A robot joint compliance device

Abstract

This invention relates to a robot joint compliance device, comprising a connecting shell with an internal conductor disposed inside the shell. Addressing the dynamic changes in the robot's working environment and human-robot interaction safety issues, this device is designed based on passive compliance control. It can buffer the impact force or torque generated by the contact and collision between the end effector and the target during robot task execution in both the planar orthogonal direction and the rotational direction. The elastic damping member of the outer ring can directly buffer the impact force in the orthogonal force system caused by the difference in speed between the end effector and the target, while the rotating spring plate and one-way bearing of the inner ring can buffer the corresponding impact torque in the rotational direction. The connecting shell is fixedly connected to the next execution unit, and the internal rotor drive shaft is fixedly connected to the robot joint output device. Through multiple sets of springs and a reasonably arranged spring plate branch structure, bidirectional compliance buffering is achieved while reducing the strength requirements of individual springs.

Description

Technical Field

[0001] This invention relates to a robot joint compliance device. Background Technology

[0002] Traditional compliant joints in robots generally suffer from problems such as positional vibration and low control precision. Existing joint compliance devices mainly include variable stiffness buffer devices and series rotational elastic devices.

[0003] Variable stiffness buffer devices typically incorporate a stiffness adjustment mechanism on the transmission chain, consisting of elastic elements and a cohesive structure. This mechanism controls the pre-compression of the elastic elements to dynamically adjust the joint stiffness characteristics. They are mainly classified into three types: linkage type, lever type, and cam type. This type of structure often neglects the active-passive fusion control mechanism for joint stiffness during robot dynamic motion, resulting in poor joint stiffness characteristics and overly complex structural control, making it difficult to meet the integration and dynamic motion requirements of robots.

[0004] The series-connected compliant elastic device incorporates an elastic element between the drive motor and the load. It utilizes the flexible deformation of its own mechanism to transmit force and motion, significantly reducing the overall stiffness of the mechanism and effectively mitigating the impact of joint rotation during robot collisions. However, this design often uses torsion springs as the elastic element, resulting in poor overall adaptability and a lack of compactness, leading to low overall integration. Furthermore, this device can only buffer impacts in one rotational direction, and the use of rotating spring components inevitably introduces vibration into the system. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a robot joint compliance device.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a robot joint compliance device, including a connecting shell, wherein an internal conductor is disposed inside the connecting shell;

[0007] The inner conductor is connected to the connecting shell by several sets of circumferentially distributed elastic damping components. The elastic damping components extend radially to buffer and unload the impact force in the straight direction.

[0008] The internal conductor includes a coaxially mounted rotor drive shaft, on which rotating spring plates with opposite helical directions are coaxially mounted via one-way bearings. The one-way bearings of the rotating spring plates with opposite helical directions also have opposite helical directions, in order to eliminate elastic vibration.

[0009] Preferably, each of the elastic damping components includes a buffer spring and a damping connecting post, with the buffer spring coaxially sleeved on the outer periphery of the damping connecting post.

[0010] Preferably, the connecting shell is annular in shape, the outer ends of the damping connecting columns are all fixed to the outer ring connector, the inner ends of the damping connecting columns are all fixed to the inner ring connector, the outer ring connector is screwed to the connecting shell, the inner ring connector is screwed to the inner conductor, and the spring is coaxially sleeved on the outer periphery of the damping connecting column between the outer ring connector and the inner ring connector.

[0011] Preferably, the inner conductor, along the axial direction of the rotor drive shaft, sequentially includes a first end cover, a first inner conductor ring, a rotating spring plate, a spring plate blocking ring, a rotating spring plate, a second inner conductor ring, and a second end cover. It is then secured together by a plurality of circumferentially distributed bolts that pass sequentially from one end to the other through the first end cover, the first inner conductor ring, the rotating spring plate, the spring plate blocking ring, the rotating spring plate, the second inner conductor ring, and the second end cover, and are locked together by nuts.

[0012] Preferably, the rotating spring plates on both ends of the spring plate blocking ring have opposite helical directions, and a blocking ring is coaxially fixed between the one-way bearings of the two rotating spring plates on the rotor drive shaft.

[0013] Preferably, each of the one-way bearings has a stepped retaining ring coaxially sleeved on the rotor drive shaft on its outer end face. Each stepped retaining ring has an annular damper abutting its outer end face. The outer end face of one annular damper abuts against the damping concave surface of the inner end face of the first end cover and is adapted in shape. The outer end face of the other annular damper abuts against the damping concave surface of the inner end face of the second end cover and is adapted in shape.

[0014] Preferably, each of the rotating spring plates includes an inner plate and an outer ring, and the inner plate and the outer ring are connected as one unit by a plurality of circumferentially distributed arc-shaped elastic spokes, and the plurality of arc-shaped elastic spokes on the same rotating spring plate have the same rotation direction.

[0015] Preferably, the end of the arc-shaped elastic spoke that connects to the inner sheet has a slot.

[0016] Preferably, the end of the arc-shaped elastic spoke that connects to the outer ring body has a slot.

[0017] Preferably, the material of the annular damper is rubber.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) This device is designed directly for the force conditions of robot joints. For the collision contact process of robot end, it can buffer the impact force in the planar orthogonal force system and the impact torque in the rotation direction.

[0020] (2) It has strong adaptability, can buffer a large rotation angle, has strong load-bearing capacity, can be applied to various robot joints, and has a high degree of overall integration.

[0021] (3) By using a one-way bearing to limit the direction of force on the rotating spring plate, and by installing the rotating spring plate in both directions, it is not restricted to rotating in a single direction, resulting in a compact structure.

[0022] (4) By designing a damping structure, the system vibration caused by the traditional spring structure during operation is overcome.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0024] Figure 1 This is a perspective view of an embodiment of the present invention.

[0025] Figure 2 This is a cross-sectional view of an embodiment of the present invention.

[0026] Figure 3 This is an exploded view diagram of an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of an explosion of an internal conductor.

[0028] Figure 5 This is a schematic diagram of the explosion of two rotating spring plates. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] like Figures 1-5 As shown, this embodiment provides a robot joint compliance device, including a connecting shell 1, and an inner conductor 2 is disposed inside the connecting shell;

[0033] The inner conductor is connected to the connecting shell by several sets of circumferentially distributed elastic damping components 3. The elastic damping components extend radially to buffer and unload the impact force in the straight direction.

[0034] The internal conductor includes a rotor drive shaft 4 coaxially mounted, on which rotating spring plates 6 with opposite helical directions are coaxially mounted via one-way bearings 5. The one-way bearings of the rotating spring plates with opposite helical directions also have opposite helical directions, in order to eliminate elastic vibration.

[0035] In this embodiment of the invention, each elastic damping component includes a buffer spring 7 and a damping connecting post 8, with the buffer spring coaxially sleeved on the outer periphery of the damping connecting post. The damping connecting post is made of rubber and can achieve damping and dissipation through deformation.

[0036] In this embodiment of the invention, the connecting shell is annular in shape, the outer ends of the damping connecting columns are all fixed to the outer ring connector 9, the inner ends of the damping connecting columns are all fixed to the inner ring connector 10, the outer ring connector is screwed to the connecting shell by screws 11, the inner ring connector is screwed to the inner conductor by screws, and the spring is coaxially sleeved on the outer periphery of the damping connecting column between the outer ring connector and the inner ring connector.

[0037] In this embodiment of the invention, the inner conductor, along the axial direction of the rotor drive shaft, sequentially includes a first end cover 12, a first inner conduction ring 13, a rotating spring plate, a spring plate blocking ring 14, a rotating spring plate, a second inner conduction ring 15, and a second end cover 16. It is then secured together by a plurality of circumferentially distributed bolts 17 passing sequentially from one end to the other, including the first end cover, the first inner conduction ring, the rotating spring plate, the spring plate blocking ring, the rotating spring plate, the second inner conduction ring, and the second end cover, and finally locked together by nuts 18.

[0038] In this embodiment of the invention, the spiral directions of the rotating spring plates on both ends of the spring plate blocking ring are opposite, and the blocking ring 19 is coaxially fixed between the one-way bearings of the two rotating spring plates on the rotor drive shaft.

[0039] In this embodiment of the invention, the outer end face of each one-way bearing is provided with a stepped retaining ring 20 coaxially sleeved on the rotor drive shaft. The outer end face of each stepped retaining ring is abutted by an annular damper 21 coaxially sleeved on the rotor drive shaft. The outer end face of one annular damper abuts against the damping concave surface 22 of the inner end face of the first end cover and the shape is adapted to it. The outer end face of the other annular damper abuts against the damping concave surface of the inner end face of the second end cover and the shape is adapted to it.

[0040] In this embodiment of the invention, each of the rotating spring plates includes an inner plate body 23 and an outer ring body 24. The inner plate body and the outer ring body are connected as one unit by a plurality of circumferentially distributed arc-shaped elastic spokes 25. The plurality of arc-shaped elastic spokes on the same rotating spring plate have the same rotation direction.

[0041] In this embodiment of the invention, a slot 26 is provided at the end where the arc-shaped elastic spoke connects to the inner sheet.

[0042] In this embodiment of the invention, a slot is provided at the end where the arc-shaped elastic spoke connects to the outer ring body.

[0043] In this embodiment of the invention, the material of the annular damper is rubber.

[0044] In this embodiment of the invention, the working method of the robot joint compliance device is as follows:

[0045] This invention is a robot joint compliance device, mainly designed to address the force conditions of robot joints when performing tasks.

[0046] To mitigate the linear impact generated when the robot's end effector contacts the target, an elastic damping component in the outer ring is used. By strategically positioning the springs, the impact force is unloaded, and vibrations are eliminated via damping connecting posts. The rotational impact torque on the joint is then transmitted through this elastic damping component to the inner conductor in the inner ring structure.

[0047] The internal conductor operates using a combination of a rotating spring plate structure and a one-way bearing. The rotating spring plate acts in only one direction. The spring plate consists of three or more spring segments, i.e., arc-shaped elastic spokes. Slots are opened at both ends of the arc-shaped elastic spokes. Deformation of these slots increases the device's rotational angle, achieving greater rotational elasticity. The one-way bearing restricts the direction of the torque it bears, preventing it from bearing any reverse rotational torque. By arranging the rotating spring plates and one-way bearing structure in both forward and reverse directions, the device can operate in both directions. The specific operating process is as follows:

[0048] When the robot collides with the target, the impact force is transmitted through the connecting shell. The buffer spring and damping connecting column undergo linear deformation to buffer and unload the impact force in the straight direction. The rotational torque is transmitted to the internal conductor through this elastic damping component.

[0049] When the internal conductor is activated, assuming the first rotating spring plate is under force, the spring body of the first rotating spring plate undergoes deformation with a large rotation angle, generating an elastic torque. At this time, due to the presence of the one-way bearing, the second rotating spring plate is not under force. When the torque rebounds, the first rotating spring plate is not under force under the action of the one-way bearing, and the second rotating spring plate undergoes elastic deformation. During this process, the annular damper continuously acts to eliminate elastic vibration.

[0050] This invention addresses the dynamic changes in the robot's working environment and the safety issues of human-robot interaction. Based on passive compliant control, it designs a robot joint compliant device that can buffer the impact force or torque generated by the contact and collision between the end effector and the target during robot task execution in both planar orthogonal and rotational directions. When the device is in operation, the elastic damping member of the outer ring can directly buffer the impact force in the orthogonal force system caused by the difference in speed between the end effector and the target, while the rotating spring plate and one-way bearing of the inner ring can buffer the corresponding impact torque in the rotational direction. The device can be divided into two layers: an outer shell fixedly connected to the next execution unit, and an internal rotor drive shaft fixedly connected to the robot joint output device. Through multiple sets of springs and a reasonably designed spring plate branch structure, it achieves bidirectional compliant buffering while reducing the strength requirements of individual springs.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A robot joint compliance device, characterized in that: Includes a connecting housing, the interior of which is provided with an internal conductor; The inner conductor is connected to the connecting shell by several sets of circumferentially distributed elastic damping components. The elastic damping components extend radially to buffer and unload the impact force in the straight direction. The internal conductor includes a coaxially mounted rotor drive shaft, on which rotating spring plates with opposite helical directions are coaxially mounted via one-way bearings. The one-way bearings of the rotating spring plates with opposite helical directions also have opposite helical directions, in order to eliminate elastic vibration. Each elastic damping component includes a buffer spring and a damping connecting post, with the buffer spring coaxially sleeved on the outer periphery of the damping connecting post.

2. The robot joint compliance device according to claim 1, characterized in that: The connecting shell is ring-shaped. The outer ends of the damping connecting columns are all fixed to the outer ring connector, and the inner ends of the damping connecting columns are all fixed to the inner ring connector. The outer ring connector is screwed to the connecting shell, and the inner ring connector is screwed to the inner conductor. The buffer spring is coaxially sleeved on the outer periphery of the damping connecting column between the outer ring connector and the inner ring connector.

3. The robot joint compliant device according to claim 1, characterized in that: The inner conductor, along the axial direction of the rotor drive shaft, includes, from one end to the other, a first end cover, a first inner conductor ring, a rotating spring plate, a spring plate blocking ring, a rotating spring plate, a second inner conductor ring, and a second end cover. It is then secured together by a number of circumferentially distributed bolts that pass through the first end cover, the first inner conductor ring, the rotating spring plate, the spring plate blocking ring, the rotating spring plate, the second inner conductor ring, and the second end cover in sequence from one end to the other, and are locked together by nuts.

4. The robot joint compliant device according to claim 3, characterized in that: The rotating spring plates on both ends of the spring plate blocking ring have opposite helical directions, and a blocking ring is coaxially fixed between the one-way bearings of the two rotating spring plates on the rotor drive shaft.

5. The robot joint compliant device according to claim 4, characterized in that: Each of the one-way bearings has a stepped retaining ring coaxially sleeved on the rotor drive shaft on its outer end face. Each of the stepped retaining rings has an annular damper abutting on its outer end face. The outer end face of one annular damper abuts against the damping concave surface of the inner end face of the first end cover and is adapted to its shape. The outer end face of the other annular damper abuts against the damping concave surface of the inner end face of the second end cover and is adapted to its shape.

6. The robot joint compliant device according to claim 1, characterized in that: Each rotating spring sheet includes an inner sheet and an outer ring. The inner sheet and the outer ring are connected as one unit by several circumferentially distributed arc-shaped elastic spokes. The several arc-shaped elastic spokes on the same rotating spring sheet have the same rotation direction.

7. The robot joint compliant device according to claim 6, characterized in that: The ends of the arc-shaped elastic spokes that connect to the inner sheet are provided with slots.

8. The robot joint compliance device according to claim 6, characterized in that: The end of the arc-shaped elastic spoke that connects to the outer ring body has a slot.

9. The robot joint compliance device according to claim 5, characterized in that: The annular damper is made of rubber.

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