JP2018189151A - Joint, gear mechanism, drive device, robot, and joint manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint which enables improvement of durability while absorbing misalignment of axes of two shafts.SOLUTION: A joint 1 includes: a fastening member 11; an intermediate member 14 which is spaced apart from the fastening member 11; and a plate-like flexible member 13A which connects the fastening member 11 to the intermediate member 14 so that the fastening member 11 can swing relative to the intermediate member 14. The flexible member 13A has: an end portion 131A having a joint surface 131A1 joined to the fastening member 11; an end portion 132A having a joint surface 132A2 jointed to the intermediate member 14; and an intermediate portion 133A disposed between the end portion 131A and the end portion 132A. The end portions 131A, 132A are thicker than the intermediate portion 133A in an arrow X direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a joint that supports a swingable member, a gear mechanism having a joint, a driving device having a gear mechanism, a robot having a driving device, and a method for manufacturing the joint.

  Patent Document 1 proposes a swing-type speed reducer. The speed reducer described in Patent Document 1 has a oscillating gear for oscillating motion and a fixed gear meshed with the oscillating gear, and rotates an input shaft connected to a drive source such as a motor. Decelerate and output from the output shaft.

  If there is a misalignment between the input shaft and the output shaft, rotation irregularities and torque transmission errors occur, and the power transmission efficiency from the input shaft to the output shaft decreases. On the other hand, in Patent Document 2, as a mechanism for efficiently transmitting power from an input shaft to an output shaft, two shaft fastening bodies and a flexible member disposed between the two shaft fastening bodies are provided. A joint with has been proposed. In the fifth embodiment of Patent Document 2, it is described that the shaft fastening body and the flexible member are joined by welding.

JP 2014-66280 A JP 2004-30882 A

  In order to absorb the deviation of the axial center between the two axes, it is necessary to reduce the rigidity of the flexible member in the axial direction, and it is necessary to reduce the thickness of the flexible member. However, the thin flexible member is difficult to handle, and has a problem that it is melted by heat at the time of joining with the shaft fastening body and the durability is lowered.

  Therefore, an object of the present invention is to improve the durability of the joint while absorbing the shift of the shaft center between the two shafts.

  The joint of the present invention includes a first member, a second member spaced from the first member, and the first member and the first member so that the first member can swing relative to the second member. A plate-like third member that connects the second member, and the third member is joined to the first member having a first joint surface joined to the first member and the second member. A second portion having a second joint surface, and a third portion disposed between the first portion and the second portion, wherein the first portion and the second portion are It is characterized by being thicker than the third part in the thickness direction of the three members.

  According to the present invention, the bonding strength between the first member and the third member and the bonding strength between the second member and the third member are ensured, the durability is improved, and the shaft center between the two shafts is stabilized. Misalignment can be absorbed.

It is explanatory drawing which shows the structure of the robot apparatus which concerns on 1st Embodiment. It is explanatory drawing of the drive device which concerns on 1st Embodiment. It is a disassembled perspective view of the reduction gear which concerns on 1st Embodiment. (A) is a perspective view of the joint concerning a 1st embodiment. FIG. 2B is an exploded perspective view of the joint according to the first embodiment. It is a partial sectional view of the joint concerning a 1st embodiment. It is a flowchart which shows the manufacturing method of the coupling 1 which concerns on 1st Embodiment. (A)-(d) is a figure for demonstrating the manufacturing process of the manufacturing method of the coupling which concerns on 1st Embodiment. (A) is a figure which shows the state which joined the fastening member and the flexible member. (B) is the fragmentary perspective view of the base material shown in FIG.7 (c). It is a partial sectional view of a joint of a modification. It is a partial sectional view of a joint concerning a 2nd embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is an explanatory diagram illustrating a configuration of the robot apparatus 500 according to the first embodiment. A robot apparatus 500 shown in FIG. 1 includes an industrial robot 100 that performs operations such as assembly of a workpiece W, a control device 200 that controls the robot 100, and a teaching pendant 300 that teaches the robot 100. . The teaching pendant 300 is connected to the control device 200, and the control device 200 is connected to the robot 100. The robot 100 includes a robot arm 101 that is a robot main body, and a robot hand 102 that is an example of an end effector attached to the robot arm 101.

  The robot arm 101 is, for example, a vertical articulated robot arm, and includes a plurality of links 120 to 125 that are coupled to each other at respective joints J1 to J5 so as to be rotatable or pivotable. That is, the link 121 is movable with respect to the link 120, the link 122 is movable with respect to the link 121, the link 123 is movable with respect to the link 122, the link 124 is movable with respect to the link 123, and the link 125 is linked. It moves with respect to 124. In the present embodiment, the links 120 to 124 on the proximal end side relative to the joints J1 to J5 are the first links, and the links 121 to 121 on the distal end side relative to the joints J1 to J5. 125 is the second link. The robot arm 101 has driving devices 110 disposed at the joints J1 to J5. The driving device 110 disposed at each joint J1 to J5 rotates or turns each link 121 to 125 with respect to each link 120 to 124.

  The robot hand 102 includes a hand main body 191 that is a first link, a plurality of fingers 192 that are second links movable with respect to the hand main body 191, and a driving device 110 that drives the fingers 192. In the present embodiment, the robot hand 102 has two fingers 192 and can grip or release the workpiece W by opening and closing the two fingers 192. The robot hand 102 includes a force sensor (not shown) that can detect a force acting on the finger 192. In addition, although each drive device 110 of the robot 100 has different capabilities such as output torque, the basic configuration is the same.

  The teaching pendant 300 is configured to be able to input a command for driving and controlling the robot 100 to the control device 200. The control device 200 drives and controls the robot 100 in accordance with various programs stored in a storage device (not shown) based on a command input from the teaching pendant 300. For example, the control device 200 controls the driving devices 110 of the joints J1 to J5 of the robot arm 101 according to the input command, and causes the driving devices 110 to drive the links 121 to 125, thereby causing the robot hand 102 to move. Move to any 3D position. Then, according to the input command, the control device 200 causes the finger 192 to grip the work W while detecting a force acting on the finger 192 with a force sensor (not shown), and causes the work W to be assembled. .

  Next, the configuration of each driving device 110 will be described. FIG. 2 is an explanatory diagram of the driving device 110 according to the first embodiment. The drive device 110 includes a motor 111 that is an example of a drive source, and a speed reducer 112 that is an example of a gear mechanism connected to the motor 111. FIG. 3 is an exploded perspective view of the speed reducer 112 according to the first embodiment. In addition, in FIG. 2, the cross section is shown about the reduction gear 112. FIG. The speed reducer 112 is a so-called oscillating speed reducer, which reduces the rotational speed of the rotor of the motor 111 to increase the torque and transmits power to the output side. The housing that holds the stator of the motor 111 is fixed to the first link. The reduction gear 112 includes a housing 30 connected to the first link, an input shaft 2 connected to the rotor of the motor 111, and an output shaft 50 connected to the second link.

  The housing 30 has two cases 31 and 32. The case 31 has an opening, and the case 32 is a lid that closes the opening of the case 31. The housing 30 is configured by connecting the cases 31 and 32 to each other.

  The input shaft 2 is rotatably supported by the case 31 via bearings 41 and 42. The output shaft 50 is supported by the case 32 via bearings 51 and 52 so as to be coaxial with the input shaft 2. An inclination shaft 26 that is inclined with respect to the input shaft 2 is connected to the input shaft 2. That is, the axis C3 that is the center line of the tilt shaft 26 is inclined with respect to the axis C1 that is the center line of the input shaft 2.

  The speed reducer 112 includes an output gear (first gear) 3 having the number of teeth Z and the tooth surface formed in an annular shape, and an oscillating gear having a tooth number (Z + 1) and the tooth surface formed in an annular shape. (Second gear) 4. The output gear 3 is fixed to the output shaft 50. The oscillating gear 4 is supported on the inclined shaft 26 via bearings 61 and 62 so as to be rotatable about the inclined shaft 26, that is, the axis C3. The oscillating gear 4 is engaged with the output gear 3 at a predetermined angle with respect to the output gear 3.

  Axial misalignment (positional deviation or angular deviation) between the input shaft 2 and the output shaft 50, that is, an axis between the axis C1 that is the center line of the input shaft 2 and the axis C2 that is the center line of the output shaft 50 In order to absorb the misalignment, the joint 1 is disposed between the swing gear 4 and the case 31 of the housing 30. The joint 1 is fixed to the case 31 of the housing 30 and supports the swing gear 4 so as to be swingable and non-rotatable with respect to the housing 30.

  When the rotor of the motor 111 rotates, the inclined shaft 26 rotates about the axis C1 together with the input shaft 2. Since the oscillating gear 4 is supported by the inclined shaft 26 via the bearings 61 and 62 and is connected to the housing 30 by the joint 1, the rotation of the inclined shaft 26 is not transmitted to the oscillating gear 4. Therefore, the swing gear 4 does not rotate with respect to the housing 30. On the other hand, the tilt of the tilt shaft 26 is transmitted to the swing gear 4 and swings with respect to the housing 30 and the output gear 3.

  Due to the oscillating motion of the oscillating gear 4, the output gear 3 rotates by an angle corresponding to the difference in the number of teeth between the oscillating gear 4 and the output gear 3. That is, when the input shaft 2 rotates (Z + 1), the output gear 3 rotates once. Therefore, the output shaft 50 is decelerated to 1 / (Z + 1) and rotated with respect to the rotation of the input shaft 2. For example, when Z = 49, a reduction ratio of 1/50 is obtained.

  FIG. 4A is a perspective view of the joint 1 according to the first embodiment, and FIG. 4B is an exploded perspective view of the joint 1 according to the first embodiment. In the reduction gear 112, the joint 1 has an axis C1 that is a center line passing through the center of the input shaft 2 shown in FIG. 2 and an axis C0 that is a center line passing through the center of the joint 1 shown in FIG. Thus, it is assembled to the case 31 of the housing 30 with high accuracy. The joint 1 includes a pair of fastening members 11 and 12 and an intermediate member 14 disposed between the pair of fastening members 11 and 12.

  The fastening member 11 and the fastening member 12 are formed in an annular shape with the axis C0 as the center, and are disposed to face each other with an interval in the direction of the arrow X extending the axis C0. The intermediate member 14 is formed in a cylindrical shape centered on the axis C0. The fastening member 11 and the intermediate member 14 are arranged at an interval in the arrow X direction. Moreover, the fastening member 12 and the intermediate member 14 are arrange | positioned at intervals in the arrow X direction.

  Furthermore, the joint 1 includes a flexible member 13 </ b> A disposed between the fastening member 11 and the intermediate member 14, and a flexible member 13 </ b> B disposed between the fastening member 12 and the intermediate member 14. . The flexible members 13A and 13B are plate-like members thinner than the fastening members 11 and 12, and are formed in an annular shape centering on the axis C0. The flexible member 13 </ b> A connects the fastening member 11 and the intermediate member 14, and the flexible member 13 </ b> B connects the fastening member 12 and the intermediate member 14. By connecting the fastening member 11 and the intermediate member 14 with the flexible member 13A, the fastening member 11 can swing relative to the intermediate member 14 by the flexible member 13A being bent and deformed. In other words, the intermediate member 14 can swing with respect to the fastening member 11. In addition, since the fastening member 12 and the intermediate member 14 are connected by the flexible member 13 </ b> B, the flexible member 13 </ b> B is bent and deformed, so that the fastening member 12 can swing with respect to the intermediate member 14. In other words, the intermediate member 14 can swing with respect to the fastening member 12. And, by these connecting structures, the flexible members 13A and 13B are bent and deformed, so that the fastening member 11 can swing with respect to the fastening member 12. In other words, the fastening member 12 can swing with respect to the fastening member 11.

  The fastening member 12 is fastened to the case 31 by a bolt (not shown), and the fastening member 11 is fastened to the swing gear 4 by a bolt (not shown). Therefore, the rocking gear 4 cannot be rotated with respect to the housing 30 by being connected to the housing 30 by the joint 1, and can flexibly follow the inclined shaft 26 by the flexible members 13 </ b> A and 13 </ b> B of the joint 1. It can swing.

  Further, since the flexible members 13A, 13B are plate-like thinner than the fastening members 11, 12, the deformation in the direction of the arrow X, which is the direction in which the axis C0 extends, is a deformation in the out-of-plane direction. Sufficiently low rigidity. On the other hand, the torsional deformation around the axis C0 is a deformation in the in-plane direction, and the rigidity is sufficiently high. Therefore, the shift of the shaft center between the input shaft 2 and the output shaft 50 can be effectively absorbed by the joint 1, and the power of the motor 111 can be transmitted with high accuracy and high efficiency by the joint 1. it can.

  The case 32 is fastened to the case 31 with a bolt (not shown). By adjusting the tightening force of a bolt (not shown), the output gear 3 and the swing gear 4 can be engaged with each other with a pressure applied between the output gear 3 and the swing gear 4. The power is transmitted to the output shaft 50 while preventing backlash.

  The fastening member 11 and the flexible member 13A are joined by laser welding. Further, the intermediate member 14 and the flexible member 13A are joined by laser welding. The fastening member 12 and the flexible member 13B are joined by laser welding. The intermediate member 14 and the flexible member 13B are joined by laser welding.

  By the way, a laser capable of continuously performing seam welding can reduce the joint seam as much as possible, and is effective as a joining method for reducing rotation unevenness and torque fluctuation. However, in laser welding accompanied by heat generation, the welded part may be largely melted by the heat, and it is very difficult to set welding conditions. In particular, when joining small or thin members having a small heat capacity, the material itself may be lost due to heat.

  FIG. 5 is a partial cross-sectional view of the joint 1 according to the first embodiment. The flexible member 13A includes an end portion 131A having a joint surface 131A1 joined to the fastening member 11. The flexible member 13A includes an end portion 132A having a joint surface 132A2 joined to the intermediate member 14. Furthermore, the flexible member 13A includes an intermediate portion 133A disposed between the end portion portion 131A and the end portion portion 132A. Similarly, the flexible member 13B includes an end portion 131B having a joint surface 131B1 joined to the fastening member 12. Further, the flexible member 13B includes an end portion 132B having a joining surface 132B2 joined to the intermediate member 14. Furthermore, the flexible member 13B includes an intermediate portion 133B disposed between the end portion portion 131B and the end portion portion 132B.

  Here, for the flexible member 13A, one of the fastening member 11 and the intermediate member 14 to be joined is the first member and the other is the second member. For example, when the fastening member 11 is the first member, the intermediate member 14 is the second member. In this case, in the flexible member 13A that is the third member, the end portion 131A is the first portion and the end portion 132A is the second portion. Further, the joining surface 131A1 is a first joining surface, and the joining surface 132A2 is a second joining surface. The intermediate part 133A is a third part.

  For the flexible member 13B, one of the fastening member 12 and the intermediate member 14 to be joined is the first member and the other is the second member. For example, when the fastening member 12 is the first member, the intermediate member 14 is the second member. In this case, in the flexible member 13B that is the third member, the end portion 131B is the first portion, and the end portion 132B is the second portion. Further, the joint surface 131B1 is a first joint surface, and the joint surface 132B2 is a second joint surface. The intermediate part 133B is a third part. Since the flexible member 13A and the flexible member 13B have substantially the same configuration, the flexible member 13A will be described in detail below, and the description of the flexible member 13B will be omitted.

  In the flexible member 13A, each part 131A, 132A, 133A is formed in an annular shape centering on the axis C0. The end portion 131A is arranged on the outer side in the first embodiment on the inner side and the outer side in the radial direction R centering on the axis C0 with respect to the intermediate portion 133A. Further, the end portion 132A is disposed on the other side of the inner side and the outer side in the radial direction R centering on the axis C0 with respect to the intermediate portion 133A, on the inner side in the first embodiment. That is, the end portions 131A and 132A are portions constituting the end portion in the radial direction R of the flexible member 13A. The intermediate portion 133A is a plate-like portion having a pair of surfaces 133A1 and 133A2 in the arrow X direction that is the thickness direction.

  Since the end portions 131A and 132A are respectively joined to the fastening member 11 and the intermediate member 14, the flexibility is lower than that of the intermediate portion 133A. Conversely, the intermediate part 133A connects the end part 131A and the end part 132A, has high flexibility, and the intermediate part 133A is mainly bent and deformed.

  The end portions 131A and 132A are formed thicker than the intermediate portion 133A in the arrow X direction, which is the thickness direction of the flexible member 13A. This prevents the end portions 131A and 132A of the flexible member 13A from being lost during welding. Further, there is no need to add a meltable material, the welding quality can be improved, and the thickness is partially increased, so that the rigidity is increased and the deformation is difficult to be damaged. Thereby, durability of 13 A of flexible members and by extension, durability of the coupling 1 can be improved. In addition, since the durability of the flexible member 13A is improved, it is possible to stably absorb the shift of the axis between the two axes (between the input shaft 2 and the output shaft 50).

  In the first embodiment, in order to make the end portions 131A and 132A thicker than the intermediate portion 133A, the end portions in the radial direction R of the annular base material (plate material) are bent. Thus, the end portions 131A and 132A with increased thickness are formed without increasing the number of parts. In addition, the cost is reduced by reducing the number of parts. Furthermore, the cost can be reduced by reducing the number of man-hours required to adjust the coaxiality of parts during assembly.

  Further, in the first embodiment, in order to make the end portions 131A and 132A thicker than the intermediate portion 133A, the end portions 131A and 132A are formed by bending the base material to the opposite side of the joining surfaces 131A1 and 132A2. Yes. Accordingly, the joining surface 131A1 is on the same surface as the one surface 133A1 of the pair of surfaces 133A1 and 133A2 of the intermediate portion 133A, and the joining surface 132A2 is the other surface of the pair of surfaces 133A1 and 133A2 of the intermediate portion 133A. It is in the same plane as 133A2. Therefore, the end portion 131A protrudes from the intermediate portion 133A in the direction opposite to the bonding surface 131A1 (the direction of the arrow X1 in FIG. 5). The end portion 132A protrudes from the intermediate portion 133A in the direction opposite to the joining surface 132A2 (in the direction of arrow X2 in FIG. 5). For this reason, in the joint 1, the thickness of the arrow X direction can be made thin and the joint 1 can be reduced in size.

  Next, the manufacturing method of the joint 1 which concerns on 1st Embodiment, ie, the assembly method of the joint 1, is demonstrated. FIG. 6 is a flowchart showing a method for manufacturing the joint 1 according to the first embodiment. The plate-like base material is processed to form the flexible members 13A and 13B (S1: processing step). In the processing step of step S1, the base material is processed so that the end portions 131A and 132A are thicker than the intermediate portion 133A in the arrow X direction (thickness direction). The flexible members 13A and 13B are preferably made of precipitation hardening stainless steel (SUS631, TOKKIN AM350, etc.). This material can be tempered to have good workability by conditioning, and after carrying out plastic working or cutting, the yield strength can be improved by performing precipitation hardening treatment. Suitable for the material of the members 13A, 13B.

  Next, the joining surface 131A1 of the flexible member 13A is joined to the fastening member 11, and the joining surface 132A2 of the flexible member 13A is joined to the intermediate member 14. Further, the joining surface 131B1 of the flexible member 13B is joined to the fastening member 12, and the joining surface 132B2 of the flexible member 13B is joined to the intermediate member 14 (S2: joining step). In the joining step of step S2, laser welding is performed. The material of the fastening members 11 and 12 is preferably SUS316L, which is austenitic stainless steel. Since this material is a material having a low carbon content, it has good weldability, can be joined with a small amount of heat, and the influence of heat on each member can be reduced. Various materials including other austenitic stainless steels are applicable.

  Hereinafter, the processing step of step S1 will be described in detail. Note that in the processing step of step S1, the flexible member 13A and the flexible member 13B are manufactured in the same work process, and therefore the flexible member 13A will be described.

  Drawing 7 (a)-Drawing 7 (d) are figures for explaining the processing process of the manufacturing method of joint 1 concerning a 1st embodiment. In the processing step of the first embodiment, the flexible member 13A is formed by pressing. In FIGS. 7A to 7D, illustration of carriers, bridges, and the like at the time of progressive transmission is omitted.

  First, as shown in FIG. 7A, an annular base material 1301 centering on the axis C0 is formed from a plain base material. The base material 1301 is a flat member. A radial direction centering on the axis C0 is R, and a circumferential direction centering on the axis C0 is C11.

  Next, as shown in FIG. 7B, a plurality of notches N are formed at one end 141 and the other end 142 in the radial direction R of the base material 1301 at intervals in the circumferential direction C11. Thus, the notched base material 1302 is obtained. The shape of the notch N is a triangle. Thereby, the one end part 141 and the other end part 142 of the base material 1302 in the radial direction R are formed in a shape in which a plurality of pieces S are arranged in the circumferential direction C11. Note that the base material 1302 shown in FIG. 7B may be formed from the plain base material without passing through the base material 1301 shown in FIG.

  By providing the notch N as shown in FIG. 7B, it becomes possible to reduce the force at the time of bending, and even a press machine with a small capacity can be molded. Further, the stress effect on the intermediate portion 133A, which is a thin portion of the flexible member 13A, due to the press working is reduced, the rigidity becomes uniform, and highly accurate torque transmission can be realized.

  Next, the one end portion 141 and the other end portion 142 of the base material 1302 are bent in an L shape in opposite directions, whereby the base material 1303 shown in FIG. 7C is obtained. Next, the flexible member 13A shown in FIG. 7D is obtained by hemming bending the one end portion 141 and the other end portion 142 of the base material 1303. That is, the one end portion 141 of the base material 1302 is folded so as to be folded, and the other end portion 142 of the base material 1301 is folded so as to be folded back to the side opposite to the one end portion 141. Finally, the flexible member 13A is separated from the carrier. The flexible member 13A is manufactured through the above steps.

  Fig.8 (a) is a figure which shows the state which joined the fastening member 11 and 13 A of flexible members. By making the bending length L1 in the radial direction R substantially the same as the length L2 in the radial direction R of the joint surface 131A1 by the above bending process, the respective welded part volumes are substantially matched, and the welding quality can be improved. It becomes possible. The same applies to the joint surface 132A2. The same applies to the flexible member 13B.

  FIG. 8B is a partial perspective view of the base material 1303 shown in FIG. As shown in FIG. 8B, the inner diameter side of the end 141 is bent (started up) from the notch N. In order to perform welding with high precision and uniformity, it is necessary to adjust the area and volume of the welded part, but it is also necessary to make the irradiation distance from the laser emitting part to the welded part uniform. . In particular, in YAG welding (laser using an arc tube with yttrium, aluminum, and garnet as a cooling medium), the laser beam generated by the laser generator is sent through a fiber to the output unit equipped with the lens and irradiated by the lens. The diameter is reduced and the desired position is irradiated. For this reason, if the irradiation distance varies, the irradiation diameter of the laser beam also varies, resulting in a non-uniform molten state. Therefore, in the first embodiment, since bending (starting up) is performed from the inside of the notch N, the portion irradiated with the laser light has a smooth shape and the irradiation distance is constant, so uniform welding is performed. It becomes possible.

  In the first embodiment, the triangular notch N is used. However, the present invention is not limited to this, and various shapes of notches can be applied. For example, the shape of the notch N may be a semicircular shape, a long hole shape, a rectangular shape, or the like.

[Modification]
In the above description, the case where the two flexible members 13A and 13B are disposed between the fastening members 11 and 12 has been described. However, the present invention is not limited to this. FIG. 9 is a cross-sectional view of a part of a modified joint. As shown in FIG. 9, one flexible member 13 </ b> A may be disposed between the fastening members 11 and 12. In this case, since there is no intermediate member, one of the fastening members 11 and 12 is the first member and the other is the second member. Moreover, although illustration is abbreviate | omitted, the case where a joint has three or more flexible members may be sufficient, and in that case, it is necessary to arrange | position two or more intermediate members.

[Second Embodiment]
Next, the joint according to the second embodiment and the method for manufacturing the joint will be described. FIG. 10 is a cross-sectional view of a part of the joint 201 according to the second embodiment. Hereinafter, in the joint 201 of the second embodiment, a configuration different from that of the first embodiment will be described, and the same configuration will be denoted by the same reference numeral and description thereof will be omitted. The joint 201 includes flexible members 213A and 213B, which are third members having a configuration different from that of the flexible members 13A and 13B of the first embodiment.

  In the first embodiment, the case where the flexible members 13A and 13B are formed by bending a plate-like base material in the processing step of step S1 in FIG. 6 has been described, but in the second embodiment, a plate-like shape is formed. The flexible members 213A and 213B are formed by etching the substrate. Also in the second embodiment, the flexible member 213A and the flexible member 213B have the same configuration. Hereinafter, the flexible member 213A will be described, and the description of the flexible member 213B will be omitted.

  In the second embodiment, by partially reducing the thickness of the annular base material (plate material) by etching, the thick end portions 231A and 232A having the respective joint surfaces 231A1 and 232A2, and the thin wall Intermediate part 233A is formed. Thereby, the flexible member 213A is formed. As in the first embodiment, of the pair of surfaces 233A1 and 233A2 in the arrow X direction of the intermediate portion 233A, the surface 233A1 and the bonding surface 231A1 are on the same surface, and the surface 233A2 and the bonding surface 232A2 are on the same surface. is there. That is, the end portion 231A protrudes from the intermediate portion 233A in the direction opposite to the bonding surface 231A1, and the end portion 232A protrudes from the intermediate portion 233A in the direction opposite to the bonding surface 232A2.

  By performing a chemical etching process, it is possible to accurately form a desired shape without changing the mechanical properties of the material itself and without applying unnecessary stress. Therefore, the rigidity difference can be reduced, and the power transmission error can be reduced.

  The flexible members 213A and 213B are preferably formed of precipitation hardening stainless steel (SUS631, TOKKIN AM350, etc.). This material can be tempered to have good workability by conditioning, and after carrying out plastic working or cutting, the yield strength can be improved by performing precipitation hardening treatment. Suitable for the material of the members 213A, 213B. In the case of this material, processing can be performed in a state where workability is good, and thereafter, the yield strength can be improved, so that the flexible members 213A and 213B are formed by cutting instead of etching. May be.

  In the second embodiment, by performing an etching process or a cutting process, the surface opposite to the joint surface of the flexible members 213A and 213B does not have a shape having a notch, and non-uniformity in heat transfer during welding hardly occurs. High quality welding is possible. Also in the press working, by using the drawing process for forming the thick portion, a continuous joint surface can be formed, and high quality welding is possible.

  The material of the fastening members 11 and 12 is preferably SUS316L, which is austenitic stainless steel. Since this material is a material having a low carbon content, it has good weldability, can be joined with a small amount of heat, and the influence of heat on each member can be reduced. Various materials including other austenitic stainless steels are applicable.

  In addition, although the case where two flexible members 213A and 213B are disposed between the fastening members 11 and 12 has been described, the present invention is not limited to this. Similarly to the above-described modification example, one flexible member 213 </ b> A may be disposed between the fastening members 11 and 12. In this case, since there is no intermediate member, one of the fastening members 11 and 12 is the first member and the other is the second member. Further, the joint may have three or more flexible members. In that case, it is necessary to arrange two or more intermediate members.

  The present invention is not limited to the embodiments described above, and many modifications are possible within the technical idea of the present invention. In addition, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

DESCRIPTION OF SYMBOLS 1 ... Joint, 3 ... Output gear (1st gear), 4 ... Swing gear (2nd gear), 11 ... Fastening member (1st member), 13A ... Flexible member (3rd member), 14 ... Middle Member (second member), 100 ... robot, 110 ... drive device, 111 ... motor (drive source), 112 ... speed reducer (gear mechanism), 131A ... end part (first part), 131A1 ... joint surface (first 1 joint surface), 132A ... end part (second part), 132A2 ... joint surface (second joint surface), 133A ... intermediate part (third part), C0 ... axis

Claims (13)

A first member;
A second member disposed at a distance from the first member;
A plate-like third member that connects the first member and the second member so that the first member can swing relative to the second member;
The third member is
A first portion having a first joint surface joined to the first member;
A second portion having a second joint surface joined to the second member;
A third part disposed between the first part and the second part,
The first portion and the second portion are thicker than the third portion in the thickness direction of the third member. The third part is an annular part centered on the axis,
The first part is arranged on one of the inner side and the outer side in the radial direction centering on the axis with respect to the third part,
2. The joint according to claim 1, wherein the second part is disposed on the other of the inner side and the outer side in the radial direction with respect to the third part. The third part has a pair of surfaces,
The first joining surface is on the same surface as one of the pair of surfaces,
The joint according to claim 1, wherein the second joint surface is on the same surface as the other of the pair of surfaces. The joint according to any one of claims 1 to 3,
A first gear;
A gear mechanism comprising: a second gear supported by the joint so as to be swingable and meshing with the first gear at an angle. A driving source;
The gear mechanism according to claim 4, which transmits power of the drive source. The first link,
A second link movable relative to the first link;
A robot comprising: the drive device according to claim 5 that drives the second link. A first member;
A second member disposed at a distance from the first member;
A plate-like third member that connects the first member and the second member so that the first member can swing relative to the second member;
The third member is
A first portion having a first joint surface joined to the first member;
A second portion having a second joint surface joined to the second member;
A third part disposed between the first part and the second part;
A processing step of processing the substrate to form the third member;
Joining the first joining surface to the first member and joining the second joining surface to the second member,
In the processing step, the base material is processed so that the first part and the second part are thicker than the third part in the thickness direction of the third member. . The base material is a flat member,
In the processing step, one end portion of the base material is bent and overlapped to form the first portion, and the other end portion of the base material is bent and overlapped to form the second portion. A method for manufacturing a joint according to claim 7. The base material has an annular shape centered on an axis;
9. The joint according to claim 8, wherein the one end portion in the radial direction centered on the axis of the base material has a shape in which a plurality of pieces are arranged in a circumferential direction centered on the axis. Production method.   The method for manufacturing a joint according to claim 9, wherein the other end portion in the radial direction of the base material has a shape in which a plurality of pieces are arranged in the circumferential direction.   The method for manufacturing a joint according to any one of claims 8 to 10, wherein in the processing step, the other end portion of the base material is bent to the side opposite to the one end portion. The base material is a plate-shaped member,
The method for manufacturing a joint according to claim 7, wherein in the processing step, the third member is formed by etching or cutting the base material.   The method for manufacturing a joint according to any one of claims 7 to 12, wherein laser welding is performed in the joining step.

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