Front-End Motor-Generator System for High-Torque Hybrid Engines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid electric vehicle systems face challenges in scaling up to handle high-torque outputs of large engines, particularly commercial vehicle diesel engines, due to engineering difficulties and inefficiencies in energy management, leading to increased weight, cost, and complexity, as well as limitations in independently meeting accessory power demands without auxiliary power units that are costly and hazardous.
Innovation Solution
A hybrid electric vehicle system with a front-end motor-generator arrangement that includes a switchable coupling and torque transfer segment, allowing for flexible torque exchange between the engine crankshaft and motor-generator, enabling independent operation of engine accessories and supplemental propulsion, while minimizing space and weight requirements, using a combination of batteries and supercapacitors for energy storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a belt-driven alternator and separate starter motor are used, then the engine can be started and electrical power can be generated, but the system weight and cost increase due to duplicate components
Solution Approach 1:
The patent combines the alternator and starter motor functions into a single integrated motor-generator unit. This unit can operate as a motor to start the engine and as a generator to produce electrical power, eliminating the need for separate components and reducing overall system weight.
Solution Approach 2:
The motor-generator unit is designed to perform multiple functions: it can operate as an electric motor for engine starting, as an electric generator for power generation, and can also provide torque assistance during vehicle operation. This multi-functionality replaces multiple single-purpose components.
2Ease of manufacture
If the starter-generator is mounted at the front end of the engine, then it can directly drive the belt coupled to the engine crankshaft, but the system becomes difficult to adapt to large engines due to high torque demands
Solution Approach 1:
The patent introduces a torque transfer segment (TTS) as an intermediary mechanism between the motor-generator and the engine crankshaft. The TTS includes a pulley system with variable ratio capability, allowing the motor-generator to operate at optimal torque levels while still providing sufficient force to the crankshaft, thereby making the system adaptable to large engines without requiring an oversized motor-generator.
Solution Approach 2:
The torque transfer segment incorporates a variable ratio pulley system that can dynamically adjust the torque multiplication ratio based on operating conditions. This allows the motor-generator to maintain optimal operating parameters across different engine sizes and load conditions, improving adaptability.
3Force
If thicker and broader drive belts and pulleys are used to handle high torque demands, then the torque capacity increases, but the weight, size, and cost become prohibitive
Solution Approach 1:
The variable ratio pulley system in the torque transfer segment allows the drive belts and pulleys to operate with optimized dimensions by dynamically adjusting the torque ratio. This eliminates the need for excessively large and heavy fixed-ratio components, as the system can achieve high torque capacity through mechanical advantage rather than component size.
4Use of energy by moving object
If hybrid electric systems are implemented, then fuel efficiency and emissions are improved, but the system complexity and cost increase
Solution Approach 1:
The motor-generator unit serves multiple functions including engine starting, electrical power generation, and torque assistance, eliminating the need for separate alternator, starter, and torque assist motor components. This multi-functionality reduces system complexity despite the advanced capabilities provided.
Solution Approach 2:
The patent merges the electrical power generation system with the engine starting system into a single motor-generator unit with integrated control. This consolidation simplifies the overall hybrid electric system architecture while maintaining the fuel efficiency and emissions benefits of hybrid operation.
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 solution enhances fuel efficiency, reduces emissions, and eliminates the need for heavy auxiliary power units by allowing the motor-generator to independently power accessories and provide supplemental propulsion, while maintaining vehicle performance and safety, thus addressing the inefficiencies and challenges of existing systems.
Implementation Method 1
a motor-generator (3) arranged in front of the engine
Implementation Method 2
an electrical energy storage system have been the focus of considerable attention
Data Source
AI summary
A system and method are provided for hybrid electric internal combustion engine applications in which a motor-generator, a narrow switchable coupling and a torque transfer unit therebetween are arranged and positioned in the constrained environment at the front of an engine in applications such as commercial vehicles, off-road vehicles and stationary engine installations. The motor-generator is preferably positioned laterally offset from the switchable coupling, which is co-axially-arranged with the front end of the engine crankshaft. The switchable coupling is an integrated unit in which a crankshaft vibration damper, an engine accessory drive pulley and a disengageable clutch overlap such that the axial depth of the clutch-pulley-damper unit is nearly the same as a conventional belt drive pulley and engine damper. The front end motor-generator system includes an electrical energy store that receives electrical energy generated by the motor-generator when the coupling is engaged. When the coupling is disengaged, the motor-generator may drive the pulley portion of the clutch-pulley-damper to drive the engine accessories using energy returned from the energy store, independent of the engine crankshaft.