Compact Differential Assembly Torque Vectoring Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing differential gear units for torque vectoring in vehicles are bulky due to the radial placement of reversing and control motors, making them difficult to integrate into compact designs while maintaining efficiency and power transmission.
Innovation Solution
A compact differential assembly with a simple structure, utilizing a complex planetary gear set comprising internal and external gears, where the first to third gears and their respective eccentric gears are supported by an eccentric member, allowing for differential rotation and torque distribution between coaxial rotary shafts, and incorporating a control motor to adjust torque distribution ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the reversing mechanism and control motor are arranged radially outer side of the ring gears, then the torque distribution control is achieved, but the radial size of the drive gear unit increases
Solution Approach 1:
The patent relocates the reversing mechanism from a radial arrangement to an axial arrangement along the input shaft. The first and second pinions are positioned at opposite ends of the input shaft, eliminating the need for radial space while maintaining the torque reversal function. This dimensional repositioning resolves the contradiction between achieving torque distribution control and minimizing radial size.
Solution Approach 2:
The patent integrates the reversing mechanism components (pinions, input shaft) with the existing differential gear structure. The pinions are directly mounted on the input shaft, merging the reversing function with the power transmission path. This consolidation eliminates separate radial mounting requirements while achieving both torque reversal and distribution control.
2Quantity of substance
If a speed reducing mechanism with large speed reducing ratio is arranged between the control motor and the ring gear, then the control motor size is reduced, but the overall drive gear unit size increases
Solution Approach 1:
The patent combines the speed reducing mechanism with the differential gear components themselves. The pinions acting as reversing elements also serve as the speed reducing mechanism, eliminating the need for a separate speed reducing mechanism. This integration achieves torque multiplication and reversal without adding extra components that would increase overall unit size.
Solution Approach 2:
The pinions perform multiple functions simultaneously: they act as reversing elements to change torque direction, as speed reducing mechanism to multiply torque, and as mounting elements for the control motor. This multi-functionality eliminates the need for dedicated separate components, reducing both motor size and overall unit size while achieving control objectives.
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 enables a compact, efficient differential unit that can be easily integrated into vehicles, improving power transmission efficiency and reducing the size of the differential assembly while maintaining control over torque distribution between wheels.
Implementation Method 1
a first gear that is arranged around a common rotational axis of the first rotary shaft and the second rotary shaft to be rotated integrally with the first rotary shaft; a second gear that is arranged around the common rotational axis to be rotated integrally with the second rotary shaft and to be rotated relatively to the first gear
Implementation Method 2
a first eccentric gear that is arranged around an eccentric axis offset from the common rotational axis to be meshed with the first gear; a second eccentric gear that is arranged around the eccentric axis to be meshed with the second gear and to be rotated integrally with the first eccentric gear
Data Source
AI summary
A downsized differential assembly having a simple structure, which can be mounted easily on automobiles. The differential assembly comprises a set of first to third gears arranged coaxially while being allowed to rotate relatively to one another. A first eccentric gear meshes with the first gear, a second eccentric gear meshes with the second gear, and a third eccentric gear meshes with the third gear, while being supported by an eccentric member in such a manner as to rotate around an eccentric axis which is offset from a rotational axis. Gear ratios between the first to third gears and the first to third eccentric gears are set to different values so that rotational speeds of the first gear and the second gear are reduced slower than that of the eccentric member.