Dual-Mass Flywheel Pre-Damper for Torsional Vibration and Noise
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Solution Overview
Problem
Existing torsional vibration dampers in motor vehicle drive trains fail to adequately address noise and vibration issues, particularly in hybrid applications, due to limitations in insulation and protection against overload and noise-related rattling.
Innovation Solution
Integration of a friction-free pre-damper with a characteristic curve having the flattest possible slope, positioned at a distance from the pendulum masses, which includes compression springs and friction rings to enhance insulation and protect against excessive torques, while being simple to construct and cost-effective.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a centrifugal pendulum is used to dampen torsional vibrations, then vibration isolation is improved, but the device becomes susceptible to overload and noise generation
Solution Approach 1:
The pre-damper is positioned to engage before the centrifugal pendulum masses reach their extreme positions during torsional vibrations. By providing preliminary damping action at lower torque levels, the pre-damper prevents the pendulum masses from experiencing overload conditions while also reducing the amplitude of vibrations that would generate noise.
Solution Approach 2:
The pre-damper acts as a cushioning element that absorbs and dampens torsional vibrations before they can transmit excessive forces to the centrifugal pendulum masses. This beforehand cushioning protects the pendulum mechanism from overload while maintaining effective vibration isolation.
2Reliability
If friction elements are added to protect against overload, then protection against excessive torque is improved, but noise generation increases
Solution Approach 1:
The pre-damper is designed with localized friction elements positioned only where needed for overload protection, rather than throughout the entire centrifugal pendulum mechanism. This localized approach provides torque protection while minimizing the generation of noise from friction.
Solution Approach 2:
The pre-damper serves as an intermediary element between the primary and secondary flywheel masses, providing friction-based overload protection without directly involving the centrifugal pendulum masses in the friction interaction. This mediation allows torque protection while keeping the pendulum mechanism quiet.
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 audible and noticeable vibrations, improving driving comfort by providing enhanced insulation and protection against noise and excessive torques, suitable for hybrid applications and series/parallel power-split hybrid applications.
Implementation Method 1
the pre-damper encloses a support flange guided between two spaced-apart side plates, which is positively connected to the side plates laterally associated with the support flange via circumferentially distributed compression springs
Implementation Method 2
each side plate of the pre-damper is assigned a friction ring. A first friction ring is positioned directly on the primary part, and a second friction ring is axially pre-tensioned and simultaneously guided radially by an associated disc spring on a primary part cover
Implementation Method 3
pendulum masses of a centrifugal pendulum are further attached in a manner movable on both sides
Implementation Method 4
a primary part and a secondary part which are rotatable about an axis of rotation and rotatable relative to each other and which are connected via a damping device enclosing arc springs
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a torsional vibration damper (1) in the form of a dual-mass flywheel having a primary part (2) and a secondary part (3) which are rotatable about a rotational axis and can be twisted relative to one another and which are connected via a damping device (4) that includes bent springs, wherein the bent springs are supported with one end on stops of the primary part (2) and with a further end on flange wings (7) of a support flange (5) associated with the secondary part (3), to which support flange pendulum masses (22) of a centrifugal pendulum absorber (25) are fastened and are arranged so as to be movable on either side, and the torsional vibration damper (1) includes, in a manner circumferentially spaced apart from the pendulum masses (22), a pre-damper (10) connected to the support flange (5).