Mechanical Variable Timing Device for Rocker Arm Pivot Adjustment

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Solution Overview

Problem

Existing internal combustion engine rocker arm systems lack a purely mechanical means to adjust the pivot point along a vertical axis independently of engine RPM, which limits variability in valve timing and lift optimization across different RPMs.

Innovation Solution

A mechanically operated variable timing device that includes a cam rotating independently of engine RPM, a plunger biased by a spring, and a pivot shaft threadably engaged to the engine block, allowing adjustment of the rocker arm pivot point vertically to optimize valve timing and lift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a hydraulic lash adjuster is used to adjust the rocker arm pivot point, then the pivot point can be adjusted, but the system becomes more complex and requires hydraulic components

Engineering Contradiction:

Improvepivot point adjustment capabilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces hydraulic components (hydraulic lash adjuster) with a purely mechanical system consisting of a cam, plunger, spring, and pivot shaft to adjust the rocker arm pivot point. This substitution eliminates the need for hydraulic fluid, seals, and pumps while achieving the same pivot point adjustment function through mechanical means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and eliminates the hydraulic lash adjuster component from the valve train system, removing the complexity associated with hydraulic components while retaining the essential function of pivot point adjustment through a simplified mechanical arrangement.

Inventive Principle:

Principle #2Taking out (Extraction)

2Productivity

If the rocker arm pivot point is fixed, then the system is simpler, but valve timing and lift cannot be optimized across different RPMs

Engineering Contradiction:

Improveengine performance optimizationVSAvoidtiming adjustment mechanism

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent transforms the fixed pivot point into a dynamic, adjustable pivot point that can change position vertically along the pivot shaft. This is achieved through a cam that rotates independent of engine RPM, actuating a plunger that moves the pivot point to optimize valve timing and lift for different operating conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The cam is positioned and configured in advance to provide the necessary pivot point adjustments for different RPM ranges. The cam profile and plunger arrangement are pre-designed to automatically adjust the pivot point to optimal positions before the engine operates at specific RPM ranges, enabling performance optimization without complex real-time control.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If a cam rotating independent of engine RPM is used to adjust the pivot point, then valve timing can be optimized at different RPMs, but the device complexity increases

Engineering Contradiction:

Improvevariable timing capabilityVSAvoidindependent cam mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cam mechanism serves multiple functions: it adjusts the rocker arm pivot point vertically, controls valve timing, and optimizes valve lift across different RPM ranges. This multi-functionality is achieved within a compact arrangement that integrates the cam, plunger, spring, and pivot shaft into a unified system that replaces what would otherwise require multiple separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables independent adjustment of rocker arm pivot point to optimize valve timing and lift at various RPMs using a purely mechanical system with minimal components, enhancing engine performance and efficiency.

Implementation Method 1

The plunger is biased upwardly via a spring positioned between the ball fulcrum of the rocker arm and a bottom portion of the plunger

Methodology Applied

Scientific EffectSpring force: Spring

Data Source

PatentUS8763572B1Mechanical variable timing device that adjusts the pivot point at which a rocker arm pivots

Publication Date: 2014.07.01 DIKE ANTHONY

AI summary

The mechanically operable variable timing device for use with a rocker arm pivot point that is able to adjust the valve timing and lift on a valve stem by adjusting the pivot point of the rocker arm. The mechanically operated variable timing device includes a cam that rotates independent of engine RPM in order to adjust the pivot point of the rocker arm, which in turn adjusts the lift and valve timing of the engine at any RPM. The mechanically operated variable timing device places the cam above a plunger, which is positioned over the respective rocker arm. The plunger is biased upwardly via a spring positioned between the ball fulcrum of the rocker arm and a bottom portion of the plunger. A pivot shaft is threadably engaged to a threaded hole located on a top surface of the engine block.