ETM Crankshaft Starting Using Absolute Rotor Position Control
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Solution Overview
Problem
Existing internal combustion engine starting systems, particularly in small vehicles like snowmobiles, face challenges with weight, fuel efficiency, and handling due to the use of electric starting systems, which also require larger batteries and more complex assembly. Additionally, motor-generator units need to generate sufficient torque and manage voltage control effectively across varying rotational speeds.
Innovation Solution
A system and method utilizing an electric turning machine (ETM) connected to the crankshaft, with a sensor providing absolute angular position data to a controller, which calculates and delivers torque levels to efficiently start the engine using vector control, allowing for a smaller and lighter power source and optimizing engine starting sequence duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an electric starting system with battery and starter is used, then the engine can be started conveniently, but the vehicle weight increases and fuel efficiency decreases
Solution Approach 1:
The patent extracts the heavy battery and starter components from the vehicle's starting system, replacing them with a lighter alternative system that uses a spring-loaded mechanism to rotate the crankshaft, thereby maintaining ease of starting while significantly reducing vehicle weight
Solution Approach 2:
The patent replaces the electrical starting system (battery and starter motor) with a mechanical system using a spring-loaded mechanism that stores and releases energy to rotate the crankshaft, eliminating the need for heavy electrical components
2Device complexity
If a motor-generator unit is used to replace starter and generator, then device complexity is reduced, but the unit must be sufficiently large to provide adequate starting torque
Solution Approach 1:
The patent removes the motor-generator unit from the system entirely, replacing it with a purely mechanical spring-loaded starting mechanism that rotates the crankshaft without requiring an integrated motor-generator, thereby reducing both complexity and weight
Solution Approach 2:
The patent replaces the electromechanical motor-generator system with a purely mechanical spring-loaded mechanism that uses elastic potential energy to rotate the crankshaft, eliminating the need for complex electrical-mechanical integration
3Reliability
If high torque is provided to overcome compression during starting, then the engine can be started reliably, but the starting sequence duration increases
Solution Approach 1:
The patent employs a spring-loaded mechanism that rapidly releases stored elastic energy in a periodic impulse to rotate the crankshaft through the compression stroke, providing high torque momentarily to ensure reliable starting while minimizing the overall starting time
Solution Approach 2:
The patent pre-charges a spring mechanism before starting, storing elastic potential energy that is then rapidly released to provide the necessary torque to overcome compression, thereby ensuring reliable starting while reducing the actual starting sequence duration
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 solution enables a more efficient and lightweight electrical start procedure for internal combustion engines, improving fuel efficiency and handling by precisely controlling torque and voltage delivery, thus overcoming the limitations of traditional electric starting systems.
Implementation Method 1
an electric turning machine (ETM) operatively connected to the crankshaft... Electric power is delivered to the ETM to rotate the crankshaft
Data Source
AI summary
A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft comprises energizing an absolute position sensor adapted for providing an indication of an angular position of a rotor of the ETM and applying a current to the ETM to generate a sufficient torque to rotate the crankshaft.