The invention discloses a load sensitive turning hydraulic
system of a loading
machine. The load sensitive turning hydraulic
system is characterized in that a load sensitive
constant pressure variable
plunger pump supplies working
oil pressure to a flow enlarging valve and a turning
machine; a load feedback pressure
signal of the flow enlarging valve controls an LS control valve of a first load sensitive
constant pressure variable
plunger pump; an oil port L of the turning
machine is communicated to the right end of a main valve core L of the flow enlarging valve; an oil port R is communicated to the right end of a main valve core R of the flow enlarging valve; the load sensitive
constant pressure variable
plunger pump supplies the working
oil pressure to a load sensitive turning valve and a
pilot valve; and four control ends of the
pilot valve are respectively communicated with the load sensitive turning valve. The load sensitive turning hydraulic
system of the loading machine also comprises a turning system and convergence systems of other working systems. The load sensitive turning hydraulic system of the loading machine has the advantages that the
variable displacement function of the load sensitive constant pressure variable
plunger pump is fully used, so that the displacement of a turning pump is increased, and the turning performance is improved; and fuel is saved, and the working efficiency is improved. The flow enlarging valve is simple in structure, and
domestication is also realized; the cost of the flow enlarging valve is lower than that of an imported flow enlarging valve; and
batch production can be realized.