Vertical articulated robot

Abstract

Provided is a vertical articulated robot capable of reducing the inertia moment of a robot arm. The vertical articulated robot includes: a base; a first arm that rotates about a vertical axis with respect to the base; the second arm is connected to the first arm and rotates around a first horizontal shaft relative to the first arm; the third arm is connected to the second arm and rotates around a second horizontal shaft relative to the second arm; the first motor enables the second arm to rotate around the first horizontal shaft relative to the first arm; and a second motor that rotates the third arm about the second horizontal axis with respect to the second arm, the first motor and the second motor being disposed on the first arm, respectively.

Description

Technical Field

[0001] The invention relates to a vertical multi-joint robot. Background Art

[0002] The robot described in Patent Document 1 includes a robot body having a base and a robot arm connected to the base. The robot arm includes a first arm rotatably connected to the base; a second arm rotatably connected to the first arm; a third arm rotatably connected to the second arm; a fourth arm rotatably connected to the third arm; a fifth arm rotatably connected to the fourth arm; and a sixth arm rotatably connected to the fifth arm.

[0003] In addition, the robot described in patent document 1 has: a first motor, which rotates the first arm relative to the base; a second motor, which rotates the second arm relative to the first arm; a third motor, which rotates the third arm relative to the second arm; a fourth motor, which rotates the fourth arm relative to the third arm; a fifth motor, which rotates the fifth arm relative to the fourth arm; and a sixth motor, which rotates the sixth arm relative to the fifth arm.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-063933

[0005] However, in the robot described in Patent Document 1, the second motor and the third motor, which are heavy objects, are arranged at the longitudinal center of the second arm. Therefore, it is difficult to reduce the weight of the front end of the robot arm and the moment of inertia of the robot arm tends to increase. Summary of the Invention

[0006] The vertical multi-joint robot of the present invention has:

[0007] abutment;

[0008] a first arm, rotatable about a vertical axis relative to the base;

[0009] a second arm connected to the first arm and rotatable relative to the first arm about a first horizontal axis;

[0010] a third arm connected to the second arm and rotating relative to the second arm about a second horizontal axis;

[0011] a first motor to rotate the second arm relative to the first arm about the first horizontal axis; and

[0012] a second motor, causing the third arm to rotate relative to the second arm around the second horizontal axis;

[0013] The first motor and the second motor are respectively configured on the first arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a perspective view showing the vertical articulated robot according to the first embodiment.

[0015] Figure 2 It shows Figure 1 Schematic diagram of the joints of the vertical multi-jointed robot shown.

[0016] Figure 3 It is a cross-sectional view showing the first power transmission mechanism.

[0017] Figure 4 It is a cross-sectional view showing the second power transmission mechanism.

[0018] Figure 5 It is a cross-sectional view showing the second power transmission mechanism.

[0019] Figure 6 is a side view showing the configuration of the first motor and the second motor.

[0020] Figure 7 It is a cross-sectional view showing a vertical articulated robot according to a second embodiment.

[0021] Figure 8 is a side view showing the configuration of the first motor and the second motor.

[0022] Figure 9 It is a cross-sectional view showing a vertical articulated robot according to a third embodiment.

[0023] Figure 10 It is a cross-sectional view showing a vertical articulated robot according to a fourth embodiment.

[0024] Description of Reference Numerals

[0025] 1…Vertical multi-jointed robot, 11…Base, 12…Arm, 121…First arm, 122…Second arm, 123…Third arm, 124…Fourth arm, 125…Fifth arm, 126…Sixth arm, 131…First drive unit, 132…Second drive unit, 133…Third drive unit, 134…Fourth drive unit, 135…Fifth drive unit, 136…Sixth drive unit, 14…Control board, 15…Power board, 21…First motor, 211…Output shaft, 22…First speed reducer, 221…Cordless gear, 222…Flexible gear, 223…Wave generator, 23…First power transmission mechanism, 231…First motor-side pulley, 232…First speed reducer-side pulley, 233…First belt, 31…Second motor, 311…Output shaft, 32…Second speed reducer, 321…Cordless gear, 322…Flexible gear, 323…Wave generator , 33…Second power transmission mechanism, 34…First transmission mechanism, 341…Second motor side pulley, 342…First intermediate pulley, 343…Second belt, 35…Second transmission mechanism, 351…Second reducer side pulley, 352…Second intermediate pulley, 353…Third belt, 36…Shaft, 361…Through hole, 41…Third motor, 411…Output shaft, 42…Third reducer, 421…Rigid gear, 422…Flexible gear , 423…wave generator, 43…third power transmission mechanism, 431…third motor side pulley, 432…third reducer side pulley, 433…fourth belt, 5…connecting hole, 51…first connecting hole, 52…second connecting hole, H1…through hole, H2…through hole, J1…first rotating shaft, J2…second rotating shaft, J3…third rotating shaft, J4…fourth rotating shaft, J5…fifth rotating shaft, J6…sixth rotating shaft, L…wiring DETAILED DESCRIPTION

[0026] Hereinafter, the vertical multi-joint robot of the present invention will be described in detail based on the embodiments shown in the drawings.

[0027] In addition, for the sake of convenience, in each figure, three mutually orthogonal axes are illustrated as the X-axis, Y-axis, and Z-axis. In addition, for the sake of convenience, the direction parallel to the X-axis is also referred to as the "X-axis direction", the direction parallel to the Y-axis is also referred to as the "Y-axis direction", and the direction parallel to the Z-axis is also referred to as the "Z-axis direction". In addition, the XY plane defined by the X-axis and the Y-axis is along the horizontal plane, and the Z-axis direction is along the vertical direction. Therefore, in the following, the direction along the XY plane is also referred to as the horizontal direction, the arrow side of the Z-axis is also referred to as "up", and the opposite side is also referred to as "down". In addition, in this specification, "horizontal" not only includes the case of being completely horizontal, but also includes the degree that can be regarded as horizontal in technical common sense, such as the case of being inclined within ±5° relative to the horizontal. Similarly, "vertical" not only includes the case of being completely vertical, but also includes the degree that can be regarded as vertical in technical common sense, such as the case of being inclined within ±5° relative to the vertical.

[0028] First embodiment

[0029] Figure 1 It is a perspective view showing the vertical articulated robot according to the first embodiment. Figure 2 It shows Figure 1 Schematic diagram of the joints of the vertical multi-jointed robot shown. Figure 3 It is a cross-sectional view showing the first power transmission mechanism. Figure 4 and Figure 5 Each of them is a cross-sectional view showing the second power transmission mechanism. Figure 6 is a side view showing the configuration of the first motor and the second motor.

[0030] Figure 1 and Figure 2 The vertical articulated robot 1 shown has a base 11 and a robot arm 12 rotatably connected to the base 11. The base 11 is fixed to the ground, for example. In addition, the robot arm 12 has: a first arm 121, which is connected to the base 11 in a manner that allows it to rotate around a vertical axis along the vertical direction, that is, a first rotation axis J1 relative to the base 11; a second arm 122, which is connected to the first arm 121 in a manner that allows it to rotate around a first horizontal axis along the horizontal direction, that is, a second rotation axis J2 relative to the first arm 121; a third arm 123, which is connected to the second arm 122 in a manner that allows it to rotate around a second horizontal axis along the horizontal direction, that is, a third rotation axis J3 relative to the second arm 122; a fourth arm 124, which is connected to the third arm 123 in a manner that allows it to rotate around a fourth rotation axis J4 relative to the third arm 123; a fifth arm 125, which is connected to the fourth arm 124 in a manner that allows it to rotate around a fifth rotation axis J5 along the horizontal direction relative to the fourth arm 124; and a sixth arm 126, which is connected to the fifth arm 125 in a manner that allows it to rotate around a sixth rotation axis J6 relative to the fifth arm 125.

[0031] In addition, if Figure 1 As shown, the second arm 122 is connected to the first arm 121 from one side along the direction of the second rotation axis J2. In the example shown in the figure, the second arm 122 is connected to the first arm 121 from the positive side in the Y-axis direction. That is, the second arm 122 is cantilevered at its base end on the first arm 121. According to such a structure, the second arm 122 can be made lighter. Therefore, the entire robot arm 12 can be made lighter, and accordingly, the inertia moment of the robot arm 12 can be reduced. Therefore, the robot arm 12 can be controlled with higher precision. In addition, the inertia moment can also be referred to as inertia or inertia efficiency.

[0032] In addition, if Figure 1 As shown, the second arm 122 is supported by the third arm 123 from one side along the third rotation axis J3. In the illustrated example, the second arm 122 supports the third arm 123 from the positive side in the Y-axis direction. In other words, the second arm 122 supports the third arm 123 at its front end in a cantilever manner. This configuration allows the second arm 122 to be lightweight. Consequently, the overall weight of the robot arm 12 can be reduced, and the moment of inertia of the robot arm 12 can be correspondingly reduced. Consequently, the robot arm 12 can be controlled with higher precision.

[0033] In addition, if Figure 1 and Figure 2 As shown, the vertical articulated robot 1 includes a first drive unit 131 that rotates the first arm 121 relative to the base 11 about a first rotation axis J1; a second drive unit 132 that rotates the second arm 122 relative to the first arm 121 about a second rotation axis J2; a third drive unit 133 that rotates the third arm 123 relative to the second arm 122 about a third rotation axis J3; a fourth drive unit 134 that rotates the fourth arm 124 relative to the third arm 123 about a fourth rotation axis J4; a fifth drive unit 135 that rotates the fifth arm 125 relative to the fourth arm 124 about a fifth rotation axis J5; and a sixth drive unit 136 that rotates the sixth arm 126 relative to the fifth arm 125 about a sixth rotation axis J6. Each of the drive units 131 to 136 includes, for example, a motor as a drive source, a speed reducer that reduces the motor's rotation to increase and output a rotational force (torque), and an encoder that detects the motor's rotation amount.

[0034] In addition, if Figure 1 As shown, the vertical articulated robot 1 includes a control board 14 and a power board 15 which are arranged in a base 11. However, the arrangement of the control board 14 and the power board 15 is not particularly limited.

[0035] The control board 14 independently controls the driving of the motors provided in each drive unit 131 to 136. This control board 14 includes a wiring board, a CPU (Central Processing Unit), an example of a processor, RAM (Random Access Memory), and a ROM (Read Only Memory) storing programs. The CPU reads and executes the programs stored in the ROM, thereby functioning as a control unit that controls the driving of the vertical articulated robot 1.

[0036] The power board 15 supplies power to the control board 14. The power board 15 includes a substrate with wiring and a converter circuit installed on the substrate to convert externally supplied power to a predetermined value. The converter circuit varies depending on the configuration of the vertical articulated robot 1; examples include an AC / DC converter circuit that converts an alternating current (AC) signal into a direct current (DC) signal, and a boost or buck circuit that converts the voltage level of a signal.

[0037] The above briefly describes the overall structure of the vertical articulated robot 1. Next, the second drive unit 132 and the third drive unit 133, which are also features of the vertical articulated robot 1, will be described in detail. As previously mentioned, the second drive unit 132 rotates the second arm 122 relative to the first arm 121 about the second rotation axis J2, and the third drive unit 133 rotates the third arm 123 relative to the second arm 122 about the third rotation axis J3.

[0038] First, the second driving unit 132 is described. Figure 3 As shown, the second drive unit 132 has: a first motor 21, which is a motor with a built-in encoder; a first reducer 22, which connects the first arm 121 and the second arm 122; and a first power transmission mechanism 23, which connects the first motor 21 and the first reducer 22, and transmits the power of the first motor 21 to the first reducer 22.

[0039] The first motor 21 is arranged in the first arm 121. In addition, the output shaft 211 of the first motor 21 is arranged along the second rotation axis J2. In addition, the first motor 21 is arranged at a position where the output shaft 211 deviates from the second rotation axis J2. In the present embodiment, when viewed from above in the Z-axis direction, the first motor 21 is arranged at a position deviated to the negative side in the X-axis direction relative to the second rotation axis J2. Such a first motor 21 is not particularly limited, but in the present embodiment is a servo motor, in particular a three-phase motor driven by three-phase AC. By setting the first motor 21 as a servo motor, the drive of the second arm 122 can be easily and accurately controlled.

[0040] The first speed reducer 22 is a wave gear device. Using a wave gear device as the first speed reducer 22 reduces backlash in the first speed reducer 22. This allows for precise control of the second arm 122. However, the first speed reducer 22 is not particularly limited and may also be a planetary gear device, a roller cam speed reducer, or the like.

[0041] The first reducer 22 is primarily composed of a rigid gear 221, a flexible gear 222, and a wave generator 223. The rigid gear 221 is fixed to the first arm 121, the flexible gear 222 is fixed to the second arm 122, and the wave generator 223 is connected to the first motor 21 via the first power transmission mechanism 23. The wave generator 223 is cylindrical in shape. Therefore, a through hole H1 is formed in the first reducer 22 along the second rotation axis J2, connecting the interior of the first arm 121 and the interior of the second arm 122. Wiring L electrically connects at least one of the control board 14 and the power board 15 to the various drive units of the robot arm 12. Furthermore, if an inertial sensor is provided in the robot arm 12, the wiring L may also include wiring electrically connecting at least one of the control board 14 and the power board 15 to the inertial sensor. Furthermore, as described later, a shaft 36 or wiring L is inserted through the through hole H1.

[0042] The first power transmission mechanism 23 is arranged together with the first motor 21 in the first arm 121. The first power transmission mechanism 23 includes a first motor-side pulley 231 mounted on the output shaft 211 of the first motor 21; a first speed reducer-side pulley 232 mounted on the wave generator 223 serving as the input shaft of the first speed reducer 22; and a first belt 233 wound around the first motor-side pulley 231 and the first speed reducer-side pulley 232.

[0043] In this configuration, the rotation of the first motor 21 is transmitted to the wave generator 223 of the first reducer 22 via the first motor-side pulley 231, the first belt 233, and the first reducer-side pulley 232, causing the wave generator 223 to rotate about the second rotation axis J2. Furthermore, the flexible gear 222 rotates at a predetermined reduction ratio relative to the rotation of the wave generator 223, resulting in the second arm 122 rotating about the second rotation axis J2 relative to the first arm 121.

[0044] In this way, by setting a structure in which the power of the first motor 21 is transmitted to the first reducer 22 via the first power transmission mechanism 23, the configuration freedom of the first motor 21 is increased. In particular, since the output shaft 211 of the first motor 21 can be staggered from the second rotation axis J2, the overlap of the through hole H1 of the first reducer 22 and the first motor 21 can be effectively suppressed. Therefore, it becomes easy to insert the shaft 36 or the wiring L into the through hole H1. Moreover, by adjusting the diameters of the first motor side pulley 231 and the first reducer side pulley 232, for example, the first power transmission mechanism 23 can also be used as a reducer, and by using it in conjunction with the first reducer 22, a larger reduction ratio can be set. In addition, by setting a structure using two pulleys and a belt, since they can be formed of lightweight materials such as resin materials and rubber materials, it is also possible to achieve lightweighting of the first power transmission mechanism 23.

[0045] However, the first power transmission mechanism 23 is not particularly limited. For example, the first motor-side pulley 231 and the first speed reducer-side pulley 232 may be replaced with gears, and the first belt 233 may be replaced with a chain meshing with these two gears. Alternatively, the chain may be omitted, and the gears may be directly meshed with each other. However, compared to such a configuration using gears and a chain, the configuration using pulleys and a belt, as in this embodiment, reduces backlash in the first power transmission mechanism 23 and enables precise control of the second arm 122.

[0046] Next, the third driving unit 133 will be described. Figure 4 and Figure 5 As shown, the third drive unit 133 has: a second motor 31, which is a motor with a built-in encoder; a second reducer 32, which connects the second arm 122 and the third arm 123; and a second power transmission mechanism 33, which connects the second motor 31 and the second reducer 32, and transmits the power of the second motor 31 to the second reducer 32.

[0047] The second motor 31 is arranged in the first arm 121. In addition, the second motor 31 is arranged in such a manner that its output shaft 311 is along the second rotation axis J2. In addition, the second motor 31 is arranged at a position where the output shaft 311 deviates from the second rotation axis J2. Figure 3As shown, in this embodiment, the second motor 31 is positioned offset from the second rotation axis J2 in the positive direction of the X-axis when viewed from above in the Z-axis direction. While the second motor 31 is not particularly limited, in this embodiment, like the first motor 21 described above, it is a servo motor, specifically a three-phase motor driven by three-phase AC. Using a servo motor as the second motor 31 allows for easy and precise control of the third arm 123.

[0048] The second speed reducer 32, like the first speed reducer 22 described above, is a wave gear device. Using a wave gear device as the second speed reducer 32 reduces backlash in the second speed reducer 32. This allows for precise control of the third arm 123. However, the second speed reducer 32 is not particularly limited and may also be a planetary gear device, a roller cam speed reducer, or the like.

[0049] like Figure 5 As shown, the second speed reducer 32 mainly consists of a rigid gear 321, a flexible gear 322, and a wave generator 323. The rigid gear 321 is fixed to the second arm 122, the flexible gear 322 is fixed to the third arm 123, and the wave generator 323 is connected to the second motor 31 via the second power transmission mechanism 33. The wave generator 323 is cylindrical in shape. Therefore, a through hole H2 is formed in the second speed reducer 32 along the third rotation axis J3, connecting the second arm 122 and the third arm 123. A wiring L is inserted through the through hole H2.

[0050] like Figure 4 and Figure 5 As shown, the second power transmission mechanism 33 includes a first transmission mechanism 34 arranged in the first arm 121 and a second transmission mechanism 35 arranged in the second arm 122 .

[0051] The first transmission mechanism 34 includes a second motor-side pulley 341 attached to the output shaft 311 of the second motor 31; a first intermediate pulley 342 supported relative to the first arm 121 so as to be rotatable about the second rotation axis J2; and a second belt 343 looped around the second motor-side pulley 341 and the first intermediate pulley 342. Meanwhile, the second transmission mechanism 35 includes a second speed reducer-side pulley 351 attached to the wave generator 323 serving as the input shaft of the second speed reducer 32; a second intermediate pulley 352 supported relative to the second arm 122 so as to be rotatable about the second rotation axis J2; and a third belt 353 looped around the second speed reducer-side pulley 351 and the second intermediate pulley 352.

[0052] In addition, the second power transmission mechanism 33 has a shaft 36 that is inserted into the through hole H1 of the first reducer 22. The shaft 36 is coaxially arranged with the second rotation axis J2, with one end facing the inside of the first arm 121 and the other end facing the inside of the second arm 122. In addition, a first intermediate pulley 342 is fixed to one end of the shaft 36, and a second intermediate pulley 352 is fixed to the other end. That is, in the second power transmission mechanism 33, the first transmission mechanism 34 and the second transmission mechanism 35 are connected via the shaft 36. According to such a configuration, the first transmission mechanism 34 arranged in the first arm 121 and the second transmission mechanism 35 arranged in the second arm 122 can be connected with a simple configuration.

[0053] In this configuration, the rotation of the second motor 31 is transmitted to the first intermediate pulley 342 via the second motor-side pulley 341 and the second belt 343. The first intermediate pulley 342 and the second intermediate pulley 352 rotate integrally about the second rotation axis J2. Furthermore, the rotation of the second intermediate pulley 352 is transmitted to the wave generator 323 of the second speed reducer 32 via the third belt 353 and the second speed reducer-side pulley 351. The wave generator 323 rotates about the third rotation axis J3. Furthermore, the flexible gear 322 rotates at a predetermined speed reduction ratio relative to the rotation of the wave generator 323. As a result, the third arm 123 rotates about the third rotation axis J3 relative to the second arm 122.

[0054] In this second power transmission mechanism 33, the inclusion of the first transmission mechanism 34 increases the flexibility in the placement of the second motor 31. In particular, since the output shaft 311 of the second motor 31 can be offset from the second rotation axis J2, overlap between the through-hole H1 of the first speed reducer 22 and the second motor 31 can be effectively suppressed. This facilitates insertion of the shaft 36 or wiring L into the through-hole H1.

[0055] Moreover, in the second power transmission mechanism 33, by adjusting the diameters of the second motor-side pulley 341 and the first intermediate pulley 342, the first transmission mechanism 34 can also be used as a speed reducer. Similarly, by adjusting the diameters of the second speed reducer-side pulley 351 and the second intermediate pulley 352, the second transmission mechanism 35 can also be used as a speed reducer. In this way, it is also possible to use two speed reducers consisting of the first transmission mechanism 34 and the second transmission mechanism 35 and the second speed reducer 32 to set a larger reduction ratio. In addition, by setting the first transmission mechanism 34 and the second transmission mechanism 35 to use a structure using two pulleys and a belt, they can be formed of lightweight materials such as resin materials and rubber materials, thereby also achieving lightweighting of the second power transmission mechanism 33.

[0056] However, the second power transmission mechanism 33 is not particularly limited. For example, the first transmission mechanism 34 can be configured such that the second motor-side pulley 341 and the first intermediate pulley 342 are each replaced with gears, and the second belt 343 is replaced with a chain meshing with these two gears. Alternatively, the chain can be omitted, and the gears can be directly meshed with each other. Similarly, the second transmission mechanism 35 can be configured such that the second reducer-side pulley 351 and the second intermediate pulley 352 are each replaced with gears, and the third belt 353 is replaced with a chain meshing with these two gears. Alternatively, the chain can be omitted, and the gears can be directly meshed with each other. However, compared to such a configuration using gears and a chain, the configuration using pulleys and a belt as in this embodiment can reduce the backlash of the second power transmission mechanism 33, allowing for precise control of the third arm 123. Alternatively, the first transmission mechanism 34 can be omitted, and the second motor 31 can be directly connected to the shaft 36. In this case, the shaft 36 and the output shaft 311 can be integrally formed.

[0057] In addition, if Figure 3 As shown, in this embodiment, the shaft 36 is a hollow shaft, and a through hole 361 is formed inside the shaft to connect the first arm 121 and the second arm 122. The wiring L is routed from the first arm 121 to the second arm 122 via the through hole 361. With this structure, it is easy to route the wiring L from the first arm 121 to the second arm 122. Figure 5 As shown, the wiring L routed to the second arm 122 passes through the through hole H2 of the second speed reducer 32 and is routed to the third arm 123 in front of the second arm 122. This configuration facilitates routing the wiring L from the second arm 122 to the third arm 123.

[0058] As described above, in the vertical articulated robot 1, the first motor 21 of the second drive unit 132 and the second motor 31 of the third drive unit 133 are both located within the first arm 121, which is located at the base of the robot arm 12. By arranging the first and second motors 21 and 31, which act as heavy objects, within the first arm 121, the weight at the tip of the robot arm 12 can be reduced, and accordingly, the moment of inertia of the robot arm 12 can be reduced. Consequently, the robot arm 12 can be controlled with high precision.

[0059] In particular, in this embodiment, only the second transmission mechanism 35 (including components associated with the second transmission mechanism 35, such as the bearing member) and the wiring L (including components associated with the wiring L, such as the tying portion (TY-Rap) that binds the wiring L) are located within the second arm 122. In other words, no components other than the second transmission mechanism 35 and the wiring L are located within the second arm 122. Consequently, the second arm 122 is further lightweight, further reducing the moment of inertia of the robot arm 12. Furthermore, by reducing the number of components located within the second arm 122, the second arm 122 can be shortened, further reducing the moment of inertia of the robot arm 12. Furthermore, in this embodiment, the drive units 134, 135, and 136 for the fourth, fifth, and sixth arms 124, 125, and 126 can be located at the distal end of the second arm 122. This can reduce the weight of the distal end of the robot arm 12.

[0060] In addition, in this embodiment, Figure 3 and Figure 6 As shown, when viewed from a horizontal direction perpendicular to the second rotation axis J2, i.e., the X-axis, the first motor 21 and the second motor 31 overlap. In other words, the first motor 21 and the second motor 31 are arranged side by side in the horizontal direction. Furthermore, the phrase "the first motor 21 and the second motor 31 overlap when viewed from a horizontal direction perpendicular to the second rotation axis J2" means that at least a portion of the first motor 21 and the second motor 31 overlap when viewed from a horizontal direction perpendicular to the second rotation axis J2. This configuration allows the first motor 21 and the second motor 31 to be positioned as close as possible to the lower end of the first arm 121, further lowering the center of gravity of the robot arm 12. Consequently, the moment of inertia of the robot arm 12 can be further reduced. Furthermore, in this embodiment, the output shafts 211 and 311 of the first motor 21 and the second motor 31 are located below the second rotation axis J2. This further lowers the center of gravity of the robot arm 12, making the aforementioned effects more pronounced.

[0061] In addition, in this embodiment, Figure 3 and Figure 6 As shown, when viewed from above from a vertical direction, the second rotation axis J2 is located between the first motor 21 and the second motor 31. That is, the first motor 21 is located on one side of the second rotation axis J2 in the horizontal direction, and the second motor 31 is located on the other side. Alternatively, when viewed from above from a vertical direction, the first rotation axis J1 may be located between the first motor 21 and the second motor 31, that is, the first motor 21 is located on one side of the first rotation axis J1 in the horizontal direction, and the second motor 31 is located on the other side. This configuration effectively suppresses the deviation of the center of gravity of the first arm 121 from the first rotation axis J1. As a result, the first arm 121 can rotate about the first rotation axis J1 more smoothly and with greater precision.

[0062] In addition, in this embodiment, the first motor 21 and the second motor 31 are arranged inside the first arm 121. However, the present invention is not limited thereto, and at least one of the first motor 21 and the second motor 31 may be arranged outside the first arm 121. In other words, at least one of the first motor 21 and the second motor 31 may be exposed outside the vertical multi-jointed robot 1.

[0063] The vertical multi-joint robot 1 has been described above. As described above, the vertical multi-joint robot 1 includes: a base 11; a first arm 121 that rotates relative to the base 11 about a first rotation axis J1, which serves as a vertical axis; a second arm 122 connected to the first arm 121 and rotates relative to the first arm 121 about a second rotation axis J2, which serves as a first horizontal axis; a third arm 123 connected to the second arm 122 and rotates relative to the second arm 122 about a third rotation axis J3, which serves as a second horizontal axis; a first motor 21 that rotates the second arm 122 relative to the first arm 121 about the second rotation axis J2; and a second motor 31 that rotates the third arm 123 relative to the second arm 122 about the third rotation axis J3. The first motor 21 and the second motor 31 are each disposed on the first arm 121. Thus, by disposing the first and second motors 21, 31, which serve as heavy components, on the first arm 121, the weight of the tip of the robot arm 12 can be reduced, thereby reducing the moment of inertia of the robot arm 12. Therefore, the robot arm 12 can be controlled with high precision.

[0064] As previously described, the vertical articulated robot 1 includes a first speed reducer 22 connecting the first arm 121 and the second arm 122, and a first power transmission mechanism 23 connecting the first motor 21 and the first speed reducer 22 to transmit the power of the first motor 21 to the first speed reducer 22. This configuration increases the degree of freedom in the placement of the first motor 21.

[0065] In addition, as described above, the first power transmission mechanism 23 includes: a first motor-side pulley 231, which is arranged on the output shaft 211 of the first motor 21; a first reducer-side pulley 232, which is arranged on the wave generator 223, which serves as the input shaft of the first reducer 22; and a first belt 233, which is wound around the first motor-side pulley 231 and the first reducer-side pulley 232. According to this structure, the structure of the first power transmission mechanism 23 becomes simple. In addition, by adjusting the diameters of the first motor-side pulley 231 and the first reducer-side pulley 232, the first power transmission mechanism 23 can also be used as a reducer. Therefore, it is also possible to form a larger reduction ratio using the first power transmission mechanism 23 and the first reducer 22. Moreover, the tooth backlash of the first power transmission mechanism 23 can be reduced, and the second arm 122 can be controlled with good precision.

[0066] Furthermore, as previously described, the vertical articulated robot 1 includes a second speed reducer 32 connecting the second arm 122 and the third arm 123, and a second power transmission mechanism 33 connecting the second motor 31 and the second speed reducer 32 to transmit the power of the second motor 31 to the second speed reducer 32. This configuration increases the degree of freedom in the placement of the second motor 31.

[0067] As previously described, the second power transmission mechanism 33 includes a first transmission mechanism 34 disposed within the first arm 121 and a second transmission mechanism 35 disposed within the second arm 122. The first transmission mechanism 34 includes a second motor-side pulley 341 disposed on the output shaft 311 of the second motor 31; a first intermediate pulley 342 that rotates about the second rotation axis J2; and a second belt 343 that is wound around the second motor-side pulley 341 and the first intermediate pulley 342. The second transmission mechanism 35 includes a second intermediate pulley 352 that rotates along with the first intermediate pulley 342 about the second rotation axis J2; a second speed reducer-side pulley 351 disposed on the wave generator 323 serving as the input shaft of the second speed reducer 32; and a third belt 353 that is wound around the second intermediate pulley 352 and the second speed reducer-side pulley 351. This configuration simplifies the structure of the second power transmission mechanism 33. Furthermore, by adjusting the diameters of the second motor-side pulley 341 and the first intermediate pulley 342, the first transmission mechanism 34 can be used as a speed reducer, and by adjusting the diameters of the second speed reducer-side pulley 351 and the second intermediate pulley 352, the second transmission mechanism 35 can be used as a speed reducer. Consequently, a higher reduction ratio can be achieved using the first transmission mechanism 34, the second transmission mechanism 35, and the second speed reducer 32. Furthermore, the backlash of the second power transmission mechanism 33 can be reduced, enabling precise control of the third arm 123.

[0068] As previously described, the first speed reducer 22 is provided with a through-hole H1 extending along the second rotation axis J2, connecting the interior of the first arm 121 with the interior of the second arm 122. Furthermore, the first intermediate pulley 342 and the second intermediate pulley 352 are connected via the shaft 36 inserted through the through-hole H1. This configuration allows the first intermediate pulley 342 and the second intermediate pulley 352 to be connected with a simple structure, rotating integrally about the second rotation axis J2.

[0069] As described above, the shaft 36 is a hollow shaft, and the wiring L is routed to the first arm 121 and the second arm 122 through the inside of the shaft 36. With this configuration, routing of the wiring L becomes easy.

[0070] Furthermore, as previously described, the second arm 122 is connected to the first arm 121 from one side along the second rotation axis J2. In other words, the second arm 122 is cantilevered from the first arm 121. This configuration allows for a lighter second arm 122. Consequently, the overall weight of the robot arm 12 can be reduced, and the moment of inertia of the robot arm 12 can be correspondingly reduced.

[0071] Furthermore, as previously mentioned, the first motor 21 and the second motor 31 overlap when viewed from a horizontal direction perpendicular to the second rotation axis J2. This configuration allows both the first motor 21 and the second motor 31 to be positioned closer to the lower end of the first arm 121, further lowering the center of gravity of the robot arm 12. Consequently, the robot arm 12's moment of inertia can be further reduced.

[0072] Furthermore, as previously described, when viewed from a vertical direction, the second rotation axis J2 is located between the first motor 21 and the second motor 31. This configuration effectively suppresses deviation of the center of gravity of the first arm 121 relative to the first rotation axis J1. Consequently, the first arm 121 can rotate about the first rotation axis J1 more smoothly and accurately.

[0073] Second embodiment

[0074] Figure 7 It is a cross-sectional view showing a vertical articulated robot according to a second embodiment. Figure 8 is a side view showing the configuration of the first motor and the second motor.

[0075] This embodiment is identical to the first embodiment described above, except for the configuration of the first motor 21 and the second motor 31 within the first arm 121. In the following description, this embodiment will be described primarily with respect to the differences from the first embodiment, and descriptions of similarities will be omitted. In the figures of this embodiment, components identical to those in the previous embodiment are designated with the same reference numerals.

[0076] like Figure 7 and Figure 8 As shown, in the vertical multi-joint robot 1 of the present embodiment, when viewed from the vertical direction, that is, the Z-axis direction, the first motor 21 and the second motor 31 overlap with each other. In other words, the first motor 21 and the second motor 31 are arranged in the vertical direction. In addition, the aforementioned "the first motor 21 and the second motor 31 overlap with each other when viewed from the vertical direction" means that at least a part of the first motor 21 and the second motor 31 overlap with each other when viewed from the Z-axis direction. According to such a structure, the expansion of the first arm 121 in the horizontal direction can be suppressed, and the first arm 121 can be miniaturized. Therefore, the weight of the first arm 121 can be reduced, and the moment of inertia of the robot arm 12 can be further reduced.

[0077] Furthermore, in this embodiment, the first motor 21 is located above the second motor 31, but the present invention is not limited thereto. For example, the first motor 21 may be located below the second motor 31. Furthermore, in this embodiment, the first motor 21 is located above the second rotation axis J2, and the second motor 31 is located below the second rotation axis J2. However, the present invention is not limited thereto. For example, the first motor 21 may be located below the second rotation axis J2, and the second motor 31 may be located above the second rotation axis J2. Alternatively, both the first motor 21 and the second motor 31 may be located above the second rotation axis J2. Alternatively, both the first motor 21 and the second motor 31 may be located below the second rotation axis J2.

[0078] As described above, in the vertical multi-jointed robot 1 of this embodiment, the first motor 21 and the second motor 31 overlap when viewed from above. This configuration suppresses horizontal expansion of the first arm 121, allowing for a smaller size. Consequently, the weight of the first arm 121 can be reduced, further reducing the moment of inertia of the robot arm 12.

[0079] According to the second embodiment, the same effects as those of the first embodiment can be achieved.

[0080] Third embodiment

[0081] Figure 9 It is a cross-sectional view showing a vertical articulated robot according to a third embodiment.

[0082] This embodiment is similar to the first embodiment described above, except for the differences in the configuration of the second arm 122, the second drive unit 132, and the third drive unit 133. Furthermore, in the following description, this embodiment will be described primarily with respect to the differences from the first embodiment, and descriptions of similarities will be omitted. Furthermore, in the figures of this embodiment, configurations identical to those in the previous embodiment are designated with the same reference numerals.

[0083] like Figure 9 As shown, in the vertical multi-jointed robot 1 of this embodiment, the second arm 122 is connected to the first arm 121 from both sides along the second rotation axis J2. In other words, the second arm 122 is doubly supported by the first arm 121. This configuration improves the rigidity of the second arm 122 compared to the first embodiment described above, for example. Consequently, vibration of the second arm 122 can be effectively suppressed.

[0084] In addition, at the connection portion on one side along the second rotation axis J2, the first arm 121 and the second arm 122 are connected via the first speed reducer 22, similar to the first embodiment described above. Conversely, at the connection portion on the other side along the second rotation axis J2, the first arm 121 and the second arm 122 are connected via a bearing. Furthermore, in this portion, a connecting hole 5 is formed along the second rotation axis J2, connecting the interiors of the first arm 121 and the interiors of the second arm 122. The connecting hole 5 is formed by overlapping a first connecting hole 51 formed in the first arm 121 and a second connecting hole 52 formed in the second arm 122. Furthermore, the shaft 36 connecting the first intermediate pulley 342 and the second intermediate pulley 352 is inserted through the connecting hole 5. Furthermore, the wiring L is routed from the first arm 121 to the second arm 122 through the shaft 36.

[0085] In this embodiment, there is no need to insert the shaft 36 or the wiring L into the first reducer 22. Therefore, the wave generator 223 of the first reducer 22 has a solid structure. By making the wave generator 223 a solid structure, the rigidity of the first reducer 22 can be improved compared to the first embodiment described above. Therefore, the vibration of the second arm 122 can be effectively suppressed. Furthermore, compared to the first embodiment described above, the first reducer 22 can be made smaller and lighter, and accordingly, the robot arm 12 can be made smaller and lighter. Consequently, the moment of inertia of the robot arm 12 can be reduced.

[0086] As described above, in the vertical multi-jointed robot 1 of this embodiment, the second arm 122 is connected to the first arm 121 from both sides along the second rotation axis J2. This configuration improves the rigidity of the second arm 122. Furthermore, the shaft 36 connecting the first intermediate pulley 342 and the second intermediate pulley 352 can be arranged at a different connection point from the first speed reducer 22. This allows the wave generator 223 to be made solid, thereby improving the rigidity of the first speed reducer 22. Consequently, vibrations of the second arm 122 can be effectively suppressed.

[0087] According to the third embodiment, the same effects as those of the first embodiment can be achieved.

[0088] Fourth embodiment

[0089] Figure 10 It is a cross-sectional view showing a vertical articulated robot according to a fourth embodiment.

[0090] This embodiment is similar to the first embodiment described above, except that the third motor 41 of the first drive unit 131 is disposed within the first arm 121. Furthermore, in the following description, this embodiment will be described primarily with respect to the differences from the first embodiment, and descriptions of similarities will be omitted. Furthermore, in the figures of this embodiment, components identical to those of the previous embodiment are labeled with the same reference numerals.

[0091] like Figure 10 As shown, in the vertical articulated robot 1 of this embodiment, a third motor 41 is disposed within the first arm 121, which is provided in the first drive unit 131 and rotates the first arm 121 relative to the base 11 about the first rotation axis J1. Although not specifically described, in the first embodiment described above, the third motor 41 is disposed within the base 11. In contrast, by disposing the third motor 41 within the first arm 121 as in this embodiment, the base 11 can be miniaturized. Consequently, the installation area of ​​the vertical articulated robot 1 can be reduced.

[0092] In addition, the first drive unit 131 and the second drive unit 132 also have: a third motor 41, which is a motor with a built-in encoder; a third reducer 42, which connects the base 11 and the first arm 121; and a third power transmission mechanism 43, which connects the third motor 41 and the third reducer 42, and transmits the power of the third motor 41 to the third reducer 42.

[0093] Like the first motor 21, the third motor 41 is a servo motor, specifically a three-phase motor driven by three-phase AC. Furthermore, like the first reducer 22, the third reducer 42 is a wave gear device, primarily composed of a rigid gear 421, a flexible gear 422, and a wave generator 423. Furthermore, like the first power transmission mechanism 23, the third power transmission mechanism 43 comprises: a third motor-side pulley 431 mounted on the output shaft 411 of the third motor 41; a third reducer-side pulley 432 mounted on the wave generator 423, which serves as the input shaft of the third reducer 42; and a fourth belt 433 wound around these third motor-side pulleys 431 and 432.

[0094] The fourth embodiment described above can also produce the same effects as those of the first embodiment described above.

[0095] While the vertical multi-jointed robot of the present invention has been described above based on the illustrated embodiments, the present invention is not limited thereto, and the configuration of each component can be replaced with any configuration having the same function. Furthermore, other arbitrary configurations may be added to the present invention. Furthermore, the aforementioned embodiments may be appropriately combined.

Claims

1. A vertical multi-joint robot, characterized in that: have: abutment; a first arm, rotatable about a vertical axis relative to the base; a second arm connected to the first arm and rotatable relative to the first arm about a first horizontal axis; a third arm connected to the second arm and rotating relative to the second arm about a second horizontal axis; a first motor to rotate the second arm relative to the first arm about the first horizontal axis; as well as a second motor, causing the third arm to rotate relative to the second arm around the second horizontal axis; The first motor and the second motor are respectively configured on the first arm.

2. The vertical multi-joint robot according to claim 1, wherein: The vertical multi-joint robot has: a first speed reducer connecting the first arm and the second arm; The first power transmission mechanism connects the first motor and the first reducer to transmit the power of the first motor to the first reducer.

3. The vertical multi-joint robot according to claim 2, wherein: The first power transmission mechanism comprises: a first motor side pulley, configured on the output shaft of the first motor; A first speed reducer side pulley, arranged on the input shaft of the first speed reducer; as well as The first belt is wound around the first motor side pulley and the first reducer side pulley.

4. The vertical multi-joint robot according to claim 3, wherein: The vertical multi-joint robot has: a second speed reducer connecting the second arm and the third arm; and The second power transmission mechanism connects the second motor and the second reducer to transmit the power of the second motor to the second reducer.

5. The vertical multi-joint robot according to claim 4, wherein: The second power transmission mechanism includes a first transmission mechanism disposed in the first arm and a second transmission mechanism disposed in the second arm. The first transmission mechanism comprises: a second motor side pulley, configured on the output shaft of the second motor; a first intermediate pulley, rotating about the first horizontal axis; as well as The second belt is hung around the second motor side pulley and the first intermediate pulley, The second transmission mechanism comprises: a second intermediate pulley, rotating together with the first intermediate pulley about the first horizontal axis; A second speed reducer side pulley, configured on the input shaft of the second speed reducer; as well as The third belt is wound around the second intermediate pulley and the second speed reducer side pulley.

6. The vertical multi-joint robot according to claim 5, wherein: The first reducer is provided with a through hole along the first horizontal axis and connecting the first arm and the second arm. The first intermediate pulley and the second intermediate pulley are connected via a shaft inserted through the through hole.

7. The vertical multi-joint robot according to claim 6, wherein: The shaft is a hollow shaft, Wiring is routed through the shaft to the first arm and the second arm.

8. The vertical multi-joint robot according to claim 1, wherein: The second arm is coupled to the first arm from one side in a direction along the first horizontal axis.

9. The vertical multi-joint robot according to claim 1, wherein: The second arm is coupled to the first arm from both sides in a direction along the first horizontal axis.

10. The vertical multi-joint robot according to claim 1, wherein: The first motor and the second motor overlap with each other when viewed from above in a horizontal direction orthogonal to the first horizontal axis.

11. The vertical multi-joint robot according to claim 10, wherein: When viewed from a vertical direction, the first horizontal axis is located between the first motor and the second motor.

12. The vertical multi-joint robot according to claim 1, wherein: When viewed from a vertical direction, the first motor and the second motor overlap with each other.

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