Pendulum Rocker Damper Preload Design for Roller Contact Stability
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Solution Overview
Problem
Pendulum rocker dampers in drive trains experience issues with rollers lifting off or sliding due to dynamic effects, leading to noise and increased wear, particularly at low torque levels, and external excitation can cause vibrations that modulate contact forces, resulting in undesirable noise and vibration harshness.
Innovation Solution
Incorporating a second energy storage element that exerts a perpendicular preload force on the rollers, ensuring they remain in contact and preventing sliding, while also adjusting the natural frequency of the system to avoid resonance, using components like helical compression springs and spring plates to maintain contact and minimize rattling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pendulum rocker damper is used to modulate stiffness in a drive train, then the transmission ratio can be adjusted and vibration damping is improved, but rollers may lift off or slide during operation causing noise and increased wear
Solution Approach 1:
A second energy storage element (preload spring) is introduced to exert a preliminary counteracting force on the rollers, preventing them from lifting off during operation. This preload force acts in opposition to the dynamic forces that would otherwise cause roller separation, eliminating the harmful lifting and sliding motions that generate noise and wear.
2Adaptability or versatility
If the pitch of the ramp mechanism is variably adjusted to change transmission ratio, then stiffness adjustment is improved, but play occurs at minimal angle of rotation causing rattling noise
Solution Approach 1:
The preload spring applies a preliminary force to maintain constant contact between rollers and roller conveyors even at minimal angles of rotation. This preliminary action ensures that no play or gaps develop in the mechanism, preventing the rattling noise that would otherwise occur during variable stiffness adjustment.
3Ease of operation
If rollers are prestressed against roller tracks by the first energy storage element, then transmission ratio adjustment is enabled, but dynamic effects at low torque levels cause rollers to lift off
Solution Approach 1:
Two different energy storage elements are used with different local functions: the first energy storage element (main spring) provides the primary prestressing force for transmission ratio adjustment, while the second energy storage element (preload spring) provides a localized counteracting force specifically at the roller contact points to prevent lifting during dynamic operation at low torque levels.
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
Prevents roller lifting and sliding, reduces noise and wear, and shifts natural frequencies out of the critical range, ensuring robust operation under dynamic conditions, thereby enhancing the performance and durability of the pendulum rocker damper.
Implementation Method 1
at least one first energy storage element for exerting a first preload force
Implementation Method 2
The at least one roller is pre-tensioned against the roller tracks by means of the at least one first energy storage element
Implementation Method 3
at least one second energy storage element is provided in the roller or in at least one of the roller tracks for exerting a second pre-tensioning force
Implementation Method 4
by means of the second pre-tensioning force the roller is pre-tensioned perpendicular to the track against at least one of the roller tracks
Implementation Method 5
the at least one roller is mounted so as to roll on a rocker-side roller track and an outer roller track complementary to the rocker-side roller track
Implementation Method 6
This pendulum rocker damper converts the relative angle of rotation between the input and output sides into a spring deflection of the energy storage elements
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a pendulum rocker damper (1) with an axis of rotation (2) for a drive train (3), comprising at least the following components: a primary side (4) that is torque-transmittingly connected to a first outer connection (6); at least one rocker element (8); at least one first energy storage element (9) for exerting a first pretensioning force (10); at least one roller (11, 12); and a secondary side (5) that is torque-transmittingly connected to a second outer connection (7), wherein the at least one roller (11, 12) is mounted such that it can roll on a rocker-side roller track (13) and a outer roller track (14) that is complementary to the rocker-side roller track (13), and same can be pretensioned against the roller tracks (13, 14) using the first pretensioning force (10) of the at least one first energy storage element (9). The pendulum rocker damper (1) is primarily characterised in that at least one second energy storage element (15) is provided in the roller (11, 12) or in at least one of the roller tracks (13, 14) for exerting a second pretensioning force (16), wherein the roller (11, 12) is pretensioned against at least one of the roller tracks (13, 14), perpendicular to the track, at least in the resting position of the first energy storage element (9), using the second pretensioning force (16). Using the pendulum rocker element according to the invention, interfering noise can be reduced and a sliding of a roller can be safely prevented by shifting the natural frequency into non-critical ranges.