Offset Pinion Single Reduction Carrier for Independent Suspension

Solution Overview

Problem

Traditional independent suspension systems require double reduction carriers for large pinion offsets, which increase weight and cost due to additional components like helical gears and bearings, necessitating a more efficient single reduction carrier solution.

Innovation Solution

A single reduction carrier with a laterally offset pinion input and a centered differential, utilizing a pinion gear that drives independently suspended wheels, and an adjuster mechanism with a threaded and toothed portion to set differential bearing preload, allowing for independent wheel movement without the need for extra components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a double reduction carrier configuration is used to accommodate large pinion offsets, then the pinion offset requirement is met, but the weight and cost increase due to additional components

Engineering Contradiction:

Improvepinion offset accommodationVSAvoidcarrier weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

Instead of using a traditional double reduction carrier where the pinion is centered and gears reduce speed twice, this invention inverts the approach by using a single reduction carrier with the pinion significantly offset from the centerline. The differential case itself is used to accommodate the offset pinion, eliminating the need for additional reduction stages and components.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention extracts and eliminates the unnecessary double reduction components (additional helical gears, bearings, case portions) from the traditional carrier design. By using only the single reduction with offset pinion directly driving the differential, it removes redundant parts while maintaining the required pinion offset and suspension travel capabilities.

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If a double reduction carrier configuration is used to accommodate large pinion offsets, then the pinion offset requirement is met, but the cost increases due to additional components

Engineering Contradiction:

Improvepinion offset accommodationVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the unnecessary double reduction components (additional helical gears, bearings, case portions) from the traditional carrier design. By using only the single reduction with offset pinion directly driving the differential, it removes redundant parts while maintaining the required pinion offset and suspension travel capabilities.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The differential case is designed to serve multiple functions: it houses the differential mechanism and simultaneously accommodates the offset pinion mounting. This multi-functionality eliminates the need for separate components to handle the offset configuration, reducing part count and manufacturing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If the pinion is aligned close to the vehicle centerline in a traditional carrier, then the carrier structure is simplified, but the suspension travel and driveline angle requirements cannot be met

Engineering Contradiction:

Improvecarrier structureVSAvoidsuspension travel capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

Instead of using a traditional double reduction carrier where the pinion is centered and gears reduce speed twice, this invention inverts the approach by using a single reduction carrier with the pinion significantly offset from the centerline. The differential case itself is used to accommodate the offset pinion, eliminating the need for additional reduction stages and components.

Inventive Principle:

Principle #13The other way round (Inversion)

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

Enables independent wheel movement with reduced weight and cost by eliminating the need for double reduction carriers, using existing output shafts and bearings, and providing precise preload adjustments for improved performance.

Implementation Method 1

The threaded portion is threaded on to one of the first and second case portions until the desired differential bearing preload is achieved

Methodology Applied

Scientific EffectThreading: Screw

Data Source

PatentUS8371415B2Single reduction carrier for independent suspension

Publication Date: 2013.02.12 ARVINMERITOR TECHNOLOGY LLC

AI summary

A drive unit for an independent suspension includes a single reduction carrier with an offset pinion configuration. The single reduction carrier includes a pinion input gear defining a pinion gear axis of rotation. The pinion gear drives a ring gear, which is coupled to a differential. The differential is laterally positioned to be centered along a longitudinally extending vehicle centerline and the pinion gear axis of rotation is significantly offset from the longitudinally extending vehicle centerline in a lateral direction.