Transfer Case Nested Coaxial Shaft Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing transfer cases for commercial vehicles face challenges in achieving a compact design with a lockable differential and a power take-off that can operate efficiently when stationary without increasing the overall length, while maintaining efficient operation across various driving conditions.
Innovation Solution
A transfer case design featuring a coaxial arrangement of the drive shaft and first output shaft, with a second output shaft positioned at a distance and a coaxial differential gear, incorporating a planetary gear differential with a power take-off in permanent connection to the drive shaft, allowing decoupling of output shafts from the differential gear and engagement/disengagement via a clutch for stationary operation, and an optional differential lock for enhanced locking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the transfer case includes a lockable differential gear and power take-off for stationary operation, then the functionality and versatility are improved, but the overall length of the transfer case increases
Solution Approach 1:
The patent implements a nested arrangement where the first output shaft is positioned coaxially inside the drive shaft, and the second output shaft is arranged within the first output shaft. This nested configuration allows multiple functional components (differential gear, power take-off, output shafts) to occupy overlapping spatial volumes, thereby providing lockable differential and stationary power take-off functionality without increasing the overall length of the transfer case.
Solution Approach 2:
The patent transitions from a conventional linear arrangement of shafts to a coaxial multi-dimensional configuration. By arranging the drive shaft, first output shaft, and second output shaft in concentric coaxial relationships, the design utilizes the radial dimension to accommodate additional functionality while maintaining a compact axial length, thus resolving the contradiction between enhanced adaptability and length constraints.
2Productivity
If the power take-off is in permanent connection with the drive shaft, then the operational efficiency at standstill is improved, but the device complexity increases
Solution Approach 1:
The patent merges the power take-off mechanism with the differential gear assembly by positioning the power take-off shaft coaxially within the differential gear structure. This integration allows the power take-off to draw power directly from the drive shaft through the planetary gear mechanism without requiring separate transmission paths or additional coupling devices, thereby maintaining operational efficiency at standstill while minimizing device complexity.
3Adaptability or versatility
If the first output shaft is decoupled from the differential gear for stationary operation, then the power take-off can operate at standstill, but the mechanism complexity increases
Solution Approach 1:
The patent implements a dynamic switching mechanism where the first output shaft can be selectively coupled or decoupled from the differential gear through a switching device. This dynamic configuration allows the system to adapt its operational mode: when decoupled, the power take-off can operate independently at standstill; when coupled, the full differential functionality is available. The switching mechanism is integrated into the existing gear structure, minimizing additional complexity while maximizing operational versatility.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The utility model relates to a transfer case, transfer case has differential mechanism (8) with the coaxial setting of drive shaft (1), through this differential mechanism can drive with first driven shaft (11) of the coaxial setting of drive shaft (1) and with drive shaft (1) at a distance of second driven shaft (14) that set up, transfer case still has through the supplementary actuating mechanism of the full -time driven of cylindrical gearing mechanism (2).