Crankshaft Pendulum Absorbers Reduce Vibration Friction
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Solution Overview
Problem
Crankshaft flexing and vibration limit engine speed and increase engine vibration, leading to decreased power output, fuel economy, and increased friction losses, weight, and cost due to the need for additional main bearing journals.
Innovation Solution
Incorporating an unsupported axially-aligned shaft section with pendulum absorbers, including blades and pendulous counterweights, to enhance mass balancing and stiffness, reducing noise, vibration, and harshness (NVH) while allowing for adaptability across various engine configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a large number of main bearing journals are added to support the crankshaft, then crankshaft flexing and vibration are reduced, but engine friction losses increase
Solution Approach 1:
The patent extracts the vibration reduction function from the main bearing journals and relocates it to dedicated pendulum absorbers. This separation allows the bearing journals to be reduced in number (lowering friction) while the pendulum absorbers handle the vibration control independently.
Solution Approach 2:
The patent employs dynamic pendulum absorbers that move relative to the crankshaft to actively counterbalance vibrations. These absorbers use dynamic motion (pendulum movement) to generate counteracting forces, rather than relying solely on static structural support from multiple bearing journals.
2Stability of the object's composition
If a large number of main bearing journals are added to support the crankshaft, then crankshaft flexing and vibration are reduced, but engine power output decreases
Solution Approach 1:
The patent extracts the vibration reduction function from the main bearing journals and relocates it to dedicated pendulum absorbers. This separation allows the bearing journals to be reduced in number (lowering friction) while the pendulum absorbers handle the vibration control independently.
Solution Approach 2:
The patent employs dynamic pendulum absorbers that move relative to the crankshaft to actively counterbalance vibrations. These absorbers use dynamic motion (pendulum movement) to generate counteracting forces, rather than relying solely on static structural support from multiple bearing journals.
3Stability of the object's composition
If a large number of main bearing journals are added to support the crankshaft, then crankshaft flexing and vibration are reduced, but engine weight increases
Solution Approach 1:
The patent extracts the vibration reduction function from the main bearing journals and relocates it to dedicated pendulum absorbers. This separation allows the bearing journals to be reduced in number (lowering friction) while the pendulum absorbers handle the vibration control independently.
Solution Approach 2:
The patent employs dynamic pendulum absorbers that move relative to the crankshaft to actively counterbalance vibrations. These absorbers use dynamic motion (pendulum movement) to generate counteracting forces, rather than relying solely on static structural support from multiple bearing journals.
4Stability of the object's composition
If a large number of main bearing journals are added to support the crankshaft, then crankshaft flexing and vibration are reduced, but manufacturing cost increases
Solution Approach 1:
The patent extracts the vibration reduction function from the main bearing journals and relocates it to dedicated pendulum absorbers. This separation allows the bearing journals to be reduced in number (lowering friction) while the pendulum absorbers handle the vibration control independently.
Solution Approach 2:
The patent employs dynamic pendulum absorbers that move relative to the crankshaft to actively counterbalance vibrations. These absorbers use dynamic motion (pendulum movement) to generate counteracting forces, rather than relying solely on static structural support from multiple bearing journals.
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 reduces engine vibrations, increases crankshaft longevity, and decreases friction losses, thereby enhancing power output, fuel efficiency, and customer satisfaction while maintaining engine adaptability and reducing manufacturing costs.
Implementation Method 1
a pendulum absorber coupled to the unsupported axially-aligned shaft section, the pendulum absorber including a blade extending from the unsupported axially-aligned shaft section and a pendulous counterweight coupled to the blade
Implementation Method 2
a pendulum absorber coupled to the unsupported axially-aligned shaft section, the pendulum absorber including a blade extending from the unsupported axially-aligned shaft section and a pendulous counterweight coupled to the blade
Implementation Method 3
The pendulum absorbers provide mass balancing to the crankshaft as well as increase the stiffness of the crankshaft in unsupported areas
Data Source
AI summary
A crankshaft is provided. The crankshaft includes an unsupported axially-aligned shaft section interposing an outer main bearing journal and an inner main bearing journal, the unsupported axially-aligned shaft section having a central axis aligned with a rotational axis of the crankshaft, and a pendulum absorber coupled to the unsupported axially-aligned shaft section, the pendulum absorber including a blade extending from the unsupported axially-aligned shaft section and a pendulous counterweight coupled to the blade.