Waist and leg two-point fixing type underwater propelling system based on universal detachable tool battery

Abstract

The invention discloses a waist and leg two-point fixing type underwater propulsion system based on a universal detachable tool battery, and belongs to the technical field of underwater movement auxiliary equipment. The system comprises an integrated power module which is integrated with an underwater propeller, a propeller electronic speed controller and a waterproof quick-connection interface; the two-point type torque restraining and stabilizing system comprises a main waistband rigidly connected with the power module and an auxiliary bandage connected with the bottom of the module through a flexible belt and used for fixing thighs, and the main waistband and the auxiliary bandage cooperate to restrain the equipment from rotating around the waist axis of the human body; the waterproof quick-connection interface comprises an original tool battery slide rail base and waterproof pouring sealant wrapped in all directions, so that a battery pack meeting the standard of a commercially available handheld electric tool interface can synchronously realize mechanical locking, electrical connection and waterproof sealing underwater. According to the invention, direct manual control (delay lt; according to the invention, a general battery underwater hot plug and waist and leg two-point stable structure is adopted, the problems of large response delay, anxiety in endurance, high cost and poor stability in the prior art are solved, and zero learning cost operation, infinite endurance, significant cost reduction and excellent underwater movement stability are realized.

Description

A two-point fixed underwater propulsion system based on a universal removable tool battery. Technical Field

[0001] This invention relates to the field of underwater sports assistance equipment technology, specifically to an integrated propulsion system that utilizes a detachable battery pack conforming to the interface standards of commercially available handheld power tools (such as Makita and Bosch) as its power source, and is secured by a rigid waist connection and thigh auxiliary straps to provide stable underwater thrust. This system is particularly suitable for applications requiring hands-free operation and demanding high mobility, endurance flexibility, and low operating costs, such as swimming assistance, diving exploration, underwater photography, underwater operations, and rescue. Background Technology

[0002] As auxiliary equipment for underwater movement, exploration, and operations, underwater propulsion devices have long been developed with the goal of "freeing up hands" and "stability and reliability." However, existing mainstream technologies all have inherent defects and are difficult to meet the needs of practical applications: 1. Handheld propulsion devices (such as the "Aiyuedong" electric float): Although the control is direct, it requires the user's hands to be occupied continuously, and the center of gravity of the device is far from the core of the human body, resulting in unstable operation. Prolonged use can easily cause shoulder fatigue, which seriously limits the user's autonomy in performing delicate operations such as underwater photography and sampling.

[0003] 2. Biosignal-sensor-based thrusters (e.g., Chinese patent CN117184371A): This type of solution relies on an IMU sensor to detect the leg-kicking frequency, which is then processed by a microprocessor to output a control signal. This results in an inherent delay of at least 200-500 milliseconds, causing a severe disconnect between power output and user intent, affecting precise maneuvers such as emergency obstacle avoidance. Users must maintain a specific leg-kicking motion (≥3 times / second) to sustain power; significant leg fatigue occurs after 15 minutes, defeating the purpose of the assistive device. Furthermore, the underwater environment makes the sensor susceptible to interference from water flow and temperature, reducing reliability by more than 30%.

[0004] 3. Complex mechanical structure propellers (such as Chinese patent CN115571300B): This type of solution uses a reversible shaftless propeller, which achieves anti-entanglement through hinged components, limit magnetic attraction and other structures. However, the increase in moving parts leads to an increase in sealing surfaces, and the failure rate is more than 30% higher than that of ordinary shafted propellers. The manufacturing cost increases by about 50%, and maintenance is complex and expensive.

[0005] Of particular importance is the existence of an unresolved technological bottleneck and bias in this field. While commercially available removable battery packs for handheld power tools (such as those from Makita and Bosch) offer significant advantages including standardization, high energy density (≥200Wh / kg), low cost (approximately 50-100 RMB per unit), and easy availability, the industry generally believes that their non-waterproof electrical interfaces pose serious safety risks of short circuits, contact corrosion, and seal failure when directly applied to underwater environments. Therefore, this mature and inexpensive energy solution has never been successfully applied to underwater propulsion. This invention overcomes this technological bias through a targeted waterproof potting process. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome one or more of the following defects in the prior art: the inherent response delay (≥200ms), high learning cost, easy user fatigue, and low reliability of biosignal control schemes; the high manufacturing cost (increased by about 50%), increased reliability risk (failure rate increased by 30%), and difficult maintenance caused by complex mechanical structure schemes; and the common problems of endurance anxiety (built-in battery endurance ≤30 minutes), high operating cost (dedicated battery unit price ≥200 yuan), bulky structure (weight ≥4kg), and insufficient stability (rotation around waist axis ≥15°) of existing underwater propulsion equipment.

[0007] This provides an underwater propulsion solution that is ready to use immediately, has a response latency of <50ms, is stable and reliable (rotation angle <3°), is low-cost (40% lower than dedicated battery solutions), lightweight (less than 1.5kg), and offers flexible and scalable endurance. To solve the above technical problems, this invention adopts the following technical solution:

[0008] An underwater propulsion system is innovative in that the control logic, energy system and stable structure are designed in a coordinated manner. In terms of control, the indirect biological signal sensing mode is abandoned and a direct control unit integrated on the integrated power module (10) is adopted. The user can operate directly with his / her fingers, eliminating the delay links such as signal sampling and algorithm calculation from the physical level. The measured control response delay is <50ms, ensuring the real-time synchronization of the user's intention and the power output.

[0009] In terms of energy, a waterproof quick-connect interface (50) that conforms to the removable battery interface standard of commercially available handheld power tools (such as Makita and Bosch) is creatively adopted. Its core is: a slide rail base (51) that is compatible with the mechanical structure of the original interface of the general-purpose tool battery of a specific brand; the base is subjected to all-round, highly reliable waterproof sealing treatment, and 704 silicone rubber (100) is used for overall potting with a potting thickness of ≥3mm, which completely covers the metal spring and welding points of the slide rail base; ensuring that the battery pack (40) can achieve the synchronous establishment or release of mechanical locking, electrical connection and IP68 waterproof sealing through a single plug-in action underwater.

[0010] Structurally, a two-point torque suppression and stabilization system for the waist and legs is designed. This system provides the main load-bearing point through a rigid connection (such as an M5 stainless steel screw) between the main waist belt (20) and the integrated power module (10); and an auxiliary strap (30) connected to the bottom of the module via a flexible strap, fixed to the user's thigh root to provide an auxiliary restraint point. Together, these components form a mechanically stable structure that suppresses the device's rotation around the human waist axis. Testing shows that this suppresses the rotation angle from ≥15° to <3°. Compared with existing technologies, the technical solution of this invention produces the following significant beneficial effects:

[0011] A revolutionary improvement in control: Direct manual control enables intuitive operation with zero learning cost (no need to learn specific actions). Testing shows that from the user's operation of the controller to the thruster generating thrust, the system response latency is <50ms, an improvement of over 80% compared to biosignal sensing solutions (latency ≥200ms), fundamentally improving the user experience.

[0012] A qualitative leap in stability: The innovative two-point torque suppression and stabilization structure of the waist and legs effectively suppresses the "seesaw effect" through mechanical optimization, making the equipment fit firmly against the core of the human body, with a rotation angle of less than 3° around the waist axis (compared to ≥15° for single-point fixation), improving propulsion efficiency by more than 25%, and significantly enhancing control confidence.

[0013] A breakthrough in both battery life and cost: The plug-and-play nature of the external universal tool battery, combined with underwater hot-swappable functionality (replacement time <10 seconds), makes "unlimited battery life" possible. At the same time, users can utilize existing tool batteries, eliminating the need to purchase dedicated backup power supplies or carry heavy, high-capacity batteries, reducing the device's weight by 3-5 kg ​​and lowering the total lifecycle cost by approximately 60%.

[0014] The various technical features of this invention form a functionally coupled closed-loop system: direct handheld control (delay <50ms) places sensitive demands on structural stability, driving the two-point support design for the waist and legs; the increased structural weight (approximately 150g) from the two-point support forces the external energy system to control the overall weight; the need for quick-change external batteries requires the propulsion, control, and interface to be integrated into a single unit. These three aspects are mutually causal and mutually restrictive, constituting an inseparable overall inventive concept. Attached Figure Description

[0015] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some, and not all, of the embodiments of the present invention.

[0016] Figure 1 is a schematic diagram of the underwater propulsion system of the present invention in its worn state.

[0017] The figure shows the system worn on the left side of the user's body, clearly showing the integrated power module (10) located at the hip, the main waist belt (20) around the waist, the auxiliary strap (30) around the left thigh, the universal tool battery (40) plugged into the waterproof quick-connect interface (50), the underwater thruster (60) linked to the module (10), the power controller (70) integrated on the housing of the module (10), and the booster ESC (80) waterproof sealed inside the module (10).

[0018] Figure 2 is a three-dimensional structural diagram of the integrated power module (single thruster version) and the two-point torque suppression and stabilization system of the present invention.

[0019] The figure clearly shows the connection status of the streamlined housing (10), underwater thruster (60), waterproof quick-connect interface (50), universal tool battery (40), as well as the rigid connection point between the main belt (20) and the housing and the connection relationship between the auxiliary strap (30) and the housing.

[0020] Figure 3 is a three-dimensional structural diagram of the integrated power module (dual-thruster version) of the present invention.

[0021] The figure shows the structure in which the left thruster (60a) and the right thruster (60b) are arranged symmetrically and independently on an integrated power module (10a, 10b).

[0022] Figure 4 is a schematic diagram of the structure of the thruster, the battery hot-swappable interface module, and the integrated power module.

[0023] This figure is the core attached figure, which clearly shows the internal structural relationship of the integrated power module (10), including: the underwater thruster (60) is installed with the module housing by connecting hinges, the original tool battery slide rail base (51), the waterproof potting compound (100) inside the all-around base, and the power output wire (110) led out from the potting compound.

[0024] Figure 5 is an internal rear view of the integrated power module (10).

[0025] The figure highlights the installation layout of the thruster ESC module (80) and power controller (70) inside the power module base (10), and also reiterates the full-coverage state of the waterproof potting compound (100).

[0026] In Figure 1: 10-integrated power module, 20-main belt, 30-auxiliary strap, 40-universal tool battery, 50-waterproof quick connector, 60-underwater thruster, 70-power controller, 80-booster ESC, 100-waterproof potting compound.

[0027] In Figure 2: 10 - streamlined housing, 20 - main belt, 30 - auxiliary straps, 40 - universal tool battery, 50 - waterproof quick-connect interface, 60 - underwater thruster.

[0028] In Figure 3: 60 - left thruster, 60 - right thruster, 10 - integrated power module.

[0029] In Figure 4: 10-integrated power module, 51-original tool battery slide rail base, 60-underwater thruster, 100-waterproof potting compound inside the base, 110-power output wire (110).

[0030] In Figure 5: 10 - Integrated power module base, 70 - Power controller, 80 - Booster ESC module, 100 - Waterproof potting compound. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Those skilled in the art, guided by the principles of the present invention, can make appropriate changes or combinations to the specific embodiments, and such changes or combinations should be considered to fall within the protection scope of the present invention. In this embodiment, a basic configuration of a waist-leg two-point fixed underwater propulsion system based on a universal removable tool battery is provided. Its structure is simple and its cost is low, making it suitable for personal underwater recreation or light-duty operations.

[0032] Integrated power module (10): A 150W DC brushless underwater thruster (60) is used as the power source. The thruster is hinged to a 3D-printed ABS engineering plastic shell, which is streamlined to reduce water flow resistance. As a preferred option, the shell can be made of polycarbonate (PC), nylon with glass fiber (PA+GF), or reinforced with carbon fiber composite material to improve structural strength, corrosion resistance and service life. A 40A booster ESC (80) is integrated inside the shell as the thruster ESC, and its output is directly connected to the thruster with a waterproof wire (110). The booster ESC (80) and a power controller (70) together constitute the control unit. The power controller (70) is a potentiometer module with a waterproof knob, which is directly exposed on the surface of the shell. The user can directly adjust the thruster power with their fingers.

[0033] Waterproof quick-connect interface (50): The original slide rail power take-up base of Makita 18.5V power tool battery is used as the base (51). To achieve underwater waterproofing, 704 silicone rubber is used to fully pot and seal the power take-up base to form a waterproof potting compound (100), ensuring that the electrical contacts are completely isolated from the external water. After potting, the power drawn from the power take-up base is connected to the input terminal of the thruster ESC (80) and controlled by the power controller (70). The thickness of the 704 silicone rubber potting is not less than 3mm, completely covering the metal spring and welding points of the slide rail base (51). After potting, it is left to stand for more than 24 hours to ensure complete curing. According to actual tests, the interface can work continuously for 30 minutes in a 3-meter water depth environment without leakage, and can withstand more than 100 underwater plugging and unplugging cycles. The insulation resistance remains >10MΩ, and no short circuit or sealing failure occurs, which meets the IP68 protection level requirements.

[0034] Two-point torque suppression and stabilization system: The main waist belt (20) is a 5cm wide nylon webbing with neoprene foam material attached to its inner side to enhance comfort. The two ends of the webbing are adjusted for length and quick on / off via a plastic quick-release buckle. The main waist belt (20) is rigidly connected to the back of the housing of the integrated power module (10) via two M5 stainless steel screws. The auxiliary strap (30) is a 3cm wide elastic webbing connected to the bottom connection hole of the integrated power module (10), and the other end is fixed in a ring around the thigh via a plastic buckle. The user can adjust the length and tightness of the main waist belt (20) and the auxiliary strap (30) to adapt to different leg movements. Comparative tests show that when only the waist is fixed at a single point, the reaction torque of the thruster causes the device to swing around the waist axis by ±15°, and the user needs to consume an additional 30% of physical strength to maintain balance; after adopting the two-point fixation of the present invention, the swing angle is reduced to ±2.5°, and the propulsion efficiency is increased by more than 25%.

[0035] Energy System: The system directly uses commercially available Makita 18.5V, 2.0Ah lithium-ion tool batteries (40) as its power source. These batteries have high energy density, are lightweight (approximately 0.35kg), and can be shared with other tools, significantly reducing energy costs for users. Given the wide variety of removable batteries available for commercially available handheld power tools, all with a standard voltage of 18.5V and capacities of 1.5Ah, 2.0Ah, 3.0Ah, and 5.0Ah, this system will provide more options for single-charge operation.

[0036] Control method: The user controls the thrust by directly operating the power controller (70) knob on the housing of the integrated power module (10), achieving intuitive operation with zero delay. In addition, as an alternative, the system can also be equipped with a commercially available 2.4GHz model aircraft wireless remote controller as a handheld controller, whose receiver module is pre-integrated inside the power module (10).

[0037] Instructions for use: Wearing: First, the user wraps the main waistband (20) around the waist and fastens it, adjusting it to a comfortable and secure tightness. Then, the auxiliary strap (30) is wrapped around the base of one thigh (usually the dominant leg) and fastened.

[0038] Power supply: Insert the universal Makita tool battery (40) along the slide rail into the waterproof quick connector (50). A "click" sound indicates that the connection is in place.

[0039] Operation: After entering the water, the user can directly start and steplessly adjust the thruster by rotating the power controller (70) knob on the housing with their thumb and forefinger or by using the knob on the handheld wireless remote control to obtain the appropriate forward or upward propulsion. Actual testing showed that using a Makita 18.5V 2.0Ah lithium-ion tool battery as the sole power source, this system can provide stable propulsion for a 70kg adult user while maintaining a streamlined freestyle swimming posture and without leg kicking. During a complete battery discharge cycle (15 to 20 minutes), the average movement speed can reach 1.2 m / s.

[0040] Battery Life and Maintenance: When one battery is depleted, the user can directly remove the depleted battery underwater and insert another fully charged utility battery of the same specifications, achieving hot-swapping underwater and theoretically "unlimited battery life." Routine maintenance only requires rinsing the exterior of the system with fresh water and checking the integrity of the waterproof potting compound (100). The effect comparison analysis is shown in the table below:

[0041]

[0042] Example 2: Enhanced implementation of the dual-thruster version In this example, in order to provide stronger thrust and more balanced load distribution, a dual-thruster system is used with two power modules (10) fixed on the left and right sides of the hip respectively.

[0043] System Composition: This system comprises two structurally identical integrated power modules (10), referred to as the left power module and the right power module, respectively. The structure of each module is basically the same as that of the single module in Embodiment 1, and each includes an underwater thruster (60), a booster ESC (80), a power controller integrated into the housing (70), and an independent waterproof quick-connect interface (50).

[0044] Fixing system: The main waist belt (20) is the same as in embodiment 1, and the connection points at both ends are rigidly connected to the housings of the left and right integrated power modules (10) through quick-release buckles. There are two auxiliary straps (30) respectively, which are connected to the bottom of the left and right power modules and are fixed around the user's left and right thighs.

[0045] Control and Energy System: Both power modules can independently configure the thruster (60) power via the power controller (70) on the integrated power module housing (10). Alternatively, the system can be paired with a commercially available 2.4GHz model aircraft wireless remote controller as a handheld controller, with its receiver module pre-integrated inside the power module (10). The energy system also uses two independent universal utility batteries (40), which are inserted into the waterproof quick-connect interfaces (50) of the left and right power modules respectively, forming independent power supply circuits and improving system redundancy and reliability.

[0046] Instructions for use: Wearing: The user wraps the main waist belt (20) around the waist and adjusts the left and right power modules to comfortable positions on the left and right sides of the hips, then fastens the main waist belt. Subsequently, the left and right auxiliary straps (30) are wrapped around the left and right thigh roots and fastened.

[0047] Power supply: Insert the two utility batteries (40) into the interfaces of the left and right power modules respectively.

[0048] Operation: Dual-side synchronous propulsion: The thrust of the propellers can be steplessly adjusted by rotating the power controller (70) knob on the left and right sides with either hand. Both propellers output thrust simultaneously to achieve high-speed movement. When the system is configured in dual-propeller mode, that is, when the two propellers are fixed on both sides of the user's body, the performance is significantly improved. According to actual testing, under the same usage conditions in Example 1:

[0049] High-performance mode: cruise speed up to 1.7 m / s, continuous working time up to 15 minutes, suitable for strong current environments or rapid movement requirements; Economy mode: maintains a basic cruise speed of 1.2 m / s, and extends the working time to 35 minutes, meeting the needs of long-term underwater operations.

[0050] This configuration not only enhances the maximum propulsion capability but also allows for flexible coverage of a wide range of scenarios, demonstrating the high flexibility of the invention in system configuration.

[0051] Single-sided operation: When precise operation is required or power saving is desired, only one side of the power module can be activated.

[0052] Using larger capacity batteries: Based on actual testing and theoretical calculations, the estimated range and weight supported by batteries of different capacities are shown in the table below.

[0053]

[0054] Verification of the effects of the embodiments: The physical tests of the above embodiments show that the underwater propulsion system of the present invention has the following significant effects: control responsiveness: the delay time from the user issuing the command to the thruster generating thrust is less than 50 milliseconds, realizing real-time synchronization with the user's intention.

[0055] Stability: The waist and leg two-point fixation system effectively suppresses the "seesaw effect" of the equipment around the waist axis when the equipment is running underwater, and the dual-module design further improves load balance and motion stability.

[0056] Economy and convenience: The use of general-purpose utility batteries results in extremely low energy costs per use, and battery replacement is convenient. The hot-swappable function in water has been verified, and no electrical failures have occurred.

[0057] System reliability and flexibility: After more than 50 hours of underwater testing, the waterproof quick-connect interface (50) showed no leakage or short circuit. Single-module and dual-module configurations provide application flexibility to meet different needs.

[0058] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0059] Synergistic mechanism: The technical solution of this invention is not a simple superposition of the features, but rather forms a positive cycle of functional dependence.

[0060] Handheld direct control requires ultra-low latency: If bio-signal sensing control is used (latency ≥ 200ms), the user's sensitivity to mechanical shaking is reduced, and the two-point support structure for the waist and legs becomes unnecessary; conversely, after handheld control achieves a latency of ≤ 50ms, the user's requirements for stability are extremely high, forcing the two-point support to become a necessary feature.

[0061] Two-point support increases system weight: The rigid waist connector and leg hinge add about 150g to the system's weight. If a built-in dedicated battery (which is not replaceable) is used, range anxiety will offset the stability advantage. Conversely, the external universal battery quick-change (weight transfer to the battery pack) reduces the system's net weight to 0.8kg, improving user acceptance.

[0062] External battery quick-change requires module centralization: if the thruster, ESC, and battery interface are scattered, blind operation of plugging and unplugging in water will be extremely difficult; conversely, an integrated power module integrates the three, allowing users to complete battery replacement with one hand.

[0063] The above closed-loop logic proves that the present invention possesses an indivisible overall inventiveness.

Claims

1. An underwater propulsion system, characterized in that, include: An integrated power module (10) internally integrates at least one underwater brushless thruster (60), a booster ESC (80), and a waterproof quick-connect interface (50); a two-point torque suppression and stabilization system includes a main waist belt (20) for wrapping around and securing to the user's waist and an auxiliary strap (30) for wrapping around and securing to one side of the user's thigh; wherein, the main waist belt (20) is rigidly connected to the housing of the integrated power module (10) through a metal connector to provide the main load-bearing point; the auxiliary strap (30) is connected to the bottom of the integrated power module (10) through a flexible band to provide an auxiliary restraint point; the rigid connection and The flexible strips work together to form a mechanically stable structure that can effectively suppress the rotation of the integrated power module (10) around the waist axis of the human body when the thruster is working; the waterproof quick-connect interface (50) includes an original slide rail base (51) of a commercially available handheld power tool battery pack. The base (51) and its electrical contacts are fully wrapped and sealed with waterproof potting compound (100), so that the universal tool battery pack (40) that meets the corresponding interface standard can achieve the synchronous establishment or release of mechanical locking, electrical connection and waterproof sealing through a single plug-in action underwater; so that the system can achieve direct underwater control, stable propulsion and unlimited energy extension, while the overall equipment achieves a lightweight and portable design.

2. The underwater propulsion system according to claim 1, characterized in that, The waterproof potting compound (100) is 704 silicone rubber or epoxy resin potting compound, and the potting thickness is not less than 3mm.

3. The underwater propulsion system according to claim 1 or 2, characterized in that, The interface standard of the commercially available handheld power tool battery packs is the 18V / 20V MAX platform (nominal 18V) slide rail interface standard selected from mainstream brands such as Makita, Bosch, Dayi, and Worx.

4. The underwater propulsion system according to claim 1, characterized in that, The integrated power module (10) has an integrated control unit for directly and manually controlling the switch and power of the underwater thruster (60).

5. The underwater propulsion system according to claim 1, characterized in that, The number of underwater thrusters (60) is two, and they are symmetrically arranged on the left and right sides of the integrated power module (10).

6. The underwater propulsion system according to claim 1, characterized in that, The control unit is a waterproof knob or button integrated on the housing of the integrated power module (10), or a handheld wireless remote control paired with a wireless receiver integrated inside the module.

Images