Integrated Journal Bearing Layout for High-Speed Whip Stability
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Solution Overview
Problem
Fluid film bearings (FFBs) suffer from unstable vibrations at high speeds due to oil whip, while active magnetic bearings (AMBs) face reliability issues and require redundant backup systems, limiting their performance and efficiency.
Innovation Solution
An integrated journal bearing (IJB) combines fluid film and active magnetic bearings, allowing the fluid film bearing to carry the load and the magnetic bearing to act as a controller, eliminating whip instabilities and enhancing load capacity, damping, and control features without needing a backup bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If fluid film bearing is used to carry load, then load carrying capacity is improved, but whip instability occurs at high speeds
Solution Approach 1:
The patent combines a fluid film bearing and an active magnetic bearing into a single integrated bearing assembly. The fluid film bearing carries the load while the active magnetic bearing provides stability control to eliminate whip instability, resolving the contradiction between load capacity and high-speed stability.
2Stability of the object's composition
If active magnetic bearing is used for contactless support, then whip instability is eliminated, but reliability issues occur requiring backup bearing
Solution Approach 1:
The integrated bearing assembly merges the fluid film bearing and active magnetic bearing into a unified system where both components work together. This combination provides the stability benefits of the magnetic bearing while the fluid film bearing contributes to reliability, eliminating the need for a separate backup bearing.
3Force
If integrated journal bearing is designed, then device complexity increases, but both load capacity and stability are improved
Solution Approach 1:
The patent integrates two separate bearing systems into a single unified assembly, combining the fluid film bearing and active magnetic bearing into one compact unit. This merging approach improves both load capacity and stability while containing the complexity within a single integrated structure rather than requiring separate systems.
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 IJB provides superior load carrying capacity, passive damping, and controllable stiffness and damping, operating at high speeds without whip instabilities and ensuring reliable operation without a backup bearing.
Implementation Method 1
Fluid Film Bearings (FFBs)... Journal Bearings (JBs), are superior load carrying elements due to their larger load carrying capacity and their ability to introduce passive damping to the rotor system
Implementation Method 2
Active Magnetic Bearings (AMBs)... provide contactless rotor support, at high speeds and are free from whip instabilities. They have an added feature which is their capabilities as controlling elements. AMBs can provide variable and controllable stiffness and damping
Data Source
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AI summary
An integrated journal bearing (IJB) is disclosed that comprises a shaft extending in an axial direction; a housing through which the shaft extends in the axial direction, the housing surrounding the shaft in a radial direction; an active magnetic bearing (AMB) arranged within the housing and surrounding the shaft in the radial direction; at least a first fluid film journal bearing (JB) arranged within the housing and surrounding the shaft in the radial direction, the first JB being axially adjacent to the AMB such that first JB and the AMB do not share a common radial clearance; and a controller in signal communication with the AMB and configured to supply current thereto to operate the AMB by controlling a magnetic force generated thereby. Oil conduits are defined through the housing that are configured to feed and drain oil through both the AMB and first JB clearances.