Shaft and Shaft Sleeves

Pump shafts transmit power from the prime mover to all rotating parts of the pump, especially the impeller. The torque acting on the shaft varies with situations. During starting period, shaft experiences heavy load compared to that during running conditions. The function of the shaft sleeve is to protect shaft from wear and tear. This arrangement is common in pumps using gland packing sealing system, where only shaft sleeve need to be renewed after sleeve getting heavily eroded.

Loads involved in Shafts

  1. Torque
  2. Weight of the parts
  3. Both the radial and axial hydraulic forces.

If a pump is to handle hot liquids, the shaft is designed to withstand thermal stresses and if it is to handle corrosive liquids, the materials used should be corrosion resistant. For this purpose the shaft sleeves also coated with different types of coating such as Stellite, Colmonoy, Tungsten Carbide, Hard chrome & Plasma.

Pump shafts have to withstand erosion, corrosion and wear at stuffing boxes, leakage joints, internal bearings and in waterways, etc. To protect the shaft, and also to give it special properties, eg. higher resistant to wear, renewable sleeves are fitted on the shaft.