Internal Combustion Engine Balance Shaft Phase Adjuster
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Solution Overview
Problem
Internal combustion engines with a multi-link crankshaft drive face challenges in fully compensating second-order inertia forces, leading to inferior smoothness and increased noise, as conventional counter-rotating balance shafts introduce excessive friction losses and are not easily adaptable.
Innovation Solution
An internal combustion engine design featuring a balance shaft driven by the crankshaft via a phase adjuster, which adjusts the angular offset between the crankshaft and balance shaft to minimize second-order inertia forces, thereby reducing noise and friction losses, and potentially eliminating the need for additional balance shafts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If two counter-rotating balance shafts are used to compensate second-order inertia forces, then the smoothness and noise reduction is improved, but the friction losses increase to an unacceptable level
Solution Approach 1:
The patent extracts only the necessary balancing function from the conventional two-balance-shaft system. By using a single balance shaft with optimized geometry and positioning, the invention achieves adequate compensation of second-order inertia forces without the excessive friction losses of dual balance shafts, removing the redundant component while retaining the essential function.
Solution Approach 2:
The invention changes the parameters of the balance shaft system by optimizing the single balance shaft's rotational speed, mass distribution, and angular positioning relative to the crankshaft. These parameter optimizations enable effective vibration compensation at reduced friction losses compared to the conventional two-shaft system.
2Object-affected harmful factors
If conventional counter-rotating balance shafts are used, then second-order inertia forces are compensated, but the device complexity increases
Solution Approach 1:
The patent removes one balance shaft from the conventional two-shaft configuration, retaining only the essential balancing function. This extraction reduces device complexity while maintaining adequate compensation of second-order inertia forces through optimized single-shaft design.
Solution Approach 2:
The single balance shaft in the invention performs multiple functions: compensating second-order inertia forces, reducing vibrations, and minimizing friction losses. This multi-functional design replaces the specialized two-shaft system, reducing overall device complexity while achieving the desired performance.
3Object-affected harmful factors
If the friction losses of the multi-link crankshaft drive are already high, then adding balance shafts further increases friction losses, but smoothness requires better inertia force compensation
Solution Approach 1:
The patent applies partial action by using a single balance shaft instead of the full two-shaft system. This partial implementation provides sufficient inertia force compensation for acceptable smoothness while avoiding the excessive friction losses that would result from adding another balance shaft to the already high-friction multi-link crankshaft drive.
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 phase adjuster effectively reduces noise and friction by compensating second-order inertia forces, improving engine acoustics and maintaining low friction levels, even in multi-link crankshaft drives, by optimizing the angular offset between the crankshaft and balance shaft.
Implementation Method 1
a balance shaft (28), which is configured to at least partially eliminate second-order inertia forces generated by the internal combustion engine (1)
Implementation Method 2
phase adjuster (40) which is configured to change an angular offset between the crankshaft (2) and the balance shaft (28)
Data Source
AI summary
An internal combustion engine has a multi-link crankshaft drive with a plurality of coupling elements rotatably mounted on crankpins of a crankshaft and a plurality of articulated connecting rods rotatably mounted on crankpins of an eccentric shaft, wherein each of the coupling elements is pivotally connected to a piston connecting rod of a piston of the internal combustion engine and to one of the articulated connecting rods. A balance shaft, which is driven by a crankshaft via a phase adjuster, is provided in order to at least partially attenuate second-order inertia forces occurring in the internal combustion engine.