(2) Rotational speed
① The maximum speed at which a hydraulic pump can operate normally for a long time under rated pressure is called the rated speed nn.
② The maximum speed nmax is the speed at which a hydraulic pump can operate briefly beyond its rated speed at rated pressure.
③ The minimum speed allowed for normal operation, nmin, is called the minimum speed of the hydraulic pump. The commonly used legal unit of measurement for rotational speed (rated speed, maximum speed, minimum speed, etc.) is r/min (revolutions per minute). Sometimes the angular velocity w is also used to represent the pump speed, with the unit of w being rad/s (radians per second) [1 r/min=(π/30) rad/s].
