Height-Adjustable Ballast Receiving Device for Mobile Cranes

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Solution Overview

Problem

The existing mobile crane systems face difficulties in efficiently and safely attaching and removing superstructure ballast, which is time-consuming and requires significant effort, often necessitating auxiliary equipment and posing risks to personnel.

Innovation Solution

A mobile crane design featuring a height-adjustable ballast receiving device with a single connecting element for vertical load and a centering mechanism to absorb transverse forces, allowing for quick and secure attachment and detachment of the superstructure ballast, even by a single person, using a lifting device that can lift and lower the ballast between the superstructure and the ground.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple bolted connections are used to attach the superstructure ballast, then the connection strength is improved, but the attachment time and complexity increase significantly

Engineering Contradiction:
Improveconnection strengthVSAvoidattachment time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The connection system is segmented into two functional parts: a single connecting element for vertical load bearing and multiple centering elements for lateral force absorption. This segmentation allows the vertical connection to be simplified to a single fastener while lateral stability is handled separately by the centering mechanism, reducing attachment time while maintaining overall connection strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The problem is solved by adding a dimensional aspect to the connection system. Instead of using multiple vertical fasteners, the solution introduces centering elements that act in the lateral dimension (horizontal plane) to absorb transverse forces. This dimensional separation allows a single vertical connecting element to suffice for load-bearing while lateral stability is provided by the centering mechanism.

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

2Reliability

If multiple bolted connections are used to attach the superstructure ballast, then the connection reliability is improved, but the operational complexity and skill requirement increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoidattachment ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The connection system is divided into specialized components: a connecting element for vertical attachment and centering elements for lateral alignment. This segmentation allows each component to be optimized for its specific function, with the connecting element requiring only simple vertical insertion and the centering elements automatically providing lateral stability, thereby improving ease of operation while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The centering elements are designed to automatically engage and absorb lateral forces without requiring manual adjustment or additional fastening operations. When the ballast is lifted into position, the centering elements self-align and self-engage, providing automatic lateral stabilization that reduces the skill and effort required by the operator while ensuring reliable connection.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the ballast receiving device is fixed at a single height, then the structural simplicity is improved, but the adaptability to different loading conditions deteriorates

Engineering Contradiction:
Improvestructural simplicityVSAvoidheight adjustability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The ballast receiving device transitions from a fixed position to a dynamically adjustable position through the lifting device. This allows the receiving device to move vertically between a first position (for loading/unloading) and a second position (for operation), providing adaptability to different operational requirements while maintaining relatively simple structural implementation through a single lifting mechanism.

Inventive Principle:
Principle #15Dynamics

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

This solution simplifies and accelerates the attachment and removal processes, ensuring safety and stability by centralizing the connection point and distributing transverse forces effectively, reducing the need for manual alignment and external tools.

Implementation Method 1

the ballast receiving device (16) is height-adjustable by means of a lifting device (30) of the superstructure (12)

Methodology Applied
Scientific EffectHydraulic lifting: Hydraulic Press

Implementation Method 2

Solutions exist where the superstructure ballast is first prepared or stacked on the ground and then lifted onto the superstructure using hydraulic lifting cylinders

Methodology Applied
Scientific EffectMechanical lifting: Mechanical Force

Implementation Method 3

a centering means (20, 22) is provided which is designed to absorb lateral forces occurring in the mounting position that act between the superstructure (12) and the superstructure ballast (14)

Methodology Applied
Scientific EffectForce absorption: Damping

Data Source

PatentEP3995436B1Mobile crane with height-adjustable superstructure ballast
Publication Date: 2024.05.08 LIEBHERR WERK NENZING
  • EP3995436B1 patent drawingFigure 1
  • EP3995436B1 patent drawingFigure 2
  • EP3995436B1 patent drawingFigure 3

AI summary

The invention relates to a mobile crane (10), in particular a crawler crane, comprising an undercarriage with a chassis, a superstructure (12) rotatably mounted on the undercarriage, and a superstructure ballast (14), wherein the superstructure ballast includes a ballast receiving device (16) that is height-adjustable by means of a lifting device of the superstructure. According to the invention, the ballast receiving device can be attached to the superstructure in a mounting position by means of a single connecting element that bears the vertical load of the superstructure ballast. Furthermore, a centering means is provided which is designed to absorb lateral forces occurring in the mounting position.