A gas-liquid elastic dual-frequency vibration isolator

Abstract

The invention discloses a gas-liquid elastic dual-frequency vibration isolator, and belongs to the technical field of vibration isolation design. The gas-liquid elastic dual-frequency vibration isolator comprises a shell, an inner cylinder, elastic rubber, a piston body, a lower cover body and an air cavity additionally-arranged air chamber; one end of the inner cylinder is arranged inside the shell, the elastic rubber is arranged between the shell and the inner cylinder, and the side face of the elastic rubber, the shell and the inner cylinder are bonded to form a sealed upper liquid cavity;anti-falling bolts are arranged in the circumferential direction of the shell to prevent the elastic rubber from falling off; one end of the inner cylinder is provided with an air compensating cavity,the air compensating cavity is provided with the piston body, a lower liquid cavity is formed between the piston body and the inner cylinder, and the lower liquid cavity communicates with the upper liquid cavity; the air compensating cavity is provided with a lower cover body in an internally screwed mode, and the cavity between the lower cover body and the piston body communicates with the air cavity additionally-arranged air chamber for changing the supporting rigidity of the piston body; and the gas-liquid elastic dual-frequency vibration isolator is arranged in a main supporting reductionrod of a helicopter through the shell and the lower cover body and used for isolating vibration. The gas-liquid elastic dual-frequency vibration isolator has the advantages that the structure is simple, the weight is small, the frequency band of vibration isolation is wide, and the dynamic stiffness of antiresonance points is low.

Description

technical field [0001] The invention belongs to the technical field of vibration isolation design, and in particular relates to a gas-liquid elastic dual-frequency vibration isolator. Background technique [0002] Helicopter vibration is characterized by the superposition of periodic vibration and random vibration related to the typical rotor speed frequency. Through frequency spectrum analysis, it can be seen that the rotor vibration load is the most important source of vibration, especially the body vibration and component systems caused by vibration loads of integer multiples of rotor speed frequency. Accounting for more than 90% of the total value, in the concerned frequency range (within 60Hz), sometimes it will seriously affect the performance of the helicopter and become one of the core issues of the modern helicopter development plan. Reducing the vibration level during helicopter flight has always been an important issue studied and solved in the process of helicopt...

AI Technical Summary

Problems solved by technology

[0008] The above-mentioned vibration control technologies have their technical advantages and disadvantages. For example, the vibration reduction efficiency of the hub vibration absorber with constant frequency decreases rapidly with the change of rotational speed; the inherent limitations of the passive vibration reduction system (large weight cost, narrow frequency band) , the vibration reduction efficiency is limited), it is difficult to meet the requirements of keeping the vibration level of the helicopter body at a low level within a wide flight envelope; active vibration control technology can usually reduce vibration by more than 70%, and the design technology of dynamic vibration absorber itself is relatively mature , but the optimal installation position on the body structure and the optimized design of the dynamic vibration absorber parameters are the core technologies of the body structure vibration reduction design

Traditional dynamic vibration-absorbing main damping and isolation systems are all mechanical. Since the lever swing arm needs movement space, it is limited by the strength and rigidity of the main damping installation structure.

Therefore, the traditional vibration reduction method can no longer meet the needs of multi-frequency vibration reduction for variable speed helicopters.

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