Electric Excavator Layout for Larger Batteries and Cooling

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Solution Overview

Problem

Existing electric work machines face challenges in achieving a compact layout that accommodates a larger battery unit while ensuring efficient cooling of the electric motor, hydraulic pump, and hydraulic oil tank.

Innovation Solution

The electric work machine is designed with the electric motor, hydraulic pump, and hydraulic oil tank arranged side by side below the battery unit on a machine body frame, optimizing space utilization and facilitating increased battery capacity without compromising cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the battery unit is increased in size to increase capacity, then the electric power storage capacity is improved, but the layout compactness deteriorates because separate space must be secured for the hydraulic oil tank

Engineering Contradiction:
Improvebattery capacityVSAvoidlayout compactness
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The battery unit and hydraulic oil tank are merged into a single integrated structure. The hydraulic oil tank is positioned on top of the battery unit, allowing both components to occupy the same vertical space. This integration eliminates the need for separate spaces for each component, enabling the battery capacity to be increased without compromising layout compactness.

Inventive Principle:
Principle #5Merging (Combining)

2Power

If the electric motor and hydraulic pump are driven, then the work output is improved, but the temperature increases causing heat generation that requires cooling consideration

Engineering Contradiction:
Improvework outputVSAvoidheat generation
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The heat generated by the electric motor and hydraulic pump during operation is converted into a beneficial cooling effect for the hydraulic oil tank. The warm air rising from the motor and pump passes through the hydraulic oil tank, transferring heat to the hydraulic oil and cooling the components. This transforms the harmful heat generation into a useful cooling mechanism for the hydraulic system.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4357536B1Electric work machine
Publication Date: 2025.06.04 YANMAR HLDG CO LTD
  • EP4357536B1 patent drawingFigure 1
  • EP4357536B1 patent drawingFigure 2
  • EP4357536B1 patent drawingFigure 3

AI summary

[Problem] To provide an electric work machine having a compact layout and facilitating an increase in capacity of a battery unit while taking into consideration cooling efficiency when cooling an electric motor, a hydraulic pump, and a hydraulic oil tank. [Solution] A hydraulic excavator as an electric work machine includes: an electric motor; a battery unit that stores electric power for driving the electric motor; a hydraulic oil tank that contains hydraulic oil, and a hydraulic pump that is driven by the electric motor and connected to the hydraulic oil tank. The electric motor, the hydraulic pump, and the hydraulic oil tank are arranged below the battery unit on a machine body frame, and are arranged side by side in a lateral direction of the machine body frame.