JP2017127969A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator reduced in size.SOLUTION: An actuator comprises: an input shaft member; an input gear rotating integrally with the input shaft member; an output shaft member formed with a hole; an output gear rotating integrally with the output shaft member; one or more intermediate shaft members; large-diameter gears each rotating integrally with each of the one or more intermediate shaft members; small-diameter gears each having a smaller diameter than a diameter of the large-diameter gear fixed to the same intermediate shaft member; and a detection part for detecting rotation angles of the two shaft members. The large-diameter gear meshes with one of the input gear and the small-diameter gear which is fixed to the other intermediate shaft member lying on the input shaft member side. The small-diameter gear meshes with one of the output gear and the large-diameter gear which is fixed to the other intermediate shaft member lying on the output shaft member side.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an actuator.

  In a conventional gear rotation angle detection device used for an actuator or the like, for example, as described in Patent Document 1, three shafts on which gears are arranged, a shaft to be measured, a first support shaft, and a second shaft are arranged. There are known devices having a plurality of spindles. In this apparatus, a first support shaft, which is a shaft other than the shaft to be measured, is disposed on the first shaft, and a gear that meshes with the gear of the shaft to be measured and a gear that meshes with the gear of the second shaft. And the rotation angle of the shaft to be measured are calculated based on the combination of rotation angles detected at the second support shaft.

JP 2004-61428 A

  However, the rotation angle detection device described in Patent Document 1 has a problem that if the diameter of the support shaft from which the rotation angle is detected increases, the detection device increases accordingly. For this reason, there has been a demand for a technology for downsizing the detection device in the rotation angle detection device. In addition, in the conventional rotation angle detection device, it has been desired to reduce the cost, facilitate the manufacture, and improve the degree of freedom in design.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one form of this invention, the actuator which is used for the joint of a robot and has a motor is provided. The actuator includes: an input shaft member that rotates about the shaft center by rotation of the motor; an input gear that is fixed to the input shaft member and rotates integrally with the input shaft member; An output shaft member formed with a hole through which wiring used for controlling the robot along the axial direction is formed; an output gear fixed to the output shaft member and rotating integrally with the output shaft member; One or more intermediate shaft members that rotate about an axis; a large-diameter gear that is fixed to each of the one or more intermediate shaft members and rotates integrally with each of the one or more intermediate shaft members; A diameter of the large-diameter gear fixed to each of the one or more intermediate shaft members and rotating integrally with each of the one or more intermediate shaft members, and fixed to the same intermediate shaft member; A small-diameter gear having a smaller diameter; and a detection unit that detects a rotation angle of two of the input shaft member and the one or more intermediate shaft members; and the one or more intermediate shaft members The large-diameter gear fixed to each of the first gear meshes with one of the input gear and the small-diameter gear fixed to the other intermediate shaft member located on the input shaft member side; The small diameter gear fixed to each of the intermediate shaft members meshes with one of the output gear and the large diameter gear fixed to the other intermediate shaft member located on the output shaft member side. According to the actuator of this embodiment, the rotation angle of the output shaft member can be calculated by detecting the rotation angle of the shaft member other than the output shaft member, and the rotation angle of the output shaft member having a large diameter in which the hole is formed is detected. Therefore, the actuator can be reduced in size because a large detection unit is not required. In addition, when there is a shaft member with a large diameter other than the output shaft member, the rotation angle of the output shaft member can be calculated by detecting the rotation angle of the shaft member other than the shaft member with a large diameter. Can be In addition, since the rotation angle of the output shaft member is calculated by the detection unit, the rotation angle of the output shaft member is extended over a wide range of 360 degrees or more using a detection unit having a simple configuration that can detect only the absolute angle of the shaft member. The cost of the actuator can be suppressed.

(2) In the actuator of the above aspect, the number of the intermediate shaft members is two or more; the detection unit may detect a rotation angle of the two intermediate shaft members. According to the actuator of this aspect, since the rotation of the rotor of the motor is decelerated and transmitted to the output shaft member by more intermediate shaft members, a large torque can be generated by the output shaft member.

(3) In the actuator of the above aspect, the number of teeth of the large-diameter gear and the number of teeth of the small-diameter gear that are meshed with each other in the two shaft members from which the rotation angle is detected may be coprime. . According to the actuator of this form, even if the first shaft member of the two shaft members rotates 360 degrees and the detected rotation angle of the first shaft member is 0 degrees, the other first shaft member The rotation angle of the second shaft member is detected as a different angle compared to before the first shaft member rotates 360 degrees. As a result, the rotation angle of the output shaft member can be calculated over a wider range than 360 degrees by the combination of the rotation angle of the first shaft member and the rotation angle of the second shaft member.

(4) The actuator according to the above aspect further includes: a control board on which a control unit that controls the motor is disposed; the detection unit; a first detection unit that is attached to a shaft member that detects a rotation angle; A second detection unit formed on the control board; and the control board is disposed at a position intersecting with an axis of two shaft members to which the first detection unit is attached; The unit may be disposed between the control board and the small-diameter gear fixed to each of the two shaft members to which the first detection unit is attached. Since the actuator of this embodiment is used for a joint of a robot, it is difficult to reduce the size. Since the detection unit is arranged in a limited narrow space, it is difficult to mount the detection unit inside the actuator. On the other hand, according to the actuator of this embodiment, the control unit and the second detection unit are integrated on the control board, so that the second detection unit can be handled as a medium-sized component. Therefore, the assembly work of the small robot can be facilitated by using the actuator of the present embodiment for the small robot. In addition, since the control substrate faces the axial center direction of the two shaft members, the actuator can be miniaturized with an accuracy that can withstand practical use. Moreover, the manufacturing process of a control part and a 2nd detection part can be integrated, and the manufacturing cost of an actuator can be suppressed. In addition, since the control unit and a part of the second detection unit are integrated, the actuator can be further downsized and the manufacturing of the actuator can be facilitated.

(5) In the actuator of the above aspect, the detection unit may be a magnetic angle sensor. According to the actuator of this embodiment, for example, an inexpensive detection unit that detects a rotation angle of less than 360 degrees is used without using an expensive detection unit that can detect multiple rotations capable of measuring a rotation angle in a range of 360 degrees or more. Therefore, the cost of the actuator can be further suppressed.

  A plurality of constituent elements of each embodiment of the present invention described above are not essential, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with another new component, and partially delete the limited contents of some of the plurality of components. In order to solve some or all of the above-described problems or achieve some or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  For example, an aspect of the present invention includes an input shaft member, an input gear, an output shaft member, an output gear, one or more intermediate shaft members, a large diameter gear, a small diameter gear, and a detection unit. It can be realized as a device including some or all of the eight elements. That is, this apparatus may or may not have the input shaft member. The device may or may not have an input gear. Moreover, the apparatus may or may not have the output shaft member. The device may or may not have an output gear. In addition, the apparatus may or may not have one or more intermediate shaft members. The device may or may not have a large-diameter gear. The device may or may not have a small-diameter gear. Moreover, the apparatus may or may not have the detection unit. For example, the input shaft member may rotate about the shaft center by the rotation of the motor. For example, the input gear may be fixed to the input shaft member and rotated integrally with the input shaft member. For example, the output shaft member may be formed with a hole that rotates around the axis and through which the wiring used for controlling the robot passes along the axial direction. For example, the output gear may be fixed to the output shaft member and rotate integrally with the output shaft member. For example, the one or more intermediate shaft members may rotate about the respective shaft centers. For example, the large-diameter gear is fixed to each of the one or more intermediate shaft members and rotates integrally with each of the one or more intermediate shaft members, and is positioned on the input gear and the input shaft member side. You may mesh with one of the said small diameter gears fixed to the other said intermediate shaft member. For example, the small diameter gear is fixed to each of the one or more intermediate shaft members and rotates integrally with each of the one or more intermediate shaft members, and the large diameter gear fixed to the same intermediate shaft member. The diameter may be smaller than the diameter of the gear, and may mesh with one of the output gear and the large-diameter gear fixed to the other intermediate shaft member located on the output shaft member side. For example, the detection unit may detect a rotation angle of two shaft members of the input shaft member and the one or more intermediate shaft members. Such a device can be realized as an actuator, for example, but can also be realized as a device other than the actuator. According to such a form, it is possible to solve at least one of various problems such as improvement and simplification of the operability of the device, integration of the device, and improvement of convenience of the user who uses the device. it can. Any or all of the technical features of each form of the actuator described above can be applied to this apparatus.

  The present invention can be realized in various forms other than the actuator. For example, it can be realized in the form of a robot including an actuator, a control method for a robot including an actuator, a robot system including an actuator, and the like.

It is explanatory drawing which shows schematic structure of the robot in embodiment of this invention. It is explanatory drawing which shows schematic structure of the actuator in this embodiment.

A. Embodiment:
FIG. 1 is an explanatory diagram showing a schematic configuration of a robot 200 according to the embodiment of the present invention. The robot 200 in this embodiment is a 6-axis vertical articulated industrial robot.

  The robot 200 includes a base portion 2 fixed to a horizontal plane of an installation site (site) such as a factory, a shoulder portion 3 supported by the base portion 2 so as to be rotatable about a first axis in the vertical direction, and a horizontal direction. A lower arm 4 whose lower end is supported by the shoulder portion 3 so as to be able to turn around the second axis of the lower arm 4 and a rear upper arm supported at the tip of the lower arm 4 so as to be able to turn around the third axis in the horizontal direction 5, a front upper arm 6 supported by the rear upper arm 5 so as to be able to twist and rotate about a fourth axis orthogonal to the third axis, and a fifth axis orthogonal to the fourth axis And a wrist 7 supported at the tip of the front upper arm 6 so as to be pivotable, and a flange 8 supported on the wrist 7 so as to be able to twist and rotate about a sixth axis orthogonal to the fifth axis. Yes. An end effector such as a hand for gripping a workpiece can be attached to the flange 8. An end effector other than a hand (for example, a visual inspection camera) can be attached. Actuators are arranged on the respective axes from the first axis to the sixth axis. By controlling the actuators, for example, the position of the lower arm 4 or the like is changed, and the robot 200 is operated in various ways. Do the work.

  FIG. 2 is an explanatory diagram illustrating a schematic configuration of the actuator 100 according to the present embodiment. The actuator 100 is a device that is used for a rotary joint of the robot 200 and includes a speed reducer 95 and a motor 20. As shown in FIG. 2, the actuator 100 includes a control board 10, a motor 20, an input shaft 50 connected to the motor 20, an output shaft 90, a speed reducer 95, a first angle sensor 30, Two angle sensors 40. The speed reducer 95 includes a first intermediate shaft 60, a second intermediate shaft 70, and a third intermediate shaft 80.

  The control board 10 has a control unit 19 for supplying power and transmitting / receiving signals. The control unit 19 is connected to the motor 20, the first angle sensor 30, and the second angle sensor 40. The control unit 19 controls the electric power applied to the motor 20 to rotate the rotor built in the motor 20, and the rotation speed and the rotation angle of the output shaft 90 that is rotated by the rotation of the rotor of the motor 20 are transmitted. Control. The control unit 19 acquires the rotation angles of the second intermediate shaft 70 and the third intermediate shaft 80 detected by the first angle sensor 30 and the second angle sensor 40 described later, and sends them to the motor 20. Feedback control is performed to control the applied power and the like.

  The rotor of the motor 20 rotates around the input axis OLI together with the connected input shaft 50 by the electric power applied by the control unit 19. An input gear 11 that rotates integrally with the input shaft 50 about the input shaft center OLI is fixed to the input shaft 50. The output shaft 90 rotates around the output axis OLO. The output shaft 90 is a shaft in which a hole 92 is formed along the output shaft center OLO. Various wires (not shown) for supplying electric power and the like for controlling the robot 200 pass through the hole 92 of the output shaft 90. For this reason, the outer diameter of the output shaft 90 is larger than the outer diameters of the other shafts. An output gear 18 that rotates integrally with the output shaft 90 about the output shaft center OLO is fixed to the output shaft 90. The output gear 18 is a gear having a diameter larger than that of a third large-diameter gear 16 described later. The input shaft 50 corresponds to the input shaft member in the claims, and the output shaft 90 corresponds to the output shaft member in the claims. Further, in FIG. 2 and FIG. 3 described later, various gears such as the input gear 11 and the output gear 18 are simply described in a disk shape, but teeth as gears are formed on the outer diameters of the various gears. .

  The first intermediate shaft 60 rotates around the first intermediate axis OL1. A first large-diameter gear 12 and a first small-diameter gear 13 that rotate integrally with the first intermediate shaft 60 around the first intermediate axis OL1 are fixed to the first intermediate shaft 60. Yes. The first large-diameter gear 12 is a gear having a diameter larger than that of the first small-diameter gear 13 and the input gear 11. Since the first large-diameter gear 12 and the input gear 11 mesh with each other, the first intermediate shaft 60 rotates as the input shaft 50 rotates.

  The second intermediate shaft 70 rotates around the second intermediate axis OL2. A second large-diameter gear 14 and a second small-diameter gear 15 that rotate integrally with the second intermediate shaft 70 are fixed to the second intermediate shaft 70 around the second intermediate axis OL2. . The second large diameter gear 14 is a gear having a larger diameter than the second small diameter gear 15 and the first small diameter gear 13. Since the second large diameter gear 14 and the first small diameter gear 13 mesh with each other, the second intermediate shaft 70 rotates with the rotation of the first intermediate shaft 60. Further, the second intermediate shaft 70 is disposed at a position where the second intermediate axis OL2 of the second intermediate shaft 70 and the control board 10 intersect. A first magnet 32 that is a part of a first angle sensor 30 described later is disposed between the second small-diameter gear 15 and the control board 10 so as to face the control board 10 in the second intermediate shaft 70. Has been.

  The third intermediate shaft 80 rotates around the third intermediate axis OL3. A third large-diameter gear 16 and a third small-diameter gear 17 that rotate integrally with the third intermediate shaft 80 around the third intermediate axis OL3 are fixed to the third intermediate shaft 80. . The third large diameter gear 16 is a gear having a larger diameter than the third small diameter gear 17 and the second small diameter gear 15. In the present embodiment, the number of teeth of the second small-diameter gear 15 and the third large-diameter gear 16 is set so as to have a prime relationship with each other. Since the third large-diameter gear 16 and the second small-diameter gear 15 mesh with each other, the third intermediate shaft 80 rotates as the second intermediate shaft 70 rotates. Further, the third intermediate shaft 80 is disposed at a position where the third intermediate axis OL3 of the third intermediate shaft 80 and the control board 10 intersect. A second magnet 42 that is a part of a second angle sensor 40 described later is disposed between the third small gear 17 and the control board 10 so as to face the control board 10 in the third intermediate shaft 80. Has been.

  Since the output gear 18 and the third small diameter gear 17 mesh with each other, the output shaft 90 rotates with the rotation of the third intermediate shaft 80. As described above, the rotation of the rotor of the motor 20 is transmitted to the output shaft 90 via the input shaft 50, the first intermediate shaft 60, the second intermediate shaft 70, and the third intermediate shaft 80. Further, since the diameter of the gear on the input side in each axis is large, the rotation of the motor 20 is performed via the input shaft 50, the first intermediate shaft 60, the second intermediate shaft 70, and the third intermediate shaft 80. The speed is decelerated and transmitted to the output shaft 90. In addition, the 1st intermediate shaft 60 in this embodiment, the 2nd intermediate shaft 70, and the 3rd intermediate shaft 80 are equivalent to the 1 or more intermediate shaft in a claim. Further, the gear on the input shaft member side in the claims refers to a gear (for example, in the first intermediate shaft 60) that meshes with a gear fixed to the shaft close to the input shaft 50 out of two gears fixed to the same shaft. The first large-diameter gear 12) refers to the gear on the output shaft member side, which is a gear meshing with a gear fixed to the shaft close to the output shaft 90 (for example, the first small-diameter gear 13 in the first intermediate shaft 60). Say. The closest two shaft members in the claims are not two shaft members that are close in distance, but two shaft members that are close to each other via a gear. For example, the axis closest to the output shaft 90 is the third intermediate shaft 80, and the next closest axis is the second intermediate shaft 70.

  The first angle sensor 30 is a magnetic rotary encoder that detects the rotation angle of the second intermediate shaft 70. The first angle sensor 30 detects the absolute angle of the second intermediate shaft 70. That is, the first angle sensor 30 detects the rotation angle of the second intermediate shaft 70 within a range of 0 degree or more and less than 360 degrees. The first angle sensor 30 includes a first magnet 32 disposed on the second intermediate shaft 70, and a first reader 31 formed on the control board 10. The first reader 31 sends the rotation angle of the second intermediate shaft 70 specified based on the change in the electric signal accompanying the rotation of the first magnet 32 to the control unit 19 of the connected control board 10. Send as. Similar to the first angle sensor 30, the second angle sensor 40 is a magnetic rotary encoder that detects the rotation angle of the third intermediate shaft 80. The second angle sensor 40 includes a second magnet 42 disposed on the third intermediate shaft 80 and a second reader 41 formed on the control board 10. Note that the second angle sensor 40 differs from the first angle sensor 30 only in the detected intermediate axis, and thus the description of the configuration of the second angle sensor 40 is omitted. The first angle sensor 30 and the second angle sensor 40 in the present embodiment correspond to a detection unit in the claims. In addition, the first magnet 32 and the second magnet 42 in the present embodiment correspond to the first detection unit in the claims, and the first reader 31 and the first magnet 32 in the present embodiment are This corresponds to the second detection unit in the claims.

  The control unit 19 uses the rotation angles of the second intermediate shaft 70 and the third intermediate shaft 80 acquired by the first angle sensor 30 and the second angle sensor 40, respectively, to adjust the output shaft 90. Calculate the rotation angle. Each of the first angle sensor 30 and the second angle sensor 40 can measure the respective rotation angles of the second intermediate shaft 70 and the third intermediate shaft 80 only to a range of less than 360 degrees. However, since the number of teeth of the second small-diameter gear 15 and the third large-diameter gear 16 is a prime relationship, the rotation angle of the second intermediate shaft 70 and the rotation angle of the third intermediate shaft 80 are By combining, the rotation angle of the output shaft 90 can be detected in a wide range of 360 degrees or more. For example, even if the third intermediate shaft 80 rotates 360 degrees and the rotation angle of the third intermediate shaft 80 detected by the second angle sensor 40 is 0 degree, the third large gear 16 and the first Since the two small-diameter gears 15 have a prime relationship with each other, the first angle sensor 30 detects a different rotation angle every time the third intermediate shaft 80 rotates 360 degrees. Therefore, the control unit 19 can measure the rotation period of the third intermediate shaft 80 using the rotation angle of the second intermediate shaft 70 detected by the first angle sensor 30, and the rotation angle of the output shaft 90. Can be measured in a wide range.

  As described above, in the actuator 100 according to this embodiment, the output shaft 90 has the hole 92 through which various wires for controlling the robot 200 pass, and the first angle sensor 30 rotates the second intermediate shaft 70. The angle is detected, and the second angle sensor 40 detects the rotation angle of the third intermediate shaft 80. Since the actuator 100 according to the present embodiment is used for a rotary joint of the robot 200, a hole 92 for passing various wires is formed inside the output shaft 90, and the diameter of the output shaft 90 tends to increase. Therefore, when directly measuring the rotation angle of the output shaft 90, it is necessary to arrange a rotary encoder corresponding to the diameter of the output shaft 90. However, in the actuator 100 of the present embodiment, the rotation angle of the output shaft 90 can be calculated by detecting the rotation angles of the second intermediate shaft 70 and the third intermediate shaft 80 that are axes other than the output shaft 90. Therefore, a large rotary encoder for detecting the rotation angle of the large-diameter output shaft 90 in which the hole 92 is formed is unnecessary, and the actuator 100 can be downsized. Further, when there is an axis having a large diameter other than the output shaft 90, the rotation angle of the output shaft 90 can be calculated by detecting the rotation angle of an axis other than the axis having a large diameter, so that the actuator 100 can be further downsized. . Further, since the rotation angle of the output shaft 90 is calculated by the two sensors of the first angle sensor 30 and the second angle sensor 40, the second intermediate shaft 70 and the third intermediate shaft 80 are respectively The rotation angle of the output shaft 90 can be calculated over a wide range of 360 degrees or more using a sensor with a simple configuration that can detect only an absolute angle, and the cost of the actuator 100 can be suppressed.

  In the actuator 100 according to the present embodiment, the number of intermediate shafts is two or more, and each of the first angle sensor 30 and the second angle sensor 40 includes a second intermediate shaft 70 other than the input shaft 50. A rotation angle with respect to the third intermediate shaft 80 is detected. Therefore, in the actuator 100 of the present embodiment, the rotation of the rotor of the motor 20 is decelerated and transmitted to the output shaft 90 by more intermediate shafts, so that a large torque can be generated by the output shaft 90.

  In the actuator 100 according to the present embodiment, the number of teeth of the second small-diameter gear 15 of the second intermediate shaft 70 close to the input shaft 50 out of the second intermediate shaft 70 and the third intermediate shaft 80, and The number of teeth of the third large-diameter gear 16 of the third intermediate shaft 80 close to the output shaft 90 is set to a number that is relatively prime. Therefore, in the actuator 100 of the present embodiment, for example, even if the third intermediate shaft 80 rotates 360 degrees and the rotation angle of the third intermediate shaft 80 detected by the second angle sensor 40 is 0 degree. The first angle sensor 30 detects a different rotation angle each time the third intermediate shaft 80 rotates 360 degrees. As a result, the rotation angle of the output shaft 90 can be calculated over a wider range than 360 degrees by the combination of the rotation angle of the second intermediate shaft 70 and the rotation angle of the third intermediate shaft 80.

  In the actuator 100 according to the present embodiment, the first reader 31 and the second angle sensor 40 of the first angle sensor 30 are provided on the control board 10 having the control unit 19 that controls the power supplied to the motor 20. The second reader 41 is formed. Further, the control board 10 is disposed at a position where the second intermediate axis OL2 of the second intermediate shaft 70 and the third intermediate axis OL3 of the third intermediate axis 80 and the control board 10 intersect. The first magnet 32 of the first angle sensor 30 is disposed between the second small-diameter gear 15 of the second intermediate shaft 70 and the control board 10, and the second magnet 42 of the second angle sensor 40 is The third intermediate shaft 80 is disposed between the third small diameter gear 17 and the control board 10. Since the actuator 100 of this embodiment is used for a joint of a robot, it is difficult to reduce the size. Since the first angle sensor 30 and the second angle sensor 40 are arranged in a limited narrow space, it is difficult to attach them inside the actuator 100. On the other hand, in the actuator 100 of the present embodiment, the control unit 19, the first reader 31, and the second reader 41 are integrated in the control board 10, so that the first reader 31 and the second reader 41 are integrated. Can be handled as a medium-sized component. Therefore, by using the actuator 100 of this embodiment for a small robot, the assembly work of the small robot can be facilitated. In addition, since the control substrate 10 faces the axial direction of the second intermediate axis OL2 and the third intermediate axis OL3, the actuator 100 can be miniaturized with an accuracy that can withstand practical use. Further, the manufacturing process for forming the control unit 19, the first reader 31, and the second reader 41 on the control substrate 10 can be integrated, and the manufacturing cost of the actuator 100 can be suppressed.

  Further, in the actuator 100 according to the present embodiment, the first angle sensor 30 and the second angle sensor 40 have rotation angles as absolute angles of the second intermediate shaft 70 and the third intermediate shaft 80, respectively. It is a magnetic rotary encoder to detect. Therefore, the actuator 100 of this embodiment uses an inexpensive sensor that detects a rotation angle of less than 360 degrees without using an expensive sensor that can detect multiple rotations that can measure a rotation angle in a range of 360 degrees or more. The cost of the actuator 100 can be further suppressed.

  Further, in the actuator 100 according to the present embodiment, the rotation angle of the output shaft 90 is determined by detecting the respective rotation angles of the second intermediate shaft 70 and the third intermediate shaft 80 that are the axes closest to the output shaft 90. calculate. Therefore, in the actuator 100 of the present embodiment, the rotation angle of the output shaft 90 can be calculated with higher accuracy than the rotation angle of the output shaft 90 is calculated by detecting the rotation angle of the shaft far from the output shaft 90.

B. Variations:
In addition, this invention is not limited to the said embodiment, It can implement in a various aspect in the range which does not deviate from the summary, For example, the following deformation | transformation is also possible.

B1. Modification 1:
In the above embodiment, the mode in which the rotation of the motor 20 is transmitted to the output shaft 90 by the three intermediate shafts has been described. However, the number of intermediate shafts is not limited to this, and various modifications can be made. The actuator 100a may have four or more intermediate shafts.

B2. Modification 2:
In the above embodiment, the magnetic rotary encoder is used as a sensor for detecting the rotation angle as the absolute angle between the second intermediate shaft 70 and the third intermediate shaft 80. However, the sensor for detecting the rotation angle of the shaft is used. However, the present invention is not limited to this and can be variously modified. For example, an optical angle sensor may be used, or different angle sensors may be used for the first angle sensor 30 and the second angle sensor 40. The sensor that detects the rotation angle may be a sensor that can detect not only an absolute angle but also a multi-rotation angle.

  In the above embodiment, the first reader 31 of the first angle sensor 30 and the second reader 41 of the second angle sensor 40 are integrally formed on the substrate of the control substrate 10, but are not rotated. The position of the sensor that detects the angle is not limited to this, and can be variously modified. For example, the first angle sensor 30 and the second angle sensor 40 may be arranged by a mounting substrate for an angle sensor different from the control unit 19 that controls the motor 20.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each form described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 2 ... Base part 3 ... Shoulder part 4 ... Lower arm 5 ... Rear upper arm 6 ... Front upper arm 7 ... Wrist 8 ... Flange 10 ... Control board 11 ... Input gear 12 ... First large diameter gear 13 ... First small diameter Gear 14 ... Second large-diameter gear 15 ... Second small-diameter gear 16 ... Third large-diameter gear 17 ... Third small-diameter gear 18 ... Output gear 19 ... Control unit 20 ... Motor 30 ... First angle sensor 31 ... first reader 32 ... first magnet 40 ... second angle sensor 41 ... second reader 42 ... second magnet 50 ... input shaft 60 ... first intermediate shaft 70 ... second intermediate shaft 80 ... Third intermediate shaft 90 ... Output shaft 92 ... Hole 95 ... Reduction gear 100 ... Actuator 200 ... Robot OL1 ... First intermediate axis OL2 ... Second intermediate axis OL3 ... Third intermediate axis OLI ... Input shaft center OLO ... Output shaft center

Claims (4)

An actuator having a motor used for a robot joint,
An input shaft member that rotates about an axis by rotation of the motor;
An input gear fixed to the input shaft member and rotating integrally with the input shaft member;
An output shaft member that is rotated about an axis and formed with a hole through which a wiring used for control of the robot passes along the axial direction;
An output gear fixed to the output shaft member and rotating integrally with the output shaft member;
Three or more intermediate shaft members that rotate about their respective shaft centers, each of which is fixed to each of the intermediate shaft members and rotates together with each of the intermediate shaft members, and each of the intermediate shaft members A small-diameter gear having a diameter smaller than the diameter of the large-diameter gear fixed and rotated integrally with each of the intermediate shaft members and fixed to the same intermediate shaft member. Intermediate shaft member of
Two of the three or more intermediate shaft members that are disposed only on the two intermediate shaft members that are closest to the output shaft member and that detect the rotation angles of the two intermediate shaft members that are closest to the output shaft member. A magnetic detection unit;
A control unit that calculates a rotation angle of the output shaft member using a combination of rotation angles of two intermediate shaft members closest to the output shaft member detected by the two magnetic detection units;
An actuator. The actuator according to claim 1,
The number of the intermediate shaft members is three, that is, a first intermediate shaft member, a second intermediate shaft member, and a third intermediate shaft member,
The two magnetic detection units may rotate the second intermediate shaft member and the third intermediate shaft member as two intermediate shaft members closest to the output shaft member among the three intermediate shaft members. An actuator that detects the angle. The actuator according to claim 1 or 2,
In the two intermediate shaft members closest to the output shaft member where the rotation angle is detected, the number of teeth of the large-diameter gear and the number of teeth of the small-diameter gear meshing with each other are relatively prime. The actuator according to any one of claims 1 to 3, further comprising:
A control board on which the control unit is disposed;
Each of the two magnetic detection units includes a magnet attached to two intermediate shaft members closest to the output shaft member, and a reader formed on the control board,
The control board is disposed at a position intersecting with the axis of two intermediate shaft members closest to the output shaft member to which the magnet is attached,
The magnet is an actuator arranged between the control board and the small-diameter gear fixed to each of the two intermediate shaft members closest to the output shaft member to which the magnet is attached.

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