Spherical Differential Assembly Zero Lash Spring Washers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing differential assemblies in motor vehicles experience excessive lash between pinion and side gears, leading to undesirable 'clunk' noises during direction changes, which is not tolerated by modern standards, and the use of spherically shaped components reduces the feasibility of large Belleville washers for biasing, necessitating a solution for zero lash assembly.
Innovation Solution
A differential assembly with spherically shaped components and spring washers positioned between the housing and gears, where the spring washers provide a biasing force to maintain side gears in a zero lash position, reducing noise by minimizing gear clearance and using gap or overlap-type spring washers to maintain engagement without excessive wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spherically shaped components are used in the differential assembly, then structural durability and manufacturing ease are improved, but the back face area for spring positioning is reduced, making traditional biasing solutions infeasible
Solution Approach 1:
The patent applies spheroidality by using spherically shaped pinion gears and side gears that conform to the spherical cavity in the housing. This curvature design improves structural durability and manufacturing ease while reducing lash between gears. The spherical geometry allows the components to self-center and maintain optimal contact surfaces throughout operation.
Solution Approach 2:
The patent changes the parameter of spring positioning by moving from traditional large Belleville washers requiring extensive back face area to compact spring washers that can be positioned on the limited back face area of spherical side gears. This parameter change enables the use of spherical components while maintaining the necessary biasing function.
2Manufacturing precision
If traditional large Belleville washers are used to bias side gears, then gear lash reduction is achieved, but the device complexity and manufacturing difficulty increase due to the need for large planar back surfaces
Solution Approach 1:
The patent extracts the essential biasing function from the traditional large Belleville washer configuration and implements it through compact spring washers positioned on the limited back face area of spherical side gears. This extraction allows gear lash control to be achieved without requiring large planar surfaces, simplifying manufacturing.
Solution Approach 2:
The patent uses simpler, more manufacturable spring washer components instead of complex traditional biasing arrangements. These compact springs provide the necessary gear lash control while being easier and less costly to manufacture, even if they require more frequent replacement.
3Object-affected harmful factors
If zero lash positioning is maintained continuously, then noise reduction is improved, but wear on the spring washers increases due to constant engagement
Solution Approach 1:
The patent implements periodic action by allowing the spring washers to engage and disengage from the side gears in a cyclic manner. During straight-line travel, the springs maintain zero lash positioning to eliminate noise. During directional changes, the design allows maximum lash to occur, reducing spring washer wear while accepting temporary noise generation.
Solution Approach 2:
The patent applies dynamics by creating a system that adapts between two states: zero lash positioning for noise reduction during straight travel, and maximum lash positioning during directional changes to minimize wear. This dynamic behavior optimizes both noise performance and component longevity based on operating conditions.
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 effectively reduces noise generation by maintaining side gears in a zero lash position during straight travel and allowing maximum lash only when necessary, thereby minimizing wear and extending the life of the spring washers while ensuring noise reduction at low cost.
Implementation Method 1
A pair of springs are positioned within the chamber. Each spring is engaged with one of the end faces of the side gears to minimize gear lash between the side gears and the pinion gears.
Implementation Method 2
spring washers to place the differential gears in a zero lash condition
Data Source
Figure 1
Figure 2~3
AI summary
A differential assembly includes a differential housing (12) including a substantially spherically shaped chamber. A pair of spherically shaped side gears (36) are rotatably positioned in the chamber in driving communication with a pair of spherically shaped pinion gears (34). A pair of springs (90) are positioned in engagement with the end faces of the side gears (36) to minimize gear lash between the side gears (36) and the pinion gears (34).