Half-section type free lacing wire structure of turbine blade with top tangent circle

Abstract

The invention provides a half-section type free lacing wire structure of a turbine blade with a top tangent circle, wherein the cross section of a part of the half-section type free lacing wire structure cooperating with a lacing wire hole of the turbine blade is shaped as follows: tangent circles are arranged on circular top and bottom parts respectively; and the height of each tangent circle is less than or equal to 20% the circular semi-diameter. A lacing wire of the half-section type free lacing wire structure has good sectional property which is beneficial to the bending of the lacing wire; two contact points exist between the lacing wire structure and the blade; through the adding of the contact points between the lacing wire and the blade, the total frictional force can be increased, so that the damping is increased and the vibration of the blade is decreased; and additionally, the lacing wire not only can decrease the vibration of a blade assembly along the radial direction and the peripheral direction, but also can effectively decrease the axial vibration and the torsion vibration of the blade assembly.

Description

technical field [0001] The invention belongs to the field of impeller machinery, and relates to the tie bars of steam turbine blades, in particular to a half-section loose tie bar structure with tangential circles. Background technique [0002] Steam turbine is an important power machine in the fields of energy, chemical industry and national defense. The blade is the most important component for the mutual transformation of thermal energy and mechanical energy when the steam turbine is working. The steam turbine blade mainly includes the blade body, blade root and blade crown. Some steam turbine blades also have tie bars. structure. [0003] The safety of steam turbine blades is often the most concerned issue for designers. The vibration of steam turbine blades during operation is the most important factor causing blade damage. There are two main methods to solve this problem. One is to avoid The resonance frequency reduces the response under the exciting force; the second...

AI Technical Summary

Problems solved by technology

[0005] Under the action of the tie bars, the blades can form a full-circle connection and generate frictional damping to reduce the dynamic stress of the blades. However, the current common tie bars and blades are often only in single-point contact during work, so the damping produced is only limited to the circumferential direction. and radial vibration are more obvious. At the same time, because the tendon is generally round and the flexural section modulus of the cross section of the tendon is large, it is difficult to process and bend the tendon, and it is difficult to ensure high processing accuracy.

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