Axle Lubricant Reservoir and Trough Layout for Low-Speed Lubrication

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Solution Overview

Problem

Existing axle assemblies with lubricant reservoirs face inefficiencies in lubricant distribution, leading to inadequate lubrication of components, especially during low-speed operations or when the differential assembly is not rotating.

Innovation Solution

The axle assembly incorporates a lubricant reservoir positioned above the differential assembly to capture splashed lubricant and a lubricant distribution trough with a dam separating two troughs, ensuring efficient lubricant distribution to various components, including input shaft bearings, interaxle differential units, and drop gear sets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lubricant reservoir is disposed above the differential assembly to capture splashed lubricant, then lubrication is maintained during low-speed operations or when the differential assembly is not rotating, but the complexity of the lubrication system increases due to the additional reservoir and distribution trough structure

Engineering Contradiction:
Improvelubrication reliabilityVSAvoidlubrication system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lubrication system is segmented into multiple functional components: a lubricant reservoir for storage, a distribution trough with separate chambers for different lubrication zones, and targeted delivery paths to various bearings and gears. This segmentation allows independent optimization of each component while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lubricant reservoir is positioned above the differential assembly to capture splashed lubricant in advance, creating a reserve supply before lubrication is needed during low-speed or stationary operations. The distribution trough pre-separates lubricant paths to ensure immediate delivery to critical components when required.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If a dam separates the first trough from the second trough in the lubricant distribution system, then lubricant is efficiently distributed to specific components (input shaft bearing, interaxle differential unit, drop gear set), but the manufacturing complexity increases due to the multi-chamber trough structure

Engineering Contradiction:
Improvelubricant distribution efficiencyVSAvoidmanufacturing ease
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The distribution trough is segmented into multiple chambers separated by dams, with each chamber dedicated to delivering lubricant to specific components. This segmentation enables precise lubricant distribution to the input shaft bearing, interaxle differential unit, and drop gear set, maximizing lubrication efficiency while allowing modular manufacturing of each chamber.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the distribution trough are designed with locally optimized characteristics - the first trough serves the input shaft bearing area, while the second trough serves the differential and gear components. Each chamber's geometry and positioning are tailored to its specific lubrication requirements, improving overall distribution efficiency.

Inventive Principle:
Principle #3Local quality

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 enhances lubrication efficiency by reducing drag and churning losses, improving component life, and maintaining lubrication even when the differential assembly is not rotating, thereby reducing friction and wear.

Implementation Method 1

captures lubricant that is splashed by the ring gear

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

lubricant reservoir that is disposed above the differential assembly and that captures lubricant

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 3

a lubricant distribution trough that receives lubricant from the lubricant reservoir

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4184038B1Axle assembly having a lubricant reservoir
Publication Date: 2025.04.23 ARVINMERITOR TECHNOLOGY LLC
  • EP4184038B1 patent drawingFigure 1
  • EP4184038B1 patent drawingFigure 2
  • EP4184038B1 patent drawingFigure 3

AI summary

An axle assembly (10) comprising: a differential assembly (34) that is rotatable about an axis (170) and that has a ring gear (180); a housing assembly (20) that receives the differential assembly (34); a lubricant reservoir (50') that is disposed above the differential assembly (34) and that captures lubricant (82) that is splashed by the ring gear (180); and a lubricant distribution trough (260) that receives lubricant (82) from the lubricant reservoir (50'), the lubricant distribution trough (260) including: a first trough (270) that receives lubricant (82) from the lubricant reservoir (50'); a second trough (272) that is disposed below the first trough (270); and a dam (274) that separates the first trough (270) from the second trough (272).An axle assembly that has a lubricant reservoir. The lubricant reservoir may be disposed above a differential assembly and may capture lubricant that is splashed by the differential assembly. The lubricant reservoir may have at least one tank. The lubricant reservoir may optionally provide lubricant to a lubricant distribution trough.