JP2024123745A - Power transmission mechanism, joint mechanism and multi-joint robot - Google Patents

Abstract

To inhibit increase in the size of an applied device in a power transmission mechanism using wires.SOLUTION: A power transmission mechanism includes: a plurality of driving sources disposed at a base part; wires each fixed at one end to the driving sources; a first shaft serving as a rotary shaft of a first joint disposed at the drive source side; a second shaft serving as a rotary shaft of a second joint connected to the first joint and disposed at a position which is perpendicular to the first shaft and is a skew position relative to the first shaft; a plurality of first shaft pulleys each disposed on the first shaft so that its diameter reduces to one axial side of the first shaft; and a plurality of second shaft pulleys each disposed on the second shaft so that its diameter reduces to one axial side of the second shaft. A tangent line of each of the first shaft pulleys matches with a tangent line of each of the second shaft pulleys. Each of the wires is wound around the second shaft pulley so as to extend from the first shaft pulley along the tangent line.SELECTED DRAWING: Figure 2

Description

This disclosure relates to a power transmission mechanism, a joint mechanism, and a multi-joint robot.

Power transmission mechanisms using wires have been known for some time (see, for example, Patent Document 1).

Wire-driven articulated robots are also known from the past (for example, Patent Document 2 and Non-Patent Document 1).

JP 2000-108072 A U.S. Pat. No. 4,903,536

Endo, G, Horigome, A., & Takata, A. (2019). Super dragon: A 10-m-long-coupled tendon-driven articulated manipulator. IEEE Robotics and Automation Letters, 4(2), 934-941.

However, in a mechanism that transmits power using a wire, multiple pulleys are placed at different positions for each wire. When multiple pulleys are placed at different positions in this way, devices that use a wire-based power transmission mechanism tend to become larger.

The purpose of this disclosure is to prevent the size of the device being increased when using a power transmission mechanism that uses wires.

One aspect of the present disclosure is a power transmission mechanism having a plurality of drive sources arranged on a base portion, a wire having one end fixed to each of the plurality of drive sources, a first axis which is a rotation axis of a first joint arranged on the drive source side, a second axis which is a rotation axis of a second joint connected to the first joint and arranged at a right angle to the first axis and in a twisted position, a plurality of first shaft pulleys arranged on the first shaft so that their diameters decrease toward one axial side of the first shaft, and a plurality of second shaft pulleys arranged on the second shaft so that their diameters decrease toward one axial side of the second shaft, the tangents of the plurality of first shaft pulleys coincide with the tangents of the plurality of second shaft pulleys, and each of the plurality of wires is hung from the first shaft pulley to the second shaft pulley along the tangent.

Another aspect of the present disclosure is a method for manufacturing a rotary actuator having a rotary shaft that includes a plurality of drive sources disposed on a base portion, a wire having one end fixed to each of the plurality of drive sources, a first axis that is a rotation axis of a first joint disposed on the drive source side, a second axis that is a rotation axis of a second joint connected to the first joint and disposed at a right angle to the first axis and in a twisted position, a plurality of first axis pulleys disposed on the first axis in the axial direction of the first axis, and a plurality of second axis pulleys disposed on the second axis in the axial direction of the second axis, the plurality of first axis pulleys being disposed such that their diameters decrease from both axial ends of the first axis toward the axial center, the plurality of second axis pulleys being disposed such that their diameters decrease from both axial ends of the second axis toward the axial center, and the plurality of first axes A tangent to the pulley coincides with a tangent to the second shaft pulleys, each of the wires is hung on the second shaft pulley along the tangent from the first shaft pulley, the wires hung on the first shaft pulleys located in a paired position from the axial center of the first shaft form a pair, the pair of wires are hung in opposite directions on the first shaft pulleys located in the paired positions, the other end of the wire hung on the first shaft pulley located on the outermost axial side of the first shaft is fixed to a first fixed member to which the first shaft is fixed, and the other end of the pair of wires hung on the first shaft pulley located on the other outermost axial side of the first shaft is fixed to a first fixed member to which the first shaft is fixed, in this joint mechanism.

Yet another aspect of the present disclosure is a multi-joint robot having a base portion, a plurality of driving sources arranged on the base portion, wires having one end fixed to each of the plurality of driving sources, and a plurality of joints through which the plurality of wires pass, the multi-joint robot having, as the plurality of joints, a first axis which is a rotation axis of a first joint arranged on the driving source side, a second axis which is a rotation axis of a second joint connected to the first joint and arranged at a right angle to the first axis and in a twisted position, a plurality of first shaft pulleys arranged on the first shaft in the axial direction of the first shaft, and a plurality of second shaft pulleys arranged on the second shaft in the axial direction of the second shaft, the plurality of first shaft pulleys being arranged so that their diameters become smaller from both axial ends of the first shaft toward the axial center, and the plurality of second shaft pulleys being arranged from both axial ends of the second shaft, The multiple-joint robot is arranged so that the diameter decreases from the center to the center in the axial direction, the tangents of the multiple first shaft pulleys coincide with the tangents of the multiple second shaft pulleys, each of the multiple wires is hung on the second shaft pulley along the tangent from the first shaft pulley, the wires hung on the first shaft pulleys located in pairs from the axial center of the first shaft form a pair, the pair of wires are hung on the first shaft pulleys located in pairs in opposite directions, the other end of the wire hung on the first shaft pulley located on the outermost axial side of the first shaft is fixed to a first fixed member to which the first shaft is fixed, and the other end of the pair of wires hung on the first shaft pulley located on the other outermost axial side of the first shaft is fixed to a first fixed member to which the first shaft is fixed.

According to the present disclosure, it is possible to prevent the size of the device to which the power transmission mechanism using the wire is applied from increasing.

FIG. 2 is a side view of the articulated robot. FIG. 2 is a block diagram showing the relationship between each shaft pulley and each wire. FIG. 2 is an enlarged view of a main part of the robot shown in FIG. 1 . 4 is a diagram showing the relationship between a tangent to a first shaft pulley and a tangent to a second shaft pulley; FIG. FIG. 2 is a perspective view showing a configuration around a first joint. FIG. 4 is a front view seen from the direction of arrow 6A in FIG. 3. This is a cross-sectional view taken along line 6B-6B in FIG. 6A.

Below, an example of an embodiment of the present disclosure will be described with reference to the drawings. Note that the same reference symbols are used for identical or equivalent components and parts in each drawing. Also, the dimensions and proportions in the drawings have been exaggerated for the convenience of explanation and may differ from the actual proportions.

(Articulated robot)
As shown in Fig. 1, the articulated robot 20 according to this embodiment is, for example, a robot having six degrees of freedom. The articulated robot 20 has a base unit 22, a plurality of driving sources 30, a plurality of wires 40, and a plurality of joints 60, 61, 70, 71, 90, and 91. Note that, for example, the articulated robot 20 according to this embodiment has seven driving sources 30 and fourteen wires 40. The driving portion of the articulated robot 20 is referred to as an arm unit 26. The arm unit 26 includes a plurality of joints 60, 61, 70, 71, 90, and 91.

The base portion 22 is a portion that is installed on an installation target (e.g., an installation stand). This base portion 22 has a pair of base plates 24 arranged opposite each other. In this embodiment, the pair of base plates 24 are plate materials that are long in one direction. An arm portion 26 is attached to one end of the pair of base plates 24 in the longitudinal direction. Each of the pair of base plates 24 may be formed from a resin material from the viewpoint of weight reduction, or may be formed from another material.

As shown in FIG. 1, the base portion 22 is installed on the installation target with one base plate 24 on top and the other base plate 24 on the bottom. Here, the upper base plate 24 is referred to as base plate 24A, and the lower base plate 24 is referred to as base plate 24B.

As shown in FIG. 1, the multiple driving sources 30 are attached to the base plate 24A. Specifically, seven driving sources 30 are attached to the base plate 24A at intervals in the longitudinal direction. The seven driving sources 30 are referred to as driving sources 30A, 30B, 30C, 30D, 30E, 30F, and 30G in the order of furthest from one end of the longitudinal direction of the base plate 24A.

In this embodiment, an electric motor is used as the driving source 30 as an example. A rotating shaft 32 is connected to the motor shaft of the driving source 30. The motor shaft of the driving source 30 and the rotating shaft 32 may be connected via a gear box or directly. The rotating shaft 32 passes through the base plate 24B and is rotatably supported by a bearing 34 attached to the base plate 24B. The amount of rotation of the driving source 30 may be controlled by providing an encoder.

The first motor shaft pulley 35 and the second motor shaft pulley 36 for winding the wire 40 are attached to the rotating shaft 32 with a gap in the axial direction. The first motor shaft pulley 35 is located above the second motor shaft pulley 36. The first motor shaft pulley 35 and the second motor shaft pulley 36 rotate together with the rotating shaft 32. When the rotating shaft 32 rotates in one direction, the wire 40 is wound around the first motor shaft pulley 35. At this time, the wire 40 is sent out from the second motor shaft pulley 36. That is, the first motor shaft pulley 35 and the second motor shaft pulley 36 are configured so that the winding and sending out of the wire 40 are reversed with respect to the rotation of the rotating shaft 32. For example, the wire 40 wound around the first motor shaft pulley 35 and the wire 40 wound around the second motor shaft pulley 36 are wound in opposite directions.

In FIG. 1, the rotating shafts corresponding to each drive source 30 are indicated by reference numerals 32A, 32B, 32C, 32D, 32E, 32F, and 32G, and the bearings corresponding to each drive source 30 are indicated by reference numerals 34A, 34B, 34C, 34D, 34E, 34F, and 34G. The first motor shaft pulleys corresponding to each rotating shaft 32 are indicated by reference numerals 35A, 35B, 35C, 35D, 35E, 35F, and 35G, and the second motor shaft pulleys corresponding to each rotating shaft 32 are indicated by reference numerals 36A, 36B, 36C, 36D, 36E, 36F, and 36G (see FIG. 2).

The multiple wires 40 are connected to the multiple driving sources 30, respectively. Specifically, one end of each of the multiple wires 40 is fixed to the multiple driving sources 30 via a motor shaft pulley.

As shown in FIG. 2, the multiple wires 40 include a wire 40A1 connected to the first motor shaft pulley 35A, a wire 40B1 connected to the first motor shaft pulley 35B, a wire 40C1 connected to the first motor shaft pulley 35C, a wire 40D1 connected to the first motor shaft pulley 35D, a wire 40E1 connected to the first motor shaft pulley 35E, a wire 40F1 connected to the first motor shaft pulley 35F, and a wire 40G1 connected to the first motor shaft pulley 35G.
In addition, the multiple wires 40 include a wire 40A2 connected to the second motor shaft pulley 36A, a wire 40B2 connected to the second motor shaft pulley 36B, a wire 40C2 connected to the second motor shaft pulley 36C, a wire 40D2 connected to the second motor shaft pulley 36D, a wire 40E2 connected to the second motor shaft pulley 36E, a wire 40F2 connected to the second motor shaft pulley 36F, and a wire 40G2 connected to the second motor shaft pulley 36G.

Wires 40A1 and 40A2 are a pair of wires, and when drive source 30A rotates in one direction, wire 40A1 is wound around first motor shaft pulley 35A and wire 40A2 is sent out from second motor shaft pulley 36B. The pair of wires 40A1 and 40A2 are looped around the paired first motor shaft pulley 35A in opposite directions. Wires 40B1 and 40B2, wires 40C1 and 40C2, wires 40D1 and 40D2, wires 40E1 and 40E2, wires 40F1 and 40F2, and wires 40G1 and 40G2 are each paired.

As shown in FIG. 1, joint 60 and joint 61 are joints located on the root side of arm unit 26. Joint 60 and joint 61 are adjacent joints in the longitudinal direction of arm unit 26. In this embodiment, joint 60 is located closer to the root side of arm unit 26 than joint 61. The root side of arm unit 26 may also be referred to as the drive source 30 side.

1 and 2, the joint 60 has a first shaft 62 and a plurality of first shaft pulleys 66. Note that the first shaft 62 is an example of a first shaft in this disclosure, and the first shaft pulleys 66 are an example of a first shaft pulley in this disclosure.

The first shaft 62 is rotatably supported at both ends by a pair of base plates 24. In this embodiment, the axial direction of the first shaft 62 is parallel to the axial direction of each of the rotation shafts 32. The first shaft 62 is fixed to a first fixing member 100. The first fixing member 100 has plate portions facing each other in the vertical direction, and the first shaft 62 passes through these plate portions. In this embodiment, the first fixing member 100 may be formed from a resin material from the viewpoint of weight reduction, or may be formed from other materials.

As shown in FIG. 4, the multiple first shaft pulleys 66 are arranged on the first shaft 62 so that their diameters become smaller toward the axial inner side (axial center side) of the first shaft 62. In other words, multiple first shaft pulleys 66 are arranged on the first shaft 62, and the pulleys arranged closer to the axial center side of the first shaft 62 have smaller diameters. Here, in this embodiment, the multiple first shaft pulleys 66 are arranged so that their diameters become smaller from both axial ends of the first shaft 62 toward the axial center side. Specifically, seven first shaft pulleys 66 are arranged so that their diameters become smaller from one axial end side of the first shaft 62 (upper side in FIG. 1) toward the axial center side, and seven first shaft pulleys 66 are arranged so that their diameters become smaller from the other axial end side of the first shaft 62 (lower side in FIG. 1) toward the axial center side (see FIG. 2). In this embodiment, the first shaft pulleys 66 above the axial center of the first shaft 62 are referred to as first shaft pulleys 66A1, 66B1, 66C1, 66D1, 66E1, 66F1, and 66G1 in order from the axial outside. Also, the first shaft pulleys 66 below the axial center of the first shaft 62 are referred to as first shaft pulleys 66A2, 66B2, 66C2, 66D2, 66E2, 66F2, and 66G2 in order from the axial outside. The first shaft pulleys 66A1 and 66A2 are a pair and have the same diameter. The first shaft pulleys 66B1 and 66B2, the first shaft pulleys 66C1 and 66C2, the first shaft pulleys 66D1 and 66D2, the first shaft pulleys 66E1 and 66E2, the first shaft pulleys 66F1 and 66F2, and the first shaft pulleys 66G1 and 66G2 are each paired and have the same diameter. The first shaft pulleys 66A1 and 66A2, which are located at the axially outermost positions of the first shaft 62, are fixed to the first shaft 62 and rotate together with the first shaft 62 and the first fixed member 100. On the other hand, the first shaft pulleys 66B1, 66C1, 66D1, 66E1, 66F1, 66G1, 66B2, 66C2, 66D2, 66E2, 66F2, and 66G2 are each capable of rotating independently of the first shaft 62.

As shown in FIG. 2, wires 40A1, 40B1, 40C1, 40D1, 40E1, 40F1, and 40G1 are hung on the first shaft pulleys 66A1, 66B1, 66C1, 66D1, 66E1, 66F1, and 66G1, respectively. The other end of wire 40A1 is fixed to one plate portion of the first fixing member 100.

Furthermore, wires 40A2, 40B2, 40C2, 40D2, 40E2, 40F2, and 40G2 are hung on the first shaft pulleys 66A2, 66B2, 66C2, 66D2, 66E2, 66F2, and 66G2, respectively. The other end of wire 40A2 is fixed to the other plate portion of the first fixing member 100. Here, when wire 40A1 is wound, the first fixing member 100 rotates in one direction around the first shaft 62. At this time, wire 40A2 is let out. On the other hand, when wire 40A2 is wound, the first fixing member 100 rotates in the opposite direction to the one direction around the first shaft 62. At this time, wire 40A1 is let out.

In addition, when the articulated robot 20 is viewed from the side, the wires 40A1, B1, 40C1, 40D1, 40E1, 40F1, 40G1 extend from the first motor shaft pulleys 35A, 35B, 35C, 35D, 35E, 35F, 35G toward the first shaft pulleys 66A1, 66B1, 66C1, 66D1, 66E1, 66F1, 66G1 in a direction approximately perpendicular to the first shaft 62 (see Figure 3). In other words, when viewed from the side of the articulated robot 20, the positions of the first motor shaft pulleys 35A, 35B, 35C, 35D, 35E, 35F, 35G and the first shaft pulleys 66A1, 66B1, 66C1, 66D1, 66E1, 66F1, 66G1 are each adjusted so that the wires 40A1, B1, 40C1, 40D1, 40E1, 40F1, 40G1 each extend in a direction approximately perpendicular to the first axis 62.
Similarly, when the articulated robot 20 is viewed from the side, the wires 40A2, 40B2, 40C2, 40D2, 40E2, 40F2, 40G2 each extend from the second motor shaft pulleys 36A, 36B, 36C, 36D, 36E, 36F, 36G toward the first shaft pulleys 66A2, 66B2, 66C2, 66D2, 66E2, 66F2, 66G2 in a direction approximately perpendicular to the first shaft 62. In other words, when viewed from the side of the articulated robot 20, the positions of the second motor shaft pulleys 36A, 36B, 36C, 36D, 36E, 36F and the first shaft pulleys 66A2, 66B2, 66C2, 66D2, 66E2, 66F2, 66G2 are each adjusted so that the wires 40A2, 40B2, 40C2, 40D2, 40E2, 40F2, 40G2 each extend in a direction approximately perpendicular to the first shaft 62.

As shown in FIG. 1 and FIG. 2, the joint 61 has a second shaft 64 and a plurality of second shaft pulleys 68. Note that the second shaft 64 is an example of a second shaft in this disclosure, and the second shaft pulleys 68 are an example of a second shaft pulley in this disclosure.

The second shaft 64 is disposed at a right angle to the first shaft 62 and in a twisted position. Specifically, the first shaft 62 and the second shaft 64 are disposed so as to be perpendicular to each other when viewed from the longitudinal direction of the base plate. Both ends of this second shaft 64 are rotatably supported by the first fixing member 100. The second shaft 64 is also fixed to the second fixing member 110. The second fixing member 110 has plate portions facing each other in the vertical direction, and the second shaft 64 passes through these plate portions. Note that the second fixing member 110 of this embodiment may be formed of a resin material from the viewpoint of weight reduction, or may be formed of another material.

The second shaft pulleys 68 are arranged on the second shaft 64 so that their diameters become smaller toward the axial inner side (axial center side) of the second shaft 64. In other words, the second shaft pulleys 68 are arranged on the second shaft 64, and the pulleys arranged closer to the axial center side of the second shaft 64 have smaller diameters. Here, in this embodiment, the second shaft pulleys 68 are arranged so that their diameters become smaller from both axial ends of the second shaft 64 toward the axial center side. Specifically, six second shaft pulleys 68 are arranged so that their diameters become smaller from one axial end side of the second shaft 64 toward the axial center side, and six second shaft pulleys 68 are arranged so that their diameters become smaller from the other axial end side of the second shaft 64 toward the axial center side. In this embodiment, the second shaft pulleys 68 above the axial center of the second shaft 64 are referred to as second shaft pulleys 68B1, 68C1, 68D1, 68E1, 68F1, and 68G1 in order from the axial outside. The second shaft pulleys 68 below the axial center of the second shaft 64 are called second shaft pulleys 68B2, 68C2, 68D2, 68E2, 68F2, and 68G2 in order from the axially outer side. The second shaft pulleys 68B1 and 68B2 are paired and have the same diameter. The second shaft pulleys 68C1 and 68C2, the second shaft pulleys 68D1 and 68D2, the second shaft pulleys 68E1 and 68E2, the second shaft pulleys 68F1 and 68F2, and the second shaft pulleys 68G1 and 68G2 are paired and have the same diameter. The second shaft pulleys 68B1 and 68B2 located at the axially outermost positions of the second shaft 64 are fixed to the second shaft 64 and rotate together with the second shaft 64 and the second fixed member 110. On the other hand, the second shaft pulleys 68B1, 68C1, 68D1, 68E1, 68F1, 68G1, 68B2, 68C2, 68D2, 68E2, 68F2, and 68G2 are each capable of rotating independently with respect to the second shaft 64.

As shown in FIG. 2, wires 40C1, 40D1, 40E1, 40F1, and 40G1 are respectively hung on second shaft pulleys 68B1, 68C1, 68D1, 68E1, 68F1, and 68G1.

Wires 40C2, 40D2, 40E2, 40F2, and 40G2 are hung on the second shaft pulleys 68B2, 68C2, 68D2, 68E2, 68F2, and 68G2, respectively.
The pair of wires 40 are wound around the second shaft pulleys 68 in the paired positions in the opposite directions. Here, the pair of wires 40 refers to wires that obtain power from the same drive source.

Also, as shown in Figure 4, when the main parts of the articulated robot 20 are viewed from above, the tangents of the multiple first shaft pulleys 66 coincide with the tangents of the multiple second shaft pulleys 68. Specifically, the tangent 66TLB1 of the first shaft pulley 66B1 coincides with the tangent 68TLB1 of the second shaft pulley 68B1. In other words, the positions of the first shaft pulley 66B1 and the second shaft pulley 68B1 are adjusted so that the tangents 66TLB1 and 68TLB1 coincide with each other. Similarly, the tangents (not shown) of the first shaft pulleys 66C1, 66D1, 66E1, 66F1, 66G1, 66B2, 66C2, 66D2, 66E2, 66F2, and 66G2 coincide with the tangents (not shown) of the second shaft pulleys 68C1, 68D1, 68E1, 68F1, 68G1, 68B2, 68C2, 68D2, 68E2, 68F2, and 68G2, respectively.

Here, the multiple wires 40 are hung from the multiple first shaft pulleys 66 to the second shaft pulley 68 along tangents. Specifically, the wire 40B1 is hung from the first shaft pulley 66B1 to the second shaft pulley 68B1 along tangent 68TLB1. Similarly, wires 40C1, 40D1, 40E1, 40F1, 40G1, 40B2, 40C2, 40D2, 40E2, 40F2, and 40G2 are hung from first shaft pulleys 66C1, 66D1, 66E1, 66F1, 66G1, 66B2, 66C2, 66D2, 66E2, 66F2, and 66G2 along tangents (not shown) to second shaft pulleys 68C1, 68D1, 68E1, 68F1, 68G1, 68B2, 68C2, 68D2, 68E2, 68F2, and 68G2, respectively.

As shown in FIG. 5, a first suppression portion 104 is disposed radially outward of the multiple first shaft pulleys 66. This first suppression portion 104 has the function of suppressing the wire 40 hung on the first shaft pulley 66 from coming off by contacting the wire 40. Specifically, the first suppression portion 104 is formed integrally with the first fixing member 100. In addition, the first suppression portion 104 is formed in a stepped shape so as to keep the distance (radial distance) between the first shaft pulleys 66 constant.

As shown in FIG. 6A, a first guide portion 108 is disposed between each driving source 30 and each first shaft pulley 66. These first guide portions 108 are portions for guiding the sending out and winding of each wire 40. Specifically, the first guide portions 108 are through holes formed in the first suppressing portion 104 (see FIG. 6B). Each wire passes through a corresponding through hole and is hung on each first shaft pulley 66. That is, the movement of each wire related to sending out and winding between each driving source 30 and each first shaft pulley 66 is guided by the through hole that is the first guide portion 108.

As shown in FIG. 5, a second suppression portion 114 is disposed radially outward of the multiple second shaft pulleys 68. This second suppression portion 114 has the function of suppressing the wire 40 hung on the second shaft pulley 68 from coming off by contacting the wire 40. Specifically, the second suppression portion 114 is formed integrally with the second fixing member 110. In addition, the second suppression portion 114 is formed in a stepped shape so as to keep the distance (radial distance) between the multiple second shaft pulleys 68 constant.

As shown in FIG. 6A, second guide portions 118 are disposed between each drive source 30 and each second shaft pulley 68. These second guide portions 118 are portions for guiding the sending out and winding of each wire 40. Specifically, the second guide portions 118 are through holes formed in the second suppressing portion 114 (see FIG. 6B). Each wire 40 passes through a corresponding through hole and is hung on each second shaft pulley 68. That is, the movement of each wire related to sending out and winding between each first shaft pulley 66 and each second shaft pulley 68 is guided by the through hole that is the second guide portion 118.

Joint 70 and joint 71 are joints located in the center of arm section 26. Joint 70 and joint 71 are adjacent joints in the longitudinal direction of arm section 26. In this embodiment, joint 70 is located closer to the base of arm section 26 than joint 71. In other words, joint 70 is located closer to joint 61 in arm section 26.

As shown in FIG. 1 and FIG. 2, the joint 70 has a third shaft 72 and a plurality of third shaft pulleys 78. The joint 70 also has a third fixed member 120 to which the third shaft 72 is fixed. Note that the third shaft 72 is an example of a first shaft in this disclosure, and the third shaft pulley 78 is an example of a first shaft pulley in this disclosure. Also, the third fixed member 120 may be formed of a resin material from the viewpoint of weight reduction, or may be formed of another material.

The joint 71 has a fourth shaft 74 and a plurality of fourth shaft pulleys 80. The joint 71 also has a fourth fixing member 130 to which the fourth shaft 74 is fixed. The fourth shaft 74 is an example of a second shaft in this disclosure, and the fourth shaft pulley 80 is an example of a second shaft pulley in this disclosure. The fourth fixing member 130 may be formed of a resin material from the viewpoint of weight reduction, or may be formed of another material.

The third axis 72 is arranged parallel to the second axis 64. The fourth axis 74 is arranged perpendicular to the third axis 72 and in a twisted position.

Furthermore, the fourth fixed member 130 is provided with a guide shaft 76. This guide shaft 76 is rotatably supported by the fourth fixed member 130. The guide shaft 76 is disposed at a right angle to the fourth shaft 74 and in a twisted position. A plurality of guide shaft pulleys 82 are disposed on the guide shaft 76.

In this embodiment, five third shaft pulleys 78 are provided on each third shaft 72. The third shaft pulley 78 with the largest diameter is fixed to the third shaft 72, and the other third shaft pulleys 78 are rotatably supported on the third shaft 72.

In this embodiment, four fourth shaft pulleys 80 are provided on each fourth shaft 74. The fourth shaft pulley 80 with the largest diameter is fixed to the fourth shaft 74, and the other fourth shaft pulleys 80 are rotatably supported on the fourth shaft 74.

In this embodiment, three guide shaft pulleys 82 are provided on each guide shaft 76. All guide shaft pulleys 82 are rotatably supported on the guide shaft 76.

Note that the rest of the configuration of joints 70 and 71 is similar to that of joints 60 and 61, respectively, so details are omitted.

Joint 90 and joint 91 are joints located at the tip side of arm section 26. Joint 90 and joint 91 are adjacent joints in the longitudinal direction of arm section 26. In this embodiment, joint 90 is located closer to the base of arm section 26 than joint 91. In other words, joint 90 is located closer to joint 71 in arm section 26.

1 and 2, the joint 90 has a fifth shaft 92, a plurality of fifth shaft pulleys 96, and a sixth shaft 94. The joint 90 also has a fifth fixing member 140 to which the fifth shaft 92 is fixed. The fifth shaft 92 is an example of a first shaft in this disclosure, and the fifth shaft pulley 96 is an example of a first shaft pulley in this disclosure. The fifth fixing member 140 may be formed of a resin material from the viewpoint of weight reduction, or may be formed of another material.

The joint 91 has a sixth shaft 94 and a plurality of sixth shaft pulleys 98. The joint 91 also has a sixth fixing member 150 to which the sixth shaft 94 is fixed. Note that the sixth shaft 94 is an example of a second shaft in this disclosure, and the sixth shaft pulley 98 is an example of a second shaft pulley in this disclosure. Also, the sixth fixing member 150 may be formed from a resin material from the viewpoint of weight reduction, or may be formed from another material.

The fifth shaft 92 is arranged parallel to the guide shaft 76. The sixth shaft 94 is arranged at a right angle to the fifth shaft 92 and in a twisted position.

In this embodiment, three fifth shaft pulleys 96 are provided on each fifth shaft 92. The fifth shaft pulley 96 with the largest diameter is fixed to the fifth shaft 92, and the other fifth shaft pulleys 96 are rotatably supported on the fifth shaft 92.

In this embodiment, two sixth shaft pulleys 98 are provided on each sixth shaft 94. The sixth shaft pulley 98 with the largest diameter is fixed to the sixth shaft 94, and the other sixth shaft pulleys 98 are rotatably supported on the sixth shaft 94.

Note that the rest of the configuration of joints 90 and 91 is similar to that of joints 70 and 71, respectively, and so details are omitted.

A hand unit 200 is provided at the tip of the arm unit 26. The other ends of the wires 40G1 and 40G2 are fixed to a drive unit that drives the hand unit 200. As an example, when the wire 40G1 is wound up and the wire 40G2 is sent out, the hand unit 200 closes, and when the wire 40G2 is wound up and the wire 40G1 is sent out, the hand unit 200 opens.

The hand unit 200 may also be provided with an imaging device (so-called camera) for grasping an object by the hand unit 200. Then, the operation (output) of each drive source 30 may be controlled based on information from the imaging device.

In addition, in this embodiment, each wire 40 is wound around the corresponding shaft pulley at least one turn. As an example, wire 40A1 is wound around the first shaft pulley 66A1 at least one turn. The same applies to the other wires 40.

In this embodiment, the multiple wires 40 drive the pulleys located toward the center of the axial direction of the first shaft 62, and the parts closer to the tip of the robot. Specifically, the hand unit 200 is driven by the wires 40G1 and 40G2 that are hung on the first shaft pulleys 66G1 and 66G2 with the smallest diameter.

The power transmission mechanism and joint mechanism according to the present disclosure include a plurality of drive sources 30, a plurality of wires 40, a first shaft 62, a third shaft 72, and a fifth shaft 92, a second shaft 64, a fourth shaft 74, and a sixth shaft 94, a first shaft pulley 66, a third shaft pulley 78, and a fifth shaft pulley 96, and a second shaft pulley 68, a fourth shaft pulley 80, and a sixth shaft pulley 98.

Next, the operation of this embodiment will be described.
In this embodiment, the joint 60 has a first shaft 62 and a plurality of first shaft pulleys 66, and the joint 61 has a second shaft 64 arranged at a right angle to the first shaft 62 and in a twisted position, and a plurality of second shaft pulleys 68. Here, for example, when the driving source 30A is driven to wind the wire 40A1 and feed the wire 40A2, the first fixing member 100 rotates in one direction around the first shaft 62. When the driving source 30A is rotated in the reverse direction to wind the wire 40A2 and feed the wire 40A1, the first fixing member 100 rotates in the opposite direction to the one direction around the first shaft 62. When the wire 40B1 is wound and the wire 40B2 is fed, the second fixing member 110 rotates in one direction around the second shaft 64. When the wire 40B2 is wound and the wire 40B1 is fed, the second fixing member 110 rotates in the opposite direction to the one direction around the second shaft 64. At this time, the wires 40B1, 40B2 are supported by the second shaft pulleys 68B1, 68B2. As described above, in this embodiment, the joints 60 and 61 driven by the wire 40 can be operated in a plurality of different directions. Similarly, the joints 70 and 71 and the joints 90 and 91 can be operated in a plurality of different directions.

In addition, in this embodiment, the arm portion 26 can be rotated around one axis using one driving source 30, which makes it possible to reduce weight compared to a configuration in which multiple driving sources are used to rotate the arm portion 26 around one axis.

In addition, in this embodiment, all drive sources 30 are attached to the base portion 22, making the arm portion 26 lighter than in a configuration in which drive sources are provided around each axis.

In this embodiment, the size of the shaft pulleys is reduced from both axial ends of each shaft toward the axial center. This configuration allows the number of wires passing through each joint to be increased with a simple structure.

In addition, in this embodiment, since multiple shaft pulleys are arranged on one shaft, the size of the device that applies the power transmission mechanism using wires can be suppressed compared to a configuration in which, for example, shaft pulleys are arranged in different locations for each wire. In other words, the size of the articulated robot 20 that applies the power transmission mechanism of the present disclosure is suppressed.

In addition, in this embodiment, the wires that are hung on the axially outermost shaft pulleys of each shaft are fixed to each fixed member, so that each fixed member can be rotated around each shaft. In this embodiment, the arm portion 26 can be driven with such a simple configuration.

In addition, in this embodiment, the wires hanging on the shaft pulleys closer to the center of each shaft are the ones that drive the tip of the robot. In other words, the closer to the tip of the articulated robot 20, the lighter it is and the smaller the moment acting on it is, so a smaller pulley can be used.

In addition, in this embodiment, the wire is wound around the shaft pulley one or more times, which prevents the wire from coming off the shaft pulley.

In addition, in this embodiment, each suppression section is provided around each shaft pulley, and the contact between each suppression section and each wire prevents each wire from coming off the shaft pulley.

In addition, in this embodiment, each suppression section is provided with a guide that guides the wire, which, for example, prevents the wire from coming loose when being fed out.

In the above embodiment, the driving source 30 is an electric motor, but the driving source 30 may have another configuration as long as the wire can be wound and fed by the driving source. For example, the driving source 30 may be a cylinder, a linear motor, etc.

In the above embodiment, the driving sources 30 are arranged along the longitudinal direction of the base plate 24, but the present disclosure is not limited to this configuration. For example, the driving sources 30 may be arranged in a staggered pattern or in other arrangements.

The multiple drive sources 30 may all be electric motors of the same capacity, or may be electric motors of different capacities. Since the tip of the robot is lighter and has a smaller moment, the electric motor may be set according to the required force.

Although a shaft pulley is disposed on each axial side of each shaft, the present disclosure is not limited to this configuration. Multiple shaft pulleys may be disposed so that the diameter decreases toward one side of each shaft. In other words, multiple shaft pulleys may be disposed so that the diameter decreases on each shaft from one axial end to the other end of each shaft. In this case, since the wire can only provide a rotational force in one direction relative to the shaft, a biasing member may be used to provide a rotational force in the other direction. Examples of biasing members include a spring.

The following are additional notes regarding this disclosure:

(Additional Note 1)
A plurality of drive sources disposed on a base portion;
a wire having one end fixed to each of the plurality of driving sources;
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys are arranged on the first shaft so that their diameters become smaller toward one axial side of the first shaft;
A plurality of second shaft pulleys are arranged on the second shaft so that their diameters become smaller toward one axial side of the second shaft;
having
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
A power transmission mechanism, wherein each of the multiple wires is hung from the first shaft pulley to the second shaft pulley along the tangent line.

(Additional Note 2)
The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center side, which is the one side,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center side, which is the one side.
2. The power transmission mechanism according to claim 1.

(Additional Note 3)
The other end of the wire hung on the first shaft pulley located at the axially outermost position of the first shaft is fixed to a first fixed member to which the first shaft is fixed.

(Additional Note 4)
The other end of the wire hung on the second shaft pulley located at the axially outermost position of the second shaft is fixed to a second fixed member to which the second shaft is fixed.

(Additional Note 5)
A power transmission mechanism according to appended claim 2, appended claim 3 which references appended claim 2, or appended claim 4 which references appended claim 2, wherein the wires hung on the first shaft pulleys which are located in pairs from the axial center of the first shaft are paired, and the pair of wires are hung on the first shaft pulleys which are located in pairs in opposite directions to each other.

(Additional Note 6)
5. The power transmission mechanism according to claim 1, wherein the wire is wound around at least one of the first shaft pulley and the second shaft pulley at least once.

(Additional Note 7)
A first suppression portion that is disposed radially outside the first shaft pulley and suppresses derailment of the wire hung on the first shaft pulley by contact;
A second suppression portion that is disposed radially outside the second shaft pulley and suppresses derailment of the wire hung on the second shaft pulley by contact;
The power transmission mechanism according to any one of claims 1 to 6, further comprising:

(Additional Note 8)
a first guide portion disposed on the tangent line between the driving source and the first shaft pulley and configured to guide the wire being let out and taken up;
A second guide portion is disposed on the tangent line between the first shaft pulley and the second shaft pulley and guides the wire being let out and taken up;
The power transmission mechanism according to any one of claims 1 to 7, further comprising:

(Additional Note 9)
The power transmission mechanism according to any one of appendix 1 to appendix 8, wherein the drive source is a motor, one end of the wire is fixed to a motor shaft pulley connected to a shaft of the motor, and the wire is wound around the motor shaft pulley by rotation of the motor.

(Additional Item 10)
A plurality of drive sources disposed on a base portion;
a wire having one end fixed to each of the plurality of driving sources;
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys arranged on the first shaft in the axial direction of the first shaft;
A plurality of second shaft pulleys arranged on the second shaft in the axial direction of the second shaft;
having
The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center,
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
Each of the plurality of wires is hung on the second shaft pulley along the tangent line from the first shaft pulley,
The wires are wound around the first shaft pulleys at a paired position from the axial center of the first shaft, and the paired wires are wound around the first shaft pulleys at the paired position in opposite directions to each other,
The other end of the wire hung on the first shaft pulley located at the axial outermost position of the first shaft is fixed to a first fixing member to which the first shaft is fixed,
The other end of the pair of wires hung on the first shaft pulley located on the other axially outermost side of the first shaft is fixed to a first fixed member to which the first shaft is fixed.
Joint mechanism.

(Additional Item 11)
A base portion;
A plurality of driving sources disposed on the base portion;
a wire having one end fixed to each of the plurality of driving sources;
A plurality of joints through which a plurality of the wires pass;
An articulated robot having
The articulated robot has the following joints:
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys arranged on the first shaft in the axial direction of the first shaft;
A plurality of second shaft pulleys arranged on the second shaft in the axial direction of the second shaft;
It has
The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center,
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
Each of the plurality of wires is hung on the second shaft pulley along the tangent line from the first shaft pulley,
The wires are wound around the first shaft pulleys at a paired position from the axial center of the first shaft, and the paired wires are wound around the first shaft pulleys at the paired position in opposite directions to each other,
The other end of the wire hung on the first shaft pulley located at the axial outermost position of the first shaft is fixed to a first fixing member to which the first shaft is fixed,
An articulated robot, wherein the other end of the pair of wires hung on the first shaft pulley located on the other axially outermost side of the first shaft is fixed to a first fixed member to which the first shaft is fixed.

(Additional Item 12)
The articulated robot according to claim 11, wherein the wire hung on the first shaft pulley located on the axial center side of the first shaft drives a portion of the robot closer to a tip end.

20 Articulated robot 22 Base unit 26 Arm unit 30 Driving source 35 First motor shaft pulley (an example of a motor shaft pulley)
36 Second motor shaft pulley (an example of a motor shaft pulley)
40 Wire 60 Joint (an example of the first joint)
61 Joint (an example of a second joint)
62 First shaft 64 Second shaft 66 First shaft pulley 66TLB1 Tangent 68 Second shaft pulley 68TLB1 Tangent 70 Joint (an example of a first joint)
71 Joint (an example of a second joint)
72 Third axis (an example of the first axis)
74 Fourth axis (an example of the second axis)
76 Guide shaft 78 Third shaft pulley (an example of a first shaft pulley)
80 Fourth shaft pulley (an example of a second shaft pulley)
82 Guide shaft pulley 90 Joint (an example of a first joint)
91 Joint (an example of a second joint)
92 Fifth axis (an example of the first axis)
94 Sixth axis (an example of the second axis)
96 Fifth shaft pulley (an example of a first shaft pulley)
98 Sixth shaft pulley (an example of a second shaft pulley)
100 First fixing member 104 First suppression portion 108 First guide portion 110 Second fixing member 114 Second suppression portion 118 Second guide portion 120 Third fixing member (an example of the first fixing member)
130 Fourth fixing member (an example of the second fixing member)
140 Fifth fixing member (an example of the first fixing member)
150 Sixth fixing member (an example of the second fixing member)
200 Hand section

Claims (12)

A plurality of drive sources disposed on a base portion;
a wire having one end fixed to each of the plurality of driving sources;
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys are arranged on the first shaft so that their diameters become smaller toward one axial side of the first shaft;
A plurality of second shaft pulleys are arranged on the second shaft so that their diameters become smaller toward one axial side of the second shaft;
having
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
A power transmission mechanism, wherein each of the multiple wires is hung from the first shaft pulley to the second shaft pulley along the tangent line. The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center side, which is the one side,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center side, which is the one side.
2. The power transmission mechanism according to claim 1. The power transmission mechanism according to claim 1, wherein the other end of the wire hung on the first shaft pulley located at the outermost axial position of the first shaft is fixed to a first fixed member to which the first shaft is fixed. The power transmission mechanism according to claim 1, wherein the other end of the wire hung on the second shaft pulley located at the axially outermost position of the second shaft is fixed to a second fixed member to which the second shaft is fixed. The power transmission mechanism according to claim 2, wherein the wires that are hung on the first shaft pulleys that are located in pairs from the axial center of the first shaft are in pairs, and the pair of wires are hung on the first shaft pulleys that are located in pairs in opposite directions to each other. The power transmission mechanism according to claim 1, wherein the wire is wound around at least one of the first shaft pulley and the second shaft pulley at least once. A first suppression portion that is disposed radially outside the first shaft pulley and suppresses derailment of the wire hung on the first shaft pulley by contact;
A second suppression portion that is disposed radially outside the second shaft pulley and suppresses derailment of the wire hung on the second shaft pulley by contact;
The power transmission mechanism of claim 1 further comprising: a first guide portion disposed on the tangent line between the driving source and the first shaft pulley and configured to guide the wire being let out and taken up;
A second guide portion is disposed on the tangent line between the first shaft pulley and the second shaft pulley and guides the wire being let out and taken up;
The power transmission mechanism of claim 1 further comprising: The power transmission mechanism according to claim 1, wherein the driving source is a motor, one end of the wire is fixed to a motor shaft pulley connected to the shaft of the motor, and the wire is wound around the motor shaft pulley by the rotation of the motor. A plurality of drive sources disposed on a base portion;
a wire having one end fixed to each of the plurality of driving sources;
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys arranged on the first shaft in the axial direction of the first shaft;
A plurality of second shaft pulleys arranged on the second shaft in the axial direction of the second shaft;
having
The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center,
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
Each of the plurality of wires is hung on the second shaft pulley along the tangent line from the first shaft pulley,
The wires are wound around the first shaft pulleys at a paired position from the axial center of the first shaft, and the paired wires are wound around the first shaft pulleys at the paired position in opposite directions to each other,
The other end of the wire hung on the first shaft pulley located at the axial outermost position of the first shaft is fixed to a first fixing member to which the first shaft is fixed,
The other end of the pair of wires hung on the first shaft pulley located on the other axially outermost side of the first shaft is fixed to a first fixed member to which the first shaft is fixed.
Joint mechanism. A base portion;
A plurality of driving sources disposed on the base portion;
a wire having one end fixed to each of the plurality of driving sources;
A plurality of joints through which a plurality of the wires pass;
An articulated robot having
The articulated robot has the following joints:
A first axis which is a rotation axis of a first joint arranged on the drive source side;
A second axis is a rotation axis of a second joint connected to the first joint and is disposed at a right angle to the first axis and in a twisted position;
A plurality of first shaft pulleys arranged on the first shaft in the axial direction of the first shaft;
A plurality of second shaft pulleys arranged on the second shaft in the axial direction of the second shaft;
It has
The first shaft pulleys are arranged such that their diameters become smaller from both axial ends of the first shaft toward the axial center,
The second shaft pulleys are arranged such that their diameters become smaller from both axial ends of the second shaft toward the axial center,
tangents of the first shaft pulleys coincide with tangents of the second shaft pulleys;
Each of the plurality of wires is hung on the second shaft pulley along the tangent line from the first shaft pulley,
The wires are wound around the first shaft pulleys at a paired position from the axial center of the first shaft, and the paired wires are wound around the first shaft pulleys at the paired position in opposite directions to each other,
The other end of the wire hung on the first shaft pulley located at the axial outermost position of the first shaft is fixed to a first fixing member to which the first shaft is fixed,
An articulated robot, wherein the other end of the pair of wires hung on the first shaft pulley located on the other axially outermost side of the first shaft is fixed to a first fixed member to which the first shaft is fixed. The articulated robot according to claim 11 , wherein the wire is hung on the first shaft pulley located on the axial center side of the first shaft, and the portion of the robot closer to the tip end side is driven.