Electric Work Vehicle Battery Casing and Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional electric work vehicles with multiple batteries distributed above and below the chassis experience temperature variance issues due to differing airflow, leading to inefficient and disadvantageous cooling systems for each battery.

Innovation Solution

The electric work vehicle features a battery casing with an upper and lower casing forming an L-shape, positioning the battery unit below the motor unit and transmission mechanisms, which reduces inertial moment and improves stability, while a circulation fan ensures uniform temperature distribution within the battery casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple batteries are distributed above and below the chassis, then the battery capacity is sufficient to power the work implements and driving wheels, but the temperature variance among batteries increases due to different airflow conditions

Engineering Contradiction:
Improvebattery capacityVSAvoidtemperature variance among batteries
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent consolidates multiple batteries into a single integrated battery unit housed in one battery casing, rather than distributing them separately above and below the chassis. This merging approach ensures uniform airflow and temperature distribution across all batteries, eliminating the temperature variance problem while maintaining sufficient total battery capacity.

Inventive Principle:
Principle #5Merging (Combining)

2Quantity of substance

If batteries are arranged in different positions with different airflow, then the battery casing can accommodate large-capacity batteries, but each battery requires its own cooling system which is inefficient

Engineering Contradiction:
Improvebattery capacityVSAvoidcooling system complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent combines all batteries into a single unified battery unit that can be cooled by a common cooling system, eliminating the need for multiple separate cooling systems. This reduces system complexity and improves cooling efficiency while still accommodating large-capacity batteries in the integrated casing.

Inventive Principle:
Principle #5Merging (Combining)

3Quantity of substance

If the battery unit is positioned above the chassis, then the battery capacity is maximized, but the center of gravity is high which reduces running stability

Engineering Contradiction:
Improvebattery capacityVSAvoidrunning stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent repositions the battery unit from an above-chassis location to a below-chassis location, utilizing the vertical space underneath the vehicle frame. This dimensional relocation lowers the center of gravity, improving running stability, while the battery casing is designed to maximize battery capacity within the available space.

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 arrangement enhances running stability by lowering the battery's center of gravity, reduces the need for multiple cooling systems, and maintains efficient airflow for temperature regulation.

Implementation Method 1

a circulation fan ensures uniform temperature distribution within the battery casing

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP3078526B1Electric work vehicle
Publication Date: 2018.01.03 KUBOTA CORP
  • EP3078526B1 patent drawingFigure 1
  • EP3078526B1 patent drawingFigure 2
  • EP3078526B1 patent drawingFigure 3

AI summary

An electric work vehicle includes a motor unit (40) including a left motor (4L) and a right motor (4R) arranged side by side in a transverse direction of the vehicle and connected to a vehicle frame (2), a left transmission mechanism (43) extending rearward in a fore-and-aft direction of the vehicle from a left side of the left motor to transmit power from the left motor to a left rear wheel, a right transmission mechanism (44) extending rearward in the fore-and-aft direction from a right side of the right motor to transmit power from the right motor to a right rear wheel, and a battery unit (6A) housed in a battery casing (60). The battery casing includes an upper casing extending rearward of the left transmission mechanism and the right transmission mechanism from a top of the motor unit, and a lower casing projecting downward from a bottom of a rear half of the upper casing.