Fluidtight Stator End Plate Structure for Direct Winding Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric drive machines, the existing cooling systems face challenges in efficiently dissipating heat from winding overhangs while maintaining a small magnetic air gap to prevent frictional losses and ensure high torque efficiency, particularly when using liquid cooling with a sleeve that can reduce efficiency and torque.
Innovation Solution
A stator design with fluidtight slot insulation and end plates having a radial and axial part, where the axial part includes a structurally reinforcing insert to enhance load-bearing capacity and prevent fluid ingress into the rotor space, allowing for direct cooling of windings with a low-cost, processable material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sleeve is used to seal the stator space and prevent coolant ingress, then reliability is improved, but device complexity increases and the magnetic air gap becomes larger
Solution Approach 1:
The patent uses a thin-walled sleeve (5) made of fiber-reinforced plastic that is flexible yet strong enough to withstand coolant pressure. This thin-walled structure prevents coolant ingress while maintaining a small magnetic air gap, avoiding the complexity of thick-walled rigid sleeves and preserving motor performance.
Solution Approach 2:
The sleeve is made from fiber-reinforced plastic composite material, combining the strength of fibers with the formability of plastic. This allows the creation of a thin-walled structure that is both mechanically strong enough to contain coolant pressure and thin enough to minimize air gap increase, resolving the contradiction between reliability and device complexity.
2Strength
If the sleeve wall thickness is increased to withstand coolant pressure, then strength is improved, but the magnetic air gap becomes larger reducing efficiency
Solution Approach 1:
By using fiber-reinforced plastic composite material, the sleeve achieves high strength-to-weight ratio and high strength-to-thickness ratio. The fiber reinforcement provides the necessary load-bearing capacity to withstand coolant pressure, while the thin plastic matrix keeps the overall wall thickness minimal, thus maintaining a small magnetic air gap and reducing frictional losses.
Solution Approach 2:
The patent changes the material parameters by selecting fiber-reinforced plastic with specific fiber orientation and density to optimize the strength-thickness ratio. This allows the sleeve to withstand coolant pressure with minimal wall thickness, preventing energy losses while maintaining structural integrity.
3Temperature
If direct winding cooling is implemented, then heat dissipation is improved, but manufacturing complexity increases
Solution Approach 1:
The cooling system is segmented into modular components: the sleeve (5) containing cooling channels, the stator core (1) with slots, and the winding assembly. This segmentation allows each component to be manufactured separately using standard processes, then assembled together, reducing overall manufacturing complexity while enabling direct winding cooling for improved heat dissipation.
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 dissipates heat from winding overhangs without increasing the magnetic air gap, enhancing the stator's load-bearing capacity and efficiency, and allows for the use of higher cooling fluid pressures, resulting in improved heat dissipation and reduced risk of failure.
Implementation Method 1
The heat produced in the electric motor is dissipated into the coolant by heat conduction and convection
Implementation Method 2
The heat produced in the electric motor is dissipated into the coolant by heat conduction and convection
Implementation Method 3
providing slot insulation so as to ensure that a slot interior of each slot of the plurality of slots is electrically insulated from the main body
Implementation Method 4
the end plates are attached in a fluidtight manner to the main body so as to ensure that no fluid can get between the end plate and the main body and reach the cavity of the main body
Data Source
AI summary
A method for producing a stator includes: providing a main body, the main body having: a cavity for accommodating a rotor, and a plurality of slots, extending axially through the main body, the plurality of slots accommodating electrical conductors of a winding, providing slot insulation so as to ensure that a slot interior of each slot of the plurality of slots is electrically insulated from the main body and is fluidtight; and forming a respective end plate on each of two ends of the main body, the end plates being attached in a fluidtight manner to the main body so as to ensure that no fluid can get between the end plate and the main body and reach the cavity of the main body. Each end plate has a radial part and an axial part, and the axial part has an insert.