Link Type Variable Stroke Engine Counterweight Balancing
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Solution Overview
Problem
Link type variable stroke engines experience half-order rotational inertial forces at the eccentric shaft, which are not effectively suppressed by conventional balancers, leading to uncomfortable vibrations, noise, and reduced engine component strength.
Innovation Solution
The engine incorporates counterweight parts that rotate with the rotary shaft, with their centers of gravity positioned on the opposite side of the rotary shaft's axis from the eccentric shaft's axis, effectively opposing the direction of half-order inertial forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a link type variable stroke engine uses an eccentric shaft rotated at a speed reduction ratio of 1/2 from the crankshaft, then variable stroke control is achieved, but half-order rotational inertial force occurs at the eccentric shaft causing uncomfortable vibration and noise
Solution Approach 1:
The patent introduces counterweight parts that rotate with the rotary shaft, positioned so their centers of gravity are located on the opposite side of the rotary shaft's axis from the eccentric shaft's axis. These counterweight parts generate inertial forces that oppose and balance the half-order rotational inertial force produced by the eccentric shaft, thereby reducing vibration and noise while maintaining variable stroke control capability
2Reliability
If conventional integer order balancers are used in the link type variable stroke engine, then first order and second order vibrations are suppressed, but half-order inertial exciting force remains ineffective and excessive vibration occurs
Solution Approach 1:
The patent changes the balancing approach by introducing counterweight parts specifically designed to address half-order rotational inertial force, rather than relying on conventional integer order balancers. The counterweight parts are positioned and dimensioned to generate opposing inertial forces at the correct frequency (half-order), fundamentally changing the balancing parameters to match the unique vibration characteristics of the variable stroke mechanism
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 configuration significantly reduces and suppresses half-order inertial exciting forces at the eccentric shaft, improving operational comfort and reducing vibration-induced noise and component stress.
Implementation Method 1
a counterweight part is provided so that in a projection view on a plane orthogonal to the axis of the rotary shaft, a center of gravity of the counterweight part is located on an opposite side of the axis of the rotary shaft from an axis of the eccentric shaft, and rotates together with the rotary shaft
Data Source
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AI summary
In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, a counterweight part (64) which is provided so that in a projection view on a plane orthogonal to an axis of a rotary shaft, a center of gravity (G1) of the counterweight part is located on an opposite side of the axis of the rotary shaft from an axis of the eccentric shaft (53) rotates together with the rotary shaft. Accordingly, it is possible to effectively suppress and lessen half- order inertial exciting force occurring at the eccentric shaft.