1. Hydraulic Pump Pressure
Hydraulic pump working pressure refers to the pump (or motor) in the actual work output (or input) oil pressure, determined by the external load.
Rated pressure refers to the maximum pressure to operate continuously under the standard of test under normal working conditions. Its size is limited by life expectancy, and the service life of the pump (or motor) will be shorter than the design life if it exceeds the rated pressure. Overload is called when work pressure is greater than rated pressure.
Working speed refers to the actual rotational speed of the pump (or motor) at work.
Rated speed refers to the maximum speed that can operate continuously for a long time under the rated pressure. If the pump exceeds the rated speed of work will cause the lack of oil, vibration and large noise, parts will suffer cavitation damage, life reduced.
The lowest stable speed is the minimum speed allowed for the normal operation of the motor. At this speed, the motor does not appear crawling phenomenon.
3. Displacement, flow
Displacement is the volume of the liquid that is discharged (or imported) by the change of the geometrical dimension of the sealing chamber, and the Common Unit is ML/R (ml/rpm). Displacement can be changed by adjusting the variable pump (or variable motor), the displacement can not be changed into a quantitative pump (or quantitative motor).
The actual flow is the flow of the pump (or motor) at the exit (or inlet) at work. Because the pump itself has internal leakage, its actual flow is less than the theoretical flow. Because the motor itself also exists inside the leakage, to achieve the specified speed, to compensate for leakage, the actual flow of input must be greater than the theoretical flow.
Volumetric efficiency, to the hydraulic pump refers to its actual flow and theoretical flow ratio. The hydraulic motor refers to the ratio of theoretical flow to actual flow.
Mechanical efficiency, to the hydraulic pump refers to its theoretical torque and the actual input torque ratio. The torque of the hydraulic motor whose actual output is the theoretical torque overcomes the torque after friction, so its mechanical efficiency is the ratio of the actual output torque to the theoretical torque.
Total efficiency refers to the ratio of the output power of the pump (or motor) to the input power. Total efficiency equals the product of volumetric efficiency and mechanical efficiency.