Single and double acting reciprocating pump relies on the reciprocating operation of plug or plunger pump cylinder to periodically expand the working volume of pump cylinder and shrink the suction and discharge liquid reciprocating pump. The mechanical energy is converted into pressure energy by two basic parts, and the liquid part is called the hydraulic cylinder part or the hydraulic end; the other end force transmission part is called the force end plug reciprocating operation, which is called the piston stroke or the distance between the internal and external stop points of the two working cycle suction and discharge paths of the working cycle reciprocating pump. Reciprocating pump instantaneous flow pulse and average flow constant value reciprocating pump liquid medium suction and discharge alternately carry out plug (or plunger) displacement range, and its speed break changes. The instantaneous flow of cylinder pump only changes with time and adopts double acting structure continuously. The differential structure cylinder pump structure reduces the instantaneous flow pulse amplitude and instantaneous flow pulse of the pipeline to avoid the theoretical flow and discharge pressure being closed and the single action pump flow intermittently transports away from the pump with the liquid characteristics being closed, and the liquid cylinder discharge is evenly measured.
Because of the simple structure of the pump head of the single acting pump, it brings a lot of convenience to the processing and manufacturing, especially the straight through structure.
In summary, the structure of single acting pump has two characteristics:
1. Short stroke and high reciprocating times;
Due to the problem of sealing without piston rod, it can increase the number of reciprocations. At present, it has reached more than 200 times/min, which can shorten the stroke and reduce the cylinder diameter, so that the volume and weight of the whole pump are greatly reduced under the premise of equal flow.
2. Piston structure of single acting pump;
Generally made into bowl or disc shape, it is easy to install, dismantle, replace and wash the friction surface. And because of the small cylinder diameter, the piston is easier to seal. In addition, under high pressure, the piston is more reliable due to its self sealing function. Single acting pump has higher working pressure than double acting pump.
Furthermore, due to the high number of reciprocations, the range of flow regulation can be expanded to realize multi-level speed regulation. The wearing parts of single acting pump are less, and the replacement is simple and convenient.
When the single acting pump is three cylinders, its discharge flow changes little, and the pressure fluctuation is small, so that the pump runs stably and the impact load is small.