Working principle progressing cavity pumps

The eccentric pump type is part of the positive displacement pump group. The most important parts of the system are the moving part, the rotor and the fixed part, the stator, in which the rotor rotates.

The rotor can be viewed as being a screw with an extremely high speed, great eccentric movement and a small diameter. The stator has one worm thread more than the rotor and twice the thread of the pitch. Consequently, there are continuously shift spaces (“progressing cavities“) between the rotor and the stator.

Basic elements Verderpro

An eccentric progressing cavity pump includes a number of fundamental basic elements

The rotor

The rotor is a helical worm that makes a rotary eccentric movement (via a connecting rod, couplings, drive shaft and engine).

The stator

The stator is the second base pump element. The stator does not rotate and it has the same internal form and geometric measurements as the rotor with the exception that it has a double 180° shifted double thread and twice the pitch.

Couplings

The simplest coupling for the connecting rod is the easy to assemble pin coupling.
These wear-resistant and hardened couplings consist of the following parts: a coupling rod bush, a coupling rod pin and two guides. These elements are attached to the rotor and pin shaft head through a coupling sleeve. The coupling is then filled with a special lubricant and a cuff/packing seal is slid over the entire element. The cuff/packing seal is kept in place with claming strips.

Pin shaft connection

There is a pin shaft connection between the pump and the drive on the bearing housing enabling easy maintenance and easy exchange of the rotor and shaft seal. The drive or bearing housing need not be disassembled.

Shaft seals

Verderpro progressing cavity pumps have a wide range of sealing possibilities. The most common ones are listed below:

• Great variety of gland packings
• Mechanical seals (single, double, back-to-back, with barrier fluid, etc)

What does it mean for your process

The most inportant question after reading this 'technical story' is: What does it mean for my process? Please let us answer this question and contact us with your specific application and process requirements