Hydroformed Helical Stator for Progressing Cavity Pumps
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Solution Overview
Problem
Existing progressing cavity pumps face challenges in efficiently pumping materials like solids, semi-solids, and viscous fluids due to the limitations in stator design, particularly in achieving a consistent and efficient flow without pulsation and requiring additional material for non-helical stator surfaces.
Innovation Solution
The development of an equal wall stator formed through hydroforming, where a cylindrical stator component is expanded radially to conform to a helical shape using an intensifier rod, allowing for a consistent thickness and reduced material usage, and featuring a stator liner with a double lead helical nut design for efficient fluid handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional stator design is used, then the pump can handle various materials, but the flow is pulsating and efficiency is reduced
Solution Approach 1:
The stator is designed with a helical curvature profile that creates smooth, continuous cavity progression. The helical grooves are formed with precise curvature radii that ensure uniform material flow progression from suction to discharge, eliminating pulsations and improving pumping efficiency for viscous and shear-sensitive materials.
Solution Approach 2:
The invention optimizes specific geometric parameters including the helix angle, lead profile, and wall thickness distribution. By carefully controlling these parameters, the stator achieves balanced hydrodynamic conditions that maintain steady flow rates and improve overall pumping efficiency while handling various material viscosities.
2Manufacturing precision
If a helical stator shape is achieved through conventional manufacturing, then the stator can interact with the rotor, but material waste is high and precision is low
Solution Approach 1:
The invention employs hydroforming technology where a fluid medium is used to plasticize and form the stator material into the precise helical shape. This hydraulic forming process allows for complex curved geometries to be achieved with minimal material waste compared to conventional subtractive manufacturing methods.
Solution Approach 2:
The manufacturing process utilizes controlled temperature and pressure parameters during hydroforming to achieve the desired helical shape. By optimizing these process parameters, the invention attains high manufacturing precision for the stator geometry while maintaining material efficiency through form-over-stock manufacturing.
3Ease of manufacture
If the stator wall thickness is varied, then the stator can accommodate the helical shape, but the structure becomes unbalanced and harder to manufacture
Solution Approach 1:
The equal wall thickness design maintains structural balance while achieving the helical shape through uniform material distribution. The consistent wall thickness allows for balanced manufacturing processes and ensures uniform stress distribution during pump operation, simplifying both fabrication and quality control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a stator assembly that provides predictable, pulsationless flow and reduced material usage, enhancing the efficiency and reliability of progressing cavity pumps for various fluid types, including viscous and shear-sensitive materials.
Implementation Method 1
hydroforming the stator casing into a generally helical shape
Implementation Method 2
increasing the pressure of the fluid by inserting an intensifier rod into the stator component to cause the stator component to expand radially outwardly
Implementation Method 3
The hydroforming step includes placing the stator component in a state of compression, wherein the compression of the stator component and the movement of the intensifier rod are independently controlled
Data Source
AI summary
A method for making a stator assembly including the steps of providing a generally cylindrical stator casing, hydroforming the stator casing into a generally helical shape, and positioning a stator liner having a generally helical shape inside the stator casing.