Disc Brake Planetary Gear Concentric Alignment via Intermediary Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In disc brakes, the non-concentric arrangement of the sun gear and internal gear leads to unstable meshing, affecting wear durability and requiring costly improvements in shape and assembling accuracy of the gears.
Innovation Solution
A disc brake design where the internal gear has a tubular support portion to rotatably support the sun gear, ensuring concentric alignment and stabilizing the meshing between the sun gear and planetary gears, thereby improving reliability and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sun gear is rotatably supported by a shaft pivotally supported on the cover while the internal gear is non-rotatably supported on the housing, then the planetary gear reduction mechanism can be assembled, but a variation in the distance between the axis of the sun gear and the axis of the internal gear increases during assembly, leading to poor concentricity and unstable meshing
Solution Approach 1:
A support portion is introduced as an intermediary component between the internal gear and the sun gear. This support portion rotatably supports the sun gear on the internal gear, serving as a mediator that ensures precise concentric alignment. The support portion acts as a dedicated bearing structure that maintains the correct distance and alignment between the gear axes, thereby stabilizing meshing without requiring high manufacturing precision of the gears themselves.
2Reliability
If the shape accuracy of the sun gear, planetary gears, and internal gear is improved to ensure stable meshing, then meshing stability increases, but manufacturing costs increase
Solution Approach 1:
The support portion serves as a mediator that transfers the load and maintains alignment between the internal gear and sun gear. By introducing this intermediary bearing structure, the requirement for high shape accuracy of the gears themselves is reduced. The support portion absorbs the alignment requirements, allowing the gears to be manufactured with standard tolerances while still achieving stable meshing, thus reducing manufacturing costs.
Solution Approach 2:
The support portion is designed to automatically maintain concentric alignment through its rotational support function. As the sun gear rotates on the support portion, the geometry of the support portion self-adjusts to maintain optimal meshing conditions, eliminating the need for expensive precision machining of the gear components themselves.
3Reliability
If the assembling accuracy of the sun gear, planetary gears, and internal gear is improved to achieve good concentricity, then meshing stability improves, but manufacturing complexity and cost increase
Solution Approach 1:
The support portion is designed as a pre-fabricated component with built-in alignment features. By introducing this intermediary element, the assembly process becomes simpler because the support portion inherently guides the sun gear into correct alignment with the internal gear. This eliminates the need for complex alignment procedures and specialized assembly tools, reducing both assembly complexity and the need for highly skilled assembly operations.
Data Source
AI summary
To provide a disc brake having a planetary gear reduction mechanism that may be satisfactory costly and achieve improved reliability, a planetary gear reduction mechanism of a disc brake according to the present disclosure includes a sun gear having an input gear portion to which rotation from a motor is transmitted and an output gear portion extending axially from a radial central region of the input gear portion, a plurality of planetary gears configured to mesh with the output gear portion of the sun gear, and an internal gear configured to mesh with each planetary gear, and the internal gear has a cylindrical support portion configured to rotatably support the sun gear. Accordingly, at the time of assembly, the axis of the sun gear and the axis of the internal gear may be arranged substantially concentrically, which may result in improved reliability and cost satisfaction.