Vehicle Transmission Structure Reducing Weight and Torque Interruption
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Solution Overview
Problem
Conventional vehicle transmission systems increase weight and volume by excessive use of gears to improve efficiency, leading to decreased fuel efficiency and torque interruption during gear shifts.
Innovation Solution
A transmission structure with three engine gears and two motor gears, incorporating synchronizing units and a one-way clutch to reduce parts, weight, and prevent torque interruption, while improving fuel efficiency and shifting smoothness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If shift gears are excessively applied to improve transmission efficiency, then transmission efficiency is improved, but weight and volume of the transmission are increased
Solution Approach 1:
The transmission system is segmented into two independent input shafts (first input shaft for engine, second input shaft for motor) with separate gear sets. This allows selective engagement of gear stages based on operating conditions, reducing the need for excessive gears while maintaining transmission efficiency across different operating ranges.
Solution Approach 2:
The transmission structure enables a single gear stage to serve multiple functions by allowing different input sources (engine or motor) to drive the same output through different input shafts. The synchronizing units and one-way clutchs enable flexible power path selection, making each gear stage universally applicable to multiple operating scenarios.
2Loss of energy
If shift gears are excessively applied to improve transmission efficiency, then transmission efficiency is improved, but volume of the transmission is increased
Solution Approach 1:
The transmission is divided into separate gear sets for each input shaft, with the first gear set for engine-driven operation and the second gear set for motor-driven operation. This segmentation allows compact arrangement of gear stages, reducing overall transmission volume while maintaining efficient power transmission across different operating conditions.
Solution Approach 2:
The transmission structure employs nested arrangement where gear stages are positioned concentrically or in overlapping configurations. The first and second gear sets share common spaces and mounting structures, allowing one gear set to be nested within or adjacent to the other, thereby reducing the total volume occupied by the transmission system.
3Power
If conventional transmission structure is used, then power transmission is achieved, but torque interruption is generated when gear is shifted
Solution Approach 1:
The synchronizing units are engaged before the actual gear shifting occurs, pre-synchronizing the rotational speeds of the input shaft and output shaft. This preliminary synchronization action eliminates speed differences that would cause torque interruption during shifting, ensuring smooth and continuous power transmission throughout the gear change process.
Solution Approach 2:
The one-way clutch acts as an intermediary element during gear shifting, allowing temporary disconnection and reconnection of power flow without causing torque interruption. The one-way clutch enables the output shaft to freewheel momentarily during the shift transition, mediating the torque flow to prevent interruptions while maintaining overall power transmission continuity.
Data Source
AI summary
A transmission of a vehicle is provided. The transmission includes: a first input shaft receiving engine power; a second input shaft receiving motor power; an output shaft; a first stage driving gear at the first input shaft; a second stage driving gear at the second input shaft; a third stage driving gear at the second input shaft; a first synchronizing unit connecting one of the second input shaft and the first stage driving gear to the first input shaft; a second synchronizing unit connecting the second input shaft to the third stage driving gear; first and third stage driven gears engaged with the first and third stage driving gears to form shift ratios of first and third stages; and a second stage driven gear through a one-way clutch while being engaged with the second stage driving gear to form a shift ratio of second state.