A series elastic actuator for a robotic joint

Abstract

The present invention discloses a series elastic actuator for a robot joint, which includes an input mechanism, an output mechanism and a transmission mechanism; the output mechanism is used for the robot joint to output externally; the output mechanism includes an output base plate, and a plurality of transmission columns are fixedly connected to one end of the output base plate away from the input mechanism, and the plurality of transmission columns are fixedly connected to the outer wall of a transmission disc; an output shaft is in rolling contact with one end of the transmission column away from the output base plate, and the transmission disc is sleeved on the output shaft; the output shaft is used to bear the load of the robot joint; the transmission mechanism, the transmission mechanism includes a friction assembly, one end of the friction assembly is abutted against the input mechanism, and the other end of the friction assembly is abutted against the output base plate; a pressing assembly is abutted against one end of the output base plate away from the friction assembly, and the pressing assembly and the input mechanism are threadedly installed through an adjusting bolt. The structure of the present invention is simple, the transmission efficiency is high, and the flexible connection of the robot joint is realized; when the actuator is disengaged, automatic reset can be achieved, reducing the workload of manual reset.

Description

Technical Field

[0001] The invention relates to the technical field of robots, in particular to a series elastic driver for robot joints. Background Art

[0002] In recent years, robotics has made great progress, especially the research and development of robots with flexible joints such as humanoid robots, service robots, rehabilitation robots, and collaborative robots. The joints of humanoid joint robots use elastic drive, which overcomes the disadvantage that rigid connections are prone to damage to the operated object or robot parts under impact loads such as collisions. It has the advantages of passive compliance, low impedance, impact resistance, force perception, and precise force control. It is an effective solution for realizing intelligent interaction of robots and is favored by more and more researchers.

[0003] A series elastic actuator is a type of flexible joint in robots. Currently, there have been a large number of studies on the use of series elastic actuators in flexible joints in robots. The series elastic actuator requires the integration of elastomers into the robot joints, which improves the flexibility of the robot joints. However, the structure of the existing series elastic actuators is complex. When the resistance torque is greater than the driving torque, the device will automatically disconnect to prevent damage. When it is reused, it needs to be manually repaired and restored, which is a cumbersome process. Therefore, there is an urgent need for a series elastic actuator for robot joints to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a series elastic driver for a robot joint to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a series elastic driver for a robot joint, comprising:

[0006] An input mechanism, the input mechanism being drivingly connected to a drive assembly for shutting down the robot;

[0007] An output mechanism, the output mechanism is used for the robot joint to output externally; the output mechanism comprises an output base plate, a plurality of transmission columns are fixedly connected to one end of the output base plate away from the input mechanism, and the plurality of transmission columns are fixedly connected to the outer wall of the transmission disk; an output shaft is in rolling contact with one end of the transmission column away from the output base plate, and the transmission disk is sleeved on the output shaft; the output shaft is used to bear the load of the robot joint;

[0008] The transmission mechanism comprises a friction assembly, one end of which abuts against the input mechanism, and the other end of which abuts against the output base plate; one end of the output base plate away from the friction assembly abuts against a clamping assembly, and the clamping assembly and the input mechanism are installed by adjusting bolt threads.

[0009] Preferably, the transmission disc comprises a main body sleeved on the output shaft, the outer wall of the main body is provided with a plurality of transmission grooves, an elastic transmission member is slidably connected in the transmission groove, and the elastic transmission member extends out of the main body and is fixedly connected to the transmission column.

[0010] Preferably, the elastic transmission member includes a transmission spring sheet slidably connected in the transmission groove, one end of the transmission spring sheet located in the transmission groove is fixedly connected to a first spring, the other end of the first spring is fixedly connected to a transmission block, and a second spring is fixedly connected between the transmission block and the bottom end of the transmission groove; the transmission block is interference fit with the transmission groove, and the transmission block is detachably connected to the output shaft through a lever member.

[0011] Preferably, the lever member includes a connecting groove opened between the inner hole of the main body and the transmission groove, a connecting rod is rotatably connected in the connecting groove, one end of the connecting rod is hinged to the transmission block, and the other end of the connecting rod is attracted and abutted against the output shaft through a magnetic head.

[0012] Preferably, a reset block is sleeved and fixedly connected to one end of the connecting rod close to the transmission block, and the reset block is slidably connected in the reset groove, and the reset groove is symmetrically arranged on both sides of the connecting groove; a third spring is fixedly connected between the two ends of the reset block and the two ends of the reset groove respectively.

[0013] Preferably, the reset block is located between the rotating shaft of the connecting rod and the transmission block; the reset block and the reset groove are interference fit.

[0014] Preferably, the friction assembly includes a first friction block abutting against the input mechanism and a second friction block abutting against the output base plate, an isolation ring abutting against the first friction block and the second friction block, the isolation ring is rotatably connected to the input mechanism, and the output base plate is sleeved outside the input mechanism and rotatably connected thereto.

[0015] Preferably, the clamping assembly includes a clamping plate abutting against one end of the output base plate away from the second friction block, a clamping shaft abutting against the clamping plate, the clamping shaft passes through the clamping plate and extends toward the input mechanism; the adjusting bolt is threadedly connected to the clamping shaft; the input mechanism is sleeved outside the clamping shaft and rotatably connected thereto; the output shaft is rotatably connected to the clamping shaft.

[0016] Preferably, the input mechanism includes an input shaft, which is transmission-connected to the driving assembly of the robot; the input shaft is located between the clamping shaft and the output base plate and is rotationally connected thereto respectively; the isolation ring is rotationally connected to the input shaft; an installation groove is provided at one end of the input shaft away from the clamping shaft, and the adjusting bolt abuts against the bottom end of the installation groove and is threadedly connected to the clamping shaft.

[0017] The invention discloses the following technical effects: the invention discloses a series elastic driver for robot joints, which is mainly used at the joints of the robot to realize flexible humanoid motion; at the same time, when the torque of the resistance is greater than the input torque, the input and output are automatically disengaged, and automatic reset is realized in the subsequent operation; the input mechanism is connected to the driving assembly of the robot shutdown, and the driving torque is provided for the series elastic driver of the present application; the output base plate and the output shaft of the output mechanism are transmitted through the transmission disk, and the output shaft is loaded with a load, and when the load is greater than the input torque, the output shaft and the transmission disk are idling and sliding; the transmission mechanism includes a friction assembly, which transmits power from the input mechanism to the output base plate through friction, and when the resistance is too large or impacted, the friction force of the friction assembly changes to realize the connection and disconnection of the transmission; the clamping assembly is threadedly connected to the input mechanism through an adjusting bolt, and the distance between the input mechanism and the output base plate can be adjusted, and then the friction between the friction assembly can be adjusted, so as to facilitate different quantitative adjustments according to actual conditions. The invention has a simple structure, high transmission efficiency, and realizes the flexible connection of the robot shutdown; when the driver is disengaged, automatic reset can be realized, and the workload of manual reset is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the structure of the series elastic driver used for the robot joint of the present invention;

[0020] Figure 2 It is a schematic diagram of the top view of the transmission disc of the present invention;

[0021] Figure 3 for Figure 2 A partial enlarged view of middle A;

[0022] Among them, 1. input mechanism; 2. output mechanism; 3. transmission mechanism; 4. input frame; 5. output frame; 11. adjusting bolt; 12. input shaft; 13. mounting groove; 14. third bearing; 21. output base plate; 22. transmission column; 23. transmission disk; 24. output shaft; 25. load; 26. main body; 27. transmission groove; 28. transmission spring; 29. ​​first spring; 210. transmission block; 211. second spring; 212. connecting groove; 213. connecting rod; 214. magnetic head; 215. reset block; 216. reset groove; 217. third spring; 218. rotating shaft; 219. first bearing; 220. second bearing; 31. first friction block; 32. second friction block; 33. isolation ring; 34. clamping plate; 35. clamping shaft; 36. fourth bearing. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Reference Figure 1-3 The present invention provides a series elastic driver for a robot joint, comprising:

[0026] An input mechanism 1, the input mechanism 1 is drivingly connected to a driving assembly for shutting down the robot;

[0027] Output mechanism 2, output mechanism 2 is used for external output of the robot joint; the output mechanism 2 includes an output base plate 21, a plurality of transmission columns 22 are fixedly connected to one end of the output base plate 21 away from the input mechanism 1, and the plurality of transmission columns 22 are fixedly connected to the outer wall of the transmission disk 23; an output shaft 24 is in rolling contact with one end of the transmission column 22 away from the output base plate 21, and the transmission disk 23 is sleeved on the output shaft 24; the output shaft 24 is used to bear the load 25 of the robot joint;

[0028] The transmission mechanism 3 includes a friction assembly, one end of which abuts against the input mechanism 1, and the other end of which abuts against the output base plate 21; one end of the output base plate 21 away from the friction assembly abuts against a clamping assembly, and the clamping assembly and the input mechanism 1 are threadedly installed through an adjusting bolt 11.

[0029] The present invention discloses a series elastic driver for robot joints, which is mainly used at the joints of the robot to realize flexible humanoid motion. At the same time, when the torque of the resistance is greater than the input torque, the input and output are automatically disengaged, and then automatically reset. The input mechanism 1 is connected to the driving assembly of the robot shutdown, providing the driving torque for the series elastic driver of the present application. The output base plate 21 and the output shaft 24 of the output mechanism 2 are transmitted through the transmission disk 23, and the output shaft 24 is loaded with a load 25. When the load 25 is greater than the input torque, the output shaft 24 and the transmission disk 23 slide in idle rotation. The transmission mechanism 3 includes a friction assembly, which transmits power from the input mechanism 1 to the output base plate 21 through friction. When the resistance is too large or impacted, the friction force of the friction assembly changes to realize the connection and disconnection of the transmission. The clamping assembly is threadedly connected to the input mechanism 1 through the adjusting bolt 11, and the distance between the input mechanism 1 and the output base plate 21 can be adjusted, thereby adjusting the friction between the friction assemblies, so as to facilitate different quantitative adjustments according to actual conditions.

[0030] A further optimized solution is that the transmission disk 23 includes a main body 26 sleeved on the output shaft 24, and a plurality of transmission grooves 27 are opened on the outer wall of the main body 26. An elastic transmission member is slidably connected in the transmission groove 27, and the elastic transmission member extends out of the main body 26 and is fixedly connected to the transmission column 22; the elastic transmission member includes a transmission spring 28 slidably connected in the transmission groove 27, and one end of the transmission spring 28 located in the transmission groove 27 is fixedly connected to a first spring 29, and the other end of the first spring 29 is fixedly connected to a transmission block 210, and a second spring 211 is fixedly connected between the transmission block 210 and the bottom end of the transmission groove 27; the transmission block 210 is interference fit with the transmission groove 27, and the transmission block 210 is detachably connected to the output shaft 24 through a lever member. When the load 25 is 0, the input mechanism 1 drives the output base plate 21 to rotate through the friction assembly, and then drives the main body 26 to rotate through the elastic transmission space of the transmission disk 23, and the main body 26 drives the output shaft 24 to rotate; when the load 25 is greater than 0 but less than the input torque, the friction assembly drives the input base plate to rotate, the transmission column 22 drives the transmission spring 28 to slide in the transmission groove 27, the transmission block 210 remains stationary, the first spring 29 is stretched, and the output shaft 24 is driven to rotate through the main body 26; when the load 25 is greater than the input torque, the friction assembly drives the output base plate 21 to rotate, the transmission spring 28 pulls the first spring 29, so that the transmission block 210 slides, and then the transmission block 210 drives the lever member and the output shaft 24 to slide relative to each other, so that the main body 26 cannot drive the output shaft 24 to rotate, but it can also prevent the output shaft 24 from reversing and causing the load 25 to fall. When the action is completed, the load 25 is unloaded, the first spring 29 and the second spring 211 drive the transmission block 210 to reset, and the lever member connects the main body 26 with the output shaft 24 again, which is convenient for the next action.

[0031] In a further optimized solution, the lever member includes a connecting groove 212 provided between the inner hole of the main body 26 and the transmission groove 27, a connecting rod 213 is rotatably connected in the connecting groove 212, one end of the connecting rod 213 is hinged to the transmission block 210, and the other end of the connecting rod 213 is attracted and abutted against the output shaft 24 through the magnetic head 214. When the transmission block 210 slides, the connecting rod 213 hinged thereto is driven to rotate, and the magnetic head 214 and the output shaft 24 are relatively displaced by the lever action, and then relative sliding occurs.

[0032] Further optimized solution, a reset block 215 is sleeved and fixedly connected to one end of the connecting rod 213 close to the transmission block 210, and the reset block 215 is slidably connected in the reset groove 216, and the reset groove 216 is symmetrically arranged on both sides of the connecting groove 212; the third spring 217 is fixedly connected between the two ends of the reset block 215 and the two ends of the reset groove 216; the reset block 215 is located between the rotating shaft 218 of the connecting rod 213 and the transmission block 210; the reset block 215 is interference fit with the reset groove 216. The combination of the reset block 215 and the third spring 217 enables the connecting rod 213 to be quickly reset after the load 25 is unloaded.

[0033] Further optimized solution, the friction assembly includes a first friction block 31 abutting against the input mechanism 1 and a second friction block 32 abutting against the output bottom plate 21, an isolation ring 33 abutting against the first friction block 31 and the second friction block 32, the isolation ring 33 is rotatably connected with the input mechanism 1, and the output bottom plate 21 is sleeved outside the input mechanism 1 and rotatably connected thereto. The input mechanism 1 drives the isolation ring 33 to rotate through the first friction block 31, and then drives the output bottom plate 21 to rotate through the second friction block 32; when the resistance is too much or the input force is too fast, sliding friction occurs between the first friction block 31, the isolation ring 33, the second friction block 32 and the output bottom plate 21, so that the power cannot be fully transmitted, which plays a protective role and prevents the movable parts of the joint from being overloaded and damaged.

[0034] In a further optimized solution, the clamping assembly includes a clamping sheet 34 abutting against one end of the output bottom plate 21 away from the second friction block 32, a clamping shaft 35 abutting against the clamping sheet 34, the clamping shaft 35 passes through the clamping sheet 34 and extends toward the input mechanism 1; the adjusting bolt 11 is threadedly connected to the clamping shaft 35; the input mechanism 1 is sleeved outside the clamping shaft 35 and is rotatably connected thereto; the output shaft 24 is rotatably connected to the clamping shaft 35. The adjusting bolt 11 presses the friction assembly in the middle through the clamping shaft 35 to achieve power transmission, and realizes the application of the same series elastic driver in different occasions corresponding to different resistance torque conditions.

[0035] Furthermore, the clamping sheet 34 is preferably a disc spring, which can achieve reset when the adjusting bolt 11 is loosened.

[0036] A further optimized solution is that the input mechanism 1 includes an input shaft 12, which is transmission-connected to the driving assembly of the robot; the input shaft 12 is located between the clamping shaft 35 and the output base plate 21 and is rotationally connected thereto respectively; the isolation ring 33 is rotationally connected to the input shaft 12; an installation groove 13 is provided at one end of the input shaft 12 away from the clamping shaft 35, and the adjusting bolt 11 abuts against the bottom end of the installation groove 13 and is threadedly connected to the clamping shaft 35.

[0037] Furthermore, bearings are provided between the rotatably connected parts of the present application; a third bearing 14 is provided between the input shaft 12 and the isolation ring 33; a second bearing 220 is provided between the input shaft 12 and the clamping shaft 35, a first bearing 219 is provided between the output base plate 21 and the input shaft 12, and a fourth bearing 36 is provided between the output shaft 24 and the clamping shaft 35; thereby reducing rotational energy loss and parts wear.

[0038] Furthermore, the input shaft 12 is rotatably connected to the input frame 4, and the output shaft 24 is rotatably connected to the output frame 5, so as to achieve stable fixation of the device.

[0039] Directions:

[0040] The input frame 4 and the output frame 5 of the device are installed at appropriate positions of the robot joints, and then the series elastic drive device of the present application is assembled, and the drive component (not shown in the figure) is connected to the input shaft 12 through a transmission method including but not limited to steel wire, belt, chain, etc., and finally the adjustable load 25 is connected to the output shaft 24.

[0041] According to the actual needs and work content of the robot, the appropriate connection tightness of the adjusting bolt 11 is selected to make the friction coefficient between the friction components meet the use requirements.

[0042] The driving assembly is started to drive the input shaft 12 to rotate, and the input shaft 12 drives the output base plate 21 to rotate through the friction assembly, and the motion is transmitted to the output shaft 24 through the transmission column 22 and the transmission disc 23.

[0043] Modify the size of the load 25. When the load 25 is 0, the input mechanism 1 drives the output base plate 21 to rotate through the friction component, and then drives the main body 26 to rotate through the elastic transmission of the transmission disk 23, and the main body 26 drives the output shaft 24 to rotate; when the load 25 is greater than 0 but less than the input torque, the friction component drives the input base plate to rotate, the transmission column 22 drives the transmission spring 28 to slide in the transmission groove 27, the transmission block 210 remains stationary, the first spring 29 is stretched, and the output shaft 24 is driven to rotate through the main body 26; when the load 25 is greater than the output When the torque is input, the friction assembly drives the input base plate to rotate, and the transmission spring piece 28 pulls the first spring 29 to make the transmission block 210 slide, and then the transmission block 210 drives the lever member and the output shaft 24 to slide relative to each other, so that the main body 26 cannot drive the output shaft 24 to rotate, but it can also prevent the output shaft 24 from reversing and causing the load 25 to fall. When the action is completed, the load 25 is unloaded, and the first spring 29 and the second spring 211 drive the transmission block 210 to reset, and the lever member connects the main body 26 with the output shaft 24 again, which is convenient for the next action.

[0044] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] The above embodiments are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A series elastic actuator for a robot joint, characterized in that, it comprises: an input mechanism (1), the input mechanism (1) is in transmission connection with the drive assembly of the robot joint; an output mechanism (2), the output mechanism (2) is used for the external output of the robot joint; the output mechanism (2) includes an output bottom plate (21), and a plurality of transmission columns (22) are fixedly connected to one end of the output bottom plate (21) away from the input mechanism (1), and the plurality of transmission columns (22) are fixedly connected to the outer wall of a transmission disk (23); one end of the transmission column (22) away from the output bottom plate (21) is in rolling contact with an output shaft (24), and the transmission disk (23) is sleeved on the output shaft (24); the output shaft (24) is used to bear the load (25) of the robot joint; a transmission mechanism (3), the transmission mechanism (3) includes a friction assembly, one end of the friction assembly is in contact with the input mechanism, and the other end of the friction assembly is in contact with the output bottom plate (21); a pressing assembly is in contact with one end of the output bottom plate (21) away from the friction assembly, and the pressing assembly and the input mechanism (1) are threadedly installed through an adjusting bolt (11); the transmission disk (23) includes a main body (26) sleeved on the output shaft (24), a plurality of transmission grooves (27) are formed in the outer wall of the main body (26), an elastic transmission member is slidably connected in the transmission groove (27), and the elastic transmission member extends out of the main body (26) and is fixedly connected to the transmission column (22); the elastic transmission member includes a transmission elastic sheet (28) slidably connected in the transmission groove (27), a first spring (29) is fixedly connected to one end of the transmission elastic sheet (28) located in the transmission groove (27), the other end of the first spring (29) is fixedly connected to a transmission block (210), and a second spring (211) is fixedly connected between the transmission block (210) and the bottom end of the transmission groove (27); the transmission block (210) is in interference fit with the transmission groove (27), and the transmission block (210) is detachably connected to the output shaft (24) through a lever member; the lever member includes a connection groove (212) formed between the inner hole of the main body (26) and the transmission groove (27), a connecting rod (213) is rotatably connected in the connection groove (212), one end of the connecting rod (213) is hinged to the transmission block (210), and the other end of the connecting rod (213) is attracted and abutted against the output shaft (24) through a magnetic head (214).

2. The series elastic actuator for a robot joint according to claim 1, characterized in that: a reset block (215) is sleeved and fixedly connected to one end of the connecting rod (213) close to the transmission block (210), the reset block (215) is slidably connected in a reset groove (216), and the reset groove (216) is symmetrically formed on both sides of the connection groove (212); third springs (217) are fixedly connected between the two ends of the reset block (215) and the two ends of the reset groove (216) respectively.

3. The serial elastic actuator for a robot joint according to claim 2, Features: The reset block (215) is located between the rotating shaft (218) of the connecting rod (213) and the transmission block (210); the reset block (215) and the reset groove (216) are interference fit.

4. The serial elastic actuator for a robot joint according to claim 1, Features: The friction assembly comprises a first friction block (31) abutting against the input mechanism (1) and a second friction block (32) abutting against the output base plate (21); an isolation ring (33) abuts between the first friction block (31) and the second friction block (32); the isolation ring (33) is rotatably connected to the input mechanism (1); and the output base plate (21) is sleeved outside the input mechanism (1) and rotatably connected thereto.

5. The serial elastic actuator for a robot joint according to claim 4, Features: The clamping assembly comprises a clamping plate (34) abutting against one end of the output base plate (21) away from the second friction block (32); a clamping shaft (35) abutting against the clamping plate (34); the clamping shaft (35) passes through the clamping plate (34) and extends toward the input mechanism (1); the adjusting bolt (11) is threadedly connected to the clamping shaft (35); the input mechanism (1) is sleeved outside the clamping shaft (35) and is rotatably connected thereto; the output shaft (24) is rotatably connected to the clamping shaft (35).

6. The serial elastic actuator for a robot joint according to claim 5, Features: The input mechanism (1) comprises an input shaft (12), the input shaft (12) being transmission-connected to the driving assembly of the robot; the input shaft (12) being located between the clamping shaft (35) and the output base plate (21) and being rotationally connected thereto respectively; the isolation ring (33) being rotationally connected to the input shaft (12); a mounting groove (13) being provided at one end of the input shaft (12) away from the clamping shaft (35), the adjusting bolt (11) being abutted against the bottom end of the mounting groove (13) and being threadedly connected to the clamping shaft (35).

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