Untitled record

The invention relates to a diaphragm pump for impure, in particular sand-containing, liquids having a cup-shaped rubber membrane, in which there is a pressure fluid which is moved by a plunger. In the known diaphragm pumps of this type, the cup-like membrane is freely expanded in its disassembled position, that is not supported. The tensile stresses occurring in the rubber body must be completely absorbed by the attachment point of the membrane, so that the risk exists. that the very heavily loaded rubber body suffers at higher pressures and longer service life at its attachment point. This disadvantage is avoided according to the invention in that the cup-shaped rubber membrane on the closed arched bottom has an axial support pin which in a. Bore of the pump housing stores. By this arrangement, a considerable strain relief of the attachment point of the rubber membrane is achieved, since a substantial part of the tensile stresses occurring during bulging is transmitted through the support pin on the housing. Also, the pot bottom of the membrane attaches to the round walls of the housing, whereby the membrane is very gentle.

In the drawing, an embodiment of the diaphragm pump is shown in a longitudinal section. The diaphragm pump is double-acting and consists of a pump housing i, the two suction valves 2, 3, the common suction line 4, and the two pressure valves 5, 6, the common pressure line. 7 lock or unlock alternately. In the pump housing i, two blanket cylinders 2i, 22 are arranged, the inner annular flanges 8 and g are clamped by stuffing boxes 14, 15 against shoulder-like lugs 16, 17 of the housing i. In the stuffing boxes 14, 15 a plunger i8. Slidably mounted, which alternately enters the filled with pure pressure fluid blanket cylinder, so this alternately bulges.

In the drawing, the plunger 18 is drawn in its rechts'Endstellung. The right blanket cylinder 22 is bulged, while the left blanket cylinder 21 assumes its rest position. The pump housing i is filled with sand-containing water. The right blanket cylinder 22 had just brought about its bulging a reduction of the right working space i9 and promoted the sand-containing water through the pressure valve 6 in the pressure line 7, while the left blanket cylinder 21 by its reduction to the streamlined position by the suction valve 2 from the suction line 4th had sucked in sand-containing liquid. Now goes to the plunger 18 to the left, so reduces the rubber membrane 22 from the bulged position to the streamlined position and sucks through the suction valve 3 with the pressure valve closed 6 liquid, while on the other side, the rubber diaphragm 2r bulges and e closed with the suction valve the sand-containing liquid from the left working space 2o promotes x through the pressure valve 5 in the common pressure line. ,

The rubber membrane 21, 22 has at its outer ends a round closed bottom 2 yes, 22a, which in an axial support pin gib, 22b merges, which in a bore 2Ic, 22c: stored at the ends of the pump housing z. In the respective bulging of the rubber membrane 21, 22 of the pressure generated in the interior of the membrane gib, 22b is received by the support pin and transmitted to the housing. It therefore occurs at these bearings almost no stress on the rubber membrane, whereby the membrane is very gentle. The displacer volume of the plunger 18 and the work spaces rg, 2o are sized so that the removed membrane almost or completely rests against the curved inner wall 25 of the pump housing, whereby harmful spaces are avoided as far as possible and another. Support of the rubber membrane is achieved.

The drive of the pump is made by a motor which engages in the middle of the plunger in one of the known ways. Of course, the diaphragm pump can also be designed to be single-acting. The suction and pressure valves are expediently arranged opposite each other at the largest bulge.