Double-suction internal gear pump structure

A liquid inlet of a pump shell is communicated with a rear inlet cavity and a front inlet cavity, and a liquid outlet of the pump shell is communicated with a rear outlet cavity and a front outlet cavity, so that liquid enters from the liquid inlet of the pump shell and enters a gear cavity through two sides of the rear inlet cavity of the pump shell and the front inlet cavity of a front cover; the large gear and the small gear are arranged in the pump shell, then are discharged from the gear cavity to the two sides of the rear outlet cavity of the pump shell and the two sides of the front outlet cavity of the front cover from the pump outlet side, and are converged at a liquid outlet of the pump shell to flow out, so that the purposes of two-way suction and two-way discharge are achieved; the liquid enters from two sides to reduce high net positive suction head caused by high-speed fluid entering from one side. The axial projection area of the rear inlet cavity of the pump shell and the axial projection area