JP2008057634A - Spherical bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-assemble spherical bearing capable of smoothly and accurately rotating or tilting a rod. <P>SOLUTION: The spherical bearing includes a large ball provided with the rod in at least one of an upper part or a lower part, a housing having a hollow part defined by a spherical recessed wall housing the large ball via a gap and an opening face formed in at least one of the upper part or the lower part, a cylindrical small ball holder arranged in the gap, provided with a plurality of through holes on a circumferential wall, and having an outer diameter smaller than a diameter an opening face of the housing and an inner diameter larger than a diameter of the large ball, and a plurality of small balls each housed in the through holes of the small ball holder, and rotatably arranged in the gap in a state contacting a large ball surface and the spherical recessed wall. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spherical bearing that is advantageously used as a part of a three-dimensional positioning device or an industrial robot.

  It is known that spherical bearings are connected between a stage of a three-dimensional positioning device or an arm of an industrial robot and each driving device, and are used to move the stage and the arm with multiple degrees of freedom.

  A conventional spherical bearing includes a housing having a spherical cavity opening at the upper surface, a sphere slidably fitted in the cavity, and a rod connected to the sphere and extending to the outside of the housing through the opening. It is composed of In such a spherical bearing, if the clearance between the housing and the sphere is wide, the accuracy of the rotation or tilting of the rod is low, and if the above clearance is narrow, it is difficult to smoothly rotate or tilt the rod. have. For this reason, the conventional spherical bearing has not been sufficiently satisfactory, for example, as a component for constituting a highly accurate three-dimensional positioning device.

In consideration of the above circumstances, in Patent Document 1, the large sphere of a rod having a large sphere (spherical tip) at the tip is held via a plurality of small spheres (rolling elements). Surrounding and supported by a hollow spherical small ball holder (cage) that is open to the inside, the holder is configured to be supported inside an annular housing (outer peripheral member) whose inner surface is spherically processed. Spherical bearings have been proposed. In this spherical bearing, since the large sphere is closely fitted to the housing via a plurality of small spheres held by the small sphere holder, the rod can be rotated or tilted smoothly and accurately. The bearing is suitable for use in precision positioning devices and the like.
JP-A-8-338422

  The hollow spherical small sphere holder of the spherical bearing of Patent Document 1 is composed of a divided body that is divided into a plurality (for example, six) in advance in the vertical direction to surround and support the large sphere. The housing (outer peripheral member) into which the large sphere is fitted is also composed of an upper housing member (second outer peripheral member) and a lower housing member (first outer peripheral member) that are divided in advance vertically.

  In the spherical bearing of the same document, first, a plurality of divided bodies each holding a small sphere are arranged around a large sphere, and then these are joined together to form a small sphere holder. The assembly is performed by a complicated procedure of sandwiching the upper housing member and the lower housing member and fixing them together with bolts.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spherical bearing capable of rotating or tilting a rod smoothly and with high accuracy and easy to assemble.

  As a result of repeated research on the above-mentioned problems, the present inventor has used a cylindrical small sphere holder having a predetermined outer diameter and inner diameter instead of the conventional hollow spherical small sphere holder. The present invention has been found by providing a spherical bearing that is easy to assemble because there is no need to divide the housing and the housing in advance, and that can rotate or tilt the rod smoothly and with high precision.

  Accordingly, the present invention has a large sphere provided with a rod on at least one of the upper and lower sides, a hollow portion defined by a spherical concave wall that accommodates the large sphere through a gap and an opening surface formed on at least one of the upper and lower sides. Housing, a cylindrical small sphere holding having a plurality of through holes in the peripheral wall disposed in the gap and having an outer diameter smaller than the diameter of the opening surface of the housing and an inner diameter larger than the diameter of the large sphere And a spherical bearing including a plurality of small balls disposed in each of the through holes of the small ball holder and rotatably disposed in contact with the large spherical surface and the spherical concave wall. is there.

The configuration of the spherical bearing having the large sphere including the rod as described above is hereinafter referred to as a first configuration. A preferable aspect of the spherical bearing of the first configuration is as follows.
(1) Opening surfaces are formed on the upper and lower sides of the housing.
(2) A large sphere has a rod only on one of the upper and lower sides.

  The present invention also provides a large sphere provided with a through-hole opening in the upper and lower sides, a spherical concave wall that accommodates the large sphere through a gap, and a cavity defined by at least one of the upper and lower opening surfaces. A cylindrical housing having a plurality of through holes in the peripheral wall, the outer diameter being smaller than the diameter of the opening surface of the housing and the inner diameter being larger than the diameter of the large sphere. A spherical surface including a plurality of small spheres accommodated in each of the through holes of the sphere holder and the small sphere holder and rotatably disposed in contact with the surface of the large sphere and the spherical concave wall There is also a bearing.

In this manner, the configuration of the spherical bearing having the large sphere having the through hole is hereinafter referred to as a second configuration. A preferable aspect of the spherical bearing of the second configuration is as follows.
(1) Opening surfaces are formed on the upper and lower sides of the housing.
(2) In the spherical bearing of the above aspect (1), the upper end and the lower end of the small ball holder protrude outward from the upper and lower opening surfaces of the housing, respectively, and the upper end surface and the lower side of the holder from the center of the large sphere. The distance to the outer peripheral edge of each end face is greater than the distance from the center of the large sphere to the peripheral edges of the upper and lower opening faces of the housing. More preferably, an annular large sphere brake that restricts the inclination movement by contacting the small sphere holder when the large sphere tilts in the vertical direction around or near the opening of the large sphere. Prepare.

  The spherical bearing of the first configuration of the present invention accommodates a cylindrical small ball holder in the hollow portion of the housing, for example, a small ball is accommodated in each of a plurality of through holes in the lower portion of the holder. After that, insert the large sphere inward from the opening of the upper end surface of the holder with the rod facing downward, and tilt the rod together with the large sphere to expose the upper part of the holder exposed above the housing. It can be easily assembled by accommodating small balls in the through holes.

  The spherical bearing of the second configuration of the present invention is similar to the spherical bearing of the first configuration, and includes a plurality of transparent parts in the lower portion of the cylindrical small ball holder accommodated in the cavity of the housing. After the small sphere is accommodated in each of the holes, a large sphere having a through-hole is inserted inward from the opening of the upper end surface of the holder, and the large sphere is inclined to be generated between the large sphere and the holder. Assembling can be easily performed by accommodating the small spheres in the through holes in the upper portion of the holder using the gap.

  As described above, the spherical bearing according to the present invention can be easily assembled because it is not necessary to divide the small ball holder and the housing in advance, and a plurality of small balls in which the large ball is held by the holder. Since it is closely fitted into the cavity of the housing via the sphere, the rod can be rotated or inclined and moved smoothly and with high accuracy.

  First, the spherical bearing of the 1st structure of this invention is demonstrated using an accompanying drawing. FIG. 1 is a cross-sectional view showing an example of the spherical bearing of the first configuration of the present invention, and FIG. 2 is a cross-sectional view showing a state in which the rod 11 of the spherical bearing 10 of FIG. 3 is a front view showing a configuration of a cylindrical small ball holder 20 provided in the spherical bearing 10 of FIG. 1, and FIG. 4 is a plan view of the small ball holder 20 of FIG. In FIGS. 1 and 2 (and FIGS. 5 to 7 described later), the large sphere 12 and the small sphere 22 including the rod 11 are not shown as cross sections. Further, in FIGS. 1 and 2 (and drawings to be described later), in order to facilitate the understanding of the configuration of the spherical bearing, the small spheres and small spheres that are located on the far side of the figure than the small spheres entered in the respective drawings are retained. The through hole of the tool is not filled in.

A spherical bearing 10 shown in FIGS. 1 and 2 is formed in a large sphere 12 having a rod 11 on one of the upper and lower sides (for example, the lower side), a spherical concave wall 14 that accommodates the large sphere 12 via a gap 13, and the upper and lower sides. A housing 17 having a cavity 16 defined by the opened surfaces 15a and 15b, a plurality of through holes 19 in the peripheral wall 18 disposed in the gap, and having an outer diameter (D ₁ ) of the housing. A cylindrical small sphere holder 20 having a diameter (D _H ) smaller than the diameter (D _H ) of 17 and an inner diameter (D ₂ ) larger than the diameter (D _B ) of the large sphere 12, A plurality of small spheres 22 disposed in the gap so as to be rotatable while being accommodated in each of 19 and in contact with the large spherical surface 21 and the spherical concave wall 14. In addition, the housing 17 of the spherical bearing 10 shown in FIGS. 1 and 2 is provided with a mounting hole (which may be a screw hole) 17a.

  In the spherical bearing 10, when the rod 11 is inclined and moved together with the large sphere 12, a plurality of small spheres 22 disposed in the gap 13 roll along with the inclined movement of the large sphere 12. By the rolling of these small balls 22, the rod 11 of the spherical bearing 10 can be smoothly tilted (or rotated about the length direction) without causing a large frictional resistance with respect to the housing 17. ing. Since the spherical ball bearing 10 is closely fitted to the cavity 16 of the housing 17 through a plurality of small balls 22 in which the large ball 12 is held by the cylindrical small ball holder 20, the rod 11 is smoothly fitted. In addition, it can rotate or tilt with high accuracy.

  As the material of the housing 17, the rod 11, the large sphere 12, and the small sphere 22 constituting the spherical bearing 10, a metal material such as aluminum, copper alloy (eg, brass), steel, or stainless steel is usually used. Further, for example, when the spherical bearing is used in an underwater or high temperature environment, a ceramic material can also be used. Further, in order to reduce the weight of the spherical bearing, a resin material (for example, a resin material exemplified as a material of a small ball holder 20 described later) can be used.

  The small ball holder 20 holds a small ball 22 accommodated in each of the plurality of through holes 19 in the peripheral wall 18 in the gap 13 between the large ball 12 and the spherical concave wall 14 of the housing 17, and the rod 11. When the spheres 22 are tilted, the adjacently arranged small spheres 22 are prevented from coming into contact with each other while rolling, thereby improving the durability of the spherical bearing 10.

As described above, the small ball holder 20 of the spherical bearing 10 has an outer diameter (D ₁ ) smaller than the diameter (D _H ) of the opening surface of the housing 17 and an inner diameter (D ₂ ) of the large sphere 12. It is set to a cylindrical shape larger than (D _B ). Such a setting makes it possible to easily assemble the spherical bearing 10 as will be described later, even if the small ball holder 20 (and the housing 17) is not prepared in advance.

  3 and 4, a set of through holes including ten through holes 19 arranged at equal intervals along the circumferential direction of the holder 20 is long on the peripheral wall 18 of the small ball holder 20. Three sets are provided along the vertical direction (vertical direction in the figure).

  The peripheral wall 18 of the small ball holder 20 is arranged at equal intervals along the circumferential direction of the holder 20, depending on the load resistance required for the spherical bearing and the size of the large ball 12. It is preferable that a set of through holes composed of ˜20 through holes is provided in the range of 2 to 6 sets along the length direction. If the number of through holes is too small, the number of small spheres that support the large spheres in the cavity of the housing will be small, and the rotation and tilting movement of the large spheres will become unstable, and the load bearing capacity of the spherical bearing will be small. Become. On the other hand, if the number of through holes is too large, it takes time to produce the small sphere holder, and the number of small spheres to be used increases, which increases the manufacturing cost of the spherical bearing.

  As a material of the small ball holder 20, for example, a metal material (for example, a metal material exemplified as the material of the housing or the like) or a resin material is used. Further, when the spherical bearing is used in water or in a high temperature environment as described above, a ceramic material can be used. The small sphere holder is preferably made of a resin material because it is easy to manufacture and low in manufacturing cost. As the resin material, it is preferable to use a polyacetal resin, a polyamide resin, a polyphenylene sulfide resin, or a polyether ether ketone resin because the heat resistance and strength of the small ball holder are improved.

  Each of the plurality of small spheres 22 held by the small sphere holder 20 is disposed in the gap 13 between the large sphere 12 and the spherical concave wall 14 while being pressurized by the large sphere 12 and the housing 17. It is preferable that This is because the large sphere 12 is more closely fitted into the cavity 16 of the housing 17 and the accuracy of rotating or tilting the rod is improved. In order to pressurize each small sphere 22 in this way, the distance between the large spherical surface 21 and the spherical concave wall 14 is slightly smaller than the diameter of the small sphere 22 (depending on the size of the small sphere, for example, And an interval smaller by about 1 to 5 μm than the diameter of the small spheres.

  Next, a procedure for assembling the spherical bearing having the first configuration will be described. The spherical bearing 10 having the first configuration shown in FIGS. 1 and 2 can be assembled, for example, according to the procedure described below.

  First, as shown in FIG. 5, a cylindrical small ball holder 20 is accommodated in the hollow portion 16 of the housing 17, and a small ball 22 is accommodated in each of the plurality of through holes 19 in the lower portion of the holder 20. After that, the large sphere 12 is inserted inward from the opening of the upper end surface of the holder 20 with the rod 11 facing downward. Next, as shown in FIG. 6, the small balls 22 are accommodated in the through holes 19 in the upper portion of the small ball holder 20 exposed above the housing 17 by tilting the rod 11 together with the large balls 12. Then, the operation of accommodating the small sphere in the through hole in the upper portion of the small sphere holder 20 is repeated while changing the direction in which the rod 11 and the large sphere 12 are inclined and moved, so that a plurality of the upper portions of the holder 20 are arranged. The spherical bearing 10 can be assembled by placing the rod 11 vertically after accommodating the small sphere 22 in each of the through-holes 19.

  As described above, the spherical bearing 10 of the present invention can be easily assembled because it is not necessary to divide the small ball holder 20 and the housing 17 in advance, and the large ball 12 is held by the holder as described above. The rod 11 is tightly fitted to the hollow portion 16 of the housing 17 via a plurality of small balls 22 held by the rod 20, so that the rod 11 can be rotated or inclined and moved smoothly and with high accuracy.

As described above, the cylindrical small sphere holder 20 used for the spherical bearing 10 has an outer diameter (FIG. 1: D ₁ ) smaller than the diameter (FIG. 1: D _H ) of the opening surface of the housing 17 and an inner diameter. (FIG. 1: D ₂ ) is set to a cylindrical shape larger than the diameter of the large sphere 12 (FIG. 1: D _B ). This is because, when the spherical bearing 10 is assembled as described above, if the outer diameter of the small sphere holder 20 is larger than the diameter of the opening surface of the housing 17, the holding tool 20 is inserted into the hollow portion 16 of the housing 17 from the opening surface. This is because if the inner diameter of the holder 20 is smaller than that of the large sphere 12, the large sphere 12 cannot be inserted inside the holder 20 accommodated in the cavity 16.

  Thus, the cylindrical small ball holder used for the spherical bearing of the present invention has an opening surface of the housing (when the opening surfaces are formed on the upper and lower sides of the housing as in the spherical bearing of FIG. It is necessary to have a shape and a size that can be inserted into the hollow portion from any one of the opening surfaces) and that a large sphere can be inserted inward from any of the upper and lower openings of the holder.

  That is, the “cylindrical small sphere holder” in this specification does not include only a strictly cylindrical small sphere holder, but a small sphere deformed within a range that satisfies the above conditions. A holder is also included. For example, the cylindrical small sphere holder of the present invention includes one having a shape in which the center in the length direction is slightly expanded outward or inward. In this case, the “outer diameter” of the small ball holder means the maximum outer diameter, and the “inner diameter” means the minimum inner diameter. Furthermore, for example, when a large sphere is inserted from the opening of the upper end surface of the small sphere holder 20 as in the spherical bearing 10 shown in FIG. 5, the “cylindrical small sphere holder” If at least the upper half part has an inner diameter larger than the diameter of the large sphere, the lower half part is deformed to have an inner diameter smaller than the diameter of the large sphere as long as it does not contact the surface of the large sphere. Included. However, since it is usually easy to manufacture, a cylindrical small sphere holder whose inner diameter and outer diameter do not vary in the length direction is used.

  FIG. 7 is a cross-sectional view showing another example of the spherical bearing having the first configuration according to the present invention. The configuration of the spherical bearing 70 in FIG. 7 is the same as that of the spherical bearing 10 in FIG. 1 except that the opening surface 15 b is formed only on one of the upper and lower sides (downward) of the housing 17. For example, by attaching three spherical bearings 70 to the lower surface of the stage of the three-dimensional positioning device on the upper surface (plane) of each housing 17, the stage can be moved with multiple degrees of freedom while being supported by these spherical bearings. It becomes possible to do.

  The spherical bearing 70 accommodates, for example, a cylindrical small ball holder 20 in the hollow portion 16 of the housing 17, and a small ball 22 is formed in each of the plurality of through holes 19 in the upper portion of the holder 20. After the housing, the large ball 12 is inserted inward from the lower opening of the holder 20 with the rod 11 facing downward, and the rod 11 is moved together with the large ball 12 to move the lower side of the housing 17. The small ball 22 is accommodated in the through-hole 19 in the lower part of the holding tool 20 exposed to the above, so that it can be easily assembled.

  FIG. 8 is a cross-sectional view showing an example of the spherical bearing of the second configuration of the present invention, and FIG. 9 is a cross-sectional view of the spherical bearing 80 cut along the cutting line I-I written in FIG. It is. In FIGS. 8 and 9 (and FIGS. 10 and 11 described later), the small spheres 22 are not shown as cross sections.

As shown in FIGS. 8 and 9, the spherical bearing 80 of the second configuration of the present invention accommodates a large sphere 32 having a through-hole 31 opening in the vertical direction in the center, and the large sphere 32 through the gap 13. A housing 17 having a hollow portion 16 defined by a spherical concave wall 14 and upper and lower opening surfaces 15a and 15b, a plurality of through holes 19 in a peripheral wall 18 disposed in the gap, and having an outer diameter ( A cylindrical small ball holder 20 in which D ₁ ) is smaller than the diameter (D _H ) of the opening surface of the housing 17 and the inner diameter (D ₂ ) is larger than the diameter (D _B ) of the large ball 32, and small ball holding Each of the through holes 19 of the tool 20 includes a plurality of small spheres 22 disposed in the gap so as to be rotatable in contact with the large spherical surface 41 and the spherical concave wall 14. .

  The spherical bearing 80 of the second configuration is not provided with a rod in the large sphere 32, and is used for rotating or tilting the rod by inserting and fixing the rod in the through hole 31 of the large sphere 32. Can be used in the same manner as the spherical bearing of the first configuration. Similarly to the case of the spherical bearing of the first configuration, the housing of the spherical bearing of the second configuration can also be used in which an opening surface is formed only on one of the upper and lower sides.

  When the large sphere and the rod are separated in this way, the user prepares a plurality of rods of a size corresponding to the through-hole of the spherical ball of the spherical bearing, and the end of each rod is used for various purposes. It is possible to set the size and shape appropriately (for example, processing the end of the rod to a diameter suitable for the object supported by the spherical bearing, or providing a thread in the end of the rod) Therefore, the versatility of the spherical bearing increases. In addition, compared to the case where the rod is fixed to the surface of the large sphere by a method such as welding, the spherical ball can be processed more easily and with higher accuracy when the through hole is formed in the large sphere. It can be offered at a low price.

  Next, a procedure for assembling the spherical bearing having the second configuration will be described. The spherical bearing 80 having the second configuration shown in FIGS. 8 and 9 can be assembled, for example, according to the procedure described below.

  First, as shown in FIG. 10, a cylindrical small ball holder 20 is accommodated in the hollow portion 16 of the housing 17, and a small ball 22 is accommodated in each of the plurality of through holes 19 in the lower portion of the holder 20. After that, the large sphere 32 having the through hole 31 is inserted into the inside from the opening of the upper end surface of the holder 20. Next, as shown in FIG. 11, the large sphere 32 is tilted and moved to the through hole 19 in the upper portion of the holder 20 using a gap generated between the large sphere 32 and the small sphere holder 20. 22 is accommodated. Then, the operation of accommodating the small sphere in the through hole in the upper part of the small ball holder 20 is repeated while changing the direction in which the large ball 32 is inclined and moved, so that a plurality of through holes in the upper part of the holder 20 are obtained. The spherical bearing 80 can be assembled by housing the small spheres 22 in the respective 19 and arranging the large spheres 32 so that the through-holes 31 face the vertical direction.

  Thus, the spherical bearing 80 of the second configuration of the present invention can also be easily assembled because it is not necessary to divide and manufacture the small ball holder 20 and the housing 17 in advance. Since it is tightly fitted to the cavity 16 of the housing 17 via a plurality of small balls 22 held by the holder 20, the rod attached to the through-hole 31 can be rotated or tilted smoothly and accurately. can do.

  12 is a cross-sectional view showing an example of use of the spherical bearing 80 of FIG. 8, FIG. 13 is an enlarged view of the spherical bearing 80 shown in FIG. 12, and FIG. 14 is a spherical bearing shown in FIG. 8 is a cross-sectional view showing a state in which a rod 51a attached to 80 is inclined and moved. FIG. 12 to 14 (and later-described FIGS. 15 and 16), the small sphere 22, the rod 51a (and the rods 51b and 51c in FIGS. 15 and 16 to be described later), and the nut 61 are shown as cross sections. Not done.

  As shown in FIGS. 12-14, the rod 51a is inserted in the through-hole 31 of the large sphere 32 of the spherical bearing 80 of the 2nd structure, and it forms in each of the upper part and lower part of this rod 51a. The nut 61 fitted in the threaded groove 62 is fixed by tightening. The spherical bearing 80 is used for rotating or tilting the rod 51 a inserted and fixed in the through hole 31 of the large sphere 32. Each thread groove 62 of the rod 51a is also used when the spherical bearing 80 and an object (for example, an arm of an industrial robot) supported by the bearing 80 are connected.

As shown in FIGS. 12 to 14, in the spherical bearing 80 of the second configuration, the upper end and the lower end of the small ball holder 20 protrude outward from the upper and lower opening surfaces 15 a and 15 b of the housing 17, respectively. The distances from the center of the large sphere 32 to the outer peripheral edges of the upper end surface and the lower end surface of the holder 20 (for example, FIG. 13: L ₁ ) are respectively the opening surfaces above and below the housing 17 from the center of the large sphere 32. the distance to the periphery (e.g., FIG. 13: L ₂₎ is preferably greater than.

  Thereby, for example, when the rod 51a is tilted as shown in FIG. 14, the portion near the upper end of the small ball holder 20 comes into contact with the peripheral portion of the opening surface of the housing 17 (FIG. 12: 15a). The inclined movement of the small ball holder 20 can be restricted. When the tilting movement of the small ball holder 20 is restricted, the rolling of the small ball 22 stops, and the tilting movement of the large ball 32 stops, so that the rod inserted and fixed in the large ball 32 and the through hole 31 thereof. The inclination movement of 51a can be restricted (the large sphere 32 and the rod 51a can be prevented from inclining at an extremely large angle).

  Furthermore, as shown in FIGS. 12 to 14, the spherical bearing 80 contacts the small ball holder 20 when the large ball 32 is inclined and moved in the vertical direction in the vicinity of the periphery of the opening of the large ball 32. Thus, it is preferable to include an annular large ball brake 23a that restricts the tilt movement. Each large sphere brake 23a is fixed in the vicinity of the periphery of each opening of the large sphere 32 by tightening a nut 61 fitted in the thread groove 62 of the rod 51a.

  When such a large ball brake 23a is provided, when the rod 51a is inclined as shown in FIG. 14, for example, the upper large ball brake 23a is located near the upper end of the small ball holder 20. Therefore, the tilt movement of the large sphere 32 and the rod 51a inserted and fixed in the through hole 31 can be restricted (the large sphere 32 and the rod 51a can be prevented from tilting at an extremely large angle).

  In the state where the portion near the upper end of the small ball holder 20 is in contact with the peripheral portion of the opening surface of the housing as described above, a larger force is applied to the rod 51a and the large ball braking device 23a rotates the small ball 22. It is possible to prevent the large sphere 32 from further tilting in a state where the movement is stopped (the large sphere 32 is slid while the rolling of the small sphere 22 is stopped). That is, by using the large ball brake tool 23a, it is possible to reliably limit the tilt movement (tilt angle) of the large ball 32 and the rod 51a inserted and fixed in the through hole 31 thereof. In addition, the large ball brake may be provided only in one of the upper and lower openings of the large ball.

  FIG. 15 is a cross-sectional view showing another example of how the spherical bearing 80 of FIG. 8 is used. A rod 51b in which the diameter of the upper part is set larger than the diameter of the through hole 31 is inserted into the through hole 31 of the large sphere 32 of the spherical bearing 80 shown in FIG. The nut 61 fitted in the formed thread groove 62 is fastened and fixed. When the rod 51b having such a configuration is used, the number of nuts necessary for inserting and fixing the rod 51b into the through hole 31 of the large sphere 32 is one, and therefore, the work of attaching the rod 51b to the spherical bearing 80 is easy. Become.

  FIG. 16 is a cross-sectional view showing still another example of the usage of the spherical bearing 80 of FIG. In the through hole 31 of the large sphere 32 of the spherical bearing 80 shown in FIG. 16, a rod 51c whose upper portion has the same diameter as the outer diameter of the large sphere brake 23a is inserted. The nut 61 fitted in the thread groove 62 formed in the portion is fixed by tightening. As shown in FIG. 16, the upper part of the rod 51c is in contact with a portion in the vicinity of the upper end of the small ball holder 20 when the rod 51c is inclined to move, and the large ball braking tool that restricts the inclined movement of the large ball 32. It is used as. When the rod 51c having such a configuration is used, the number of nuts necessary for inserting and fixing the rod 51c into the through hole 31 of the large sphere 32 is one as in the case of using the rod 15b shown in FIG. Since the number of large-ball brakes used is one, the work of attaching the rod 51c to the spherical bearing 80 is further facilitated.

  FIG. 17 is a cross-sectional view showing still another example of the usage mode of the spherical bearing 80 of FIG. In FIG. 17, the small sphere 22 and the rod 51d are not shown as cross sections.

  A rod 51d whose diameter near the upper end is set to the same size as the outer diameter of the large ball brake 23a is inserted into the through hole 31 of the large ball 32 of the spherical bearing 80 shown in FIG. By screwing the screw groove 62 formed in the lower portion into a screw hole formed at the upper end of an arm 63 (for example, an arm of an industrial robot, etc.) that is an object supported by a spherical bearing, and tightening It is fixed. As shown in FIG. 17, the portion in the vicinity of the upper end of the rod 51d contacts the portion near the upper end of the small ball holder 20 when the rod 51d is tilted, thereby restricting the tilting movement of the large sphere 32. It is used as a ball brake. In this way, the arm 63 that is the object supported by the spherical bearing can be easily fixed to the rod 51d inserted into the through hole 31 of the large sphere 32 of the spherical bearing 80.

  FIG. 18 is a cross-sectional view showing another example of the spherical bearing of the second configuration of the present invention. In FIG. 18, the small sphere 22 is not shown as a cross section. The configuration of the spherical bearing 90 in FIG. 18 is the same as that of the spherical bearing 80 in FIG. 8 except that each large ball brake 23 b is press-fitted and fixed in advance in each opening of the large ball 32.

  For example, when the spherical bearing 80 of FIG. 8 is transported or handled in a state before the large ball brake tool 23a and the rod 51a are attached to the through hole 31 of the large ball 32, the large ball 32 has a large angle (for example, 11 (to the angle shown in FIG. 11), the small sphere 22 accommodated in the through hole 19 of the small sphere holder 20 may fall out of the gap between the holder 20 and the large sphere 32. Like the spherical bearing 90 in FIG. 18, when the large ball brake 23 b is fixed in advance to each opening of the large ball 23, it is possible to prevent such a small ball from dropping off.

  FIG. 19 is a partially cutaway perspective view showing still another example of the spherical bearing of the second configuration of the present invention and a mode of use thereof, and FIG. 20 is a cutting line II-II entered in FIG. FIG. 21 is a cross-sectional view of the spherical bearing 100, the rod 51e, and the mounting jig 64 cut along the line, and FIG. 21 is a cross-section of the spherical bearing 100 cut along the cutting line III-III in FIG. FIG. In FIGS. 20 and 21, the small sphere 22 is not shown as a cross section.

  The configuration of the spherical bearing 100 shown in FIGS. 19 to 21 is the same as that of the spherical bearing 90 shown in FIG. 18 except that a screw hole 27 a for attachment is formed in the housing 27. A rod 51e is inserted into the through hole 31 of the large sphere 32 of the spherical bearing 100, and is fixed by, for example, an adhesive. An attachment jig 64 is fixed to the rod 51e, and a screw hole 65 for attaching an object supported by the spherical bearing 100 is formed on the upper surface of the jig 64.

  For example, three spherical bearings 100 each having a drive shaft of a linear motion drive device connected and fixed to each screw hole 27 a are attached to the lower surface of the stage of the three-dimensional positioning device on the upper surface of each jig 64. The stage can be moved with multiple degrees of freedom while being supported by these spherical bearings.

  As described above, since the spherical bearing of the present invention is closely fitted to the hollow portion of the housing via the plurality of small spheres held by the holding tool, the rod ( (The rod inserted and fixed in the large sphere) can be rotated or tilted smoothly and accurately, and has the advantage that it can be provided at low cost because its assembly is extremely easy. Have.

It is sectional drawing which shows an example of the spherical bearing of the 1st structure of this invention. However, the rod 11, the large sphere 12, and the small sphere 22 are not shown as cross sections. It is sectional drawing which shows the state which carried out the inclination movement of the rod 11 with which the spherical bearing 10 of FIG. 1 is provided. It is a front view which shows the structure of the cylindrical small ball holder 20 with which the spherical bearing 10 of FIG. 1 is provided. It is a top view of the small ball holder 20 of FIG. It is sectional drawing which shows the assembly method of the spherical bearing 10 of FIG. FIG. 5 is another cross-sectional view showing a method for assembling the spherical bearing 10 of FIG. 1. It is sectional drawing which shows another example of the spherical bearing of the 1st structure of this invention. However, the rod 11, the large sphere 12 and the small sphere 22 are not shown as cross sections. It is sectional drawing which shows an example of the spherical bearing of the 2nd structure of this invention. However, the small sphere 22 is not shown as a cross section. It is sectional drawing of the spherical bearing 80 cut | disconnected along the cutting line II line entered in FIG. However, the small sphere 22 is not shown as a cross section. It is sectional drawing which shows the assembly method of the spherical bearing 80 of FIG. FIG. 9 is another cross-sectional view illustrating a method for assembling the spherical bearing 80 of FIG. 8. It is sectional drawing which shows an example of the mode of use of the spherical bearing 80 of FIG. However, the small ball 22, the rod 51a, and the nut 61 are not shown as cross sections. It is an enlarged view of the spherical bearing 80 shown in FIG. It is sectional drawing which shows the state which inclinedly moved the rod 51a attached to the spherical bearing 80 shown in FIG. It is sectional drawing which shows another example of the aspect of use of the spherical bearing 80 of FIG. However, the small sphere 22, the rod 51b, and the nut 61 are not shown as cross sections. It is sectional drawing which shows another example of the aspect of use of the spherical bearing 80 of FIG. However, the small ball 22, the rod 51c, and the nut 61 are not shown as cross sections. It is sectional drawing which shows another example of the aspect of use of the spherical bearing 80 of FIG. However, the small sphere 22 and the rod 51d are not shown as cross sections. It is sectional drawing which shows another example of the spherical bearing of the 2nd structure of this invention. However, the small sphere 22 is not shown as a cross section. It is a partially notched perspective view which shows another example of the spherical bearing of the 2nd structure of this invention, and the mode of its use. It is sectional drawing of the spherical bearing 100 cut | disconnected along the cutting line II-II line entered in FIG. 19, the rod 51e, and the jig | tool 64 for attachment. However, the small sphere 22 is not shown as a cross section. It is sectional drawing of the spherical bearing 100 cut | disconnected along the cutting line III-III line entered in FIG. However, the small sphere 22 is not shown as a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Spherical bearing 11 Rod 12 Large ball 13 Space | gap 14 Spherical concave wall 15a, 15b Opening surface 16 Hollow part 17 Housing 17a Mounting hole 18 Peripheral wall 19 Through-hole 20 Small ball holder 21 Large ball surface 22 Small ball 23a, 23b Large Ball brake tool 27 Housing 27a Screw hole 31 for mounting 31 Through hole 32 Large ball 41 Large ball surface 51a, 51b, 51c, 51d, 51e Rod 61 Nut 62 Screw groove 63 Arm 64 Fixing tool 65 Screw hole 70, 80 , 90, 100 Spherical bearing

Claims (7)

  A large sphere provided with a rod on at least one of the upper and lower sides, a housing having a hollow portion defined by a spherical concave wall that accommodates the large sphere via a gap and an opening surface formed on at least one of the upper and lower sides, A cylindrical small ball holder having a plurality of through holes in the peripheral wall, the outer diameter being smaller than the diameter of the opening surface of the housing and the inner diameter being larger than the diameter of the large sphere, and the small balls A spherical bearing including a plurality of small spheres accommodated in each of the through holes of the holder and rotatably disposed in contact with the large spherical surface and the spherical concave wall.   The spherical bearing according to claim 1, wherein an opening surface is formed on each of the upper and lower sides of the housing.   The spherical bearing according to claim 1, wherein the large sphere includes a rod on only one of the upper and lower sides.   A large sphere provided with a through-hole opening in the top and bottom, a housing having a hollow portion defined by a spherical concave wall that accommodates the large sphere through a gap and an opening surface formed in at least one of the top and bottom; A cylindrical small ball holder having a plurality of through holes in the peripheral wall, the outer diameter being smaller than the diameter of the opening surface of the housing and the inner diameter being larger than the diameter of the large sphere, disposed in the gap; and A spherical bearing including a plurality of small spheres accommodated in each of the through holes of the small sphere holder and rotatably disposed in the gap in contact with the surface of the large sphere and the spherical concave wall.   The spherical bearing according to claim 4, wherein an opening surface is formed on each of the upper and lower sides of the housing.   The upper and lower ends of the small ball holder protrude outward from the upper and lower opening surfaces of the housing, and the distance from the center of the large sphere to the outer peripheral edge of each of the upper and lower end surfaces of the holder is large. The spherical bearing according to claim 5, wherein the spherical bearing is larger than a distance from a center of the sphere to a peripheral edge of each of the upper and lower opening surfaces of the housing.   7. An annular large ball brake for restricting the inclined movement by contacting the small ball holder when the large ball is inclined and moved in the vertical direction around or near the opening of the large ball. Spherical bearing as described in.

Images