Submersible Motor Pump Magnetic Coupling Cooling
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Solution Overview
Problem
Existing submersible pump assemblies face limitations in robustness and longevity due to lack of radial support in magnetic couplings, leading to overheating and reduced torque transmission at high shaft speeds, especially with viscous fluids.
Innovation Solution
Incorporation of a magnetic coupling cooling device that pumps fluid through the coupling to remove excessive heat, utilizing an oil/water separator or pumping stages to cool the magnets, and radial bearings to support the coupling and minimize vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the magnetic coupling operates at high shaft speeds with viscous fluids, then productivity increases, but overheating occurs due to viscous friction causing magnets to lose magnetic properties
Solution Approach 1:
The patent extracts the harmful heat from the magnetic coupling by introducing a cooling device that circulates fluid through channels in the coupling housing, separating the heat generation source from the magnetic components and removing it through thermal exchange with cooling fluid
Solution Approach 2:
The patent introduces a cooling fluid as an intermediary substance that absorbs heat from the magnetic coupling through thermal conduction and convection, acting as a heat transfer medium between the hot magnetic components and the external cooling system
2Device complexity
If the magnetic coupling lacks radial support, then device complexity is reduced, but robustness and reliability deteriorate at high shaft speeds
Solution Approach 1:
The patent integrates multiple functions into the coupling housing: it serves as both the structural housing containing the magnetic components and as the mounting structure for radial bearings, while also incorporating cooling fluid channels, making the housing a multi-functional component that supports radial loads and provides thermal management
3Temperature
If the gap between protective screen and driven half-coupling is increased to allow cooling fluid passage, then cooling effectiveness improves, but torque transmission capability decreases
Solution Approach 1:
The patent segments the coupling structure into distinct functional zones: the protective screen is positioned at one end of the magnetic coupling, creating separated regions for magnetic field interaction and cooling fluid flow, allowing the cooling fluid to pass through gaps and channels without interfering with the magnetic torque transmission zone
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
Enables reliable torque transmission and extended service life by maintaining magnet magnetic properties and preventing overheating, even at high shaft speeds and viscosities.
Implementation Method 1
torque from the motor shaft is transferred to the pump shaft due to the engagement between permanent magnets attached to the driving and driven half-couplings of the magnetic coupling
Implementation Method 2
substantial heating occurs in the magnetic coupling due to viscous friction in a fluid layer adjacent to the rotatable wall
Implementation Method 3
The device pumps the fluid through the coupling and removes excessive heat therefrom
Data Source
AI summary
The invention relates to pump engineering and, in particular, to submersible pump assemblies driven by a sealed submersible electric motor for pumping well fluids. The submersible pump assembly comprises a pump, a motor, and a magnetic coupling comprising driving and driven half-couplings having permanent magnets and affixed to the motor rotor and pump rotor, respectively, a protective screen arranged between the rotors, and an intermediate bearing support. The assembly further comprises a magnetic coupling cooling device for cooling the magnetic coupling. When well fluid is a mixture of water and oil, a separator is preferably used as the magnetic coupling cooling device. When producing low-viscosity well fluid, the coupling is sufficiently cooled without additional separation of the produced fluid, and for this reason a set of pumping stages may be used as the cooling device. The invention increase operation time of the pump assembly at high shaft speeds and high shaft torques.