Flexured Standpipe Support for Bull Gear Radial Load Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current propulsion systems face issues with ball bearings absorbing radial loads, leading to fretting and increased complexity or cost due to the need for flexible case extensions or unclamped bearings, which are not efficiently addressed by existing configurations.
Innovation Solution
A flexured standpipe is used that flexes in response to radial loads from the bull gear, with a ball bearing configured to absorb axial loads and clamped to both the standpipe and bull gear, reducing the need for additional flexures and supporting structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If an unclamped or floating ball bearing is used to provide radial clearance, then the ball bearing can move radially to avoid absorbing significant radial load, but this leads to undesired movement within the bearing, causing fretting and general bearing deterioration
Solution Approach 1:
The patent employs a flexured standpipe with a flexible wall that can deflect radially to accommodate ball bearing movement. The flexible wall acts as a compliant support structure that allows the ball bearing to move radially without requiring an unclamped configuration, thereby preventing fretting and bearing deterioration while still permitting the ball bearing to avoid absorbing significant radial load.
2Force
If flexured case extensions or flexured appendages are used to support the ball bearing and permit radial movement, then the ball bearing can move radially when subjected to radial loads, but this adds weight, cost and complexity to the propulsion assembly
Solution Approach 1:
The standpipe serves multiple functions: it provides structural support for the ball bearing, allows radial movement through its flexible wall, and eliminates the need for separate flexured case extensions or appendages. By integrating the flexure directly into the standpipe wall, the design consolidates multiple functions into a single component, reducing overall assembly complexity, weight, and cost.
3Reliability
If a clamped ball bearing configuration is used to prevent bearing movement, then bearing deterioration is reduced, but the ball bearing cannot move radially and must absorb radial loads, leading to fretting and bearing deterioration
Solution Approach 1:
The flexible wall of the standpipe provides a compliant interface that allows controlled radial movement of the ball bearing while maintaining a clamped configuration. This prevents the bearing from absorbing excessive radial loads and avoids fretting and deterioration, while still providing the stability and support of a clamped bearing arrangement.
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
This solution effectively manages radial loads without causing fretting and reduces weight and cost by integrating the flexured standpipe with the ball bearing retention system, simplifying the design and eliminating the need for complex case extensions.
Implementation Method 1
The flexured standpipe flexes in response to radial loads from the bull gear
Implementation Method 2
a ball bearing to absorb the axial loads of the bull gear
Data Source
AI summary
A propulsion assembly includes a rotor assembly, a mast coupled to the rotor assembly and a bull gear coupled to the mast. The bull gear is subject to radial and axial loads. The propulsion assembly includes a flexured standpipe extending through the bull gear and a ball bearing including inner and outer races interposed between the bull gear and the flexured standpipe. The ball bearing is configured to absorb axial loads from the bull gear. The bull gear is rotatably coupled to the flexured standpipe via the ball bearing. The flexured standpipe flexes in response to radial loads from the bull gear.