Speed Reducer Gear Deformation for Understeering Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Symmetric vehicles experience neutral steering during operations, leading to consistent yaw motion due to lack of understeering propensity, necessitating a solution to ensure neutral steering with understeering characteristics.
Innovation Solution
A speed reducer is designed with a structure that induces minute deformation by altering the shape of spur and mounting gears, incorporating features like bushing portions and rubber gaskets to reduce rotation angles, thereby changing steering characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a completely symmetric vehicle structure is used, then space utilization is improved, but neutral steering occurs causing consistent yaw motion
Solution Approach 1:
The patent applies asymmetry by providing different gear units in left and right independent steering systems. Specifically, the left vehicle wheel assembly has a first gear unit with different gear ratios than the second gear unit in the right vehicle wheel assembly. This asymmetric gear configuration generates differential lateral forces that produce understeering characteristics, counteracting the neutral steering tendency inherent in completely symmetric vehicle structures.
2Ease of manufacture
If symmetric gear units are used in independent steering systems, then manufacturing cost is reduced, but understeering characteristics cannot be achieved
Solution Approach 1:
The patent applies local quality by making the gear units locally different while keeping other components symmetric. Specifically, only the gear units in the left and right steering systems have different configurations (different gear ratios), while other components such as the upper arms, knuckle units, and mounting structures remain symmetric. This localized differentiation achieves the desired understeering characteristics with minimal impact on manufacturing cost.
3Ease of operation
If gear ratios are differentiated between left and right steering systems, then understeering characteristics are improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the steering system into independent left and right modules, each with its own motor, speed reducer, and gear unit. This modular segmentation allows the gear ratios to be differentiated between left and right sides while keeping each module's internal structure relatively simple and standardized. The segmentation isolates the complexity to specific components rather than the entire system.
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 solution provides vehicles with understeering characteristics by minimizing deformation, reducing costs, and enhancing steering control.
Implementation Method 1
a speed reducer which is configured to implement understeering characteristics by providing a structure which is minutely deformed even when no external force is applied
Data Source
AI summary
A speed reducer includes an input shaft configured to receive power from a drive portion, a gear unit fastened to the input shaft to receive the power from the drive portion through the input shaft, and an output shaft coupled to the gear unit and configured to transmit driving power, in which the gear unit includes a spur gear coupled to the input shaft, and a mounting gear positioned coaxially with the spur gear and coupled to the output shaft, and in which a rotation angle of the output shaft is decreased by minute deformation of the gear unit.