Front-End Motor-Generator 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 output engines, particularly commercial 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, which pose safety hazards and inefficiencies.
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
1Weight of stationary object
If starter-generators are mounted at the front end of the engine, then weight and cost are reduced, but the system becomes difficult to adapt to large commercial vehicle diesel engines due to high torque demands
Solution Approach 1:
The system separates the starter and generator functions into distinct operational modes. The motor-generator can operate independently as a starter for engine starting, and as a generator for accessory power and electrical energy generation, without requiring a single oversized unit that handles all torque demands simultaneously.
Solution Approach 2:
The motor-generator is designed to perform multiple functions: engine starting, accessory power supply, regenerative braking, and electrical energy generation. This multi-functional design eliminates the need for separate starter and alternator components, reducing overall system weight while maintaining compatibility with large commercial vehicle engines through flexible torque management.
2Force
If belt drive systems are enlarged to handle high torque demands, then torque capacity is increased, but the system becomes weight, size and cost prohibitive
Solution Approach 1:
The system replaces the traditional mechanical belt-driven alternator with an electric motor-generator that can be directly coupled to the engine or drivetrain. This substitution eliminates the need for large, heavy belt drive components while providing sufficient torque capacity through electrical power generation and storage systems.
3Power
If auxiliary power units are used to meet accessory power demands, then power availability is improved, but safety hazards and system complexity increase
Solution Approach 1:
The system merges the power generation, energy storage, and accessory power supply functions into a single integrated motor-generator system. The motor-generator charges energy storage devices that independently power accessories, eliminating the need for separate auxiliary power units and reducing overall system complexity while improving safety.
4Force
If motor-generator is integrated into the rear of the engine, then torque delivery to driveline is improved, but the system increases weight and complexity
Solution Approach 1:
The system places the motor-generator at the front end of the engine where it can directly drive accessories and generate electrical energy without requiring integration into the rear drivetrain. This localized positioning provides sufficient torque for accessory power while using energy storage devices to decouple the motor-generator weight from the main vehicle weight.
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) positioned in front of the engine, with the motor-generator (3) being arranged in a manner that requires little or no extension of the length of the front of the vehicle
Implementation Method 2
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
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.