The motor of the lathe develops a power of 4.5 KW. Determine the cutting speed m / min

The motor of the lathe develops a power of 4.5 KW. Determine the cutting speed m / min if the cutting force is 3.6 kN. The efficiency of the motor is 80%.

Initial data: Ns (the power that the lathe motor develops) = 4.5 kW (4.5 * 10 ^ 3 W); F (cutting force of the lathe cutter) = 3.6 kN (3.6 * 10 ^ 3 N); η (machine engine efficiency) = 80% (0.8).

We express the cutting speed from the formula for calculating the efficiency: η = Np / Nc = F * V / Nc, whence V = η * Nc / F.

Let’s make a calculation: V = 0.8 * 4.5 * 10 ^ 3 / (3.6 * 10 ^ 3) = 1 m / s.

Answer: The cutting speed is 1 m / s.