回かい転てん数すう

noun

number of revolutions; rotational speed

Used for engine RPM, motor speed, or any rotating object's revolution count. Often appears in technical contexts.

• エンジンの回かい転てん数すうが上あがると、車くるまは速はやくなる。

  When the engine's RPM increases, the car goes faster.

• このモーターの最さい高こう回かい転てん数すうは毎まい分ふん3000回かいです。

  The maximum rotational speed of this motor is 3000 revolutions per minute.