Subsea Proximity Sensor Assemblies for Rotating Shaft Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In subsea fluid extraction wells, existing sensor assemblies struggle to accurately monitor the health of rotating equipment due to unique environmental conditions, leading to delayed detection of equipment issues and potential failures.
Innovation Solution
The development of proximity sensor assemblies that can directly monitor the position of a rotating shaft without physical contact, using RF radiation, light, or other energy types, and are designed to withstand high pressures and be flexible and adjustable for various configurations, allowing for precise monitoring of dynamic and static parameters of motor shafts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If indirect monitoring methods such as accelerometers mounted to motor case are used, then the sensor assembly can be installed without direct shaft access, but the measurement precision and diagnostic accuracy deteriorate due to signal attenuation and environmental interference
Solution Approach 1:
The patent introduces a magnetic coupling intermediary system consisting of a magnet on the rotating shaft and a corresponding sensor on the motor case. This magnetic field mediator transmits rotational position information from the shaft to the stationary sensor without direct mechanical contact, eliminating the need for physical shaft access while maintaining measurement accuracy. The magnetic coupling acts as an intermediary that bridges the gap between the rotating component and the stationary monitoring system.
2Ease of operation
If indirect monitoring through motor case movement is used, then the sensor assembly avoids direct contact with rotating shaft, but the reliability deteriorates due to inability to distinguish normal off-center orbits from problematic patterns in fluid film bearings
Solution Approach 1:
The patent replaces mechanical contact-based monitoring with a magnetic field-based sensing system. By using a magnet mounted on the shaft and a magnetic sensor on the motor case, the system eliminates mechanical coupling while maintaining the ability to monitor shaft position. This substitution allows for more reliable detection of shaft movement patterns, including the ability to distinguish between normal off-center orbits in fluid film bearings and actual problematic patterns, thereby improving diagnostic reliability.
3Reliability
If proximity sensor assemblies are designed for high pressure subsea environments, then the device can withstand harsh conditions, but the device complexity increases due to pressure compensation mechanisms and sealed constructions
Solution Approach 1:
The patent employs flexible membranes and thin film structures in the pressure sensor assembly design. These flexible elements can withstand high subsea pressures while maintaining the integrity of the sealed construction. The flexible shells allow for pressure equalization and compensation without requiring complex mechanical pressure relief mechanisms, thereby achieving reliable subsea operation with reduced overall device complexity.
4Measurement precision
If direct shaft monitoring is implemented, then the measurement precision improves for detecting shaft position and movement, but the ease of operation deteriorates due to need for physical shaft access and precise sensor positioning
Solution Approach 1:
The patent uses a magnetic field as an intermediary to transmit shaft position information without requiring direct physical access to the shaft. The magnet mounted on the shaft creates a magnetic field that can be sensed from the motor case, serving as a mediator that conveys rotational position data across the air gap. This intermediary approach maintains high measurement precision while eliminating the need for complex installation procedures involving direct shaft contact and precise positioning.
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
These sensor assemblies provide accurate and timely health assessments of subsea equipment, enabling early detection of issues and preventing equipment failures, while being compatible with harsh subsea environments and existing machinery standards.
Implementation Method 1
Proximity sensors typically actively emit RF (radio-frequency) radiation, light, sound, or other types of energy, and detect changes in the electromagnetic field or return signal.
Implementation Method 2
Proximity sensors typically actively emit RF (radio-frequency) radiation, light, sound, or other types of energy, and detect changes in the electromagnetic field or return signal.
Implementation Method 3
Proximity sensors typically actively emit RF (radio-frequency) radiation, light, sound, or other types of energy, and detect changes in the electromagnetic field or return signal.
Data Source
AI summary
Integrated penetrator and proximity sensor probe assemblies are provided for monitoring a position of a rotating target within a subsea rotating device such as subsea motors and pumps. The integrated penetrator and proximity sensor probe assemblies are configured to communicate information related to the position of the rotating target through a wall of the device housing, and can be inserted through an opening in the wall of the device housing and mounted to the wall of the device to position a proximity sensor tip assembly adjacent the rotating target. The proximity sensor probe assemblies are pressure-compensated and configured to withstand subsea pressures and conditions.