Rocker-Bogie Suspension Layout for Compact Uneven-Terrain Travel

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Solution Overview

Problem

Existing suspension devices using rocker bogie mechanisms are large in size, limiting their compactness and efficiency, particularly in navigating uneven terrain.

Innovation Solution

The suspension device incorporates a bogie link member and a rocker link member oscillatable around specific axes, with a support bearing allowing relative rotation, and a pivoting support mechanism for driven wheels, optimizing the positional relationship between wheels to reduce size while maintaining stability and traction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional rocker bogie mechanism is used, then the suspension device can navigate uneven terrain, but the device size becomes large

Engineering Contradiction:
Improveability to navigate uneven terrainVSAvoidsize of suspension device
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent repositions the first oscillation axis from a conventional location to a position above the drive wheel rotation axis and inside the drive wheel contour. This spatial relocation in the vertical dimension allows the oscillation axis to be contained within the drive wheel's bounding box, reducing the overall front-rear dimension of the suspension device while preserving the rocker bogie mechanism's terrain navigation capability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The first oscillation axis is positioned inside the contour of the drive wheel, effectively nesting the oscillation mechanism within the space already occupied by the drive wheel assembly. This nesting approach eliminates the need for additional external space that would normally be required for the oscillation axis, thereby compacting the suspension device

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If the first oscillation axis is positioned closer to the first driven wheel side, then the device size is reduced, but the reaction force ratio between wheels may be affected

Engineering Contradiction:
Improvefront-rear dimension of suspension deviceVSAvoidreaction force ratio between wheels
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent carefully selects and optimizes the positional parameters of the first oscillation axis, specifically its vertical height above the rotation axis and its front-rear position relative to the drive wheel and first driven wheel. By adjusting these parameters within constrained ranges, the invention achieves compact dimensions while maintaining the appropriate reaction force distribution between wheels for reliable operation

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4166347B1Suspension device and traveling device
Publication Date: 2024.07.24 SUMITOMO HEAVY IND LTD
  • EP4166347B1 patent drawingFigure 1
  • EP4166347B1 patent drawingFigure 2
  • EP4166347B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a technique for reducing the size of a suspension device 14 using a rocker bogie mechanism. The suspension device 14 includes a drive wheel 24; a first driven wheel 26 that is disposed on one side in a front-rear direction with respect to the drive wheel 24; a second driven wheel 28 that is disposed on the other side in the front-rear direction with respect to the drive wheel 24; a bogie link member 38 that supports the drive wheel 24 and the first driven wheel 26 and is oscillatable around a first oscillation axis 44; and a rocker link member 40 that supports the second driven wheel 28 and the bogie link member 38 and is oscillatable around a second oscillation axis 50. When viewed from a left-right direction, the first oscillation axis 44 is not on the same vertical line as a rotation axis 70 of the drive wheel 24 and is located above the rotation axis 70 in a vertical direction and located inside a contour of the drive wheel 24.