- Figure 4 Shows A Hydrostatic Transmission Circuit Used In A Hoist System The System Specifications Are Given Below Fi 1 (114.53 KiB) Viewed 22 times
Figure 4 shows a hydrostatic transmission circuit used in a hoist system. The system specifications are given below : Fixed-Displacement Pump = 80 cm³/rev = 1500 rpm constant Vp np npv = 95% 7pm = 85 % (a) Determine : (i) Variable- Displacement Um nmv = 500 cm³/rev = 93% mm = 83% The pressure relief valve is set at 270 bar and the pipe friction total up to around 8 bar on the high-pressure side. Ans: (a) (i) 212 rpm (iii) 1730.5 rpm, Motor the minimum speed of hydraulic motor in rpm. the maximum leakage flow in litres/min from hydraulic pump and motor. Hence deduce the required delivery in litres/min from the replenishment pump. (iii) the maximum load torque in Nm that the hydraulic motor can drive before the pressure relief valve begins to open. (iv) the maximum power in kW drawn from the electric motor. (b) If the hydrostatic drive is to be converted to a reversible drive. State two protective features that must be incorporated. (ii) 14 litres/min (iv) 63.53 kW Figure 4 Load