Magnetic adsorption wheel structure of underwater robot

Abstract

The application discloses a magnetic adsorption wheel structure of an underwater robot, which comprises a magnetic adsorption wheel unit, a rubber wheel connected to a hub connecting flange on the left side of the magnetic adsorption wheel unit, a frameless motor stator, a frameless motor rotor, a motor output shaft, a harmonic reducer assembly and a plurality of permanent magnet assemblies which are installed in the magnetic adsorption wheel unit in an axial direction; the motor output shaft transmits rotating power to the rubber wheel through the harmonic reducer assembly and the hub connecting flange to drive the rubber wheel to rotate; when the rubber wheel is attached to a ship wall, the permanent magnet assemblies generate corresponding magnetic force at a certain distance from the ship wall, so that the height of the connection part of the wall climbing and cleaning robot and the magnetic adsorption wheel structure is relatively high, the chassis of the wall climbing and cleaning robot is also relatively high, and therefore the wall climbing and cleaning robot can maintain stable adsorption force and has strong obstacle crossing ability during the cleaning process.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, and specifically relates to a magnetic adsorption wheel structure for an underwater robot. Background Technology

[0002] With the rapid development of ocean shipping, ships, as the main means of maritime transportation, often accumulate stubborn marine organisms on their surfaces, leading to reduced speed and increased transportation costs. Therefore, regular cleaning is necessary to ensure economical and safe operation. Currently, ship surface cleaning is mostly done manually, which is inefficient. Therefore, developing automated wall-climbing cleaning robots is key to improving cleaning efficiency and safety. Wall-climbing cleaning robots achieve adhesion to ship or metal surfaces by mounting permanent magnets or electromagnets on their chassis. This design allows the robot to overcome its own gravity by utilizing the synergistic effect of magnetic and frictional forces, thus crawling on inclined or even vertical metal surfaces. Electromagnetic adhesion robots are more complex to control, and their weight is usually greater than that of permanent magnet robots to achieve the same adhesion force. Therefore, the application scenarios for electromagnetic adhesion robots are relatively limited, only suitable for special situations. In contrast, robots using permanent magnet adhesion have become the dominant trend in the current market due to their stability and efficiency.

[0003] Current wall-climbing robots used in ship cleaning applications have several shortcomings, one major one being their limited obstacle-crossing ability, stemming from the fact that these robots, with permanent magnets mounted on their chassis, have limited ability to overcome obstacles. To maximize the use of the permanent magnets' attraction and enhance the robot's stability during cleaning, the magnets must be positioned close to the ship's hull. This results in a low chassis for the robot, which may get stuck when traversing obstacles, requiring additional design improvements to enhance its obstacle avoidance and crossing capabilities. Magnetic adsorption robots used for ship cleaning primarily employ a parallel wheel drive system, moving mainly by reciprocating around the ship's outer surface. A drawback is that on curved hulls, this can cause the robot to scrape the bottom during cleaning, potentially scratching the paint or even causing the wheels to become suspended and unable to move. Furthermore, in some designs, the magnetic field lines of the permanent magnets may not be evenly distributed, leading to variations in attraction force across different areas, affecting the robot's stability and adsorption effect. Therefore, they are not suitable for applications requiring stable operation, such as ship cleaning and inspection. Additionally, ships can have drafts of tens of meters, so the robot itself, including its magnetic adsorption wheels, needs to be able to operate at depths of tens of meters.

[0004] Therefore, it is necessary to propose a new magnetic adsorption wheel structure for underwater robots that is highly integrated, miniaturized, adaptable to complex underwater environments, and capable of working both on land and at depths of tens of meters underwater. Summary of the Invention

[0005] This invention provides a magnetic adsorption wheel structure for an underwater robot, which can solve the following problems of existing wall cleaning robots: 1. Inability to adapt to changes in the curvature of the hull; 2. The permanent magnet needs to be close to the hull, resulting in a low chassis and limited obstacle-crossing ability; 3. Low magnet utilization, bulky structure, excessive weight, leading to increased driving force and high energy consumption.

[0006] To solve the above problems, the technical solution provided by the present invention is as follows:

[0007] This invention provides a magnetic adsorption wheel structure for an underwater robot, including a magnetic adsorption wheel unit (2). A rubber wheel (1) is connected to a hub connecting flange (5) on the left side of the magnetic adsorption wheel unit (2). A watertight connector (3) and a pressure compensation interface (4) are connected to a sealing end cap (24) on the right side of the magnetic adsorption wheel unit (2). The watertight connector (3) is used for sealing. The pressure compensation interface (4) is used to connect an external pressure compensator so that the magnetic adsorption wheel structure can adapt to underwater operation.

[0008] The magnetic adsorption wheel unit (2) includes a magnetic adsorption unit shell (13). The magnetic adsorption unit shell (13) has an annular slot (13-1) and an annular groove (13-2) arranged from the outside to the inside. Multiple sets of permanent magnet components are arranged in an array in the annular slot (13-1). Each set of permanent magnet components includes two magnetic adsorption modules. Each magnetic adsorption module includes two yoke irons (27) and three magnets (31). The three magnets (31) are attached between the two yoke irons (27). A first frameless motor stator (14) and a second frameless motor stator (28) are aligned and installed in the annular groove (13-2). A frameless motor rotor (29) is provided between the sub-units (28), and a motor output shaft (30) is connected inside the frameless motor rotor (29); one end of the motor output shaft (30) is installed on the end cover sliding bearing (23) of the sealing end cover (24), and a motor sensor (26) is installed on the end of the motor output shaft (30) near the sealing end cover (24); a first magnetic protective cover (18) and an encoder (19) are installed on the groove of the motor sensor (26); a bushing (33) is installed on the other end of the motor output shaft (30), and a motor flange (12) is installed on the end face of the bushing (33) and fixed with screws on the left side of the magnetic adsorption unit housing (13).

[0009] In an optional embodiment of the present invention, the two magnetic adsorption modules in each group of permanent magnet components are arranged with their magnetic poles set in a Halbach array manner. The N poles of the magnets in the left magnetic adsorption module are right, down, and left from left to right; the N poles of the magnets in the right magnetic adsorption module are left, up, and right from left to right. The left and right magnetic adsorption modules form a magnetic circuit.

[0010] In an optional embodiment of the present invention, the magnet (31) and the yoke (27) in the magnetic adsorption module are both 76.2×124.8×28mm in size.

[0011] In an optional embodiment of the present invention, a harmonic reducer assembly (9) is installed on one side of the bushing (33) of the motor output shaft (30) by screws and washers, and the harmonic reducer assembly (9) is fitted to the shoulder of the motor output shaft (30).

[0012] In an optional embodiment of the present invention, a sliding bearing (6) is also installed between the boss end face of the hub connecting flange (5) and the outer shell (13) of the magnetic adsorption unit, and the harmonic reducer assembly (9) is connected to the hub connecting flange (5) so that the rotation of the motor output shaft (30) is transmitted to the rubber wheel (1) to drive the rubber wheel (1) to rotate.

[0013] In an optional embodiment of the present invention, the hub connecting flange (5) is machined with a sealing groove along the circumferential direction, and a combination gasket (36) is installed in the sealing groove; a first O-ring groove is machined on the other end face of the hub connecting flange (5), and a first O-ring seal (7) is installed in the first O-ring groove; the hub connecting flange (5) is connected to the end face of the connecting part of the cleaning robot by a plurality of first auxiliary screws (32) and a plurality of second auxiliary screws (35).

[0014] In an optional embodiment of the present invention, the outer shell (13) of the magnetic adsorption unit and the sealing end cap (24) are made of magnetically conductive material; the hub connecting flange (5) is made of non-magnetically conductive material.

[0015] Compared with the prior art, the present invention provides a magnetic adsorption wheel structure for an underwater robot, which has the following advantages: (1) The robot equipped with this magnetic adsorption wheel can adapt to the changes in the arc surface of the ship it is adsorbed on, and can arbitrarily design the chassis height, thus having a strong obstacle-crossing ability. (2) The magnetic lines of force of the robot equipped with this magnetic adsorption wheel are evenly distributed, and the adsorption force is stable. (3) By installing a pressure compensation interface on the magnetic adsorption wheel and connecting it to an external pressure compensator, the adsorption wheel can adapt to underwater environments at depths of tens or even hundreds of meters. (4) The motor output shaft transmits the rotational power to the rubber wheel through the harmonic reducer assembly and the hub connection flange, driving the rubber wheel to rotate; when the rubber wheel is in contact with the ship wall, the permanent magnet assembly will also generate a corresponding magnetic force when it is a certain distance away from the ship wall, ensuring that the design height between the connecting parts of the wall-climbing cleaning robot and the magnetic adsorption wheel structure is relatively high, so that the chassis of the wall-climbing cleaning robot is relatively high. Therefore, the wall-climbing cleaning robot can maintain a stable adsorption force and has a strong obstacle-crossing ability during the cleaning process. The magnetic adsorption wheel has a compact structure and high reliability. It integrates a brushless motor and a reducer, making it highly integrated and allowing for flexible configuration onto robots. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the external structure of a magnetic adsorption wheel structure for an underwater robot provided in an embodiment of this application.

[0018] Figure 2 This is a cross-sectional schematic diagram of a magnetic adsorption wheel structure for an underwater robot provided in an embodiment of this application.

[0019] Figure 3 The image shows a right view of a magnetic adsorption wheel structure for an underwater robot, as provided in an embodiment of this application.

[0020] Figure 4 The left view shows a magnetic adsorption wheel structure for an underwater robot provided in an embodiment of this application.

[0021] Figure 5 This is a schematic diagram of a set of permanent magnet components for a magnetic adsorption wheel structure of an underwater robot provided in an embodiment of this application.

[0022] Figure 6 A top-down view of the magnetic flux of a set of permanent magnet components for a magnetic adsorption wheel structure of an underwater robot provided in this application embodiment.

[0023] Figure 7 A top-view cloud image of the magnetic flux of a set of permanent magnet components for a magnetic adsorption wheel structure of an underwater robot provided in an embodiment of this application.

[0024] Figure 8 A side-view cloud map of the magnetic flux of a set of permanent magnet components for a magnetic adsorption wheel structure of an underwater robot provided in an embodiment of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] like Figure 1 , Figure 2 , Figure 3 and Figure 4 The diagram illustrates a magnetic adsorption wheel structure for an underwater robot, as shown in this embodiment of the invention. The magnetic adsorption wheel structure includes a magnetic adsorption wheel unit 2. A rubber wheel 1 is connected to a hub connecting flange 5 on the left side of the magnetic adsorption wheel unit 2. A watertight connector 3 and a pressure compensation interface 4 are connected to a sealing end cap 24 on the right side of the magnetic adsorption wheel unit 2. The watertight connector 3 serves a sealing function. The pressure compensation interface 4 is used to connect an external pressure compensator, enabling the magnetic adsorption wheel structure to operate in underwater environments at depths of 30 meters and above. This allows it to be used on hull-climbing cleaning robots on land and in water depths of tens of meters.

[0027] like Figure 2 As shown, the magnetic adsorption wheel unit 2 includes a hub connecting flange 5, a sliding bearing 6, a first O-ring seal 7, a first screw 8, a harmonic reducer assembly 9, a second screw 10, a third screw 11, a motor flange 12, a magnetic adsorption unit housing 13, a first frameless motor stator 14, a fourth screw 16, a second O-ring 17, a first magnetic protective cover 18, an encoder 19, an external sensor 20, a second magnetic protective cover 21, a fifth screw 22, an end cover sliding bearing 23, a sealed end cover 24, a screw 25, an output shaft sensor 26, a yoke 27, a second frameless motor stator 28, a frameless motor rotor 29, a motor output shaft 30, a permanent magnet 31, a first auxiliary screw 32, a bushing 33, a locking nut 34, a first auxiliary screw 35, a combination washer 36, and screw fasteners.

[0028] The magnetic adsorption wheel unit 2 includes a magnetic adsorption unit housing 13. The housing 13 has an annular groove 13-1 and an annular recess 13-2 arranged from the outside in. Multiple sets of permanent magnet assemblies are arrayed within the annular groove 13-1, and these assemblies are fixed to the annular groove 13-2 of the magnetic adsorption unit 2 housing by screws. Each set of permanent magnet assemblies includes two magnetic adsorption modules. Each module includes two yokes 27 and three magnets 31, with the three magnets 31 attached between the two yokes 27. The yokes 27 and the three magnets 31 are fixed to four nuts by two screws 25.

[0029] The first frameless motor stator 14 and the second frameless motor stator 28 are installed in the annular groove 13-2 with an interference fit. A frameless motor rotor 29 is positioned between the first frameless motor stator 14 and the second frameless motor stator 28, and the frameless motor rotor 29 is connected to the motor output shaft 30. The sealing end cover 24 is fixed to the right side of the magnetic adsorption wheel unit 2 by a locking nut 34. One end of the motor output shaft 30 is mounted on the end cover sliding bearing 23 of the sealing end cover 24, and a motor sensor 26 is mounted on the end of the motor output shaft 30 near the sealing end cover 24. A first magnetic protective cover 18 and an encoder 19 are mounted on the groove of the motor sensor 26. A bushing 33 is mounted on the other end of the motor output shaft 30, and a motor flange 12 is mounted on the end face of the bushing 33 and fixed to the left side of the magnetic adsorption unit housing 13 with a third screw 11. A harmonic reducer assembly 9 is mounted on one side of the bushing 33 of the motor output shaft 30 via a second screw 10 and a washer, and the harmonic reducer assembly 9 is fitted against the shoulder of the motor output shaft 30. The inner hole of the harmonic reducer assembly 9 is installed on the motor output shaft 30 on the bushing side and is in close contact with the shoulder of the motor output shaft 30.

[0030] Figure 5 , Figure 6 , Figure 7 and Figure 8 Combination Figure 2 In each permanent magnet assembly, the two magnetic adsorption modules are arranged with their magnetic poles oriented using a Halbach array. The structures in the two paired magnetic adsorption wheels are identical, but the magnetization directions of the central permanent magnets are different. Taking the plane directly opposite the cleaning robot as a reference, the N poles of the magnets in the left magnetic adsorption module are right, down, left from left to right; the N poles of the magnets in the right magnetic adsorption module are left, up, right from left to right. The left and right magnetic adsorption modules form a magnetic circuit, and this arrangement creates a good magnetic circuit. Simulations show that the single-wheel adsorption force can reach 2846.2 N. The dimensions of the magnet 31 and yoke 27 in the magnetic adsorption module are both 76.2 × 124.8 × 28 mm, and the fan angle of both the permanent magnet and the yoke is preferably 120°.

[0031] In this embodiment, a sealing end cap 24, secured with screws, is tightly mounted on the magnetic adsorption unit housing 13 on the open side. A countersunk hole coaxial with the small round hole is machined on the left end face of the magnetic adsorption unit housing 13. Outside the small round hole is a small annular groove, which mates with the input end boss of the harmonic reducer assembly 9. The entire harmonic reducer assembly 9 is placed in the countersunk hole, with a clearance fit between the harmonic reducer assembly 9 and the countersunk hole. The input side end face of the harmonic reducer assembly 9 is tightly attached to the bottom of the countersunk hole and secured with bolts.

[0032] The motor output shaft 30 is interference-fitted onto the frameless motor rotor 29, with one end face of the frameless motor rotor 29 closely abutting the shoulder of the motor output shaft 30. A motor sensor 26 is mounted on one end of the motor output shaft 30, passing through and engaging with the end cover sliding bearing 23. A second magnetic protective cover 21 and an external sensor 20 are mounted on the groove of the motor sensor 26. A bushing 33 is mounted on the other end of the motor output shaft 30, and a nut secures the bushing 33 to the shoulder. The bushing 33 is installed inside a small round hole in the housing of the magnetic adsorption unit 2, and a motor flange 12 is mounted on the end face of the bushing 33, which is then fixed to the housing of the magnetic adsorption unit 2 with a third screw 11. This secures both the bushing and the end cover sliding bearing 23 to the shoulder.

[0033] The inner hole of the harmonic reducer assembly 9 is installed onto the motor output shaft 30 on the bushing side, and is tightly abutted against the shoulder of the motor output shaft 30; on the other side, the harmonic reducer assembly 9 is fixed to the motor output shaft 30 using a second screw 10 and a washer. The outer shell of the harmonic reducer assembly 9 is fixed to the magnetic adsorption unit shell 13 by a first screw 8.

[0034] A sliding bearing 6 is installed between the boss end face of the hub connecting flange 5 and the magnetic adsorption unit housing 13, and the harmonic reducer assembly 9 is connected to the hub connecting flange 5 so that the rotation of the motor output shaft 30 is transmitted to the rubber wheel 1, driving the rubber wheel 1 to rotate. Specifically, in this embodiment, the hub connecting flange 5 is generally a three-layer stepped boss with two-stage countersunk holes at the bottom. The second-stage countersunk hole of the hub connecting flange 5 fits with the output boss end face of the harmonic reducer assembly 9, and the hub connecting flange 5 and the output boss of the harmonic reducer 9 are fixedly connected on the other side with screws. At this time, the hub connecting flange 5 and the harmonic reducer assembly 9 are both installed in the same countersunk hole on the same side of the magnetic adsorption unit housing 13. The outer circle of the sliding bearing 6 is interference-fitted on the countersunk hole of the magnetic adsorption unit housing, and one end face fits with the first-stage boss end face of the hub connecting flange 5. The inner circle of the sliding bearing 6 is clearance-fitted with the middle flange of the hub connecting flange 5. There is a countersunk hole on each side of the rubber wheel 1, and a through hole in the middle. The through hole in the middle of the rubber wheel 1 transitions to the three-stage boss of the hub connecting flange 5, and the rubber wheel 1 is fixed to the hub connecting flange 5 with screws on one side of the boss end face, so that the rotation of the motor output shaft is transmitted to the rubber wheel.

[0035] like Figure 2 and Figure 5 As shown, the hub connecting flange 5 has a sealing groove machined along the circumferential direction, and a combination gasket 36 is installed in the sealing groove. A first O-ring groove is machined on the other end face of the hub connecting flange 5, and a first O-ring seal 7 is installed in the first O-ring groove. The hub connecting flange 5 is provided with a plurality of first auxiliary screws 32 and a plurality of second auxiliary screws 35, and the hub connecting flange 5 mates with the end face of the connecting part of the cleaning robot through the plurality of first auxiliary screws 32 and the plurality of second auxiliary screws 35.

[0036] like Figure 2 and Figure 3 As shown, the sealing end cap 24 has a boss in the middle that transitions with the annular groove of the adsorption unit housing 13. The sealing end cap 24 has an axially machined motor bearing hole for mounting the end cap sliding bearing 23. The sealing end cap 24 has a second O-ring seal groove machined circumferentially, on which a second O-ring seal 17 is mounted. A countersunk hole is machined inside the O-ring seal groove, which is also used to mount the first magnetic protective cover 18 and the external sensor 20, and is secured with a fifth screw 22. The side of the second O-ring seal groove also has threaded holes for mounting the watertight connector 3 and for mounting the pressure compensator interface 4. A fourth screw 16 is also provided on the sealing end cap 24.

[0037] Preferably, the magnetic adsorption unit housing 13 and the sealing end cap 24 are made of magnetically conductive material; the hub connecting flange 5 is made of non-magnetically conductive material.

[0038] The magnetic adsorption wheel structure of an underwater robot of the present invention internally houses a frameless motor stator, a frameless motor rotor, a motor shaft, a harmonic reducer assembly, and multiple sets of permanent magnet assemblies mounted axially upwards. The motor output shaft transmits rotational power to the rubber wheel through the harmonic reducer assembly and the wheel hub connecting flange, driving the rubber wheel to rotate. When the rubber wheel is in contact with the ship's wall, the permanent magnet assembly generates a corresponding magnetic force at a certain distance from the ship's wall, ensuring a relatively high design height between the connecting parts of the wall-climbing cleaning robot and the magnetic adsorption wheel structure. This results in a relatively high chassis for the wall-climbing cleaning robot, thus enabling it to maintain stable adsorption force and possess strong obstacle-crossing ability during the cleaning process.

[0039] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A magnetic adsorption wheel structure for an underwater robot, characterized in that, The magnetic adsorption wheel unit (2) is provided with a rubber wheel (1) connected to a hub connecting flange (5) on the left side of the magnetic adsorption wheel unit (2) and a watertight connector (3) and a pressure compensation interface (4) connected to a sealing end cap (24) on the right side of the magnetic adsorption wheel unit (2). The watertight connector (3) is used for sealing. The pressure compensation interface (4) is used to connect an external pressure compensator so that the magnetic adsorption wheel structure can adapt to underwater operation. The magnetic adsorption wheel unit (2) includes a magnetic adsorption unit shell (13). The magnetic adsorption unit shell (13) has an annular slot (13-1) and an annular groove (13-2) arranged from the outside to the inside. Multiple sets of permanent magnet components are arranged in an array in the annular slot (13-1). Each set of permanent magnet components includes two magnetic adsorption modules. Each magnetic adsorption module includes two yoke irons (27) and three magnets (31). The three magnets (31) are attached between the two yoke irons (27). A first frameless motor stator (14) and a second frameless motor stator (28) are installed in the annular groove (13-2). The first frameless motor stator (14) and the second frameless motor stator (28) are installed in alignment. A frameless motor rotor (29) is provided between the sub-units (28), and a motor output shaft (30) is connected inside the frameless motor rotor (29); one end of the motor output shaft (30) is installed on the end cover sliding bearing (23) of the sealing end cover (24), and a motor sensor (26) is installed on the end of the motor output shaft (30) near the sealing end cover (24); a first magnetic protective cover (18) and an encoder (19) are installed on the groove of the motor sensor (26); a bushing (33) is installed on the other end of the motor output shaft (30), and a motor flange (12) is installed on the end face of the bushing (33) and fixed with screws on the left side of the magnetic adsorption unit housing (13); The harmonic reducer assembly (9) is mounted on one side of the bushing (33) of the motor output shaft (30) by screws and washers, and the harmonic reducer assembly (9) is fitted to the shoulder of the motor output shaft (30). A sliding bearing (6) is also installed between the boss end face of the hub connecting flange (5) and the magnetic adsorption unit housing (13), and the harmonic reducer assembly (9) is connected to the hub connecting flange (5) so that the rotation of the motor output shaft (30) is transmitted to the rubber wheel (1) to drive the rubber wheel (1) to rotate. The two magnetic adsorption modules in each permanent magnet assembly are arranged with their magnetic poles set in a Halbach array. The N poles of the magnets in the left magnetic adsorption module are right, down, and left from left to right; the N poles of the magnets in the right magnetic adsorption module are left, up, and right from left to right. The left and right magnetic adsorption modules form a magnetic circuit.

2. The magnetic adsorption wheel structure for an underwater robot according to claim 1, characterized in that, The magnet (31) and yoke (27) in the magnetic adsorption module are both 76.2×124.8×28mm in size.

3. The magnetic adsorption wheel structure for an underwater robot according to claim 1, characterized in that, The hub connecting flange (5) has a sealing groove machined along the circumferential direction, and a combination gasket (36) is installed in the sealing groove; a first O-ring groove is machined on the other end face of the hub connecting flange (5), and a first O-ring seal (7) is installed in the first O-ring groove; the hub connecting flange (5) is connected to the end face of the connecting part of the cleaning robot by a plurality of first auxiliary screws (32) and a plurality of second auxiliary screws (35).

4. The magnetic adsorption wheel structure for an underwater robot according to claim 3, characterized in that, The magnetic adsorption unit housing (13) and the sealing end cap (24) are made of magnetically conductive material; the hub connecting flange (5) is made of non-magnetically conductive material.

Images