Auto-restoring spring damper

Bidirectional spring damper with linear restoration using a series arrangement of urethane blocks, coil springs, and symmetrical shape-memory steel rods

This technology is an auto-restoring spring damper that absorbs external forces through elastic deformation. It features a hollow cylinder with fixed plates at both ends, where first and second moving plates on two shafts slide. Urethane blocks are placed between the moving plates, and coil springs are positioned between each moving plate and the fixed plate. Superelastic shape-memory steel rods are attached around the coil springs, extending either in tandem with or independently of the springs to reduce external forces.

Conventional seismic dampers using friction plates and shape-memory rods for earthquakes and typhoons were difficult to adjust once assembled without complete disassembly. Because they partially relied on dissipating vibration energy as frictional heat, achieving full restoration was challenging, and repairing or reinforcing deformed components was often difficult.

This technology features multiple detachable shape-memory steel rods arranged symmetrically around the coil springs. One end of each rod is fixed to a plate, while the other passes through a sleeve on the moving plate to be secured. The rods slide within the sleeves to prevent buckling during compression, and the coil springs can also be made of superelastic shape-memory alloy. Applicable to seismic isolation for steel buildings, bridge bearings, and plant equipment, the system ensures smooth restoration to its original length. Damping force can be adjusted without disassembly simply by changing the number of rods.

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Key Features:

• A hollow cylinder with fixed plates at both ends, guiding the sliding of first and second internal moving plates
• First and second moving plates coupled to the opposing ends of shafts passing through the fixed plates, sliding along the interior of the cylinder
• Urethane blocks positioned between the moving plates, and first and second coil springs between the moving plates and fixed plates to dampen external forces via elastic deformation
• Multiple detachable, symmetrically opposed superelastic shape-memory steel rods installed around the coil springs, extending in tandem with or independently of the springs

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This invention was developed with support from the Ministry of Education for the verification and evaluation of the seismic performance of frame structures using friction-type auto-restoring dampers.

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