Torsional Vibration Damper Corner Geometry for Low Sliding Resistance

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Solution Overview

Problem

Existing torsional vibration dampers experience reduced vibration damping performance due to sliding resistance between the flange portions of the rolling mass and the rotary member, which can hinder the reciprocating motion and lead to collision noise and abrasion.

Innovation Solution

The rolling mass is designed with a first corner having a curvature radius of 0.2 mm to 2.0 mm and a flange portion that is isolated from the rotary member by an axial thrust force, preventing contact and sliding resistance through a configuration that allows smooth oscillation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the flange portion is brought into contact with the rotary member to prevent detachment, then the rolling mass is secured in position, but sliding resistance acts between the flange portion and rotary member which hinders reciprocating motion and reduces vibration damping performance

Engineering Contradiction:
Improveprevention of detachmentVSAvoidsliding resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The first corner of the rolling mass is formed with a curved surface having a specific curvature radius (0.2mm to 2.0mm). This curvature allows the rolling mass to smoothly engage with the second corner of the rotary member during oscillation, preventing detachment while minimizing sliding resistance through rolling contact geometry.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention specifies a particular curvature radius range (0.2mm to 2.0mm) for the first corner to optimize the balance between preventing detachment and reducing sliding resistance. This parameter optimization ensures the rolling mass maintains reliable contact without excessive friction during reciprocating motion.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the rolling mass is constrained to prevent detachment from the chamber, then positional stability is improved, but reciprocating motion may be hindered by sliding resistance

Engineering Contradiction:
Improvepositional stabilityVSAvoidreciprocating motion
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The curved surface at the first corner with optimized curvature radius enables the rolling mass to maintain stable positioning within the chamber while facilitating smooth reciprocating motion. The curvature geometry allows the mass to navigate the corner region without excessive friction or binding.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Manufacturing precision

If the curvature radius of the first corner is too small, then the rolling mass fits tightly in the bore, but contact and sliding resistance occur; if the curvature radius is too large, then the rolling mass does not contact the rotary member sufficiently for effective damping

Engineering Contradiction:
Improvefit in boreVSAvoidsliding resistance
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The invention defines a specific curvature radius range (0.2mm to 2.0mm) for the first corner that optimizes the balance between achieving proper fit in the bore and minimizing sliding resistance. This parameter specification ensures effective vibration damping while maintaining smooth reciprocating motion.

Inventive Principle:
Principle #35Parameter changes

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 ensures effective vibration damping performance by preventing contact between the rolling mass and rotary member, reducing sliding resistance, and minimizing damage and noise generation.

Implementation Method 1

A rotary member 18 which is rotated by a torque, a bore 20 which is formed on the rotary member 18, and a rolling mass 19 which is oscillated along a raceway surface 21 of the bore 20 by a rotation of the rotary member 18

Methodology Applied
Scientific EffectTorsional vibration: Vibration

Implementation Method 2

the rolling mass has an H-shaped cross-section, and a first flange portion and a second flange portion of the rolling body have different configurations

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

The first corner includes a first curved surface and a curvature radius of the first curved surface (33) falls within a range from 0.2 mm to 2.0 mm. The second corner includes a chamfered portion or a second curved surface. The first corner includes an opposing point that is to be opposed to the radially outer corner of the rotary member in an axial direction when the rolling mass is oscillated along a raceway surface of the bore. An axial length between a starting point of the first corner and the opposing point in the rolling mass is longer than an axial length of the second corner in the rotary member

Methodology Applied
Scientific EffectContact force: Force

Data Source

PatentEP3396200B1Torsional vibration damper
Publication Date: 2026.04.08 TOYOTA JIDOSHA KK
  • EP3396200B1 patent drawingFigure 1
  • EP3396200B1 patent drawingFigure 2
  • EP3396200B1 patent drawingFigure 3

AI summary

A torsional vibration damper (1) in which vibration damping performance is ensured by preventing a contact between a rolling mass and a rotary member. A rolling mass (19) includes a trunk (26) penetrating through a bore (20). A first corner (32) formed in an axial end of the trunk (26) is rounded. A rotary member (18) includes a second corner (35) formed in the bore (29). an axial length (B) of the first corner (32) of the rolling mass (19) is longer than an axial length (A) of the second corner (35) of the rotary member (18).