Compact Differential Gear With Optimized Pinion And Side Gear Parameters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing differential gears for front-drive vehicles face challenges in maintaining strength while minimizing size, particularly in the vehicle-width direction, due to limitations in space and the need to balance gear ratios and tooth counts.
Innovation Solution
The differential gear design features pinion gears with 9 teeth and side gears with 13 teeth, optimized parameters such as cone distance, module, depth, clearance, and skirt thickness to achieve a compact configuration with improved strength, using specific relationships like 0.28≦F=(R−MD)/R≦0.31 and St/M≧0.534, ensuring favorable meshing and rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the number of teeth of pinion gears and side gears is reduced to improve strength, then the gear strength is improved, but the reference cone angle and cone distance vary making it necessary to increase the size of the differential case
Solution Approach 1:
The patent applies parameter changes by precisely adjusting the number of teeth (9 teeth for pinion gears, 13 teeth for side gears), module (M), whole depth (h), clearance (CL), and skirt thickness (St) to achieve optimal strength while maintaining compact dimensions. The specific parameter relationships (0.28≦F≦0.31, St/M≧0.534, 0.025≦CL/M≦0.038, h/M≧2) enable strength improvement without increasing differential case size
Solution Approach 2:
The patent addresses the size-strength contradiction by optimizing the axial dimension through the assembly distance parameter (MD=Rp+CL+St) and its relationship with cone distance (MD≧R×cos(θ)). This dimensional optimization allows the differential gear to maintain compact overall size while achieving improved gear strength through careful parameter selection
2Strength
If additional pinion gears are provided to improve strength, then the gear strength is improved, but the weight and number of parts increase
Solution Approach 1:
The patent improves gear strength by changing the parameters of existing components rather than adding components. By reducing the number of teeth to 9 and 13 respectively and optimizing module, depth, and clearance parameters, the patent achieves stronger gears with the same number of parts, thereby improving strength without increasing weight
3Volume of moving object
If the reference cone angle of side gears is decreased to reduce size, then the differential gear becomes more compact, but it becomes difficult to suppress increase in dimension while securing the strength of side gears
Solution Approach 1:
The patent simultaneously optimizes multiple parameters including reference cone angle, module (M), whole depth (h), and skirt thickness (St) to achieve compact size while maintaining strength. The specific relationships (h/M≧2, St/M≧0.534) ensure that even with reduced dimensions, the side gears maintain sufficient strength through increased tooth depth and optimized geometry
Data Source
AI summary
A differential gear for a vehicle including a pair of pinion gears and a pair of side gears meshed with the pair of pinion gears at a right angle. In order to improve the strength of the pinion gears and the side gears, less teeth are provided, and the size of each tooth is increased. The reference cone angle and the cone distance may be varied in accordance with the gear ratio, which may make it necessary to increase the size of a differential case that houses the gears. For front-drive vehicles, which is greatly limited in terms of space it may be difficult to suppress an increase in dimension of the differential gear. Accordingly, provided is a compact gearing that has improved strength in the pinion and side gears.