Rear Housing Motor Layout With Internal Oil Path for Electric Work Vehicles

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Solution Overview

Problem

Existing electric work vehicles face challenges in efficiently powering multiple components such as rear wheels, a Power Take-Off (PTO), and hydraulic systems, while maintaining a compact and lightweight design.

Innovation Solution

The electric work vehicle is designed with a rear housing that supports multiple electric motors for driving rear wheels and a PTO, along with a hydraulic system, and incorporates a unique oil path system for lubrication and cooling, allowing for efficient power distribution and component operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple electric motors are installed in the rear housing to drive rear wheels and PTO, then power transmission capability is improved, but device complexity increases

Engineering Contradiction:
Improvepower transmission capabilityVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent combines multiple motor assemblies (first motor for left rear wheel, second motor for right rear wheel, and third motor for PTO) within a single rear housing structure. This merging approach allows power transmission to multiple components while consolidating the overall structural complexity into one integrated housing unit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rear housing serves multiple functions simultaneously: it supports the first motor for driving the left rear wheel, supports the second motor for driving the right rear wheel, and supports the third motor for driving the PTO. This multi-functional design improves power transmission capability without proportionally increasing device complexity.

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

2Reliability

If a first oil path is defined within the rear housing for lubrication and cooling, then component operation reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecomponent operation reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the oil path system directly within the rear housing structure, combining the lubrication and cooling functions with the motor support structure. The first oil path includes inlet and outlet openings positioned to serve all three motors, eliminating the need for separate external lubrication systems and reducing overall device complexity while improving reliability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4556276A1Electric work vehicle
Publication Date: 2025.05.21 KUBOTA CORP
  • EP4556276A1 patent drawingFigure 1A
  • EP4556276A1 patent drawingFigure 1B
  • EP4556276A1 patent drawingFigure 1C

AI summary

An electric work vehicle 1 includes a rear housing 12, a first motor 19 to drive a first rear wheel 4L, the first motor 19 being supported by the rear housing 19, and a second motor to drive a second rear wheel 4R, the second motor being supported by the rear housing 19. A first oil path 550 is defined within the rear housing 12. The first oil path 550 includes a first inlet opening 551 which is provided in a front portion of the rear housing 12 in a front-rear direction of the electric work vehicle 1.