Dual-Engine Driveline Phase Control for Torsional Vibration
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Solution Overview
Problem
Conventional driveline arrangements experience unwanted noise and gear wear due to torsional vibrations from internal combustion engines, particularly in unloaded gears.
Innovation Solution
A driveline arrangement with two internal combustion engines, where the combustion stages are controlled to occur at different crank angle degrees, using a control unit to adjust the crank angle of one engine relative to the other, thereby reducing torsional vibrations and noise. The control unit, which may include a microprocessor or programmable logic device, adjusts the combustion timing to minimize vibration levels by acquiring data from a database and feedback from vibration sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single internal combustion engine is used in the driveline arrangement, then the device complexity is reduced, but torsional vibrations cause unwanted noise and gear wear in unloaded gears
Solution Approach 1:
The driveline arrangement is segmented into two separate internal combustion engines instead of using a single engine. Each engine has its own combustion cycle and crankshaft, allowing independent control of combustion timing. This segmentation enables the torsional vibrations from each engine to be desynchronized, preventing them from adding up constructively and causing excessive noise and gear wear.
Solution Approach 2:
The combustion process in each engine operates periodically, and by controlling the combustion stages to occur at different crank angle degrees, the periodic torsional vibrations are phased differently. This periodic action with phase difference ensures that when one engine produces peak torsional vibration, the other is at a different point in its cycle, reducing the overall vibration amplitude transmitted to the transmission arrangement.
2Object-generated harmful factors
If two internal combustion engines are used simultaneously, then torsional vibrations are reduced through phase difference, but the device complexity increases
Solution Approach 1:
The crank angle degree parameter for combustion timing is changed for each engine. By adjusting the combustion stage timing of each engine to occur at different crank angle degrees, the torsional vibrations are phase-shifted. This parameter change in combustion timing allows the system to reduce noise and vibration while managing the complexity of having two engines through optimized operational parameters.
3Ease of operation
If combustion stages are synchronized in time, then the control system is simpler, but unloaded gears experience increased rattle and wear
Solution Approach 1:
The combustion process in each engine operates periodically, and by controlling the combustion stages to occur at different crank angle degrees, the periodic torsional vibrations are phased differently. This periodic action with phase difference ensures that when one engine produces peak torsional vibration, the other is at a different point in its cycle, reducing the overall vibration amplitude transmitted to the transmission arrangement.
Solution Approach 2:
The crank angle degree parameter for combustion timing is changed for each engine. By adjusting the combustion stage timing of each engine to occur at different crank angle degrees, the torsional vibrations are phase-shifted. This parameter change in combustion timing allows the system to reduce noise and vibration while managing the complexity of having two engines through optimized operational parameters.
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 approach effectively reduces unwanted noise and wear in transmission arrangements by minimizing torsional vibrations, allowing for efficient operation of driveline systems with two internal combustion engines.
Implementation Method 1
a first internal combustion engine comprising a first combustion cylinder housing a first reciprocating piston connected to a first crank shaft, wherein the first internal combustion engine is configured to assume a combustion stage in which a combustible gas is combusted in the first combustion cylinder
Implementation Method 2
The rattle is generated by the torsional vibrations generated by the internal combustion engine
Data Source
AI summary
A driveline arrangement, comprising a first internal combustion engine, a second internal combustion engine, and a transmission arrangement comprising a first input shaft drivingly connected to a first crank shaft of the first internal combustion engine, and a second input shaft drivingly connected to the second crank shaft of the second internal combustion engine, the transmission arrangement being configured to simultaneously receive a torque from the first and second crank shafts. Further, control circuitry of a control unit is configured to control the first internal combustion engine to assume a combustion stage at a different point in time compared to the point in time at which the second internal combustion engine assumes its combustion stage by adjusting a crank angle degree of the first crank shaft.