Robot joint transmission structure

Abstract

The utility model relates to the technical field of robots, in particular to a robot transmission structure which comprises a motor assembly, a friction type brake assembly, a harmonic reducer and a shaft set which are arranged from top to bottom, and the brake assembly comprises a brake pad, a brake pad fixing piece and a brake body. The shaft set comprises an input shaft, an output shaft, a first input bearing and a second input bearing, the input shaft and the output shaft are coaxially arranged, the output shaft is a hollow shaft, and the input shaft is arranged on the output shaft in a sleeving mode. The first input bearing is arranged between the top end of the input shaft and the shell, and the second input bearing is arranged on the lower portion of the input shaft. According to the robot joint transmission structure, double-bearing support for the input shaft is formed, so that the stability of motor driving and braking can be greatly improved, the input shaft is prevented from jumping or shaking, and the vibration of the input shaft is greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of robots, in particular to a robot joint transmission structure. Background Art

[0002] With the rapid development of automation technology, robots, as an important automation equipment, are gaining more and more attention and are being used more and more widely. As an important branch of robots, medical robots are developing rapidly. More and more medical robots are being developed and put into the market after rigorous testing, becoming a powerful assistant for frontline medical staff and patients.

[0003] Due to the particularity of medical application scenarios, there are many stringent requirements for the safety and reliability of medical robots, and the core component that determines the motion performance of medical robots is the joint module. Therefore, the operating accuracy and reliability of the joint module of medical robots are required to be high. In the robot joint module of the related technology, when the motor rotor and the input shaft of the reducer are matched, the coaxiality error between the two is large, resulting in large vibrations in the joint module during operation, which affects the operating accuracy of the joint module. Utility Model Content

[0004] In view of this, the utility model provides a robot joint transmission structure, which at least partially solves the problems existing in the prior art.

[0005] A robot joint transmission structure is arranged in a robot joint, wherein the robot joint comprises a motor assembly, a friction brake assembly, a harmonic reducer and a shaft group passing through the motor assembly, the friction brake assembly and the harmonic reducer arranged from top to bottom, wherein:

[0006] The motor assembly includes a housing, a rotor, and a stator, wherein the housing is a cylindrical metal structure, and the stator is arranged on the inner wall of the housing;

[0007] The brake assembly comprises a brake pad, a brake pad fixing part, and a brake body, wherein the brake body is connected to the housing, the brake pad fixing part is connected to the input shaft, and the rotor is sleeved on the brake pad fixing part;

[0008] The harmonic reducer includes a flexible wheel, a steel wheel, a reducer bearing, and a wave generator;

[0009] The shaft group includes an input shaft and an output shaft arranged coaxially, and also includes a first input bearing and a second input bearing, wherein the output shaft is a hollow shaft, and the input shaft is sleeved on the output shaft;

[0010] The first input bearing is arranged between the top end of the input shaft and the housing, and the second input bearing is arranged between the lower part of the input shaft and the brake body.

[0011] Preferably, a second bearing mounting position for mounting the second input bearing is provided on the lower end surface of the brake body, and the inner ring of the second input bearing is fixedly mounted on the lower part of the input shaft.

[0012] Preferably, the shaft group also includes an input locking nut, the upper end of the input shaft is provided with a first thread matching the input locking nut, the input locking nut is connected to the upper end of the input shaft through the first thread, and the lower end of the input locking nut abuts against the upper end of the brake pad fixing.

[0013] Preferably, an annular boss is provided at the upper end of the input locking nut, and an outer edge bearing mounting position and an inner edge bearing mounting position are respectively provided on the outer edge and inner edge of the annular boss, the inner ring of the first input bearing is installed at the outer edge bearing mounting position, and the outer ring of the first input bearing cooperates with the inner wall of the upper end of the shell.

[0014] Preferably, a mounting flange is provided at the lower end of the input shaft, and the wave generator is assembled on the mounting flange and forms a harmonic reducer together with the flexible wheel, the steel wheel and the reducer bearing.

[0015] Preferably, the lower end of the output shaft is a flange-shaped structure, and the upper end surface of the output shaft flange is fixedly connected to the steel wheel and the inner ring of the reducer bearing.

[0016] Preferably, the shaft assembly further comprises an output locking nut and a first output bearing, an output bearing mounting position is arranged on the outer edge of the output locking nut, and the first output bearing is arranged at the output bearing mounting position and the inner edge bearing mounting position.

[0017] Preferably, the upper end of the output shaft is higher than the upper end of the input shaft, and a second thread matching the output locking nut is provided on the upper end of the output shaft.

[0018] Preferably, the brake pad fixing part and the brake body are both sleeved on the middle part of the input shaft, wherein the brake pad fixing part is fixed on the input shaft, the outer edge of the brake body extends to the outer surface of the shell in the diameter direction and is fixedly connected to the shell, and the brake pad is connected to the lower end surface of the brake pad fixing part and constitutes a braking surface with the upper end surface of the brake body.

[0019] Preferably, the outer edge of the flexible wheel extends to the outer surface of the housing in the diameter direction and is fixedly connected to the housing, the brake body and the outer ring of the reducer bearing.

[0020] The robot joint transmission structure described in the utility model has a first input bearing and a second input bearing respectively arranged at the top of the input shaft and the bottom of the input shaft, thereby forming a double-bearing support for the input shaft; since the braking surface of the brake assembly and the rotor of the motor assembly are both arranged between the double bearings of the input shaft, the double-bearing structure of the input shaft can greatly improve the stability of the motor drive and braking, prevent the input shaft from jumping or shaking, and greatly reduce the vibration of the input shaft;

[0021] Moreover, due to the use of friction brake components, the brake pads will automatically hold the brake body for braking when the power is off, thereby greatly increasing safety and reliability; in addition, because the brake component is arranged in the middle of the input shaft, the input shaft is subjected to more balanced force during braking, the shaft vibration is smaller, and the braking stability is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a three-dimensional schematic diagram of the robot joint transmission structure according to an embodiment of the utility model;

[0024] Figure 2 It is a cross-sectional schematic diagram of the robot joint transmission structure according to an embodiment of the utility model;

[0025] Figure 3 This is an exploded view of the robot joint transmission structure according to an embodiment of the utility model;

[0026] Figure 4 A schematic diagram of a brake assembly of a robot joint transmission structure according to an embodiment of the utility model;

[0027] Figure 5 An exploded diagram of a harmonic reducer of a robot joint transmission structure according to an embodiment of the utility model;

[0028] Figure 6 It is an exploded view of the axis group of the robot joint transmission structure described in the embodiment of the utility model.

[0029] Description of reference numerals:

[0030] 1-motor assembly, 11-housing, 12-rotor, 13-stator;

[0031] 2-brake assembly, 21-brake pad fixing member, 22-brake pad, 23-brake body, 231-second bearing mounting position;

[0032] 3-harmonic reducer, 31-flexible wheel, 32-steel wheel, 33-reducer bearing, 34-wave generator;

[0033] 4-shaft group, 41-input shaft, 411-locating shoulder, 412-first thread, 42-input locking nut, 43-first input bearing, 44-second input bearing, 45-output shaft, 451-second thread, 46-output locking nut, 47-first output bearing. DETAILED DESCRIPTION

[0034] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0035] It should be noted that the following embodiments and features in the embodiments may be combined with each other in the absence of conflict; and, based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making any creative work are within the scope of protection of the present disclosure.

[0036] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0037] Figures 1 to 6 The robot joint transmission structure described in the embodiment of the utility model is a three-dimensional schematic diagram, a cross-sectional schematic diagram, an overall exploded diagram and an exploded diagram of each component. The robot joint transmission structure is now described in detail in conjunction with the accompanying drawings.

[0038] See also Figures 1 to 6As shown, the robot joint transmission structure described in this embodiment is arranged in the robot joint, and the robot joint includes a motor assembly 1, a friction brake assembly 2, a harmonic reducer 3 and a shaft group 4 that runs through the motor assembly 1, the friction brake assembly 2 and the harmonic reducer 3, which are arranged from top to bottom, wherein: the motor assembly 1 includes a housing 11, a rotor 12, and a stator 13; the brake assembly 2 includes a brake pad 22, a brake pad fixing member 21, and a brake body 23; the harmonic reducer 3 includes a flexible wheel 31, a steel wheel 32, a reducer bearing 33, and a wave generator 34; the shaft group 4 includes a coaxially arranged input shaft 41 and an output shaft 45, and also includes an input locking nut 42, a first input bearing 43, a second input bearing 44, an output locking nut 46 and a first output bearing 47;

[0039] Among them, the stator 13 is provided with a winding coil, the rotor 12 is a permanent magnet, the output shaft 45 is a hollow shaft, the input shaft 41 is sleeved on the output shaft 45, the shell 11 is a cylindrical metal structure, and the stator 13 is arranged on the inner wall of the shell 11; the brake body 23 and the brake pad fixing part 21 are both flange-like structures, the stator 13 is sleeved on the brake pad fixing part 21, the brake pad fixing part 21 and the brake body 23 are both sleeved in the middle of the input shaft 41, the brake pad fixing part 21 is fixed on the input shaft 41, the outer edge of the brake body 23 extends to the outer surface of the shell 11 along the diameter direction and is fixedly connected to the shell 11, the brake pad 22 is connected to the lower end surface of the brake pad fixing part 21 and constitutes a braking surface with the upper end surface of the brake body 23; the first input bearing 43 is arranged between the top end of the input shaft 41 and the shell, and the second input bearing 44 is arranged between the lower part of the input shaft 41 and the brake body 23.

[0040] The above-mentioned robot joint transmission structure adopts a friction brake component 2, in which a permanent magnet is built. When power is on, the coil generates magnetic force to offset the magnetic force of the permanent magnet, so that the robot joint module can operate normally. On the contrary, when the power is off, the coil is powered off and has no magnetic force to offset the magnetic force of the permanent magnet. The permanent magnet absorbs the brake spring to brake, that is, when the power is off, the brake pad 22 will automatically hold the brake body 23 for braking, thereby greatly improving safety and reliability. In addition, because the brake component 2 is arranged in the middle of the input shaft 41, during braking, the input shaft 41 is subjected to a more balanced force, the shaft runout is smaller, and the braking stability is good. Moreover, because the brake body 23 extends to the outer surface of the shell 11 along the diameter direction, it is not only larger in size and higher in heat capacity, but also has fast heat dissipation, which greatly improves the adaptability of the robot joint transmission structure and improves reliability.

[0041] Reference Figure 1 , Figure 3It can be seen that the outer surface of the shell 11 is provided with convex rib-shaped heat dissipation ribs, and the stator 13 is arranged on the inner wall of the shell 11. Therefore, the heat generated by the stator 13 during operation can be quickly dissipated through the heat dissipation ribs of the shell 11, and heat accumulation will not be generated in the joints, which greatly improves the working environment of the motor assembly 1 and the brake assembly 2. In addition, the heat dissipation ribs of the shell 11 can also play the role of reinforcing ribs. Under the premise of ensuring the strength of the shell 11, the weight of the shell 11 is reduced, which not only reduces the material cost of the shell 11, but also reduces the inertia of the joint when it moves with the robot arm, and reduces the control difficulty of the robot arm. In other embodiments, the heat dissipation ribs on the outer surface of the shell 11 can also be grille-shaped. In some other embodiments, the shell 11 and the brake body 23 are an integrated metal structure.

[0042] Reference Figure 2 , Figure 3 , Figure 6 It can be seen that a mounting flange is provided at the lower end of the input shaft 41, the wave generator 34 is assembled on the mounting flange and forms a harmonic reducer 3 with the flexible wheel 31, the steel wheel 32 and the reducer bearing 33, and the upper end surface of the output shaft 45 flange is fixedly connected to the inner ring of the steel wheel 32 and the reducer bearing 33. Moreover, the outer edge of the flexible wheel 31 extends to the outer surface of the housing 11 along the diameter direction and is fixedly connected to the housing 11, the brake body 23 and the outer ring of the reducer bearing 33. A heat conductive adhesive is provided between the brake body 23 and the housing 11, and / or between the brake body 23 and the flexible wheel 31.

[0043] Through the above structure, the heat generated by the harmonic reducer 3 during operation can be transferred to the outer surface of the robot joint through the flexible wheel 31 on the one hand, and dissipated through the steel wheel 32 and the reducer bearing 33 on the other hand, and can also be dissipated through the flange-like structure at the lower end of the output shaft 45.

[0044] In summary, although the embodiment of the present invention adopts a friction brake component 2 that is very easy to generate a lot of heat and the brake component 2 is arranged between the motor component 1 and the harmonic reducer 3, because heat dissipation ribs are arranged on the outer surface of the shell 11, the heat generated by the stator 13 can be quickly dissipated. The outer edge of the brake body 23 of the brake component extends all the way to the outer edge of the shell 11, has a high heat capacity and can also quickly dissipate the heat of the brake component. Coupled with the three-way heat dissipation route of the harmonic reducer 3, the heat dissipation capacity of the robot joint described in this embodiment is extremely excellent. Therefore, it can have the high safety and high reliability of the friction brake component 2, and will not cause the internal working environment of the robot joint to deteriorate due to heat accumulation.

[0045] As is known to all, the harmonic drive reducer relies on the wave generator 34 to assemble a flexible bearing to make the flexible wheel 31 produce controllable elastic deformation, and mesh with the rigid wheel to transmit the purpose of reduction transmission. In order to achieve controllable elastic deformation, it is necessary to take a variety of measures. On the one hand, the material of the flexible wheel 31 is set to a thin steel sheet, and the shape is set to a trumpet shape. Figure 5 It can be seen that the closer to the steel wheel 32, the larger the opening is. Therefore, the position of the wave generator 34 in the flexible wheel 31 needs to be kept constant. If the position is too low, it will easily cause the flexible wheel 31 to crack. If the position is too high, it will cause insufficient torque and fail to achieve the desired transmission efficiency. The wave generator 34 is assembled on the mounting flange at the lower end of the input shaft 41. Therefore, the assembly accuracy of the input shaft 41 in the vertical direction will directly affect the life and transmission efficiency of the harmonic reducer 3.

[0046] Reference Figure 2 , Figure 3 , Figure 6 It can be seen that a positioning shoulder 411 is provided in the middle of the input shaft 41, and the brake pad fixing part 21 is sleeved on the input shaft 41 and the lower end face abuts against the positioning shoulder 411. The upper end of the input shaft 41 is provided with a first thread 412 matching the input locking nut 42, and the input locking nut 42 is connected to the upper end of the input shaft 41 through the first thread 412, and the lower end of the locking nut abuts against the upper end of the brake pad fixing part 21. It can be seen from the above structure that as long as the position accuracy of the positioning shoulder 411 on the input shaft 41, the length accuracy of the brake pad fixing part 21 and the height accuracy of the input locking nut 42 are ensured, the height accuracy of the top surface of the input locking nut 42 relative to the bottom surface of the wave generator 34 can be ensured.

[0047] An annular boss is provided at the upper end of the input locking nut 42, and an outer edge bearing mounting position and an inner edge bearing mounting position are respectively provided on the outer edge and inner edge of the annular boss. The inner ring of the first input bearing 43 is installed in the outer edge bearing mounting position, and the outer ring of the first input bearing 43 cooperates with the inner wall of the upper end of the shell 11. Therefore, as long as the assembly accuracy of the outer ring of the first input bearing 43 on the inner wall of the upper end of the shell 11 can be ensured, the assembly accuracy of the input shaft 41 in the vertical direction can be ensured, thereby ensuring that the wave generator 34 is installed in a suitable position.

[0048] As can be seen from the above, the robot joint described in this embodiment mainly ensures the installation accuracy of the wave generator 34 at the bottom end of the input shaft 41, the processing accuracy of the positioning shoulder 411 and the processing accuracy of the installation position of the first input bearing 43, and then cooperates with the high processing accuracy of the brake pad fixing 21 and the input locking nut 42 to ensure the assembly accuracy of the wave generator 34, which greatly reduces the difficulty of assembling the robot joint and reduces the errors caused by human factors, thereby ensuring the life and transmission efficiency of the harmonic reducer 3 and improving the product qualification rate.

[0049] Reference Figure 2 , Figure 4 and Figure 6 It can be seen that a second bearing mounting position 441 for mounting a second input bearing 44 is provided on the lower end surface of the brake body 23. The inner ring of the second input bearing 44 is fixedly mounted on the input shaft 41. The second input bearing 44 is located at a position slightly lower than the middle of the input shaft 41, and cooperates with the first input bearing 43 located at the top of the input locking nut 42 to form a double bearing support for the input shaft 41. Since the braking surface of the brake assembly 2 and the rotor 12 of the motor assembly 1 are both arranged between the double bearings of the input shaft 41, the double bearing structure of the input shaft 41 can greatly improve the stability of the motor drive and braking, prevent the input shaft 41 from jumping or shaking, and greatly reduce the vibration of the input shaft 41.

[0050] Reference Figure 2 , Figure 3 , Figure 6 It can be seen that the lower end of the output shaft 45 is a flange-shaped structure, and the upper end surface of the output shaft 45 flange is directly fixedly connected to the steel wheel 32 and the inner ring of the reducer bearing 33, that is, a bearing is arranged at the lower end of the output shaft 45. The upper end of the output shaft 45 is higher than the upper end of the input shaft 41, and a second thread 451 matching the output locking nut 46 is arranged at the upper end of the output shaft 45, and an output bearing mounting position is arranged at the outer edge of the output locking nut 46, and the first output bearing 47 is arranged at the output bearing mounting position and the inner edge bearing mounting position, that is, a bearing is arranged at the top end of the output shaft 45. Therefore, the output shaft 45 forms a double bearing support through the reducer bearing 33 and the first output bearing 47. This structure greatly reduces the vibration of the output shaft 45, and can effectively prevent the output shaft 45 from jumping or shaking, and ensure the coaxiality with the input shaft 41.

[0051] It can be seen from the above that the double bearing structure of the input shaft 41 and the double bearing structure of the output shaft 45 together constitute the four-bearing support structure of the robot joint described in this embodiment, which greatly improves the stress environment of the input shaft 41 and the output shaft 45, improves the coaxiality and stability of the input shaft 41 and the output shaft 45, reduces vibration during operation, and thus improves the control accuracy of the robot joint and extends the service life of the robot joint.

[0052] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A robot joint transmission structure, arranged in a robot joint, characterized in that: The robot joint comprises a motor assembly (1), a friction brake assembly (2), a harmonic reducer (3) and a shaft assembly (4) which passes through the motor assembly (1), the friction brake assembly (2) and the harmonic reducer (3) and is arranged from top to bottom, wherein: The motor assembly (1) comprises a housing (11), a rotor (12), and a stator, wherein the housing (11) is a cylindrical metal structure, and the stator (13) is arranged on the inner wall of the housing (11); The brake assembly (2) comprises a brake pad (22), a brake pad fixing member (21), and a brake body (23), wherein the brake body (23) and the brake pad fixing member (21) are both flange-shaped structures, and the rotor (12) is sleeved on the brake pad fixing member (21); The harmonic reducer (3) comprises a flexible wheel (31), a steel wheel (32), a reducer bearing (33), and a wave generator (34). The shaft assembly (4) comprises an input shaft (41) and an output shaft (45) which are coaxially arranged, and also comprises a first input bearing (43) and a second input bearing (44), wherein the output shaft (45) is a hollow shaft, and the input shaft (41) is sleeved on the output shaft (45). The first input bearing (43) is arranged between the top end of the input shaft (41) and the housing (11), and the second input bearing (44) is arranged between the lower part of the input shaft (41) and the brake body (23).

2. The robot joint transmission structure according to claim 1, characterized in that: A second bearing mounting position (231) for mounting the second input bearing (44) is provided on the lower end surface of the brake body (23), and the inner ring of the second input bearing (44) is fixedly mounted on the lower part of the input shaft (41).

3. The robot joint transmission structure according to claim 1, characterized in that: The shaft assembly (4) further comprises an input locking nut (42); the upper end of the input shaft (41) is provided with a first thread (412) matching the input locking nut (42); the input locking nut (42) is connected to the upper end of the input shaft (41) via the first thread (412), and the lower end of the input locking nut (42) abuts against the upper end of the brake pad fixing member (21).

4. The robot joint transmission structure according to claim 3, characterized in that: An annular boss is provided at the upper end of the input locking nut (42), an outer edge bearing mounting position and an inner edge bearing mounting position are respectively provided at the outer edge and inner edge of the annular boss, the inner ring of the first input bearing (43) is mounted on the outer edge bearing mounting position, and the outer ring of the first input bearing (43) is matched with the inner wall of the upper end of the housing (11).

5. The robot joint transmission structure according to claim 1, characterized in that: A mounting flange is provided at the lower end of the input shaft (41), and the wave generator (34) is mounted on the mounting flange and forms a harmonic reducer (3) together with the flexible wheel (31), the steel wheel (32) and the reducer bearing (33).

6. The robot joint transmission structure according to claim 5, characterized in that: The lower end of the output shaft (45) is a flange-shaped structure, and the upper end surface of the flange of the output shaft (45) is fixedly connected to the steel wheel (32) and the inner ring of the reducer bearing (33).

7. The robot joint transmission structure according to claim 4, characterized in that: The shaft assembly (4) further comprises an output locking nut (46) and a first output bearing (47), wherein an output bearing mounting position is arranged on the outer edge of the output locking nut (46), and the first output bearing (47) is arranged at the output bearing mounting position and the inner edge bearing mounting position.

8. The robot joint transmission structure according to claim 7, characterized in that: The upper end of the output shaft (45) is higher than the upper end of the input shaft (41), and a second thread (451) matching the output locking nut (46) is provided on the upper end of the output shaft (45).

9. The robot joint transmission structure according to claim 1, characterized in that: The brake pad fixing part (21) and the brake body (23) are both sleeved on the middle part of the input shaft (41), wherein the brake pad fixing part (21) is fixed on the input shaft (41), the outer edge of the brake body (23) extends to the outer surface of the shell (11) along the diameter direction and is fixedly connected to the shell (11), and the brake pad (22) is connected to the lower end surface of the brake pad fixing part (21) and forms a braking surface with the upper end surface of the brake body (23).

10. The robot joint transmission structure according to claim 1, characterized in that: The outer edge of the flexible wheel (31) extends to the outer surface of the housing (11) along the diameter direction and is fixedly connected to the housing (11), the brake body (23) and the outer ring of the reducer bearing (33).

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