Transmission Countershaft Motor Generator for Engine Defueling
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Solution Overview
Problem
Automated mechanical transmission systems in vehicles face challenges in achieving optimal fuel efficiency and reducing electrical system complexity while maintaining power to accessories during engine defueling and coasting.
Innovation Solution
A transmission system with a motor generator coupled to a countershaft, a master clutch, and a controller that selectively operates in various modes to defuel the engine while moving, route rotational energy into the motor generator, and charge batteries, replacing traditional front-end accessory drives with a configuration that provides electrical power from the transmission countershaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is defueled while the vehicle is moving, then fuel efficiency is improved, but electrical power supply to accessories is interrupted
Solution Approach 1:
A motor generator is introduced as an intermediary component coupled to the transmission countershaft. This motor generator acts as a mediator that can provide electrical power to accessories independently of the engine's operation, enabling the engine to be defueled while maintaining electrical power supply through the motor generator's generation mode.
Solution Approach 2:
The motor generator is designed with multi-functionality, serving both as a motor during engine starting and as a generator during engine defueling. This universal component replaces the need for separate starter and alternator systems, allowing the system to maintain electrical power supply regardless of engine state.
2Reliability
If traditional front-end accessory drives are used, then electrical power is available during engine operation, but system weight and complexity increase
Solution Approach 1:
The motor generator combines the functions of the traditional starter motor and alternator into a single integrated component. This merging eliminates the need for separate starter and alternator systems, reducing system complexity and weight while maintaining electrical power supply capability during both engine operation and defueling modes.
Solution Approach 2:
The motor generator serves multiple functions: it acts as a motor for engine starting, as a generator for electrical power generation during engine defueling, and can provide power to accessories. This universal component replaces the traditional multi-component front-end accessory drive system, reducing overall system complexity.
3Use of energy by moving object
If the motor generator is coupled to the countershaft, then engine-off coasting with continuous electrical power is enabled, but additional components are added to the transmission system
Solution Approach 1:
The motor generator coupled to the countershaft serves multiple functions: enabling engine-off coasting by providing electrical generation during vehicle motion, providing engine starting capability, and powering accessories. This single multi-functional component enables fuel efficiency improvement without requiring multiple separate systems.
Solution Approach 2:
The motor generator acts as an intermediary between the transmission countershaft and the electrical system. By coupling to the countershaft, it converts mechanical energy from vehicle motion into electrical energy, enabling continuous electrical power supply during engine-off coasting without adding complex control systems.
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 enables engine-off coasting with continuous electrical power, improving fuel efficiency by up to three percent and reducing system weight and complexity by eliminating components like starters and alternators, while maintaining power to accessories.
Implementation Method 1
A motor generator can be coupled to a second countershaft of the transmission
Implementation Method 2
The master clutch includes a driving portion connected to the engine crankshaft and a driven portion coupled to the transmission input shaft and adapted to frictionally engage the driving portion between open and closed positions
Data Source
AI summary
A transmission system selectively coupled to an engine crankshaft of an internal combustion engine arranged on a vehicle includes a transmission, a motor generator, a master clutch and a controller. The transmission includes an input shaft, a mainshaft, an output shaft and a countershaft offset from the input shaft. The countershaft is drivably connected to the first input shaft and the mainshaft. The motor generator is selectively coupled to the countershaft. The master clutch includes a driving portion connected to the engine crankshaft and a driven portion coupled to the transmission input shaft and adapted to frictionally engage the driving portion between open and closed positions. The controller selectively operates the transmission system in a first operating mode that includes defueling the engine while the vehicle is moving based on vehicle operating conditions and routes rotational energy from the output shaft, through the countershaft and into the motor generator.