Arm Stopper Mechanism Vector Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric power-steering devices face difficulties due to increased bending loads on the output shaft, leading to vibrations and difficult steering, as the angle configuration between the pitman arm and the stopper in the arm stopper mechanism does not effectively cancel the input and abutting load vectors, resulting in excessive bending load vectors.
Innovation Solution
The arm stopper mechanism is reconfigured to increase the angle between the contact faces of the stopper and the abutting faces of the pitman arm, ensuring the input and abutting load vectors cancel each other, thereby reducing the bending load vector applied to the output shaft, with the stopper's contact faces set at 90° or more and the abutting faces set at less than 90°, allowing the abutting center position to approach the tie rod holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the arm stopper mechanism uses a conventional configuration with stopper contact faces, then the maximum steering angle can be restricted, but the bending load vector applied to the output shaft increases causing vibrations and difficult steering
Solution Approach 1:
The patent changes the angle parameter between the stopper contact faces and the pitman arm abutting faces. Specifically, the stopper contact faces are configured at an angle of 90° or more, while the abutting faces are set at less than 90°, creating an optimal geometric relationship that causes the input load vector and abutting load vector to cancel each other, thereby reducing the bending load vector on the output shaft
Solution Approach 2:
The patent applies the counterweight principle by configuring the abutting load vector from the stopper to oppose and cancel the input load vector from the tie rods. By positioning the abutting center position close to the tie rod holes and setting appropriate face angles, the two load vectors create opposing forces that neutralize each other, significantly reducing the net bending load on the output shaft
2Reliability
If the abutting center position is positioned far from the tie rod holes, then the stopper can effectively restrict turning angle, but the bending load vector becomes excessive
Solution Approach 1:
The patent applies local quality by precisely positioning the abutting center position (the point where the stopper contact face meets the pitman arm abutting face) in close proximity to the tie rod holes. This localized positioning creates an optimal leverage relationship where the abutting load vector and input load vector act at similar radial distances from the output shaft center, enabling them to cancel each other effectively and minimize bending moment
Data Source
AI summary
An arm stopper mechanism, includes a pitman arm which includes an output shaft hole into which an output shaft is fitted, two tie rod holes onto which tie rods are respectively mounted, and two abutting faces to which a stopper is abutted; and the stopper which includes two contact faces, in which an angle formed by the two contact faces of the stopper is greater than an angle formed by the two abutting faces of the pitman arm and is 90° or more.