Wedge-shaped mechanical joint

Abstract

The invention relates to the technical field of robot joints, and discloses a wedge-shaped mechanical joint which comprises a first connecting arm and a second connecting arm which are arranged up and down, and at least two connecting parts which are vertically arranged are arranged between the first connecting arm and the second connecting arm. Each connecting part and the adjacent connecting part are spliced together through the close end parts, each splicing surface is obliquely arranged and is of a circular surface structure, each connecting part is rotationally connected with the corresponding splicing surface, and the rotating mode is that each connecting part rotates around the axis of the corresponding splicing surface; the connecting part closest to the first connecting arm is rotationally connected with the first connecting arm, and the connecting part closest to the second connecting arm is rotationally connected with the second connecting arm; a plurality of connecting parts are used for replacing traditional ball joints, and compared with the prior art, the self-locking ball joint has the advantages of being high in structural strength, good in durability, capable of achieving a self-locking function and good in sealing performance.

Description

Technical Field

[0001] This invention relates to a wedge-shaped mechanical joint, belonging to the technical field of robot joints. Background Technology

[0002] Robotic joints are movable connections between different parts of a robot's body, much like human joints. Robotic joints enable robots to bend, twist, and move in various directions, allowing them to perform tasks and interact with their environment. Robotic joints come in many forms, including rotary joints in arms and legs, as well as robotic grippers and other tools. These joints are typically equipped with actuators, sensors, and mechanical components to facilitate controlled motion and precise positioning. Currently, the common types of robotic joints include: 1. Rotational joint; a joint that allows rotation along an axis, similar to the wrist or elbow in the human body.

[0003] 2. Translational joint; a joint that allows linear movement along an axis, similar to the extension and retraction of a human arm.

[0004] 3. Fixed joint: A joint that does not allow any relative movement and is mainly used to fix two parts.

[0005] 4. Compound joints: Joints that combine rotation and translation functions, enabling more complex movements.

[0006] 5. Ball joint: Allows rotational movement on three mutually perpendicular axes, similar to the human shoulder joint.

[0007] With the continuous development of robotics technology, the requirements for the flexibility of robot movement are also increasing. As a mechanical joint that can provide multi-directional movement, ball joints have been increasingly used in the field of robot joints due to their unique advantages.

[0008] A ball joint mainly consists of a ball head and a ball socket. By rotating the ball head within its fitted ball socket, it can perform three rotational degrees of freedom, thus meeting the requirements for robot mobility. However, traditional ball joints have the following problems in practical use: (1) Low structural strength and poor durability: In order to achieve flexible rotation of the ball head in the socket, there needs to be a certain gap between the ball head and the socket. This gap can easily lead to uneven force transmission on the ball joint when it is under stress. When the ball joint is under a large force, uneven force can easily lead to excessive stress in local areas of the ball joint, which will reduce the structural strength of the ball joint and make it prone to breakage.

[0009] (2) No self-locking function; when the ball joint is stationary, the contact area between the ball head and the ball socket is relatively small, and the contact point will change continuously with the rotation of the ball head, so a stable frictional torque cannot be formed to resist the action of external force, thus it cannot have a self-locking function.

[0010] (3) Poor sealing performance; in order not to affect the rotation of the ball head, the seal used cannot completely cover the gap between the ball head and the ball socket, which will cause dust, moisture and other impurities to easily enter the ball joint through this gap. Summary of the Invention

[0011] To address the aforementioned problems in the existing technology, the present invention provides a wedge-shaped mechanical joint.

[0012] The technical solution of the present invention is as follows: A wedge-shaped mechanical joint includes a first connecting arm and a second connecting arm arranged vertically. The first connecting arm is positioned above the second connecting arm. At least two connecting components are arranged vertically between the first and second connecting arms. Each connecting component is spliced ​​together with its adjacent connecting component through close-fitting ends. Each splicing surface is inclined and has a circular structure. Each connecting component is rotatably connected to its corresponding splicing surface, and the rotation is around the axis of the corresponding splicing surface. The connecting component closest to the first connecting arm is rotatably connected to the first connecting arm, and the connecting component closest to the second connecting arm is rotatably connected to the second connecting arm.

[0013] Furthermore, the acute angle formed between each splicing surface and the central axis of the corresponding connecting component is angle α.

[0014] Furthermore, there are two connecting components, namely a first connecting component and a second connecting component. The first connecting component is disposed above the second connecting component. The ends of the first connecting component and the second connecting component that are close to each other are both elliptical cylindrical structures with inclined end faces, and the inclined end faces are both circular structures. The ends of the first connecting component and the second connecting component that are close to each other are spliced ​​together through the inclined end faces to form a splicing surface. The end of the first connecting component that is close to the first connecting arm is cylindrical and rotatably connected to the first connecting arm. The end of the second connecting component that is close to the second connecting wall is cylindrical and rotatably connected to the second connecting arm. How the wedge-shaped mechanical joint is used: When adjusting the YOZ plane: the first connecting component rotates clockwise by an angle β around the axis of the first connecting arm, with the first connecting arm as a stationary reference; the second connecting component rotates counterclockwise by an angle δ around the axis of the splicing surface, with the first connecting component as a stationary reference; the second connecting arm rotates clockwise by an angle β around the second connecting component, with the second connecting component as a stationary reference; the acute angle formed between the axis of the first connecting component and the axis of the second connecting component is angle γ. When the first connecting component rotates clockwise around the axis of the first connecting arm by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm and the second connecting arm will not be limited to adjustment in the YOZ plane. Functional relationships are formed between angles γ and β, and between angles γ and δ.

[0015] Furthermore, the functional relationships between the γ angle and the β angle, and between the γ angle and the δ angle, are as follows:

[0016] When making the required adjustments to this wedge-shaped mechanical joint, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

[0017] Furthermore, there are three connecting components, namely a third connecting component, a fourth connecting component, and a fifth connecting component. The third connecting component, the fourth connecting component, and the fifth connecting component are arranged sequentially from top to bottom. The ends of the third connecting component and the fourth connecting component that are close to each other, as well as the ends of the fourth connecting component and the fifth connecting component that are close to each other, are all elliptical cylindrical structures with inclined end faces, and the inclined end faces are all circular structures. The ends of the third connecting component and the fourth connecting component that are close to each other are spliced ​​together through the inclined end faces, and the ends of the fourth connecting component and the fifth connecting component that are close to each other are spliced ​​together through the inclined end faces to form two splicing surfaces. The end of the third connecting component that is close to the first connecting arm is cylindrical and rotatably connected to the first connecting arm. The end of the fifth connecting component that is close to the second connecting arm is cylindrical and rotatably connected to the second connecting arm. How the wedge-shaped mechanical joint is used: When performing YOZ plane adjustment: the third connecting component rotates clockwise by an angle β around the axis of the first connecting arm, with the first connecting arm as a stationary reference; the fourth connecting component rotates counterclockwise by an angle δ around the axis of the splicing surface, with the third connecting component as a stationary reference; the fifth connecting component rotates clockwise by an angle δ around the axis of the splicing surface, with the fourth connecting component as a stationary reference; the second connecting arm rotates clockwise by an angle β around the axis of the fifth connecting component, with the fifth connecting component as a stationary reference; the acute angles formed between the axes of the third and fourth connecting components and between the axes of the fourth and fifth connecting components are both angles γ. When the third connecting component rotates clockwise around the axis of the first connecting arm by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm and the second connecting arm will not be limited to adjustment in the YOZ plane. Functional relationships are formed between angles γ and β, and between angles γ and δ.

[0018] Furthermore, the functional relationships between the γ angle and the β angle, and between the γ angle and the δ angle, are as follows:

[0019] When making the required adjustments to this wedge-shaped mechanical joint, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

[0020] Furthermore, there are two connecting components, namely a sixth connecting component and a seventh connecting component. The sixth connecting component is disposed above the seventh connecting component. The ends of the sixth and seventh connecting components that are close to each other are both spherical cap structures with inclined end faces, and the inclined end faces are both circular structures. The ends of the sixth and seventh connecting components that are close to each other are spliced ​​together through the inclined end faces to form a splicing surface. The end of the sixth connecting component that is close to the first connecting arm is cylindrical and rotatably connected to the first connecting arm. The end of the seventh connecting component that is close to the second connecting arm is cylindrical and rotatably connected to the second connecting arm. How the wedge-shaped mechanical joint is used: When adjusting the YOZ plane: the sixth connecting component rotates clockwise by an angle β around the axis of the first connecting arm with the first connecting arm as a stationary reference; the seventh connecting component rotates counterclockwise by an angle δ around the axis of the splicing surface with the sixth connecting component as a stationary reference; the second connecting arm rotates clockwise by an angle β around the seventh connecting component with the seventh connecting component as a stationary reference; the acute angle formed between the axis of the sixth connecting component and the axis of the seventh connecting component is angle γ; When the sixth connecting component rotates clockwise around the axis of the first connecting arm by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm and the second connecting arm will not be limited to adjustment in the YOZ plane. Functional relationships are formed between angles γ and β, and between angles γ and δ.

[0021] Furthermore, the functional relationships between the γ angle and the β angle, and between the γ angle and the δ angle, are as follows:

[0022] When making the required adjustments to this wedge-shaped mechanical joint, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

[0023] Furthermore, the number of connecting components is three, namely the eighth connecting component, the ninth connecting component, and the tenth connecting component. The eighth connecting component, the ninth connecting component, and the tenth connecting component are arranged sequentially from top to bottom. The ends of the eighth connecting component and the ninth connecting component that are close to each other, and the ends of the ninth connecting component and the tenth connecting component that are close to each other, are all set with a spherical cap structure with inclined end faces, and the inclined end faces are all circular. The ends of the eighth connecting component and the ninth connecting component that are close to each other are spliced ​​together through the inclined end faces, and the ends of the ninth connecting component and the tenth connecting component that are close to each other are spliced ​​together through the inclined end faces to form two splicing surfaces. The end of the eighth connecting component that is close to the first connecting arm is set with a cylindrical structure and is rotatably connected to the first connecting arm. The end of the tenth connecting component that is close to the second connecting arm is set with a cylindrical structure and is rotatably connected to the second connecting arm. How the wedge-shaped mechanical joint is used: When performing YOZ plane adjustment: the eighth connecting component rotates clockwise by an angle β around the axis of the first connecting arm, with the first connecting arm as a stationary reference; the ninth connecting component rotates counterclockwise by an angle δ around the axis of the splicing surface, with the eighth connecting component as a stationary reference; the tenth connecting component rotates clockwise by an angle δ around the axis of the splicing surface, with the ninth connecting component as a stationary reference; the second connecting arm rotates clockwise by an angle β around the axis of the tenth connecting component, with the tenth connecting component as a stationary reference; the acute angles formed between the axes of the eighth and ninth connecting components and between the axes of the ninth and tenth connecting components are both angles γ. When the eighth connecting component rotates clockwise around the axis of the first connecting arm by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm and the second connecting arm will not be limited to adjustment in the YOZ plane. Functional relationships are formed between angles γ and β, and between angles γ and δ.

[0024] Furthermore, the functional relationships between the γ angle and the β angle, and between the γ angle and the δ angle, are as follows:

[0025] When making the required adjustments to this wedge-shaped mechanical joint, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

[0026] The present invention has the following beneficial effects: 1. This invention sets up several connecting components, allowing the ends of adjacent connecting components to be spliced ​​together through an inclined circular splicing surface. Each connecting component can rotate around the axis of the corresponding splicing surface. In use, by rotating each connecting component around the corresponding splicing surface to a specific angle, the first and second connecting arms connected to it can swing in the three planes of XOZ, XOY, and YOZ, thereby simulating the swinging motion required by the human shoulder joint. Compared with traditional ball joints, the connection between adjacent connecting components is tighter, which can ensure the uniformity of force transmission, thereby improving the external force that this wedge-shaped mechanical joint can withstand. It has the advantages of high structural strength and good durability.

[0027] 2. This invention proposes to use several connecting parts instead of traditional ball joints. The splicing surfaces (i.e., contact surfaces) between adjacent connecting parts are all planar structures, which can provide sufficient contact area and stable contact points. This can generate a stable frictional torque to resist external forces when the parts are moving, thus enabling a self-locking function.

[0028] 3. This invention proposes to use several connecting parts to replace the traditional ball joint. Each connecting part can perform the functions of the traditional ball joint by rotating in a specific way. When the connecting parts rotate, they rotate in a planar manner around the splicing surface, without the need for multi-directional rotation like the ball head. This allows the seal to completely seal the gap between adjacent connecting parts. In addition, the planar structure also facilitates the installation of the seal. Compared with the prior art, it has the advantage of good sealing performance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the first structure after rotation according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the second structure after rotation according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the structure after rotation according to Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the structure of Embodiment 3 of the present invention; Figure 7 This is a schematic diagram of the structure after rotation according to Embodiment 3 of the present invention; Figure 8 This is a schematic diagram of the structure of Embodiment 4 of the present invention; Figure 9 This is a schematic diagram of the structure after rotation in Embodiment 4 of the present invention; Figure 10 The graph shows the functions β(t), δ(t), and γ(t) of the robotic arm swinging at a constant speed. Figure 11 The graph shows the function graphs of β(t), δ(t), and γ(t) of the robotic arm's variable-speed swing.

[0030] The reference numerals in the figure are as follows: 1. First connecting arm; 2. Second connecting arm; 3. Splicing surface; 4. First connecting component; 5. Second connecting component; 6. Third connecting component; 7. Fourth connecting component; 8. Fifth connecting component; 9. Sixth connecting component; 10. Seventh connecting component; 11. Eighth connecting component; 12. Ninth connecting component; 13. Tenth connecting component. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] Example 1: Please refer to Figures 1-3 This embodiment provides a wedge-shaped mechanical joint, including a first connecting arm 1 and a second connecting arm 2 arranged vertically. Both the first connecting arm 1 and the second connecting arm 2 are hollow mechanical arm structures, which can be common rectangular mechanical arms, cylindrical mechanical arms, etc., and can be selected according to actual conditions. The first connecting arm 1 is located above the second connecting arm 2. At least two connecting components are arranged vertically between the first connecting arm 1 and the second connecting arm 2. Each connecting component is spliced ​​together with its adjacent connecting component through close-fitting ends. Each splicing surface 3 is inclined and has a circular structure. The acute angle formed between each splicing surface 3 and the central axis of the corresponding connecting component is angle α, which is a constant and its specific value is determined according to the specific structure of the connecting component. Each connecting component is tightly fitted and rotatably connected to the corresponding splicing surface 3, and the rotation is around the axis of the corresponding splicing surface 3. The connecting component closest to the first connecting arm 1 is rotatably connected to the first connecting arm 1, and the connecting component closest to the second connecting arm 2 is rotatably connected to the second connecting arm 2.

[0033] In this embodiment, there are two connecting components, specifically a first connecting component 4 and a second connecting component 5. The first connecting component 4 is positioned above the second connecting component 5. The ends of both the first connecting component 4 and the second connecting component 5 that are close to each other are elliptical cylindrical structures with inclined end faces, and both inclined end faces are circular. That is, the connecting components in this embodiment are actually elliptical cylinders with elliptical cross-sections obliquely cut into the first connecting component 4 and the second connecting component 5, with both having circular oblique cross-sections. The ends of the first connecting component 4 and the second connecting component 5 that are close to each other are tightly spliced ​​together through the inclined end faces and rotated to form a splicing surface 3. The end of the first connecting component 4 that is close to the first connecting arm 1 is cylindrical and rotatably connected to the first connecting arm 1. The end of the second connecting component 5 that is close to the second connecting wall is cylindrical and rotatably connected to the second connecting arm 2. Since the cross-sections of the first connecting component 4 and the first connecting arm 1 are different, a transition section can be provided to connect them for easier connection. Similarly, the second connecting component 5 can also be provided with a transition section to connect with the second connecting arm 2.

[0034] The wedge-shaped mechanical joint is used as described in this embodiment: When adjusting the YOZ plane: the first connecting component 4 rotates clockwise by an angle β around the axis of the first connecting arm 1 with the first connecting arm 1 as a stationary reference; the second connecting component 5 rotates counterclockwise by an angle δ around the axis of the splicing surface 3 with the first connecting component 4 as a stationary reference; the second connecting arm 2 rotates clockwise by an angle β around the second connecting component 5 with the second connecting component 5 as a stationary reference; the acute angle formed between the axis of the first connecting component 4 and the axis of the second connecting component 5 is angle γ; When the first connecting component 4 rotates clockwise around the axis of the first connecting arm 1 by an angle β and an offset value β' is added so that β = β(γ) + β', the first connecting arm 1 and the second connecting arm 2 will not be limited to adjustment in the YOZ plane. The offset value β' is the specific rotation angle in the XOY plane or XOZ plane according to the actual adjustment requirements.

[0035] Functional relationships are formed between angles γ and β, and between angles γ and δ.

[0036] In this embodiment, the functional relationships between angles γ and β, and between angles γ and δ, are as follows:

[0037] When making adjustments, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

[0038] When adjusting the YOZ plane, the β and δ angles obtained by substituting the γ angle are the angles required for adjusting this wedge-shaped mechanical joint in the YOZ plane.

[0039] With the aforementioned setup and the above functional relationship, the first connecting arm 1 and the second connecting arm 2 can swing freely in the YOZ plane, thereby obtaining the swinging ability of a knee joint. When needed, a new β angle is formed by adding an offset value β' to the β angle, i.e., β = β(γ) + β'. Then, by substituting the new β angle into the above functional relationship, the first connecting arm 1 and the second connecting arm 2 can also swing freely in the XOY plane and the XOZ plane, thereby obtaining the ability to swing freely within a hemispherical region like a shoulder joint. This can effectively replace the traditional ball joint.

[0040] Example 2: Please refer to Figure 4 and Figure 5 This embodiment provides a wedge-shaped mechanical joint, which differs from Embodiment 1 in that the connecting components are different. In this embodiment, there are three connecting components: a third connecting component 6, a fourth connecting component 7, and a fifth connecting component 8. These three components are arranged sequentially from top to bottom. The ends of the third connecting component 6 and the fourth connecting component 7 that are close to each other, as well as the ends of the fourth connecting component 7 and the fifth connecting component 8 that are close to each other, are all elliptical cylindrical structures with inclined end faces, and the inclined end faces are all circular structures. That is, the connecting components in this embodiment are actually elliptical cylinders with elliptical cross-sections obliquely cut into the third connecting component 6, the fourth connecting component 7, and the fifth connecting component 8. The ends of the third connecting component 6 and the fourth connecting component 7 that are close to each other are tightly spliced ​​together through the inclined end faces and rotated to each other, and the ends of the fourth connecting component 7 and the fifth connecting component 8 that are close to each other are tightly spliced ​​together through the inclined end faces and rotated to each other to form two splicing surfaces 3. The third connecting component 6 is cylindrical and rotatably connected to the first connecting arm 1, located near its end. Similarly, the fifth connecting component 8 is cylindrical and rotatably connected to the second connecting arm 2, located near its end. Since the cross-sections of the third connecting component 6 and the first connecting arm 1 are different, a transition section can be provided to facilitate their connection. Likewise, the fifth connecting component 8 can also have a transition section to connect to the second connecting arm 2.

[0041] The wedge-shaped mechanical joint is used as described in this embodiment: When performing YOZ plane adjustment: the third connecting component 6 rotates clockwise by an angle β around the axis of the first connecting arm 1 with the first connecting arm 1 as a stationary reference; the fourth connecting component 7 rotates counterclockwise by an angle δ around the axis of the splicing surface 3 with the third connecting component 6 as a stationary reference; the fifth connecting component 8 rotates clockwise by an angle δ around the axis of the splicing surface 3 with the fourth connecting component 7 as a stationary reference; the second connecting arm 2 rotates clockwise by an angle β around the axis of the fifth connecting component 8 with the fifth connecting component 8 as a stationary reference; the acute angles formed between the axis of the third connecting component 6 and the axis of the fourth connecting component 7, and between the axis of the fourth connecting component 7 and the axis of the fifth connecting component 8, are both angles γ. When the third connecting component 6 rotates clockwise around the axis of the first connecting arm 1 by an angle β, and an offset value β' is added so that β = β(γ) + β', the first connecting arm 1 and the second connecting arm 2 will no longer be limited to adjustment in the YOZ plane. The offset value β' is the specific rotation angle in the XOY plane or XOZ plane according to the actual adjustment requirements.

[0042] A functional relationship is formed between angles γ and β, and between angles γ and δ. This functional relationship is the same as that provided in Embodiment 1. When needed, a new angle β is formed by adding an offset value β' to angle β, i.e., β = β(γ) + β'. The new angle β is then substituted into this functional relationship, which allows the first connecting arm 1 and the second connecting arm 2 to swing freely in the XOY plane and the XOZ plane. This allows the wedge-shaped mechanical joint provided in this embodiment to obtain the same capabilities as in Embodiment 1, thus effectively replacing the traditional ball joint.

[0043] Example 3: Please refer to Figure 6 and Figure 7 This embodiment provides a wedge-shaped mechanical joint, which differs from Embodiment 1 in that the connecting components are different. In this embodiment, there are two connecting components, namely a sixth connecting component 9 and a seventh connecting component 10. The sixth connecting component 9 is disposed above the seventh connecting component 10. The ends of the sixth connecting component 9 and the seventh connecting component 10 that are close to each other are both spherical cap structures with inclined end faces, and the inclined end faces are both circular. That is, the connecting component in this embodiment is actually a cylinder inserted into a sphere to form an assembly, with the central axis of the cylinder passing through the center of the sphere. The sphere of the assembly is obliquely cut to form the sixth connecting component 9 and the seventh connecting component 10, and their oblique sections are circular. The ends of the sixth connecting component 9 and the seventh connecting component 10 that are close to each other are tightly spliced ​​together through the inclined end faces and rotated to form a splicing surface 3. The end of the sixth connecting component 9 that is close to the first connecting arm 1 is cylindrical and rotated to be connected to the first connecting arm 1. The end of the seventh connecting component 10 that is close to the second connecting arm 2 is cylindrical and rotated to be connected to the second connecting arm 2.

[0044] The wedge-shaped mechanical joint is used as described in this embodiment: When adjusting the YOZ plane: the sixth connecting component 9 rotates clockwise by an angle β around the axis of the first connecting arm 1 with the first connecting arm 1 as a stationary reference; the seventh connecting component 10 rotates counterclockwise by an angle δ around the axis of the splicing surface 3 with the sixth connecting component 9 as a stationary reference; the second connecting arm 2 rotates clockwise by an angle β around the seventh connecting component 10 with the seventh connecting component 10 as a stationary reference; the acute angle formed between the axis of the sixth connecting component 9 and the axis of the seventh connecting component 10 is angle γ; When the sixth connecting component 9 rotates clockwise around the axis of the first connecting arm 1 by an angle β, and an offset value β' is added so that β = β(γ) + β', the first connecting arm 1 and the second connecting arm 2 will no longer be limited to adjustment in the YOZ plane. The offset value β' is the specific rotation angle in the XOY plane or XOZ plane according to the actual adjustment requirements.

[0045] A functional relationship is formed between angle γ and angle β, and between angle γ and angle δ. This functional relationship is the same as that provided in Embodiment 1. When needed, a new angle β is formed by adding an offset value β' to angle β, i.e., β = β(γ) + β'. The new angle β is then substituted into this functional relationship, which allows the first connecting arm 1 and the second connecting arm 2 to swing freely in the XOY plane and the XOZ plane. This allows the wedge-shaped mechanical joint provided in this embodiment to also obtain the same capabilities as in Embodiment 1, thus effectively replacing the traditional ball joint.

[0046] Example 4: Please refer to Figure 8 and Figure 9This embodiment provides a wedge-shaped mechanical joint, which differs from Embodiment 1 in that the connecting components are different. In this embodiment, there are three connecting components: an eighth connecting component 11, a ninth connecting component 12, and a tenth connecting component 13. These components are arranged sequentially from top to bottom. The ends of the eighth connecting component 11 and the ninth connecting component 12, and the ends of the ninth connecting component 12 and the tenth connecting component 13 that are close to each other, are all spherical cap structures with inclined end faces, and these inclined end faces are all circular. In other words, the connecting components in this embodiment are actually formed by eccentrically inserting a cylinder into a sphere to form an assembly, where the central axis of the cylinder cannot pass through the center of the sphere. The sphere of this assembly is obliquely cut in two directions to form the eighth connecting component 11, the ninth connecting component 12, and the tenth connecting component 13. The oblique cut surfaces between the eighth connecting component 11, the ninth connecting component 12, and the tenth connecting component 13 are circular. The ends of the eighth connecting component 11 and the ninth connecting component 12 that are close to each other are tightly spliced ​​together by inclined end faces and rotated together to form two splicing surfaces 3. In this embodiment, the eighth connecting component 11 and the tenth connecting component 13 are composed of a cylinder and a partial sphere, and the axis of the cylinder must pass through the center of the splicing surface 3. The end of the eighth connecting component 11 that is close to the first connecting arm 1 is cylindrical and rotated together with the first connecting arm 1, and the end of the tenth connecting component 13 that is close to the second connecting arm 2 is cylindrical and rotated together with the second connecting arm 2.

[0047] The wedge-shaped mechanical joint is used as described in this embodiment: During YOZ plane adjustment: the eighth connecting component 11 rotates clockwise by an angle β around the axis of the first connecting arm 1, with the first connecting arm 1 as a stationary reference; the ninth connecting component 12 rotates counterclockwise by an angle δ around the axis of the splicing surface 3, with the eighth connecting component 11 as a stationary reference; the tenth connecting component 13 rotates clockwise by an angle δ around the axis of the splicing surface 3, with the ninth connecting component 12 as a stationary reference; and the second connecting arm 2 rotates clockwise by an angle β around the axis of the tenth connecting component 13, with the tenth connecting component 13 as a stationary reference. The acute angles formed between the axes of the eighth connecting component 11 and the ninth connecting component 12, and between the axes of the ninth connecting component 12 and the tenth connecting component 13, are both angles γ.

[0048] When the eighth connecting component 11 rotates clockwise around the axis of the first connecting arm 1 by an angle β, and an offset value β' is added to make β = β(γ) + β', the first connecting arm 1 and the second connecting arm 2 will no longer be limited to adjustment in the YOZ plane. The offset value β' is the specific rotation angle in the XOY plane or XOZ plane according to the actual adjustment requirements.

[0049] A functional relationship is formed between angle γ and angle β, and between angle γ and angle δ. This functional relationship is the same as that provided in Embodiment 1. When needed, a new angle β is formed by adding an offset value β' to angle β, i.e., β = β(γ) + β'. The new angle β is then substituted into this functional relationship, which allows the first connecting arm 1 and the second connecting arm 2 to swing freely in the XOY plane and the XOZ plane. This allows the wedge-shaped mechanical joint provided in this embodiment to also obtain the same capabilities as in Embodiment 1, thus effectively replacing the traditional ball joint.

[0050] The aforementioned embodiments one through four provide four types of wedge-shaped mechanical joints, which can be categorized into two-segment elliptical cross-section tubular wedge joints, three-segment elliptical cross-section tubular wedge joints, two-segment spherical wedge joints, and three-segment spherical wedge joints based on their specific structures. All four types of wedge joints possess the ability to swing freely within a hemispherical region, effectively replacing traditional ball joints. Furthermore, due to the different structures of these four wedge-shaped mechanical joints, their range of motion, flexibility, and load-bearing capacity will vary. For example, the two-segment structure is relatively simple and suitable for scenarios requiring a relatively small range of motion and simple movements; while the three-segment structure can provide more complex and wider motion trajectories. The elliptical cross-section tubular wedge joint has better load distribution capabilities in the three-axis direction and is suitable for scenarios requiring the bearing of large lateral forces; while the spherical wedge joint performs better in all-around load bearing and is suitable for applications requiring the bearing of complex loads in multiple directions. This allows operators to select wedge joints with different structures according to actual needs, ensuring good scenario-specific application. In practical use, power components such as motors and reduction gears can be arranged in the hollow structure of the first connecting arm 1 and the second connecting arm 2, so that the power source does not have to be placed at the joint position.

[0051] The following will use the wedge-shaped mechanical joint provided in Embodiment 1 as an example to illustrate the derivation and calculation process of the functional relationship. For ease of subsequent discussion, the functional relationship between angle γ and angle β will be taken as Function 1, and the functional relationship between angle γ and angle δ will be taken as Function 2.

[0052] Based on the biomimetic movement characteristics of finger joints, elbow joints, and knee joints, the upper and lower arms of the arm swing within a single plane. To conform to these biomimetic movement characteristics, functions 1 and 2 are derived to allow the first and second connecting arms of the robotic arm to swing within the YOZ plane. However, to achieve the ability to swing freely within a hemispherical region, similar to the shoulder joint, an offset value β' can be added to the rotation angle β of the above two functions. This allows the upper and lower arms to swing freely within a hemispherical region, rather than being confined to the YOZ plane.

[0053] Let the central axis of the first connecting component be called line A1, the normal to the inclined end face (circular surface) of the first connecting component be called line A2, the surface containing lines A1 and A2 be called surface A1-2, and the inclined end face of the first connecting component be called the inclined section (circular surface) A2. The angle formed by the inclined section A2 and line A1 is angle α, which is a constant. Since we only care about the direction of lines A1 (central axis) and A2 (normal), their length can be set to unit 1.

[0054] The central axis of the second connecting component is called line B1, the normal to the inclined end face (circular surface) of the second connecting component is called line B2, the surface containing lines B1 and B2 is called surface B1-2, and the inclined end face of the second connecting component is called the inclined section (circular surface) of B2. The angle formed by the inclined section of B2 and line B1 is angle α, which is a constant. Since only the direction of lines B1 (central axis) and B2 (normal) is of concern, their length can be assumed to be unit 1.

[0055] Place the first connecting component and the second connecting component in a spatial rectangular coordinate system. Before the wedge-shaped mechanical joint moves, the following relationship exists: The central axis A1 of the first connecting component can be represented by a unit vector. Express.

[0056] The normal line A2 of the inclined end face of the first connecting component can be represented by a unit vector. Express.

[0057] Regardless of how the first connecting component rotates, the angle between lines A1 and A2 remains constant; this angle value is... ,Right now

[0058] The plane containing the central axis A1 and normal A2 of the first connecting component is plane A1-2, and its equation is y=0.

[0059] The central axis B1 of the second connecting component can be represented by a unit vector. Express.

[0060] The normal line B2 of the inclined end face of the second connecting component can be represented by a unit vector. Express.

[0061] Regardless of how the second connecting component rotates, the angle between lines B1 and B2 remains constant; this angle value is... ,Right now

[0062] The plane containing the central axis B1 and normal B2 of the second connecting component is plane B1-2, and its equation is y=0.

[0063] The first connecting component rotates clockwise by an angle β around the central axis A1, while the second connecting component rotates counterclockwise by an angle δ around the normal B2, causing the wedge-shaped mechanical joint to form a bend angle γ in the YOZ plane. This bend angle γ is the supplementary angle ε between the central axes A1 and B1, where ε = 180° - γ.

[0064] ① Based on the biomimetic motion characteristics of finger / knee joints, the first and second connecting arms of the robotic arm need to swing within a plane, which means that the central axis A1 of the first connecting component can be represented by a unit vector. The constant expressed; the central axis B1 of the second connecting component can be represented by a unit vector. The variables are expressed. This allows the first and second connecting parts to swing only in the YOZ plane, with a swing angle of γ.

[0065] ② When the first connecting component rotates clockwise around the central axis A1, the angle β reaches its maximum value. The second connecting component rotates counterclockwise by an angle δ around the normal B2 until it reaches its maximum value. The first and second connecting arms of the robotic arm reach their maximum swing angle γ in the YOZ plane. The angle ε between the central axis A1 and the central axis B1 reaches its minimum value. The following are the value ranges for each angle variable:

[0066] ③ When the first connecting component rotates clockwise by an angle β around the central axis A1, the normal line A2 of the inclined end face of the first connecting component can be represented by a unit vector. It is indicated that normal A2 and normal B2 have opposite directions, therefore normal B2 can be represented by a unit vector. express.

[0067] ④ According to points ① and ③ above, regardless of how the second connecting component rotates, the angle between lines B1 and B2 is constant, and this angle value is... ,Right now:

[0068] ⑤ Solve the equation in section ④ above to calculate the functional relationship between the rotation angle β and the variable γ:

[0069] ⑥ When the first and second connecting arms of the robotic arm are required to swing at an angle γ in the YOZ plane, the first connecting component rotates clockwise around the central axis A1 by an angle β, which is obtained from the above function 1.

[0070] Now we need to solve for the function 2 of the second connecting component rotating counterclockwise by angle δ around the normal B2 as a function of the independent variable angle γ.

[0071] 1. The plane containing the central axis A1 and normal A2 of the first connecting component is called plane A1-2. Let the normal to plane A1-2 be normal A3. They have the following relationship: A1, A2, and A3 are all unit vectors. The angle between the central axis A1 and the normal A2 of the first connecting component is constant. .

[0072]

[0073] 2. The plane containing the central axis B1 and normal B2 of the second connecting component is called plane B1-2. Let the normal to plane B1-2 be normal B3. They have the following relationship: B1, B2, and B3 are all unit vectors. The angle between the central axis B1 and the normal B2 of the second connecting component is constant. .

[0074]

[0075] 3. The second connecting component rotates counterclockwise by an angle δ around normal B2, and has the following relationship with normals A3 of surface A1-2 and B3 of surface B1-2:

[0076] 4. Substituting the relationship between β and variable γ described in function 1 into the above cosδ equation, we can obtain:

[0077] 5. Express the function in section 4 above using the inverse cosine function as:

[0078] (8) In summary, in order for the wedge-shaped mechanical joint to form a bend angle γ in the YOZ plane, the first connecting component rotates clockwise by an angle β around the central axis A1 according to the β-γ relationship described by function 1, while the second connecting component rotates counterclockwise by an angle δ around the normal B2 according to the δ-γ relationship described by function 2. Various liquid and gas pipes and cables need to be installed inside the wedge-shaped mechanical joint to connect the first and second connecting arms. In order to prevent the liquid and gas pipes and cables from twisting during joint movement, that is, the first and second connecting arms do not twist relative to each other except for bending by an angle γ, the second connecting arm needs to rotate clockwise by an angle ζ relative to the second connecting component of the joint.

[0079] ① When the joint is not bent, i.e., γ=0; β=0; δ=0, the plane containing the central axis B1 and normal B2 of the second connecting component is plane B1-2. Let the normal to plane B1-2 be normal B3. , and is perpendicular to the positive direction of the X-axis of the coordinate system, that is As shown below:

[0080] ② When the joint is fully bent, i.e., γ=π-2α; β=π / 2; δ=π, and the positive direction of the X-axis In the same direction, that is

[0081]

[0082] ③ Relative to the X-axis, when the second connecting component rotates counterclockwise The second connecting arm rotates clockwise in the opposite direction by ζ, so that the liquid and gas pipes and cables inside the first and second connecting arms do not twist during joint movement.

[0083]

[0084] ④ It can be proven that function 1 and function 3 are equal.

[0085]

[0086] List the β, δ, and ζ functions in an Excel spreadsheet, as shown in Table 1 below. By changing the value of γ, it is eventually found that β equals ζ.

[0087] Table 1. β, δ, ζ functions

[0088] (9) When the robotic arm moves, it may be required to swing at a constant speed or swing at a slow-fast-slow speed, that is, we expect its swing angle-time function to be a function γ(t). Then, the clockwise rotation angle β of the first connecting part around the central axis A1 can be denoted as the function β(t); the counterclockwise rotation angle δ of the second connecting part around the normal B2 can be denoted as the function δ(t). The functions β(t), δ(t) and γ(t) are shown below ( (This means: the robotic arm starts moving when t=0; the robotic arm ends moving when t=T).

[0089] ① When the robotic arm is required to swing at a constant speed, the swing angle-time function γ(t) = ωt, where ω is a constant, should be plotted as follows: Figure 10 The functions β(t), δ(t), and γ(t) represent the uniform swing of the robotic arm.

[0090] ② The robotic arm is required to perform a slow-fast-slow oscillation, with the oscillation angle as a function of time:

[0091] Plot the functions β(t), δ(t), and γ(t), as follows: Figure 11 The functions β(t), δ(t), and γ(t) of the robotic arm's variable-speed swing are shown.

[0092] The robotic arm is required to move according to an arbitrary function γ(t). Based on the above relationship, the corresponding functions β(t) and δ(t) can be obtained to achieve this movement.

[0093] When the rotation angle β is added with an offset value β', the first and second connecting arms are not limited to swinging in the YOZ plane. The wedge-shaped mechanical joint can swing freely in the hemispherical region, just like the human shoulder joint.

[0094] ① To ensure that the first and second connecting arms are not limited to swinging in the YOZ plane, the angle β of the clockwise rotation of the first connecting component about the axis of the first connecting arm is determined by the following formula.

[0095] Where β(γ) is the function 1 mentioned above; by adding an offset value β' to the β angle to form a new β angle, the first connecting arm 1 and the second connecting arm 2 can also swing freely in the XOY plane and the XOZ plane. Where β'=ωt, ω represents the angular velocity of the swing, that is, the swing period is (2π / ω), and t represents the time variable. In this way, the first connecting arm will drive the second connecting arm to perform conical swing with a period of (2π / ω).

[0096] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A wedge-shaped mechanical joint, characterized in that: It includes a first connecting arm (1) and a second connecting arm (2) arranged vertically. The first connecting arm (1) is located above the second connecting arm (2). At least two connecting parts are arranged vertically between the first connecting arm (1) and the second connecting arm (2). Each connecting part is spliced ​​together with its adjacent connecting part by the end that is close to each other. Each splicing surface (3) is inclined and has a circular structure. Each connecting part is rotatably connected to the corresponding splicing surface (3), and the rotation is around the axis of the corresponding splicing surface (3). The connecting part closest to the first connecting arm (1) is rotatably connected to the first connecting arm (1), and the connecting part closest to the second connecting arm (2) is rotatably connected to the second connecting arm (2).

2. A wedge-shaped mechanical joint according to claim 1, characterized in that: The acute angle formed between each splicing surface (3) and the central axis of the corresponding connecting component is an angle α.

3. A wedge-shaped mechanical joint according to claim 2, characterized in that: The number of connecting parts is two, namely a first connecting part (4) and a second connecting part (5). The first connecting part (4) is located above the second connecting part (5). The ends of the first connecting part (4) and the second connecting part (5) that are close to each other are both elliptical cylindrical structures with inclined end faces and the inclined end faces are both circular structures. The ends of the first connecting part (4) and the second connecting part (5) that are close to each other are spliced ​​together through the inclined end faces to form a splicing surface (3). The end of the first connecting part (4) that is close to the first connecting arm (1) is cylindrical and is rotatably connected to the first connecting arm (1). The end of the second connecting part (5) that is close to the second connecting wall is cylindrical and is rotatably connected to the second connecting arm (2). How the wedge-shaped mechanical joint is used: When performing YOZ plane adjustment: the first connecting component (4) rotates clockwise by an angle β around the axis of the first connecting arm (1) with the first connecting arm (1) as a stationary reference; the second connecting component (5) rotates counterclockwise by an angle δ around the axis of the splicing surface (3) with the first connecting component (4) as a stationary reference; the second connecting arm (2) rotates clockwise by an angle β around the axis of the second connecting component (5) with the second connecting component (5) as a stationary reference; the acute angle formed between the axis of the first connecting component (4) and the axis of the second connecting component (5) is angle γ; When the first connecting component (4) rotates clockwise around the axis of the first connecting arm (1) by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm (1) and the second connecting arm (2) will not be limited to adjustment in the YOZ plane; Functional relationships are formed between angles γ and β, and between angles γ and δ.

4. A wedge-shaped mechanical joint according to claim 3, characterized in that: The functional relationships between angles γ and β, and between angles γ and δ, are shown below: When making adjustments, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

5. A wedge-shaped mechanical joint according to claim 2, characterized in that: The number of connecting parts is three, namely the third connecting part (6), the fourth connecting part (7) and the fifth connecting part (8). The third connecting part (6), the fourth connecting part (7) and the fifth connecting part (8) are arranged in order from top to bottom. The ends of the third connecting part (6) and the fourth connecting part (7) that are close to each other, and the ends of the fourth connecting part (7) and the fifth connecting part (8) that are close to each other are all set in an elliptical cylindrical structure with inclined end faces and the inclined end faces are all circular structures. The ends of the third connecting part (6) and the fourth connecting part (7) that are close to each other are spliced ​​through the inclined end faces, and the ends of the fourth connecting part (7) and the fifth connecting part (8) that are close to each other are spliced ​​through the inclined end faces to form two splicing surfaces (3). The end of the third connecting part (6) that is close to the first connecting arm (1) is set in a cylindrical structure and is rotatably connected to the first connecting arm (1). The end of the fifth connecting part (8) that is close to the second connecting arm (2) is set in a cylindrical structure and is rotatably connected to the second connecting arm (2). How the wedge-shaped mechanical joint is used: When performing YOZ plane adjustment: the third connecting component (6) rotates clockwise by an angle β around the axis of the first connecting arm (1) with the first connecting arm (1) as a stationary reference; the fourth connecting component (7) rotates counterclockwise by an angle δ around the axis of the splicing surface (3) with the third connecting component (6) as a stationary reference; the fifth connecting component (8) rotates clockwise by an angle δ around the axis of the splicing surface (3) with the fourth connecting component (7) as a stationary reference; the second connecting arm (2) rotates clockwise by an angle β around the axis of the fifth connecting component (8) with the fifth connecting component (8) as a stationary reference; the acute angle formed between the axis of the third connecting component (6) and the axis of the fourth connecting component (7) and the acute angle formed between the axis of the fourth connecting component (7) and the axis of the fifth connecting component (8) are both angles γ. When the third connecting component (6) rotates clockwise around the axis of the first connecting arm (1) by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm (1) and the second connecting arm (2) will not be limited to adjustment in the YOZ plane; Functional relationships are formed between angles γ and β, and between angles γ and δ.

6. A wedge-shaped mechanical joint according to claim 5, characterized in that: The functional relationships between angles γ and β, and between angles γ and δ, are shown below: When making adjustments, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

7. A wedge-shaped mechanical joint according to claim 2, characterized in that: The number of connecting parts is two, namely the sixth connecting part (9) and the seventh connecting part (10). The sixth connecting part (9) is located above the seventh connecting part (10). The ends of the sixth connecting part (9) and the seventh connecting part (10) that are close to each other are both set with a spherical cap structure with an inclined end face and the inclined end face is a circular structure. The ends of the sixth connecting part (9) and the seventh connecting part (10) that are close to each other are spliced ​​together through the inclined end face to form a splicing surface (3). The end of the sixth connecting part (9) that is close to the first connecting arm (1) is set with a cylindrical structure and is rotatably connected to the first connecting arm (1). The end of the seventh connecting part (10) that is close to the second connecting arm (2) is set with a cylindrical structure and is rotatably connected to the second connecting arm (2). How the wedge-shaped mechanical joint is used: When performing YOZ plane adjustment: the sixth connecting component (9) rotates clockwise by an angle β around the axis of the first connecting arm (1) with the first connecting arm (1) as a stationary reference; the seventh connecting component (10) rotates counterclockwise by an angle δ around the axis of the splicing surface (3) with the sixth connecting component (9) as a stationary reference; the second connecting arm (2) rotates clockwise by an angle β around the axis of the seventh connecting component (10) with the seventh connecting component (10) as a stationary reference; the acute angle formed between the axis of the sixth connecting component (9) and the axis of the seventh connecting component (10) is angle γ; When the sixth connecting component (9) rotates clockwise around the axis of the first connecting arm (1) by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm (1) and the second connecting arm (2) will not be limited to adjustment in the YOZ plane; Functional relationships are formed between angles γ and β, and between angles γ and δ.

8. A wedge-shaped mechanical joint according to claim 7, characterized in that: The functional relationships formed between angle γ and angle β, angle γ and angle δ, and angle γ and the new angle β are shown below: When making adjustments, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

9. A wedge-shaped mechanical joint according to claim 2, characterized in that: The number of connecting components is three, namely the eighth connecting component (11), the ninth connecting component (12), and the tenth connecting component (13). The eighth connecting component (11), the ninth connecting component (12), and the tenth connecting component (13) are arranged sequentially from top to bottom. The ends of the eighth connecting component (11) and the ninth connecting component (12) that are close to each other, and the ends of the ninth connecting component (12) and the tenth connecting component (13) that are close to each other, are all set with spherical cap structures with inclined end faces, and the inclined end faces are all circular structures. The eighth connecting component... (11) The ends that are close to the ninth connecting component (12) are spliced ​​together by an inclined end face. The ends that are close to the ninth connecting component (12) and the tenth connecting component (13) are spliced ​​together by an inclined end face to form two splicing surfaces (3). The end of the eighth connecting component (11) that is close to the first connecting arm (1) is set in a cylindrical structure and is rotatably connected to the first connecting arm (1). The end of the tenth connecting component (13) that is close to the second connecting arm (2) is set in a cylindrical structure and is rotatably connected to the second connecting arm (2). How the wedge-shaped mechanical joint is used: When adjusting the YOZ plane: the eighth connecting component (11) rotates clockwise by an angle β around the axis of the first connecting arm (1) with the first connecting arm (1) as a stationary reference; the ninth connecting component (12) rotates counterclockwise by an angle δ around the axis of the splicing surface (3) with the eighth connecting component (11) as a stationary reference; the tenth connecting component (13) rotates clockwise by an angle δ around the axis of the splicing surface (3) with the ninth connecting component (12) as a stationary reference; the second connecting arm (2) rotates clockwise by an angle β around the axis of the tenth connecting component (13) with the tenth connecting component (13) as a stationary reference; the acute angle formed between the axis of the eighth connecting component (11) and the axis of the ninth connecting component (12) and the acute angle formed between the axis of the ninth connecting component (12) and the axis of the tenth connecting component (13) are both angles γ. When the eighth connecting component (11) rotates clockwise around the axis of the first connecting arm (1) by an angle β plus an offset value β' such that β=β(γ)+β', the first connecting arm (1) and the second connecting arm (2) will not be limited to adjustment in the YOZ plane; Functional relationships are formed between angles γ and β, and between angles γ and δ.

10. A wedge-shaped mechanical joint according to claim 9, characterized in that: The functional relationships between angles γ and β, and between angles γ and δ, are shown below: When adjusting the YOZ plane, the β angle and δ angle can both be expressed as the β angle and δ angle in the above functional relationship, and the corresponding γ angle can be calculated.

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