JP2023082269A - Encoder, driving device, and method for assembling encoder - Google Patents

Abstract

To provide an encoder that can be easily assembled, a driving device, and a method for assembling an encoder.SOLUTION: An encoder comprises: a rotation shaft 51; a main shaft gear 610 that has a shank 613 and has a hole 611 into which the rotation shaft 51 is inserted; a first sub shaft gear 621 that is meshed with the main shaft gear 610; a second sub shaft gear 622 that is meshed with the main shaft gear 610; a base 600 that has the main shaft gear 610, first sub shaft gear 621, and second sub shaft gear 622 arranged therein, and is provided with a through hole 601 into which the rotation shaft 51 is inserted; a first magnet 631 that is arranged in the first sub shaft gear 621; a second magnet 632 that is arranged in the second sub shaft gear 622; a first magnetic sensor 641 on which a magnetic field of the first magnet 631 acts; and a second magnetic sensor 642 on which a magnetic field of the second magnet 632 acts. The shank 613 of the main shaft gear 610 has a positioning part 614 that determines a position of the main shaft gear 610 with respect to the base 600 in a direction orthogonal to the axial direction of the rotation shaft 51.SELECTED DRAWING: Figure 3

Description

The present invention relates to an encoder, a driving device, and a method of assembling the encoder.

In Patent Document 1, a main driving gear connected to a motor shaft and a plurality of driven gears arranged to mesh with the main driving gear are provided, and the phase of the main driving gear and the phases of the plurality of driven gears are determined. Based on this, the structure of an encoder for calculating the rotation angle of a motor shaft is disclosed.

The method of assembling the encoder includes, for example, inserting the motor shaft into the main driving gear while aligning the phases of the main driving gear with the phases of the plurality of driven gears in a state in which the main driving gear is movable in a direction orthogonal to the central axis of the main driving gear.

JP 2015-31511 A

However, in conventional encoders, the main driving gear is movable in a direction perpendicular to the central axis, so when inserting the motor shaft into the main driving gear, the central axis of the main driving gear and the central axis of the motor shaft are aligned. If it is misaligned, it may not be inserted properly. That is, there is a problem that assembly is difficult.

The encoder has a rotating shaft that rotates when driven by a motor, and a shaft portion provided with a hole at the center of rotation. A shaft gear, a second countershaft gear meshing with the main shaft gear, the main shaft gear, the first countershaft gear, and the second countershaft gear are arranged, and a through hole is provided in which the rotating shaft is inserted. a first magnet arranged on the first countershaft gear; a second magnet arranged on the second countershaft gear; and a first magnet on which the magnetic field of the first magnet acts A sensor and a second magnetic sensor on which the magnetic field of the second magnet acts, wherein the shaft portion of the main shaft gear measures the position of the main shaft gear with respect to the base portion in a direction perpendicular to the axial direction of the rotating shaft. has a positioning portion that determines the

A driving device includes the encoder described above and the motor connected to the rotating shaft.

A method of assembling an encoder includes: placing the first magnetic sensor and the second magnetic sensor on the base; placing the first countershaft gear on which the first magnet is placed on the base; The step of arranging the second countershaft gear on which a magnet is arranged, the phases of the first countershaft gear and the second countershaft gear, and the phase of the main shaft gear are matched, The method includes a step of fitting the through hole and the positioning portion, and a step of inserting the rotation shaft into the hole of the main shaft gear after the fitting step.

1 is a perspective view showing the configuration of a robot system; FIG. Sectional drawing which shows the structure of a drive device. Sectional drawing which shows the structure of an encoder. FIG. 2 is a cross-sectional view showing the configuration of main members of the encoder; Sectional drawing which shows the structure of a main shaft gear. Sectional drawing which shows the assembly method of an encoder. Sectional drawing which shows the assembly method of an encoder. Sectional drawing which expands and shows the A section of the encoder shown in FIG. Sectional drawing which shows the assembly method of an encoder. Sectional drawing which shows the assembly method of an encoder. Sectional drawing which shows the structure of the encoder of a modification.

First, the configuration of the robot system 1 will be described with reference to FIG.

As shown in FIG. 1, a robot system 1 is used, for example, to perform operations such as supplying, removing, transporting, and assembling precision equipment and parts constituting the same. The robot system 1 has a robot 2 that performs a predetermined work and a control device 3 that controls driving of the robot 2 .

The robot 2 is, for example, a 6-axis robot. The robot 2 has a base 20 fixed to a floor, a wall, a ceiling, or the like, a robot arm 21 supported by the base 20, and an end effector 22 attached to the tip of the robot arm 21.

The robot arm 21 includes an arm 211 rotatably connected to the base 20, an arm 212 rotatably connected to the arm 211, an arm 213 rotatably connected to the arm 212, and an arm 213 connected to the arm 213. It has an arm 214 rotatably connected, an arm 215 rotatably connected to the arm 214 , and an arm 216 rotatably connected to the arm 215 . An end effector 22 is attached to the arm 216 .

The configuration of the robot 2 is not particularly limited, and for example, the number of arms 211 to 216 may be 1 or more and 5 or less, or may be 7 or more. Also, for example, the robot 2 may be a scalar robot, a dual-arm robot, or the like.

The robot 2 includes a driving device 41 that rotates the arm 211 with respect to the base 20, a driving device 42 that rotates the arm 212 with respect to the arm 211, and a driving device 43 that rotates the arm 213 with respect to the arm 212. , a driving device 44 for rotating the arm 214 with respect to the arm 213, a driving device 45 for rotating the arm 215 with respect to the arm 214, a driving device 46 for rotating the arm 216 with respect to the arm 215, have These driving devices 41 to 46 are independently controlled by the control device 3, respectively.

The control device 3 receives a position command from a host computer (not shown) and independently controls the driving of the driving devices 41 to 46 so that the arms 211 to 216 are positioned according to the position command. The control device 3 is composed of, for example, a computer, and has a processor (CPU) for processing information, a memory communicably connected to the processor, and an external interface. The memory stores various programs that can be executed by the processor, and the processor can read and execute various programs stored in the memory.

Next, the configuration of the driving devices 41 to 46 will be described with reference to FIGS. 2 and 3. FIG. Since the driving devices 41 to 46 have the same configuration, the driving device 41 will be described as a representative, and the description of the other driving devices 42 to 46 will be omitted.

As shown in FIGS. 2 and 3 , the drive device 41 has a motor 5 and an encoder 6 that detects the rotation state of the rotating shaft 51 of the motor 5 .

The motor 5 is, for example, various motors such as a 2-phase AC brushless motor, a 3-phase AC brushless motor, and a 3-phase synchronous motor. The motor 5 houses a rotating shaft 51 arranged along an axis aZ parallel to the Z axis, a rotor 52 fixed to the rotating shaft 51, a stator 53 arranged around the rotor 52, and It has a cylindrical housing 54 that supports the stator 53 and bearings 55 and 56 that support the rotating shaft 51 rotatably about the axis aZ with respect to the housing 54 .

Housing 54 is, for example, fixed to base 20 . An arm 211 is connected to the end of the rotating shaft 51 opposite to the encoder 6 . As a result, the output of the motor 5 is transmitted from the base 20 to the arm 211 and the arm 211 rotates with respect to the base 20 .

The encoder 6 is arranged above the motor 5, that is, on the +Z axis side. The encoder 6 includes, for example, a rotating shaft 51, a main shaft gear 610 into which the rotating shaft 51 is inserted, a counter shaft gear 620 that meshes with the main shaft gear 610, a base 600 in which the main shaft gear 610 and the counter shaft gear 620 are arranged, It has a magnetic sensor 640 and an optical sensor 650 .

The main shaft gear 610 is provided with a hole 611 into which the rotating shaft 51 is inserted, in other words, the rotating shaft 51 is inserted, at the center of rotation. The hole 611 is formed halfway in the thickness direction so that the tip of the rotating shaft 51 can be received. In addition, as long as the hole is smaller than the diameter of the hole 611, the hole may be penetrated. The rotating shaft 51 is rotatably supported by the base 600 via a third bearing 663 .

The countershaft gear 620 has a first countershaft gear 621 that meshes with the main shaft gear 610 and a second countershaft gear 622 that meshes with the main shaft gear 610 . As shown in FIG. 3 , a first magnet 631 is arranged on the first countershaft gear 621 . A second magnet 632 is arranged on the second countershaft gear 622 .

The first countershaft gear 621 and the first magnet 631 are arranged on the base 600 via the first bearing 661 . The second countershaft gear 622 and the second magnet 632 are arranged on the base 600 via the second bearing 662 .

The base 600 houses, for example, the main shaft gear 610, the counter shaft gear 620, the magnetic sensor 640, the optical sensor 650, etc., and is provided with a through hole 601 into which the rotating shaft 51 is inserted.

The magnetic sensor 640 has a first magnetic sensor 641 on which the magnetic field of the first magnet 631 acts, and a second magnetic sensor 642 on which the magnetic field of the second magnet 632 acts. The first magnetic sensor 641 and the second magnetic sensor 642 are arranged on the sensor substrate 643 . The magnetic sensor 640 detects the rotating states of the first magnet 631 and the second magnet 632 .

The optical sensor 650 is arranged on the sensor substrate 643 so as to be separated from the optical disk 651 . The optical disc 651 is fixed to a support portion 652 fixed to the rotating shaft 51 . The optical sensor 650 includes a light-emitting element (not shown) that emits light toward a detection pattern (not shown) on the optical disc 651, a light-receiving element (not shown) that receives light reflected by the detection pattern, have The optical sensor 650 can detect the rotation angle θ within the 360° range of the optical disc 651 .

As described above, the encoder 6 has the magnetic sensor 640 and the optical sensor 650, so based on the output of the magnetic sensor 640, the rotation speed n of the rotary shaft 51 of the motor 5 is detected, and based on the output of the optical sensor 650, The rotation angle θ of the rotating shaft 51 within a range of 360° can be detected. Then, the amount of rotation of the rotary shaft 51 can be detected from the rotation speed n and the rotation angle θ.

Next, configurations of the encoder 6 and the main shaft gear 610 will be specifically described with reference to FIGS. 4 and 5. FIG.

As shown in FIG. 4, the encoder 6 has a rotating shaft 51, a main shaft gear 610, sub shaft gears 621, 622, a base 600, and magnetic sensors 641, 642.

The main shaft gear 610 rotates together with the rotating shaft 51 around the axis aZ. The first countershaft gear 621 is rotatably supported about an axis aZ1 parallel to the axis aZ, and is driven by the main shaft gear 610 to rotate by a rotation amount corresponding to a gear ratio with the main shaft gear 610. Similarly, the second countershaft gear 622 is rotatably supported about an axis aZ2 parallel to the axis aZ, and follows the main shaft gear 610 to rotate by a rotation amount corresponding to the gear ratio with the main shaft gear 610.

As shown in FIG. 5, the main shaft gear 610 has a tooth portion 612 that meshes with the first counter shaft gear 621 and the second counter shaft gear 622, and a shaft portion 613 that fits with the base portion 600 in the assembly process.

The shaft portion 613 has a positioning portion 614 that determines the position so that the main shaft gear 610 does not shift in the direction orthogonal to the axial direction of the rotating shaft 51, in other words, in the X direction during the assembly process. The diameter of the positioning portion 614 and the diameter of the through hole 601 of the base portion 600 are the same.

The shaft portion 613 has a tip portion 615 smaller in diameter than the positioning portion 614 on the tip side (opening side of the hole 611 ) of the positioning portion 614 . The tip portion 615 has, for example, a tapered shape that narrows toward the tip side. Since the tip 615 is smaller in diameter than the positioning portion 614, the tip 615 can serve as a guide for alignment when the shaft 613 of the main shaft gear 610 is inserted into the through hole 601 of the base 600. , and the position of the through-hole 601 and the position of the shaft portion 613 can be easily aligned.

Next, a method for assembling the encoder 6 of this embodiment will be described with reference to FIGS. 6 to 10. FIG.

In the process shown in FIG. 6 , a first countershaft gear 621 , a second countershaft gear 622 , a first magnetic sensor 641 and a second magnetic sensor 642 are arranged on the base 600 .

Specifically, a first magnet 631 is arranged on the first countershaft gear 621 . A second magnet 632 is arranged on the second countershaft gear 622 . Illustration of the first bearing 661, the second bearing 662, and the third bearing is omitted. The first magnetic sensor 641 and the second magnetic sensor 642 are arranged on the sensor substrate 643 .

In the process shown in FIG. 7, the main shaft gear 610 is set on the base 600 . Specifically, first, the phases of the first countershaft gear 621 and the second countershaft gear 622 and the phase of the main shaft gear 610 are matched. In other words, the tooth portion provided on the first countershaft gear 621 and the tooth portion provided on the main shaft gear 610 are meshed, and furthermore, the tooth portion provided on the second countershaft gear 622 and the main shaft gear and the teeth provided on 610 are meshed with each other.

Next, as shown in FIG. 8, the positioning portion 614 of the main shaft gear 610 is inserted into the through hole 601 of the base portion 600 in the engaged state. In other words, fit. Thereby, the position of the main shaft gear 610 can be determined with respect to the base 600 . In other words, the position of main shaft gear 610 can be fixed. That is, assembly can be easily performed.

The process shown in FIG. 9 inserts the rotary shaft 51 into the hole 611 of the main shaft gear 610 . Since the position of the main shaft gear 610 is fixed, the central axis 611a of the hole 611 of the main shaft gear 610 and the central axis 51a of the rotating shaft 51 can be aligned. Therefore, the rotating shaft 51 can be easily inserted into the hole 611 of the main shaft gear 610 .

The process shown in FIG. 10 removes the main shaft gear 610 from the through hole 601 of the base 600 and pulls it away. Specifically, after inserting the rotating shaft 51 into the hole 611 of the main shaft gear 610, the rotating shaft 51 is further pushed up. As a result, the positioning portion 614 of the main shaft gear 610 is removed from the through hole 601 of the base portion 600 in the thrust direction. That is, the positioning portion 614 is out of contact with the base portion 600 . Therefore, the rotary shaft 51 and the main shaft gear 610 can be rotated smoothly.

As described above, the encoder 6 of the present embodiment has the rotating shaft 51 that rotates when driven by the motor 5 and the shaft portion 613 having the hole 611 at the center of rotation. The rotating shaft 51 is inserted into the hole 611. main shaft gear 610, first countershaft gear 621 meshing with main shaft gear 610, second countershaft gear 622 meshing with main shaft gear 610, main shaft gear 610, first countershaft gear 621, and second countershaft gear 622 is arranged, the base 600 is provided with a through hole 601 into which the rotating shaft 51 is inserted, the first magnet 631 is arranged on the first countershaft gear 621, and the second countershaft gear 622 is arranged. A second magnet 632, a first magnetic sensor 641 on which the magnetic field of the first magnet 631 acts, and a second magnetic sensor 642 on which the magnetic field of the second magnet 632 acts. It has a positioning portion 614 that determines the position of the main shaft gear 610 with respect to the base portion 600 in the direction perpendicular to the axial direction of the rotating shaft 51 .

According to this configuration, since the main shaft gear 610 has the positioning portion 614, the main shaft gear 610 can be positioned with respect to the base portion 600 while the phase of the main shaft gear 610 and the counter shaft gear 620 are matched. , in other words, the main shaft gear 610 can be immobilized. Therefore, the central axis 611a of the hole 611 of the main shaft gear 610 and the central axis 51a of the rotating shaft 51 can be aligned, and the rotating shaft 51 can be easily inserted into the hole 611 of the main shaft gear 610. That is, assembly can be easily performed.

Moreover, in the encoder 6 of the present embodiment, the diameter of the positioning portion 614 is preferably the same as the diameter of the through hole 601 of the base portion 600 . According to this configuration, since the diameter of the positioning portion 614 and the diameter of the through hole 601 are the same, the position of the main shaft gear 610 can be fixed by aligning the positioning portion 614 with the through hole 601 as a reference.

Moreover, in the encoder 6 of the present embodiment, the shaft portion 613 preferably has a tip portion 615 smaller in diameter than the positioning portion 614 on the opening side of the hole 611 . According to this configuration, since the tip portion 615 is smaller in diameter than the positioning portion 614, the tip portion 615 functions as a guide for alignment when the shaft portion 613 of the main shaft gear 610 is inserted into the through hole 601 of the base portion 600. This makes it possible to easily match the position of the through hole 601 and the position of the shaft portion 613 .

Also, in the encoder 6 of the present embodiment, the positioning portion 614 preferably does not come into contact with the base portion 600 after the rotary shaft 51 is inserted into the hole 611 of the main shaft gear 610 . According to this configuration, after the rotating shaft 51 is inserted into the main shaft gear 610, the positioning portion 614 does not contact the base portion 600, so that the rotating shaft 51 and the main shaft gear 610 can be smoothly rotated.

Further, the driving devices 41 to 46 of this embodiment include the encoder 6 described above and the motor 5 connected to the rotary shaft 51. According to this configuration, it is possible to provide the driving devices 41 to 46 that can be easily assembled.

In addition, the method for assembling the encoder 6 of the present embodiment includes the steps of arranging the first magnetic sensor 641 and the second magnetic sensor 642 on the base 600; a step of arranging the gear 621 and the second countershaft gear 622 on which the second magnet 632 is arranged; the phases of the first countershaft gear 621 and the second countershaft gear 622; the phase of the main shaft gear 610; a step of fitting the through hole 601 and the positioning portion 614 in a state in which they are aligned; and a step of inserting the rotating shaft 51 into the hole 611 of the main shaft gear 610 after the fitting step.

According to this method, since the main shaft gear 610 has the positioning portion 614, the main shaft gear 610 can be positioned with respect to the base portion 600 while the phases of the main shaft gear 610 and the counter shaft gear 620 are aligned. , in other words, the main shaft gear 610 can be immobilized. Therefore, the central axis 611a of the hole 611 of the main shaft gear 610 and the central axis 51a of the rotating shaft 51 can be aligned, and the rotating shaft 51 can be easily inserted into the hole 611 of the main shaft gear 610. That is, assembly can be easily performed.

Modifications of the above embodiment will be described below.

As described above, the portion where the through hole 601 of the base portion 600 and the positioning portion 614 of the main shaft gear 610 are fitted is not limited to being parallel to the axis aZ, and as shown in FIG. It may be tapered with an angle θ1. In other words, the positioning portion 614 gradually decreases in diameter toward the opening side of the hole 611 (see FIG. 5). Specifically, the positioning portion 614a of the main shaft gear 610 is tapered. Furthermore, the through hole 601a of the base 600 is tapered.

In this way, since the diameter of the positioning portion 614a is gradually reduced, as the positioning portion 614a is inserted into the through hole 601a, the positions of the main shaft gear 610 and the base portion 600 can be aligned smoothly. 610 can be fitted to base 600 .

As described above, it is preferable that the diameter of the positioning portion 614 a gradually decreases toward the opening side of the hole 611 . According to this configuration, since the diameter of the positioning portion 614a is gradually reduced, as the positioning portion 614a is inserted into the through hole 601a, the positions of the main shaft gear 610 and the base portion 600 can be aligned smoothly. A main shaft gear 610 can be fitted to the base 600 .

As shown in FIG. 8 described above, the positioning portion 614 is not limited to having no gap between the through hole 601 of the base portion 600 and the positioning portion 614 of the main shaft gear 610, and the entire portion of the positioning portion 614 is in contact with the through hole 601. It may be absent, and there may be a part with a gap.

DESCRIPTION OF SYMBOLS 1... Robot system, 2... Robot, 3... Control device, 5... Motor, 6... Encoder, 20... Base, 21... Robot arm, 22... End effector, 41 to 46... Drive device, 51... Rotary shaft, 51a... Central shaft 52 Rotor 53 Stator 54 Housing 55, 56 Bearing 211 to 216 Arm 600 Base 601 Through hole 601a Through hole 610 Main shaft gear 611 Hole 611a... Central shaft 612... Tooth part 613... Shaft part 614... Positioning part 614a... Positioning part 615... Tip part 620... Counter shaft gear 621... First counter shaft gear 622... Second counter shaft Gears 631 First magnet 632 Second magnet 640 Magnetic sensor 641 First magnetic sensor 642 Second magnetic sensor 643 Sensor substrate 650 Optical sensor 651 Optical disk 652 Supporting portion 661...first bearing, 662...second bearing, 663...third bearing.

Claims (7)

a rotating shaft that rotates by driving a motor;
a main shaft gear having a shaft portion provided with a hole at the center of rotation, the rotary shaft being inserted into the hole;
a first countershaft gear that meshes with the mainshaft gear;
a second countershaft gear that meshes with the main shaft gear;
a base on which the main shaft gear, the first countershaft gear, and the second countershaft gear are arranged and provided with a through hole into which the rotating shaft is inserted;
a first magnet disposed on the first countershaft gear;
a second magnet disposed on the second countershaft gear;
a first magnetic sensor on which the magnetic field of the first magnet acts;
a second magnetic sensor on which the magnetic field of the second magnet acts;
with
The encoder, wherein the shaft portion of the main shaft gear has a positioning portion that determines the position of the main shaft gear with respect to the base portion in a direction perpendicular to the axial direction of the rotating shaft. An encoder according to claim 1, wherein
The encoder, wherein the diameter of the positioning portion is the same as the diameter of the through hole of the base. An encoder according to claim 1 or claim 2,
The encoder according to claim 1, wherein the shaft portion has a tip portion smaller in diameter than the positioning portion on the opening side of the hole. The encoder according to any one of claims 1 to 3,
The encoder, wherein the positioning portion gradually decreases in diameter toward the opening side of the hole. The encoder according to any one of claims 1 to 4,
The encoder, wherein the positioning part does not come into contact with the base part after the rotating shaft is inserted into the hole of the main shaft gear. an encoder according to any one of claims 1 to 5;
the motor connected to the rotating shaft;
a driving device. An assembly method for assembling the encoder according to any one of claims 1 to 5,
placing the first magnetic sensor and the second magnetic sensor on the base;
arranging the first countershaft gear on which the first magnet is arranged and the second countershaft gear on which the second magnet is arranged on the base;
a step of fitting the through hole and the positioning portion in a state where the phases of the first countershaft gear and the second countershaft gear and the phase of the main shaft gear are matched;
a step of inserting the rotating shaft into the hole of the main shaft gear after the fitting step;
A method for assembling an encoder.

Images