A friction pendulum type anti-shock structure for marine steam turbines

Abstract

The present invention relates to a friction pendulum type marine steam turbine anti-shock structure, which includes fixing bolts, limit shims, pressure-bearing rubber plates, cylindrical bases, shear pins, stoppers and polytetrafluoroethylene sliding plates. The stopper is installed on one side of the common frame through a shear pin and is connected to the cylindrical base for restricting the lateral movement of the cylindrical base. A polytetrafluoroethylene sliding plate is placed between the inclined surface of the cylindrical base and the common frame. The upper part of the cylindrical base is connected to the steam turbine foot through a pressure-bearing rubber plate. The limit shim is fixed above the steam turbine foot and the shear pin through a fixing bolt to restrict the upward freedom of the steam turbine foot and prevent the shear pin from falling out. The present invention makes full use of the existing installation space of the steam turbine, improves the anti-shock ability of the steam turbine, and enables the unit to have the ability of self-recovery after being impacted. The safety and maintainability of the steam turbine after being impacted are greatly improved, and this structure can be extended and applied to other marine steam turbines.

Description

Technical Field

[0001] The present invention relates to a foot structure of a marine steam turbine, in particular to an anti-shock structure of a marine steam turbine. Background Art

[0002] The foot is one of the important components for fixing the steam turbine to the common frame. Most existing marine steam turbines use a cat's paw structure for fixing, as Figure 1 shown. The existing foot of the marine steam turbine consists of a fastening bolt, a limit stop block, and a cushion block. The limit stop block is connected to the common frame by bolts, and the cushion block is placed between the limit stop block and the common frame for adjustment. The foot of the steam turbine is connected to the common frame through the limit stop block and the cushion block. Such a connection method enables the foot of the steam turbine to have the ability to thermally expand along the axial direction of the unit. However, when encountering a large-amplitude lateral impact, the fracture of the fastening bolt will cause the foot of the steam turbine to completely lose its fixation, resulting in a large displacement of the unit. Summary of the Invention

[0003] The present invention aims to propose an anti-shock structure of a friction pendulum type marine steam turbine, which can achieve the fixation of the unit under a large-amplitude impact.

[0004] To achieve the above object, the technical solution of the present invention is: an anti-shock structure of a friction pendulum type marine steam turbine, including a fixing bolt, a limit retaining piece, a pressure-bearing rubber plate, a cylindrical base, a shear pin, a stop block, and a polytetrafluoroethylene sliding plate. The stop block is installed on one side of the common frame through the shear pin and is connected to the cylindrical base for restricting the lateral movement of the cylindrical base. A polytetrafluoroethylene sliding plate is placed between the cylindrical base and the inclined surface of the common frame. The upper part of the cylindrical base is connected to the foot of the steam turbine through the pressure-bearing rubber plate. The limit retaining piece is fixed above the foot of the steam turbine and the shear pin through the fixing bolt to restrict the upward degree of freedom of the foot of the steam turbine and prevent the shear pin from falling out.

[0005] Further, the anti-shock structure of the friction pendulum type marine steam turbine as a whole presents a semi-circular structure. The feet of the steam turbines on both sides of the unit are mirror-symmetrical to each other. The feet of the steam turbines on both sides are made in a cylindrical form, and under the condition of receiving lateral impacts on both sides, the function of anti-shock and energy dissipation can be achieved.

[0006] Further, when a lateral impact occurs, after the shear pin is cut off, the foot of the steam turbine drives the cylindrical base to move outwards, and the foot of the steam turbine will swing along the concave spherical surface of the common frame, using the simple pendulum principle to extend the natural vibration period of the steam turbine, so as to reduce the effect of the impact force on the structure of the steam turbine.

[0007] Furthermore, when the turbine feet move on the surface of the common frame, the upper structure of the unit is lifted, and the impact energy is absorbed by being converted into potential energy. After the impact, the support is automatically reset under the action of the self-weight of the upper structure of the turbine.

[0008] Furthermore, during use, first place the cylindrical base and the polytetrafluoroethylene sliding plate above the common frame, then place the pressure-bearing rubber plate and the turbine above them. Place stoppers on both sides of the cylindrical base and install shear pins for fixation.

[0009] The beneficial effects of the present invention are as follows:

[0010] The anti-impact structure of the friction pendulum type marine steam turbine proposed by the present invention makes full use of the existing installation space of the steam turbine, improves the anti-impact ability of the steam turbine, and enables the unit to have the ability to self-recover after being impacted. It greatly improves the safety and maintainability of the steam turbine after being impacted, and this structure can be extended and applied to other marine steam turbines. Description of the Drawings

[0011] Figure 1 is a schematic diagram of the existing structure of the turbine feet;

[0012] Figure 2 is a schematic diagram of the anti-impact structure of the friction pendulum type marine steam turbine of the present invention. Detailed Embodiments

[0013] The present invention will be further described below in conjunction with the drawings and embodiments.

[0014] As Figure 2 shown, the embodiment of the present invention proposes a structure of the friction pendulum type marine steam turbine feet. This structure adopts a pendulum type feet structure, which can achieve the purpose of vibration reduction and energy dissipation when the steam turbine is subjected to a large impact. Its main structure includes a fixing bolt 1, a limit retaining piece 2, a pressure-bearing rubber plate 4, a cylindrical base 5, a shear pin 6, a stopper 7, and a polytetrafluoroethylene sliding plate 8.

[0015] The surface of the common frame 9 is cylindrical. The stopper 7 is installed on one side of the common frame 9 through the shear pin 6. The stopper 7 restricts the lateral movement of the cylindrical base 5. The cylindrical base 5 is placed above the polytetrafluoroethylene sliding plate 8. The turbine feet 3 are placed above the cylindrical base 5 through the pressure-bearing rubber plate 4. The fixing bolt 1 fixes the limit retaining piece 2 above the turbine feet 3 and the shear pin 6 to limit the upward freedom of the turbine feet 3 and prevent the shear pin 6 from falling out.

[0016] From Figure 2In this steam turbine impact-resistant structure, it can be observed that the overall structure presents a semi-circular shape, and the feet on both sides are mirror-symmetrical to each other. Therefore, the feet on both sides of the steam turbine are both semi-circular structures. Under normal operating conditions, the blocks and shear pins on the friction pendulum steam turbine impact-resistant structure fix the cylindrical base, and the cylindrical base is restricted on the common frame. When a lateral impact occurs, the shear pins are cut, and the feet of the steam turbine drive the cylindrical base to move outward. The feet of the steam turbine will swing along the concave spherical surface of the common frame, using the simple pendulum principle to extend the natural vibration period of the steam turbine, so as to reduce the impact force on the steam turbine structure. At the same time, when the feet of the steam turbine move on the surface of the common frame, the upper structure of the unit will rise. The impact energy is absorbed by being converted into potential energy. After the impact, the automatic reset of the support can be realized under the action of the self-weight of the upper structure of the steam turbine. The feet of the steam turbines on both sides of the unit are made in the form of cylinders, and under the condition of receiving lateral impacts on both sides, they can both play the role of impact resistance and energy dissipation.

[0017] During use, first place the cylindrical base and the polytetrafluoroethylene sliding plate above the common frame, then place the pressure-bearing rubber plate and the steam turbine above them. Place blocks on both sides of the cylindrical base and install shear pins for fixation, and then the installation of the friction pendulum marine steam turbine impact-resistant structure can be completed.

Claims

1. A friction pendulum type shock-resistant structure for marine steam turbines, characterized in that: It includes fixed bolts, limit retaining plates, pressure-bearing rubber plates, cylindrical bases, shear pins, stoppers and polytetrafluoroethylene sliding plates. The stopper is installed on one side of the common frame through shear pins and is connected to the cylindrical base, and is used to limit the lateral movement of the cylindrical base. A polytetrafluoroethylene sliding plate is placed between the cylindrical base and the inclined surface of the common frame. The upper part of the cylindrical base is connected to the turbine foot through a pressure-bearing rubber plate; the limit retaining plate is fixed above the turbine foot and the shear pin through fixed bolts to limit the upward degree of freedom of the turbine foot and prevent the shear pin from falling out.

2. The shock-resistant structure of the friction pendulum type marine steam turbine according to claim 1, wherein: The anti-shock structure of the friction pendulum marine steam turbine as a whole presents a semi-circular structure. The turbine feet on both sides of the unit are mirror-symmetrical to each other. The turbine feet on both sides are made in the form of cylinders, and can play the role of anti-shock energy dissipation under the condition of receiving lateral impacts on both sides.

3. The shock-resistant structure of the friction pendulum type marine steam turbine according to claim 2, wherein: When a lateral impact occurs and the shear pin is cut off, the turbine foot drives the cylindrical base to move outwards, and the turbine foot will swing along the concave spherical surface of the common frame, using the simple pendulum principle to extend the natural vibration period of the steam turbine so as to reduce the effect of the impact force on the steam turbine structure.

4. The shock-resistant structure of the friction pendulum type marine steam turbine according to claim 3, wherein: When the turbine foot moves on the surface of the common frame, the upper structure of the unit is lifted, and the impact energy is absorbed by being converted into potential energy. After the impact, under the action of the self-weight of the upper structure of the steam turbine, the automatic reset of the support is realized.

5. The shock-resistant structure of the friction pendulum type marine steam turbine according to claim 1, characterized in that: During use, first place the cylindrical base and the polytetrafluoroethylene sliding plate above the common frame, then place the pressure-bearing rubber plate and the turbine foot above the cylindrical base, place a stopper on one side of the cylindrical base, and install and fix the shear pin.

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