Question

An electric motor running at 1750 rev/min drives a pump through single-stage reduction gearing. The motor pinion has 16 teeth and the spur gear on the pump shaft has 80 teeth. At what speed will the pump rotate?

Answer 1

An electric motor running at 1750 rev/min drives a pump through single-stage reduction gearing. The motor pinion has 16 teeth and the spur gear on the pump shaft has 80 teeth. At what speed will the pump rotate?

**Solution:**

For the single-stage reduction gearing linear velocities of the motor pinion and pump shaft are identical, hence the speed is inversely proportional to the number of teeth on each element:

$$\frac{16 \text{ teeth}}{80 \text{ teeth}} = \frac{\omega_{\text{pump}}}{1750 \frac{\text{rev}}{\text{min}}}$$ $$\omega_{\text{pump}} = \frac{16 \text{ teeth}}{80 \text{ teeth}} \cdot 1750 \frac{\text{rev}}{\text{min}} = 350 \frac{\text{rev}}{\text{min}}$$

**Answer:** rotational speed of the pump is $350 \frac{\text{rev}}{\text{min}}$