Fluid Coupling Torque Transmission for Vehicle Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle drive apparatuses face inefficiencies in energy regeneration during vehicle deceleration due to direct coupling between the engine and rotating electric machine, leading to friction losses and reduced regeneration efficiency.
Innovation Solution
A vehicle drive apparatus utilizing a fluid coupling to connect the engine and rotating electric machine, allowing torque transmission via an impeller and turbine, which separates the engine from the rotating electric machine during energy regeneration, thereby reducing friction losses and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the engine and rotating electric machine are directly coupled, then the structure is simple, but the energy regeneration efficiency deteriorates due to friction loss
Solution Approach 1:
A fluid coupling is introduced as an intermediary device between the engine and rotating electric machine. The fluid coupling includes an impeller connected to the engine and a turbine connected to the rotating electric machine, with working fluid flowing between them to transmit torque. This intermediary structure allows the engine and rotating electric machine to be mechanically separated while maintaining torque transmission, thereby eliminating friction losses during energy regeneration while preserving structural simplicity.
2Length of moving object
If the engine and rotating electric machine are directly coupled, then the torque transmission path is short, but the friction loss increases during energy regeneration
Solution Approach 1:
The fluid coupling acts as an intermediary that transmits torque from the engine to the rotating electric machine through fluid dynamics rather than direct mechanical contact. The impeller converts mechanical energy to fluid kinetic energy, which then drives the turbine connected to the rotating electric machine. This indirect torque transmission path eliminates friction losses at the connection interface while maintaining an efficient torque transmission path through the fluid medium.
Solution Approach 2:
The fluid coupling utilizes hydraulic principles where working fluid flows from the impeller to the turbine to transmit torque. During energy regeneration, the rotating electric machine drives the turbine, which rotates the impeller, and the working fluid flows back to the engine side, creating a hydraulic connection that eliminates mechanical friction while maintaining torque transmission capability.
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 configuration enhances energy regeneration efficiency by minimizing friction losses and optimizing torque transmission paths, improving the overall performance of the vehicle drive system during energy regeneration.
Implementation Method 1
a fluid coupling connected to an engine; a rotating electric machine connected to the engine via the fluid coupling
Implementation Method 2
an impeller to which torque having been output from the engine is input, the impeller rotating about a rotation axis of an output shaft of the engine
Implementation Method 3
a turbine facing the impeller, the turbine to which torque having been output from the impeller is input via a fluid, the turbine rotating about the rotation axis
Data Source
AI summary
A vehicle drive apparatus includes a fluid coupling connected to an engine, and a rotating electric machine connected to the engine via the fluid coupling. The fluid coupling has an impeller to which torque having been output from the engine is input, and a turbine facing the impeller. The impeller rotates about a rotation axis. Torque having been output from the impeller is input to the turbine via a fluid. The turbine rotates about the rotation axis. The vehicle drive apparatus has a path provided between an output shaft of the engine and the impeller, the path through which torque having been output from the engine is transmitted to the impeller not via the turbine, and paths through which torque having been input to the impeller is output via the rotating electric machine, passing through a radially outside relative to the impeller with respect to the rotation axis from the impeller via the turbine.