Engine Mass Centralization via Asymmetric Shaft Angles
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Solution Overview
Problem
Existing engine designs with a main shaft, crankshaft, and balance shaft fail to adequately centralize mass, leading to inefficiencies and interference issues.
Innovation Solution
The engine is configured such that the main shaft, balance shaft, and drive shaft are arranged relative to a virtual half line extending from the crank axis, with specific angular relationships (θ1 < θ2 and θ1 < θ3) to optimize mass centralization, and the cylinder is positioned closer to the balance shaft to reduce interference, allowing the main shaft to be positioned closer to the crank axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the main shaft is arranged on the opposite side of the balance shaft across the crankshaft, then vibration is reduced, but mass centralization deteriorates
Solution Approach 1:
The patent applies asymmetry by positioning the main shaft at an angle θ1 less than 90 degrees relative to the virtual half line, breaking the symmetric opposite-side arrangement. This asymmetric positioning allows the main shaft to be closer to the crank axis while still maintaining vibration reduction through the balance shaft arrangement, thereby improving mass centralization without sacrificing vibration control.
Solution Approach 2:
The patent changes the angular parameter θ1 from the conventional 90 degrees (opposite side arrangement) to less than 90 degrees. This parameter change repositions the main shaft closer to the crank axis, improving mass centralization while the balance shaft continues to fulfill its vibration reduction function through its eccentric arrangement.
2Weight of moving object
If the main shaft is positioned closer to the crank axis, then mass centralization is improved, but interference with the cylinder increases
Solution Approach 1:
The patent uses asymmetric positioning where the main shaft is placed at an angle θ1 less than 90 degrees from the virtual half line, and the cylinder axis is positioned at an angle θ2 greater than 90 degrees. This asymmetric angular distribution creates sufficient spatial separation between the main shaft and cylinder, preventing interference while allowing the main shaft to be closer to the crank axis for improved mass centralization.
Solution Approach 2:
The patent resolves the spatial conflict by utilizing angular positioning in the rotational plane around the crank axis. By defining specific angular relationships (θ1 < 90° for main shaft, θ2 > 90° for cylinder), the invention creates three-dimensional spatial separation that allows the main shaft to be closer to the crank axis without interfering with the cylinder.
3Object-affected harmful factors
If the main shaft is arranged at a larger angle from the virtual half line, then interference with the cylinder is reduced, but mass centralization deteriorates
Solution Approach 1:
The patent applies asymmetric angular positioning where the main shaft is placed at θ1 < 90 degrees and the cylinder at θ2 > 90 degrees. This asymmetric arrangement optimizes the balance between mass centralization and interference reduction by positioning each component at its optimal angle rather than using a symmetric opposite-side arrangement.
Solution Approach 2:
The patent optimizes the angular parameter θ1 to be less than 90 degrees, which is a specific parameter change from conventional designs. This parameter optimization achieves the dual benefit of improving mass centralization (by bringing the main shaft closer to the crank axis) while maintaining adequate separation from the cylinder through the asymmetric angular relationship.
Data Source
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AI summary
The main shaft 67 is arranged so as to fulfill the relationship of angle θ1 < angle θ2. More specifically, to encourage mass centralization, the main shaft 67 is arranged close to the virtual half line Lh starting from the crank axis C61 so as to fulfill this angular relationship. By doing so, mass centralization can be encouraged in the engine 5 provided with the main shaft 67, the crankshaft 61, and the balance shaft 63.