WO2022079951A1

WO2022079951A1 - Rotating joint, and manipulator having rotating joint

Info

Publication number: WO2022079951A1
Application number: PCT/JP2021/024508
Authority: WO
Inventors: 英樹有田; 直哉竹原; 雅比古有田; 秀人石黒
Original assignee: 株式会社石黒エンジニアリング
Priority date: 2020-10-12
Filing date: 2021-06-29
Publication date: 2022-04-21
Also published as: JP6820633B1; JP2022063827A; JP2022063521A

Abstract

The present disclosure addresses the problem of providing a rotating joint that functions as a joint for a manipulator. The rotating joint comprises a casing, an input rotating body, a drive motor, and an output rotating body. The input rotating body surrounds at least part of the casing. The drive motor is secured to the casing, surrounds the input rotating body, and causes the input rotating body to rotate about the at least part of the casing. The output rotating body surrounds the drive motor, is such that at least part thereof is exposed from the casing, and rotates coaxially with a rotating shaft of the input rotating body.

Description

Manipulator with rotary joints and rotary joints

One of the embodiments of the present invention relates to a rotary joint that functions as a joint portion of a manipulator and a manipulator including this rotary joint.

Currently, industrial manipulators (robots) are used in various fields. The manipulator has a plurality of arms (links) and joints connecting the arms as a basic configuration. The joint changes the angle (offset angle) between the directions in which the two connected arms extend, or changes the helix angle between the connected arms, thereby providing an end effector attached to the end arm. You can move it to any location. A motor is attached to each joint, and the movement of the industrial robot is controlled by appropriately operating the motor (see Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2018-040460 Japanese Unexamined Patent Publication No. 2012-241723 Japanese Unexamined Patent Publication No. 2015-161382

One of the tasks of the embodiment of the present invention is to provide a rotary joint having a novel structure that functions as a joint for a manipulator. Alternatively, one of the embodiments of the present invention is to provide a rotary joint capable of forming a manipulator having a compact shape. Alternatively, one of the embodiments of the present invention is to provide a manipulator including the rotary joint.

One of the embodiments of the present invention is a rotary joint. The rotary joint comprises a housing, an input rotating body, a drive motor, and an output rotating body. The input rotating body surrounds at least a part of the housing. The drive motor is fixed to the housing, surrounds the input rotating body, and rotates the input rotating body around at least a part of the housing. The output rotating body surrounds the drive motor, at least a part of which is exposed from the housing, and rotates coaxially with the rotating axis of the input rotating body.

One of the embodiments of the present invention is a manipulator. The manipulator comprises a rotary joint and a first arm connected to the rotary joint. The rotary joint comprises a housing, an input rotating body, a drive motor, and an output rotating body. The input rotating body surrounds at least a part of the housing. The drive motor is fixed to the housing, surrounds the input rotating body, and rotates the input rotating body around at least a part of the housing. The output rotating body surrounds the drive motor, at least a part of which is exposed from the housing, and rotates coaxially with the rotating axis of the input rotating body. The first arm is connected to the output rotating body of the rotating joint.

One of the embodiments of the present invention is a manipulator. This manipulator comprises a rotary joint and a second arm. The rotary joint comprises a housing, an input rotating body, a drive motor, and an output rotating body. The input rotating body surrounds at least a part of the housing. The drive motor is fixed to the housing, surrounds the input rotating body, and rotates the input rotating body around at least a part of the housing. The output rotating body surrounds the drive motor, at least a part of which is exposed from the housing, and rotates coaxially with the rotating axis of the input rotating body. The housing is arranged so as to sandwich the output rotating body, and has a pair of screw holes extending perpendicularly to the rotation axis from the outer surface of the housing. The second arm is fixed via a pair of screw holes.

A rotary joint according to one of the embodiments of the present invention, and a schematic perspective view of a manipulator including the rotary joint. The conceptual diagram which shows the structure of the rotary joint which concerns on one of the Embodiments of this invention. The schematic perspective view of the rotary joint which concerns on one of the Embodiments of this invention. The schematic perspective view of the rotary joint which concerns on one of the Embodiments of this invention. Schematic cross-sectional perspective view of a rotary joint according to one of the embodiments of the present invention. Schematic cross-sectional view of a rotary joint according to one of the embodiments of the present invention. Schematic cross-sectional view of a part of a rotary joint according to one of the embodiments of the present invention. Schematic cross-sectional view of a part of a rotary joint according to one of the embodiments of the present invention. Schematic cross-sectional view of a part of a rotary joint according to one of the embodiments of the present invention.

Hereinafter, the manipulator 200 including the rotary joint 100 and the rotary joint 100 according to the embodiment of the present invention will be described with reference to the drawings and the like. However, the present invention can be carried out in various embodiments without departing from the gist thereof, and is not construed as being limited to the description contents of the embodiments exemplified below.

The drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment in order to clarify the explanation, but the drawings are merely examples and limit the interpretation of the present invention. It's not something to do. In the present specification and each figure, elements having the same functions as those described with respect to the above-mentioned figures may be designated by the same reference numerals and duplicate description may be omitted. Hyphens and natural numbers are used as symbols when representing multiple elements having the same or similar composition individually, and only the code is used when representing multiple or individual elements without distinguishing between these multiple elements. When representing a part of one element, a code and a lowercase alphabet are used.

In the present specification and the scope of patent claims, when expressing an aspect of arranging another structure on one structure, when the term "above" is simply used, the structure shall be used unless otherwise specified. It includes both the case where another structure is placed directly above the structure so as to be in contact with each other, and the case where another structure is placed above one structure via yet another structure.

Hereinafter, the expression "a structure is exposed from another structure" means an aspect in which a part of one structure is not covered by another structure, and is not covered by another structure. The portion also includes an embodiment covered by yet another structure.

1. 1. Manipulator FIG. 1 shows a schematic perspective view of a manipulator 100 including a rotary joint 100 and a rotary joint 100. Details will be described later, but in this figure, the housing 110 and the output rotating body 190, which are a part of the structure of the rotating joint 100, are shown.

The rotary joint 100 has a cylindrical shape as a whole, and a part of the housing 110 constitutes a part of a side surface of the cylindrical shape. The output rotating body 190 has a cylindrical shape and constitutes a part of the cylindrical side surface of the rotating joint 100. As will be described later, the output rotating body 190 is housed around the central axis of the cylindrical shape (the axis penetrating the center of the upper surface and the bottom surface of the cylindrical shape, and the rotating axis _Ar parallel to the x direction in the drawing). It rotates around a part of the body 110 (arrow 216 in the figure). The output rotating body 190 is arranged so as to be sandwiched between a part of the housing 110 in the x direction. Here, the cylinder refers to a three-dimensional shape formed from a top surface and a bottom surface parallel to each other and a curved side surface connecting the top surface and the bottom surface. The cross section of the top surface, bottom surface, and side surface parallel to the top surface or bottom surface is a circle, and the side surface is a surface having a normal line perpendicular to the axis penetrating the center of the top surface and bottom surface. Hereinafter, for convenience, the surface on the more positive side in the x direction (the surface on the right side shown in FIG. 1) is referred to as the upper surface, and the surface facing the surface (not shown) is referred to as the bottom surface.

At least two arms 202 can be connected to the rotary joint 100. One arm 202-1 is connected to the output rotating body 190 directly or via an indirect member such as a connector 204 by a screw or the like. The arm 202-1 or the connector 204 can incorporate a motor (not shown) that rotates the arm 202-1 around a rotation axis (arm rotation axis) that extends in the direction in which the arm 202-1 extends. As a result, the rotation function centered on the rotation axis _Ar due to the rotation of the output rotating body 190 (arrow 208 in the figure) and the rotation function centering on the arm rotation axis by the built-in motor (arrow 210 in the figure) are armed. It can be given to 202-1.

By connecting the arm 202-1 to the output rotating body 190, the arm 202-1 can be extended from the side surface instead of the upper surface or the bottom surface of the cylindrical shape of the rotating joint 100. Therefore, it is not necessary to offset the arm 202-1 in the x direction when connecting to the rotary joint 100, it is possible to prevent the manipulator 200 from becoming bulky in the x direction, and it is possible to provide a manipulator having a compact shape. .. Although not shown, an end effector may be connected to the end of the arm 202-1 opposite to the rotary joint 100.

The other arm 202-2 is connected to the housing 110. Here, the arm 202-2 is connected to the side surface of the housing 110, not to the upper surface or the bottom surface of the cylindrical shape. More specifically, the arm 202-2 is directly connected to the surface of the portion of the housing 110 that sandwiches the output rotating body 190 and has a normal line perpendicular to the rotation axis _Ar , or is connected via the connector 206. Will be done. A motor (not shown) is built in the arm 202-2 or the connector 206, and the arm 202 has a rotation function (arrow 212 in the figure) centered on a rotation axis in which the arm 202-2 extends in the extending direction by the motor. Given to -2. With this rotation function, the rotation joint 100 and the arm 202-1 can be rotated about the rotation axis of the arm 202-2.

As described above, the arm 202-2 is fixed to the side surface of the housing 110 instead of the top surface or the bottom surface of the cylindrical shape. Therefore, it is not necessary to offset the arm 202-2 in the x direction when connecting to the rotary joint 100. Further, when fixing the arm 202-2, it is not necessary to use a fixing member such as a clamp that clamps the rotary joint 100 in the x direction. Therefore, it is possible to prevent the manipulator 200 from becoming bulky in the x direction, and it is possible to provide a manipulator having a compact shape.

2. 2. Rotating joint Hereinafter, the structure of the rotating joint 100 will be described with reference to FIGS. 2 to 8. FIG. 2 is a conceptual diagram for explaining the structure of the rotary joint 100, and FIGS. 3A and 3B are schematic perspective views showing the entire example of the rotary joint 100. In FIG. 2, for ease of viewing, only a part of the housing 110 is shown, and the output rotating body 190 is shown by a dotted line. 4 and 5 are a schematic cross-sectional perspective view and a cross-sectional view of an example of the rotary joint 100, respectively. FIG. 6 is a schematic cross-sectional view corresponding to FIG. 5, in which members other than the housing 110 are shown by dotted lines. 7 and 8 are schematic cross-sectional views of a part of an example of the rotary joint 100.

2-1. Overview The rotary joint 100 includes an input rotating body 130 and a drive motor 150 as a basic configuration in addition to the housing 110 and the output rotating body 190 described above (FIG. 2). The rotary joint 100 can further include a speed reducer 170 that transmits the rotational driving force of the input rotating body 130 to the output rotating body 190. The drive motor 150 causes the input rotating body 130 to rotate around a part of the housing 110 in a circumferential shape. The rotational driving force of the input rotating body 130 can be transmitted to the output rotating body 190 via the speed reducer 170, while the output rotating body 190 surrounds a part of the housing 110, the input rotating body 130, and the drive motor 150. , Rotate around these in a circle. The axis of rotation of the output rotating body 190 and the input rotating body 130 is coaxial, and is the rotation axis _Ar .

As will be described later, the rotary joint 100 is further provided with an encoder 160 for determining the position of the output rotating body 190, side caps 112 on the portions corresponding to the upper and lower surfaces of the cylindrical shape of the rotary joint 100, and the like as an arbitrary configuration. It may be (see FIGS. 3A to 6). Further, although not shown, a brake may be provided to stop the operation of the input rotating body 130 and the output rotating body 190.

2-2. Housing (1) Structure and function There are no restrictions on the configuration or structure of the housing 110, but as shown in FIGS. 4 and 5, the housing 110 includes a drive motor 150 and a speed reducer fixed in the housing 110. The 170 is fixed and configured to accommodate the input rotating body 130 and the output rotating body 190 which are movable parts. Further, the housing 110 is configured so that a part thereof is surrounded by the input rotating body 130 and covers the inside of the input rotating body 130. Further, the housing 110 is configured so as to partially sandwich the output rotating body 190 in the x direction. The housing 110 may be configured so that the side cap 112 can be fixed at the portions corresponding to the upper surface and the bottom surface of the cylindrical shape.

For example, as shown in FIG. 6, the part 110a, which is a part of the housing 110, accommodates the input rotating body 130 so as to sandwich it, and covers the inside of the input rotating body 130 to protect the input rotating body 130 and protect the input rotating body 130. It functions as a support for fixing the speed reducer 170.

The part 110b, which is another part of the housing 110, imparts sufficient physical strength to the housing 110, covers the side surface of the output rotating body 190 in the x direction, and sandwiches the output rotating body 190. The outer surface of the part 110b and the output rotating body 190 (the outer surface having a normal line perpendicular to the axis of rotation _Ar ) constitutes a cylindrical side surface. The outer surface of the part 110b and the output rotating body 190 may be on the same curved surface. That is, in the direction perpendicular to the rotation axis _Ar , the distance from the rotation axis _Ar to the outer surface of the housing 110 and the distance from the rotation axis _Ar to the outer surface of the output rotating body 190 may be the same. Alternatively, the difference between these distances may be 1 mm or more and 10 mm or less. By configuring the housing 110 and the output rotating body 190 in this way, not only the design can be improved, but also the interference between the arm 202 and the housing 110 can be prevented when the arm 202 is rotated. Here, the outer surface of each member refers to a surface far from the rotation axis _Ar in the direction perpendicular to the rotation axis _Ar .

The part 110c, which is still another part of the housing 110, protects the drive motor 150 and the input rotating body 130 by covering the drive motor 150 and the input rotating body 130 in cooperation with the part 110b, and is used as a support for fixing the encoder 160. Can be done.

The part 110d, which is still another part of the housing 110, can function as a rib for fixing the side cap 112. The part 110d can be configured to separate the side cap 112 from other parts of the housing 110 (eg,

parts

110a, 110b, etc.) to form a space 118 inside the rotary joint 100. The part 110d can be provided with an opening through which the rotation axis _Ar passes, whereby the space 118 can be opened in the x direction by removing the side cap 112.

The above-mentioned

parts

110a, 110b, 110c, 110d are defined by functions and do not necessarily have to be physically separable. Further, the housing 110 may include parts other than the above-mentioned

parts

110a, 110b, 110c and 110d. Therefore, the housing 110 may be a single integrated structure, or may be configured by fixing a plurality of parts with bolts, adhesives, or the like. For example, the above-mentioned parts 110a to 110d may be integrated or may be independent members connected to each other. The housing 110 may be made of a metal material such as iron, aluminum or titanium, or an alloy material such as stainless steel, or may be made of a material containing a polymer such as fiber reinforced plastic.

(2) Through hole As shown in FIGS. 2, 4 and 5, the housing 110 may have a through hole _110f extending along the rotation axis Ar and connecting to the space 118. The size of the through hole 110f can be arbitrarily set, and for example, the diameter thereof may be appropriately selected from the range of 1 cm or more and 20 cm or less. By providing the through hole 110f, the rotary joint 100 has a so-called hollow structure, and by using this through hole 110f, the motor for driving the arms 202-1 and 202-2 and the sensor mounted on these are used. A power cable for can be arranged through the through hole 110f. As a result, the portion where the power cable of the manipulator 200 is exposed to the outside can be significantly reduced. This contributes not only to the provision of the manipulator 200 having high design, but also to the prevention of accidents and malfunctions due to the interference of the power cable.

(3) Opening The housing 110 may be further provided with an opening 110g for inserting a power cable for connecting the drive motor 150 to a power source and a power cable extending from the arm 202 (FIGS. 2 and 4). See FIG. 5). The opening 110g is provided on the outer surface of the housing 110 having a normal line perpendicular to the rotation axis _Ar . When the through hole 110f is provided, the opening 110g is formed so as to be connected to the through hole 110f, and the space 118 is connected to the opening 110g.

The openings 110g are provided at least two, preferably four or more. When two openings 110g are provided, both of the openings 110g may be provided on the same side with respect to the output rotating body 190, and the two openings 110g may be arranged so as to overlap each other via the rotation axis _Ar . The two openings 110g are connected via the space 118, and the power cable can be passed from one opening 110g to the other opening 110g via the space 118. When four openings 110g are provided, one pair of openings 110g is provided on one side of the output rotating body 190, and these openings 110g are arranged so as to overlap each other via the rotation axis _Ar . .. On the other hand, the other pair of openings 110g is provided on the side opposite to the one pair of openings 110g with respect to the output rotating body 190, and the other pair of openings _110g overlap each other via the rotation axis Ar. Place in. Since each pair of openings 110 g is connected to the space 118, the power cable can be arranged on both the top surface side and the bottom surface side, and the degree of freedom in wiring arrangement can be improved.

(4) Screw holes The housing 110 can be further provided with screw holes 110e for connecting to the arm 202-2 (FIGS. 3A, 3B, 4). The screw hole _110e extends in a direction perpendicular to the rotation axis Ar from the outer surface having a normal line perpendicular to the rotation axis _Ar of the housing 110, that is, the surface constituting the side surface of the cylindrical shape. It is preferable to provide at least two screw holes 110e, and four screw holes 110e may be provided. When two screw holes 110e are provided, they are provided so as to sandwich the output rotating body 190. When the four screw holes 110e are provided, one pair of screw holes 110e is provided on one side of the output rotating body 190, and the other pair of screw holes 110e is provided on the other side of the output rotating body 190. Preferably, a pair of screw holes 110e are provided so as to sandwich the opening 110g. By providing the screw holes 110e in this way, a pair of screw holes 110e can be arranged in the vicinity of the opening 110g, so that not only the arm 202-2 can be reliably connected, but also the power cable extending from the arm 202-2 is a manipulator. The length of the portion exposed from 200 can be reduced.

2-3. Input rotating body The input rotating body 130 has a cylindrical shape that surrounds at least a part of the housing 110 (for example, the above-mentioned part 110a), and rotates around a part of the housing 110 in a circumferential shape. Arranged (FIGS. 2, 4, 5). A permanent magnet is arranged on the input rotating body 130, and is driven by an induction action by a current flowing through the drive motor 150.

There is no limitation on the size of the input rotating body 130, and the inner diameter thereof may be equal to or larger than the outer diameter of a part of the housing 110 (for example, the part 110a) surrounded by the input rotating body 130. The outer diameter of the input rotating body 130 can be selected in the range of, for example, larger than 3 cm and 50 cm or less. The length (length in the x direction) of the input rotating body 130 can be arbitrarily set, and may be selected from a range of, for example, 10 cm or more and 50 cm or less.

2-4. Drive motor The drive motor 150 is a motor having a cylindrical shape for rotating the input rotating body 130, is fixed to the housing 110, and is provided so as to surround at least a part of the outer periphery of the input rotating body 130. The central axis of the cylindrical shape formed by the drive motor 150 may be coaxial with the rotation axis _Ar . Power is supplied to the drive motor 150 from an external power source via a power cable passing through the space 118 and the opening 110 g, and this electric energy is used for the rotation of the input rotating body 130.

The method of fixing the drive motor 150 is arbitrary, and it may be fixed with screws or may be fixed with an adhesive. In the latter case, as shown in FIG. 7, a groove 110i may be provided on the surface of the housing 110 in contact with the drive motor 150, and the adhesive may be injected into the groove 110i. As a result, the drive motor 150 can be fixed with a sufficient amount of adhesive, so that the drive motor 150 can be firmly fixed in the rotary joint 100. Further, since it is not necessary to use a screw, the weight of the rotary joint 100 can be reduced.

2-5. Reducer The speed reducer 170 reduces the rotation speed of the input rotating body 130 and transmits the rotation driving force obtained from the input rotating body 130 to the output rotating body 190 at a rotation speed lower than the rotation speed of the input rotating body 130. The output rotating body 190 is configured to rotate. The speed reducer 170 may be configured so that the rotation direction of the output rotating body 190 is the same as the rotation direction of the input rotating body 130, or the rotation directions may be opposite to each other.

There are no restrictions on the configuration of the speed reducer 170, and it can be configured by, for example, a circular spline 170a, a wave generator 170b, a flexible spline 170c, or the like (FIG. 5). The circular spline 170a and the flexible spline 170c are fixed to the output rotating body 190 and the housing 110, respectively. On the other hand, the wave generator 170b is directly or indirectly connected to the input rotating body 130. The fixing method of the speed reducer 170 is arbitrarily selected, and may be performed by using an adhesive, bolts, screws, or the like. In the example shown in FIGS. 4 and 5, a motor shaft 132 is connected to the input rotating body 130, and the input rotating body 130 is fixed to the wave generator 170b by a bolt via the motor shaft 132. Therefore, the rotation of the input rotating body 130 is transmitted to the wave generator 170b via the motor shaft 132. Similarly, the flexible spline 170c is also fixed to the housing 110 by bolts. The inside of the circular spline 170a and the outside of the flexible spline 170c are engraved with teeth, but since the number of teeth in the latter is larger than the number of teeth in the former, the number of rotations in the latter is less than the number of rotations in the input rotating body 130. Rotates, and along with this, the output rotating body 190 rotates with the torque increased by the speed reducer 170.

2-6. The output rotating body The output rotating body 190 is a rotating body having a substantially cylindrical shape in appearance, and is not only a part of the housing 110 surrounded by the input rotating body 130 inside the tubular shape, but also the drive motor 150. , The input rotating body 130 is arranged (FIG. 2, FIG. 4, FIG. 5). In other words, the output rotating body 190 is configured to surround a part of the housing 110, the drive motor 150, and the input rotating body 130. The rotation of the input rotating body 130 is transmitted to the output rotating body 190 by the speed reducer 170, and as a result, the output rotating body 190 rotates around a part of the housing 110, the input rotating body 130, and the drive motor 150. Rotate. The rotation axis of the output rotating body 190 is coaxial with that of the input rotating body 130, and each rotating body rotates about the rotation axis _Ar . Examples of the material contained in the output rotating body 190 include metals such as iron, aluminum and titanium, and alloys such as stainless steel.

At least a part of the output rotating body 190 is exposed from the housing, and the exposed surface, that is, the outer surface (the surface having a normal line perpendicular to the rotation axis _Ar ) is also connected to the arm 202-1. A screw hole 190a for the purpose can be provided (FIGS. 3A to 5). The screw hole 190a extends from the outer surface of the output rotating body 190 in a direction perpendicular to the rotation axis _Ar . It is preferable to provide at least two screw holes 190a, and four screw holes 190a may be provided. When two screw holes 190a are provided, they are arranged so as to be located on a straight line parallel to the axis of rotation _Ar . When four screw holes 110e are provided, one pair of screw holes 190a is arranged so as to be located on a straight line parallel to the rotation axis _Ar , and the other screw holes _190a are also different parallel to the rotation axis Ar. It is arranged so that it is located on a straight line. Further, one of one pair of screw holes 190a and one of the other pair of screw holes 190a are arranged on the circumference centered on one point on the rotation axis _Ar , and with the other of one pair of screw holes 190a. The other of the other pair of screw holes 190a is arranged on a different circumference centered on a point on the axis of rotation _Ar . By providing the screw hole 190a in this way, the arm 202-1 can be reliably connected to the output rotating body 190.

2-7. Encoder There are no restrictions on the configuration of the encoder 160, which is an arbitrary configuration, and an optical encoder, a magnetic encoder, or an electromagnetic induction encoder may be used. In the case of a magnetic encoder, as shown in FIG. 5, the encoder 160 includes a magnetically patterned magnetic ring 160a, a magnetic sensor 160b for detecting the magnetic field of the magnetic ring 160a, an encoder substrate 160c for controlling the magnetic sensor 160b, and the like. Can be configured with. The magnetic ring 160a is attached to an input rotating body 130 or a member fixed to the input rotating body 130 and rotating at the same time (for example, a motor shaft 132), and rotates together with the input rotating body 130. On the other hand, the magnetic sensor 160b and the encoder board 160c are fixed to the housing 110. The change in the magnetic field due to the rotation of the magnetic ring 160a is detected by the magnetic sensor 160b, and the change is processed by the encoder board 160c to calculate the number of rotations and the position of the input rotating body 130, and the output rotating body is based on this data. The relative position of the 190 with respect to the housing 110 is determined. Although not shown, the magnetic ring 160a of the encoder 160 is attached to the output rotating body 190 or a member fixed to the output rotating body 190, and the rotating joint 100 is configured so that the magnetic change due to the rotation of the output rotating body 190 is detected by the magnetic sensor 160b. May be good.

2-8. Side cap The side cap 112, which is an arbitrary configuration, has a main surface perpendicular to the rotation axis _Ar , and can be arranged so as to form a top surface or a bottom surface of the cylindrical shape of the rotation joint 100. The side cap 112 is attached to the housing 110 so as to be attached to and detached from the housing 110 using only frictional force or using screws 114 and 116 (FIGS. 3A and 3B). The side cap 112 can function as a side wall of the space 118 connected to the opening 110 g, and is provided so that the space 118 can be opened in the x direction by removing the side cap 112. Therefore, by removing the side cap 112, the power cable arranged in the space 118 can be visually recognized, and as a result, the state of the power cable can be easily confirmed.

Although not shown, the side cap 112 may be provided with a through hole that overlaps with the through hole 110f of the housing 110 in the x direction. By providing the through hole in the side cap 112, the power cable connecting the arm 202-1 and the power supply can be extended from the through hole of the side cap 112 to the through hole 110f of the housing 110, so that the power cable is the manipulator 200. The length of the portion exposed from the can be reduced.

2-9. The bearing rotary joint 100 includes an input rotating body 130 and an output rotating body 190 as rotatable portions. Therefore, bearings may be provided in order to smoothly rotate these rotating bodies. The arrangement of the bearings is arbitrary, but as shown in FIG. 5, for example, a pair of

bearings

140 and 142 can be provided between the output rotating body 190 and the housing 110. Similarly, a pair of

bearings

144 and 146 can be provided between the input rotating body 130 and the housing 110. There are no restrictions on the structure or number of bearings, and bearings having any configuration may be used. For example, three or more bearings may be provided between the output rotating body 190 and the housing 110.

These

bearings

140, 142, 144, 146 can be provided so as to mesh with the step provided in the housing 110. For example, as shown in the partially enlarged view (FIG. 8) of FIG. 5, the housing has a step _110h formed by a surface whose cross section perpendicular to the rotation axis _Ar is concentric with the rotation axis Ar and a surface perpendicular to the surface. The

bearings

140 and 142 can be arranged at the 110 so as to mesh with the step 110h. That is, the

bearings

140 and 142 can be arranged so that the two surfaces of the housing 110 constituting the step 110h are in contact with the bearing 140 or 142 at the same time. Although not shown, the same applies to the

bearings

144 and 146. By adopting such an arrangement, the bearing can be stably arranged in the housing 110.

The method of fixing the

bearings

140, 142, 144, 146 is arbitrary, and they may be simply physically arranged or fixed with screws or adhesives. When fixing with an adhesive, a groove is formed on the surface of the housing 110, the input rotating body 130, and / or the output rotating body 190 in contact with the bearing, and the bearing is fixed by injecting the adhesive into the groove. You may. For example, as shown in FIG. 8, a groove 190b may be provided on a part of the surface of the output rotating body 190 in contact with the bearing 140, and an adhesive (not shown) may be injected into the groove 190b. Similarly, a groove 110i may be provided on a part of the surface where the housing 110 comes into contact with the bearing 142, and the adhesive may be injected into the groove 110i. Although not shown, a groove may be formed in a part of the surface of the input rotating body 130 in contact with the bearing 144 or 146, and an adhesive may be applied to the groove. Similarly, with the

bearings

140 and 142 of the housing 110. A groove may be formed on the contact surface, and an adhesive may be provided in the groove. In this way, by providing a groove on the surface of the member with which the bearing comes into contact and injecting the adhesive, the bearing can be fixed with a sufficient amount of adhesive, so that the bearing can be firmly fixed in the rotary joint 100. Can be done. Further, since it is not necessary to use a screw, the weight of the rotary joint 100 can be reduced.

2-10. The oil seal reducer 170 uses a relatively large amount of oil to prevent wear. An oil seal can be provided to prevent this oil from leaking to the outside or entering the drive motor 150. The number, structure, and arrangement of oil seals can be selected as appropriate. In the example shown in FIG. 5, oil seals 120 and 126 for preventing leakage to the outside are provided between the housing 110 and the output rotating body 190, and further, an oil seal for preventing intrusion into the drive motor 150. 122 and 124 are provided between the housing and the motor shaft 132. The oil seal has a ring shape, and its cross section (a cross section parallel to the rotation axis _Ar when placed on the rotary joint 100) is a flat surface on the outside of the oil seal and sharp on the inside. .. In the rotary joint 100, these

oil seals

120, 122, 124, 126 may be arranged so that the housing 110, which is a fixing portion, is in contact with the outside of the oil seal, or the inside is in contact with the housing 110. It may be arranged.

As described above, the rotary joint 100 according to one of the embodiments of the present invention includes an input rotating body 130 and an output rotating body 190 that coaxially rotate around the housing 110, and the output rotating body 190 rotates as an input. While surrounding the body 130, it rotates around the input rotating body 130 in a circumferential shape. The central axis of the cylindrical drive motor 150 that drives the input rotating body 130 may be coaxial with the rotating axis _Ar of the input rotating body 130 and the output rotating body 190. Further, the output rotating body 190 is configured so that the arm is connected to an outer surface having a normal line perpendicular to the rotation axis _Ar , and the housing 110 has an outer surface having a normal line perpendicular to the rotation axis _Ar . It is configured so that other arms are connected to it. Therefore, when connecting the two arms with the rotary joint 100, it is not necessary to offset the arms in the rotation axis _Ar direction (see FIG. 1), and it is possible to provide the manipulator 200 having a compact shape. ..

As an embodiment of the present invention, a person skilled in the art has appropriately added, deleted, or changed the design of components based on the above-described embodiment, or added, omitted, or changed the conditions of the present invention. As long as it has the gist of the above, it is included in the scope of the present invention. Of course, other effects different from those brought about by the embodiments described above, which are obvious from the description of the present specification or which can be easily predicted by those skilled in the art, are described in the present invention. It is understood that it is brought about by the invention.

100: Rotating joint, 110: Housing, 110a: Parts, 110b: Parts, 110c: Parts, 110d: Parts, 110e: Screw holes, 110f: Through holes, 110g: Openings, 110h: Steps, 110i: Grooves, 112: Side cap, 114: screw, 116: screw, 120: oil seal, 122: oil seal, 124: oil seal, 126: oil seal, 130: input rotating body, 132: motor shaft, 140: bearing, 142: bearing, 144: Bearing, 146: Bearing, 150: Drive motor, 160: Encoder, 160a: Magnetic ring, 160b: Magnetic sensor, 160c: Encoder board, 170: Reducer, 170a: Circular spline, 170b: Wave generator, 170c: Flexible Spline, 190: Output rotating body, 190a: Screw hole, 190b: Groove, 200: Manipulator, 202: Arm, 202-1: Arm, 202-2: Arm, 204: Connector, 206: Connector, 208: Arrow, 210 : Arrow, 212: Arrow, 216: Arrow

Claims

Housing,
A cylindrical input rotating body that surrounds at least a part of the housing,
A drive motor fixed to the housing, surrounding the input rotating body and rotating the input rotating body around at least a part of the housing, and surrounding the drive motor, at least a part from the housing. It is equipped with an output rotating body that is exposed and rotates coaxially with the rotating axis of the input rotating body.
The surface of the housing having a normal perpendicular to the axis of rotation has a pair of connecting portions for connecting the arms.
The pair of connecting portions are rotary joints arranged so as to sandwich the output rotating body.
The rotary joint according to claim 1, wherein the housing has a through hole extending along the rotary axis.
The rotary joint according to claim 1, further comprising a speed reducer that transmits the rotational driving force of the input rotating body to the output rotating body.
It has a first oil seal between the housing and the output rotating body.
The rotary joint according to claim 1, wherein a second oil seal is provided between the housing and the input rotating body.
It has a first bearing between the housing and the output rotating body.
It has a second bearing between the housing and the input rotating body.
The rotary joint according to claim 1, wherein both the first bearing and the second bearing are fixed by an adhesive.
The rotary joint according to claim 1, wherein the drive motor is fixed to the housing by an adhesive.
The rotary joint according to claim 1, wherein the output rotating body has a screw hole extending in a direction perpendicular to the rotating axis.
Each of the pair of connecting portions is a screw hole.
The rotary joint according to claim 1, wherein the screw hole extends perpendicularly to the rotary axis from the outer surface of the housing.
A manipulator comprising the rotary joint according to claim 1 and a first arm connected to the output rotating body of the rotary joint.
The rotary joint according to claim 1 and a second arm connected to the housing of the rotary joint are provided.
The housing is arranged so as to sandwich the output rotating body, and has a pair of screw holes extending perpendicularly to the rotation axis from the outer surface of the housing.
The second arm is a manipulator fixed via the pair of screw holes.