![]() The system efficiency is very much dependent on the type of hydraulic work tool equipment, the hydraulic pumps and motors used and power input to the hydraulics may vary considerably. ![]() The oil volume in the hydraulic tank is also acting as a heat accumulator when peak power is used. In normal case however, the peak power is used for only short periods, thus the actual cooler capacity required might be considerably less. Minimum cooler capacity, Ecooler = 0.25EdieselĪt least 25% of the input power must be dissipated by the cooler when peak power is utilized for long periods. The basic estimation would be:Ĭalculation of preliminary cooler capacity: Heat dissipation from hydraulic oil tanks, valves, pipes and hydraulic components is less than a few percent in standard mobile equipment and the cooler capacity must include some margins. the point where pressure times flow reach their maximum value. STEP 1įirst check the maximum power point, i.e. Follow these 3 steps to calculate the required maximum power output for the diesel engine. Moreover, the general power loss in a hydraulic energy transmission is around 25% or more at ideal viscosity range 25-35. And hydraulic axial piston motors and pumps have 0.87. And the total system efficiency (without including the pressure drop in the hydraulic pipes and valves) will end up at approximately 0.75.Ĭylinders normally have a total efficiency of around 0.95. The hydraulic motors and cylinders that the pump supplies with hydraulic power also have efficiencies. ![]() The average for axial piston pumps, ηtotal = 0.87.įurthermore, the power source (for example a diesel engine or an electric motor), must be capable of delivering at least 75 ÷ 0.87 = 86. This efficiency is the product of volumetric efficiency, ηvol and the hydromechanical efficiency, ηhm. The total pump efficiency, ηtotal, must be included when calculating the power input to the pump. This would always depend on the type of pump being used, i.e. ** based upon 100% efficiency 90% efficiency would equate to 75 ÷ 0.9 = 83.3kW. Example: if a pump delivers 180 litres/minute and the pressure is 250 bar, then the hydraulic calculation for prime mover power of the pump is:
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