Tenon connection structure design method for turbine rotor of long-service-life small turbofan engine

Abstract

The invention relates to a tenon connection structure design method for a turbine rotor of a long-service-life small turbofan engine, and relates to the technical field of turbofan engines. Accordingto the tenon connection structure design method for a turbine rotor of a long-service-life small turbofan engine, in order to reduce the average load of tenon teeth, a four-pair-tooth structure is adopted, the area of a tenon and mortise working face bearing face is increased, the bottom of a mortise is changed into large fillet transition, mortise stress concentration is reduced, the stress levelof a key position is effectively reduced, and the bearing capacity of the tenon and mortise is effectively improved. And through the optimal design of the characteristic size of the tenon connectionstructure, the stress concentration of the key positions of the tenon and mortise strength is reduced, the stress level of the key positions is further reduced, and the bearing capacity of the structure is improved.

Description

technical field [0001] The invention relates to the technical field of turbofan engines, in particular to a tenon connection structure design method for long-life small turbofan engine turbine rotors. Background technique [0002] The turbine disk and turbine rotor blades of a turbine engine generally adopt a fir tree-shaped tenon connection structure, which has a great impact on the strength, life and failure of the turbine disk and turbine blades. In the existing tenon connection structure, the tenon is installed in the tenon groove through three pairs of tenon teeth to realize the connection between the blade and the wheel ( figure 1 ). When the engine is working, the centrifugal force of the blade is transmitted to the wheel disk through three pairs of mortise teeth working surfaces. [0003] During the working process of the engine, the turbine blades mainly bear centrifugal loads caused by high-speed rotation, temperature loads caused by high-temperature environments...

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Problems solved by technology

[0004] The fillet at the root of the third pair of teeth and the fillet at the root of the tenon and groove ( image 3 ) under the superposition of the radial stress at the root of the wheel rim lug, the bending stress of the mortise teeth, and the circumferential stress of the rim, the stress level is relatively high, and low-cycle fatigue damage is prone to occur after long-term repeated use

[0005] Through analysis, it is concluded that the current turbine rotor adopts a three-pair tooth fir tree-shaped tenon connection structure, which has a high stress level at the key strength position, and the stress distribution on the side of the blade pot and the back side is uneven, and the risk of damage during the engine's working process is high.

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