Wing Spindle Retention With Drive Ring to Minimize Free Play

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing actuator mechanisms in tiltrotor aircraft for converting between flight modes suffer from inefficiencies in rotational and axial free play, leading to suboptimal performance and reliability in wing conversion systems.

Innovation Solution

A wing conversion system featuring a spindle rotatably supported for rotation with the engine and wing section, utilizing a drive ring and holding element with complementary tapered surfaces to ensure secure engagement between the spindle and output shaft, and a retention nut to maintain this engagement, minimizing free play through intermeshed splines and drive dogs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing actuator mechanisms are used for wing conversion, then the system can convert between flight modes, but rotational and axial free play occurs leading to suboptimal performance and reliability

Engineering Contradiction:
ImprovereliabilityVSAvoidfree play
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The drive ring is divided into multiple segments that can be independently positioned and secured to the spindle. This segmentation allows for precise alignment and elimination of free play between the actuator output shaft and the wing conversion mechanism, while maintaining the overall function of mode conversion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drive ring acts as an intermediary element between the actuator output shaft and the wing conversion mechanism. It transmits torque while eliminating free play through its splined engagement with both components, improving reliability without requiring direct connection between the actuator and wing mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If existing actuator mechanisms are used for wing conversion, then the system can convert between flight modes, but rotational and axial free play occurs leading to suboptimal performance

Engineering Contradiction:
ImproveperformanceVSAvoidfree play
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The drive ring is divided into multiple segments that can be independently positioned and secured to the spindle. This segmentation allows for precise alignment and elimination of free play between the actuator output shaft and the wing conversion mechanism, while maintaining the overall function of mode conversion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The splined engagement mechanism changes the physical parameters of the connection between the drive ring and the spindle, transforming from a loose fit with free play to a precise fit that eliminates rotational and axial play, thereby improving conversion performance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a secure engagement mechanism is implemented to minimize free play, then reliability and performance improve, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drive ring serves multiple functions: it transmits torque from the actuator to the wing conversion mechanism, eliminates free play through splined engagement, and provides a mounting interface for securing the segments to the spindle. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The segmented drive ring segments are nested around the actuator output shaft, with each segment independently secured to the spindle. This nested arrangement allows for compact integration of the engagement mechanism within the existing actuator housing, minimizing the increase in overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4707171A1Wing spindle retention
Publication Date: 2026.03.11 TEXTRON EAVIATION INC
  • EP4707171A1 patent drawingFigure 1
  • EP4707171A1 patent drawingFigure 2A
  • EP4707171A1 patent drawingFigure 2B

AI summary

A wing conversion system (106) is configured to rotate an engine of a vertical takeoff and landing aircraft (100) relative to a wing section (110, 112) between flight modes. The wing conversion system includes a spindle (130), a conversion actuator (136), a drive ring (162), and a holding element. The spindle is rotatably supported for rotation with the engine (104) and relative to the wing section about a spindle axis. The drive ring is drivingly engaged between the spindle and the output shaft (142), with the output shaft and spindle being rotatable with each other about the spindle axis. The holding element engages the drive ring and urges the drive ring into engagement with the output shaft and spindle.