Servo motors and robotic devices

Abstract

The present invention provides a servo motor and a robot device that achieve increased design freedom and miniaturization. The servo motor and the robot device comprise: a drive unit having a rotor and a stator; an input shaft to which the driving force of the drive unit is transmitted and rotates integrally with the rotor; a speed reducer that reduces the rotational speed of the input shaft and outputs the reduced speed; an output shaft that transmits the driving force transmitted to the input shaft via the speed reducer; an input-side encoder mounted on the input shaft; an output-side encoder mounted on the output shaft; a circuit substrate having a predetermined circuit pattern formed thereon; an input-side sensor mounted on the circuit substrate so as to face the input-side encoder; and an output-side sensor mounted on the circuit substrate so as to face the output-side encoder, wherein at least one of the input-side sensor and the output-side sensor is mounted on the circuit substrate via a spacer substrate connected to the circuit substrate, and electronic components different from those of the input-side sensor and the output-side sensor are mounted on the circuit substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of a servo motor having an encoder and a robot device including such a servo motor. Background Art

[0002] Servo motors equipped with encoders that detect the rotational position and angle of each component are used in various structures, such as robotics. With the advancement of industrial automation, various types of robotics have been developed, each with its own structure and performance, depending on its industrial application.

[0003] Among robot devices, there is a type called a multi-joint robot, for example, which is formed by connecting multiple robot connecting bodies used as robot joints and robot arms. Among multi-joint robots, there is also a robot device that can reorganize the connection status of the robot connecting bodies to form a structure corresponding to the purpose of use.

[0004] In encoders used in various structures of such robotic devices, etc., a sensor mounted on a substrate is located opposite to the code disk. The sensor detects the magnetic force generated in the magnet and the light emitted from the light source, thereby detecting the rotation position and rotation angle of the rotor and various rotating bodies that rotate with the rotor (for example, refer to patent document 1).

[0005] Patent document 1 describes an example of a magnetic encoder and an optical encoder. In the optical encoder, a light receiving portion functioning as a sensor is mounted on a substrate via a spacer, and the distance between the magnet and the sensor in the magnetic encoder is optimized. In the optical encoder, the distance between the code disk and the sensor (light receiving portion) is optimized.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2-90017 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] In a servo motor having an encoder such as the one described above, the rotational speed of an input shaft that rotates integrally with a rotor is reduced by a speed reducer and the driving force of the rotor is transmitted to an output shaft. In order to improve the reliability of the operation, there is a servo motor having an input-side encoder that detects the rotational state of the input shaft and an output-side encoder that detects the rotational state of the output shaft.

[0011] In such a servo motor, an input-side sensor for detecting the rotational position of the input shaft and an output-side sensor for detecting the rotational position of the output shaft are mounted on a circuit board. The input-side sensor is located opposite the input-side encoder mounted on the input shaft, while the output-side sensor is located opposite the output-side encoder mounted on the output shaft. To ensure optimal detection by each sensor, the positions of the circuit board and encoder are set so that the spacing between each sensor and encoder is appropriately predetermined.

[0012] Incidentally, in a servo motor, in order to effectively utilize the installation space of the circuit substrate and achieve miniaturization, it is sometimes desirable to install electronic components different from the sensors on the surface of the circuit substrate opposite to the encoder, such as a CPU (Central Processing Unit) as a central processing unit connected to each sensor, and an EEPROM (Electrically Erasable Programmable Read-Only Memory) as a non-volatile memory.

[0013] However, in order to ensure the sensor's higher detection capability, the appropriate spacing between the sensor and the code disk is generally set to a smaller spacing, which limits the size (height) of the electronic components that can be installed. Due to this limitation, there is a situation where the design freedom is reduced or miniaturization is hindered.

[0014] Therefore, an object of the servo motor and robot device according to the present invention is to achieve improvement in design freedom and miniaturization.

[0015] Means used to solve problems

[0016] The servo motor involved in at least some embodiments of the present invention includes: a drive unit, which has a rotor and a stator; an input shaft, which is transmitted with the driving force of the drive unit and rotates integrally with the rotor; a reducer, which reduces the rotation speed of the input shaft and outputs it; an output shaft, which transmits the driving force transmitted to the input shaft via the reducer; an input-side code disk, which is mounted on the input shaft; an output-side code disk, which is mounted on the output shaft; a circuit substrate, which is formed with a predetermined circuit pattern; an input-side sensor, which is mounted on the circuit substrate in a state opposite to the input-side code disk; and an output-side sensor, which is mounted on the circuit substrate in a state opposite to the output-side code disk, at least one of the input-side sensor and the output-side sensor is mounted on the circuit substrate via a spacer substrate connected to the circuit substrate, and electronic components different from the input-side sensor and the output-side sensor are mounted on the circuit substrate.

[0017] As a result, at least one of the interval between the input side code disk and the input side sensor and the interval between the output side code disk and the output side sensor is increased by an amount corresponding to the portion where the spacer substrate exists, so that it is less likely to produce restrictions related to the size of electronic components that can be mounted on the circuit substrate.

[0018] Preferably, in the servo motor according to at least some embodiments of the present invention, one of the input-side sensor and the output-side sensor is mounted on the circuit board via the spacer board.

[0019] Thus, the distance between one of the input-side code wheel and the output-side code wheel and the circuit board can be increased according to the internal structure of the servo motor.

[0020] Preferably, in the servo motor according to at least some embodiments of the present invention, the input-side sensor and the output-side sensor are each mounted on the circuit board via the spacer board.

[0021] This makes it possible to increase both the distance between the input-side code disk and the circuit substrate and the distance between the output-side code disk and the circuit substrate.

[0022] Preferably, in the servo motor according to at least some embodiments of the present invention, the input-side sensor and the output-side sensor are located at positions separated from or aligned with each other in a radial direction with respect to the rotation center of the input shaft.

[0023] This allows the input-side sensor and the output-side sensor to be mounted at close positions on the circuit board.

[0024] Preferably, in the servo motor according to at least some embodiments of the present invention, the electronic component, the input-side sensor, and the output-side sensor are located at positions separated or aligned in a radial direction with respect to the rotation center of the input shaft.

[0025] This allows the input-side sensor, the output-side sensor, and the electronic components to be mounted at close positions on the circuit board.

[0026] Preferably, in the servo motor according to at least some embodiments of the present invention, the electronic component includes a component constituting a drive circuit that drives the drive unit.

[0027] Therefore, since the input side sensor and the output side sensor are mounted on the circuit board and the electronic components include components constituting the driver, components constituting the driver circuit are mounted on the board on which the input side sensor and the output side sensor are mounted.

[0028] Preferably, in the servo motor involved in at least some embodiments of the present invention, a portion of the outer circumferential surface of the input shaft is formed as an input side mounting portion for mounting the input side code disk, and a portion of the outer circumferential surface of the output shaft is formed as an output side mounting portion for mounting the output side code disk, and at least one of the diameters of the input side mounting portion and the output side mounting portion are formed to be the same size in the axial direction.

[0029] Thus, at least one of the axial mounting position of the input-side code wheel relative to the input-side mounting portion and the axial mounting position of the output-side code wheel relative to the output-side mounting portion can be adjusted.

[0030] A robot device according to at least some embodiments of the present invention is a robot device in which a servo motor is provided in at least one of a plurality of robot-connected bodies, wherein the servo motor comprises: a drive unit having a rotor and a stator; an input shaft to which the driving force of the drive unit is transmitted and rotates integrally with the rotor; a reducer that reduces the rotational speed of the input shaft and outputs the reduced speed; an output shaft that transmits the driving force transmitted to the input shaft via the reducer; an input-side code disk mounted on the input shaft; an output-side code disk mounted on the output shaft; a circuit substrate having a predetermined circuit pattern formed thereon; an input-side sensor mounted on the circuit substrate in a state opposing the input-side code disk; and an output-side sensor mounted on the circuit substrate in a state opposing the output-side code disk, wherein at least one of the input-side sensor and the output-side sensor is mounted on the circuit substrate via a spacer substrate connected to the circuit substrate, and electronic components different from those of the input-side sensor and the output-side sensor are mounted on the circuit substrate.

[0031] Therefore, in the servo motor, at least one of the interval between the input side code disk and the input side sensor and the interval between the output side code disk and the output side sensor is increased by an amount corresponding to the portion where the spacer substrate exists, so that it is less likely to produce restrictions related to the size of electronic components that can be mounted on the circuit substrate.

[0032] Effects of the Invention

[0033] According to the present invention, at least one of the interval between the input side code disk and the input side sensor and the interval between the output side code disk and the output side sensor is increased by an amount corresponding to the portion where the spacer substrate exists. Therefore, it is less likely to produce restrictions related to the size of electronic components that can be mounted on the circuit substrate, and it is possible to achieve increased freedom of design and miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is with Figures 2 to 6This figure shows an embodiment of the servo motor and the robot device according to the present invention together. This figure is a schematic perspective view of the robot device.

[0035] Figure 2 This is a cross-sectional view of a robot connection body having a servo motor.

[0036] Figure 3 This is an enlarged cross-sectional view showing an encoder, etc.

[0037] Figure 4 This is a conceptual diagram showing an example of the arrangement positions of sensors and electronic components.

[0038] Figure 5 This is an enlarged cross-sectional view showing an example in which the input-side sensor and the output-side sensor are mounted on the first circuit substrate via spacer substrates.

[0039] Figure 6 This is an enlarged cross-sectional view showing an example in which the output-side sensor is mounted on the first circuit substrate via a spacer substrate. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the servo motor and the robot device according to the present invention will be described with reference to the accompanying drawings.

[0041] The following embodiments illustrate examples of the robot device of the present invention being applied to a type installed on a floor, etc. However, the application scope of the robot device of the present invention is not limited to the type installed on a floor, etc., and the robot device of the present invention can also be applied to a type installed on a ceiling or wall.

[0042] It should be noted that the front, back, top, bottom, left, and right directions shown below are for convenience of description, and the implementation of the present invention is not limited to these directions.

[0043] <Overview of the Robot Device's Structure>

[0044] First, the schematic structure of the robot device 1 will be described (see Figure 1 The robot device 1 has a function of transferring objects such as boxes and commodities, and is used for purposes such as packing commodities.

[0045] The robot device 1 includes robot coupling bodies 3, 3, ..., sequentially coupled to a base 2 placed on a floor 100 or the like. The robot coupling body 3 at one end on the lower side is rotatably coupled to the base 2. For example, an arm (not shown) is coupled to the robot coupling body 3 at one end on the upper side, and the arm grips an object to be transported and moves it to a predetermined location.

[0046] As the robot connection body 3 , a robot joint 3A or a robot arm 3B is used.

[0047] The robot joint 3A includes, for example, a base 4 having a substantially cylindrical outer shape and a protrusion 5 . The protrusion 5 protrudes from an axially intermediate portion of the base 4 in a direction perpendicular to the axial direction of the base 4 .

[0048] As the robot arm 3B, a same-diameter arm 6 having a roughly cylindrical shape with the same diameter, a different-diameter elbow 7 having a curved shape with a diameter that changes in the axial direction, and a different-diameter arm 8 having a diameter that is different from that of other parts are used.

[0049] Note that, in the robot connected body 3 , a cover 9 is attached to the end portion not connected to other robot connected bodies 3 or the base 2 , and the cover 9 closes the portion not connected to other robot connected bodies 3 or the base 2 .

[0050] In the robot device 1, the robot joints 3, 3, ..., sequentially connected as described above, can be made smaller at the distal end (upper side) of the robot joints 3A relative to the proximal end (lower side) by, for example, using the reducing elbows 7 and reducing arms 8. Thus, the use of the reducing elbows 7 and reducing arms 8 enables the robot device 1 to be made smaller and lighter, and the resulting lighter weight can lead to faster motion speeds.

[0051] <Structure of the robot connector>

[0052] Hereinafter, an example of the structure of the robot connection body 3 will be described (refer to Figures 2 to 4 ).

[0053] The robot connection body 3 includes a substantially cylindrical housing 10, a first circuit board 11 mounted on the housing 10, a second circuit board 12 located opposite the first circuit board 11, and a servo motor 13 disposed inside the housing 10 except for a portion thereof (see FIG. Figure 2 ).

[0054] A fixing body 20 is coupled to one axial end portion of the frame body 10 by, for example, a fastening bolt (not shown).

[0055] The first circuit board 11 and the second circuit board 12 are formed into a substantially circular shape, for example. Predetermined circuit patterns are formed on both surfaces of the first circuit board 11 and the second circuit board 12. The first circuit board 11 and the second circuit board 12 are connected to a power supply (not shown).

[0056] The surface of the first circuit board 11 opposite to the surface facing the second circuit board 12 forms a first mounting surface 11a, and the surface facing the second circuit board 12 forms a second mounting surface 11b. The surface of the second circuit board 12 opposite to the first circuit board 11 forms a first mounting surface 12a, and the surface opposite to the surface facing the first circuit board 11 forms a second mounting surface 12b.

[0057] The first circuit board 11 is mounted to the frame 10 via first mounting pins 14, 14, ..., and the second circuit board 12 is mounted to the frame 10 via second mounting pins 15, 15, .... The first circuit board 11 and the second circuit board 12 are located outside the frame 10 in the axial direction of the frame 10. The second circuit board 12 is located on the opposite side of the frame 10 with the first circuit board 11 therebetween and is connected to the first circuit board 11 and to connection terminals described later via a connector.

[0058] It should be noted that a cover 9 may be attached to the frame 10 to cover the first circuit board 11 and the second circuit board 12 .

[0059] The servo motor 13 includes a driving unit 16 , a brake 17 , an input shaft 18 , an output shaft 19 , and an encoder 21 .

[0060] The drive unit 16 is arranged inside the housing 10 and comprises a rotor 22 and a stator 23. The stator 23 is arranged on the outer circumference of the rotor 22. The rotor 22 has a generally cylindrical base portion 22a and a magnet 22b mounted on the outer circumference of the base portion 22a. The stator 23 has a generally cylindrical coil holder 23a and a plurality of coils 23b held by the coil holder 23a in a circumferentially separated state. The plurality of coils 23b are located opposite the magnet 22b.

[0061] When the coil 23 b is energized in the drive unit 16 , the rotor 22 rotates relative to the stator 23 in a direction corresponding to the direction in which the coil 23 b is energized.

[0062] The brake 17 is annularly arranged inside the housing 10. The brake 17 has the function of stopping the rotation of the rotor 22. By stopping the rotation of the rotor 22 by the brake 17, excessive rotation of the rotor 22 due to inertia is prevented, thereby ensuring the proper rotation state of the rotor 22.

[0063] The input shaft 18 is formed into a generally cylindrical shape and is disposed within the housing 10 except for one end in the axial direction, with the one end protruding from the housing 10. A portion of the input shaft 18 is located inside the rotor 22, and the portion located inside the rotor 22 is coupled to the base cylinder portion 22a of the rotor 22. Thus, the driving force of the drive unit 16 is transmitted to the input shaft 18.

[0064] A bearing (not shown) is disposed between the housing 10 and the input shaft 18 , and the input shaft 18 rotates integrally with the rotor 22 relative to the housing 10 via the bearing.

[0065] The output shaft 19 includes a cylindrical center tube portion 24 and a flange-shaped transmitted portion 25 extending outward from one axial end of the center tube portion 24. The center tube portion 24, except for a portion thereof, is located inside the input shaft 18. The output shaft 19 is longer in the axial direction of the center tube portion 24 than in the axial direction of the input shaft 18. A portion of the center tube portion 24 protrudes axially from the input shaft 18. A portion of the center tube portion 24 and the transmitted portion 25 are located outside the housing 10.

[0066] A bearing (not shown) is disposed between the input shaft 18 and the output shaft 19 , and the output shaft 19 is rotatable relative to the input shaft 18 via the bearing.

[0067] The outer circumferential surface of the other axial end of the input shaft 18 forms an input-side mounting portion 26, and the outer circumferential surface of the other axial end of the center cylindrical portion 24 of the output shaft 19 forms an output-side mounting portion 27. Both the input-side mounting portion 26 and the output-side mounting portion 27 are formed to have the same axial diameter. Therefore, no outwardly projecting protrusions are provided on the other end of the input shaft 18 or the other end of the center cylindrical portion 24.

[0068] A speed reducer (not shown) is disposed inside fixed body 20. The speed reducer has the function of reducing the rotational speed of input shaft 18 and outputting the driving force transmitted from drive unit 16 to input shaft 18 to output shaft 19. Thus, the driving force of drive unit 16 is transmitted to output shaft 19 via input shaft 18 and the speed reducer, and output shaft 19 rotates at a lower speed than the rotational speed of input shaft 18.

[0069] The encoder 21 includes an input side code disk 28, an output side code disk 29, an input side sensor 30, and an output side sensor 31 (see Figure 2 as well as Figure 3 ).

[0070] The input-side code disk 28 is annular in shape, with its thickness aligned with the axial direction of the input shaft 18 , and includes, for example, a plurality of magnets (not shown). The input-side code disk 28 is attached to the input-side attachment portion 26 of the input shaft 18 via a disk hub 32 .

[0071] The output-side code disc 29 has an annular facing surface 29a having a smaller diameter than the input-side code disc 28, and a cylindrical mounted portion 29b protruding from the inner circumference of the facing surface 29a. The facing surface 29a has, for example, a plurality of magnets (not shown). The thickness direction of the output-side code disc 29 is aligned with the axial direction of the output shaft 19, and the mounted portion 29b of the output-side code disc 29 is mounted to the output-side mounting portion 27 of the output shaft 19.

[0072] The other axial end of the central cylindrical portion 24 of the output shaft 19 protrudes axially from the input shaft 18 , so the input-side code disk 28 mounted on the input shaft 18 and the output-side code disk 29 mounted on the output shaft 19 are located at different positions in the thickness direction.

[0073] The input side code disk 28 is mounted on the input shaft 18 in a state where the input side mounting portion 26 is inserted into the disk hub 32. However, as described above, the input side mounting portion 26 is formed to have the same diameter in the axial direction. Therefore, by appropriately moving the disk hub 32 axially relative to the input side mounting portion 26, the mounting position of the input side code disk 28 relative to the input shaft 18 can be adjusted.

[0074] In addition, the output side code disc 29 is installed on the output shaft 19 in a state where the output side mounting portion 27 is inserted therethrough, but as described above, the output side mounting portion 27 is formed so that the diameter is the same in the axial direction. Therefore, by appropriately moving the output side code disc 29 axially relative to the output side mounting portion 27, the mounting position relative to the output shaft 19 can be adjusted.

[0075] The position adjustment of the axial installation position of the input side code disk 28 relative to the input side mounting portion 26 and the axial installation position of the output side code disk 29 relative to the output side mounting portion 27 can be performed in this way, so the distance between the input side code disk 28 and the input side sensor 30 and the distance between the output side code disk 29 and the output side sensor 31 can be appropriately adjusted, which can improve the design freedom.

[0076] It should be noted that in a structure capable of adjusting the axial installation position of the input side code disk 28 relative to the input side mounting portion 26 and the axial installation position of the output side code disk 29 relative to the output side mounting portion 27, for example, it is preferred to provide position limiting portions such as stop protrusions on the outer periphery of the input side mounting portion 26 and the output side mounting portion 27.

[0077] By setting such a position limiting portion, when adjusting the position, the position of the disc hub 32 relative to the input side mounting portion 26 and the position of the output side code disc 29 relative to the output side mounting portion 27 are limited to a certain range, which can avoid contact between the disc hub 32 and the reducer, etc., and contact between the output side code disc 29 and the input shaft 18, etc., and ensure the appropriate position of the input side code disc 28 and the output side code disc 29.

[0078] It should be noted that the servo motor 13 may be configured to be capable of adjusting either the axial mounting position of the input side code disc 28 relative to the input side mounting portion 26 or the axial mounting position of the output side code disc 29 relative to the output side mounting portion 27 .

[0079] The input-side sensor 30 and the output-side sensor 31 are both mounted on the first mounting surface 11a of the first circuit substrate 11. The input-side sensor 30 is mounted on the first circuit substrate 11 via a spacer substrate 33, which functions as an auxiliary substrate and is electrically connected to the first circuit substrate 11. Thus, power is supplied from a power source to the input-side sensor 30 via the spacer substrate 33 and the first circuit substrate 11, and signals are transmitted and received between the input-side sensor 30 and the first circuit substrate 11 via the spacer substrate 33.

[0080] The input-side sensor 30 is located at a position facing the input-side code wheel 28 , and the output-side sensor 31 is located at a position facing the output-side code wheel 29 .

[0081] The input side sensor 30 and the output side sensor 31 are mounted on the first mounting surface 11a, for example, at positions aligned in the radial direction or at positions separated in the radial direction, and are located at positions separated or aligned in the radial direction with respect to the rotation center of the input shaft 18 (see Figure 4 ).

[0082] Therefore, the input-side sensor 30 and the output-side sensor 31 can be mounted at similar locations on the first circuit board 11. This allows the circuit patterns connected to the input-side sensor 30 and the output-side sensor 31 to be concentrated in a single location, simplifying and miniaturizing the structure of the first circuit board 11. Furthermore, since the input-side sensor 30 and the output-side sensor 31 can be mounted at similar locations on the first circuit board 11, noise can be reduced by shortening the wiring path.

[0083] It should be noted that the input-side sensor 30 and the output-side sensor 31 may be mounted at any position on the first mounting surface 11 a as long as they are positioned facing the input-side code wheel 28 and the output-side code wheel 29 , respectively.

[0084] In the servo motor 13, as described above, the input side sensor 30 is mounted on the first circuit substrate 11 via the spacer substrate 33. The spacing S1 between the first mounting surface 11a of the first circuit substrate 11 and the input side code disk 28 is larger than the spacing S2 between the first mounting surface 11a of the first circuit substrate 11 and the output side code disk 29. The spacing H1 between the input side sensor 30 and the input side code disk 28 is the same as the spacing H2 between the output side sensor 31 and the output side code disk 29 (see FIG. 1 ). Figure 3Thus, there is a space between the first circuit substrate 11 and the input-side code wheel 28 that is larger than the space between the first circuit substrate 11 and the output-side code wheel 29 .

[0085] Thus, by having a large space between the first circuit substrate 11 and the input side code disk 28, electronic components 34, 34, ... having a high height are arranged in the large space. The electronic components 34 are, for example, a CPU (Central Processing Unit) as a central processing unit connected to the input side sensor 30 and the output side sensor 31, an EEPROM (Electrically Erasable Programmable Read-Only Memory) as a non-volatile memory, etc. The electronic components 34, 34, ... are mounted on the first mounting surface 11a of the first circuit substrate 11 together with the input side sensor 30 and the output side sensor 31 (see Figure 4 ).

[0086] The electronic component 34 is arranged on the first mounting surface 11a together with the input side sensor 30 and the output side sensor 31 at positions aligned in the radial direction or at positions separated in the radial direction. The electronic component 34 is located at positions separated or aligned in the radial direction with respect to the rotation center of the input shaft 18 (see FIG. Figure 4 34(A), 34(B)).

[0087] Therefore, the input-side sensor 30, the output-side sensor 31, and the electronic component 34 can be mounted in close proximity on the first circuit board 11. Consequently, the circuit patterns connected to the input-side sensor 30, the output-side sensor 31, and the electronic component 34 can be concentrated in a single location, further simplifying and miniaturizing the structure of the first circuit board 11. Furthermore, since the input-side sensor 30, the output-side sensor 31, and the electronic component 34 can be mounted in close proximity on the first circuit board 11, noise can be reduced by shortening the wiring paths.

[0088] It should be noted that the electronic components 34 , 34 , . . . can be mounted at any position on the first mounting surface 11 a .

[0089] It should be noted that the electronic component 34 may be arranged at a position separated from the input side sensor 30 and the output side sensor 31 in the circumferential direction (see Figure 434 (C)). However, it is preferable that the wiring path between the electronic component 34 and the input-side sensor 30 and the output-side sensor 31 be short. Therefore, even if the electronic component 34 is arranged at a position separated from the input-side sensor 30 and the output-side sensor 31 in the circumferential direction, it is preferably arranged at a position close to the input-side sensor 30 and the output-side sensor 31.

[0090] In addition, when the height of the electronic component 34 is relatively low, the electronic component 34 can also be arranged in the space between the first circuit substrate 11 and the output side code disk 29 (see Figure 4 34(D), 34(E)). In this case, it is also preferable that the wiring path between the electronic component 34 and the input-side sensor 30 and the output-side sensor 31 is short, and therefore it is also preferable that the electronic component 34 is arranged at a position close to the input-side sensor 30 and the output-side sensor 31.

[0091] The first circuit board 11 is provided with connection terminals 35 (see Figure 2 as well as Figure 3 The connecting terminal 35 is, for example, a DIP (Dual Inline Package) component, and is a type of component that is joined by solder or the like while the terminal portion passes through the substrate. The connecting terminal 35 includes a terminal body 35a and terminal portions 35b, 35b. The terminal body 35a of the connecting terminal 35 is mounted on the second mounting surface 11b of the first circuit substrate 11, while the terminal portions 35b, 35b pass through the first circuit substrate 11 and are joined to the first mounting surface 11a by solder 50, 50.

[0092] The connection terminal 35 is mounted at a position relative to the first circuit substrate 11 such that the terminal portions 35b, 35b extend through the first circuit substrate 11 and are located within a relatively large space formed between the first circuit substrate 11 and the input-side code disk 28. Therefore, the terminal portions 35b, 35b of the connection terminal 35 are mounted at a position opposing the input-side code disk 28.

[0093] As described above, in the servo motor 13, the input side sensor 30 is mounted on the first circuit substrate 11 via the spacer substrate 33, thereby forming a larger space between the first circuit substrate 11 and the input side code disk 28. The terminal portions 35b, 35b of the connecting terminal 35 are located in the space, so the connecting terminal 35 can be mounted on the first circuit substrate 11 without interfering with other components.

[0094] Therefore, compared with the case of using surface mount components as connection terminals, the connection terminals 35 have higher bonding strength with respect to the first circuit board 11 , thereby ensuring a stable bonding state and improving reliability of bonding with respect to the first circuit board 11 .

[0095] A connector 36 is mounted on the first mounting surface 12a of the second circuit board 12, and the connector 36 is connected to the terminal body 35a of the connection terminal 35. Thus, the second circuit board 12 is connected to the first circuit board 11 via the connection terminal 35 and the connector 36.

[0096] It should be noted that, in the servo motor 13, as described above, two substrates, a first circuit substrate 11 and a second circuit substrate 12, are provided. The first circuit substrate 11 and the second circuit substrate 12 are arranged in a state of being opposite to each other in the thickness direction, thereby achieving radial miniaturization of the servo motor 13 while ensuring a larger mounting area for electronic components.

[0097] Furthermore, the input-side sensor 30 , the output-side sensor 31 , and electronic components 34 , 34 , . . . are mounted on the first circuit board 11 . The electronic components 34 , 34 , . . . include components constituting a drive circuit for driving the drive unit 16 .

[0098] Therefore, since the input side sensor 30 and the output side sensor 31 are installed on the first circuit substrate 11, and the components constituting the drive circuit are included in the electronic components 34, 34,..., the components constituting the drive circuit are installed on the substrate on which the input side sensor 30 and the output side sensor 31 are installed. This can reduce the number of substrates required for the installation of the drive circuit and achieve simplification and miniaturization of the structure.

[0099] <Other sensor configuration examples>

[0100] In the above description, an example is shown in which the input side sensor 30 is mounted on the first circuit substrate 11 via the spacer substrate 33. However, for example, both the input side sensor 30 and the output side sensor 31 may be mounted on the first circuit substrate 11 via the spacer substrates 33 and 33, respectively (see FIG. Figure 5 In this case, the input-side code disk 28 and the output-side code disk 29 are located at the same position in the thickness direction. There is a large space between the first circuit substrate 11 and the input-side code disk 28 and between the first circuit substrate 11 and the output-side code disk 29. In this space, taller electronic components 34, 34, ... can be arranged.

[0101] In this way, the input side sensor 30 and the output side sensor 31 are respectively installed on the first circuit substrate 11 via the spacer substrates 33 and 33, thereby increasing the distance between the input side code disk 28 and the first circuit substrate 11 and the distance between the output side code disk 29 and the first circuit substrate 11, thereby increasing the freedom of the installation position of the electronic component 34 relative to the first circuit substrate 11.

[0102] In addition, the output side sensor 31 of the input side sensor 30 and the output side sensor 31 may be mounted on the first circuit substrate 11 via the spacer substrate 33 (see Figure 6 In this case, the input side code disk 28 and the output side code disk 29 are located at different positions in the thickness direction, and there is a large space between the first circuit substrate 11 and the output side code disk 29. In this large space, taller electronic components 34, 34, ... can be arranged.

[0103] However, in the servo motor 13 , as described above, the input sensor 30 may be mounted on the first circuit board 11 via the spacer substrate 33 , and either the input sensor 30 or the output sensor 31 may be mounted on the first circuit board 11 via the spacer substrate 33 .

[0104] By installing one of the input side sensor 30 and the output side sensor 31 on the first circuit substrate 11 via the spacer substrate 33 in this way, the distance between one of the input side code disk 28 and the output side code disk 29 and the first circuit substrate 11 can be increased according to the internal structure of the servo motor 13. Therefore, the electronic components 34, 34, ... can be installed at appropriate positions in the first circuit substrate 11 on the basis of improving the design freedom.

[0105] Note that the size (height) of the spacer substrate 33 can be appropriately set according to the size (height) of the input-side sensor 30 or the output-side sensor 31 mounted on the first circuit substrate 11 .

[0106] In addition, by configuring the spacer substrate 33, the distance between the input side sensor 30 and the input side code disk 28 or the distance between the output side sensor 31 and the output side code disk 29 changes according to the height of the spacer substrate 33, but by appropriately setting the axial position of the input side code disk 28 or the output side code disk 29 or adjusting it during the assembly of each component, the distance between the input side sensor 30 and the input side code disk 28 or the distance between the output side sensor 31 and the output side code disk 29 can be formed to an appropriate distance.

[0107] Summary

[0108] As described above, the servo motor 13 and the robot device 1 equipped with the servo motor 13 include: a circuit substrate (first circuit substrate 11) having a predetermined circuit pattern; an input side sensor 30 mounted on the circuit substrate in a state opposite to the input side code disk 28; and an output side sensor 31 mounted on the circuit substrate in a state opposite to the output side code disk 29, at least one of the input side sensor 30 and the output side sensor 31 being mounted on the circuit substrate via a spacer substrate 33 connected to the circuit substrate, and an electronic component 34 being mounted on the circuit substrate.

[0109] Therefore, at least one of the interval between the input side code disk 28 and the input side sensor 30 and the interval between the output side code disk 29 and the output side sensor 31 is increased by an amount corresponding to the portion where the spacer substrate 33 exists, so it is less likely to produce restrictions related to the size (height) of the electronic component 34 that can be mounted on the circuit substrate, thereby achieving increased design freedom and miniaturization.

[0110] In addition, the electronic components 34 connected to the input side sensor 30 and the output side sensor 31 can be arranged in a space with a larger interval and the wiring path used to connect the input side sensor 30 and the output side sensor 31 and the electronic components 34 can be shortened, which can suppress the generation of noise and improve the reliability of the operation.

[0111] <Other>

[0112] In the above, an example is shown in which a magnetic encoder 21 having an input side code disk 28, an output side code disk 29, an input side sensor 30 and an output side sensor 31 is provided in the servo motor 13, but the encoder provided in the servo motor 13 is not limited to the magnetic type, and an optical encoder, an electromagnetic induction encoder or an electrostatic capacitance encoder may also be provided in the servo motor 13.

[0113] Description of reference numerals:

[0114] 1: Robotic device;

[0115] 11: first circuit substrate;

[0116] 15: Servo motor;

[0117] 16: driving unit;

[0118] 18: input shaft;

[0119] 19: output shaft;

[0120] 21: encoder;

[0121] 22: rotor;

[0122] 23: stator;

[0123] 28: Input side code disk;

[0124] 29: Output side code disk;

[0125] 30: input side sensor;

[0126] 31: output side sensor;

[0127] 33: spacer substrate;

[0128] 34: Electronic components.

Claims

1. A servo motor, wherein: The servo motor has: a drive unit having a rotor and a stator; an input shaft to which a driving force of the driving portion is transmitted and rotates integrally with the rotor; a speed reducer that reduces the rotation speed of the input shaft and outputs the reduced speed; an output shaft to which the driving force transmitted to the input shaft is transmitted via the speed reducer; an input-side code disc formed in a circular ring shape and mounted on the input shaft; An output-side code disc mounted on the output shaft; a circuit substrate having a predetermined circuit pattern formed thereon; an input-side sensor mounted on the circuit substrate in a state facing the input-side code disk; as well as an output-side sensor mounted on the circuit substrate in a state facing the output-side code disc, The rotation axis of the input shaft coincides with the rotation axis of the output shaft, The input shaft is cylindrical, and the output shaft is inserted into the interior of the input shaft. The input-side code disc and the output-side code disc are located on the same side relative to the circuit substrate in the axial direction of the input shaft. The output-side code disc is located inward of the inner circumferential surface of the input-side code disc in the radial direction of the input shaft. The input side sensor and the output side sensor are mounted on the same surface of the circuit substrate. At least one of the input-side sensor and the output-side sensor is mounted on the circuit substrate via a spacer substrate connected to the circuit substrate. Electronic components different from the input-side sensor and the output-side sensor are mounted on the circuit board.

2. The servo motor according to claim 1, wherein One of the input-side sensor and the output-side sensor is mounted on the circuit board via the spacer board.

3. The servo motor according to claim 1, wherein The input-side sensor and the output-side sensor are respectively mounted on the circuit substrate via the spacer substrate.

4. The servo motor according to any one of claims 1 to 3, wherein The input-side sensor and the output-side sensor are located at positions separated from or aligned with each other in a radial direction with the rotation center of the input shaft as a reference.

5. The servo motor according to claim 4, wherein: The electronic component, the input-side sensor, and the output-side sensor are located at positions separated from or aligned with each other in a radial direction with the rotation center of the input shaft as a reference.

6. The servo motor according to any one of claims 1 to 3, wherein The electronic components include components constituting a drive circuit that drives the drive unit.

7. The servo motor according to any one of claims 1 to 3, wherein A portion of the outer peripheral surface of the input shaft is formed as an input side mounting portion for mounting the input side code disc. A portion of the outer peripheral surface of the output shaft is formed as an output side mounting portion for mounting the output side code disc. At least one of a diameter of the input-side mounting portion and a diameter of the output-side mounting portion is formed to have the same size in the axial direction.

8. A robot device comprising a plurality of robot-connected bodies, wherein at least one of the robot-connected bodies is provided with a servo motor, wherein: The servo motor has: a drive unit having a rotor and a stator; an input shaft to which a driving force of the driving portion is transmitted and rotates integrally with the rotor; a speed reducer that reduces the rotation speed of the input shaft and outputs the reduced speed; an output shaft that transmits the driving force transmitted to the input shaft via the speed reducer; an input-side code disc formed in a circular ring shape and mounted on the input shaft; An output-side code disc mounted on the output shaft; a circuit substrate having a predetermined circuit pattern formed thereon; an input-side sensor mounted on the circuit substrate in a state facing the input-side code disk; as well as an output-side sensor mounted on the circuit substrate in a state facing the output-side code disc, The rotation axis of the input shaft coincides with the rotation axis of the output shaft, The input shaft is cylindrical, and the output shaft is inserted into the interior of the input shaft. The input-side code disc and the output-side code disc are located on the same side relative to the circuit substrate in the axial direction of the input shaft. The output-side code disc is located inward of the inner circumferential surface of the input-side code disc in the radial direction of the input shaft. The input side sensor and the output side sensor are mounted on the same surface of the circuit substrate. At least one of the input-side sensor and the output-side sensor is mounted on the circuit substrate via a spacer substrate connected to the circuit substrate. Electronic components different from the input-side sensor and the output-side sensor are mounted on the circuit board.

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