Question

A DC servomotor is directly driving an NC table. The pitch of the lead screw of the table is $5mm$. The motor rotates at $100rpm$ for an applied voltage of $10V$. If the voltage speed characteristic of the motor is linear, the applied voltage for a table of $3m/min$ is equal to

• A. $30V$
• B. $33V$
• C. $50V$
• D. $60V$

Answer 1

The correct option is D $60V$

Distance travlled on load screw $=5mm$
Motor speed $=10rpm$
Line for one revolution $=1/100min$
Speed of motion on load screw $=\frac{5}{1/100}=500mm/min$
Considering linear characteristic or $0.5m/min$
To get travel speed of $3m/min$, we have to increase the voltage by $\frac{3}{0.5}=6times$
i.e., $10\times 6=60V$