A multi-stage gradient anti-silt underwater device

Abstract

The application discloses a multi-stage gradient anti-silt underwater equipment, which comprises a static part and a rotating part rotating relative to each other. Outside the core support gap, a flow guiding and sand throwing part and an expansion and sedimentation part are arranged in sequence from upstream to downstream along the water flow direction. The flow guiding and sand throwing part is an annular step arranged on the static part, which utilizes water flow inertia separation to throw large particle silt out of the side; the expansion and sedimentation part is an annular groove arranged on the inner hole wall of the static part, which utilizes the low-speed vortex area formed by the sudden change of the flow passage section to make fine sand particles settle and be intercepted in the groove; the two parts are cooperated with each other, and the different particle size silt is classified and intercepted through inertia separation and vortex settlement respectively. An end face flow guiding part can also be arranged, which generates centrifugal force relying on the mechanical movement of the rotating part to dredge fine particles. The application has simple structure, no vulnerable parts, and is suitable for silt-containing underwater working conditions, and can prolong the service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of underwater equipment technology, specifically to an underwater device suitable for underwater working conditions with high sediment content and equipped with a multi-level sediment protection structure, including but not limited to underwater thrusters, underwater motors, underwater pumps, underwater work equipment, underwater robots, etc. Background Technology

[0002] When underwater equipment operates in water environments with high sediment content, sediment particles carried by the water flow may enter the mating gaps of relatively rotating parts inside the equipment. Long-term operation may cause problems such as wear on mating surfaces, rotational jamming, and increased operating resistance. In severe cases, it may lead to seal failure and internal water ingress, affecting the service life and operational reliability of the equipment.

[0003] Existing underwater equipment sediment protection technologies employ single-layer baffles, one-way seals, or simple flow-guiding structures. While these structures offer some interception of large sediment particles, their effectiveness against fine sand and silt is limited, failing to meet the requirements for sediment protection across the entire particle size range. Other complex sediment protection structures may increase water flow resistance, affecting internal lubrication and heat dissipation, and are relatively complex with numerous vulnerable parts, resulting in higher maintenance costs. Therefore, a sediment protection solution is needed that can achieve multi-stage sediment protection without significantly impacting normal equipment operation and possesses a simple structure. Summary of the Invention

[0004] Core working principle

[0005] This invention, based on particle dynamics and fluid boundary layer theory, utilizes the working principles of stepwise interception, gradient protection, and self-guiding water flow. A multi-level anti-siltation structure is installed on the outer side of the mating parts of the relatively rotating components to protect the internal core support gaps from silt abrasion. The specific mechanism of action is as follows:

[0006] The first stage is the flow guiding and sand-throwing section, located on the outermost side, which is an annular step on a stationary component. When sand-laden water flows through this step, the cross-section of the flow channel changes abruptly, and the direction of the water flow is forced to deflect. Large particles of sediment, due to their greater inertia, cannot turn rapidly with the water flow and are thrown to the outside of the flow channel and discharged with the mainstream.

[0007] The second stage: the expansion and settling section, which connects with the flow-guiding and sand-throwing section, is an annular groove on the inner wall of the stationary component. When water enters this groove, the cross-section suddenly expands, forming a low-speed vortex zone. Fine sand particles lose kinetic energy in the vortex zone and settle towards the bottom of the channel; the settled particles are captured by the vortex and are not easily swept up by the main flow, thus depositing at the bottom of the annular channel.

[0008] Third stage: End face guide section. Optionally, an end face guide section can also be provided on the end face of the rotating component. This end face guide section can be configured as a radial groove or a spiral groove. When the rotating component rotates, centrifugal force is generated in the groove, which throws the fine particles close to the end face gap outward; at the same time, the groove acts as a water flow channel, guiding the water flow into the core support gap.

[0009] The three-stage structure described above is connected sequentially from the outside in. Each stage employs different physical mechanisms (inertial separation, eddy current settling, and centrifugal sand throwing) for particles of different size ranges, working in synergy with each other. The entire process relies on the movement of the water flow itself and the mechanical motion of the rotating components, requiring no additional power.

[0010] Technical issues

[0011] This invention aims to provide a multi-level gradient underwater sediment-resistant device to solve the problems of poor interception effect of existing underwater sediment-resistant technologies for fine sand, complex structure, many vulnerable parts, and impact on normal operation of the equipment. It achieves graded interception of sediment across the entire particle size range, requires no external power, and has a simple and reliable structure.

[0012] Technical solution

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] An underwater device for resisting sediment includes a stationary component and a rotating component that rotate relative to each other, with a core support gap between them. On the outside of the core support gap, a flow guiding and sediment-throwing section and a volume-expanding and settling section are arranged sequentially from upstream to downstream along the water flow direction. The flow guiding and sediment-throwing section is an annular step set on the stationary component to deflect the sediment-laden water flow and throw large particles of sediment outward. The volume-expanding and settling section is an annular groove set on the inner wall of the stationary component to allow fine sand particles to settle and be trapped in the groove through a low-speed vortex zone formed by the abrupt change in the flow channel cross-section.

[0015] Furthermore, the height of the annular step and its angle with the axis can generate sufficient water flow deflection to throw large particles of silt outward, and the height is adapted to the size of the main channel.

[0016] Furthermore, the width and depth of the annular groove can form a stable low-speed vortex zone within the groove to achieve the settling and retention of fine sand particles, and the ratio of the width to the depth is adapted to the vortex formation requirements.

[0017] Furthermore, it also includes an end face guide section, which is a radial groove or spiral groove provided on the end face of the rotating component, used to guide fine particles outward by using rotational centrifugal force and to provide a water flow channel.

[0018] Furthermore, the depth, width, and number of the radial grooves or spiral grooves of the end face guide portion are adapted to the rotational speed requirements of the rotating component, and the number is evenly distributed to ensure balanced centrifugal force, thereby producing an effective centrifugal guiding effect.

[0019] Furthermore, the multi-stage anti-sediment structure is located upstream of the water inlet side of the core support gap to provide clean water flow to the core support gap.

[0020] Furthermore, the present invention also provides a method for preventing underwater equipment from accumulating sediment, comprising the following steps:

[0021] a) Make the sand-laden water flow through the annular steps on the stationary component, and use the annular steps to deflect the water flow, throwing large particles of silt outwards.

[0022] b) The water flow after step a) is passed through the annular groove on the inner wall of the stationary component. The low-speed vortex zone formed by the annular groove causes the fine sand particles to settle and be trapped in the groove.

[0023] c) Allow the water treated in step b) to enter the core support gap of the equipment;

[0024] In this process, steps a) and b) work together, with the water flow deflection angle in step a) matching the eddy current intensity in step b), so that particles of different sizes are intercepted in sequence; and this matching process does not require additional power or human intervention, but is achieved automatically through the movement of the water flow itself.

[0025] Furthermore, after step b) and before step c), the process includes a step of allowing water to flow through radial or spiral grooves on the end face of the rotating component, using centrifugal force to guide fine particles outward.

[0026] Beneficial effects

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Through the inertial separation of the guide sand-throwing section and the eddy current settling of the expansion settling section, different particle sizes of mud and sand can be intercepted in stages, significantly reducing the mud and sand entering the core support gap and extending the service life of the equipment.

[0029] 2. No sensors, controllers or other active control devices are required throughout the process. The structure is simple, highly reliable and low in cost, making it suitable for long-term maintenance-free operation.

[0030] 3. It is driven by the movement of the water flow itself and the mechanical movement of the rotating parts, with no additional energy consumption.

[0031] 4. It is compatible with water film support structures, providing them with clean water flow to achieve synergistic protection. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of the overall structure of the present invention; Figure 2 This is a partially enlarged schematic diagram of a multi-level anti-sediment structure.

[0033] Explanation of reference numerals in the attached drawings: 1—Stationary component; 2—Rotating component; 3—Flow guiding and sand-throwing section (annular step); 4—Expanding and settling section (annular groove); 5—End face flow guiding section (radial groove / spiral groove); 6—Core support gap. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. This embodiment takes a shaftless rim propeller as an example and is only used to explain the principle of the invention. Any technical solution that follows the core principle of the present invention (at least an annular step and an annular groove are provided on the outside of the core support gap 6, and the step is provided first and the groove is provided later along the water flow direction) falls within the protection scope of the present invention.

[0035] It should be noted that:

[0036] • The “core support gap” referred to in this invention refers to the main fitting gap between relatively rotating components, such as bearing gap, water film gap or sealing gap, which is the area of ​​equipment that needs to be protected.

[0037] • In this invention, “main flow channel” refers to the main channel through which water flows inside the equipment, and its height H refers to the characteristic dimension of the flow channel in the radial direction.

[0038] • The “annular step” referred to in this invention includes continuous annular steps, as well as a ring structure formed by multiple arc segments arranged at intervals along the circumference, as long as the structure can deflect and inertially separate the water flow in the circumferential direction as a whole.

[0039] • The phrase “arranged sequentially from upstream to downstream along the water flow direction” as described in claim 1 allows for necessary rounded corners, chamfers, or non-functional transition sections between the flow guiding and sand-throwing section 3 and the expansion and settling section 4, but does not allow for additional structures with sediment interception functions.

[0040] like Figure 1 , Figure 2 As shown, an underwater device for resisting sediment, taking a shaftless rim propeller as an example, includes a stationary support (stationary component 1) and a rotating duct (rotating component 2), which are coaxially fitted and rotate relative to each other. On the outer side of the mating part of the stationary support and the rotating duct, a flow guiding and sediment-throwing section 3 and a volume-expanding and settling section 4 are arranged sequentially from upstream to downstream along the water flow direction, and an end-face flow guiding section 5 is arranged on the end face of the rotating duct.

[0041] The sand-throwing section 3 is an annular step on the inner hole of the stationary support. The preferred range for the ratio h / H of the step height h to the main channel height H is 0.2 to 0.5, the preferred range for the angle θ between the step surface and the axis is 30° to 60°, and the rounded corner R of the step inlet edge is 0.5 to 1 mm. When the sand-laden water flows through the step, the direction of the water flow deflects due to the abrupt change in the channel cross-section. The deflection angle is approximately 45° to 60°. Large particles of sediment, due to their greater inertia, cannot follow the rapid turn of the water flow and are thrown to the outside of the channel, and are discharged from the equipment with the main channel. When the step angle is too small (e.g., less than 30°), the water flow deflection angle is insufficient, and large particles of sediment are difficult to be effectively thrown out; when the angle is too large (e.g., greater than 60°), the local resistance of the channel increases significantly, affecting the overall efficiency. The above numerical ranges are only preferred examples and are not necessary conditions for achieving the purpose of this invention.

[0042] Expanded Settling Section 4: This is an annular groove on the inner wall of the stationary support. The preferred range for the groove width W is 1–5 mm, the preferred range for the groove depth D is 2–5 mm, and the preferred W:D ratio is 1:1–1:2. After the water flows into the groove, the cross-section suddenly expands, forming a low-velocity vortex zone. Because the groove depth is greater than the height of the main channel, the flow velocity inside the groove is low, and the kinetic energy of the fine sand particles decreases in the vortex, causing them to settle towards the bottom of the groove. The shear stress on the settled particles is less than their starting critical stress, so they are not easily re-rolled by the main channel and are deposited at the bottom of the annular groove. If the groove width is too small (e.g., less than 1 mm), the vortex space is insufficient, resulting in low settling efficiency; if the groove width is too large (e.g., greater than 5 mm), it may affect the structural strength. If the groove depth is too small (e.g., less than 2 mm), an effective low-velocity vortex zone cannot be formed; if the groove depth is too large (e.g., greater than 5 mm), the processing difficulty increases. The above numerical ranges are only preferred examples and are not necessary conditions for achieving the purpose of this invention.

[0043] Under different sediment concentrations, the water flow deflection angle and eddy intensity automatically match through the water flow's own motion: when the sediment concentration is high, the inertial separation effect is enhanced, the deflection angle increases slightly, and the flow velocity in the eddy zone is adjusted accordingly to ensure fine sand settling; when the sediment concentration is low, the deflection angle decreases, the eddy intensity weakens, and unnecessary energy loss is avoided. This adaptation process requires no external control and is entirely achieved through the coupling effect between the water flow and the structure.

[0044] End face guide section 5: The outlet of the expansion and settling section 4 is connected to the axial gap between the end face of the rotating component. After the water flows out of the groove, it flows radially inward along the end face gap and enters the end face guide section 5. This section is a radial groove or spiral groove provided on the end face of the rotating component. The groove depth is preferably 0.1 to 0.3 mm, the groove width is preferably 1.0 to 2.0 mm, the number is preferably 4 to 6, evenly distributed, and the groove edge is rounded with a radius of R0.1 mm. When the rotating component rotates, centrifugal force is generated in the groove, which throws the fine particles close to the end face gap outward; at the same time, the groove acts as a water flow channel, guiding the water flow into the core support gap 6.

[0045] After the clean water flows into the core support gap 6, it can provide a clean operating environment for the relatively rotating parts and reduce wear on the mating surfaces.

[0046] Synergistic application with water film support structure

[0047] The anti-sediment structure of this invention can work in conjunction with the water film support structure. As an optional implementation, the core support gap 6 can be a water film support gap, such as the water film support structure described in the applicant's patent "Adaptive Establishment and Stabilization Method and Structure of Rotary Auxiliary Water Film" filed on the same day. This water film support structure adopts an axially segmented conical surface with the same taper, forming a non-contact water film through hydrodynamic pressure effect. The anti-sediment structure of this invention is located upstream of the water inlet side of the water film support structure. Clean water flow, after multi-stage interception, enters the water film support gap, providing a clean lubricating medium for the water film support structure and preventing sediment particles from entering the water film gap and causing wear or water film instability. Functionally, the two complement each other: the anti-sediment structure ensures the quality of the incoming water, and the water film support structure enables non-contact operation, jointly extending the service life of underwater equipment under sediment-laden conditions.

[0048] This invention can be adapted to various underwater equipment with different structural forms, such as internal rotors and external rotors, and can also be used in combination with water film support structures.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An underwater device for resisting sediment, comprising a stationary component (1) and a rotating component (2) that rotate relative to each other, with a core support gap (6) between them, characterized in that: On the outside of the core support gap (6), a flow guiding and sand-throwing section (3) and an expansion and settling section (4) are arranged sequentially from upstream to downstream along the water flow direction; the flow guiding and sand-throwing section (3) is an annular step set on the stationary component, which is used to deflect the sand-laden water flow to throw large particles of silt outward; the expansion and settling section (4) is an annular groove set on the inner wall of the stationary component, which is used to allow fine sand particles to settle and be retained in the groove through the low-speed vortex zone formed by the abrupt change in the flow channel cross section.

2. The underwater equipment for resisting sediment as described in claim 1, characterized in that, The height of the annular step and its angle with the axis are sufficient to deflect the water flow and throw large particles of silt outwards. The height is adapted to the size of the main channel.

3. The underwater equipment for resisting sediment as described in claim 1, characterized in that, The width and depth of the annular groove can form a stable low-speed vortex zone within the groove to achieve the settling and retention of fine sand particles, and the ratio of the width to the depth is adapted to the vortex formation requirements.

4. The underwater equipment for resisting sediment as described in claim 1, characterized in that, It also includes an end face guide section (5), which is a radial groove or spiral groove provided on the end face of the rotating component, used to guide fine particles to the outside by using rotational centrifugal force and to provide a water flow channel.

5. The underwater equipment for resisting sediment as described in claim 4, characterized in that, The depth, width, and number of radial or spiral grooves in the end face guide section (5) are adapted to the rotation speed requirements of the rotating component, and the number is evenly distributed to ensure centrifugal force balance, thereby producing an effective centrifugal guiding effect.

6. The underwater equipment for resisting sediment as described in claim 1, characterized in that, The multi-stage anti-silt structure is located upstream of the water inlet side of the core support gap (6) to provide clean water flow to the core support gap.

7. A method for preventing underwater equipment from accumulating sediment, characterized in that, Includes the following steps: a) Make the sand-laden water flow through the annular steps on the stationary component, and use the annular steps to deflect the water flow, throwing large particles of silt outwards. b) The water flow after step a) is passed through the annular groove on the inner wall of the stationary component. The low-speed vortex zone formed by the annular groove causes the fine sand particles to settle and be trapped in the groove. c) Allow the water flow processed in step b) to enter the core support gap (6) of the equipment; In this process, steps a) and b) work together, with the water flow deflection angle in step a) matching the eddy current intensity in step b), so that particles of different sizes are intercepted in sequence; and this matching process does not require additional power or human intervention, but is achieved automatically through the movement of the water flow itself.

8. The method according to claim 7, characterized in that, After step b) and before step c), the process also includes a step of allowing water to flow through radial or spiral grooves on the end face of the rotating component, using centrifugal force to guide fine particles outward.

Images