Robot, robot assembly method, and robot system

Abstract

To provide a robot, a method of assembling a robot, and a robot system comprising the robot, that enable winding a belt around a driving pulley while suppressing a load applied to the belt.SOLUTION: A robot includes a first member and a second member. The first member includes: a housing having a first wall and a second wall disposed to face each other, a first protrusion, and a second protrusion; a drive section having a motor body, a drive pulley and a flange; a joint section having a driven pulley; a drive pulley; and a belt. The first protrusion and the second protrusion include: support sections that support both end portions of the flange, a separation distance between the support sections being shorter than a length of the flange in which the flange protrudes; and missing sections configured such that a separation distance between the missing sections is longer than the length of the flange in a direction in which the flange protrudes, both end portions of the flange passing through the missing sections.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a robot, a method for assembling a robot, and a robot system. [Background technology]

[0002] Patent Document 1 discloses a horizontal SCARA robot including a base having a housing, a first arm pivotally supported on the base, and a second arm pivotally attached to the first arm. The first arm is provided to be rotatable about a first axis passing through the base, and the second arm is provided to be rotatable about a second axis passing through the first arm.

[0003] A first servomotor is connected to the lower end of the first shaft via a timing belt winding mechanism. A second servomotor is connected to the lower end of the second shaft via a timing belt winding mechanism. Of these, the first servomotor is housed in and fixed to a housing provided in the base.

[0004] One method for fixing a servo motor to a housing is to place (engage) the flange attached to the servo motor on a protrusion that protrudes from the inner wall of the housing. Because the flange is wider than the main body of the servo motor, placing the flange on the protrusion enables highly accurate positioning in the vertical direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-123986 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when assembling the robot described in Patent Document 1, the first servo motor is fixed to the housing, and then the timing belt is looped around the pulley connected to the first servo motor, but in order to loop the timing belt around the pulley connected to the first servo motor, the timing belt needs to be bent strongly, which applies a strong load to the timing belt and can cause damage to the timing belt.

[0007] Therefore, the challenge is to loop the timing belt around the pulley connected to the servo motor while suppressing the load on the timing belt. [Means for solving the problem]

[0008] A robot according to an application example of the present invention includes: A first member; a second member that rotates relative to the first member; Equipped with The first member is a housing having a first wall portion and a second wall portion arranged facing each other and spaced apart, a first protrusion protruding from the first wall portion toward the second wall portion, and a second protrusion protruding from the second wall portion toward the first wall portion; a motor body that generates a driving force to rotate around a drive shaft, a drive pulley connected to the motor body, and a drive unit having a flange that protrudes from the motor body in a direction intersecting the drive shaft; connected to the housing and connected to the second member, a joint portion having a driven pulley and transmitting the driving force to the second member; a belt wound around the driving pulley and the driven pulley; and The first protrusion and the second protrusion are 、 before The flange protrudes protrusion Support parts that support both ends in the direction 、 beforeBoth ends of the flange pass through possible A defect portion; With death, a distance between the support portion of the first protrusion and the support portion of the second protrusion is shorter than a length of the flange in the protruding direction; The distance between the cutout portion of the first protruding portion and the cutout portion of the second protruding portion is longer than the length of the flange in the protruding direction. It is characterized by:

[0009] A method for assembling a robot according to an application example of the present invention includes the steps of: A first member; a second member that rotates relative to the first member; A method for assembling a robot comprising: a housing having a first wall portion and a second wall portion arranged facing each other and spaced apart, a first protrusion protruding from the first wall portion toward the second wall portion, and a second protrusion protruding from the second wall portion toward the first wall portion; a motor body that generates a driving force that rotates around a drive shaft, a drive pulley connected to the motor body, and a drive unit that has a flange protruding from the motor body in a direction intersecting the drive shaft; connected to the housing and connected to the second member, a joint portion having a driven pulley and transmitting the driving force to the second member; and a belt, wherein the first protrusion and the second protrusion are The flange has support portions capable of supporting both end portions in a protruding direction in which the flange protrudes, and cutout portions through which the both end portions of the flange can pass, and a separation distance between the support portion of the first protruding portion and the support portion of the second protruding portion is shorter than a length of the flange in the protruding direction, and a separation distance between the cutout portion of the first protruding portion and the cutout portion of the second protruding portion is longer than a length of the flange in the protruding direction. preparing the first member before assembly; looping the belt around the driven pulley; The aforementioned protrusion In the direction The aforementioned bringing the drive unit closer to the belt in a path that passes through the recessed portion; looping the belt around the drive pulley; fixing the flange to the support; The present invention is characterized by having the following.

[0010] A robot system according to an application example of the present invention includes: A robot according to an application example of the present invention; a control device for controlling the operation of the robot; The present invention is characterized by comprising: [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view showing a robot system according to an embodiment. [Figure 2] FIG. 2 is a partial cross-sectional view of the base shown in FIG. [Figure 3] 3 is a perspective view showing only a housing and a drive unit of the base of FIG. 2. FIG. [Figure 4] 4 is a cross-sectional view of the housing shown in FIG. 3 and a top view of the drive unit. FIG. [Figure 5] 1A to 1C are process diagrams illustrating a method for assembling a robot according to an embodiment. [Figure 6] 6 is a cross-sectional view for explaining a method of assembling the robot shown in FIG. 5. FIG. [Figure 7] FIG. 6 is a top view for explaining a method of assembling the robot shown in FIG. 5. [Figure 8] 6 is a cross-sectional view for explaining a method of assembling the robot shown in FIG. 5. FIG. [Figure 9] 6 is a cross-sectional view for explaining a method of assembling the robot shown in FIG. 5. FIG. [Figure 10] FIG. 6 is a side view for explaining a method of assembling the robot shown in FIG. 5. [Figure 11] 6 is a cross-sectional view for explaining a method of assembling the robot shown in FIG. 5. FIG. [Figure 12] 6 is a cross-sectional view for explaining a method of assembling the robot shown in FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a robot, a robot assembly method, and a robot system according to the present invention will now be described in detail with reference to the accompanying drawings.

[0013] 1.Robot System First, a robot system according to an embodiment will be described.

[0014] FIG. 1 is a side view showing a robot system 1 according to an embodiment. FIG. 2 is a partial cross-sectional view of a base 21 shown in FIG. 1. In each drawing of the present application, for convenience of explanation, three mutually orthogonal axes are set as an x-axis, a y-axis, and a z-axis, and each is indicated by an arrow. In the following explanation, the direction parallel to the x-axis is referred to as the "x-axis direction," the direction parallel to the y-axis is referred to as the "y-axis direction," and the direction parallel to the z-axis is referred to as the "z-axis direction." In addition, in the following explanation, the tip end side of each illustrated arrow is referred to as "+ (plus)" and the base end side is referred to as "- (minus)." Furthermore, in the following explanation, for convenience of explanation, the +z-axis direction is referred to as "up" and the -z-axis direction is referred to as "down." In addition, in this specification, "connection" refers to a state in which two members are in direct contact with each other, as well as a state in which two members are in contact with each other via an arbitrary member. indirect Furthermore, in this specification, "parallel" refers to a state in which lines, surfaces, or a line and a surface are parallel to each other, or are tilted from that state within a range of ±5 degrees or less.

[0015] 1 includes a robot 2 and a control device 3 that controls the operation of the robot 2. The uses of the robot system 1 are not particularly limited, but examples thereof include workpiece holding, transport, assembly, and inspection.

[0016] 2. Robot In this embodiment, the robot 2 is a horizontal articulated robot (SCARA robot). The robot 2 includes a base 21 (first member) and a robot arm 20. In this embodiment, the robot arm 20 includes a first arm 22 (second member), a second arm 23, a shaft 24, a payload 244, and an end effector 29, which will be described later.

[0017] 2.1. Overview of the base The base 21 is fixed to an installation surface (not shown) with bolts, etc. Examples of the installation surface include a floor surface, a wall surface, a ceiling surface, and the top surface of a table or a stand.

[0018] As shown in FIG. 2, the base 21 includes a housing 51, a drive unit 261, a joint unit 53, and a belt 55.

[0019] 2 has a substantially rectangular parallelepiped shape having an internal space 510. The external shape of the base 21 is not limited to the shape shown in Fig. 2 and may be any shape. As shown in Fig. 2, the internal space 510 of the housing 51 accommodates the drive unit 261, the joint unit 53, the belt 55, etc.

[0020] Examples of materials that can be used to form the housing 51 include metal materials and resin materials, but metal materials are preferred, which can increase the rigidity of the housing 51 and suppress unintended vibrations of the base 21.

[0021] The driving unit 261 generates a driving force that rotates the first arm 22 about the first axis AX1 relative to the base 21. The driving unit 261 also has an encoder (not shown) that detects the amount of rotation. The rotation angle of the first arm 22 relative to the base 21 can be detected from the output from this encoder.

[0022] The joint portion 53 transmits a driving force to the first arm 22. Specifically, the joint portion 53 converts the driving force from the driving portion 261 into an action of rotating the first arm 22. The belt 55 is an endless belt that transmits the driving force from the driving unit 261 to the joint unit 53 .

[0023] 2.2. Overview of the Robot Arm The robot arm 20 is connected to a base 21, and its posture is controlled by a control device 3. This allows the end effector 29 to be held at a desired position and posture to perform various tasks. In the robot arm 20 shown in FIG. 1, a first arm 22, a second arm 23, a shaft 24, a payload 244, and an end effector 29 are connected in this order. In the following description, for convenience of explanation, the end effector 29 side of the robot 2 will be referred to as the "tip" and the base 21 side will be referred to as the "base end."

[0024] The first arm 22 is rotatable about a first axis AX1 parallel to the z-axis relative to the base 21. The second arm 23 is provided at the tip of the first arm 22 and is rotatable about a second axis AX2 parallel to the first axis AX1. The shaft 24 is provided at the tip of the second arm 23 and is rotatable about a third axis AX3 parallel to the second axis AX2 and is translatable along the third axis AX3.

[0025] The second arm 23 has a base 231 , an upper cover 232 , a lower cover 233 , drive units 262 , 263 , and 264 , a joint unit 240 , and an inertial sensor 4 .

[0026] The base 231 is the skeleton of the second arm 23 and supports the drive units 262, 263, 264, etc. The upper cover 232 is provided above the base 231 and covers the drive units 262, 263, 264, etc. The lower cover 233 is provided below the base 231 and covers the inertial sensor 4, etc., placed on the lower surface of the base 231. Examples of the inertial sensor 4 include an angular velocity sensor and an acceleration sensor. The inertial sensor 4 may be omitted.

[0027] The driving unit 262 is located at the base end of the base 231, and generates a driving force that rotates the second arm 23 about the second axis AX2 relative to the first arm 22. The driving unit 262 includes a motor, a reducer, an encoder, etc., which are not shown. The rotation angle of the second arm 23 relative to the first arm 22 can be detected based on the output from the encoder.

[0028] The driving unit 263 is located between the base end and the tip end of the base 231, and generates a driving force that rotates the ball screw nut 241 and translates the shaft 24 in a direction along the third axis AX3. The driving unit 263 includes a motor, a reducer, an encoder, and the like, all of which are not shown. The amount of translation of the shaft 24 relative to the second arm 23 can be detected by the output from the encoder.

[0029] The driving unit 264 is located between the base end and the tip end of the base 231, and generates a driving force that rotates the spline nut 242 and rotates the shaft 24 about the third axis AX3. The driving unit 264 includes a motor, a reducer, an encoder, etc., which are not shown. The amount of rotation of the shaft 24 relative to the second arm 23 can be detected by the output from the encoder.

[0030] The joint unit 240 transmits a driving force to the shaft 24. Specifically, the joint unit 240 converts the driving force from the driving units 263 and 264 into the translational and rotational movements of the shaft 24.

[0031] The shaft 24 is a cylindrical shaft body and is capable of translating along a third axis AX3 that is aligned in the vertical direction relative to the second arm 23, and is also rotatable around the third axis AX3.

[0032] A ball screw nut 241 and a spline nut 242 are provided midway along the length of the shaft 24, and the shaft 24 is supported by these.

[0033] A payload 244 for mounting an end effector 29 is provided at the tip of the shaft 24. The end effector 29 mounted on the payload 244 is not particularly limited, and examples thereof include a hand for holding an object, a tool for processing an object, and an inspection device for inspecting an object. Note that the robot arm 20 may also be configured without the end effector 29.

[0034] 2.3. Details of the base Next, the base 21 will be described in detail.

[0035] Fig. 3 is a perspective view showing only the housing 51 and the drive unit 261 of the base 21 in Fig. 2. Fig. 4 is a cross-sectional view of the housing 51 and a top view of the drive unit 261 shown in Fig. 3. Note that Figs. 3 and 4 are views showing the base 21 when assembly is complete. Also, the arrows shown in Figs. 3 and 4 indicate the position of the drive unit 261 when assembly is complete.

[0036] 3 is configured with a drive unit housing portion 51a that houses the drive unit 261 and a joint unit housing portion 51b that houses the joint unit 53. An internal space 510 is configured with the interior of the drive unit housing portion 51a and the interior of the joint unit housing portion 51b. As will be described later, the internal space 510 is defined by a first wall portion 511, a second wall portion 512, a top plate 513, a bottom plate 514, and the joint unit housing portion 51b that configure the housing 51.

[0037] The drive unit housing portion 51a is substantially rectangular parallelepiped in shape, with its major axis extending parallel to the z-axis. The drive unit housing portion 51a has a first wall portion 511 and a second wall portion 512 extending along the zy-plane. The first wall portion 511 and the second wall portion 512 are disposed facing each other and spaced apart (with an internal space 510 interposed therebetween). The drive unit housing portion 51a also has a top plate 513 and a bottom plate 514 extending along the xy-plane. The top plate 513 is connected to the upper end of the first wall portion 511 and the upper end of the second wall portion 512. The bottom plate 514 is connected to the lower end of the first wall portion 511 and the lower end of the second wall portion 512.

[0038] The second wall portion 512 has a side window portion 515 that connects the internal space 510 to the external space. The top plate 513 has an upper window portion 516 (opening) that connects the internal space 510 to the external space. The side window portion 515 may be provided in the first wall portion 511 instead of the second wall portion 512, or may be provided in both the first wall portion 511 and the second wall portion 512. The side window portion 515 and the upper window portion 516 are each closed with a lid (not shown), and the edges of the side window portion 515 and the upper window portion 516 are stepped or tapered so that a lid can be placed on them and fixed with screws or the like. The windows may not be closed with a lid.

[0039] The drive unit housing portion 51a is a portion of the housing 51 on the positive side of the y-axis, and has a full-front window 517 connecting the internal space 510 to the external space. The full-front window 517 extends along the entire longitudinal axis of the drive unit housing portion 51a. This full-front window 517 can be used as a carry-in path when carrying components into the internal space 510. Note that the full-front window 517 may extend only partially along the longitudinal axis of the drive unit housing portion 51a, rather than along the entire longitudinal axis. The full-front window 517 may also be closed by a lid (not shown).

[0040] 3 and 4, the drive unit housing portion 51a has a first protrusion 518 and a second protrusion 519. The first protrusion 518 protrudes from the first wall portion 511 toward the internal space 510. The second protrusion 519 protrudes from the second wall portion 512 toward the internal space 510.

[0041] The first protrusion 518 and the second protrusion 519 form a pair and support the drive unit 261 housed in the internal space 510 .

[0042] As shown in FIG. 3, the drive unit 261 includes a motor body 261a, a drive pulley 261b, and a flange 261c. The motor body 261a generates a driving force that rotates around the drive axis AX4. When the drive unit 261 is installed in the housing 51, the drive axis AX4 extends substantially parallel to the first axis AX1. The drive pulley 261b is connected to the motor body 261a. The flange 261c is plate-shaped with its thickness oriented in the z-axis direction and protrudes from the motor body 261a in the x-axis direction. By placing the flange 261c on the first protrusion 518 and the second protrusion 519, the drive unit 261 can be positioned in the z-axis direction relative to the housing 51. Note that the protruding direction of the flange 261c may be any direction intersecting the drive axis AX4 and is not limited to the x-axis direction. The flange 261c is provided with a fixing hole 261d that penetrates the flange 261c. A screw (not shown) can be passed through this fixing hole 261d, and the flange 261c can be fastened to the first protruding portion 518 and the second protruding portion 519 using the screw.

[0043] As shown in FIG. 4, the first protrusion 518 and the second protrusion 519 each have a support portion 521 and a cutout portion 522.

[0044] The flange 261c is placed on the support portion 521, thereby supporting the flange 261c. The support portion 521 has a contact surface 523 that comes into contact with the flange 261c. The contact surface 523 is recessed compared to the portions of the first protruding portion 518 and the second protruding portion 519 other than the contact surface 523. The flange 261c is supported by the support portion 521 by bringing the flange 261c into contact with the contact surface 523, that is, by the engagement between the contact surface 523 and the flange 261c. The flange 261c has a rectangular shape that is long in the protruding direction, which in this embodiment is the x-axis direction, and both ends of the flange 261c come into contact with the contact surface 523.

[0045] The support portion 521 also has a fastening hole 525 extending along the z-axis. The fastening hole 525 is used to fasten the flange 261c with a screw after the flange 261c is brought into contact with the contact surface 523.

[0046] As will be described in detail later, the cutout 522 has a shape that allows both ends of the flange 261c to pass through when the posture of the drive unit 261 is changed in association with the assembly of the robot 2. Specifically, the cutout 522 has grooves 524 that penetrate the first protrusion 518 and the second protrusion 519 in the z-axis direction. By providing such grooves 524, when assembling the base 21 as described below, it becomes possible for both ends of the flange 261c to move along a path that passes through the cutout 522. This allows the belt 55 shown in FIG. 2 to be looped around the drive pulley 261b while suppressing the load applied to the belt 55.

[0047] 4 may be expanded on the negative y-axis side from the position shown in Fig. 4. However, expanding groove 524 may reduce the mechanical strength of first protrusion 518 and second protrusion 519, which in turn may reduce the mechanical strength of housing 51. Therefore, the width of groove 524, i.e., the length of groove 524 in the y-axis direction, may be sufficient to allow both ends of flange 261c to pass through, and is preferably not wider than necessary.

[0048] The joint housing portion 51b is a portion of the housing 51 on the negative side of the y-axis. The joint housing portion 51b is generally cylindrical with open upper and lower ends, and has a long axis extending parallel to the z-axis. As shown in FIG. 2, the first arm 22 is connected to the upper end of the joint housing portion 51b. The joint housing portion 51b houses the joint portion 53 shown in FIG. 2.

[0049] As shown in Fig. 2, the joint portion 53 has a driven pulley 532 and a reducer 534. The driven pulley 532 is connected to the reducer 534. The reducer 534 is connected to the first arm 22 shown in Fig. 2. An example of the reducer 534 is a planocentric reducer.

[0050] The belt 55 transmits a driving force from the driving unit 261 housed in the driving unit housing portion 51a to the joint unit 53 housed in the joint unit housing portion 51b. Therefore, as shown in Fig. 2, the belt 55 is stretched around the driving pulley 261b and the driven pulley 532. With the driving unit 261 and the joint unit 53 installed in the housing 51, the belt 55 is stretched in a loop extending within the xy plane.

[0051] The material of the belt 55 is not particularly limited, but may be, for example, a composite material of a reinforcing material and an elastic material. The belt 55 made of such a composite material has the mechanical strength to transmit a high torque driving force.

[0052] Examples of reinforcing materials include glass fiber, polyester fiber, nylon fiber, aramid fiber, carbon fiber, cotton thread, etc., and one or a mixture of two or more of these fibers is used. Of these, glass fiber or carbon fiber is preferably used as the reinforcing material.

[0053] The elastic material may be at least one selected from the group consisting of nitrile rubber, carboxylated nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, chlorosulfonated polyethylene, polybutadiene rubber, natural rubber, EPM, EPDM, urethane rubber, and acrylic rubber. Of these, materials classified as ultra-high hardness synthetic rubber are preferably used as the elastic material.

[0054] 3. Control device The operation of the robot 2 is controlled by a control device 3. The control device 3 may be disposed outside the base 21 as shown in FIG. 1, or may be built into the base 21. The control device 3 controls the driving of the driving units 261, 262, 263, and 264 in accordance with a pre-stored operation program. This controls the posture of the robot arm 20.

[0055] 4. How to assemble the robot Next, a method for assembling the robot according to the embodiment will be described.

[0056] Fig. 5 is a process diagram for explaining a method for assembling a robot according to the embodiment. Figs. 6, 8, 9, 11, and 12 are cross-sectional views for explaining a method for assembling the robot shown in Fig. 5. Fig. 7 is a top view for explaining a method for assembling the robot shown in Fig. 5. Fig. 10 is a side view for explaining a method for assembling the robot shown in Fig. 5. Note that part of belt 55 is not shown in Figs. 9 and 11.

[0057] 5 includes a preparation step S102, a first belt winding step S104, a drive unit attitude changing step S106, a second belt winding step S108, and a flange fixing step S110. Each step will be described below.

[0058] 4.1. Preparation process In the preparation step S102, the base 21 (first member) before assembly shown in Fig. 6 is prepared. The base 21 before assembly shown in Fig. 6 has a housing 51, a drive unit 261, a joint unit 53, and a belt 55, but the belt 55 is not yet connected to the drive unit 261.

[0059] As shown in Fig. 3, the housing 51 has a first wall portion 511, a second wall portion 512, a first protrusion portion 518, and a second protrusion portion 519. As shown in Fig. 2, the drive portion 261 has a motor body 261a, a drive pulley 261b, and a flange 261c. The joint portion 53 has a driven pulley 532 and a reducer 534. The first protrusion portion 518 and the second protrusion portion 519 each have a support portion 521 and a cutout portion 522.

[0060] The housing 51 is manufactured by, for example, a casting method, a die-casting method, or the like. Furthermore, a portion of the housing 51 may be formed by a machining method. Examples of machining methods include cutting and grinding. Examples of portions formed by a machining method include the contact surface 523, the groove 524, and the fastening holes 525. Forming these portions by a machining method can easily improve machining accuracy. For example, the coplanarity of the contact surface 523 of the first protrusion 518 and the contact surface 523 of the second protrusion 519, i.e., the degree to which they are contained within the same plane, can be improved. Furthermore, the positions of the groove 524 and the fastening holes 525 in the xy plane, as well as the parallelism of the fastening holes 525 with respect to the z axis, can be brought sufficiently close to their design values. As a result, the accuracy of the position and orientation of the drive unit 261 relative to the housing 51 can be improved.

[0061] Furthermore, if the contact surface 523, groove 524, fastening hole 525, etc. can be processed by machining, there is no need to produce them by casting or die-casting, which reduces the difficulty of manufacturing the housing 51.

[0062] As described above, the top plate 513 shown in FIG. 3 has an upper window 516. When viewed from a position along the drive axis AX4, that is, from a position above the upper window 516, the upper window 516 overlaps with the notched portion 522. This makes it possible to insert a processing tool through the upper window 516 and machine the contact surface 523, groove 524, fastening hole 525, etc. This facilitates the manufacture of the housing 51, and ultimately makes it possible to realize a robot 2 that is easy to manufacture.

[0063] The joint 53 is then installed in advance in the joint housing portion 51b of the housing 51. As shown in FIG. 6 , the joint 53 is installed in a state in which the driven pulley 532 is positioned below the reducer 534 and the driven pulley 532 is rotatable. The reducer 534 is fixed to the housing 51.

[0064] 4.2. First belt wrapping process In the first belt winding step S104, as shown in FIG. 6, one end of the belt 55 is wound around the driven pulley 532. As described above, the belt 55 has the mechanical strength to transmit a high torque driving force. Therefore, the belt 55 itself has high rigidity, and when one end of the belt 55 is wound around the driven pulley 532, the other end of the belt 55 extends toward the drive unit housing portion 51a. Even if this does not happen, the other end of the belt 55 does not hang down. Therefore, in the second belt winding step S108 described later, the drive pulley 261b can be inserted inside the other end of the belt 55. This makes it relatively easy to wind the belt 55 around the drive pulley 261b.

[0065] 4.3.Driver position change process In the drive unit attitude changing step S106, the drive unit 261 is moved into the internal space 510 of the housing 51, and the attitude of the drive unit 261 is changed. This creates a state in which the drive pulley 261b can be easily inserted inside the other end of the belt 55.

[0066] Specifically, first, as shown by arrow M1 in Fig. 7, drive unit 261 is moved from the external space toward internal space 510. Fig. 7 is a schematic diagram showing how drive unit 261 is moved from the external space of housing 51 toward internal space 510. Drive unit 261 shown by a solid line in Fig. 7 is drive unit 261 at a position before the movement shown by arrow M1, and drive unit 261 shown by a dashed line in Fig. 7 is drive unit 261 at a position after the movement shown by arrow M1.

[0067] In this step, when viewing the housing 51 from the positive side of the z axis toward the negative side of the z axis, the drive unit 261 is held at a position where the cutout portion 522 and the flange 261c overlap, as shown by the solid line in Fig. 7. At this time, the position of the drive unit 261 in the z axis direction is below the second protrusion 519, as shown in Fig. 6. Furthermore, the orientation of the drive unit 261 is such that the drive axis AX4 and the y axis are substantially parallel and the flange 261c is substantially parallel to the xz plane, as shown in Figs. 6 and 7.

[0068] 4.4. Second belt wrapping process In the second belt suspension process S108, as shown by arrow M2 in FIG. 8, the driving part 261 is translated toward the +z-axis side along a path where both ends of the flange 261c pass through the missing part 522. FIG. 8 shows the state when both ends of the flange 261c are passing through the missing part 522. By moving the driving part 261 upward from below the first protruding part 518 and the second protruding part 519 in this way, the driving pulley 261b can be brought closer from below the other end of the belt 55. That is, when the position where the first protruding part 518 and the second protruding part 519 are provided in the z-axis direction is defined as the "reference position", due to the presence of the missing part 522, the driving part 261 can be translated from below (the region opposite to the joint part 53) to above (the region where the joint part 53 is located) the reference position. By enabling such translation, even when one end of the belt 55 is already wound around the driven pulley 532 in advance, the driving pulley 261b can be inserted from below the other end of the belt 55. As a result, finally, the belt 55 can be wound around the driving pulley 261b without strongly bending the belt 55.

[0069] In FIG. 7, the separation distance between the contact surface 523 of the first protruding part 518 and the contact surface 523 of the second protruding part 519, that is, the separation distance between the support parts 521 is denoted as S1, and the separation distance between the groove 524 of the first protruding part 518 and the groove 524 of the second protruding part 519, that is, the separation distance between the missing parts 522 is denoted as S2. These separation distances S1 and S2 refer to the distances in the x-axis direction. Also, in FIG. 7, the width of the motor body 261a is denoted as W1, and the width of the flange 261c is denoted as W2. These widths W1 and W2 refer to the lengths in the x-axis direction.

[0070] These separation distances S1, S2 and widths W1, W2 satisfy the following formula (1). W1 < S1 < W2 < S2 … (1)

[0071] In the above formula (1), since W1 < S1 holds, when the driving part 261 is translated as shown by arrow M2 in FIG. 8, the motor body 261a can pass between the support parts 521.

[0072] Also, in the above formula (1), W2 < S2 holds. Further, as shown in FIG. 6, the width W3 of the groove 524 in the y-axis direction is wider than the thickness t1 of the flange 261c. Therefore, when the driving part 261 is translated as indicated by the arrow M2 in FIG. 8, both ends of the flange 261c can pass through the missing part 522.

[0073] Next, when the flange 261c has finished passing through the missing part 522, the translation is stopped and the driving part 261 is held. FIG. 9 shows the state where the flange 261c has finished passing through the missing part 522, that is, the state where the movement of the driving part 261 indicated by the arrow M2 in FIG. 8 is completed. In FIG. 9, the driving pulley 261b is inserted from below the other end of the belt 55. At this time, it is not necessarily required that the driving pulley 261b is inserted into the other end of the belt 55, and it is sufficient that the other end of the belt 55 and the driving pulley 261b are close to each other.

[0074] FIG. 10 is a view of the state where the flange 261c has finished passing through the missing part 522 as seen from a different perspective from FIG. 9. As shown in FIG. 10, at this time, the flange 261c is located above the first protruding part 518 and the second protruding part 519. In the present embodiment, even when the flange 261c is located above the first protruding part 518 and the second protruding part 519, a part of the motor body 261a is located between the first protruding part 518 and the second protruding part 519. The form of the driving part 261 is not limited to the illustrated form.

[0075] Next, as shown in FIG. 11, the drive unit 261 is rotated about an axis parallel to the x-axis as the central axis. Specifically, the drive unit 261 is rotated as indicated by arrow M3 in FIG. 11 with the ridge line located at the lower end of the flange 261c shown in FIG. 11 as the rotation axis. As a result, the drive pulley 261b moves upward and the motor body 261a moves downward. Consequently, the posture of the drive pulley 261b inserted inside the belt 55 changes, and accordingly, the other end of the belt 55 is wound around the drive pulley 261b. Also, both ends of the flange 261c come into contact with the contact surface 523. This completes the operation of winding the belt 55 around the drive pulley 261b and the operation of positioning the drive unit 261 in the z-axis direction.

[0076] In the above formula (1), since S1 < W2 holds, when the drive unit 261 is rotated as indicated by arrow M3 in FIG. 11, the flange 261c can be placed on the contact surface 523. This makes it possible to support the flange 261c with the support portion 521.

[0077] By adopting the procedure of winding the belt 55 around the drive pulley 261b while changing the posture of the drive unit 261 as described above, when winding the belt 55 around the drive pulley 261b, it is not necessary to strongly bend the belt 55. Also, in the robot 2, in the direction along the drive shaft AX4, the motor body 261a is located on the opposite side of the speed reducer 534 via the belt 55. That is, the speed reducer 534 is located above the belt 55 and the motor body 261a is located below the belt 55. For this reason, the belt 55 can be wound around the drive pulley 261b simply by inserting the drive pulley 261b from below the other end of the belt 55, and it is difficult for the belt 55 and the motor body 261a to interfere during the process of that operation. Therefore, from that perspective as well, it is not necessary to strongly bend the belt 55. For these reasons, it is possible to avoid damage to the belt 55.

[0078] On the other hand, in the past, even if you tried to fix the servomotor to the housing while changing the position of the servomotor so that the pulley could be inserted inside the timing belt, the flange would interfere with the protrusion that protrudes from the inner wall of the housing when you changed the position of the servomotor, making it impossible to change the position of the servomotor and therefore impossible to insert the pulley inside the timing belt.

[0079] In contrast to such conventional technology, the above-described structure and procedure make it possible to suppress the load on the belt 55, loop the belt 55 around the drive pulley 261b connected to the motor main body 261a, and position the drive unit 261 by utilizing the engagement between the flange 261c of the drive unit 261 and the housing 51 of the base 21.

[0080] Furthermore, there is no need to reserve space for bending the belt 55. Specifically, when looping the belt 55 around the drive pulley 261b that is supported in advance on the housing 51, the belt 55 needs to be looped around the drive pulley 261b while being bent, and therefore space is required for greatly bending the belt 55. For example, when bending the belt 55 upward significantly, the distance between the reducer 534 and the driven pulley 532 needs to be extended in the z-axis direction to avoid interference between the reducer 534 and the belt 55. However, if this distance is extended, a load is more likely to be applied to the reducer 534, which may shorten the life of the reducer 534.

[0081] In this embodiment, since there is no need to bend the belt 55 significantly, it is possible to reduce the distance in the z-axis direction between the reducer 534 and the belt 55. This reduces the load applied to the reducer 534, thereby extending the life of the reducer 534.

[0082] Furthermore, a part of the motor body 261a is arranged to overlap with the joint housing portion 51b, thereby making it possible to reduce the size of the housing 51.

[0083] 4.5.Flange fixing process In the flange fixing step S110, as shown in Fig. 12, the flange 261c is fixed to the support part 521 using the screw 526. Specifically, the screw 526 shown in Fig. 12 is inserted into the fixing hole 261d of the flange 261c shown in Fig. 3, and the screw 526 is screwed into the fastening hole 525 shown in Fig. 4. Note that the method of fixing the flange 261c to the support part 521 is not limited to the method using the screw 526, and other methods may be used.

[0084] Furthermore, the screw 526 and a tool for threading the screw 526 into the fastening hole 525 can be inserted into the internal space 510 through the upper window 516. Therefore, by providing the upper window 516, the efficiency of the assembly work of the robot 2 can be improved.

[0085] Furthermore, as shown in Figure 3 Drive unit housing portion 51a As described above, the robot 2 has a side window 515 and a full-front window 517. The position and posture of the drive unit 261 can be changed by an operator or a working robot inserting an arm through at least one of the side window 515 and the full-front window 517. Therefore, by providing the side window 515 and the full-front window 517, the efficiency of the assembly work of the robot 2 can be improved.

[0086] In this manner, the base 21 is assembled. Thereafter, the robot arm 20 is connected to the base 21, and the robot 2 is assembled.

[0087] When the base 21 shown in FIG. 2 is viewed from a position along the drive axis AX4, the recessed portion 522 is located between the drive axis AX4 and the joint portion 53. In other words, the position of the recessed portion 522 in the y-axis direction is between the drive axis AX4 and the joint portion 53 shown in FIG. 2. By providing the recessed portion 522 in such a position, the change in the posture of the drive unit 261 becomes smooth when the posture of the drive unit 261 is transitioned from the posture shown in FIG. 8 to the posture shown in FIG. 12. In other words, after the drive unit 261 is translated as shown by the arrow M2 in FIG. 8, the drive pulley 261b can be easily inserted from below the other end of the belt 55 as shown in FIG. 9.

[0088] Furthermore, the upper window 516, the side window 515, and the full-face window 517 can also be used as a work path when repairing or maintaining the robot 2 after assembly. Due to the existence of this work path, the assembled base 21 can be used for repairs or the like in the installed position without having to be turned upside down. Furthermore, there is no need to remove the robot arm 20 from the base 21 when performing repairs or the like. This improves the efficiency of repairs or other work.

[0089] 5. Effects of the embodiment As described above, the robot assembly method according to the embodiment is a method for assembling a robot 2 that includes a base 21 (first member) and a first arm 22 (second member) that rotates relative to the base 21, and includes a preparation step S102, a first belt routing step S104, a drive unit posture change step S106, a second belt routing step S108, and a flange fixing step S110.

[0090] In the preparation step S102, the base 21 before assembly, which includes the housing 51, the drive unit 261, the joint unit 53, and the belt 55, is prepared.

[0091] The housing 51 has a first wall portion 511, a second wall portion 512, a first protrusion portion 518, and a second protrusion portion 519. The first wall portion 511 and the second wall portion 512 are disposed facing each other and spaced apart (with the internal space 510 interposed therebetween). The first protrusion portion 518 protrudes from the first wall portion 511 toward the second wall portion 512. The second protrusion portion 519 protrudes from the second wall portion 512 toward the first wall portion 511.

[0092] The drive unit 261 has a motor body 261a, a drive pulley 261b, and a flange 261c. The motor body 261a generates a drive force that rotates around a drive shaft AX4. The drive pulley 261b is connected to the motor body 261a. The flange 261c protrudes from the motor body 261a in a direction that intersects with the drive shaft AX4. The joint portion 53 has a driven pulley 532 and transmits a driving force to the first arm 22 .

[0093] The first protruding portion 518 and the second protruding portion 519 have a support portion 521 and a cutout portion 522. At the support portions 521, the distance S1 between them is shorter than the length (width W2) in the direction in which the flange 261c protrudes. At the cutout portions 522, the distance S2 between them is longer than the length (width W2) in the direction in which the flange 261c protrudes.

[0094] In the first belt winding step S104, the belt 55 is wound around the driven pulley 532. In the drive unit attitude changing step S106, the drive unit 261 is moved closer to the belt 55 along a path in which both ends of the flange 261c in the protruding direction pass through the cutout portion 522.

[0095] In the second belt winding step S108, the belt 55 is wound around the drive pulley 261b. In the flange fixing step S110, the flange 261c is fixed to the support portion 521.

[0096] According to this assembly method, the belt 55 can be looped around the drive pulley 261b while suppressing the load applied to the belt 55. Furthermore, the drive unit 261 can be positioned by utilizing the engagement between the flange 261c of the drive unit 261 and the housing 51 of the base 21. Therefore, according to the assembly method described above, it is possible to assemble a highly reliable robot 2 while suppressing damage to the belt 55.

[0097] The robot 2 according to the embodiment includes a base 21 (first member) and a first arm 22 (second member) that rotates relative to the base 21.

[0098] The base 21 includes a housing 51 , a drive unit 261 , a joint unit 53 , and a belt 55 . The housing 51 has a first wall portion 511, a second wall portion 512, a first protrusion portion 518, and a second protrusion portion 519. The first wall portion 511 and the second wall portion 512 are disposed facing each other and spaced apart (with the internal space 510 interposed therebetween). The first protrusion portion 518 protrudes from the first wall portion 511 toward the second wall portion 512. The second protrusion portion 519 protrudes from the second wall portion 512 toward the first wall portion 511.

[0099] The drive unit 261 has a motor body 261a, a drive pulley 261b, and a flange 261c. The motor body 261a generates a drive force that rotates around a drive shaft AX4. The drive pulley 261b is connected to the motor body 261a. The flange 261c protrudes from the motor body 261a in a direction that intersects with the drive shaft AX4.

[0100] The joint portion 53 has a driven pulley 532 and transmits a driving force to the first arm 22 . The belt 55 is stretched over the driving pulley 261 b and the driven pulley 532 .

[0101] The first protruding portion 518 and the second protruding portion 519 have supporting portions 521 and cutout portions 522. The supporting portions 521 are spaced apart by a distance S1 that is shorter than the length (width W2) of the flange 261c in the protruding direction, and support both ends of the flange 261c in the protruding direction. The cutout portions 522 are spaced apart by a distance S2 that is longer than the length (width W2) of the flange 261c in the protruding direction, and are configured to allow both ends of the flange 261c to pass through.

[0102] According to this configuration, it is possible to obtain a robot 2 in which the belt 55 can be looped around the drive pulley 261b while suppressing the load applied to the belt 55. In such a robot 2, damage to the belt 55 is suppressed, thereby improving reliability. Furthermore, by engaging the flange 261c of the drive unit 261 with the housing 51 of the base 21, it is possible to position the drive unit 261 with respect to the housing 51.

[0103] In addition, in the robot 2 according to this embodiment, the missing portion 522 is located between the drive axis AX4 and the joint portion 53 when viewed from a position along the drive axis AX4.

[0104] By providing the cutout 522 at such a position, the posture of the drive unit 261 can be smoothly changed when the posture of the drive unit 261 transitions from the posture shown in Fig. 8 to the posture shown in Fig. 12. This makes it possible to realize a robot 2 that is easy to assemble.

[0105] Furthermore, in the robot 2 according to this embodiment, the housing 51 has an upper window 516 which is an opening that connects the external space to an internal space 510 defined by at least the first wall 511 and the second wall 512. When viewed from a position along the drive axis AX4, that is, from a position above the upper window 516, the upper window 516 and the cutout 522 overlap.

[0106] This makes it possible, for example, to insert a machining tool into the internal space 510 from the upper window 516 when forming the notches 522 in the first protruding portion 518 and the second protruding portion 519 using the machining tool. Therefore, the grooves 524 can be machined without changing the position of the housing 51 from that shown in FIG.

[0107] In the robot 2 according to this embodiment, the support portion 521 has a fastening hole 525. The flange 261c is fastened to the support portion 521 using this fastening hole 525.

[0108] According to this configuration, the flange 261c can be reliably fixed to the support portion 521, and can also be easily released from the fixed state as needed. This makes it possible to improve the assembly efficiency of the robot 2 and also improve the ease of maintenance.

[0109] Furthermore, in the robot 2 according to this embodiment, when viewed from a position along the drive axis AX4, the upper window portion 516, which is an opening, overlaps with the fastening hole 525. In other words, when the robot 2 is viewed from above, the fastening hole 525 is arranged so that it can be seen through the upper window portion 516.

[0110] According to this configuration, the work of machining the fastening holes 525 and the work of threading the screws 526 into the fastening holes 525 can be performed efficiently through the upper window portion 516.

[0111] Furthermore, in the robot 2 according to this embodiment, the support part 521 has a contact surface 523 that comes into contact with the flange 261c. This contact surface 523 is preferably a machined surface. This increases the coplanarity of the two contact surfaces 523. As a result, it is possible to increase the accuracy of the position and orientation of the drive part 261 relative to the housing 51. Note that the support part 521 may not be provided with the contact surface 523.

[0112] In the robot 2 according to this embodiment, the joint 53 has a reducer 534 connected to the driven pulley 532. The motor main body 261a is located on the opposite side of the reducer 534 across the belt 55 in the direction along the drive axis AX4.

[0113] This allows belt 55 to be looped around drive pulley 261b without bending belt 55 too strongly or without securing space for bending belt 55. As a result, damage to belt 55 can be avoided and the distance between reducer 534 and belt 55 can be reduced. This allows the lifespan of belt 55 and reducer 534 to be extended.

[0114] The robot system 1 according to this embodiment also includes a robot 2 and a control device 3 that controls the operation of the robot 2.

[0115] As described above, the robot 2 has high reliability and a long lifespan due to the belt 55 and the reducer 534. Therefore, it is possible to realize a robot system 1 that is highly reliable and has a long lifespan.

[0116] The robot, robot assembly method, and robot system of the present invention have been described above based on the illustrated embodiments. However, the robot and robot system of the present invention are not limited to the above embodiments. For example, the parts of the above embodiments may be replaced with any configuration having the same function, any component may be added to the above embodiments, or a plurality of the above embodiments may be combined. Furthermore, the method for assembling a robot of the present invention may be such that any desired process is added to the above-described embodiment. [Explanation of symbols]

[0117] 1...robot system, 2...robot, 3...control device, 4...inertial sensor, 20...robot arm, 21...base, 22...first arm, 23...second arm, 24...shaft, 29...end effector, 51...casing, 51a...drive unit housing portion, 51b...joint unit housing portion, 53...joint portion, 55...belt, 231...base, 232...upper cover, 233...lower cover, 240...joint portion, 241...ball screw nut, 242...spline nut, 244...payload, 261...drive unit, 261a...motor body, 261b...drive pulley, 261c...flange, 261d...fixing hole, 262...drive unit, 263...drive unit, 264...drive unit, 510...internal space, 511... First wall portion, 512...second wall portion, 513...top plate, 514...bottom plate, 515...side window portion, 516...upper window portion, 517...full window portion, 518...first protrusion portion, 519...second protrusion portion, 521...support portion, 522...missing portion, 523...contact surface, 524...groove, 525...fastening hole, 526...screw, 532...driven pulley, 534...reduction gear, AX1...first axis, AX2...second axis, AX3...third axis, AX4...drive axis, M1...arrow, M2...arrow, M3...arrow, t1...thickness, S1...separation distance, S2...separation distance, S102...preparation process, S104...first belt winding process, S106...drive unit position changing process, S108...second belt winding process, S110...flange fixing process, W1...width, W2...width, W3...width

Claims

1. A first member; a second member that rotates relative to the first member; Equipped with The first member is a housing having a first wall portion and a second wall portion disposed facing each other and spaced apart, a first protruding portion protruding from the first wall portion toward the second wall portion, and a second protruding portion protruding from the second wall portion toward the first wall portion; a motor body that generates a driving force to rotate around a drive shaft, a drive pulley connected to the motor body, and a drive unit having a flange that protrudes from the motor body in a direction intersecting the drive shaft; a joint portion connected to the housing and the second member, the joint portion having a driven pulley, and the joint portion transmitting the driving force to the second member; a belt wound around the driving pulley and the driven pulley; and The first protrusion and the second protrusion are a support portion for supporting both ends of the flange in a protruding direction; a cutout portion through which both ends of the flange can pass; and a distance between the support portion of the first protrusion and the support portion of the second protrusion is shorter than a length of the flange in the protruding direction; The robot is characterized in that the distance between the cutout portion of the first protrusion and the cutout portion of the second protrusion is longer than the length of the flange in the protrusion direction.

2. The robot according to claim 1 , wherein the missing portion is located between the drive shaft and the joint portion when viewed from a position along the drive shaft.

3. the housing has an opening that connects an internal space defined by at least the first wall portion and the second wall portion with an external space, The robot according to claim 1 or 2, wherein the opening and the cutout overlap when viewed from a position along the drive shaft.

4. The support portion has a fastening hole; The robot according to claim 1 or 2, wherein the flange is fastened to the support portion using the fastening hole.

5. the housing has an opening that connects an internal space defined by at least the first wall portion and the second wall portion with an external space, The robot according to claim 4 , wherein the opening and the fastening hole overlap when viewed from a position along the drive shaft.

6. the support portion has a contact surface that comes into contact with the flange, 6. The robot according to claim 1, wherein the contact surface is a machined surface.

7. the joint portion has a reducer connected to the driven pulley, 7. The robot according to claim 1, wherein the motor body is located on an opposite side of the belt from the reducer in a direction along the drive shaft.

8. A first member; a second member that rotates relative to the first member; A method for assembling a robot comprising: a housing having a first wall portion and a second wall portion disposed facing each other and spaced apart, a first protrusion protruding from the first wall portion toward the second wall portion, and a second protrusion protruding from the second wall portion toward the first wall portion; a motor body generating a driving force that rotates around a drive shaft, a drive pulley connected to the motor body, and a drive unit having a flange protruding from the motor body in a direction intersecting the drive shaft; and a driven pulley connected to the housing and connected to the second member, the driven pulley being attached to the second member. a step of preparing the first member before assembly, the first member having a joint portion that transmits the driving force and a belt, the first protruding portion and the second protruding portion having support portions that can support both ends of the flange in a protruding direction in which the flange protrudes and cutout portions through which the both ends of the flange can pass, the distance between the support portions of the first protruding portion and the support portions of the second protruding portion being shorter than the length of the flange in the protruding direction, and the distance between the cutout portions of the first protruding portion and the cutout portions of the second protruding portion being longer than the length of the flange in the protruding direction; looping the belt around the driven pulley; bringing the drive unit closer to the belt along a path in which both end portions in the protruding direction pass through the recessed portion; looping the belt around the drive pulley; fixing the flange to the support; A robot assembly method comprising the steps of:

9. The robot according to any one of claims 1 to 7, a control device for controlling the operation of the robot; A robot system comprising:

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