Problems 5 (hydrostatic drive): The hydrostatic drive shown below in part (b) is driven by a torque source, T(t), which is assumed known. The hydraulic pump and motor are assumed to be positive-displacement (PD) hydraulic machines with displacements of dp and dm, respectively, where pump flow, Qp, is related to pump shaft speed, wp, by the relation, Qp = dpwp, and similarly for the motor Qm = dmwm. T(t) 19 @ PD machine T(1) PD pump Q=d.w T=d.AP (a) Net losses, R Fluid supply (b) d +444 T -T @ Q PD motor @ m B