ESP Load-Absorbing Splined Coupling for Shaft Breakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric submersible pump (ESP) shaft breakages are common due to torsional stresses at spline connections, leading to increased warranty claims and significant downtime for maintenance.
Innovation Solution
The implementation of torque-absorbing splined couplings with angled groove sidewalls allows for deformation of shafts and teeth, distributing torque loads across the length of the coupling, reducing stress concentrations and the likelihood of shaft breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional rigid couplings are used to connect shafts, then torsional rigidity is improved, but stress concentration at spline connections increases leading to shaft breakage
Solution Approach 1:
The coupling design changes the geometric parameters of the groove sidewalls from vertical to angled (e.g., 15-45 degrees relative to the shaft axis). This parameter change allows the coupling to deform elastically under torque, distributing stress along the spline length rather than concentrating it at the end, thereby resolving the contradiction between rigidity and stress concentration
Solution Approach 2:
The coupling incorporates a flexible deformation mechanism through its angled groove design, allowing the coupling body to act as a flexible element that can elastically deform under torsional load. This flexibility absorbs stress peaks and prevents brittle failure, addressing the strength issue while maintaining adequate torsional rigidity for power transmission
2Reliability
If shaft replacement is performed after breakage, then system reliability is restored, but maintenance downtime increases significantly
Solution Approach 1:
The coupling is designed as a replaceable protective component that can be quickly swapped in the event of failure. By making the coupling a separate, easily replaceable part rather than integrating it permanently with the shaft, the system enables rapid maintenance replacement that restores reliability without requiring extensive downtime for shaft replacement
Solution Approach 2:
The coupling is designed as a separate, modular component that can be independently replaced from the shaft and pump assembly. This segmentation allows maintenance crews to replace only the coupling rather than the entire shaft or pump, significantly reducing maintenance downtime while restoring system reliability
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 design enhances the shaft load rating, reduces the likelihood of breakage during normal operation and shutdown conditions, and minimizes maintenance downtime by distributing torque loads effectively.
Implementation Method 1
The angling of the sidewalls in the grooves allows the deformation of at least a portion of the teeth and of the shafts under the load experienced by the startup or operation of the electric motor
Implementation Method 2
Splined couplings couple the shafts for rotary motion by receiving teeth on the shafts within grooves in the splined couplings
Data Source
AI summary
An electric submersible pump (ESP) assembly that includes an electric motor with a splined drive shaft with drive shaft teeth, an ESP mechanically coupled to the electric motor that includes a splined ESP shaft with ESP shaft teeth, and a downhole component mechanically coupled to the electric motor that includes a splined component shaft with component shaft teeth. Splined couplings each include a central axis and grooves through the coupling with groove sidewalls sized to receive the shaft teeth. The grooves are angled relative to the central axis to form a space on either side of each tooth in each groove for at least a portion of the overlapped length of the tooth within the groove. Each coupling is engageable with the teeth of two of the drive shaft, the pump shaft, or the component shaft to mechanically couple the electric motor, the ESP, and the downhole component.