Non-Coplanar Balancer Shaft Reciprocating Machine Vibration Control
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Solution Overview
Problem
Conventional reciprocating machines with non-co-planar balancer shafts struggle to control rotational vibration, as existing design methods fail to balance the moments generated by the primary inertial and centrifugal forces, leading to uncontrolled rotational vibration.
Innovation Solution
A reciprocating machine design where the axis of the crankshaft, first balancer shaft, and second balancer shaft are not on the same plane, with specific coordinate transformations and unbalance settings to balance the primary inertial and centrifugal forces, and their moments, allowing for control of both translational and rotational vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the axis of the crankshaft, first balancer shaft, and second balancer shaft are not arranged on the same plane, then the compactness of the machine is improved, but the rotational vibration cannot be controlled
Solution Approach 1:
The invention transitions from a two-dimensional planar arrangement (all axes on the same plane) to a three-dimensional spatial arrangement (axes on different planes). The first and second balancer shafts are positioned on opposite sides of the crankshaft axis in the vertical direction, creating a non-coplanar configuration that reduces the machine's overall width while maintaining vibration balance through spatial distribution of balancing masses.
Solution Approach 2:
The invention uses counterbalancing masses on the first and second balancer shafts to offset the rotational vibration generated by the reciprocating motion. The unbalance amounts and phases of these counterweights are specifically designed to cancel out the moment variations caused by the non-coplanar axis arrangement, thereby controlling rotational vibration while enabling compact dimensions.
2Device complexity
If conventional design methods are used with non-co-planar balancer shafts, then the device complexity is reduced, but the moments generated by inertial and centrifugal forces cannot be balanced
Solution Approach 1:
The invention replaces complex mechanical moment balancing mechanisms with a simplified computational design approach. By using specific formulas to calculate the unbalance amounts and phases of the balancer shafts based on the machine's geometric parameters, the design process avoids complex mechanical adjustments while achieving precise moment balance between the inertial and centrifugal forces.
Solution Approach 2:
The invention changes the design parameters from qualitative mechanical adjustments to quantitative calculated values. The unbalance amounts (UB(Fr), UB(Rr)) and phases (αB(Fr), αB(Rr)) of the balancer shafts are determined through specific mathematical formulas that relate them to the machine's mass distribution and geometric dimensions, enabling precise control of moment balance without increasing device complexity.
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 design effectively balances the primary inertial and centrifugal forces and their moments, enabling high control over both translational and rotational vibrations, even when the balancer shafts are not on the same plane, enhancing the compactness and performance of engines like those for motorcycles.
Implementation Method 1
an inertial force is generated by the movement of a reciprocal movement portion such as a piston
Implementation Method 2
a rotary movement portion such as a crankshaft and a balancer shaft are given an unbalance so as to generate a centrifugal force that is in balance with the inertial force
Implementation Method 3
The first balancer shaft is configured to rotate, together with the rotation of the crankshaft, at the same rotation speed as that of the crankshaft in an opposite rotation direction to that of the crankshaft
Data Source
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AI summary
A machine having a reciprocating slider crank mechanism, wherein an axis of a crankshaft, an axis of a first balancer shaft and an axis of a second balancer shaft are not arranged on the same plane, wherein vibration is highly controlled. The machine includes the reciprocating slider crank mechanism configured so as to satisfy setting formulae below: UCr=UP×0.5 αCr=180° UBFr=U1BFr2+U2BFr21/2 U1BFr=−UP×0.5×Lx′BRr/Lx′BRr−Lx′BFr U2BFr=−UP×0.5×Ly′B/Lx′BRr−Lx′BFr αBFr=180°−arctanU2BFr+U1BFr UBRr=U1BRr2+U2BRr21/2 U1BRr=−UP×0.5×Lx′BFr/Lx′BFr−Lx′BRr U2BRr=−U2BFr αBRr=180°−arctanU2BRr+U1BRr.