Engine Balancer Gear Layout for Lower Meshing and Rattling Noise
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Solution Overview
Problem
Internal combustion engine balancer structures experience noise issues due to gear deformation and rattling sounds caused by uneven load distribution and rotation speed fluctuations, which are not adequately addressed by existing designs.
Innovation Solution
The balancer structure includes a first and second balance shaft with integral balancer weights and gears, where the output portion is located on the first balance shaft to reduce load on the second shaft, and the diameters of the balancer driving and driven gears are smaller than the transmission gears to minimize deformation and rattling sounds, with the balancer driving gear positioned between the output and transmission driven gear to increase inertia and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the oil pump is coupled to the driven balance shaft, then the driven balance shaft receives the load from the oil pump, but the deformation of the balancer driven gear increases and meshing sound occurs
Solution Approach 1:
The patent inverts the conventional coupling configuration by coupling the oil pump to the driving balance shaft instead of the driven balance shaft. This reversal changes the load distribution in the gear meshing system, reducing the deformation of the balancer driven gear and thereby suppressing the meshing sound while still achieving the required oil pump operation.
2Object-generated harmful factors
If the diameters of the balancer driving and driven gears are reduced, then the deformation and rattling sounds are minimized, but the torque transmission capability may be affected
Solution Approach 1:
The patent applies parameter changes by optimizing the diameter dimensions of the balancer driving and driven gears to specific ranges that minimize deformation and rattling sounds. Simultaneously, the inverse relationship between gear diameter and center distance is utilized to maintain adequate torque transmission capability while keeping the gear sizes compact.
Solution Approach 2:
The patent compensates for the reduced gear diameter by adjusting the center distance between gears in the spatial dimension. By optimizing the spatial arrangement and center distance, the system maintains sufficient torque transmission capability despite the smaller gear dimensions, effectively controlling noise while preserving power transmission.
3Object-generated harmful factors
If the balancer driving gear is positioned between the output and transmission driven gear, then the inertia is increased and noise is reduced, but the structural complexity increases
Solution Approach 1:
The balancer driving gear positioned between the output and transmission driven gear serves multiple functions: it transmits torque from the driving balance shaft, provides additional inertia to reduce noise, and maintains the rotational balance. This multi-functional arrangement reduces noise while the compact integration keeps structural complexity manageable.
Data Source
AI summary
A balancer structure for an internal combustion engine and the internal combustion engine are provided. A transmission driving gear are arranged to be rotatable integrally with a crankshaft. A transmission driven gear is arranged to be rotatable integrally with a first balance shaft. The transmission driven gear meshes with the transmission driving gear. A balancer driving gear is arranged to be rotatable integrally with the first balance shaft. A balancer driven gear is arranged to be rotatable integrally with the second balance shaft. The balancer driven gear meshes with the balancer driving gear. The first balance shaft includes an output portion. The output portion outputs torque to an engine-driven accessory.