The sewage pump is a so-called "wet" pump. Depending on the pressure/capacity, sewage pumps all have the same structure: The suction side is generally at the bottom with the pressure side (outlet) on the side, with or without a flange on a so-called suspension hook. The E-motor is built directly on the pump housing, in general the impeller is mounted directly on the extended motor shaft. Technically speaking, there is not much difference with the standard types of submersible pumps. Submersible pumps also include specific pumps for clean water, waste water, but also for cooling water and various other mediums that are pumped directly from a tank. The pump can be divided into three parts: the bearing bracket, the liquid part and the shaft seal(s).
The E-motor is closed off from the medium part by means of a mechanical seal, this can be a single mechanical seal but also a double mechanical seal with a buffer chamber in between that is usually filled with oil. The E-motor is usually cooled by the medium in which the pump is suspended, unlike a dry E-motor where it is cooled with air by a fan. There are versions where the E-motor has a flow internally from the medium side through which it is cooled, which is done when the level in the tank where the pump is installed falls so low that the medium is below the E-motor surface. In addition, there are also submersible pumps that are completely filled with a special oil that partly provides cooling and lubrication, since the bearing of the entire pump is built into the E-motor.
This is an integral part between the liquid part of the pump and the shaft. In the case of a submersible pump, so-called "mechanical seal(s)" are used, which actually have a stationary and a rotating part and use extremely flat races that, if chosen and installed correctly, guarantee a very high degree of sealing. .
These are actually a pump housing with a suction and a pressure connection, in which the impeller rotates. The rear of the housing is closed by a back plate through which the axle comes through and the axle seal is mounted.
.png)
