TW202000404A - Manipulator and flexing meshing gear device wherein the manipulator includes a first arm member, a second arm member, and a driving device - Google Patents

Abstract

The present invention provides a manipulator capable of improving the service life of a main bearing of a reduction gear mounted at a joint portion, and a flexible meshing type reduction gear suitable for the manipulator. The manipulator includes a first arm member (13), a second arm member (17), and a driving device (19) that drives the second arm member (17) relative to the first arm member (13). The driving device (19) includes a fixing member (51) fixed to the first arm member (13), a decelerating mechanism (50), an output member (52) transmitting rotation that is decelerated by the decelerating mechanism (50) and connected to the second arm member (17), and a main bearing (59) arranged between the fixing member (51) and the output member (52). When the main bearing (59) is viewed in the radial direction, the center of gravity (G17) of the second arm member (17) overlaps with the range (W1) of the rolling surface of a rolling body of the main bearing.

Description

Manipulator and deflection meshing gear device

The invention relates to a manipulator and a flexing meshing gear device.

The industrial manipulator has a joint part of an arm and a turning arm, and a speed reducer that reduces the rotational motion generated by a motor or the like and transmits it to the arm is provided on the joint part (for example, refer to Patent Document 1). The speed reducer 31 provided in the joint portion of Patent Document 1 includes a housing 31b fixed to the frame, an input gear 31a for rotational motion input, and an output shaft 31c connected to the arm 4. As shown in FIGS. 2 and 4 of Patent Document 1, the arm 4 of the industrial manipulator is often connected to the axially outer side of the output shaft 31c of the reducer 31, and extends from the connecting portion along the radius of rotation Configuration. (Prior technical literature) (Patent Literature) Patent Document 1: Japanese Patent Laid-Open No. 2014-69269

(Problem to be solved by the present invention) The reduction gear is provided with a fixed member connected to the base member, an output member connected to the power output target, that is, the target member, and a main bearing arranged between the fixed member and the output member. In addition, the output member is rotatably supported by the fixed member via the main bearing. As in the conventional industrial manipulator described above, when the arm is connected to the axially outer side of the output member of the reducer and is arranged so as to extend along the radius of rotation from there, the main bearing is used as a fulcrum, and the length of the slave arm is along the longitudinal direction. The arm becomes longer when the load is applied. The force arm represents the distance between the fulcrum and the line of action of the force. The product of the load and the arm is the moment applied to the fulcrum. Therefore, if the arm of the reducer becomes longer, even if the load is small, a large moment will be applied to the main bearing. Therefore, a conventional industrial manipulator in which a reducer with a long arm is installed in a joint portion is likely to apply a large torque to the main bearing of the reducer, which causes a problem that the life of the main bearing becomes short. An object of the present invention is to provide a manipulator capable of improving the life of a main bearing of a speed reducer provided in a joint portion, and a flexural mesh type speed reducer suitable for the manipulator. (Means to solve the problem) The manipulator related to the present invention includes a first arm member, a second arm member, and a drive device that relatively drives the second arm member to the first arm member, The manipulator is constructed as follows: The driving device includes: a fixing member fixed to the first arm member, a speed reduction mechanism, an output member that transmits rotation decelerated by the speed reduction mechanism and is connected to the second arm member, and is disposed between the fixing member and the output member Between the main bearings, When viewed from the radial direction of the main bearing, the center of gravity of the second arm member overlaps the range of the rolling surface of the rolling element of the main bearing. A flexural meshing gear device according to the present invention includes: a vibrating body, an external gear deformed by deflection of the vibrating body, a first internal gear and a second internal gear meshed with the external gear, and are arranged on the first The main bearing between the internal gear and the second internal gear, The deflection meshing gear device is constructed as follows: The first internal gear is configured to rotate integrally with the outer ring of the main bearing, and the second internal gear is configured to rotate integrally with the inner ring of the main bearing, The second internal gear has an extension that extends radially outward of the outer ring member constituting the outer ring of the main bearing. (Effect of invention) According to the present invention, there is an effect that the life of the main bearing of the speed reduction mechanism provided at the joint portion between the first arm member and the second arm member can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a side view showing a manipulator according to an embodiment of the present invention. FIG. 2 is a rear view of the manipulator of FIG. 1 viewed from the rotation direction of the second arm. The manipulator 1 of the embodiment of the present invention is an industrial manipulator or a cooperative manipulator that cooperates with humans, and specifically is a multi-joint manipulator. The robot 1 includes a base member 11, a first swing arm 13, a first drive device 15, a second arm 17, a second drive device 19, a third arm 21, a third drive device 23, a fourth swing arm 25, a first 4 Drive device 27, fifth arm 29, fifth drive device 31, sixth arm 33, sixth drive device 35, processing head 41, and head drive device 43. Among these, the first swing arm 13 corresponds to an example of the first arm member related to the present invention. The second arm 17 corresponds to an example of a second arm member related to the present invention. The second drive device 19 corresponds to an example of the drive device according to the present invention. The base member 11 is fixed to the work space and becomes the base of the robot 1. The first swing arm 13 is rotatably supported by the base member 11 via the first drive device 15. The second arm 17 is rotatably supported by the first swing arm 13 via the second drive device 19. The third arm 21 is rotatably supported by the second arm 17 via the third drive device 23. The fourth swing arm 25 is rotatably supported by the third arm 21 via the fourth drive device 27. The fifth arm 29 is rotatably supported by the fourth swing arm 25 via the fifth drive device 31. The sixth arm 33 is rotatably supported by the fifth arm 29 via the sixth drive device 35. Focusing on the second arm 17, one end of the second arm 17 in the longitudinal direction is rotatably supported by the first swing arm 13 via the second drive device 19, and the other end of the second arm 17 in the longitudinal direction passes through the The 3 driving device 23 rotatably supports the third arm 21. The first to sixth drive devices 15, 19, 23, 27, 31, and 35 respectively function as the first to sixth joint parts between the arms. The first drive device 15 includes a fixed member connected to the base member 11, an output member supported by the fixed member so as to be rotatable about the rotation axis A1, a motor that generates power, and decelerates the rotational motion of the motor and transmits it to the output Speed reduction mechanism of components. The first swing arm 13 is connected to the output member of the first drive device 15, and is driven by the first drive device 15 to rotate around the rotation axis A1. The second drive device 19 includes a fixed member 51 (FIG. 3) connected to the first swing arm 13, and an output member 52 (FIG. 3) supported by the fixed member 51 so as to be rotatable about the rotation axis A2. Furthermore, the second drive device 19 includes a motor 61 that generates power, and a speed reduction mechanism 50 that reduces the rotational motion of the motor 61 and transmits it to the output member 52. The second arm 17 is connected to the output member 52 of the second drive device 19, and rotates about the rotation axis A2 by the drive of the second drive device 19. The third drive device 23 includes a fixed member connected to the second arm 17, an output member supported by the fixed member rotatably around the rotation axis A3, a motor that generates power, and decelerates and transmits the rotational motion of the motor to The speed reduction mechanism of the output member. The third arm 21 is connected to the output member of the third drive device 23, and rotates about the rotation axis A3 by the drive of the third drive device 23. The fourth drive device 27 includes a fixed member connected to the third arm 21, an output member supported by the fixed member rotatably around the rotation axis A4, a motor that generates power, and decelerates and transmits the rotational motion of the motor to The speed reduction mechanism of the output member. The fourth swing arm 25 is connected to the output member of the fourth drive device 27 and is driven to rotate around the swing axis A4 by the drive of the fourth drive device 27. The fifth drive device 31 includes a fixed member connected to the fourth swing arm 25, an output member supported by the fixed member rotatably around the rotation axis A5, a motor that generates power, and decelerates and transmits the rotational motion of the motor Reducer mechanism to output member. The fifth arm 29 is connected to the output member of the fifth drive device 31, and is driven to rotate about the rotation axis A5 by the fifth drive device 31. The sixth drive device 35 includes a fixed member connected to the fifth arm 29, an output member supported by the fixed member rotatably around the rotation axis A6, a motor that generates power, and decelerates and transmits the rotational motion of the motor to The speed reduction mechanism of the output member. The sixth arm 33 is connected to the output member of the sixth drive device 35, and rotates about the rotation axis A6 by the drive of the sixth drive device 35. In addition, the driving devices such as the fifth driving device 31 and the sixth driving device 35 that are closer to the processing head 41 side may be configured as follows: power is transmitted from a motor provided at a position away from the driving unit. In addition, the driving devices such as the fifth driving device 31 and the sixth driving device 35 that are close to the processing head 41 may be configured as follows: the speed reduction mechanism is omitted, and the motion is transmitted without amplifying the torque. In each of the first to sixth drive devices 15, 19, 23, 27, 31, and 35, a bearing (hereinafter referred to as "main bearing") is provided between the fixed member and the output member, and the output member can be rotated via the main bearing Or it is supported by a fixed member in a rotating manner. The processing head 41 is held by the front end portion of the sixth arm 33, and performs processing such as welding on the object to be processed. The head driving device 43 is held by the third arm 21 and supplies energy such as laser light or electric power to the processing head 41. With such a configuration, the robot 1 rotates the first and fourth swing arms 13, 25 and rotates the second, third, fifth, and sixth arms 17, 21, 29, and 33, thereby enabling The machining head 41 is moved axially and its angle is changed. Thereby, the robot 1 can move the processing head 41 with a high degree of freedom, and perform processing on various positions of the object to be processed from various angles. <Second drive device> 3 is a cross-sectional view showing the second arm and the second driving device. In this specification, unless otherwise specified, when it is described as an axial direction, it indicates the direction along the rotation axis O1 of the second drive device 19, and unless otherwise specified, when it is described as a radial direction, it indicates a direction perpendicular to the rotation axis O1. As described above, the second drive device 19 includes the speed reduction mechanism 50, the fixing member 51, the output member 52, the main bearing 59, and the motor 61. Among these, the configuration of the combined reduction mechanism 50, the fixing member 51, the output member 52, and the main bearing 59 corresponds to an example of the flexural meshing gear device according to the present invention. The speed reduction mechanism 50 includes an input shaft 53 having a vibrator 53a, an external gear 55 deflected by the vibrator 53a, and a first internal gear 51g and a second internal gear 52g that mesh with the external gear 55. Furthermore, the speed reduction mechanism 50 further includes input bearings 58A and 58B that support the input shaft 53 and a vibrator bearing 56 disposed between the external gear 55 and the vibrator 53a. The fixing member 51 is configured by connecting the first member 51A provided with the first internal gear 51g, the second member 51B in which the input bearing 58A is embedded, and the third member 51C in which the main bearing 59 is embedded. Since a part of the third member 51C functions as an outer ring of the main bearing 59, the fixing member 51 can rotate integrally with the outer ring of the main bearing 59. The fixing member 51 corresponds to an example of the outer ring member related to the present invention. In addition, the fixing member 51 may be integrally formed of the first member 51A, the second member 51B, and the third member 51C by one member, or may be divided into a plurality of members at other places and connected by a connecting member. In addition, since the fixing member 51 and the first internal gear 51g are integral members, the fixing member 51 itself can be referred to as the first internal gear. The output member 52 is configured by connecting the first member 52A provided with the second internal gear 52g and fitted with the main bearing 59, and the second member 52B fitted with the input bearing 58B. Since a part of the first member 52A functions as an inner ring of the main bearing 59, the output member 52 can rotate integrally with the inner ring of the main bearing 59. The second member 52B has an extension portion 52ex that extends from the outer peripheral side of the input bearing 58B through the counter motor side of the fixing member 51 to the radially outer side of the fixing member 51. The extension 52ex extends in the axial direction to a position closer to the motor side than the main bearing 59. The motor side indicates the side where the motor 61 is arranged in the axial direction, and the reverse motor side indicates the opposite side. The second member 52B has a form in which the side where the main bearing 59 is arranged is axially inward and does not protrude outward in the axial direction more than the input bearing 58B. In other words, in the axial direction of the speed reduction mechanism 50, the end of the output member 52 on the anti-motor side is located at the same position as the end of the input bearing 58B on the anti-motor side, or inward in the axial direction. In addition, the output member 52 may be integrally formed of the first member 52A and the second member 52B by one member, or may be divided into a plurality of members at other places and connected to each other via a connecting member. In addition, since the output member 52 and the second internal gear 52g are integral members, the output member 52 itself can be referred to as the second internal gear. The input shaft 53 has a vibrating body 53a having a hollow shaft shape and a cross section perpendicular to the rotation axis O1 having an elliptical shape (not necessarily a geometrically complete ellipse) and two axial directions provided in the vibrating body 53a The lateral and perpendicular to the cross-section of the rotation axis O1 are circular shaft portions 53b and 53c. A motor shaft 61 a of the motor 61 is connected to the one end of the input shaft 53 via a connecting member 61 b, and a driving force is input from the motor 61. The input shaft 53 is rotated about the rotation axis O1 by the power of the motor 61. The external gear 55 is a flexible cylindrical metal, and the outer periphery is provided with teeth. The external gear 55 is held rotatably with the vibrator 53 a via the vibrator bearing 56. Of the first internal gear 51g and the second internal gear 52g, one meshes with the tooth portion of the external gear 55 in the axial direction from the center half, and the other meshes with the tooth portion of the external gear 55 in the axial direction from the center half . The first internal gear 51g is configured such that a tooth portion is formed at a corresponding position on the inner peripheral portion of the first member 51A of the fixing member 51. The second internal gear 52g is configured such that a tooth portion is formed at a corresponding position on the inner peripheral portion of the first member 52A of the output member 52. The input bearings 58A and 58B are sealed bearings provided with a lubricant sealing member. Therefore, no oil seal is additionally arranged between the input shaft 53 and the fixing member 51 and the output member 52, thereby shortening the axial dimension of the device. The input bearing 58A is disposed between the second member 51B of the fixed member 51 and the shaft portion 53b of one side (motor side) of the input shaft 53. The input bearing 58B is disposed between the second member 52B of the output member 52 and the other (counter motor side) shaft portion 53c of the input shaft 53. The input shaft 53 is rotatably supported by the fixed member 51 and the output member 52 via input bearings 58A, 58B. The main bearing 59 is, for example, a cross roller bearing, and can bear both an axial load and a radial load. The rolling element of the main bearing 59 includes a plurality of first rollers and a plurality of second rollers arranged in a direction crossing the rotation axis with the first roller. The main bearing 59 is arranged between the inner peripheral side of the third member 51C of the fixed member 51 and the outer peripheral side of the first member 52A of the output member 52. With the main bearing 59, the output member 52 is supported to be able to rotate relative to the fixed member 51. As described above, in this embodiment, a part of the fixing member 51 functions as an outer ring of the main bearing 59, and a part of the output member 52 functions as an inner ring of the main bearing 59. However, the main bearing 59 may have a dedicated outer ring and inner ring, and the outer ring and the fixing member 51 may be fitted so that the outer ring can rotate integrally with the fixing member 51. Alternatively, the inner ring and the output member 52 may be fitted so that the inner ring can rotate integrally with the output member 52. As described above, the second drive device 19 is driven by the motor 61 to rotate the vibrator 53 a of the input shaft 53. When the vibrator 53a rotates, the motion is transmitted to the external gear 55. At this time, the external gear 55 is restricted to a shape along the outer peripheral surface of the vibrating body 53a, and when viewed from the axial direction, deflects in an elliptical shape. Furthermore, in the external gear 55, the portion of the elliptical long axis position viewed from the axial direction meshes with the first internal gear 51g and the second internal gear 52g. Therefore, the external gear 55 does not rotate at the same rotational speed as the vibrator 53a, but the vibrator 53a relatively rotates inside the external gear 55. With this relative rotation, the external gear 55 deflects so that the elliptical long-axis position and short-axis position move in the peripheral direction when viewed from the axial direction. The period of this deformation is proportional to the rotation period of the vibrator 53a. When the external gear 55 deflects and deforms, its long-axis position moves, so that the meshing position of the external gear 55 and the first internal gear 51g changes in the rotation direction. Here, the number of teeth of the external gear 55 is set to 100, and the number of teeth of the first internal gear 51g is set to 102. Due to the difference in the number of teeth, the meshing teeth of the external gear 55 and the first internal gear 51g gradually shift each time the meshing position of the teeth makes one revolution, and the external gear 55 rotates (rotates). With the above-mentioned number of teeth, the rotational motion of the input shaft 53 is reduced at a reduction ratio of 100:2 and transmitted to the external gear 55. On the other hand, due to the rotation of the vibrator 53a, the meshing position of the external gear 55 and the second internal gear 52g also changes in the direction of rotation. Here, the external gear 55 and the second internal gear 52g have the same number of teeth. At this time, the external gear 55 and the second internal gear 52g do not rotate relatively, and the rotational motion of the external gear 55 is transmitted to the second internal gear 52g at a reduction ratio of 1:1. With this action, the rotational motion of the input shaft 53 is reduced at a reduction ratio of 100:2 and transmitted to the second internal gear 52g, and the rotational motion is output to the output member 52. <Connection of the first swing arm, the second drive device, and the second arm> As shown in FIG. 3, the first swing arm 13 is connected to the fixing member 51 via a connection member C1 such as a bolt. Although only one joint is shown in the cross section of FIG. 3, many places in the peripheral direction are similarly connected. The first swing arm 13 is arranged on the motor side of the speed reduction mechanism 50 and is connected to the fixing member 51 from the motor side. The first swing arm 13 is provided with a through hole h1 in the extending direction of the motor shaft 61a. The casing 61d of the motor 61 is fixed to the first swing arm 13 on the opposite side of the speed reduction mechanism 50, and the motor shaft 61a is connected to the input shaft 53 through the through hole h1. The second arm 17 has, at one end in the longitudinal direction, a hollow portion 173 in which the reduction mechanism 50 is arranged, a first frame member 171 arranged on the motor 61 side of the hollow portion 173, and a first frame member 171 arranged on the reverse motor side of the hollow portion 173 2Frame Member 172. For example, the first frame member 171 and the second frame member 172 are connected to the side wall portion provided so as to surround the hollow portion 173 and integrated. The first frame member 171 is provided with a through hole h2 leading to the hollow portion 173 in the axial extension direction of the speed reduction mechanism 50. The first frame member 171 is connected to the extending portion 52ex of the output member 52 via a connecting member C2 such as a bolt in a state where the connecting portion of the fixing member 51 and the first swing arm 13 passes through the through hole h2. The first frame member 171 is arranged closer to the motor than the extension 52ex, and is connected to the extension 52ex from the motor. In addition, the second frame member 172 may be connected to the output member 52 from the counter motor side. As shown in FIG. 3, the center of gravity G17 of the second arm 17 is located in the range W1 overlapping the rolling surface of the main bearing 59 when viewed from the radial direction of the reduction mechanism 50 (the radial direction of the main bearing 59 ). Here, the center of gravity G17 of the second arm 17 represents the center of gravity of the weight of the constituent element that is fixed to the second arm 17 in total and does not move relative to the second arm 17 (without displacement). That is, in the example of the manipulator 1 in FIG. 1, the center of gravity G17 of the second arm is formed by the weight of the components including the second arm 17 and the third drive device 23, except for the third movement relative to the second arm 17. The weight of each component of the arm 21 to the processing head 41 is calculated. FIG. 4 is a cross-sectional view of a joint portion of a comparative example. The joint part of the comparative example is an example in which the first swing arm 13 is connected to the fixed member 51 from the motor side via the connecting member C11, and the first frame member 171 of the second arm 17 is connected to the output from the counter motor side via the connecting member C12 Member 52. In the comparative example, when the main bearing 59 is used as the fulcrum and the force application point of the force applied to the output member 52 in the radial direction is set as the center of gravity G17 of the second arm 17, the force arm L1 becomes longer. Therefore, when a load is applied from the center of gravity G17 of the second arm 17 in the radial direction of the speed reduction mechanism 50, a large torque, which is a product of the load and the force arm L1, is applied to the main bearing 59. On the other hand, in the second joint portion of the present embodiment shown in FIG. 3, when the main bearing 59 is used as a fulcrum and the force application point of the force applied to the output member 52 in the radial direction is taken as the center of gravity G17 of the second arm 17 The force arm is close to zero. Therefore, in the joint portion of this embodiment, even when a large load is applied from the center of gravity G17 of the second arm 17 to the radial direction of the speed reduction mechanism 50, only a small torque is applied to the main bearing 59. Therefore, in the second joint portion of this embodiment, the life of the main bearing 59 can be improved compared to the joint portion of the comparative example. However, a typical manipulator sometimes includes a multi-joint arm in which a plurality of arms are sequentially connected in a manner to rotate in the same direction with each other. Turning in the same direction means that the rotation axes of the joints between the arms are parallel to each other. Here, the center of gravity of the main bearing provided at each joint part and the arm of the joint part connected to the output member is set to be substantially away from each other in the axial direction as shown in FIG. 4. Furthermore, from the root side to the tip side of the multi-joint arm, the direction of the shift of the center of gravity of the arm of each joint is set to the same direction. In such a configuration, the shift of the center of gravity of the plurality of arms from the root side to the front end side acts cumulatively on the joint part on the root side, and therefore, it becomes a very poorly balanced configuration. In general, in order to prevent such a balance difference, the designer of a multi-articulated arm designs so that the center of gravity of the multiple arms does not accumulate from the root side to the front end side. Specifically, in the combination of several joints and the arms connected thereto, the designer sets the offset direction of the center of gravity of the arm and the offset direction of the center of gravity of the arms of the other joints to be opposite directions. The offset of the center of gravity of the plurality of arms from the root side to the front end side is offset midway. In addition, the weight of the plurality of arms and the shift amount of the center of gravity of the arms on the joints are considered so that the overall balance becomes good. However, such a design for adjusting the balance is very complicated. Furthermore, if the specifications of all arms from the root side to the front end side are uncertain, it is difficult to realize the most appropriate design. However, in the second joint portion of this embodiment, when viewed from the radial direction, the center of gravity G17 of the second arm 17 is located at a position overlapping the range of the rolling surface of the main bearing 59. Therefore, even in the case where such joint parts and arms are sequentially spliced to form a multi-joint arm, the deviation of the center of gravity of each arm does not accumulate and the balance is greatly broken. Therefore, by applying the same configuration as the second drive device 19 and the second arm 17 of the present embodiment to a plurality of joints and a plurality of arms, a multi-joint arm capable of easily designing and adjusting a balanced manipulator can be obtained Advantage. Alternatively, the advantages of a multi-joint arm of a manipulator that can be designed and adjusted even if the specifications of all arms are not determined can be obtained. Furthermore, according to the second drive device 19 of the present embodiment, the output member 52 that rotates integrally with the inner ring of the main bearing 59 has an extension portion 52ex that extends radially outward of the fixing member 51 that rotates integrally with the outer ring. In addition, the second arm 17 is connected to the extension 52ex. Thus, even when a simple form such as a frame shape that is long in one direction is adopted as the second arm 17, a configuration in which the center of gravity G17 of the second arm 17 is arranged at a radial position of the main bearing 59 can be easily achieved Effect. Here, as a comparative example, the following configuration is considered: a member that rotates integrally with the outer ring of the main bearing 59 is connected to the second arm 17, and a member that rotates integrally with the inner ring of the main bearing 59 is fixed to the base end side The first swing arm 13. In the configuration of this comparative example, the inner ring of the main bearing 59 is stationary, and the outer ring rotates. For example, the rolling bearing of the main bearing 59 has less sliding wear than the sliding bearing, but the sliding wear in the rolling bearing is hardly completely zero. In addition, if the same rotation speed is output, if the inner ring is stationary and the rotary motion is extracted from the outer ring and the outer ring is stationary and the rotary motion is extracted from the inner ring, then the former outer ring extracts the scroll The sliding speed of the body is larger. Therefore, the latter inner ring extraction configuration can suppress the occurrence of sliding wear in the main bearing 59 to be low. Therefore, in this embodiment, the second arm 17 is connected to the output member 52 that rotates integrally with the inner ring of the main bearing 59, and compared with the above-described comparative example, the occurrence of sliding wear of the main bearing 59 can be more suppressed and the life can be improved. This configuration is especially effective when the joint of a robot is used in a severe environment. Furthermore, according to the second drive device 19 of this embodiment, the input bearing 58B on the counter motor side is a sealed bearing. Therefore, there is no need to arrange the seal member 60 of the lubricant on the side of the anti-motor beyond the input bearing 58B (see FIG. 4 ). Therefore, the size of the speed reduction mechanism 50 in the axial direction can be shortened, and accordingly, the second arm 17 can be made thin. Furthermore, the second drive device 19 according to the present embodiment has a form in which the second member 52B of the output member 52 does not protrude outward in the axial direction than the input bearing 58B on the counter motor side. Therefore, the axial dimension of the speed reduction mechanism 50 including the output member 52 can be shortened, and accordingly, the second arm 17 can be made thin. The embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the first swing arm 13 is shown as the first arm member related to the present invention. However, as long as the first arm member related to the present invention is a member to which the fixing member of the driving device is fixed, its shape and configuration There are no restrictions. For example, when the drive device according to the present invention is disposed on the most proximal end side of the articulated arm, the base member of the articulated arm corresponds to the first arm member according to the present invention. In addition, in the embodiment, the multi-joint manipulator is described as an example, but the type of the manipulator is not particularly limited, and as long as the manipulator has the first arm member and the second arm member, it can be widely used. Moreover, in the above-mentioned embodiment, the main bearing according to the present invention is shown as a pair of main bearings. However, the main bearing may also be composed of a group of two or more pairs of bearings arranged differently in the axial direction. In this case, the "range of the rolling surface of the rolling element of the main bearing" related to the present invention is defined as the range from the rolling surface on the most axial side to the rolling surface on the other side in the axial direction . Furthermore, in the above embodiment, the speed reduction mechanism 50 of the flexure meshing gear device is shown as the speed reduction mechanism 50 provided in the second joint portion of the manipulator 1. However, as the speed reduction mechanism provided in the driving device of the manipulator related to the present invention, a speed reduction mechanism such as an eccentric swing type speed reduction device or a simple planetary speed reduction device that obtains a deceleration effect by swinging an external gear or an internal gear by an eccentric body may also be used. As for the eccentric oscillating speed reducer, a so-called center crank type eccentric oscillating speed reducer with an eccentric shaft disposed on the axis of the reduction mechanism may be used, or two or more eccentric bodies may be arranged offset from the axis of the reduction mechanism The so-called distributed eccentric swing type speed reducer. In addition, the details shown in the embodiments can be appropriately changed without departing from the gist of the invention.

1‧‧‧manipulator 13‧‧‧1st swing arm 17‧‧‧ 2nd arm 19‧‧‧ 2nd driving device 50‧‧‧Reduction mechanism 51‧‧‧Fixed member 51g‧‧‧1st internal gear 52‧‧‧Output member 52ex‧‧‧Extension 52g‧‧‧Second internal gear 53‧‧‧ input shaft 55‧‧‧External gear 56‧‧‧ Vibrating body bearing 58A, 58B‧‧‧ input bearing 59‧‧‧Main bearing 61‧‧‧Motor 61a‧‧‧Motor shaft 61b‧‧‧Connecting member C1, C2‧‧‧Connecting member 171‧‧‧First frame member 172‧‧‧The second frame member G17‧‧‧Center of gravity of the second arm W1‧‧‧Range of rolling surface

Fig. 1 is a side view showing a manipulator according to an embodiment of the present invention. FIG. 2 is a rear view of the manipulator of FIG. 1 viewed from the rotation direction of the second arm. 3 is a cross-sectional view showing the second arm and the second driving device. FIG. 4 is a cross-sectional view of a joint portion of a comparative example.

13‧‧‧1st swing arm

17‧‧‧ 2nd arm

19‧‧‧ 2nd driving device

50‧‧‧Reduction mechanism

51‧‧‧Fixed member

51A‧‧‧First component

51B‧‧‧The second component

51C‧‧‧The third component

51g‧‧‧1st internal gear

52‧‧‧Output member

52A‧‧‧Part 1

52B‧‧‧The second component

52ex‧‧‧Extension

52g‧‧‧Second internal gear

53‧‧‧ input shaft

53a‧‧‧Vibrating body

53b, 53c‧‧‧Shaft

55‧‧‧External gear

56‧‧‧ Vibrating body bearing

58A, 58B‧‧‧ input bearing

59‧‧‧Main bearing

61‧‧‧Motor

61a‧‧‧Motor shaft

61b‧‧‧Connecting member

61d‧‧‧Shell

171‧‧‧First frame member

172‧‧‧The second frame member

173‧‧‧ Hollow Department

C1, C2‧‧‧Connecting member

G17‧‧‧Center of gravity of the second arm

h1, h2‧‧‧through hole

O1‧‧‧rotation axis

W1‧‧‧Range of rolling surface

Claims (5)

A manipulator includes a first arm member, a second arm member, and a drive device that relatively drives the second arm member to the first arm member, and is characterized by: The drive device includes a fixing member fixed to the first arm member, a speed reduction mechanism, an output member connected to the second arm member that transmits rotation reduced by the speed reduction mechanism, and disposed between the fixing member and the output member Between the main bearings, When viewed from the radial direction of the main bearing, the center of gravity of the second arm member overlaps the range of the rolling surface of the rolling element of the main bearing. The manipulator described in item 1 of the patent application scope, where, The fixing member is configured to rotate integrally with the outer ring of the main bearing, The output member is configured to rotate integrally with the inner ring of the main bearing, The output member has an extending portion extending radially outward of the fixing member, and the second arm member is connected to the extending portion. The manipulator described in item 1 or 2 of the patent application scope further includes an input bearing arranged between the output member and the input shaft of the speed reduction mechanism, The input bearing is a sealed bearing having a sealing member. According to the manipulator described in Item 3 of the patent application range, the side where the main bearing is arranged is regarded as the axially inner side, and the output member does not protrude outward in the axial direction than the input bearing. A deflection meshing gear device includes a vibrator, an external gear deformed by the deflection of the vibrator, a first internal gear and a second internal gear that mesh with the external gear, and are disposed on the first internal gear and The main bearing between the above second internal gears is characterized by: The first internal gear is configured to rotate integrally with the outer ring of the main bearing, and the second internal gear is configured to rotate integrally with the inner ring of the main bearing, The second internal gear has an extending portion that extends radially outward of the outer ring member constituting the outer ring of the main bearing.

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