Contactless Power Transfer Between Crane and Tractor

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Solution Overview

Problem

Existing yard tractors at container terminals face inefficiencies due to the need for extensive installation of power supplying devices and prolonged stopping times for charging, especially when using electric tractors that require battery recharging.

Innovation Solution

A contactless power transmission system between a crane and a tractor, utilizing a power supplying unit and a power collecting unit with a pick-up unit and driving unit for electromagnetic induction, allowing power transfer without the need for extensive device installation and reducing charging time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If power supplying devices are installed over the entire working area, then continuous power supply to tractor is enabled, but installation cost and device complexity increase significantly

Engineering Contradiction:

Improvecontinuous power supplyVSAvoidinstallation of power supplying devices

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the power supplying function from the ground infrastructure and relocates it to the mobile crane. Instead of installing fixed power supplying devices throughout the working area, the power supply capability is taken out and embedded in a mobile platform (crane) that moves to provide power where needed. This reduces overall device complexity while maintaining continuous power supply capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary wireless power transmission system between the crane and tractor. Rather than direct physical connection or extensive ground infrastructure, a wireless electromagnetic field serves as the intermediary medium to transfer power. This mediator enables power transmission without requiring complex installation of physical power supplying devices across the entire working area.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If tractor stops at designated charging place, then battery can be recharged, but work efficiency and productivity decrease due to stopping time

Engineering Contradiction:

Improvebattery rechargingVSAvoidwork efficiency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The invention enables continuous power transmission to the tractor during container handling operations. The wireless power supply system maintains uninterrupted energy flow to the tractor's battery while the tractor remains in position performing work, eliminating the need to stop at designated charging places. This continuity of useful action maintains both energy replenishment and operational productivity simultaneously.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The power supplying crane positions itself in advance near where the tractor will be located during container handling. By anticipating the tractor's position and pre-positioning the power supply source, the system ensures power is already available when the tractor arrives, eliminating waiting time and maintaining continuous operation without stopping for charging.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If electric tractor is used instead of diesel tractor, then environmental pollution is reduced, but operational flexibility decreases due to limited battery capacity

Engineering Contradiction:

Improveenvironmental pollutionVSAvoidoperational flexibility

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The invention creates a dynamic power supply system where the crane moves to track and provide power to the tractor throughout the working area. This dynamic positioning enables the electric tractor to operate beyond the limits of static battery capacity by continuously receiving replenishing power from the mobile crane, thereby restoring operational flexibility while maintaining environmental benefits.

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 eliminates the need for extensive power device installation and minimizes the time required for tractors to stop for charging, enhancing operational efficiency and reducing costs by enabling continuous operation during container handling tasks.

Implementation Method 1

the power collecting pick-up unit of the tractor generates an induced current by responding to a magnetic field change from the power supplying unit of the crane

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2952379B1Electricity-charging system between a crane and tractor

Publication Date: 2019.05.01 KANG DA

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AI summary

Disclosed is a crane and a tractor used at a container base of a harbor or a container terminal, and more particularly, a charging system in which a power supplying device capable of supplying power in a contactless fashion is installed at the crane and a power collecting device capable of receiving power from the power supplying device is installed at the tractor, so that the tractor receives power from the power supplying unit installed at the crane while performing lifting or landing works below the crane to charge power required for movement of the tractor.