DJ-300 Shear-Type Vibration Isolator — 300 kg, 7 Hz Natural Frequency

The DJ-300 is the 300 kgf rated member of Hicool’s DJ shear-type vibration isolator series — the performance choice when maximum isolation and noise reduction outweigh captive fail-safe requirements. The rubber element is loaded primarily in shear rather than compression, yielding a soft vertical stiffness and a natural frequency tuned to 7.0 ± 0.5 Hz regardless of load within the rated band. This delivers greater than 95 percent isolation for disturbance frequencies above 25 Hz — typical for high-speed marine diesels, pump sets, and centrifugal compressors running at 1,500 to 3,000 RPM. Measured airborne and structure-borne noise reduction exceeds 30 dB across the mid-frequency band. The DJ series does not include integral captive retention and is therefore specified for non-safety-critical machinery rather than main propulsion. Standard construction uses NR rubber with galvanized steel plates; corrosion-protected stainless-steel hardware is available for direct seawater exposure.