VFG Rotor Winding Support With Flexible Bus Bar Jumpers

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Solution Overview

Problem

Traditional variable frequency generator (VFG) rotor main field windings experience fatigue due to radial shifting of end winding supports caused by start/stop and high speeds, leading to pole-to-pole jumper wire failures.

Innovation Solution

A flexible bus bar jumper system is introduced, comprising flexible bus bar jumpers connected to winding ends that flex with radial movement, and second winding support segments that move radially to retain windings, improving the connection stability and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If rigid winding supports are used to maintain structural stability, then mechanical strength is improved, but radial shifting occurs during start/stop and high-speed operations causing jumper wire fatigue

Engineering Contradiction:
Improvemechanical strengthVSAvoidjumper wire reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies the dynamics principle by transitioning from rigid winding supports to flexible supports that can dynamically adapt to radial movements during operation. The flexible bus bar jumpers and flexible winding supports allow the structure to accommodate radial shifting without causing jumper wire fatigue, while still maintaining mechanical integrity through the flexibility of the components.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of the winding supports from rigid to flexible, altering the mechanical properties to allow controlled radial movement. This parameter change enables the supports to absorb radial displacement without transmitting excessive stress to the jumper wires, thereby preventing fatigue while maintaining structural strength.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If flexible bus bar jumpers are used to accommodate radial movement, then jumper wire reliability is improved, but structural rigidity decreases

Engineering Contradiction:
Improvejumper wire reliabilityVSAvoidstructural rigidity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs flexible bus bar jumpers that function as flexible conductive elements to accommodate radial movement of the winding supports. These flexible jumpers maintain electrical connectivity while allowing the structural components to move radially without causing wire fatigue, thus improving reliability while accepting reduced rigidity in the electrical connection path.

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of manufacture

If separate pole connections are implemented to improve manufacturability, then manufacturing complexity is reduced, but additional connection points increase potential failure points

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidconnection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the rotor winding structure into separate pole connections, with each pole having its own flexible bus bar jumper and winding support. This segmentation simplifies manufacturing by allowing independent assembly and connection of each pole, while the flexible design of each segment ensures that connection reliability is maintained through accommodation of radial movements at each connection point.

Inventive Principle:
Principle #1Segmentation

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 solution enhances the lifespan of VFG rotors by preventing pole-to-pole jumper breaks and improving manufacturability through separate pole connections wound in a single direction.

Implementation Method 1

at least one flexible bus bar jumper connected to two first winding ends of adjacent windings and configured to flex with radial movement of the winding support segments

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3624311B1Variable frequency generator rotor winding support structure
Publication Date: 2025.10.29 HAMILTON SUNDSTRAND CORP
  • EP3624311B1 patent drawingFigure 1
  • EP3624311B1 patent drawingFigure 2
  • EP3624311B1 patent drawingFigure 3

AI summary

A variable frequency generator (VFG) rotor can include a plurality of windings (103a,b,c,d) configured to form a plurality of magnetic poles, each winding comprising a first winding end (105) and a second winding end (107), and a first winding support structure comprising a plurality of first winding support segments (109a,b,c,d) configured to retain a first portion of each winding, each winding support segment being configured to move radially relative to an axis of rotation of the rotor. The first winding end of each winding extends from each winding support segment. The rotor can include at least one flexible bus bar jumper (111) connected to two first winding ends of adjacent windings and configured to flex with radial movement of the winding support segments of respective windings attached to the flexible bus bar jumper.