Electric Pump Stator Cooling via Compartment Segmentation
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Solution Overview
Problem
Existing electric pumps, particularly 'wet rotor' designs, fail to efficiently cool stator windings and control electronics due to high operating temperatures, especially in high-power applications.
Innovation Solution
The electric pump features a casing with separate compartments for the stator and rotor, where the liquid circulates to remove heat, and includes thermally conductive materials and strategically designed gaps to enhance heat exchange, along with a thermally conductive filler between the electronic card and the casing to maximize cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a wet rotor design is used where liquid circulates around the rotor, then the liquid can remove some heat from the motor, but the cooling performance is insufficient for high-power applications
Solution Approach 1:
The pump is divided into separate compartments: a first compartment housing the stator and a second compartment housing the rotor. This segmentation allows the liquid to be directed through specific cooling paths around the stator windings, enabling targeted cooling of the stator while the rotor operates in the liquid-filled second compartment. The separation ensures that cooling liquid flows through defined channels that maximize heat removal from the stator windings.
Solution Approach 2:
A thermally conductive material is introduced as an intermediary between the stator windings and the cooling liquid. This material enhances the heat transfer efficiency from the stator windings to the liquid, acting as a thermal bridge that improves cooling performance without requiring direct contact between the windings and the liquid.
2Device complexity
If control electronics are housed in the rear cover, then the pump structure is compact, but the control electronics reach high temperatures without efficient cooling
Solution Approach 1:
The cooling liquid serves multiple functions: it cools the rotor through direct contact in the second compartment, it cools the stator windings by flowing through the first compartment and thermally conductive paths, and it cools the control electronics housed in the rear cover. This multi-functional cooling approach allows a single liquid circulation system to address thermal management needs of all major components, maintaining compact structure while effectively cooling the control electronics.
3Temperature
If the stator and rotor are housed in separate compartments, then the cooling liquid can be directed through specific paths to remove heat from the stator, but the device structure becomes more complex
Solution Approach 1:
The first compartment housing the stator and the second compartment housing the rotor are merged into a single integrated pump structure. The cooling liquid flows continuously from the first compartment through the second compartment, combining the cooling functions for both stator and rotor in a unified system. This merging approach reduces the number of separate cooling systems needed while maintaining effective cooling of both components through the liquid's continuous circulation path.
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 effectively cools the stator windings and control electronics, improving the overall performance and reliability of the pump by efficiently dissipating heat generated during operation.
Implementation Method 1
the liquid inside the motor also removes part of the heat generated from the stator during operation
Implementation Method 2
the liquid moved by the pump can circular in the annular gap... the liquid circulating in the corresponding gap removes heat from the stator
Data Source
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AI summary
Described is an electric pump (1) for moving a liquid comprising a casing formed by a central portion (2), by a rear cover (3) and by a front cover (4), having an inlet and an outlet for the liquid; the central portion (2) has a first and a second compartment (10, 11), which are separate from each other, with the second compartment (11) in fluid communication with the inside of the front cover; the pump comprises an impeller (6) and an electric motor (5), for operating the impeller, comprising a stator (7) housed in the first compartment (10), a rotor (8), coaxial with the stator (7), housed in the second compartment (11) and an electronic card (9) for supplying the stator (7) at least partly housed in the rear cover (3); the central portion (2) comprises a plurality of walls (12, 13, 18) delimiting a plurality of gaps (14) in fluid communication with the second compartment (11) and with the inside of the front cover (4) in such a way that the liquid also circulates in the gaps (14); the walls (12, 13, 18) are at least partly facing the stator in such a way that the liquid circulating in the corresponding gap removes heat from the stator.