Device for measuring rotary inertia of allotypic object

The utility model discloses a device for measuring the rotary inertia of shaped objects, compising a photoelectric data processing unit, a rotating disk, a luminous vibrator, a linear spring, a regulating nut and a supporter. The rotating disk is hinged on the horizontal shaft arranged on the supporter, a string are enwound around the rotating disk, one end of the string is connected with the photoelectric vibrator, and the other end is connected with the linear spring whose other end is fixed on the regulating nut. The photoelectric data processing unit is composed of a light activated element, a triode, an SCM, a latch, a memory and key switches. The light sensitive element inducting the light source emitted by the photoelectric vibrator, the light source is magnified by the triode and then is sent to the SCM for timing and testing the vibration period of the photoelectric vibrator, and processing the period signals to get the average value; various messages are stored in the latch and the memory, the rotary inertia of the shaped object is calculated according to the established procedure, and various calculated results are selected and displayed through the key switches. The utility model has simple structure, convenience, low cost, high degree of automation and accurate measuring.