Pump-jet propeller guide pipe based on rubber vibration reduction and design and manufacturing method of pump-jet propeller guide pipe

Abstract

The invention belongs to the technical field of propeller structures, and particularly discloses a pump-jet propeller guide pipe based on rubber vibration reduction and a design and manufacturing method thereof. Comprising a catheter front section and a catheter rear section which are fixedly connected, and the vibration reduction rubber ring module is arranged on the inner wall of the guide pipe rear section, the front end of the vibration reduction rubber ring module is located in front of the rotor blade tip guide edge, and the rear end of the vibration reduction rubber ring module is located behind the rotor blade tip following edge. The overall axial size of the damping rubber ring module is larger than the axial length of the blade tip of the rotor, and the damping rubber ring module is embedded into the inner wall of the guide pipe. In the invention, the line type of the inner surface of the damping rubber ring module is consistent with the line type of the inner wall of the conduit, so that the hydrodynamic performance of the conduit is not changed, and vibration energy transmitted to the conduit is absorbed and dissipated at the same time. The overall vibration and noise level of the pump-jet propeller is obviously reduced, and the design is simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of thruster structures, and more specifically, relates to a pump-jet thruster duct based on rubber vibration damping and its design and manufacturing method. Background Technique

[0002] There is a narrow gap between the tip of the pump-jet thruster rotor and the inner wall of the duct. When the pump-jet rotor rotates, a complex vortex flow system will be formed in the narrow gap, and this unsteady vortex flow system will transmit unsteady pressure pulsations through the nearby duct wall surface. Since the entire surface of the duct is a composite skin with high stiffness and strength, they will transmit more vibration energy under high-frequency excitation, ultimately exacerbating the overall excitation of the pump-jet thruster. To address this problem, the present invention innovatively applies rubber material with excellent damping performance to the inner wall of the duct at the tip of the rotor. This rubber vibration damping ring can quickly absorb and dissipate vibration energy, thereby effectively suppressing vibration transmission, and further reducing the overall excitation of the pump-jet thruster, so as to achieve the purpose of vibration reduction and noise reduction.

[0003] Currently, the vibration reduction and noise reduction measures for pump-jet thrusters mainly focus on aspects such as rotor blade profile design, rotor tip design, matching design between the rotor and the stator, and structural design of the duct wall surface corresponding to the rotor tip. The present invention innovatively inlays rubber material on the annular wall surface of the inner wall of the duct corresponding to the rotor tip, utilizes the excellent damping performance of the rubber material, quickly absorbs and dissipates the vibration energy transmitted to the inner wall of the duct, thereby effectively suppressing vibration transmission, reducing the overall excitation of the pump-jet thruster, and realizing vibration reduction and noise reduction of the pump-jet thruster.

[0004] It is very different from the current mainstream vibration reduction methods. First, the mainstream vibration reduction methods mainly focus on starting from the vibration source to suppress or reduce the occurrence of vibration, while the vibration reduction method based on rubber vibration damping starts from the vibration propagation path to absorb and dissipate vibration energy to achieve the purpose of vibration reduction. The design of the mainstream vibration reduction methods is highly difficult and requires considering relatively more factors. Secondly, such methods have high requirements for both processing and installation accuracy. No matter which link has problems, it will have a great impact on the vibration reduction effect, and may even have a negative impact. Summary of the Invention

[0005] In view of the above defects or improvement requirements of the prior art, the present invention provides a pump-jet propulsor duct based on rubber vibration damping and its design and manufacturing method. By combining the characteristics of the structure of the pump-jet propulsor itself and its working mechanics, the specific structure of the pump-jet propulsor duct is studied and designed. Accordingly, a vibration damping rubber ring is installed on the inner wall of the duct corresponding to the tip of the rotor blade. By virtue of the excellent performance of the high damping of the rubber, the vibration energy transmitted to the duct is quickly absorbed and dissipated, and the overall excitation of the pump-jet propulsor is reduced without affecting the hydrodynamic performance of the pump-jet, so as to achieve vibration reduction and noise reduction of the pump-jet propulsor.

[0006] To achieve the above object, according to one aspect of the present invention, a pump-jet propulsor duct based on rubber vibration damping is proposed, including:

[0007] A front duct section and a rear duct section fixedly connected; and

[0008] A vibration damping rubber ring module provided on the inner wall of the rear duct section, the front end of the vibration damping rubber ring module is located before the leading edge of the rotor blade tip, the rear end of the vibration damping rubber ring module is located after the trailing edge of the rotor blade tip, and the inner surface line type of the vibration damping rubber ring module is consistent with the line type of the inner wall of the duct to ensure that the hydrodynamic performance of the duct does not change, and at the same time absorb and dissipate the vibration energy transmitted to the duct.

[0009] As a further preference, the overall axial dimension of the vibration damping rubber ring module is larger than the axial length of the rotor blade tip and is embedded in the inner wall of the duct.

[0010] As a further preference, the vibration damping rubber ring module includes a multi-layer composite vibration damping rubber ring, and the multi-layer composite vibration damping rubber ring includes a high damping rubber layer, an intelligent rubber material layer and a high strength rubber layer arranged from the inside to the outside.

[0011] As a further preference, the intelligent rubber material layer includes FBG sensors for monitoring the strain state of the rubber material.

[0012] As a further preference, the intelligent rubber material layer includes piezoelectric sensors for monitoring vibration or impact information.

[0013] As a further preference, a groove for accommodating the vibration damping rubber ring module is provided on the inner wall of the rear duct section.

[0014] As a further preference, the interface between the front duct section and the rear duct section is connected by a trapezoidal interface, and bolts are used to fix the interface between the front duct section and the rear duct section.

[0015] According to another aspect of the present invention, there is also provided a design and manufacturing method for a pump-jet propulsor duct based on rubber damping, which is used to design and manufacture a pump-jet propulsor duct based on rubber damping according to any of the above embodiments or a combination of multiple embodiments.

[0016] As a further preference, for the damping rubber ring module on the inner wall of the rear section of the duct, when the pump-jet propulsor operates, the damping rubber ring module absorbs and dissipates the vibration energy transmitted to the duct while ensuring that the hydrodynamic performance of the duct remains unchanged.

[0017] As a further preference, when the pump-jet propulsor operates, the vibration generated by the rotor blade tip is first absorbed and dissipated by the inner high-damping rubber layer; the intelligent rubber material layer in the middle layer monitors the vibration state in real time through its self-sensing function and transmits the data to the external control system; the outer high-strength rubber layer provides structural support to protect the internal materials from mechanical damage.

[0018] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following technical advantages are mainly possessed:

[0019] 1. By installing a damping rubber ring on the inner wall of the duct corresponding to the rotor blade tip, the present invention quickly absorbs and dissipates the vibration energy transmitted to the duct by virtue of the excellent performance of high damping of rubber, and reduces the overall excitation of the pump-jet propulsor without affecting the hydrodynamic performance of the pump-jet propulsion, so as to achieve vibration reduction and noise reduction of the pump-jet propulsor.

[0020] 2. The present invention only needs to open a corresponding annular groove on the inner wall of the duct corresponding to the rotor blade tip, and then embed a damping rubber ring in the annular groove, ensuring that the geometric shape of the duct after embedding the damping rubber ring remains unchanged compared with before, and the design is relatively simple.

[0021] 3. By integrating the multi-layer composite damping structure and intelligent rubber material technology into the design of the pump-jet propulsor duct, the present invention can not only effectively improve the vibration reduction and noise reduction performance, but also realize intelligent management and maintenance, providing an innovative technical solution for the development of related fields.

[0022] 4. Through the synergistic effect of different materials, the multi-layer composite structure of the present invention can more effectively absorb and dissipate vibration energy, and significantly reduce the overall vibration and noise level of the pump-jet propulsor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic cross-sectional view of a pump-jet propulsor duct based on rubber damping according to an embodiment of the present invention;

[0024] Figure 2 is a three-dimensional structure schematic diagram of a pump-jet propulsor duct based on rubber damping according to an embodiment of the present invention.

[0025] In all the drawings, the same reference numerals denote the same technical features, specifically: 1 - front section of the duct, 2 - rear section of the duct, 3 - vibration damping rubber ring. Detailed implementation manners

[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] As Figure 1 and Figure 2 shown, a pump-jet propeller duct based on rubber vibration damping provided by an embodiment of the present invention includes a front section of the duct and a rear section of the duct which are fixedly connected; and a vibration damping rubber ring module provided on the inner wall of the rear section of the duct. The front end of the vibration damping rubber ring module is located before the leading edge of the rotor blade tip, the rear end of the vibration damping rubber ring module is located after the trailing edge of the rotor blade tip, and the inner surface line type of the vibration damping rubber ring module is consistent with the line type of the inner wall of the duct, so as to ensure that the hydrodynamic performance of the duct does not change, and at the same time absorb and dissipate the vibration energy transmitted to the duct. More specifically, the structure of the pump-jet propeller duct based on rubber vibration damping includes a front section of the duct 1, a rear section of the duct 2, and a vibration damping rubber ring 3. The overall structure is relatively simple. For the convenience of the later installation of the rotor, at a certain position away from the leading edge of the rotor blade tip, the duct is divided into a front section and a rear section. The interfaces of these two sections are connected by trapezoidal interfaces and fixed by 16 radially distributed bolts in the circumferential position. A vibration damping rubber ring is arranged in the rear section of the duct. The rubber ring is located at the inner wall of the duct corresponding to the rotor blade tip. Its front end is located before the leading edge of the rotor blade tip, and its rear end is located after the trailing edge of the rotor blade tip. The overall axial dimension is slightly larger than the axial length of the rotor blade tip and is embedded in the inner wall of the duct. The inner surface line type of the rubber ring follows the line type of the original corresponding position of the duct to ensure that the hydrodynamic performance of the duct does not change. The vibration damping rubber ring and the rear section of the duct are connected by an adhesive bonding method. That is, in this embodiment, only a corresponding annular groove needs to be opened on the inner wall of the duct corresponding to the rotor blade tip, and then the vibration damping rubber ring is embedded in the annular groove to ensure that the geometric shape of the duct after the vibration damping rubber ring is embedded does not change compared with before. The design is relatively simple. In this embodiment, by installing a vibration damping rubber ring on the inner wall of the duct corresponding to the rotor blade tip, relying on the excellent performance of the high damping of the rubber, the vibration energy transmitted to the duct is quickly absorbed and dissipated, and the overall excitation of the pump-jet propeller is reduced without affecting the hydrodynamic performance of the pump-jet propulsion, so as to achieve the vibration reduction and noise reduction of the pump-jet propeller.

[0028] In a preferred embodiment of the present invention, there is a narrow gap between the tip of the pump-jet propeller rotor and the inner wall of the duct. When the pump-jet rotor rotates, a complex vortex flow system will be formed in the narrow gap, and this unsteady vortex flow will transmit unsteady pressure pulsations through the nearby duct wall surface. Since the entire surface of the duct is made of composite skin with high stiffness and strength, they will transmit more vibration energy under high-frequency excitation, ultimately exacerbating the overall excitation of the pump-jet propeller. To address this problem, in this embodiment, a rubber material with excellent damping performance is applied to the inner wall of the duct at the tip of the rotor, and at the same time, a multi-layer composite structure and intelligent material technology are combined to further improve the vibration and noise reduction effect. Specifically, the damping rubber ring module includes a multi-layer composite damping rubber ring, and the multi-layer composite damping rubber ring includes a high-damping rubber layer, an intelligent rubber material layer, and a high-strength rubber layer arranged from the inside to the outside.

[0029] Based on the above embodiment, the inner layer is a high-damping rubber layer, which uses a high-damping rubber material to directly contact the vibration generated by the rotor tip and quickly absorb and dissipate the vibration energy. The middle layer is an intelligent rubber material layer. An intelligent rubber material with self-sensing and self-healing functions is used, and microencapsulated repair agents and micro sensors are embedded inside, which can monitor the vibration state in real time and automatically repair the damage. The outer layer is a high-strength rubber layer, which provides structural support and protection and has high tensile strength and wear resistance.

[0030] Based on any of the above embodiments or a combination of multiple embodiments, when the pump-jet propeller is running, the vibration generated by the rotor tip is first absorbed and dissipated by the high-damping rubber in the inner layer. The intelligent rubber material in the middle layer monitors the vibration state in real time through its self-sensing function and transmits the data to the external control system. The high-strength rubber layer in the outer layer provides structural support and protects the internal materials from mechanical damage.

[0031] Based on any of the above embodiments or a combination of multiple embodiments, micro sensors are embedded inside the intelligent rubber material, and these sensors can monitor physical parameters such as the stress, strain, temperature, and vibration frequency of the material in real time. The specific implementation method is as follows:

[0032] Strain gauges or fiber Bragg grating sensors can be attached to or embedded in rubber materials. When the rubber material is subjected to an external force, the strain gauge will deform, resulting in a change in its resistance value; the reflection wavelength of the fiber Bragg grating will also change accordingly. By measuring these changes, the strain state of the rubber material can be monitored in real time to determine whether there is excessive stress or damage. Piezoelectric sensors can convert mechanical energy into electrical energy. When the rubber material is subjected to vibration or impact, the piezoelectric sensor will generate an electrical signal, the intensity and frequency of which are related to the amplitude and frequency of the vibration. By analyzing these electrical signals, the intensity of the vibration and the possible damage location can be determined. Temperature sensors can also be embedded in the smart rubber material to monitor the temperature change inside the material. When the material is damaged or undergoes excessive friction, the local temperature may increase. By monitoring the temperature change, potential damage can be detected in advance.

[0033] Based on the above embodiments, in this embodiment, the data collected by the above-mentioned multiple or multiple sensors are sent to an external control system through a wireless transmission module (such as Bluetooth, Wi-Fi or low-power wide area network). The control system analyzes the data in real time and uses the following methods to judge the health state of the material: Utilize signal processing algorithms such as wavelet transform and Fourier transform to analyze the stress, strain or vibration signals collected by the sensors. By extracting the characteristic parameters of the signals (such as frequency, amplitude, phase, etc.), it is judged whether the material is in a normal working state or whether there is damage. Based on machine learning algorithms (such as support vector machines, neural networks, etc.), the sensor data is classified and predicted. By training the model to identify the signal characteristics in the normal state and the damaged state, real-time diagnosis of the health state of the material is achieved.

[0034] According to another aspect of the present invention, there is also provided a design and manufacturing method for a vibration damping rubber ring module of a pump-jet propeller duct based on rubber vibration damping. An injection mold is used to inject a rubber layer. The injection mold consists of two parts. The design of the mold needs to consider sufficient strength and stiffness to withstand an injection pressure of up to 12 - 14 MPa. For this purpose, high-hardness pre-hardened mold steel (NAK80 steel) is selected as the manufacturing material for the mold. It has excellent cutting performance and high-temperature stability and can meet the requirements of rubber injection molds for high precision and long life. The manufacturing process of the mold includes multiple steps such as milling machine processing, drilling machine punching, and grinding machine polishing to ensure the accuracy and surface quality of the mold. In addition, a reasonable parting surface, gating system, and exhaust system, etc. also need to be designed according to the geometric shape and molding requirements of the vibration damping rubber ring.

[0035] During the injection molding process, strict control of temperature, pressure, and time is required. Temperature control: Different rubber raw materials require different temperatures during injection molding. It is necessary to precisely control the temperatures of the injection machine barrel, nozzle, and mold to ensure the fluidity and vulcanization effect of the rubber compound. Pressure control: Injection pressure and holding pressure have important impacts on the molding quality and dimensional accuracy of the product, and need to be adjusted according to the specific requirements of the product. Time control: It includes injection time, holding time, cooling time, etc. The control of these times has important impacts on the molding efficiency and quality of the product.

[0036] Based on any of the above embodiments, in this embodiment, a process for the manufacture and installation of a multi-layer composite vibration damping rubber ring is provided:

[0037] (1) Mold preparation. According to the design dimensions of the multi-layer composite rubber ring, a high-precision injection mold is processed and made of NAK80 steel. Check the parting surface, gating system, and exhaust system of the mold to ensure its accuracy and surface quality.

[0038] (2) Material preparation. Prepare high-damping rubber material, intelligent rubber material, and high-strength rubber material. Pretreat the intelligent rubber material and embed microcapsules and micro sensors.

[0039] (3) Injection molding. Inject the high-damping rubber material into the inner cavity of the mold, control the injection temperature at 140 °C, and the injection pressure at 12 MPa. After the inner layer is formed, inject the intelligent rubber material into the middle layer cavity, control the injection temperature at 150 °C, and the injection pressure at 13 MPa. Finally, inject the high-strength rubber material into the outer layer cavity, control the injection temperature at 160 °C, and the injection pressure at 14 MPa.

[0040] (4) Post-treatment and installation. Take out the formed multi-layer composite rubber ring from the mold, perform surface polishing and dimensional inspection. Coat a high-strength adhesive in the annular groove on the inner wall of the conduit, and embed the rubber ring into the groove to ensure a tight fit.

[0041] (5) System integration and testing. Assemble the conduit installed with the multi-layer composite vibration damping rubber ring with the pump-jet propeller. Start the propeller, real-time monitor the vibration data through an external control system, and adjust the operating parameters according to the feedback. Conduct long-term operation tests to verify the vibration damping effect and the reliability of the intelligent function.

[0042] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pump-jet propeller duct based on rubber damping, characterized in that, Comprising: A front section of a conduit and a rear section of the conduit that are fixedly connected; And A vibration damping rubber ring module provided on the inner wall of the rear section of the conduit, with the front end of the vibration damping rubber ring module located before the leading edge of the rotor tip and the rear end of the vibration damping rubber ring module located after the trailing edge of the rotor tip, and the inner surface line type of the vibration damping rubber ring module being consistent with the line type of the inner wall of the conduit to ensure that the hydrodynamic performance of the conduit does not change, while absorbing and dissipating the vibration energy transmitted to the conduit.

2. The duct of the pump-jet propulsor based on rubber damping according to claim 1, wherein The overall axial dimension of the vibration damping rubber ring module is greater than the axial length of the rotor tip and is embedded in the inner wall of the conduit.

3. A pump-jet propeller duct based on rubber damping according to claim 1, characterized in that, The vibration damping rubber ring module comprises a multi-layer composite vibration damping rubber ring, and the multi-layer composite vibration damping rubber ring comprises a high-damping rubber layer, an intelligent rubber material layer, and a high-strength rubber layer arranged from the inside to the outside.

4. A pump-jet propeller duct based on rubber damping according to claim 1, characterized in that, The intelligent rubber material layer comprises FBG sensors for monitoring the strain state of the rubber material.

5. A pump-jet propulsor duct based on rubber damping according to claim 1, characterized in that, The intelligent rubber material layer comprises piezoelectric sensors for monitoring vibration or impact information.

6. A pump-jet propulsor duct based on rubber damping according to any one of claims 1-5, characterized in that, A groove for accommodating the vibration damping rubber ring module is formed on the inner wall of the rear section of the conduit.

7. A pump-jet propulsor duct based on rubber damping according to any one of claims 1-5, characterized in that, The interface between the front section of the conduit and the rear section of the conduit is connected by a trapezoidal interface, and bolts are used to fix the interface between the front section of the conduit and the rear section of the conduit.

8. A design and manufacturing method for a pump-jet propeller duct based on rubber damping, characterized in that, For designing and manufacturing a pump-jet propeller conduit based on rubber vibration damping as described in any one of claims 1-7.

9. A flow guiding method for a pump-jet propulsor duct based on rubber damping according to claim 8, characterized in that The vibration damping rubber ring module on the inner wall of the rear section of the conduit, when the pump-jet propeller operates, absorbs and dissipates the vibration energy transmitted to the conduit while ensuring that the hydrodynamic performance of the conduit does not change.

10. A design and manufacturing method of a pump-jet propeller duct based on rubber damping according to claim 8, characterized in that, When the pump-jet propeller operates, the vibration generated by the rotor tip is first absorbed and dissipated by the inner high-damping rubber layer; the middle intelligent rubber material layer monitors the vibration state in real time through its self-sensing function and transmits the data to an external control system; the outer high-strength rubber layer provides structural support and protects the internal materials from mechanical damage.

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