摘要 |
A pump includes a cylindrical main body comprising a central channel, four valve assemblies each threadedly fastened in a radial hole, first and second cavities disposed to each hole and communicating therewith, a spring activated first check valve in each first cavity, a spring activated second check valve in each second cavity, an outlet, a threaded outlet orifice communicating with the outlet, an inlet, a threaded inlet orifice communicating with the inlet, four plungers each in a plunger chamber communicating between the hole and the channel, opposite outlet and inlet tunnels, two snapping members each having a central hole and a snapping bifurcation at either bent end, the snapping bifurcation slidably put on an end of the plunger; a top cover; a bottom cover; and an eccentric shaft having one end secured to motor shaft and other portions in the main body to operatively secure to the snapping members. |