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

Abstract

The invention relates to the technical field of speed reducers, in particular to a flexible robot joint module based on a harmonic speed reducer and a torque control method.The flexible robot joint module comprises the harmonic speed reducer, a power module is arranged at the input end of the harmonic speed reducer, and the harmonic speed reducer comprises a shell, an inner wheel arranged in the shell and a driving assembly; a rigid gear is arranged on the inner wall of the shell, the inner gear comprises a flexible gear and an output shaft, and the driving assembly is connected with the flexible gear in an inserted mode. The power module comprises a mounting shell, a control assembly is arranged in the mounting shell, the control assembly is in power connection with the driving assembly through a connecting assembly, the rotating speed of the driving assembly and the rotating speed of the cam are changed by controlling the output torque of the power assembly, and the meshing frequency of the flexible gear and the rigid gear is also changed accordingly. 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 otherwise, the output torque of the output shaft is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of speed reducer, in particular to a flexible robot joint module based on a harmonic reducer and a torque control method. BACKGROUND

[0002] The harmonic reducer is also called harmonic transmission reducer, which is composed of three basic components: a fixed inner tooth rigid gear, a flexible gear (i.e. an elastic thin-walled sleeve cup connected to the driven shaft, and a wave generator that causes radial deformation of the flexible gear), and a wave generator that causes radial deformation of the flexible gear. The use of flexible gears produces controllable elastic deformation waves, causing the teeth of the rigid gear and the flexible gear to be misaligned, thereby transmitting power and motion. This transmission is fundamentally different from general gear transmission and has special properties in terms of meshing theory, set calculation and structural design. The harmonic gear reducer has the advantages of high precision and high bearing capacity, and compared with ordinary reducers, the volume and weight are also reduced due to the reduction of the material used.

[0003] In the field of modern robots, the performance requirements of speed reducers are constantly improving as the application scenarios diversify. Due to the space and weight limitations faced by some robots, especially flexible robots, during design, traditional reducers are difficult to meet the requirements in terms of volume and weight. Harmonic reducers, which use eccentric gears and flexible wave gears, achieve efficient speed reduction and precise positioning control, making them ideal for use in environments with limited space. With their excellent transmission efficiency and low reverse backlash, harmonic reducers are widely used in fields such as micro robots, surgical robots, aerospace, and other fields with high space and weight requirements. As manufacturing processes improve, the performance of harmonic reducers continues to improve, providing greater design freedom and performance assurance for robot design.

[0004] However, in actual use, the output torque of the harmonic reducer is difficult to change, which leads to the following problems: when the robot is used to transport workpieces of different weights, if the weight of the workpiece is large, the robot may fail to transport the workpiece, increasing the burden of transportation and potentially damaging the robot. If the weight of the workpiece is small, the robot's transportation speed will not increase, thereby affecting the efficiency of transportation. SUMMARY

[0005] The present application aims to solve the problems in the prior art, such as the difficulty of changing the output torque of the harmonic reducer, the failure of the robot to transport heavy workpieces, the increase in the burden of transportation, the damage to the robot, and the slow transportation speed of the robot when transporting light workpieces, thereby affecting the efficiency of transportation. The present application provides a flexible robot joint module based on a harmonic reducer and a torque control method.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The application discloses a flexible robot joint module based on a harmonic reducer, which comprises a harmonic reducer, and a power module is arranged at the input end of the harmonic reducer.

[0008] The power module comprises a mounting shell, a control assembly is arranged in the mounting shell, the control assembly is connected with the driving assembly through a connecting assembly, and a driving motor is fixedly arranged on the mounting shell.

[0009] Further, the output end of the driving assembly is fixedly provided with a cam, the cam is in abutment with the flexible gear, and the abutment part of the flexible gear and the cam is convex and connected with the rigid gear.

[0010] Further, the mounting shell is provided with an adjusting assembly matched with the control assembly, and an adjusting motor is fixedly arranged on the mounting shell and connected with the adjusting assembly.

[0011] Further, the control assembly comprises two oppositely arranged friction members, the two friction members are conical frustums, a transmission belt is arranged on the two friction members, and the transmission belt is connected with the two friction members.

[0012] Further, the friction members are rotationally connected with the mounting shell, and the two friction members are connected with the connecting assembly and the driving motor respectively.

[0013] Further, the adjusting assembly comprises an adjusting member arranged in the mounting shell, a positioning groove matched with the transmission belt is arranged on the adjusting member, and a plurality of supporting rollers matched with the transmission belt are rotationally arranged in the positioning groove.

[0014] Further, a screw rod is rotationally arranged in the mounting shell, a nut seat is threadedly connected with the screw rod, and the nut seat is connected with the adjusting member.

[0015] Further, an insertion slot is arranged on the nut seat, an insertion piece matched with the insertion slot is fixedly arranged on the adjusting member, and a tension spring is arranged between the insertion piece and the insertion slot.

[0016] Further, the connecting assembly comprises two meshed conical gears, and the two conical gears are arranged at the output end of the control assembly and the input end of the driving assembly respectively.

[0017] The shell is provided with a liquid inlet hole and a liquid outlet hole, a liquid storage cavity is fixedly arranged at the lower end of the shell, and a liquid supply pipe and a liquid return hole matched with the liquid inlet hole and the liquid outlet hole are arranged on the liquid storage cavity.

[0018] The gear pump is fixedly arranged in the liquid storage cavity, a driving shaft is rotationally arranged on the mounting shell and is in power connection with the gear pump, the driving shaft is in power connection with the control assembly, an output end of the gear pump is connected with the liquid supply pipe, and a filter screen matched with the liquid return hole is fixedly arranged in the liquid storage cavity.

[0019] The application further provides a torque control method of the flexible robot joint module, and the torque control method comprises the flexible robot joint module based on the harmonic reducer and the following steps.

[0020] S1, the power module is used to provide power for the driving assembly, so as to drive the driving assembly and the cam to rotate;

[0021] S2, when the cam rotates, the flexible gear and the rigid gear are engaged to drive the flexible gear to rotate, and the output shaft rotates along with the flexible gear;

[0022] S3, the output torque of the power module is changed, so that the rotating speed of the driving assembly and the cam is changed, the engagement frequency of the flexible gear and the rigid gear is also changed, and the torque of the output shaft is changed.

[0023] The flexible robot joint module based on the harmonic reducer and the torque control method have the following beneficial effects.

[0024] In the application, the control assembly of the power module is matched with the driving motor, the driving assembly is provided with power under the action of the connecting assembly, so as to drive the driving assembly and the cam to rotate, and the flexible gear is engaged with the rigid gear under the action of the cam. Since the flexible gear and the rigid gear are in internal engagement with a small tooth difference, the flexible gear is driven to rotate, the output shaft rotates along with the flexible gear, power output is formed, and when the power module works, the lubricating liquid in the liquid storage cavity is input into the harmonic reducer through the gear pump to reduce friction, so that the service life is increased.

[0025] Secondly, in the application, the output torque of the power assembly is changed, so that the rotating speed of the driving assembly and the cam is changed, the engagement frequency of the flexible gear and the rigid gear is also changed, and 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, so that the heavy object is carried. Conversely, when the weight of the object is small, the output torque of the output shaft is reduced, so that the object is quickly carried to improve the efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a structural schematic view of the flexible robot joint module based on the harmonic reducer;

[0027] Figure 2 FIG. 2 is a structural schematic view of the cam;

[0028] Figure 3 Structure diagram of the flexible gear of the present application;

[0029] Figure 4 Structure diagram of the friction part of the present application;

[0030] Figure 5 Structure diagram of the installation shell of the present application;

[0031] Figure 6 Structure diagram of the A area of the present application;

[0032] Figure 7 Structure diagram of the bevel gear of the present application;

[0033] Figure 8 Structure diagram of the B area of the present application;

[0034] Figure 9 Structure diagram of the liquid storage cavity of the present application;

[0035] Figure 10 Structure diagram of the driving shaft of the present application.

[0036] In the figure: 1, harmonic reducer; 2, power module; 21, installation shell; 22, control assembly; 221, friction part; 222, transmission belt; 23, connecting assembly; 231, bevel gear; 24, driving motor; 25, adjusting assembly; 251, adjusting part; 252, supporting roller; 253, screw rod; 254, nut seat; 255, plug-in part; 256, tension spring; 26, adjusting motor; 3, shell; 31, rigid gear; 32, liquid inlet hole; 33, liquid outlet hole; 34, liquid storage cavity; 341, liquid supply pipe; 342, liquid return hole; 343, gear pump; 344, driving shaft; 345, filter screen; 4, inner gear; 41, flexible gear; 42, output shaft; 5, driving assembly; 6, cam. DETAILED DESCRIPTION

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

[0038] Reference Figures 1-10 , the flexible robot joint module based on the harmonic reducer, comprising a harmonic reducer 1, the input end of the harmonic reducer 1 is provided with a power module 2, the harmonic reducer 1 comprises a shell 3, an inner gear 4 and a driving assembly 5 arranged in the shell 3, the inner wall of the shell 3 is provided with a rigid gear 31, the inner gear 4 comprises a flexible gear 41 and an output shaft 42, and the driving assembly 5 is inserted with the flexible gear 41;

[0039] The power module 2 comprises a mounting shell 21, a control assembly 22 is arranged in the mounting shell 21, the control assembly 22 is power-connected with the driving assembly 5 through a connecting assembly 23, and a driving motor 24 is fixedly arranged on the mounting shell 21.

[0040] In the application, the control assembly 22 of the power module 2 cooperates with the driving motor 24, power is provided for the driving assembly 5 under the action of the connecting assembly 23, the driving assembly 5 is driven to rotate, the partial meshing of the flexible gear 41 and the rigid gear 31 is achieved, in the process, the internal meshing of the flexible gear 41 and the rigid gear 31 with a small tooth difference is achieved, so that the rotation of the flexible gear 41 is driven by the transmission of the motion, the output shaft 42 rotates with the flexible gear 41, and power output is formed.

[0041] Further, in the embodiment, the output end of the driving assembly 5 is fixedly provided with a cam 6, the cam 6 abuts against the flexible gear 41, the abutting part of the flexible gear 41 and the cam 6 is outwardly convex and is meshingly connected with the rigid gear 31, when the cam 6 rotates, the meshing part of the flexible gear 41 and the cam 6 changes, the internal meshing of the flexible gear 41 and the rigid gear 31 with a small tooth difference is achieved, so that the rotation of the flexible gear 41 and the output shaft 42 is driven by the transmission of the motion.

[0042] In the embodiment, the mounting shell 21 is provided with an adjusting assembly 25 matched with the control assembly 22, the mounting shell 21 is fixedly provided with an adjusting motor 26 power-connected with the adjusting assembly 25, the output torque of the control assembly 22 is changed by the cooperation of the adjusting motor 26 and the adjusting assembly 25, so that the rotation speed of the driving assembly 5 is changed, the rotation speed of the flexible gear 41 and the output shaft 42 is changed, the output torque of the output shaft 42 is changed, and the weight of the object carried by the robot is adjusted.

[0043] Further, in the embodiment, the control assembly 22 comprises two oppositely arranged friction members 221, the two friction members 221 are conical frustums, a transmission belt 222 is sleeved on the two friction members 221, the transmission belt 222 is in a tension state, the transmission belt 222 is power-connected with the two friction members 221, when one friction member 221 rotates, the transmission belt 222 and the other friction member 221 are driven to rotate, when the position of the transmission belt 222 changes, the contact part of the transmission belt 222 and the two friction members 221 changes, since the two friction members 221 are conical frustums and the transmission belt 222 contacts and frictions with the side surface of the conical frustum, the transmission ratio of the two friction members 221, that is, the speed change of the rotation of the driven friction member 221 driven by the transmission belt 222.

[0044] In the embodiment, the friction members 221 are all rotationally connected with the mounting shell 21, and the two friction members 221 are respectively connected with the connecting assembly 23 and the driving motor 24, the driving motor 24 drives one friction member 221 to rotate, and the other friction member 221 is driven to rotate under the action of the transmission belt 222, the friction member 221 driven to rotate by the transmission belt 222 provides power for the connecting assembly 23.

[0045] It should be noted that, in the embodiment, the adjusting assembly 25 comprises an adjusting member 251 arranged in the mounting shell 21, the adjusting member 251 is provided with a positioning groove matched with the transmission belt 222, and a plurality of supporting rollers 252 matched with the transmission belt 222 are rotationally arranged in the positioning groove, the position of the transmission belt 222 is changed by moving the position of the adjusting member 251, and the friction between the transmission belt and the adjusting member 251 is reduced by arranging the supporting rollers 252.

[0046] In the embodiment, a lead screw 253 is rotationally arranged in the mounting shell 21, a nut seat 254 is threadedly connected with the lead screw 253, the nut seat 254 is connected with the adjusting member 251, an output shaft of an adjusting motor 26 is fixedly connected with the lead screw 253, the rotation of the lead screw 253 is controlled by the adjusting motor 26, so that the position of the nut seat 254 and the adjusting member 251 is changed, the position of the transmission belt 222 is changed, the adjusting motor 26 and the driving motor 24 are both servo motors of an external controller, and in some embodiments, a guide rail matched with the nut seat 254 is fixedly arranged in the mounting shell 21.

[0047] In addition, in the embodiment, the nut seat 254 is provided with a slot, the adjusting member 251 is fixedly provided with an insert 255 matched with the slot, a tension spring 256 is arranged between the insert 255 and the slot, the insert 255 and the adjusting member 251 are forced to move by the tension spring 256, so that the transmission belt 222 is tensioned to prevent slipping.

[0048] In detail, in the embodiment, the connecting assembly 23 comprises two meshing connecting bevel gears 231, the two bevel gears 231 are respectively arranged at the output end of the control assembly 22 and the input end of the driving assembly 5, the bevel gear 231 is driven to rotate by the friction member 221, the other bevel gear 231 is driven to rotate by the bevel gear 231, and the driving assembly 5 comprises an input shaft, the bevel gear 231 is fixedly connected or keyed connected with the input shaft.

[0049] In more detail, in the embodiment, the housing 3 is provided with a liquid inlet hole 32 and a liquid outlet hole 33, a liquid storage cavity 34 is fixedly arranged at the lower end of the housing 3, lubricating liquid is stored in the liquid storage cavity 34, a liquid supply pipe 341 and a liquid return hole 342 matched with the liquid inlet hole 32 and the liquid outlet hole 33 are arranged on the liquid storage cavity 34, the liquid supply pipe 341 is connected with the liquid inlet hole 32 through a hose, and the liquid return hole 342 is connected with the liquid outlet hole 33 through a hose.

[0050] In the embodiment, the gear pump 343 is fixedly arranged in the liquid storage cavity 34, and in some embodiments, the gear pump 343 can also be replaced by other types of pumps. The driving shaft 344 which is in power connection with the gear pump 343 is rotatably arranged on the mounting shell 21. The driving shaft is arranged on one friction piece 221 of the control assembly 22, penetrates the mounting shell 21, and is provided with a gear on the driving shaft 344. The two gears are in power connection. The driving shaft 344 is in power connection with the control assembly 22. The output end of the gear pump 343 is connected with the liquid supply pipe 341. The input end of the gear pump 343 is located in the liquid storage cavity 34. When the control assembly 22 drives the harmonic reducer 1, the driving shaft 344 is driven to rotate, thereby providing power for the gear pump 343. The gear pump 343 inputs the lubricating liquid into the shell 3 to lubricate the inside of the harmonic reducer 1. The filter screen 345 which is matched with the liquid return hole 342 is fixedly arranged in the liquid storage cavity 34, and is used for filtering impurities such as iron powder in the backflow lubricating liquid, so as to avoid damaging the gear pump 343.

[0051] The application further provides a torque control method of the flexible robot joint module, comprising the flexible robot joint module based on the harmonic reducer, and further comprising the following steps.

[0052] S1, the power module 2 is used for providing power for the driving assembly 5, thereby driving the driving assembly 5 and the cam 6 to rotate;

[0053] S2, when the cam 6 rotates, the flexspline 41 is engaged with the rigid gear 31 to drive the flexspline 41 to rotate, and the output shaft 42 rotates with the flexspline 41;

[0054] S3, the output torque of the power module 2 is changed, thereby changing the rotating speed of the driving assembly 5 and the cam 6, the engagement frequency of the flexspline 41 and the rigid gear 31 is also changed, thereby changing the torque of the output shaft 42, and the weight of the object carried by the robot is adjusted.

[0055] When the torque is adjusted, the motor 26 is adjusted to control the rotation of the screw rod 253, thereby changing the positions of the nut seat 254 and the adjusting piece 251, and thereby changing the position of the transmission belt 222, and the contact part of the two friction pieces 221 is changed. Since the two friction pieces 221 are both conical frustums, and the transmission belt 222 is in contact and friction with the side surface of the conical frustum, the transmission ratio of the two friction pieces 221 is changed, that is, the rotating speed of the friction piece 221 which is driven to rotate by the transmission belt 222 is changed, thereby changing the torque output by the friction piece 221 and the input torque of the driving assembly 5, the rotating speed of the driving assembly 5 is changed, thereby changing the rotating speed of the flexspline 41 and the output shaft 42, and finally the output torque of the output shaft 42 is changed, so that the weight of the object carried by the robot is adjusted.

[0056] When the friction member 221 rotates, the driving main shaft rotates, and under the action of the two meshing gears, the driving shaft 344 rotates to provide power for the gear pump 343. The lubricating liquid is input into the shell 3 through the gear pump 343 to lubricate the inside of the harmonic reducer 1, reduce the wear between the flexspline 41 and the rigid wheel 31, and the excess lubricating liquid flows back to the storage cavity 34 for storage. The impurities such as iron powder in the backflow lubricating liquid are filtered through the filter screen 345 to avoid damaging the gear pump 343.

[0057] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

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), and the harmonic reducer (1) comprises: a housing (3), an inner wheel (4) arranged 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) comprises a flexible wheel (41) and an output shaft (42), and the drive assembly (5) is plugged into the flexible wheel (41); The power module (2) comprises a mounting shell (21), a control component (22) is arranged in the mounting shell (21), the control component (22) is connected to the drive component (5) through a connecting component (23), and a drive motor (24) is fixedly arranged on the mounting shell (21).

2. The flexible robot joint module based on a harmonic reducer according to claim 1, characterized in that: A cam (6) is fixedly provided at the output end of the driving assembly (5), the cam (6) abuts against the flexible wheel (41), and the abutting portion of the flexible wheel (41) and the cam (6) is convex outward and meshedly connected with the rigid wheel (31).

3. The flexible robot joint module based on a harmonic reducer according to claim 1, characterized in that: The mounting shell (21) is provided with an adjusting component (25) matched with the control component (22), and the mounting shell (21) is fixedly provided with an adjusting motor (26) connected to the adjusting component (25) in power.

4. The flexible robot joint module based on a harmonic reducer according to claim 3 is characterized in that: The control assembly (22) comprises two friction members (221) arranged opposite to each other, the two friction members (221) being of a frustum structure, and a transmission belt (222) being sleeved on the two friction members (221), the transmission belt (222) being in power connection with the two friction members (221).

5. The flexible robot joint module based on a harmonic reducer according to claim 4 is characterized in that: The friction members (221) are both rotatably connected to the mounting shell (21), and the two friction members (221) are respectively power-connected to the connecting assembly (23) and the driving motor (24).

6. The flexible robot joint module based on a harmonic reducer according to claim 4, characterized in that: The adjusting assembly (25) includes an adjusting member (251) disposed in the mounting shell (21), wherein a positioning groove cooperating with the transmission belt (222) is provided on the adjusting member (251), and a plurality of supporting rollers (252) cooperating with the transmission belt (222) are rotatably disposed in the positioning groove.

7. The flexible robot joint module based on a harmonic reducer according to claim 6, characterized in that: A screw rod (253) is rotatably arranged in the mounting shell (21), a nut seat (254) is threadedly connected to the screw rod (253), the nut seat (254) is connected to the adjusting member (251), a slot is provided on the nut seat (254), a plug-in unit (255) that matches the slot is fixedly arranged on the adjusting member (251), and a tension spring (256) is provided between the plug-in unit (255) and the slot.

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

9. The flexible robot joint module based on a harmonic reducer according to claim 8, characterized in that: A gear pump (343) is fixedly provided in the liquid storage chamber (34); a drive shaft (344) connected to the power of the gear pump (343) is rotatably provided on the mounting shell (21); the drive shaft (344) is connected to the power of the control component (22); the output end of the gear pump (343) is connected to the liquid supply pipe (341); and a filter screen (345) matched with the liquid return hole (342) is fixedly provided in the liquid storage chamber (34).

10. A torque control method for a flexible robot joint module, characterized in that: The method comprises using the joint module according to any one of claims 1 to 9, characterized in that it further comprises the following steps: S1, providing power to the driving assembly (5) through the power module (2), thereby driving the driving assembly (5) and the cam (6) to rotate; S2. When the cam (6) rotates, the flexible wheel (41) engages with the rigid wheel (31) to drive the flexible wheel (41) to rotate, and the output shaft (42) rotates along with the flexible wheel (41); S3, changing the output torque of the power module (2), thereby changing the rotation speed of the drive assembly (5) and the cam (6), and 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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