Labyrinth-Sealed Filtering Pulley for Torsional Vibration Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filtering pulleys face issues with relative rotation between the crown and hub, dust and debris ingress causing noise and reduced lifespan, and ineffective damping of torsional vibrations in internal combustion engines.
Innovation Solution
A filtering pulley design featuring a hub, annular crown, elastic groups, actuator, and a dust protection lip with an L-shaped bush and labyrinthine dust protection system to manage relative rotation, prevent debris ingress, and absorb axial loads, while using a dynamic damper for torsional vibration damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a filtering pulley is used to reduce torsional vibrations, then vibration damping is improved, but relative rotation between crown and hub increases causing noise and reduced lifespan
Solution Approach 1:
A dust protection lip is introduced as an intermediary element between the crown and hub. This lip prevents direct contact and relative rotation between the crown and hub surfaces, eliminating the source of noise and wear while preserving the vibration damping function of the elastic groups.
Solution Approach 2:
The harmful relative rotation between crown and hub is extracted and eliminated from the system. The dust protection lip effectively separates the crown and hub, preventing the harmful interaction while maintaining the necessary torque transmission through the elastic groups.
2Power
If the crown and hub are allowed to rotate relative to each other for torque transmission, then torque transmission is improved, but dust and debris ingress causes noise and reduced lifespan
Solution Approach 1:
The dust protection lip acts as a protective intermediary that blocks dust and debris from entering the interface between crown and hub. It allows the necessary relative rotation for torque transmission while preventing contaminant ingress that would cause noise and wear.
Solution Approach 2:
The dust protection lip provides preliminary protection by preventing dust and debris from reaching the crown-hub interface before contamination can occur. This proactive protection eliminates the harmful effects of particle ingress on torque transmission surfaces.
3Stability of the object's composition
If elastic groups are used to transmit torque from hub to crown, then vibration filtering is improved, but overrunning moments between crown and hub increase
Solution Approach 1:
The dust protection lip serves as a mediator that reduces the direct impact of overrunning moments between crown and hub. By preventing direct surface contact, it diminishes the harmful effects of these moments while allowing the elastic groups to continue filtering torsional vibrations.
4Ease of manufacture
If a simple filtering pulley design is used, then manufacturing cost is reduced, but dust protection and contamination prevention are insufficient
Solution Approach 1:
The dust protection lip is a simple intermediary element that can be easily manufactured and integrated into the existing filtering pulley design. It provides effective contamination prevention without significantly increasing manufacturing complexity or cost.
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 design effectively reduces noise, extends pulley lifespan by preventing contamination, and enhances damping of torsional vibrations, ensuring smooth operation and increased durability.
Implementation Method 1
one or more elastic groups arranged circumferentially in the chamber 15, each group comprising at least one spring (31) mounted between the projections (16)
Implementation Method 2
The dust protection lip (50) comprises a central portion (50a), a lower radial lip (50c) and an upper radial lip (50b) respectively shaped for extending axially beyond the central portion (50a) and radially above with respect to the same
Implementation Method 3
The actuator (35) can be placed in contact with the elastic groups (30), possibly with a circumferential interference value so as to preload the elastic groups (30) inside the seat (15)
Data Source
AI summary
Filtering pullies with a hub adapted to be fixed to a rotating shaft, a crown mounted coaxially and rotationally free on the hub, at least one elastic group arranged circumferentially with respect to the hub and the crown and interposed, each, between a pair of first elements integral with the hub and between a pair of second elements integral with the crown are disclosed. The pulley has a dust protection lip carried integrally by said hub and configured to slide, in tight manner, with respect to an element integral with said crown. The dust protection lip is a labyrinthine sealing lip.