A vibration-damping and torsion-resistant ring rib for a rudder propeller and its design method

Abstract

This invention relates to a vibration-damping and torsional-resistant ring rib for a rudder propeller and its design method. The vibration-damping and torsional-resistant ring rib consists of a ring rib and a viscous damping layer, with the viscous damping layer located on the edge of the central through-hole of the ring rib. The ring rib is a rotating body with its thickness decreasing from the edge to the center. The viscous damping layer is a circular ring structure of uniform thickness. The vibration-damping and torsional-resistant design of this invention for the rudder column of a rudder propeller, after installing the vibration-damping and torsional-resistant ring rib, can significantly improve the torsional stiffness of the rudder column, reduce torsional deformation during actual operation, and simultaneously reduce the vibration intensity under the action of propeller pulsation forces, which is beneficial for improving the service life of the rudder propeller unit and the comfort of shipboard installation.

Description

Technical Field

[0001] This invention relates to a marine propulsion rudder propeller, and more particularly to a vibration-damping and torsion-resistant ring rib for a rudder propeller. Background Technology

[0002] A rudder propeller, a common marine propulsion unit, combines rudder control and propulsion functions and is often used in vessels requiring high maneuverability. For example... Figure 1 This diagram shows typical components of a rudder propeller. The rudder column 11, as the main longitudinal torque transmission component, bears significant torque during rudder turning and yaw. To avoid transmission failures or sealing failures due to large deformation of the rudder column 11, its torsional stiffness is required to be high in its structural design. On the other hand, from a structural vibration perspective, the duct 14 and propeller 12 are located in the non-uniform wake behind the ship, inevitably experiencing pulsating forces during operation, which are the vibration excitation source for the entire rudder propeller unit. As a structural component connecting the propeller 12 and the upper hull structure, the rudder column 11 is the main pathway for transmitting propeller 12 vibration; therefore, vibration issues need special consideration in its structural design, and vibration reduction design should be implemented. Summary of the Invention

[0003] To address the design requirements of torsional rigidity and vibration reduction for the propeller rudder column, this invention proposes a vibration-damping and torsional rigidity ring rib and its design method. The ring rib is installed inside the rudder column by welding or integral casting, which can simultaneously increase the torsional stiffness of the rudder column and reduce the vibration amplitude.

[0004] To achieve the above objectives, the technical solution of the present invention is: a vibration-damping and torsional-resistant ring rib for a rudder propeller, which is composed of a ring rib and a viscous damping layer, wherein the viscous damping layer is provided on the edge of the central through hole of the ring rib.

[0005] Furthermore, the ring rib is a rotating body with a thickness that decreases from the edge to the center.

[0006] Furthermore, the thickness decreases according to a power-law decay law for the rotating body of the ring rib.

[0007] Furthermore, the thickness of the rotating body of the ring rib Distance from the center of rotation is The specific expression for time is: ,in: For coefficients, It is an index.

[0008] Furthermore, the viscous damping layer is a circular ring structure of uniform thickness.

[0009] Furthermore, the inner radius of the uniform thickness circular ring structure is the same as the inner radius of the ring rib, and the outer radius is adjustable, which is used to increase local vibration damping and absorb vibration energy.

[0010] Furthermore, the viscous damping layer material is butyl rubber.

[0011] Furthermore, the vibration-damping and torsion-resistant ring ribs for the rudder propeller are installed inside the rudder column by welding.

[0012] Furthermore, the vibration-damping and torsion-resistant ring ribs for the rudder propeller are installed inside the rudder column by integral casting.

[0013] A design method for vibration-damping and torsion-resistant ring ribs for rudder propellers, the specific steps of which are as follows:

[0014] (1) Analyze the operating environment and operating conditions of the rudder propeller, and obtain the frequency corresponding to the main energy peak of the vibration excitation source through model tests or numerical simulations. ;

[0015] (2) Adjust the thickness distribution of the ring ribs so that the first natural frequency of the ring ribs is consistent with that of the ring ribs. Approaching, while adjusting Guarantee coefficient ;

[0016] (3) Meeting the above two design requirements will enable the ring rib and the rudder column to generate local anti-resonance. For the ring rib, the most intense vibration is at the inner edge. By arranging a viscous damping layer at the inner edge, the vibration energy can be absorbed.

[0017] The beneficial effects of this invention are:

[0018] The vibration-damping and torsional-resistant design of the rudder column of the present invention can significantly improve the torsional stiffness of the rudder column and reduce torsional deformation in actual operation after the installation of the vibration-damping and torsional-resistant ring ribs. At the same time, it can reduce the vibration intensity under the action of propeller pulsation force, which is beneficial to improving the service life of the rudder column and the comfort of the ship. Attached Figure Description

[0019] Figure 1 This is a typical component diagram of a propeller;

[0020] Figure 2 This is an isometric view of the vibration-damping and torsion-resistant ring rib of the present invention;

[0021] Figure 3 This is a cross-sectional view of the vibration-damping and torsion-resistant ring rib of the present invention;

[0022] Figure 4 This is a diagram showing the variation pattern of the ring rib thickness;

[0023] Figure 5 This is a schematic diagram of the installation of the vibration damping and torsion-resistant ring rib;

[0024] Figure 6 It is a comparison diagram of the torsion angle before and after the installation of the vibration damping and anti-torsion ring rib;

[0025] Where: (a) not installed, (b) installed;

[0026] Figure 7 This is a comparison chart of vibration velocity levels before and after the installation of the vibration damping and anti-torsion ring ribs.

[0027] In the figure: 1-ring rib, 2-viscous damping layer, 11-rudder column, 12-propeller, 14-duct, 15-duct hanger, 100-vibration damping and torsional ring rib. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figure 2 As shown in Figure 3, a vibration-damping and torsional-resistant ring rib for a rudder propeller according to the present invention consists of two parts: a ring rib 1 and a viscous damping layer 2. The ring rib 1 is a body of revolution, with its thickness decreasing from the edge to the center, and the decreasing law follows a power-law decay. For a rigorous description of the thickness decreasing law, see [reference needed]. Figure 4 In the picture The distance between the center of rotation and the center of rotation is The thickness at that time. The specific expression is: ,in For coefficients, The design work of the ring rib mainly involves determining the index. and The numerical value.

[0030] Figure 2 and 3 In the middle section, the viscous damping layer 2 is a uniform thickness circular ring structure made of butyl rubber. Its inner radius is the same as the inner radius of the ring rib, while its outer radius can be adjusted appropriately. Its main function is to increase local vibration damping and absorb vibration energy. The installation effect of the vibration-damping and anti-torsion ring rib 100 is shown in [reference needed]. Figure 5 .

[0031] The specific design method of this invention is as follows:

[0032] (1) Analyze the operating environment and operating conditions of the rudder propeller, and obtain the frequencies corresponding to the main energy peaks of the vibration excitation source through model tests or numerical simulations. .

[0033] (2) Adjust the thickness distribution of the ring ribs so that the first natural frequency of the ring ribs is consistent with that of the ring ribs. Approaching, while adjusting Guarantee coefficient .

[0034] (3) Meeting the above two design requirements can achieve local anti-resonance between the ring rib and the steering column. For the ring rib, the most intense vibration is at the inner edge, and the vibration energy can be absorbed by arranging a viscous damping layer at the inner edge.

[0035] Based on this invention, the applicable scenarios are as follows:

[0036] Based on the above vibration-damping and anti-torsion ring rib design, a numerical analysis of the actual effectiveness of the vibration-damping and anti-torsion ring rib was conducted. The results show that under the actual operating steering torque, after installing the vibration-damping and anti-torsion ring rib 100, the relative torsional angle between the upper and lower end faces of the steering column 11 decreased from 1.2° to 0.8°, a decrease of 33%. Figure 6 (a) and (b); Under the pulsating force of actual operating conditions, after installing the vibration damping and anti-torsion ring rib 100, the maximum vibration velocity level on the steering column 11 decreased from 183dB to 174dB, a significant decrease (see [reference]). Figure 7 ).

Claims

1. A vibration-damping and torsion-resistant ring rib for a rudder propeller, characterized in that: It consists of a ring rib and a viscous damping layer, with the viscous damping layer located on the edge of the central through-hole of the ring rib; the ring rib is a body of revolution, with its thickness decreasing from the edge to the center; the thickness decrease of the body of revolution of the ring rib follows a power-law decay law; the thickness of the body of revolution of the ring rib... Distance from the center of rotation is The specific expression for time is: ,in: For coefficients, The index is used; the viscous damping layer is a circular ring structure of equal thickness; the inner radius of the circular ring structure of equal thickness is the same as the inner radius of the ring rib, and the outer radius can be adjusted to increase local vibration damping and absorb vibration energy.

2. The vibration-damping and torsion-resistant ring rib for a rudder propeller according to claim 1, characterized in that: The viscous damping layer material is butyl rubber.

3. The vibration-damping and torsion-resistant ring rib for a rudder propeller according to claim 1, characterized in that: The vibration-damping and torsion-resistant ring ribs for the rudder propeller are installed inside the rudder column by welding.

4. The vibration-damping and torsion-resistant ring rib for a rudder propeller according to claim 1, characterized in that: The vibration-damping and torsion-resistant ring ribs for the rudder propeller are installed inside the rudder column by integral casting.

5. A design method for a vibration-damping and torsional-resistant ring rib for a rudder propeller as described in any one of claims 1-4, characterized in that, The specific steps are as follows: (1) Analyze the operating environment and operating conditions of the rudder propeller, and obtain the frequency corresponding to the main energy peak of the vibration excitation source through model tests or numerical simulations. ; (2) Adjust the thickness distribution of the ring ribs so that the first natural frequency of the ring ribs is consistent with that of the ring ribs. Approaching, while adjusting Guarantee coefficient ; (3) Meeting the above two design requirements will enable the ring rib and the rudder column to generate local anti-resonance. For the ring rib, the most intense vibration is at the inner edge. By arranging a viscous damping layer at the inner edge, the vibration energy can be absorbed.

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