Balancer Device Ring Grooves Suppress Engine Noise
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Solution Overview
Problem
Existing balancer devices for internal combustion engines face issues with rattling noise due to misalignment between the crankshaft and balancer device, which is exacerbated by the use of scissors gears that increase costs and complexity.
Innovation Solution
The balancer device incorporates ring-shaped grooves on the drive and driven gears with different diameters, allowing for vibration absorption and reduced noise without the need for scissors gears, thereby improving noise/vibration performance and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If scissors gear is used to reduce rattling noise, then rattling noise is reduced, but device complexity and cost increase
Solution Approach 1:
The invention extracts the vibration-absorbing function from the complex scissors gear structure and implements it through simple ring-shaped grooves on the gear surfaces. These grooves allow the gear body to deform elastically, absorbing vibrations directly at the source without requiring additional complex mechanical components.
Solution Approach 2:
The invention replaces the expensive scissors gear with a simple groove structure that can be manufactured through conventional machining processes. The grooves are easily formed on standard gear bodies, eliminating the need for specialized expensive components while achieving the same vibration reduction effect.
2Object-affected harmful factors
If scissors gear is used to reduce rattling noise, then rattling noise is reduced, but manufacturing complexity increases
Solution Approach 1:
The invention extracts the vibration-absorbing function from the complex scissors gear assembly and implements it through simple ring-shaped grooves that can be machined directly onto standard gear bodies. This eliminates the need for separate vibration-absorbing components and simplifies the manufacturing process.
Solution Approach 2:
The invention merges the vibration-absorbing function with the existing gear body structure by machining grooves into it. This integration eliminates the need for separate vibration-absorbing components and simplifies both manufacturing and assembly processes.
3Manufacturing precision
If misalignment between crankshaft and balancer device occurs, then positioning error increases, but rattling noise is generated
Solution Approach 1:
The ring-shaped grooves are pre-formed on the gear surfaces to provide vibration absorption capacity before misalignment occurs. When positioning errors or misalignments happen during operation, these grooves immediately begin absorbing the resulting vibrations, preventing rattling noise without requiring active correction.
Solution Approach 2:
The invention changes the physical structure of the gear surface by adding ring-shaped grooves, which modify the mechanical properties of the gear body. This structural parameter change enables the gear to deform elastically and absorb vibrations caused by misalignment, converting rigid contact into flexible engagement.
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 effectively suppresses both rattling noise and engagement noise, enhancing the overall noise/vibration characteristics while simplifying assembly and reducing costs by eliminating the need for scissors gears.
Implementation Method 1
ring-shaped grooves whose diameters are different from each other are provided on both axial direction side surfaces of at least one of the drive gear, the balancer drive gear and the balancer driven gear. The ring-shaped grooves are formed up to a depth from a surface of the gear at which both the ring-shaped grooves overlap each other in an axial direction
Implementation Method 2
The ring-shaped grooves are formed up to a depth from the surface of the gear at which both the ring-shaped grooves overlap each other in the axial direction
Data Source
AI summary
A balancer device of an internal combustion engine, has a drive gear engaged with an input gear to which a rotation force is transmitted from a crankshaft; a balancer drive shaft to which the rotation force is transmitted from the drive gear and which has a balancer weight; a balancer drive gear rotating integrally with the balancer drive shaft; a balancer driven gear engaged with the balancer drive gear; and a balancer driven shaft rotating integrally with the balancer driven gear and having a balancer weight. At least one of the drive gear, the balancer drive gear and the balancer driven gear is provided, on both axial direction side surfaces thereof, with ring-shaped grooves whose diameters are different from each other. The ring-shaped grooves are formed up to a depth from the surface of the gear at which both the ring-shaped grooves overlap each other in the axial direction.