Multi-Section Downhole Fluid Motor for Rotor-Stator Alignment
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Solution Overview
Problem
Existing downhole fluid motors face challenges in design and construction, particularly in maintaining efficient operation and longevity due to issues with rotor-stator contact and alignment, which affect the overall performance and durability.
Innovation Solution
The development of a downhole fluid motor with a multi-section stator, where stator sections are rotationally indexed and aligned using various securing methods such as deformation of the housing, use of alignment mandrels, and application of a lining to enhance sealing and reduce friction, allowing for continuous lobe engagement and improved rotor-stator interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a multi-section stator is used with rotational indexing and alignment, then manufacturing precision and rotor-stator alignment are improved, but device complexity increases
Solution Approach 1:
The stator is divided into multiple axially-spaced sections (first stator section, second stator section, etc.) that can be separately manufactured and then assembled. Each section contains stator lobes that engage with rotor lobes, allowing the stator to be constructed from modular components rather than a single monolithic piece.
Solution Approach 2:
Alignment features (such as index features, alignment keys, or positioning structures) are pre-formed on the stator sections during manufacturing. These preliminary alignment features ensure that when sections are assembled axially, they automatically achieve the correct rotational alignment with each other and with the rotor, eliminating the need for complex post-assembly adjustment procedures.
2Reliability
If deformation of housing is used to secure stator sections, then reliability of stator-rotor contact is improved, but manufacturing complexity increases
Solution Approach 1:
The housing is designed with deformable sections that can be elastically or plastically deformed during assembly to create interference fits or mechanical locking features. This dynamic deformation process allows the housing to transition from a rigid assembly structure to a state where it actively secures the stator sections through controlled deformation, improving reliability without requiring additional fasteners or complex joining mechanisms.
3Productivity
If alignment mandrels and lining are applied, then operational efficiency is improved, but device complexity and manufacturing steps increase
Solution Approach 1:
Alignment mandrels serve as temporary intermediary tools during assembly. These mandrels are inserted into the stator sections to maintain precise rotational alignment while the lining is being applied. The mandrels act as mediators that hold the stator sections in the correct position, allowing the lining material to be uniformly applied without disturbing the alignment. After the lining cures or sets, the mandrels are removed, leaving the stator sections permanently aligned.
Solution Approach 2:
A lining material is applied to the stator lobes or housing interior surfaces. This lining changes the surface parameters (friction coefficient, sealing properties, wear resistance) of the stator-rotor interface. The lining material may be elastomeric, polymeric, or composite, and its application transforms the raw metal-to-metal contact into a controlled interface with optimized tribological properties, thereby improving operational efficiency.
Data Source
AI summary
A downhole fluid motor can include a tubular housing and multiple stator sections. Each of the stator sections has a helical stator profile formed therein. Deformation of the housing secures each respective stator section in the housing. A method of producing a downhole fluid motor can include securing multiple stator sections to each other, each of the stator sections having a stator profile formed therein, and securing the stator sections in a tubular housing. The securing steps can be performed without any welding. The step of the securing the stator sections in the housing can include deforming the housing toward the stator sections.