Slider-Crank Engine Balancing for Higher-Order Vibration Elimination

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Solution Overview

Problem

Existing engine balancing systems fail to effectively eliminate second-order and higher-order vibrations caused by the reciprocating motion of pistons, which can lead to engine damage and operator discomfort, as they only conditionally balance first-order inertial forces.

Innovation Solution

The implementation of an engine balancing system with at least two slider-crank mechanisms, where the ratio of their lengths and accelerations are carefully controlled to ensure that the inertial forces of the piston assembly and counterweight are balanced, with phase angles differing by 180°±15°, and the counterweight is connected through auxiliary rods to minimize inertial forces on the engine body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If multiple counterweights are added to balance higher-order vibrations, then vibration elimination improves, but device complexity increases

Engineering Contradiction:

Improvevibration elimination effectivenessVSAvoidnumber of counterweights and connecting mechanisms

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges multiple balancing functions into a unified counterweight system where the first, second, and third counterweights are all connected to the same crankshaft through slider-crank mechanisms. This integration allows simultaneous balancing of first-order, second-order, and higher-order vibrations through a coordinated system rather than separate independent mechanisms, thereby reducing overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The crankshaft serves as a universal driving element that simultaneously drives all three counterweights through different slider-crank mechanisms. This multi-functional design allows a single component (crankshaft) to perform multiple balancing functions, reducing the need for separate driving mechanisms for each counterweight and thereby simplifying the overall system.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If counterweights are designed with complex motion trajectories to eliminate higher-order vibrations, then balancing performance improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improvebalancing performanceVSAvoidtrajectory accuracy and phase angle control

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent replaces complex mechanical trajectory control with a simplified slider-crank mechanism that naturally generates the required motion patterns. The geometric parameters of the slider-crank mechanisms (crank lengths, connecting rod lengths) are designed to automatically produce the correct phase relationships and motion trajectories for vibration balancing, eliminating the need for complex mechanical guidance systems and reducing manufacturing precision requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent achieves different motion trajectories and phase relationships by changing the geometric parameters of the slider-crank mechanisms rather than using complex mechanical constraints. By adjusting crank lengths, connecting rod lengths, and initial phase angles, the system generates the required motion patterns for balancing different vibration orders, thereby simplifying the mechanical design and reducing manufacturing precision requirements.

Inventive Principle:

Principle #35Parameter changes

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 thoroughly eliminates first-order, second-order, and higher-order vibrations, reducing equipment damage and improving user experience by ensuring balanced inertial forces and minimizing stress on the engine body, while also reducing the engine's overall size and enhancing its service life.

Implementation Method 1

the first-order inertial forces generated from the reciprocating motion of the piston

Methodology Applied

Scientific EffectInertial force: Inertia

Implementation Method 2

a guide rail interconnected to one of the counterweight and the crankcase housing; and a slot that is formed in the other one of the counterbalance weight and the crankcase housing and receives at least a part of the guide rail so that the guide rail guides the counterweight during the reciprocating motion of the counterweight

Methodology Applied

Scientific EffectMechanical guidance:

Data Source

PatentUS11466615B2Engine balancing system

Publication Date: 2022.10.11 CHONGQING ZONGSHEN GENERAL POWER MACHINE

AI summary

An engine balancing system includes an engine body. At least two slider-crank mechanisms are provided inside the engine body. One of the slider-crank mechanisms is arranged opposite to the other slider-crank mechanism. A slider in one of the slider-crank mechanisms is moved at a speed and acceleration similar to a speed and acceleration of a slider in the other slider-crank mechanism. The slider-crank mechanism includes a connecting rod and a crankshaft with a crank. One end of one of the slider-crank mechanisms and one end of the other slider-crank mechanism are connected to the same crankshaft through the crank. The balancing system can effectively eliminate first-order, second-order and higher-order vibrations generated during engine operation, thus reducing the probability of equipment damage.