Fixed-Vessel Hydrodynamic Launch Coupling for Low Rotational Inertia

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Solution Overview

Problem

Conventional torque converters have high primary rotational inertia due to their mass and direct connection to the driving elements of the powertrain, which negatively affects the efficiency of the powertrain system and fuel economy.

Innovation Solution

A launch device with a fixed, non-rotating containment vessel replaces the conventional rotating shell, featuring a driving element and a driven element within the vessel, along with a stator supported by the vessel, and selectable clutches for direct drive and bypassing the hydraulic circuit, reducing primary inertia and eliminating ballooning effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional rotating shell is used in the torque converter, then the structural strength and ballooning resistance are improved, but the primary rotational inertia increases

Engineering Contradiction:

Improveshell strengthVSAvoidprimary rotational inertia

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent divides the traditional integrated rotating shell into separate components: a stationary containment vessel and independent rotating elements (impeller, turbine, stator). This segmentation allows the heavy shell structure to remain stationary while only the necessary rotating components move, significantly reducing primary rotational inertia while maintaining structural strength through the stationary vessel.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent inverts the conventional design by making the containment vessel stationary rather than rotating. Traditionally, the shell rotates with the impeller, but this patent fixes the shell to the transmission case and allows only the internal hydrodynamic components to rotate, thereby eliminating the shell's contribution to primary rotational inertia.

Inventive Principle:

Principle #13The other way round (Inversion)

2Stability of the object's composition

If a thick steel shell is used to mitigate ballooning effects, then the structural stability is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:

Improveballooning resistanceVSAvoidmanufacturing complexity

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent separates the ballooning resistance function from the rotating components and assigns it to the stationary containment vessel. This allows the vessel to be designed specifically for structural stability without the constraints of rotating component design, simplifying manufacturing while effectively mitigating ballooning effects through proper stationary structure design.

Inventive Principle:

Principle #1Segmentation

3Power

If the shell is directly connected to the prime mover output, then the torque transfer efficiency is improved, but the primary inertia resistance to rotational acceleration increases

Engineering Contradiction:

Improvetorque transfer efficiencyVSAvoidresistance to rotational acceleration

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

The patent segments the torque transfer path into a stationary containment vessel and separate rotating hydrodynamic components. The stationary vessel provides the structural connection to the prime mover while the lightweight rotating components (impeller, turbine, stator) perform the actual torque multiplication, reducing the mass that must be accelerated while maintaining effective torque transfer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a stationary containment vessel as an intermediary between the prime mover and the rotating hydrodynamic components. This intermediary provides the necessary structural connection and torque transfer path while allowing the rotating components to be lightweight, thus reducing primary inertia resistance without compromising torque transfer efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 decreases primary inertia, enhancing fuel economy and powertrain efficiency, allowing for increased packaging density and reduced energy losses, while enabling efficient torque transfer and direct drive modes.

Implementation Method 1

Rotation of the impeller directs a hydrodynamic fluid outward and toward a turbine, where the force imparted on the turbine by the fluid rotationally drives the turbine

Methodology Applied

Scientific EffectHydrodynamic fluid flow:

Implementation Method 2

A stator, positioned between the turbine and the impeller, further redirects the fluid to efficiently transfer the fluid back to the impeller, thereby multiplying the torque being transferred

Methodology Applied

Scientific EffectHydrodynamic torque multiplication:

Data Source

PatentUS12253147B2Low inertia hydrodynamic launch device

Publication Date: 2025.03.18 EXEDY GLOBALPARTS CORP

AI summary

A launch device for coupling the rotary output of a prime mover to the rotary input of a driven device. The launch device includes a containment vessel defining a chamber. A driving element, located within the chamber and being rotatable relative to the containment vessel, is configured to be coupled to the output of the prime mover, while a driven element, also located within the chamber and being rotatable relative to the containment vessel, is configured to be coupled to the input of the driven device. The driven element is fluidically coupled to the driving element and is rotationally driven thereby during rotation of the driving element by the prime mover.