Torque-Actuated VCR Phaser Using Lead Screw Compression Control

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Solution Overview

Problem

Existing variable compression ratio (VCR) engines require high-power actuators like electric motors or hydraulic pumps to vary compression ratios, which increase complexity and cost, and do not efficiently utilize existing torque oscillations in the 6-bar linkage mechanism.

Innovation Solution

A torque-activated VCR phaser that converts torque into linear force using a helical lead screw and spline connector, allowing the control shaft to phase relative to the crankshaft, thereby varying the compression ratio without the need for high-power actuators, utilizing existing energy in the linkage mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If high-power actuators (electric motors or hydraulic pumps) are used to vary compression ratio, then compression ratio control capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvecompression ratio control capabilityVSAvoidactuator system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses the engine's own torque oscillations to drive the compression ratio variation. The torque from the crankshaft directly actuates the phaser mechanism through the torque conversion mechanism, eliminating the need for external high-power actuators. The engine's natural torque fluctuations become the driving force for VCR control.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces electrical/hydraulic actuator systems with a purely mechanical torque conversion mechanism. The helical lead screw and spline connector convert torque directly into linear motion to adjust the phaser, substituting complex electro-hydraulic systems with simpler mechanical components.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If high-power actuators are used to vary compression ratio, then compression ratio control capability is improved, but cost increases

Engineering Contradiction:

Improvecompression ratio control capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent employs simpler, more cost-effective mechanical components (helical lead screw, spline connector, spring stack) instead of expensive electric motors or hydraulic pumps. These mechanical components are easier to manufacture and maintain, reducing overall system cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

By utilizing the engine's existing torque output, the system eliminates the need to purchase and install costly external actuators, reducing both initial manufacturing cost and ongoing maintenance expenses.

Inventive Principle:

Principle #25Self-service

3Use of energy by moving object

If torque oscillations are utilized through torque conversion mechanism, then energy efficiency is improved, but device complexity increases

Engineering Contradiction:

Improveenergy utilization efficiencyVSAvoidtorque conversion mechanism complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent converts what could be considered wasted energy (torque oscillations) into useful work for varying compression ratio. The torque conversion mechanism captures these oscillations and transforms them into controlled linear motion, turning a potentially harmful or useless energy form into a beneficial control mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The helical lead screw and spline connector act as intermediary mechanisms that bridge the torque input from the crankshaft and the linear motion output needed for phaser adjustment. This intermediary mechanism efficiently transfers and transforms energy while maintaining system simplicity.

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

This solution reduces complexity and cost by eliminating the need for high-power actuators, enabling quick compression ratio changes by leveraging torque oscillations, improving efficiency and power utilization in VCR engines.

Implementation Method 1

the first shaft on which the control shaft gear comprises a helical lead screw at a distal end of the first shaft

Methodology Applied

Scientific EffectHelical lead screw mechanism: Screw

Implementation Method 2

the torque conversion mechanism further comprises a spring stack configured to be compressed by the spline connector

Methodology Applied

Scientific EffectSpring compression and expansion: Spring

Data Source

PatentUS11280263B2Torque-actuated variable compression ratio phaser

Publication Date: 2022.03.22 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A variable compression ratio (VCR) phaser configured to control a compression ratio of an engine having a crankshaft and a control shaft. The variable compress ratio phaser comprises: i) a control shaft gear configured to mesh with a gear on the control shaft of the engine and to receive torque from the control shaft; ii) a crankshaft gear configured to mesh with a gear on the crankshaft of the engine and to deliver torque to the crankshaft; and iii) a torque conversion mechanism configured to receive torque from the control shaft and to convert the torque to a linear force that changes the compression ratio of the engine.