Belt Pulley Decoupler Hub Balancing for Spring-End Imbalance
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Solution Overview
Problem
Belt pulley decouplers with helical torsion springs face imbalance issues due to ground spring ends, leading to increased vibration and loads on generator bearings, especially at high speeds.
Innovation Solution
The hub is designed with an imbalance that compensates for the spring imbalance, ensuring the combined imbalance vectors are smaller than the spring imbalance alone, thereby reducing the overall imbalance of the belt pulley decoupler through strategically shaped spring plates and axial spring supports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spring ends are ground to ensure proper torque transmission, then the torque transmission capability is improved, but the imbalance of the helical torsion spring increases leading to higher vibration and bearing loads
Solution Approach 1:
The patent applies the counterweight principle by designing the hub with an intentional imbalance that acts as a counterbalancing mass. The hub imbalance vector is specifically designed to oppose and compensate for the spring imbalance vector, thereby reducing the overall imbalance of the decoupler assembly while maintaining the grinding of spring ends for proper torque transmission
Solution Approach 2:
The patent applies local quality by creating a non-uniform mass distribution specifically in the hub region. The hub is designed with varying density or mass distribution in specific areas to generate the required imbalance vector that compensates for the spring imbalance, while other parts of the assembly maintain their standard properties
2Stability of the object's composition
If the helical torsion spring is used to compensate torsional vibrations, then the vibration compensation capability is improved, but the ground spring ends create an imbalance that increases generator bearing loads
Solution Approach 1:
The hub imbalance serves as a counterbalancing mechanism that offsets the harmful forces generated by the ground spring ends. By carefully designing the hub mass distribution, the patent reduces the net imbalance force transmitted to the generator bearings while preserving the spring's torsional vibration compensation function
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 design significantly improves vibration behavior and reduces loads on generator bearings, particularly at high speeds, by balancing the belt pulley decoupler and minimizing the imbalance, thus enhancing operational efficiency.
Implementation Method 1
the decoupling effect of the helical torsion spring, which, depending on the design of the belt pulley decoupler, elastically transfers the torque from the belt pulley to the hub and/or from the hub to the belt pulley
Implementation Method 2
the hub should have an imbalance which compensates for an imbalance of the helical torsion spring resulting from the ground portion of the spring ends
Data Source
AI summary
The disclosure relates to a belt pulley decoupler for transmitting torque between the belt of a belt drive and a shaft in driving connection therewith. The belt pulley decoupler includes: a hub fastened to the shaft, a belt pulley rotatably mounted on the hub, a helical torsion spring arranged in a torque flow path between the belt pulley and the hub, a first spring plate extending in the torque flow path on a side of the belt pulley, and a second spring plate rotationally fixed to the hub.The hub has an imbalance which compensates for an imbalance of the helical torsion spring resulting from a ground portion of the spring ends in such a way that the following relationship applies for the spring imbalance {right arrow over (U)}s and the hub imbalance {right arrow over (U)}b:|{right arrow over (U)}s+{right arrow over (U)}b|<|{right arrow over (U)}s|