Aircraft landing gear hydraulic pressure relief valve with damped closing element

Abstract

The invention is intended to reduce vibration-induced instability of the conical valve closing element (4) in aircraft landing-gear hydraulic systems, suppress hydraulic fluid pressure pulsations, and ensure stable valve operation under external mechanical vibrations occurring during landing. The objective of the invention is to increase the safety and reliability of the aircraft landing-gear hydraulic system by preventing unintended valve opening and ensuring faster response to actual pressure changes. The main components of the hydraulic pressure relief valve include a valve body (1) with a conical valve closing element (4), which is acted upon by a dual-spring system consisting of an upper spring (12) and a lower spring (7). The key element of the vibration-damping system is a flexible damping disc (13) slidably mounted between these springs. The flexible damping disc (13) incorporates throttling holes arranged symmetrically about the disc’s vertical axis at an angular interval β=360⁰n. This disc (13) divides the internal part of the adjusting screw (11) into a lower chamber (6) and an upper chamber (9). The upper chamber (9) is connected, via the accumulator pressure channel (10), to an external hydropneumatic accumulator, thereby enhancing the damping effect. The hydraulic pressure relief valve is intended for use in aircraft landing-gear hydraulic systems; however, its design may also be applied to other high-pressure hydraulic systems exposed to external mechanical vibrations and hydraulic fluid pulsations. Due to the use of the flexible damping disc (13) and the combined damping provided by the lower spring (7), the upper spring (12), and the pre-set pressure acting on the upper chamber (9) via the accumulator pressure channel (10), vibrations in the low, mid, and high frequency ranges are significantly reduced. The invention ensures that the valve remains closed under hydraulic fluid pulsations and mechanical vibrations, thereby minimizing hydraulic fluid flow losses, reducing wear of system components, and increasing the efficiency and safety of the aircraft landing-gear hydraulic system.