Toroidal Fuel Tank Layout for Compact Tail Swing Excavators

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Solution Overview

Problem

Existing working machines face challenges in minimizing the footprint of the superstructure and fuel tank volume while maintaining maneuverability and fuel storage efficiency, particularly in compact tail swing excavators.

Innovation Solution

A toroidal fuel tank is positioned between the superstructure and undercarriage, extending around the rotational axis, with a continuously curved cross-sectional profile and a single-piece construction, allowing for compact packaging and even pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a conventional fuel tank arrangement is used in the superstructure, then fuel storage capacity is achieved, but the footprint of the superstructure increases and operator visibility is impacted

Engineering Contradiction:
Improvefuel storage capacityVSAvoidsuperstructure footprint
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The fuel tank is repositioned from a conventional location to an interposed position between the superstructure and undercarriage, utilizing the vertical space and rotating around the rotational axis in a toroidal configuration. This dimensional repositioning allows the fuel tank to occupy space that would otherwise be unused, achieving fuel storage without increasing the superstructure footprint or impacting operator visibility.

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

Solution Approach 2:

The fuel tank is designed with a toroidal shape that extends around the rotational axis of the superstructure. This curved, toroidal configuration allows the tank to efficiently utilize the available space between the superstructure and undercarriage, maximizing fuel storage capacity within the constrained vertical space without projecting beyond the platform footprint.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If a conventional fuel tank shape is used, then manufacturing is simplified, but pressure distribution becomes uneven when loaded with pressurised fuel

Engineering Contradiction:
Improvetank manufacturing simplicityVSAvoidpressure distribution uniformity
Core Design Contradiction:
Ease of manufactureVSStress or pressure

Solution Approach 1:

The fuel tank employs a toroidal shape with a continuously curved cross-sectional profile. This curved geometry is specifically designed to distribute pressure evenly throughout the tank walls when loaded with pressurized fuel, eliminating stress concentration points that would occur in conventional angular or flat-sided tanks. The continuous curvature ensures uniform stress distribution while maintaining manufacturing feasibility through techniques such as blow moulding.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of manufacture

If a multi-piece fuel tank construction is used, then manufacturing and assembly are easier, but welds or joins weaken the tank body for high pressure storage

Engineering Contradiction:
Improveassembly easeVSAvoidtank body strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The fuel tank is constructed as a single integrated piece without welds, joins, or seams. This unitary construction eliminates potential weak points where connections might fail under high pressure, ensuring the tank body can safely store and contain pressurized fuel. The seamless design is achieved through manufacturing processes such as blow moulding that can produce large, complex shapes in one piece.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4177404B1A working machine
Publication Date: 2026.03.25 J C BAMFORD EXCAVATORS LTD
  • EP4177404B1 patent drawingFigure 1
  • EP4177404B1 patent drawingFigure 2
  • EP4177404B1 patent drawingFigure 3

AI summary

A working machine includes either front and rear wheels or a pair of endless tracks supporting an undercarriage, a drive arrangement including a prime mover configured to provide motive power to propel the working machine, a superstructure connected to the undercarriage via a rotary connector, and a working arm connected to the superstructure. The machine also includes a fuel tank assembly comprising at least one fuel tank defining an internal volume for storing fuel to be supplied to the prime mover, wherein the at least one fuel tank is interposed between the superstructure and the undercarriage.