it is a capacitance inner clutch gear  pump ,Its inner gear (outer rotor) is a round arc gear shape and the outer gears (inner rotor ) is a short amplitude outer cycloid new type  gear pump. Relief valve also cna be installed with pump .
It can be widely used in low pressure system because of its simple stricture, low noisy ,steady and flat oil-line  and good selfpriming  performance high speed characteristic.It can be used as the dynastic  pump or lubracting  pump and cooling pump .This pump is suitable for transmiting all kinds of oil .