Variable-load self-adaptive mechanical claw

Abstract

The invention discloses a variable-load self-adaptive mechanical gripper, and relates to the technical field of mechanical grippers. The transmission shaft penetrates through the bottom plate, an upper gear and a lower gear are installed on the top of the transmission shaft, and the bottom end of the transmission shaft is connected with an external driving motor. The fixed side clamping jaw is provided with a rack meshed with the upper gear. The bottom of the rack is slidably connected with a guide rail through a sliding block. The sliding blocks are connected with the racks through anti-interference spring block assemblies, the worm and gear driving assembly controls the rotating side clamping jaws to rotate, and the two clamping jaw heads are installed above the two racks. The two clamping jaw structures are divided into the fixed side clamping jaw structure and the rotating side clamping jaw structure, opening and closing actions are controlled through positive and negative rotation of a transmission shaft, the rotating side clamping jaw is provided with an anti-interference spring block assembly to guarantee stable operation in the angle adjusting process, and different waste rocks are effectively grabbed in combination with power changes of a driving motor and configuration changes of two clamping jaw heads.

Description

Technical Field

[0001] This invention relates to the field of mechanical gripper technology, specifically an adaptive mechanical gripper with variable load. Background Technology

[0002] During coal mining, raw coal contains a large amount of gangue, which is rock that is associated with coal during its formation. Its main components include claystone and sandstone. In underground coal seam mining, the coal and gangue extracted by mechanized mining machines are mixed together. With the large-scale mining of coal resources, the development of gangue beneficiation technology has become particularly important to meet the different quality requirements of users. The presence of a large amount of gangue reduces coal quality because gangue has extremely low or even no calorific value, and it also increases the costs of coal transportation and storage. If gangue is not beneficiated, it will absorb heat during coal combustion, leading to a decrease in coal utilization efficiency. Therefore, it is necessary to effectively reduce the ash content of coal through gangue beneficiation to improve coal quality.

[0003] Traditional coal mine gangue sorting has long relied on manual labor, requiring workers to use rakes to sort the gangue alongside high-speed conveyor belts. This method is inefficient and labor-intensive, with a gangue removal rate of only 10% to 20%. With the development of industrial automation, the emergence of gangue sorting mechanical claws has followed this trend. These claws can be installed on automated gangue sorting equipment and, through program control, achieve precise gangue gripping and separation. This not only reduces labor costs and the labor intensity of workers but also greatly improves the efficiency and accuracy of gangue sorting. The gangue removal rate of intelligent mechanical claw systems can reach over 95%.

[0004] However, most of the mechanical grippers currently used in gangue sorting technology are single-function. Grasping grippers have high requirements for the robot's load-bearing capacity and obvious drawbacks. For example, early mechanical sorting technologies used X-ray recognition + air blowing sorting and single-function grippers. Single-function grippers only support one action: grasping or separating, making it difficult to adapt to irregular gangue shapes and densely distributed scenarios. Later, multi-functional multi-link mechanical gripper systems emerged, using worm gear transmission and cylinders to control four sets of parallelogram linkage mechanisms, enabling free switching between grasping, separating, and dual-machine collaborative gripping modes. However, the mechanical structure is cumbersome and maintenance is complex. The multi-link mechanism is prone to joint jamming due to dust accumulation during high-speed movement, requiring frequent cleaning. Separating grippers are prone to accidentally pushing coal blocks, have poor compatibility with large gangue, have a high risk of accidental separation, and easily wear down the conveyor belt surface.

[0005] In summary, pneumatically driven mechanical grippers currently dominate the field, but their dual-cylinder design leads to complex structures and high failure rates. Furthermore, traditional mechanical grippers cannot balance efficiency and accuracy when dealing with varying sizes of gangue. Although gangue sorting technology is constantly evolving and mechanical gripper designs are continuously being updated, in practical applications, the diverse shapes and sizes of gangue in coal mean that existing mechanical grippers lack adaptive load-bearing capabilities. This often results in gangue of unusual shapes or sizes being difficult for the grippers to effectively grasp, leading to incomplete gangue sorting – a problem that urgently needs to be addressed. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a variable load adaptive mechanical gripper, which consists of two gripper structures: a fixed side and a rotating side. The opening and closing action is controlled by the forward and reverse rotation of the drive shaft. The rotating side gripper is equipped with an anti-interference spring block assembly to ensure stable operation during the angle adjustment process. Combined with the power variation of the drive motor and the configuration changes of the two gripper heads, it can effectively grasp different types of gangue.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a variable load adaptive mechanical gripper, comprising a fixed-side gripper, a rotating-side gripper, a gear transmission structure, an anti-interference spring block assembly, a worm gear drive assembly, and a base plate. The gear transmission structure includes a drive shaft and an upper gear and a lower gear coaxially mounted on its top. The drive shaft passes through a pre-made central hole in the base plate, and the bottom end of the drive shaft is connected to an external drive motor via a coupling. The external drive motor adjusts its output power in real time according to load changes. The fixed-side gripper is provided with a fixed-side rack that meshes with the upper gear. The bottom of the fixed-side rack is connected to a fixed-side slider. The fixed-side guide rail is slidably connected and fixed to the base plate. The rotating-side gripper is provided with a rotating-side rack that meshes with the lower gear. A rotating-side guide rail is provided below the rotating-side rack. A rotating-side slider is slidably connected to the rotating-side guide rail. The rotating-side slider and the rotating-side rack are connected by an anti-interference spring block assembly. The anti-interference spring block assembly provides elastic support force to the rotating-side rack for the downward gear during the rotation of the rotating-side gripper. The worm gear drive assembly is used to control the rotating-side gripper to rotate around the center of the rotating-side guide rail. Two gripper heads are installed above the outer edges of the rotating-side rack and the fixed-side rack.

[0008] Furthermore, the anti-interference spring block assembly consists of a slider connecting block, a rack connecting block, and a spring. The slider connecting block is fixed to the top of the rotating slider, and a groove is machined along the vertical direction of the rotating guide rail on the side of the middle position of the slider connecting block adjacent to the drive shaft. The rack connecting block is fixed to the bottom of the rotating rack and slides in cooperation with the groove. The spring is supported and fixed between the rack connecting block and the closed end of the groove.

[0009] Furthermore, the worm gear drive assembly is fixed on the base plate, and the worm gear drives the vertical shaft to rotate by the control motor. The vertical shaft is connected and fixed to the center position of the rotating side guide rail.

[0010] Furthermore, the two gripper heads are initially arranged opposite each other on both sides of the drive shaft in a straight line configuration. When the rotating gripper deflects with the worm gear drive assembly, the included angle between the two gripper heads changes, forming a V-shaped configuration.

[0011] Furthermore, in a V-shaped configuration, the mechanical gripper uses two or more grippers distributed around the object to be gripped to perform coordinated gripping.

[0012] Furthermore, the two gripper heads are replaceable.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention utilizes two gears on the transmission shaft to drive the guide rail slider in conjunction with the rack and pinion, and the opening and closing action of the two gripper heads can be realized by forward and reverse control. The structure is simple and practical. It adopts adaptive variable load technology. The transmission shaft is connected to an external drive motor to adjust the output power in real time according to the load change. The mechanical gripper is divided into two gripper structures, a fixed side and a rotating side. The angle between the rotating side gripper and the fixed side gripper can be adjusted by the worm gear drive assembly. An anti-interference spring block assembly is set to avoid the interference of the gear and rack during the rotation of the rotating side gripper, ensuring the stable operation of the rotating side gripper. Combined with the power change of the drive motor and the configuration change of the two gripper heads, it can effectively grasp different types of gangue. Under the premise of a high gangue removal rate, it further solves the problem of incomplete gangue selection. Attached Figure Description

[0014] Figure 1 This is a front view schematic diagram of the overall structure of the mechanical claw of the present invention; Figure 2 This is a side view schematic diagram of the overall structure of the mechanical claw of the present invention; Figure 3 This is an assembly diagram of the anti-interference spring block assembly in this invention.

[0015] In the diagram: 1. First gripper head; 2. Long connecting arm; 3. Lower gear; 4. Fixed side guide rail; 5. Rotating side rack; 6. Anti-interference spring block assembly; 7. Rotating side slider; 8. Second gripper head; 9. Upper gear; 10. Short connecting arm; 11. Fixed side rack; 12. Fixed side slider; 13. T-shaped support frame; 14. Rotating side guide rail; 15. Worm gear drive assembly; 16. Base plate; 17. Coupling; 18. Drive shaft; 19. Flat key. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] like Figures 1-3 As shown, an adaptive mechanical gripper with variable load is mainly divided into three parts: a fixed-side gripper, a rotating-side gripper, and a gear transmission structure. The fixed-side gripper includes a second gripper head 8, a short connecting arm 10, a fixed-side rack 11, a fixed-side slider 12, and a fixed-side guide rail 4. The rotating-side gripper includes a first gripper head 1, a long connecting arm 2, a rotating-side rack 5, a rotating-side slider 7, and a rotating-side guide rail 14. The gear transmission structure includes a lower gear 3, an upper gear 9, and a transmission shaft 18.

[0018] The base plate 16 serves as the foundation for the mechanical gripper and is used for loading the three parts. The gear transmission structure loading is specifically as follows: the drive shaft 18 passes through the pre-drilled center hole in the base plate 16; the top of the drive shaft 18 is coaxially positioned and mounted with the upper gear 9 and the lower gear 3 via a flat key 19; the bottom of the drive shaft 18 is connected to an external drive motor via a coupling 17 as power input; the external drive motor can adjust its output power in real time according to load changes. The fixed-side gripper loading is specifically as follows: the fixed-side rack 11 is horizontally arranged and meshes with the upper gear 9; the fixed-side guide rail 4 is horizontally positioned below the fixed-side rack 11; the fixed-side guide rail 4 is connected to the base plate 16 via a T-shaped support frame 13. The fixed-side slider 12 is fixed to the bottom of the fixed-side rack 11 and slidably connected to the fixed-side guide rail 4. The second gripper head 8 is fixedly installed above the outer edge of the fixed-side rack 11 via the short connecting arm 10. The loading of the rotating gripper is as follows: the rotating-side rack 5 is horizontally arranged and meshes with the lower gear 3. The rotating-side rack 5 and the fixed-side rack 11 are located on opposite sides of the drive shaft 18. The rotating-side guide rail 14 is horizontally arranged below the rotating-side rack 5. The rotating-side slider 7 is slidably connected to the rotating-side guide rail 14 and supports the rotating-side rack 5. The first gripper head 1 is fixedly installed above the outer edge of the rotating-side rack 5 via the long connecting arm 2. In the initial state, the first gripper head 1 and the second gripper head 8 are arranged opposite each other on both sides of the drive shaft 18 in a straight line configuration. By controlling the forward and reverse rotation of the drive shaft 18, the distance between the first gripper head 1 and the second gripper head 8 can be changed to achieve a central gripping action.

[0019] Furthermore, the rotation of the rotating gripper is achieved by a worm gear drive assembly 15, which is fixed on the base plate 16 and located below the rotating guide rail 14. The worm gear drive assembly 15 is powered by a control motor, which drives the worm gear transmission worm wheel to rotate the vertical shaft. The vertical shaft is fixedly connected to the center of the rotating guide rail 14. The deflection angle of the rotating guide rail 14 and its upper components is adjusted by the worm gear drive assembly 15, and the self-locking characteristic of the worm gear ensures the stability of the rotating guide rail 14 during deflection. When the first gripper head 1 deflects with the worm gear drive assembly 15, the angle between the first gripper head 1 and the second gripper head 8, centered on the transmission shaft 18, changes, forming a V-shape. The angle between the first gripper head 1 and the second gripper head 8 can be changed by controlling the forward and reverse rotation of the worm gear drive assembly 15, thus achieving an offset gripping action.

[0020] To prevent interference between the rotating rack 5 and the lower gear 3 during the rotation of the rotating gripper, an anti-interference spring block assembly 6 is added between the rotating rack 5 and the rotating slider 7 to connect them. The anti-interference spring block assembly 6 consists of a slider connecting block, a rack connecting block, and a spring. The slider connecting block is fixed to the top of the rotating slider 7, and a groove is machined along the vertical direction of the rotating guide rail 14 on the side of the slider connecting block adjacent to the drive shaft 18. The rack connecting block is fixed to the bottom of the rotating rack 5 and slides in cooperation with the groove of the slider connecting block. The spring is fixed between the rack connecting block and the closed end of the groove. The anti-interference spring block assembly 6 can prevent interference that may occur when the rotating rack 5 deflects around the lower gear 3 to a certain extent. Its working principle is as follows: when the rotating gripper rotates under the control of the worm gear drive assembly 15, the meshing point position between the rotating rack 5 and the lower gear 3 changes, and the distance between the rotating rack 5 and the lower gear 3 will decrease. The rotating rack 5 is fixed on the rack connecting block, and the rack connecting block can move along the slide groove of the slider connecting block. The spring always provides elastic support force to the rotating rack 5 for the lower gear 3, so that the distance between the rotating rack 5 and the lower gear 3 is maintained within a reasonable range, and normal meshing can be performed to ensure the stable operation of the rotating gripper.

[0021] The mechanical gripper of this invention can adaptively adjust to changes in load during operation. The transmission shaft 18 is connected to an external drive motor, which adjusts the output power in real time according to load changes. The forward and reverse rotation of the transmission shaft 18 drives the rotating side rack 5 and the fixed side rack 11, thereby enabling the first gripper head 1 and the second gripper head 8 to move closer or further apart. The rotating side gripper can deflect between itself and the fixed side gripper under the control of the worm gear drive assembly 15, realizing two configuration transformations: a straight-line central gripping configuration and a V-shaped offset gripping configuration. It can more effectively grip gangue of different sizes and shapes, and has certain advantages in terms of use and control.

[0022] In addition, multiple mechanical grippers can work together for more effective gripping. Specifically, two or more mechanical grippers of this invention can rotate adaptively and then grip together. The upper computer analyzes the data and transmits information to the lower computer for control. For example, in coal gangue identification, if the image identifies that the gangue volume is too large for a single gripper to grasp, the upper computer issues a coordination command. Because the coordination involves changing the angles of the first gripper head 1 and the second gripper head 8 (V-shaped configuration), two or more mechanical grippers can be distributed around the object to be gripped to coordinate the gripping. A more effective gripping point can be selected to form a larger gripper or encircling structure for gripping. Furthermore, by replacing the spring gripper heads, it can be made more adaptable to objects with complex shapes. Through these actions, it is possible to grip complex-shaped gangue at different positions, improving stability and reducing motor load. This coordinated work increases the gripping range and enhances adaptability, resulting in significant improvements in performance and efficiency.

[0023] The main problem solved by the mechanical gripper of this invention is: Key Issue: In practical applications of waste rock quarrying, the loads borne by the mechanical gripper structure are often complex and variable. Adaptive variable load technology enables the mechanical gripper structure to better adapt to these actual working conditions, allowing for more effective gripping of waste rock. Simultaneously, mechanical structures are prone to fatigue damage under alternating loads. Adaptive variable load technology can effectively extend the service life of the mechanical gripper by rationally adjusting the load magnitude and distribution, avoiding prolonged high stress concentration in localized areas of the structure. In the complex environment of mines, adaptive variable load mechanical grippers exhibit greater stability and reliability.

[0024] Secondary issue: Adaptive variable load technology allows for real-time adjustment of the drive motor's output power based on load changes, significantly improving the overall system's energy efficiency. A closed-loop control system, comprised of sensors, controllers, and actuators, enables real-time monitoring, analysis, and processing of load information, allowing for corresponding adjustments.

[0025] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0026] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A variable-load adaptive mechanical gripper, characterized in that: The system includes a fixed-side gripper, a rotating-side gripper, a gear transmission structure, an anti-interference spring block assembly (6), a worm gear drive assembly (15), and a base plate (16). The gear transmission structure includes a drive shaft (18) and an upper gear (9) and a lower gear (3) coaxially mounted on its top. The drive shaft (18) passes through a pre-drilled center hole in the base plate (16). The bottom end of the drive shaft (18) is connected to an external drive motor via a coupling (17). The external drive motor adjusts its output power in real time according to load changes. The fixed-side gripper is equipped with a fixed-side rack (11) that meshes with the upper gear (9). The bottom of the fixed-side rack (11) is slidably connected to the fixed-side guide rail (4) via a fixed-side slider (12). The fixed-side guide rail (4) The rotating side gripper is fixed to the base plate (16). The rotating side gripper is provided with a rotating side rack (5) that meshes with the lower gear (3). A rotating side guide rail (14) is provided below the rotating side rack (5). A rotating side slider (7) is slidably connected to the rotating side guide rail (14). The rotating side slider (7) and the rotating side rack (5) are connected by an anti-interference spring block assembly (6). The anti-interference spring block assembly (6) provides elastic support force of the lower gear (3) to the rotating side rack (5) during the rotation of the rotating side gripper. The worm gear drive assembly (15) is used to control the rotating side gripper to rotate around the center of the rotating side guide rail (14). Two gripper heads are installed above the outer edges of the rotating side rack (5) and the fixed side rack (11).

2. The adaptive mechanical gripper with variable load according to claim 1, characterized in that: The anti-interference spring block assembly (6) consists of a slider connecting block, a rack connecting block and a spring. The slider connecting block is fixed on the top of the rotating side slider (7), and a groove is machined along the vertical direction of the rotating side guide rail (14) on the side of the middle position of the slider connecting block adjacent to the transmission shaft (18). The rack connecting block is fixed on the bottom of the rotating side rack (5) and slides in cooperation with the groove. The spring is supported and fixed between the rack connecting block and the closed end of the groove.

3. The adaptive mechanical gripper with variable load according to claim 1 or 2, characterized in that: The worm gear drive assembly (15) is fixed on the base plate (16). The worm gear drives the vertical shaft to rotate, and the vertical shaft is connected and fixed to the center position of the rotating side guide rail (14).

4. The adaptive mechanical gripper with variable load according to claim 1, characterized in that: The two gripper heads are initially arranged opposite each other on both sides of the drive shaft (18) in a straight line configuration. When the rotating gripper deflects with the worm gear drive assembly (15), the angle between the two gripper heads changes, forming a V-shape.

5. The adaptive mechanical gripper with variable load according to claim 4, characterized in that: The mechanical gripper, in a V-shaped configuration, uses two or more grippers distributed around the object to be gripped to perform coordinated gripping.

6. The adaptive mechanical gripper with variable load according to claim 1, characterized in that: The two gripper heads are replaceable.

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