A Shear-Capped Centrifuge Governor with a Computed Trip Speed, Overshoot Budget and Containment Margin

Centrifuge overspeed is a low-frequency, high-consequence failure: rotors store enough energy to destroy their housings, and the protection is usually a speed switch whose setting is a matter of procedure. This paper specifies a governor whose trip speed is derived from a shear-cap analogue, the rotor material's shear bound translated into a tip-speed limit with the arithmetic shown, rather than chosen as a round margin below burst. For a 0.090-metre steel rotor the capped tip speed of 380 metres per second gives a trip speed of 40319 revolutions per minute and a stored energy at trip of 79.4 kilojoules. The overshoot budget, from a two-millisecond governor latency at the worst-case angular acceleration, adds 0.09 metres per second of tip speed, 0.02 per cent, leaving a containment margin of 15.5 per cent against the burst speed. SIMULATED, NOT MEASURED: the governor is specified and computed, and no rotor has been spun.