Electric rotating joint, robot upper limb and robot

Abstract

The invention relates to the technical field of machine rotating joints, and discloses an electric rotating joint, a robot upper limb and a robot, the electric rotating joint comprises a shell and a rear cover which are connected, and further comprises an input shaft encoder coded disc, an output shaft encoder coded disc, a motor, a speed reducer, an input shaft body and an output shaft; the input shaft body is hollow, the outer wall of the left end of the input shaft body is rotationally connected with the inner wall of the shell through a first bearing, and the right end of the input shaft body extends out of the shell and is rotationally connected with the inner wall of a shell port through a third bearing. A stator part of the motor is fixed to the inner wall of the shell, and a rotor part of the motor is connected with the outer wall of the input shaft body. Through the arrangement of the motor, the input shaft body, the speed reducer, the output shaft and other structures, power output and power input structures form a joint module with compact layout, the axial space layout is reasonably utilized, and the power output structure and the power input structure are compact; and optimal distribution of joint performance and boundary dimension.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machine rotary joint, in particular to an electric rotary joint, a robot upper limb and a robot. BACKGROUND

[0002] At present, the robot joint is mainly divided into an electric rotary joint and a linear thrust joint, wherein the electric rotary joint is generally composed of a motor, a speed reducer, a driver and an encoder, the motor generates high-speed small torque, the speed reducer converts the high-speed small torque into low-speed large torque suitable for robot movement, the motor output shaft inputs the speed reducer, and the speed reducer is converted into an output shaft through planetary reduction or harmonic reduction, wherein the motor input shaft and the speed reducer output shaft need to be connected with an encoder disc, and the relative and absolute positions of the input shaft and the output shaft are read by a corresponding chip read head.

[0003] The higher the axial and radial position accuracy of the encoder disc center is, the better the shaft position accuracy read by the chip read head is, and the existing joint product generally adopts the mode that the encoder support is connected to the shaft end, the axial error accumulated from the bearing chamber is large, and it is not easy to control the accurate axial relative distance of the disc and the read head, and when the output shaft is long and the disc is large, the radial runout of the shaft end disc connected therewith is not easy to guarantee, and the above two factors make the installation of the encoder disc crucial to the position accuracy control of the joint. SUMMARY

[0004] In view of the defects of the prior art, the present application provides an electric rotary joint, a robot upper limb and a robot, which solve the problems mentioned in the background.

[0005] The present application provides the following technical scheme: an electric rotary joint, comprising a shell and a rear cover connected in sequence, further comprising: an input shaft encoder disc, an output shaft encoder disc, a motor, a speed reducer, an input shaft body and an output shaft;

[0006] The input shaft body is hollow, the left end outer wall thereof is rotationally connected to the inner wall of the shell through bearing one, and the right end thereof protrudes out of the shell and is rotationally connected to the inner wall of the shell port through bearing three;

[0007] The stator part of the motor is fixed to the inner wall of the shell, and the rotor part of the motor is connected to the outer wall of the input shaft body;

[0008] The speed reducer is connected to the right side outer wall of the shell, and the input end thereof is connected to the input shaft body;

[0009] The left end of the output shaft is inserted into the input shaft body and rotationally connected to the inner wall of the input shaft body through bearing two, and the radially extending end of the output shaft is connected to the output end of the speed reducer;

[0010] The input shaft encoder code disc and the output shaft encoder code disc are arranged concentrically, the input shaft encoder code disc is fixedly connected to the left end of the input shaft body, and the output shaft encoder code disc is fixedly connected to the left end of the output shaft.

[0011] Preferably, a driving plate fixed in the rear cover is further included; and the motor is electrically connected to the driving plate through three-phase power lines.

[0012] Preferably, the three-phase power lines pass through the arc-shaped hollow provided in the shell.

[0013] Preferably, an encoder reading head is installed on the side of the driving plate facing the input shaft encoder code disc and the output shaft encoder code disc.

[0014] Preferably, the diameter of the input shaft body matched with the third inner ring of the bearing is Ds1, and the diameter of the input shaft body matched with the first inner ring of the bearing is Ds3; Ds3 is twice Ds1.

[0015] Preferably, at least one ventilation channel is provided between the left end and the right end of the input shaft body.

[0016] Preferably, the end faces of the input shaft encoder code disc and the output shaft encoder code disc are flush.

[0017] The present application provides the following technical solutions: a robot upper limb of an electric rotary joint, comprising: a robot upper limb assembly connected with the output shaft.

[0018] The present application provides the following technical solutions: a robot upper limb and a robot, comprising: a robot body connected with a shell.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1、The present application, by setting the motor, the input shaft body, the speed reducer, the output shaft and other structures, forms a compact joint module for power output and power input structure, reasonably utilizes the axial space layout, optimally distributes the joint performance and the outer shape size.

[0021] 2、The present application, by setting the joint parts, has simple assembly, small axial cumulative tolerance and high assembly precision.

[0022] 3、The present application, by setting the input shaft encoder code disc and the output shaft encoder code disc, has high central axial and radial position precision, good reliability and improved joint position precision control.

[0023] 4、The present application, by setting the speed reducer and the upper limb robot arm position control precision, good coordination and wide scene application of the output shaft used in cooperation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Figure 1 is a perspective view of the electric joint of the present application;

[0025] Figure 2 Figure 2 is a perspective view of the electric joint of the present application in cross section;

[0026] Figure 3 Figure 3 is a perspective view of the encoder read head of the present application;

[0027] Figure 4 Figure 4 is a perspective view of the input shaft body of the present application;

[0028] Figure 5 Figure 5 is a perspective view of bearing two of the present application in cross section;

[0029] Figure 6 Figure 6 is a perspective view of the relative position of the magnetic encoder principle of the present application;

[0030] In the figure: 1, the shell; 2, the back cover; 3, the drive board; 4, the input shaft encoder disc; 5, the output shaft encoder disc; 6, the encoder read head; 7, the motor; 8, the three-phase power line; 9, the input shaft body; 10, bearing one; 11, bearing two; 12, bearing three; 13, the speed reducer; 14, the output shaft; 15, the disc one fixed threaded hole; 16, the input shaft through hole; 17, the bearing one inner ring assembly surface; 18, the motor rotor cylindrical assembly surface; 19, the bearing three inner ring assembly surface; 20, the multi-magnetic-pole rotary encoder. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0032] Please refer to Figures 1-6 An electric rotary joint, comprising a shell 1 and a back cover 2 connected, further comprising: an input shaft encoder disc 4, an output shaft encoder disc 5, a motor 7, a speed reducer 13, an input shaft body 9 and an output shaft 14.

[0033] The input shaft body 9 is hollow, the outer wall of the left end thereof is rotationally connected with the inner wall of the shell 1 through bearing one 10, the right end thereof protrudes out of the shell 1 and is rotationally connected with the inner wall of the port of the shell 1 through bearing three 12; the stator part of the motor 7 is fixed with the inner wall of the shell 1, the rotor part of the motor 7 is connected with the outer wall of the input shaft body 9; the reducer 13 is connected with the right outer wall of the shell 1, the input end thereof is connected with the input shaft 9; the left end of the output shaft 14 is inserted into the input shaft body 9 and is rotationally connected with the inner wall of the input shaft body 9 through bearing two 11; the radially extending end of the output shaft 14 is connected with the output end of the reducer 13. The power output and power input structure forms a compact layout joint module, the axial space layout is reasonably utilized, the axial cumulative tolerance is small, and the assembly precision is improved.

[0034] The outer wall of the input shaft body 9 is provided with a code disc one fixing threaded hole 15, the inner wall of the input shaft body 9 is provided with an input shaft through hole 16, the outer wall of the input shaft body 9 is provided with a bearing one inner ring assembly surface 17, the outer wall of the input shaft body 9 is provided with a motor rotor cylindrical assembly surface 18, and the outer wall of the input shaft body 9 is provided with a bearing three inner ring assembly surface 19.

[0035] The input shaft encoder code disc 4 and the output shaft encoder code disc 5 are concentrically arranged, the input shaft encoder code disc 4 is fixedly connected with the left end of the input shaft body 9, and the output shaft encoder code disc 5 is fixedly connected with the left end of the output shaft 14. The end faces of the input shaft encoder code disc 4 and the output shaft encoder code disc 5 are flush, so that the input shaft encoder code disc 4 and the output shaft encoder code disc 5 on the device are arranged on the same horizontal plane, and the input shaft encoder code disc 4 and the output shaft encoder code disc 5 correspond to the input shaft body 9 and the output shaft 14 respectively, and convert the rotation angle of the input shaft body 9 and the output shaft 14 into digital signals when the input shaft body 9 and the output shaft 14 mechanically move. In this way, the central axial and radial position accuracy of the input shaft encoder code disc and the output shaft encoder code disc is high, and the joint position accuracy control is improved.

[0036] Wherein; the driving board 3 in the rear cover 2; the motor 7 is electrically connected with the driving board 3 through the three-phase power line 8, and is installed in the inner cavity of the rear cover 2 through the driving board 3 on the device, so that the motor 7 on the device is connected with the driving board 3 through the three-phase power line 8.

[0037] Wherein; the three-phase power line 8 passes through the arc-shaped cavity left in the shell 1, and the arc-shaped cavity with a size of about 6*8mm is left in the inner wall of the shell 1 on the device, so that the three-phase power line 8 on the device passes through the cavity and is connected with the driving board 3.

[0038] Wherein; the encoder read head 6 is installed on the side of the drive plate 3 facing the input shaft encoder disc 4 and the output shaft encoder disc 5, and when the magnetic poles generated between the input shaft encoder disc 4 and the output shaft encoder disc 5 on the device change, the magnetic field sensor of the encoder read head 6 will pass through the magnetic poles between the input shaft encoder disc 4 and the output shaft encoder disc 5, respectively generating a sinusoidal signal.

[0039] Wherein; the diameter of the input shaft body 9 matched with the inner ring of bearing three 12 is Ds1, and the diameter of the input shaft body 9 matched with the inner ring of bearing one 10 is Ds3; the diameter of the Ds3 part on the device is about twice the diameter of Ds1.

[0040] Wherein; the side end surface of the drive plate 3 is sleeved with the inner wall of the shell 1, and the output shaft encoder read head 6 is installed near the side end surface of the drive plate 3; the side end surface of the drive plate 3 is axially positioned and stopped by the step on the inner wall of the shell 1, so that the output shaft encoder read head 6 is installed on the inner wall of the shell 1 and near the side end surface of the drive plate 3, and the magnetic field sinusoidal signal of the N and S poles inside the device is aligned.

[0041] Working principle, first drive the input shaft body 9 to rotate through the motor 7 on the device, the input shaft body 9 generates high-speed small torque mechanical energy, which is transmitted to the speed reducer 13, and the speed reducer 13 converts the high-speed small torque mechanical energy of the input shaft body 9 into low-speed large torque mechanical energy transmission medium, and uses the output shaft 14 to connect the upper limbs of the robot and drive the upper limbs to complete the corresponding mechanical movement; in this process, in order to accurately control the movement speed and position of the upper limbs, the absolute position and relative position of the two rotating shafts of the input shaft body 9 and the output shaft 14 need to be read in real time;

[0042] The multi-pole rotary encoder 20 is mainly composed of an input shaft encoder disc 4, an output shaft encoder disc 5 and an encoder read head 6, as shown in Figure 6 The input shaft encoder disc 4 and the output shaft encoder disc 5 are composed of two concentric magnetic tracks with N and S arranged alternately; the number of magnetic poles of the two magnetic tracks is different, usually by one magnetic pole; for example, the outer track can have 32 magnetic poles, and the inner track can have 31 magnetic poles; around the magnetic disc, the magnetic poles between the inner track and the outer track are aligned in constant change; at any given position around the magnetic disc, the offset angle between the inner magnetic pole and the outer magnetic pole is unique; when the encoder works, the two magnetic field sensors on the read head will respectively generate a sinusoidal signal when passing through the N and S levels; the phase shift between the two signals is unique for each position around the magnetic disc; the read head will convert this analog phase shift into a digital signal, and each digital signal corresponds to a unique rotating position on the magnetic ring.

[0043] The application further discloses a robot upper limb comprising an electric rotary joint, which comprises a robot upper limb assembly connected with an output shaft 14, the shaft end of the output shaft 14 is connected with the robot upper limb, and the output shaft 14 drives the upper limb to complete corresponding mechanical movement; the high-speed small-torque mechanical energy is transmitted to a speed reducer 13 through an input shaft body 9 on the device, so that the speed reducer 13 on the device converts the high-speed small-torque mechanical energy of the input shaft body 9 into low-speed large-torque mechanical energy transmission medium, and the speed reducer 13 converts the kinetic energy to the output shaft 14 through harmonic reduction, so that the output shaft 14 is connected with the robot upper limb, and drives the upper limb to complete corresponding mechanical movement. In this way, the upper limb robot arm has high position control precision, good coordination and wide scene application.

[0044] The application further discloses a robot comprising a robot upper limb, which comprises a robot body connected with a shell 1, the device as a whole is installed on the robot body through the shell 1 on the device, so that the device as a whole can be arranged on the robot body.

[0045] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An electric rotary joint, comprising a housing (1) and a back cover (2) connected to each other, characterized in that: Also includes: Input shaft encoder code disc (4), output shaft encoder code disc (5), motor (7), speed reducer (13), input shaft body (9) and output shaft (14); The input shaft body (9) is hollow, and the outer wall of the left end thereof is rotatably connected to the inner wall of the housing (1) through a bearing 1 (10), and the right end thereof protrudes out of the housing (1) and is rotatably connected to the inner wall of the port of the housing (1) through a bearing 3 (12); The stator portion of the motor (7) is fixed to the inner wall of the housing (1), and the rotor portion of the motor (7) is connected to the outer wall of the input shaft body (9); The reducer (13) is connected to the right outer wall of the housing (1), and its input end is connected to the input shaft body (9); The left end of the output shaft (14) is inserted into the input shaft body (9) and is rotatably connected to the inner wall of the input shaft body (9) through the second bearing (11); the radially extending end of the output shaft (14) is connected to the output end of the reducer (13); The input shaft encoder code disc (4) and the output shaft encoder code disc (5) are concentrically arranged, the input shaft encoder code disc (4) is fixedly connected to the left end of the input shaft body (9), and the output shaft encoder code disc (5) is fixedly connected to the left end of the output shaft (14).

2. An electric rotary joint according to claim 1, characterized in that: It also includes a drive plate (3) fixed in the rear cover (2); the motor (7) is electrically connected to the drive plate (3) via a three-phase power line (8).

3. The electric rotary joint according to claim 1, characterized in that: The three-phase power line (8) passes through an arc-shaped cavity provided in the housing (1).

4. The electric rotary joint according to claim 2, characterized in that: An encoder reader (6) is installed on one side of the drive plate (3) facing the input shaft encoder code disc (4) and the output shaft encoder code disc (5).

5. The electric rotary joint according to claim 1, characterized in that: The diameter of the input shaft body (9) and the inner ring of the bearing three (12) is Ds1, and the diameter of the input shaft body (9) and the inner ring of the bearing one (10) is Ds3; Ds3 is twice Ds1.

6. The electric rotary joint according to claim 1, characterized in that: At least one ventilation channel is provided between the left end and the right end of the input shaft (9).

7. The electric rotary joint according to claim 1, characterized in that: The end faces of the input shaft encoder code disc (4) and the output shaft encoder code disc (5) are flush.

8. A robot upper limb comprising the electric rotary joint according to claim 1, characterized in that: include: A robot upper limb assembly is connected to the output shaft (14).

9. A robot comprising the robot upper limb according to claim 8, characterized in that: include: A robot body is connected to the housing (1).

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