Elastomeric Torsional Coupling for Misaligned Fracturing Pumps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
U-joint shafts used to compensate for misalignment between motors and equipment in hydraulic fracturing operations introduce inefficiencies, requiring a minimum 3 degrees of offset and increased separation, which is problematic in space-constrained setups.
Innovation Solution
A torsional coupling system with motor and pump components that allow for radial, axial, or angular misalignment while maintaining torque transmission, using elastomeric inserts and a retainer cap to absorb movement and prevent debris ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a U-joint shaft is used to compensate for misalignment between motor and equipment, then misalignment compensation is achieved, but energy loss increases by up to 10% or more
Solution Approach 1:
The patent replaces the traditional U-joint shaft mechanical system with a magnetic coupling system that uses magnetic fields to transmit torque. This substitution eliminates the mechanical contact and friction inherent in U-joint shafts, thereby reducing energy loss while maintaining the ability to compensate for misalignment between motor and pump shafts.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the motor shaft and pump shaft. The magnetic coupling creates a magnetic bridge that transmits rotational force without direct mechanical contact, allowing misalignment compensation while minimizing energy dissipation through reduced friction and mechanical inefficiencies.
2Ease of operation
If a U-joint shaft is used to allow misalignment, then shaft connection is achieved, but the minimum 3 degrees offset requirement leads to longer shaft length and greater separation
Solution Approach 1:
The patent replaces the long U-joint shaft with a compact magnetic coupling system. The magnetic field transmission allows for misalignment accommodation without requiring the extended mechanical shaft length that would be necessary to achieve the same angular offset tolerance with traditional U-joint mechanics.
Solution Approach 2:
The patent changes the fundamental parameter of torque transmission from mechanical contact through a long shaft to magnetic field interaction. This parameter change allows the system to tolerate misalignment (3 degrees or more) while maintaining a much shorter effective coupling length, as magnetic fields can accommodate angular deviations without the geometric constraints of long shaft mechanics.
3Adaptability or versatility
If U-joint shaft is used for misalignment compensation, then connection flexibility is improved, but device complexity increases
Solution Approach 1:
The patent replaces the complex U-joint shaft assembly with a simpler magnetic coupling system. The magnetic coupling consists of magnetic assemblies on either side of the air gap, eliminating the need for U-joints, bearing surfaces, and complex mechanical alignment features, thereby reducing device complexity while maintaining connection flexibility.
Solution Approach 2:
The patent extracts the essential function of misalignment compensation from the complex U-joint shaft mechanism and implements it through a simplified magnetic field-based system. By taking out the misalignment compensation function and implementing it through magnetic coupling, the patent eliminates unnecessary mechanical complexity while preserving the adaptability needed for flexible connections.
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
The torsional coupling reduces energy loss to 1% or less, allows for a shorter driveshaft, and requires less space, improving efficiency and setup flexibility in space-constrained environments.
Implementation Method 1
The pump component or the motor component can further include elastomeric inserts positioned between the pump coupling claws or the motor coupling claws, respectively, to provide a buffer therebetween and to absorb movement and vibration in the torsional coupling.
Data Source
AI summary
A system for hydraulically fracturing an underground formation in an oil or gas well, including a pump for pumping hydraulic fracturing fluid into the wellbore, the pump having a pump shaft, and an electric motor with a motor shaft mechanically attached to the pump to drive the pump. The system further includes a torsional coupling connecting the motor shaft to the pump shaft. The torsional coupling includes a motor component fixedly attached to the motor shaft and having motor coupling claws extending outwardly away from the motor shaft, and a pump component fixedly attached to the pump shaft of the pump and having pump coupling claws extending outwardly away from the pump shaft. The motor coupling claws engage with the pump coupling claws so that when the motor shaft and motor component rotate, such rotation causes the pump component and the pump shaft to rotate, thereby driving the pump.