Crankshaft Pendulum Assembly With Rupture Containment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing crankshaft assemblies with centrifugal pendulums face challenges in space efficiency, weight, and potential weakening of the crankshaft due to additional installation requirements and increased weight, which affect functionality, strength, manufacturability, and costs.
Innovation Solution
A crankshaft assembly design that incorporates a centrifugal pendulum directly attached to the crankshaft segment, utilizing a carrier with pendulum masses moving along a predetermined track to absorb natural frequency vibrations, with a rupture containment means and a friction device to enhance vibration isolation and prevent component loss, while maintaining structural integrity and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a centrifugal pendulum is attached to the crankshaft to absorb natural frequency vibrations, then vibration absorption is improved, but the overall weight of the crankshaft increases
Solution Approach 1:
The centrifugal pendulum is nested within a rupture containment means (catcher) that is integrated with the crankshaft segment. The carrier is secured to the crankshaft segment, and the rupture containment means engages radially externally around the centrifugal pendulum, creating a compact nested structure that reduces overall weight while maintaining vibration absorption functionality.
Solution Approach 2:
The rupture containment means is merged with the crankshaft segment by securing it directly to the crankshaft segment. This integration combines the vibration protection function with the structural support function, eliminating the need for separate components and reducing overall weight.
2Reliability
If a centrifugal pendulum is attached to the crankshaft to absorb natural frequency vibrations, then vibration absorption is improved, but additional installation space is required
Solution Approach 1:
The centrifugal pendulum is nested within the rupture containment means, which is itself integrated with the crankshaft segment. This nested arrangement allows the centrifugal pendulum to occupy space within the existing crankshaft structure rather than requiring additional external installation space.
Solution Approach 2:
The rupture containment means engages radially externally around the centrifugal pendulum, utilizing the radial dimension of the crankshaft structure. This radial engagement allows compact integration without increasing the axial or circumferential footprint of the crankshaft assembly.
3Reliability
If a centrifugal pendulum is attached to the crankshaft to absorb natural frequency vibrations, then vibration absorption is improved, but the crankshaft strength is weakened
Solution Approach 1:
The rupture containment means is pre-designed and pre-positioned on the crankshaft segment before the centrifugal pendulum is attached. This preliminary arrangement ensures that the attachment points and mounting structure are optimized for strength, allowing the centrifugal pendulum to be secured without compromising crankshaft integrity.
Solution Approach 2:
The carrier acts as an intermediary component between the centrifugal pendulum and the crankshaft segment. The carrier is secured to the crankshaft segment and provides a dedicated mounting interface that distributes loads and protects the crankshaft structure from direct stress, maintaining crankshaft strength while enabling vibration absorption.
4Reliability
If a rupture containment means is added to catch loose components from the centrifugal pendulum, then component protection is improved, but device complexity increases
Solution Approach 1:
The rupture containment means is merged with the crankshaft segment by securing it directly to the crankshaft segment. This integration combines the vibration protection function with the structural support function, eliminating the need for separate components and reducing overall complexity.
Solution Approach 2:
The rupture containment means serves multiple functions: it provides structural support for the centrifugal pendulum, contains loose components during operation, and protects surrounding components from damage. This multi-functionality reduces the need for additional specialized components, simplifying the overall device.
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 achieves efficient vibration absorption, reduces the overall weight of the crankshaft assembly, prevents component damage, and maintains the structural integrity and cost-effectiveness of the crankshaft, by effectively compensating for torsional vibrations and imbalance without increasing the crankshaft's mass.
Implementation Method 1
a centrifugal pendulum which is fastened, in particular directly, to the crankshaft segment... at least one pendulum mass that moves relative to the carrier along a predetermined track... the centrifugal pendulum serves to absorb the natural frequency vibration of the crankshaft
Implementation Method 2
the centrifugal pendulum is tuned to higher orders of vibration... to fulfill the resonance condition for compensating for torsional vibrations
Implementation Method 3
the rupture containment means... engages radially externally around the centrifugal pendulum such that components of the centrifugal pendulum that come loose when the centrifugal pendulum rotates are caught and/or braked by the rupture containment means... form a barrier for components flying outwards due to the centrifugal force
Implementation Method 4
the friction device applies to the pendulum mass a frictional moment counteracting the relative movement when the pendulum mass moves relative to the carrier... the additional friction, which acts on the relative movement/vibrating movement of the centrifugal pendulum, improves isolation of the natural frequency vibration of the crankshaft
Data Source
AI summary
A crankshaft assembly for a motor vehicle drive train includes a crankshaft segment and a centrifugal pendulum secured to same, which has a carrier secured to the crankshaft segment and at least one pendulum mass that moves relative to the carrier along a predetermined track. The crankshaft assembly has a rupture containment means, which engages radially externally around the centrifugal pendulum such that components of the centrifugal pendulum coming lose during rotation of the centrifugal pendulum are collected by the rupture containment means.