Segmented Shaft Geometry for Jam-Free Receiver Insertion

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Solution Overview

Problem

The challenge of inserting a shaft into a shaft receiver often results in a 'sticky drawer effect' due to similar cross-sectional areas, leading to prolonged assembly times and potential material deformations when cooling or heating is used to facilitate insertion.

Innovation Solution

A shaft design featuring a nominal, intermediate, and guide shaft portion with specific radial dimensions and contours allows for efficient insertion and alignment, reducing the likelihood of jamming by enabling pivoting and smooth movement into the receiver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the cross-sectional area of the shaft is made similar to the cross-sectional area of the opening of the shaft receiver to obtain a tight fit, then the fit quality is improved, but the assembly process becomes difficult due to the sticky drawer effect

Engineering Contradiction:
Improvefit qualityVSAvoidassembly process
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The shaft is divided into three distinct portions along its axial extension: a nominal shaft portion with a first cross-sectional area for tight fit, an intermediate shaft portion with a second cross-sectional area smaller than the nominal, and a guide shaft portion with a third cross-sectional area. This segmentation allows different portions of the shaft to serve different functions during assembly and operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the shaft are given different cross-sectional areas to optimize their specific functions. The nominal shaft portion has a larger cross-sectional area for tight fit quality, while the intermediate and guide portions have smaller cross-sectional areas to facilitate assembly by reducing friction and enabling the sticky drawer effect to be overcome.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If cooling or heating is applied to the shaft or shaft receiver to increase the difference in cross sectional areas, then the insertion process becomes smoother, but additional equipment is required and permanent deformations or changes in material properties may occur

Engineering Contradiction:
Improveinsertion processVSAvoidadditional equipment
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The shaft is pre-designed with varying cross-sectional areas in different portions before assembly. The intermediate shaft portion is manufactured with a smaller cross-sectional area than the nominal shaft portion, creating a tapered or stepped configuration that inherently facilitates insertion without requiring external cooling or heating equipment during the assembly process.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If cooling or heating is applied to the shaft or shaft receiver to increase the difference in cross sectional areas, then the insertion process becomes smoother, but permanent deformations or changes in material properties may occur

Engineering Contradiction:
Improveinsertation processVSAvoidmaterial properties
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The shaft is pre-designed with varying cross-sectional areas in different portions before assembly. The intermediate shaft portion is manufactured with a smaller cross-sectional area than the nominal shaft portion, creating a tapered or stepped configuration that inherently facilitates insertion without requiring external cooling or heating equipment during the assembly process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4006366B1A shaft
Publication Date: 2023.08.02 VOLVO TRUCK CORP
  • EP4006366B1 patent drawingFigure 1
  • EP4006366B1 patent drawingFigure 2
  • EP4006366B1 patent drawingFigure 3~4

AI summary

The present disclosure relates to a shaft adapted to be at least partially inserted into an opening (24) of a shaft receiver (14). The shaft (16) has an axial extension along an axial direction (A) and, as seen in a direction along the axial direction (A) towards an end of the shaft (16), the shaft (16) comprises: - a nominal shaft portion (28) adapted to be at least partially inserted into the opening (24) of the shaft receiver (14), followed by - an intermediate shaft portion (30) that in turn is followed by - a guide shaft portion (32) terminating the shaft (16). The shaft (16) having a central axis (C) extending in the axial direction (A) and being located in the centre of the cross-section perpendicular to the axial direction (A) of the nominal shaft portion (28). The central axis (C) extends in a direction from the nominal shaft portion (28) towards the guide shaft portion (32). The shaft (16) comprises a cross-section with a cross-sectional contour (34) in a plane including the central axis (C), the cross-sectional contour (34) comprising a nominal shaft portion contour (36) of the nominal shaft portion (28), an intermediate shaft portion contour (38) of the intermediate shaft portion (30) and a guide shaft portion contour (40) of the guide shaft portion (32). The cross-sectional contour (34) comprises a radial direction (R) being perpendicular to the central axis (C), wherein, as seen in the radial direction (R), the nominal shaft portion contour (36) is located at a nominal radial distance (Ro) from the central axis (C).