an extension line in a normal direction at a contact portion between the ball and the outer ring and the inner ring does not interfere with the concave stepped portion.   The angular ball bearing according to claim 1, wherein the concave step portion includes a groove into which an annular seal body is inserted and an opposing seal labyrinth portion.   An annular seal body is inserted into the concave step portion of either the inner ring or the outer ring, and the annular seal body is in contact with or not in contact with the concave step of the inner ring and outer ring corresponding to the inserted side. The angular ball bearing according to any one of claims 1 to 3, wherein the angular ball bearing is configured so as to be formed.

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