Vehicle AC Generator Retainer Fixation and Cooling Gap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional AC generators for vehicles face issues with reduced bearing durability, compromised coolability, noise due to wind sound, and susceptibility to water and dust intrusion due to the screw through-hole seat at the outer edge of the bearing box.
Innovation Solution
The AC generator design eliminates the screw through-hole seat by using a cylindrical retainer with a threaded portion that directly engages with the bearing box, increasing bearing size, enhancing coolability, reducing noise, and preventing water and dust intrusion through a uniform gap and labyrinth seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw through-hole seat is provided at the outer edge of the bearing box to fasten the retainer, then the retainer can be securely fixed, but the bearing size must be reduced to avoid interference with the cooling fan, deteriorating bearing durability
Solution Approach 1:
The invention extracts and eliminates the screw through-hole seat from the bearing box outer edge, removing the source of interference that limited bearing size. The retainer is now fixed using a different mechanism that does not require protruding into the bearing box space, allowing the bearing to be enlarged for improved durability while maintaining secure fixation.
Solution Approach 2:
The invention changes the fixation approach from a radial/directional insertion (screw through-hole) to an axial engagement method where the retainer is pressed against the bearing outer ring from the axial direction. This dimensional change eliminates the need for screw through-holes in the bearing box and allows larger bearing dimensions.
2Reliability
If the screw through-hole seat is provided at the outer edge of the bearing box, then the retainer can be fastened, but the non-uniform gap between the cooling fan and bearing box causes wind sound noise
Solution Approach 1:
The invention removes the screw through-hole seat from the bearing box structure, eliminating the feature that created non-uniform gaps and subsequent wind sound noise. The retainer fixation is achieved through alternative means that do not interfere with the uniform spacing between the cooling fan and bearing box.
3Reliability
If a separately provided screw is used to fasten the bracket bearing box and retainer, then the assembly can be secured, but the gap between the retainer and bearing box end face allows water or dust to intrude into the bearing box
Solution Approach 1:
The invention eliminates the separate screw fastening mechanism and the associated gap between the retainer and bearing box end face. The retainer is directly pressed against the bearing outer ring, creating a tight fit that prevents water and dust intrusion while maintaining secure fixation.
Solution Approach 2:
The invention employs a sealing structure where the retainer acts as a barrier element that, when pressed against the bearing, creates a seal similar to a flexible membrane preventing contaminant intrusion. The close fit between the retainer and bearing box forms a protective barrier against water and dust.
Data Source
AI summary
In An AC generator for a vehicle in which a bearing is inserted into a bearing box formed in a bracket and the bearing is fixed and retained by a retainer, the retainer (8, 10) has a cylindrical shape and a threaded portion (81, 101) is formed on the cylindrical section thereof, a threaded portion (111, 112) is formed on the bearing box, and the threaded portion of the retainer is directly screwed to the threaded portion of the bearing box in order to fix and retain the bearing (3), so that the gap between the outer circumference surface of the bearing box or the outer circumference surface of the retainer and the opposing side of a cooling fan is made uniform.