Bearing-Shaft Installation Tooling for Tight-Tolerance Engine Assembly
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Solution Overview
Problem
Bearing and shaft assemblies in aircraft engines face challenges during installation due to tight assembly tolerances and potential damage during handling, manual alignment is difficult, and maintaining precise positioning is challenging.
Innovation Solution
A tool comprising a rod, sleeves, and a holder is used to pre-assemble the bearing and shaft assembly, which includes securing sleeves around the shaft to maintain bearing alignment and using a holder to axially load the bearings, allowing for precise insertion into the engine housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If bearing and shaft assemblies are pre-assembled with tight tolerances, then installation precision is improved, but handling complexity increases and risk of damage during handling worsens
Solution Approach 1:
The bearing and shaft assembly is pre-assembled on the tooling before installation into the housing. The rod is inserted through the hollowed shaft, sleeves are positioned over the shaft to protect the bearings, and the holder is engaged to secure the assembly. This preliminary assembly on the tooling ensures precise alignment and protects the tight-tolerance components from damage during the subsequent installation process.
2Ease of operation
If manual alignment is used for bearing and shaft assembly, then operation simplicity is maintained, but alignment precision deteriorates under tight tolerances
Solution Approach 1:
The tooling acts as an intermediary device between the operator and the bearing-shaft assembly. The rod provides a precise alignment reference that extends through the hollowed shaft, while the holder engages the second end of the shaft. This intermediary tooling system enables accurate alignment that would be difficult to achieve through manual alignment alone, while still maintaining operational simplicity through the use of a dedicated installation tool.
3Stability of the object's composition
If holder is engaged to second rod end, then shaft positioning stability is improved, but bearing loading complexity increases
Solution Approach 1:
The holder combines multiple functions into a single component: it engages the second end of the hollowed shaft to provide positioning stability, and simultaneously applies axial loading to the bearing against the sleeve. This merging of functions reduces the overall device complexity compared to using separate components for positioning and loading, while achieving both shaft positioning stability and bearing installation in one operation.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A tool (30) for mounting a bearing and shaft subassembly (20) in an aircraft engine component, including a rod (35) extending from a first end (12A) to a second end (12B) and adapted to extend through a hollowed shaft (12), the rod (35) having a shaft seating portion (36) at the first end (36A) adapted to engage a first end (12A) of the shaft (12). A holder (37) is engageable to the second rod end (36B) to receive a second end (12B) of the shaft (12). The holder (37) is displaceable towards the shaft seating portion (36) during engagement to the second rod end (36B). At least one sleeve (31; 32) is adapted to wrap about a shaft outer surface (12C), removably securable to the shaft (12), and having an end (31E) defining a bearing facing surface (31D) to axially engage the bearing (16). The holder (37) is displaceable towards that surface to axially load the bearing (16) against the sleeve (31) and maintain the shaft (12) between the holder (37) and the shaft seating portion (36).