Motor Case Coolant Storage for Simpler Work Vehicle Cooling

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Solution Overview

Problem

Existing work vehicles with motors configured to supply power to travel devices face challenges in efficiently cooling components like motors and inverters due to complex cooling structures that require dedicated coolant tanks.

Innovation Solution

The work vehicle integrates a case housing the motor with a storage portion for coolant below the motor, utilizing a pump to supply coolant to cooling targets, and includes a dispersion prevention mechanism to minimize coolant adhesion on current flow members, simplifying the cooling structure by eliminating the need for a dedicated coolant tank.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dedicated coolant tank is used to store coolant, then the cooling function is reliable, but the cooling structure becomes complex

Engineering Contradiction:
Improvecooling function reliabilityVSAvoidcooling structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the motor case and coolant storage tank into a single integrated structure. The motor case serves dual functions: housing the motor and storing coolant. This eliminates the need for a separate dedicated coolant tank, simplifying the cooling structure while maintaining reliable coolant storage and delivery to cooling targets through the integrated pump system.

Inventive Principle:
Principle #5Merging (Combining)

2Quantity of substance

If coolant is stored in a separate tank, then coolant storage capacity is sufficient, but the overall vehicle structure becomes more complex

Engineering Contradiction:
Improvecoolant storage capacityVSAvoidvehicle structure complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The motor case is designed with multi-functionality, serving both as the motor housing and as the coolant storage tank. This universal structure provides sufficient coolant storage capacity while reducing vehicle structure complexity by eliminating separate dedicated coolant storage components and their associated mounting structures.

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

3Stability of the object's composition

If coolant is allowed to disperse freely in the case, then coolant distribution is uniform, but coolant adheres to current flow members causing degradation

Engineering Contradiction:
Improvecoolant distribution uniformityVSAvoidcurrent flow member durability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The motor case interior is segmented into distinct functional zones using partition walls and positioning structures. The coolant storage area is separated from the current flow member area, creating controlled pathways for coolant flow. This segmentation prevents coolant from freely dispersing and adhering to current flow members while still achieving uniform coolant distribution to cooling targets through the pump system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Partition walls and positioning structures act as intermediaries between the coolant storage area and the current flow members. These intermediary structures guide coolant flow along designated paths, preventing direct contact between coolant and current flow members, thus avoiding adhesion and degradation while maintaining effective coolant distribution to motor and inverter components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 simplifies the cooling structure by integrating coolant storage within the motor case, reducing coolant adhesion, and minimizing degradation of current flow members, while effectively cooling the motor and inverter components.

Implementation Method 1

a pump configured to supply the coolant to a cooling target

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

the coolant is supplied to a cooling target by a pump to cool the cooling target

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4606610A1Work vehicle
Publication Date: 2025.08.27 KUBOTA CORP
  • EP4606610A1 patent drawingFigure 1
  • EP4606610A1 patent drawingFigure 2
  • EP4606610A1 patent drawingFigure 3

AI summary

Provided is a work vehicle having a motor configured to supply power to a travel device and a simplified cooling structure for cooling a cooling target. The work vehicle includes a travel device, a battery, motors 21 and 22 configured to supply power to the travel device, a case 12 housing the motors 21 and 22, and an inverter that operates the motors 21 and 22. The work vehicle also includes a storage portion 33 provided downward of the motors 21 and 22 inside the case 12 and storing a coolant A, and a pump that supplies the coolant A to the cooling target.