| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive rotational speed measurement device which is less likely to break down.SOLUTION: A rotational speed measurement device which measures the rotational speed of a rotor includes: a casing; the rotor pivoted by the casing; a pinion gear to integrally rotate with the rotor; a belt formed with a rack to engage with the pinion gear and a plurality of identification parts; and a detection part mounted on the casing to detect the passage of the identification parts, therein a movement required time from one identification part to another identification part is measured by using an output signal from the detection part such that the rotational speed of the rotor is measured.SELECTED DRAWING: Figure 3 |
