Answer:
[tex](M_t)_{rated}=61.11lb-in[/tex]
Explanation:
speed of motor (N)=1500 rpm
power=4 hp = [tex]4 \times 0.7457 [/tex] =2.9828 KW
service factor(k)= 2.75
now,
[tex]KW=\frac{2\pi n M_t}{60 \times 10^6} \\2.9828=\frac{2\pi \times 1500 M_t}{60 \times 10^6}\\M_t=\frac{2.9828\times 60 \times 10^6}{2\pi \times 1500 }[/tex]
[tex]M_t= 18,989.09 \ N-mm= 168.06 lb-in[/tex]
torque rating
[tex](M_t)_{design}=k_s\times (M_t)_{rated}\\168.06= 2.75\times (M_t)_{rated}\\(M_t)_{rated}=\frac{168.06}{2.75} \\(M_t)_{rated}=61.11lb-in[/tex]
