Flywheel Arrangement with Interlocking Device for Engine Start-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual-mass flywheels in internal combustion engines face high torsional vibration levels during start-up due to natural frequency matching engine excitation frequencies below 400 rpm, potentially causing damage and noise issues.
Innovation Solution
A flywheel arrangement with a starter motor pinion gear in constant engagement with a crank gear via a one-way clutch, featuring an interlocking device that raises the torsional natural frequency during engine start-up by locking the flywheel bodies together and releasing them once rotational motion occurs, preventing relative rotation and reducing vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a one-way clutch is used to transmit torque from starter motor to crankshaft, then torque transmission in one direction is improved, but impact noise from clutch engagement is generated
Solution Approach 1:
The pinion gear acts as an intermediary between the starter motor and the one-way clutch. By engaging the pinion with the flywheel teeth before the clutch engages, the system gradually transfers torque and reduces impact noise. The pinion gear meshing provides a smooth transition, mediating the engagement process to minimize shock and noise while maintaining effective torque transmission capability.
2Object-generated harmful factors
If the two flywheels are allowed to move relative to each other to reduce vibrations, then vibration damping is improved, but during start-up resonance they may move in opposite directions and cause damage when springs become solid
Solution Approach 1:
The system dynamically adjusts the degree of freedom between the two flywheel masses based on operating conditions. During start-up resonance, the relative motion is controlled and limited, preventing the springs from becoming solid while still providing some vibration damping. During normal operation, the system allows greater relative motion for optimal vibration reduction, thus protecting structural integrity while maintaining damping performance.
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
Effectively reduces torsional vibrations during engine start-up by preventing resonance and minimizing damage, while maintaining smooth operation and noise reduction.
Implementation Method 1
a one-way clutch unit which transmits torque from the crank wheel to a crankshaft during start-up of the engine and prevents reverse torque transmission
Implementation Method 2
interconnected by a compliant member such as a spring damper system to lower the level of torsional vibrations
Implementation Method 3
spring damper system to lower the level of torsional vibrations generated by a firing internal combustion engine
Implementation Method 4
the centrifugal force generated by the latching pins and plungers will exceed the spring force from the radially oriented springs. This will force the latching pins to slide radially outward out of their respective latching slots
Implementation Method 5
If the engine RPMs are below a predetermined level, then the spring force from the radially oriented springs will exceed the centrifugal force generated by the latching pins and plungers
Data Source
Figure 1
AI summary
The present invention relates to a flywheel arrangement for an internal combustion engine comprising a starter motor (1) having a pinion gear (2) at an output shaft. The pinion gear (2) constantly engages a corresponding crank gear of a crank wheel (3) located between an engine block and a flywheel assembly (9) of the engine. The crank wheel (3) is operatively connected to a crankshaft (4) of the engine via a one-way clutch unit (5). The flywheel assembly (9) comprises a first flywheel body (6) connected to the crankshaft (4) of the engine. A second flywheel body (7) is rotatable relative to the first flywheel body (6) and coupled thereto such that is able to move elastically through a limited angular distance relative to the first flywheel body (6). An interlocking device includes at least one locking arrangement (8) and is adapted to produce an interlocking connection between the second flywheel body (7) and the first flywheel body (6) during cranking of the internal combustion engine.