Two-Mass Flywheel Sealing via Inverted Membrane

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Solution Overview

Problem

Dual-mass flywheels are sensitive to dirt and moisture, making them difficult to produce and maintain effectively.

Innovation Solution

A dual-mass flywheel design with a sealing membrane attached to the input part facing the secondary flywheel mass, which is also connected to a friction ring, providing a welded connection and partial openings to prevent water and dirt ingress, along with a high-strength plastic axial friction ring and a sliding bearing with a low surface roughness to enhance durability and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sealing membrane is firmly attached to the output part by means of a riveted connection, then the sealing is secured, but the production becomes more complex and sensitive to dirt and moisture

Engineering Contradiction:
Improvesealing reliabilityVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing membrane is extracted from the output part and reattached to the input part, separating the sealing function from the rotating component. This eliminates the need for riveted connections on the output part and simplifies manufacturing while maintaining sealing reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing membrane acts as an intermediary element that is attached to the stationary input part rather than the rotating output part. This intermediary positioning allows sealing without requiring complex assembly of multiple components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the sealing membrane is attached to the output part, then sealing is provided, but the membrane is more exposed to water column and dirt ingress

Engineering Contradiction:
Improvesealing functionVSAvoidexposure to water and dirt
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Instead of attaching the sealing membrane to the output part (rotating side), the membrane is inverted and attached to the input part (stationary side). This reversal positions the sealing membrane in a more protected location that is less exposed to water column and dirt ingress while maintaining its sealing function.

Inventive Principle:
Principle #13The other way round (Inversion)

3Duration of action of stationary object

If a plastic friction ring is used in the bearing device, then wear is reduced and bearing life is increased, but axial bearing friction increases

Engineering Contradiction:
Improvebearing lifeVSAvoidaxial bearing friction
Core Design Contradiction:
Duration of action of stationary objectVSForce

Solution Approach 1:

A composite bearing structure is used combining a plastic friction ring made of high-strength material (such as PEEK) with a sliding bearing. This composite design reduces wear and extends bearing life while managing the trade-off of increased axial friction through the low-friction properties of the plastic material.

Inventive Principle:
Principle #40Composite materials

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 improves sealing efficiency, reduces wear, and increases bearing life, while maintaining torque transmission even in failure scenarios, with temperature-sensitive markings for operational monitoring.

Implementation Method 1

A sealing membrane (44) is provided in the channel (42) between the flange (40) and a part (36) of the input part (12) facing the secondary flywheel mass (38), which encapsulates the energy store (30) in a sealing manner

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

at least one energy store (30), in particular an arc spring (32)

Methodology Applied
Scientific EffectElastic energy storage: Elasticity

Implementation Method 3

the bearing device (22) has a sliding bearing (26) and an axial friction ring (54) made of a high-strength plastic material, in particular polyetheretherketone (PEEK)

Methodology Applied
Scientific EffectFriction reduction: Friction

Implementation Method 4

The integral connection between the sealing membrane and the part of the input part is in particular a welded connection

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2909501B1Two-mass flywheel and torque transmission device having a two-mass flywheel
Publication Date: 2019.12.11 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP2909501B1 patent drawingFigure 1
  • EP2909501B1 patent drawingFigure 2

AI summary

The invention relates to a two-mass flywheel comprising an input part having a primary flywheel mass, and an output part which is delimited with respect to said input part and rotatably mounted counter to the action of at least one energy store and which has a secondary flywheel mass, wherein the at least one energy store is comprised by the input part, forming a duct extending radially in the direction of the energy store, and a flange of the output part reaches through the duct as far as an end of the energy store, and wherein, in said duct, a sealing diaphragm which encapsulates the energy store in a sealing manner is provided between the flange and a part of the input part that faces a secondary flywheel mass. According to the invention the sealing diaphragm is connected integrally and/or in a form-fitting manner to the part of the input part that faces the secondary flywheel mass and is supported on a plastic friction ring fixed to the flange or directly on the flange. The invention further relates to a torque transmission device having such a two-mass flywheel.