The impeller and pump shaft are connected by a key. The key is commonly known as the pin, which is the connecting part of the rotating part. The sewage pump usually adopts the flat key, which can only transmit the torque but not fix the axial position of the impeller. In large and medium water pumps, the axial position of impeller is usually positioned by the nut of the axle sleeve.

Material of pump shaft of sewage pump:

Material and structure of the pump shaft, because the pump shaft is used for the transmission of power and high-speed rotation, in a pump conveying clear water and other non-corrosive media, 45 steel is generally used and the quenching and tempering process is used. The pump shaft material is 40Cr, and the quenching and tempering process is used in the pumps to convey weak corrosive medium such as salt solution. In the anti-corrosion pump, it is used to transport acid, alkali and other corrosive medium pump, the material of the pump shaft is generally lCr18N19lCr18Ni9Ti and other stainless steel.

The pump shaft of a pipe centrifugal pump is a part of a step shaft, generally a whole, but in the anticorrosive pump, because of the high price of stainless steel, sometimes it adopts the combination,
the parts of the contact medium are made of stainless steel, and the parts of the bearing and couplings are made of high quality carbon cable. The connection between stainless steel and carbon steel is made up of socket connection, interference fit and reinforcement with pins.