JP7631010B2 - Rolling bearings - Google Patents

Description

The present invention relates to a rolling bearing.

There are known rolling bearings in which the outer and inner rings are each a one-piece integral structure (e.g., Patent Document 1). There are also known rolling bearings in which the outer and inner rings each have a mounting hole formed therein for mounting a mating member (e.g., Patent Documents 2 and 3).

Patent No. 5451988 JP 2016-019447 A JP 2019-039464 A

It is sometimes desirable to fit a rolling bearing into a small space. It is also desirable for the rolling bearing to be easy to install. Therefore, one of the objectives is to provide a rolling bearing that can be fitted into a small space and is easy to install.

The rolling bearing according to the present disclosure is a rolling bearing comprising an outer ring having a raceway groove formed on its inner circumferential surface, an inner ring having a common central axis with the outer ring and having a raceway groove formed on its outer circumferential surface, and a plurality of rolling elements arranged in a raceway formed by the raceway groove of the outer ring and the raceway groove of the inner ring. The rolling bearing has a protrusion continuous with the outer ring or the inner ring. The protrusion protrudes outward in the axial direction from the outer ring and the inner ring, and is formed radially at the same or inner side as the outer periphery of the outer ring and at the same or outer side as the inner periphery of the inner ring. The protrusion has a mounting hole formed in it for fixing the outer ring or the inner ring to an external part. The mounting hole is formed to extend parallel to a plane perpendicular to the axis of the rolling bearing.

The above rolling bearing can be installed in a small space, providing an easy-to-install rolling bearing.

FIG. 1A is a perspective view showing a rolling bearing according to a first embodiment. FIG. 1B is a perspective view showing the rolling bearing in the first embodiment. FIG. 1C is a perspective view showing the rolling bearing in the first embodiment. FIG. 2 is a cross-sectional perspective view of the rolling bearing according to the first embodiment. FIG. 3A is a plan view showing the outer ring of the rolling bearing in embodiment 1. FIG. FIG. 3B is a plan view showing the outer ring of the rolling bearing in embodiment 1. FIG. 3C is a perspective view showing the outer ring of the rolling bearing in embodiment 1. FIG. 4 is a cross-sectional view of the outer ring of the rolling bearing in the first embodiment. FIG. 5 is a cross-sectional view of the outer ring of the rolling bearing in the first embodiment. FIG. 6A is a plan view showing an inner ring of the rolling bearing in embodiment 1. FIG. FIG. 6B is a plan view showing the inner ring of the rolling bearing in embodiment 1. FIG. 6C is a perspective view showing the inner ring of the rolling bearing in embodiment 1. FIG. 7 is a cross-sectional view of the inner ring of the rolling bearing according to the first embodiment. FIG. 8 is a cross-sectional view of the inner ring of the rolling bearing according to the first embodiment. FIG. 9A is a perspective view showing a rolling bearing according to the second embodiment. FIG. 9B is a plan view showing the rolling bearing in embodiment 2. FIG. 9C is a plan view showing the rolling bearing in embodiment 2. FIG. 10A is a perspective view showing a rolling bearing according to the third embodiment. FIG. 10B is a perspective view showing the rolling bearing in embodiment 3. FIG. 10C is a plan view showing the rolling bearing in embodiment 3. FIG. 11A is a perspective view showing a rolling bearing according to the fourth embodiment. FIG. 11B is a perspective view showing the rolling bearing in the fourth embodiment. FIG. 11C is a plan view showing the rolling bearing in embodiment 4. FIG. 11D is a cross-sectional view showing the rolling bearing in embodiment 4. FIG. 12A is a perspective view showing a rolling bearing according to the fifth embodiment. FIG. 12B is a perspective view showing the rolling bearing in embodiment 5. FIG. 12C is a plan view showing the rolling bearing in embodiment 5. FIG. 13A is a perspective view showing a rolling bearing according to the sixth embodiment. FIG. 13B is a perspective view showing the rolling bearing in embodiment 6. FIG. 13C is a plan view showing the rolling bearing in embodiment 6. FIG. 14 is a perspective view of a knuckle according to the present disclosure. FIG. 15A is a perspective view of a frame of an assembly according to the present disclosure. FIG. 15B is a perspective view of an assembly according to the present disclosure. FIG. 16A is a top view of an assembly according to the present disclosure. FIG. 16B is a perspective view of an assembly according to the present disclosure. FIG. 17 is a perspective view of a frame of an assembly according to the present disclosure. FIG. 18A is a top view of an assembly according to the present disclosure. FIG. 18B is a perspective view of an assembly according to the present disclosure. FIG. 19 is a perspective view of a frame of an assembly according to the present disclosure. FIG. 20 is a cross-sectional view of a frame of an assembly according to the present disclosure. FIG. 21A is a perspective view of an assembly according to the present disclosure. FIG. 21B is a top view of an assembly according to the present disclosure. FIG. 21C is a perspective view of an assembly according to the present disclosure.

[Overview of the embodiment]
First, the embodiments of the present disclosure will be described. The rolling bearing according to the present disclosure is a rolling bearing including an outer ring having a raceway groove formed on its inner circumferential surface, an inner ring having a common central axis with the outer ring and having a raceway groove formed on its outer circumferential surface, and a plurality of rolling elements arranged in a raceway formed by the raceway groove of the outer ring and the raceway groove of the inner ring. The rolling bearing has a protruding portion continuous with the outer ring or the inner ring. The protruding portion protrudes outward in the axial direction from the outer ring and the inner ring, and is formed radially at the same or inner side as the outer periphery of the outer ring and at the same or outer side as the inner periphery of the inner ring. The protruding portion has a mounting hole formed therein for fixing the outer ring or the inner ring to an external part. The mounting hole is formed to extend parallel to a plane perpendicular to the axis of the rolling bearing.

Conventionally, a rolling bearing is known, for example, as disclosed in Patent Document 1. The rolling bearing disclosed in Patent Document 1 is a cross roller bearing, and a thin rolling bearing is provided by forming a separator arranged between the rollers, which are rolling bodies, into a specific shape. However, this rolling bearing does not have a mounting hole for fixing the rolling bearing to an external part. Therefore, when fixing the rolling bearing to an external part, another member such as a housing or a pressing plate is required. On the other hand, the rolling bearing of Patent Document 2 has a mounting hole that penetrates in the axial direction on the outside of the raceway surface of the outer ring and on the inside of the raceway surface of the inner ring. Also, the rolling bearing of Patent Document 3 has a mounting hole that extends in the axial direction at a position axially separated from the raceway surface of the outer ring and the inner ring.

On the other hand, for example, a bearing used in a robot joint structure that is similar in size to a human finger is desired to have a small diameter, such as an outer diameter of about 20 mm. It is also preferable that such a bearing has a small axial dimension. At the same time, it is desired that it is easy to attach and assemble to external parts. In view of this situation, rolling bearings have been repeatedly studied. Then, it was conceived of providing a protrusion that is continuous with the outer or inner ring of the rolling bearing and protrudes outward in the axial direction, and providing a mounting hole in such a protrusion. Furthermore, it was conceived of forming the radial dimension of this protrusion so that it does not protrude outward beyond the outer ring, and does not protrude inward beyond the inner circumference of the inner ring. In addition, it was conceived of forming a mounting hole so that it extends parallel to a plane perpendicular to the axis of the rolling bearing.

The rolling bearing of the present disclosure allows the rolling bearing to be attached to an external component without creating any parts that protrude radially outward beyond the outer and inner rings of the rolling bearing. In addition, the mounting holes extend parallel to a plane perpendicular to the axis, thereby suppressing the increase in axial dimension caused by providing mounting holes. The rolling bearing of the present disclosure allows for compact mounting. The above configuration of the rolling bearing of the present disclosure makes it possible to arrange multiple bearings in a small space. In particular, when used in the finger joint structure of a robot hand, a compact joint structure can be realized that is easy to mount and assemble and does not deviate from the size of a human finger.

In the above rolling bearing, the mounting holes can be formed to extend in a tangential direction of the outer ring and the inner ring. By making the mounting holes extend in a tangential direction, a fixing member such as a screw or bolt can be inserted from the tangential direction and fixed. This configuration makes it easier to fix to an external part such as a frame.

In the above rolling bearing, the protrusion can be continuous with the outer ring, and the radially outer surface of the protrusion can be a surface formed by a part of the outer peripheral surface of the outer ring extending in the axial direction. In addition, in the above rolling bearing, the protrusion can be continuous with the inner ring, and the radially inner surface of the protrusion can be a surface formed by a part of the inner peripheral surface of the inner ring. By making one of the surfaces defining the protrusion a surface extending from the outer peripheral surface of the outer ring or the inner peripheral surface of the inner ring, the strength of the protrusion can be made sufficient compared to when the protrusion is formed from a separate part. In addition, in manufacturing, by processing the protrusion at the same time as processing the outer ring or inner ring, the increase in manufacturing steps can be suppressed and the functional precision of the bearing can be improved.

In the above rolling bearing, the protrusion may include a first protrusion that is continuous with the outer ring and protrudes axially outward from the outer ring, and a second protrusion that is continuous with the inner ring and protrudes axially outward from the inner ring. The first protrusion may be formed with a first mounting hole for fixing the outer ring to an external part, and the second protrusion may be formed with a second mounting hole for fixing the inner ring to an external part. When mounting holes of the above configuration are provided in both the outer ring and the inner ring, the protrusion that is the mounting part can be contained within the radial dimension, and the increase in the dimension of the bearing due to the provision of the mounting part can be further suppressed.

In the rolling bearing, two first mounting holes and two second mounting holes are formed, and the two first mounting holes are parallel to each other, and the two second mounting holes are parallel to each other. By providing two mounting holes in parallel, it is easier to machine the mounting holes and to attach them to an external member.

In the rolling bearing, the distance between the two first mounting holes and the distance between the two second mounting holes can be made equal. This configuration allows the mounting pitch of screws and bolts to be the same, making it possible to standardize parts.

The present disclosure may also be an assembly including the rolling bearing and a frame having a mounting portion to which the rolling bearing is fixed. The assembly of the present disclosure is compact in both radial and axial dimensions and can be installed in a small space.

The above assembly may have a frame with two mounting parts, and two of the rolling bearings may be fixed to the frame. By connecting multiple such assemblies, it is possible to provide a small, multi-joint structure that is easy to assemble.

The present disclosure also relates to a robot finger joint in which multiple such assemblies are connected. The robot finger joint of the present disclosure can be a small joint comparable in size to a human finger. In addition, since the bearings can be easily attached and the joint can be easily assembled, and the structure is simple, it can be used to insert cables such as electric wires inside, and can be designed in a wide range of ways to suit desired applications.

[Specific Example of the Embodiment]
Next, an example of a specific embodiment of the rolling bearing of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
Figures 1A to 1C are perspective views showing the structure of a rolling bearing in one embodiment (embodiment 1) of the present disclosure. Figures 1A to 1C are perspective views of the same rolling bearing viewed from different angles. Figure 2 is a cross-sectional view taken along line A-A in Figure 1A. Figures 3A to 5 are views showing the outer ring of the rolling bearing in embodiment 1. Figures 6A to 8 are views showing the inner ring of the rolling bearing in embodiment 1.

Referring to Figures 1A to 1C, the rolling bearing 1 includes an outer ring 10, an inner ring 50, and rollers 80 as a plurality of rolling elements. The outer ring 10 and the inner ring 50 have a common center axis R. The center axis R is the rotation axis of the rolling bearing 1. The inner ring 50 is disposed on the inner periphery side of the outer ring 10. Referring to Figure 2, the outer ring 10 and the inner ring 50 are each formed into a one-piece integral structure. A first raceway groove 11 having a V-shaped cross section is formed on the inner periphery surface 10b of the outer ring 10. The first raceway groove 11 includes a first raceway surface 11a and a second raceway surface 11b. A groove 11c, which is an escape groove, is formed between the first raceway surface 11a and the second raceway surface 11b. A second raceway groove 51 is formed on the outer periphery surface 50a of the inner ring 50 so as to face the first raceway groove 11. The second raceway groove 51 includes a first raceway surface 51a and a second raceway surface 51b. A groove 51c, which is an escape groove, is formed between the second raceway surface 51a and the second raceway surface 51b.

The first raceway groove 11 and the second raceway groove 51 form an annular raceway 101. The rollers 80 roll within the raceway 101. The outer ring 10 and the inner ring 50 are rotatable relative to each other via the rollers 80.

1A and 2, the outer ring 10 is formed with a through hole 12. The through hole 12 is a circular hole that penetrates radially from the outer peripheral surface 10a of the outer ring 10 to the first raceway groove 11 of the inner peripheral surface 10b. The rollers 80 and the separator 83 can be assembled into the raceway 101 through the through hole 12. After the rollers 80 and the separator 83 are assembled, the through hole 12 is sealed with the lid 13. The lid 13 is fixed to the outer ring 10 by inserting a fixing pin 15 extending parallel to the axial direction of the outer ring 10 through a pin fixing through hole 16 of the outer ring 10 and a pin fixing through hole 17 of the lid 13. The outer ring 10 is also formed with a pin fixing through hole 16 and a fitting/removal through hole 14 that is larger in diameter than the through hole 16 and communicates with the through hole 16. The lid 13 is formed with a groove that matches the first raceway groove 11.

The rollers 80 include a plurality of first rollers 81 and a plurality of second rollers 82 assembled in mutually orthogonal directions. The first rollers 81 and the second rollers 82 are arranged so as to be alternately positioned. Furthermore, one or a plurality of separators 83 are assembled between the first rollers 81 and the second rollers 82. The first rollers 81 and the second rollers 82 have a cylindrical shape. The first rollers 81 and the second rollers 82 have the same shape, except that the assembled direction is different. The length and diameter of the cylindrical shapes of the first rollers 81 and the second rollers 82 are approximately the same dimensions. The first rollers 81 and the second rollers 82 may be made of steel. The separator 83 may be made of resin.

(Structure of outer ring and protrusion)
Figures 3 to 5 are views showing the outer ring 10 of the rolling bearing 1. Specifically, Figures 3A to 3C are plan views, side views and perspective views of the outer ring 10. Figure 4 is a cross-sectional view taken along line B-B in Figure 3A. However, Figure 4 shows a rotated view of the B-B cross section. Figure 5 is a cross-sectional view taken along line C-C in Figure 3B.

3A to 3C, a first protrusion 110 is provided continuous with the outer ring 10. The first protrusion 110 protrudes outward from the rolling bearing 1 in the direction in which the central axis R of the rolling bearing 1 extends. The first protrusion 110 is an arc-shaped protrusion that protrudes in the axial direction of the rolling bearing 1 and extends along the circumference of the outer ring 10. The outer peripheral surface 110a of the first protrusion 110 is seamlessly continuous with the outer peripheral surface 10a of the outer ring 10. In other words, the outer peripheral surface 110a of the first protrusion 110 is a surface formed by extending the outer peripheral surface 10a of the outer ring 10. The inner peripheral surface 110b of the first protrusion 110 is part of the peripheral surface of a cylinder centered on the central axis R. The inner peripheral surface 10b of the outer ring 10 and the inner peripheral surface 110b of the first protrusion 110 are connected by a slope 110f that rises from the inner peripheral surface 10b of the outer ring 10 and extends toward the central axis R. The diameter of the inner peripheral surface 110b of the first protrusion 110 is slightly larger than the diameter of the inner peripheral surface 50b of the inner ring 50 (FIG. 2). In other words, the first protrusion 110 is formed radially outboard of the inner circumference of the inner ring 50 and flush with the outer peripheral surface 10a of the outer ring 10.

Referring to Figs. 3A to 3C and Fig. 5, the first protrusion 110 has a first surface 110c and a second surface 110d, which are mounting surfaces for mounting to an external part. The first surface 110c and the second surface 110d are on the same plane and extend parallel to the central axis R. The first surface 110c and the second surface 110d are respectively formed with mounting holes 121 and 122 as first mounting holes, which are screw holes for mounting the outer ring 10 to an external part. The mounting holes 121 and 122 are formed so as to be perpendicular to the first surface 110c and the second surface 110d. The mounting holes 121 and 122 are parallel to each other. The mounting holes 121 and 122 extend parallel to a plane perpendicular to the central axis R of the rolling bearing 1. The mounting holes 121 and 122 are formed in the tangential direction of the outer ring 10.

3B, the axial dimension of the first protrusion 110, i.e., the thickness _d2 of the first protrusion 110, is approximately twice the diameter _d1 of the mounting holes 121, 122. In other words, the increase in the axial dimension due to the provision of the first protrusion 110 is suppressed to approximately twice the diameter of the bolt, which is the mounting part. Also, as described above, the first protrusion 110 is provided outside the inner circumference of the inner ring 10 and flush with the outer circumference of the outer ring 10 in terms of the radial dimension, so that the provision of the first protrusion 110 does not result in an increase in the radial dimension.

Referring to FIG. 4, the through hole 16 for fixing the pin 15 to the first outer ring 10 is a through hole that communicates with the through hole 14 for inserting and removing the pin in the first protruding portion 110, and penetrates from the outer surface 110e of the first protruding portion 110 to the outer ring 10. The diameter of the through hole 14 for inserting and removing the pin in the first protruding portion 110 is larger than the diameter of the through hole 16 for fixing the pin in the outer ring 10. This configuration makes it easier and more reliable to insert and remove the pin 15.

(Structure of inner ring and protrusion)
Figures 6 to 8 are views showing the inner ring 50 of the rolling bearing 1. Specifically, Figures 6A to 6C are plan, side and perspective views of the inner ring 50. Figure 7 is a cross-sectional view taken along line D-D in Figure 6A. Figure 8 is a cross-sectional view taken along line E-E in Figure 6B.

6A to 6C, a second protrusion 150 is provided continuous with the inner ring 50. The second protrusion 150 protrudes outward from the rolling bearing 1 in the direction in which the central axis R of the rolling bearing 1 extends, in the opposite direction to the first protrusion 110. The second protrusion 150 protrudes in the axial direction of the rolling bearing 1 and is an arc-shaped protrusion extending along the circumference of the inner ring 50. The inner surface 150b of the second protrusion 150 is seamlessly continuous with the inner surface 50b of the inner ring 50. In other words, the inner surface 150b of the second protrusion 150 is a surface formed by extending the inner surface 50b of the inner ring 50. The outer surface 150a of the second protrusion 150 is a part of the peripheral surface of a cylinder centered on the central axis R. The outer peripheral surface 50a of the inner ring 50 and the outer peripheral surface 150a of the second protrusion 150 are connected by a slope 150f that rises from the outer peripheral surface 50a of the inner ring 50 and extends in a direction away from the central axis R. The diameter of the outer peripheral surface 150a of the second protrusion 150 is slightly smaller than the diameter of the outer peripheral surface 10a of the outer ring 10 (FIG. 2). In other words, the second protrusion 150 is formed radially inward from the outer periphery of the outer ring 10 and flush with the inner peripheral surface 50b of the inner ring 50.

6B, 6C, and 8, the second protrusion 150 has a first surface 150c and a second surface 150d, which are mounting surfaces with an external part. The first surface 150c and the second surface 150d are on the same plane and extend parallel to the central axis R. The first surface 150c and the second surface 150d are formed with mounting holes 161 and 162, which are screw holes for mounting the inner ring 50 to an external part, as second mounting holes. The mounting holes 161 and 162 are formed so as to be perpendicular to the first surface 150c and the second surface 150d. The mounting holes 161 and 162 are parallel to each other. The mounting holes 161 and 162 extend parallel to a plane perpendicular to the central axis R of the rolling bearing 1. The mounting holes 161 and 162 are formed in the tangential direction of the inner ring 50.

Referring to FIG. 6B, the axial dimension of the second protrusion 150, i.e., the thickness d ₃ of the second protrusion 150, is approximately twice the diameter d ₄ of the mounting holes 161, 162. That is, the increase in the axial dimension due to the provision of the second protrusion 150 is suppressed to approximately twice the diameter of the bolt, which is the mounting part. As described above, the second protrusion 150 is provided flush with the inner peripheral surface of the inner ring in terms of the radial dimension and inside the outer periphery of the outer ring 10, so that the provision of the second protrusion 150 does not increase the radial dimension of the rolling bearing 1. Here, the pitch W ₁ (FIG. 3B) between the two mounting holes 121, 122 in the first protrusion 110 and the pitch W ₂ between the two mounting holes 161, 162 in the second protrusion 150 are equal to each other. By making the pitches equal, it is possible to standardize parts, improving the rationality of manufacturing and assembly.

Referring to FIG. 1B and FIG. 2, the rolling bearing 1 has two mounting holes in each of the outer ring 10 and the inner ring 50, but the radial dimensions are within the range of the dimensions of the outer ring 10 and the inner ring 50, so there is no increase in the radial dimensions due to the mounting parts. In addition, in the axial dimensions, protrusions with a thickness about twice the diameter of the mounting holes are provided on the outside of the outer ring 10 and the inner ring 50, respectively. With this configuration, the increase in the axial dimensions is suppressed compared to a form in which a mounting member such as a bolt is inserted in the axial direction. The specific dimensions of the rolling bearing 1 are not limited because they can be set appropriately depending on the application and purpose, but for example, the rolling bearing can have an outer diameter of about φ21 to φ540 mm, an inner diameter of about φ10 to φ400 mm, and an axial dimension including the protrusions of about 15 to 100 mm.

(Modification)
In the first embodiment, the rolling elements are rollers, but the rolling elements may be balls. Also, a separator and a retainer may be provided together with the rolling elements, or the separator and the retainer may be omitted. Also, the specific shape of the protrusions can be widely changed according to the shape of the mounting counterpart, etc.

(Embodiment 2)
A second embodiment of the rolling bearing according to the present disclosure will be described. Figures 9A to 9C show a rolling bearing 2 according to the second embodiment. Figure 9A is a perspective view showing the rolling bearing 2 in the second embodiment. Figure 9B is a plan view of the rolling bearing 2 as viewed from the side indicated by the arrow F in Figure 9A. Figure 9C is a plan view of the rolling bearing 2 as viewed from the side indicated by the arrow G in Figure 9A. In the rolling bearing 2 in the second embodiment, the structures of the outer ring 10, the inner ring 50 and the rollers 80 of the bearing are the same as those in the first embodiment. The second embodiment differs from the first embodiment in the shape of the protrusions continuing from the outer ring 10 and the inner ring 50. The following description will focus on the differences from the first embodiment.

9A and 9B, two protrusions 211, 212 are provided in series with the outer ring 10 and protrude outward in the axial direction. Mounting holes 221, 222 are formed in the two protrusions 211, 212, respectively. The mounting holes 221, 222 are parallel to each other and extend in a plane perpendicular to the central axis R. The protrusions 211, 212 have the same shape and are provided symmetrically with respect to the central axis R. The outer peripheral surfaces 211a, 212a of the protrusions are surfaces formed by extending the outer peripheral surface 10a of the outer ring 10. The inner peripheral surfaces 211b, 212b of the protrusions are located radially outward from the inner peripheral surface 50b of the inner ring 50. In the second embodiment, the mounting holes 221, 222 may penetrate the protrusions 211, 212. In the first embodiment, two mounting holes are formed in one protrusion (first protrusion 110) that extends in an arc shape, but in the second embodiment, the protrusion is divided into two, and a mounting hole is formed in each. In addition, a through hole 16 that penetrates the outer ring 10 in the axial direction is formed.

9A and 9C, two protrusions 511, 512 are provided, which are continuous with the inner ring 50 and protrude outward in the axial direction in the opposite direction to the protrusions 211, 212. Mounting holes 521, 522 are formed in the two protrusions 511, 512, respectively. The mounting holes 521, 522 are parallel to each other and extend in a plane perpendicular to the central axis R. The protrusions 511, 512 have the same shape and are provided symmetrically with respect to the central axis R. The inner peripheral surfaces 511b, 512b of the protrusions are surfaces formed by extending the inner peripheral surface 50b of the inner ring 50. The outer peripheral surfaces 511a, 512a of the protrusions are located radially inward from the outer peripheral surface 10a of the outer ring 10. The mounting holes 521, 522 may penetrate the protrusions 511, 512. When increasing the rotational speed, it is necessary to adjust the rotational balance in the design of the mounting parts to prevent vibrations that are difficult to prevent with a one-sided cut-off structure, or when mounting to a T-shaped mounting part that passes through the rotating shaft or a point-symmetrical part, the second embodiment is more preferable.

(Embodiment 3)
A third embodiment of the rolling bearing according to the present disclosure will be described. FIGS. 10A to 10C show a rolling bearing 3 according to the third embodiment. FIG. 10A is a perspective view showing the rolling bearing 3 in the third embodiment. FIG. 10B is a perspective view of the rolling bearing 3 from the side of the arrow H in FIG. 10A. FIG. 10C is a plan view of the rolling bearing 3 from the side of the arrow I in FIG. 10B. In the rolling bearing 3 in the third embodiment, the structures of the outer ring 10, the inner ring 50 and the rollers 80 of the bearing are the same as those in the first embodiment. In addition, the structure of the first protruding portion 110 protruding from the outer ring 10 is the same as that in the first embodiment. The rolling bearing 3 differs from the rolling bearing 1 in the structure of the protruding portion 650 continuing from the inner ring 50. The following description will focus on the differences from the first embodiment.

10A to 10C, a protrusion 650 is provided that is continuous with the inner ring 50 of the rolling bearing 3 and protrudes outward in the axial direction. The inner peripheral surface 650b of the protrusion 650 is an extension of the inner peripheral surface 50b of the inner ring 50. The outer peripheral surface 650a of the protrusion 650 is located inside the outer peripheral surface 10a of the outer ring 10. In other words, the radial dimension of the protrusion 650 is flush with the inner peripheral surface of the inner ring 50 and smaller than the outer periphery of the outer ring 10. The protrusion 650 is an annular protrusion centered on the central axis R of the rolling bearing 3. A groove 681 is formed on the outer peripheral surface 650a of the protrusion 650. The groove 681 is used when inserting and removing the pin 15 (FIG. 1A) into and from the through hole 16 of the outer ring 10.

The protruding portion 650 has holes 621, 622, 623, and 624 formed therein, which are screw holes for mounting and extend parallel to the central axis R. That is, the inner ring 50 can be fixed to an external member by utilizing mounting holes extending in the axial direction of the rolling bearing 3. In terms of radial dimensions, the rolling bearing 3 has no part that protrudes outward beyond the outer periphery of the outer ring 10, and no part that protrudes inward beyond the inner periphery of the inner ring 50. For example, the rolling bearing 3 can be preferably used when mounting strength and rigidity are required.

(Embodiment 4)
A fourth embodiment of the rolling bearing according to the present disclosure will be described. FIGS. 11A to 11D show a rolling bearing 4 according to the fourth embodiment. FIG. 11A is a perspective view showing the rolling bearing 4 in the fourth embodiment. FIG. 11B is a perspective view showing the rolling bearing 4 from the side of the arrow J in FIG. 11A. FIG. 11C is a plan view of the rolling bearing 4 from the side of the arrow K in FIG. 11B. FIG. 11D is a cross-sectional view taken along the line L-L in FIG. 11A. However, FIG. 11D shows the L-L cross section rotated. In the rolling bearing 4 in the fourth embodiment, the outer ring 10 of the bearing, the first protruding portion 110 protruding from the outer ring 10, and the rollers 80 have the same structure as in the first embodiment. The rolling bearing 4 differs from the rolling bearing 1 in that the inner peripheral surface of the inner ring 60 is used as the mounting portion. Hereinafter, the differences from the first embodiment will be mainly described.

11A to 11D, in the rolling bearing 4, the inner peripheral surface 60b of the inner ring 60 is formed with a screw groove. That is, the inner peripheral surface 60b can be used as a mounting portion of the inner ring 60. The inner ring 60 has a protrusion 61 that is continuous with the inner ring 60 and extends in the direction of the central axis R. The outer peripheral surface 61a of the protrusion 61 is a surface formed by extending the outer peripheral surface 60a of the inner ring 60. The inner peripheral surface 61b of the protrusion 61 is a surface formed by extending the inner peripheral surface 60b of the inner ring 60. The inner peripheral surface 60b and the inner peripheral surface 61b are formed with a screw groove that continues across the inner peripheral surface 60b and the inner peripheral surface 61b. Referring to FIG. 11B, the outer periphery of the protrusion 61 has two cutout portions 63, which are partially cut out of the outer periphery, formed at positions facing each other. The cutout portions 63 can be used during assembly or for mounting separate parts.

Referring to Figures 11B and 11C, the rolling bearing 4 has no radially extending parts that protrude inward beyond the inner circumference of the inner ring, and no parts that protrude outward beyond the outer circumference of the outer ring. Furthermore, in terms of the axial dimension, the mounting parts of the outer ring 10 have mounting holes 121, 122 extending perpendicular to the central axis R, thereby suppressing an increase in the axial dimension. Furthermore, by providing a protrusion 61 that extends the inner ring 60 outward, and using the inner circumferential surfaces 60b, 61b as mounting holes, an increase in the axial dimension can be further suppressed. Furthermore, since there is no part that protrudes outward from the inner ring 60 in the circumferential direction, the through hole 16 is always exposed, making assembly easier.

(Embodiment 5)
A fifth embodiment of the rolling bearing according to the present disclosure will be described. FIGS. 12A to 12C show a rolling bearing 5 according to the fifth embodiment. FIG. 12A is a perspective view showing the rolling bearing 5 in the fifth embodiment. FIG. 12B is a perspective view of the rolling bearing 5 from the side of the arrow M in FIG. 12A. FIG. 12C is a plan view of the rolling bearing 5 from the side of the arrow N in FIG. 12B. In the rolling bearing 5 in the fifth embodiment, the structures of the inner ring 50 of the bearing, the second protruding portion 150 protruding from the inner ring 50, and the rollers 80 are the same as those in the first embodiment. The rolling bearing 5 differs from the rolling bearing 1 in the structure of the protruding portion 130 continuing from the outer ring 10. The following description will focus on the differences from the first embodiment.

Referring to Figures 12A to 12C, a protrusion 130 is provided that protrudes outward in the axial direction, continuing from the outer ring 10 of the rolling bearing 5. The outer peripheral surface 130a of the protrusion 130 is an extension of the outer peripheral surface 10a of the outer ring 10. The inner peripheral surface 130b of the protrusion 130 is located radially outward from the inner peripheral surface 50b of the inner ring 50. In other words, the radial dimension of the protrusion 130 is outside the inner peripheral surface of the inner ring 50 and is the same as the outer circumference of the outer ring 10. The protrusion 130 is an annular protrusion centered on the central axis R of the rolling bearing 5. The protrusion 130 has a through hole 16 that axially penetrates the outer ring 10 and a through hole 14 that is larger in diameter than the through hole 16.

The protrusion 130 has holes 131, 132, 133, and 134 formed therein, which are screw holes for mounting and extend parallel to the central axis R. That is, the outer ring 10 can be fixed to an external member by utilizing the mounting holes extending in the axial direction of the rolling bearing 5. In terms of radial dimensions, the rolling bearing 5 has no parts that protrude outward beyond the outer periphery of the outer ring 10, and no parts that protrude inward beyond the inner periphery of the inner ring 50. For example, the rolling bearing 5 can be suitably used when the mounting surface and thickness required to form a housing hole can be secured, a large moment load is expected, or precision in the mounting position is required.

(Embodiment 6)
A sixth embodiment of the rolling bearing according to the present disclosure will be described. FIGS. 13A to 13C show a rolling bearing 6 according to the sixth embodiment. FIG. 13A is a perspective view showing the rolling bearing 6 in the sixth embodiment. FIG. 13B is a perspective view showing the rolling bearing 6 from the opposite side to FIG. 13A. FIG. 13C is a plan view of the rolling bearing 6 showing the rolling bearing 6 from the side of the arrow O in FIG. 13A. In the rolling bearing 6 in the sixth embodiment, the structures of the inner ring 50, the second protruding portion 150 protruding from the inner ring 50, and the rollers 80 are the same as those in the first embodiment. The rolling bearing 6 differs from the rolling bearing 1 in that an extension portion 710 protruding radially outward from the outer ring 10 is provided. The following description will focus on the differences from the first embodiment.

Referring to Figures 13A to 13C, an extension portion 710 is provided that extends radially outwardly from the outer ring 10 of the rolling bearing 6. The axial thickness of the extension portion 710 is the same as the thickness of the outer ring 10. An assembly hole 712 that penetrates to the outer ring 10 is formed on the outer peripheral surface of the extension portion 710. The extension portion 710 is provided with mounting holes 721, 722, 723, and 724 that are countersunk holes extending parallel to the central axis R. That is, the outer ring 10 can be fixed to an external member by using the mounting holes that extend in the axial direction of the rolling bearing 6. In the axial dimension of the rolling bearing 6, the only part that protrudes outward from the outer ring 10 and the inner ring 50 is the second protruding portion 150 that is the mounting portion of the inner ring 50, so that the increase in the axial dimension due to the provision of the mounting portion is small. The outer ring 10 is provided with a through hole 16 that penetrates the outer ring 10 in the axial direction. For example, if the mounting surface is large enough and the thickness is sufficient to form a screw hole, a rolling bearing 6 can be used.

(Joint structure)
The present disclosure also relates to an assembly in which the above-mentioned rolling bearing and frame are combined. Furthermore, the present disclosure relates to a finger joint of a robot in which a plurality of assemblies of rolling bearings and frames are combined. FIG. 14 is a perspective view showing a finger joint 9 according to an embodiment of the present disclosure. Referring to FIG. 14, the finger joint 9 includes four rolling bearings 1 according to the first embodiment, a first frame 91, a second frame 92, a third frame 93, and a fourth frame 94. The finger joint 9 includes three radial joints and one thrust joint. One rolling bearing 1 is attached to the first frame 91. Two rolling bearings 1 are attached to each of the second frame 92, the third frame 93, and the fourth frame 94. In the finger joint 9, the first frame 91 corresponds to the fingertip side, and the fourth frame 94 corresponds to the wrist side.

Figure 15A is a perspective view showing the first frame 91. Figure 15B is a perspective view showing an assembly 931 in which the rolling bearing 1 is attached to the first frame 91. Referring to Figure 15A, the first frame 91 includes a fingertip portion 911, a thick portion 912 which is an attachment portion of the rolling bearing 1, and a plate 914. A hole 913 is formed at the tip of the fingertip portion 911. The hole 913 may be used for wiring or piping, or any member such as a sensor, a jig, or a cap may be installed, or may be closed. The hole 913 may be further processed depending on the purpose and use. The thick portion 912 includes surfaces 915 and 916 which are attachment surfaces of the rolling bearing, holes 917 and 918 formed in the attachment surfaces 915 and 916, respectively, and a slit 919 which communicates with the hole 913. Holes 917 and 918 are configured to communicate with the outside, and mounting bolts can be inserted through holes 917 and 918.

Referring to FIG. 15B, the inner ring 50 of the rolling bearing 1 is fixed to the first frame 91. The mounting surfaces 150c, 150d (see FIG. 1B) of the second protrusion 150, which is continuous with the inner ring 50, are arranged to face the mounting surfaces 915, 916 of the first frame 91, respectively. The bolt 950 is inserted so as to span the holes 917 and 161 (see FIG. 1B) and is fixed. Similarly, the bolt is inserted so as to span the holes 918 and 162 (see FIG. 1B) and is fixed. A series of communication parts is formed from the hole 913 through the slit 919 to the inner diameter of the rolling bearing 1, and a cable or the like can be inserted using the communication parts.

Fig. 16A is a plan view showing an assembly 932 in which two rolling bearings 1 are attached to a second frame 92. Fig. 16B is a perspective view showing the assembly 932. Fig. 17 is a perspective view showing the second frame 92. Referring to Fig. 16A, two rolling bearings 1 are arranged in parallel on the second frame 92. The distance _L1 between the two bearings is not particularly limited, but may be at least about 0.04 mm. Since the rolling bearings 1 do not have an attachment portion that protrudes outward from the bearing, interference between the bearings is unlikely to occur, and it is possible to arrange a plurality of bearings side by side in close positions.

Referring to FIG. 17, the second frame 92 includes a plate 921 having a shape corresponding to the two bearings, a first thick portion 922 which is a first mounting portion, and a second thick portion 923 which is a second mounting portion. The first thick portion 922 includes mounting surfaces 922c and 922d. The mounting surfaces 922c and 922d are respectively formed with holes 924 and 925 which are mounting holes. The holes 924 and 925 are connected to the outside so that a fixing bolt can be inserted from the outside. A slit 928 is formed between the holes 924 and 925. The mounting surfaces 923c and 923d in the second thick portion 923 are respectively formed with holes 926 and 927 which are mounting holes. The holes 926 and 927 are connected to the outside so that a fixing bolt can be inserted from the outside. A slit 929 is formed between the holes 926 and 927. Slit 928 and slit 929 are connected.

16B and 17, on the side of the first thick portion 922 of the second frame 92, the mounting surfaces 922c and 922d are arranged to face the surfaces 110c and 110d (see FIG. 1B) of the first protruding portion 110 protruding from the outer ring 10 of the rolling bearing 1. Bolts are inserted into the mounting hole 121 (see FIG. 1B) and the hole 924, and into the mounting hole 122 (see FIG. 1B) and the hole 925, respectively, and fixed. That is, on the side of the first thick portion 922, the second frame 92 and the outer ring 10 of the rolling bearing 1 are fixed. Also, on the side of the second thick portion 923, the mounting surfaces 923c and 923d are arranged to face the surfaces 150c and 150d (see FIG. 1B) of the second protruding portion 150 protruding from the inner ring 50 of the rolling bearing 1, respectively. Bolts are inserted into mounting hole 161 (see FIG. 1B) and hole 926, and into mounting hole 162 (see FIG. 1B) and hole 927, respectively, and fixed in place. That is, on the second thick portion 923 side, the second frame 92 and the inner ring 50 of the rolling bearing 1 are fixed in place. A communication portion is formed that runs from the inner diameter of one rolling bearing 1 through slits 928 and slits 929 to the inner diameter of the other rolling bearing. This communication portion can be used to insert a cable or the like.

Figure 18A is a plan view showing assembly 933 in which two rolling bearings 1 are attached to third frame 93. Figure 18B is a perspective view showing assembly 933. Figure 19 is a perspective view showing third frame 93 and a part of bolt 950, which is an attachment member. Figure 20 is a cross-sectional view taken along line P-P in Figure 19. Assembly 932 and assembly 933 are basically of the same configuration, except that the outline shapes of the frames are different. Referring to Figure 18A, two rolling bearings 1 are arranged in parallel on third frame 93.

Referring to FIG. 19, the third frame 93 includes a plate 931 having a shape corresponding to the two bearings, a first thick portion 932 which is a first mounting portion, and a second thick portion 933 which is a second mounting portion. The first thick portion 932 includes mounting surfaces 932c and 932d. The mounting surfaces 932c and 932d are respectively formed with holes 934 and 935 which are mounting holes. Referring to FIG. 19 and FIG. 20, the holes 934 and 935 communicate with the outside so that a fixing bolt can be inserted from the outside. A slit 938 is formed between the holes 934 and 935. The mounting surfaces 933c and 933d in the second thick portion 933 are respectively formed with holes 936 and 937 which are mounting holes. A slit 939 is formed between the holes 936 and 937. The holes 936 and 937 communicate with the outside so that a fixing bolt 950 can be inserted from the outside. In the third frame 93, the mounting surfaces 932c and 932d and the mounting surfaces 933c and 933d are configured to face each other at an angle of approximately 60°. The holes 935 and 937 are connected by crossing each other. Therefore, the slits 938 and 939 are connected via the holes 935 and 937.

18B and 19, on the side of the first thick portion 932 of the third frame 93, the mounting surfaces 932c and 932d are arranged to face the surfaces 150c and 150d (see FIG. 1B) of the second protruding portion 150 protruding from the inner ring 50 of the rolling bearing 1. Bolts are inserted into the mounting hole 161 (see FIG. 1B) and the hole 934, and into the mounting hole 162 (see FIG. 1B) and the hole 935, respectively, and fixed. That is, on the side of the first thick portion 932, the third frame 93 and the inner ring 50 of the rolling bearing 1 are fixed. Also, on the side of the second thick portion 933, the mounting surfaces 933c and 933d are arranged to face the surfaces 110c and 110d (see FIG. 1B) of the first protruding portion 110 protruding from the outer ring 10 of the rolling bearing 1, respectively. Bolts 950 are inserted into mounting hole 121 (see FIG. 1B) and hole 936, and into mounting hole 122 (see FIG. 1B) and hole 937, respectively, and fixed in place. That is, on the second thick portion 933 side, the third frame 93 and the outer ring 10 of the rolling bearing 1 are fixed in place. A communication portion is formed that runs from the inner diameter of one rolling bearing 1 through slit 939, holes 937 and 935, and slit 938 to the inner diameter of the other rolling bearing. This communication portion can be used to insert a cable or the like.

Figure 21A is a perspective view showing an assembly 934 in which two rolling bearings 1 are attached to a fourth frame 94. Figures 21B and 21C are plan and perspective views of the assembly 934 from different angles. With reference to Figures 21A to 21C, two rolling bearings 1 are attached to the fourth frame 94 in a direction perpendicular to each other. The fourth frame 94 includes a plate 941 having a shape corresponding to the two bearings, a first thick portion 942 which is a first mounting portion, and a second thick portion 943 which is a second mounting portion. The first thick portion 942 and the second thick portion 943 are provided in a direction perpendicular to each other. Although not shown in the figure, the first thick portion 942 includes a mounting surface, and holes 944 and 945 which are mounting holes communicating with the outside are formed in the mounting surface. A slit 948 is formed between the holes 944 and 945. Holes 946 and 947 are formed on the mounting surface of the second thick portion 943, and are mounting holes that communicate with the outside. A fixing bolt 950 is inserted into the holes 946 and 947. A slit 949 is formed between the holes 946 and 947. Referring to FIG. 21A, the holes 945, 947, slit 948, and slit 949 communicate with each other.

Referring to Figures 21A to 21C, the first thick portion 942 of the fourth frame 94 is fixed to the second protruding portion 150 of the rolling bearing 1 on the side of the first thick portion 942. That is, the fourth frame 94 is fixed to the inner ring 50 of the rolling bearing 1. On the other hand, the second thick portion 943 is fixed to the first protruding portion 110 of the rolling bearing 1 on the side of the second thick portion 943. That is, the fourth frame 94 is fixed to the outer ring 10 of the rolling bearing 1. A communication portion is formed from the inner diameter of one rolling bearing 1 through the slit 949, holes 947, 945, and slit 948 to the inner diameter of the other rolling bearing. A cable or the like can be inserted through this communication portion.

Referring to FIG. 14, the finger joint 9 including the rolling bearing 1 can be compact in both radial and axial dimensions. The finger joint 9 also has a communication section that is continuously connected from the hole 913 of the first frame 91 to the rolling bearing 1 attached to the end of the fourth frame. This configuration allows wiring without exposing cables, etc. to the outside. As a variant, the slits may be multiple circular holes. In that case, they can also be used as screw holes for pneumatic or hydraulic connections.

It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

1, 2, 3, 4, 5, 6 Rolling bearing,
10 outer ring 101 raceway, 10a outer peripheral surface, 10b inner peripheral surface, 11 raceway groove, 11a, 11b raceway surface, 11c groove, 12, 14, 16, 17 through hole, 13 cover, 15 pin, 110 first protrusion, 110a outer peripheral surface, 110b inner peripheral surface, 110c first surface, 110d second surface, 121 mounting hole, 122 mounting hole, 130 protrusion, 130a outer peripheral surface, 130b inner peripheral surface, 131, 132, 133, 134 hole,
211, 212, 511, 512 protrusion, 211a, 212a, 511a, 512a outer peripheral surface, 211b, 212b, 511b, 512b inner peripheral surface, 221, 222, 521, 522 mounting hole,
50 Inner ring, 50a Outer peripheral surface, 50b Inner peripheral surface, 51 Raceway groove, 51a, 51b Raceway surface, 51c Groove, 150 Second protrusion, 150a Outer peripheral surface, 150b Inner peripheral surface, 150c First surface, 150d Second surface, 161 Mounting hole, 162 Mounting hole,
60 Inner ring, 60a Outer peripheral surface, 60b Inner peripheral surface, 61 Protrusion, 61a Outer peripheral surface, 61b Inner peripheral surface, 63 Notch, 650 Protrusion, 650a Outer peripheral surface, 650b Inner peripheral surface, 681 Groove, 621, 622, 623, 624 Hole,
710 extension, 712, 721, 722, 723, 724 hole,
80 roller, 81 first roller, 82 second roller, 83 separator,
9 Finger joints, 91, 92, 93, 94 Frame, 931, 932, 933, 934 Assembly, 911 Fingertip, 912, 922, 923, 932, 933, 942, 943 Thickened portion, 922c, 922d, 923c, 923d, 932c, 932d, 933c, 933d Mounting surface, 913, 917, 918, 924, 925, 926, 927, 934, 935, 936, 937, 944, 945, 946, 947 Hole, 914, 921, 931, 941 Plate, 915, 916 Surface, 919, 928, 929, 938, 939, 948, 949 Slit, 950 Bolt.

Claims (11)

an outer ring having a raceway groove formed on its inner circumferential surface;
an inner ring having a common center axis with the outer ring and a raceway groove formed on an outer peripheral surface thereof;
a plurality of rolling elements disposed in a raceway defined by the raceway groove of the outer ring and the raceway groove of the inner ring,
The rolling bearing comprises:
a protrusion continuous with the outer ring or the inner ring,
The protrusion is
a bearing protruding outward in the axial direction from the outer ring and the inner ring, and formed radially at the same position as or inside the outer periphery of the outer ring and at the same position as or outside the inner periphery of the inner ring,
The protruding portion is formed with a mounting hole for fixing the outer ring or the inner ring to an external component,
The mounting hole is formed so as to extend parallel to a plane perpendicular to the axis of the rolling bearing and to extend in a tangential direction of the outer ring and the inner ring . an outer ring having a raceway groove formed on its inner circumferential surface;
an inner ring having a common center axis with the outer ring and a raceway groove formed on an outer peripheral surface thereof;
a plurality of rolling elements disposed in a raceway defined by the raceway groove of the outer ring and the raceway groove of the inner ring,
The rolling bearing comprises:
a protrusion continuous with the outer ring or the inner ring,
The protrusion is
a bearing protruding outward in the axial direction from the outer ring and the inner ring, and formed radially at the same position as or inside the outer periphery of the outer ring and at the same position as or outside the inner periphery of the inner ring,
The protruding portion is formed with a mounting hole for fixing the outer ring or the inner ring to an external component,
The mounting holes are a pair of mounting holes formed parallel to each other and extending parallel to a plane perpendicular to the axis of the rolling bearing. an outer ring having a raceway groove formed on its inner circumferential surface;
an inner ring having a common center axis with the outer ring and a raceway groove formed on an outer peripheral surface thereof;
a plurality of rolling elements disposed in a raceway defined by the raceway groove of the outer ring and the raceway groove of the inner ring,
The rolling bearing comprises:
a protrusion continuous with the outer ring or the inner ring,
The protrusion is
a bearing protruding outward in the axial direction from the outer ring and the inner ring, and formed radially at the same position as or inside the outer periphery of the outer ring and at the same position as or outside the inner periphery of the inner ring,
The protruding portion is formed with a mounting hole for fixing the outer ring or the inner ring to an external component,
The mounting hole is formed to extend parallel to a plane perpendicular to an axis of the rolling bearing, and extends in a direction not intersecting the axis. 4. The rolling bearing according to claim 1, wherein the protrusion is continuous with the outer ring, and a radially outer surface of the protrusion is a surface formed by a part of an outer peripheral surface of the outer ring extending in the axial direction. 4. The rolling bearing according to claim 1, wherein the protrusion is continuous with the inner ring, and a radially inner surface of the protrusion is formed by an extension of a portion of an inner circumferential surface of the inner ring. The protrusion is
a first protruding portion that is continuous with the outer ring and protrudes outward in the axial direction from the outer ring;
a second protruding portion that is continuous with the inner ring and protrudes outward in the axial direction from the inner ring;
Including,
The first protrusion has a first mounting hole for fixing the outer ring to an external component.
6. The rolling bearing according to claim 1 , wherein the second protrusion is formed with a second mounting hole for fixing the inner ring to an external component. The first mounting holes and the second mounting holes are each formed in twos,
The two first mounting holes are parallel to each other,
The two second mounting holes are parallel to each other.
7. A rolling bearing according to claim 6 . A distance between the two first mounting holes;
The distance between the two second mounting holes is equal.
8. A rolling bearing according to claim 7 . A rolling bearing according to any one of claims 1 to 8 ;
a frame having a mounting portion to which the rolling bearing is fixed;
An assembly comprising: 10. The assembly according to claim 9 , wherein said frame has two mounting parts and two of said rolling bearings are fixed thereto. A finger joint of a robot, comprising a plurality of assemblies according to claim 9 or 10 connected together.

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