Hybrid AWD Torque Vectoring With Open Differential and Dual Clutches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current on-demand all-wheel drive (AWD) systems in vehicles are limited by the need for torque to be transferred through clutch packs, which results in mechanical losses, wear, and restricted negative torque vectoring capabilities, especially in hybrid vehicles where both primary and secondary drive sources are used.
Innovation Solution
A drive system that incorporates a secondary input gear set to reduce rotation speed before entering the clutch pack and an open differential, allowing for independent control of torque distribution between wheels, enabling both positive and negative torque vectoring through the use of two clutch packs and an open differential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If torque is transferred through clutch packs in conventional on-demand AWD systems, then torque distribution between axles is controlled, but mechanical losses and wear increase
Solution Approach 1:
The patent extracts the clutch pack from the torque transfer path by introducing a mechanical differential connection. The differential mechanism allows direct mechanical torque transfer between the primary and secondary drive axles without requiring clutch engagement, thereby eliminating the mechanical losses and wear associated with clutch operation while maintaining torque distribution control.
Solution Approach 2:
The patent introduces a mechanical differential mechanism as an intermediary between the primary and secondary drive axles. This differential acts as a mediator that enables smooth torque transfer and distribution without the need for clutch packs, reducing mechanical losses while maintaining the ability to control torque distribution between axles.
2Ease of operation
If clutch packs are used for torque vectoring, then torque distribution between wheels is controlled, but wear and mechanical losses increase
Solution Approach 1:
The patent removes the clutch pack from the torque vectoring mechanism and replaces it with a mechanical differential connection. This extraction eliminates the wear-prone clutch components while maintaining the ability to actively control torque distribution between wheels through the differential mechanism and associated control systems.
Solution Approach 2:
The patent replaces the friction-based clutch pack mechanism with a mechanical differential system. This substitution transitions from a friction-dependent torque transfer method to a mechanical gear-based system that achieves torque vectoring without the wear and reliability issues associated with clutch packs.
3Adaptability or versatility
If conventional AWD systems are used, then torque distribution is limited, but negative torque vectoring capability is restricted
Solution Approach 1:
The patent implements a dynamic torque distribution system using a mechanical differential mechanism that can actively adjust torque split between wheels and axles. This dynamic system enables negative torque vectoring capabilities by allowing one wheel to receive less torque than the other, with the differential mechanism accommodating reverse torque flows that were previously restricted in conventional AWD systems.
Solution Approach 2:
The mechanical differential mechanism serves multiple functions: it enables torque distribution between axles, torque vectoring between wheels, and negative torque vectoring capabilities. This multi-functional approach expands the adaptability of the AWD system while eliminating the harmful restriction on negative torque vectoring present in conventional designs.
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
This configuration enhances torque vectoring capabilities, reduces mechanical losses and wear, and allows for more efficient energy management in hybrid vehicles by enabling negative torque vectoring, thereby improving vehicle performance and driving dynamics.
Implementation Method 1
The secondary input (12) gear set (60) may be a compound planetary gear set (60'), wherein the source of the secondary input (12) drives a sun gear (62) of the compound planetary gear set (60'), and the output of the compound planetary gear set (60') - a planet carrier (65) - transmits torque to an input of the open differential (40).
Implementation Method 2
an open differential (40) having one torque input (42) and two torque outputs (44, 46)
Implementation Method 3
independently controllable first (50) and a second (52) clutch packs, each having a clutch pack input (50a, 52a) mutually connected in fixed rotational relation, and each having a clutch pack output (50b, 52b)
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Provided is a drive system (100) for a vehicle for variable distribution of torque, from a primary input (10) and secondary input (12), between a left wheel (22) and a right wheel (32) of a vehicle, the drive system (100) comprising a first (20) and second (30) torque output shaft, one for each of the left wheel (22) and the right wheel (32), an open differential (40), and independently controllable first (50) and a second (52) clutch packs, configured such that: torque from the primary input (10) is transferred to each of the torque output shafts (20, 30) via the clutch packs (50, 52); torque from the secondary input (12) is transferred to each of the torque output shafts (20, 30) via the open differential (40); torque from one output (44) of the open differential (40) is summed with torque from one clutch pack (50) output (50b) in the first (20) torque output shaft; and torque from another output (46) of the open differential (40) is summed with torque from the other clutch pack (52) output (52b) in the second (30) torque output shaft.