Submerged Pump Assembly With Fluid-Cooled Seal-Free Bearings
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Solution Overview
Problem
Existing pump systems immersed in fluids face issues with mechanical seals failing due to wear and tear, leading to fluid ingress and heat trapping, which damages components and requires constant lubrication and cooling, especially for submerged applications like swimming pools and ponds.
Innovation Solution
A pump assembly design with a shell and inner casing that allows fluid pathways for cooling and lubrication, featuring a stator with heat sinks and fins, and a rotor with blade assemblies for propulsion, eliminating the need for mechanical seals by using fluid pathways for cooling and lubricating bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical seal is used to prevent fluid ingress, then sealing reliability is improved, but the seal fails due to wear and tear and spring mechanism weakening
Solution Approach 1:
The patent removes the mechanical seal from the system entirely. Instead of using a traditional sealed motor arrangement with mechanical seals, the invention extracts the sealing function and replaces it with an open rotor design where the rotor hub is directly exposed to the pumped fluid, eliminating the wear-prone mechanical seal component.
Solution Approach 2:
The patent replaces the mechanical sealing system with an electromagnetic coupling system. The stator windings generate a magnetic field that couples with the rotor magnets to transmit torque without mechanical contact, substituting mechanical transmission with electromagnetic interaction to eliminate mechanical wear.
2Reliability
If the pump body is perfectly sealed, then fluid ingress is prevented, but heat generated by the electric motor becomes trapped and damages components
Solution Approach 1:
The patent extracts the heat dissipation function from the sealed enclosure concept. By removing the sealed motor housing and exposing the rotor to the pumped fluid, the system allows heat to be carried away by the fluid flow, eliminating the heat trapping problem inherent in sealed designs.
Solution Approach 2:
The patent uses the pumped fluid itself as a cooling medium. The fluid flowing through the pump housing and around the motor components carries away heat through convection, utilizing hydraulic flow for thermal management without requiring separate cooling systems.
3Productivity
If the rotor is continuously rotated to propel fluid, then pump productivity is improved, but bearings require constant lubrication and cooling which is challenging in submerged applications
Solution Approach 1:
The patent implements self-lubrication and self-cooling of the bearings through the pumped fluid. The fluid flow automatically provides lubrication to the bearing surfaces and carries away heat, eliminating the need for external lubrication systems or sealed bearing arrangements.
Solution Approach 2:
The patent utilizes the pumped fluid as both the working medium and the lubrication/cooling medium. The hydraulic flow provides continuous lubrication to the bearings and removes heat through convection, simplifying the bearing support system for submerged applications.
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 design effectively prevents fluid ingress, reduces heat buildup, and maintains component integrity by utilizing fluid pathways for cooling and lubrication, enhancing the longevity and efficiency of submerged pump systems.
Implementation Method 1
the stator comprises a heat sink surrounding the stator
Implementation Method 2
heat sink surrounding the stator
Implementation Method 3
a second fluid pathway is defined around the inner casing for cooling of the inner casing and the interior of the inner casing
Implementation Method 4
the heat sink comprises fins extending into the second fluid pathway
Implementation Method 5
fins extending into the second fluid pathway for cooling
Implementation Method 6
a second fluid pathway is defined around the inner casing for cooling of the inner casing and the interior of the inner casing
Implementation Method 7
an electric motor located within the inner space and adapted for fluid to traverse the electric motor for propulsion of the fluid, the electric motor comprises a stator and a rotor
Data Source
AI summary
A pump assembly comprising a shell, an inner casing adapted to allow fluid therethrough and an electric motor comprises a stator and a rotor defined by a hollow body comprising a blade assembly for propulsion of the fluid wherein the shell and/or inner casing may be configured so that a second fluid pathway is defined around the inner casing for colling. The inner casing may be configured for diverting fluid from the second fluid pathway into the interior of the inner casing for fluid contacting bearings of ends of the rotor for cooling and lubrication. The inner casing may also be configured to receive ends of the rotor having opens with ring bearings permitting flow of the fluid through the bearings.