Adjustable mechanical arm gravity compensation device, mechanical arm and robot

Abstract

The invention discloses an adjustable mechanical arm gravity compensation device, a mechanical arm and a robot. The mechanical arm gravity compensation device comprises a base, a gravity compensation mechanism, a rotatable connecting mechanism and a connecting rod. The base is connected with the connecting rod through the rotatable connecting mechanism, the rotatable connecting mechanism is rotatably mounted on the base, and the rotatable connecting mechanism is fixedly connected with the connecting rod; the rotatable connecting mechanism is connected with a clamping hook at the upper end of the gravity compensation mechanism; in the gravity compensation mechanism, an elastic piece is connected between the upper end of the gravity compensation mechanism and the lower end of the gravity compensation mechanism; when the rotatable connecting mechanism rotates relative to the base, the lower end of the gravity compensation mechanism is fixedly mounted at a position on the base, and the rotatable connecting mechanism drives the upper end of the gravity compensation mechanism to move, so that the elastic piece performs gravity compensation through deformation; the number of the elastic pieces connected into the gravity compensation mechanism and / or the installation position of the lower end of the gravity compensation mechanism on the base are supported to be adjusted.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of mechanical arms, in particular to an adjustable mechanical arm gravity compensation device, a mechanical arm and a robot. BACKGROUND

[0002] At present, the mechanical arm as a common robot actuator can be widely applied to various industrial fields, such as article sorting, precision part machining, automatic welding and a series of applications. A kind of intelligent garbage collection robot for sweeping robot is disclosed in Chinese patent No. CN110051283B, the robot is internally equipped with an extendable mechanical arm, the mechanical arm grasps the dust collecting box of the sweeping robot through mechanical connection, and translates the dust collecting box of the sweeping robot to a preset position on the horizontal plane of the bearing seat body, so that the dust box suction port of the dust collecting box is aligned with the dust collecting inlet, thereby automatically guiding the sweeping robot to complete the collection of dust and small debris garbage in the dust collecting box through the cooperation of the guide surface and the mechanical arm, reducing the manual labor of the user.

[0003] However, due to the self-gravity of the mechanical arm, additional torque will be generated at the joint, which will seriously affect the dynamic performance of the mechanical arm. Firstly, it reduces the load capacity of the mechanical arm, thereby affecting the motion accuracy and stability. Secondly, it prevents personnel and article damage caused by brake failure. Therefore, the gravity compensation device needs to be considered when designing and manufacturing the mechanical arm.

[0004] For example, Chinese patent No. CN107738275A is based on a cam spring mechanism for gravity compensation. However, the cam mechanism increases wear due to point-line contact, and the stroke is small and the compensation range is not large. At the same time, the method mentioned in this patent can only compensate for gravity in one direction, and the cam spring mechanism cannot provide reverse tension for compensation when the mechanical arm moves in the opposite direction, thus limiting the movement space of the mechanical arm.

[0005] For example, Chinese utility model patent No. CN213499285U compensates for gravity by changing the number of counterweight strips. This patent is a typical counterweight compensation mechanism. However, this method increases the overall weight of the mechanical arm, and the way of increasing the counterweight by changing the number of counterweight strips for gravity compensation is not precise.

[0006] In summary, the existing gravity compensation for mechanical arms still has some technical defects, including the following two points: first, the precise counterweight adjustment mechanism can accurately adjust the number of counterweight blocks according to the weight of the mechanical arm and the end load, which may increase the overall weight of the mechanical arm; second, it cannot compensate for gravity in the full workspace, and the common compensation range is less than 180 degrees, which cannot meet the working requirements of the mechanical arm in a larger working angle space. SUMMARY

[0007] The application discloses an adjustable mechanical arm gravity compensation device, a mechanical arm and a robot, and specific technical solutions are as follows: The adjustable mechanical arm gravity compensation device comprises a base, a gravity compensation mechanism, a rotatable connecting mechanism and a connecting rod. The base is connected with the connecting rod through the rotatable connecting mechanism. The rotatable connecting mechanism is rotatably installed on the base, and the rotatable connecting mechanism is fixedly connected with the connecting rod. The rotatable connecting mechanism is hook-connected with the upper end of the gravity compensation mechanism, so that the upper end of the gravity compensation mechanism moves along with the rotatable connecting mechanism. Inside the gravity compensation mechanism, an elastic member is connected between the upper end of the gravity compensation mechanism and the lower end of the gravity compensation mechanism. When the rotatable connecting mechanism rotates relative to the base, the lower end of the gravity compensation mechanism is fixedly installed at a position on the base, the rotatable connecting mechanism drives the upper end of the gravity compensation mechanism to move, and the elastic member compensates gravity by deforming. The mechanical arm gravity compensation device or the mechanical arm gravity balance is realized. Therefore, no matter whether the rotatable connecting mechanism 3 drives the connecting rod 4 to rotate forward or reversely, gravity compensation can be realized, the mechanical arm gravity compensation device becomes a passive tension spring compensation mechanism supporting bidirectional compensation of gravity, and the required working angle application range in the activity space of the mechanical arm is expanded.

[0008] The number of the elastic members connected inside the gravity compensation mechanism and / or the installation position of the lower end of the gravity compensation mechanism on the base are adjustable. Based on this, the more the number of the elastic members connected inside the gravity compensation mechanism, the closer the installation position of the lower end of the gravity compensation mechanism on the base to the lower end of the base, the greater the stretching length of each elastic member between the upper end of the gravity compensation mechanism and the lower end thereof, the greater the range of the reverse torque generated by all the elastic members in the gravity compensation mechanism, and the easier or more accurate the gravity compensation is realized. Therefore, the mechanical arm gravity compensation device becomes an accurate reverse torque adjusting mechanism. Compared with a traditional counterweight adjusting mechanism, the application does not compensate gravity by increasing or decreasing counterweight blocks, but adjusts by adjusting the number and the stretching length of the elastic members, so that accurate reverse torque adjustment can be realized.

[0009] Further, the mechanical arm gravity compensation device is provided with a base, two gravity compensation mechanisms and a rotatable connecting mechanism; the two sides of the rotatable connecting mechanism are respectively connected with the upper ends of the two gravity compensation mechanisms through hooks, and the lower ends of the two gravity compensation mechanisms are respectively adjustably installed on the corresponding two sides of the base; in the interior of each gravity compensation mechanism, an elastic member is connected between the upper end and the lower end of the same gravity compensation mechanism; when the rotatable connecting mechanism rotates to the right relative to the base, the left side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected therewith to move, and the lower end of the gravity compensation mechanism connected therewith is kept fixedly installed at a position on the base, while the right side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected therewith to disengage; when the rotatable connecting mechanism rotates to the left relative to the base, the right side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected therewith to move, and the lower end of the gravity compensation mechanism connected therewith is kept fixedly installed at a position on the base, while the left side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected therewith to disengage.

[0010] In summary, when the rotatable connecting mechanism 3 drives the connecting rod 4 to rotate clockwise or counterclockwise, the rotatable connecting mechanism 3 drives the gravity compensation mechanism on the corresponding side to move, so that the elastic member in the interior of the gravity compensation mechanism generates a reverse torque, and then the changed gravitational potential energy of the connecting rod is converted into elastic potential energy, without the need to increase the counterweight, so that the mechanical arm gravity compensation device achieves complete gravity balance effect in the working space; when applied to the scene of mechanical arm rotation operation, the gravity compensation can be provided whether the rotation is forward or reverse, so as to achieve the gravity compensation effect in the whole working space.

[0011] Further, for the same gravity compensation mechanism, when the installation position of the lower end of the gravity compensation mechanism on the base changes, the length of each elastic member between the upper end and the lower end of the gravity compensation mechanism changes, and the range of the reverse torque generated by all the elastic members in the gravity compensation mechanism changes; when the number of the elastic members connected in the interior of the gravity compensation mechanism changes, the range of the reverse torque generated by all the elastic members in the gravity compensation mechanism changes; when the installation position of the lower end of the gravity compensation mechanism on the base changes and the number of the elastic members connected in the interior of the gravity compensation mechanism changes, the range of the reverse torque generated by all the elastic members in the gravity compensation mechanism changes.

[0012] Therefore, by adjusting the mounting position of the lower end of the gravity compensation mechanism on the base and / or adjusting the number of elastic members connected inside the gravity compensation mechanism, the value of the gravity compensation can be adjusted, the optimal gravity compensation point can be easily reached or the accuracy requirement of other counter torques can be met, and the stability of the mechanical arm to which the gravity compensation device of the mechanical arm is assembled / connected can be improved. Compared with the prior art gravity compensation mechanism using counterweights, the present application does not adjust by increasing or decreasing counterweights, but adjusts by adjusting the number of elastic members and the stretching length of the elastic members, so that accurate counter torque adjustment can be achieved.

[0013] Further, the gravity compensation mechanism comprises a movable rod, an elastic member, a fixed rod, an inner bolt, a fixed pin and an outer bolt, wherein the movable rod is located at the upper end of the gravity compensation mechanism, and the fixed rod is located at the lower end of the gravity compensation mechanism; both ends of the movable rod are provided with a support clamping groove for mounting to the upper end of the base; in the movable rod, a preset number of hook clamping grooves are sequentially arranged between the two support clamping grooves along the axial direction of the movable rod, and a first elastic member mounting groove is arranged between adjacent two hook clamping grooves; both ends of the fixed rod are mounted to the base below the support clamping grooves through the inner bolt, the fixed pin and the outer bolt; at each end of the fixed rod, the inner bolt and the outer bolt are respectively mounted at both ends of the fixed pin, the fixed pin is connected to one end of the fixed rod through the inner bolt, and the fixed pin is sleeved in the base; in the fixed rod, a matching number of second elastic member mounting grooves are sequentially arranged along the axial direction of the fixed rod, and the difference between the preset number and the value 1 is equal to the matching number, each second elastic member mounting groove is arranged in alignment with the corresponding first elastic member mounting groove in the movable rod, wherein the lower end of a group of adjustable number of elastic members is connected to one second elastic member mounting groove, and the upper end of the same group of adjustable number of elastic members is connected to one first elastic member mounting groove.

[0014] Based on this, when the rotatable connecting mechanism is connected with the upper end of the gravity compensation mechanism by hooking, the rotatable connecting mechanism is connected with the hook clamping groove by hooking, and the movable rod can move relative to the base under the driving of the rotatable connecting mechanism. One side of the rotatable connecting mechanism is used to drive the upper end (movable rod) of the gravity compensation mechanism connected by hooking to move, and keep the lower end (fixed rod) of the gravity compensation mechanism connected by hooking fixedly installed at a position on the base, so that the elastic members connected between the second elastic member mounting grooves and the first elastic member mounting grooves are stretched to produce elastic deformation.

[0015] Further, the rotatable connecting mechanism comprises a rotating shaft and hook assemblies arranged on both sides of the rotating shaft; on each side of the rotating shaft, a preset number of hooks are arranged along the axial direction of the rotating shaft, and gaps exist between adjacent two hooks to accommodate a first elastic member mounting slot, each hook is connected with a corresponding hook clamping groove in the gravity compensation mechanism, one side of the rotatable connecting mechanism is connected with the upper end of the gravity compensation mechanism, and then the connecting rod is connected with the gravity compensation mechanism; the rotatable connecting mechanism further comprises a motor, and the motor is used to drive the hooks on both sides of the rotating shaft and the connecting rod to rotate around the rotating shaft as the rotation center, so that the rotatable connecting mechanism rotates relative to the base. Wherein, the hooks on one side drive the movable rod where the corresponding hook clamping groove connected by the hooks is located to move upward to stretch the elastic member connected in the corresponding first elastic member mounting slot in the movable rod moving upward, and the hooks on the other side do not stretch the corresponding elastic member through the corresponding hook clamping groove. Thus, the hooks on one side drive the movable rod where the corresponding hook clamping groove connected by the hooks is located to move upward to stretch the elastic member connected in the corresponding first elastic member mounting slot in the movable rod moving upward, so that the elastic member connected between the first elastic member mounting slot and the second elastic member mounting slot arranged in alignment is elastically deformed to form a counter torque for gravity compensation. At the same time, the hooks on the other side do not stretch the corresponding elastic member through the corresponding hook clamping groove, and the hooks on the other side are disconnected from the hook clamping groove in the gravity compensation mechanism on the corresponding side. Then, the rotating shaft does not drive the movable rod of the disengaged hook clamping groove to move relative to the base, but stays at the upper end of the base, which does not affect the rotating movement of the rotating shaft driving the connecting rod, the upward movement of the movable rod where the corresponding hook clamping groove connected by the hooks is located, and the stretching of the elastic member connected in the corresponding first elastic member mounting slot.

[0016] Further, the base comprises two shaft joint support seats and a fixed seat body; the two shaft joint support seats are symmetrically erected in the middle of the surface of the fixed seat body along the first direction, the top of each shaft joint support seat is provided with a shaft joint positioning installation hole, and the center of each shaft joint positioning installation hole is on the same straight line, and the shaft joint positioning installation holes of the two shaft joint support seats are respectively used for inserting the two ends of the rotating shaft. The rotatable connecting mechanism is rotatably installed on the base.

[0017] Furthermore, the base also includes two support frames; the two support frames are respectively disposed on both sides of the shaft joint support seat, and the two support frames are distributed at both ends of the surface of the fixed base body along the second direction, wherein the two shaft joint support seats constitute a shaft joint support seat; for the same support frame, the same support frame includes two sub-support frames symmetrically erected about the vertical center line on the surface of the fixed base body, the two sub-support frames are distributed at both ends of the same support frame along the first direction, and each of the two sub-support frames has an assembly groove at its upper end, each assembly groove is arranged opposite to each other along the first direction, and each assembly groove is connected to the support slot at the corresponding end of the movable rod, so as to cooperate with the hook to drive the movable rod where the hook slot connected to the hook is located to move; each of the two sub-support frames has a positioning rail in the middle, and the opening of each positioning rail is arranged opposite to each other along the first direction, and the corresponding end of the fixed rod is detachably installed to a position of the positioning rail using an inner bolt, a fixing pin and an outer bolt; on the surface of the fixed base body, the first direction and the second direction are arranged perpendicularly. This design allows the movable rods within the gravity compensation mechanisms on both sides of the base to have their positions fixed relative to the base and connecting rod. When the connecting rod rotates without moving the movable rod in the corresponding gravity compensation mechanism, the movable rod in that mechanism will remain within the mounting groove of the sub-support frame, without affecting movement. Alternatively, the fixed rod can be moved up and down within the positioning track by adjusting the mounting positions of the inner bolts, fixing pins, and outer bolts, thereby expanding the range of the reverse torque and making it relatively easy to meet the accuracy requirements of the reverse torque.

[0018] A robotic arm includes a gravity compensation device. This provides a bidirectionally adjustable gravity compensation robotic arm, enabling gravity compensation throughout the entire workspace, and allowing for fine adjustment of the gravity compensation according to actual needs.

[0019] Furthermore, the connecting rod is a first connecting rod, and the robotic arm also includes a second connecting rod, a third connecting rod, and an end effector; the first end of the first connecting rod is fixedly connected to the rotatable connecting mechanism; the first end of the second connecting rod is connected to the second end of the first connecting rod, and the second connecting rod contains a first motor, which drives the second connecting rod to rotate about the hinge axis in the connecting bracket between the second connecting rod and the first connecting rod; the first end of the third connecting rod is hinged to the second end of the second connecting rod, and the second connecting rod contains a second motor, which drives the mounting bracket to rotate about the hinge axis between the second connecting rod and the third connecting rod; the end effector is mounted on the second end of the third connecting rod. Thus, the base, gravity compensation mechanism, rotatable connecting mechanism, first connecting rod, second connecting rod, third connecting rod, and end effector together form a complete robotic arm with gravity compensation function.

[0020] A robot has at least one of the aforementioned robotic arms. After the robot is equipped with the robotic arms, the robotic arms grasp a target object through a mechanical connection and move the target object onto a work surface while maintaining gravitational balance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a gravity compensation device for a robotic arm installed in the main body of a robotic arm, as disclosed in one embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the internal structure of the base 1 in the gravity compensation device of the robotic arm, as disclosed in one embodiment of this application.

[0023] Figure 3 This is a schematic diagram of the planar structure of the gravity compensation mechanism 2 in the gravity compensation device of the robotic arm, as disclosed in one embodiment of this application.

[0024] Figure 4 This is a partially enlarged structural schematic diagram of the rotatable connecting mechanism 3 in the gravity compensation device of the robotic arm, as disclosed in one embodiment of this application.

[0025] Figure 5 This is a schematic diagram of the structure of a robotic arm disclosed in one embodiment of this application.

[0026] Figure label: 1. Base; 10. First axis joint support; 11. Second axis joint support; 12. Fixed base; 13. First support frame; 131. First assembly groove; 132. First positioning rail; 14. Second support frame; 141. Second assembly groove; 142. Second positioning rail; 2. Gravity compensation mechanism; 200. Movable rod; 2001. Support slot; 2002. Hook slot; 201. Fixed rod; 2011. Elastic element mounting slot; 202. Elastic element; 203. Inner bolt; 204. Fixing pin; 205. Outer bolt; 3. Rotatable connecting mechanism; 301. Rotating shaft; 302. Hook; 4. First link; 5. Second link; 6. Third link; 7. End effector. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features.

[0028] Gravity compensation methods include passive and active compensation. Active compensation provides gravity compensation by adjusting the output torque of the motor; however, this method requires real-time detection of the robotic arm's center of gravity, making its control algorithm very complex and placing high demands on the motor, thus increasing manufacturing costs. Passive compensation compensates for gravity based on the reverse torque generated at the joints by an energy storage device, mainly including counterweight compensation mechanisms.

[0029] This application discloses an adjustable gravity compensation device for a robotic arm to solve the problems of increased overall weight of the robotic arm due to the increase in the number of counterweights, as well as the limitations of unidirectional rotation and the restricted range of rotation. It achieves spring-loaded gravity compensation at least during both forward and reverse rotation, and also supports adjustment of the number and fixed position of the elastic elements within the gravity compensation mechanism to comprehensively and accurately adjust the reverse torque, lever arm, assist effect, and resistance effect provided by the elastic elements.

[0030] like Figure 1As shown, the mechanical arm gravity compensation device includes a base 1, a gravity compensation mechanism 2, a rotatable connecting mechanism 3, and a connecting rod, which is the first connecting rod 4 shown in the figure. The base 1 is connected to the first connecting rod 4 through the rotatable connecting mechanism 3. The rotatable connecting mechanism 3 is rotatably mounted on the base 1. The base 1 is fixed and has at least one rotating axis that rotates relative to the base around the rotating axis (with the rotating axis as the rotation center). The rotating axis can be inserted into the positioning hole at the upper end of the base. The rotating axis can also be defined as the rotation center / rotation center / joint axis, etc. The rotatable connecting mechanism 3 is fixedly connected to the first connecting rod 4. The rotatable connecting mechanism 3 is equipped with a motor, which drives the first connecting rod 4 to rotate clockwise or counterclockwise relative to the base 1. When the first connecting rod 4 rotates relative to the base 1, the rotatable connecting mechanism 3 is also considered to have rotated by the same angle in the same clockwise direction relative to the base 1. The rotation axis of the rotatable connecting mechanism 3 is set at the common connection node between the rotatable connecting mechanism 3 and the base 1 (e.g., the positioning hole at the upper end of the base). In this application, the base 1, the gravity compensation mechanism 2, the rotatable connecting mechanism 3 and the first connecting rod 4 form a robotic arm, or the first connecting rod 4 (when it is equipped with a motor or is hinged to the motor output shaft) forms a robotic arm on its own. The first connecting rod 4 can be hinged to other robotic arms in the corresponding mounting bracket through the rotating shaft.

[0031] exist Figure 1 From a vertical perspective, the rotatable connecting mechanism 3 is hooked to the upper end of the gravity compensation mechanism 2, fixing the upper end of the gravity compensation mechanism 2 to the rotatable connecting mechanism 3. This allows the upper end of the gravity compensation mechanism to move with the rotatable connecting mechanism, for example, allowing the upper end of the gravity compensation mechanism 2 to rotate around the aforementioned rotation axis. It is understood that the base 1 provides a space to accommodate the gravity compensation mechanism 2, including a slot for the upper end of the gravity compensation mechanism 2 to allow movement with the rotatable connecting mechanism 3, and a detachable mounting slot for the lower end of the gravity compensation mechanism 2. Figure 1 Inside the arc-shaped hollow section shown, Figure 1 The thick black circle shown indicates the lower end of gravity compensation mechanism 2.

[0032] Inside the gravity compensation mechanism 2, an elastic element connects the upper and lower ends of the gravity compensation mechanism 2. This elastic element can represent a type of elastic component that can be mounted around the edges of both ends of the gravity compensation mechanism 2 and remains taut so that an elastic force change immediately occurs when the elastic element is stretched by an external mechanical component. The elastic element in the gravity compensation mechanism 2... Figure 1 From the perspective of the viewer, it overlaps with the two sides of the arc-shaped hollow part of the base 1 or is hidden inside the base 1. The elastic element is made of elastic materials such as elastic rope and elastic steel wire.

[0033] When the rotatable connecting mechanism 3 rotates relative to the base 1, the lower end of the gravity compensation mechanism 2 is fixedly mounted on the base 1 at a certain position. The rotatable connecting mechanism 3 drives the upper end of the gravity compensation mechanism 2 to move, schematically shown as being located at... Figure 1 The upper end of the gravity compensation mechanism on the left side of the base 1 moves, causing the elastic element to deform and compensate for the gravity of the rotatable connecting mechanism 3, the first link 4, and / or other mechanical arms hinged to it; the rotatable connecting mechanism 3 moves clockwise relative to the base 1 (e.g., ...). Figure 1 (indicated by the arrow on the right) or counterclockwise (as shown by the arrow on the right) Figure 1 When the rotatable connecting mechanism 3 rotates (indicated by the left arrow), it drives the first link 4 to rotate. The first link 4, which has already rotated, and the other mechanical arms it is hinged to generate an additional torque (also called moment) on the rotation center in the rotatable connecting mechanism 3 due to their own weight. The additional torque drives the first link 4 to move. Since the rotatable connecting mechanism 3 is hooked to the upper end of the gravity compensation mechanism 2, the upper end of the gravity compensation mechanism 2 will also rotate. That is, the rotatable connecting mechanism 3 drives the upper end of the gravity compensation mechanism 2 to move. During this movement, the lower end of the gravity compensation mechanism 2 remains stationary, thereby stretching the elastic element of the rotatable connecting mechanism 3. The elastic element undergoes elastic deformation and generates elastic force. The elastic force will generate a torque on the rotation center in the rotatable connecting mechanism 3 that is opposite to the aforementioned additional torque (the direction of the moment is opposite), which is called the reverse torque. When the additional torque and the reverse torque can completely cancel each other out, the gravity compensation device or gravity balance of the mechanical arm is achieved. Therefore, whether the rotatable connecting mechanism 3 drives the first link 4 to rotate forward or backward, gravity compensation can be achieved, making the mechanical arm gravity compensation device a passive tension spring compensation mechanism that supports bidirectional gravity compensation, thus expanding the applicable range of working angles required in the mechanical arm's activity space.

[0034] Furthermore, the number of elastic elements in the internal connections of the gravity compensation mechanism and / or the mounting position of the lower end of the gravity compensation mechanism on the base are both adjustable, and gravity compensation can be performed based on the adjustment result. Among them, the change in the number of elastic elements in the internal connections of the gravity compensation mechanism causes a change in the torque and value generated by all elastic elements connected in the same gravity compensation mechanism (which can be uniformly defined as the reverse torque generated on the rotation center in the rotatable connection mechanism 3), thereby adjusting the resistance effect on the rotation of the first link 4. The mounting position of the lower end of the gravity compensation mechanism on the base determines the starting point of the elastic deformation of the elastic elements in the internal connections of the gravity compensation mechanism.

[0035] When the lower end of the gravity compensation mechanism is mounted on the base further away from the lower end of the base (the greater the height), the original length of the elastic element between the lower end and the upper end of the gravity compensation mechanism (the length before the upper end of the gravity compensation mechanism moves) may be less than the vertical height of the base. Before the elastic element is stretched by the rotatable connecting mechanism 3, a relative original elastic deformation is generated between the lower end and the upper end of the gravity compensation mechanism. After the elastic element is stretched by the rotatable connecting mechanism 3, the elastic deformation generated by the elastic element is smaller, and the corresponding reverse torque is smaller.

[0036] When the lower end of the gravity compensation mechanism is installed closer to the lower end of the base (the smaller the height), the original length of the elastic element between the lower end and the upper end of the gravity compensation mechanism (the length before the upper end of the gravity compensation mechanism moves) may be greater than the vertical height of the base. Before the elastic element is stretched by the rotatable connecting mechanism 3, a certain original elastic deformation is generated between the lower end and the upper end of the gravity compensation mechanism. After the elastic element is stretched by the rotatable connecting mechanism 3, the elastic deformation generated by the elastic element will be greater, and the corresponding reverse torque will be greater.

[0037] Based on this, the more elastic elements connected internally in the gravity compensation mechanism, and the closer the lower end of the gravity compensation mechanism is to the lower end of the base, the greater the tensile length of each elastic element between its upper and lower ends. This results in a wider range of reverse torques generated by all the elastic elements within the gravity compensation mechanism, making gravity compensation easier and more precise. Consequently, the mechanical arm gravity compensation device becomes a precise reverse torque adjustment mechanism. Compared to traditional counterweight adjustment mechanisms, this application does not perform gravity compensation by adding or removing counterweights, but rather by adjusting the number and tensile length of the aforementioned elastic elements, thus achieving precise reverse torque adjustment.

[0038] Specifically, such as Figure 1 As shown, the mechanical arm gravity compensation device includes a base 1 and two gravity compensation mechanisms. Figure 1 This only represents a gravity compensation mechanism 2 on the left and a rotatable connecting mechanism 3; each side of the rotatable connecting mechanism 3 is connected to the upper end of a gravity compensation mechanism by hooks, so that when the rotatable connecting mechanism 3 rotates relative to the base 1, it can stretch the elastic element inside the gravity compensation mechanism on one side by driving the upper end of the gravity compensation mechanism on that side to generate a reverse torque for gravity compensation.

[0039] Each gravity compensation mechanism has its lower end adjustablely mounted on the corresponding two sides of the base. Inside each gravity compensation mechanism, there is an elastic element connecting the upper end and the lower end of the same gravity compensation mechanism. When the rotatable connecting mechanism 3 drives the upper end of one side of the gravity compensation mechanism to move, the lower end of the gravity compensation mechanism on that side is fixedly mounted on the same side of the base. The elastic element connecting the lower end and the upper end of the gravity compensation mechanism on that side undergoes elastic deformation, which hinders the rotation of the rotatable connecting mechanism 3.

[0040] Combination Figure 1 It can be seen that when the rotatable connecting mechanism 3 rotates to the right relative to the base 1, the rotatable connecting mechanism 3 drives the first connecting rod 4 to rotate clockwise. The left side of the rotatable connecting mechanism 3 is used to drive the upper end of the gravity compensation mechanism 2 connected by its hook to move, and to keep the lower end of the gravity compensation mechanism 2 connected by its hook fixedly installed on the base at a certain position. Generally, it is detachably installed. Figure 1 The lower end of the arc-shaped hollowed-out portion on the left side of the base 1 shown is such that when the rotatable connecting mechanism 3 rotates, the lower end of the gravity compensation mechanism 2 remains fixedly installed; simultaneously, the gravity compensation mechanism (located on the right side of the rotatable connecting mechanism 3, used to drive its hook connection) is located at... Figure 1 The upper end of the base (right side) is detached from the connection, but the gravity compensation mechanism (located in...) Figure 1 The upper end of the base 1 (right side) remains mounted on the upper end of the right support frame of the base 1 to prevent it from affecting the movement generated by the rotatable connection mechanism 3. At this time, the gravity compensation mechanism (located on the right side of the base 1) Figure 1 The upper end of the base 1 (right side) remains mounted on the upper end of the right support frame of the base 1, and the gravity compensation mechanism (located in...) Figure 1 The lower end of the right side of the middle base 1 is fixedly installed in the base 1; preferably, the elastic element is always kept in a taut state in the gravity compensation mechanism on both sides of the base 1.

[0041] It should be noted that when the motor inside the rotatable connecting mechanism 3 drives the first link 4 to rotate clockwise, the rotating rotatable connecting mechanism 3, the first link 4, and the other mechanical arms hinged to it generate an additional torque on the rotation center of the rotatable connecting mechanism 3 due to their own gravity. The gravity compensation mechanism 2 mounted on the left side of the base 1 generates a reverse torque and acts as a resistance to the clockwise rotation of the first link 4. At the same time, the upper end of the gravity compensation mechanism mounted on the right side of the base 1 does not move, does not stretch the elastic element mounted on the right side of the base 1, and does not generate a torque in the same direction as the additional torque (it does not provide assistance to the first link 4). Thus, gravity compensation is achieved through the gravity compensation mechanism mounted on the left side of the base 1 during the clockwise rotation of the first link 4.

[0042] CombinationFigure 1 It can be seen that when the rotatable connecting mechanism 3 rotates to the left relative to the base 1, the rotatable connecting mechanism 3 drives the first connecting rod 4 to rotate counterclockwise, and the right side of the rotatable connecting mechanism 3 is used to drive the gravity compensation mechanism connected by its hook ( Figure 1 (There is no marking in the middle, but the upper end of the gravity compensation mechanism 2 on the left is symmetrically arranged about the vertical center line of the base 1.) The lower end of the gravity compensation mechanism, which is connected by a hook, is fixedly installed on the base at a position. It is generally detachably installed. Figure 3 The lower end of the arc-shaped hollow part on the right side of the base 1 is such that when the rotatable connecting mechanism 3 rotates, the lower end of the gravity compensation mechanism remains fixedly installed. At the same time, the upper end of the gravity compensation mechanism 2 connected to the left side of the rotatable connecting mechanism 3 is disengaged from the hook connection, but the upper end of the gravity compensation mechanism 2 remains mounted on the upper end of the left support frame of the base 1 to prevent affecting the current movement of the rotatable connecting mechanism 3. At this time, the upper end of the gravity compensation mechanism 2 remains mounted on the upper end of the right support frame of the base 1, and the lower end of the gravity compensation mechanism 2 remains fixedly installed in the base 1. Preferably, the elastic element in the gravity compensation mechanism on both sides of the base 1 is always kept in a taut state.

[0043] It should be noted that when the motor inside the rotatable connection mechanism 3 drives the first link 4 to rotate counterclockwise, the rotating first link 4 and the other mechanical arms it is hinged to generate an additional torque on the rotation center in the rotatable connection mechanism 3 due to their own gravity. The gravity compensation mechanism mounted on the right side of the base 1 generates a reverse torque and acts as a resistance to the counterclockwise rotation of the first link 4. At the same time, the upper end of the gravity compensation mechanism mounted on the left side of the base 1 does not move, does not stretch the elastic element mounted on the left side of the base 1, and does not generate a torque in the same direction as the additional torque (does not provide assistance to the first link 4). Thus, gravity compensation is achieved through the gravity compensation mechanism mounted on the right side of the base 1 during the counterclockwise rotation of the first link 4.

[0044] In summary, when the rotatable connecting mechanism 3 drives the first connecting rod 4 to rotate clockwise or counterclockwise, the rotatable connecting mechanism 3 causes the elastic element inside the gravity compensation mechanism to generate a reverse torque through the movement of the gravity compensation mechanism on the corresponding side. This converts the gravitational potential energy of the connecting rod into elastic potential energy, eliminating the need for additional counterweights and achieving complete gravity balance in the workspace. When applied to scenarios involving rotating robotic arms, it provides gravity compensation regardless of whether the rotation is clockwise or counterclockwise, achieving gravity compensation throughout the entire workspace.

[0045] Combination Figure 3 and Figure 1It is understood that in some embodiments, for the same gravity compensation mechanism, when the number of elastic members connected internally to the gravity compensation mechanism remains constant, and the installation position of the lower end of the gravity compensation mechanism on the base 1 changes, the length of each elastic member between the upper end and the lower end of the gravity compensation mechanism changes, as expressed as: Figure 3 The lengths of the elastic elements 202 in each group, which are respectively wound around the corresponding slots of the movable rod 200 and the fixed rod 201, change. Even if the movable rod 200 is not driven by the rotatable connecting mechanism 3, the lengths of the elastic elements 202 will still change. Since each elastic element performs a straightening operation between its upper and lower ends in the gravity compensation mechanism, its length can be regarded as a stretching length. This stretching length can be stretched from the original length (the length before the movement of the upper end of the gravity compensation mechanism, or the length without deformation). Therefore, the reverse torque generated by all elastic elements in the gravity compensation mechanism (which can be regarded as the same gravity compensation mechanism) The range of the sum of the torques generated by each elastic element changes. If the lower end of the gravity compensation mechanism is installed lower on the base 1, the generated reverse torque will be greater. When the movable rod 200 is driven by the rotatable connecting mechanism 3, the range of the reverse torque may be expanded, making it relatively easy to cover the optimal gravity compensation point and other reverse torque accuracy requirements. Therefore, by adjusting the installation position of the lower end of the gravity compensation mechanism on the base 1, the value of gravity compensation can be adjusted, making it easy to achieve the optimal gravity compensation point or meet other reverse torque accuracy requirements, thereby improving the stability of the robotic arm that is assembled / connected to the gravity compensation device.

[0046] Combination Figure 3 and Figure 3 It can be seen that, in some embodiments, for the same gravity compensation mechanism, there exists a situation where the lower end of the gravity compensation mechanism is fixed in its mounting position on the base, which is represented as... Figure 2The two ends of each set of elastic elements 202 are fixedly connected to the corresponding slots of the movable rod 200 and the fixed rod 201, respectively. When the number of elastic elements connected inside the gravity compensation mechanism changes, the range of the reverse torque generated by all elastic elements in the gravity compensation mechanism changes. Specifically, when the movable rod 200 is not driven by the rotatable connecting mechanism 3, and the number of elastic elements 202 accommodated in the corresponding slots of the movable rod 200 and the fixed rod 201 changes, even if the length of each elastic element stretched between the upper and lower ends of the gravity compensation mechanism remains unchanged, the range of the reverse torque generated by all elastic elements in the gravity compensation mechanism (which can be regarded as the sum of the torques generated by each elastic element in the same gravity compensation mechanism) changes. When the number of elastic elements 202 increases, the range of reverse torque may expand. When the movable rod 200 is driven by the rotatable connecting mechanism 3, the range of reverse torque and other accuracy requirements of reverse torque may be further expanded, making it easier to cover the optimal gravity compensation point. Therefore, by adjusting the number of elastic elements 202 connected inside the gravity compensation mechanism, the value of gravity compensation can be adjusted, making it easier to reach the optimal gravity compensation point or meet other accuracy requirements of reverse torque, thereby improving the stability of the robotic arm assembled / connected with the gravity compensation device.

[0047] In summary, for the same gravity compensation mechanism, there are also issues: when the installation position of the lower end of the gravity compensation mechanism on the base changes, and the number of elastic elements connected internally within the gravity compensation mechanism changes, the range of the reverse torque generated by all elastic elements within the gravity compensation mechanism also changes. For example, when it is necessary to adjust the magnitude of the reverse torque according to actual needs, the reverse torque can be roughly adjusted first by adjusting the number of elastic elements connected internally within the gravity compensation mechanism (including increasing or decreasing the number of elastic elements). Then, by adjusting the installation position of the lower end of the gravity compensation mechanism on the base (including raising or lowering the installation position of the lower end of the gravity compensation mechanism along the vertical direction of the base), the original length of the elastic elements can be changed without the movable rod 200 being driven by the rotatable connecting mechanism 3, thereby completing the fine adjustment of the reverse torque. For example, when it is necessary to adjust the magnitude of the reverse torque according to actual needs, the reverse torque is first roughly adjusted by adjusting the installation position of the lower end of the gravity compensation mechanism on the base so that the original length of the elastic element is changed when the movable rod 200 is not driven by the rotatable connecting mechanism 3. Then, the reverse torque is finely adjusted by adjusting the number of elastic elements connected internally by the gravity compensation mechanism.

[0048] Compared to existing technologies that use counterweights for gravity compensation, this application does not adjust by adding or removing counterweights, but rather by adjusting the number of elastic elements and the stretching length of the elastic elements, which can achieve precise adjustment of the reverse torque.

[0049] As one example, such as Figure 3 As shown, the gravity compensation mechanism includes a movable rod 200, an elastic element 202, a fixed rod 201, an inner bolt 203, a fixing pin 204, and an outer bolt 205. The movable rod 200 is located at the upper end of the gravity compensation mechanism 2, and the fixed rod 201 is located at the lower end of the gravity compensation mechanism 2. Each end of the movable rod 200 is provided with a support slot for mounting to the upper end of the base; that is, each end of the movable rod 200 is provided with a support slot 2001, and the two support slots 2001 are respectively mounted to... Figure 3 In the first support frame 1021 and the second support frame 1022 arranged on the same side, one side of the base 1 can be fitted with one of the gravity compensation mechanisms. In this embodiment, the movable rod 200 and both ends can be regarded as being arranged at the upper end of the gravity compensation mechanism.

[0050] like Figure 3 As shown, in the movable rod 200, between the two support slots 2001, along the axial direction of the movable rod 200 (corresponding to... Figure 3 A preset number of hook slots 2002 are sequentially arranged in the horizontal direction of the movable rod 200. A first elastic element mounting groove is provided between two adjacent hook slots 2002. The preset number is preferably 5, so 4 first elastic element mounting grooves are arranged along the axial direction of the movable rod 200. The first elastic element mounting groove and the hook slot can be separated by a rib. The outermost hook slot 2002 and the support slot 2001 of the movable rod 200 can be separated by a bone.

[0051] like Figure 1 As shown, both ends of the fixing rod 201 are installed to the base 1 via inner bolts 203, fixing pins 204, and outer bolts 205, and are located below the support slot 201. At each end of the fixing rod 201, the inner bolts 203 and outer bolts 205 are respectively installed at both ends of the fixing pin 204. The fixing pin 204 is connected to one end of the fixing rod 201 via the inner bolts 203. The fixing pin 204 is sleeved in the base 1, so that the fixing rod 201 is detachably installed in the base 1 using fixing pins. The fixing rod 201 and its two ends can be regarded as being located at the lower end of the gravity compensation mechanism. Therefore, if it is necessary to adjust the magnitude of the reverse torque according to actual needs, the installation position of the lower end of the gravity compensation mechanism on the base (i.e., the installation position of the fixing rod 201 in the base 1 using fixing pins) can be adjusted.

[0052] like Figure 4As shown, in the fixed rod 201, a matching number of second elastic element mounting slots 2011 are sequentially arranged along the axial direction of the fixed rod 201. The difference between the preset number and the value 1 is equal to the matching number. When the preset number is preferably 5, the matching number is equal to 4. Each second elastic element mounting slot 2011 is aligned with the corresponding first elastic element mounting slot in the movable rod 200. A rib is provided between two adjacent second elastic element mounting slots 2011 to separate them. The axial length of this rib is close to the axial length of the hook slot 2002. The axial length of 011 is equal to the axial length of the first elastic element mounting groove. The lower end of a group of adjustable elastic elements 202 is connected to a second elastic element mounting groove 2011, and the upper end of the same group of adjustable elastic elements 202 is connected to a first elastic element mounting groove. Each first elastic element mounting groove and an aligned second elastic element mounting groove 2011 are connected to multiple elastic elements 202 connected in parallel in the same group. The number of elastic elements 202 wound in a group can be increased or decreased, and there is no limit to the number of elastic elements 202 increased or decreased in different groups.

[0053] Based on this, when the rotatable connecting mechanism 3 is connected to the upper end of the gravity compensation mechanism via a hook, the rotatable connecting mechanism 3 is hooked to the hook groove 2002, and the movable rod 200 can move relative to the base 1 under the drive of the rotatable connecting mechanism 3. One side of the rotatable connecting mechanism is used to drive the upper end (movable rod 200) of the gravity compensation mechanism connected by its hook to move, and to keep the lower end (fixed rod 201) of the gravity compensation mechanism connected by its hook fixedly installed at a position on the base, so that the elastic element 202 connected between the second elastic element mounting groove 2011 and the first elastic element mounting groove is stretched to produce elastic deformation.

[0054] Preferably, the first elastic element mounting slot and the second elastic element mounting slot are detachably connected to elastic elements of the same type.

[0055] Preferably, the center of the fixed rod 201 and the center of the movable rod 200 are located on the same vertical line, ensuring that the same elastic element connecting the relatively aligned first elastic element mounting groove and the second elastic element mounting groove is always in a taut state.

[0056] When it is necessary to adjust the magnitude of the reverse torque generated by the gravity compensation mechanism on one side according to actual needs, the overall reverse torque can be adjusted directly within the gravity compensation mechanism by changing the number of connections of the elastic element 202 before the rotatable connecting mechanism 3 drives the movable rod 200 to move. This ensures that the mechanical arm gravity compensation device obtains the initial compensation value for the mechanical arm where the first connecting rod 4 is located and / or other mechanical arms hinged to it before the rotatable connecting mechanism 3 drives the first connecting rod 4 to rotate, thereby accelerating the rotation of the rotatable connecting mechanism 3 to the optimal gravity compensation point or achieving a complete gravity balance effect. Alternatively, during the movement of the movable rod 200 driven by the rotatable connecting mechanism 3, the overall reverse torque can be adjusted directly within the gravity compensation mechanism by changing the number of connections of the elastic element 202, thus adjusting the reverse torque without adding counterweights.

[0057] As one example, such as Figure 3 and Figure 4 As shown, the rotatable connection mechanism includes a rotating shaft 301 and hook assemblies fixedly disposed on both sides of the rotating shaft 301. In the hook assembly on each side of the rotating shaft 301, a predetermined number of hooks 302 are sequentially arranged along the axial direction of the rotating shaft 301. There is a gap between adjacent hooks 302 to accommodate one first elastic element mounting groove. This can be understood as the axial length of the first elastic element mounting groove being equal to the width of the gap between adjacent hooks 302. The axial length of each hook 302 is equal to the axial length of each hook slot 2002 in the movable rod 200. Each hook is hooked to a corresponding hook slot 2002 in the gravity compensation mechanism. Each hook is fixed into a corresponding hook slot 2002 in the gravity compensation mechanism. Then, one side of the rotatable connecting mechanism is connected to the upper hook of the gravity compensation mechanism, realizing the connection between the first link 4 and the gravity compensation mechanism. That is, the connection between the gravity compensation mechanism and the first link 4 is through the hooks 302 and hook slots 2002 on both sides of the base 1, so that each hook 302 hooks more tightly into the corresponding hook slot 2002 in the movable rod 200. Then, during the rotation of the rotating shaft 301, the hook 302 rotates with the rotating shaft 301, stably driving the movable rod 200 where the hook slot 2002 is hooked to move.

[0058] The rotatable connection mechanism also includes a motor, which drives the hooks on both sides of the rotating shaft 301 and the first connecting rod 4 to rotate around the rotating shaft 301 as the rotation center. This can be understood as the motor driving the first connecting rod 4 and the hooks to rotate around the rotating shaft 301, causing the rotatable connection mechanism 3 to rotate relative to the base 1. The first connecting rod 4 and the motor are fixedly connected, and the hook assembly is also fixedly connected to the motor.

[0059] In some embodiments, the output shaft of the motor is considered as the rotating shaft. Alternatively, a driven gear is provided on the rotating shaft, and a driving gear meshing with the driven gear is provided on the output shaft of the motor. Thus, when the output shaft of the motor rotates, it drives the rotating shaft 301 to rotate, thereby driving the hooks on both sides of the rotating shaft 301 and the first connecting rod 4 to rotate about the rotating shaft 301 as the rotation center.

[0060] One end of the rotating shaft 301 is inserted into (or understood as hinged to) the relevant positioning hole at the upper end of the base 1; when the rotating shaft 301 cannot drive the base 1 to rotate, the motor drives the first connecting rod 4 and the hook assembly to rotate around the rotating shaft 301, so that the first connecting rod 4, the hook assembly and the motor can only rotate left and right around the rotating shaft 301.

[0061] It should be noted that when the motor inside the rotatable connection mechanism 3 drives the first link 4 to rotate, the motor itself, the hook, and the first link 4 also rotate in the same direction. As a result, the motor itself, the hook, the first link 4, and the other mechanical arms hinged to it generate an additional torque on the rotation center (the location of the rotation shaft 301) in the rotatable connection mechanism 3 due to their own gravity. The gravity compensation mechanism mounted on one side of the base 1 generates a torque (reverse torque) that is opposite to the aforementioned additional torque (the direction of the torque is opposite), and it acts as a resistance to the rotation of the first link 4.

[0062] Combination Figure 4 and Figure 2 It is understood that when the motor drives the rotating shaft 301 to rotate, it drives the hooks 302 on both sides of the rotating shaft 301 to rotate relative to the base 1. Among them, the hook 302 on one side drives the movable rod where the hook slot 2002 connected to the corresponding hook to move upward, thereby stretching the elastic element connected in the first elastic element mounting groove in the upward-moving movable rod. This causes the elastic element 202 connected between the first elastic element mounting groove and the second elastic element mounting groove 2011, which are aligned with each other, to undergo elastic deformation, forming a reverse torque for gravity compensation. At the same time, it drives the hook on the other side to stretch the corresponding elastic element without being connected to the hook slot of the corresponding hook. For example, it drives the hook on the other side to disengage from the hook slot in the gravity compensation mechanism on the corresponding side. Then the rotating shaft 301 does not drive the movable rod of the disengaged hook slot to move relative to the base 1, but stays at the upper end of the base 1. This does not affect the rotation of the first connecting rod 4 driven by the rotating shaft 301, the upward movement of the movable rod where the hook slot 2002 connected to the corresponding hook, and the stretching of the elastic element connected in the first elastic element mounting groove.

[0063] In one embodiment, the base includes two shaft joint support seats and a fixed base. The two shaft joint support seats are symmetrically erected about a vertical center line on the center of the surface of the fixed base and distributed along a first direction. Each of the two shaft joint support seats has a shaft joint positioning and mounting hole on its top, and the centers of each shaft joint positioning and mounting hole are on the same straight line. The shaft joint positioning and mounting holes of the two shaft joint support seats are respectively used to insert the two ends of the rotating shaft. Specifically, as shown... Figure 2 As shown, the two shaft joint supports are a first shaft joint support 10 and a second shaft joint support 11. The first shaft joint support 10 and the second shaft joint support 11 are symmetrically erected about the vertical centerline on the middle of the surface of the fixed base 12 and distributed along a first direction (which can be considered as a transverse distribution). The distance between the first shaft joint support 10 and the second shaft joint support 11 is less than the length of the long side of the surface of the fixed base 12. A shaft joint positioning and mounting hole 101 is opened at the top of the first shaft joint support 10 and the top of the second shaft joint support 11, and the two shaft joints... The joint positioning mounting holes 101 are of the same size and their centers are on the same horizontal straight line. The distance between the two joint positioning mounting holes 101 is less than or equal to the axial length of the rotating shaft 301 to be assembled. The joint positioning mounting holes 101 of the first joint support 10 and the joint positioning mounting holes 101 of the second joint support 11 are respectively inserted into the two ends of the rotating shaft 301. Then the motor and the connecting rod are rotatably set in the joint positioning mounting holes 101 through the rotating shaft 301, so that the rotatable connecting mechanism is rotatably mounted on the base.

[0064] Based on the above embodiments, the base further includes two support frames; the two support frames are respectively disposed on both sides of the shaft joint support seat, and the two support frames are distributed at both ends of the surface of the fixed base body along the second direction, wherein the two shaft joint support seats constitute a shaft joint support seat; for the same support frame, the same support frame includes two sub-support frames symmetrically erected about the vertical center line on the surface of the fixed base body, the two sub-support frames are distributed at both ends of the same support frame along the first direction, and each of the two sub-support frames has an assembly groove at its upper end, each assembly groove is arranged opposite to each other along the first direction, and each assembly groove is connected to the support slot at the corresponding end of the movable rod, so as to cooperate with the hook to drive the movable rod where the hook slot connected to the hook is located to move; each of the two sub-support frames has a positioning rail in the middle, each positioning rail is arranged opposite to each other along the first direction, and the corresponding end of the fixed rod is detachably installed to a position of the positioning rail using an inner bolt, a fixing pin and an outer bolt; wherein, on the surface of the fixed base body, the first direction is perpendicular to the second direction.

[0065] Specifically, such as Figures 2 to 4As shown, the two support frames are the first support frame 13 and the second support frame 14; in Figure 1 From the perspective of [the location], the first support frame 13 is located on the left side of the shaft joint support seat, and the second support frame 14 is located on the right side of the shaft joint support seat. The first support frame 13 and the second support frame 14 are distributed along the second direction at both ends of the surface of the fixed seat 12. The first shaft joint support seat 10 and the second shaft joint support seat 11 are integrally molded as shaft joint support seats. The distance between the first shaft joint support seat 10 and the second shaft joint support seat 11 is less than the length of the first support frame 13 along the first direction and also less than the length of the second support frame 14 along the first direction. The length of the first support frame 13 along the first direction is equal to the length of the long side of the surface of the fixed seat 12, and the length of the second support frame 14 along the second direction is equal to the length of the long side of the surface of the fixed seat 12.

[0066] The first support frame 13 is provided with two sub-support frames, which are distributed at both ends of the first support frame 13 along a first direction and stand symmetrically on the surface of the fixed base 12 about the vertical center line. This can be understood as symmetrically arranged at both ends of the first support frame 13. Each of the two sub-support frames has a first mounting groove 131 with the same opening size at its upper end, and a first positioning track 132 with the same size in its middle section. Each first mounting groove 131 is arranged opposite to the first direction, and the openings of each first positioning track 132 are also arranged opposite to each other along the first direction.

[0067] The second support frame 14 is provided with two sub-support frames, which are distributed at both ends of the second support frame 14 along the first direction and stand symmetrically on the surface of the fixed base 12 about the vertical center line. This can be understood as symmetrically arranged at both ends of the second support frame 14. Each of the two sub-support frames has a second mounting groove 141 with the same opening size at its upper end, and a second positioning track 142 with the same size in its middle section. Each second mounting groove 141 is arranged opposite to the other along the first direction, and the openings of each second positioning track 142 are also arranged opposite to each other along the first direction.

[0068] Combination Figures 2 to 3It is understood that each first mounting groove 131 is respectively used to connect with the support slot 2001 at the corresponding end of the movable rod 200 in the gravity compensation mechanism on one side, so as to cooperate with the hook 302 to drive the movable rod 200 in the hook slot 2002 connected to the corresponding hook to move, or to cooperate to assemble the movable rod 200 when not driving the movable rod 200 to move. Similarly, each second mounting groove 141 is respectively used to connect with the support slot at the corresponding end of the movable rod in the gravity compensation mechanism on the other side, so as to cooperate with the hook to drive the movable rod in the hook slot connected to the corresponding hook to move, or to cooperate to assemble the movable rod when not driving the movable rod to move. In this way, the movable rods in the gravity compensation mechanisms on both sides of the base are fixed in positional relationship with the base and the connecting rod. When the connecting rod rotates but does not drive the movable rod in the corresponding gravity compensation mechanism on one side to move, the movable rod in the corresponding gravity compensation mechanism on one side will stop in the mounting groove of the sub-support frame and will not affect the movement.

[0069] Schematic, driven by the motor, each hook 302 on the left side of the first connecting rod 4 and the rotating shaft 301 rotates clockwise around the rotating shaft 301. This causes the rotatable connecting mechanism 3 to rotate to the right relative to the base 1. Each hook 302 on the left side of the rotating shaft 301 drives the movable rod 200 of the gravity compensation mechanism 2 connected to it to move, while keeping the fixed rod 201 at the lower end of the gravity compensation mechanism 2 fixed in the first positioning track 132, typically secured by inner bolts, fixing pins, and outer bolts. Simultaneously, each hook on the left side of the first connecting rod 4 and the rotating shaft 301 drives the gravity compensation mechanism (located in...) Figure 3 The movable rod on the right side of the base 1 is disengaged, but remains fitted in the second mounting groove 141 to prevent it from affecting the movement generated by the rotatable connection mechanism 3.

[0070] Combination Figure 1 It is known that the fixing rod 201 is set at the lower end of the gravity compensation mechanism 2. The two ends of the fixing rod 201 are respectively detachably installed in a corresponding first positioning track 132 using an inner bolt 203, a fixing pin 204, and an outer bolt 205. The two ends of the fixing rod 201 are respectively fixedly connected to a height position of one of the two first positioning tracks 132. Since the two ends of the fixing rod 201 are detachably installed in the two first positioning tracks 132, the height position is adjustable to change the stretching length of the elastic element 202 between the fixing rod 201 and the movable rod 200. Therefore, the first positioning track 132 becomes the length adjustment track in the first support frame 13. By adjusting the assembly position of the inner bolt, the fixing pin, and the outer bolt in the first positioning track 132, the fixing rod 201 can slide up and down in the first positioning track 132.

[0071] Schematic illustration: As the mounting position on base 1 changes, the length of each elastic element between its upper and lower ends in the gravity compensation mechanism changes, represented as follows: Figure 5 The lengths of the elastic elements 202 in the first positioning track 132 vary depending on whether the movable rod 200 is driven by the rotatable connecting mechanism 3 or not. The lower the installation position of the fixed rod 201 in the first positioning track 132, the greater the length of each elastic element 202 will be stretched, resulting in a larger reverse torque and potentially expanding the range of the reverse torque, thus making it relatively easier to meet the accuracy requirements of the reverse torque.

[0072] Based on the foregoing embodiments, this application discloses a robotic arm from the perspective of overall layout. The robotic arm is considered to include the aforementioned robotic arm gravity compensation device, that is, the base 1, gravity compensation mechanism 2, rotatable connection mechanism 3, and first link 4 disclosed in the foregoing embodiments constitute a complete robotic arm. The number of elastic elements 202 connected internally by the gravity compensation mechanism 2 and / or the installation position of the lower end of the gravity compensation mechanism 2 on the base 1 are adjustable, and gravity compensation can be performed based on the adjustment result. The robotic arm is preferably a three-degree-of-freedom robotic arm. The robotic arm can also be hinged to other robotic arms through corresponding mounting brackets to adapt to the needs of actual working scenarios. Of course, the aforementioned robotic arm gravity compensation device can still compensate for the gravity of the assembled robotic arm.

[0073] Combination Figure 5 or Figure 2 It is known that when the motor inside the rotatable connecting mechanism 3 drives the first link 4 to rotate clockwise, the rotating rotatable connecting mechanism 3, the first link 4, and the other mechanical arms hinged to it generate an additional torque on the rotation center of the rotatable connecting mechanism 3 due to their own gravity. The gravity compensation mechanism 2 mounted on the left side of the base 1 generates a reverse torque and acts as a resistance to the clockwise rotation of the first link 4. At the same time, the upper end of the gravity compensation mechanism mounted on the right side of the base 1 does not move, does not stretch the elastic element mounted on the right side of the base 1, and does not generate a torque in the same direction as the additional torque (does not provide assistance to the first link 4). Thus, gravity compensation is achieved through the gravity compensation mechanism mounted on the left side of the base 1 during the clockwise rotation of the first link 4.

[0074] When the motor inside the rotatable connection mechanism 3 drives the first link 4 to rotate counterclockwise, the rotating first link 4 and the other mechanical arms it is hinged to generate an additional torque on the rotation center in the rotatable connection mechanism 3 due to their own gravity. The gravity compensation mechanism mounted on the right side of the base 1 generates a reverse torque and acts as a resistance to the counterclockwise rotation of the first link 4. At the same time, the upper end of the gravity compensation mechanism mounted on the left side of the base 1 does not move, does not stretch the elastic element mounted on the left side of the base 1, and does not generate a torque in the same direction as the additional torque (does not provide assistance to the first link 4). Thus, gravity compensation is achieved through the gravity compensation mechanism mounted on the right side of the base 1 during the counterclockwise rotation of the first link 4.

[0075] In summary, this application provides a bidirectional adjustable gravity-compensated robotic arm, which can achieve gravity compensation throughout the entire workspace and allows for fine adjustment of the gravity compensation according to actual needs.

[0076] As one example, such as ​ As shown, the robotic arm also includes a second link 5, a third link 6, and an end effector 7; to a certain extent, the second link 5 and the third link 6 can each be designed independently as a robotic arm, which is equipped with a motor and can be hinged to other robotic arms.

[0077] The first end of the first connecting rod 4 is fixedly connected to the rotatable connecting mechanism 3; the first end of the second connecting rod 5 is connected to the second end of the first connecting rod 4, and the second connecting rod 5 and the first connecting rod 4 are connected together by a connecting bracket. The second connecting rod 5 is equipped with a first motor, which drives the second connecting rod 5 to rotate about a hinge axis in the connecting bracket between the second connecting rod 5 and the first connecting rod 4, including clockwise or counterclockwise rotation about the hinge axis in the connecting bracket between the second connecting rod 5 and the first connecting rod 4; wherein, the hinge axis is set on a connecting bracket between the second connecting rod 5 and the first connecting rod 4. Specifically, the second connecting rod 5 and the first connecting rod 4 are each provided with a hinge axis to the connecting bracket, and the hinge axis required for the second connecting rod 5 to rotate around is also considered as the hinge axis provided by the second connecting rod 5 in the connecting bracket.

[0078] The first end of the third link 6 is hinged to the second end of the second link 5. The hinge axis between the third link 6 and the second link 5 can be considered as the joint axis of the robotic arm. The end effector 7 is mounted on the second end of the third link 6, and the end effector 7 is preferably a mechanical gripper. The robotic arm is equipped with a second motor, which drives the third link 6 to rotate about the hinge axis between the second link 5 and the third link 6, including clockwise or counterclockwise rotation about the hinge axis between the second link 5 and the third link 6. When the base 1 is fixedly installed on the working surface and the rotatable connecting mechanism 3 rotates about the rotation axis 301, the first link 4 also rotates, driving the second link 5, the third link 6 and the end effector 7 to rotate together. At this time, the gravity compensation mechanism 2 stretches the elastic element through the rotatable connecting mechanism 3 to cause elastic deformation, compensating for the gravity of the first link 4, the second link 5, the third link 6 and the end effector 7. Thus, the base 1, gravity compensation mechanism 2, rotatable connection mechanism 3, first link 4, second link 5, third link 6 and end effector 7 are combined to form a complete robotic arm with gravity compensation function.

[0079] Based on the foregoing embodiments, this application also discloses a robot having at least one robotic arm as disclosed in the foregoing embodiments. The robotic arm can be mounted on one or more sides of the robot's body. Each robotic arm supports bidirectional gravity compensation, thus enabling gravity compensation throughout the robot's entire workspace. Furthermore, the gravity compensation can be finely adjusted according to actual needs. After the robotic arm is mounted, it grasps a target object via a mechanical connection. Specifically, it grasps the target object through a linkage and an end effector (e.g., a mechanical gripper) and moves the target object onto the work surface while maintaining gravity balance.

[0080] It should be noted that the aforementioned mounting bracket and end effector are not closely related to the actual technical problem solved by this application and will not be described in detail. Furthermore, the content not described in detail in this specification belongs to prior art known to those skilled in the art, and the standard parts used can all be purchased commercially. Some specially shaped parts (e.g.) ​ The parts for the base mold shown can all be customized according to the instructions and attached drawings. The specific connection methods of each part can all adopt conventional methods such as bolts, rivets, welding, and snap-fit, which are mature technologies. The bracket, parts and motor equipment all adopt conventional models in the existing technology. The circuit connection adopts conventional connection methods in the existing technology, which will not be described in detail here.

[0081] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An adjustable gravity compensation device for a robotic arm, characterized in that, The mechanical arm gravity compensation device includes a base, a gravity compensation mechanism, a rotatable connection mechanism, and a connecting rod; The base is connected to the connecting rod via a rotatable connecting mechanism, wherein the rotatable connecting mechanism is rotatably mounted on the base and is fixedly connected to the connecting rod; The rotatable connecting mechanism is connected to the upper end of the gravity compensation mechanism by a hook, so that the upper end of the gravity compensation mechanism moves with the rotatable connecting mechanism; inside the gravity compensation mechanism, there is an elastic element connecting the upper end and the lower end of the gravity compensation mechanism. When the rotatable connecting mechanism rotates relative to the base, the lower end of the gravity compensation mechanism is fixedly installed at a position on the base. The rotatable connecting mechanism drives the upper end of the gravity compensation mechanism to move, so that the elastic element can compensate for gravity by deforming. The number of elastic elements in the internal connection of the gravity compensation mechanism and / or the mounting position of the lower end of the gravity compensation mechanism on the base are both adjustable.

2. The mechanical arm gravity compensation device according to claim 1, characterized in that, The mechanical arm gravity compensation device is equipped with a base, two gravity compensation mechanisms and a rotatable connection mechanism; Each side of a rotatable connecting mechanism is connected to the upper end of a gravity compensation mechanism via a hook. The lower ends of each gravity compensation mechanism are adjustablely mounted on the corresponding sides of the base. Inside each gravity compensation mechanism, there is an elastic element connecting the upper end and the lower end of the same gravity compensation mechanism. When the rotatable connecting mechanism rotates to the right relative to the base, the left side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected by its hook to move, and keep the lower end of the gravity compensation mechanism connected by its hook fixedly installed on the base at a certain position. At the same time, the right side of the rotatable connecting mechanism is used to drive the upper end of the gravity compensation mechanism connected by its hook to disengage. When the rotatable connecting mechanism rotates to the left relative to the base, the right side of the rotatable connecting mechanism drives the upper end of the gravity compensation mechanism connected by its hook to move, while keeping the lower end of the gravity compensation mechanism connected by its hook fixedly installed on the base at a certain position. At the same time, the left side of the rotatable connecting mechanism drives the upper end of the gravity compensation mechanism connected by its hook to disengage.

3. The mechanical arm gravity compensation device according to claim 2, characterized in that, For the same gravity compensation mechanism, the following exists: When the number of elastic elements connected internally in the gravity compensation mechanism remains constant, and the installation position of the lower end of the gravity compensation mechanism on the base changes, the length of each elastic element between the upper end and the lower end of the gravity compensation mechanism changes, and the range of the reverse torque generated by all elastic elements in the gravity compensation mechanism changes. When the lower end of the gravity compensation mechanism is fixed in its mounting position on the base, the range of the reverse torque generated by all the elastic elements inside the gravity compensation mechanism changes when the number of elastic elements connected inside the gravity compensation mechanism changes. When the installation position of the lower end of the gravity compensation mechanism on the base changes, and the number of elastic components connected internally to the gravity compensation mechanism changes, the range of the reverse torque generated by all elastic components within the gravity compensation mechanism changes.

4. The gravity compensation device for the robotic arm according to claim 1, characterized in that, The gravity compensation mechanism includes a movable rod, an elastic element, a fixed rod, an inner bolt, a fixing pin, and an outer bolt, wherein the movable rod is located at the upper end of the gravity compensation mechanism, and the fixed rod is located at the lower end of the gravity compensation mechanism. Each end of the movable rod is provided with a support slot for mounting to the upper end of the base; in the movable rod, between the two support slots, a preset number of hook slots are sequentially provided along the axial direction of the movable rod, and a first elastic element mounting slot is provided between two adjacent hook slots. Both ends of the fixing rod are installed to the base and located below the support slot by inner bolts, fixing pins and outer bolts; at each end of the fixing rod, the inner bolts and outer bolts are respectively installed at both ends of the fixing pin, the fixing pin is connected to one end of the fixing rod by the inner bolt, and the fixing pin is sleeved in the base; In the fixed rod, a matching number of second elastic element mounting slots are sequentially arranged along the axial direction of the fixed rod. The difference between the preset number and the value 1 is equal to the matching number. Each second elastic element mounting slot is aligned with the corresponding first elastic element mounting slot in the movable rod. The lower end of a group of adjustable elastic elements is connected to a second elastic element mounting slot, and the upper end of the same group of adjustable elastic elements is connected to a first elastic element mounting slot.

5. The mechanical arm gravity compensation device according to claim 4, characterized in that, The rotatable connection mechanism includes a rotating shaft and hook assemblies disposed on both sides of the rotating shaft; In the hook assembly on each side of the rotating shaft, the preset number of hooks are arranged sequentially along the axial direction of the rotating shaft. There is a gap between two adjacent hooks to accommodate a first elastic element mounting groove. Each hook is connected to a corresponding hook slot in the gravity compensation mechanism, so that one side of the rotatable connecting mechanism is connected to the upper hook of the gravity compensation mechanism, thereby realizing the connection between the connecting rod and the gravity compensation mechanism. The rotatable connection mechanism also includes a motor, which drives the hooks on both sides of the rotating shaft and the connecting rod to rotate around the rotating shaft as the rotation center, so that the rotatable connection mechanism rotates relative to the base. The hook on one side drives the movable rod in the hook slot connected to the corresponding hook to move upward to stretch the elastic element connected in the first elastic element mounting slot in the upwardly moving movable rod, and drives the hook on the other side to stretch the corresponding elastic element without going through the hook slot connected to the corresponding hook.

6. The mechanical arm gravity compensation device according to claim 5, characterized in that, The base includes two shaft joint support seats and a fixed seat body; Two shaft joint support seats are symmetrically erected about the vertical center line on the middle of the surface of the fixed seat and distributed along the first direction. Each of the two shaft joint support seats has a shaft joint positioning and mounting hole on its top, and the center of each shaft joint positioning and mounting hole is on the same straight line. The shaft joint positioning and mounting holes of the two shaft joint support seats are respectively used to insert the two ends of the rotating shaft.

7. The mechanical arm gravity compensation device according to claim 6, characterized in that, The base also includes two support frames; the two support frames are respectively disposed on both sides of the shaft joint support seat, and the two support frames are distributed along the second direction at both ends of the surface of the fixed seat body, wherein the two shaft joint support seats constitute a shaft joint support seat; For the same support frame, the same support frame includes two sub-support frames that are symmetrically erected on the surface of the fixed base about the vertical center line. The two sub-support frames are distributed at both ends of the same support frame along a first direction. Each of the two sub-support frames has an assembly groove at its upper end. Each assembly groove is arranged opposite to the other along the first direction. Each assembly groove is connected to the support slot at the corresponding end of the movable rod to cooperate with the hook to drive the movable rod where the hook slot is connected to the hook to move. Each of the two sub-support frames has a positioning rail in the middle. The opening of each positioning rail is arranged opposite to the other along the first direction. The corresponding end of the fixed rod is detachably installed to a position of the positioning rail using an inner bolt, a fixing pin, and an outer bolt. On the surface of the fixed base, the first direction is perpendicular to the second direction.

8. A robotic arm, characterized in that, The robotic arm includes the robotic arm gravity compensation device as described in any one of claims 1 to 7.

9. The robotic arm according to claim 8, characterized in that, The link is a first link, and the robotic arm also includes a second link, a third link, and an end effector; The first end of the first connecting rod is fixedly connected to the rotatable connecting mechanism; The first end of the second link is connected to the second end of the first link. The second link is equipped with a first motor, which drives the second link to rotate about the hinge axis in the connecting bracket between the second link and the first link. The first end of the third link is hinged to the second end of the second link. The second link is equipped with a second motor, which drives the mounting bracket to rotate about the hinge axis between the second link and the third link. An end effector is installed at the second end of the third link.

10. A robot, characterized in that, The robot has at least one robotic arm as described in claim 8 or 9.

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