Filtering Pulley Interference Preload for Quiet Torque Transmission

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Solution Overview

Problem

Existing filtering pulleys for internal combustion engine crankshafts suffer from noise, energy loss, and reduced lifespan due to vibrations and wear caused by the impact of actuator elements on elastic components.

Innovation Solution

A filtering pulley design featuring a hub connected to a shaft, an annular crown with integral radial walls and elastic groups, and an actuator with circumferential interference to preload the elastic groups, reducing noise and wear by enhancing damping and preventing axial movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If traditional filtering pulley design with actuator elements and elastic elements is used, then torsional oscillations are filtered, but noise is generated due to impact between components

Engineering Contradiction:

Improvetorsional oscillation filteringVSAvoidnoise

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The actuator element is preloaded against the elastic elements before torsional oscillations occur, establishing initial contact and eliminating gaps. This preliminary action prevents impact noise by ensuring smooth engagement when oscillations begin, while still allowing the elastic elements to function as intended for filtering torsional vibrations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The elastic elements serve as an intermediary between the actuator element and the drive shaft, providing a compliant interface that reduces impact forces. The elastomeric material absorbs shock and distributes loads smoothly, mediating the interaction between rigid components to minimize noise generation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If actuator elements impact elastic elements during operation, then torque is transmitted, but energy is lost and wear increases

Engineering Contradiction:

Improvetorque transmissionVSAvoidenergy loss

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The actuator element is preloaded against the elastic elements before torque transmission begins, establishing continuous contact. This eliminates impact losses by ensuring smooth engagement, allowing torque to be transmitted through gradual deformation of the elastomeric material rather than through repetitive impact events.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The elastomeric material properties are selected to optimize the balance between torque transmission capability and energy loss. By controlling the hardness, elasticity, and damping characteristics of the elastomeric material, the system achieves efficient torque transmission while minimizing energy dissipation through controlled deformation rather than impact.

Inventive Principle:

Principle #35Parameter changes

3Power

If actuator elements repeatedly impact elastic elements, then torque transmission occurs, but component lifespan decreases

Engineering Contradiction:

Improvetorque transmissionVSAvoidpulley lifespan

Core Design Contradiction:

PowerVSDuration of action of stationary object

Solution Approach 1:

The actuator element is preloaded against the elastic elements before operation begins, establishing continuous contact and eliminating impact events. This preliminary engagement ensures that torque transmission occurs through smooth, controlled deformation of the elastomeric material, significantly reducing mechanical stress and wear on both the actuator and elastic elements, thereby extending component lifespan.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The elastomeric material provides beforehand cushioning by being pre-compressed between the actuator element and the drive shaft. This cushioning effect absorbs and distributes impact forces before they can cause damage, protecting the actuator and elastic elements from wear during torque transmission cycles and extending the operational life of the filtering pulley.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 solution effectively reduces noise, wear, and energy loss by increasing damping and preventing axial movements, thereby extending the pulley's lifespan and improving operational efficiency.

Implementation Method 1

at least one elastic group (30) arranged free in the chamber (15) and in contact with the actuator (35), wherein the actuator (35) is in contact with the elastic groups (30) with a circumferential interference value (beta) so as to preload the elastic groups (30) inside the chamber (15)

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

one or more damping elements (19) arranged between the hub (2) and the crown (3)

Methodology Applied

Scientific EffectVibration damping: Damping

Data Source

PatentUS12173781B2Filtering pulley

Publication Date: 2024.12.24 MUVIQ SRL

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 at least one elastic group is placed with a circumferential interference (β) with respect to the first elements integral with said hub.