Power Transmission Device Torque Opposition Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power transmission devices with differential gears face issues where the torques of output shafts can oppose each other during four-wheel drive, leading to inefficiencies and potential damage.
Innovation Solution
A power transmission device with a differential gear and an engagement device that selectively connects any two of the three rotation elements, allowing for the limitation of differential action, thereby suppressing torque opposition between output shafts, and includes a planetary gear device and transmission mechanisms for efficient power distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If power is transmitted via a differential gear in four-wheel drive mode, then power distribution to front and rear wheels is achieved, but the torques of the output shafts may oppose each other causing inefficiency and potential damage
Solution Approach 1:
The patent applies the dynamics principle by making the engagement device switchable between engaged and disengaged states. This allows the system to dynamically adapt its behavior: when engaged, the device limits differential action to prevent torque opposition; when disengaged, it allows free differential action for normal operation. This dynamic switching resolves the contradiction by enabling the system to change its characteristics based on operational needs.
Solution Approach 2:
The patent applies parameter changes by modifying the differential gear's operational parameters through the engagement device. When the engagement device connects two of the three rotation elements, it changes the differential gear from a state of free differential action to a state of limited differential action, effectively altering the torque distribution parameters to prevent opposition while maintaining four-wheel drive capability.
2Reliability
If the differential action of the differential gear is limited by the engagement device, then torque opposition is suppressed, but the device complexity increases
Solution Approach 1:
The engagement device is designed to perform multiple functions: it can connect different combinations of rotation elements (first and second, first and third, or second and third) to achieve various operational modes. This multi-functionality reduces the need for separate mechanisms for each function, thereby managing complexity while providing comprehensive control over the differential gear's behavior.
Solution Approach 2:
The engagement device acts as an intermediary between the differential gear and the output shafts. Rather than fundamentally redesigning the differential gear itself, the engagement device mediates the torque transmission by selectively connecting rotation elements, thus preventing torque opposition through a controlled intermediate mechanism rather than a complete system overhaul.
3Adaptability or versatility
If the engagement device is switched between engagement and disengagement states, then drive mode adaptability is improved, but the ease of operation decreases
Solution Approach 1:
The engagement device is designed to automatically switch between engaged and disengaged states based on the operational requirements of the four-wheel drive system. This self-service capability eliminates the need for manual intervention or complex control mechanisms, thereby maintaining ease of operation while achieving drive mode adaptability. The system essentially manages its own engagement state based on detected conditions.
Data Source
AI summary
A power transmission device includes a first input shaft configured to input power from a first power source, a second input shaft configured to input power from a second power source, a first output shaft configured to transmit power to a first drive wheel, a second output shaft configured to transmit power to a second drive wheel, and a differential gear including, as three rotation elements, a first rotation element to which the second input shaft is connected, a second rotation element to which the second output shaft is connected, and a third rotation element to which the first input shaft and the first output shaft are connected, in which an engagement device configured to selectively connect any two of the three rotation elements is provided.