Transmission Gear Cover Layout to Reduce Lubricating Oil Agitation

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Solution Overview

Problem

The agitation of lubricating oil by power transmission gears in a transmission case leads to increased power transmission loss, which affects the efficiency of motive power transmission in work vehicles.

Innovation Solution

The use of gear covers to prevent the agitation of lubricating oil by power transmission gears, specifically split covers for the first and second power transmission gears, which are integrated with or supported by the transmission case, reducing drive load and enhancing power transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the gear pair is disposed in a bottom section of the transmission case to utilize lubricating oil storage space, then the transmission case can efficiently store lubricating oil, but the power transmission gears agitate the lubricating oil and increase drive load

Engineering Contradiction:
Improvelubricating oil storageVSAvoidpower transmission loss
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The transmission case is divided into two distinct sections: a lower lubricating oil storage section and an upper power transmission section. The gear cover acts as a partition wall separating these sections, preventing the gears from directly agitating the lubricating oil while maintaining efficient oil storage capacity in the bottom section.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If a gear cover is provided to cover the power transmission gears, then the agitation of lubricating oil is reduced, but the device complexity increases

Engineering Contradiction:
Improvepower transmission lossVSAvoidtransmission case structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The gear cover is merged with the gear pair assembly, forming an integrated unit that can be installed as a single component. This integration reduces the number of separate parts and simplifies the overall transmission case structure while still effectively preventing lubricating oil agitation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gear cover serves multiple functions simultaneously: it acts as a protective cover for the gears, a partition wall separating the oil storage section from the power transmission section, and a structural support element. This multi-functionality reduces the need for additional separate components.

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

3Device complexity

If the gear cover is provided as a single integrated piece, then the structure is simple, but it is difficult to attach to the transmission case

Engineering Contradiction:
Improvegear cover structureVSAvoidgear cover attachment
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The gear cover is divided into multiple separate sections or segments that can be individually manufactured and then assembled together. This segmentation makes the gear cover easier to attach to the transmission case while maintaining structural integrity and effectiveness in preventing oil agitation.

Inventive Principle:
Principle #1Segmentation

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

The gear covers effectively minimize the agitation of lubricating oil, thereby reducing power transmission loss and enhancing the efficiency of motive power transmission in work vehicles.

Implementation Method 1

the gear cover prevents the agitation of the lubricating oil by the first power transmission gear and the second power transmission gear from spreading into the lubricating oil storage area in the transmission case

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP4296544B1Work vehicle
Publication Date: 2025.09.03 KUBOTA CORP
  • EP4296544B1 patent drawingFigure 1
  • EP4296544B1 patent drawingFigure 2
  • EP4296544B1 patent drawingFigure 3

AI summary

A work vehicle including: a transmission (18) configured to receive motive power input from a motive power source (4), and shift and output the input motive power to a travel device (1); a transmission case (12) housing the transmission (18); and a gear pair (39, 40) disposed in the transmission (18), in a bottom section (12d) of an internal space of the transmission case (12), and including (i) a first power transmission gear (40a) configured to rotate about a first rotation axis, and (ii) a second power transmission gear (40b) configured to mesh with the first power transmission gear (40a) and rotate about a second rotation axis that is parallel with the first rotation axis. The work vehicle further includes at least one gear cover (41, 42) covering the first power transmission gear (40a) and the second power transmission gear (40b).