Working Machine Direction Change Braking for Smoother Reversals

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Solution Overview

Problem

The frequent direction changes in off-highway working machines cause significant stress on the drive arrangement and jolting, reducing the machine's lifetime and operator comfort, as they rely on the transmission for deceleration during direction changes.

Innovation Solution

Implementing an automated braking system that uses a forward-neutral-reverse drive selector to control the braking system, applying a braking force proportional to the speed or rotational speed of the drive arrangement, thereby decelerating the machine smoothly and reducing stress on the transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transmission is used to decelerate the working machine during direction changes, then the driving direction can be changed, but significant stress acts on the drive arrangement reducing its lifetime

Engineering Contradiction:
Improvelifetime of drive arrangementVSAvoidstress on drive arrangement
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

A control system is introduced as an intermediary between the operator's direction change input and the drive arrangement. This control system automatically manages the braking and direction change sequence, preventing direct operator-induced stress on the transmission while achieving smooth direction changes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The control system performs preliminary deceleration actions before the actual direction change occurs. By automatically decelerating the machine to a stop before engaging the new driving direction, the transmission is protected from experiencing high stress during the transition, thereby extending its lifetime.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the drive arrangement applies torque to decelerate the working machine during direction changes, then the driving direction can be changed, but the machine jolts on initiation of the direction changing process

Engineering Contradiction:
Improvesmoothness of direction changeVSAvoidjolting force during direction change
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The control system incorporates feedback mechanisms that monitor the machine's motion state and automatically adjust the deceleration profile. This feedback control ensures smooth deceleration and eliminates jolting forces during direction changes, improving operator comfort and ease of operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the deceleration rate based on the machine's current state. Rather than applying fixed torque, the control system modulates the braking force dynamically to achieve smooth deceleration, preventing jolts during the direction change initiation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4177406B1Working machine and method of changing the driving direction of such working machine
Publication Date: 2024.12.25 J C BAMFORD EXCAVATORS LTD
  • EP4177406B1 patent drawingFigure 1
  • EP4177406B1 patent drawingFigure 2
  • EP4177406B1 patent drawingFigure 3

AI summary

A working machine includes a body, a ground-engaging propulsion structure supporting the body, a drive arrangement configured to provide motive power to the ground engaging propulsion structure, a braking system actuatable to apply a braking force to the ground engaging propulsion structure, a control system, and a sensor assembly configured to determine an output of the drive arrangement and to provide an output to the control system. The control system is configured to apply a first braking force to the ground engaging propulsion structure that is based on the determined output of the drive arrangement.