Limited-Slip Differential Gears With Offset Meshing Events
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional differential gear mechanisms with side gears of the same geometry result in concurrent meshing events, leading to noise and stress issues due to synchronized contact points, which can be detrimental to the operational efficiency and reliability.
Innovation Solution
The implementation of side gears with distinct outer diameters, where the first and second pinion gears are meshed with the first and second side gears during staggered events, creating distinct contact ratios, lengths of contact, and out-of-phase meshing frequencies, thereby reducing noise and stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If side gears of the same geometry are used in conventional differential gear mechanisms, then the structure is simple and manufacturing is easier, but concurrent meshing events occur leading to noise and stress issues
Solution Approach 1:
The patent applies asymmetry by providing side gears with different outer diameters (first side gear with larger diameter, second side gear with smaller diameter). This asymmetric configuration causes the meshing events of the pinion gears with the side gears to occur at different angular positions and times, transforming the symmetric concurrent meshing into asymmetric staggered meshing. This resolves the technical contradiction by eliminating noise and stress from concurrent meshing while maintaining manufacturing feasibility through standardized gear production processes.
Solution Approach 2:
The patent changes the geometric parameter of the side gears, specifically the outer diameter, to create different meshing characteristics. By varying the outer diameter parameter of the side gears, the meshing events are offset in time, creating distinct contact ratios and reducing the harmful effects of synchronized contact. This parameter change approach maintains ease of manufacture while eliminating noise and stress issues.
2Object-affected harmful factors
If side gears with distinct outer diameters are used to offset meshing events, then noise and stress are reduced, but the device complexity increases
Solution Approach 1:
The asymmetric design of side gears with different outer diameters achieves noise and stress reduction through staggered meshing events. While this introduces geometric complexity, the overall device complexity remains manageable because the asymmetric configuration is limited to the side gear dimensions rather than requiring complex mechanisms or additional components throughout the differential assembly.
Solution Approach 2:
By changing only the outer diameter parameter of the side gears while maintaining other geometric parameters within standard ranges, the patent achieves noise reduction without substantially increasing device complexity. The modified parameters can be incorporated into existing manufacturing processes, and the overall structural complexity of the differential mechanism remains comparable to conventional designs.
3Reliability
If staggered meshing events are implemented with distinct outer diameters, then operational efficiency and reliability are improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent changes the outer diameter parameter of side gears to achieve staggered meshing and improved reliability. While this requires precise control of the diameter difference to ensure proper meshing offset, the absolute precision requirements remain within standard manufacturing capabilities. The design allows for controlled parameter variation that improves reliability without demanding ultra-precise manufacturing tolerances.
Solution Approach 2:
The asymmetric side gear configuration improves reliability by eliminating concurrent meshing stresses that can cause premature failure. The manufacturing precision required for this asymmetric design is focused on maintaining the specified diameter difference between side gears, which can be achieved through standard quality control processes without requiring exceptional manufacturing precision across all components.
Data Source
Figure 1~2
Figure 3~4
AI summary
A differential gear mechanism includes a differential case, a first side gear, a second side gear, a first pinion and a second pinion. The first side gear is rotatably mounted within the differential case and has a first outer diameter. The second side gear is rotatably mounted within the differential case and has a second diameter. The first pinion gear is meshed for rotation with the first side gear during a first meshing event. The second pinion gear is meshed for rotation with the second side gear during a second meshing event. The first and second pinion gears form a torque transfer arrangement configured for transferring torque between the first and second pinion gears and the first and second side gears to rotate the first and second side gears. The first and second outer diameters are distinct such that the first and second meshing events are offset in time.