Seal Runner Axial Compactness and Stability
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Solution Overview
Problem
Current seal runners occupy significant axial space on shafts to avoid interference with bearings and hardware, limiting their compactness and stability, especially when designed with a low axial length-to-radius aspect ratio.
Innovation Solution
A seal runner system with a seal runner disposed circumferentially around a shaft, featuring an air cavity covered by a heat shield, a bearing, and a bearing nut that secures the seal runner and bearing in a fixed axial position, utilizing snap portions for mechanical interface with the shaft and radial fluid passages for cooling/lubricating fluid, allowing for reduced axial length and enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If seal runner axial length is reduced to improve compactness, then axial space consumption decreases, but stability and ability to avoid interference with bearing hardware deteriorates
Solution Approach 1:
The patent transitions from a conventional low aspect ratio seal runner to a high aspect ratio design where the axial length exceeds the radial width. This dimensional change allows the seal runner to achieve compactness in the radial direction while maintaining stability through extended axial positioning, effectively resolving the contradiction between axial length reduction and stability maintenance
Solution Approach 2:
The seal runner is divided into multiple functional segments including a body portion with fluid passages, a seal interface portion, and a bearing interface portion. This segmentation allows each segment to be optimized independently - the body portion can be compact while the interface portions extend axially to ensure stability and proper mechanical interface with bearing hardware
2Device complexity
If seal runner axial length is reduced to improve compactness, then device complexity decreases, but interference with bearing and bearing compartment hardware increases
Solution Approach 1:
The patent merges the seal runner with the bearing retainer function by integrating bearing support surfaces and hardware interface features directly into the seal runner body. This consolidation eliminates the need for separate spacers and intermediate components, reducing overall device complexity while preventing interference with bearing hardware through integrated positioning features
Solution Approach 2:
The seal runner is designed to perform multiple functions simultaneously: fluid sealing through the outer annular member, fluid distribution through internal passages, bearing support through integrated surfaces, and axial positioning through the bearing nut interface. This multi-functionality reduces the need for additional components and simplifies the overall assembly
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
The solution provides improved axial compactness and dynamic/static stability for the shaft, eliminating the need for additional spacers and preventing unwanted axial movement, while maintaining effective fluid sealing and lubrication.
Implementation Method 1
a radial fluid passage configured to permit the cooling/lubricating fluid to pass from the lower fluid passage and through the inner annular member of the seal runner
Implementation Method 2
The seal runner includes an inner annular member having a plurality of snap portions. The shaft includes an axial shoulder and an axial land wherein the snap portion of the inner annular member fits in mechanical communication against the axial land
Implementation Method 3
The bearing nut is configured to retain the bearing and the seal runner in fixed axial position with respect to the shaft. The bearing and the seal runner are prevented from traveling axially in the positive X direction
Implementation Method 4
an air cavity disposed facially about an annulus of a face of the seal runner and covered by a heat shield
Data Source
AI summary
A seal runner may have an inner annular member, an outer annular member, and a radial wall member joined to the inner annular member according to an angle and extending from the inner annular member to the outer annular member. The seal runner may be positioned axially along a shaft and a bearing may be positioned axially along the shaft such that it is radially between the inner annular member and the outer annular member. In this regard, the seal runner may resemble a “C-shape.” A seal may interface with a seal land radially outboard of the outer annular member. Thus, the seal may be positioned axially near to the bearing so that the axial length of a shaft and accompanying bearing compartment hardware may be minimized.