| 摘要 |
A double diaphragm pump with a novel compressed air control means is described, in which, in addition to a main control valve piston for the control of the compressed air fed to the two air chambers of the diaphragm pump, a pilot control valve means is provided, which drives the main control valve piston pneumatically such that the main valve is retarded at approximately half of the length of its stroke, at which point the main control valve piston separates the two air chambers both from the compressed air inlet and from the exhaust air outlet, and instead connects them together for the purpose of pressure equalization. By this measure in conjunction with novel sealing means for the moving parts, the pressure losses are reduced and thus the efficiency of the pump is increased, the danger of icing up the air exhaust is reduced, and separate provisions for lubrication, such as oil mist lubrication, are dispensed with. |
