バランスプラットフォーム設計計算機

A balancing platform (soft support) is a simple structure — typically a steel frame or plate — mounted on springs. It supports a rotor for field balancing by allowing free vibration response at operating speed. The platform's natural frequency is tuned well below operating speed (typically ≤ 1/3).

The natural frequency must be well below operating speed to ensure the system operates in the isolation region — above the resonance peak. At a frequency ratio of 3, transmissibility drops to about 12.5%, meaning the rotor vibrates freely and the balancing instrument can accurately detect unbalance.

Common configurations:

• 4 springs — most common, one at each corner
• 2 springs — small, lightweight rotors
• 3 springs — triangular platforms
• 6–8 springs — large, heavy rotors

All springs must have equal stiffness and the load must be centered.

Welded steel frame or plate (10–20 mm thick) is most common. Aluminum for smaller rotors. Platform mass is typically 10–25% of rotor mass. Ensure the platform is flat and all spring mounting points are at equal height.

Yes, but rubber mounts have higher damping (reducing measurement precision), and stiffness varies with temperature and load history. Coil springs are preferred for their consistent, well-defined stiffness and low damping. Dynamic rubber stiffness is typically 1.3–2× higher than static stiffness.