Variable-Inertia Tilger for Wide-Range Torsional Vibration Damping
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Solution Overview
Problem
Existing vehicle torque converters with pendulum dampers are expensive and generate noise, while known tilgers are tuned to a single natural frequency, failing to effectively absorb torsional vibrations at high engine speeds, which can damage transmission systems.
Innovation Solution
A tilger apparatus with an annular body and springs configured to change natural frequency based on rotational speed, using detachable rings that expand and contract to adjust inertia, improving damping performance across a wide range of engine speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single natural frequency tilger is used, then it can effectively absorb torsional vibrations at that specific frequency, but it fails to effectively absorb torsional vibrations at high engine speeds
Solution Approach 1:
The patent applies the dynamics principle by making the inertia mass variable rather than fixed. The inertia ring is designed to expand and contract based on rotational speed, changing the natural frequency of the tilger dynamically. At low speeds, the ring contracts to increase inertia for low-frequency damping; at high speeds, the ring expands to decrease inertia for high-frequency damping, allowing effective vibration absorption across the entire engine speed range.
Solution Approach 2:
The patent implements parameter changes by modifying the physical state of the inertia ring. The ring transitions between contracted and expanded states, fundamentally changing the inertia parameter of the system. This parameter change is triggered by centrifugal force at different rotational speeds, automatically adjusting the tilger's natural frequency to match the operating conditions.
2Reliability
If pendulum dampers are used in torque converters, then they can provide damping function, but they generate noise and are expensive
Solution Approach 1:
The patent replaces expensive pendulum dampers with a simpler, more cost-effective tilger design. The tilger uses basic mechanical components (springs, inertia ring, annular body) that are cheaper to manufacture and maintain. While pendulum dampers provide damping, they generate noise and cost more; the tilger achieves comparable or superior damping performance without these drawbacks.
3Reliability
If the ring expands at high rotational speed, then the total inertia applied to the spring decreases improving high-speed damping, but the ring must disconnect from the annular body
Solution Approach 1:
The inertia ring's expansion and contraction is driven by centrifugal force generated during rotation itself. The system uses its own operational energy (rotational speed) to automatically adjust the ring's state. At low speeds, the ring naturally contracts; at high speeds, centrifugal force causes it to expand and disconnect from the annular body, eliminating the need for external control mechanisms or complex engagement systems.
Solution Approach 2:
The engagement and disengagement of the ring with the annular body is dynamic rather than static. The ring automatically transitions between engaged and disengaged states based on rotational speed thresholds, allowing the system to adapt its inertia characteristics dynamically to match operating conditions without complex control systems.
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 tilger apparatus effectively absorbs torsional vibrations and sudden rotational movements across a wide range of engine speeds, reducing wear on transmission systems and eliminating noise, while being cost-effective.
Implementation Method 1
a spring interposed between the first annular body and the rotatable portion. Rotation of the rotatable portion relative to the annular body is to compress and decompress the spring
Implementation Method 2
a ring positioned on an outer surface of the annular body and configured to expand as a rotational speed of the ring increases to decrease a total inertia of the annular body and the ring applied to the spring
Implementation Method 3
The tilger apparatus effectively absorbs torsional vibrations and sudden rotational movements across a wide range of engine speeds
Implementation Method 4
A tilger apparatus with an annular body and springs configured to change natural frequency based on rotational speed
Data Source
AI summary
A tilger for a rotating body includes an annular body movably coupled to a rotatable portion of the rotating body. The tilger includes a spring interposed between the first annular body and the rotatable portion. Rotation of the rotatable portion relative to the annular body is to compress and decompress the spring. The tilger includes a ring positioned on an outer surface of the annular body and configured to expand as a rotational speed of the ring increases to decrease a total inertia of the annular body and the ring applied to the spring.