Long-life sealing solution for building vibration dampers Spring energized seals

Hydraulic dampers for building vibration isolation serve as the core critical components for seismic and wind vibration resistance of building structures, and are widely applied in key projects such as super high-rise buildings, long-span venues and transportation hubs. As a special type of hydraulic component, they impose stringent requirements on operational stability and durability. Not only must they accurately exert vibration isolation performance under extreme working conditions such as earthquakes and strong winds, but also achieve an ultra-long maintenance-free service life of decades. As the "protective barrier" of damper cylinders, the performance of the sealing system directly determines the effective service life of dampers.

Conventional rubber and plastic seals are prone to oil leakage and failure during service due to defects such as easy aging, rapid wear and poor compensation capacity, which has become a core pain point restricting the long-term stable operation of dampers.

DMS SEALS has developed a full spring energized seal system for long-life cylinder sealing, which takes spring energized sealing technology as the core and integrates an innovative sealing structure design. It fundamentally overcomes the typical failure modes of conventional rubber and plastic seals, extending the effective service life of the damper sealing system to more than 30 years with a target service life of 50 years. At present, it has been matched for many domestic damper manufacturers and become the preferred solution for the sealing upgrade of hydraulic dampers for building vibration isolation, with applications including Beijing Daxing International Airport.

The working environment of hydraulic dampers for building vibration isolation features both static pressure bearing and dynamic reciprocating motion, and the sealing effect of hydraulic oil inside the cylinder directly affects the transmission and regulation of damping force. Conventional rubber and plastic seals (e.g., O-rings, ordinary lip seals) are prone to various failure problems in this application scenario due to their own material characteristics and structural limitations:

Aging and performance attenuation: Under long-term working conditions such as outdoor temperature differences and environmental corrosion, rubber and plastic materials are prone to hardening, embrittlement and swelling, with gradual loss of elasticity. They fail to maintain close contact with the sealing surface, ultimately leading to oil leakage.

Wear and eccentric sealing failure: The reciprocating motion of the piston rod during damper operation is likely to cause excessive wear of the rubber and plastic seal lip. In addition, conventional seals lack active compensation capacity and cannot fit in real time in the case of slight eccentricity and radial deflection of the sealing surface, forming sealing gaps.

Low-pressure sealing failure: Rubber and plastic seals rely on assembly interference to generate preload. Insufficient preload under low-pressure working conditions easily causes micro-leakage, and the long-term accumulation will lead to the loss of hydraulic oil in the cylinder and the decline of damper performance.

Mismatch between service life and engineering requirements: The dynamic sealing service life of conventional rubber and plastic seals is usually only a few years, which is seriously inconsistent with the decades-long service requirements of construction engineering for dampers. Frequent replacement of seals not only increases maintenance costs, but also affects the seismic safety of building structures.

The core of the above failure problems is that conventional rubber and plastic seals lack a continuous and active sealing force compensation mechanism, and cannot adapt to the "long-cycle, low-maintenance and multi-working-condition" service requirements of hydraulic dampers for building vibration isolation.

Based on the core advantages of spring energized seals, our company has developed a full spring energized seal system for long-life cylinder sealing by combining the cylinder structure and working characteristics of hydraulic dampers for building vibration isolation. Through an innovative sealing structure design, it realizes the in-depth adaptation of the sealing system and dampers, and completely overcomes various failure modes of conventional seals:

Full spring energized seal layout: Abandoning the mixed use mode of conventional rubber and plastic seals and spring energized seals, the full spring energized seal configuration is adopted. Spring energized active sealing is realized in all links from piston rod sealing, end cover sealing to piston sealing, eliminating weak sealing points and achieving long-term sealing of the entire cylinder chamber.

Optimized sealing groove design: Customized sealing grooves are designed according to the structural characteristics of spring energized seals, and the ratio of static seal lip to dynamic seal lip is optimized. The static seal lip increases the contact area to prevent the seal from displacement and rotation under pressure; the dynamic seal lip optimizes the front angle design to reduce friction resistance during reciprocating motion, cutting down energy consumption and wear.

Anti-extrusion and anti-eccentric wear design: A special anti-extrusion retainer is added to the sealing system, which can withstand the extrusion risk of seals under high pressure and adapt to the high-pressure requirements of dampers under extreme working conditions. Meanwhile, the matching accuracy between the seal and the piston rod is optimized to effectively prevent eccentric wear and further improve the stability of the sealing system.