Gear Assembly Elastic Connecting Element Vibration Damping
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Solution Overview
Problem
Existing gear drives in internal combustion engines face challenges in reducing noise and vibrations between the crankshaft and balance shaft due to meshing teeth, and existing solutions do not effectively decouple the idler gear to achieve universal usage and improved noise reduction.
Innovation Solution
The idler gear is configured with an elastic connecting element attached to the axial end faces of both the fixed gear and the idler, allowing for selective placement within the torque flow or not, and utilizing a sleeve spring for decoupling, which reduces noise by minimizing the elastic connecting element's presence in the torque flow and enhances positioning through low radial stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the idler gear is decoupled using a sleeve spring connected to radial end faces, then vibrations are dampened, but the gear rim assumes an eccentric position causing high mechanical load on the sleeve spring
Solution Approach 1:
The idler gear is segmented into two separate radial toothings: a first radial toothing on the idler gear body and a second radial toothing on the fixed gear. This segmentation allows the elastic connecting element to connect these separate toothings rather than relying on a sleeve spring, distributing the load and avoiding the eccentric position problem that causes high mechanical load on the sleeve spring.
Solution Approach 2:
The elastic connecting element serves as an intermediary between the first radial toothing and the second radial toothing. It mediates the torque transmission while providing vibration damping, replacing the sleeve spring's function but connecting axial end faces instead of radial end faces, thereby avoiding the eccentric positioning issue.
2Power
If the elastic connecting element is positioned in the torque flow, then torque is transmitted through the elastic element, but high shear and tensile stresses occur leading to high mechanical load
Solution Approach 1:
The elastic connecting element is repositioned from a radial configuration (in the torque flow) to an axial configuration (between axial end faces). This dimensional change allows the elastic element to primarily handle axial forces and bending moments rather than high shear and tensile stresses from torque transmission, reducing mechanical load while maintaining vibration damping functionality.
3Object-affected harmful factors
If the idler gear is decoupled to reduce noise, then vibration damping is improved, but the positioning precision and mechanical load resistance may be compromised
Solution Approach 1:
The gear system is segmented into a fixed gear with second radial toothing and an idler gear with first radial toothing, connected by an elastic connecting element. This segmentation enables independent optimization: the fixed gear provides stable positioning, while the elastic connecting element provides vibration damping, achieving both noise reduction and positioning precision simultaneously.
Solution Approach 2:
Different parts of the system have different qualities: the fixed gear and idler gear bodies are rigid for positioning precision, while the elastic connecting element is flexible for vibration damping. This local quality differentiation allows the system to achieve both noise reduction and reliable positioning without compromising mechanical load resistance.
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 reduces noise and vibrations by allowing the idler gear to assume an eccentric position, reducing tooth flank clearance, and improving the positioning of the gear assembly, while maintaining low radial stiffness and high mechanical load resistance.
Implementation Method 1
the fixed gear is connected to the idler by means of at least one elastic connecting element
Implementation Method 2
Vibrations are thus decoupled in order to damp peaks of the driving torques in the event of rotational irregularities
Data Source
AI summary
The invention relates to a gear assembly (12) comprising a fixed gear (13) having a first radial toothing (16) and an idler (14) having a second radial toothing (17), the first radial toothing (16) being disposed at least approximately at the same radial height as the second radial toothing (17), and the fixed gear (13) further comprises a first axial end face (18) and the idler (14) comprises a second axial end face (19), and the fixed gear (13) is connected to the idler (14) by means of at least one elastic connecting element (21), for which purpose the elastic connecting element (21) is connected on the one hand to the first axial end face (18) of the fixed gear (13) and on the other hand to the second axial end face (19) of the idler (14).