Robot hand

Abstract

A robot hand (100) has: a plurality of first positioning worm gears (WG1) that are disposed in a palm portion (PM) and that transmit a force for controlling the posture of a first finger portion (FP1); a plurality of second positioning worm gears (WG2) that are disposed in the palm portion (PM) and that transmit a force for controlling the posture of a second finger portion (FP2); and a gripping worm gear (WG10) that is disposed in the palm portion (PM) and that transmits a force for gripping an object by means of the first finger portion (FP1) and the second finger portion (FP2). The gripping worm gear (WG10) is disposed in the palm portion (PM) such that a first angle (α) formed between a first plane (VL1) including a worm shaft (WX2) of each of the plurality of second positioning worm gears (WG2), and a worm shaft (WX10) of the gripping worm gear (WG10) is less than 20 degrees.

Description

Robot Hand

[0001] The present disclosure relates to a robot hand.

[0002] Conventionally, a humanoid electric hand (robot hand) configured to move fingers by means of a motor and a worm gear is known (see Patent Document 1). In this robot hand, the worm gear is arranged to be driven by a motor provided in a proximal phalanx of the finger.

[0003] Japanese Patent No. 5787325 Specification

[0004] However, there is a possibility that the above-mentioned robot hand cannot cope with a case where one finger is driven by a plurality of motors to achieve complex movements. This is because there is a possibility that a space for installing the motors and the worm gears cannot be secured.

[0005] Therefore, it is desirable to provide a robot hand capable of arranging a plurality of worm gears with higher space efficiency.

[0006] A robot hand according to an embodiment of the present disclosure includes: a first finger portion; a second finger portion; a palm portion; a plurality of first positioning worm gears arranged on the palm portion and transmitting force for controlling a posture of the first finger portion; a plurality of second positioning worm gears arranged on the palm portion and transmitting force for controlling a posture of the second finger portion; and a gripping worm gear arranged on the palm portion and transmitting force for gripping an object by the first finger portion and the second finger portion, wherein the gripping worm gear is arranged on the palm portion such that a first angle formed between a first plane including the respective worm shafts of the plurality of second positioning worm gears and a worm shaft of the gripping worm gear is less than 20 degrees.

[0007] The above-described robot hand can arrange a plurality of worm gears with higher space efficiency.

[0008] This is a schematic diagram showing an example configuration of a robot system including a robot hand according to an embodiment of the present disclosure. This is a perspective view of the robot hand. This is a top view of the main part of the robot hand. This is a left side view of the main part of the robot hand. This is a rear view of the main part of the robot hand. This is a schematic perspective view of the members constituting the fingers and the wires for moving the fingers. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing an example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a diagram showing another example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a diagram showing yet another example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a perspective view of the positioning device. This is a perspective view of the members constituting the positioning device. This is a top view of the palm, the gripping device, and the fixed pulley and movable pulley on which the gripping wire is attached. This is a left side view of a movable positioning worm and movable positioning worm wheel. This is a perspective view of a robot hand including a palm that is moved by a rocking device. This is a top view, rear view, and bottom view of the palm and rocking device. This is a left side view of a robot hand rocked by a rocking device. This is a rear view of a robot hand rocked by a rocking device. This is a rear view of a fixed pulley, gripping device, slack suppression mechanism, palm, rocking shaft, and rocking worm wheel. This is a perspective view of a slack suppression mechanism provided on the palm. This is a rear view of a fixed pulley, rocking pulley, rocking shaft, palm, and gripping wire.

[0009] Hereinafter, a robot hand 100 according to an embodiment of this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram showing an example configuration of a robot system 600 including the robot hand 100. The robot system 600 comprises the robot hand 100, a robot 110, a camera 120, and a control device 610. The robot 110 has a plurality of joints, a plurality of arms, and a plurality of actuators. The robot hand 100 is attached to the tip of the arm of the robot 110. The control device 610 includes a picking robot controller 620 that controls the movement of the robot 110, and a hand controller 630 that controls the movement of the robot hand 100.

[0010] Camera 120 photographs the workpiece 700. Camera 120 is electrically connected to the control device 610 (picking robot controller 620). Information about the workpiece 700 captured by camera 120 is output to the picking robot controller 620. Camera 120 is an example of an input unit that inputs information about the workpiece 700 to the control device 610 (picking robot controller 620). The input unit is not limited to camera 120 and may be other devices such as LiDAR.

[0011] The control device 610 is, for example, a device equipped with a microcomputer, and includes a CPU, a volatile memory device, a non-volatile memory device, and an input / output interface. The same applies to the picking robot controller 620 and the hand controller 630. In the illustrated example, the picking robot controller 620 and the hand controller 630 are separate and independent devices, but they may be configured as an integrated unit. The hand controller 630 may be mounted on the robot hand 100 or on the robot 110.

[0012] The picking robot controller 620 can perform various processes based on information about the workpiece 700 acquired by the camera 120, for example. The picking robot controller 620 is also electrically connected to the robot 110. The picking robot controller 620 can control the operation of multiple joints, multiple arms, and multiple actuators of the robot 110.

[0013] The hand controller 630 can output various commands, such as positioning commands and gripping commands, to the robot hand 100. The robot hand 100 sets the position (orientation) of each of the multiple fingers that make up the robot hand 100 to a predetermined position (orientation) according to the positioning command output from the hand controller 630. The robot hand 100 also performs a gripping operation to grip the workpiece 700 by closing the multiple fingers that are in the predetermined orientation according to the gripping command output from the hand controller 630. The hand controller 630 is also configured to provide feedback control of the movement of various actuators mounted on the robot hand 100 based on the output of various sensors mounted on the robot hand 100. The various sensors include, for example, a force detection sensor that detects the force acting on the robot hand 100, and a rotation angle sensor that detects the rotation angle of various rotating members. The various actuators include a positioning motor for positioning the fingers, and a gripping motor for performing the gripping operation.

[0014] In the illustrated example, the hand controller 630 is configured to output 13 types of positioning commands and controls the movement of the robot hand 100 so that the position of the multiple fingers constituting the robot hand 100 is one of the 13 positions. The picking robot controller 620 can determine which of the 13 positions is suitable for grasping the workpiece 700 based on information about the workpiece 700 acquired by the camera 120. The robot system 600 can grasp the workpiece 700 using the robot hand 100 by controlling the movements of the robot hand 100 and the robot 110 in this way.

[0015] Next, the robot hand 100 will be described in detail with reference to Figures 2 to 5. Figure 2 is a perspective view of the robot hand 100, Figure 3 is a top view of the main part of the robot hand 100 (excluding the finger portions FP), Figure 4 is a left side view of the main part of the robot hand 100, and Figure 5 is a rear view of the main part of the robot hand 100. In Figures 3 to 5, the finger portions FP that make up the robot hand 100 are omitted from the illustration for clarity.

[0016] In Figure 2, X1 represents one direction of the X-axis in the three-dimensional Cartesian coordinate system, and X2 represents the other direction of the X-axis. Similarly, Y1 represents one direction of the Y-axis in the three-dimensional Cartesian coordinate system, and Y2 represents the other direction of the Y-axis. Likewise, Z1 represents one direction of the Z-axis in the three-dimensional Cartesian coordinate system, and Z2 represents the other direction of the Z-axis. In Figure 2, the X1 side of the robot hand 100 corresponds to the front side of the robot hand 100, and the X2 side of the robot hand 100 corresponds to the rear side of the robot hand 100. Also, the Y1 side of the robot hand 100 corresponds to the left side of the robot hand 100, and the Y2 side of the robot hand 100 corresponds to the right side of the robot hand 100. Furthermore, the Z1 side of the robot hand 100 corresponds to the top side of the robot hand 100, and the Z2 side of the robot hand 100 corresponds to the bottom side of the robot hand 100. The same applies to other figures.

[0017] In the illustrated example, the robot hand 100 is a device corresponding to a human right hand and has finger portions FP and palm portions PM. The robot hand 100 may also be configured to correspond to a human left hand.

[0018] The finger portion FP includes the first finger portion FP1 corresponding to the thumb, the second finger portion FP2 corresponding to the index finger, the third finger portion FP3 corresponding to the middle finger, and the fourth finger portion FP4 corresponding to the ring finger. The finger portion FP may also include the fifth finger portion corresponding to the little finger. In addition, the number of finger portions other than the first finger portion FP1 may be one, two, three, four, or five or more.

[0019] Specifically, as shown in Figure 2, the first finger portion FP1 has a first distal phalanx DP1 and a first proximal phalanx BP1. The first distal phalanx DP1 and the first proximal phalanx BP1 are connected via joint DJ1, and the first proximal phalanx BP1 and the palm portion PM are connected via joint BJ1. The second finger portion FP2 has a second distal phalanx DP2, a second middle phalanx CP2, and a second proximal phalanx BP2. The second distal phalanx DP2 and the second middle phalanx CP2 are connected via joint DJ2, the second middle phalanx CP2 and the second proximal phalanx BP2 are connected via joint CJ2, and the second proximal phalanx BP2 and the palm portion PM are connected via joint BJ2. The third finger portion FP3 and the fourth finger portion FP4 have the same configuration as the second finger portion FP2.

[0020] The palm portion PM corresponds to the palm of a human hand. In the illustrated example, the palm portion PM includes a first palm portion PM1 to which the first finger portion FP1 is attached, and a second palm portion PM2 to which the second finger portion FP2 to the fourth finger portion FP4 are attached. The first palm portion PM1 and the second palm portion PM2 are connected so that they can swing relative to each other around the pivot axis PX (see Figure 5), as indicated by the arrow AR1.

[0021] Furthermore, the robot hand 100 includes a positioning device PD (see Figure 2), a gripping device GD (see Figure 2), and a rocking device SD (see Figure 5).

[0022] The positioning device PD is a device that positions the finger portion FP (a device that controls the posture of the finger portion FP). In the illustrated example, the positioning device PD includes a first positioning device PD1 that controls the posture of the first finger portion FP1, a second positioning device PD2 that controls the posture of the second finger portion FP2, a third positioning device PD3 that controls the posture of the third finger portion FP3, and a fourth positioning device PD4 that controls the posture of the fourth finger portion FP4.

[0023] The first positioning device PD1 includes a first fixed positioning device PD1F that is not movable in the X-axis direction relative to the palm portion PM, and a first movable positioning device PD1M that is movable in the X-axis direction relative to the palm portion PM. As shown in Figure 4, the first fixed positioning device PD1F has a first fixed positioning worm gear WG1F as a first fixed positioning power transmission mechanism, a first fixed wire WR1F as a first fixed positioning power transmission member, and a first fixed motor MT1F as a first fixed positioning actuator. The first fixed positioning worm gear WG1F has a first fixed positioning worm WM1F and a first fixed positioning worm wheel WH1F. The first movable positioning device PD1M has a first movable positioning worm gear WG1M as a first movable positioning power transmission mechanism, a first movable wire WR1M as a first movable positioning power transmission member, and a first movable motor MT1M as a first movable positioning actuator. The first movable positioning worm gear WG1M includes a first movable positioning worm WM1M and a first movable positioning worm wheel WH1M. The first fixed positioning power transmission member and the first movable positioning power transmission member may be a link mechanism instead of a wire.

[0024] The second positioning device PD2 includes a second fixed positioning device PD2F that is not movable in the X-axis direction relative to the palm portion PM, and a second movable positioning device PD2M that is movable in the X-axis direction relative to the palm portion PM. As shown in Figure 3, the second fixed positioning device PD2F has a second fixed positioning worm gear WG2F as a second fixed positioning power transmission mechanism, a second fixed wire WR2F as a second fixed positioning power transmission member, and a second fixed motor MT2F as a second fixed positioning actuator. The second fixed positioning worm gear WG2F has a second fixed positioning worm WM2F and a second fixed positioning worm wheel WH2F. The second movable positioning device PD2M has a second movable positioning worm gear WG2M as a second movable positioning power transmission mechanism, a second movable wire WR2M as a second movable positioning power transmission member, and a second movable motor MT2M as a second movable positioning actuator. The second movable positioning worm gear WG2M includes a second movable positioning worm WM2M and a second movable positioning worm wheel WH2M. The second fixed positioning power transmission member and the second movable positioning power transmission member may be a link mechanism instead of a wire.

[0025] The third positioning device PD3 and the fourth positioning device PD4 have the same configuration as the second positioning device PD2. Specifically, the third positioning device PD3 includes a third fixed positioning device PD3F which includes a third fixed positioning worm gear WG3F (third fixed positioning worm WM3F and third fixed positioning worm wheel WH3F), a third fixed wire WR3F, and a third fixed motor MT3F, and a third movable positioning device PD3M which includes a third movable positioning worm gear WG3M (third movable positioning worm WM3M and third movable positioning worm wheel WH3M), a third movable wire WR3M, and a third movable motor MT3M. Furthermore, the fourth positioning device PD4 includes a fourth fixed positioning device PD4F which includes a fourth fixed positioning worm gear WG4F (fourth fixed positioning worm WM4F and fourth fixed positioning worm wheel WH4F), a fourth fixed wire WR4F, and a fourth fixed motor MT4F, and a fourth movable positioning device PD4M which includes a fourth movable positioning worm gear WG4M (fourth movable positioning worm WM4M and fourth movable positioning worm wheel WH4M), a fourth movable wire WR4M, and a fourth movable motor MT4M.

[0026] The gripping device GD is a device that controls the gripping force, which is the force used to grip an object such as a workpiece 700 with the finger portion FP. In the illustrated example, as shown in Figure 3, the gripping device GD has a gripping worm gear WG10 as a gripping power transmission mechanism, a gripping wire WR10 as a gripping power transmission member, and a gripping motor MT10 as a gripping actuator. As shown in Figure 5, the gripping worm gear WG10 has a gripping worm WM10 and a gripping worm wheel WH10.

[0027] The control device 610 (hand controller 630) can, for example, determine the orientation of the finger portion FP by the positioning device PD (after the finger portion FP is in contact with an object), and then generate a desired gripping force using the gripping device GD.

[0028] The oscillating device SD is a device that causes the first palm portion PM1 and the second palm portion PM2 to oscillate relative to each other. In the illustrated example, as shown in Figure 5, the oscillating device SD has an oscillating worm gear WG20, a first gear GR21, a second gear GR22, an oscillating shaft SH20 as an oscillating power transmission mechanism, and an oscillating motor MT20 as an oscillating actuator. The oscillating worm gear WG20 has an oscillating worm WM20 and an oscillating worm wheel WH20.

[0029] In the following, the first fixed wire WR1F and the first movable wire WR1M may be collectively referred to as "first wire WR1." The same applies to the second wire WR2 (second fixed wire WR2F and second movable wire WR2M), the third wire WR3 (third fixed wire WR3F and third movable wire WR3M), and the fourth wire WR4 (fourth fixed wire WR4F and fourth movable wire WR4M). Furthermore, the first movable wires WR1M to the fourth movable wires WR4M may be collectively referred to as "movable wires," and the first fixed wires WR1F to the fourth fixed wires WR4F may be collectively referred to as "fixed wires." In addition, "movable wires" and "fixed wires" may be collectively referred to as "wires."

[0030] Furthermore, the first fixed-position worm gear WG1F and the first movable-position worm gear WG1M may be collectively referred to as "first-position worm gear WG1". The same applies to the second-position worm gear WG2 (second fixed-position worm gear WG2F and second movable-position worm gear WG2M), the third-position worm gear WG3 (third fixed-position worm gear WG3F and third movable-position worm gear WG3M), and the fourth-position worm gear WG4 (fourth fixed-position worm gear WG4F and fourth movable-position worm gear WG4M). In addition, the first to fourth-position worm gears WG1 to WG4 may be collectively referred to as "worm gear WG".

[0031] Furthermore, the first fixed-positioning worm WM1F and the first movable-positioning worm WM1M may be collectively referred to as "first-positioning worm WM1". The same applies to the second-positioning worm WM2 (second fixed-positioning worm WM2F and second movable-positioning worm WM2M), the third-positioning worm WM3 (third fixed-positioning worm WM3F and third movable-positioning worm WM3M), and the fourth-positioning worm WM4 (fourth fixed-positioning worm WM4F and fourth movable-positioning worm WM4M). In addition, the first to fourth-positioning worms WM1 to WM4, the gripping worm WM10, and the oscillating worm WM20 may be collectively referred to as "worm WM", and the axis of the worm WM may be referred to as "worm axis WX". Note that "worm" may also be called a "screw gear" or "worm shaft".

[0032] Furthermore, the first fixed-positioning worm wheel WH1F and the first movable-positioning worm wheel WH1M may be collectively referred to as "first-positioning worm wheel WH1". The same applies to the second-positioning worm wheel WH2 (second fixed-positioning worm wheel WH2F and second movable-positioning worm wheel WH2M), the third-positioning worm wheel WH3 (third fixed-positioning worm wheel WH3F and third movable-positioning worm wheel WH3M), and the fourth-positioning worm wheel WH4 (fourth fixed-positioning worm wheel WH4F and fourth movable-positioning worm wheel WH4M). In addition, the first to fourth-positioning worm wheels WH1 to WH4, the gripping worm wheel WH10, and the oscillating worm wheel WH20 may be collectively referred to as "worm wheel".

[0033] Furthermore, the first fixed motor MT1F and the first movable motor MT1M may be collectively referred to as "first motor MT1". The same applies to the second motor MT2 (second fixed motor MT2F and second movable motor MT2M), the third motor MT3 (third fixed motor MT3F and third movable motor MT3M), and the fourth motor MT4 (fourth fixed motor MT4F and fourth movable motor MT4M). In addition, the first motors MT1 to the fourth motors MT4, the gripping motor MT10, and the oscillating motor MT20 may be collectively referred to as "motor MT", and the rotation axis of motor MT may be referred to as "rotation axis RX".

[0034] Next, with reference to Figure 6, an example of the movement of the finger portion FP by the positioning device PD will be described. Figure 6 is a schematic perspective view of some of the components constituting the second finger portion FP2 and the second wire WR2. Specifically, the top image of Figure 6 (the uppermost image) shows the state when the second finger portion FP2 is extended straight. The second image from the top of Figure 6 shows the movement of the second distal phalanx DP2, the second middle phalanx CP2, and the second proximal phalanx BP2, each oscillating around their respective joints. The third image from the top of Figure 6 shows the movement of the second distal phalanx DP2 and the second middle phalanx CP2, each oscillating around their respective joints without oscillating the second proximal phalanx BP2. The bottom image of Figure 6 shows the movement of only the second proximal phalanx BP2 oscillating around its corresponding joint without oscillating either the second distal phalanx DP2 or the second middle phalanx CP2. The following explanation, with reference to Figure 6, pertains to the movement of the second finger portion FP2 by the second positioning device PD2, but it also applies similarly to the movement of the first finger portion FP1 by the first positioning device PD1, the movement of the third finger portion FP3 by the third positioning device PD3, and the movement of the fourth finger portion FP4 by the fourth positioning device PD4.

[0035] In the example shown in Figure 6, the second distal section DP2 is pivotably connected to the second middle section CP2 via joint DJ2. A fixing pin PN1 and a fixing drum FD1 are fixed to the second distal section DP2. The second middle section CP2 is pivotably connected to the second proximal section BP2 via joint CJ2. A fixing pin PN2 and a fixed pulley FYa are attached to the second middle section CP2. The second proximal section BP2 is pivotably connected to the second palm section PM2 via joint BJ2. A fixing drum FD2 and a fixed drum FD3 are fixed to the second proximal section BP2. A fixed pulley FYb is also attached to the second palm section PM2. The second movable wire WR2M is fixed at one end (distal end) to a fixed pin PN1 and at the other end (proximal end) to a second movable positioning worm wheel WH2M, and is arranged to be wound onto or unwound from the second movable positioning worm wheel WH2M. The second fixed wire WR2F is fixed at one end (distal end) to a fixed pin PN2 and at the other end (proximal end) to a second fixed positioning worm wheel WH2F, and is arranged to be wound onto or unwound from the second fixed positioning worm wheel WH2F. For clarity, in Figure 6, the second movable wire WR2M is represented by a dashed line, and the second fixed wire WR2F is represented by a solid line. In Figure 6, except for the upper diagram, most of the second wire WR2 (the portion along the second finger FP2) is omitted from the illustration.

[0036] As shown in the second figure from the top of Figure 6, when the second fixed wire WR2F is held (without being wound up or unwound) and the second movable wire WR2M is wound up as indicated by arrow AR2, the second finger portion FP2 changes its posture as indicated by arrow AR3. Specifically, the second finger portion FP2 is configured to allow the second distal phalanx DP2, the second middle phalanx CP2, and the second proximal phalanx BP2 to swing evenly around their respective joints.

[0037] Furthermore, as shown in the third figure from the top in Figure 6, when the second movable wire WR2M is held (without being wound up or unwound) and the second fixed wire WR2F is wound up as indicated by arrow AR4, the second finger portion FP2 changes its posture as indicated by arrow AR5. Specifically, the second finger portion FP2 is configured to allow the second distal portion DP2 and the second middle portion CP2 to swing evenly around their respective joints without swinging the second proximal portion BP2.

[0038] Furthermore, as shown in the bottommost figure of Figure 6, when the second fixing wire WR2F is wound up as indicated by arrow AR6 and unwound as indicated by arrow AR7, the second finger portion FP2 changes its posture as indicated by arrow AR8. Specifically, the second finger portion FP2 is configured to allow only the second proximal phalanx BP2 to oscillate around the corresponding joint, without causing the second distal phalanx DP2 and the second middle phalanx CP2 to oscillate.

[0039] Thus, the second positioning device PD2 can achieve the desired posture of the second finger portion FP2 by appropriately combining the winding, holding, and unwinding of the second fixed wire WR2F with the winding, holding, and unwinding of the second movable wire WR2M. For example, the second positioning device PD2 can also move the fingertip of the second finger portion FP2 along a straight trajectory. In the example shown in Figure 6, the second finger portion FP2 is configured to return to its initial state (the state shown in the topmost figure of Figure 6) by torsion springs (not shown) attached to each joint when the force applied by the second positioning device PD2 to change the posture of the second finger portion FP2 disappears. However, the second finger portion FP2 may also be configured to return to its initial state by winding or unwinding another wire.

[0040] Next, with reference to Figures 7A to 7C, another example of the configuration of the finger FP will be described. Figures 7A to 7C show some of the components of the first finger FP1 mounted on the robot hand 100 shown in Figure 2 and the arrangement of the first wire WR1. Specifically, Figure 7A is a left side view, Figure 7B is a bottom view, and Figure 7C is a top view.

[0041] In the example shown in Figures 7A to 7C, the first finger portion FP1 includes tensioners TS1 to TS3, fixed drums FD1 to FD5, and a fixed pulley FYa. The first wire WR1 includes the first fixed wire WR1F and the first movable wire WR1M. The first fixed wire WR1F includes the first fixed wire WR1F1 and the first fixed wire WR1F2. The tensioner TS1 is a member to which one end (distal end) of the first movable wire WR1M is fixed, and is fixed to the first distal phalanx portion DP1 (see Figure 2) of the first finger portion FP1. The fixed drum FD1 is a fixed drum on which the first movable wire WR1M is hung, and is fixed to the first distal phalanx portion DP1 (see Figure 2). Tensioner TS2 is a member to which one end (distal end) of the first fixed wire WR1F1 is fixed, and is fixed to the first proximal phalange BP1 (see Figure 2) of the first finger portion FP1. Tensioner TS3 is a member to which one end (distal end) of the first fixed wire WR1F2 is fixed, and is fixed to the first proximal phalange BP1 (see Figure 2). Fixed drum FD2 is a fixed drum on which the first fixed wire WR1F (first fixed wire WR1F1 and first fixed wire WR1F2) is hung, and is fixed to the first proximal phalange BP1 (see Figure 2). Fixed pulley FYa is a fixed pulley on which the first movable wire WR1M is hung, and is attached to the first proximal phalange BP1 (see Figure 2). Fixed drum FD3 is a fixed drum on which the first fixed wire WR1F2 is hung, and is fixed to the first palm portion PM1 (see Figure 2). Fixed drum FD4 is a fixed drum on which the first fixed wire WR1F1 is attached, and is fixed to the first palm portion PM1 (see Figure 2). Fixed drum FD5 is a fixed drum on which the first movable wire WR1M is attached, and is fixed to the first palm portion PM1 (see Figure 2).

[0042] With this configuration, the first positioning device PD1 can achieve the desired position of the first finger portion FP1 by appropriately combining the winding, holding, and unwinding of the first fixed wire WR1F with the winding, holding, and unwinding of the first movable wire WR1M, similar to the configuration shown in Figure 6.

[0043] Next, with reference to Figures 8A to 8C, yet another example of the configuration of the finger portion FP will be described. Figures 8A to 8C show some of the components of the second finger portion FP2 mounted on the robot hand 100 shown in Figure 2 and the arrangement of the second wire WR2. Specifically, Figure 8A is a top view, Figure 8B is a left side view, and Figure 8C is a right side view.

[0044] In the example shown in Figures 8A to 8C, the second finger portion FP2 includes tensioners TS1 to TS4, fixed drums FD1 to FD6, and fixed pulleys FYa to FYb. The second wire WR2 includes the second fixed wire WR2F and the second movable wire WR2M. The second fixed wire WR2F includes the second fixed wire WR2F11, the second fixed wire WR2F12, the second fixed wire WR2F21, and the second fixed wire WR2F22. The fixed drum FD1 is a fixed drum on which the second fixed wire WR2F (second fixed wire WR2F12 and second fixed wire WR2F22) is attached, and is fixed to the second distal phalanx portion DP2 of the second finger portion FP2 (see Figure 2). The fixed drum FD2 is a fixed drum on which the second fixed wires WR2F12 and WR2F22 are hung, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. The fixed pulley FYa is a fixed pulley on which the second movable wire WR2M is hung, and is attached to the second middle node CP2 (see Figure 2). The tensioner TS1 is a member on which the other end (proximal end) of the second fixed wire WR2F12 is fixed, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. The tensioner TS2 is a member on which the other end (proximal end) of the second fixed wire WR2F22 is fixed, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. Tensioner TS3 is a member to which one end (distal end) of the second fixing wire WR2F11 is fixed, and is fixed to the second proximal phalange BP2 (see Figure 2) of the second finger portion FP2. Tensioner TS4 is a member to which one end (distal end) of the second fixing wire WR2F21 is fixed, and is fixed to the second proximal phalange BP2 (see Figure 2) of the second finger portion FP2. Fixing drum FD3 is a fixing drum on which the second fixing wire WR2F (second fixing wire WR2F1 and second fixing wire WR2F2) is hung, and is fixed to the second proximal phalange BP2 (see Figure 2). Fixing drum FD4 is a fixing drum on which the second fixing wire WR2F21 is hung, and is fixed to the second palm portion PM2 (see Figure 2). Fixed drum FD5 is a fixed drum on which the second fixed wire WR2F11 is attached, and is fixed to the second palm portion PM2 (see Figure 2). Fixed drum FD6 is a fixed drum on which the second movable wire WR2M is attached, and is fixed to the second palm portion PM2 (see Figure 2).

[0045] With this configuration, similarly to the configuration shown in FIG. 6, the second positioning device PD2 can achieve a desired posture of the second finger portion FP2 by appropriately combining the winding, holding, and feeding-out of the second fixed wire WR2F with the winding, holding, and feeding-out of the second movable wire WR2M. The same applies to the third positioning device PD3 and the fourth positioning device PD4 mounted on the robot hand 100 shown in FIG. 2.

[0046] Next, an example of the positional relationship between the worm shaft WX and the rotating shaft RX will be described with reference to FIG. 9. FIG. 9 is a diagram showing the positional relationship between the worm shaft WX and the rotating shaft RX. Specifically, the left diagram of FIG. 9 is a front view of the worm WM and the motor MT mounted on the robot hand 100 shown in FIG. 2, the upper right diagram of FIG. 9 is a top view of the worm WM and the motor MT, and the lower right diagram of FIG. 9 is a left side view of the worm WM and the motor MT.

[0047] In the illustrated example, as shown in the upper right of Figure 9, in a top view along the Z-axis, the six positioning worms are arranged such that each of the six worm axes (worm axis WX2 of the second positioning worm WM2 (worm axis WX2F and worm axis WX2M), worm axis WX3 of the third positioning worm WM3 (worm axis WX3F and worm axis WX3M), and worm axis WX4 of the fourth positioning worm WM4 (worm axis WX4F and worm axis WX4M)) is parallel to the X-axis (parallel to each other). In other words, as shown in the left of Figure 9, the six positioning worms are arranged such that each worm axis lies on the first plane VL1 in a front view along the X-axis. Furthermore, the six positioning motors are arranged such that, in a top view, each of the six rotation axes (the rotation axis RX2 of the second motor MT2 (rotation axis RX2F and rotation axis RX2M), the rotation axis RX3 of the third motor MT3 (rotation axis RX3F and rotation axis RX3M), and the rotation axis RX4 of the fourth motor MT4 (rotation axis RX4F and rotation axis RX4M)) and each of the six worm axes WX are aligned in the same straight line. In addition, the gripping worm WM10 is arranged such that, in a top view, the worm axis WX10 and the rotation axis RX10 of the gripping motor MT10 are aligned in the same straight line. Furthermore, in a top view, the gripping worm WM10 is arranged such that the worm axis WX10 is perpendicular to the worm axis of each of the six positioning worms. In other words, the gripping worm WM10 is positioned such that, in a top view, its worm axis WX10 is parallel to the second plane VL2, which is perpendicular to the worm axis of each of the six positioning worms. The oscillating worm WM20 is positioned such that, in a top view, its worm axis WX20 (see the lower right diagram in Figure 9) and the rotation axis RX10 of the gripping motor MT10 overlap (are parallel). The oscillating motor MT20 is also positioned such that, in a top view, its rotation axis RX20 and the rotation axis RX10 of the gripping motor MT10 are parallel to the Y-axis (parallel to each other).

[0048] Furthermore, as shown in the left diagram of FIG. 9, in a front view viewed along the X-axis direction, the ten positioning worms are arranged such that each of the ten worm shafts (worm shaft WX1 (worm shaft WX1F and worm shaft WX1M), worm shaft WX2 (worm shaft WX2F and worm shaft WX2M), worm shaft WX3 (worm shaft WX3F and worm shaft WX3M), worm shaft WX4 (worm shaft WX4F and worm shaft WX4M), worm shaft WX10, and worm shaft WX20) is parallel to the XY plane.

[0049] As shown in the lower right diagram of FIG. 9, this arrangement provides the effect of suppressing an excessive increase in the distance between the lower end of the positioning device PD and the upper end of the gripping device GD (height dimension HT, value HT1) in a left side view viewed along the Y-axis direction. In other words, this arrangement provides the effect that the positioning device PD and the gripping device GD can be accommodated within the height dimension HT.

[0050] Furthermore, this arrangement provides the effect of suppressing an excessive increase in the distance between the front end of the positioning device PD and the rear end of the gripping device GD (depth dimension DT, value DT1) in the left side view. In other words, this arrangement provides the effect that the positioning device PD and the gripping device GD can be accommodated within the depth dimension DT.

[0051] Next, another example of the positional relationship between the worm shaft WX and the rotating shaft RX will be described with reference to FIG. 10. FIG. 10 is a diagram showing another example of the positional relationship between the worm shaft WX and the rotating shaft RX, and corresponds to FIG. 9. Note that in FIG. 10, illustration of the swinging motor MT20 and the swinging worm WM20 is omitted for clarity.

[0052] The example shown in Figure 10 differs from the example shown in Figure 9 in that, as shown in the left diagram of Figure 10, the worm axis WX10 of the gripping worm WM10 is inclined with respect to the first plane VL1 in a front view along the X-axis. In the example shown in Figure 9, the worm axis WX10 is parallel to the first plane VL1. Specifically, in the example shown in Figure 10, the gripping worm WM10 is positioned such that a first angle α is formed between the worm axis WX10 and the first plane VL1. The first angle α is, for example, less than 20 degrees. In addition, the gripping motor MT10 is positioned such that the rotation axis RX10 and the worm axis WX10 are on the same straight line.

[0053] In this configuration, the height dimension HT between the lower end of the positioning device PD and the upper end of the gripping device GD (gripping motor MT10) is HT2, which is slightly larger than the value HT1 in the example shown in Figure 9, but smaller than when the first angle α is 20 degrees or more. Also, in the example shown in the left diagram of Figure 10, the gripping motor MT10 and the gripping worm WM10 are positioned at an angle such that the upper end of the left end of the gripping motor MT10 is higher than the upper end of the right end of the gripping worm WM10. However, the gripping motor MT10 and the gripping worm WM10 may also be positioned at an angle such that the upper end of the left end of the gripping motor MT10 is lower than the upper end of the right end of the gripping worm WM10. In this case, the height dimension HT between the lower end of the positioning device PD and the upper end of the gripping device GD (gripping worm WM10) may be smaller than the value HT1 in the example shown in Figure 9.

[0054] Next, with reference to Figure 11, another example of the positional relationship between the worm shaft WX and the rotation shaft RX will be described. Figure 11 is a diagram showing yet another example of the positional relationship between the worm shaft WX and the rotation shaft RX, and corresponds to Figures 9 and 10. Note that in Figure 11, for clarity, the oscillating motor MT20 and the oscillating worm WM20 are omitted from the illustration.

[0055] The example shown in Figure 11 differs from the examples shown in Figures 9 and 10 in that, as shown in the upper right view of Figure 11, the worm axis WX10 of the gripping worm WM10 is inclined with respect to the second plane VL2 in a top view along the Z-axis direction. In the examples shown in Figures 9 and 10, the worm axis WX10 is parallel to the second plane VL2. Specifically, in the example shown in Figure 11, the gripping worm WM10 is positioned such that a second angle β is formed between the worm axis WX10 and the second plane VL2. The second angle β is, for example, less than 20 degrees. In addition, the gripping motor MT10 is positioned such that the rotation axis RX10 and the worm axis WX10 are on the same straight line.

[0056] In this configuration, the depth dimension DT between the front end of the positioning device PD and the rear end of the gripping device GD (gripping motor MT10) is DT2, which is slightly larger than the value DT1 in the example shown in Figure 9, but smaller than when the second angle β is 20 degrees or more. Also, in the example shown in the upper right diagram of Figure 11, the gripping motor MT10 and the gripping worm WM10 are positioned at an angle such that the rear end of the left end of the gripping motor MT10 is located behind the rear end of the right end of the gripping worm WM10. However, the gripping motor MT10 and the gripping worm WM10 may also be positioned at an angle such that the rear end of the left end of the gripping motor MT10 is located in front of the rear end of the right end of the gripping worm WM10. In this case, the depth dimension DT between the front end of the positioning device PD and the rear end of the gripping device GD (gripping worm WM10) may be smaller than the value DT1 in the example shown in Figure 9.

[0057] Next, the details of the gripping device GD will be described with reference to Figures 12 to 15. Figure 12 is a perspective view of the positioning device PD, in which a part of the components (movable assembly MA) is moved by the gripping device GD. Specifically, the upper part of Figure 12 is a perspective view of the second positioning device PD2, and the lower part of Figure 12 is a perspective view of the frame FM (second frame FM2) that constitutes the second positioning device PD2. Figure 13 is a perspective view of the components that constitute the second positioning device PD2. Specifically, the upper part of Figure 13 is a perspective view of a part of the second frame FM2, the movable assembly MA (second movable assembly MA2), and the second movable positioning worm WM2M that constitute the second positioning device PD2, the middle part of Figure 13 is a perspective view of the second movable assembly MA2, and the lower part of Figure 13 is a perspective view of a part of the second frame FM2, the second movable positioning worm WM2M, and the biasing spring SP (second biasing spring SP2). Figure 14 is a top view of the palm section PM, the gripping device GD, and the fixed pulley FY and movable pulley MP on which the gripping wire WR10 is attached. Specifically, the left side of Figure 14 shows the state before the gripping operation is performed (initial state), and the right side of Figure 14 shows the state after the gripping operation is performed (gripping state). Figure 15 is a left side view of the second movable positioning worm gear WG2M (second movable positioning worm WM2M and second movable positioning worm wheel WH2M). Specifically, the upper side of Figure 15 shows the state before the gripping operation is performed, and the lower side of Figure 15 shows the state after the gripping operation is performed. The following explanation, referring to Figures 12 to 15, mainly concerns the second positioning device PD2, but also applies similarly to the first positioning device PD1, the third positioning device PD3, and the fourth positioning device PD4.

[0058] As shown in Figure 12, the second positioning device PD2 includes a second frame FM2. The second fixed positioning worm WM2F, the second movable positioning worm WM2M, the second fixed positioning worm wheel WH2F, the second movable positioning worm wheel WH2M, the second fixed motor MT2F, and the second movable motor MT2M are mounted on the second frame FM2. In other words, the second positioning device PD2 is unitized (modularized) including the second motor MT2, the second positioning worm gear WG2, and the second frame FM2.

[0059] The second frame FM2 includes frame members FM21 to FM26. Frame members FM21 to FM23 are plate-shaped members extending along the XZ plane. Frame member FM21 has a circular hole RH1 and a rectangular opening RA1, frame member FM22 has a circular hole RH2 and a rectangular opening RA2, and frame member FM23 has a circular hole RH3 and a rectangular opening RA3.

[0060] The second fixed-position worm wheel WH2F has its shaft inserted through the circular hole RH1 of frame member FM21 and the circular hole RH2 of frame member FM22, respectively. The second fixed-position worm wheel WH2F is supported by frame members FM21 and FM22 so as to be rotatable around a rotation axis parallel to the Y axis and immovable in the X axis direction. A rotation angle sensor, such as a potentiometer, is attached near the rotation axis of the second fixed-position worm wheel WH2F. The rotation angle sensor may also be attached to the motor shaft.

[0061] The second movable positioning worm wheel WH2M has its shaft inserted through slide blocks SB (second slide block SB2), which are fitted into rectangular openings RA2 of frame member FM22 and RA3 of frame member FM23, respectively. The second slide block SB2 is supported by frame members FM22 and FM23 so as to be movable in the X-axis direction. The second movable positioning worm wheel WH2M is also supported by the second slide block SB2 so as to be rotatable around a rotation axis parallel to the Y-axis. A rotation angle sensor, such as a potentiometer, is attached near the rotation axis of the second movable positioning worm wheel WH2M. The rotation angle sensor may also be attached to the motor shaft.

[0062] In the illustrated example, the rotation axis of the second fixed-positioning worm wheel WH2F and the rotation axis of the second movable-positioning worm wheel WH2M are arranged parallel to the Y-axis and offset in the X-axis direction. This arrangement has the effect of facilitating the installation of rotation angle sensors corresponding to each rotation axis.

[0063] Frame member FM24 is fixed to the rear ends of each of frame members FM21 to FM23, and is also fixed to the upper end surface of the rear wall portion of frame member FM26. Frame member FM25 is positioned to support the lower surfaces of the central portions of each of frame members FM21 to FM23, and is fixed to the inner bottom surface of frame member FM26. Frame member FM26 is a member having a front wall portion and a rear wall portion. The front ends of each of frame members FM21 to FM23 are fixed to the upper end surface of the front wall portion of frame member FM26.

[0064] A force detection sensor SG (second force detection sensor SG2) is attached to the frame portion surrounding the rectangular opening RA1 of the frame member FM21. The force detection sensor SG is a device for detecting the force acting on the robot hand 100. In the illustrated example, as shown in Figure 2, the force detection sensor SG includes a first force detection sensor SG1 for detecting the force acting on the first finger portion FP1, a second force detection sensor SG2 for detecting the force acting on the second finger portion FP2, a third force detection sensor SG3 for detecting the force acting on the third finger portion FP3, and a fourth force detection sensor SG4 for detecting the force acting on the fourth finger portion FP4. As shown in the lower diagram of Figure 12, the second force detection sensor SG2 consists of at least one (four in the illustrated example) strain gauge sensors attached to the frame portion (elongated portion) of the frame member FM21. That is, each strain gauge sensor is attached to a part (strain-generating body) that is easily expanded or contracted when subjected to force. The same applies to the first force detection sensor SG1, the third force detection sensor SG3, and the fourth force detection sensor SG4. However, the force detection sensors SG (first force detection sensor SG11 to fourth force detection sensor SG14) may be attached to the palm part PM as shown in Figure 16, or to other parts of the robot hand 100. Furthermore, the force detection sensors SG may be piezoelectric sensors, capacitive sensors, or sensors of other types.

[0065] This arrangement of the force detection sensor SG has the effect of simplifying the structure of the robot hand 100. This is because there is no need to route cables for electrically connecting the force detection sensor SG and the control device 610 (hand controller 630) within the finger portion FP. Furthermore, this arrangement has the effect of improving the waterproofness and water resistance of the robot hand 100. This is because the electronic equipment, including the force detection sensor SG, can be placed (housed) in the palm portion PM instead of the finger portion FP. Additionally, attaching (sticking) the force detection sensor SG to the frame portion (elongated part) of the frame member FM21 also has the effect of simplifying the structure of the robot hand 100. This is because there is no need to provide special structures such as structures suitable for sensing the force detection sensor SG, and consequently, the number of parts can be reduced.

[0066] The control device 610 (hand controller 630) detects the change in tension of the wire (especially the fixed wire) when the finger portion FP of the robot hand 100 comes into contact with an object such as a workpiece 700, based on the output of the force detection sensor SG. By detecting this change in tension, the control device 610 (hand controller 630) can detect that the finger portion FP has come into contact with the object.

[0067] Furthermore, the second positioning device PD2 includes a second movable assembly MA2, as shown in Figure 13. Specifically, the second movable assembly MA2 includes a second movable positioning worm wheel WH2M, a second slide block SB2, and a movable pulley MP (second movable pulley MP2), as shown in the center view of Figure 13. The second slide block SB2 includes a central part CB, protrusions PT (left protrusion PTL and right protrusion PTR), and a movable pulley support block BK. The left protrusion PTL, which has a substantially rectangular end face, is fitted into a rectangular opening RA2 of the frame member FM22 so as to be slidable in the X-axis direction, and the right protrusion PTR, which has a substantially rectangular end face, is fitted into a rectangular opening RA3 of the frame member FM23 so as to be slidable in the X-axis direction. The central part CB is configured so that its rear surface is in contact with four biasing springs SP (second biasing spring SP2, see the lower view of Figure 13). The second biasing spring SP2 is compressed by the rear surface of the central part CB when the second movable assembly MA2 moves to the rear (X2 side), generating a restoring force.

[0068] As shown in Figure 14, the gripping device GD is configured to wind up or unwind the gripping wire WR10. Specifically, the gripping device GD includes a gripping motor MT10, a gripping worm gear WG10 (gripping worm WM10 and gripping worm wheel WH10), and a gripping wire WR10. The gripping device GD is configured to wind up the gripping wire WR10 by rotating the gripping motor MT10 in one direction (forward) and to unwind the gripping wire WR10 by rotating the gripping motor MT10 in the other direction (reverse). The gripping motor MT10 is configured to output a force greater than that generated by the positioning motor. This is to enable the generation of a tension greater than the wire tension generated by the positioning motor.

[0069] The gripping wire WR10 has one end (distal end) fixed to a fixing pin PN10 (see Figure 5) provided on the first palm portion PM1, and the other end (proximal end) fixed to a gripping worm wheel WH10 (see Figure 5). The gripping wire WR10 has its intermediate portion hooked onto a plurality of fixed wire attachment members (fixed pulleys FY (fixed pulleys FY1 to FY15, see Figures 3 and 4)) and a plurality of movable wire attachment members (movable pulleys MP (first movable pulley MP1 to fourth movable pulley MP4)). The plurality of movable pulleys MP include the first movable pulley MP1 provided on the first positioning device PD1, the second movable pulley MP2 provided on the second movable positioning device PD2M, the third movable pulley MP3 provided on the third movable positioning device PD3M, and the fourth movable pulley MP4 provided on the fourth movable positioning device PD4M.

[0070] With this configuration, the gripping device GD can move the movable pulley MP from its initial position (see left diagram in Figure 14) to its gripping position (see right diagram in Figure 14) by winding the gripping wire WR10 onto the gripping worm wheel WH10. Specifically, as shown in the right diagram in Figure 14, the gripping device GD can move the first movable pulley MP1 in the direction indicated by arrow AR11, the second movable pulley MP2 in the direction indicated by arrow AR12, the third movable pulley MP3 in the direction indicated by arrow AR13, and the fourth movable pulley MP4 in the direction indicated by arrow AR14. As a result, in the illustrated example, the first movable positioning device PD1M, equipped with the first movable pulley MP1, moves backward (towards X2) by a distance DS1, the second movable positioning device PD2M, equipped with the second movable pulley MP2, moves backward (towards X2) by a distance DS2, the third movable positioning device PD3M, equipped with the third movable pulley MP3, moves backward (towards X2) by a distance DS3, and the fourth movable positioning device PD4M, equipped with the fourth movable pulley MP4, moves backward (towards X2) by a distance DS4. This movement can achieve an action (gripping action) similar to the action (positioning action) of the finger portion FP caused by winding up the movable wire. The gripping action can also be described as an action that brings the tip of the first finger portion FP1 closer to the tips of the second finger portion FP2 to the fourth finger portion FP4.

[0071] Specifically, as shown by arrow AR12 in the right-hand diagram of Figure 14, when the second movable pulley MP2 moves backward, the entire second movable assembly MA2 (see the center diagram in Figure 13) moves backward. Then, as shown by arrow AR16, the second movable positioning worm wheel WH2M moves backward (towards X2) while rolling clockwise on the second movable positioning worm WM2M, as indicated by arrow AR15 in the upper diagram of Figure 15, and winds up the second movable wire WR2M. As a result, the tension of the second movable wire WR2M increases. In the illustrated example, the second movable positioning worm WM2M does not rotate around the worm shaft WX2M during the gripping operation, but it may rotate around the worm shaft WX2M. That is, the positioning operation and the gripping operation may be performed simultaneously.

[0072] In the example shown in Figure 15, the second movable positioning worm wheel WH2M rolls on the second movable positioning worm WM2M so as to rotate by an angle γ around its central axis (worm wheel axis). The central axis of the second movable positioning worm wheel WH2M then moves backward (towards X2) by a distance DS10.

[0073] In this way, the gripping device GD can bring the tip of the first finger FP1 closer to the tips of the second finger FP2 to the fourth finger FP4 by winding up each of the movable wires (first movable wire WR1M to fourth movable wire WR4M). That is, the robot hand 100 can grip an object such as a workpiece 700.

[0074] Furthermore, this configuration using a movable pulley MP has the effect of increasing the gripping force of each finger FP with a single gripping motor MT10. Additionally, this configuration has the effect of equalizing the gripping force of each finger FP.

[0075] Furthermore, when the gripping motor MT10 rotates in reverse and the gripping force provided by the gripping motor MT10 weakens, the second movable assembly MA2 moves forward while rolling in the reverse direction (counterclockwise) on the second movable positioning worm WM2M due to the restoring force of the second biasing spring SP2. In other words, the second movable assembly MA2 moves toward its original position (the position before the gripping operation began). Note that when the gripping motor MT10 is stopped, the second movable positioning worm WM2M functions as a stopper, so the second movable assembly MA2 does not move in the front-rear direction (X-axis direction). Also, when the positioning operation by the second movable motor MT2M is performed without increasing or decreasing the gripping force provided by the gripping motor MT10, the movement of the second movable assembly MA2 toward the rear is restricted by the second biasing spring SP2. Therefore, the second movable positioning worm wheel WH2M rotates without rolling on the second movable positioning worm WM2M which is rotating around the worm shaft WX2, and can wind up the second movable wire WR2M.

[0076] Next, the details of the rocking device SD will be explained with reference to Figures 16 to 19. Figure 16 is a perspective view of the robot hand 100, including the palm section PM, which is moved by the rocking device SD. In Figure 16, the palm section PM is in its initial state (the plate surface of the base PM1B of the first palm section PM1 and the plate surface of the second palm section PM2 are parallel). Also, for clarity, the positioning device PD, which is actually mounted on the palm section PM, is not shown in Figure 16. Figure 17 is a diagram of the palm section PM and the rocking device SD. Specifically, the top, middle, and bottom views of Figure 17 are the top, rear, and bottom views of the rocking device SD mounted on the palm section PM. Figure 18 is a left side view of the robot hand 100 being rocked by the rocking device SD. Specifically, the upper part of Figure 18 shows the robot hand 100 when the palm portion PM is in its initial state, and the lower part of Figure 18 shows the robot hand 100 when the palm portion PM is in a swinging state (the plate surface of the base PM1B of the first palm portion PM1 and the plate surface of the second palm portion PM2 are not parallel). Figure 19 is a rear view of the robot hand 100 being oscillated by the swinging device SD. Specifically, the upper part of Figure 19 shows the robot hand 100 when the palm portion PM is in its initial state, and the lower part of Figure 18 shows the robot hand 100 when the palm portion PM is in a swinging state.

[0077] The oscillating device SD is a device that causes the first palm portion PM1 and the second palm portion PM2 to oscillate relative to each other. In the illustrated example, as shown in Figure 17, the oscillating device SD has an oscillating worm gear WG20, a first gear GR21, a second gear GR22, an oscillating shaft SH20 as an oscillating power transmission mechanism, and an oscillating motor MT20 as an oscillating actuator. The oscillating worm gear WG20 has an oscillating worm WM20 and an oscillating worm wheel WH20.

[0078] The first palm section PM1 is supported by the second palm section PM2 so that it can oscillate around the pivot axis PX of the pivot shaft SH20 and the pivot worm wheel WH20 as they rotate around the pivot axis PX. The pivot motor MT20, the first gear GR21, the second gear GR22, and the pivot worm WM20 are mounted on the second palm section PM2.

[0079] The oscillating motor MT20 rotates the first gear GR21, the second gear GR22, and the oscillating worm WM20 in sequence, thereby rotating the oscillating worm wheel WH20 and the oscillating shaft SH20 around the oscillating shaft PX, and consequently causing the first palm portion PM1 to oscillate. Note that the first gear GR21 and the second gear GR22 may be replaced with other rotational transmission mechanisms using belts and pulleys, etc.

[0080] Next, with reference to Figures 20 and 21, the slack suppression mechanism LP, which suppresses the slack of the gripping wire WR10 when the first palm portion PM1 is oscillated by the oscillating device SD, will be described. Figure 20 is a rear view of the fixed pulley FY, gripping device GD, slack suppression mechanism LP, palm portion PM, oscillating shaft SH20, and oscillating worm wheel WH20. Figure 21 is a perspective view of the slack suppression mechanism LP provided on the palm portion PM. Specifically, the left view of Figure 21 (upper left and lower left views) is a perspective view of the slack suppression mechanism LP provided on the palm portion PM viewed from the front left diagonally from above, and the right view of Figure 21 (upper right and lower right views) is a perspective view of the slack suppression mechanism LP provided on the palm portion PM viewed from the rear right diagonally from above. Furthermore, the upper diagrams of Figure 21 (upper left and upper right) are perspective views of the palm area PM in its initial state, while the lower diagrams of Figure 21 (lower left and lower right) are perspective views of the palm area PM in a oscillating state.

[0081] The slack suppression mechanism LP includes an oscillating pulley MP30 as an oscillating wire hanging member, and a pulley support block BK30. As shown in Figure 20, the oscillating pulley MP30 is a member on which a portion of the gripping wire WR10 is hung between the fixed pulleys FY9 and FY10, and is positioned so that its rotation axis RX30 extends parallel to the oscillating axis PX. The pulley support block BK30 is a member that rotatably supports the oscillating pulley MP30, and is positioned so that it can oscillate around the oscillating axis PX independently of the rotation of the oscillating worm wheel WH20 and the oscillating shaft SH20. In other words, the pulley support block BK30 is configured to oscillate around the oscillating axis PX while maintaining a state in which the rotation axis RX30 of the oscillating pulley MP30 and the oscillating axis PX are parallel, even when the oscillating worm wheel WH20 and the oscillating shaft SH20 are not rotating.

[0082] The rotation axes of fixed pulley FY9, fixed pulley FY10, and oscillating pulley MP30 are parallel to the oscillating axis PX and perpendicular to the rotation axis of fixed pulley FY8 in a top view as shown in Figure 3. In addition, the rotation axis of fixed pulley FY8 is perpendicular to the rotation axes of fixed pulleys FY4 to FY7 in a front view.

[0083] With this configuration, the relaxation suppression mechanism LP can prevent the gripping wire WR10 from becoming loose between the fixed pulley FY9 and the fixed pulley FY10, even when the palm portion PM changes from the initial state (see upper diagram in Figure 22) to the oscillating state (see lower diagram in Figure 22) by the oscillating device SD.

[0084] Figure 22 is a rear view of the fixed pulley FY9, fixed pulley FY10, oscillating pulley MP30, oscillating shaft SH20, palm section PM, and gripping wire WR10. Specifically, the upper part of Figure 22 shows the arrangement of each component when the palm section PM is in its initial state, and the lower part of Figure 22 shows the arrangement of each component when the palm section PM is in the oscillating state. In the lower part of Figure 22, for the sake of clarity, the positions of the fixed pulley FY10 and oscillating pulley MP30 in the initial state are shown with dashed lines.

[0085] As shown in Figure 22, when the first palm portion PM1 is oscillated relative to the second palm portion PM2 by the oscillating device SD, the center of the fixed pulley FY10 fixed to the first palm portion PM1 oscillates downward along the circumference of a circle with radius RD1 centered on the oscillating axis PX, when viewed from the rear along the X-axis. The center of the oscillating pulley MP30, which is pivotably mounted relative to the oscillating axis PX, oscillates downward along the circumference of a circle with radius RD2 centered on the oscillating axis PX due to the tension of the gripping wire WR10. The oscillating angle θ1 of the fixed pulley FY10 is greater than the oscillating angle θ2 of the oscillating pulley MP30. The oscillating angle θ1 of the fixed pulley FY10 corresponds to the oscillating angle of the first palm portion PM1. Furthermore, the length of the portion between point CT1 (a point on the gripping wire WR10 that is in contact with the fixed pulley FY9) and point CT2 (a point on the gripping wire WR10 that is in contact with the fixed pulley FY10) on the gripping wire WR10 remains constant whether the palm portion PM is in its initial state or in a swinging state.

[0086] If the oscillating pulley MP30 were a fixed pulley (non-oscillating pulley) with the oscillating axis PX as its axis of rotation, then when the first palm portion PM1 (fixed pulley FY10) oscillates around the oscillating axis PX, the gripping wire WR10 would slacken between the fixed pulley (non-oscillating pulley) and the fixed pulley FY10. This is because the length of the portion of the gripping wire WR10 that was in contact with the fixed pulley (non-oscillating pulley) (the wrapped portion) would shorten. The slackening suppression mechanism LP can suppress such slack by allowing the pulley support block BK30, which supports the oscillating pulley MP30, to oscillate freely around the oscillating axis PX. Specifically, when the palm portion PM is in a swinging state (as shown in the lower diagram of Figure 22), the distance between the rotation axis of the fixed pulley FY10 and the rotation axis of the swinging pulley MP30 increases as the swing angle θ1 is greater than the swing angle θ2, compared to when the palm portion PM is in its initial state (as shown in the upper diagram of Figure 22). The slack suppression mechanism LP can then absorb the slack in the gripping wire WR10 due to this increase.

[0087] Thus, the slack suppression mechanism LP is configured such that the pulley support block BK30, which supports the swing pulley MP30, swings around the swing axis PX due to the tension of the gripping wire WR10. Therefore, the slack suppression mechanism LP can suppress the gripping wire WR10 from slackening even when the palm portion PM changes from an initial state to a swinging state. Therefore, the slack suppression mechanism LP can prevent the movement of the robot hand 100 from being hindered by the slack of the gripping wire WR10. In addition, the slack suppression mechanism LP can prevent the swing angle of the first finger portion FP1 from being limited by the slack of the gripping wire WR10, and prevent the amount of winding of the gripping wire WR10 by the gripping device GD from increasing due to the slack of the gripping wire WR10.

[0088] As shown in the lower part of Figure 22, the oscillating pulley MP30 is configured to oscillate on the side closer to the fixed pulley FY10 (Y1 side) than the oscillating axis PX in the Y-axis direction. However, it may also be configured to oscillate on the side further from the fixed pulley FY10 (Y2 side) than the oscillating axis PX. Furthermore, as shown in the upper part of Figure 22, the oscillating pulley MP30 is positioned such that the distance between the rotation axis RX30 of the oscillating pulley MP30 and the oscillating axis PX (radius RD2) is smaller than the distance between the rotation axis of the fixed pulley FY10 and the oscillating axis PX (radius RD1). However, if the oscillating pulley MP30 is configured to oscillate on the side further from the fixed pulley FY10 (Y2 side) than the oscillating axis PX, it may be positioned such that the radius RD2 is larger than the radius RD1.

[0089] As described above, the robot hand 100 according to the embodiment of this disclosure, as shown in Figure 2, includes a first finger portion FP1, a second finger portion FP2, a palm portion PM, a plurality of first positioning worm gears WG1 (see Figure 4) arranged in the palm portion PM and transmitting a force to control the posture of the first finger portion FP1, a plurality of second positioning worm gears WG2 (see Figure 3) arranged in the palm portion PM and transmitting a force to control the posture of the second finger portion FP2, and a gripping worm gear WG10 arranged in the palm portion PM and transmitting a force to grip an object (workpiece 700, see Figure 1) by the first finger portion FP1 and the second finger portion FP2. As shown in Figure 10, the gripping worm gear WG10 is positioned in the palm portion PM such that the first angle α formed between the first plane VL1, which includes the worm shafts WX2 (worm shafts WX2F and WX2M) of each of the multiple second positioning worm gears WG2 (second fixed positioning worm WM2F and second movable positioning worm WM2M), and the worm shaft WX10 of the gripping worm gear WG10 (gripping worm WM10) is less than a predetermined angle. The predetermined angle is preferably 20 degrees, more preferably 10 degrees, and even more preferably 5 degrees.

[0090] This configuration has the effect of allowing multiple worm gears WG to be arranged with greater space efficiency. Furthermore, as shown in Figure 10, this configuration has the effect of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited height dimension HT of the palm portion PM.

[0091] Furthermore, the gripping worm gear WG10 may be positioned in the palm portion PM such that, as shown in Figure 11, the second angle β formed between the second plane VL2 perpendicular to the worm axis WX2 of the second positioning worm gear WG2 and the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) is less than a predetermined angle. The predetermined angle is preferably 20 degrees, more preferably 10 degrees, and even more preferably 5 degrees.

[0092] As shown in Figure 11, this configuration has the advantage of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited depth dimension DT of the palm portion PM.

[0093] Furthermore, the gripping worm gear WG10 may be arranged such that the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) is parallel to the first plane VL1, as shown in Figure 9. Alternatively, the gripping worm gear WG10 may be arranged such that the first angle α and the second angle β are zero degrees, as shown in Figure 9. The robot hand 100 may also have a gripping motor MT10 as a gripping rotary actuator that drives the gripping worm gear WG10, as shown in Figure 9. In this case, the gripping worm gear WG10 may be arranged such that the rotation axis RX10 of the gripping motor MT10 and the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) are on the same straight line. Furthermore, as shown in Figure 9, the robot hand 100 may have a second motor MT2 as a second positioning rotary actuator that drives the second positioning worm gear WG2. In this case, the second positioning worm gear WG2 may be arranged such that the rotation axis RX2 of the second motor MT2 and the worm axis WX2 of the second positioning worm gear WG2 (second positioning worm WM2) are located on the same straight line.

[0094] As shown in Figure 9, this configuration has the advantage of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited height dimension HT of the palm portion PM and within the limited depth dimension DT of the palm portion PM.

[0095] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure has a plurality of finger portions FP, a palm portion PM, and a force detection sensor SG that detects when at least one of the plurality of finger portions FP touches an object (workpiece 700). The force detection sensor SG is located on the palm portion PM.

[0096] This configuration has the effect of realizing a function (contact detection function) that detects contact between the finger portion FP and an object such as the workpiece 700 with a simpler structure. Furthermore, this configuration allows for the detection of contact between the finger portion FP and the workpiece 700 without delay, enabling the robot hand 100 to stably grip the workpiece 700. This configuration also simplifies the structure of the robot hand 100 because it eliminates the need to route cables for electrically connecting the force detection sensor SG and the control device 610 (hand controller 630) within the finger portion FP. Additionally, this configuration enhances the waterproof and water-resistant properties of the robot hand 100 because the electronic equipment, including the force detection sensor SG, can be housed in the palm portion PM instead of the finger portion FP.

[0097] Furthermore, the force detection sensor SG may be arranged to correspond to at least one of the multiple finger portions FP.

[0098] This configuration has the effect of being able to determine that at least one of the multiple finger portions FP has come into contact with an object. With this configuration, the hand controller 630 can determine, for example, that at least one of the four finger portions FP has come into contact with an object.

[0099] Furthermore, as shown in Figure 2, multiple force detection sensors SG may be arranged to correspond to each of the multiple finger portions FP.

[0100] This configuration has the effect of being able to identify which of the multiple finger portions FP has made contact with the object. With this configuration, the hand controller 630 can determine, for example, that all four finger portions FP have made contact with the object. Alternatively, the hand controller 630 can determine, for example, that only the third finger portion FP3 of the four finger portions FP has not made contact with the object.

[0101] Furthermore, as shown in Figure 2, the multiple finger portions FP may have a first finger portion FP1 and a second finger portion FP2, and may be arranged so that the first finger portion FP1 and the second finger portion FP2 can grip an object (workpiece 700). The force detection sensor SG may be arranged to correspond to the second finger portion FP2.

[0102] This configuration has the effect of being able to determine with high accuracy whether or not the second finger portion FP2 has come into contact with an object. Furthermore, compared to a configuration in which force detection sensors SG are attached to the palm portion PM corresponding to each of the multiple finger portions FP, this configuration has the effects of reducing the manufacturing cost of the robot hand 100, reducing the number of parts, improving space efficiency in the parts constituting the palm portion PM, and saving space for the robot hand 100.

[0103] Furthermore, as shown in Figure 2, the force detection sensor SG may include at least one of a strain gauge sensor, a piezoelectric sensor, and a capacitive sensor for detecting the magnitude of deformation of the palm portion PM when at least one of the first finger portion FP1 and the second finger portion FP2 touches an object (workpiece 700). The robot hand 100 may also have a control device for processing the signal output by the force detection sensor SG. The control device may be a control device 610, a picking robot controller 620, or a hand controller 630.

[0104] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure includes a finger portion FP including a first finger portion FP1 and a second finger portion FP2, a palm portion PM, a positioning device PD including a first movable positioning device PD1M (see Figure 4) disposed on the palm portion PM and controlling the posture of the first finger portion FP1, and a second movable positioning device PD2M disposed on the palm portion PM and controlling the posture of the second finger portion FP2, and a gripping device GD disposed on the palm portion PM and controlling the force with which the first finger portion FP1 and the second finger portion FP2 grip an object (workpiece 700, see Figure 1). The first movable positioning device PD1M includes a first movable positioning worm gear WG1M as a first movable positioning power transmission mechanism disposed on the palm portion PM, as shown in Figure 4. Furthermore, as shown in Figure 3, the second movable positioning device PD2M has a second movable positioning worm gear WG2M as a second movable positioning power transmission mechanism located in the palm portion PM. Also, as shown in Figure 3, the gripping device GD has a gripping worm gear WG10 as a gripping power transmission mechanism located in the palm portion PM, and a gripping wire WR10, one end of which is fixed to the palm portion PM and the other end of which is fixed to the gripping worm gear WG10 (gripping worm wheel WH10, see Figure 5) and wound up. Furthermore, the middle portion of the gripping wire WR10 is attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. As shown in Figure 14, the robot hand 100 increases the gripping force on the object (workpiece 700) by causing the gripping device GD to wind the gripping wire WR10, thereby moving the first movable positioning worm gear WG1M and the second movable positioning worm gear WG2M away from the finger portion FP.

[0105] This configuration allows for the implementation of a gripping device GD using a simple machine such as a pulley system (a combination of a fixed pulley FY and a movable pulley MP), resulting in a space-saving design for the robot hand 100. Furthermore, this configuration allows for the increased gripping force provided by the first finger portion FP1 and the second finger portion FP2 to be achieved with a single wire (gripping wire WR10).

[0106] Furthermore, the finger portion FP may include a third finger portion FP3, as shown in Figure 2. In this case, the positioning device PD may include a third movable positioning device PD3M, which is positioned on the palm portion PM and controls the posture of the third finger portion FP3. The third movable positioning device PD3M may also have a third movable positioning worm gear WG3M, which is a third movable positioning power transmission mechanism positioned on the palm portion PM, as shown in Figure 3. Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, a third movable wire attachment member (third movable pulley MP3) provided on the third movable positioning worm gear WG3M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. By winding the gripping wire WR10 onto the gripping device GD, the first movable positioning worm gear WG1M, the second movable positioning worm gear WG2M, and the third movable positioning worm gear WG3M may be moved away from the finger portion FP, thereby increasing the gripping force on the object (workpiece 700).

[0107] This configuration has the effect of increasing the gripping force provided by the first finger portion FP1, the second finger portion FP2, and the third finger portion FP3 using a single wire (gripping wire WR10).

[0108] Furthermore, the finger portion FP may further include a fourth finger portion FP4, as shown in Figure 2. In this case, the positioning device PD may include a fourth movable positioning device PD4M, which is positioned on the palm portion PM and controls the posture of the fourth finger portion FP4. The fourth movable positioning device PD4M may also have a fourth movable positioning worm gear WG4M, which is a fourth movable positioning power transmission mechanism positioned on the palm portion PM, as shown in Figure 3. Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, a third movable wire attachment member (third movable pulley MP3) provided on the third movable positioning worm gear WG3M, a fourth movable wire attachment member (fourth movable pulley MP4) provided on the fourth movable positioning worm gear WG4M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. Furthermore, by winding the gripping wire WR10 onto the gripping device GD, the first movable positioning worm gear WG1M, the second movable positioning worm gear WG2M, the third movable positioning worm gear WG3M, and the fourth movable positioning worm gear WG4M may be moved away from the finger portion FP, thereby increasing the gripping force on the object (workpiece 700).

[0109] This configuration has the effect of increasing the gripping force provided by the first finger portion FP1 and the second to fourth finger portions FP2 to FP4 using a single wire (gripping wire WR10).

[0110] Furthermore, the worm gear (movable positioning worm gear) may include a worm (movable positioning worm) and a worm wheel (movable positioning worm wheel). In this case, the robot hand 100 may increase the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby causing the (movable positioning worm wheel) to roll on the worm (movable positioning worm) in a direction away from the finger portion FP. Also, the movable wire attachment member may be a pulley, pin, or ring, etc. Similarly, the fixed wire attachment member may be a pulley, pin, or ring, etc.

[0111] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure includes a finger portion FP including a first finger portion FP1 and a second finger portion FP2, a palm portion PM including a first palm portion PM1 on which the first finger portion FP1 is located and a second palm portion PM2 on which the second finger portion FP2 is located, and a swing mechanism that swings the first palm portion PM1 and the second palm portion PM2 relative to each other around a swing axis PX (see Figure 5) located between the first palm portion PM1 and the second palm portion PM2. The device SD (see Figure 5) includes a positioning device PD which includes a first movable positioning device PD1M positioned on the palm PM and controlling the posture of the first finger portion FP1, and a second movable positioning device PD2M positioned on the palm PM and controlling the posture of the second finger portion FP2, and a gripping device GD positioned on the palm PM and controlling the force with which the first finger portion FP1 and the second finger portion FP2 grip an object (workpiece 700). The gripping device GD includes a gripping worm gear WG10 as a gripping power transmission mechanism positioned on the palm PM, and a gripping wire WR10 which has one end fixed to the palm PM and the other end fixed to the gripping worm gear WG10 (gripping worm wheel WH10) and wound up. As shown in Figure 20, the middle portion of the gripping wire WR10 is attached to a first fixed wire attachment member (fixed pulley FY10) that is immovably mounted on the first palm part PM1, a second fixed wire attachment member (fixed pulley FY9) that is immovably mounted on the second palm part PM2, and a swinging wire attachment member (swinging pulley MP30) that is swingable around the swing axis PX. The robot hand 100 then increases the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby moving the first finger part FP1 and the second finger part FP2 so that the tips of the first finger part FP1 and the second finger part FP2 move closer to each other.

[0112] This configuration has the effect of enabling the gripping device GD and the rocking device SD to operate appropriately. Furthermore, this configuration has the effect of enabling the gripping device GD, which increases the gripping force of multiple finger parts FP including the first finger part FP1 using a single gripping wire WR10, and the rocking device SD, which rocks the first palm part PM1 (first finger part FP1), to operate appropriately. As a result, with this configuration, the robot hand 100 can assume a gripping posture with a greater degree of freedom.

[0113] Furthermore, as shown in Figure 22, the gripping wire WR10 may be arranged such that a third wire portion WP3, located between a first wire portion WP1 that contacts the first fixed wire hanging member (fixed pulley FY10) and a second wire portion WP2 that contacts the second fixed wire hanging member (fixed pulley FY9), contacts the oscillating wire hanging member (oscillating pulley MP30). Also, as shown in Figure 22, the oscillating wire hanging member (oscillating pulley MP30) may be positioned closer to the oscillating axis PX than the first fixed wire hanging member (fixed pulley FY10) and the second fixed wire hanging member (fixed pulley FY9).

[0114] Furthermore, as shown in Figure 4, the first movable positioning device PD1M may include a first movable positioning worm gear WG1M positioned on the first palm portion PM1, and a first movable wire WR1M, one end of which is fixed to the first finger portion FP1 and the other end of which is fixed to and wound up by the first movable positioning worm gear WG1M (first movable positioning worm wheel WH1M). Furthermore, as shown in Figure 3, the second movable positioning device PD2M may include a second movable positioning worm gear WG2M positioned on the second palm portion PM2, and a second movable wire WR2M, one end of which is fixed to the second finger portion FP2 and the other end of which is fixed to and wound up by the second movable positioning worm gear WG2M (second movable positioning worm wheel WH2M). Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first fixed wire attachment member (fixed pulley FY10), a second fixed wire attachment member (fixed pulley FY9), a first movable wire attachment member (first movable pulley MP1, see Figure 14) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2, see Figure 14) provided on the second movable positioning worm gear WG2M, and a swinging wire attachment member (swinging pulley MP30), as shown in Figure 22. The robot hand 100 may increase the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby moving the first movable positioning worm gear WG1M and the second movable positioning worm gear WG2M away from the finger portion FP. Furthermore, the swinging wire hanger, the movable wire hanger, and the fixed wire hanger may each be a pulley, a pin, or a ring, etc.

[0115] This configuration has the effect of suppressing the slack in the gripping wire WR10 when the first palm portion PM1 is swung by the swinging device SD.

[0116] Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications and substitutions can be applied to the embodiments described above without departing from the scope of the present invention. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not conflict technically.

[0117] This application claims priority based on Japanese Patent Application No. 2025-032335, filed on 28 February 2025, and the entire contents of that Japanese Patent Application are incorporated herein by reference.

[0118]

Claims

1. A robot hand comprising: a first finger portion; a second finger portion; a palm portion; a plurality of first positioning worm gears disposed on the palm portion for transmitting a force to control the posture of the first finger portion; a plurality of second positioning worm gears disposed on the palm portion for transmitting a force to control the posture of the second finger portion; and a gripping worm gear disposed on the palm portion for transmitting a force to grip an object by the first finger portion and the second finger portion, wherein the gripping worm gear is disposed on the palm portion such that the first angle formed between a first plane containing the worm axes of each of the plurality of second positioning worm gears and the worm axis of the gripping worm gear is less than 20 degrees.

2. The robot hand according to claim 1, wherein the gripping worm gear is positioned in the palm portion such that the second angle formed between a second plane perpendicular to the worm axis of the second positioning worm gear and the worm axis of the gripping worm gear is less than 20 degrees.

3. The robot hand according to claim 1, wherein the gripping worm gear is arranged such that the worm axis of the gripping worm gear is parallel to the first plane.

4. The robot hand according to claim 2, wherein the gripping worm gear is arranged such that the first angle and the second angle are zero degrees.

5. The robot hand according to claim 1, further comprising a gripping rotary actuator for driving the gripping worm gear, wherein the gripping worm gear is arranged such that the rotation axis of the gripping rotary actuator and the worm axis of the gripping worm gear are located on the same straight line.

6. The robot hand according to claim 1, further comprising a second positioning rotary actuator for driving the second positioning worm gear, wherein the second positioning worm gear is positioned such that the rotation axis of the second positioning rotary actuator and the worm axis of the second positioning worm gear are on the same straight line.

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