A full-ocean-depth flexible electro-mechanical gripper and method of use

Abstract

A full-sea-depth flexible electric mechanical gripper and a use method thereof, comprising an upper shell, a main shell and a lower shell, a main shaft is fitted and installed in the main shell, a rotor of a frameless motor is fixedly installed on the main shaft, and a driver is fixed on a stator of the frameless motor by means of gluing; a harmonic reducer is fixedly installed in the upper shell, the harmonic reducer is connected with an end portion of the main shaft, an output flange of the harmonic reducer is connected with a shaft coupling through bolts, the shaft coupling is inserted into a ball screw, a protruding shaft is fixed with a nut of the ball screw through bolts, and rotary motion output by the harmonic reducer is converted into linear motion of the protruding shaft; a connecting block is fixedly connected with the protruding shaft through countersunk head bolts, and the outer circumferential surface of the end portion of the upper shell is hingedly connected with three groups of clamping jaws at equal intervals through No. 1 pin shafts, each clamping jaw is hingedly connected with the connecting block through a connecting rod, and the three groups of clamping jaws realize enveloping and clamping actions on an object under the power action of the protruding shaft extending or retracting, and the actions are stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of underwater operation tools for underwater engineering, and in particular to a full-ocean-depth flexible electromechanical gripper and its usage method. Background Technology

[0002] In recent years, with the development of marine technology, people's underwater activities have become more frequent, and deep-sea archaeology and deep-sea biological research have gradually developed. A large number of cultural relics that have sunk to the seabed have become brittle and fragile due to seawater corrosion and erosion.

[0003] When a submersible performs grasping operations underwater, it mainly relies on hydraulic manipulators. Hydraulic manipulators have a high power-to-weight ratio and high reliability, and can complete most tasks.

[0004] However, most traditional robotic end effectors are rigid mechanisms, making it difficult to control the force. As a result, they have poor precision operation capabilities, poor object grasping stability, and are prone to damaging fragile cultural relics. Summary of the Invention

[0005] In response to the shortcomings of the existing production technology, the applicant provides a full-ocean-depth flexible electromechanical gripper and its usage method, which can conveniently complete deep-sea gripping actions, greatly improve underwater precision work capabilities, and is less likely to damage the target.

[0006] The technical solution adopted in this invention is as follows:

[0007] A full-ocean-depth flexible electromechanical gripper includes a gripper housing with a split structure comprising an upper housing, a main housing, and a lower housing. A main shaft is fitted inside the main housing, and a frameless motor rotor is fixedly mounted on the main shaft. Bearings are installed on both sides of the main shaft of the frameless motor. A driver is glued to the stator of the frameless motor. A harmonic reducer is fixedly mounted inside the upper housing and connected to the end of the main shaft. The output flange of the harmonic reducer is bolted to a coupling, which is inserted into a ball screw. An extension shaft is bolted to the nut of the ball screw, converting the rotational motion output by the harmonic reducer into linear motion of the extension shaft. A connecting block is fixed to the extension shaft with countersunk bolts. Three sets of grippers are evenly hinged to the outer circumferential surface of the upper housing end via a first pin. Each gripper is hinged to the connecting block via a connecting rod. Under the power of the extension shaft extending or retracting, the three sets of grippers achieve enveloping and clamping actions on the object.

[0008] Its further technical solution lies in:

[0009] The upper shell, main shell, and lower shell are fixed together by bolts and formed a sealed connection by a sealing ring.

[0010] The space between the main housing and the lower housing is filled with compensating oil, and forms a sealed oil cavity with the inner cavity of the clamp through the compensating membrane.

[0011] The bottom of the compensation membrane is sandwiched between the compensation membrane pressure plate and the piston, and is pressed and sealed by the venting bolt.

[0012] The piston has a guide seat and a compression spring at the bottom. When the compression spring is in a compressed state, it generates pre-pressure on the compensation oil of the compensation membrane through the movable piston.

[0013] The structure of a single gripper is as follows: it includes a first joint, a second joint, and a third joint connected to each other by a second pin. There are permanent magnet groups between the first joint and the second joint, and between the second joint and the third joint. The permanent magnet groups of the same polarity repel each other between each pair.

[0014] Each set of permanent magnets is equipped with a force sensor, which transmits the repulsive force of the electromagnets between the joints to the force sensor when grasping an object through the nylon pad.

[0015] Plastic pads are installed on joints No. 1, No. 2 and No. 3.

[0016] The structure of the venting bolt includes a bolt body, an adjusting nut, a guide post, a second compression spring, and a sealing screw. A sealing ring is provided between the bolt body and the sealing screw. The venting operation can be achieved by pulling the bolt body outward. The second compression spring and the guide post achieve pre-tightening sealing. The pre-tightening force can be adjusted by the adjusting nut, thereby adjusting the sealing pressure inside the cavity.

[0017] A method for using a full-ocean-depth flexible electromechanical gripper includes the following operating steps:

[0018] Step 1: Preparation;

[0019] During the preparation phase on deck, fill the electromechanical clamp with compensating oil and vent the air from the cavity through the bleed bolt.

[0020] Step 2: Attach the electromechanical gripper to the end of the underwater manipulator to replace the gripper of the underwater manipulator;

[0021] Step 3: As the submersible descends to the predetermined depth, the electromechanical gripper is used by the operator to move the robotic arm closer to the target.

[0022] Step 4: The submariner activates the electromechanical gripper, controls the internal frameless motor to rotate forward, opens the grippers, and places the target inside the grippers;

[0023] Step 5: Control the internal frameless motor to reverse, close the gripper, and hold the target. The submariner can adjust the gripping force in real time based on the feedback from the electromechanical gripper.

[0024] Step 6: Operate the robotic arm to place the target in the sampling basket, turn off the electromechanical gripper, operate the robotic arm to reset, and the submersible will rise back to the surface.

[0025] The beneficial effects of this invention are as follows:

[0026] This invention features a compact and reasonable structure, and is easy to operate. By redesigning the structure of the grippers and the specific structure of the electromechanical gripper, it can easily perform precise gripping actions in the deep-sea environment, greatly facilitating deep-sea operations. It has strong precision operation capabilities, good object gripping stability, and will not damage fragile cultural relics.

[0027] In addition, the present invention also has the following advantages:

[0028] (1) The present invention adopts an operation mode in which an electromechanical gripper is mounted on the end of an underwater hydraulic manipulator, which fully combines the high reliability of the hydraulic manipulator and the high control precision of the electric manipulator, thereby improving the underwater precision operation capability.

[0029] (2) The present invention adopts a frameless motor, harmonic reducer and ball screw structure design, and a rear compensation membrane. The overall structure is compact, highly integrated and lightweight, and can be applied to most underwater manipulators.

[0030] (3) In this invention, the electromechanical gripper achieves gripping and buffering by means of the repulsion of like magnets at the joints, and performs fine operation by means of contact force feedback from the force sensor, which can achieve non-destructive gripping of fragile and brittle underwater items.

[0031] (4) The electromechanical clamp in this invention adopts a hydraulic compensation design, which transmits the external environmental pressure through the compensation membrane, and can meet the operation in the entire sea area depth range, with a wide range of applications. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a side view of the present invention.

[0034] Figure 3 This is a partial cross-sectional view of the device of the present invention.

[0035] Figure 4 This is a schematic diagram of the gripper structure of the present invention.

[0036] Figure 5 This is a partial cross-sectional view of the gripper of the present invention.

[0037] Figure 6 This is a schematic diagram of the relaxed state of the gripper in this invention.

[0038] Figure 7 This is a schematic diagram of the gripper under pressure in this invention.

[0039] Figure 8 This is a schematic diagram of the venting bolt structure of the present invention.

[0040] Figure 9 This is a schematic diagram illustrating the application of the electromechanical clamp of the present invention.

[0041] The components are: 1. Gripper; 2. Connecting block; 3. No. 1 pin; 4. Connecting rod; 5. Countersunk bolt; 6. Ball screw; 7. Coupling; 8. Harmonic reducer; 9. Bearing; 10. Driver; 11. Frameless motor; 12. Compensating oil; 13. Compensating diaphragm plate; 14. Vent bolt; 15. Guide seat; 16. Extending shaft; 17. Main shaft; 18. Compensating diaphragm; 19. Piston; 20. No. 1 compression spring.

[0042] 21. Upper housing; 22. Main housing; 23. Lower housing; 101. Joint No. 1; 102. Joint No. 2; 103. Joint No. 3; 104. Pin No. 2; 105. Force sensor; 106. Nylon pad; 107. Permanent magnet assembly; 108. Plastic pad; 1401. Bolt body; 1402. Adjusting nut; 1403. Guide post; 1404. Compression spring No. 2; 1405. Sealing screw. Detailed Implementation

[0043] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0044] like Figures 1-9 As shown, the full-ocean-depth flexible electromechanical gripper of this embodiment includes an electromechanical gripper housing. The electromechanical gripper housing adopts a split structure, including an upper housing 21, a main housing 22, and a lower housing 23. A main shaft 17 is installed inside the main housing 22. The rotor of a frameless motor 11 is fixedly installed on the main shaft 17, and bearings 9 are installed on the main shaft 17 on both sides of the frameless motor 11. The driver 10 is fixed to the stator of the frameless motor 11 by adhesive. A harmonic reducer 8 is fixedly installed inside the upper housing 21. The harmonic reducer 8 is connected to the end of the main shaft 17. The output flange of the harmonic reducer 8 is connected to the coupling 7 by bolts. The coupling 7 is inserted into the ball screw 6. The extension shaft 16 is fixed to the nut of the ball screw 6 by bolts, converting the rotational motion output by the harmonic reducer 8 into the linear motion of the extension shaft 16. The connecting block 2 is fixed to the extension shaft 16 by countersunk bolts 5. Three sets of grippers 1 are evenly hinged to the outer circumferential surface of the end of the upper housing 21 by the first pin 3. Each gripper 1 is hinged to the connecting block 2 by the connecting rod 4. Under the power of the extension shaft 16 extending or retracting, the three sets of grippers 1 realize the enveloping and clamping action of the object.

[0045] The upper housing 21, the main housing 22, and the lower housing 23 are fixed together by bolts and form a sealed connection by a sealing ring.

[0046] The position between the main housing 22 and the lower housing 23 is filled with compensating oil 12, and forms a sealed oil cavity with the inner cavity of the clamp through the compensating membrane 18.

[0047] The bottom of the compensation membrane 18 is sandwiched between the compensation membrane pressure plate 13 and the piston 19, and is pressed and sealed by the venting bolt 14.

[0048] The piston 19 has a guide seat 15 and a first compression spring 20 at its bottom. When the first compression spring 20 is in a compressed state, it generates pre-pressure on the compensation oil 12 of the compensation membrane 18 through the movable piston 19.

[0049] The structure of a single gripper 1 is as follows: it includes a first joint 101, a second joint 102 and a third joint 103 connected to each other by a second pin 104. A permanent magnet group 107 is provided between the first joint 101 and the second joint 102, and between the second joint 102 and the third joint 103. The permanent magnet groups 107 repel each other if they are of the same polarity.

[0050] Each permanent magnet group 107 is equipped with a force sensor 105, which transmits the repulsive force of the electromagnets between the joints to the force sensor 105 when grasping an object through the nylon pad column 106.

[0051] Plastic pads 108 are installed on joint 101, joint 202 and joint 303.

[0052] The structure of the venting bolt 14 includes a bolt body 1401, an adjusting nut 1402, a guide post 1403, a second compression spring 1404, and a sealing screw 1405. A sealing ring is provided between the bolt body 1401 and the sealing screw 1405. The venting operation can be achieved by pulling the bolt body 1401 outward. The second compression spring 1404 and the guide post 1403 achieve pre-tightening sealing. The pre-tightening force can be adjusted by the adjusting nut 1402, thereby adjusting the sealing pressure inside the cavity.

[0053] The method of using the full-ocean-depth flexible electromechanical gripper in this embodiment includes the following operating steps:

[0054] Step 1: Preparation;

[0055] During the preparation phase on the deck, the electromechanical clamp is filled with compensating oil 12 and the air in the cavity is vented through the vent bolt 14.

[0056] Step 2: Attach the electromechanical gripper to the end of the underwater manipulator to replace the gripper of the underwater manipulator;

[0057] Step 3: As the submersible descends to the predetermined depth, the electromechanical gripper is used by the operator to move the robotic arm closer to the target.

[0058] Step 4: The submariner activates the electromechanical gripper, controls the internal frameless motor 11 to rotate forward, opens the grippers, and places the target into the gripper 1;

[0059] Step 5: Control the internal frameless motor 11 to reverse, the gripper 1 closes, and the target is gripped. The submariner can adjust the gripping force in real time through the feedback from the electromechanical gripper.

[0060] Step 6: Operate the robotic arm to place the target in the sampling basket, turn off the electromechanical gripper, operate the robotic arm to reset, and the submersible will rise back to the surface.

[0061] The specific structure and function of the full-ocean-depth flexible electromechanical gripper described in this invention are as follows:

[0062] It mainly includes gripper 1, connecting block 2, No. 1 pin 3, connecting rod 4, countersunk bolt 5, ball screw 6, coupling 7, harmonic reducer 8, bearing 9, driver 10, frameless motor 11, compensating oil 12, compensating diaphragm pressure plate 13, vent bolt 14, guide seat 15, extension shaft 16, main shaft 17, compensating diaphragm 18, piston 19, No. 1 compression spring 20, upper housing 21, main housing 22, and lower housing 23.

[0063] The electromechanical clamp housing is mainly composed of an upper housing 21, a main housing 22, and a lower housing 23. The housings are fixed together by bolts and sealed by sealing rings.

[0064] The main housing 22 houses a main shaft 17, on which the rotor of the frameless motor 11 is fixed. The stator of the frameless motor 11 is correspondingly fixed inside the main housing 22 by cylindrical pins. Bearings 9 are provided on both sides of the frameless motor 11 to ensure that the frameless motor 11 is not affected by radial and axial forces during the rotation of the main shaft 17. The driver 10 is fixed to the stator of the frameless motor 11 by adhesive. The harmonic reducer 8 is fixed inside the upper housing 21 by bolts. The harmonic reducer 8 is connected to the end of the main shaft 17 and serves as the input end of the torque of the frameless motor 11. The output flange of the harmonic reducer 8 is connected to the coupling 7 by bolts to output the increased torque rotational motion. The other end of the coupling 7 is inserted into the screw shaft of the ball screw 6. The protruding shaft 16 is fixed to the nut of the ball screw 6 by bolts, converting the rotational motion output by the harmonic reducer 8 into the linear motion of the protruding shaft 16. The three sets of grippers 1, connecting rod 4, and connecting block 2 on the outer shell of the electromechanical gripper are fixedly connected by a first pin 3 to form a linkage mechanism. The connecting block 2 is fixedly connected to the extension shaft 16 by a countersunk bolt 5. Under the power of the extension shaft 16 extending / retracting, the three sets of grippers 1 can achieve the envelopment and clamping of the object.

[0065] The electromechanical gripper is filled with compensating oil 12, which forms a sealed oil chamber with the gripper's inner cavity through the compensating membrane 18. This chamber transmits external water pressure to achieve a compensation effect, ensuring that the electromechanical gripper can work normally at great depths on the seabed. The bottom of the compensating membrane 18 is clamped between the compensating membrane pressure plate 13 and the piston 19, and is pressed and sealed by the vent bolt 14. This ensures that the compensating membrane 18 can move up and down in an orderly manner during changes in external water pressure. The bottom of the piston 19 is equipped with a guide seat 15 and a first compression spring 20. When the first compression spring 20 is in a compressed state, the movable piston 19 generates pre-pressure on the compensating oil 12 of the compensating membrane 18, so that the pressure in the sealed oil chamber is always higher than the seawater pressure, preventing external seawater from flowing back in when the seawater pressure changes.

[0066] The gripper 1 is mainly composed of three sections: joint 101, joint 102, and joint 103, which are interconnected by a second pin 104. Permanent magnet groups 107 are installed between joint 101 and joint 102, or between joint 102 and joint 103. The like poles of the permanent magnet groups 107 repel each other when gripping an object. When gripping an object, the greater the gripping force, the smaller the distance between the permanent magnets in the three joints, and the greater the repulsive force, thus forming a flexible grip and envelopment of the object. Each permanent magnet group 107 is equipped with a force sensor 105. The repulsive force between the electromagnets of the joints during object gripping is transmitted to the force sensor 105 through a nylon pad 106. Real-time feedback of the gripping force can be achieved through calculation. Plastic pads 108 are installed on each of the three joints to increase the friction of the gripped object and avoid hard contact with the object during gripping. With the combined effect of these three functions, the gripper 1 can achieve non-destructive gripping of fragile and easily broken items underwater.

[0067] The venting bolt 14 mainly consists of a bolt body 1401, an adjusting nut 1402, a guide post 1403, a second compression spring 1404, and a sealing screw 1405. A sealing ring is provided between the bolt body 1401 and the sealing screw 1405. Venting can be achieved by pulling the bolt body 1401 outwards. Pre-tightening sealing is achieved through the second compression spring 1404 and the guide post 1403. The pre-tightening force can be adjusted by the adjusting nut 1402, thereby regulating the sealing pressure within the cavity.

[0068] The specific working process of this invention is as follows:

[0069] During the deck preparation phase, first fill the electromechanical clamp with compensating oil 12 and then vent the air in the cavity through the vent bolt 14.

[0070] Install the electromechanical gripper at the end of the underwater manipulator to replace the gripper 1 of the underwater manipulator;

[0071] As the submersible descends to the predetermined depth, the electromechanical gripper is used by the crew to move the robotic arm closer to the target.

[0072] The submariner activates the electromechanical gripper, controls the internal frameless motor 11 to rotate forward, opens the gripper 1, and places the target inside the gripper 1;

[0073] The internal frameless motor 11 is reversed, the gripper 1 closes, and the target is gripped. The submariner can adjust the gripping force in real time based on the feedback from the electromechanical gripper.

[0074] The robotic arm is operated to place the target in the sampling basket, the electromechanical gripper is turned off, the robotic arm is reset, and the submersible rises back to the surface.

[0075] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A full-ocean-depth flexible electromechanical gripper, characterized in that: The device includes an electromechanical gripper housing, which has a split structure and comprises an upper housing (21), a main housing (22), and a lower housing (23). A main shaft (17) is installed inside the main housing (22), and the rotor of a frameless motor (11) is fixedly mounted on the main shaft (17). Bearings (9) are installed on the main shaft (17) on both sides of the frameless motor (11). A driver (10) is fixedly attached to the stator of the frameless motor (11) by adhesive bonding. A harmonic reducer (8) is fixedly installed inside the upper housing (21), and the harmonic reducer (8) is connected to the end of the main shaft (17). The output flange of the harmonic reducer (8) is... The coupling (7) is connected to the ball screw (6) by bolts. The extension shaft (16) is fixed to the nut of the ball screw (6) by bolts, which converts the rotational motion output by the harmonic reducer (8) into the linear motion of the extension shaft (16). The connecting block (2) is fixed to the extension shaft (16) by countersunk bolts (5). The outer circumferential surface of the upper housing (21) is hinged with three sets of grippers (1) at even intervals by a first pin (3). Each gripper (1) is hinged to the connecting block (2) by a connecting rod (4). Under the power of the extension shaft (16) extending or retracting, the three sets of grippers (1) realize the enveloping and clamping action of the object. The structure of a single gripper (1) is as follows: it includes a first joint (101), a second joint (102) and a third joint (103) connected to each other by a second pin (104). Permanent magnet groups (107) are provided between the first joint (101) and the second joint (102), and between the second joint (102) and the third joint (103). The permanent magnet groups (107) are like-pairs and repel each other. Each permanent magnet group (107) is equipped with a force sensor (105), which transmits the repulsive force of the inter-joint electromagnets to the force sensor (105) when grasping an object through the nylon pad column (106).

2. The full-ocean-depth flexible electromechanical gripper as described in claim 1, characterized in that: The upper housing (21), the main housing (22), and the lower housing (23) are fixed together by bolts and form a sealed connection by a sealing ring.

3. The full-ocean-depth flexible electromechanical gripper as described in claim 2, characterized in that: The position between the main housing (22) and the lower housing (23) is filled with compensating oil (12) and forms a sealed oil cavity with the inner cavity of the clamp through the compensating membrane (18).

4. The full-ocean-depth flexible electromechanical gripper as described in claim 3, characterized in that: The bottom of the compensation membrane (18) is sandwiched between the compensation membrane pressure plate (13) and the piston (19), and is pressed and sealed by the venting bolt (14).

5. The full-ocean-depth flexible electromechanical gripper as described in claim 4, characterized in that: The piston (19) has a guide seat (15) and a first compression spring (20) at the bottom. When the first compression spring (20) is in a compressed state, it generates pre-pressure on the compensation oil (12) of the compensation membrane (18) through the movable piston (19).

6. The full-ocean-depth flexible electromechanical gripper as described in claim 1, characterized in that: Plastic pads (108) are installed on the first joint (101), the second joint (102) and the third joint (103).

7. A method of using the full-ocean-depth flexible electromechanical gripper as described in claim 1, characterized in that: The following steps are included: Step 1: Preparation; During the preparation phase on the deck, compensating oil (12) is added to the electromechanical clamp, and air in the cavity is vented through the vent bolt (14); Step 2: Attach the electromechanical gripper to the end of the underwater manipulator to replace the gripper of the underwater manipulator; Step 3: As the submersible descends to the predetermined depth, the electromechanical gripper is used by the operator to move the robotic arm closer to the target. Step 4: The submariner starts the electromechanical gripper, controls the internal frameless motor (11) to rotate forward, opens the gripper, and places the target in the gripper (1); Step 5: Control the internal frameless motor (11) to reverse, the gripper (1) closes, and the target is gripped. The submariner can adjust the gripping force in real time by the feedback from the electromechanical gripper. Step 6: Operate the robotic arm to place the target in the sampling basket, turn off the electromechanical gripper, operate the robotic arm to reset, and the submersible will rise back to the surface.

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