The double gear pump is equivalent to the combination of two double-acting gear pumps or two single-acting gear pumps. The two gear pumps are connected in parallel. The two sets of rotors, stator and oil distribution plate of the gear pump are installed in one pump. Inside the body, the pump body has a working oil suction port. The double gear pump has a common oil suction port (or one oil suction port) and two independent oil discharge ports. The two rotors are driven by the same transmission shaft. The oil pressure port of the pump core is on the pump body flange, and the pressure oil port of the pump core is on the end cover. The big collapse in the two pumps is always at the flange end of the gear pump. The dual output of the dual gear pump can be used separately, can be combined, or can be used together. The gear pumps can also be different. The high pressure small flow gear pump and low pressure large flow gear pump are often used in parallel. When the light load is in fast motion, the metering gear pump supplies oil to the system at the same time. In the slow motion, only the high pressure and small flow gear pump is used to provide high pressure oil. The output of the low pressure and large flow gear pump directly flows back to the mailbox. Unloading of low-pressure large-flow gear pump.