To determine the regulation of the maximum speed on an assembly of ball screw-nut, it is necessary to consider two basical points: PERIPHERICAL SPEED OF THE BALLS and CRITICAL SPEED OF THE SCREW.
The peripheral speed is consequent to the runway of the balls along the circumference. It has a limit value calculated depending on several factors. Basically this value is defined by multiplying the screw diameter X revolutions per minute.
SPEED n max = 1200/do (min-1)
Speed of the screw is limited by its natural frequency of vibration, on which appear unbalanced forces may appear. This critical speed depends upon its diameter, length and type of supports.
To determine the allowable speed for a screw. On the following graphic we can calculate this value directly with more usual types of supports, with the parameters of screw diameter and length between supports. The graphic is made including a safety coefficient.
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