Centrifugal Pendulum Spring Coupling for Vibration Damping
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Solution Overview
Problem
Centrifugal pendulums with pendulums coupled in the circumferential direction by spring elements exhibit phase-shifted vibrations, which can lead to noise and instability during engine startup and shutdown.
Innovation Solution
A centrifugal pendulum design that incorporates a rotatable pendulum carrier with spring elements between adjacent pendulums, where the spring rate and pendulum mass are adjusted to account for gravity, ensuring a predefined excitation order and reduced phase-shifted vibrations by configuring the pendulum masses and spring rates based on the radius from the axis of rotation and gravitational acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spring elements are arranged between adjacent pendulums to couple them elastically, then pendulum synchronization is improved and pendulums are prevented from falling out of bearings, but phase-shifted vibration occurs between pendulums
Solution Approach 1:
The patent applies parameter changes by carefully selecting and adjusting the spring rate of the spring elements to account for gravitational forces. The spring rate is specifically configured to compensate for gravity-induced phase shifts, thereby maintaining pendulum synchronization while eliminating harmful vibrations. This parameter optimization resolves the contradiction by tuning the elastic coupling characteristics to counteract gravitational effects.
Solution Approach 2:
The patent employs an anti-weight principle by configuring the spring elements to counteract gravitational forces acting on the pendulums. The spring rate is designed to provide a compensating force that balances the gravity-induced phase shifts, effectively using the spring coupling to counterweight the harmful gravitational effect and maintain synchronized pendulum motion.
2Stability of the object's composition
If spring elements with predefined spring rate are used to couple pendulums, then pendulums are synchronized elastically, but phase-shifted vibration occurs particularly at low rotational speeds
Solution Approach 1:
The patent applies parameter changes by selecting spring rates that are specifically optimized for low rotational speed conditions. The spring element parameters are chosen to provide adequate coupling strength at low speeds where gravity has the most significant effect, thereby maintaining synchronization stability while preventing phase-shifted vibrations during engine startup, shutdown, and idle operation.
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
Significantly reduces phase-shifted vibrations and enhances vibration insulation in drivetrains by synchronizing pendulum motion with the engine's excitation order, particularly at low rotational speeds and during engine startup/shutdown.
Implementation Method 1
a spring element, which acts in the circumferential direction, with a predefined spring rate is provided in each case between two adjacent pendulums
Implementation Method 2
pendulums are deflected in the centrifugal force field of the rotating pendulum carrier depending on torque non-uniformity with respect to the pendulum carrier on predefined pendulum paths
Implementation Method 3
taking into account gravity acting on the pendulums... As a result of the phase-shifted positioning of the pendulums on the rotating pendulum carrier with respect to the axis of rotation and thus a phase-shifted action of gravity on the pendulums
Data Source
AI summary
A centrifugal pendulum includes a pendulum carrier arranged rotatably about an axis of rotation and a plurality of pendulums distributed over a circumference of the pendulum carrier. The plurality of pendulums are received on the pendulum carrier so as to be able to move along pendulum paths with a predefined pendulum mass. A spring element acting in a circumferential direction, and with a predefined spring rate, is provided between two adjacent pendulums in the circumferential direction. The pendulums and the spring elements are adjusted to a predefined excitation order taking into account the gravity acting on the pendulums.