Slotted Ring Gear Differential Assembly for Lower NVH
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional differential gear assemblies are excessively heavy due to robust construction, generate unwanted NVH (Noise, Vibration, and Harshness), and are time-consuming to assemble, with unsymmetrical geometry causing gear deflection and efficiency degradation.
Innovation Solution
A simplified and lightweight differential gear assembly design featuring an annular ring gear with slots for pinion pin alignment, reducing the number of parts and allowing for symmetrical construction, which simplifies assembly and improves torque transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional robust construction is used to support torque load, then strength and reliability are improved, but weight increases and construction becomes unnecessarily heavy
Solution Approach 1:
The patent combines the pinion pin support function directly into the ring gear structure by integrating slots into the ring gear that receive and support the pinion pin. This eliminates the need for a separate differential housing structure, merging multiple functions into a single component and reducing overall weight while maintaining torque load support capability.
Solution Approach 2:
The patent extracts the pinion pin support function from the traditional differential housing and relocates it to the ring gear itself. By taking out the housing structure and integrating its support function into the ring gear slots, the design eliminates unnecessary structural weight while preserving the required strength for torque transmission.
2Ease of manufacture
If conventional unsymmetrical geometry is used in gear assembly, then manufacturing is simplified, but gear deflection fluctuates over revolution causing NVH and efficiency degradation
Solution Approach 1:
The patent applies asymmetry by positioning the pinion pin slots at specific angular locations (e.g., 90 degrees apart) in the ring gear, creating a symmetrical support arrangement that balances the gear assembly. This symmetrical configuration ensures uniform gear deflection characteristics throughout rotation, eliminating the fluctuating NVH problems associated with unsymmetrical designs while maintaining manufacturing simplicity.
3Adaptability or versatility
If many different parts are used in differential gear assembly, then functionality and adaptability are improved, but assembly time increases and manufacturing becomes more complex
Solution Approach 1:
The patent merges the differential housing structure with the ring gear by integrating the pinion pin support slots directly into the ring gear. This consolidation reduces the number of separate parts from multiple components (housing, ring gear, pinion supports) to fewer integrated components, significantly reducing assembly time and manufacturing complexity while preserving all necessary differential gear functions.
Data Source
AI summary
A differential gear assembly for a vehicle includes: an annular ring gear having internal and external surfaces, and rotates around a rotational axis extending in an axial direction; first and second side gears respectively distribute a first and second output torque to first and second drive shafts; first and second differential pinion gears respectively engage the first and second side gears; a pinion pin extends diametrically across the ring gear, where the first and second differential pinion gears are rotatably arranged on the pinion pin. The ring gear comprises first and second slots for receiving the pinion pin, where the slots are arranged in connection to the internal surface and extend partly through the ring gear in the axial direction.