JP6843541B2 - Drive mechanism, robot device, manufacturing method of goods, and control method - Google Patents

Description

The present invention is a drive mechanism provided with a torque sensor, a robot apparatus provided with a drive rotation mechanism, a method of manufacturing an article, and a control method.

In recent years, articulated robots have come to be used in various industrial product production lines. However, there are many processes that are difficult to realize with robots. For example, robots can realize processes that require a load of several grams to be applied to parts, such as assembling workpieces made of flexible materials, lightweight materials, or low-strength members, and processes that perform precision fitting. There were various difficulties in doing so.

When handling workpieces such as flexible objects, lightweight objects, and low-strength members as described above, for example, in order to prevent the workpieces from being damaged or deformed, a large force cannot be applied to these workpieces. Therefore, when operating this type of work with an articulated robot, it is necessary to control the force acting on the work with high accuracy. Specifically, the force acting on the work is detected and fed back to the drive control of the robot arm.

As a method of detecting the force acting on the work, a configuration is known in which a torque sensor for detecting the torque applied to the joint is arranged in each joint of the robot arm (see, for example, Patent Document 1). The force acting on the tip of the robot arm, that is, the work can be detected by the torque acting on each joint of the robot arm.

Japanese Unexamined Patent Publication No. 10-286789

In the conventional configuration, the electric motor is arranged on the first link on the fixed side, and the rotating shaft of the electric motor is connected to the input shaft of the speed reducer via a transmission mechanism including a belt and a pulley. Then, the output shaft of the speed reducer is connected to the second link on the drive side via a torque sensor. Therefore, the torque sensor detects the torque between the output shaft of the reducer and the second link as the torque acting on the second link.

By the way, it is necessary to pull out the wiring such as the signal line of the torque sensor to the first link side which is the fixed side. The wiring drawn out to the first link side is connected to the control device. This enables wired communication between the torque sensor and the control device.

However, when the torque sensor is arranged between the second link and the output shaft of the reducer, the wiring routed from the torque sensor to the first link side responds to the rotational drive of the second link. Deformation such as bending and twisting occurs. Therefore, a force due to deformation such as bending or twisting of the wiring of the torque sensor is applied between the first link and the second link. In other words, when the wiring is deformed, a force that tries to restore it to its original state acts between the links. Therefore, the torque value detected by the torque sensor has an error due to the force received from the wiring. Therefore, in the conventional configuration, there is a problem that the torque acting on the second link cannot be accurately detected.

Further, since the second link is rotationally driven with respect to the first link, the wiring of the torque sensor is repeatedly deformed such as bending and twisting, so that the wiring is loaded for a long period of time and the conductor of the wiring. Was a factor that shortened the life of the wiring, such as disconnection.

Therefore, the present invention prevents the wiring of the torque sensor from being repeatedly deformed even if the second link is rotationally driven with respect to the first link, and the torque sensor acts on the second link. The purpose is to detect torque with high accuracy.

The drive mechanism of the present invention is a drive mechanism that relatively displaces the first and second links, and includes a motor, a speed reducer, and a torque sensor, and the speed reducer is driven by the motor. A rotating input shaft is provided, the torque sensor is arranged between the speed reducer and the first link, and the input shaft passes through the inside of the torque sensor .

According to the present invention, even if the second link is rotationally driven with respect to the first link, it is possible to prevent the wiring of the torque sensor from being repeatedly deformed, and the life of the wiring can be extended. Further, it is possible to prevent the force due to the deformation of the wiring from being superimposed on the detection result of the torque sensor, and the torque sensor can detect the torque acting on the second link with high accuracy.

It is a perspective view which shows the schematic structure of the robot apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the drive mechanism which concerns on 1st Embodiment. It is a schematic diagram which shows the drive part of the drive mechanism which concerns on 1st Embodiment. It is a schematic diagram which shows the drive mechanism which concerns on 2nd Embodiment. It is a schematic diagram which shows the drive mechanism which concerns on 3rd Embodiment. It is a schematic diagram which shows the drive mechanism which concerns on 4th Embodiment. It is a schematic diagram which shows the drive mechanism which concerns on 5th Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective view showing a schematic configuration of a robot device according to the first embodiment. As shown in FIG. 1, the robot device 100 includes a robot 200 and a robot control device 300 that controls the operation of the robot 200. Further, the robot device 100 includes a teaching pendant 400 as a teaching device for transmitting data of a plurality of teaching points to the robot control device 300. The teaching pendant 400 is operated by a human and is used to specify the operation of the robot 200 and the robot control device 300.

The robot 200 includes a vertical articulated robot arm 201 and a robot hand 202 as an end effector attached to the tip of the robot arm 201.

The base end of the robot arm 201 is a fixed end fixed to the pedestal B. The tip of the robot arm 201 is a free end. The robot arm 201 can have its hand (the tip of the robot arm 201) directed to any three-dimensional posture at any three-dimensional position within the movable range.

The robot arm 201 has a plurality of joints, for example, six joints J _{1 to} J ₆ . The robot arm 201 has a plurality (six) drive units 510 that rotationally drive the _{joints J 1 to} J ₆ around the rotation axes C _{1 to} C _{6, respectively.}

The robot arm 201 has a plurality of links 210 _{0 to 210 6} , and the plurality of links 210 _{0 to 210 6} are rotatably connected by joints J _{1 to} J _6. Here, from the proximal side to the distal side, the link ₂₁₀ 0-210 ₆ are sequentially connected in series.

Each driving unit 510, a pair of links ₂₁₀ i-1, which is articulated _{J i,} 210 _i of the second link 210 is a driving side with respect to the first link _{210 i-1} is a fixed side _{Drive i} to rotate. Here, i = 1 to 6.

In addition, each joint _{J i,} the torque sensor 520 for detecting the torque acting on the first link _{210 i-1} to the second link 210 _i are arranged.

The robot arm 201 further has a servo control device 230 as a control device for driving and controlling each drive unit 510. Based on the torque command input from the robot control device 300, the servo control device 230 outputs a current command to each drive unit 510 so that the torques of the _{joints J 1 to} J _{6 follow the torque command, and drives each drive.} Controls the operation of unit 510. In the present embodiment, the servo control device 230 is described as being composed of one control device, but it may be composed of a plurality of control devices corresponding to each drive unit 510. Further, the servo control device 230 is arranged in the base end (link 210) of the robot arm 201, but is not limited to this, and may be arranged in, for example, the housing of the robot control device 300. ..

In the first embodiment, in each joint _{J i,} the first link _{210 i-1,} and the second link 210 _i, and the driving unit 510, the drive mechanism 500 is configured to have a torque sensor 520 There is. Therefore, the robot arm 201 includes six drive mechanisms 500.

FIG. 2 is a schematic view showing a drive mechanism according to the first embodiment. FIG. 2 schematically illustrates the drive mechanism 500 in any one of the plurality of joints of the robot arm 201.

The drive unit 510 and the torque sensor 520 are arranged between the _{pair of links 210 i-1} and 210 _i. The second link 210 _i is driven by the driving unit 510 and rotates the rotation axis _{C i} around the first link _{210 i-1.}

FIG. 3 is a schematic view showing a driving unit of the driving mechanism according to the first embodiment. As shown in FIGS. 2 and 3, the drive unit 510 is a unitized drive unit having an electric motor 530, a transmission mechanism 540, a speed reducer 550, and a support member 560.

The electric motor 530 is, for example, a brushless DC motor. The electric motor 530 has a housing 531 which is a fixing member, a stator (not shown) which is arranged inside the housing 531 and fixed to the housing 531, a rotor (not shown) which rotates with respect to the stator, and a rotor. It has a rotating shaft 532 extending outward from the housing 531. Rotation axis 532 is rotated about the axis _{C A} relative to the housing 531 (the stator).

The speed reducer 550 reduces the rotation speed of the rotation shaft 532 of the electric motor 530 by a predetermined reduction ratio and outputs the speed reduction gear, for example, a strain wave gearing speed reducer. Hereinafter, the case where the speed reducer 550 is a strain wave gearing speed reducer will be described, but the speed reduction gear is not limited to this, and any speed reducer such as a swing gear speed reducer and a planetary gear speed reducer may be used. ..

The speed reducer 550 has a housing 551 which is a fixing member, and an input shaft 552 which is an input member which receives a rotation input and rotates with respect to the housing 551. Housing 551 is a circular spline with gears formed inside.

Further, the speed reducer 550 has an output shaft 553 which is an output member that rotates with respect to the housing 551 at a rotation speed decelerated with respect to the input shaft 552. The speed reducer 550 decelerates the rotation received by the input shaft 552 and outputs it on the output shaft 553.

Further, as shown in FIG. 3, the speed reducer 550 includes a web generator 554 fixed to the input shaft 552 and a flexspline 555 fixed to the output shaft 553. The flexspline 555 is arranged between the web generator 554 and the housing 551 which is a circular spline, is decelerated at a predetermined reduction ratio with respect to the rotation of the web generator 554, and rotates relative to the housing 551.

The input shaft 552 is rotatably supported by the housing 551 via a bearing 556. The output shaft 553 is rotatably supported by the housing 551 via a bearing 557. The input shaft 552 and output shaft 553 is disposed coaxially rotates relative to the housing 551 about the axis C _B. Center axis C _B is the central axis of the reduction gear 550.

Reducer 550, as shown in FIG. 2, the central axis C _B are arranged so as to overlap the rotational axis C _i. The housing 551 of the speed reducer 550 and the housing 531 of the electric motor 530 are fixedly supported by the support member 560. The support member 560 is a box-shaped member, and a transmission mechanism 540 is arranged inside.

Electric motor 530, the central axis C _A is supported by the supporting member 560 with a shift to the rotation axis C _i. Is parallel with the center axis C _A and the rotation axis C _i. That is, the electric motor 530 is arranged in parallel next to the speed reducer 550, and the driving force of the electric motor 530 is transmitted to the speed reducer 550 via the transmission mechanism 540. Thus, the size of the direction of the drive portion 510 of the rotational axis C _i is reduced, thereby achieving a compactness of the robot arm 201.

The electric motor 530 is arranged so that _{the rotating shaft 532 projects toward the first link 210 i-1.} Further, the reduction gear 550, input shaft 552 is arranged so as protrude toward the first link _{210 i-1,} the output shaft 553 projecting toward the second link 210 _i.

The transmission mechanism 540 transmits the rotation of the rotation shaft 532 of the electric motor 530 to the input shaft 552 of the speed reducer 550. The transmission mechanism 540 is wound between the drive side pulley 541 fixed to the rotating shaft 532 of the electric motor 530, the driven side pulley 542 fixed to the input shaft 552 of the speed reducer 550, and the pulleys 541 and 542. It is configured to have an endless belt 543.

The torque sensor 520, the center axis C _C of the torque sensor 520 is arranged so as to overlap the rotational axis C _i. Torque sensor 520 includes a primary member 521 and secondary member 522, the torque around the rotation axis _{C i} (center axis _{C C)} which acts on the primary side member 521 on the secondary side member 522 To detect. For example the torque sensor 520 connected to the primary side member 521 and the secondary side member 522, around the rotational axis C _i according to the torque acting between the primary member 521 and secondary member 522 It has an elastic member (not shown) that elastically deforms. Further, the torque sensor 520 has a detection element (not shown) that detects the amount of deformation of the elastic member. When torque around the rotation axis C _i between the primary member 521 and secondary member 522 is applied, the elastic member (not shown) is deformed. Further, the torque sensor 520 acquires the result of detecting the deformation amount of the elastic member by a detection element (not shown), converts the deformation amount into a torque value using a sensitivity matrix for converting the deformation amount into torque, and converts the deformation amount into a torque value as a signal. It has an arithmetic circuit (not shown) that outputs.

Displacement detection methods for the torque sensor 520 include strain gauge methods, capacitance methods, magnetic methods, encoder methods, and the like. In the torque sensor 520, the primary side member 521, the secondary side member 522, and the elastic member (not shown) may be formed of separate members or may be formed of an integral structure.

The primary side member 521 of the torque sensor 520 is fixedly connected to _{the first link 210 i-1.} The secondary side member 522 of the torque sensor 520 is fixedly connected to the support member 560. That is, the secondary side member 522 of the torque sensor 520 is connected to the housing 551 of the speed reducer 550 via the support member 560. The output shaft 553 of the speed reducer 550 is fixedly connected to _{the second link 210 i.} Thus, the second link 210 _i are relative to the housing 551 of the speed reducer 550 is relatively rotated about the rotational axis _{C i.}

The wiring 523 extending from the torque sensor 520 is pulled out to the side of the _{first link 210 i-1.} The wiring 523 is disposed along the first link _{210 i-1,} are fixed by clamping member 601 to the first link _{210 i-1.}

The wiring 533 extending from the electric motor 530 is pulled out to the side of the _{first link 210 i-1.} The wiring 533 is disposed along the first link _{210 i-1,} are fixed by clamping member 602 to the first link _{210 i-1.}

With the above configuration, when the second link 210 _i is rotationally driven, the rotor of the electric motor 530 is rotated to rotate the rotary shaft 532. As the rotation shaft 532 rotates, the input shaft 552 of the speed reducer 550 rotates via the transmission mechanism 540. The output shaft 553 rotates at a rotation speed decelerated by a predetermined reduction ratio due to the rotation of the input shaft 552, and the second link 210 _i connected to the output shaft 553 rotates about the rotation axis C _i .

On the other hand, _{when a torque (external force) acts on the second link 210 i} , the torque is transmitted to the output shaft 553 of the speed reducer 550, but due to the engagement between the flexspline 555 shown in FIG. 3 and the housing 551 which is a circular spline. Rotation is regulated. Therefore, the torque transmitted to the flexspline 555 is transmitted to the housing 551. The torque transmitted to the housing 551 is transmitted to the secondary side member 522 of the torque sensor 520 via the support member 560. In this way, most of the torque transmitted to the flexspline 555 is transmitted to the secondary side member 522 of the torque sensor 520 via the housing 551.

A part of the torque transmitted to the flexspline 555 is transmitted to the web generator 554, the input shaft 552, the transmission mechanism 540, and the electric motor 530, but is transmitted from the electric motor 530 to the support member 560, and as a result, the secondary torque sensor 520 is transmitted. It is transmitted to the side member 522. Thus, the torque sensor 520 can detect the torque of the rotation axis C _i around acting on the second link 210 _i with high accuracy.

Further, in the first embodiment, the primary side member 521 of the _{torque sensor 520 is connected to the first link 210 i-1,} and the wiring 523 of the torque sensor 520 is pulled out to the side of the _{first link 210 i-1.} It has been. That is, the torque sensor 520 is arranged between the drive unit 510 and the first link 210 _{i-1 on the fixed side.} As a result, the _{movable range of the second link 210 i} is not limited by the wiring 523.

The second link 210 _i are also rotation, never second link 210 _i wiring 523 in accordance with the rotation operation of deformation such as bending or twisting. In this way, it is possible to prevent the wiring 523 of the torque sensor 520 from being repeatedly deformed, and since the wiring 523 is not repeatedly loaded, the life of the wiring 523 can be extended. Since the wiring 533 of the electric motor 530 is also _{pulled out to the side of the first link 210 i-1} , the life can be extended.

Further, it is possible to prevent the force due to the deformation of the wirings 523 and 533 from being superimposed on the detection torque of the torque sensor 520, and the torque sensor 520 can detect the torque acting on _{the second link 210 i with high accuracy.} Wear.

Furthermore, according to the first embodiment, since the fixed in parallel to the electric motor 530 and reduction gear 550 with respect to the support member 560, the joints J _i than to place the electric motor 530 and reduction gear 550 in series The width can be reduced. As a result, it is possible to realize a miniaturized robot 200 having excellent workability even in a narrow space.

Further, since the central axis C _C of the torque sensor 520, that is, the rotating axis C _i and the central axis C _B of the speed reducer 550 overlap, _{the weight balance at the joint J i} is improved and the operation of the robot 200 is stabilized.

[Second Embodiment]
Next, the driving mechanism of the robot according to the second embodiment of the present invention will be described. FIG. 4 is a schematic view showing a drive mechanism according to the second embodiment. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The drive mechanism 500A of the second embodiment includes a first link 210 _i-1 , a second link 210 _i , a drive unit 510 A that rotationally drives the second link 210 _{i, and a torque sensor 520.} ing. The drive unit 510A includes an electric motor 530, a transmission mechanism 540A, a speed reducer 550, and a support member 560A. The central axis C _B of the speed reducer 550 overlaps with the _{rotating axis C i.} It is also overlapped with the rotational axis _{C i} the center axis _{C C} of the torque sensor 520.

In the first embodiment fixed in a state where the center axis C _A of the electric motor 530 is shifted to a parallel to the rotation axis C _i to the rotation axis C _i, the housing 531 of the electric motor 530 to the support member 560 The case where it is done was explained. In the second embodiment, in a state where the center axis _{C A} of the electric motor 530 is shifted crossed (orthogonal) to to the rotation axis _{C i} to the rotation axis _{C i,} the housing 531 of the electric motor 530 is the support member 560A It is fixed to. That is, the housing 531 and the housing 551 of the speed reducer 550 of the electric motor 530, and the center axis _{C A} and the center axis _{C B} are supported by the support member 560A on and intersecting (orthogonal).

Similar to the first embodiment, the transmission mechanism 540A transmits the rotation of the rotation shaft 532 of the electric motor 530 to the input shaft 552 of the speed reducer 550, but the configuration is different from that of the first embodiment. That is, the transmission mechanism 540A has a first bevel gear 541A fixed to the rotating shaft 532 and a second bevel gear 542A fixed to the input shaft 552 and meshed with the first bevel gear 541A.

As described above, according to the second embodiment, even if the second link 210 _{i is rotationally driven with respect to the first link 210 i-1} , the wiring 523 of the torque sensor 520 is repeatedly deformed as in the first embodiment. Can be prevented from occurring, and the life of the wiring 523 can be extended. Since the wiring 533 of the electric motor 530 is also _{pulled out to the side of the first link 210 i-1} , the life can be extended. Further, it is possible to prevent the force due to the deformation of the wirings 523 and 533 from being superimposed on the detection result of the torque sensor 520, and the torque sensor 520 can detect the torque acting on _{the second link 210 i with high accuracy.} Wear.

[Third Embodiment]
Next, the driving mechanism of the robot according to the third embodiment of the present invention will be described. FIG. 5 is a schematic view showing a drive mechanism according to the third embodiment. In the third embodiment, the same components as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

The drive mechanism 500B of the third embodiment includes a first link 210 _i-1 , a second link 210 _i , a drive unit 510B that rotationally drives the second link 210 _{i, and a torque sensor 520.} ing. The drive unit 510B includes an electric motor 530, a transmission mechanism 540, a speed reducer 550B, and a support member 560B.

The speed reducer 550B reduces the rotation speed of the rotation shaft 532 of the electric motor 530 by a predetermined reduction ratio and outputs the speed reduction gear, for example, a strain wave gearing speed reducer. The speed reducer 550B has a housing 551B which is a fixing member, and an input shaft 552B which is an input member which receives a rotation input and rotates with respect to the housing 551B. Further, the speed reducer 550 has an output member 553B that rotates with respect to the housing 551B at a rotation speed decelerated with respect to the input shaft 552B.

The input shaft 552B and the output member 553B is disposed coaxially rotates relative to the housing 551B about the axis _{C B.} Specifically, the output member 553B is a cylindrical member, and the input shaft 552B is arranged inside the output member 553B.

The housing 531 of the electric motor 530 and the housing 551B of the speed reducer 550B are fixed to the support member 560B. The central axis C _B of the speed reducer 550 B overlaps with the _{rotating axis C i.} It is also overlapped with the rotational axis _{C i} the center axis _{C C} of the torque sensor 520.

The electric motor 530 is arranged so that _{the rotating shaft 532 projects toward the second link 210 i.} Further, the speed reducer 550B is arranged so that the input shaft 552B and the output member 553B project toward _{the second link 210 i.} Then, the transmission mechanism 540 is arranged in the vicinity of _{the second link 210 i.} The drive-side pulley 541 of the transmission mechanism 540 is fixed to the rotating shaft 532, and the driven-side pulley 542 is fixed to the input shaft 552B.

The primary side member 521 of the torque sensor 520 is connected to the _{first link 210 i-1.} The secondary side member 522 of the torque sensor 520 is connected to the housing 551B of the speed reducer 550B via the support member 560B. The output member 553B of the speed reducer 550B is connected to _{the second link 210 i.}

As described above, the electric motor 530 and the reduction gear 550B are supported by the support member 560B so that the rotation shaft 532 of the electric motor 530 and the input shaft 552B of the reduction gear 550B project in the opposite direction to the first embodiment. However, the same effect as that of the first embodiment is obtained. That is, even if the second link 210 _{i is rotationally driven with respect to the first link 210 i-1} , it is possible to prevent the wiring 523 of the torque sensor 520 from being repeatedly deformed, and the life of the wiring 523 can be extended. Can be extended. Since the wiring 533 of the electric motor 530 is also _{pulled out to the side of the first link 210 i-1} , the life can be extended. Further, it is possible to prevent the force due to the deformation of the wirings 523 and 533 from being superimposed on the detection result of the torque sensor 520, and the torque sensor 520 can detect the torque acting on _{the second link 210 i with high accuracy.} Wear.

[Fourth Embodiment]
Next, the driving mechanism of the robot according to the fourth embodiment of the present invention will be described. FIG. 6 is a schematic view showing the drive mechanism according to the fourth embodiment. In the fourth embodiment, the same reference numerals are given to the same configurations as those in the first to third embodiments, and the description thereof will be omitted.

The drive mechanism 500C of the fourth embodiment includes a first link 210 _i-1 , a second link 210 _i , a drive unit 510, a torque sensor 520, and a bearing 570. In the fourth embodiment, the first link _{210 i-1,} is arranged a bearing 570 between the second link 210 _i, the first link _{210 i-1,} and the second link 210 _i , The bearing 570 enables relative rotation.

According to the drive mechanism 500C of the fourth embodiment, the same effect as that of the first embodiment is obtained. Furthermore, according to the fourth embodiment, the bearing 570, the second link 210 _i (joint _{J i),} also the direction of the force other than the rotation direction about the rotation axis _{C i} acts, the bearing 570 Because the force is received, the force does not act on the torque sensor 520. Therefore, since a force in a direction other than the rotation direction does not act on the torque sensor 520, a phenomenon called other-axis interference, in which the torque sensor 520 erroneously detects the torque, does not occur. Therefore, the torque sensor 520 can detect the torque with high accuracy. Further, since the amount of load acting on the torque sensor 520 is relaxed, the strength specification of the torque sensor 520 can be relaxed, and the degree of freedom in joint layout design and torque sensor design is improved.

The drive unit of the fourth embodiment has the configuration of the drive unit 510 described in the first embodiment, but the present invention is not limited to this, and the drive unit 510A and the third embodiment described in the second embodiment are not limited to this. The drive unit 510B described in the above may be configured.

[Fifth Embodiment]
Next, the driving mechanism of the robot according to the fifth embodiment of the present invention will be described. FIG. 7 is a schematic view showing the drive mechanism according to the fifth embodiment. In the fifth embodiment, the same components as those in the first to fourth embodiments are designated by the same reference numerals, and the description thereof will be omitted.

The drive mechanism 500D of the fifth embodiment includes a first link 210 _i-1 , a second link 210 _i , a drive unit 510D that rotationally drives the second link 210 _{i, and a torque sensor 520.} ing. The drive unit 510D includes an electric motor 530, a transmission mechanism 540, and a speed reducer 550. The primary side member 521 of the torque sensor 520 is fixedly connected to _{the first link 210 i-1 as in the first embodiment.} In the fifth embodiment, the secondary side member 522 of the torque sensor 520 is directly fixed and connected to the housing 551 which is a fixing member of the speed reducer 550. The output shaft 553 of the speed reducer 550 is fixedly connected to _{the second link 210 i as in the first embodiment.} The wiring 523 of the torque sensor 520 is pulled out to the side of the _{first link 210 i-1 as in the first embodiment.} The speed reducer 550 is arranged so that _{the central axis C B} overlaps with the rotation axis C _i.

In the fifth embodiment, the arrangement of the electric motor 530 is different from that in the first to fourth embodiments. Specifically, the housing 531 of the electric motor 530 is fixedly supported by _{the first link 210 i-1.}

Electric motor 530, the central axis C _A are arranged in a state where the rotation axis C _i the center axis C _A A parallel to the deviates to the rotation axis C _i. Then, the rotation of the rotation shaft 532 of the electric motor 530 is transmitted to the input shaft 552 of the speed reducer 550 by the transmission mechanism 540.

With the above configuration, when the second link 210 _i is rotationally driven, the rotor of the electric motor 530 is rotated to rotate the rotary shaft 532. As the rotation shaft 532 rotates, the input shaft 552 of the speed reducer 550 rotates via the transmission mechanism 540. The output shaft 553 rotates at a rotation speed decelerated by a predetermined reduction ratio due to the rotation of the input shaft 552, and the second link 210 _i connected to the output shaft 553 rotates about the rotation axis C _i .

On the other hand, _{when a torque (external force) acts on the second link 210 i} , the torque is transmitted to the output shaft 553 of the speed reducer 550 and is transmitted to the housing 551 via a flexspline (not shown). The torque transmitted to the housing 551 is transmitted to the secondary side member 522 of the torque sensor 520. In this way, _{most of the torque acting on the second link 210 i} is transmitted to the secondary side member 522 of the torque sensor 520 via the housing 551.

A part of the torque acting on the second link 210 _i is sequentially transmitted to the input shaft 552 of the speed reducer 550, the transmission mechanism 540, the electric motor 530, and the first link 210 _i-1 , and the torque sensor is transmitted to the transmission path. 520 is not included. Therefore, in the fifth embodiment, the accuracy of the torque detected by the torque sensor 520 is inferior to that in the first to fourth embodiments, but even if the second link 210 _i rotates, the second link The wiring 523 does not deform such as bending or twisting due to the rotational operation of _{210 i.} In this way, it is possible to prevent the wiring 523 of the torque sensor 520 from being repeatedly deformed, and since the wiring 523 is not repeatedly loaded, the life of the wiring 523 can be extended. Since the wiring 533 of the electric motor 530 is also _{pulled out to the side of the first link 210 i-1} , the life can be extended.

Further, it is possible to prevent the force due to the deformation of the wirings 523 and 533 from being superimposed on the detection torque of the torque sensor 520, and the torque sensor 520 can detect the torque acting on _{the second link 210 i with high accuracy.} Wear.

Further, according to the fifth embodiment, since the electric motor 530 and the speed reducer 550 are _{arranged in parallel with respect to the first link 210 i-1} , the electric motor 530 and the speed reducer 550 are arranged in series. also it is possible to miniaturize the width of the joint J _i. As a result, it is possible to realize a miniaturized robot 200 having excellent workability even in a narrow space.

The present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention. Moreover, the effects described in the embodiments are merely a list of the most preferable effects arising from the present invention, and the effects according to the present invention are not limited to those described in the embodiments.

In the above-described embodiment, the electric motor and the speed reducer are arranged in parallel to transmit the power via the transmission mechanism, but the present invention is not limited to this. The rotating shaft of the electric motor may be directly connected to the input shaft of the speed reducer without using a transmission mechanism. In this case, since the speed reducer and the electric motor are arranged in series so that the center axis of the electric motor and the center axis of the speed reducer overlap, the length of the drive mechanism in the extending direction of the rotation axis becomes long.

Further, in the above-described embodiment, the case where the robot arm is a vertical articulated type has been described, but the present invention is not limited to this. The robot arm may be various robot arms such as a horizontal articulated robot arm, a parallel link robot arm, and a Cartesian robot. Further, the number of joints of the robot arm is not limited to six.

Further, the case where all the joints of the robot arm are the above-mentioned drive mechanism has been described, but the present invention is not limited to this, and at least one joint may be the above-mentioned drive mechanism.

Further, in the above-described embodiment, the case where the reduction gear is a wave gear reduction gear has been described, but the present invention is not limited to this, and any configuration reduction gear such as a swing gear reduction gear or a planetary gear reduction gear can be used. There may be.

100 ... Robot device, 200 ... Robot, 201 ... Robot arm, 210 _i-1 ... First link, 210 _i ... Second link, 500 ... Drive mechanism, 510 ... Drive unit, 520 ... Torque sensor, 521 ... 1 Next side member 522 ... Secondary side member 523 ... Wiring 530 ... Electric motor 533 ... Housing 532 ... Rotating shaft 533 ... Wiring 540 ... Transmission mechanism 550 ... Reducer, 551 ... Housing (fixing member) , 552 ... Input shaft (input member), 535 ... Output shaft (output member), 560 ... Support member

Claims (17)

A drive mechanism that relatively displaces the first and second links.
With the motor
With the reducer,
Equipped with a torque sensor,
The speed reducer includes an input shaft that is rotated by driving the motor.
The torque sensor is arranged between the speed reducer and the first link.
The input shaft passes through the inside of the torque sensor.
A drive mechanism characterized by that. In the drive mechanism according to claim 1,
The motor includes a motor rotation shaft.
The motor rotation shaft and the input shaft are arranged so that the motor rotation shaft and the input shaft are parallel to each other.
A drive mechanism characterized by that. In the drive mechanism according to claim 2,
A transmission mechanism for transmitting the drive of the motor rotating shaft to the input shaft while the motor rotating shaft and the input shaft are arranged in parallel is provided.
The motor and the torque sensor are provided on the first link.
The transmission mechanism is provided on the opposite side of the motor and the torque sensor with the first link interposed therebetween.
A drive mechanism characterized by that. In the drive mechanism according to claim 3,
The wiring of the torque sensor is pulled out to the first link side.
A drive mechanism characterized by that. In the drive mechanism according to claim 4,
The wiring of the torque sensor is fixed to the first link.
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 1 to 5,
The torque sensor is
A hollow first member, a hollow second member, and a connecting member for relatively movably connecting the first member and the second member are provided.
Either one of the first member and the second member is connected to the first link.
A drive mechanism characterized by that. In the drive mechanism according to claim 6,
The other of the first member and the second member is connected to the speed reducer via a support member.
The torque sensor is arranged between the support member and the first link.
A drive mechanism characterized by that. In the drive mechanism according to claim 6 or 7.
The torque sensor is
A detection unit for detecting the relative movement amount between the first member and the second member is provided at a predetermined position between the first member and the second member.
A drive mechanism characterized by that. In the drive device according to any one of claims 1 to 8.
The motor is fixed to the first link,
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 1 to 9,
The first link and the second link rotate relative to each other along a predetermined rotation axis.
The speed reducer is arranged so that the central axis of the speed reducer coincides with the predetermined rotation axis.
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 1 to 9,
The first link and the second link rotate relative to each other along a predetermined rotation axis.
The torque sensor is arranged so as to be deformed around the predetermined rotation axis.
The input shaft is arranged so that the rotation axis of the input shaft coincides with the predetermined rotation axis.
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 10 or 11.
The motor is arranged so that the central axis of the motor is deviated from the predetermined rotation axis.
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 1 to 12,
A bearing further provided between the first link and the second link.
A drive mechanism characterized by that. In the drive mechanism according to any one of claims 1 to 13.
The wiring of the motor is pulled out to the side of the first link and fixed to the first link.
A drive mechanism characterized by that. A robot device including the drive mechanism according to any one of claims 1 to 14. A method for manufacturing an article, which comprises manufacturing the article using the robot device according to claim 15. It is a control method of a drive mechanism that relatively displaces the first and second links.
The drive mechanism is
With the motor
With the reducer,
Hollow torque sensor and
A control device for controlling the motor is provided.
The speed reducer includes an input shaft that is rotated by driving the motor.
The torque sensor is arranged between the speed reducer and the first link.
The input shaft is through the inner portion of the torque sensor,
The control device is
The motor is operated based on the detection result of the torque sensor, and the motor is operated.
The operation of the motor rotates the input shaft, and the first link and the second link are relatively displaced via the speed reducer.
A control method characterized by that.

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