Four Pinion Differential Cross Pin Retainer Assembly

Solution Overview

Problem

Existing heavy-duty vehicle differentials with multiple pinion shafts face complex and costly coupling challenges to the differential housing, necessitating a simpler and more cost-effective securing method.

Innovation Solution

A differential design incorporating a retainer assembly with a collar, pin portions, and a clip that secures the second set of bevel pinions to the differential housing, using a clip with deflectable barbs to resist withdrawal and limit axial movement, allowing for robust and efficient coupling of pinion shafts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple pinion shafts are used in heavy duty differentials, then the differential can handle heavier loads, but the coupling of pinion shafts to the differential housing becomes complex and costly

Engineering Contradiction:

Improveload handling capacityVSAvoidcoupling complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent combines multiple pinion shafts (first and second pinion shafts) with the differential housing into a unified structure where the pinion shafts are integrally formed with or directly coupled to the housing. This merging eliminates the need for separate complex coupling mechanisms, thereby maintaining heavy load handling capability while reducing coupling complexity and manufacturing cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The differential housing is designed to serve multiple functions: it acts as both the structural enclosure and the mounting structure for multiple pinion shafts. By making the housing multi-functional, the patent eliminates the need for separate coupling components, thus reducing device complexity while supporting heavy duty applications.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Strength

If multiple pinion shafts are used in heavy duty differentials, then the differential can handle heavier loads, but the manufacturing cost increases

Engineering Contradiction:

Improveload handling capacityVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent combines multiple pinion shafts (first and second pinion shafts) with the differential housing into a unified structure where the pinion shafts are integrally formed with or directly coupled to the housing. This merging eliminates the need for separate complex coupling mechanisms, thereby maintaining heavy load handling capability while reducing coupling complexity and manufacturing cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The differential housing is designed to serve multiple functions: it acts as both the structural enclosure and the mounting structure for multiple pinion shafts. By making the housing multi-functional, the patent eliminates the need for separate coupling components, thus reducing device complexity while supporting heavy duty applications.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If complex coupling methods are used to secure pinion shafts, then structural integrity is maintained, but the assembly process becomes time-consuming

Engineering Contradiction:

Improvestructural integrityVSAvoidassembly time

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent combines multiple pinion shafts (first and second pinion shafts) with the differential housing into a unified structure where the pinion shafts are integrally formed with or directly coupled to the housing. This merging eliminates the need for separate complex coupling mechanisms, thereby maintaining heavy load handling capability while reducing coupling complexity and manufacturing cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The pinion shafts are designed to be pre-positioned or pre-integrated with the differential housing, allowing for quicker assembly. The housing structure itself is prepared in advance to receive and secure the pinion shafts without requiring complex coupling operations during assembly, thus reducing assembly time while maintaining structural integrity.

Inventive Principle:

Principle #10Preliminary action

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 solution provides a robust, cost-effective, and efficient method to secure multiple pinion shafts to the differential housing, simplifying the assembly process and reducing costs while maintaining structural integrity.

Implementation Method 1

At least one of the leg members carries a deflectable barb that deflects to an engaging position after the clip has been installed. The engaging position resists withdrawal of the leg members from the holes.

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS7951037B2Four pinion differential with cross pin retention unit and related method

Publication Date: 2011.05.31 AMERICAN AXLE & MANUFACTURING INC

AI summary

A differential having four pinions supported for rotation on cross pins within a differential case. The differential employs a retainer system for securing the cross pins relative to the differential case. The retainer system can include a retainer, such as a clip or a pair of roll pins, that can secure at least one of the cross pins in place.