Tilting Pad Bearing Structure for Fluid Supply and Startup Stability
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Solution Overview
Problem
Tilting pad bearings face challenges in achieving both a structure that enables fluid supply to the pad and a structure that biases the pad toward the rotor shaft, while maintaining stability and reducing axial vibration.
Innovation Solution
A tilting pad bearing design that includes a plurality of pads, a housing, a support portion, and a fluid supply unit, where the support portion includes a pivot with a pad support surface and a pivot curved surface, and a biasing member is used to bias the liner toward the pivot, allowing for fluid supply through dedicated flow channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the radial gap between the pad and the rotor shaft is reduced to increase bearing rigidity, then the stability of the rotor shaft is improved, but the heat generated by friction increases and the pad and rotor shaft may come into direct contact
Solution Approach 1:
The patent applies preliminary action by supplying fluid to the pad before the rotor shaft starts rotating or at the start time, creating a fluid film that prevents direct contact between the pad and rotor shaft during the critical startup phase when thermal expansion has not yet occurred. This preliminary fluid supply ensures the pad is protected from direct contact and excessive heat generation from the beginning of operation.
Solution Approach 2:
The patent uses fluid (oil or gas) as an intermediary substance between the pad and the rotor shaft. This fluid film acts as a mediator that separates the pad from the rotor shaft surface, preventing direct metal-to-metal contact while still allowing the pad to maintain close proximity for load support, thereby reducing friction heat generation.
2Reliability
If a spring is used to bias the pad toward the rotor shaft to apply pressure, then the pad can be separated from the rotor shaft during thermal expansion, but the structure becomes complex requiring both fluid supply mechanism and biasing mechanism
Solution Approach 1:
The patent merges the fluid supply function and the pad biasing function into a single integrated structure. The biasing member is positioned within the housing and directly biases the pad toward the rotor shaft while the fluid supply channels are formed in the housing and pad, eliminating the need for separate spring mechanisms and fluid supply systems. This unified structure reduces overall device complexity while maintaining both functions.
Solution Approach 2:
The housing structure serves multiple functions simultaneously: it provides the fluid supply channels, houses the biasing member, supports the pad, and maintains the radial gap. The biasing member not only applies pressure to the pad but also works in conjunction with the fluid supply system to prevent direct contact. This multi-functionality reduces the number of separate components needed.
3Reliability
If fluid is supplied to float the pad at startup to prevent contact, then direct contact is avoided, but it becomes difficult to achieve both fluid supply structure and pad biasing structure
Solution Approach 1:
The patent combines the fluid supply channels and biasing member into a single integrated housing structure. The housing contains both the fluid supply channels that deliver fluid to the pad and the biasing member that applies mechanical pressure to the pad, merging what would traditionally be separate systems into one unified component that achieves both functions simultaneously.
Solution Approach 2:
The housing is designed as a multi-functional component that simultaneously provides fluid supply pathways, houses the biasing mechanism, supports the pad assembly, and maintains the operational gap. This universal design eliminates the need for separate dedicated structures for each function, reducing overall system complexity.
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 design achieves a simple structure that enables both fluid supply to the pad and pad biasing toward the rotor shaft, enhancing bearing rigidity, stability, and reducing axial vibration.
Implementation Method 1
a fluid supply unit configured to supply a fluid from an outside of the housing to the pad surface... enables supply of a fluid such as gas or oil to the pad and the pad is floated so as to be separated from the rotor shaft by static pressure
Implementation Method 2
a biasing member disposed between the liner and the housing, biasing the liner toward the pivot with respect to the housing
Implementation Method 3
the pivot includes a pad support surface in contact with the pad outside surface and a pivot curved surface curved facing and protruding toward a side opposite to the pad support surface in the radial direction, a liner disposed between the housing and the pivot and including a first liner surface formed linearly and being in contact with the pivot curved surface
Data Source
AI summary
A tilting pad bearing includes a plurality of pads slidably supporting an outside surface of a rotor shaft, a housing covering the plurality of pads, a support portion swingably supporting the pad with respect to the housing, and a fluid supply unit configured to supply a fluid to a pad surface. The support portion includes a pivot having a pad support surface in contact with a pad outside surface and a pivot curved surface facing and protruding toward a side opposite to the pad support surface, a liner having a first liner surface in contact with the pivot curved surface, and a biasing member biasing the liner toward the pivot with respect to the housing.