Pick and Carry Crane Suspension Dynamics

Solution Overview

Problem

Pick and carry cranes face a trade-off between increased load capacity and maneuverability, with higher rated capacities leading to decreased maneuverability and increased susceptibility to sideways tipping, especially when operating on different terrains and public roads at speed.

Innovation Solution

A pick and carry crane design featuring a front and rear chassis connected by articulation, with hydraulic suspension systems including dampers between wheels and chassis, and a controller to selectively connect dampers for enhanced suspension travel and stability, allowing for improved traction and ride comfort across uneven terrain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rated capacity of the pick and carry crane is increased, then the load carrying capability is improved, but the maneuverability decreases and susceptibility to sideways tipping increases

Engineering Contradiction:

Improveload carrying capabilityVSAvoidmaneuverability

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The suspension system dynamically adjusts damper connections based on operating conditions. The controller selectively connects dampers on opposite sides of the crane through hydraulic interconnections, transitioning between independent and coupled configurations to optimize performance for different operational states (travel vs. lifting).

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the connectivity parameter of the suspension system by selectively opening or closing hydraulic connections between dampers. This parameter change allows the same physical suspension components to provide different functional characteristics - independent wheel movement during travel and coupled movement during lifting operations.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the rated capacity of the pick and carry crane is increased, then the load carrying capability is improved, but the susceptibility to sideways tipping increases

Engineering Contradiction:

Improveload carrying capabilityVSAvoidsusceptibility to sideways tipping

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The suspension system dynamically adjusts damper connections based on operating conditions. The controller selectively connects dampers on opposite sides of the crane through hydraulic interconnections, transitioning between independent and coupled configurations to optimize performance for different operational states (travel vs. lifting).

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the connectivity parameter of the suspension system by selectively opening or closing hydraulic connections between dampers. This parameter change allows the same physical suspension components to provide different functional characteristics - independent wheel movement during travel and coupled movement during lifting operations.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the crane operates on different terrains at speed, then the operational versatility is improved, but the ride comfort decreases

Engineering Contradiction:

Improveoperational versatilityVSAvoidride comfort

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The suspension system dynamically adjusts damper connections based on operating conditions. The controller selectively connects dampers on opposite sides of the crane through hydraulic interconnections, transitioning between independent and coupled configurations to optimize performance for different operational states (travel vs. lifting).

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses hydraulic interconnections to couple or decouple the suspension dampers on opposite sides of the crane. This hydraulic linkage allows the suspension system to provide coordinated wheel movement for improved ride comfort during travel while maintaining the ability to operate independently on uneven terrain.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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

The solution enhances the crane's operational scope on uneven terrain, increases safety, and maintains maneuverability while supporting higher load capacities, allowing access to previously inaccessible areas with improved traction and reduced wear on tires.

Implementation Method 1

the front hydraulic suspension system includes hydraulic dampers acting between respective front wheels and the front chassis; the rear hydraulic suspension system includes hydraulic dampers acting between respective rear wheels and the rear chassis

Methodology Applied

Scientific EffectHydraulic damping: Viscous Damping

Data Source

PatentUS11440369B2Pick and carry crane suspension

Publication Date: 2022.09.13 TEREX AUSTRALIA

AI summary

A crane, in particular a pick and carry crane, may have a front chassis with front wheels and a back chassis with back wheels, the front chassis being articulated relative to the back chassis so that the crane can travel whilst carrying a load suspended from a boom. The back and front wheels have independent suspensions which are capable of connection to one another so that movement of a left wheel influences movement of a right wheel, thereby improving the handing of the crane, particularly over rough terrain.