Engine Balance System Counterweight Hinged Arms

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Solution Overview

Problem

Single cylinder internal combustion engines experience significant vibrations due to piston reciprocation, which are not fully mitigated by conventional counterweight systems, leading to operator discomfort, maintenance issues, and reduced machine lifespan.

Innovation Solution

A balance system is designed with a counterweight coupled to the crankcase via a pair of hinged arms, rather than a single hinged arm, to maintain identical positioning of connecting arms relative to eccentrics, reducing undesirable rotational movements and vibrations, and using a single counterweight with connecting arms made of lighter materials to simplify manufacturing and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single hinged arm is used to couple the counterweight to the crankcase, then the device complexity is reduced, but the manufacturing precision and positioning accuracy of the counterweight relative to the crankshaft deteriorates

Engineering Contradiction:

Improvenumber of hinged armsVSAvoidpositioning accuracy of connecting arms relative to eccentrics

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The single hinged arm connection is segmented into a pair of hinged arms (first and second hinged arms) that connect to opposite ends of the counterbalance weight. This segmentation allows each arm to independently maintain positioning accuracy while distributing the mechanical loads, thereby achieving both precise positioning and reduced complexity in the overall assembly process

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If crankshaft counterweights are designed to fully cancel piston acceleration forces, then the vibration along the piston axis is reduced, but lateral vibration increases due to centrifugal force components

Engineering Contradiction:

Improvevibration along piston axisVSAvoidlateral vibration

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

A counterbalance weight is introduced that operates in opposition to the piston's reciprocating motion. The counterbalance assembly is designed to generate forces that counteract the primary vibration along the piston axis caused by piston acceleration and deceleration, while the hinged arm mechanism controls the counterbalance's motion path to minimize lateral vibration generation

Inventive Principle:

Principle #8Anti-weight (Counterweight)

3Manufacturing precision

If the counterbalance weight is heavily constrained to prevent rotational movement, then positioning accuracy improves, but the ease of manufacture and assembly deteriorates

Engineering Contradiction:

Improvepositioning accuracy of counterbalance weightVSAvoidassembly complexity of hinged arms

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of rigidly constraining the counterbalance weight, the system uses dynamic hinged arm connections that allow controlled movement while maintaining positioning accuracy. The hinged arms provide the necessary constraints to prevent unwanted rotational movement while accommodating the natural dynamics of the counterbalance assembly during operation, simplifying manufacturing and assembly

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

The system effectively balances piston forces, minimizing vibrations and weight shifting, while being easier to manufacture and assemble, thereby enhancing engine stability and longevity.

Implementation Method 1

first and second hinged arms rotatably coupled proximate the first and second ends of the counterbalance weight, respectively

Methodology Applied

Scientific EffectHinge mechanism: Hinge

Implementation Method 2

at least one eccentric portion provided along the at least one shaft portion... rotating an eccentric portion supported by the crankshaft as the crankshaft rotates

Methodology Applied

Scientific EffectEccentric rotation: Eccentric

Implementation Method 3

the centrifugal force of such rotating crankshaft counterweights also has a component transverse to the piston axis that produces lateral vibration

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS9228633B2Engine balance system

Publication Date: 2016.01.05 DISCOVERY ENERGY LLC

AI summary

A balance system for implementation within an engine crankcase, as well as an engine employing such a system and a method of balancing forces as performed by such a system, are disclosed. In at least one embodiment, the balance system includes a crankshaft with at least one eccentric portion and a counterbalance assembly having at least one connecting arm and a counterbalance weight with first and second ends, where each of the at least one connecting arm includes a respective circular orifice that is positioned around and supported by a respective one of the at least one eccentric portion. The balance system further includes first and second hinged arms rotatably coupled proximate the first and second ends of the counterbalance weight, respectively, where the arms at least indirectly link the ends of the counterbalance weight to a portion of the engine crankcase and guide movement of the counterbalance weight.