Hoist Cable Drum With Integral Ball Spline and Internal Gear Ring

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Solution Overview

Problem

Hoist mechanisms in airborne environments are inefficient due to occupying space and adding weight, as they require significant space and weight for their operation, which reduces the efficiency of aircraft.

Innovation Solution

A cable drum assembly with an integral ball spline and internal gear ring is designed, where the shaft is mechanically coupled to the ball spline and includes a track to guide ball bearings, allowing torque transmission and axial translation, and a levelwind shaft provides linear motion to the drum, enabling compact and efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a conventional hoist mechanism is used, then the hoist can perform lifting operations, but it occupies significant space and adds weight, reducing aircraft efficiency

Engineering Contradiction:
Improveweight of hoist mechanismVSAvoidoperational efficiency
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent combines the drum, ball spline, and gear ring into a single integrated assembly. The drum is formed as a hollow cylinder with the ball spline internally, and the gear ring is integrated into the drum structure. This merging of components reduces the overall weight and space occupation while maintaining the hoist's lifting capability, directly addressing the contradiction between weight reduction and operational efficiency maintenance

Inventive Principle:
Principle #5Merging (Combining)

2Volume of moving object

If a conventional hoist mechanism is used, then the hoist can perform lifting operations, but it occupies significant space, reducing aircraft efficiency

Engineering Contradiction:
Improvespace occupied by hoist mechanismVSAvoidoperational efficiency
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent employs a nested configuration where the ball spline is positioned inside the hollow drum structure, and the gear ring is integrated within the drum assembly. This nesting arrangement allows multiple functional components to occupy the same spatial envelope, significantly reducing the overall volume of the hoist mechanism while preserving its operational efficiency for lifting operations

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If the drum rotates freely, then the cable can be wound and unwound, but the cable may wind in an disordered manner causing inefficiency

Engineering Contradiction:
Improvecable winding operationVSAvoidwinding efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent introduces a levelwind shaft as an intermediary component between the drum rotation and cable winding. The levelwind shaft features a groove that guides the cable, ensuring it winds in an ordered, layered pattern around the drum. This intermediary mechanism maintains ease of cable winding operation while significantly improving winding efficiency by preventing disordered cable arrangement

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reduces the weight and space occupied by the hoist mechanism while maintaining efficiency by integrating the torque delivery mechanism into the ball spline shaft and using a self-reversing levelwind shaft for orderly winding of the lifting medium, thus enhancing the operational efficiency of airborne hoists.

Implementation Method 1

The shaft may include a track configured to guide a ball bearing of the ball spline in response to an axial translation of the internal hub relative to the shaft

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Data Source

PatentEP3248931B1Hoist cable drum with an integral ball spline and internal gear ring
Publication Date: 2020.12.30 GOODRICH CORP
  • EP3248931B1 patent drawingFigure 1
  • EP3248931B1 patent drawingFigure 2
  • EP3248931B1 patent drawingFigure 3

AI summary

A cable drum assembly (100) may comprise a shaft (102) configured to rotate about an axis. A drum (112) may be positioned radially outward from the shaft (102) and configured to rotate about the axis. A ball spline (131) may be in operable communication with the shaft (102) and the drum (112), the ball spline (131) disposed between the shaft (102) and the drum (112) and configured to orbit the axis.