Crankshaft Pendulum Assembly With Segmented Friction Damping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing crankshaft assemblies with centrifugal pendulums face challenges of increased installation space and weight, as well as potential weakening of the crankshaft due to the attachment of these pendulums, which negatively impact functionality, strength, manufacturability, and costs.

Innovation Solution

A crankshaft assembly design featuring a centrifugal pendulum directly secured to the crankshaft segment, with a carrier and pendulum mass moving along a predetermined track, incorporating a friction device that applies counteracting torque to improve vibration isolation, and a segmented friction device that only covers the required peripheral section to minimize additional contact surfaces and weight, allowing the pendulum to act as both a vibration absorber and imbalance compensator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a centrifugal pendulum is attached to the crankshaft to absorb natural vibrations, then vibration absorption is improved, but the overall weight of the crankshaft increases

Engineering Contradiction:

Improvevibration absorptionVSAvoidoverall weight of the crankshaft

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The centrifugal pendulum is nested within an existing recess of the crankshaft segment, utilizing the available space efficiently. The pendulum assembly is positioned within the recess to minimize additional space requirements and reduce the overall weight increase by leveraging the existing structural void.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The friction device is designed to extend over a peripheral section of less than 360 degrees, applying frictional torque only in the specific region where it is required for vibration absorption. This localized approach reduces the amount of frictional material needed, thereby reducing the overall weight while maintaining effective vibration control.

Inventive Principle:

Principle #3Local quality

2Reliability

If a centrifugal pendulum is attached to the crankshaft to absorb natural vibrations, then vibration absorption is improved, but additional installation space is required

Engineering Contradiction:

Improvevibration absorptionVSAvoidinstallation space

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The pendulum mass moves along a predetermined three-dimensional track that combines radial and circumferential components. This spatial utilization allows the pendulum to achieve effective vibration absorption while occupying minimal installation space by utilizing the depth and circumference of the recess rather than requiring additional external volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If a centrifugal pendulum is attached to the crankshaft to absorb natural vibrations, then vibration absorption is improved, but the crankshaft is weakened

Engineering Contradiction:

Improvevibration absorptionVSAvoidcrankshaft strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The recess for the centrifugal pendulum is designed and prepared in advance during crankshaft manufacturing, with predetermined geometry and positioning. The connection features are pre-formed to ensure optimal load distribution and minimal stress concentration, thereby maintaining crankshaft strength while enabling vibration absorption functionality.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The connection between the centrifugal pendulum and the crankshaft segment utilizes composite construction techniques, combining different materials with complementary properties. The friction device and connection elements are designed to distribute stresses evenly, preventing localized weakening while maintaining the structural integrity of the crankshaft.

Inventive Principle:

Principle #40Composite materials

4Reliability

If a friction device is added to apply frictional torque on the pendulum mass, then vibration isolation is improved, but the device complexity increases

Engineering Contradiction:

Improvevibration isolationVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The friction device is designed to extend over a peripheral section of less than 360 degrees, applying frictional torque only in the specific region where it is required for vibration absorption. This localized approach simplifies the overall device structure by eliminating unnecessary friction surfaces while maintaining effective vibration isolation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The friction device is segmented into discrete components that can be independently manufactured and assembled. This modular approach reduces manufacturing complexity and allows for easier installation and maintenance while achieving the required vibration isolation performance through distributed friction contact.

Inventive Principle:

Principle #1Segmentation

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

This design achieves efficient vibration absorption and imbalance compensation without increasing the crankshaft's weight or weakening it, while reducing manufacturing costs by utilizing existing space and material, thus maintaining the crankshaft's functionality and strength.

Implementation Method 1

a friction device, in particular non-rotatably secured to the carrier, which rests against the at least one pendulum mass in such a way that when the pendulum mass moves relative to the carrier, the friction device applies a frictional torque counteracting the relative movement to the pendulum mass

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

The centrifugal pendulum serves to absorb the natural vibration of the crankshaft. Torsional vibrations/rotation of the crankshaft can therefore be eliminated by the centrifugal pendulum

Methodology Applied

Scientific EffectVibration absorption: Vibration

Implementation Method 3

at least one pendulum mass that moves relative to the carrier along a predetermined track. In order to fulfill the resonance condition for compensating for torsional vibrations, the track preferably has sections in the circumferential direction and in the radial direction

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS12104671B2Crankshaft assembly with a centrifugal pendulum attached to the crankshaft

Publication Date: 2024.10.01 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A crankshaft assembly for a motor vehicle drive train, including a crankshaft segment and a centrifugal pendulum secured thereon, 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 friction unit connected to the carrier, which rests on the at least one pendulum mass such that, with a relative movement of the pendulum mass in relation to the carrier, the friction unit applies a frictional torque on the pendulum mass counteracting the relative movement, wherein the friction unit extends over a peripheral section of less than 360°.