What is the primary purpose of a submersible screw pump in elevator systems?

The primary purpose of a submersible screw pump in elevator systems is to avoid metal-to-metal contact between the rotor and the idlers. This is critical in maintaining the longevity and efficiency of the pump. Submersible screw pumps are designed to operate with the rotor submerged in the fluid, which serves to create a hydrodynamic barrier. This barrier prevents direct contact between moving parts, thereby reducing wear and tear due to friction.

This design feature not only enhances the efficiency of the pump by minimizing energy loss through friction but also eliminates the potential for damage that can occur with metal-to-metal contact. By avoiding such contact, the pump can operate smoothly at optimal performance levels while extending the overall lifespan of both the pump and the elevator system it serves.