Electric Excavator Battery Layout With Cross-Body Cooling Airflow

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Solution Overview

Problem

Existing electric work machines face challenges in maximizing battery capacity within limited machine body space while efficiently cooling devices, with a focus on improving cooling efficiency in electric construction machines.

Innovation Solution

The configuration includes a battery unit, electric motor, hydraulic pump, oil cooler, and fan placement within the machine body, utilizing specific openings and orientations to facilitate efficient cooling and maximize battery capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a large battery unit is placed in the machine body to increase battery capacity, then the operating time is extended, but the space for cooling devices is reduced

Engineering Contradiction:
Improveoperating timeVSAvoidcooling space
Core Design Contradiction:
Duration of action of moving objectVSArea of stationary object

Solution Approach 1:

The patent positions the oil cooler to face the second lateral opening and the fan to face the first lateral opening, creating a three-dimensional cooling airflow path that passes through the battery unit. This spatial arrangement enables efficient cooling of the large battery unit without requiring additional lateral space, thus resolving the contradiction between battery size and cooling space.

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

2Duration of action of moving object

If the battery unit is enlarged to achieve higher battery capacity, then the operating time increases, but the cooling efficiency of devices decreases

Engineering Contradiction:
Improveoperating timeVSAvoidcooling efficiency
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The fan draws cool air from the first lateral opening into the machine body before the air reaches the battery unit and other heat-generating devices. This preliminary cooling action ensures that the battery unit and hydraulic components are cooled efficiently even when the battery capacity is enlarged, maintaining high cooling efficiency and system reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a vertical and lateral airflow path through strategic positioning of openings and cooling components. The cooling air flows from the first lateral opening, passes through the battery unit and hydraulic components, exits through the second lateral opening, and is drawn in again by the fan. This multi-dimensional airflow ensures efficient heat dissipation from enlarged battery units.

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

3Reliability

If space is allocated for both large battery unit and cooling devices, then the battery capacity is limited, but the cooling performance improves

Engineering Contradiction:
Improvecooling performanceVSAvoidbattery capacity
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The machine body structure serves multiple functions: it houses the large battery unit, provides lateral openings for air intake and exhaust, and guides the cooling airflow through strategic positioning of the fan and oil cooler. This multi-functional design enables both high battery capacity and effective cooling performance within the same space.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes the lateral dimensions of the machine body by positioning openings on opposite lateral sides and arranging the fan and oil cooler to face these openings. This creates an efficient cooling pathway that does not compete with the battery unit for internal space, allowing both large battery capacity and high cooling performance to coexist.

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

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 configuration allows for a larger battery capacity by efficiently cooling devices within the machine body, optimizing space utilization and cooling efficiency.

Implementation Method 1

a fan that draws air into the machine body

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

an oil cooler that cools hydraulic oil discharged from the hydraulic pump

Methodology Applied
Scientific EffectHeat Exchanger: Heat Exchanger

Data Source

PatentEP4481122B1Electric work machine
Publication Date: 2026.04.15 YANMAR HLDG CO LTD
  • EP4481122B1 patent drawingFigure 1
  • EP4481122B1 patent drawingFigure 2
  • EP4481122B1 patent drawingFigure 3

AI summary

[Problem] To provide an electric work machine including a battery unit as large as possible in the limited space in a machine body while efficiently cooling a device in the machine body, achieving a higher battery capacity. [Solution] A hydraulic excavator as an electric work machine includes, in a machine body, a battery unit that stores electric power, an electric motor that is driven by the electric power supplied from the battery unit, a hydraulic pump that is driven by the electric motor, an oil cooler that cools hydraulic oil discharged from the hydraulic pump, and a fan that draws air into the machine body. The machine body has a first opening and a second opening, and the first opening is provided on a first lateral side of the machine body, and the second opening is provided on a second lateral side of the machine body. The fan is placed to face the first opening in the machine body, and the oil cooler is placed to face the second opening in the machine body.