Rotor End Winding Support and Cooling for High-Speed Operation
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Solution Overview
Problem
Conventional electric machines face challenges in operating at high speeds due to centrifugal and axial forces that can weaken or break rotor windings, and result in windage losses that reduce efficiency.
Innovation Solution
The proposed solution involves an improved rotor winding end turn support structure that includes a set of collars, a coupling disc, and a support disc, which provide continuous support and reduce windage losses, while also enhancing cooling efficiency through a coolant distribution ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If rotor windings are operated at high speeds, then power density increases, but centrifugal and axial forces weaken or break rotor windings
Solution Approach 1:
The rotor winding end turns are divided into multiple segments supported by separate collars (first collar, second collar, third collar) positioned at different axial locations. This segmentation allows each collar to independently support specific portions of the windings, distributing the mechanical stress and preventing catastrophic failure at high speeds
Solution Approach 2:
The support structure extends into the axial dimension with collars positioned at different axial locations along the rotor winding end turns. This multi-dimensional support arrangement provides comprehensive reinforcement against centrifugal and axial forces while maintaining the electrical functionality of the windings
2Device complexity
If conventional rotor support structures are used, then device complexity is low, but windage losses increase and efficiency decreases
Solution Approach 1:
A coolant distribution ring with coolant channels is integrated into the support structure, using fluid dynamics to provide cooling to the rotor windings. This hydraulic approach removes heat generated during high-speed operation, improving efficiency while the streamlined design reduces windage losses
3Temperature
If rotor windings are cooled during operation, then temperature control improves, but device complexity increases
Solution Approach 1:
The cooling system is merged with the mechanical support structure by integrating coolant channels directly into the collars and support assembly. This combination eliminates the need for separate cooling components, reducing overall device complexity while providing effective temperature control during high-speed operation
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 solution effectively retains and supports rotor winding end turns, improves dynamic balance, reduces deflection and windage losses, and enhances cooling efficiency, allowing for higher speed operation with increased power density and reliability.
Implementation Method 1
delivering a fluid coolant flow radially outward from the rotatable shaft to the coupling disc; delivering the fluid coolant flow through the coupling disc to the coolant distribution ring
Implementation Method 2
The coolant distribution ring delivers the coolant flow radially outward to the rotor winding end turns, removing heat through thermal conduction from the windings to the coolant
Data Source
Figure 1
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AI summary
A rotor assembly includes a rotor core (100) having a rotatable shaft (40) and defining at least one rotor post (108), and a winding (110) wound around the post that defines a set of winding end turns (112). An end winding support assembly (140) is rotatably coupled to the rotatable shaft (40) and defines a cavity in fluid communication with a fluid coolant flow through the end winding support assembly (140). The winding end turns (112) extends into the cavity.