Torque Converter Damper Inertia Segmentation Resonance

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Solution Overview

Problem

Existing power transmission devices, such as lock-up devices for torque converters, experience significant variation in rotation speed, particularly at low engine speeds, due to resonance issues, leading to inefficiencies and increased hysteresis torque.

Innovation Solution

The power transmission device incorporates a damper device with a float member and an inertia member that is rotatable relative to the float member, allowing the float member to slide against the first elastic member and preventing resonance, while also generating friction to inhibit speed variation, and includes a coil spring and inertia rings to reduce hysteresis torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If an inertia member is coupled to the intermediate member for coupling torsion springs, then variation in speed of rotation is inhibited, but the inertia member resonates with engine rotation speed variation causing large speed variation at low engine speeds

Engineering Contradiction:

Improvespeed variation inhibitionVSAvoidresonance at low speeds

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The inertia member is divided into a first inertia member coupled to the outer peripheral side torsion springs and a second inertia member coupled to the inner peripheral side torsion springs. This segmentation allows each inertia member to operate at different rotational speeds, preventing resonance while maintaining speed variation inhibition functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An intermediate member is introduced between the first and second inertia members. This intermediary component couples the two segmented inertia members while allowing them to rotate at different speeds, mediating their interaction to prevent resonance issues.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of energy

If a lock-up device is used to directly transmit torque from front cover to turbine, then fuel consumption is reduced, but variation in rotation speed is transmitted to the transmission

Engineering Contradiction:

Improvefuel consumptionVSAvoidrotation speed variation

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The lock-up device incorporates multiple inertia members that can rotate independently at different speeds, creating a dynamic system that absorbs speed variations. This dynamic configuration allows the device to maintain direct torque transmission while filtering out rotation speed variations through the differential rotation of segmented inertia members.

Inventive Principle:

Principle #15Dynamics

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 configuration effectively inhibits variation in rotation speed, especially at low engine speeds, and reduces hysteresis torque, enhancing the damper function and improving power transmission efficiency.

Implementation Method 1

The first elastic member couples the input-side rotary member and the output-side rotary member to enable relative rotation between the input-side rotary member and the output-side rotary member

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The float member is configured to slide against the first elastic member when rotated

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

The damper device is mounted to the float member and includes an inertia member that is rotatable relative to the float member

Methodology Applied

Scientific EffectInertia: Inertia

Data Source

PatentUS9915329B2Power transmission device and lock-up device for torque converter

Publication Date: 2018.03.13 EXEDY CORP

AI summary

The power transmission device transmits power from an engine to a transmission and includes an input-side rotary member, an output-side rotary member, a first elastic member, a float member and a damper device. The input-side rotary member receives the power inputted thereto from the engine. The output-side rotary member outputs the power to the transmission. The first elastic member couples the input-side rotary member and the output-side rotary member to enable relative rotation therebetween. The float member is rotatable relative to the input-side rotary member, the output-side rotary member and the first elastic member and is configured to slide against the first elastic member when rotated. The damper device is mounted to the float member and includes an inertia member that is rotatable relative to the float member.