Flexible robot joint module based on harmonic reducer and torque control method

Abstract

The application relates to the technical field of reducers, in particular to a flexible robot joint module based on a harmonic reducer and a torque control method, which comprises a harmonic reducer, the input end of the harmonic reducer is provided with a power module, and the harmonic reducer comprises an outer shell, an inner wheel arranged in the outer shell and a driving assembly; the inner wall of the outer shell is provided with a rigid wheel; the inner wheel comprises a flexible wheel and an output shaft; the driving assembly is inserted with the flexible wheel; the power module comprises a mounting shell; a control assembly is arranged in the mounting shell; the control assembly is power-connected with the driving assembly through a connecting assembly; the output torque of the power assembly is controlled, then the rotating speed of the driving assembly and the cam is changed, the meshing frequency of the flexible wheel and the rigid wheel is also changed, and finally the torque of the output shaft is changed; when the weight of the carried object is large, the torque output by the output shaft is increased, and vice versa.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, and in particular to a flexible robot joint module and torque control method based on a harmonic speed reducer. Background Technology

[0002] A harmonic reducer, also known as a harmonic drive reducer, consists of three basic components: a fixed internal gear, a flexible gear (i.e., an elastic thin-walled sleeve whose base is connected to the driven shaft, with a gear ring formed on the generatrix at the beginning of the flexible gear), and a wave generator that causes radial deformation of the flexible gear. It utilizes the flexible gear to generate controllable elastic deformation waves, causing relative tooth misalignment between the teeth of the rigid and flexible gears to transmit power and motion. This transmission method differs fundamentally from ordinary gear transmission, possessing unique characteristics in meshing theory, assembly calculations, and structural design. Harmonic gear reducers offer advantages such as high precision and high load-bearing capacity. Compared to ordinary reducers, their size and weight are reduced due to the use of less material.

[0003] In the field of modern robotics, with the diversification of application scenarios, the performance requirements for reducers are constantly increasing. Due to space and weight constraints in the design of some robots, especially flexible robots, traditional reducers are difficult to meet the requirements in terms of size and weight. Harmonic reducers have become an ideal choice. They adopt the design of eccentric wheels and flexible impellers to achieve efficient deceleration and precise positioning control. They are suitable for providing stable transmission performance in environments with limited space. Combined with their excellent transmission efficiency and low backlash, harmonic reducers are widely used in fields with extremely high space and weight requirements, such as micro-robots, surgical robots, and aerospace. With the advancement of manufacturing processes, the performance of harmonic reducers continues to improve, providing greater design freedom and performance assurance for robot design.

[0004] However, in actual use, because the output torque of the harmonic reducer is difficult to change, when the robot is handling workpieces of different weights, the robot is prone to failure when the workpiece is heavy, which increases the handling burden and is easy to damage the robot. When the workpiece is light, the robot's handling speed will not increase, thus affecting the handling efficiency. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies, such as the difficulty in changing the output torque of harmonic reducers, which can easily lead to robot handling failure when the workpiece is heavy, increasing the handling burden and easily damaging the robot, while the robot handling speed will not increase when the workpiece is light, thus affecting the handling efficiency. The invention proposes a flexible robot joint module and torque control method based on harmonic reducers.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] Design a flexible robot joint module based on a harmonic reducer, including a harmonic reducer, a power module at the input end of the harmonic reducer, the harmonic reducer including: a shell, an inner wheel disposed inside the shell and a drive assembly, a rigid wheel provided on the inner wall of the shell, the inner wheel including a flexible wheel and an output shaft, and the drive assembly being inserted into the flexible wheel;

[0008] The power module includes a mounting housing, a control component is disposed inside the mounting housing, the control component is poweredly connected to the drive component through a connecting component, and a drive motor is fixedly disposed on the mounting housing.

[0009] Furthermore, a cam is fixedly provided at the output end of the drive component, the cam abuts against the flexible wheel, and the portion of the flexible wheel that abuts against the cam protrudes outward and meshes with the rigid wheel.

[0010] Furthermore, the mounting housing is provided with an adjustment component that cooperates with the control component, and an adjustment motor that is power-connected to the adjustment component is fixedly mounted on the mounting housing.

[0011] Furthermore, the control component includes two opposing friction elements, both of which are frustoconical structures, and a transmission belt is fitted onto both friction elements, the transmission belt being dynamically connected to the two friction elements.

[0012] Furthermore, all the friction elements are rotatably connected to the mounting housing, and the two friction elements are respectively poweredly connected to the connecting assembly and the drive motor.

[0013] Furthermore, the adjustment assembly includes an adjustment member disposed within the mounting housing, the adjustment member having a positioning groove that cooperates with the transmission belt, and a plurality of support rollers that cooperate with the transmission belt being rotatably disposed within the positioning groove.

[0014] Furthermore, a lead screw is rotatably disposed inside the mounting housing, and a nut seat is threadedly connected to the lead screw, the nut seat being connected to the adjusting component.

[0015] Furthermore, a slot is provided on the nut seat, and an insert that mates with the slot is fixedly provided on the adjusting member, with a tension spring provided between the insert and the slot.

[0016] Furthermore, the connecting component includes two meshing bevel gears, which are respectively located at the output end of the control component and the input end of the drive component.

[0017] The outer shell is provided with a liquid inlet and a liquid outlet. A liquid storage chamber is fixedly provided at the lower end of the outer shell. The liquid storage chamber is provided with a liquid supply pipe and a liquid return hole that cooperate with the liquid inlet and the liquid outlet.

[0018] A gear pump is fixedly installed inside the liquid storage chamber. A drive shaft that is rotatably connected to the gear pump is mounted on the mounting housing. The drive shaft is connected to the control component. The output end of the gear pump is connected to the liquid supply pipe. A filter screen that cooperates with the return hole is fixedly installed inside the liquid storage chamber.

[0019] This invention also proposes a torque control method for a flexible robot joint module, including the aforementioned flexible robot joint module based on a harmonic reducer, and further comprising the following steps:

[0020] S1. Power is provided to the drive assembly through the power module, thereby driving the drive assembly and the cam to rotate;

[0021] S2. When the cam rotates, the flexible wheel meshes with the rigid wheel, driving the flexible wheel to rotate, and the output shaft rotates with the flexible wheel;

[0022] S3. Change the output torque of the power module, thereby changing the rotational speed of the drive assembly and the cam. The meshing frequency of the flexible wheel and the rigid wheel also changes accordingly, thereby changing the torque of the output shaft.

[0023] The flexible robot joint module and torque control method based on harmonic reducers proposed in this invention have the following advantages:

[0024] In this invention, the control component of the power module works with the drive motor to provide power to the drive component under the action of the connecting component, thereby driving the drive component and the cam to rotate. The flexible wheel meshes with the rigid wheel under the action of the cam. Due to the small tooth difference between the flexible wheel and the rigid wheel, the flexible wheel rotates on its own. The output shaft rotates with the flexible wheel, forming a power output. When the power module is working, the lubricating fluid in the reservoir is input into the harmonic reducer through the gear pump to reduce friction and thus increase service life.

[0025] Secondly, in this invention, by controlling the output torque of the power component, the rotational speed of the drive component and the cam is changed, and the meshing frequency of the flexible wheel and the rigid wheel is also changed accordingly, ultimately changing the torque of the output shaft. When the weight of the object being transported is large, the output torque of the output shaft is increased, thereby transporting heavy objects. Conversely, when the weight of the object is small, the output torque of the output shaft is reduced, thereby improving efficiency by transporting the object quickly. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the flexible robot joint module based on a harmonic reducer proposed in this invention;

[0027] Figure 2 This is a schematic diagram of the cam structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the flexible wheel of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the friction component of the present invention;

[0030] Figure 5 This is a schematic diagram of the mounting shell of the present invention;

[0031] Figure 6 This is a schematic diagram of the enlarged structure of region A of the present invention;

[0032] Figure 7 This is a schematic diagram of the bevel gear of the present invention;

[0033] Figure 8 This is a schematic diagram of the enlarged structure of region B of the present invention;

[0034] Figure 9 This is a schematic diagram of the liquid storage cavity of the present invention;

[0035] Figure 10 This is a schematic diagram of the drive shaft of the present invention.

[0036] In the diagram: 1. Harmonic reducer; 2. Power module; 21. Mounting housing; 22. Control component; 221. Friction component; 222. Transmission belt; 23. Connecting component; 231. Bevel gear; 24. Drive motor; 25. Adjusting component; 251. Adjusting component; 252. Support roller; 253. Lead screw; 254. Nut seat; 255. Insert; 256. Tension spring; 26. Adjusting motor; 3. Housing; 31. Rigid wheel; 32. Liquid inlet; 33. Liquid outlet; 34. Liquid storage chamber; 341. Liquid supply pipe; 342. Liquid return hole; 343. Gear pump; 344. Drive shaft; 345. Filter screen; 4. Inner wheel; 41. Flexible wheel; 42. Output shaft; 5. Drive component; 6. Cam. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] Reference Figure 1-10 A flexible robot joint module based on a harmonic reducer includes a harmonic reducer 1. The input end of the harmonic reducer 1 is provided with a power module 2. The harmonic reducer 1 includes: a housing 3, an inner wheel 4 disposed inside the housing 3, and a drive assembly 5. The inner wall of the housing 3 is provided with a rigid wheel 31. The inner wheel 4 includes a flexible wheel 41 and an output shaft 42. The drive assembly 5 is inserted into the flexible wheel 41.

[0039] The power module 2 includes a mounting housing 21, a control component 22 is provided inside the mounting housing 21, the control component 22 is connected to the drive component 5 via a connecting component 23, and a drive motor 24 is fixedly mounted on the mounting housing 21.

[0040] In this invention, the control component 22 of the power module 2 cooperates with the drive motor 24, and under the action of the connecting component 23, it provides power to the drive component 5, causing the drive component 5 to rotate, so that the flexible wheel 41 partially meshes with the rigid wheel 31. During this process, due to the small tooth difference between the flexible wheel 41 and the rigid wheel 31, the motion is transmitted to drive the flexible wheel 41 to rotate, and the output shaft 42 rotates with the flexible wheel 41 to form power output.

[0041] Furthermore, in this embodiment, a cam 6 is fixedly provided at the output end of the drive component 5. The cam 6 abuts against the flexible wheel 41. The part of the flexible wheel 41 that abuts against the cam 6 protrudes outward and meshes with the rigid wheel 31. When the cam 6 rotates, the meshing part of the flexible wheel 41 and the cam 6 changes. Due to the small tooth difference between the flexible wheel 41 and the rigid wheel 31, the motion is transmitted to drive the flexible wheel 41 and the output shaft 42 to rotate.

[0042] In this embodiment, the mounting housing 21 is provided with an adjustment component 25 that cooperates with the control component 22. The mounting housing 21 is fixedly provided with an adjustment motor 26 that is poweredly connected to the adjustment component 25. By cooperating with the adjustment component 25, the adjustment motor 26 changes the output torque of the control component 22, thereby changing the rotational speed of the drive component 5, and further changing the rotational speed of the flexible wheel 41 and the output shaft 42, thereby changing the output torque of the output shaft 42, which is adjusted according to the weight of the object being transported by the robot.

[0043] Furthermore, in this embodiment, the control component 22 includes two opposing friction elements 221. The two friction elements 221 are frustoconical structures, and a transmission belt 222 is sleeved on the two friction elements 221. The transmission belt 222 is in a tensioned state and is poweredly connected to the two friction elements 221. When one friction element 221 rotates, it drives the transmission belt 222 and the other friction element 221 to rotate. When the position of the transmission belt 222 changes, the contact portion with the two friction elements 221 changes. Since both friction elements 221 are frustoconical structures, and the transmission belt 222 contacts and rubs against the side of the frustum, the transmission ratio of the two friction elements 221, that is, the speed at which the actively rotating friction element 221 drives the other friction element 221 to rotate changes through the transmission belt 222.

[0044] In this embodiment, the friction elements 221 are rotatably connected to the mounting shell 21. The two friction elements 221 are respectively powered to the connecting assembly 23 and the drive motor 24. The drive motor 24 drives one friction element 221 to rotate, and the other friction element 221 is driven to rotate by the transmission belt 222. The friction element 221 driven to rotate by the transmission belt 222 provides power to the connecting assembly 23.

[0045] It should be noted that, in this embodiment, the adjustment component 25 includes an adjustment member 251 disposed in the mounting housing 21. The adjustment member 251 is provided with a positioning groove that cooperates with the transmission belt 222. Multiple support rollers 252 that cooperate with the transmission belt 222 are rotatably disposed in the positioning groove. The position of the transmission belt 222 is changed by moving the position of the adjustment member 251. The friction between the transmission belt and the adjustment member 251 is reduced by setting the support rollers 252.

[0046] In this embodiment, a lead screw 253 is rotatably mounted inside the mounting housing 21. A nut seat 254 is threaded onto the lead screw 253. The nut seat 254 is connected to the adjusting member 251. The output shaft of the adjusting motor 26 is fixedly connected to the lead screw 253. By controlling the rotation of the lead screw 253 through the adjusting motor 26, the positions of the nut seat 254 and the adjusting member 251 are changed, thereby changing the position of the transmission belt 222. Both the adjusting motor 26 and the drive motor 24 are servo motors of an external controller. In some embodiments, a guide rail that cooperates with the nut seat 254 is fixedly mounted inside the mounting housing 21.

[0047] Furthermore, in this embodiment, a slot is provided on the nut seat 254, and an insert 255 that cooperates with the slot is fixedly provided on the adjusting member 251. A tension spring 256 is provided between the insert 255 and the slot. The tension spring 256 applies force to the insert 255 and the adjusting member 251, causing them to move, thereby tensioning the transmission belt 222 to prevent slippage.

[0048] In detail, in this embodiment, the connecting component 23 includes two meshing bevel gears 231. The two bevel gears 231 are respectively disposed at the output end of the control component 22 and the input end of the drive component 5. The friction element 221 drives the bevel gear 231 to rotate, and the bevel gear 231 drives the other bevel gear 231 to rotate. The drive component 5 includes an input shaft, and the bevel gear 231 is fixedly connected to or keyed to the input shaft.

[0049] More specifically, in this embodiment, the outer shell 3 is provided with an inlet hole 32 and an outlet hole 33. The lower end of the outer shell 3 is fixedly provided with a liquid storage chamber 34, which stores lubricating fluid. The liquid storage chamber 34 is provided with a supply pipe 341 and a return hole 342 that cooperate with the inlet hole 32 and the outlet hole 33. The supply pipe 341 is connected to the inlet hole 32 through a hose, and the return hole 342 is connected to the outlet hole 33 through a hose.

[0050] In this embodiment, a gear pump 343 is fixedly installed inside the liquid storage chamber 34. In some embodiments, the gear pump 343 can be replaced with other types of pumps. A drive shaft 344, which is poweredly connected to the gear pump 343, is rotatably installed on the mounting housing 21. A drive shaft is installed on a friction member 221 of the control component 22. The drive shaft passes through the mounting housing 21, and both the drive shaft and the drive shaft 344 are equipped with gears. The two gears mesh and are poweredly connected. The drive shaft 344 is poweredly connected to the control component 22. The output end of the gear pump 343 is connected to the liquid supply pipe 341, and the input end of the gear pump 343 is located inside the liquid storage chamber 34. When the control component 22 drives the harmonic reducer 1, it drives the drive shaft 344 to rotate, providing power to the gear pump 343. The gear pump 343 inputs lubricating fluid into the housing 3 to lubricate the inside of the harmonic reducer 1. A filter screen 345, which cooperates with the return hole 342, is fixedly installed inside the liquid storage chamber 34 to filter impurities such as iron powder in the returned lubricating fluid, so as to avoid damaging the gear pump 343.

[0051] This invention also proposes a torque control method for a flexible robot joint module, including the aforementioned flexible robot joint module based on a harmonic reducer, and further comprising the following steps:

[0052] S1. Power is provided to drive component 5 through power module 2, which drives drive component 5 and cam 6 to rotate.

[0053] S2. When the cam 6 rotates, the flexible wheel 41 meshes with the rigid wheel 31, driving the flexible wheel 41 to rotate, and the output shaft 42 rotates with the flexible wheel 41.

[0054] S3. Change the output torque of the power module 2, thereby changing the rotation speed of the drive component 5 and the cam 6. The meshing frequency of the flexible wheel 41 and the rigid wheel 31 also changes accordingly, thereby changing the torque of the output shaft 42, which is adjusted according to the weight of the object being transported by the robot.

[0055] When adjusting the torque, the lead screw 253 is rotated by adjusting the motor 26, thereby changing the position of the nut seat 254 and the adjusting component 251, which in turn changes the position of the transmission belt 222. The contact portion with the two friction components 221 changes. Since both friction components 221 are frustum structures and the transmission belt 222 contacts and rubs against the side of the frustum, the transmission ratio of the two friction components 221, that is, the speed at which the actively rotating friction component 221 drives the other friction component 221 to rotate changes through the transmission belt 222, thereby changing the output torque of the friction component 221 and the input torque of the drive component 5. The rotational speed of the drive component 5 changes, which in turn changes the rotational speed of the flexible wheel 41 and the output shaft 42, and finally changes the output torque of the output shaft 42, so as to achieve adjustment according to the weight of the object being transported by the robot.

[0056] When the friction component 221 rotates, it drives the drive shaft to rotate. Under the action of two meshing gears, it drives the drive shaft 344 to rotate, providing power to the gear pump 343. The gear pump 343 inputs lubricating fluid into the housing 3 to lubricate the inside of the harmonic reducer 1, reducing the wear between the flexible wheel 41 and the rigid wheel 31. Excess lubricating fluid flows back to the storage chamber 34 for storage, and impurities such as iron powder in the returned lubricating fluid are filtered through the filter screen 345 to avoid damaging the gear pump 343.

[0057] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flexible robot joint module based on a harmonic reducer, comprising a harmonic reducer (1), characterized in that, The input end of the harmonic reducer (1) is provided with a power module (2). The harmonic reducer (1) includes: a housing (3), an inner wheel (4) disposed in the housing (3) and a drive assembly (5). The inner wall of the housing (3) is provided with a rigid wheel (31). The inner wheel (4) includes a flexible wheel (41) and an output shaft (42). The drive assembly (5) is inserted into the flexible wheel (41). The power module (2) includes a mounting housing (21), within which a control component (22) is disposed. The control component (22) is poweredly connected to the drive component (5) via a connecting component (23). A drive motor (24) is fixedly disposed on the mounting housing (21). An adjustment component (25) cooperating with the control component (22) is disposed on the mounting housing (21). An adjustment motor (26) poweredly connected to the adjustment component (25) is fixedly disposed on the mounting housing (21). The control component (22) includes two opposing friction elements (221), which are frustum-shaped structures. A transmission belt (222) is fitted on the two friction elements (221). The transmission belt (222) is poweredly connected to the two friction elements (221). The friction elements (221) are rotatably connected to the mounting shell (21). The two friction elements (221) are poweredly connected to the connecting assembly (23) and the drive motor (24) respectively. The adjusting assembly (25) includes an adjusting element (251) disposed in the mounting shell (21). The adjusting element (251) is provided with a positioning groove that cooperates with the transmission belt (222). Multiple support rollers (252) that cooperate with the transmission belt (222) are rotatably disposed in the positioning groove.

2. The flexible robot joint module based on a harmonic reducer according to claim 1, characterized in that: The output end of the drive assembly (5) is fixedly provided with a cam (6), which abuts against the flexible wheel (41). The part of the flexible wheel (41) that abuts against the cam (6) protrudes outward and meshes with the rigid wheel (31).

3. The flexible robot joint module based on a harmonic reducer according to claim 1, characterized in that: A lead screw (253) is rotatably disposed inside the mounting housing (21). A nut seat (254) is threaded onto the lead screw (253). The nut seat (254) is connected to the adjusting member (251). A slot is provided on the nut seat (254). A plug (255) that mates with the slot is fixedly disposed on the adjusting member (251). A tension spring (256) is provided between the plug (255) and the slot.

4. The flexible robot joint module based on a harmonic reducer according to claim 1, characterized in that: The outer shell (3) is provided with an inlet hole (32) and an outlet hole (33). A liquid storage chamber (34) is fixedly provided at the lower end of the outer shell (3). A liquid supply pipe (341) and a return hole (342) are provided on the liquid storage chamber (34) to cooperate with the inlet hole (32) and the outlet hole (33).

5. The flexible robot joint module based on a harmonic reducer according to claim 4, characterized in that: A gear pump (343) is fixedly installed inside the liquid storage chamber (34). A drive shaft (344) that is poweredly connected to the gear pump (343) is rotatably installed on the mounting shell (21). The drive shaft (344) is poweredly connected to the control component (22). The output end of the gear pump (343) is connected to the liquid supply pipe (341). A filter screen (345) that cooperates with the return hole (342) is fixedly installed inside the liquid storage chamber (34).

6. A torque control method for a flexible robot joint module, characterized in that, Including the joint module of claim 2, characterized in that it further includes the following steps: S1. Power is provided to the drive assembly (5) through the power module (2), thereby driving the drive assembly (5) and the cam (6) to rotate; S2. When the cam (6) rotates, the flexible wheel (41) meshes with the rigid wheel (31) to drive the flexible wheel (41) to rotate, and the output shaft (42) rotates with the flexible wheel (41); S3. Change the output torque of the power module (2), thereby changing the rotation speed of the drive component (5) and the cam (6). The meshing frequency of the flexible wheel (41) and the rigid wheel (31) also changes accordingly, thereby changing the torque of the output shaft (42).

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