Pendulum Damper Sprocket for Engine Timing Chain Vibration
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Solution Overview
Problem
Engine timing chain assemblies experience undesirable torque variation and vibration due to oscillations from multi-cylinder engines, leading to premature wear and improper operation.
Innovation Solution
A damper assembly incorporating pendulum masses and connection elements within sprockets, allowing for radial and circumferential displacement, to attenuate torque variation and chain vibration by engaging a continuous chain or belt with radially outward protrusions and strategically placed openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional timing chain assembly is used, then the structure is simple, but torque variation and chain vibration occur due to engine oscillations
Solution Approach 1:
The patent applies the dynamics principle by introducing pendulum masses that can move dynamically within the sprocket assembly. These pendulum masses oscillate in response to engine vibrations and torque variations, actively counterbalancing the harmful oscillations. The connection elements allow the pendulum masses to move radially and circumferentially, creating a dynamic response system that adapts to varying engine conditions rather than using fixed static components.
Solution Approach 2:
The patent implements the anti-weight principle by using pendulum masses positioned on opposite radial sides of the sprocket. These masses act as counterweights that generate opposing forces to balance the torque variations and vibrations caused by multi-cylinder engine oscillations. The gravitational force and inertial forces of the pendulum masses create counteracting moments that reduce the net vibration transmitted through the timing chain.
2Reliability
If pendulum masses are added to reduce vibration, then torque variation is attenuated, but the device complexity increases
Solution Approach 1:
The patent applies the merging principle by integrating the pendulum masses and connection elements directly into the sprocket assembly as a unified structure. Rather than adding separate vibration damping devices, the pendulum mechanism is combined with the existing sprocket components, allowing the timing chain to engage with both the sprocket teeth and the pendulum masses. This integration reduces the number of separate components and simplifies the overall assembly process.
Solution Approach 2:
The patent implements the universality principle by designing the pendulum assembly to serve multiple functions simultaneously. The pendulum masses not only reduce vibration and torque variation but also maintain chain tension and guide the chain movement. The connection elements serve both to attach the pendulum masses to the sprocket and to allow their dynamic movement. This multi-functionality reduces the need for additional dedicated vibration damping components.
3Ease of manufacture
If openings are created in the sprocket for connection elements, then pendulum masses can be integrated, but manufacturing complexity increases
Solution Approach 1:
The patent applies the segmentation principle by dividing the sprocket into functional zones: the main sprocket body with teeth for chain engagement, and integrated openings that accommodate the connection elements. The pendulum assembly is segmented into the pendulum masses, connection elements, and the openings in the sprocket, allowing each component to be manufactured separately and then assembled together. This segmentation enables flexible manufacturing approaches and reduces the complexity of creating precision openings in a fully integrated sprocket.
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 effectively reduces undesirable torque variation and chain vibration, extending the lifespan of engine timing chain assembly components by dampening angular oscillations associated with second, third, and fourth order oscillations in four, six, and eight cylinder engines.
Implementation Method 1
at least one pendulum mass assembly including: a first pendulum mass disposed on a first radial side of the first sprocket; second pendulum mass disposed on a second radial side, opposite the first radial side, of the first sprocket
Implementation Method 2
The solution effectively reduces undesirable torque variation and chain vibration, extending the lifespan of engine timing chain assembly components by dampening angular oscillations
Data Source
AI summary
A chain or belt drive assembly, including: a first sprocket with: a first plurality of radially outwardly extending protrusions; and at least one opening passing through material forming the sprocket and wholly surrounded by the material forming the first sprocket; and a second sprocket including a second plurality of radially outwardly extending protrusions, The assembly includes a continuous chain or belt engaged with the first and second pluralities of protrusions; and at least one pendulum mass assembly including: a first pendulum mass disposed on a first radial side of the first sprocket; second pendulum mass disposed on a second radial side, opposite the first radial side, of the first sprocket; and at least one connection element fixedly secured to the first and second pendulum masses and passing through the at least one opening. The connection element is displaceable within the at least one opening in radial and circumferential directions.